Conclusion

Au cours de ce travail, nous avons synthétisé plusieurs familles connecteurs dans le but de les impliquer dans la formation de cages moléculaires (MOC) octaédriques à base d'entités macrocycliques de type calixarène. Ces connecteurs sont de nature métallo-organiques ou purement organiques. Deux nouvelles familles de MOC (12 nouvelles cages) ont été obtenues: dix MOC à base de connecteurs dipyrrine métallo-organiques et deux MOC à base de connecteurs organiques triazine ont été mises en évidence. Ces cages ont été parfaitement caractérisées d'un point de vue structural. Les cages octaédriques obtenues [Co4SO2TCA]6[rac-Co(L1)3]8 et [Ni4SO2TCA]6[rac-Co(L1)3]8 ont démontré, entre autre, de bonnes propriétés d'adsorption et d'excellentes propriétés de séparation de gaz IAST (C2H2/CH4; C2H6/CH4; CO2/N2). En outre, la cage à base de triazine [Co4SO2TCA]6[L8]8 a également démontré d'excellentes propriétés d'adsorption, surpassant de nombreuses MOC similaires ainsi que les MOC à base de dipyrrhine démontrées dans ce travail

Table of contents

I. Historical review of covalent and coordination cage . ............................................................ I.1. Crown-ethers of Pedersen ............................................................................................... I.2. Cryptands of Dietrich, Lehn and

I.3. Macrooligocycle of

II.

Non-calixarene MOCs: classification and properties . .......................................................... II.1. Strategies for synthetic approaches . ............................................................................... II.2. Geometrical analysis ...................................................................................................... II.3. Reported properties of MOCs ........................................................................................ III. Calixarene-based MOCs ...................................................................................................... III.1. Generalities on calix[4] III. 6. Calixarene-based MOC with Metal-Organic connectors ............................................. IV. Conclusion ........................................................................................................................... V. Presentation of the scientific project. .................................................................................... Chapter II. Synthesis of the connectors . 1. Triangular and linear dipyrrin connectors...................................................................... II.2. Synthesis of racemic triangular tris(dipyrrin) connectors (rac-M(HL1)3 , rac-Co(HL2)3) . .............................................................................................................................................. II.3. Chiral resolution of the triangular connector rac-M(HL1)3 (Λ-M(HL1)3 and Δ-M(HL1)3) . .............................................................................................................................................. II.4. The synthesis of linear dipyrrin connectors (Pd(HL1)2, Ni(H2L3)) . ............................... III. Phenanthroline-based metal-organic connector................................................................... III.1. Complexes of phenanthroline: review ..........................................................................

Chapter III. Formation and structural investigations of

I. Synthesis of crystalline molecular cages . ............................................................................. I.1. Determination of the synthetic conditions . ................................................................... I.2. Synthesis of crystalline cages using metal-organic connectors . ................................... I.3. Synthesis of crystalline cages using organic connectors (H3L8-H3L11) ..

. II.3. Cages metrics ............................................................................................................... II.4. Packing of the dipyrrin-based MOCs in the unit cell .................................................. III. Structural investigation of chiral dipyrrin-based MOCs: XRD analysis . .......................... MOCs .................................. IV. 1. CD and chiral HPLC of enantiomerically pure cages . ............................................... IV.2. MS characterization in solution .................................................................................. IV. 3. XRPD in the solid state for racemic cages . ................................................................ IV. 4. TGA measurements and IR analysis of the racemic cages . ....................................... IV.5. Conclusion .................................................................................................................. V. Structural investigation of MOCs based on organic connectors . ....................................... V.1. Crystalline data for [M4SO2TCA(μ4-OH2)]6 [L8]8 (M = Co II , Ni II ) . ............................. V.2.Cages metrics ................................................................................................................ V.3. Packing of the Cages . .................................................................................................. V.4. TGA and IR for triazine-based MOCs......................................................................... VI. Conclusion .........................................................................................................................

IV. Additional characterizations techniques for dipyrrin-based

Chapter IV. Gas adsorption properties of synthetized calixarene-based

I. 1. Context of the study ...................................................................................................... I.2. The performed measurements on the synthetized MOCs . ............................................ I.3. Activation of samples .................................................................................................... MOC .................................................................... II.1. Behaviour of the sample after activation . .................................................................... II.2. N2(g) adsorption and surface area evaluation . ............................................................... II.3. CO2 MOCs ................................................................ III.1. Behaviour of the samples after activation . ................................................................. III.2. N2(g) adsorption and surface area investigation . ......................................................... III.3. Adsorption of other small molecules . ......................................................................... III.4. Estimation of gas adsorption selectivity . .................................................................... IV. Conclusion .........................................................................................................................

II. Adsorption properties of triazine-based

III. Adsorption properties of dipyrrin-based

General conclusion

I. Results of the

II. Perspectives for this

II. 1. Improvement of the synthesis for the formation of MOCs .......................................... II.2. Further investigation of gas adsorption properties of the reported MOCs . ................. II.3. Investigation of catalytic properties ............................................................................. II.4. Investigation of the molecular recognition properties . ................................................ II.5. Other properties ...........................................................................................................

Experimental part

I. Synthesis of calixarenes . ......................................................................................................

Introduction

Le domaine de recherche lié aux cages supramoléculaires est très actif, avec des applications dans les domaines de la catalyse, des matériaux ou du transport de molécules par exemple, ces assemblages ayant la capacité d'encapsuler et de libérer sélectivement des molécules invitées. Les cages supramoléculaires sont des structures auto-assemblées formées grâce à l'utilisation d'interactions non-covalentes entre les différents composants, telles que les liaisons hydrogène, les liaisons de coordination et les forces de van der Waals, etc. 1 Ces dernières années, on recense de nombreux progrès concernant la conception et la synthèse de cages supramoléculaires avec des tailles, des formes et des fonctionnalités contrôlables.

Une variété de cages supramoléculaires particulièrement intéressante est les Cages Métallo-Organiques (MOC). Les MOC sont généralement synthétisées par auto-assemblage d'ions métalliques et de ligands organiques (connecteurs), qui forment spontanément une structure autoassemblée présentant la forme d'une cage. La taille, la géométrie ainsi que la capacité de coordination du centre métallique, de même que la nature et le nombre de ligands impliqués, peuvent être ajustés afin d'obtenir des MOC présentant des propriétés souhaitées. 2 Parmi tous les types de MOC reportés dans la littérature, on note des MOC construits à partir de macrocycles de type calixarène (calix [4]arène, thiacalix [4]arène et tetrasulfonylcalix [4]arène): ils combinent les propriétés structurales uniques inhérentes aux calixarènes et les propriétés fonctionnelles des ions métalliques et des ligands constituants la cage. Un avantage majeur de l'utilisation de calixarènes est, entre autre, leur grande stabilité thermique. 3 En conséquence, les applications possibles des MOC à base de calixarènes ne sont pas limitées par la stabilité thermique des calixarènes, ce qui offre un large éventail d'applications, telles que la catalyse à haute température et le stockage de gaz. En outre, l'utilisation de connecteurs métallo-organiques au lieu de connecteurs purement organiques pour la synthèse de MOC à base de calixarène, ouvre de nouvelles possibilités d'applications, telles que la catalyse en espace confiné. 4 Les MOC sont synthétisées au cours d'une réaction d'auto-assemblage entre des noeuds et des connecteurs qui forment une structure discrète et cohérente maintenue par des liaisons de coordination. De très nombreuses géométries des MOC résultants peuvent être observées : cubiques, octaédriques, tétraédriques, etc. Dans ce travail, des connecteurs linéaires et triangulaires ont été utilisés pour l'auto-assemblage de MOC, et nous nous sommes centrés sur la formation de MOC adoptant une géométrie octaédrique. Selon les connecteurs utilisés, il est possible d'obtenir différents types de cages. Dans le cas de l'utilisation d'un connecteur linéaire bidentate, un MOC Résumé octaédrique de type "Edge-panelled" est obtenu, alors que dans le cas de l'utilisation d'un connecteur trigonal, un MOC octaédrique de type "Face-panelled" est observé, comme representé en Figure 1. 2

Figure 1

Les réactions d'auto-assemblage des ions métalliques, des connecteurs et des sulfonylcalix [4]arènes pour la formation de MOC présentant une géométrie octaédrique

Pour la formation de MOC à base de l'entité calixarène, on utilise le plus souvent les thiacalix [4]arènes et les sulfonylcalix [4]arènes, en raison de la présence d'atomes de soufre et d'atomes d'oxygène sur le macrocycle, ce qui leur confère de meilleures propriétés de coordination vis-à-vis des métaux et en fait des candidats parfaits pour la formation de MOC multimétalliques.

Ce travail, qui consiste en la formation et l'étude des propriétés des MOC à base de sulfonylcalix [4]arènes et plus particulièrement en utilisant des connecteurs métallo-organiques. Cette approche a jusqu'à présent été très peu explorée. L'intérêt de tels MOC réside dans leur utilisation potentielle dans le stockage et la séparation de gaz en raison de la porosité inhérente des calixarènes et la formation de cages à larges cavités. De plus, la présence de connecteurs métalloorganiques permet d'envisager des applications potentielles de ces cages en catalyse.

Résultats et discussion

1) Choix et synthèse des nouveaux connecteurs utilisés

Afin d'obtenir de nouvelles cages multimétalliques octaédriques à partir de calixarènes et de connecteurs métallo-organiques, en utilisant le schéma de synthèse présenté figure 1, le choix des connecteurs appropriés est crucial. Dans ce travail, plusieurs familles de connecteurs ont été synthétisées (Figure 2). Ils ont été choisis selon certains critères :

Résumé

• La nombre et la position des groupements coordinants. Pour tous les connecteurs, les groupement carboxylates sont des sites de coordination qui permettent la formation de liaisons de coordination avec les noeuds métalliques des calixarènes.

• La géométrie des connecteurs. Les connecteurs tridentates ou bidentates doivent présenter respectivement une géométrie trigonale ou linéaire afin de former les MOC ciblés (MOC octaédrique de type "Edge-panelled" ou de type "Face-panelled", comme présenté Figure 1).

• Les propriétés intrinsèques des connecteurs (sites métalliques accessibles pour catalyse, luminescence) qui pourraient être amplifiées lorsque le connecteur est intégré dans le MOC.

La famille des connecteurs métallo-organiques de type tris(dipyrrine) et bis(dipyrrine) (Figure 2a) a été choisie en raison de la nature tridentate et de la géométrie triangulaire du connecteur tris(dipyrrine) : rac-M(HL1)3 (M = Co III , Fe III 5 Par ailleurs, il a été possible de synthétiser un connecteur tris(dipyrrine) élargi (rac-Co(L3)3) dans le but d'obtenir des MOC de plus grande taille et de modifier ainsi les propriétés d'adsorption.

Le connecteur de type tris(phénanthroline) (Figure 2b) ([rac-Fe(HL4)3][PF6]2) a été choisi pour les mêmes raisons. Il possède une nature ionique, de sorte que la cage obtenue pourrait être soluble dans l'eau, ce qui est important pour certaines applications. Enfin, le connecteur tris(phénanthroline) ([rac-Fe(HL4)3][PF6]2) est photosensible et pourrait être utilisé pour la photocatalyse. 5 Le connecteur de type porphyrine (Ni(H2L6)) possédant deux fonctions acides carboxyliques en position trans (Figure 2c) présente une géométrie linéaire. L'analogue de type corrole tri-substitué (Co(H3L7)) présente une géométrie en T dont la flexibilité pourrait être suffisante pour conduire aux MOC ciblés (Figure 2d). Ces deux macrocycles tétrapyrroliques sont également photochimiquement actifs. De plus, les ions métalliques présents dans leur cavités ont des sites de coordination axiaux libres qui peuvent être utiles pour la coordination lors des réactions catalytiques. 6 La famille des connecteurs de type bis(terpyridine) (Figure 2e): [M(HL5)2][PF6]2 (M = Fe II , Co II , Ru II ), de géométrie linéaire, sont de nature ionique et photochimiquement actifs : ils peuvent notamment être utilisés dans les réactions formation du dihydrogène. [START_REF] Huo | Ruthenium Complex-Incorporated Two-Dimensional Metal-Organic Frameworks for Cocatalyst-Free Photocatalytic Proton Reduction from Water[END_REF]

Résumé

Enfin, parallèlement à ces différentes familles de connecteurs métallo-organiques, nous avons également synthétisé des nouveaux connecteurs organiques : les connecteurs de type triazine (Figure 2f) (H3L8, H3L9, H3L10) trisubstitués qui présentent une géométrie trigonale. Le coeur du groupement triazine présente une densité de charge positive qui peut être utilisée pour la π-reconnaissance d'anions, 8 procurant ainsi aux cages formées des propriétés potentielles de reconnaissance inédites.

Figure 2

Les familles de connecteurs qui ont été utilisés pour la formation de cages octaédriques nanométriques

Tous les connecteurs mentionnés ci-dessus (Figure 2) ont été synthétisés avec succès et caractérisés par différentes techniques en solution et à l'état solide (spectroscopie RMN, spectrométrie de masse, spectroscopie IR, microanalyse).

2) Synthèse et caractérisation structurale des MOC

Les connecteurs obtenus ont ensuite été utilisés dans des réactions d'auto-assemblage avec des sels métalliques et l'espèce macrocyclique sulfonylcalix [4]arène en solution et à température ambiante (la diffusion liquide-liquide) ou en chauffant (la synthèse solvothermale), afin d'obtenir de nouvelles cages octaédriques multimétalliques à base de calixarène, comme présenté figure 1.

Afin d'étudier la structure des cages obtenues, l'obtention de monocristaux afin d'effectuer des analyses de diffraction de RX sur monocristaux est indispensable.

Au cours de cette étude, il a été démontré que les familles de connecteurs les plus prometteuses pour la formation de MOC cristallines à base de calixarènes sont les connecteurs à base de tris(dipyrrine) (Figure 2a, connecteurs rac-M(HL1)3, Δ-Co(HL1)3, Λ-Co(HL1)3) et un Résumé dérivé de la famille de connecteurs de triazine (connecteur H3L8, Figure 2f). Les cristaux obtenus ont un pouvoir diffractant faible, et les structures ont pu être obtenues en utilisant des diffractomètres puissants associés à des temps d'enregistrements importants, en collaboration avec le groupe du Pr. Kari Rissanen (Université de Jyvaskyla, Finlande).

Ainsi, une série de 12 nouveaux MOC octaédriques a été obtenue et caractérisée à l'état solide par DRX. Ce sont des cages présentant la formule brute suivante :[M4SO2TCA]6[Cx]8 (M =

Co II , Ni II ; Cx = rac-Co(L1)3, rac-Fe(L1)3, rac-Rh(L1)3, Δ-Co(L1)3, Λ-C(L1)3, L8). Ils présentent tous les mêmes caractéristiques structurales : ils sont constitués de six unités tétranucléaires de sulfonylcalix [4]arène connectées les unes aux autres par l'intermédiaire de huit connecteurs triangulaires occupant les faces de la cage octaédriques, conduisant ainsi à des cages nanométriques octaédriques de type de type "Face-panelled", comme présenté Figure 3. Les MOC sont soit homo-soit hétéro-métalliques, selon la nature du cation métallique coordiné au calixarène et celui présent dans le connecteur métallo-organique :

Résumé

Il convient de mentionner que la caractérisation par DRX des différents assemblages a été un grand défi, notamment avec les connecteurs rac-M(HL1)3. En effet, le volume de la maille est très important, et comme déjà mentionné les cristaux ont un faible pouvoir diffractant en raison de la présence d'une grande quantité de solvants désordonnés à l'intérieur et à l'extérieur de la cage.

Les cages octaédriques formées possèdent une cavité interne de grande taille (Figure 3) dont le diamètre est proche de 19Å pour les cages à base de rac-M(HL1)3 et d'environ 16Å pour les cages à base de H3L8. Les cages cristallisent dans le système hexagonal avec des volumes de maille : proche de 225 000Å 3 pour les cages à base de rac-M(HL1)3 et d'environ 65 000Å 3 pour les cages à base de H3L8.

Pendant le travail de doctorat, il n'a pas été possible d'obtenir la structure cristalline des MOC avec d'autres connecteurs que ceux mentionnés ci-dessus. Cependant, certaines de ces modifications ont conduit à la formation de nouveaux cristaux qui n'ont pas encore été analysés.

Ces travaux sont toujours en cours, notamment en explorant de nouvelles voies de synthèse qui permettraient d'aboutir à la formation de cristaux souhaités. Par conséquent, les résultats actuels n'indiquent pas que ces connecteurs ne sont pas adaptés à la formation de nanoconteneurs multimétalliques, mais plutôt que la recherche est en cours et nécessite des investigations supplémentaires.

3) Propriétés des MOC a) Propriétés optiques

Parmi les connecteurs métallo-organiques employés, certains présentent une chiralité liée à la présence du métal (Λ-Co(HL1)3, Δ-Co(HL1)3). Lors de la synthèse, les différents énantiomères ont pu être séparés et leur pureté a été démontrée par dichroïsme circulaire ainsi que par chromatographie chirale. Les cages correspondantes (

[Co4SO2TCA]6[Λ-Co(L1)3]8, [Co4SO2TCA]6[Δ-Co(L1)3]8, [Ni4SO2TCA]6[Λ-Co(L1)3]8, [Ni4SO2TCA]6[Δ-Co(L1)3]8)
énantiomériquement pures ont été préparées et caractérisées par DRX. L'activité optique de ces cages a également été mesurée.

Afin de mettre en évidence la reconnaissance d'espèces chirales de la part de ces cages Chapter I.

énantiomériquement pures ([Co4SO2TCA]6[Λ-Co(L1)3]8, [Co4SO2TCA]6[Δ-Co(L1)3]8, [Ni4SO2TCA]6[Λ-Co(L1)3]8, [Ni4SO2TCA]6[Δ-Co(L1)3]

I. Historical review of covalent and coordination cage

Supramolecular cages are self-assembled structures that are formed through the use of noncovalent interactions, such as hydrogen bonding, metal coordination, and van der Waals forces that distinguishes them from purely covalent cages, mainly formed through covalent bonds. 1 Both supramolecular cages and covalent cages have the ability to selectively encapsulate and release guest molecules, making them useful in a wide range of applications including drug delivery, catalysis, and material science. In the recent years, there has been a large progress in the design and synthesis of supramolecular cages with controllable sizes, shapes, and functionalities.

The field of supramolecular cages is a rapidly expanding area of research that has the potential to fundamentally change the way we view materials and their related properties. Overall, the study of supramolecular cages is an exciting and rapidly growing field with a vast array of potential applications.

This brief introduction aims to provide an overview of supramolecular cages, beginning with the history of the first covalent cage-like structures and their subsequent evolution into coordination cages and sophisticated calixarene-based metal-organic cages. By tracing this developmental path, we can gain a better understanding concerning their properties and potential applications of these structures.

Below, a historical review with the beginning of recognition chemistry and some chosen examples (not an exhaustive list) will be provided.

I.1. Crown-ethers of Pedersen

The development of supramolecular cages has a history spanning over 50 years. The origins of this field can be traced back to the work of Pedersen et al., reported in 1967. 11 In this work, 33 crown ethers were described for the first time. These macrocycles were found to form strong inclusion complexes with ions, including Li + , Na + , NH4 + , RNH3 + , K, Rb + , Cs + , Ag + , Au + , Ca 2 +, Sr 2+ , Ba 2+ , Cd 2+ , Hg + , Hg 2+ , La 3+ , Tl + , Ce 3+ , and Pb 2+ . The preference for certain ions towards specific crown-ethers was explained by the cavity size of corresponding crown-ethers (Figure 4).

Figure 4

The most stable complexes for different sizes of crown-ethers [START_REF] Lehn | Supramolecular Chemistry: Concepts and Perspectives: A Personal Account Built upon the George Fisher Baker Lectures in Chemistry at Cornell University [and] Lezioni Lincee[END_REF]

§.I. Historical review of covalent and coordination cage

There are several reasons why crown-ethers may be regarded as the first covalent cages.

Firstly, crown-ethers possess an internal cavity that is able to be adapted. Secondly, it is demonstrated in Figure 4 that crown-ethers can selectively bind specific metal ions. In fact, crownethers can be considered as a type of "covalent organic cage", as they are composed of covalent bonds, have an inherent cavity and able to selectively bind certain species.

I.2. Cryptands of Dietrich, Lehn and Sauvage

The development of supramolecular cages was reported by the group of Dietrich, Lehn, and Sauvage in 1969. [START_REF] Dietrich | Diaza-polyoxa-macrocycles et macrobicycles[END_REF] They described the synthesis of more sophisticated molecules, called "cryptands", suitable for host-guest interactions. Cryptands are macrobicycles (Figure 5) that allows them to form more stable complexes with ions compared to crown ethers. While crown ethers form a 2D cavity, macrobicycles form a 3D cavity that is suitable for bonding with spherical alkali and alkali earth cations. It was found that the bonding strength of macrobicycles (cryptands) exceeds the one of macrocycles (crown-ethers) by several orders of magnitude and the formation selectivity is much higher, depending on the size of the cavity and the hard-soft acids and bases affinity. These phenomena led to the concept of "spherical recognition", which is now a common type of supramolecular interaction based on non-covalent interactions.

Figure 5

Structure of [2. 2.2]cryptand

I.3. Macrooligocycle of Kiggen

In 1984, Kiggen et al. reported the first recognizable prototype of a supramolecular cage.

This sophisticated ligand is a cage-like "macrooligocycle", which exhibits a cavity bounded on three sides and has functional groups suitable for the binding of metals (Figure 6). [START_REF] Quan | Constrictive Binding of Large Guests by a Hemicarcerand Containing Four Portals[END_REF] This molecule, called a "hemicarcerand", has a barrel-shaped cage structure and is able to exhibit host-guest interactions with guests like anthraquinone, camphor, and anthracene (Figure 7). The hemicarcerand described by this group was the first recognizable cage structure and paved the way for the synthesis of larger structures suitable for encapsulating larger guest molecules.

Figure 7

Structure of the first hemicarcerand and its guest molecules (from ref. [START_REF] Quan | Constrictive Binding of Large Guests by a Hemicarcerand Containing Four Portals[END_REF] ) §.I. Historical review of covalent and coordination cage

I.5. The first metal-organic cages and their development through decades

The next major development in the field of supramolecular cages was the first report of the synthesis of Metal-Organic Cages (MOCs). The first pioneering work in this field was reported in 1988 by Saalfrank et al. 16 The authors reported the formation of a Mg II -based MOC that displays a tetrahedral shape (Figure 8). However, the reported MOC presents a small cavity (diameter is approximately 6Å) and did not demonstrate good host-guest interactions.

Figure 8

The structure of the first MOC reported by Saalfrank et al. in 1988 (from ref. 16 )

The next breakthrough was done by Fujita et al. in 1990. In this pioneering work a watersoluble Pd II -square "proto-MOC" was reported. This compound demonstrated great recognition properties in aqueous media with 1,3,5-trimethoxybenzene (Figure 9a). [START_REF] Fujita | )Pd(4,4'-Bpy)]4(NO3)8 (En = Ethylenediamine, Bpy = Bipyridine), Which Recognizes an Organic Molecule in Aqueous Media[END_REF] In 1995, the same group reported the first recognizable MOCs and their encapsulation properties were demonstrated. The authors reported the formation of three MOCs displaying an octahedral shape using tridentate ligands. One of the obtained MOC is a cage formed by 2,4,6-tri(pyridin-4-yl)-1,3,5-triazine, and cis-protected Pd(NO3)2(en) through the process of self-assembly (Figure 9b).

Figure 9

Proto-MOC(a); The first MOC presenting recognition properties (from ref. [START_REF] Percástegui | Design and Applications of Water-Soluble Coordination Cages[END_REF] )

The octahedral shape assemblies present an ionic nature (the octahedron is charged positively, and anions are located inside and outside), making it water-soluble. Additionally, this MOC has a large accessible internal cavity with a diameter approximately of 12Å, suitable for recognition of relatively large species, for example, adamantyl carboxylate ions.

Figure 10

Pd II -based MOCs with the different encapsulated species (from ref. [START_REF] Fujita | Coordination Assemblies from a Pd(II)-Cornered Square Complex[END_REF] )

The ground-breaking researches conducted by M. Fujita et al. in the area of MOCs had a significant impact in the field, leading to its rapid growth in the following decades.

By 2002, a large number of MOCs displaying different geometries have been synthesized, leading to a specific classification, according to platonic bodies and describing two types of selfassembly processes for MOCs: "edge-directed" and "face-directed". [START_REF] Seidel | High-Symmetry Coordination Cages via Self-Assembly[END_REF] In the following two decades, the field of MOCs continued to expand rapidly, with the discovery of new structures possessing unique properties and applications, and new classes of MOCs were formed. Some of them will be described here below in a non-exhaustive list.

Up to 2018 a huge number of MOCs based on bis-monodentate ligands (MnL2n) were reported in the literature. [START_REF] Saha | Structure Relationships between Bis-Monodentate Ligands and Coordination Driven Self-Assemblies[END_REF] Reported MOCs display completely different geometries depending on their composition. It was well-demonstrated that similar ligands are able to form completely different structures (knots, spheres, polyhedra). The geometry of the final MOC is generally driven by the nature of bis-monodentate ligand and the angle between coordination positions. As a result, §.I. Historical review of covalent and coordination cage this family of MOCs, based on rigid pyridyl ligands, demonstrates the possibility to precisely tune the properties of the desired MOCs by manipulating rigid ligands geometry and especially the angle between the coordinating positions (Figure 11).

Figure 11

The formation of MOCs series from ligands with different angles between coordination sites (from the ref. [START_REF] Saha | Structure Relationships between Bis-Monodentate Ligands and Coordination Driven Self-Assemblies[END_REF] )

The Fujita's approach also influenced another interesting class of MOCs developed in the last decades -water soluble MOCs based on charged ligands that focused applications on the fields of molecular recognition, chemical transport, catalysis, and guest stabilization. [START_REF] Percástegui | Design and Applications of Water-Soluble Coordination Cages[END_REF] For example, Pr.

Nitschke et al. reported tetrahedral Fe II pyridyl-imine water soluble MOC. [START_REF] Mal | An Unlockable-Relockable Iron Cage by Subcomponent Self-Assembly[END_REF] The authors reported "subcomponent self-assembly method" for MOCs synthesis involving the simultaneous formation of dynamic coordinative N→M and covalent C=N bonds, leading to the in situ building of pyridylimine chelating ligands and their organization around metal ions acting as templates, forming the negatively charged MOCs (Figure 12). This method demonstrated its usefulness for the formation of many water-soluble cages.

Chapter I. Introduction §.I. Historical review of covalent and coordination cage

Figure 12

The synthesis of negatively charged MOC using the method of subcomponent selfassembly (from ref. [START_REF] Mal | An Unlockable-Relockable Iron Cage by Subcomponent Self-Assembly[END_REF] )

It is worth mentioning that MOCs structural developments can be provided not only through chemical modifications of the ligands but also of the "metal nodes" (point building units). For example, the increasing number of metal ions that forms one node has been reported. [START_REF] Zheng | Cubic Polyoxometalate-Organic Molecular Cage[END_REF] The higher number of metal ions forming one node is usually related to larger MOCs with better thermal stability. However, this approach is facing a stability problem of the formed nodes. The most frequent way to stabilise these polymetallic nodes is to coordinate free coordination positions of metal with certain organic species: formation of metallocenic [START_REF] Liu | In Situ Construction of a Coordination Zirconocene Tetrahedron[END_REF] or calixarene-based 4 clusters. The calixarene-based approach will be discussed in details in the §III. of this chapter.

In conclusion, the field of metal-organic cages

II. Non-calixarene MOCs: classification and properties

In order to correctly classify the different MOCs, useful concepts for their description will be defined here below:

Nodea point building unit in a supramolecular cage, where two or more connectors are joint/ vertex of a polyhedron.

Connectora prolongated building unit in a supramolecular cage, which links two or more nodes/ surface or edge of a polyhedron.

As it was demonstrated in the previous section, many different MOCs were synthetized over the years. These cages display different connectors structure, different nodes composition and it is hard to strictly classify them. In this section, MOCs classification will be divided in accordance with the nature of the used nodes:

• Metal-organic cages based on non-calixarene nodes

• Metal-organic cages based on calixarene nodes, which is the topic of this work

II.1. Strategies for synthetic approaches

As previously mentioned, metal-organic cages (MOCs) belong to a class of porous materials that are composed of metal nodes and organic or metal-organic connectors, which form a cage-like structure under conditions suitable for self-assembly.

The size, the shape, and the properties of the resulting MOCs can be precisely controlled by manipulating the size and shape of the metal nodes and the connectors. MOCs have attracted interest due to their large internal cavity and as a consequence high surface area, which make them suitable for a range of applications. The size, shape and coordination ability of the metal centres, as well as the nature and number of ligands, can be tailored to obtain MOCs with desired properties. 2 MOCs and metal-organic frameworks (MOFs) share a close relationship from a structural point of view since both involve the combination of metal ions or clusters with organic ligands.

However, the primary distinction between them is that MOCs are formed through the selfassembly of specifically chosen metal ions and ligands, leading to discrete, finite structures, while MOFs are formed through the coordination of metal ions and ligands to form porous extended or infinite network. 2 For the formation of MOCs, the choice of the nature of the metal ions and connectors is of utmost importance because the coordination ability of the metal ions and the geometry of the connectors determine the resulting cage geometry. The selection of metal ions and ligands in Chapter I. Introduction §. II. Non-calixarene MOCs: classification and properties MOCs is aimed at capping coordination sites, resulting to the formation of discrete molecular entities rather than extended frameworks. The most common metal ions used for MOCs synthesis are d-metals and f-metals, which have the ability to coordinate with ligands and form polyhedral structures while other elements are less commonly used due to their lower coordination number.

Furthermore, as it was discussed in §I. 5. of this chapter, it is possible to obtain MOCs based on clusters of d-metals forming a node. [START_REF] Zheng | Cubic Polyoxometalate-Organic Molecular Cage[END_REF] On the other side, the selection of appropriate connectors is also crucial for the synthesis of MOCs, as they must be able to coordinate to metal ions and contribute to the overall stability of the cage structure. The most common coordinating groups that are used for MOCs synthesis are (Figure 13): carboxylate, [START_REF] Liu | In Situ Construction of a Coordination Zirconocene Tetrahedron[END_REF][START_REF] Xing | Robust Multifunctional Zr-Based Metal-Organic Polyhedra for High Proton Conductivity and Selective CO 2 Capture[END_REF] pyridyl, 26,[START_REF] Bonakdarzadeh | X-Ray Structural and Ion-Mobility Mass Spectrometric Studies on Electron-Deficient and Electron-Rich M6L4 Coordination Cages[END_REF] or alcoholate, [START_REF] Norjmaa | Microsolvation and Encapsulation Effects on Supramolecular Catalysis: C-C Reductive Elimination inside [Ga4L6] 12-Metallocage[END_REF][START_REF] Levin | Scope and Mechanism of Cooperativity at the Intersection of Organometallic and Supramolecular Catalysis[END_REF] however, this is a non-exhaustive list.

Figure 13

MOCs based on connectors with carboxylate(a), [START_REF] Quan | Constrictive Binding of Large Guests by a Hemicarcerand Containing Four Portals[END_REF] pyridyl(b) [START_REF] Seidel | High-Symmetry Coordination Cages via Self-Assembly[END_REF] or alcoholate (c) [START_REF] Levin | Scope and Mechanism of Cooperativity at the Intersection of Organometallic and Supramolecular Catalysis[END_REF] coordinating groups

The formation of MOCs requires a well-designed combination of metal ions and connectors, as well as the use of allosteric and chelate cooperativity. [START_REF] Von Krbek | Assessing Cooperativity in Supramolecular Systems[END_REF] In order to comply to these conditions, there are several MOCs synthetic approaches used, which are detailed below:

• The symmetry interaction approach is a strategy that uses chelating connectors to occupy all coordination sites on metal centres while maintaining a closed structure.

This approach is based on the proper alignment of both the coordinate vector of the connector and the chelate plane of the metal in order to achieve the desired structural outcome. [START_REF] Caulder | The Self-Assembly of a Predesigned Tetrahedral M4L6 Supramolecular Cluster[END_REF]32 • The directional bonding approach is a strategy that involves the combination of connectors with specific orientations of donor atoms and metal atoms with fixed angle Chapter I. Introduction §. II. Non-calixarene MOCs: classification and properties in coordination sites. This approach aims to achieve precise geometry control over the chemical bonding interactions between the connectors and the metal centres. [START_REF] Seidel | High-Symmetry Coordination Cages via Self-Assembly[END_REF][START_REF] Kuehl | Self-Assembly of Nanoscopic Coordination Cages of D3h Symmetry[END_REF] • The third strategy for the formation of MOCs involves the use of ligands as twodimensional capping agents on the faces of MOCs. This approach, known as the facepanelling strategy, differs from the symmetry interaction and directional bonding approaches, and primarily results in edge-panelled MOCs (Figure 14).

In both the directional bonding and face-panelling strategies, it is common to use additional ligands to block the unoccupied coordination sites on the metal centre, in order to stabilize the discrete nature of the structure. [START_REF] Bilbeisi | A Self-Assembled [Fe II 12 L 12 ] Capsule with an Icosahedral Framework[END_REF][START_REF] Yoshizawa | Diels-Alder in Aqueous Molecular Hosts: Unusual Regioselectivity and Efficient Catalysis[END_REF] a) b)

Figure 14

Edge-panelled MOC (a); Face-panelled MOC(b)

II.2. Geometrical analysis

There are numerous possible combinations of metal nodes and connectors, and it is also possible to use multiple types of connectors involved into the formation of MOCs. This results in a diverse range of stable cage geometries with varying sizes of internal cavities, suitable for hosting a wide range of guest molecules. Table 1 represents a summary of the most frequently observed combinations between metal node geometries and ligand geometries, the resulting cage geometries, and synthesized cages with their corresponding internal cavity diameters. They will be arranged from the simplest connectors to the most sophisticated connectors and connectors combinations. This is a non-exhaustive list and additional more geometries exist that are out of this classification (see the description after the Table 1). D=10Å (from ref. [START_REF] Kilbas | A Solvent-Responsive Coordination Cage[END_REF] ) Table 1 The most frequent combinations of metal nodes and connectors, resulted cage geometries and some examples with their internal cavity diameters

Chapter I. Introduction §II. Non-calixarene MOCs: classification and properties

The data presented in the Table 1 highlight the versatility of MOCs in terms of their geometry and internal cavity size that differs from 6 to 28Å. The table shows that 14 different geometries are the most common:

• Three types of tetrahedra,

• Three types of barrels,

• Two types of cubes,

• Three types of octahedrons,

• Cuboctahedra,

• Trigonal prisms,

• Tetragonal prisms.

However, there were many other MOCs geometries reported in the literature starting with distorted version of the mentioned polyhedra and ending with the variety of sophisticated polyhedra from MnL2n family that are represented in Figure 11 and Figure 15 It is worth to mention that for non-calixarene based MOCs, precise combinations of node/connector usually do not lead to different MOCs geometry upon different synthetic conditions. However, it is possible to obtain MOCs with different geometries by minor alteration of the angle between coordination sites of the used connector, for example, even a small change of 3 o can lead to completely different geometries of the resulting MOCs. It was well demonstrated by Fujita et al., where they reported the formation of few giant MOCs using similar bismonodentate connectors (Figure 15). 46

Figure 15

The formation of MOCs displaying different geometries, depending on the angle between coordination sites of the chosen connectors (from ref. [START_REF] Saha | Structure Relationships between Bis-Monodentate Ligands and Coordination Driven Self-Assemblies[END_REF] )

The successful formation of MOCs with a suitable internal cavity for specific guest molecules heavily relies on the careful selection of metal ions, connectors and self-assembly conditions. The ability to tune the size of the internal cavity is a critical factor which determines the properties and applications of MOCs, which will be further discussed.

Chapter I. Introduction §II. Non-calixarene MOCs: classification and properties

II.3. Reported properties of MOCs

Unique MOCs properties are explained by their tunable internal cavity, the presence of metal ions in the structure and their discrete nature.

The tunable internal cavity of MOCs enables the formation of host-guest complexes with a wide range of desired guest molecules, leading to better fitting and stronger host-guest interactions.

The presence of metal ions in the structure of MOCs generates a possibility to exhibit magnetic and optical properties (for example, single-molecule magnet behaviour and sensing). [START_REF] Bell | Design of Lanthanide Based Metal-Organic Polyhedral Cages for Application in Catalysis, Sensing, Separation and Magnetism[END_REF] The discrete nature of MOCs allows them to be soluble without destruction of the building unit (cage) in solution. [START_REF] Percástegui | Design and Applications of Water-Soluble Coordination Cages[END_REF] Cage solubility opens new horizons for their application, for example, water soluble charged cages are great candidates for the design of target drug delivery systems. [START_REF] Percástegui | Design and Applications of Water-Soluble Coordination Cages[END_REF][START_REF] Zhou | Supramolecular Chemotherapy Based on Host-Guest Molecular Recognition: A Novel Strategy in the Battle against Cancer with a Bright Future[END_REF] In comparison, MOFs, which are extended structures, are composed of repeating units and thus have less control over the overall structure, making it harder to tailor the properties of the structures and to incorporate specific functional groups in process of post-functionalization. [START_REF] Carné-Sánchez | Postsynthetic Covalent and Coordination Functionalization of Rhodium(II)-References Based Metal-Organic Polyhedra[END_REF] Additionally, the discrete nature of MOCs also allows a strong control over the chemical functionalization of the cage structure. This can be used to introduce functional groups for specific applications, such as catalytic or sensing applications. The main reported applications will be discussed here below.

II.3.1. Catalytic activity

The catalytic activity of MOCs has been the subject of extensive research due to the potential for MOCs to act as efficient catalysts with the presence of the cavity and the possibility to use confined space. Various chemical reactions catalysed with MOCs have been reported in the homogeneous catalysis conditions, for example, hydrolysis of organophosphates esters [START_REF] Taylor | Coordination-Cage-Catalysed Hydrolysis of Organophosphates: Cavity-or Surface-Based?[END_REF] and Kemp elimination. [START_REF] Cullen | Catalysis in a Cationic Coordination Cage Using a Cavity-Bound Guest and Surface-Bound Anions: Inhibition, Activation, and Autocatalysis[END_REF] The activity of MOCs in the homogeneous catalysis can be illustrated here by an example involving the use of Ga-based MOC. [START_REF] Kaphan | A Supramolecular Microenvironment Strategy for Transition Metal Catalysis[END_REF] It was demonstrated that the use of this cage significantly increased the reaction rate, reaching a magnitude of seven orders, of the reductive elimination reaction from gold and platinum species with the formation of a C-C bond (Figure 16). In this reaction, the Ga-based MOC plays a role of catalyst and gold or platinum species provide methyl groups for the C-C bond formation. §II. Non-calixarene MOCs: classification and properties

Figure 16

Cage catalysis in the reaction of reductive elimination (from ref. [START_REF] Kaphan | A Supramolecular Microenvironment Strategy for Transition Metal Catalysis[END_REF] )

The MOC's catalytic microenvironment, which acts as a functional enzyme mimic, plays a crucial role in this process. Reaction of the reductive elimination with Ga-MOC use brought to the mind an idea of introducing catalytic system with Ga-based MOC, where reductive elimination is one of the steps in the catalytic cycle. The idea was to force gold and platinum species not to act as reactants but as catalyst in the reaction mixture of other molecules that provide methyl groups for the C-C bond formation.

Previously described Ga-based MOC was sophisticated and introduced as a cocatalyst leading to dual system catalyst. The authors demonstrated the potential of the Ga-based MOC to stabilize the Pt + transition state so Pt-species does not degrade as it was demonstrated on the Figure 16. This system, consisting of Pt-catalyst and tetrahedral Ga-based MOC cocatalyst, catalyses the reaction between iodomethane and tetramethyltin (two sources of methyl groups), in the presence of KF, where the reductive elimination from Pt-species is one of the steps in the catalytic cycle (Figure 17).

Figure 17

Demonstration of system Pt/Cage dual catalysis (from ref. [START_REF] Kaphan | A Supramolecular Microenvironment Strategy for Transition Metal Catalysis[END_REF] )

II.3.2. Separation properties

Due to their solubility and large, tunable internal cavities, MOCs have the ability to selectively bind and separate target molecules from a mixture. Additionally, the versatility of MOCs allows the functionalization of their internal surfaces, which further enhances their separation abilities. Here below, we will focus on few detailed examples.

Chapter I. Introduction §II. Non-calixarene MOCs: classification and properties

The separation properties of MOCs have been widely demonstrated in various phases, such as liquid-liquid extractions, solid-liquid extractions, phase transfer, and enantiomers separation using chiral cages. One notable example of liquid-liquid extraction with MOCs is the study conducted by Nitschke et al., [START_REF] Zhang | Anion Binding in Water Drives Structural Adaptation in an Azaphosphatrane-Functionalized Fe II 4 L 4 Tetrahedron[END_REF] who synthesized a Fe II -based positively-charged tetrahedral MOC using an azaphosphatrane-based ligand. This cage was able to selectively encapsulate ReO4 -anion in a water solution through competitive guest exchange, in presence of many other ions such as F -, Cl -, Br -, I -, SO4 2-, ClO4 -, NO3 -, BF4 -, H2PO4 -, and AcO -, with 97% ReO4 -extraction efficiency.

In a follow-up study, [START_REF] Zhang | Selective Anion Extraction and Recovery Using a Fe II 4 L 4 Cage[END_REF] the same MOC was modified to be soluble in water-immiscible nitromethane, and this MOC demonstrated the ability to extract ReO 4-from the water phase to the organic phase with an extraction efficiency of up to 97% (Figure 18).

Figure 18

Selective extraction of ReO4 -anion from water phase to organic phase (Tetrahedron represents Fe-based MOC) (from ref. [START_REF] Zhang | Selective Anion Extraction and Recovery Using a Fe II 4 L 4 Cage[END_REF] )

Another example of separation properties using MOCs is the study of Zhang et al.,[START_REF] Zhang | Selective Encapsulation and Separation of Dihalobenzene Isomers with Discrete Heterometallic Macrocages[END_REF] which demonstrated the separation of para-dihalogenated benzene derivatives, using a Rh-Ag MOC. This cage was able to selectively encapsulate para-isomers from an hexane to methanol solution.

Photosensitivity of the described cage allows the release of encapsulated para-dihalogenated derivatives under light irradiation which destroys the cage.

Solid-liquid extraction was also well-demonstrated by the extraction of different fullerenes from a tetrachloroethane solution into a solid phase of MOC.

Figure 19

Proposed mechanism of R/S-BINOL enantiomers separation based on MOC (from ref. [START_REF] Wu | Homochiral D4-Symmetric Metal-Organic Cages from Stereogenic Ru(II) Metalloligands for Effective Enantioseparation of Atropisomeric Molecules[END_REF] )

These examples demonstrate the infinite possibilities of MOCs for the separation properties in solution. It is possible to achieve a selectivity towards targeted guests by connectors and nodes modification which leads to the formation of MOCs with suitable cavities.

II.3.3. MOCs in medicine: drug carriers and imaging

Figure 20

Cartoon representation of MOCs application in targeted drug delivery systems (from ref. [START_REF] Zhu | Exploring the Activity of a Polyazine Bridged Ru(II)-Pt(II) Supramolecule in F98 Rat Malignant Glioma Cells[END_REF] )

The ionic nature of some water-soluble MOCs allows them to be widely used in biological applications, such as imaging and targeted drug delivery. [START_REF] Percástegui | Design and Applications of Water-Soluble Coordination Cages[END_REF] It was shown that MOCs can have Chapter I. Introduction §II. Non-calixarene MOCs: classification and properties applications in chemotherapy due to their distinctive guest capture ability. [START_REF] Zhou | Supramolecular Chemotherapy Based on Host-Guest Molecular Recognition: A Novel Strategy in the Battle against Cancer with a Bright Future[END_REF] For example, the solubility of some poorly soluble anticancer drugs can be significantly improved when incorporated in MOCs (Figure 20). Furthermore, many anticancer agents are not stable in the body environment, but the formation of host-guest complexes with MOCs can preserve their activity. [START_REF] Zhu | Exploring the Activity of a Polyazine Bridged Ru(II)-Pt(II) Supramolecule in F98 Rat Malignant Glioma Cells[END_REF] Besides, high accumulation of the anticancer agents in a tumour can be achieved from enrichment effect of MOCs, remarkably enhancing the efficiency of the supramolecular chemotherapeutic agents and reducing the side effects towards normal tissues. [START_REF] Zhu | Metal-Organic Cages for Biomedical Applications[END_REF] One of the attractive features of MOCs as drug carriers is their ability to host multiple drug molecules, in contrast to traditional carriers like calixarenes or cyclodextrins that can only accommodate one molecule. This increased capacity can lead to higher concentrations of the therapeutic agent into targeted cells, potentially improving the efficiency of the treatment while also decreasing the overall chemical exposure of the organism by virtue of using smaller amounts of the carrier. [START_REF] Zhu | Exploring the Activity of a Polyazine Bridged Ru(II)-Pt(II) Supramolecule in F98 Rat Malignant Glioma Cells[END_REF] Another potential application of MOCs in biological fields is the selective sensing and imaging. With the outstanding sensing property, MOCs could work as chemosensors towards certain substrates, reactions or processes. [START_REF] Jiao | Cerium-Based M 4 L 4 Tetrahedra as Molecular Flasks for Selective Reaction Prompting and Luminescent Reaction Tracing[END_REF] Yu et al. reported the anion sensing of HSO3 -in aqueous solution by hexametallic-organic cages. [START_REF] Cui | Self-Assembly and Anion Sensing of Metal-Organic [M6L2] Cages from Fluorescent Triphenylamine Tri-Pyrazoles with Dipalladium(II,II) Corners[END_REF] The cages were built from tris(4-(1H-pyrazol-3-yl) phenyl)amine as tripod connector, and di-Pd II motifs as metal vertices. The structure of the resulting hexametal-organic cages can be adapted by selectively interacting with HSO3 -anions and is illustrated as efficient fluorescence sensor. Mascaren's et al. reported the anion sensing of a tetrahedral MOC, which specifically binds to the pyronine moiety, that facilitates the supramolecular complex entering the cell. [START_REF] Rodríguez | Anion Recognition as a Supramolecular Switch of Cell Internalization[END_REF] This host-guest interaction enables the complex to pass the cell membrane, while none of the components, neither the host nor the guest, are able to cross the cell membrane on their own. Sun et al. also demonstrated a rare earth Eu (III)-based tetrahedral MOC with a record emission quantum yield of 23.1%. High sensitivity and selectivity are revealed for the cage in both turn-off luminescent sensing toward I -and turn-on sensing toward Cu 2+ . 64 In this part we provided many examples of MOCs together with their geometrical features and properties. The field of their applications is very large starting from the remarkable catalytic properties and ending with the design of targeted drug delivery systems.

In the next section we will focus on the main topic of this work: calixarene-based MOCs, their geometrical characteristics and applications.

III. Calixarene-based MOCs

MOCs based on calixarene is an intriguing research area because it combines the unique structural properties of macrocyclic calixarene moieties with the functional properties of metal ions. For example, the calixarene imposes to the MOCs a larger central cavity and the ability to form inclusion complexes with larger guest molecules in comparison with other reported MOCs, while the metal ions can introduce new chemical and physical properties, such as catalytic activity, magnetic behaviour, and optical properties, as already mentioned. [START_REF] Bell | Design of Lanthanide Based Metal-Organic Polyhedral Cages for Application in Catalysis, Sensing, Separation and Magnetism[END_REF][START_REF] Atwood | Magnetism in Metal-Organic Capsules[END_REF] Here below, we will discuss special properties of calixarene moieties that make them excellent candidates for the MOCs formation.

III.1. Generalities on calix[4]arene

The calixarene derivatives, a well-known macrocyclic species, has been chosen to be one of the components for the formation of the MOCs, due to their peculiar structural features, their ability to be chemically modified, as well as their properties. [START_REF] Gutsche | Calixarenes Revisited[END_REF] One of the most notable characteristics of the family of calixarene macrocyclic moieties is the ability to adopt different conformations in solution and in the solid state, which provides to them the versatility to perform a variety of functions. For example, calix [4]arenes display the conformations of cone, partial cone, 1,2-alterante, 1,3-alternate (Figure 21). Theoretically, this feature can be useful to control the shape of the building block while building MOCs. However, it was noticed from the literature analysis, that for the formation of calixarene-based MOCs, only the cone conformation was observed.

Figure 21 Calix[4]arene conformations

There are three different calixarene families that have been mostly used for the formation of calixarene-based MOCs: classical calix [4]arene, 67 thiacalix[4]arene [START_REF] Akdas | Thiacalixarenes: Synthesis and Structural Analysis of Thiacalix[4]Arene and of p-Tert-Butylthiacalix[4]Arene[END_REF] and sulfonylcalix [4]arenes 69 (Figure 22). Due to the presence of sulphur atoms and additional oxygen atoms, families of thiacalix [4]arenes and sulfonylcalix [4]arenes display better metal coordination properties. It was demonstrated that thiacalix [4]arene and sulfonylcalix [4]arenes are able to form complexes with the variety of d-metal ions. [START_REF] Kajiwara | Transition Metal and Lanthanide Cluster Complexes Constructed with Thiacalix[n]Arene and Its Derivatives[END_REF][START_REF] Kajiwara | Highly Symmetrical Tetranuclear Cluster Complexes Supported by p -Tert -Butylsulfonylcalix[END_REF] These complexes usually consists of one calixarene Chapter I. Introduction §III. Calixarene-based MOCs species, four d-metal ions and, sometimes, one μ-water molecule located in the middle of the square formed by the metal ions. [START_REF] Liu | Intraligand Charge Transfer Sensitization on Self-Assembled Europium Tetrahedral Cage Leads to Dual-Selective Luminescent Sensing toward Anion and Cation[END_REF] This feature makes thiacalix [4]arenes and sulfonylcalix [4]arenes the best candidates for the formation of sophisticated metal nodes in the structure of MOCs, because that allows to increase the general number of metal ions involved in the structure of the desired MOCs, as it was mentioned in §I.5 of this chapter.

Figure 22

Calix [4]arene families most common in MOCs

In the following sections, we will examine the structure and geometry of MOCs based on calixarenes, as well as their advanced properties related to the presence of calixarene moieties in the structure.

III.2. First calixarene-based metal-organic cage

The idea of using calixarene moieties in the structure of MOCs was driven by the desire to improve the cage structure in order to achieve new properties. In this section, we will discuss the approaches that lead to the sophistication of metal nodes in the structure of the resulting MOCs.

One approach is the use of metal ions clusters instead of single metal ions, as described in several works. [START_REF] Zheng | Cubic Polyoxometalate-Organic Molecular Cage[END_REF] Another possibility is to use calixarene-based clusters, as it was firstly reported in 2012. [START_REF] Liu | Calixarene-Based Nanoscale Coordination Cages[END_REF][START_REF] Du | A Giant Coordination Cage Based on Sulfonylcalix[4]Arenes[END_REF] The authors used polynuclear metal clusters of p-tert-Butylthiacalix [4]arene as metal nodes. Previous studies [START_REF] Kajiwara | Transition Metal and Lanthanide Cluster Complexes Constructed with Thiacalix[n]Arene and Its Derivatives[END_REF][START_REF] Hang | A 2D Metal-Calixarene Aggregate Involving in Situ Generated 5-(4-Pyridyl)Tetrazolate Ligand[END_REF] have demonstrated that p-tert-Butylthiacalix tends to form tetranuclear complexes with transition metals, resulting in shuttlecock-like building units (Figure 23). This property to synthesize a series of octahedral calixarene-based MOC was exploited. The octahedral MOC synthesized consists of six tetracobalt-p-tert-Butylthiacalixarene units connected by tricarboxylate connectors of various sizes (Figure 23). The obtained calixarene-based MOC belongs to the class "face-panelled MOCs" discussed in §II.1. of this chapter.

Chapter I. Introduction §III. Calixarene-based MOCs

Figure 23

The process of supramolecular self-assembly of tetracobalt-p-tert-Butylthiacalix [4]arene and tricarboxylate linkers leading to the octahedral calixarene-based

MOC

The use of calixarenes in the structure of MOCs allows to open new fields for structural varieties and applications. The benefits along with geometry and properties of calixarene-based

MOCs will be discussed more in detail in the following section.

III.3. Calixarene-based MOCs: formation and synthesis

Calixarene moieties have been used for the formation of coordination cages for more than 10 years. [START_REF] Liu | Calixarene-Based Nanoscale Coordination Cages[END_REF][START_REF] Du | A Giant Coordination Cage Based on Sulfonylcalix[4]Arenes[END_REF] As it was mention in §III.1., calixarenes can be observed as bowl-shaped molecules, in cone confirmation exclusively in the structure of MOCs (Figure 21). In MOCs, they display the feature to coordinate four d-metal ions (and sometimes also one μ-H2O molecule) by one calixarene molecule (CA), leading to the formation of perfect shuttlecock nodes [M4CA(μ4-OH2)] 4+ (Figure 24). [START_REF] Kajiwara | Highly Symmetrical Tetranuclear Cluster Complexes Supported by p -Tert -Butylsulfonylcalix[END_REF] A connector is typically a ditopic ligand, able to coordinate the metals in the structure of the shuttlecock node [M4CA(μ4-OH2)] 4+ , having free positions in their coordination spheres. The most frequently encountered connectors that are used for the cage formation present the carboxyl coordinating groups. The connectors can be linear, [START_REF] Bi | A Tetragonal Prismatic {Co32} Nanocage Based on Thiacalixarene[END_REF] angular 76 and triangular [START_REF] Su | Open Pentameric Calixarene Nanocage[END_REF] with different number of binding positions. A non-exhaustive list of connectors is depicted in reference. [START_REF] Bi | Thiacalixarene-Based Nanoscale Polyhedral Coordination Cages[END_REF]

Chapter I. Introduction §III. Calixarene-based MOCs

Figure 24

Formation of calixarene shuttlecock node [M4CA(μ4-OH2)] 4+ ; self-assembly process of shuttlecock nodes with connectors for the formation of calixarene-based cage

Various synthetic conditions must be considered. The choice of these conditions is crucial to achieve the desired cavity and the desired properties of the MOCs. The synthetic approaches for the formation of these MOCs have been extensively investigated, and solvothermal [START_REF] Gosselin | Permanently Microporous Metal-Organic Polyhedra[END_REF] methods have been demonstrated to be the most effective methods for synthesizing these cages. These methods involve the use of high temperatures and high pressure to ensure the formation of the desired MOCs. However, the solvents used in the calixarene-based MOCs synthesis are limited by the requirement to solubilize connectors, calixarenes, and metal salts. Among the commonly used solvents, dimethyl sulfoxide, N,N-dimethylformamide, acetonitrile and N,N-dimethylacetamide have demonstrated a great potential for the efficient synthesis of MOCs.

It should be noted that the choice of the synthetic parameters, such as temperature, pressure, and solvent, can greatly affect the structure and properties of the resulting MOCs. Therefore, the optimization of these conditions is critical in order to obtain MOCs with the desired properties.

Moreover, while solvothermal methods are commonly used for the MOC synthesis, alternative methods such as microwave-assisted synthesis [START_REF] Zhang | Microwave-Assisted Synthesis of Zr-Based Metal-Organic Polyhedron: Serving as Efficient Visible-Light Photocatalyst for Cr(VI) Reduction[END_REF] have also been reported, which may provide more efficient and sustainable approaches for the synthesis of MOCs.

As a conclusion, the synthesis of the calixarene-based MOCs is the result of a threecomponents process, as shown in Figure 24: during the synthesis, the shuttlecock nodes §III. Calixarene-based MOCs

[M4CA(μ4-OH2)] 4+ are formed, and they are suitable to interact through coordination bonds with connectors, behaving like "complex as ligand", to lead to the formation of large cages.

III.4. Calixarene-based MOCs: geometry

Having in hands a three-components system when forming MOCs based on calixarenes, the number of reachable stable geometries is rather limited. And there are specific parameters that are orienting the type of cages that can be obtained using the combination of metals, calixarenes and connectors. The nature and geometry of the connectors along with the used stoichiometry connector/node play a significant role in determining the overall geometry of the resulting MOC. [START_REF] Bi | Thiacalixarene-Based Nanoscale Polyhedral Coordination Cages[END_REF] In Table 2 we summarized the already reported cages obtained from the combination of metals, calixarenes and connectors, along with their geometrical characteristics. [M4CA]6LB12 Octahedron [START_REF] Xiong | Truncated Octahedral Coordination Cage Incorporating Six Tetranuclear-Metal Building Blocks and Twelve Linear Edges[END_REF][START_REF] Tong | Soluble Imidazolium-Functionalized Coordination Cages for Efficient Homogeneous Catalysis of CO2 Cycloaddition Reactions[END_REF] [M4CA]6LB12 D=14Å (from ref. [START_REF] Bi | A Tetragonal Prismatic {Co32} Nanocage Based on Thiacalixarene[END_REF] ) D=9Å (from ref. [START_REF] Bi | Making a [Co24] Metallamacrocycle from the Shuttlecock-like Tetranuclear Cobalt-Calixarene Building Blocks[END_REF] ) D=16Å (from ref. Hexadecahedron [START_REF] Hang | Discrete {Ni40} Coordination Cage: A Calixarene-Based Johnson-Type (J 17) Hexadecahedron[END_REF] [M4CA]10T16 D=7Å (from ref. [START_REF] Su | Open Pentameric Calixarene Nanocage[END_REF] ) D=9Å (from ref. [START_REF] Xiong | Chlorine-Induced Assembly of a Cationic Coordination Cage with a Μ5-Carbonato-Bridged MnII24 Core[END_REF] ) D=21Å (from ref. [START_REF] Hang | Discrete {Ni40} Coordination Cage: A Calixarene-Based Johnson-Type (J 17) Hexadecahedron[END_REF] ) Octahedron 84,95- 97,98 [M4CA]6T8

Tetrahedron [START_REF] Liu | A Tetrahedral Coordination Cage Based on P-Tert-Butylthiacalix[4]Arene and 5-Sulfoisophthalic Acid[END_REF] [M4CA]4T4

Icosahedron 100 [M4CA]12T20 D=27Å (from ref. [START_REF] Du | Structure Modeling, Synthesis and X-Ray Diffraction Determination of an Extra-Large Calixarene-Based Coordination Cage and Its Application in Drug Delivery[END_REF] ) D=8Å (from ref. [START_REF] Liu | A Tetrahedral Coordination Cage Based on P-Tert-Butylthiacalix[4]Arene and 5-Sulfoisophthalic Acid[END_REF] ) D=22Å (from ref. 100 )

Table 2

The

most frequently observed combinations of (Metals + calixarenes + connectors), and resulting calixarene-based MOCs, their geometry and their internal cavity diameters §III. Calixarene-based MOCs

The data represented in Table 2 reveal that the calixarene shuttlecock nodes usually serve as vertices in the formation of polyhedral cages, and the final geometry of the cage is mostly dependent upon the flexibility, geometry, number of binding positions and angle between binding positions of the used connectors. Based on our literature review, we have documented the presence of 12 distinct geometries of calixarene-based MOCs with internal cavity diameters ranging from 7 Å to 27 Å:

• Face-panelled and edge-panelled octahedra,

• Distorted octahedra,

• Tetrahedra,

• Icosahedra,

• Hexadecahedra,

• Tetragonal pyramids,

• Truncated cuboctahedra,

• Two types of barrels,

• Macrocycles,

• Cubes.

The most frequently encountered geometry for calixarene-based MOCs is the octahedral one, which consists of an octahedron-like cage with shuttlecock units at each of the six vertices.

Controlling the geometry of the calixarene-based MOCs can be challenging as it depends on a combination of several factors. However, some control can be achieved by modifying the synthetic conditions: among them the nature of the used connectors, the concentration of components, and the reaction time. Additionally, the nature of the calixarene derivatives and metal ions can also influence the geometry of the resulting MOC.

A significant amount of calixarene-based MOCs display internal cavity diameters exceeding 10Å, indicating that they are generally characterized by large internal cavities that are well-suited for host-guest interactions with a range of molecular species.

The geometry of calixarene-based MOCs has a direct impact on their properties and potential applications. In the following section, we will discuss some of these properties and focus our attention on the possible calixarene-based MOCs applications.

Chapter I. Introduction §III. Calixarene-based MOCs

III.5. Calixarene-based MOCs based on organic connectors: properties

Besides the ability to form tetranuclear clusters with a large variety of d-metals, another one major advantage of using thiacalix [4]arenes and sulfonylcalix [4]arenes usage for the formation of MOCs, is to improve the thermal stability of the self-assembled species compared to the one of classical calixarenes. 3 This opens a wide range of applications, such as high-temperature catalysis and gas storage. Additionally, these molecules present a higher acidity, which allows a larger affinity towards metal ions and a higher metal-loading capacity.

Calixarenes moieties are famous for their natural shape as cone, and their ability to form host-guest complexes due to their macrocyclic nature, which provides perfect pores for encapsulation of small molecules, like for example, methane. 101 They present a high adsorption activity towards gas inherent to their geometry. Furthermore, calixarenes moieties have demonstrated unique properties for molecular separation, for example, extraction of organic molecules from water, selective gas adsorption, selective inclusion of organic molecules, etc. 102

The unique physical characteristics of thiacalix [4]arenes and sulfonylcalix [4]arenes, that form MOCs, confer to MOCs properties: like higher surface area, improved gas adsorption properties and ability to host larger guests. [START_REF] Du | Structure Modeling, Synthesis and X-Ray Diffraction Determination of an Extra-Large Calixarene-Based Coordination Cage and Its Application in Drug Delivery[END_REF] These unique properties of calixarene-based MOCs will be discussed in the following section.

III.5.1. Gas adsorption properties

Gas adsorption properties of calixarene-based MOCs will be discussed in depth in §I. 1. of Chapter IV. In this section we intend to provide a generalised understanding of the gas adsorption properties of MOCs and discuss the influence of a connector structure on these properties.

The adsorption properties of thiacalix [4]arene-based and sulfonylcalix [4]arene-based

MOCs have been already studied, however this field is relatively underexplored. In comparison with MOFs, MOCs usually demonstrate smaller Surface Area. For instance, MOFs frequently exceed BET surface area of 3000 or even 4000 m 2 /g. On the same time, BET surface area of the largest synthetized calixarene-based MOCs do not exceed 1300 m 2 /g. 103 However, the adsorption properties of MOCs can be modulated through the use of specific connectors.

For example, the formation of a series of octahedral MOCs (Figure 25) based on the enlarged tetracobaltthiacalix [4]arene shuttlecock units and tricarboxylate connectors with BET surface area 605m 2 /g has been reported. [START_REF] Liu | Calixarene-Based Nanoscale Coordination Cages[END_REF] This is relatively high when compared to the structurally similar calixarene-based MOCs. 98 Chapter I. Introduction

§III. Calixarene-based MOCs

Figure 25

Octahedral cage base on enlarged tetracobaltthiacalix [4]arene shuttlecock units (from ref. [START_REF] Liu | Calixarene-Based Nanoscale Coordination Cages[END_REF] )

In a noteworthy study, [START_REF] Du | Structure Modeling, Synthesis and X-Ray Diffraction Determination of an Extra-Large Calixarene-Based Coordination Cage and Its Application in Drug Delivery[END_REF] Nitrogen adsorption-desorption isotherm of cages CIAC-106 and CIAC-114 (e) (from ref. [START_REF] Du | Structure Modeling, Synthesis and X-Ray Diffraction Determination of an Extra-Large Calixarene-Based Coordination Cage and Its Application in Drug Delivery[END_REF] )

III.5.2. Recognition properties

Observation of good gas adsorption properties accounts for the fact that calixarene-based MOCs have large internal cavity that could be exploited not only for gas adsorption but also for encapsulation of other molecules in a process of recognition

Chapter I. Introduction §III. Calixarene-based MOCs

Guest recognition properties of calixarene-based MOCs are widely described in the literature. For example, host-guest properties were investigated on guest molecules as methylene blue, [START_REF] Dai | Modulating Guest Binding in Sulfonylcalixarene-Based Metal-Organic Supercontainers[END_REF] that is widely used for the investigation of adsorption properties of MOFs, and also on eosin Y. [START_REF] Sun | Sulfonylcalixaren-Based Ortho -Dicarboxylate-Bridged Coordination Containers for Guest Encapsulation and Separation[END_REF] Not only model compounds were employed to study the host-guest properties of MOCs. Also calixarene-based MOC exhibiting excellent binding properties with amine derivatives was recently described. [START_REF] Bhuvaneswari | Sensitive and Specific Guest Recognition through Pyridinium-Modification in Spindle-Like Coordination Containers[END_REF] In 2014, Wang et al. reported the host-guest properties of an octahedral MOCs based on tetranuclear-sulfonylcalix [4]arene units (M = Ni II , Co II , Mg II ) and terephthalic acid towards methylene blue and acetylsalicylic acid using various methods, including homogeneous-solution guest binding, liquid-liquid extraction, solid-liquid adsorption, and solid-gas adsorption. 104 The occurrence of host-guest interactions was demonstrated, among others, through the shift in absorbance on the UV-vis spectra observed during the titration of a MOC solution with methylene blue solution (Figure 27a). The transition of methylene blue, which is more soluble in water, to the chloroform phase in the presence of MOCs during a liquid-liquid extraction experiment was also observed (Figure 27b). The solid-liquid adsorption experiment showed that MOCs could effectively adsorb a large amount of methylene blue from the aqueous solution (5 molecules of methylene blue by the one cage) (Figure 27c). Fluorescent emission spectra of MOC 1-Zn before addition of an excess amount of proton (black) and after (cyan) (from ref. 86 )

A very recent work demonstrated the formation of MOC based on tetramagnesiumsulfonylcalix [4]arene and benzene-1,3,5-tribenzoic acid that exhibits excellent luminescent properties. 107 These properties allows the cages to be an efficient luminescent sensor for various species in the aqueous media. For example, this cage exhibits high sensitivity towards Fe 3+ and MnO4 -ions, nitrobenzene and 2,4-dinitrophenol. It was demonstrated by dramatic decreasing of luminescence with the addition of guests in small quantities (Figure 29).

Figure 29

The emission spectra of calixarene-based Mg II -MOCs excited at 328 nm with different concentrations of Fe 3+ showing its sensor capacity to Fe 3+ ions (from ref. 107 )

III.5.3. Drug delivery

As already mentioned, one of the advantages of calixarene-based MOCs is also their ability to accommodate large guests due to their spacious internal cavities. This ability has been demonstrated using the therapeutic guest ibuprofen, which was shown to be successfully hosted by MOCs through the decrease of nitrogen adsorption observed following ibuprofen adsorption (as depicted in the red adsorption-desorption isotherms of Figure 26e). 98

Chapter I. Introduction §III. Calixarene-based MOCs

Calixarene-based MOCs have been mixed with biological active compounds in order to design target drug delivery. For example, octahedral calixarene based MOCs were tested with aspirin. 104 The results of this investigation, depicted in Figure 30a These observations demonstrate the potential of calixarene-based MOCs as drug carriers capable of delivering a wide range of large active molecules under different stimuli.

III.5.4. Catalysis

The host-guest interactions properties of MOCs play a significant role in determining their catalytic properties. The ability of MOCs to selectively and strongly bind guest molecules, as demonstrated in previous studies, [START_REF] Du | Structure Modeling, Synthesis and X-Ray Diffraction Determination of an Extra-Large Calixarene-Based Coordination Cage and Its Application in Drug Delivery[END_REF]104 opens up opportunities for the stabilization of catalytic species within the internal cavity during the catalytic process, in a confined space. By designing MOCs with optimized host-guest interactions, the conditions for catalysis can be effectively controlled, in confined media, leading to improved catalytic activity. Geometrical and electronic structure of discrete calixarene-based MOCs, allow them to participate to homogeneous catalytic reactions. Moreover, it was shown that highly hydrophobic upper rim of p-tertbutylsulfonylcalix [4]arene is helpful to prevent the hydroxide attack on the tetranuclearcalixarene moieties, thus improves the stability of the coordination containers for some reactions, for instance, oxygen evolution reactions, that could be useful for catalysis under hard conditions. 108

Chapter I. Introduction §III. Calixarene-based MOCs

Catalytic activity of chiral octahedral calixarene-based MOC based on tetracarboxylate connectors with free phosphate group was demonstrated, for example, for the asymmetric Friedel-Crafts reaction of N-sulfonyl aldimines with indole (ee is up to 99%) and asymmetric [3+2] coupling reaction (ee is up 99%). 103 Catalytic activity of dimeric calixarene-based MOC with barrel-like shape was also investigated for Knoevenagel reactions as represented in the Figure 31. 89 In some cases (for example, for pyrene-1-carbaldehyde), an increase of the yields up to nearly quantitative (95%) was observed in this cage. The catalytic activity appears to be linked with the shape and not the size of the used aldehydes.

Figure 31

Proposed mechanism of the Knoevenagel condensation catalysed by a barrel-like shaped dimeric calixarene-based MOC (from ref. [START_REF] Qiao | Switching on Supramolecular Catalysis via Cavity Mediation and Electrostatic Regulation[END_REF] )

Calixarene-based MOCs presenting the same geometry were reported to be also highly efficient electrocatalysts for the oxygen evolution reaction. 108 The photocatalytic activity of octahedral and cubic calixarene-based MOCs with anthraquinone connector was recently demonstrated. It was shown that it is possible to use these cages as efficient catalysts for the reaction of photocatalytic selective [2+2] cycloaddition of α,βunsaturated carbonyl compounds, while obtaining corresponding cyclobutanes. [START_REF] Jin | Coordination-Driven Self-Assembly of Anthraquinone-Based Metal-Organic Cages for Photocatalytic Selective [2 + 2] Cycloaddition[END_REF] Catalytic activity of calixarene-based MOC can be also demonstrated by the stabilization of certain catalytically active species inside the internal cavity with perseverance of their catalytic activity. [START_REF] Fang | Formation of a Highly Reactive Cobalt Nanocluster Crystal within a Highly Negatively Charged Porous Coordination Cage[END_REF]109 This outstanding calixarene-based MOCs property was well demonstrated using a trigonal prism calixarene-based MOC with thiophene-2,5-dicarboxylic acid connector. This cage is suitable for the stabilization of Pt-nanocluster, containing less than 18 Pt atoms inside the MOC cavity (Figure 32). 109 This system exhibits higher electrocatalytic activity than commercial Pt/C towards hydrogen evolution reaction due to large accessible surface area of Pt-nanoclusters that are stabilised inside the cavity of the MOC. achieving conversion rates up to 95% and yields up to 93% which opens outstanding perspectives for applying cages in CO2 capture systems (Figure 33). The aforementioned calixarene-based MOCs were build using only organic connectors.

The use of metal-organic connectors instead of purely organic connectors in MOCs offers promising perspectives for several reasons. Firstly, metal-organic connectors increase the number and density of metal centres around the formed cage, providing new coordination positions that may be beneficial for catalysis. Additionally, metal-organic complexes are typically larger than organic connectors, offering the potential for the formation of larger cages.

Despite the potential advantages offered by the use of metal-organic connectors in MOCs, there is currently only one reported example till now (2022) of a calixarene-based MOC using such connectors -the octahedral MOC based on 6 tetrazincsulfonylcalix [4]arene units linked by 12 linear chiral Mn(II) salen connectors (Figure 34). 4 This chiral MOC is particularly interesting from the perspective of asymmetric catalysis due to several reasons. reaction mixture led to an increase in conversion compared to the use of Mn(II) salen alone. These results can be attributed to the deactivation of the Mn(II) salen catalyst during the reaction process.

The inclusion of Mn(II) salen in the cage structure helps to preserve the catalyst from deactivation along with providing an hydrophobic cavity to concentrate the reactants, contributing to the observed enhancement in catalytic activity.

This example is particularly noteworthy due to its focus on metal-organic connectors in octahedral calixarene-based MOCs. As already mentioned, to the best of our knowledge, this is the only reported work using such connectors in MOCs, making it an important contribution to the field. The authors have demonstrated the potential of these connectors in MOC synthesis and have provided a detailed investigation of their catalytic activity. This work highlights the promising possibilities for the use of metal-organic connectors in MOCs and the potential for further exploration of their properties and applications.

Chapter I. Introduction §IV. Conclusion

IV. Conclusion

The investigation of supramolecular calixarene-based MOCs appears important. Firstly, MOCs have the potential to be used as homogeneous catalysts in chemical reactions, as they can selectively bind and activate reactants. This could lead to the development of more efficient and selective catalysts (for homogeneous and heterogeneous catalysis), which would have a significant impact on many industrial processes. Additionally, the study of the catalytic activity of MOCs can provide insight into the mechanisms of chemical reactions at the molecular level in confined space, leading to an in-depth understanding of chemical transformations. The development of MOCs with tuneable catalytic properties could lead to the creation of novel materials and technologies, with applications ranging from energy production to environmental remediation.

Secondly, these structures have the potential to be used as drug delivery carriers, as they can encapsulate and release therapeutic agents in a controlled manner. This could greatly improve the efficacy and specificity of drug treatment, reducing side effects and increasing patient compliance. The study of MOCs can provide insight into the fundamental principles of selfassembly and molecular recognition, leading to a deeper understanding of chemical and biological systems.

The development of MOCs with tailored properties and functionality could lead to the creation of novel materials and technologies. The field of calixarene-based MOCs using metalorganic connectors is relatively under-explored. This study aims to contribute to the expansion of this area by synthesizing novel calixarene-based MOCs using metal-organic connectors. The significance of this research lies in the potential applications of these cages in catalysis, as the high density of metal centres within the structure allows for efficient catalytic reactions, and in gas storage and separation, as the large internal cavity volume allows for ample storage capacity.

Overall, the investigation of MOCs has the potential to have significant impact in a variety of fields, from medicine to materials science. The primary objective of this research is to investigate the synthesis of MOCs using different families of metal-organic connectors, including Co III -, Fe III -, Rh III , Pd II , Ni II -dipyrrin complexes,

Ni II -porphyrin, Co III -corrole, Fe II -phenanthroline complex and Co II ,Fe II , Ru II -terpyridine complexes. This is illustrated on the Figure 35. The structure, chirality, and separation properties of these MOCs will be studied in-depth in the coming chapters.

The research will be conducted through the following steps:

• Synthesis and characterisation of metal-organic and organic connectors

• Synthesis of octahedral MOCs using various metal-organic and organic connectors

• Characterization of the MOCs, including structural analysis and confirmation of chirality when applicable

• Investigation of the gas adsorption and gas separation potential abilities of the obtained octahedral MOCs

Figure 35

The scientific project: formation of octahedral calixarene-based MOCs from calixarene shuttlecock nodes and different types of connecto

Chapter II.

Synthesis of the connectors

I. Generalities

According to the introduction, one of the main goals of this PhD work is the synthesis of new octahedral calixarene-based MOCs using metal-organic connectors or purely organic connectors with specific properties. To obtain MOCs based on calixarenes, appropriate connectors must be chosen.

In this work, several families of connectors were chosen, based on specific criteria:

• Nature of coordinating groups: among all coordinating groups used for the MOCs formation, carboxyl group is the most preferable for the formation of calixarene-based MOCs as previously discussed in the introduction. This group allows the formation of strong bonds between calixarene nodes and connectors.

• Geometry of the connectors: in addition to the stoichiometry calixarene node/connector used for the formation of MOCs, the geometry and the size of the connectors must be taken into account. In this work, we focused on the formation of octahedral MOCs. As a consequence, connectors must comply with either triangular tridentate geometry or linear bidentate geometry to form octahedral calixarene-based face-panelled or edge-panelled MOCs respectively.

• Inherent properties of connectors: each of the chosen connectors must possess properties that make these connectors relevant for the formation of MOCs. Thus, it is important to identify the unique properties of each connector and consequently magnify them when incorporated into the MOCs structure. The inherent properties of each connector will be discussed in detail in the corresponding sections of this chapter.

• Charge of the connectors: since the desired MOCs is limited by one type of calixarenes node of formula [M II 4SO2TCA(μ-OH2] 4+ , the charge of the MOCs depends on the charge of the connectors used in the cage synthesis (structure of calixarene nodes discussed in details in Chapter IV). For example, if the neutral connectors of formula H2Lx (bidentate) or H3Ly (tridentate) are used in the MOCs formation, that leads to the neutral MOCs (Figure 36). On the other hand, ionic nature (charged) of connectors leads to the formation of charged MOCs. §I. Generalities

Figure 36 Influence of connectors charge on the charge of the desired MOCs

In order to correctly classify targeted connectors and compare them with literature examples, it is crucial to define useful concepts that will be discussed in detail for each targeted connector:

The connector size (length) is the C-C distance between carbon atoms of two different carboxyl groups (-COOH). It is essential to compare the targeted connectors with those previously reported in the synthesis of octahedral calixarene-based MOCs to evaluate their geometrical characteristics which determine the expected size of the final cage (Table 3). Table 3 Geometrical characteristics of the largest and smallest bidentate and tridentate organic connectors that were reported for the formation of calixarene-based MOCs (ad) [START_REF] Jin | Coordination-Driven Self-Assembly of Anthraquinone-Based Metal-Organic Cages for Photocatalytic Selective [2 + 2] Cycloaddition[END_REF][START_REF] Dai | Modular Assembly of Metal-Organic Supercontainers Incorporating Sulfonylcalixarenes[END_REF][START_REF] Du | Structure Modeling, Synthesis and X-Ray Diffraction Determination of an Extra-Large Calixarene-Based Coordination Cage and Its Application in Drug Delivery[END_REF]104 ; Structure of the only one metal-organic connector that was used for the formation of octahedral calixarene-based MOC (e) 4 The most preferable angles between coordinating sites for the formation of face-panelled and edge-panelled octahedral MOCs are 120° (triangular connectors) and 180° (linear connectors), respectively. As given in the Table 3c, the largest triangular tridentate connector used for the formation of calixarene-based MOCs has an equilateral triangle shape and a distance between coordinating groups equal to 19.5Å. For the smallest triangular tridentate connector, this distance is equal to 5Å (Table 3a). In the case of bidentate connectors, the size of the smallest linear one was measured 5.8Å (Table 3b), while the size of the largest one was estimated at 10Å (Table 3d).

The angle between coordinating

However, MOC based on the largest bidentate connector (Table 3d) does not demonstrate an octahedral shape but a square shape due to angular nature (145°) of the connector.

As given in Table 3e, the only one metal-organic connector used in the synthesis of octahedral calixarene-based MOC is relatively large (13.8Å) and linear bidentate. 4 In the following section, we will present the synthesis of 18 targeted connectors (dipyrrin, phenanthroline, terpyridine, porphyrin, corrole and triazine connectors) and discuss their size, geometry, and inherent properties. Most of these connectors were reported in the literature, and thus, a small review of each type will be provided with discussion of their potential properties that make them suitable candidates for the formation of new octahedral calixarene-based MOCs. It is also important to consider whether these connectors or similar species have been previously used for the formation of supramolecular species, for instance, MOFs, or non-calixarene MOCs, which provides strong support for the possibility to obtain new calixarene-based MOCs.

. Complexes of dipyrrin: review

The family of dipyrrin complexes comprises a variety of metal-organic structures based on bidentate dipyrrin ligands coordinated to a metal ion. There are several types of dipyrrin complexes with different geometries reported in the literature: mono(dipyrrin), bis(dipyrrin) and tris(dipyrrin) complexes of transition and alkaline earth metals. Dipyrrin ligands have a unique electronic structure, with two pyrrole rings connected by a meso-carbon bridge. This structure leads to a strong electron donation from the ligand to the metal centre, resulting in high stability and robustness of the metal-organic complexes. 110 Among all the dipyrrin complexes, we focused on bis(dipyrrin) (Figure 37a) and tris(dipyrrin) (Figure 37b) complexes for the formation of calixarene-based MOCs due to their geometrical characteristics. In bis(dipyrrin) complexes coordinating groups (RCOOH) can be presented at an angle close to 180 o . On the other hand, for tris(dipyrrin) complexes they are positioned at an angle close to 120 o . As a result, bis(dipyrrin) and tris(dipyrrin) complexes appear to be respectively suitable for the formation of new edge-panelled and face-panelled calixarenebased MOCs.

Figure 37

The structure of bis(dipyrrin) and tris(dipyrrin) complexes

Many bis(dipyrrin) and tris(dipyrrin) complexes have been already reported in the literature. For example, dipyrrin complexes of trivalent (Co III , Fe III , Rh III , Ga III , In III ) [111][112][113] and divalent (Ni II , Pd II , Zn II , Cu II ) 114 metals have been described. These complexes are interesting for the MOCs formation due to their inherent properties. For example, many dipyrrin complexes exhibit optical properties : bis(dipyrrin) complexes of Pd II and tris(dipyrrin) complexes of Rh III have intense absorption bands in the visible region due to π-π* transitions of the dipyrrin chromophores, 112 tris(dipyrrin) complexes of In III and Ga III exhibit luminescent behaviour. 115 These optical properties lead to many possible applications, such as photosensitizing or sensing. 112 §II. Dipyrrin-based metal-organic connectors family

In addition, tris(dipyrrin) complexes have propeller-like arrangement which means that they exist in two enantiomeric forms: Λ and Δ. As a result tris(dipyrrin) complexes exhibit chiral properties (Figure 38). 116

Figure 38 Λ-and Δenantiomers of tris(dipyrrin) complexes

Dipyrrin complexes might exhibit other properties, which are mostly related to the type of the metal ion in the structure. For instance, tris(dipyrrin) complex of Fe III demonstrated redox 117,118 properties in the cyclic voltammetry experiments, making them suitable for electrochemical applications. Thus, properties of dipyrrin complexes can be tuned by the nature of the metal.

The most intriguing field of the dipyrrin complexes application is the formation of extended symmetrical structures. There are many examples of MOFs formation with different dipyrrin complexes. 119 For example, tris(dipyrrin) complexes of Ga III and In III demonstrated the formation of 2D-MOFs when combined with silver ions (Figure 39). 113 In addition, numerous other heterometallic dipyrrin compounds have been described in the literature. 120 Furthermore, the majority of dipyrrin complexes found in MOFs are highly stable and have a variety of shapes and metal ions, resulting in a broad range of optical and electrochemical characteristics.

Figure 39

The formation of MOFs by tris(dipyrrin) complex of Ga III (from ref. and Ni(H2L3)) due to their robustness and inherent properties.

II.1.2. Triangular and linear dipyrrin connectors: size, geometry and properties

We targeted 6 dipyrrin complexes as connectors, 4 or which are tris(dipyrrin) complexes.

Triangular tris(dipyrrin) connectors (Figure 40a) are perfect for the formation of facepanelled MOCs due to their triangular tridentate nature with an angle between coordinating groups of 120°. The length of the connectors rac-Co(HL1)3, rac-Fe(HL1)3, and rac-Rh(HL1)3 was estimated approximately to 16Å from X-ray data for rac-Rh(HL1)3 connector (Figure 40a) 112 , which is suitable for the formation of large MOCs. However, it was not possible to estimate the length of the connector rac-Co(HL2)3 due to the absence of X-ray data for this connector or similar species.

Tris[5-(4-Carboxyphenyl)-4,6-dipyrrinato]Co(III) (rac-Co(HL1)3) can be easily separated into two pure enantiomers 116 that could be useful for the formation of chiral MOCs with unique properties (Figure 40a), this will be discussed in §II. 3. of this chapter. Moreover, we expected the enlarged tris(dipyrrin) connector of Co III (rac-Co(HL2)3) to have modified gas adsorption properties due to the enlarged size (Figure 40a).

Tris [5-(4-Carboxyphenyl)-4,6-dipyrrinato]Fe(III) (rac-Fe(HL1)3) is expected to present electrochemical properties related to the presence of Fe III in the structure. 117,118 (Figure 40a).

Tris[5-(4-Carboxyphenyl)-4,6-dipyrrinato]Rh(III) (rac-Rh(HL1)3
) is expected to present photosensitivity due to the presence of photosensitive Rh III ion. 112 As a result, great photocatalytic activity of related MOCs may be observed due to combination of Rh III ions photosensitivity with the enclosed space of the MOCs (Figure 40a).

Bis(dipyrrin) connectors (Figure 40b and4c) are linear bidentate connectors with tetracoordinated metal ions in the planar or distorted planar geometry. 112,121 The angle between coordinating groups is close to 180° which is perfect for the formation of edge-panelled MOCs. As represented in the Figure 40c, steric hindrances between α-pyrrolic protons (H1) of opposite pyrrolic rings lead to the distortion from perfect linear geometry of Ni(H2L3). This leads to the deviations from 180 o between coordinating positions for Ni(H2L3) (170 o ). This phenomenon is discussed in details in §II. 4. of this chapter.

Concerning the properties, bis[5-(4-Carboxyphenyl)-4,6-dipyrrinato]Pd(II) (Pd(HL1)2) is also highly photosensitive complex. 112 As it was mentioned for the rac-Rh(HL1)3, we could expect great photocatalytic properties from the MOCs based on Pd(HL1)2 due to its photosensitivity and enclosed space of the formed MOCs (Figure 40b). Bis(dipyrrin) complex of Ni II (Ni(H2L3)) is expected to have intriguing optical properties due to the distinct structure and presence of semiopened cavity in this complex (Figure 40c).

Notably, all the targeted connectors are not charged, and as a result, the MOCs formed by bis(dipyrrin) and tris(dipyrrin) connectors are expected to be neutral species. has been already reported and includes 4 steps with an overall yield of 20%, 15%, 22% respectively (Figure 41). 111,112 These low yields can be explained by multiple factors. First, the synthesis of 5-(4-Carboxymethylphenyl)dipyrromethane (first step) is a reaction with multiple possible side products, for instance, formation of oligomeric species. Furthermore, 5-(4-Carboxymethylphenyl)dipyrromethane is an easy oxidizing species and it requires to be extracted carefully and stored under the light protection at low temperature in the fridge.

The formation of dipyrrin MeL1 using DDQ as an oxidizing agent also generates multiple side products, for instance, oligomeric and cyclic (porphyrins, corroles) species.

The yields of the metallation steps are in correspondence with the reported ones. 111,112

Figure 41

The synthetic pathway for the connectors rac-Co(HL1)3, rac-Fe(HL1)3 and rac-

Rh(HL1)3

The synthetic pathway illustrated Figure 41 begins with the coupling of pyrrole and 4-(carboxymethyl)benzaldehyde. We modified the reported synthesis 123 by precipitation of 5-(4-Carboxymethylphenyl)dipyrromethane instead of a purification via a column chromatography.

This procedure leads to 5-(4-Carboxymethylphenyl)dipyrromethane with an acceptable purity.

Traces of pyrrole may still be presented but it does not impact the following step. Excluding the column chromatography purification does not impact on the yield of 5-(4-Carboxymethylphenyl)dipyrromethane.

The next step is the oxidation with DDQ, which was performed without any alterations from the previously reported procedure. 116

§II. Dipyrrin-based metal-organic connectors family

The following step is the metallation of MeL1, which was performed using different metal The synthesis of enlarged connector rac-Co(HL2)3 was not reported, however, we took inspiration from the synthesis of rac-M(HL1)3 (Figure 41). Rac-Co(HL2)3 was obtained in a 5

steps procedure with an overall yield of 13.5% (Figure 43).

Figure 43

The synthetic pathway for the connector rac-Co(HL2)3

The first step is a classical Suzuki coupling that was performed according to the already reported procedure. 124 The following steps were performed analogously to the procedure for rac-M(HL1) 3 . Particular interest however is the metallation step. This step was performed by reflux in MeOH and it was possible to achieve a yield 75% yield of the desired complex that is much higher than the yield of 45 % in the metallation step for rac-Co(MeL1)3.

Chapter II. Synthesis of the connectors §II. Dipyrrin-based metal-organic connectors family

The formation of rac-Co(MeL2)3 was evidenced by 1 H-NMR with a significant upfield shift of H1 of 1.2 ppm (from 7.67 to 6.45 ppm) compared to the starting tris(dipyrrin) (Figure 44). The procedure of enantiomers separation of rac-Co(HL1)3 has been already reported. 125 The enantiomers separation is based on the formation of diastereomeric complexes of rac-Co(HL1)3 with (-)-cinchonidine and their solubility difference in THF. We applied the same methodology in order to separate enantiomers of connectors rac-Co(HL1)3, rac-Fe(HL1)3 and rac-Rh(HL1)3.

We managed to obtain chiral connectors Λ-Co(HL1)3 and Δ-Co(HL1)3 with enantiomeric excess up to 92% that was proven by methods of CD and chiral HPLC.

The CD spectra of chiral connectors in THF solution display peaks at λ = 515 and 465 nm that are almost perfect mirror images, providing an evidence of the large enantiomeric excess (Figure 46). The synthesis of Pd(HL1)2 connector was performed according to the already reported procedure. 112 It is the similar to synthesis of rac-Co(HL1)3, rac-Fe(HL1)3 and rac-Rh(HL1)3 and it was obtained with overall yield 36.5% (Figure 49).

Chapter II. Synthesis of the connectors §II. Dipyrrin-based metal-organic connectors family

Figure 49

The synthetic pathway of the connector Pd(HL1)2

Apart from the stoichiometry used in the metallation, one of the notable differences in the synthesis of Pd(HL1)2 compare to tris(dipyrrin) complexes rac-M(HL1)3 (M = Co III , Fe III , Rh III ) is that the metallation occurs at room temperature in methanol that could be an evidence of the smaller activation energy of the reaction. The metallation step presents a yield of 83% which is one of the best among all of the dipyrrin-based connectors.

The 1 H-NMR spectrum of Pd(HL1)2 is in a perfect accordance with the literature data. 112 As it was discussed for rac-M(HL1)3 in §II.2, it is possible to track the formation of dipyrrin complexes by the significant shift of H1 after metallation. For Pd(MeL1)2 , the chemical shift for H1 is 7.41, and the upfield shift is, as expected, much smaller (ca 0.3 ppm ) compare to the ones observed for the much more constrained tris(dipyrrin) rac-M(HL1)3 analogues (Figure 52).

The formation of the connector Pd(HL1)2 was also proven by Mass-spectrometry that demonstrates a peak of mass 632. 97 [M] + for Pd(HL1)2 that is in a perfect accordance the expected mass. 112 It is worth mentioning that we succeeded to grow single-crystals of Pd(HL1)2 and characterized it for the first time by X-Ray diffraction. (Figure 50). As expected, Pd II adopts a square-planar N4 coordination geometry (see crystallographic data in annexes §I. 3.) and the angle between opposite coordinating sites equal to 180 o . Two dipyrrin ligands are parallel but not coplanar, the distance between the two planes of the dipyrrin ligands is equal to 1.95Å.

Additionally, dipyrrin ligands are not perfectly planar but slightly curved (the angle between planes of pyrrolic rings of one dipyrrin is equal to 29 o ). §II. Dipyrrin-based metal-organic connectors family Phenanthroline is a rigid bidentate ligand that can form highly stable complexes with various metal ions. These complexes are widely used in analytical chemistry, biochemistry, and material science due to their inherent properties. Phenanthroline complexes typically consist of a central metal ion that coordinates phenanthroline ligands, forming a chelate bis(phenanthroline) complex (Figure 54a) or tris(phenanthroline) complex (Figure 54b). The metal ions commonly presented in phenanthroline complexes are transition metals such as copper(I) 126 , ruthenium(II) 127 , iron(II), cobalt(II) and nickel(II). 128

Figure 54

Two types of encountered phenanthroline complexes Phenanthroline complexes exhibit a range of distinctive properties, depending on the metal ion and the ligand's substituents. For example, they can exhibit interesting photophysical properties, 5 making them useful in the design of sensors and imaging agents. They can also display catalytic properties. 129,130 Additionally, some phenanthroline complexes can undergo redox reactions, making them useful in electrochemistry and as redox-active materials. 131 Phenanthroline complexes have been already used in the field of the supramolecular chemistry for the formation of phenanthroline-based MOFs presenting interesting properties. For example, MOFs exhibit luminescent properties had been reported in several publications. 132,133 Furthermore, phenanthroline-based MOFs were studied in the field of catalysis. 134 It is worth mentioning that there are reported MOCs based on phenanthroline derivatives that demonstrated excellent fluorescent behaviour with the ability to design chemosensors for detection of many species starting with Fe III ions and finishing with antibiotics (Figure 55). 135 However, to the best of our knowledge, there are no reported calixarene-based MOCs with phenanthroline complexes in the structure. §III. Phenanthroline-based metal-organic connector 2 is an ionic species with a 2+ cationic moiety, which will influence its solubility as well as the solubility of the MOCs in which it will be included.

III.2. The synthesis of triangular phenanthroline connector ([rac-Fe(HL4)3][PF6]2)

The exact targeted phenanthroline-based connector [rac-Fe(HL4)3][PF6]2 bearing two PF6 - counterions is not reported in the literature. However, a similar complex with another counterion (SO4 2-) is reported. 136 §III. Phenanthroline-based metal-organic connector

The synthesis of [rac-Fe(HL4)3][PF6]2 includes 4 steps (Figure 57) that was performed with an overall yield 52%.

Figure 57

The

synthetic pathway for the connector [rac-Fe(HL4)3][PF6]2

The first two steps of the [rac-Fe(HL4)3][PF6]2 synthesis are well-known reported procedures. 137 For the metallation step, it was experimentally demonstrated that Mohr salt ((NH4)2Fe(SO4)2•6H2O) is more preferable for the metallation among other Fe II salts due to its stability. Moreover, we choose hexafluorophosphate as a counter anion in order to precipitate the desired complex from the solution, as frequently exploited for such charged complexes.

Both The family of terpyridine complexes comprises a variety of metal-organic structures with various metal ions together with various substituents integrated in the organic part. In general, terpyridine family consist of mono(terpyridine) and bis(terpyridine) species. (Figure 58). Prior to metal coordination, the nitrogens on the 2-pyridine cycles are arranged in a trans-trans geometry to minimize the repulsion between the lone-pairs of the nitrogen. However, upon coordination with a metal cation, a cis-cis geometry is established after chelation leading to the formation of stable complexes. 138

Figure 58

Two types of encountered terpyridine complexes

Family of terpyridine complexes represented by complexes with the variety of metal ions.

There are reported terpyridine complexes with iron(II), cobalt(II), manganese(II), zinc(II), ruthenium(II), osmium (II) and etc. [139][140][141][142][143] Terpyridine complexes are interesting complexes for the MOCs formation due to their unique inherent properties. For instance, terpyridine complexes of Ru II demonstrated redox activity 144 , terpyridine complexes of Zn II demonstrated optical properties 142 . Furthermore, Ru II -terpyridine complexes demonstrated great photochemical activity that was observed in the reactions of proton reduction from water 7 or water oxidation. 145 Mono(terpyridine) complexes of Fe II and Co II demonstrated catalytic activity in different reactions including Suzuki-Miyaura Cross-Coupling Reactions. 139,140 Some of the terpyridine complexes were already applied in the field of supramolecular chemistry for the formation of MOFs, for example, MOF based on Zn II -terpyridine with adsorption and luminescent properties has been reported. 146 Furthermore, it was possible to obtain Cu II terpyridine-based MOFs with catalytic properties 147 and Ho III terpyridine-based MOFs with ion separation properties. 148 It is worth mentioning that terpyridine molecules were also used for the formation of MOCs. For example, giant terpyridine-based MOC was reported in 2018. 149 This §IV. Terpyridine-based metal-organic connectors family MOC was formed by terpyridine ligands that self-assembled with Zn II ions in the cage like structure (Figure 59).

Figure 59

Terpyridine-based MOC (red spheres represent Zn II cations) (from ref. 149 ) Among all of the terpyridine complexes, we focused on bis(terpyridine) complexes due to their geometrical characteristic suitable for the edge-panelled MOCs formation (Figure 58b). To the best of our knowledge there are no reported MOCs where bis(terpyridine) complexes played a role of metal-organic connector, as well as, there is no reported calixarene-based MOCs with terpyridine moieties. Porphyrins are composed of four pyrrole rings, which are linked by methine bridges to form a macrocycle (Figure 62). The distinctive properties of porphyrins arise from their conjugated system of double bonds, which give them a characteristic absorption spectrum in the visible range widely used in sensors 155 .

IV.2. Linear terpyridine connectors

Porphyrin family includes derivatives with substituents in meso-and β-pyrrolic positions, as shown on Figure 62. In this work we focused on meso-substituted porphyrin derivatives due to their characteristics appropriate for our goals. There is a great variety of meso-substituted porphyrin derivatives, distinct from each other by the number, the type, and the position of the substituents (Figure 62).

Figure 62 Representation of the porphyrin macrocycle and the different types of mesosubstituted porphyrin derivatives

The porphyrin macrocycle presents a large central cavity with diameter close to 4Å that can bind a variety of metal ions to form metalloporphyrins that display unique physical and chemical properties. This coordination can affect the electronic properties of the macrocycle, leading to changes in its optical properties, 156 appearance of new electrochemical 157 and photocatalytic 158,159 properties achieved due to the highly photosensitive porphyrin macrocycle and the presence of the metal ion in the cavity of the porphyrin. In addition, the presence of one or two additional ligands in the axial positions of the metallic cations in the cavity depends on the nature and the oxidation number of the metal ion.

Metalloporphyrins exhibit a range of interesting and distinguishable properties, depending on the nature of the metal ion coordinated to the porphyrin macrocycle. For example, Fe IIIporphyrins exhibit distinct magnetic properties, related with magnetic coupling between metalloporphyrin and ferromagnetic surfaces. 160,161 Ni II -porphyrins demonstrate excellent

Chapter II. Synthesis of the connectors §V. Porphyrin-based metal-organic connector photocatalytic activity. 162 Furthermore, all of the metalloporphyrins exhibit distinct optical properties due to the porphyrin macrocycle.

The potential of metalloporphyrins in the field of supramolecular chemistry has been demonstrated by the synthesis of numerous porphyrin-based MOFs and MOCs. Metalloporphyrins have been used for the synthesis of MOFs with fluorescent 163 and catalytic properties, 158 and there is a great manifold of synthesized porphyrin-based MOCs, for example multimetallic Zn/Ru porphyrin based cage (Figure 63). 164 Furthermore, MOCs that include both metalloporphyrin and calixarene moieties have been reported in the literature, for example, MOC that included a zinc(II)porphyrin covalently connected to ionophoric calixarene was reported in 2001. 165 However, to the best of our knowledge there are no reported structure of MOCs based on calixarenes and porphyrins connected to each other through coordination bonds.

Figure 63

The representation of a multimetallic Zn/Ru porphyrin-based MOC (from ref. 164 )

Metalloporphyrin-based MOCs with calixarenes would be particularly interesting for biomedical applications, as metalloporphyrins have demonstrated anticancer 166 and antibacterial 167 properties, while the use of calixarenes in drug delivery systems is gaining increasing attention due to their ability to encapsulate guest molecules. 168 The combination of metalloporphyrins and calixarenes in MOCs can provide a new platform for drug delivery and biomedical imaging applications.

V.2. Porphyrin connector: size, geometry and properties

Among all of the variety of metalloporphyrin derivatives we focused on trans-A2B2metalloporphyrins (Figure 62) due to their linear geometry allowing angle 180 o between the coordinating positions that is suitable for the formation of edge-panelled calixarene-based MOCs.

Other derivatives are less favourable due to the potential steric hindrances between porphyrin connectors and shuttlecock calixarene-nodes that might occur. For instance, in A3Bmetalloporphyrins the angle between coordinating positions is 90 o that is not acceptable for the octahedral cage formation. A4-metalloporphyrin are also expected to have an angle 90 o between §V. Porphyrin-based metal-organic connector coordinating positions with possibility to obtain cubic MOCs, however, steric hindrances might also occur between shuttlecock calixarene units and A4-metalloporphyrin connector.

As it was discussed in the §I. of this chapter, carboxyl groups are required for the formation of calixarene-based MOCs, so we focused on a trans-A2B2-metalloporphyrin with carboxyl groups located in two opposite meso-positions (Figure 62) making it suitable for the formation of edgepanelled calixarene-based MOCs.

Concerning the metal ion present in the cavity we first targeted trans-A2B2metalloporphyrin with Ni II due to its high stability and excellent photocatalytic properties. 162 It is worth mentioning that Ni II ion perfectly fits into the cavity of the porphyrin macrocycle when compared to larger ions (for example, lanthanides) that are located above porphyrin macrocycle. 169 Usually, Ni II ion in a porphyrin cavity adopts a square planar coordination geometry with no axial ligand. However, it has been demonstrated that under certain conditions, Ni II -porphyrins can coordinate certain additional ligand, making it potentially useful for catalysis 170,171 especially in the confined space of MOCs.

Based on the aforementioned constraints, the neutral complex [5,15- The synthetic pathway was followed according to the already reported procedures. 172,159 The synthesis of Ni(H2L6) is a 3 steps procedure with an overall yield of 8.3% (Figure 65).

This low yield can be explained mainly by the first step that lead to the formation of many different oligomeric and cyclic products from numerous side reaction. The optimized conditions used leads to the formation of Me2L6 in 15%, which is acceptable for such a reaction.

Figure 65

The synthetic pathway for the connector Ni(H2L6)

Me2L6 is easily tracked by 1 H-NMR spectroscopy due to characteristic upfield shifted peak of NH-protons close to -2.7 ppm. 172 Moreover, the A2B2-nature of the porphyrin is proven by the presence of two methyl groups per porphyrin while the trans-A2B2 symmetry of the compound is confirmed by the presence of two doublets for the 8 -pyrrolic protons (Figure 66).

The second step is the metallation with the use of salt Ni(OAc)2 •4H2O. The completeness of this step is also easily tracked due to disappearance of the signals in 1 H-NMR related to the NHprotons (Figure 66). Corroles belong to a class of tetrapyrrolic macrocycles that is similar to the porphyrin family, but with a direct connection between two pyrroles. These molecules are characterized by a macrocyclic structure with a central cavity (diameter 3.7Å) that can bind numerous metal ions, forming metal complexes (metallocorroles) with a variety of interesting properties (Figure 67). A major difference between corrole and porphyrin is the presence of three inner NH group instead of two for the porphyrin. Many metallocorroles with different metals are reported. For example, metallocorroles with Co III , Mn III , Fe III , Pt IV , Ta V etc. 173 As well as metalloporphyrins, metallocorroles exhibit excellent catalytic, 174 electrochemical 175 and optical 176 properties due to highly photosensitive corrole macrocycle and the presence of the metal ion with possible available axial coordination positions.

Chapter II. Synthesis of the connectors §V. Porphyrin-based metal-organic connector

Figure 67

Structure of the metallocorrole core Metallocorroles were used for example for the formation of MOFs with large surface areas. 6,177 That means that corrole molecules are able to form periodic and highly symmetric structures. However, to the best of our knowledge, there are no examples of the MOCs with corrole moieties.

VI.2. Corrole connector: size, geometry and properties

Among all the variety of corrole derivatives we focused on species having carboxylate coordinating groups, in particular, tricarboxylate derivatives. Trans-dicarboxylate derivatives could have been of interest, but the synthesis of these corroles appears more than tedious, thus, we focused first on the synthesis of the more symmetrical corrole having the same substituents in the 3 meso-positions. For the same reason, we chose Co(III) that is stable and fits perfectly in the corrole cavity. 178 As a result, complex [5,10,15-Tris(4-carboxyphenyl)corrolato] Co(III) (Co(H3L7)) was chosen as a metal-organic neutral connector according to the aforementioned restraints (Figure 68). Connector Co(H3L7) is expected to exhibit great optical properties due to presence of corrole core and catalytic properties due to availability of axial coordination positions of Co III ions as it was demonstrated for the similar species. 174 §VI. Corrole-based metal-organic connector

Figure 68

Structure of the triangular connector Co(H3L7)

The Co(H3L7) connector possesses a unique structure and geometry, distinguishing it from other selected connectors. It is triangular tridentate connector, with the Co III in the planar environment situated within the corrole cavity. It worth mentioning that normally Co III coordinates other molecules (molecules of solvent) in the axial positions in order to fill free coordination positions, which leads to the octahedral environment. 173 However, it is possible to decoordinate these molecules or substitute them in order to achieve desired properties.

The shape of the connector is ca T geometry with two different angles between coordinating positions, namely 93 o and 173 o (Figure 68) 179 that should in principle not be appropriate to be used as a trigonal tridentate connector for the obtaining face-panelled MOCs.

However this, corrole complexes have a certain degree of flexibility, as demonstrated in the structure of one related MOF, where the angles adapt values of approximately 101 o and 157 o . 6 Consequently, we can anticipate a certain degree of flexibility in the Co(H3L7) connector, and its adaptability to be included in a distorted octahedral face-panelled MOCs.

According to aforesaid, the formation of corrole-based MOCs is a perspective field. The formed cages are expected to be face-panelled with excellent optical, catalytic and electrochemical properties due to the presence of metallocorrole Co(H3L7) in the structure of the cage.

VI.3. The synthesis of triangular corrole connector (Co(H3L7))

The synthetic pathway of Co(H3L7) is based on the already reported procedures 6,178,180 and includes 3 steps starting from dipyrromethane with an overall yield 31% (Figure 69).

Chapter II. Synthesis of the connectors §VII. Organic connectors

with the column chromatography and achieve the yield of the desired corrole Me3L7 up to 65% (see experimental part).

It is important to run the hydrolysis of the ester functions prior to the metallation because complex Co(Me3L7) is not stable upon the hydrolysis conditions. Saponification of Me3L7 leads to the tri-carboxylate corrole H3L7 in 67% yield. [M] + that is in perfect accordance with the expected mass of Co(H3L7).

The stability investigations were not performed for the connector Co(H3L7) due to its poor solubility in the variety of solvents. Furthermore, the black colour of Co(H3L7) creates obstacles for the observations of colour change if the decomposition occurs.

The connectors discussed in all the previous sections of this chapter are metal-organic molecules and the field of MOCs based on them is rather underexplored. However, we have also focused on a family of purely organic connectors, whose role in calixarene-based MOCs synthesis is also poorly explored. This family is discussed in detail in the following section.

VII. Organic connectors

Despite the wide variety of triangular organic connectors that have been used for the construction of calixarene-based MOCs, there are still many species that have not been explored for these purposes. Many organic connectors with carboxyl groups were used for the formation of calixarene-based MOCs lack groups that provide specific interactions, such as π-interactions (Figure 71). [START_REF] Bi | Thiacalixarene-Based Nanoscale Polyhedral Coordination Cages[END_REF]182 Reported calixarene-based MOCs typically vary the size and the geometry of the connectors to modify the size of the cavity to adapt them to the shape needed for the trapping of targeted species. Our objective is rather the introduction of connectors with specific properties in the cage structure in order to build cages with interesting and useful properties.

Chapter II. Synthesis of the connectors §VII. Organic connectors

Figure 71

Some of the organic connectors with carboxyl groups used for the formation of calixarene-based MOCs (from ref. [START_REF] Bi | Thiacalixarene-Based Nanoscale Polyhedral Coordination Cages[END_REF] )

One of the species that could be of interest is derivatives of 1,3,5-triazine that exhibits intriguing properties that could be exploited for the formation of large calixarene-based MOCs capable for anion-π recognition. These properties are discussed in detail in the following section.

VII.1. Triazine core: review

Anion-π recognition refers to the ability of a molecule to selectively bind and recognize anions due to non-covalent interaction between anions and the π-system of the molecule. The 1,3,5-triazine ring has a positive charge area that is widely-used for the design of anion-π recognition systems 8 arising from their electron-deficient nature (Figure 72). Thus, applying of 1,3,5-triazine core in the structure of connectors could lead to MOCs with anion recognition properties.

VII.2. Triazine connectors: size, geometry and properties

The inherent structure of 1,3,5-triazine core favours triangular geometry. Consequently, the targeted connectors are expected to be triangular tridentate species. Three neutral connectors bearing carboxyl groups were selected to form triazine connectors family (Figure 74 Connectors H3L9 and H3L10 are much more flexible than connector H3L8. As a result, we expect that these connectors are able to adapt to the geometry required for the formation of the MOCs (Figure 74).

VII.3. The synthesis of triangular 1,3,5-triazine connectors (H3L8, H3L9, H3L10)

Connectors H3L8, H3L9, H3L10 have been already reported and the synthesis was adapted from the literature procedures. 189,190 The synthesis of 1,3,5-triazine connectors is a two-steps procedure for the connector H3L8

and one-step procedure for the connectors H3L9 and H3L10 (Figure 75).

The synthesis of the H3L8 is a procedure that was performed without significant modifications from the reported one. 189 The first step of the H3L8 synthesis is the Friedel-Crafts reaction where cyanuric chloride plays a role of the electrophile after activation by AlCl3. The crude product is obtained with a yield of 75% and used without purification in the following step.

The second step is a reaction of oxidation of the 3 methyl groups directly to the carboxylic acid with a yield of 75% The overall yield of the H3L8 synthesis is 68%, which is in accordance with the literature.

Chapter II. Synthesis of the connectors §VII. Organic connectors

The synthesis of H3L9 and H3L10 are also reported procedures that were performed without significant modifications with yields 75% for H3L9 and 80% for H3L10, which corresponds with the reported yields. 190,191

Figure 75

The synthetic pathway for the connectors H3L8, H3L9, H3L10

The 1 H-NMR revealed the formation of the desired connectors and the spectra are in accordance with the literature data (see experimental part). 189,190 The formation of the desired connectors was also proved by Mass-spectrometry. The MS experiments demonstrated the formation of species with the peaks of mass 442.11 [M] + , 301.09

[M] + and 529. 18 [M] + that are in perfect accordance with the expected mass of the connectors H3L8, H3L9 and H3L10.

The connectors H3L8, H3L9 and H3L10 appeared to be stable in the solid state. The 1 H-NMR spectra of the freshly obtained connectors and the 1 H-NMR spectra of these connectors stored for a week as powders are identical.

VII.4. 1,3,5-trifluorobenzene connector: size, geometry and properties

As well as 1,3,5-triazine moiety that was described in the previous section, 1,3,5trifluorobenzene has an area of a positive charge in the middle of the benzene ring leading to the anion recognition properties of this molecule as well. 192 As a consequence we could expect the same property from the connector 4,4',4''-((2,4,6-trifluorobenzene-1,3,5-triyl)tris(ethyne-2,1-Chapter II. Synthesis of the connectors §VII. Organic connectors diyl))tribenzoic acid (H3L11) and, thus, the MOCs formed with it should also possess such properties (Figure 76). To the best of our knowledge, the connector H3L11 has never been reported.

Figure 76

Structure of the triangular organic connector H3L11

The connector H3L11 is a neutral purely organic triangular tridentate connector, perfectly suited for the formation of face-panelled MOCs. (Figure 76). The size of the connector was estimated from XRD analysis of similar species to be close to 17Å. [START_REF] Bonakdarzadeh | X-Ray Structural and Ion-Mobility Mass Spectrometric Studies on Electron-Deficient and Electron-Rich M6L4 Coordination Cages[END_REF] This size is similar to the largest organic connector used for the formation of octahedral calixarene-based MOCs. (Table 3).

1,3,5-trifluorobenzene moiety has been already reported for the synthesis of MOCs. For example, MOC with 1,3,5-trifluorobenzene derivative was reported in 2015. That MOC is octahedral with the internal cavity diameter approximately equal to 15Å. Furthermore, it demonstrated optical properties. [START_REF] Bonakdarzadeh | X-Ray Structural and Ion-Mobility Mass Spectrometric Studies on Electron-Deficient and Electron-Rich M6L4 Coordination Cages[END_REF] Therefore, based on the abovementioned facts, the formation of new MOCs based on 1,3,5trifluorobenzene connectors is a promising field, as it offers the possibility of obtaining facepanelled MOCs adapted for anion recognition.

VII.5. The synthesis of triangular 1,3,5-trifluorobenzene connector (H3L11)

The synthetic pathway was adapted from the already reported procedure. [START_REF] Bonakdarzadeh | X-Ray Structural and Ion-Mobility Mass Spectrometric Studies on Electron-Deficient and Electron-Rich M6L4 Coordination Cages[END_REF] The synthesis of the connector H3L11 is a two-steps procedure with an overall yield of 81% (Figure 77).

Chapter II. Synthesis of the connectors §VII. Organic connectors

Figure 77

The synthetic pathway for the connector H3L11

The first step involves a Sonogashira coupling. The formation of Me3L11 is proved by 1

Chapter II. Synthesis of the connectors §VIII. Conclusion

The connector H3L11 appeared to be unstable. The 1 H-NMR spectrum of freshly obtained H3L11 and the 1 H-NMR spectrum of H3L11 stored for a week demonstrate significant differences with the drastic decrease of the desired connector amount. Furthermore, H3L11 has a distinct white colour and during 1 week of observation, significant darkening was noticed.

VIII. Conclusion

The present chapter reports the synthesis of metal-organic and purely organic connectors families, which were characterized by various analytical techniques. The synthetic procedure was optimized for many of these connectors to increase yields and/or decrease the number of synthetic All of the obtained connectors, which will be used for the synthesis of calixarene-based MOCs, are summarized Table 4. A total of 18 connectors were obtained, which includes:

• 14 metal-organic,

• 4 purely organic,

• 12 triangular tridentate,

• 6 linear bidentate. • Thermogravimetric analysis (TGA) of powdered compounds

• IR-spectroscopy of powdered compounds

In addition, MOCs can be characterised in solution by some other techniques:

• Mass-spectroscopy (ESI-MS, IM-MS)

• UV-vis spectroscopy

• Circular dichroism (CD) for chiral MOCs

• Chiral HPLC of chiral MOCs

However, for such big assemblies, single-crystal XRD is the most appropriate characterisation technique that unambiguously determines the scaffold of the desired assemblies (geometry, stoichiometry, and metal environment). For this reason, we focused on the one-pot threecomponent synthesis due to its ability to generate single-crystals suitable for the XRD analysis.

I.1. Determination of the synthetic conditions

In order to obtain the desired MOCs, it is necessary to provide suitable synthetic conditions that promote the self-assembly process leading to the MOCs formation in a crystalline form. In this regard, it is important to examine and analyse the methods reported for such systems. Detailed explanations of each aspect of the synthetic techniques are discussed here below.

I.1.1. Choice of the synthetic method

The self-assembly process was conducted using two different synthetic techniques that are commonly used for the formation of MOCs and MOFs:

• Solvothermal technique that involves a reaction between reactants in appropriate solvents at high temperatures and pressures in a sealed vial. [START_REF] Du | Structure Modeling, Synthesis and X-Ray Diffraction Determination of an Extra-Large Calixarene-Based Coordination Cage and Its Application in Drug Delivery[END_REF]193 The temperatures . 193 In this technique, similarly to the solvothermal approach, diluted solutions up to 10 mM are commonly used to facilitate the formation of high-quality crystals. When compared to the solvothermal technique, the reaction time in the liquid-liquid diffusion technique depends on the nature of the used solvents (see detail in §I. 1.3. of this chapter), their relative density and their degree of miscibility However, this technique is typically slow, and it could take weeks to months to achieve complete reaction. Nevertheless, it is possible to observe the formation of the first crystals after a few hours of the reaction.

I.1.2. Choice of the metal salt for the formation of shuttlecock calixarene nodes

The selection of metal ions for the synthesis of MOCs was based on their ability to form tetranuclearsulfonylcalix [4]arene shuttlecock nodes [M4SO2TCA(μ4-OH2)] 4+ or similar tetranuclear complexes that were previously reported in the literature. The formation of calixarenebased MOCs is achieved using 3d metal salts as chlorides, 72,98 acetates 4,81 and less commonly nitrates. [START_REF] Dai | Modular Assembly of Metal-Organic Supercontainers Incorporating Sulfonylcalixarenes[END_REF] The selection of these anions is based on their solubility in a variety of solvents:

• Cobalt (II) chloride hexahydrate (CoCl2•6H2O) [START_REF] Du | Structure Modeling, Synthesis and X-Ray Diffraction Determination of an Extra-Large Calixarene-Based Coordination Cage and Its Application in Drug Delivery[END_REF] • Nickel (II) chloride hexahydrate (NiCl2•6H2O) 104

• Iron (II) chloride tetrahydrate (FeCl2•4H2O) 194

• Zinc (II) chloride hydrate (ZnCl2•xH2O) 4 • Copper (II) chloride dihydrate (CuCl2•2H2O) 195

I.1.3. Choice of bases and solvents

The reaction rate of MOCs formation can be enhanced by the deprotonation of the carboxyl groups of the connectors and the hydroxy groups of the sulfonylcalix [4]arene, as they are functional groups that participate in the metal ion coordination. Accordingly, it is necessary to introduce a base into the reaction system. The choice of a particular base is determined by the technique used and should be considered in conjunction with the choice of solvent for the reaction, as certain techniques and solvents do not require an additional base to be added to the reaction mixture.

In In the liquid-liquid diffusion technique, the choice of the solvents is obviously also determined by the solubility of the components of the reaction mixture. However, the main difference between the liquid-liquid diffusion technique and the solvothermal technique, besides the reaction temperature, is the use of at least two different solvents that are necessarily miscible.

Moreover, these solvents must have different densities to form two separate layers initially.

Consequently, the number of appropriate solvent combinations is limited. The most common combinations include DMF/alcohol, DMSO/alcohol, DMA/alcohol, and chloroform/alcohol. In this work, the solvents combination of DMF/methanol was chosen for the liquid-liquid diffusion technique due to their miscibility and their relative density (0.944 g/ml and 0.792 g/ml, respectively) but also because the three components can be dissolved in DMF while the base (triethylamine) is added to MeOH, allowing a low amount of base to be present at the interface of DMF/MeOH and thus the metallation to slowly occurred.

In comparison with the solvothermal technique where the in-situ formation of small amounts of dimethylamine eliminates the need to add bases for deprotonation, the liquid-liquid diffusion technique requires the addition of bases to initiate the reaction of MOCs formation. For this purpose, triethylamine was chosen as a base due to its stability and convenience. Furthermore, triethylamine (pKa = 10.75) has been commonly used as a non-coordinating base in the reported procedures for MOCs synthesis. 98

I.1.4. Influence of the used stoichiometry

Stoichiometry is a crucial factor in the formation of MOCs and, thus, must be carefully calculated. The stoichiometry of metal ions/calixarenes/connectors used in the synthesis determines the nature of the formed products. If the stoichiometry is not well balanced, it may result in the formation of undesired products, or powders. For instance, the excess of sulfonylcalix [4]arene may lead to the formation of polynuclear complexes with different calixarene/metal stoichiometries. On the other hand, the excess of a connector may lead to the formation of coordination polymers or MOFs. Furthermore, it was observed that the use of an §I. Synthesis of crystalline molecular cages

The structure of these complexes will be briefly discussed in this section. A huge amount of similar complexes between calixarenes and metal ions have been already reported in the literature and it is possible to compare them with the obtained ones. 194 In the obtained five metallocalixarene complexes, the conformations of calixarenes in 1,2alternate or cone (see §III. Additionally, among all the non-desired obtained compounds, single-crystals of a compound obtained due to transmetallation process were observed under solvothermal conditions, in which the metal ion (Co II ) in the structure of the metal-organic connector was replaced by the metal ion (Cu II ) from the salt used in the reaction with the obtaining of new mono(terpyridine) complex of Cu II instead of desired MOC (Figure 81). Furthermore, to the best of our knowledge, the structure of this complex was not reported in the literature (see crystallographic annexes §I.2.), however, similar structure has been reported. 199 Chapter III. Formation and structural investigations of MOCs §I. Synthesis of crystalline molecular cages sulfonylcalix [4]arene and connectors) and the resulting stability of O6 octahedral coordination geometry in the structure of MOCs. The stability of shuttlecock units [M4TCA(μ4-OH2)] 4+ (M = Co II , Ni II ) is confirmed by the fact that there is a manifold of calixarene-based MOCs with the same shuttlecock units. [START_REF] Liu | Calixarene-Based Nanoscale Coordination Cages[END_REF][START_REF] Dai | Modular Assembly of Metal-Organic Supercontainers Incorporating Sulfonylcalixarenes[END_REF][START_REF] Du | Structure Modeling, Synthesis and X-Ray Diffraction Determination of an Extra-Large Calixarene-Based Coordination Cage and Its Application in Drug Delivery[END_REF] Furthermore, shuttlecock-like units [M4TCA(μ4-OH2)] 4+ (M = Co II , Ni II ) are observed in other structures, for instance, discrete tetranuclearsulfonylcalix [4]arene clusters. [START_REF] Kajiwara | Highly Symmetrical Tetranuclear Cluster Complexes Supported by p -Tert -Butylsulfonylcalix[END_REF] The use of these ions with triangular dipyrrin connectors The structures of these new calixarene-based MOCs will be discussed in §II. of this chapter.

I.3. Synthesis of crystalline cages using organic connectors (H3L8-H3L11)

Among the variety of the purely organic connectors used for the MOCs synthesis, only one First of all, crystals of MOCs were investigated by methods of single-crystal XRD. It is important to mention that, due to large internal and external voids which are filled with a large amount of solvent molecules, the structures demonstrate a great disorder. Additionally, these

MOCs included racemate tris(dipyrrin) complexes demonstrate disorder in the N6 environment around metal cations of the connectors due to the presence of both Λ-and Δ-enantiomers. These facts lead to the poor diffracting power of the obtained MOCs crystals. As a result, it was hard to achieve a satisfactory diffracting pattern with an acceptable quality and peak intensities, which leads to the increasing of the single-crystal XRD recordings time up to 1 week. However, by using a powerful diffractometer, the group of Pr. K. RISSANEN (Jyväskylä University, Finland) was able to achieve the appropriate diffracting pattern allowing the fully resolution of the structures (see experimental part).

The following four compounds have been fully analysed with refinement of the structure using single-crystal XRD methods (see crystallographic annexes §I.1.):

• The crystalline data of these MOCs along with distinctive structural characteristics are discussed in detail in the following section.

II.1. Crystalline data

Single

II.2. Metal environment

In the [M4TCA(-OH2)] 4+ shuttlecock-like nodes, located at the vertices of the octahedron, each metal ion is in an octahedral O6 environment, coordinated to one oxygen atom from sulfonyl group, two oxygen atoms from deprotonated hydroxy groups of sulfonylcalix [4]arene, two oxygens atoms from two carboxylate-groups of two different rac-M(HL1)3 connectors and one oxygen atom from μ4-OH2, which source is the water from the hydrate of the metal salt (Figure 84a). The structure of the shuttlecock-like nodes is common for calixarene-based MOCs, as already mentioned in §I.2.1 of this chapter. The shuttlecock-like calixarene nodes presented in the obtained MOCs demonstrate the same metrics of the metal ions as ones in shuttlecock-like calixarene nodes in the structure of previously reported calixarene-based MOCs. [START_REF] Du | Structure Modeling, Synthesis and X-Ray Diffraction Determination of an Extra-Large Calixarene-Based Coordination Cage and Its Application in Drug Delivery[END_REF]109 A comparison of M-O and M-M distances in shuttlecock-like nodes of the obtained MOCs with the ones in the reported structures along with the comparison of M-N distances in the structure of connectors forming MOCs are presented in Table 7.

[M4SO2TCA(μ4-OH2)]6[rac-M'(L1)3]8•nDMF•mH2O (M = Co II , Ni II ; M' = Co III , Fe III , Rh III ) M-O(phenolate), Å M-O(H2O), Å M-O(SO2), Å M-M, Å M-N, Å [Co4SO2TCA]6[rac-Co(L1)3]8 2.

Table 7

Metal ions metrics in the obtained MOCs with the ones reported in the literature

Chapter III. Formation and structural investigations of MOCs §II. Structural investigation of racemic dipyrrin-based MOCs: XRD analysis

As shown Table 7, the observed distances M-O(phenolate) are in the 2.05-2.08Å range, depending on the nature of the metal ion in the structure of shuttlecock-like moiety, which is in accordance with observations for related MOCs. The observed distances M-O(H2O) are also in the already observed range. The observed distances M-M are in a good correspondence with the radii of metal ions in the structure of the shuttlecock node (0.89Å for Co II and 0.83Å for Ni II ).

The metal ions of the connectors rac-M(HL1)3 (M = Co III , Fe III , Rh III ) demonstrate a N6 octahedral environment which is typical for tris(dipyrrin) complexes (Figure 84b). 112 The observed M-N distances are in a good correspondence with the radii of metal ions in the structure of the connector (0.69Å for Co III , 0.69Å for Fe III , 0.81Å for Rh III ).

II.3. Cages metrics

The size of the obtained MOCs and the cavity diameter were measured. The cage size is the distance between the most remote centres of carbon atoms of methyl groups in opposite shuttlecock-like nodes, measured in the Mercury software (Figure 85). The cavity diameter is the diameter of a sphere that can be inscribed inside MOCs without crossing bonds or atoms (including hydrogen atoms) of the cage (Figure 85).

The dimensions of the obtained octahedral tris(dipyrrin)-based MOCs are approximately 46 x 46 x 46 Å 3 and the internal cavity has a diameter of 19Å (Table 8).

Chapter III. Formation and structural investigations of MOCs §II. Structural investigation of racemic dipyrrin-based MOCs: XRD analysis

Dipyrrin-based MOCs demonstrate cavities of a moderate size and inferior to the largest reported calixarene-based MOC -CIAC-114, which displays an internal cavity diameter of approximately 27Å (see §III.5.1. Chapter I). [START_REF] Du | Structure Modeling, Synthesis and X-Ray Diffraction Determination of an Extra-Large Calixarene-Based Coordination Cage and Its Application in Drug Delivery[END_REF] However, the cavity size of dipyrrin-based MOCs exceeds the one of earlier reported calixarene-based MOCs, for instance, CIAC-106 (see §III.5.1.

Chapter I). [START_REF] Du | A Giant Coordination Cage Based on Sulfonylcalix[4]Arenes[END_REF] These observations are in accordance with the lengths of the connectors used for MOCs synthesis. Thus, MOC CIAC-114 is based on a connector with a length 19 Mn II (salen) metal-organic connector 4 that was discussed in detail in the §III. 6. Chapter I. The crystal structure of that MOC demonstrated internal cavity of approximately 18Å. As a result, the cavity of the obtained dipyrrin-based MOCs is slightly larger than the cavity of calixarene-based MOC with Mn II (salen) metal-organic connector.

The portals allowing the molecular species to get inside and outside the cavity are estimated to have a diameter of approximately 6Å (Figure 86), that also was measured as a sphere that could be inscribed in the portal without crossing any bonds or atoms including hydrogen. The internal cavity demonstrates a mostly non-polar hydrophobic nature due to the absence of polar groups (for example, hydroxy-groups) orientated inside the cavity. MOCs have approximately 67-68% of the crystal total volume available for gas adsorption that might occur inside (internal porosity) and outside of the cavity (external porosity) (Table 9).

Table 9

The porosity of the obtained and refined MOCs based on connectors rac-M(HL1)3 calculated by PLATON

II.4. Packing of the dipyrrin-based MOCs in the unit cell

In the unit cell, these MOCs are packed in a hexagonal fashion in the xOy plane and aligned parallelly along the b axis. Along the c axis, they display a rotation, so they are not superimposable (Figure 87). 10).

7

Table 10 Crystallographic parameters for MOCs based on chiral dipyrrin connectors Δ-Co(HL1)3 and Λ-Co(HL1)3

The presence of numerous disordered molecules in the unit cells leads to the same difficulties that the ones faced for the racemate analogues based on rac-M(HL1)3 (M = Co III , Fe III , Rh III ) (see details in §II. of this chapter).

The obtained chiral MOCs demonstrated almost the same range of porosity as MOCs based on rac-M(HL1)3 (M = Co III , Fe III , Rh III ) connectors, however, a small increase of the porosity is observed (Table 10). This fact can be explained by the absence of the disorder in the N6 metal ion environment of the connector in the chiral version compare to cages obtained with the rac-M(HL1)3 (M = Co III , Fe III , Rh III ) connectors.

One of the most important parameters for chiral space groups in XRD analysis is the socalled Flack-parameter (Table 10). The Flack-parameter is related to the absolute configuration of stereogenic centres. It takes values from 0 to 1 and the Flack-parameter value of 0.5 indicates that the absolute configuration cannot be determined from the available data. In contrast, a Flackparameter value close to 0 indicates that the absolute configuration has been determined with the high confidence. On the other hand, the values close to 1 mean that inverted structure is likely correct. 203 In the case of chiral MOCs presented in the

Chapter III. Formation and structural investigations of MOCs §IV. Additional characterizations techniques for dipyrrin-based MOCs

can be explained by either low enantiomeric excess (ee) or due to poor diffracting power of crystals because of the large number of disordered solvent molecules that fill the voids in the structure, which is perfectly acceptable in our case considering that the high porosity (more than 70%) of the formed MOCs.

The M-O(phenolate), M-O(H2O), M-O(SO2), M-M and M-N distances are given Table 11. As expected, they are similar to the one observed in the corresponding racemate MOCs based on rac-M(HL1)3 (M = Co III , Fe III , Rh III ) (Table 11). 11 The metrics of the metal ions in the structure of MOCs based on the chiral dipyrrin connectors Δ-Co(HL1)3 and Λ-Co(HL1)3

[M4SO2TCA(μ4-OH2)]6[Δ,Λ-Co(L1)3]8•nDMF•mH2O (M = Co II , Ni II ) M-O(phenolate), Å M-O(H2O), Å M-O(SO2), Å M-M, Å M-N, Å [Co4SO2TCA]6[Λ-Co(L1)3]8
The obtained MOCs based on the connectors rac-M(HL1)3 (M = Co III , Fe III , Rh III ), Δ-Co(HL1)3 and Λ-Co(HL1)3 were further investigated with other techniques in order to evaluate the enantiomeric excess of the chiral species, thermal stability and stability in solution. These techniques along with the experiments results are discussed in the following section.

IV. Additional characterizations techniques for dipyrrin-based MOCs

The However, the CD data provide only circumstantial evidence about high ee of the obtained species, thus, we decided to run chiral HPLC measurements.

IV.1.2. Chiral HPLC measurements for enantiomerically pure cages

The strong evidences about large ee was provided using chiral HPLC measurements. The chiral HPLC experiments demonstrated the formation of chiral MOCs with ee up to 97%. The data of HPLC experiments is summarized in the following Table 12. 12 Chiral

HPLC experiments data with the values of retention time and ee for the series of chiral MOCs [M4SO2TCA(μ4-OH2)]6[Δ,Λ-Co(HL1)3]8•nDMF•mH2O, (M =

Co II , Ni II )

In conclusion, according to CD and chiral HPLC data in solution, we have the evidence that the desired chiral calixarene-based MOCs were successfully obtained with high level of enantiomeric excess up to 97%, even though high values of Flack-parameters were found during XRD measurements for-single crystals in the solid state.

IV.2. MS characterization in solution

MS

DT CCSN2 values of the obtained dipyrrin-based MOCs [M4SO2TCA(μ4-OH2)]6[rac-Co(L1)3]8 and chiral [M4SO2TCA(μ4-OH2)]6[Λ,Δ-Co(L1)3]8, (M = Co II , Ni II )

The theoretical values of T CCSN2 can be calculated from the linear size of the obtained MOCs and the linear size of the buffer gas molecules (N2). From the crystallographic data (Figure 83), it was possible to estimate the size of the cage, as a distance between two most remote methyl groups of the opposite shuttlecock moieties (approximately 45.6Å), and Van der Waals radius of N2 is approximately 1.55Å, which results in the following equation:

T CCSN2 = π * (r(cage) + r(N2)) 2 T CCSN2 = π * (22.8 + 1.55) 2 = 1862.72Å 2
The obtained experimental values DT CCSN2 have an excellent correlation with the calculated ones from single-crystal XRD structure. The small deviations in the experimental values might be explained by the minor deformations of the analysed MOCs during the collision processes. The obtained ESI-MS and IM-MS data consolidates structural similarity to the solidstate structure obtained by XRD techniques. It is worth mentioning, that the obtained MS data are also strong evidence of the MOCs high stability in solution. Thus, the presence of the particles with a mass corresponding with the expected values along with DT CCSN2 values similar to T CCSN2 proves that obtained MOCs retain structural integrity and do not degrade in solution during the experiment.

IV.3. XRPD in the solid state for racemic cages

XRPD measurement is a powerful tool to determine a crystalline phase in the solid state.

However, for large molecular species like MOCs, this is not very informative. The disorder created by the presence of solvent molecules inside and outside the cage cavity generally does not lead to resolved diffraction patterns. The XRPD traces reveal very broad peaks, which is an evidence of a poor crystallinity of the powdered samples due to the decomposition of the crystal arrangement (amorphization) related with a partial release of the solvent molecules when exposed to the air. However, this behaviour is frequently observed for such porous structures. 4,187 IV. 4

. TGA measurements and IR analysis of the racemic cages

In order to estimate the quantity of solvents present in the structure of the obtained MOCs with

IV.5. Conclusion

In conclusion, a series of isostructural dipyrrin-based MOCs was obtained. This series These cages are formed by eight L8 3-connectors located on the eight faces of the formed octahedral cage and six shuttlecock-like building units [M4TCA(μ4-OH2)] 4+ located in the vertices of the octahedron. The observed ratio shuttlecock calixarene node/triangular triazine connector = 6/8 is in perfect accordance with the already reported face-panelled octahedral MOCs (Figure 92). [START_REF] Du | Structure Modeling, Synthesis and X-Ray Diffraction Determination of an Extra-Large Calixarene-Based Coordination Cage and Its Application in Drug Delivery[END_REF] It is worth noting that the similar octahedral MOC of formula (sc4a)Fe(tatb) based on the connector H3L8 has been already reported in the literature. 187 However, the reported in the literature MOC

VI. Conclusion

In this work, we successfully synthesized a series of 12 novel MOCs using sulfonylcalix [4]arene, different connectors and different metal ions as building blocks. The structures of some MOCs obtained as single-crystals were thoroughly characterized using various analytical techniques, primarily X-ray diffraction (XRD). We have presented a summary of all the members of this series in Table 16, along with a comparison of their structural features with each other and some previously reported structures. The formulas of the solvate and μ4-OH2 are omitted for clarity.

Table 16

The comparison of the metrics and molecular weights of the obtained MOCs with the ones of MOCs reported in the literature (highlighted in yellow)

The synthesized MOCs exhibit large internal cavities and high porosity, with voids occupying of approximately 70% of the crystal volume. Consequently, these materials hold a significant potential for investigating their gas adsorption properties. The results of these investigations are presented in the following Chapter IV. Chapter IV.

Gas adsorption properties of synthetized calixarene-based MOCs

I. Generalities

In the previous Chapter III, the structures of the synthesized calixarene-based MOCs were investigated in depth, that demonstrated an high calculated porosity up to 71.5%, which is related to rigid internal cavities of the cage (internal porosity) and packing of the cages in the unit cells of the crystals (external porosity). The latter porosity appears as "flexible" due to possible changes during the desolvation and, thus, amorphization processes of the powders. The high porosity of the obtained MOCs make them great candidates for gas storage and selective gas adsorption applications.

The porosity of such polycrystalline calixarene-based MOCs will be studied in this chapter through gas adsorption.

I.1. Context of the study

As it was discussed in Chapter I, MOCs generally exhibit good gas adsorption properties due to their internal and external porosity. Thus, many MOCs resulted gas adsorption and gas separation systems. [START_REF] Gosselin | Permanently Microporous Metal-Organic Polyhedra[END_REF] On the other hand, calixarene macrocycle itself exhibit good gas adsorption properties due to their distinct structure and versatility in the solid state. 205 For example, calixarenes, mainly in cone conformation (see §III.1. Chapter I), display an internal cavity (7.2-7.8Å) suitable for the encapsulation of small molecules. 101,102,206 Additionally, the recognition and encapsulation of small gaseous molecules can be tuned by the different calixarene conformations, the wide possibilities of chemical functionalization and the presence of the external porosity.

Application of calixarene moieties embedded in MOCs (calixarene-based MOCs) opens perspectives for gas adsorption studies due to the combination of inherent properties of MOCs and calixarenes. Gas adsorption properties of some calixarene-based MOCs have already been discussed in §III.5.1. Chapter I. In this section these properties will be discussed more in detail. relatively large surface areas comparable to ones of some reported MOFs. 209,210 Out of these MOCs listed Table 17, 15 have an octahedral shape, 7 included triangular organic connectors, and only one integrates a metal-organic connector. Moreover, there are only 3 publications dedicated to studying the gas adsorption properties of MOCs with light hydrocarbons, and only two of them provide data concerning IAST selective gas adsorption. [START_REF] Hang | Discrete {Ni40} Coordination Cage: A Calixarene-Based Johnson-Type (J 17) Hexadecahedron[END_REF]100 From these observations, we can conclude that the gas adsorption properties of octahedral calixarene-based MOCs, especially their selective gas adsorption properties, are a relatively underexplored field of research.

As a result, in this work, we focused on the investigation of gas adsorption properties of some of the obtained octahedral calixarene-based MOCs. The studied gases will be N2 (for estimation of surface area and pore size distribution), and CO2, CH4, C2H2, C2H4 and C2H6 (for estimation of gas adsorption selectivity). quantities to investigate its gas adsorption properties.

I.2. The performed measurements on the synthetized MOCs

II.1. Behaviour of the sample after activation

As mentioned previously, activating of MOCs is necessary to fully unlock their potential by removing any residual solvents adsorbed in the solid state. The impact of this activation process on the structure of the MOCs is a prerequisite before performing adsorption measurements. Thus, the MOC of formula [Co4SO2TCA(-OH2)]6[L8]8 was studied using IR and TGA techniques, since XRPD measurements not always provide a non-ambiguous answer. The TGA trace demonstrates that most of the molecules of solvent were removed from the sample during the activation process. However, it also indicates that a certain amount of solvent molecules is still present in the sample (up to 10%). This fact could be explained by the adsorption of water from the air due to air exposure between the activation and TGA analysis (the sample is highly hygroscopic). This fact is in accordance with the TGA of the freshly prepared samples (see §V. 4. of Chapter III).

II.1.1. IR data

After the activation, gases adsorption experiments were performed (see details in The N2(g) uptake was measured within the range of relative pressures from 10 -6 to 0.999 P/P0 at 77K (see details in experimental part). The N2(g) adsorption-desorption experiment was performed one time in order to plot adsorption-desorption isotherm, to evaluate specific surface areas and calculate the pore size distribution. The obtained isotherm is presented in Figure 98. The N2(g) adsorption-desorption isotherm for [Co4SO2TCA( -OH2)]6[L8]8 presents a sharp peak at the relative pressure close to 1, which is related to the condensation process among the material particles ("grains") and not inside the pores. This behaviour is frequently observed for microporous materials.

From the obtained isotherm, the Langmuir and BET surface area were evaluated to be equal to 821.2 and 742.6 m 2 /g respectively, additionally the total pore volume (Vpore(DFT)) and total volume of adsorbed N2(g) (Vads(N2(g))) were evaluated ( The pore size distribution was calculated from N2(g) adsorption-desorption isotherm (Figure 98) using density functional theory (N2-DFT) in the software MicroActive. The results of these calculations are presented Figure 99 and in Table 18. 40Å with a distinguishable peak at 15Å related to the internal cavity of the MOC (Figure 99). The calculated pore size distribution is in a good accordance with the crystalline data that revealed the diameter of the internal cavity to be close to 18Å (see §V.1. Chapter III). The difference between the observed and the estimated pore size might be explained by the fact the dimension of the internal cavity from the crystal structure was estimated as a diameter of a sphere, which could be inscribed inside the cavity of MOCs without crossing any bonds or atoms (including hydrogen), while gas adsorption measurements provide information about the accessible or effective pore size, additionally, gas adsorption measurements typically assume an idealized model of the porous material (slit), which may not accurately reflect the actual pore structure of the material. Other pores (width >15Å) are related with external porosity, defects and dislocations in crystals leading to the mesostructuring of crystallites.

Table 19

Comparison of some physical characteristics of N2(g) and CO2(g) (ref. 211 )

For 20). The structural features of this MOC were discussed in §V. of Chapter III.

Table 20 N2(g) and CO2(g) uptakes for [Co4SO2TCA( -OH2)]6[L8]8

Even though CO2 has a smaller kinetic diameter than N2 ( Thus, the integrity of the MOCs scaffold when exposed to the air or when exposed to solvents has to be probed by other techniques, for example, IR that will be discussed in the next section. The TGA analysis demonstrates that almost all the molecules of solvents were removed from the sample during the activation process. However, TGA curve exhibits a negligible number of volatile molecules still present in the samples (up to 5%). This fact could be explained by the adsorption of water from the air due to air exposure between the activation and TGA analysis (the samples are hygroscopic). This fact is in accordance with the TGA of the freshly prepared samples (see §IV. 4. Chapter III).

After the activation gas adsorption experiments were conducted.

III.2. N2(g) adsorption and surface area investigation

These measurements have been performed in collaboration with the group of Pr. Fedin, A.V. Nikolaev Inorganic Chemistry Institute, Novosibirsk, Russia.

III.2.1. Measurements

Firstly, the N2(g) uptake of the activated samples of MOCs gases with different properties, sizes and shapes. Thus, we focused on the adsorption of CO2(g), CH4(g), C2H2(g), C2H4(g) and C2H6(g) molecules. As it was mentioned in §I.2. of this chapter, the adsorption of these gases is an important issue due to their significant role in industry and ecology.

In addition, the estimation of the selective adsorption behaviour of gas mixtures by both MOCs has been initiated.

III.3.1. Isotherm measurements

Isotherms for these 5 gaseous molecules were measured at two different temperatures (273K and 298K, see explanation below §III. The amount of gases uptakes (using different units) at 800 torr are summarized Table 22.

Gas

Table 22

Gas (N2(g), CO2(g), CH4(g), C2H2(g), C2H4(g) and C2H6(g)) uptakes for

III.3.2. Calculations of thermodynamic parameters

The adsorption-desorption isotherms are usually measured at two temperatures (in this work we measured at 273K and 298K) in order to calculate the zero-coverage heats of adsorption, Q o st (energy released during adsorption of one mole of gas onto the surface of a material at constant temperature at the initial stages of the adsorption process) (see calculation with the use of virial equation in annexes §II. 1. and §II.3.). This can provide a valuable information about the nature of the interactions between the gas molecules and the host compound (MOCs), as well as the effect of temperature on this interaction. Additionally, the zero-coverage heats of adsorption allow to more accurately estimate the affinity and selectivity of the host (MOCs) towards adsorbing gases.

The calculated values of zero-coverage heats of adsorption are summarized Table 23. Concerning the effect of the temperature, the IAST selectivity of gas adsorption decreases with the increase of the temperature which appears reasonable because the physical adsorption is

Q o st([Co4SO2TCA( -OH2)]

Chapter IV. Gas adsorption properties of synthetized calixarene-based MOCs §III. Adsorption properties of dipyrrin-based MOCs

usually an exothermic process. The second reason is a competitive adsorption: at high temperatures, the thermal energy of gas molecules increases, leading to a higher mobility. This can lead to lower IAST selectivity as different gas molecules compete for the same adsorption sites, reducing the IAST selectivity towards a specific gas.

III.4.2. Comparison with literature data

It is important to compare the obtained calculated values of IAST selectivity with the ones reported for known systems.

Thus, we compared the experimental C2H6 adsorption capacity and the calculated IAST selectivity towards C2H6/CH4 equimolar binary mixture to some well-known porous MOFs and MOCs presenting selective gas adsorption properties, because this mixture is the most common mixture for investigation of selective gas adsorption properties of porous materials (Table 25). The formulas of μ4-OH2 are omitted for clarity. [START_REF] Hang | Discrete {Ni40} Coordination Cage: A Calixarene-Based Johnson-Type (J 17) Hexadecahedron[END_REF] and slightly inferior to another one (LSHU01'). 100

IV. Conclusion

In this work, adsorption properties of some synthetized octahedral calixarene-based MOCs The obtained compounds appeared to be porous and it was calculated by PLATON software that these cages present a porosity about 70%, and consequently, gas adsorption properties of some of these cages were investigated in details. The presented results deserve further investigation. As demonstrated in Chapter II, the synthesis of 18 compounds was presented that can serve as connectors for the synthesis of new calixarene-based MOCs. However, only 6 of them led to the desired products, obtained in the crystalline form under the discussed synthetic conditions. In other cases, a precipitate unsuitable for XRD analysis was obtained, however, an in-depth analysis is required for such precipitated compounds. Nevertheless, there is no direct evidence that the remaining 12 connectors cannot fundamentally form the desired MOCs. Perhaps, suitable synthetic conditions can be selected in order to obtain the desired structures in the crystalline form. For instance, the temperature conditions of solvothermal technique can be changed. In this study, solvothermal synthesis was performed at 80 o C, but it can be carried out at higher or lower temperatures. Moreover, the use of more diluted solutions is possible, which may slow down the reaction rate and result in the formation of crystals. Additionally, it is possible to change the synthetic conditions in the liquidliquid diffusion technique. For instance, other combinations of solvents (DMSO/Ethanol, DMA/Ethanol) that are more suitable for the formation of stable MOCs solvates, and therefore crystalline structures, can be used. In addition, other bases (diisopropylamine for example) can be used for the deprotonation of calixarenes and connectors. In the case of connectors with an ionic nature, other counterions (SO4 2-, BF4 -) can also be used to obtain the desired structures.

Another approach is to select conditions under which non-crystalline precipitates dissolve (DMSO, CH2Cl2, acetonitrile in the ultrasonic bath) and then perform recrystallization using other methods, such as slow evaporation or gas diffusion with the use of various volatile solvents (for example, diethyl ether). Thus, there are many alternative techniques that have to be investigated in order to obtain new calixarene-based MOCs in the single-crystals form using the reported connectors.

Despite the fact that, the structure of the obtained MOCs was characterised by various techniques and gas adsorption properties of some of them were investigated in details, there are still many MOCs properties (both in solid state and in solution) that were not studied. Some of these properties are discussed below.

General conclusion §II. Perspectives for this work

II.2. Further investigation of gas adsorption properties of the reported MOCs

As demonstrated in Chapter IV, only three of the obtained crystalline calixarene-based MOCs were investigated for gas adsorption. Therefore, further investigations in this area are required to fully understand the adsorption properties of the other obtained MOCs and their influence on the gas adsorption properties. Many parameters can be studied, for example, nature of the metal ion and length of the used connector. IV). However, experimental confirmation of these data is necessary to determine the potential application of these MOCs in natural gas upgrade and flue gas separation systems. Furthermore, not all the obtained crystalline MOCs were investigated for selective gas adsorption. Thus, additional experiments in gas adsorption, selective gas adsorption and selective gas separation are required for the reported MOCs.

II.3. Investigation of catalytic properties

Since MOCs of formula [M4SO2TCA(μ4-OH2)]6[rac-Co(L1)3]8 (M = Co II , Ni II ) exhibit remarkable gas uptake properties up to 2.37 mmol/g towards small gaseous molecules (CO2, CH4, C2H2, C2H4 and C2H6) (see details in §III. 3. Chapter IV) they can lead to the design of highly active catalytic systems for chemical alterations of these small molecules, when combined with the enclosed cavity of MOCs, For instance, the catalytic hydrogenation or polymerization of unsaturated hydrocarbons (C2H2, C2H4), as well as the capture and oxidation of methane, can be studied.

Moreover, as discussed in §III. 5.4. of Chapter I, metallic nanoparticles can be stabilized using the internal cavity of MOCs, enhancing their catalytic activity. Thus, these properties require further investigations.

II.5. Other properties

In addition, properties of the obtained calixarene-based MOCs related with the structure and properties of the used connectors also hold a great perspective for the investigation.

Solvents and reagents

The reactions sensitive to oxygen or moisture were realized under argon atmosphere. All commercially available reagents have been used without further purification.

Toluene, THF and DCM were dried, when needed on the solvents drying station under argon.

• Tetrahydrofuran Fisher chemical (≥99.8%)

• Ethanol Carlo Erba (≥99.8%)

• N,N-Dimethylformamide Carlo Erba (≥99.0%)

• Acetone Carlo Erba (≥99.0%)

• Propanol-2 Carlo Erba (≥99.7%)

• Chloroform Carlo Erba (≥99.8%)

• Dichloromethane Carlo Erba (≥99.5%)

• Methanol Carlo Erba (≥99.9%)

• Diethyl Ether Carlo Erba (≥99.8%)

• Ethyl acetate (EA) Carlo Erba (≥99.8%) Spectral data are present as following:

•
• Chemical shift in ppm;

• Multiplicity of signal: bs = broad signal, s = singlet, d = doublet, t = triplet, dd = doublet 1 H-NMR (DMSO-d6, 500 MHz, 25 °C) δ ppm: 9.76 (bs, 4H, H 5 ), 9.10 (bs, 4H, H 1 ), 8.68 (bs, 4H, H 4 ), 8.35 (bs, 4H, H 3 ), 8.05 (bs, 4H, H 7 ), 8.05 (bs, 4H, H 2 ), 7.20 (bs, 4H, H 6 ) The product was synthesized according to the already reported procedure. 189

ESI

1 H-NMR (DMSO-d6, 500 MHz, 25 °C) δ ppm: 8.83 (d, J = 8.4 Hz, 6H, H 1 ), 8.20 (d, J = 8.4 Hz, 6H, H 2 )

13 C-NMR (DMSO-d6, 126 MHz, 25 °C) δ ppm: 171.09, 167.37, 139.17, 135.58, 130.31, 129.36 Theta range 2.52, 24.90 3.416, 55.764 2.26, 25.93 2.648, 55.292 3.536, 56.096 3.322, 55.146 h, k, l max 14, 16, 17 14, 15, 17 17, 31, 27 17, 30, 27 16, 10, 30 24, 15, 32 h, k, l min -11, -16, -17 -14, -15, -16 -17, -31, -20 -17, -30, -27 -16, -15, 30 -24, -13, - Ideal Adsorbed Solution Theory (IAST) calculations were used to estimate selectivity factors at different gas mixture compositions and total pressures. The relationship between P, yi and xi (Pthe total pressure of the gas phase, yimole fraction of the i-component in gas phase, ximole fraction of the i-component in absorbed state) is defined according to Equation 4:

ESI-MS

∫ 𝑛 1 𝑝= 𝑃 𝑦 1 𝑥 1 𝑝=0 (𝑝)𝑑𝑙𝑛𝑝 = ∫ 𝑛 1 𝑝= 𝑃 𝑦 2 𝑥 2 𝑝=0
(𝑝)𝑑𝑙𝑛𝑝 Equation 4Selectivity factors were calculated according to Equation 5:

𝐼𝐴𝑆𝑇 𝑠𝑒𝑙𝑒𝑐𝑡𝑖𝑣𝑖𝑦 = 𝑦 2 𝑥 2 ⁄ 𝑦 1 𝑥 1 ⁄ = 𝑥 1 (1 -𝑦 1 ) 𝑦 1 (1 -𝑥 1 )
Equation 5

Ivan KHARIUSHIN Formation de nanocontainers multimétalliques moléculaires

Résumé

Résumé en anglais

In this project, a novel series of 12 octahedral calixarene-based metal-organic cages (MOCs) were obtained. This series consists of two groups: (i) 10 MOCs based on tris(dipyrrin) metal-organic connectors, and (ii) 2 MOCs based on purely organic triazine connectors. The structures and characteristics of these MOCs were analyzed using various techniques, such as single-crystal XRD, TGA, and MS, and were found to exhibit significant porosity up to 71%. Moreover, the gas adsorption properties of some of these MOCs were investigated for a range of gases, including light hydrocarbons. In these experiments, the MOCs demonstrated excellent gas uptakes (with BET surface area around 425 m 2 /g) and superior to many systems calculated IAST gas adsorption selectivity towards equimolar gas mixtures, such as C2H6/CH4. Thus, these MOCs exhibit a great potential for the design of selective gas separation systems. Additionally, these MOCs have the potential to be explored for other properties, such as recognition properties, related to their inherent structure.

Keywords: Metal-organic cages, single-crystals XRD, porosity, gas adsorption selectivity

  .. I.4. Quan's hemicarcerand capable to encapsulate organic molecules.................................. I.5. The first metal-organic cages and their development through decades ..........................

  ..III.2. First calixarene-based metal-organic cage ................................................................... III.3. Calixarene-based MOCs: formation and synthesis ...................................................... III.4. Calixarene-based MOCs: geometry.............................................................................. III.5. Calixarene-based MOCs based on organic connectors: properties ..............................

  .. II. Dipyrrin-based metal-organic connectors family ................................................................. II.

  ...................... II. Structural investigation of racemic dipyrrin-based MOCs: XRD analysis ......................... II.1. Crystalline data

  and Rh III ) ; et de la nature bidentate et de la géométrie linéaire du connecteur bis(dipyrrine) : Pd(HL1)2, Ni(H2L3). De plus, les complexes dérivés de ces connecteurs sont chiraux (Λ-Co(HL1), Δ-Co(HL1) et peuvent ainsi conduire à la formation de cages chirales ([Co4SO2TCA]6[Λ-Co(L1)]8; [Ni4SO2TCA]6[Λ-Co(L1)]8; [Co4SO2TCA]6[Δ-Co(L1]8; [Ni4SO2TCA]6[Δ-Co(L1]8).

• 6 • 2

 62 MOC isostructuraux dont 5 hétéro-métalliques basés sur des connecteurs à base de tris(dipyrrine) de Co III , Fe III , Rh III : [Co4SO2TCA]6[rac-Co(L1)3MOC octaédrique isostructuraux basés sur le connecteur H3L8, purement organique : [Co4SO2TCA]6[L8]8, [Ni4SO2TCA]6[L8]8.

Figure 3

 3 Figure 3 Un exemple de structure cristalline d'une cage octaédrique [M4SO2TCA]6[Cx]8 obtenue à partir de connecteurs métallo-organiques triangulaires

14 ChapterFigure 6

 146 Figure 6Structure of the Kiggen's macrooligocycle (a); Structure of octahedral anionic complex involving the macroolygocycle (b) (from ref.[START_REF] Kiggen | Oligocyclic Large Cavities -A Novel Siderophore[END_REF]

Chapter I .

 . Introduction §.I. Historical review of covalent and coordination cage This work preceded a diverse family of Pd II -based cationic cages and up to 2005, a great progress in this field were demonstrated. It was shown in the review of Pr. Therrien that Pd II -based MOCs can form different polyhedra based on different connecting species. As a consequence, thiscages demonstrated a high variety of host-guest interactions, depending on their polyhedral shape (Figure10).[START_REF] Fujita | Coordination Assemblies from a Pd(II)-Cornered Square Complex[END_REF]

  the formation of isoreticular MOCs (presenting the same coordination pattern and also the same connectivity) using various sizes of tridentate connectors (Figure26a,b) was demonstrated. It was observed that the use of larger connectors provided MOCs with improved adsorption properties, as evidenced by the higher BET surface areas observed for the larger cage CIAC-114 with cavity diameter of 27Å (558 m 2 /g) compared to the smaller one CIAC-106 with cavity diameter of 19Å (410 m 2 /g). These results highlight the potential of tailoring the connector shape in order to improve adsorption properties.

Figure 26 CIAC

 26 Figure 26 CIAC-106 connector structure (a); CIAC-114 connector structure (b); Structure of CIAC-106 calixarene-based MOC (c); Structure of CIAC-114 calixarene-based MOC (d);

Figure 27

 27 Figure 27 Experiments of octahedral calixarene-based MOCs solution titration with methylene blue (MB) solution(a); results of liquid-liquid extraction experiment(b); results of liquid-solid adsorption experiment(c), where 2 is the solution of MB before addition of cage and 3 is the solution of MB after addition of MB. (from ref. 104 )

Figure 30

 30 Figure 30

  Figure 32Stabilization of Pt nanocluster (yellow spheres) inside a trigonal prism shaped calixarene-based MOC (from ref.109 )

83

 83

Figure 33

 33 Figure 33The structure of imidazolium-functionalized octahedral calixarene-based MOC (a) (from ref.[START_REF] Tong | Soluble Imidazolium-Functionalized Coordination Cages for Efficient Homogeneous Catalysis of CO2 Cycloaddition Reactions[END_REF] ); The MOC catalysed reaction of CO2 cycloaddition with epichorohydrin (b)

Figure 34

 34 Figure 34Structure of Mn (II) salen connector (a); structure of tetrazincsyulfonylcalix[4]arene unit (b); Structure of the chiral octahedral cage [Zn4(SO2TCA)]6[MnL]12 (from ref.4 )

  Chapter I. Introduction§V. Presentation of the scientific projectV. Presentation of the scientific projectThe topic of "Formation of multimetallic molecular nanocontainers" is a fascinating and cutting-edge area of research that has the potential to be developed further. Synthesis of multimetallic cages base on metal-organic connector is of particular interest due to unexplored research field. This work focuses on the expansion of the octahedral MOCs family, specifically the [M4SO2TCA(μ4-H2O)]6[connector]8 (M = Co II , Ni II ) series, with the aim of enhancing catalytic, optical, and separation properties through the incorporation of various metals in the cage structure.

  positions is defined as the angle in degrees( o ) between two bonds R-C of two different carboxyl groups (R-COOH) These characteristics allow us to compare different connectors and estimate the size of the expected calixarene-based MOCs. Furthermore, it is also possible to compare different types of connectors (linear and triangular) in terms of the size. Since, the expected geometry of calixarenebased MOCs is octahedral, the connector size is a characteristic that define the length of the octahedron edge, regardless the connector type (linear or triangular) used. Both connectors characteristics are measured from the XRD data available in the literature or estimated from XRD data of similar species.

  Chapter II. Synthesis of the connectors §II. Dipyrrin-based metal-organic connectors family II. Dipyrrin-based metal-organic connectors family II.1. Triangular and linear dipyrrin connectors II.1.1

  Figure 39The formation of MOFs by tris(dipyrrin) complex of Ga III (fromref. 113 )

  X-ray data for Pd(HL1)2 and Ni(H2L3) demonstrated the length of the connectors to be close to §II. Dipyrrin-based metal-organic connectors family 19Å (Figure40b and 4c) that might lead to MOCs that are larger than MOCs based on triangular tris(dipyrrin) connectors.122

Figure 40

 40 Figure 40 Structure of the targeted triangular tris(dipyrrin) connectors rac-Co(HL1)3, rac-Fe(HL1)3, rac-Rh(HL1)3, rac-Co(HL2)3 (a); Structure of the targeted linear bis(dipyrrin) connectors Pd(HL1)2(b) and Ni(H2L3)(c)

Rh(MeL1) 3 .

 3 salts. It was experimentally observed that sodium hexanitrocobaltate(III) (Na3[Co(NO2)6]) is the most preferable salt for obtaining rac-Co(MeL1)3, while iron (III) chloride hexahydrate (FeCl3•6H2O) is preferred for rac-Fe(MeL1)3, and rhodium (III) chloride hydrate (RhCl3•xH2O) is the preferred salt for rac-Rh(MeL1)3. The conditions of the metallation step differ, reflux in methanol have been used for rac-Co(MeL1)3 and rac-Fe(MeL1)3 and refluxin isopropanol have been used for rac-Rh(MeL1)3 due to a higher energy activation required for the formation of rac-We modified the reported synthesis 111 by excluding the column chromatography purification step by using filtration and washing of the suspension of the reaction mixture residue after solvent evaporation in cold methanol. The success of the metallation process is clearly visible in the 1 H-NMR spectra of metallated and non-metallated ligand by significant upfield shift of αpyrrolic proton (H1). The shift is explained by the interactions between H1 protons of the opposite pyrrolic rings that leads to a shift from 7.68 ppm for the non-metallated ligand, to 6.41 ppm for rac-Co(MeL1)3, and 6.66 ppm for rac-Rh(MeL1)3 (see experimental part). Due to the paramagnetic nature of rac-Fe(MeL1)3 related to the presence of Fe 3+ ion in the structure, the 1 H-NMR spectrum is not informative (Figure42).

Figure 42

 42 Figure 42 NMR spectra of tris(dipyrrin) connectors rac-Co(HL1)3, rac-Fe(HL1)3 and rac-Rh(HL1)3

Figure 44 NMR

 44 Figure 44NMR spectra of long dipyrrin ligand and rac-Co(MeL2)3

Figure 46 CD

 46 Figure 46CD spectra of Λ-Co(HL1)3 and Δ-Co(HL1)3(RT, THF, 2 mm)

Figure 47 HPLC 3

 473 Figure 47 HPLC chromatograms of Λ-Co(HL1)3 (a); Δ-Co(HL1)3 (b)

Figure 48 CD

 48 Figure 48CD spectrum of the phase containing one enantiomer of rac-Rh(HL1)3 as the major product (RT, 5*10 -5 M, THF, cuvette length = 2 mm)

Figure 50

 50 Figure 50Crystal structure of Pd(HL1)2

Figure 51

 51 Figure 51The synthetic pathway for the connector Ni(H2L3)

Figure 52 Figure 53

 5253 Figure 52NMR spectra of bis(dipyrrin) connectors

Figure 55 Figure 56 2

 55562 Figure 55The structure of phenanthroline-based MOC (from ref.135 )

  of solvents, furthermore structure of [rac-Fe(HL4)3][PF6]2 has multiple exchangeable protons, which results in non-informative NMR spectra. However, it is possible to observe the formation of the complex by Mass-spectrometry. The MS spectra demonstrated a peak of mass 559.14 [M-2PF6] 2+ for [rac-Fe(MeL4)3][PF6]2 and peak of mass 538.44 [M-2PF6] 2+ for [rac-Fe(HL4)3][PF6]2 that are in perfect accordance with the expected mass of these species. Moreover, the purity of [rac-Fe(HL4)3][PF6]2 was confirmed by elemental analysis. Chapter II. Synthesis of the connectors §IV. Terpyridine-based metal-organic connectors family IV. Terpyridine-based metal-organic connectors family IV.1. Terpyridine complexes: review

2 . 2 .

 22 Figure 60 Structure of the linear connectors [Fe(HL5)2][PF6]2, [Co(HL5)2][PF6]2 and [Ru(HL5)2][PF6]2

  bis(4-carboxyphenyl)-10,20-diphenylporphyrinato] Ni(II) (Ni(H2L6)) was chosen as targeted metal-organic connector for synthesis of novel calixarene-based MOCs (Figure64).

Figure 64

 64 Figure 64Structure of the linear connector Ni(H2L6)

Figure 66 NMR

 66 Figure 66NMR spectra ofMe2L6 and Ni(Me2L6)

Figure 72 Calculated 6 -

 726 Figure 72Calculated 6-31+G*//6-31+G* electrostatic potential surfaces for 1,3,5-triazine.Electrostatic potential surface energies range from -15 (red) to +15 (blue) kcal mol -1 (from ref.8 )

Figure 73

 73 Figure 73Triazine-based MOC with anion-π recognition properties (from ref.186 )

  3,5-triazine-2,4,6-triyl)tribenzoic acid (H3L8), 2,2',2''-((1,3,5-triazine-2,4,6triyl)tris(azanediyl))triacetic acid (H3L9) and 4,4',4''-(((1,3,5-triazine-2,4,6triyl)tris(azanediyl))tris(methylene))tribenzoic acid (H3L10). They differ by the nature of the Chapter II. Synthesis of the connectors §VII. Organic connectors junction between carboxyl groups and 1,3,5-triazine core and, as a result, they also differ in the flexibility and the size.

Figure 74

 74 Figure 74Structure of the triangular organic connectors H3L8, H3L9, H3L10

  H-NMR with the appearance of two doublets of equal integration at 8.01 ppm and 7.59 ppm corresponding to the aromatic protons Me3L11; a singlet at 3.93 ppm corresponds to methyl group of the ester function (Figure 78). Moreover, only one peak is observed at -68.90 ppm in the 19 F-NMR confirming the presence of the equivalent fluorine in the obtained structure.

Figure 78 NMR

 78 Figure 78NMR spectra of MeL11

  steps. The suitability of these connectors for their use in the formation of MOCs was assessed based on their geometrical (linear and triangular) and chemical characteristics, which revealed a range of properties, including redox activity, unique optical, and chiral properties. It is possible to use these connectors to obtain different types of octahedral calixarenebased MOCs, such as both face-panelled and edge-panelled structures. Based on the selected connectors, the formation of moderate to extra-large octahedral calixarene-based MOCs are expected. The resulting MOCs are also expected to exhibit enhanced properties, leading to a wide range of applications.

  typically used in this technique range from 60 o C to 120 o C (in this work the temperature of 80 o C was used). The quality of the resulting crystals usually depends on the crystal formation rate while slower formation usually leads to higher quality crystals. Gradual heating and cooling (at a rate of approximately 2-4 o C/h ) are commonly employed to slow down the crystal formation. For the same reasons, diluted solutions with concentrations up to 20 mM are commonly used to achieve slow and controlled crystal growth (in this work concentrations up to 10 mM were used). The reaction time in this technique is not strictly defined and depends on the nature of the reactants and the rate of heating and cooling. However, it typically takes at least one week to achieve completeness (see detail in the experimental part). • Liquid-liquid diffusion technique involves the diffusion at room temperature (RT) of a solution containing some of the components into a solution containing the other Chapter III. Formation and structural investigations of MOCs §I. Synthesis of crystalline molecular cages components , resulting in the formation of MOCs crystals at the interface of the two solvents due to the self-assembly reaction on this interface

  the solvothermal technique, choice of a solvent is determined by the solubility of all components involved in the reaction. In the formation of MOFs and MOCs, N,Ndimethylformamide (DMF), dimethylsulfoxide (DMSO), and N,N-dimethylacetamide (DMA) are commonly used solvents due to their ability to dissolve both organic (ligands) and inorganic (metal salts) species and also to their high boiling points (153 o C, 189 o C and 165 o C respectively). Other solvents are used less frequently. In this study, we selected N,N-dimethylformamide (DMF) as a Chapter III. Formation and structural investigations of MOCs §I. Synthesis of crystalline molecular cages solvent in the solvothermal synthetic technique based on two factors: firstly, DMF is able to solubilize all of the participants of one-pot three-component reaction (connector, metal salt and sulfonylcalix[4]arene); additionally, DMF is known to degrade under heat, leading to the formation of small amounts of dimethylamine, which can serve as a base which initiates the reaction.

1 Figure 80 • 198 •

 180198 Figure 80Crystal structures of the obtained side products while using solvothermal technique -metallocalixarene complexes with different stoichiometries Metal/Calixarene

8 ,

 8 (rac-M(HL1)3 M = Co III , Fe III , Rh III , Δ-Co(HL1)3, Λ-Co(HL1)3) in the liquid-liquid diffusion technique led to the formation of the greatest variety of desired calixarene-based MOCs, including ten new compounds, four of which are chiral (MOCs based on Δ(M = Co II , Ni II ) • [M4SO2TCA(μ4-OH2)]6[rac-Rh(L1)3]8, (M = Co II , Ni II ) • Chiral MOCs [M4SO2TCA(μ4-OH2)]6[Λ-Co(L1)3]8 and [M4SO2TCA(μ4-OH2)]6[Δ-Co(L1)3]8 (M = Co II , Ni II )

  rigid triangular connector (H3L8) demonstrated good results for growing single-crystals, indicating that the flexible connectors (H3L9, H3L10) are not the best for the formation of crystalline calixarene-based MOCs. H3L8 leaded to the formation of MOCs with the formula [M4SO2TCA(μ4-OH2)]6[L8]8, (M = Co II , Ni II ). Additionally, the use of H3L11 connectors also leaded to the formation of crystals, however, these crystals could not be analysed because of their low stability. MOCs based on H3L8 was formed using different conditions. Single-crystals of [Co4SO2TCA(μ4-OH2)]6[L8]8 were obtained during liquid-liquid diffusion while the Ni(II) analog, [Ni4SO2TCA(μ4-OH2)]6[L8]8 was obtained in the solvothermal conditions. Nevertheless, both MOCs based on organic connector H3L8 appeared to be isostructural (see details in §V. of this chapter). Chapter III. Formation and structural investigations of MOCs §II. Structural investigation of racemic dipyrrin-based MOCs: XRD analysis II. Structural investigation of racemic dipyrrin-based MOCs: XRD analysis The obtained crystals of calixarene-based MOCs with triangular racemic tris(dipyrrin) metal-organic connectors (rac-M(HL1)3, M = Co III , Fe III , Rh III ) were investigated in depth by different techniques in order to prove the formation of the desired structures.

8

 8 only unit cells parameters have been measured (Table6), proven clearly that they are both isostructural to the 4 MOCs based on connectors rac-M(HL1)3. This results in a total of 6 new MOCs based on the metal-organic connectors rac-M(HL1)3 (M = Co III , Fe III , Rh III ).

  Figure 83The structure of the obtained dipyrrin-based MOCs of formula [M4SO2TCA( -OH2)]6[rac-M'(L1)3]8•nDMF•mH2O (M = Co II , Ni II ; M' = Co III , Fe III , Rh III )

84

 84 Figure 84The structure of [M4TCA(μ4-OH2)] 4+ shuttlecock-like node (a); the metal ions environment of the connectors rac-M(L1)3 3-in the MOCs of formula [M4SO2TCA( -OH2)]6[rac-M'(L1)3]8•nDMF•mH2O (M = Co II , Ni II ; M' = Co III , Fe III , Rh III )

  .5Å, MOC CIAC-106 is based on a connector with a length 12Å and [M4SO2TCA(-OH2)]6[rac-M'(L1)3]8•nDMF•mH2O (M = Co II , Ni II ; M' = Co III , Fe III , Rh III ) are based on connectors with a length of 16Å (see details in §II.1. Chapter II). In addition, it is important to compare the geometrical characteristics of the obtained dipyrrin-based MOCs with the MOC based on

Figure 86

 86 Figure 86 Portals of [M4SO2TCA( -OH2)]6[rac-M'(L1)3]8•nDMF•mH2O (M = Co II , Ni II ; M' = Co III , Fe III , Rh III ); accessibility of guest molecules

  Figure 87The schematic representation for the packing of [M4SO2TCA( -OH2)]6[rac-M'(L1)3]8•nDMF•mH2O (M = Co II , Ni II ; M' = Co III , Fe III , Rh III ) in the crystal, in the xOy plane (a), in the yOz plane (b). Octahedra represent calixarene-based MOCs, green lines represent unit cell

•••

  obtained MOCs based on the connectors rac-M(HL1)3 (M = Co III , Fe III , Rh III ), Δ-Co(HL1)3 and Λ-Co(HL1)3 were further investigated with other techniques in order to evaluate the enantiomeric excess of the chiral species, and to analyse their thermal stability together with their stability in solution. The obtained vacuum dried MOCs [M4SO2TCA(-OH2)Ni II ) have very limited solubility in DMSO, DCM and acetonitrile. The obtained chiral MOCs [Co II , Ni II ) were investigated in solutions by Circular Dichroism (CD) and chiral HPLC in order to exclude any racemisation during the crystallisation process and to estimate the enantiomeric excess (ee) of the chiral MOCs. MOCs based on connectors rac-M(HL1)3 (M = Co III , Fe III , Rh III ), Δ-Co(HL1)3 and Λ-Co(HL1)3 were also investigated by different methods of mass-spectroscopy (ESI-MS, IM-MS) to provide additional evidence concerning structure of the obtained compounds. §IV. Additional characterizations techniques for dipyrrin-based MOCs The values of ellipticity of the analysed chiral MOCs are much larger than the values of ellipticity for connectors alone: Λ-Co(HL1)3 (-98.47 and 144.44 mdeg) and Δ-Co(HL1)3 (91.9 and -131.7 mdeg) ( §II.3. chapter II) using the same concentrations.

  experiments were performed for [M4SO2TCA(μ4-OH2)]6[rac-Co(L1)3]8, and enantiomerically pure [M4SO2TCA(μ4-OH2)]6[Λ-Co(L1)3]8, [M4SO2TCA(μ4-OH2)]6[Δ-Chapter III. Formation and structural investigations of MOCs §IV. Additional characterizations techniques for dipyrrin-based MOCs IM-MS arrival time distributions demonstrated single drift peaks, with similar drift times for all cages except [Ni4SO2TCA(μ4-OH2)]6[Λ-Co(L1)3]8 cage, where it was not possible to resolve drift peak. Drift time for all cages resulted in the experimental DT CCSN2 values, which are summarized Table13.

  §IV. Additional characterizations techniques for dipyrrin-based MOCs The polycrystalline samples of freshly prepared MOCs with formula [M4SO2TCA(μ4-OH2)]6[rac-Co(L1)3]8 (M = Co II , Ni II ) were analysed using the Kurchatov Synchrotron Radiation Source (Moscow, Russia). The results of XRPD experiments are depicted Figure 90.Unfortunately, it was not possible to obtain XRPD data for other dipyrrin-based MOCs due to the limited access to Kurchatov Synchrotron and XRPD measurements using a diffractometer power radiation were not successful.

  Figure 90 XRPD traces for polycrystalline samples of [Co4SO2TCA(μ4-OH2)]6[rac-Co(L1)3]8 (left); [Ni4SO2TCA(μ4-OH2)]6[rac-Co(L1)3]8 (right)

  Co II , Ni II ), TGA experiments on crystalline samples were performed. Additionally, these experiments provide valuable data concerning the thermal stability of the obtained MOCs. Unfortunately, it was not possible to obtain TGA data for other dipyrrin-based MOCs due to the insufficient amount of compounds. TGA experiments were performed with powdered samples obtained by filtration of crystals from the mother liquor. The TGA traces are demonstrated on Figure 91.

  Figure 91 TGA traces for freshly obtained [M4SO2TCA(μ4-OH2)]6[rac-Co(L1)3]8 (M = Co II , Ni II )

includes 6 V. 1 .

 61 new racemic MOCs based on the connectors rac-M(HL1)3 (M = Co III , Fe III , Rh III ) and 4 chiral MOCs based on chiral connectors Λ-Co(HL1)3 and Δ-Co(HL1)3 . XRD analysis of single-crystals revealed the formation of large, porous, octahedral MOCs with an internal cavity diameter of approximately 19 Å, which is significant for this type of structures. Chiral MOCs based on chiral connectors Λ-Co(HL1)3 and Δ-Co(HL1)3 were also Chapter III. Formation and structural investigations of MOCs §IV. Additional characterizations techniques for dipyrrin-based MOCs characterised and their chirality was supported by various techniques (CD, chiral HPLC). Furthermore, analysis by mass-spectrometry (ESI-MS and IM-MS) supported the formation of the desired structures and provided strong evidences of their stability in the solution and under ionization processes. Some of the obtained MOCs were also analysed by additional methods like XRPD but did not lead to conclusive results due to probably amorphization. Finally, TGA traces demonstrated that freshly obtained MOCs are stable until 360 o C and contain 20-25% of solvent molecules (primally DMF). Chapter III. Formation and structural investigations of MOCs §V. Structural investigation of MOCs based on organic connectors V. Structural investigation of MOCs based on organic connectors As it was discussed in the §VII. Chapter II. the chosen organic connectors are promising candidates for the formation of calixarene-based MOCs with anion-π recognition properties. The connectors H3L8-H3L11 were used in the reaction of the MOCs formation. However, according to the Table 5 in §I.1 of this chapter, only rigid H3L8 connector demonstrated the MOCs crystals formation of formula [M4SO2TCA(μ4-OH2)]6[L8]8•nDMF•mH2O (M = Co II , Ni II ) suitable for single-crystal XRD analysis. Crystalline data for [M4SO2TCA(μ4-OH2)]6[L8]8 (M = Co II , Ni II ) A single-crystal XRD study demonstrated the formation of neutral isostructural octahedral cages with formula [M4SO2TCA(μ4-OH2)]6[L8]8•nDMF•mH2O (M = Co II , Ni II ) (Figure 92).

  presents very different structure of shuttlecock-like moiety of formula [Fe4SO2TCA(μ4-Cl)] 3+ which leads to the formation of negatively charged structure. As a result, it is important to compare geometrical characteristics of the obtained MOCs [M4SO2TCA(μ4-OH2)]6[L8]8 with the ones of (sc4a)Fe(tatb) (seeTable 16 in this chapter).

Figure 92

 92 Figure 92The structure of the obtained triazine-based MOCs [M4SO2TCA(μ4-OH2)]6[L8]8•nDMF•mH2O (M = Co II , Ni II )

Figure 93 73 V. 3 . 8 .

 937338 Figure 93 Portals of [M4SO2TCA( -OH2)]6[L8]8•nDMF•mH2O (M = Co II , Ni II )

8 .

 8 It was not possible to investigate the gas adsorption properties for all the obtained and characterised calixarene-based MOCs presented in Chapter III due to the insufficient amount of Chapter IV. Gas adsorption properties of synthetized calixarene-based MOCs §II. Adsorption properties of triazine-based MOC §IV.4 and §V.4 of Chapter III, the dipyrrin-based MOCs of formula [M4SO2TCA( -OH2)]6[rac-Co(L1)3]8 (M = Co II , Ni II ) demonstrate a thermal stability up to 360 o C and triazinebased MOC of formula [Co4SO2TCA( -OH2)]6[L8]8 demonstrates thermal stability up to 400 o C. TGA traces demonstrated the mass loss related with the molecules of solvents in the range 30-200 o C. As a result, the activation procedure was conducted at 180 o C under a dynamic vacuum (vacuum level = 1.3 Pa) for 6h for all investigated MOCs.II. Adsorption properties of triazine-based MOCIn this part we will focus on the investigation of gas adsorption properties of the polycrystalline MOC of formula [Co4SO2TCA(-OH2)]6[L8]The isostructural MOC [Ni4SO2TCA(-OH2)]6[L8]8 (see details in experimental part) was also obtained but in too small

Figure 96

 96 Figure 96 gives the IR spectra of [Co4SO2TCA(-OH2)]6[L8]8 after (orange curve) activation, of p-tert-butylsulfonylcalix[4]arene (H4SO2TCA) (blue) and connector H3L8 (grey).

Figure 96 FTIR 8

 968 Figure 96 FTIR data for activated [Co4SO2TCA( -OH2)]6[L8]8(orange); for H3L8 (grey) and for H4SO2TCA (Blue)

  Figure 97TGA trace of the activated [Co4SO2TCA( -OH2)]6[L8]8

Figure 98 N2 8 (

 988 Figure 98 N2(g) adsorption-desorption isotherm at 77K for [Co4SO2TCA( -OH2)]6[L8]8(red curveadsorption, black curvedesorption)

Figure 99

 99 Figure 99Pore size distribution (green line) and cumulative pore volumes (red line) for[Co4SO2TCA( -OH2)]6[L8]8 calculated by N2-DFT Model using MicroActive software

8 ,

 8 the CO2(g) uptake was measured at 273K and within the range of relative pressures from 7*10 -5 to 0.034. The CO2(g) adsorption-desorption isotherm is presented on Figure100.

Figure 100

 100 Figure 100 CO2(g) adsorption-desorption desorption isotherm at the temperature 273K for [Co4SO2TCA( -OH2)]6[L8]8 (red curve -adsorption, black curvedesorption)

  adsorption properties of synthetized calixarene-based MOCs §III. Adsorption properties of dipyrrin-based MOCs As a result, when MOCs of formula [M4SO2TCA(-OH2)]6[rac-Co(L1)3]8 (M = Co II , Ni II ) are dried in the air, amorphization is observed leading to the broadening of the peaks in XRPD diagram (Figure 101, red curve) (see details in §IV.3. of Chapter III).

Figure 101

 101 Figure 101 XRPD data of [M4SO2TCA(μ4-H2O)]6[rac-Co(L1)3] soaked in different solvents

For 8 ,III. 3 .

 83 Co II , Ni II ) was measured within the range of relative pressures from 10 -6 to 0.995 P/P0 at 77K (see details in experimental part). They were repeated two times with the same sample, without removing the sample from the apparatus and without additional activation. The results of these experiments are presented Figure 104. §III. Adsorption properties of dipyrrin-based MOCs For [Co4SO2TCA(-OH2)]6[rac-Co(L1)3]8, one type of narrow pores of width 10Å may correspond with internal porosity of MOC. As it was discussed in §II.3. of Chapter III , we estimated that the internal cavity of this MOC has a diameter of ca samples 19Å (XRD measurements). These different values obtained from the 2 methods might be explained by the fact that XRD method provides the crystallographic dimensions of the pores, while gas adsorption measurements provide the information on the accessible or effective pore size; additionally, gas adsorption measurements typically assume an idealized model of the porous material (slit), which may not accurately reflect the actual pore structure of the material. Other pores (width > 10Å) are related with the external porosity, defects and dislocations in crystals leading to the mesostructuring of crystallites. two types of narrow pores have been evidenced: (i) pores of width 10Å which may correspond with internal porosity of MOC; (ii) the other pores with the width of 15Å related with the external porosity. However, in comparison with [Co4SO2TCA(-OH2)]6[rac-Co(L1)3]8, [Ni4SO2TCA(-OH2)]6[rac-Co(L1)3]8 demonstrates much less mesostructuring of crystallites which might be related with the more stable cage packing in the unit cells of the crystals even after the activation process. In addition, pores of width 5Å are observed, however, they are explained by anomalies during the measurements. Adsorption of other small molecules The adsorption properties of [M4SO2TCA(-OH2)]6[rac-Co(L1)3]8 (M = Co II , Ni II ) were measured with 5 other different gases in order to investigate the affinity of such MOCs towards

3 . 2 .

 32 Figure 106 Gas (CO2(g), CH4(g), C2H2(g), C2H4(g) and C2H6(g)) adsorption-desorption isotherms for [M4SO2TCA(-OH2)]6[rac-Co(L1)3]8 (M = Co II , Ni II ) (filled symbols for adsorption, hollow ones for desorption)

  [M4SO2TCA( -OH2)]6[rac-Co(L1)3]8 (M = Co II , Ni II ) §III. Adsorption properties of dipyrrin-based MOCs Both MOCs of formula [M4SO2TCA(-OH2)]6[rac-Co(L1)3]8 (M = Co II , Ni II )demonstrated almost the same behaviour towards studied gases, with gas uptakes decreasing with increasing of temperature (this is a standard observation in gas adsorption experiments due to the exothermic effect of gas adsorption). The observed differences in different gases uptakes for both MOCs can be explained by the polarizability of the gas molecules, related to the interactions towards the MOCs. The molecules with higher polarizability demonstrated better affinity towards dipyrrin-based MOCs, which corresponds to stronger interactions with the MOCs during the physisorption phenomenon. The best affinity is found to be towards C2H2 (the molecule with the highest polarizability) whereas the worst affinity corresponds to N2(g) (the molecule with the worst polarizability).

• 6

 6 were successfully investigated. The adsorption properties of two dipyrrin-based MOCs of formula [M4SO2TCA(-OH2)]6[rac-Co(L1)3]8 (M = Co II , Ni II ) and a triazine-based MOC of [Co4SO2TCA( -OH2)]6[L8]8 were investigated in depth. All the studied compounds are porous and present a high surface area. The triazine-based MOC [Co4SO2TCA( -OH2)]6[L8]8 demonstrated a high porosity and significant N2(g) adsorption capacity with pore size distribution in the interval 12-40Å with a distinguishable peak at 15Å corresponding with internal cavity of the MOC observed using XRD measurements. The investigation of dipyrrin-based MOCs of formula [M4SO2TCA(-OH2)]6[rac-Co(L1)3]8 (M = Co II , Ni II ) revealed moderate porosity and lower surface areas, but in accordance with the ones reported for calixarene-based MOCs. The pore size distribution revealed the monomodal distribution and formation of microporous materials with the distinguished pore size approximately 10Å which is in good agreement with the crystalline structure discussed in the previous Chapter III. These MOCs also demonstrate different affinity towards different small gases (CO2, CH4, C2H2, C2H4 and C2H6). Furthermore, it was possible to estimate the selectivity of gas mixtures adsorption for [M4SO2TCA(-OH2)]6[rac-Co(L1)3]8 (M = Co II , Ni II ), using the IAST model. The highest selectivity was observed towards C2H6/CH4 and C2H2/CH4 gas mixtures, which are important for natural gas upgrade. Additionally, high calculated IAST gas selectivity was observed towards CO2/CH4 and CO2/N2 gas mixtures which might be used in the design for the flue gas separation systems. In conclusion, the presented compounds hold a great potential for further studies due to underexplored adsorption properties of other members of the obtained calixarene-based MOCs discussed in Chapter II.General conclusion §I. Results of the workI. Results of the workThis work is devoted to the synthesis of a new family of calixarene-based MOCs. We focused on the formation of face-panelled and edge-panelled octahedral calixarene-based MOCs using linear bidentate and triangular tridentate metal-organic and organic connectors.A total of 18 different (nature, geometry and charge) connectors were synthetized for the obtention of new calixarene-based MOCs: among them 14 metal-organic and 4 purely organic connectors; 12 triangular tridentate and 6 linear bidentate connectors; 4 ionic and 14 neutral connectors.All of the obtained connectors were used for the formation of MOCs as single-crystals for their structural studies, combined with p-tert-butylsulfonylcalix[4]arene (H4SO2TCA) and different metal ions (M II ). That resulted in 180 types of crystallizations performed during this work. The tricarboxylate connectors leaded for the formation of calixarene-based MOCs as singlecrystals are: racemic tris(dipyrrin) connectors rac-M(HL1)3 (M = Co III , Fe III , Rh III ); chiral tris(dipyrrin) connectors Λ-Co(HL1)3 Δ-Co(HL1)3; and triazine connector H3L8. These crystals were analysed, and the structures were solved which revealed the formation of 12 new large octahedral calixarene-based MOCs: MOCs based on racemic tris(dipyrrin) connectors of formula [M4SO2TCA]6[rac-M'(L1)3]8 (M = Co II , Ni II ; M' = Co III , Fe III , Rh III ) • 4 chiral MOCs based on chiral tris(dipyrrin) connectors of formula The structures of these calixarene-based MOCs were studied in details first by singlecrystals XRD, then confirmed by other techniques in solution and in the solid state. The formed MOCs are face-panelled octahedral cages consisting of 6 "shuttlecock-like" calixarene units of formula [M4SO2TCA(μ4-OH2)] 4+ in the vertices and 8 connectors covering the faces of the octahedra.

1 .

 1 N2(g) and CO2(g) adsorption was investigated for triazine-based MOC of formula [Co4SO2TCA]6[L8]8. §II. Perspectives for this work N2(g), CO2(g), CH4(g), C2H2(g), C2H4(g) and C2H6(g) adsorption was investigated for dipyrrinbased MOCs of formula [Co4SO2TCA]6[rac-Co(L1)3]8, [Ni4SO2TCA]6[rac-Co(L1)3]8 and different affinity towards these gases was observed that allowed us to estimate the gas adsorption selectivity towards different equimolar mixtures of these gases using IAST modelling II. Perspectives for this work II.Improvement of the synthesis for the formation of MOCs

  MOCs with the formula [M4SO2TCA(μ4-OH2)]6[rac-Co(L1)3]8 (M = Co II , Ni II ) demonstrated good IAST predicted selectivity towards various equimolar gas mixtures (C2H2/C2H4; C2H2/CO2; C2H2/CH4; C2H6/CH4; CO2/CH4; CO2/N2) (see details in §III.4. Chapter

  MOCs of formula [M4SO2TCA(μ4-OH2)]6[rac-Rh(L1)3]8 (M = Co II , Ni II ) are highly interesting for the design of catalytic systems with an exceptional activity, due to the presence of Rh(III). Metal-organic complexes of Rh III often possess photoactive properties (see details in §II.1. of Chapter II), so the obtained calixarene-based MOCs [M4SO2TCA(μ4-OH2)]6[rac-Rh(L1)3]8 (M = Co II , Ni II ) may have photocatalytic potential. Currently, we intend to investigate the heterogeneous catalytical properties of these MOCs for reactions of CO2 reduction, as well as, hydrogen evolution reactions and water oxidation.

4 .

 4 Investigation of the molecular recognition propertiesIn this work, many properties of the obtained MOCs related to their internal cavity and discrete structure were not investigated, except for their gas adsorption properties. Therefore, there are significant perspectives for exploring them. As discussed in §III.5. of Chapter I, many calixarene-based MOCs reported in the literature exhibit unique properties related to selective binding, recognition of certain substances, and other host-guest interactions. For example, the binding of the obtained calixarene-based MOCs with biologically active substances in solution can be studied to design targeted drug delivery systems. Additionally, the adsorption of various dyes (both in solution and in the solid state) by the obtained calixarene-based MOCs can lead to sensor and imaging systems. Initial experiments performed using methylene blue and MOCs with the formula [M4SO2TCA(μ4-OH2)]6[rac-Co(L1)3]8 (M = Co II , Ni II ), using UV-titration methods and observing the adsorption of methylene blue from an aqueous solution by MOCs in the solid state, demonstrated the potential for further investigations in this area. Chiral calixarene-based MOCs with the formula [Co II , Ni II ) are also of great interest for studying their chiral properties. We can analyse their chiral properties in the solid state through vapor adsorption of volatile chiral compounds, such as enantiomers of 2-butanol. The experiments in this direction have been already initiated in collaboration with Pr. Beata Nowicka (Jagiellonian University, Krakow, Poland) Furthermore, we can investigate the selective adsorption for MOCs in the solid state of certain enantiomers from racemic solutions. These calixarene-based MOCs also present a possibility to investigate their chiral properties in solutions by studying their selective recognition of enantiomers or the separation of racemic mixtures. Preliminary studies have been performed, but under the selected conditions, these chiral MOCs did not demonstrate chiral properties. Thus, more extensive research is required under carefully selected conditions. The MOCs based on the organic connector H3L8 with the formula [Co4SO2TCA(-OH2)]6[L8]8 have a potential for further investigation of anion-π recognition properties due to the significant number of triazine rings with positively charged areas in their structure (see §VII.1. of Chapter II). Because of the large number of triazine rings and the enclosed structure of the cavity, these MOCs might demonstrate unique anion-π recognition properties.

•

  Silica gel Si 60 (0.040-0.063 mm) VWR chemicals 22E184126 Thin-layer chromatography • TLC Silica gel 60 F254 on aluminium sheets, Merck HX17415654 Analyses and characterizations NMR: 1 H-and 13 C-NMR spectra were recorded at room temperature on a Bruker AV 300 (300 MHz) and Bruker DRX-500 (500 MHz) spectrometers (Service commun de RMN de la Fédération de Recherche de Chimie de l'Université de Strasbourg). Chemical shifts were referenced to the residual proton or carbon peak of the solvent: 1) for 1 H-NMR: CDCl3: 7.26 ppm, (CD3)2SO: 2.50 ppm; 2) for 13 C-NMR: CDCl3: 77.36 ppm, (CD3)2SO: 39.52 ppm.

  -MS: expected m/z = 381.31 [M-2PF6 -] 2+ ; found m/z = 381.10 [M-2PF6] 2+ IR: 1716(s), 1611(m), 1543(w), 1486(w), 1472(w), 1435(w), 1418(w), 1401(m), 1367(w), 1283(s), 1252(s), 1192(m), 1154(s), 1112(s), 1064(m), 1055(s), 1046(m), 965(w), 900(w), 834(s), 791(m), 772(s), 760(m), 736(m), 705(m), 688(w), 656(w), 618(m), 605(m), 588(s), 557(s), 515(w), 462(m), 424(w) cm -1

:[

  expected m/z = 441.40 [M] + ; found m/z = 442.11[M] + IR: 2885(wb), 2548(wb), 1694(m), 1583(m), 1518(s), 1409(m), 1360(s), 1283(s), 1107(w), 1018(m), 934(w), 879(m), 829(m), 789(s), 765(s), 693(m), 672(w), 549(m), 492(m) cm -1 . Elemental Analysis: % calculated: C, 65.31%; H, 3.43%; N, 9.52% % found: C, 65.25%; H, 3.51%; N, 9.63% tube of 10 cm length and with diameter 1.5 cm, three layers of liquid are formed. The lower layer consists of sulfonylcalix[4]arene (0.02g, 23.55 μmol, 6 eq.), cobalt (II) chloride hexahydrate (0.0224g, 94.23 μmol, 24 eq.) and Δ-Co(HL1)3 (0.0296g, 31.4 μmol, 8 eq.) in 5 ml of DMF. The buffer solution consists of 1 ml MeOH + 1 ml DMF mixture. The upper layer consists of a triethylamine (0.033 ml, 235.57 μmol, 60 eq.) solution in 3 ml MeOH. Slow liquids diffusion for 2 weeks caused the formation of large red octahedral single-crystals suitable for XRD. Formula: C624H504Co32N48O126S24 ESI-MS: calculated m/z = 13346.1 [M] -; found m/z = 2227.6 [M] 6-, [M] -= 2227.6the calculated and the found values are related with the hygroscopicity of the samples (see details in Chapter IV)tube of 10 cm length and with diameter 1.5 cm, three layers of liquid are formed. The lower layer consists of sulfonylcalix[4]arene (0.02g, 23.55 μmol, 6 eq.), nickel (II) chloride hexahydrate (0.0224g, 94.23 μmol, 24 eq.) and Λ-Co(HL1)3 (0.0296g, 31.4 μmol, 8 eq.) in 5 ml of DMF. The buffer solution consists of 1 ml MeOH + 1 ml DMF mixture. The upper layer consists of a triethylamine (0.033 ml, 235.57 μmol, 60 eq.) solution in 3 ml of MeOH. Slow liquids diffusion for 2 weeks caused the formation of large red octahedral crystals suitable for XRD. Formula: C624H504Co8Ni24N48O126S24 ESI-MS: calculated m/z = 13340.7 [M] -; found m/z = 2226.2 [M] 6-, [M] -= 2226.2*z = 13357.2 IM-MS: found DT CCSN2 = peak not resolved Elemental Analysis: % calculated: C, 56.18%; H. 3,81%; N. 5,04% % found: C, 53.09%; H. 5,07%; N. 7,39% The differences in the calculated and the found values are related with the hygroscopicity of the samples (see details in Chapter IVtube of 10 cm length and with diameter 1.5 cm, three layers of liquid are formed. The lower layer consists of sulfonylcalix[4]arene (0.02g, 23.55 μmol, 6 eq.), nickel(II) chloride hexahydrate (0.0224g, 94.23 μmol, 24 eq.) and Δ-Co(HL1)3 (0.0296g, 31.4 μmol, 8 eq.) in 5 ml of DMF. The buffer solution consists of 1 ml MeOH + 1 ml DMF mixture. The upper layer consists of a triethylamine (0.033 ml, 235.57 μmol, 60 eq.) solution in 3 ml of MeOH. Slow liquids diffusion for 2 weeks caused the formation of large red octahedral single-crystals suitable for XRD. Formula: C624H504Co8Ni24N48O126S24 ESI-MS: calculated m/z = 13340.7 [M] -; found m/z = 2225.1 [M] 6-, [M] -= 2225.1the calculated and the found values are related with the hygroscopicity of the samples (see details in Chapter IV

  Ce projet a permis d'obtenir une nouvelle série originale de 12 cages métallo-organiques (MOCs) octaédriques à base de calixarène. Cette série se compose de deux groupes : (i) 10 MOCs basés sur des connecteurs métalloorganiques de type tris(dipyrrine), et (ii) 2 MOCs basés sur des connecteurs purement organiques de type triazine. Les structures et les caractéristiques de ces MOCs ont été analysées à l'aide de diverses techniques, telles que la Diffraction de RX sur monocristal , l'ATG et la Spectrométrie de masse . Ces cages présentent une porosité significative allant jusqu'à 71%. En outre, les propriétés d'adsorption de gaz de certains de ces MOCs ont été étudiées pour une série de gaz, y compris des hydrocarbures légers. Au cours de ces expériences, les MOCs ont démontré une excellente absorption de gaz (avec une surface BET d'environ 425 m 2 /g) et une sélectivité d'adsorption de gaz IAST calculée supérieure à celle de nombreux systèmes pour des mélanges de gaz équimolaires, tels que C2H6/CH4. Ces cages présentent donc un grand potentiel pour la conception de systèmes de séparation sélective des gaz. En outre, la stucture inhérente des MOCs obtenus leur confèrent des propriétés de reconnaissance potentiellement intéressantes.Mots-clés : Cages métallo-organiques, Structure DRX, porosité, sélectivité de l'adsorption de gaz.

Table of contents

 of I. Historical review of covalent and coordination cage .............................................................I.1. Crown-ethers ofPedersen ...............................................................................................

I.2. Cryptands of

Dietrich, Lehn and Sauvage ...................................................................... I.3

. Macrooligocycle of

Kiggen ............................................................................................. I.4. Quan'

s hemicarcerand capable to encapsulate organic molecules.

...............................

.. I.5. The first metal-organic cages and their development through decades .......................... II. Non-calixarene MOCs: classification and properties ........................................................... II.1. Strategies for synthetic approaches .

............................................................................... II.2. Geometrical analysis ......................................................................................................

II.3. Reported properties of

MOCs ........................................................................................

III. Calixarene-based

MOCs ......................................................................................................

III.1. Generalities on calix

[4]

arene ........................................................................................

III.2.

First calixarene-based metal-organic cage .

.................................................................. III.3. Calixarene-based MOCs: formation and synthesis ...................................................... III.4. Calixarene-based MOCs:

geometry............................................................................

.. III.5. Calixarene-based MOCs based on organic connectors: properties .............................. III.6. Calixarene-based MOC with Metal-Organic connectors ............................................. IV. Conclusion ........................................................................................................................... V. Presentation of the scientific project..................................................................................... Chapter I. Introduction §.I. Historical review of covalent and coordination cage

Connectors geometry and number of binding positions Metal nodes geometry with number of positions for coordination Resulting cage geometry Synthetized examples with cavity diameter

	Linear bidentate (Lin)	Number of positions = 3 Complex trigonal (Ctrigon)	Tetrahedron 24 Lin6Ctrigon4	Barrel 25 Lin3Ctrigon2	D=13Å (from ref. 24 )	D=6Å (from ref. 25 )
	Linear	Number of positions = 4
	bidentate (Lin)	Complex tetragonal (Ctetra)		Barrel 36 Lin4Ctetra2		D=9Å (from ref. 36 )
	Angular bidentate (An)	Number of positions = 3 Trigonal (Trigon)	Tetrahedron 29	Cube 37 An12Trigon8	D=12Å	D=19Å
			An6Trigon4		(from ref. 29 )	(from ref.

  §II. Non-calixarene MOCs: classification and properties Finally, one of the most interesting MOCs properties is the enantiomeric separation.Enantiomeric separation properties by MOCs were investigated bySu et al., for instance, separation of R/S-BINOL and R/S-spiridol by octahedral Δ and Λ mixed Pd/Ru cages.[START_REF] Wu | Homochiral D4-Symmetric Metal-Organic Cages from Stereogenic Ru(II) Metalloligands for Effective Enantioseparation of Atropisomeric Molecules[END_REF] Extraction of R/S-BINOL and R/S-spiridol as guests from diethyl-ether solution, or uptake the guest to a solid

	state in the process of sold-liquid extraction into an aqueous solution of chiral cages leaded to
	stereoselective resolution of Δ-R and Λ-S host-guest complexes with enantiomeric excess up to
	34% (Figure 19). Further, Su et al. demonstrated a new method for preparing enantiopure
	octahedral MOC from racemic Fe II -based ligands by addition of R-BINOL during self-assembly
	process. Obtained enantiopure octahedral cages could then be used for R/S-BINOL separation with
	enantiomeric excess up to 88%. 58
	56 Authors have shown temperature-
	dependent binding preference of carcerand-like MOC for C60 and C70. It was shown that both
	complexes "C60⊂carcerand" and "C70⊂carcerand" form at temperatures below 110 o C. However,
	C60⊂carcerand exclusively formed at 130 o C, leaving C70 in solution which means the possibility
	to selectively extract fullerenes from the mixture. Furthermore, it is possible to release
	encapsulated fullerenes from the MOC in 4-dimethylaminopyridine.

nature Node nature Resulted cage geometry Synthetized examples with cavity diameters

  This list is non exhaustive, though most of the examples have been reported.

	Connector
	Linear
	bidentate	Complex
	(LB)	calixarene node M4CA	Cube 75 [M4CA]8LB12	Macrocycle 81

Table of contents

 of I. Generalities............................................................................................................................. II. Dipyrrin-based metal-organic connectors family ................................................................. II.1. Triangular and linear dipyrrin connectors...................................................................... II.2. Synthesis of racemic triangular tris(dipyrrin) connectors (rac-M(HL1)3 , rac-Co(HL2)3)............................................................................................................................................... . Organic connectors ............................................................................................................VII.1. Triazine core: review .................................................................................................. VII.2. Triazine connectors: size, geometry and properties ....................................................

	II.3. Chiral resolution of the triangular connector rac-M(HL1)3 (Λ-M(HL1)3 and Δ-M(HL1)3)

............................................................................................................................................... II.4

. The synthesis of linear dipyrrin connectors (Pd(HL1)2, Ni(H2L3)) .

............................... III. Phenanthroline-based metal-organic connector................................................................... III.1. Complexes of phenanthroline:

review ........................................................................

.. III.1. Phenanthroline connector: size, geometry and properties ............................................ III.2. The synthesis of triangular phenanthroline connector ([rac-Fe(HL4)3][PF6]2) ............. IV. Terpyridine-based metal-organic connectors family ........................................................... IV.1. Terpyridine complexes: review ..

................................................................................

.. IV.2. Linear terpyridine connectors: properties, size and geometry ..................................... IV.3. The synthesis of linear terpyridine connectors ([M(HL5)2][PF6]2) .............................. V. Porphyrin-based metal-organic connector .

...........................................................................

V.

1. Porphyrin macrocycles:

review ...................................................................................

.. V.2. Porphyrin connector: size, geometry and properties

.....................................................

V.

3

. The synthesis of the linear porphyrin connector (Ni(H2L6)) .

........................................ VI. Corrole-based metal-organic

connector ............................................................................

.. VI.1. Corrole macrocycle: review ..

.....................................................................................

.. VI.2. Corrole connector: size, geometry and properties ........................................................ VI.3. The synthesis of triangular corrole connector (Co(H3L7)) ........................................... VIIVII.3. The synthesis of triangular 1,3,5-triazine connectors (H3L8, H3L9, H3L10) ................ VII.4. 1,3,5-trifluorobenzene connector: size, geometry and properties ............................... VII.5. The synthesis of triangular 1,3,5-trifluorobenzene connector (H3L11) ....................... VIII.

Conclusion ......................................................................................................................

Chapter II. Synthesis of the connectors

§I. Generalities

Table 4

 4 Structure of the targeted connector

	Chapter III.

Formation and structural investigations of MOCs Table of contents

  . Synthesis of crystalline molecular cages .............................................................................. I.1. Determination of the synthetic conditions .................................................................... .4. TGA measurements and IR analysis of the racemic cages ........................................ IV.5. Conclusion .................................................................................................................. V. Structural investigation of MOCs based on organic connectors ........................................ Co II , Ni II ) .............................. V.2.Cages metrics ................................................................................................................V.3. Packing of theCages ................................................................................................... V.4. TGA and IR for triazine-based MOCs......................................................................... §I. Synthesis of crystalline molecular cages

	V.1. Crystalline data for [M4SO2TCA(μ4-OH2)]6[L8]8 (M =

II.2. Synthesis of crystalline cages using metal-organic connectors .................................... I.3. Synthesis of crystalline cages using organic connectors (H3L8-H3L11) ........................ II. Structural investigation of racemic dipyrrin-based MOCs: XRD analysis ......................... II.1. Crystalline data

............................................................................................................ II.2. Metal environment ....................................................................................................... II.3. Cages metrics .............................................................................................................

.. II.4. Packing of the dipyrrin-based MOCs in the unit cell .................................................. III. Structural investigation of chiral dipyrrin-based MOCs: XRD analysis ...........................

IV. Additional characterizations techniques for dipyrrin-based

MOCs ..................................

IV.

1. CD and chiral HPLC of enantiomerically pure cages ................................................ IV.2. MS characterization in solution .................................................................................. IV.3

. XRPD in the solid state for racemic cages .

................................................................ IV

Table 10

 10

only one compound [Ni4SO2TCA]6[Δ-Co(L1)3]8 demonstrated a nearly acceptable Flack-parameter. These high values

Table of contents

 of I. Generalities........................................................................................................................... I.1. Context of the study ......................................................................................................I.2. The performed measurements on the synthetizedMOCs .............................................I.3. Activation ofsamples ....................................................................................................II. Adsorption properties of triazine-basedMOC .................................................................... II.1. Behaviour of the sample after activation ..................................................................... II.2. N2(g) adsorption and surface area evaluation ................................................................ II.3. CO2 adsorption .............................................................................................................III. Adsorption properties of dipyrrin-basedMOCs ................................................................ III.1. Behaviour of the samples after activation .................................................................. III.2. N2(g) adsorption and surface area investigation .......................................................... III.3. Adsorption of other small molecules .......................................................................... III.4. Estimation of gas adsorption selectivity ..................................................................... IV. Conclusion .........................................................................................................................

	Chapter

IV. Gas adsorption properties of synthetized calixarene-based MOCs §I

. Generalities

Table 17

 17

	summarizes calixarene-based MOCs for which gas adsorption properties were
	investigated.

Gas adsorption properties of synthetized calixarene-based MOCs §I. Generalities MOC MOC shape, connector geometry Investigated gases BET N2 surface area, m 2 /g

	CIAC-114 207	octahedral, triangular organic	N2	558
	CIAC-106 207	octahedral, triangular organic	N2	410
	CIAC-103, CIAC-104 72	octahedral, triangular organic	N2, H2	504, 477
	[Co II 24(BTC4A)6(BDC)12] 82	octahedral, linear organic	N2, CO2, H2	512
	ImBDC-M (M = Co II , Ni II ) 83	octahedral, linear organic	CO2	n/a
	(sc4a)Fe(btc), (tc4a)Fe(btc), (sc4a)Fe(tatb) 187	octahedral, btc-linear organic tatb-triangular organic	Ar, N2, CO2 C3H6, C3H8, C2H6, C2H4	368 (CO2), 217, 879
	CIAC-112 208	octahedral, angular organic	N2, CO2	1211
	CIAC-107 73	octahedral, triangular organic	N2	770
	LSHU01' 100	icosahedron, angular organic	N2, CO2, CH4, C2H4, C2H6, C3H8	803
	CIAC-115 94	J17 hexadecahedron, triangular organic	N2, CO2, CH4, C2H6, C3H8	646
	[M4(TBSC)]6[HL]8 (M = Co II , Ni II ) 103	octahedral, triangular organic	N2	1192, 1239
	Mn II (salen)-based chiral MOC 4	octahedral, linear metal-organic	CO2	185 (CO2)

Table 17

 17 Comparison of gas adsorption properties of the reported calixarene-based MOCsTo the best of our knowledge there are 17 reported calixarene-based MOCs for which gas adsorption properties were investigated (Table17). It is worth noting, that some of the calixarene-

	based MOCs, for example, CIAC-112 208 and [M4(TBSC)]6[HL]8 (M = Co II , Ni II ) 103 demonstrate

Table 18 )

 18 . The comparison of these observed values with the ones reported in the literature for similar MOCs is presented in §III.2.2.

	of this chapter.

Chapter IV. Gas adsorption properties of synthetized calixarene-based MOCs §II

. Adsorption properties of triazine-based MOC

MOC Specific surface area, m 2 /g Vpore (DFT) α cm 3 /g Vads (N2(g)) α , cm 3 (STP)/g Langmuir BET [Co4SO2TCA]6[L8]8 pristine

	821.2	742.6	0.204	171.4

Table 18 Characteristic

 18

N2(g) adsorption parameters for [Co4SO2TCA( -OH2)]6[L8] (αmeasured at P/P0 = 0.95) II.

2.2. Pore size estimation

Chapter IV. Gas adsorption properties of synthetized calixarene-based MOCs §II

				Cumulative Po re Vo lume vs. Po re W idth
											0.006
		0.27
											0.005
		0.26
	Cumulative Pore Volume (cm³/g)	0.23 0.24 0.25									0.002 0.003 0.004	dV/dW Pore Volume (cm³/g•Å)
		0.22
											0.001
		0.21 0.21
											0.000 0.000
		20	30	40	50	60	70	80	90	100	200
					Pore Width (Å)
					148

. Adsorption properties of triazine-based MOC II.3. CO2 adsorption On the next step, the adsorption properties of [

Co4SO2TCA( -OH2)]6[L8]8 with

  CO2(g) have been then investigated, since CO2(g) is a common component in flue gas, the study of its adsorption and capture is an important field in ecology. These experiments will provide valuable data concerning the affinity of MOC towards gases with different properties (Table19).

	Gas/Characteristic	Molecular weight, g/mol	Kinetic diameter, Å	Density (STP), kg/m 3
	N2(g)	28	3.64	1.251
	CO2(g)	44	3.3	1.977

Table 19

 19

	MOC	N2 Specific surface area, m 2 /g Langmuir BET	CO2 Specific surface area, m 2 /g Vpore (DFT N2) cm 3 /g Langmuir BET	Vads (N2(g)), cm 3 /g STP
	[Co4SO2TCA]6[L8]8	821.2	742.6	468.4	438.6	0.204	171.4
	(sc4a)Fe(tatb) (ref.

), [Co4SO2TCA( -OH2)]6[L8]8 demonstrates a higher affinity towards N2(g). This observation might be explained by

IV. Gas adsorption properties of synthetized calixarene-based MOCs §III

	Simulated pattern for [Co 4 SO 2 TCA] 6 [rac-Co(L 1 ) 3 ] 8 Dried on air Soaked in methanol Soaked in CH 2 Cl 2 200 60 70 90 100 [Co 4 SO 2 TCA] 6 [rac-Co(L 1 ) 3 ] 8 activated Simulated Dried on air pattern Soaked in methanol for Soaked in CH 2 Cl 300 400 500 [Ni 4 SO 2 TCA] 6 [rac-Co(L 1 ) 3 ] 8 activated %, Chapter 100 80 Mass	[Ni	4 SO	2 TCA]	6 [rac-Co(L 1 )	3 ]	8
	Temperature, o C
	5 Figure 103 TGA traces for the activated MOCs [M4SO2TCA( -OH2)]6[rac-Co(L1)3]8 (M = 10 15 20 25 30 5 10 15 20 25 30
	2-theta	A
	Co II , Ni II )

. Adsorption properties of dipyrrin-based MOCs

273K 298K ml/g mmol/g wt., % ml/g mmol/g wt.,% [Co4SO2TCA(-OH2)]6[rac-Co(L1)3]8

	C2H2	50.5	2.25	5.5	36.0	1.61	4.0
	C2H4	38.8	1.73	4.6	29.4	1.31	3.5
	C2H6	38.8	1.73	4.9	31.0	1.38	4.0
	CO2	40.8	1.92	7.4	25.1	1.12	4.7
	CH4	11.3	0.50	0.8	9.0	0.40	0.6
	N2	3.4	0.15	0.5	2.9	0.13	0.4
			[Ni4SO2TCA(-OH2)]6[rac-Co(L1)3]8
	C2H2	53.1	2.37	5.8	37.4	1.67	4.2
	C2H4	40.0	1.79	4.8	29.5	1.32	3.6
	C2H6	39.8	1.77	5.1	30.8	1.37	4.0
	CO2	42.3	1.89	7.7	26.1	1.16	4.9
	CH4	11.7	0.52	0.8	8.6	0.39	0.6
	N2	2.8	0.13	0.4	2.5	0.11	0.3

6[rac- Co(L1)3]8) kJ/mol Q o st([Ni4SO2TCA( -OH2)]6[rac- Co(L1)3]8) kJ/mol N2

		7.0	7.2
	CH4	11.7	14.8
	CO2	28.0	29.1
	C2H6	27.4	29.4
	C2H4	29.4	31.4
	C2H2	29.4	31.4

Table 23 The

 23

	values of zero-coverage heats of adsorption of different gases for
	[M4SO2TCA( -OH2)]6[rac-Co(L1)3]8 (M = Co II , Ni II )
	[M4SO2TCA( -OH2)]6[rac-Co(L1)3]8 (M = Co II , Ni II ) demonstrated similar behaviour
	concerning the zero-coverage heats of adsorption: they exhibit high values of zero-coverage heats
	of adsorption towards CO2, C2H2, C2H4 and C2H6 and small values towards N2 and CH4 as
	observed on the corresponding isotherms.

Based on these observations, dipyrrin-based MOCs of formula [M4SO2TCA( -OH2)]6[rac-Co(L1)3]8 (M = Co II , Ni II ) appeared to demonstrate selective gas adsorption behaviour.

Chapter IV.

Gas adsorption properties of synthetized calixarene-based MOCs §III

		273K			298K
	Equimolar Mixture	Selectivity factor			Selectivity factor
	V1/V2	KH1/ KH2	IAST	V1/V2	KH1/ KH2	IAST
		[Co4SO2TCA(

. Adsorption properties of dipyrrin-based MOCs

-OH2)]6[rac-Co(L1)3]8

	C2H2/C2H4	1.3	1.1	1.8	1.2	1.0	1.3
	C2H2/CO2	1.2	2.7	5.7	1.4	2.6	5.4
	C2H2/CH4	4.5	21.6	18.3	4.0	11.3	11.9
	C2H6/CH4	3.4	32.4	18.7	3.4	17.4	13.8
	CO2/CH4	3.6	7.9	8.9	2.8	4.3	2.7
	CO2/N2	12.0	31.1	19.3	8.7	14.7	12.5
			[Ni4SO2TCA(

-OH2)]6[rac-Co(L1)3]8

	C2H2/C2H4	1.3	1.2	2.0	1.3	1.1	1.5
	C2H2/CO2	1.3	2.9	6.1	1.4	2.7	5.7
	C2H2/CH4	4.5	21.7	19.5	4.3	11.9	12.8
	C2H6/CH4	3.4	30.0	18.5	3.6	16.5	13.6
	CO2/CH4	3.6	7.5	9.4	3.0	4.4	2.8
	CO2/N2	15.1	33.0	22.5	10.4	14.8	5.7

Table 24

 24 Despite the fact that all three methods demonstrated similar results, in this work we mostly relied on the factors calculated with the IAST model, allowing to more accurately compare the results with the literature data. However, IAST has limitations and they must be discussed in order to estimate the accuracy of the obtained data. One limitation of IAST is that it assumes that gas molecules adsorb independently and do not interact with each other. In the present case, the analysed gases do not have a tendency to react with each other, as a result, the deviations from this IAST limitation are not expected.

	Selectivity factors calculated for [M4SO2TCA( -OH2)]6[rac-Co(L1)3]8 (M =
	Co II , Ni II ) for different equimolar gas mixtures

Another limitation of IAST is that it assumes that the adsorbent surface is uniform and homogeneous. However, according to the pore size distribution calculated by QSDFT approach (see §III.

2.3. of this chapter)

, the obtained MOCs of formula [

M4SO2TCA(-OH2)]6[rac- Co(L1)3]8 (

  M = Co II , Ni II ) demonstrate highly homogeneous surface. As a result, the deviations from this IAST limitation are expected to be minor.

	According to the analysis provided in the Table 24, the highest IAST selectivity was
	demonstrated for the binary gas mixtures of light hydrocarbons C2H6/CH4 and C2H2/CH4. It is
	worth mentioning that good IAST selectivity was also observed for C2H2/CO2 mixture which is
	highly difficult to separate due to the almost the same kinetic diameter of these gases (3.3Å for
	both gases). Additionally, high IAST selectivity was observed for CO2/CH4 and CO2/N2 gas
	mixtures.

Table 25

 25 Comparison of C2H6 experimental adsorption capacity and estimated IAST selectivity towards mixture C2H6/CH4 of the studied MOCs to some reported MOFs and MOCsAccording to Table25, excellent IAST selective gas adsorption properties are observed for

	Material	T, K	C2H6 uptake, mmol/g	C2H6/CH4 IAST selectivity	BET surface area (N2(g), 77K) m 2 /g
	[Co4SO2TCA]6[rac-Co(L1)3]8	273 298	1.73 1.38	18.7 13.8	417
	[Ni4SO2TCA]6[rac-Co(L1)3]8	273 298	1.77 1.37	18.5 13.6	445
	Ni(tmbdc)(dabco)0.5 (ref. 214 )	298	5.81	29.0	940
	Cu-MOF (ref. 209 )	298	3.22	9.3	865
	MFM-202a (ref. 215 )	293	4.21	10.0	2220
	UTSA-35A (ref. 216 )	296	2.43	15.0	743
	FIR-7a-ht (ref. 210 )	298	4.06	14.6	1366
	JLU-Liu45 (ref. 217 )	298	3.78	20.1	9781
	Zr-SDBA (ref. 10 )	298	2.08	15.0	739
	UPC-33 (ref. 218 )	273	1.56	6.64	934
	FJI-H21 (ref. 9 )	298	3.45	17.1	1583
	UPC-100-In (ref. 219 )	298	5.32	17.9	1078
	LIFM-26 (ref. 220 )	273	4.6	11.0	1513
	MOC LSHU01'(ref. 100 )	295	2.49	20.0	803
	MOC CIAC-115 (ref. 94 )	298	1.1	8.3	646
	MOCs of formula [M4SO2TCA( -OH2)]6[rac-Co(L1)3]8 (M = Co II , Ni II ), which are superior to
	the ones reported for many MOFs. Only a few reported MOFs demonstrated higher estimated
	IAST gas adsorption selectivity.

As it was mentioned in §I.

1. of

this chapter, to the best of our knowledge there are only two reported MOCs for which IAST selective gas adsorption was calculated. Our MOCs of §IV. Conclusion formula [M4SO2TCA( -OH2)]6[rac-Co(L1)3]8 (M = Co II , Ni II ) are superior to one of them (CIAC-115)

NMR (CDCl3, 300 MHz, 25 °C) δ ppm

  . :8.65 (d, J = 8.2 Hz, 6H, H 1 ),7.36 (d, J = 8.1 Hz, 6H, H 2 ),2.48 (s, 9H, CH3)

	Elemental Analysis: % calculated: C, 50.21%; H, 2.77%; N, 7.98%
	% found:	C, 50.83%; H, 3.60%; N, 7.62%

1 H-

4,4',4''-(1,3,5-triazine-2,4,6-triyl)tribenzoic acid (H3L8)

II.4. Calculations of IAST selectivity of adsorption

	Annexes
	§II. Gas adsorption
							32
	Reflections collected	35715	9148	62823	118050	27832	80086
	Data /
	restraints /	8969/3/471	4942/0/347	15568/21/712	15061/0/655	8476/0/181	12561/0/289
	parameters
	Goodness-of-fit on F 2	1.017	1.528	1.033	2.510	2.347	1.336
	Final R indexes I>=2σ (I)	wR2=0.1127 R1=0.0419	wR2= 0.2050 R1= 0.0714	wR2= 0.1750 R1= 0.0620	wR2= 0.3563 R1= 0.1167	wR2=0.3004 R1=0.0962	wR2=0.2101 R1=0.0855
	Final R indexes All data	wR2=0.1252 R1= 0.0576	wR2=0.2259 R1= 0.0967	wR2=0.1965 R1= 0.0895	wR2=0.3711 R1=0.1517	wR2=0.3170 R1 =0.1093	wR2= 0.2342 R1= 0.1399
	Largest
	diff. peak	0.386, -0.334	2.798, -0.808	1.761, -1.235	6.140, -0.860	1.800, -1.330	1.030, -0.640
	and hole

H-NMR (CDCl3, 300 MHz,

°C) δ ppm:11.27 (m, 6H),9.47 (m, 6H),4.46 (s, 9H, CH3).Other peaks are not observed due to a presence of paramagnetic Fe III ion in the obtained complex.

H-NMR (CDCl3, 300 MHz,

°C) δ ppm:8.10 (d, J = 8.6 Hz, 6H, H 5 ),7.52 (d, J = 8.6 Hz, 6H, H 4 ),6.66 (m, 6H, H 1 ),6.56 (dd, J = 4.4, 1.5 Hz, 6H, H 3 ),6.33 (dd, J = 4.4, 1.5 Hz, 6H, H 2 ),3.98 (s, 9H, CH3)

H-NMR (CDCl3, 300 MHz,

°C) δ ppm:8.17 (d, J = 8.2 Hz, 4H, H 5 ),7.67 (d, J = 8.2 Hz, 4H, H 4 ),7.41 (m, 4H, H 1 ),6.65 (dd, J = 4.4, 1.4 Hz, 4H, H 3 ),6.38 (dd, J = 4.4, 1.5 Hz, 4H, H 2 ),4.00 (s, 6H, CH3)

H-NMR (CDCl3, 300 MHz,

°C) δ ppm:10.38 (bs, 4H, H 1 ),8.06 (d, J = 8.0 Hz, 4H, H 5 ), 8.00 (d, J = 4.1 Hz, 4H, H 3 ),7.45 (d, J = 8.0 Hz, 4H, H 4 ),6.68 (d, J = 4.1 Hz, 4H, H 2 ),3.96 (s, 6H, CH3)

H-NMR (DMSO-d6, 500 MHz,

°C) δ ppm:9.02 (d, J = 8.0 Hz, 2H, H 1 ),8.86 (s, 2H, H 5 ),8.93 (d, J = 5.3 Hz, 2H, H 4 ),8.39 (m, 2H, H 3 ),8.21 (d, J = 8.6 Hz, 2H, H 7 ),8.17 (d, J = 8.6 Hz, 2H, H 6 ),7.84 (m, 2H, H 2 )

H-NMR (DMSO-d6, 500 MHz,

°C, NH3 gas) δ ppm:8.89 (d, J = 4.0 Hz, 2H, Pyr-H 3 ),8.63 (d, J = 4.6 Hz, 2H, Pyr-H 1 ),8.49 (d, J = 4.0 Hz, 2H, Pyr-H 4 ),8.30 (d, J = 4.6 Hz, 2H, Pyr-H 2 ),8.27-8.14 (m, 10H, H 1,2,4 ),8.01 (d, J = 7.9 Hz, 2H, H 3 )

H-NMR (CDCl3, 300 MHz,

°C) δ ppm:8.01 (d, J = 8.8 Hz, 6H, H 1 ),7.59 (d, J = 8.7 Hz, 6H, H 2 ),3.93 (s, 9H, CH3) 19 F-NMR (CDCl3, 300 MHz, 25 °C) δ ppm: -

Sheldrick, G. M. Crystal Structure Refinement with SHELXL. Acta Crystallogr C Struct Chem 2015, 71 (1), 3-8. https://doi.org/10.1107/S2053229614024218

Acknowledgements

That is really hard to express my gratitude to all the people helped me during this PhD work. That was tough, but nevertheless, happy time. I thank Pr. Sébastien Goeb, Pr. Bruno Therrien and Pr. Nicolas Giuseppone for kindly accepting to be members of my thesis committee and their interest in my work. Their feedback and constructive criticism will help me to refine my research project further.

Experimental part

Tris[5-(4-Carboxyphenyl)-4,6-dipyrrinato] Fe(III) (rac-Fe(HL1)3)

Tris Fe (III) The product was synthesized as a racemate based on the already reported procedure with modifications. 111 5-(4-Carboxymethylphenyl)-4,6-dipyrrin (0.5g, 1.8 mmol) was dissolved in 35 ml of methanol, then 5 ml of triethylamine were added. Iron(III) chloride hexahydrate (0.1619g, 0.6 mmol) was dissolved in 5 ml of water. The solution was added to the 5-(4-Carboxymethylphenyl)-4,6-dipyrrin solution. The reaction mixture was stirred at 60 o C for 19h. The solvents were evaporated under reduced pressure. The residue was suspended in 50 ml of methanol, filtered off and washed 2 times with methanol; it afforded a red-orange powder. Yield = 0.189 (35.7%).

Experimental part

Tris

[5-(4-Carboxyphenyl)-4,6-dipyrrinato] Rh(III) (rac-Rh(HL1)3)

Tris Rh(III)

The product was synthesized as a racemate based on the already reported procedure with modifications. 112 5-(4-Carboxymethylphenyl)-4,6-dipyrrin (1 g, 3.6 mmol) was dissolved in 150 ml of isopropanol, then 5 ml of triethylamine were added. Rhodium(III) chloride hydrate (0.2637g, 1.2 mmol) was added subsequently. The reaction mixture was stirred at 100 o C for 19h. The solvents were evaporated under reduced pressure. The residue was suspended in 50 ml of methanol, filtered off and washed 2 times with methanol; it afforded a red to brown powder. Yield = 0.585g (52.2%) Experimental part Bis[5-(4-Carboxyphenyl)-4,6-dipyrrinato] Pd(II) (Pd(HL1)2)

Bis Pd(II)

The product was synthesized according to the already reported procedure. 112

Experimental part

Tris

The product was synthesized as a racemate similar to the reported procedure for Tris [5-(4-Carboxyphenyl)-4,6-dipyrrinato] Co(III) (rac-Co(HL1)3). 116 5-(4-(4-Carboxymethylphenyl)phenyl)-4,6-dipyrrin (0.431g, 1.2 mmol) was dissolved in 35 ml of methanol, then 5 ml of triethylamine were added. Sodium hexanitrocobaltate(III) (0.164g,

Experimental part

Ni-BisdpmCOOH (Ni(H2L3))

Bis

phenyl)-4,6-dipyrrinato] Ni(II)

The product was synthesized according to the already reported procedure. 121

Experimental part

II.3. Synthesis of terpyridine connectors 4'-(4-Carboxyphenyl)-2,2':6',2''-terpyridine

The product was synthesized according to the already reported procedure. 224 Experimental part Bis[4'-(4-Carboxyphenyl)-2,2':6',2''-terpyridine] Fe(II) hexafluorophosphate ([Fe(HL5)2][PF6]2)

4'-(4-Carboxyphenyl)-2,2':6',2''-terpyridine (0.3g, 0.8 mmol) was dissolved in 150 ml of methanol. Iron(II) chloride tetrahydrate (0.083g, 0.4 mmol) was added subsequently. The reaction mixture was refluxed for 24h and then allowed to cool to RT. The solvents were removed under reduced pressure. 30 ml of a KPF6 aqueous solution (0.5g, 2.7 mmol of KPF6) were added to the residue and the mixture was suspended in the ultrasonic bath and then filtered off; it afforded a dark purple solid. Yield = 0.41g (94.6%).

Experimental part [5,15-bis(4-carboxymethylphenyl)-10,20-diphenylporphyrinato] Ni(II)

The product was synthesized based on the already reported procedure with modifications. 159 5,15-bis(4-carboxymethylphenyl)-10,20-diphenylporphyrin (0.260g, 0.4 mmol) and nickel(II) acetate tetrahydate (0.450g, 1.8 mmol) were dissolved in 30 ml of DMF. The reaction mixture was heated at 105 o C for 24h. The solvent was evaporated under reduced pressure. The residue was suspended in 50 ml of methanol and the suspension was filtered off; it afforded a dark purple powder. Yield = 0.191g (68.1%) Experimental part 5,[START_REF] Gu | Structural Regulation and Light Hydrocarbon Adsorption/Separation of Three Zirconium-Organic Frameworks Based on Different V-Shaped Ligands[END_REF]

corrole

The product was synthesized based on the already reported procedure with modifications. 6 5,10,15-Tris(4-carboxymethylphenyl)corrole (0.2g, 0.3 mmol) was dissolved in 20 ml of THF. Subsequently, 20 ml of 4% KOH aqueous solution were added. The reaction mixture was refluxed overnight, allowed to cool to RT and acidified with 12% HCl to pH = 5-6. The reaction mixture was filtered off; it afforded a dark purple solid. Yield = 0.126g (67%). Experimental part II.6. Synthesis of organic connectors 4,4',4''-(1,3,5-triazine-2,4,6-triyl)tribenzoic acid (H3L8) 2,4,6-tri-p-tolyl-1,3,5-triazine The product was synthesized according to the already reported procedure. 189 Experimental part 4,4',4''-((2,4,6-trifluorobenzene-1,3,5-triyl)tris(ethyne-2,1-diyl))tribenzoic acid (H3L11) Trimethyl 4,4',4,3,

tris(ethyne-2,1-diyl))tribenzoate

The product was synthesized based on the already reported procedure with modifications. [START_REF] Bonakdarzadeh | X-Ray Structural and Ion-Mobility Mass Spectrometric Studies on Electron-Deficient and Electron-Rich M6L4 Coordination Cages[END_REF] 1,3,5-trifluoro-2,4,6-triiodobenzene (0.1g, 0.2 mmol), copper(I) iodide (0,0029g, 0.015 mmol) and Pd(PPh3)4 (0.0173g, 0.015 mmol) were dissolved in 30 ml of dry and degassed DIPEA.

The mixture was stirred 30 minutes at RT under Ar-atmosphere. Methyl 4-ethynylbenzoate (0.1572g, 1 mmol) was added subsequently. The reaction mixture was heated 70 o C for 48h and then allowed to cool to RT. The reaction mixture was portioned between CH2Cl2/H2O (100/100).

The water layer was extracted three times with 50 ml of CH2Cl2. The organic phases were collected, dried over MgSO4 and solvents were removed under reduced pressure; it afforded an orange solid. Yield = 0.105g (88.2%).

Chapter II. Synthesis of the connectors §II. Dipyrrin-based metal-organic

connectors family

The hydrolysis of the two ester groups in Ni(Me2L3) leads to the connector Ni(H2L3). The formation of Ni(H2L3) was proven by Mass-spectrometry with a peak at 583. 23 [M] + that is in accordance with the expected mass. 121 Due to the poor solubility of Ni(H2L3) it is difficult to analyse the stability of this connector.

However, the circumstantial evidence of the Ni(H2L3) stability is the stability of the complex Ni(Me2L3) in the solid state. It was noticed that there are no changes in the 1 H-NMR spectrum of Ni(Me2L3) after 1 week if the sample was stored as a powder.

Chapter II. Synthesis of the connectors §VI. Corrole-based metal-organic connector

Figure 69

The synthetic pathway for the connector Co(H3L7)

The corrole macrocycle formation looks similar to the formation of porphyrins, however, in order to favour the formation of corrole it is important to add DDQ before bilane is converted to porphyrinogen (Figure 70). In addition, a quenching with hydrazine hydrate demonstrated increasing of the reaction yield. 181

Figure 70 Differences in the synthesis of porphyrin and corrole macrocycles

The first step is the well-known reaction of 5-(4-Carboxymethylphenyl)dipyrromethene and 4-(carboxymethyl)benzaldehyde coupling that was reported by Gryko et al. 180 However, it was possible to significantly improve the reported procedure, and to skip the step of purification §I. Synthesis of crystalline molecular cages

I. Synthesis of crystalline molecular cages

All of the connectors described in the Chapter II were subsequently used for the synthesis of octahedral calixarene-based MOCs. In order to do that, a one-pot three-component approach was performed: metal-organic or organic connectors (linear or triangular) were mixed with p-tertbutylsulfonylcalix [4]arene (H4SO2TCA) and metal salts, and the conditions suitable for the selfassembling process (solvents, temperature, base, stoichiometry, time) were provided. Depending on the type of connector used for the synthesis of MOCs, we expected the formation of two different types of MOCs (Figure 79):

• face-panelled MOCs with the formula [M4SO2TCA(μ4-OH2)]6(TC)8•nS (Squantity of solvents) if triangular connectors (TC) are used.

• edge-panelled MOCs with the formula [M4SO2TCA(μ4-OH2)]6(LC)12•nS (Squantity of solvents) if linear connectors (LC) are used.

Figure 79

The schematic representation of the self-assembly reaction for the formation of

MOCs

The obtained MOCs need to be characterised from the structural point of view. It is possible to investigate MOCs structure in solid state by different techniques:

• Single-crystal X-ray diffraction analysis (XRD)

• X-ray diffraction analysis of powdered samples (XRPD)

• Extended X-ray absorption Fine Structure (EXAFS) of amorphous compounds Chapter III. Formation and structural investigations of MOCs §I. Synthesis of crystalline molecular cages excess of metal salts may lead to the crystallization of used salts instead of desired MOCs under the selected reaction conditions.

For both techniques (solvothermal and liquid-liquid diffusion) the stoichiometry used in the self-assembly process was selected based on the stoichiometry of the expected MOCs and was in accordance with stoichiometries already reported in the literature for the formation of calixarenebased MOCs. 4,[START_REF] Liu | Calixarene-Based Nanoscale Coordination Cages[END_REF] • While using linear bidentate connectors (LC) for the formation of MOCs, the chosen stoichiometry is 12/6/24 for connector/sulfonylcalix [4]arene/metal salt, respectively.

This stoichiometry favours the formation of edge-panelled MOCs.

• While using triangular tridentate connectors (TC) for the formation of MOCs, the chosen stoichiometry is 8/6/24 for connector/sulfonylcalix [4]arene/metal salt, respectively. This stoichiometry favours the formation of face-panelled MOCs.

Additionally, when using the liquid-liquid diffusion technique, a total of 60 equivalents of triethylamine were added in MeOH. This amount is compatible with the requirement to deprotonate all carboxyl groups of the connectors (two groups for each linear bidentate connector and three groups for each triangular tridentate connector) and all hydroxy groups of sulfonylcalix [4]arenes (four groups for each calixarene).

The results of the reactions conducted using both solvothermal and liquid-liquid diffusion techniques are summarized in the following Table 5 (see details in the experimental part). Metal-organic The precipitation of crystals suitable for XRD analysis that were analysed and the structure of the desired MOCs was proven The formation of amorphous precipitate The formation of crystalline structures unsuitable for XRD analysis (bad shape, twins, small size) The formation of crystals suitable for XRD that were not analysed The formation of crystals suitable for XRD analysis that were analysed and demonstrated other structures

Chapter III. Formation and structural investigations of MOCs §I. Synthesis of crystalline molecular cages

During this work, a total of 180 reactions were performed to synthesize the desired calixarene-based MOCs in a crystalline form. In every case, the precipitation of crystals or powders was observed. Based on the data represented in Table 5, several conclusions can be drawn.

I.2. Synthesis of crystalline cages using metal-organic connectors

None of the chosen large metal-organic connectors (rac-Co(HL2)3, crystalline structure not suitable for single-crystals XRD (Table 5). Besides that, crystalline structures of non-desired calixarene complexes were frequently formed instead of the desired three-components MOCs. The structure of these single-crystals was investigated by XRD which revealed the formation of five different complexes between sulfonylcalix [4]arene and metal ions used in the synthesis (see details in crystallographic annexes §I.2.): However, a side product different from solvothermal technique was observed. This is a complex of formula [CoSO2TCA]•3DMF (Figure 82), with a 1/1 ratio Co(II)/Calixarene consisting of one sulfonylcalix [4]arene in cone conformation and a Co II ion is in O6 octahedral coordination geometry where three oxygen atoms from coordinated molecules of DMF, two oxygen atoms from two alcoholate groups of calixarene and one oxygen atom from sulfonyl group of calixarene (see crystallographic annexes §I.2.). This complex has an interesting structure due to three coordinated DMF molecules. To the best of our knowledge such type of metallocalixarene has never been reported earlier.

Furthermore, it was observed that in a few cases liquid-liquid approach favours the crystal formation of the connector Pd(HL1)2 (see crystallographic annexes §I.2.). To the best of our knowledge the structure of Pd(HL1)2 was not reported in the literature. 6). For example, the cage [Co4SO2TCA(μ4-OH2)]6[rac-Co(L1)3]8 demonstrated parameters: a = 37.1152(8)Å; b = 37.1152(8)Å, c = 191.198(3)Å with a unit cell volume of about 228095Å 3 .

The unit cell parameters of the MOCs based on the connectors rac-M(HL1)3 (M = Co III , Fe III , Rh III ) are summarised in the following Table 6.

It is worth noting that the solvent molecules presented in the structure could not be modelled and were accounted for using a Solvent Mask generated by the BYPASS module within Olex2 which defined 21797.0 electrons per unit cell accounted for solvent molecules for

Table 6

The unit cell parameters of the six obtained MOCs based on rac-M(HL1)3 connectors (MOCs with only unit cell parameters measurements are highlighted yellow)

As expected, the cages are formed by eight rac-Co(L1)3 3-connectors located on the eight faces of the formed octahedron and six [M4SO2TCA(-OH2)] 4+ shuttlecock-like nodes located in the vertices of the octahedron. The observed ratio shuttlecock node/connector is thus = 6/8 is in a perfect accordance with the expected value for the face-panelled MOCs (Figure 83).

The linear size of the MOCs and the size of their internal cavity

The size of MOCs of formula

Co II , Ni II ; M' = Co III , Fe III , Rh III ) appear to be independent on the nature of metal ions (both in the shuttlecock node and in the connector). This is in accordance with the certain degree of "flexibility" (adaptation of the distances) of the observed components in such assemblies. Furthermore, IR-spectroscopy methods were applied as an auxiliary method providing additional information concerning the structure of MOCs.

• NMR-spectra of the obtained MOCs are not informative due to limited solubility and to presence of paramagnetic ions (Co II , Ni II ) in the structure.

IV.1. CD and chiral HPLC of enantiomerically pure cages

In order to prove the chirality and clearly estimate the ee of the obtained chiral cages In addition to ESI-MS, IM-MS measurements were performed. This technique refers to the separation and identification of molecules according to their mobility in a buffer gas. 204 The most important values that can be extracted from these experiments are the arrival time and collision cross section ( DT CCSN2). Both values depend on the shape and the molecular mass of the particles while they move inside the drifting tube and collide with the molecules of the buffer gas (usually N2). The demonstrated unit cell volumes (close to 58000 Å 3 ) are almost the same as the ones of structurally similar CIAC-106 and (sc4a)Fe(tatb) calixarene-based MOCs.

Table 15

The

metrics of the metal ions environment, geometrical characteristics and porosity of MOCs of formula [M4SO2TCA(μ4-OH2)]6[L8]8 (M = Co II , Ni II ),

It is important to mention, that despite the fact that the connector H3L8 is significantly smaller than the connector rac-Co(HL1)3 (12Å against 16Å), the formed triazine-based MOCs present a similar cavity size probably due to the totally planar nature of H3L8 in comparison with rac-M(HL1)3 (M = Co III , Fe III , Rh III ). The cavity demonstrates as well non-polar hydrophobic nature due to the absence of polar groups (such as hydroxy-groups) orientated inside the cavity. The portals of triazine-based MOCs allowing molecular species to get inside and outside the cavity, have a diameter of 8Å (Figure 93) which is larger than the portals of the dipyrrin-based MOCs with the material may be weaker than one of N2(g). This means that N2(g) may be more strongly adsorbed onto the material's surface. However, zero-coverage heats of adsorption were not obtained due to the lack of material for experiments under different temperature conditions.

The similar behaviour was observed for the reported triazine-based MOC of formula (sc4a)Fe(tatb). 187 However, despite the similar structure of these MOCs, generally surface areas of (sc4a

III. Adsorption properties of dipyrrin-based MOCs

In this part, we will mainly focus on the investigation of gas adsorption properties of two

III.1.1 Behaviour of the samples soaked in different solvents, XRPD measurements

As already mentioned, XRPD patterns for crystalline phases of large molecules (especially MOCs) frequently present broad peaks due to the huge amount of solvents present in the unit cell.

When crystals are exposed to the air, they begin to desolvate. This leads usually to an amorphization of the crystalline phase. 4,187 This amorphization affects the organization of the cages within the unit cell, and thus, the XRPD pattern. The spectra of the samples (freshly obtained and activated) were found to be relatively similar (Figure 102 Small differences between adsorption-desorption isotherms of pristine samples and samples after one cycle of N2(g) adsorption-desorption can be explained by changing of the cage packing in the crystals during the first N2(g) adsorption-desorption cycle.

III.2.2. Analysis and comparison of the data

The obtained isotherms were used to estimate the specific surface area using different models (Langmuir and BET), the volume of pores and the volume of the adsorbed N2(g). These characteristic parameters along with the comparison with the triazine-based MOC

Structure-adsorption properties relationships for activated [M4SO2TCA(-OH2)]6[rac-Co(L1)3]8 (M = Co II , Ni II ), [Co4SO2TCA(-OH2)]6[L8]8 and MOCs reported in the literature

According to

Chapter IV. Gas adsorption properties of synthetized calixarene-based MOCs §III. Adsorption properties of dipyrrin-based MOCs

This behaviour can be used in order to estimate the selectivity coefficients towards different gas mixtures, from a modelling point of view.

III.4. Estimation of gas adsorption selectivity

The differences in the amounts of adsorbed gases allow in principle to estimate the gas adsorption selectivity towards different gas mixtures. In order to do that we applied several computational methods that will be discussed in detail in this section and also in annexes §II.

III.4.1. Calculations and modelling

Three different methods were applied in order to estimate the selectivity of gas adsorption mixtures based on the individual gas adsorption-desorption isotherms:

• Calculation of the ratio V1/V2, where V1 is the volume of gas 1 adsorbed at 800 torr by the MOC; V2 is the volume of gas 2 adsorbed at 800 torr by the MOC

• Calculation of the ratio KH1/KH2, where KH1 is the Henry constant for gas 1, obtained from the virial coefficients of virial equation that fits adsorptiondesorption isotherm; KH2 is the Henry constant for gas 2, obtained from the virial coefficients of virial equation that fits adsorption-desorption isotherm. In gas adsorption, Henry's constant is used to describe the equilibrium of gas uptake by a solid material at low pressures, where the amount of gas adsorbed is directly proportional to the partial pressure of the gas in contact with the solid (see calculations using virial equations in annexes §II.2.)

• Modelling with the Ideal Adsorbed Solution Theory (IAST). 213 IAST assumes that the adsorption of each gas component in a mixture is independent of the other components, and that the adsorbed gases do not interact with each other. These assumptions allow IAST to "predict" the adsorption behaviour of a mixture of gases based solely on the adsorption isotherms of the individual components, without requiring any additional experimental data on the mixture itself. In this work, we applied IAST method for calculation of selective gas adsorption for equimolar 1/1 gases mixtures (see detailed calculations in annexes §II.5).

The results concerning selective gas adsorption are presented in Table 24 . According to the aforesaid there are many properties and applications of the obtained MOCs that can be further studied. As a result, this work demonstrates a great potential for further investigations that can significantly develop the field of octahedral calixarene-based MOCs, which is rather underexplored, and, in general, field of supramolecular chemistry.

General conclusion §II. Perspectives for this work

To the best of our knowledge, there is only one octahedral calixarene MOC based on metalorganic connector, except 10 new MOCs reported in this work. As a result, this work significantly contributes to the family of MOCs based on metal-organic connectors. Hopefully, this work will inspire other projects to contribute in this field and investigate the unique properties of calixarenebased MOCs that present in their structure metal-organic connectors. Co(H3L7) [5,10,15-Tris(4-carboxyphenyl)

Experimental part

Table 26

List of connectors

Experimental part

of doublets, mmultiplet;

• J-constants in Hz;

• Number of respective atoms;

• Nature of respective atoms.

IR spectra of the connectors were obtained on a Perkin Elmer FTIR 1600 spectrometer using ATR mode in a range of 4000-400 cm -1 . Spectral data are present as following: s -strong signal, m -medium signal, w -weak signal, bbroad signal, mbmedium broad signal, wbweak broad signal.

IR spectra of milled crystalline samples in KBr of activated and non-activated MOCs were recorded on a Tensor 27 Fourier-transform spectrometer (Bruker) in a range of 4000-400 cm -1 . The product was synthesized according to the already published procedure. 221 The 1 H-NMR spectrum was in accordance with the already reported one. The product was synthesized according to the already published procedure. 222 The 1 H-NMR spectrum was in accordance with the already reported one.

Mass spectra (ESI-MS

II. Synthesis of connectors

II.1. Synthesis of dipyrrin connectors

5-(4-Carboxymethylphenyl)dipyrromethane

The product was synthesized based on the already reported procedure with modifications. 123 4-carboxymethylbenzaldehyde (5g, 0.03 mol) was dissolved in 70 ml of degassed pyrrole

(1 mol) that was preliminary filtered through alumina to remove impurities. TFA (1 ml, 0.013 mol)

was added subsequently and reaction mixture was stirred at RT for 24h under light protection and Ar-atmosphere. 5 ml of triethylamine was added to quench the reaction and unreacted pyrrole was removed under reduced pressure. The residue was suspended in 50 ml of cold diethyl ether.

Suspension was filtered off and washed two times by cold diethyl ether; it afforded a white powder.

Yield = 6.8g (79.6%).

The 1 H-NMR spectrum was in accordance with the already reported one. 116

1 H-NMR (CDCl3, 300 MHz, 25 °C) δ ppm: 7.98 (d, J = 8.4 Hz, 2H, H 5 ), 7.30 (d, J = 8.4 Hz, 2H, H 4 ), 6.72 (m, 2H, H 1 ), 6.16 (m, 2H, H 3 ), 5.89 (m, 2H, H 2 ), 5.54 (s, 1H, CH), 3.91 (s, 3H, CH3) Experimental part

5-(4-Carboxymethylphenyl)-4,6-dipyrrin

The product was synthesized according to the already published procedure. Tris [5-(4-Carboxymethylphenyl)-4,6-dipyrrinato] Co(III)

The product was synthesized as a racemate based on the already reported procedure with modifications. 116 5-( 4 1 H-NMR (CDCl3, 300 MHz, 25 °C) δ ppm: 8.09 (d, J = 8.5 Hz, 6H, H 5 ), 7.52 (d, J = 8.5 Hz, 6H, H 4 ), 6.64 (dd, J = 4.3, 1.4 Hz, 6H, H 3 ), 6.40 (m, 6H, H 1 ), 6.33 (dd, J = 4.4, 1.7 Hz, 6H, H 2 ), 3.97 The product was synthesized as a racemate according to the reported procedure. 13 C-NMR (DMSO-d6, 126 MHz, 25 °C) δ ppm: 167.45, 151.95, 145.46, 141.77, 135.17, 133.31, 131.59, 130.72, 129.12, 120.13 are not observed due to a presence of paramagnetic Fe III ion in the obtained complex.

ESI-MS

13 C-NMR (DMSO-d6, 126 MHz, 25 °C) δ ppm: 168.57, 167.26, 144.86, 131.05, 129.82, 129.58, 119.22. Other peaks are not observed due to a presence of paramagnetic Fe III ion in the obtained complex. Elemental Analysis: % calculated: C, 67

ESI-MS

Experimental part Tris[5-(4-Carboxyphenyl)-4,6-dipyrrinato] Rh(III) (rac-Rh(HL1)3)

The product was synthesized as a racemate according to the already reported procedure.

Experimental part

Bis[5-(4-Carboxyphenyl)-4,6-dipyrrinato] Pd(II) (Pd(HL1)2)

The product was synthesized according to the already reported procedure. 112

1 H-NMR (DMSO-d6, 500 MHz, 25 °C) δ ppm: 8.17 (bs, 4H, H 5 ), 7.77 (bs, 4H, H 4 ), 7.45 (bs, 4H, H 1 ), 6.70 (bs, 4H, H 3 ), 6.56 (bs, 4H, H 2 )

13 C-NMR (DMSO-d6, 126 MHz, 25 °C) δ ppm: 167.43, 152.46, 146.61, 141.32, 136.37, 131.73, 131.45, 130.85, 129.17

Methyl 4'-formyl-[1,1'-biphenyl]-4-carboxylate

The product was synthesized according to the already reported procedure. 167.02, 145.15, 142.22, 138.67, 132.19, 130.15, 128.99, 128.89, 127.53, 126.93, 117.40, 108.56, 107.36, 52.18, 43.72 Experimental part 5-(4-(4-Carboxymethylphenyl) 166.94, 144.78, 143.80, 141.41, 140.71, 140.56, 137.18, 131.49, 130.26, 129.31, 128.85, 127.10, 126.50, 117.76, 52.23 Experimental part

Tris[5-(4-(4-Carboxyphenyl)phenyl)-4,6-dipyrrinato] Co(III) (rac-Co(HL2)3)

The product was synthesized as a racemate. 12H, H 6 , H 5 ), 7.56 (d, J = 7.9 Hz, 6H, H 4 ), 6.73 (dd, J = 4.4, 1.5 Hz, 6H, H 3 ), 6.45 (m, 6H, H 1 ), 6.37 (dd, J = 4.3, 1.6 Hz, 6H, H 2 ).

13 C-NMR (DMSO-d6, 126 MHz, 25 °C) δ ppm: 167.60, 151.76, 146.08, 143.51, 139.83, 137.54, 135.51, 133.33, 131.33, 130.55, 127.42, 126.67, 119.91

Experimental part

Ni-BisdpmCOOMe

The product was synthesized according to the already reported procedure. 121

1 H-NMR (CDCl3, 300 MHz, 25 °C) δ ppm: 8.14 (d, J = 8.6 Hz, 4H, H 5 ), 7.64 (d, J = 8.6 Hz, 4H, H 4 ), 6.73 (dd, J = 4.4, 1.4 Hz, 2H, H 2 ), 6.68 (d, J = 4.3 Hz, 2H, H 7 ), 6.63 (d, J = 4.4 Hz, 2H, H 6 ), 6.44 (dd, J = 4.4, 1.5 Hz, 2H, H 3 ), 5.95 (m, 2H, H 1 ), 3.98 (s, 6H, CH3) Experimental part

Ni-BisdpmCOOH (Ni(H2L3))

The product was synthesized according to the reported procedure.

Experimental part

II.2. Synthesis of phenanthroline connector Tris[2-(4-Carboxyphenyl)imidazo[4,5-f][1,10]phenanthroline] Fe(II) hexafluorophosphate ([rac-Fe(HL4)3][PF6]2) 1,10-phenanthroline-5,6-dione

The product was synthesized according to the already reported procedure. 223 The 1 H-NMR spectrum was in accordance with the already reported one.

2-(4-Carboxymethylphenyl)imidazo[4,5-f][1,10]phenanthroline

The product was synthesized based on the already reported procedure with modifications. 5 1,10-phenanthroline-5,6-dione (0.4g, 1.8 mmol) 4-carboxymethylbenzaldehyde (0.4686g, 2.7 mmol) and ammonium acetate (2.9334g, 36 mmol) were dissolved in 10 ml of glacial acetic acid. The reaction mixture was refluxed for 3h and then cooled to RT. Subsequently, the mixture was acidified with a 28% ammonia solution to pH=7 and filtered off; it afforded an orange solid.

The compound was purified by recrystallization from methanol; it afforded a bright-yellow powder. Yield = 0.53g (78.6%)

The 1 H-NMR spectrum was in accordance with the already reported one. 51 H-NMR (DMSO-d6, 500 MHz, 25 °C) δ ppm: 9.03 (m, 2H, H 3 ), 8.91 (m, 2H, H 1 ), 8.39 (d, J = 8.0 Hz, 2H, H 5 ), 8.14 (d, J = 8.0 Hz, 2H, H 4 ), 7.83 (dd, J = 8.0, 4.3 Hz, 2H, H 2 ), 3.89 (s, 3H, CH3)

Experimental part

Tris [2-(4-Carboxymethylphenyl)imidazo [4,5-f][1,10]

phenanthroline] Fe(II) hexafluorophosphate

The product was synthetized as a racemate.

2-(4-Carboxymethylphenyl)imidazo [4,5-f][1,10]phenanthroline (0.36g, 1 mmol) was dissolved in 40 ml of ethanol. (NH4)2Fe(SO4)2•6H2O (0.1383g, 0.35 mmol) was dissolved in 10 ml of water. The solution was added to the phenanthroline solution and was heated at 60 o C for 24h. The reaction mixture was cooled to RT and the solvents were evaporated under reduced pressure. Subsequently, 30 ml of a KPF6 aqueous solution (0.5g, 2.7 mmol of KPF6) were added to the residue, the mixture was suspended in ultrasonic bath, filtered off and washed two times with cold water that afforded a dark red powder. Yield = 0.33g (88.7%).

1 H-NMR (DMSO-d6, 500 MHz, 25 °C) δ ppm: 9.13 (bs, 6H, H 3 ), 8.48 (bs, 6H, H 1 ), 8.26 (bs, 6H, H 5 ), 7.82-7.73 (m, 12H, H 2 , H 4 ), 3.94 (bs, 9H, CH3)

Experimental part Tris[2-(4-Carboxyphenyl)imidazo[4,5-f][1,10]phenanthroline] Fe(II) hexafluorophosphate ([rac-Fe(HL4)3][PF6]2)

The product was synthetized as a racemate.

Tris [2-(4-Carboxymethylphenyl)imidazo [4,5-f][1,10] The product was synthesized based on the already reported procedure with modifications. The 1 H-NMR spectrum was in accordance with the already reported one.

5,15-bis(4-carboxymethylphenyl)-10,20-diphenylporphyrin

The product was synthesized according to the already reported procedure. 172

1 H-NMR (CDCl3, 300 MHz, 25 °C) δ ppm: 8.87 (d, J = 4.9 Hz, 4H, pyr-H 1 ), 8.79 (d, J = 4.9 Hz, 4H, pyr-H 2 ), 8.44 (d, J = 8.5 Hz, 4H, H 1 ), 8.31 (d, J = 8.5 Hz, 4H, H 2 ), 8.21 (m, 4H, H 4 ), 7.77 (m, 6H, H 3 , H 5 ), 4.11 (s, 6H, CH3), -2.79 (bs, 2H, NH)

Experimental part [5,15-

bis(4-carboxyphenyl)-10,20-diphenylporphyrinato] Ni(II) (Ni(H2L6

)) [5,15-bis(4-carboxymethylphenyl)-10,20-diphenylporphyrinato] Ni(II) (0.191g, 0.24 mmol) was dissolved in 20 ml of THF. Subsequently, 20 ml of 4%KOH aqueous solution were added.

The reaction mixture was refluxed for 5h and allowed to cool to RT. The reaction mixture was acidified with a 12% HCl solution until pH = 5-6, then filtered off and washed two times with water to afford a dark red powder. Yield = 0.173g (93.9%)

1 H-NMR (DMSO-d6, 500 MHz, 25 °C) δ ppm: 8.74 (bs, 8H, pyr-H 1 , pyr-H 2 ), 8.31 (d, J = 8.4 Hz, 4H, H 1 ), 8.14 (d, J = 8.4 Hz, 4H, H 2 ), 8.01 (m, 4H, H 4 ), 7.77 (m, 6H, H 3 , H 5 )

13 C-NMR (DMSO-d6, 126 MHz, 25 °C) δ ppm: 167.83, 144.82, 142.82, 142.28, 140.31, 134.14, 133.90, 133.35, 132.99, 130.98, 128.68, 128.55, 127.69, 119.75

ESI-MS

5,10,15-Tris(4-carboxymethylphenyl)corrole

The product was synthesized based on the already reported procedure with modifications. 180 5-(4-Carboxymethylphenyl)dipyrromethane (0.5g, 1.8 mmol) and 4carboxymethylbenzaldehyde (0.1464g, 0.9 mmol) were dissolved in 100 ml of degassed methanol.

Subsequently, 100 ml of 3.5% HCl aqueous solution were added dropwise under vigorous stirring for 30 minutes. The reaction mixture was stirred for 2.5h at RT under light protection. The mixture was then added to a mixture of 100 ml of CHCl3 and 100 ml of saturated NaHCO3 solution. The chloroform phase was separated, dried over MgSO4 and filtered off. The volume of the mixture was increased to 200 ml of CHCl3 and degassed. DDQ (0.4057g, 1.8 mmol) was added. The reaction mixture was stirred overnight at RT. Hydrazine (0.2 ml, 4.5 mmol) was added and the mixture was stirred additionally 10 minutes. The reaction mixture was filtered off and the filtrate was evaporated to afford the crude product. The final product was obtained by recrystallization process from DCM/methanol as a dark purple solid. Yield = 0.405g (64.8%)

1 H-NMR (CDCl3, 300 MHz, 25 °C) δ ppm: 8.90 (d, J = 4.3 Hz, 2H, Pyr-H 3 ), 8.79 (d, J = 4.8 Hz, 2H, Pyr-H 1 ), 8.51 (d, J = 4.3 Hz, 2H, Pyr-H 4 ), 8.47 (d, J = 4.8 Hz, 2H, Pyr-H 2 ), 8.44-8.32 (m, 10H, H 1,2,4 ), 8.18 (d, J = 8.0 Hz, 2H, H 3 ), 4.02 (s, 9H, CH3)

Experimental part [5,10,15-Tris(4-carboxyphenyl)

corrolato] Co(III) (Co(H3L7))

The product was synthesized based on the already reported procedure with modifications. 178 5,10,15-Tris(4-carboxyphenyl)corrole (0.126g, 0.19 mmol) and cobalt(II) acetate tetrahydrate (0.05g, 0.20 mmol) were dissolved in 50 ml of DMSO and the mixture was heated and stirred at 50°C for 5h and then cooled to RT. The crude mixture was then poured into a cold NaCl aqueous solution (around 0.8 M), the resulting suspension was filtered, and the solid was washed three times with water that afforded a black solid. Yield = 0.124g (91.1%)

1 H-NMR (DMSO-d6, 500 MHz, 25 °C, NH3 gas) δ ppm: 8.80 (d, J = 3.8 Hz, 2H, Pyr-H 3 ), 8.57 (d, J = 4.4 Hz, 2H, Pyr-H 4 ), 8.37 (d, J = 4.4 Hz, 2H, Pyr-H 1 ), 8.33 (d, J = 4.4 Hz, 2H, Pyr-H 2 ), 7.99-7.89 (m, 10H, H The product was synthesized according to the already reported procedure.

Elemental Analysis: % calculated: C, 35 The product was synthesized according to the already reported procedure. 13 H-NMR (DMSO-d6, 126 MHz, 25 °C) δ ppm: 167.64, 146.11, 129.83, 129.52, 127.90, 127.45, 43.76 4,4',4''-((2,4,6-trifluorobenzene-1,3,5-triyl)tris(ethyne-2,1-diyl))tribenzoate (0.105g, 0.17 mmol) was dissolved in 10 ml of THF. Subsequently, 10 ml of 4% KOH aqueous solution were added. The reaction mixture was refluxed for 5h and then allowed to cool to RT.

The reaction mixture was acidified with 12% HCl to pH = 5-6, filtered off and washed two times with water; it afforded a yellowish solid. Yield = 0.090g (92.1%). Due to the low stability of H3L11 it was not possible to obtained Elemental Analysis data.

Experimental part

III. Synthesis of MOCs in the crystalline form

The synthesis of metal-organic cages (MOCs) was performed using all the previously discussed connectors and two main techniques: solvothermal and liquid-liquid diffusion.

• Solvothermal technique involves the reaction of a metal salt, a connector and sulfonylcalix [4]arene in a solvent under high temperature and pressure in a sealed vial. The crystals form during the temperature decrease.

• Liquid-liquid diffusion technique involves the mutual diffusion of the base solution and the solution of metal salt, connector and sulfonylcalix [4]arene at RT, which leads to the formation of MOCs in the crystalline form at the interface of the two solvents due to the self-assembly reaction on this interface.

Solvothermal technique

Sulfonylcalix [4]arene (6 eq.), a metal salt (24 eq.) and a connector (8 eq. for triangular tridentate connectors and 12 eq. for linear bidentate connectors) in 3 ml DMF are put inside a sealed glass vessel. The vessel is heated at 80 o C for one week that causes reaction and crystals formation during the temperature decrease.

Liquid-liquid diffusion technique

Figure 107 Liquid-liquid diffusion technique

In a diffusion tube of 10 cm length and with diameter of 1.5 cm, three layers of liquid are formed. The ;ower layer consists of sulfonylcalix [4]arene (6 eq.), a metal salt (24 eq.) and a connector (8 eq. for triangular tridentate connectors and 12 eq. for linear bidentate connectors) in 5 ml of DMF. The buffer solution consists of the mixture 1 ml MeOH + 1 ml DMF. And the upper layer consists of triethylamine (60 eq.) solution in 3 ml of MeOH. The solutions of the reagents diffuse slowly into each other which causes crystals formation at the interface (Figure 107). In a diffusion tube of 10 cm length and with diameter 1.5 cm, three layers of liquid are formed. The lower layer consists of sulfonylcalix [4]arene (0.02g, 23.55 μmol, 6 eq), cobalt(II) chloride hexahydrate (0.0224g, 94.23 μmol, 24 eq.) and rac-Fe(HL1)3 (0.0267g, 31.4 μmol, 8 eq.) in 5 ml of DMF. The buffer solution consists of 1 ml MeOH + 1 ml DMF mixture. The upper layer consists of a triethylamine (0.033 ml, 235.57 μmol, 60 eq.) solution in 3 ml of MeOH. Slow liquids diffusion for 2 weeks caused the formation of large red octahedral single-crystals suitable for XRD.

Formula: C624H504Fe8Co24N48O126S24

Elemental Analysis: % calculated: C, 56.26%; H, 3.81%; N, 5.05%

% found: C, 52.52%; H, 5.05%; N, 7.48%

The differences in the calculated and the found values are related with the hygroscopicity of the samples (see details in Chapter IV).

Experimental part

In a diffusion tube of 10 cm length and with diameter 1.5 cm, three layers of liquid are formed. The lower layer consists of sulfonylcalix [4]arene (0.02g, 23.55 μmol, 6 eq.), nickel(II) chloride hexahydrate (0.0224g, 94.23 μmol, 24 eq.) and rac-Fe(HL1)3 (0.0267g, 31.4 μmol, 8 eq.) in 5 ml of DMF. The buffer solution consists of 1 ml MeOH + 1 ml DMF mixture. The upper layer consists of a triethylamine (0.033 ml, 235.57 μmol, 60 eq.) solution in 3 ml of MeOH. Slow liquids diffusion for 2 weeks caused the formation of large red octahedral single-crystals suitable for XRD.

Formula: C624H504Fe8Ni24N48O126S24

Elemental Analysis: % calculated: C, 56.28%; H, 3.82%; N, 5.05%

% found: C, 49.72%; H, 5.32%; N, 8.15%

The differences in the calculated and the found values are related with the hygroscopicity of the samples (see details in Chapter IV).

Experimental part

In a diffusion tube of 10 cm length and with diameter 1.5 cm, three layers of liquid are formed. The lower layer consists of sulfonylcalix [4]arene (0.02g, 23.55 μmol, 6 eq.), cobalt(II) chloride hexahydrate (0.0224g, 94.23 μmol, 24 eq.) and rac-Rh(HL1)3 (0.028g, 31.4 μmol, 8 eq.) in 5 ml of DMF. The buffer solution consists of 1 ml MeOH + 1 ml DMF mixture. The upper layer consists of a triethylamine (0.033 ml, 235.57 μmol, 60 eq.) solution in 3 ml of MeOH. Slow liquids diffusion for 2 weeks caused the formation of large red octahedral single-crystals suitable for XRD.

Formula: C624H504Rh8Co24N48O126S24

Elemental Analysis: % calculated: C, 54.71%; H, 3.71%; N, 4.91%

% found: C, 49.56%; H, 5.50%; N, 4.64%

The differences in the calculated and the found values are related with the hygroscopicity of the samples (see details in Chapter IV).

Experimental part

In a diffusion tube of 10 cm length and with diameter 1.5 cm, three layers of liquid are formed. The lower layer consists of sulfonylcalix [4]arene (0.02g, 23.55 μmol, 6 eq.), nickel(II) chloride hexahydrate (0.0224g, 94.23 μmol, 24 eq.) and rac-Rh(HL1)3 (0.028g, 31.4 μmol, 8 eq.) in 5 ml of DMF. The buffer solution consists of 1 ml MeOH + 1 ml DMF mixture. The upper layer consists of a triethylamine (0.033 ml, 235.57 μmol, 60 eq.) solution in 3 ml of MeOH. Slow liquids diffusion for 2 weeks caused the formation of large red octahedral single-crystals suitable for XRD.

Formula: C624H504Rh8Ni24N48O126S24

Elemental Analysis: % calculated: C, 54.74%; H, 3.71%; N, 4.91%

% found: C, 48.98%; H, 5.69%; N, 7.64%

The differences in the calculated and the found values are related with the hygroscopicity of the samples (see details in Chapter IV).

Experimental part

In a diffusion tube of 10 cm length and with diameter 1.5 cm, three layers of liquid are formed. The lower layer consists of sulfonylcalix [4]arene (0.02g, 23.55 μmol, 6 eq.), cobalt(II) chloride hexahydrate (0.0224g, 94.23 μmol, 24 eq.) and H3L8 (0.0139g, 31.4 μmol, 8 eq.) in 5 ml of DMF. The buffer solution consists of 1 ml MeOH + 1 ml DMF mixture. The upper layer consists of a triethylamine (0.033 ml, 235.57 μmol, 60 eq.) solution in 3 ml of MeOH. Slow liquids diffusion for 2 weeks caused the formation of large pink square single-crystals suitable for XRD.

Formula: C432H360Co24N24O126S24

Elemental Analysis: % calculated: C, 51.44%; H, 3.60%; N, 3.33% % found: C, 49.34%; H, 4.15%; N, 3.60%

The differences in the calculated and the found values are related with the hygroscopicity of the samples (see details in Chapter IV).

Experimental part

Sulfonylcalix [4]arene (0.005g, 5.89 μmol, 6 eq.), nickel(II) chloride hexahydrate (0.

0056g, 23.56 μmol, 24 eq.) and H3L8 (0.0035g, 7.85 μmol, 8 eq.) in 3 ml DMF were put inside a sealed glass vessel. The vessel was heated at 80 o C for one week that caused reaction and pale green tetrahedral single-crystals formation suitable for XRD.

Formula: C432H360Ni24N24O126S24

Elemental Analysis: % calculated: C, 51.47%; H, 3.60%; N, 3.33%

% found: C, 48.01%; H, 4.32%; N, 5.13%

The differences in the calculated and the found values are related with the hygroscopicity of the samples (see details in Chapter IV). The data collection and reduction were performed using the program CrysAlisPro, with an empirical absorption correction method using spherical harmonics correction and a numerical absorption correction based on gaussian integration over a multifaceted crystal model. The structure was solved with intrinsic phasing (ShelXT) 1 and refined by full-matrix least squares on F 2 using the Olex2 software, 200 which uses the ShelXL-2015 module. 2 Anisotropic displacement parameters were assigned to non-H atoms. All hydrogen atoms were refined using riding models with Ueq(H) of 1.5Ueq(C) for sp 3 hybridized carbons and Ueq(H) of 1.2Ueq(C) for sp 2 hybridized carbons.

Annexes

As a result of supramolecular and highly porous nature, MOCs displayed rapid falloff of the reflection intensities, even with prolonged exposure times using Cu radiation, with no reflections whatsoever observed beyond 0.87Å resolution. This necessitated moderate modelling using a range of restraints and constraints to account for the geometric (DFIX, DANG, FLAT) and thermal parameters (DELU, SIMU, RIGU, EADP) within parts of the structure, especially when disorder was found to be present as with the racemic M(L1)3 nodes. The solvents present in MOCs could not be modelled and were accounted using a Solvent Mask generated by the BYPASS or PLATON SQUEEZE modules within Olex2 software. The structures of metallocalixarenes and metal-organic complexes were solved using the program SHELXT-2018. 4 The refinement and all further calculations were carried out using SHELXL-2018.

The H-atoms were included in calculated positions and treated as riding atoms using SHELXL default parameters.

The non-H atoms were refined anisotropically, using weighted full-matrix least-squares on F2.

A semi-empirical absorption correction was applied using SADABS in APEX3;

transmission factors: Tmin/Tmax = xxxx/yyyy. Here, pis the pressure expressed in Torr; nis the amount adsorbed in mmol/g; Ttemperature in K; A and B -virial coefficients; i and jnumber of coefficients required to adequately describe the isotherms.

Annexes

The virial coefficients in the virial equation for gas adsorption are mathematical parameters that describe the non-ideal behaviour of gases when they are adsorbed onto a solid surface. They are summarized in Table 28.

Gas

Virial

II.3. Calculations of heats of adsorption

Isosteric heats of adsorption were calculated using virial coefficients by Equation 3:

Here, Qstcoverage-dependent isosteric heat of adsorption; Runiversal gas constant; A -virial coefficient; inumber of coefficients required to adequately describe the isotherms.