Mehmet Menaf

THE TITLE of THESIS: New Challenge in Octupolar Architecturs for Non Linear Optic (NLO)

The design of nonlinear optical (NLO) molecules has become a focus of current research in telecommunications, information technologies and optical data storage. Donor-acceptor substituted dipolar molecules have been the most investigated NLO chromophores. Dipolar molecules, however, have several limitations such as low optical transparency, low thermal stability and their strong tendency to adopt anti-parallel packing in the solid state.

Recently, a new class of materials based on octupolar symmetries, which lack permanent dipole moments, has been proposed for NLO applications. At a structural level, it can be shown that the basic template for 3D octupolar molecules comes to a cube with alternating charges at the corners such as donor and acceptor substituent. Despite all the various structures reported, it is worth noting that no molecules actually representing the "real" octupolar cube have been obtained so far.

In this thesis, we showed that the real octupolar cube can be demonstrated by lanthanide III complexes based on ABAB type phthalocyanine featuring alternating electron donor and electron acceptor groups. These structures are characterized by UV-NIR, X-Ray and exhibit highest quadratic hyperpolarizability ever reported for an octupolar molecule.

Moreover, this work was extended to nonoctupolar lanthanide homoleptic double-decker complexes based on AB 3 , A 4 , B 4 , T 4 type phthalocyanines. It was observed that these molecules present a quite large quadratic hyperpolarizability too, but smaller than the one obtained for the Ln(ABAB) 2 series, as expected. SOMMAIRE LE TITRE DE LA THÈSE: Nouveau challenge dans la conception d'architecture moléculaire pour l'optique nonlinéaire (ONL).

AUTEUR: Mehmet Menaf AYHAN

La conception de molécules pour l'optique non linéaires (ONL) est devenue un centre de recherche de pointe pour les télécommunications, les technologies de l'information et le stockage de données optiques. Les molécules dipolaires substituées par des groupes donneur-accepteur ont été les chromophores les plus

ACKNOWLEDGMENTS

On the occasion of the completion of the thesis, it is my pleasant duty to express my gratitude for all those whose support and encouragement made my task much easier.

I have no words to thank, admire and appreciate the people behind this thesis Prof. Dr. Ayşe Gül GÜREK and Dr. Chantal ANDRAUD, my research supervisors, whose invaluable suggestions and incessant encouragement helped me to understand subject better.

I take immense pleasure to offer my special thanks to Prof. Dr. Vefa AHSEN,Ass. Prof. Dr. Catherine HIREL and Dr. Yann BRETONNIERE for their helps and encouragements.

I would like to thank the other members of my committee, Prof. Dr. Ulvi AVCIATA and Prof. Dr. Ahmet GÜL.

I wish to thank Prof. Dr. Joseph ZYSS, Prof. Dr.Isabelle Ledoux-Rak, and Anu SINGH from ENS-Cachan, for all NLO measurements. I wish to thank the members of Chemistry department at GIT and ENS-Lyon for their supports and friendly environments.

I wish to express my thanks to my colleagues for their most friendly cooperation and support in the needy hours. 3.2. Analyzes of nonoctupolar bis(phthalocyaninato) Ln(III) double-decker complexes Ln(AB3) 2 (12)(13)(14)[START_REF] Yariv | Quantum Electronics[END_REF], Ln(A4) 2 [START_REF] Yariv | Quantum Electronics[END_REF][START_REF] Kajzar | [END_REF](18), Ln(B4) 2 (19)(20)[START_REF] Ashwell | Optical Materials for Non-linear Optics[END_REF][START_REF] Nalwa | Nonlinear Optics of Organic Molecules and[END_REF][START_REF] Blau | [END_REF], Ln(T4) 2 (24)(25)(26) 3.2.1. Synthesis of nonoctupolar bis(phthalocyaninato) Ln(III) doubledecker complexes Ln(AB3) 2 (12)(13)(14)[START_REF] Yariv | Quantum Electronics[END_REF], Ln(A4) 2 [START_REF] Yariv | Quantum Electronics[END_REF][START_REF] Kajzar | [END_REF](18), Ln(B4) 2 (19)(20)[START_REF] Ashwell | Optical Materials for Non-linear Optics[END_REF][START_REF] Nalwa | Nonlinear Optics of Organic Molecules and[END_REF][START_REF] Blau | [END_REF], Ln(T4) 2 (24)(25)(26)

3.2.2.UV-NIR measurements of nonoctupolar bis(phthalocyaninato)

Ln(III) double-decker complexes Ln(AB3) 2 (12)(13)(14)[START_REF] Yariv | Quantum Electronics[END_REF], Ln(A4) 2 [START_REF] Yariv | Quantum Electronics[END_REF][START_REF] Kajzar | [END_REF](18), Ln(B4) 2 (19)(20)[START_REF] Ashwell | Optical Materials for Non-linear Optics[END_REF][START_REF] Nalwa | Nonlinear Optics of Organic Molecules and[END_REF][START_REF] Blau | [END_REF], Ln(T4) 2 (24)(25)(26) 3.2.3.Hyper-Rayleigh Scattering (HRS) measurements of nonoctupolar bis(phthalocyaninato) Ln(III) double-decker complexes (Ln(AB3) 2 (12)(13)(14)[START_REF] Yariv | Quantum Electronics[END_REF], Ln(A4) 2 [START_REF] Yariv | Quantum Electronics[END_REF][START_REF] Kajzar | [END_REF](18), Ln(B4) 2 (19)(20)[START_REF] Ashwell | Optical Materials for Non-linear Optics[END_REF][START_REF] Nalwa | Nonlinear Optics of Organic Molecules and[END_REF][START_REF] Blau | [END_REF], Ln(T4) 2 (24)(25)(26))

Hyperpolarizability of oxidized form nonoctupolar

Ln(Pc) 2 (Ln(AB3) 2 (12)(13)(14), Ln(A4) 2 [START_REF] Yariv | Quantum Electronics[END_REF][START_REF] Kajzar | [END_REF](18), Ln(B4) 2 (19)(20)[START_REF] Ashwell | Optical Materials for Non-linear Optics[END_REF], Ln(T4) 2 (24)(25)(26))

3.2.3.2. Hyperpolarizability of reduced form nonoctupolar Ln(Pc) 2

(Ln(AB3) 2 (12)(13)(14), Ln(A4) 2 [START_REF] Yariv | Quantum Electronics[END_REF][START_REF] Kajzar | [END_REF](18), Ln(B4) 2 (19)(20)[START_REF] Ashwell | Optical Materials for Non-linear Optics[END_REF], Ln(T4) 2 (24)(25)(26)) 4.2.5. 2,3,16,17-tetra(hexylthio)phthalocyanine [START_REF] Butcher | The elements of nonlinear optics[END_REF] and 2,3,[START_REF] Stucky | Materials for Nonlinear Optics: Chemical Perspectives[END_REF][START_REF] Verbiest | [END_REF][START_REF] Yariv | Quantum Electronics[END_REF][START_REF] Kajzar | [END_REF] hexa(hexylthio)phthalocyanine [START_REF] Franken | [END_REF] 4.2.6. General method for the synthesis of ABAB and AB3 homoleptic bis(phthalocyaninato) lanthanide(III) complexes ((Ln(ABAB) 2 ) (7)[START_REF] Denus | [END_REF][START_REF] Stucky | Materials for Nonlinear Optics: Chemical Perspectives[END_REF][START_REF] Verbiest | [END_REF](11), (Ln(AB3) 2 ) (12-15)) (4,7,12,[START_REF] Yariv | Quantum Electronics[END_REF]tetra-substitution pattern for [2.2]p-cyclophane(pCp) as a point-charge template for an octupole Bis(phthalocyanine) (1 x 10 -5 M)

LIST OF TABLES

3.2.The second-order NLO data for the octupole Ln(ABAB) 2 (7)[START_REF] Denus | [END_REF][START_REF] Stucky | Materials for Nonlinear Optics: Chemical Perspectives[END_REF][START_REF] Verbiest | [END_REF](11) 3.3.UV-NIR spectra of oxidized forms ofLn(Eu, Dy, Lu, Nd, Y)(ABAB) 2

Bis-phthalocyanine (1 x 10 -5 M)

3.4.UV-NIR spectra of reduced forms ofLn(Eu, Dy, Lu, Nd, Y)(ABAB) 2

Bis-phthalocyanine (1 x 10 -5 M)

3.5.

The second-order NLO data for the octupole Ln(ABAB) 2 (7)[START_REF] Denus | [END_REF][START_REF] Stucky | Materials for Nonlinear Optics: Chemical Perspectives[END_REF][START_REF] Verbiest | [END_REF](11) 3.6.The second-order NLO data for the octupole Ln(ABAB) 2 (7)[START_REF] Denus | [END_REF][START_REF] Stucky | Materials for Nonlinear Optics: Chemical Perspectives[END_REF][START_REF] Verbiest | [END_REF](11) 3.7.UV-NIR spectral data of neutral forms ofLn(AB3) 2 (12)(13)(14), Ln(A4) 2 [START_REF] Yariv | Quantum Electronics[END_REF][START_REF] Kajzar | [END_REF](18), Ln(B4) 2 (19)(20)[START_REF] Ashwell | Optical Materials for Non-linear Optics[END_REF], Ln(T4) 2 (24)(25)(26) Bis(phthalocyanine) (1 x 10 - 5 M)

3.8.UV-NIR spectra of oxidized forms ofLn(AB3) 2 (12)(13)(14), Ln(A4) 2 [START_REF] Yariv | Quantum Electronics[END_REF][START_REF] Kajzar | [END_REF](18), Ln(B4) 2 (19)(20)[START_REF] Ashwell | Optical Materials for Non-linear Optics[END_REF], Ln(T4) 2 (24)(25)(26) Bis-phthalocyanine (1 x 10 -5 M)

3.9.UV-NIR spectra of reduced forms ofLn(AB3) 2 (12)(13)(14), Ln(A4) 2 [START_REF] Yariv | Quantum Electronics[END_REF][START_REF] Kajzar | [END_REF](18), Ln(B4) 2 (19)(20)[START_REF] Ashwell | Optical Materials for Non-linear Optics[END_REF], Ln(T4) 2 (24)(25)(26) Bis-phthalocyanine (1 x 10 -5 M)

3.10.

The second-order NLO data for the nonoctupole Ln(AB3) 2 (12)(13)(14), Ln(A4) 2 [START_REF] Yariv | Quantum Electronics[END_REF][START_REF] Kajzar | [END_REF](18), Ln(B4) 2 (19)(20)[START_REF] Ashwell | Optical Materials for Non-linear Optics[END_REF], Ln(T4) 2 (24)(25)(26) 3.11. The second-order NLO data for the Ln(AB3) 2 (12)(13)(14), Ln(A4) 2 [START_REF] Yariv | Quantum Electronics[END_REF][START_REF] Kajzar | [END_REF](18), Ln(B4) 2 (19)(20)[START_REF] Ashwell | Optical Materials for Non-linear Optics[END_REF], Ln(T4) 2 (24)(25)(26) 3.12. The second-order NLO data for the nonoctupole Ln(AB3) 2 (12)(13)(14), Ln(A4) 2 [START_REF] Yariv | Quantum Electronics[END_REF][START_REF] Kajzar | [END_REF](18), Ln(B4) 2 (19)(20)[START_REF] Ashwell | Optical Materials for Non-linear Optics[END_REF], Ln(T4) 2 (24)(25)(26)

INTRODUCTION

The field of nonlinear optics has attracted lot of interest in the past three decades not only because of the possible numerous applications in telecommunications, optical data storage etc., but also because of the fundamental research connected to issues like charge transfer, conjugation, polarization and crystallization into noncentrosymmetric lattices. In principle nonlinear optics (NLO) deals with the interaction of applied electromagnetic fields in various materials to generate new electromagnetic fields altered in frequency, phase or other physical properties. A variety of systems including inorganic materials, organometallic materials, organic molecules and polymers have been studied for NLO activity.

Owing to the combination of chemical tunability and choice of synthetic strategies, organic molecules in particular have received much attention. Second order nonlinear optical response in an organic chromophore is intrinsically based on electronic 'pushpull' mechanism operative in a molecule containing a donor linked to an acceptor moiety through a conjugated π-electron bridge.

The drawbacks with these systems are that they are not transparent in thevisible region and as the conjugation increases their thermal stability and photostability decreases. Another major problem is the retention of the NLO activity whenincorporated into devices. To retain the βin bulk state, they either have to crystallizeinto a non-centrosymmetric crystal or in a poled polymer the noncentrosymmetricalignment should be retained on removal of the applied electric field. Polar moleculesusually tend to crystallize into a centrosymmetric crystal restricting their usage as aNLO device in the crystal form, but these find applications in poled polymers wherelarge dipole moments (µ) play an important role. Currently the need is to developmolecules, which are transparent in the visible region and possessing enhancedhyperpolarizabilities, with SHG activity in the bulk state.

Studies based on group theory and quantum mechanics have helped set conceptual foundations to the domain of non-dipolar molecules for nonlinear optics, which became known as octupolar,and more generally multipolar molecules.Octupolar molecules, in which symmetry constraints impose a cancellation of the dipole moment, have an intrinsic hyperpolarisability β, in which all the coefficients β ijk have increased values, often higher than the simple dipolar systems built on the same motif. At a structural level, it can be shown that the most generic template for 3D octupolar molecules is amenable to a cube with alternating charges at the edges such as accounting for donor and acceptor substituents. And these 3D octupolar cubic molecules are expected show high nonlinearitiesat molecular as well as crystalline scale.In spite of all the various structures reported, there is no molecules actually representing the "real" cube (even if deformed) with eight alternated charges at the corner and delocalization of the charges between the higher and lower plans have been obtained so far.

The goal of this thesis is to synthesize the "real octupolar cube" with sandwich lanthanide complexes of ABAB phthalocyanines bearing alternated electro-donor groups at the edges. Thus, various double decker bislanthanide phthalocyanine derivatives have been designed as a octupolar real cube. As electron donating groups, we choose thiols (strong electron donor) in order to tune the nonlinear optical properties. Series of octupolar and non-octupolar double decker lanthanide bis(phthalocyanine) derivatives have been synthesized and characterized based on various techniques like 1 H-NMR, 13 C-NMR, Mass, IR, and X-Ray crystallography. Nonlinear optical properties are measured with Hyper-Rayleigh Scattering (HRS) technique in solution.

These PhD works have been achieved within a co-directed co-tutelle framework, and therefore included the complete chain from the synthesis of various double decker bis lanthanide phthalocyanine derivatives until their evaluation of nonlinear optical properties by using HRS technique. This double thematic directs the organization of this thesis, with a bibliographic part summarizing firstly nonlinear optic, its origin, and various types of NLO effects. Detailed description is given for second order effects particularly on second harmonic generation followed by review of second order NLO materials studied especially phthalocyanines so far.

Emergence and requirement of octupolar systems over dipolar systems are discussed in detail. And then results are given and discussed. We will then develop our results on a synthetic point of view and then detail the results regarding their NLO properties.

BIBLIOGRAPHIC DATA

Definition of nonlinear optic

Nonlinear optic (NLO) can be defined as a phenomena that occur with interaction of sufficiently intense light in various materials to yield new optical properties such as electromagnetic field altered in phase, frequency and amplitude [1,2]. Currently, a great deal of research is being devoted to both organic and inorganic materials that exhibit nonlinear optical (NLO) effects, particularly second harmonic generation (SHG), which, put simply, causes a doubling in the frequency of incident light.

Nowadays, nonlinearoptic has evolved into many different branches, depending on the form of the material used for studying the nonlinear phenomena.

The ability to manipulate the frequency, phase, polarisation or path of light has very important technological effects. Thegrowth of research in nonlinearoptics is closely linked to the rapid technologicaladvancesthat have occurred in related fields, such as ultra-fastphenomena, photonics, computer, optical signal processing devices, optical data storage, dynamic image processing, fiber optics, andopticalcommunications [3][4][START_REF] Butcher | The elements of nonlinear optics[END_REF].

Origin of nonlinearoptic

When a molecule is subjected to an oscillating external electric field (light), the induced change in molecular dipole moment (polarisation) can be expressed by a power series in the field strength E j (Fig. 2.1) as in eqn. (2.1), where p i is the electronic polarisation induced along the i the molecular axis, α is the linear polarisability, β the quadratic hyperpolarisability, and γ the cubic hyperpolarisability.

α in eqn. (2.1) is a second-rank tensor because it relates all of the components of the polarisation vector to all of the components of the electric field vector, and is responsible for the linear optical behaviour. Analogously, β and γ in eqn. (2.1), which relate the polarisation to the square and the cube of the field strength, are respectively, third-rank and fourth-rank tensors, responsible for second-order and third-order NLO effects. The even-order tensor, β, vanishes in a centrosymmetric environment. For small fields the quadratic and cubic terms in eqn. (2.1) can be neglected, so that the induced polarisation is proportional to the strength of the applied field (linear optical behaviour). This equation describes the full picture only if the atomic or molecular potential is classical harmonic potential. However, when a molecule is subjected to very intense field, as a laser light, the material can become so polarized that its polarisability can change and hence the induced polarisation is in nonlinear function of field strength (Fig. 2.2) and the second and third terms in eqn. (2.1)

t o t 1 t 2 Induced polarisation Applied f ield (a)
become important, such that nonlinear optical behaviour can be observed. Note that, the 'nonlinear' term originates from the nonlinear dependence (quadratic or cubic) of the induced polarisation of the applied field. Since, the second harmonic generation (SHG) is main focus phenomena in this thesis, a detailed discussion about this process is required in order to have a clear picture of the SHG effect discussed in this thesis.

2.3.Definition ofsecond-order nonlinear optic

Second harmonic generation is the main archetypal nonlinear optical process.

Second harmonic generation was discovered by Franken et al. in 1961 just after the development of intense laser sources [7]. Since then this process has become very important for many applications, such as, frequency doublers, frequency converser, electro-optic modulators and nonlinear optical microscopy [START_REF] Denus | [END_REF].

Second-order nonlinear optical effect of molecular materials is associated with first hyperpolarisability (β) also called microscopic quadratic. The process of second-harmonic generation is showed in Fig. 2.3. When a laser beam at frequency ω reaches to nonlinear optical material a new beam at frequency 2ω is created. In other words, two photons from the input beam are lost and one photon in the output

t o t 1 t 2 Induced polarisation Applied f ield (b)
beam is created. The efficiency of this process can surpass %50 under proper circumstances [START_REF] Stucky | Materials for Nonlinear Optics: Chemical Perspectives[END_REF]. the induced dipole from a molecule with a centre of inversion. Adapted from ref.

[10] Fig. . This contradiction leads to β=0. Thus the centrosymmetric molecule has zero β value [11].

On the other hand, if the restoring force is dependent upon the direction of charge displacement, then the induced polarization of the atom or molecule will not depend upon the magnitude of applied field anymore, but also upon the direction of the field. Fig. 2.5 shows the interaction of a strong oscillating electric field with this type of system. The induced polarization wave is distorted because of the nonlinear response. the induced dipole in a second-order NLO material. Adapted from ref. [START_REF] Verbiest | [END_REF] Second-order nonlinear optic effects occur thanks to the nature of this asymmetric polarization wave. Since SHG originates from asymmetry of induced polarization wave, it can say that, only materials, which can produce this asymmetric wave, can produce SHG or any other second-order NLO process [12].

Materials for second-order nonlinear optic

Nonlinear optical (NLO) materials have significant influence in nonlinear optics and especially on information technology and industrial applications. The target is to make new advance materials exhibiting large NLO response, which also posses all the technological requirements for applications such as wide transparency range, fast response, high damage threshold but also processability and adaptability [13][14][START_REF] Yariv | Quantum Electronics[END_REF][START_REF] Yariv | Quantum Electronics[END_REF].

Many research efforts have been dedicated to synthesized and designed efficient molecule-based Second-order NLO materials in order to create large first hyperpolarizability (β) values because of their potential applications [START_REF] Kajzar | [END_REF][18][19][20][START_REF] Ashwell | Optical Materials for Non-linear Optics[END_REF].Design Since the discovery of NLO effects, several classes of materialshave been developed for particular applications. NLO materials can be roughly classified in two different categories as inorganic (crystals, metal based materials) and organic materials. Each category i.e. inorganic and organic possesses its own set of benefits and drawbacks as described below [START_REF] Blau | [END_REF].

Inorganic materials

The study for effective materials were focused on inorganic materials such as quartz, potassium dihydrogen phosphate (KDP), lithium niobate (LiNbO 3 ), and its analogues, potassium titanyl phosphate (KTP) and its analogues, since SHG was first observed in single crystal quartz by Franken and co-workers in 1961 [24-28].

Inorganic materials have desirable properties for materials applications, including a large transparency range, good mechanical properties, high optical damage threshold and the fact that they can be grown as large crystals.

The inorganic materials have important drawbacks such as "trade-off' problem between response time and magnitude of optical nonlinearity. Moreover, they have insignificant optical quality because of absorption strongly in the visible region, so reducing many possible applications.

Organic materials

As an alternative to inorganic materials, organic molecules can suppress the limitations identified above and therefore have been of considerable interest for use in nonlinear optics due to their large optical nonlinearities. The NLO effects in organic materials are usually electronic in nature, which leads to fast nonlinear response [29][30][31][32][START_REF] Prasad | Nonlinear Optic and Polymer[END_REF][START_REF] Khananan | Nonlinear Optical Properties of Organic Molecules SHE[END_REF]. The architectural flexibility allows for precise molecular design and the determination of structure-property relationships.

The electronic transitions of organic materials improve the NLO efficiencies in the UV-visible region, but also causedecrease of optical transparency. Another drawback of organic materials is that they often have lower thermal and photochemical constancy.

Metal-based materials

The metal-based materials (organometallic and coordination compounds) havearising recent interestachievement in second-order Nonlinear Optic.They offer a large variety of metals that posses the polarizable d electrons and ligands.

Thereforethese have been suggested: [START_REF] Marder | [END_REF][36][37] a gives rise to what is termed a 'nonlinearity/transparency trade-off '. If a material is to be used in a frequency doubling then obviously, absorption of the harmonic light that is created will limit the effectiveness of these materials.

As mentionedabove, metal based materials have many advantages compare toorganic materials for nonlinear applications. First they have large and fast nonlinearities, easy to process and integrate into optical device, tailorability: a finetuning of the NLO properties can be achieved by rational modification of the chemical structure.

2.5.Phthalocyanines and related materials

The phthalocyanines were used as materials for Second-Order Nonlinear Optic in this thesis. Therefore, general properties and the different methods available for the preparation of metallated and metal-free phthalocyanines were briefly discussed here.

Synthesis of phthalocyanines

Phthalocyanines belong to the tetrapyrrole macrocycle class, with the structure containing an alternating nitrogen atom-carbon atom ring. Phthalocyanine was discovered accidently during preparation of ortho-cyanobenzamide from phthalamide and acetic anhydride by the British chemists Braun and Tcherniac in 1907(Fig. 2.6) [38].

Figure 2.6. The first phthalocyanines synthesis

However,the importance of this material was not recognized until the first patent was granted in 1929 including the synthesis and the properties [39]. Since then, several methods were developed for high yield formation of the metal-free and metallated phthalocyanine.

The precursors that can be used for the synthesis of metal-free phthalocyanines are shown in Fig. 2.7. The most common precursor used in the laboratory synthesis are phthalonitrile (1,2-dicyanobenzene), diiminoisoindoline or its substituted derivatives [START_REF] Leznoff | Phthalocyanines, Properties andApplications[END_REF].The metal-free phthalocyanine can be easily obtained by these precursors by heating in high boilingalcohols in the presence of strong The synthesis of metal containing phthalocyanine complexes can also be managed inseveral different ways (Fig. 2.8) [44,45]. Most metallophthalocyanines can be obtained from phthalonitrile or diiminoisoindoline in addition of a metal in high-boiling solvents such as DMAE, quinoline or 1-chloronaphthalene [START_REF] Leznoff | Phthalocyanines, Properties andApplications[END_REF]. And in case the phthalimide and phthalic acid anhydride, the urea need to be used as a source of nitrogen and a catalyst such as ammonium molybdate in order to obtain metal-containing phthalocyanines. Metal-containing phthalocyanine can also be synthesized by metallation of metal-free phthalocyanines or by the replacement of lithium (Li) from Li2Pc with suitable metal ions in refluxing solvents like DMF, quinoline or 1-chloronaphthalene [START_REF] Piechocki | [END_REF].

The metallatedphthalocyanine complexes have been studied and synthesized over the years, givingrise to compounds with different physical and chemical properties. The lanthanide (III) ions form with phthalocyanines (Pc) complexes of the type Ln(Pc) 2 ,where the lanthanide ion is sandwiched between two phthalocyanine rings,because the diameter of the trivalent lanthanide ions is too large to make them fit in the cavity of the phthalocyanines. The lanthanide phthalocyanine complexes are only known since the middle 1960's and since then they have been studiedwidely because of their electrochromicproperties [48].

2.5.2.The reaction mechanism of phthalocyanine

It must note that the mechanism of formation phthalocyanine is still not clarified, however some intermediates have been isolated and characterized. Leznoff was proposed a mechanism in 1989 and suggested that, in Pc reactions involving organic bases such as DBU and DBN or alkali metalalkoxides in alcohol, the alkoxide can act as nucleophile (Fig. 2.9). Likewise, in metal containing Pc synthesis the counter anioncan play the same role as the nucleophile [START_REF] Leznoff | Phthalocyanines: Properties and Applications[END_REF][START_REF] Tomoda | [END_REF][51]. It is of interest that the cyclotetramerization of phthalonitrile can occur even without the concurrent complexation of a metal ion -at temperature in excess of 200 C within a melt that is in cantact with certain metal alloys (e.g. InBi) [52,53].

It is not clear as to electronic state o the resulting planar metal free macrocyle, which was characterized by single crystal X-ray diffraction.

Finally, it is clear that both the electronic and steric effects of substituents can have a significant influence on the mechanism and outcome of cyclotetramerization

Figure 2.10. Nomenclatures of phthalocyanine analogues

There are sixteen possible sites for macrocyle substitution associated with the four benzo-sununits. The 2,3,9,10,1617,23,24 carbon atoms are termed the peripheral (p) sites and 1,4,8,11,15,18,22,25 carbon atoms are denote the nonperiheral (np) sites.

The abbreviation t signifies a peripherally or non-peripherally tetra-substituted Pc, which is usually composed of four isomers. In contrast, there are important materials based on octa(o)-substituted Pcs both wşth peripheral and with nonperipheral substituents and these are distinguished by the abbreviations op and onp, respectively.

Applications of phthalocyanine

Phthalocyanines are planar macrocylic aromatic compound, isoelectronic with porphyrins [START_REF] Van Der Pol | [END_REF][56]. Unsubstituted phthalocyanines and many of substituted ones are highly symmetrical compounds. A great number of unique properties arise from their electronic delocalization, which makes these compounds valuable in different applied fields.

However, the inherent symmetry of the molecule sometimes represents a limitation for many purposes. Thus, the possibility of designing and synthesizing unsymmetrical compounds with substituents located at specific positions will aloe fine-tuning of many physical properties, thus enhancing the technological applications of the phthalocyanines.

The phthalocyanines are used traditionally as colorants and as blue and green pigments [START_REF] Van Der Pol | [END_REF]. Phthalocyanine and its metal-containing derivatives comprise one of the most studied class of functional organic materials. [56][START_REF] Lec | Phthalocyanines: Properties and Applications[END_REF][START_REF] Leznoff | Phthalocyanines: Properties and Applications[END_REF][START_REF] Leznoff | Phthalocyanines: Properties and Applications[END_REF][START_REF] Leznoff | Phthalocyanines: Properties and Applications[END_REF][START_REF] Moser | Phthalocyanine Compounds[END_REF] The diverse and useful functionality of the phthalocyanine macrocycle originates from its 18π-electron aromatic system which is closely related to that of the naturally occurring porphyrin ring. The additional p-orbital conjugation, afforded by the four benzenoid units and the orbital perturbation caused by the nitrogen atoms at the four meso-positions, have a profound effect on the molecular orbital structure of the porphyrin chromophore.

These results in a bathochromic shift of the lowest energy absorption band (the Qband) in the visible region of the spectrum and a strong enhancement of its intensity (typically λ max ~680 nm, ε~200,000). Their resulting strong color, coupled with renowned chemical and thermal stability, explains the ubiquitous use of phthalocyanines as highly stable blue (or green) pigments and dyes [START_REF] Moser | The Phthalocyanines[END_REF][START_REF] Moser | The Phthalocyanines[END_REF][START_REF] Emmelius | [END_REF]. In addition to their long established use as colorants, phthalocyanines are exploited commercially for optical data storage, catalysis, and as photoconductors in Xerography [65][66][67]. They are also of interest as materials for non-linear optics, liquid crystals, ordered thin films, photodynamic cancer therapy, molecular semiconductors, components of highly conducting charge-transfer salts, and polymers, photovoltaic devices, electrochromic devices, fuel cells, and sensors [68][69][70][71][72][73][74][START_REF] Andrw | Molecular Semiconductors[END_REF][START_REF] Marks | [END_REF][77][78][79][80][81][82][83][84][85][86][START_REF]Photosensitizers in Medicine, Environment, and Security[END_REF]. The synthesis of phthalocyanine and its substituted derivatives is often driven by the desire to exploit and improve performance in one of these technological or therapeutic arenas.

2.5.4.1.Nonlinear optics

The chemical and physical properties of phthalocyanines provide requirements for NLO materials. Therefore, among metal-based compounds, phthalocyanines and its analogs (double decker Pcs, subphthalocyanines, porphyrine (see Fig. 2.11) have been intensively studied as NLO materials [START_REF] Hanack | Methods in Organic Chemistry[END_REF][START_REF] De Latorre | Supramolecular Photosensitive and Electroactive Materials[END_REF][START_REF] Nalwa | [END_REF][91][92][START_REF] Stillman | Phtalocyanines,Properties and Applications[END_REF]. A common application of Pc NLO activity is the eye protection against harm from intense red and IR light [START_REF] Shirk | [END_REF].

Pcs

The phthalocyanine molecule has a two dimensional π-electron conjugated system (an aromatic system with 18 π-electrons), and a number of adjustments can be made in the macrocycle by incorporating more than 70 different metal atoms [START_REF] Bonnett | Chemical aspects of photodynamic therapy[END_REF].

In addition, there are 16 possible sites of substitution on the fused benzene rings, which allow combination of different substituents on the peripheral or non-peripheral positions of the ring. The metallo phthalocyanines posses a tailoring of electrophysical parameters over a broad range and, finally, allow modulating the electrical and optical behavior of the compounds. Phthalocyanines as an organometalics posses metal-to-ligand charge transfer (MLCT), ligand-to-metal charge transfer (LMCT), or intraligand charge transfer (ILCT) which are related to transition dipole moments and low transition energies. Therefore, they can act as donor or acceptor groups of the D-π-A (Push-pull) system, or as polarisable bridge mation for the design of efficient chromophores.

Fig. 2.12 shows a charge transfer between electron rich ligand to an electron poor metal (LMCT) and metal to ligand (MLCT) [START_REF] Bonnett | Chemical aspects of photodynamic therapy[END_REF]. response (e.g. frequency tripling) since it only requires a highly polarisable π-system, but not an unsymmetrical structure [START_REF] Fan | [END_REF].

As mentioned before, planar centrosymmetric materials such as symmetrical phthalocyanines do not exhibit second-order activity. In order to create asymmetry, which crucial requirement of second-order NLO, two main approaches have been concerned a) peripheral substitution of the phthalocyanine core with donor and acceptor groups (Push-Pull) and b) architectural adjustment of the Pc core to reduce the symmetry for obtaining noncentrosymmetric structures, which presenting octupolarity in the nonlinear response.

2.6.Materials design for second-order nonlinear optic

In order to have high first nonlinear hyperpolarizability β, three kind of methods have been developed (i) using different types of conjugation bridge, (ii) optimizing the combination of different donors and acceptors, (iii) employing multiple charge transfer structures such as octupolar [START_REF] Prasad | Introduction to Nonlinear Optical Effects in Molecules and Polymers[END_REF][START_REF] Zhao | [END_REF][99][100]. These systems can be categorizedin two: A)Push-Pull systems and B)Octupolar systems and will be explained below.

Push-Pull Systems

The majority of molecular compounds that own large β values contain conjugated The design of chromophores with high second-order nonlinear value has focused chiefly on engineering: (i) the electronic nature of the donor and acceptor groups, and (ii) the conjugation length of the bridge [101][102][103][104][105]. The earlier controls donor-acceptor groups mixing with respect to a specific bridge, while the latter plays a role in modulating donor-acceptor electronic coupling as well as controls the magnitude of the change in dipole moment [106-108].

Organic Push-Pull Systems

Inspired by the two-level model and the development of the electric fieldinduced second harmonic generation (EFISH) technique, a few one-dimensional charge transfer systems such as p-nitroaniline (PNA) and dimethylaminonitrostilbene (DANS) were developed during the 1980s. DANS was considered to be good NLO materials and is still being used as a typical push-pull type benchmark to calculate NLO values of other molecules (Fig. The PNA molecule has conjugated system, which consists from electron donating amino (NH 2 ) and electron accepting nitro (NO 2 ) groups substituted in the para-position. From, these opposite ends of conjugated system results intramolecular charge transfer interactions. Thence, PNA shows much larger first hyperpolarizability than mono substitute benzene because of its asymmetric charge distribution. Benzene doesn't exhibit second-order NLO value because, as explained before, second-order NLO vanish in centrosymnetric media. The second order

NH 2 O 2 N N O 2 N

PNA DANS

optical nonlinearity in a donor or acceptor substituted benzene has been described in Fig. 2. 15 [110]. The next step in the modeling process was to consider doubly substituted benzenemolecules with a donor and acceptor group. The para positionresulted in the highest β followed by the ortho position with the meta position being thelowest as shown in Fig. 2. 16 [111]. This dependence on position was attributed to intramolecular charge transferbetween the donor and acceptor. In the early nineties, Marder and co-workers cemented the way for the expansion of highly advanced NLO chromophores [112,113]. He presented that for a given conjugation bridge there is an ideal combination of donor and acceptor strengths (or ground state polarization) to maximizeµβ, and that beyond this point, increased donor-acceptor strength (or further ground state polarization) will attenuate µβ. More recently, it was shown that the average difference in length between single and double bonds in the molecule, is the related parameter in the optimization of the hyperpolarizability of molecules [114][115][116]. The high degree of bond length alternation in such molecules is revealing of an inadequate contribution of the charge separated resonance form to the ground state configuration of the molecules and is a direct consequence of the loss of aromatic stabilization in the charge separated form. Thus, many studies were focused on designing molecules with less aromatic character in the ground state.

Examples of such optimized molecular structures are shown in Table 2.1, together with their hyperpolarizabilities, dipole moments and absorption characteristics. [117,118] Materials to be used for electro-optic and frequency doublingapplications must not only have good nonlinear values, but alsogood thermal, chemical stability and low opticalloss (high transparency) [118][119][120].

In order to stabilize the nonlinearresponse during treating and operation,the chromophores need to be chemically stable at all temperaturesthat the system encounters. Typically, organic moleculesfor nonlinear optical applications will have to bear extremelyhigh temperatures during fabrication processes (sometimes ashigh as 300 °C) [121].

As previous studies showed that thermal stabilities of organic materials is extremely challenging without loosing the molecules nonlinearity. Improvement of thermal stability of organic chromophores can be succeeded by adding aromatic structures instead of aliphatic ones by along the conjugation pathof the molecules.

However, as showed above, additionalaromatic structureto organic molecules causes to decrease its hyperpolarizability.

Moylan and co-workers avoided this problem by replacing aliphatic dialkylamino donor groups with diarylamino groups, which results in a substantial increase in thermal stability of a broadrange of organic chromophores without compromising the nonlinearity of the chromophore [122]. Consequently, those organic compounds posses not only very thermally stability but also high nonlinear response. Some of the investigated organic structures showed thermally stabilities as high as 400 °C.

Other organic push-pull materials with thermally stabilities above 300 °C have been established. For instance, certain naphthalene benzimidazoles display decent nonlinearity and thermal constancies in excess of 350 °C (Table 2.2,3b).

These systems are based on attached ring system that is structurally similar to polyimide, which would make them very soluble in high T d polyimides [123][124][125].

Rao et al. substituted the most reactive CN group in the tricyanovinyl group with aryl units in tricyanovinylthiophenes in order to increase their chemical and thermal stability (Table 2.2,2c) [126].

Metal based Push-Pull systems

As showed in the previous, most second-order NLO metal complexes, as organic NLO chromophores, can be foreseen within a simple molecular scheme constituted by a push-pull system, in which a metal complex selectively replace the donor and/or the acceptor, or the bridge moieties. This is because metal complexes shown in Fig. 2.17 [135]. Similarly to organic push-pull systems, an increase of the nonlinearity is observed upon increasing the acceptor strength (e.g. 3d vs 3c) and upon conjugated π-linker lengthening (e.g. proceeding from 3d to 3e) [136].

One of the advantages of metal complexes over organic compounds is the possibility of tuning NLO response by changing the metal center. For example, the Fe and Ru metal containing compounds have been studied in order to compare NLO properties to each other (Fig. peripheral groups. However, the synthesis of unsymmetrically substituted push-pull phthalocyanines is adifficult work [151][152][153][154][155][156][157][158].

Probably due to the trouble in the preparation of pure unsymmetrically substituted phthalocyanines and related compounds, few studies on the second-order NLO properties of this kind of compound have been reported.The first researches on the microscopic nonlinear exhibits of unsymmetrically substituted phthalocyanines were reported in 1996 (Fig. The approach pursued by some authors in order to improve thequadratic hyperpolarizabilities is the extension of theconjugation route. It is well identified that an increase in the number of conjugation units (double or triple bonds) between the donor and acceptor groups in a linear system causes an improvement of the secondorder NLO response [166]. For this reason, push-pull phthalocyaninesbearing πdelocalized electron acceptor substituents, which induce an extended π-conjugation length, were studied efficiently for second-order NLO[167,168].Hence, a set of Likewise, push-pull phthalocyanines bearing exocyclic conjugated nitro groups, such as 11b, were synthesized and it is also confirm the efficacy of the πelectronic extension approach (Fig. .

N N N N N N N N NO 2 R R R R R R M R R R R R R N N N N N N N N R R R R R R M R R R R R

Octupolar Systems

The "D-π-A (Push-pull)" dipolar molecules are most intensively studied as NLO chromosphores [182][183][184]. Optimisation of the structural factors such as the strength of the push and pull group and length has led to high values for the quadratic hyperpolarisabilities β. Significant efforts consequently have been made to built new materials by inserting NLO dipolar push-pull molecules in solid medium in noncentro symmetric arrangements. While these studies have detailed of relationship between the chromophore structure and NLO properties, it has became clear that dipolar molecules have assured limitations and disadvantages such as poor solubility,

14
aggregation and strong absorption of the second harmonic by the chromophore, thus leading to reduced efficiency-transparency trade off and dipole-dipole interactions, which often cause an antiparallel molecular arrangement and a following cancellation of the nonlinear response at bulk materials [185,186].

In addition to push-pull dipolar molecules, a recently new strategy was introduced for second generation of compounds, which can avoid aforementioned disadvantages. Studies based on group theory and quantum mechanics have assisted set theoretical basics to the field of non-dipolar molecules for nonlinear optics, which became known as octupolar,and more generally multipolarmolecules. The concept of octupolar nonlinearities was described in the early 1990 by .

Definition of octupolar system

Since the molecular hyperpolaribility β is a tensor, it turns out from tensorial analysis that it can have two components of order 1 and 3 which is referred to as the dipolar and octopolar irreducible components respectively [190],i.e β: β j:1 ⊕β j:3

The vectorial component (J=1) allows for three independent coefficients while the octopolar component will accommodate seven components, hence making up for the 10 components of a symmetric rank-3 tensor. Thus in addition to dipolar molecules (β J=1 )

showing NLO response, from the above analysis it can be deduced that octopolar groups like D 3h , T d etc., should also show NLO response. Molecules that show NLO response due to their octopolar (β J=3 ) nature are called octopolar molecules. For a molecule beloggingto an octupolar space group (J:3), are nonpolar molecules that have only the octupolar vector contributionof β(J:3) and a strict cancellation of all vector-like observables, including the ground-and excited-state dipole moment [191,192].

The advantages of using such nonpolar species for NLO applicaitons include easier noncentrosymmetric crytallization, no dipolar interaction and improved efficiency-transparency trade-off, which is a crucial parameter to consider while designing NLO devices.

Design of octupolar materials is now quite developed andessential criteria for exhibition of large hyperpolarizabilities have been discovered. The basic rules are as follows [193][194][195][196][197]:

-

Octupole * electron-donating group electron-withdrawing group conjugating system * noncentrosymmetric objects

Basically, purely octupolar symmetries can be derived from this cubic Td structure either by projection along a C3 axis, giving rise to D3h or D3 symmetry (TATB route), so called two-dimensional (2D) octupolar materials, or by fusion of one type of charge in the barycenter leading to, Td, or D2d symmetry ("guanidinium route"), so called three-dimensional (3D) octupolar materials. Thus, the molecular engineering of octupoles contains of a spatially controlled organization of charge transfers within a molecule so as to reach the preferred symmetry.

Two dimensional (2D) octupolar materials

Since the pioneering work of Zyss and coworkers, most studies have been dedicated to molecular optimization of octupolar molecules with a two-dimensional (2D) character of β, leading to enhanced nonlinearities [206,207]. A cubic structure can result in a two-dimensional (2D) octupolar system by projection along a C 3 axisgiving rise to the D 3h or D 3 symmetries (Fig.

2.6.2.2.1.Two dimensional (2D) octupolar organic materials

The first example of octupole molecules, namely 1,3,5-triamino-2,4,6trinitro-benzene (TATB) (Fig. 2.30), was described in 1990 by Lehn, Zyss et [208].

Since then, many 2D octupolar organic molecules with a benzene, triazine, boroxine core that symmetrically hexasubstituted and trisubstituted have been effectively

studied [209][210][211]. [216]. Besides, they showed thatβvalues also increased as the phenyl group in the conjugation bridge was replaced by the thienyl group (17b<18). This is because the thienyl group has smaller aromatic resonance energy than the phenyl group and thus simplifies the ICT from the donor group to the acceptor group.

2.6.2.2.2.Two dimensional (2D) octupolar metal based materials

Metal ions are well appropriate to building two-dimensional (2D) and three dimensional (3D) coordination molecules with 2-fold (D2) around the metal center.

Thanks to this ability, a number of NLO two-dimensional (2D) octupolar metal complexes, mainly based on bipyridine ligands, have been described in the literature [218].

2.6.2.2.3.Two-dimensional (2D) octupolarphthalocyanine materials

The 1,3,5-trisubstituted benzene material is the most studied building block for achieving for two-dimensional octupolarsymmetry and recently, 2,4,6trisubstituted 1,3,5-triazinemolecules have also been shown to be very promising applicants structures for 2D octupolar materials [225]. Thus, a series of pseudo- Figure2. 42 The structures of octupolar molecules of D 2d symmetry derived from an orthogonalized biphenyl core.

The first generation of octupolar biphenyls (25a, 25b, 25c) corresponds to molecules bearing electron-withdrawing and/or electron-donating substituents on the four ortho positions of the phenyl rings in order to allow for charge transfer from the substituents to the phenyl rings. In a second step, they have decided to extend the conjugation length of the substituents so as to further optimize the basic molecular structure, which this expansion was proven quite successful in the case of 1D pushpull dipolar chromophores. Thus, they have applied this promising strategy by designing of three dimensional (3D) organic octupolar biphenyls, which provide an interesting approach to improvednonlinearity-transparency trade-off and offer manyopportunities for optimization of the octupolarnonlinearities.

As mentioned before, push-pull organic NLO materials use traditional single They have reported a clear experimental evidence of large through-space octupolar and dipolar contributions to the second-order hyperpolarizability βvalue of various multipolar donor-acceptor groups (26a-f) in the form of a distorted cube to highlight the geometric relationships between pCP derivatives [232].

The significant nonzero β value ofthe is a first approval of the through-space ICT, althoughit is made of two centrosymmetric subunits. The three-dimensional charge transfer of D 2 symmetric26a shows a strong octupolar characteras expected.

The dipolar contribution (β j:1 : 50x10 -30 esu vs β j:3 :130x10 -30 esu) of compound is weak compare octupolar contribution but it can beincreasedby variations of the molecular geometry [232]. Moreover, compound 26a, which paracyclophane core having four N,N-dialkylamino electron donor groups on alternate positions of both benzene rings is known as the closest example for a cubic template molecule so far.

Threedimensional (3D) octupolar metal based materials

Coordination chemistry can be useful way and a powerful tool to build up three-dimensional octupolar materials. After the first demonstration of the potential of metal based complexes [Ru(bpy) 3 ] 2+ , which has two-dimensional D 3 symmetry Since, this thesis focus on the Second-order NLO, here we will present a small part for the measurements methods for second-order nonlinear optics.

Kurtz Powder:

The Kurtz powder technique is an efficient method for the determination of second order nonlinear activity of powder materials [240]. In this method a laser is directed into a powdered sample and the emitted light at the second harmonic frequency is collected and compared with reference sample to able to measure of NLO efficiency. This method is crude compare to other method but it is a very good method for the evaluation of a large numbers of powdered materials [241].

Electric field-induced second harmonic generation (EFISH):

In EFISH technique, a strong static electric field is applied to solution of NLO active molecules. The interaction of the electric field with the permanent dipoles of these molecules induces an array in the orientation of the molecules. The limited removal isotropy causes second harmonic generation (SHG) [242]. This technique allows the determination βvalue from detected second harmonic light intensity for dipolar molecules [243,244]. This method has some disadvantages. First of all, this method requires a complex apparatus and the molecules must have permanent dipole moment. Also the molecules should not ionize in solution [245].

Hyper-Rayleigh Scattering (HRS):

Hyper-Rayleigh scattering (HRS) is a method for determination the second harmonic scattered light of nonlinear optical chromophores in solution as a function of the concentration. This method requires high peak-powder fundemental laser pulses and an efficient collection system of harmonic scattered photons. Because second-order nonlinear effects are vanished in the electric dipole approximation, the efficiency of Hyper-Rayleigh scattering in bulk solution is quite low. This is why this method is discovered in 1965 just after devolopment of megawatt peak power pulsed laser [246,247]. Hyper Rayleigh scattering also is known as Harmonic light

Scattering (HLS).

The Hyper-Rayleigh scattering method is an alternative to EFISH method and this method does not require an external applied field unlike EFISH method. Thence, this method let us able to measure molecules that lack a permanent dipole moment but In the internal method, the solvent is used as a reference for solute hyperpolarizability measurement [253][254][255]. This method was used for determining β of molecules by the Hyper-Rayleigh Scattering method until 1997. However, this method was abandoned because it's a few disadvantages, which are;

• Intercepts are small and errors in determining the intercepts are large [256] • Solvent dependence of β can't be carried out unless calibration is done for each solvent.

• Solvents such as benzene can't be utilized.

As a result of these disadvantages a new method, which called external method, was proposed. The external method uses references materials, which their

β 2 value is known precisely [257].
The second harmonic intensity from known reference and the unknown solute are both measured in the same solvent and experimental set up in order to keep G and the intercept constant. Then the ratio of slopes is equal to the ratio of β's. This is described by the following equation:

𝑺𝒍𝒐𝒑𝒆 (𝒓𝒆𝒇𝒆𝒓𝒆𝒏𝒄𝒆) 𝑺𝒍𝒐𝒑𝒆 (𝒔𝒂𝒎𝒑𝒍𝒆) = 𝜷 𝟐 (𝒓𝒆𝒇𝒆𝒓𝒆𝒏𝒄𝒆) 𝜷 𝟐 (𝒔𝒂𝒎𝒑𝒍𝒆)
References materials are chosen according to HRS experiment laser wavelength and shown in Fig. 2. 49 [258,259].

Objective of the thesis

Despite all the various structures reported, it is worth noting that no molecules actually representing the "real" cube (even if deformed) with eight alternated charges at the corner and delocalization of the charges between the higher and lower plans have been obtained so far. To our knowledge the closest examples are the derivative of paracyclophane synthesised by the group of Bazan (See Fig. [232]. In these compounds there is an electronic "through space" charge delocalisation between the higher cycle and the lower cycle. The described compounds, however, only have four identical functional groups (generally electrodonor) and not eight groups with alternating electro-donor/electro-acceptor. Since, paracyclophane (pCP) derivatives are organic molecules, they have certain limitations and drawbacks as mentioned before. Our primary target in this work is to prepare a synthon, which can be used as templates for cubic octupoles, with eight alternated charges at the corner and delocalization of the charges between the higher and lower plans.

2.50)

This "through space" charge delocalisation between two cycles also exists in the "sandwiches" complexes formed by two units of phthalocyanines or porphyrins electron-donating group electron-withdrawing group conjugating system coordinated by various ions, especially lanthanides III. In these compounds, the metal ion is located between the two plans of two macrocycles [260].

The strategy to obtain an octupolar molecule, which represent a real cube and their possible assembly into 3D noncentrosymmetric cubic structures are shown in The first steric hinderance free base crosswise ABAB phthalocyanine was syhthesized by Kudrik and et. al [264]. The mixture of A4, A3B and an isomer of the ABAB type phthalocyanine with overall yield 7% were obtained by addition of a 10fold excess of phthalonitrile to a boiling solution of the 3,4-bis(decyloxy) phthalonitrile (Fig. 3.3).The ABAB form is predominant in the mixture of isomers thanks to the steric hindrance, which caused by nonperipheral substitutions.

Moreover, the steric hindrance also not allows formations of types of B4, AB3 and AABB [264].

The other procedure is involves the synthesis of the ABAB-type phthalocyanines under mild conditions from equivalent amounts of two different phthalyl derivatives, namely 1,3-diiminoisoindoline and 1,3,3-trichloroisoindolenine, in the presence of a base and a reducing agent.This regioselective method was reported first by Yound and Onyebuagu (Fig. Figure3. 4 The regioselective approach for crosswise-Pc Figure3. [START_REF] Butcher | The elements of nonlinear optics[END_REF] The regioselective approach for crosswise-Pc They suggested that the formation of AB3 may have been due to traces of water in the reaction mixture, resulting in partial hydrolyses of trichloroisoindoline, which cause a troubled the stoichiometric balance of precursors [266].

The regioselective method clearly has advantages compare to statistical method such as better yield and easy separation.Therefore, we decided to use regioselective approach to synthesis the square unit as shown in Fig. 3.1a. The 4, o-dichlorobenzene AB3 type phthalocyanine was obtained repeatedly. It seems that the reason of obtaining AB3 type Pc is not partial hydrolyses of trichloroisoindoline as suggested by Hanack and et. Al [266]. These results indicate that this method is not enough regioselective to obtain only ABAB type phthalocyanine.

Even though, the yield of this method is not high as Yound and Onyebuagu suggested, it still better than statistical methods and provide easier separation [265].

Detailed synthetic procedures were given in the Experimental Section.

3.1.2.Synthesis ofoctupolar bis(phthalocyaninato) Ln(III) doubledecker complexes (Ln(ABAB) 2 (Lu, Dy, Eu, Y, Nd))

A large number of homoleptic lanthanide sandwich complexes have been prepared with symmetrical bis(phthalocyanines), usually by cyclic tetramerization of the corresponding phthalodinitrile in the presence of a lanthanide salt and an organic base such as 1,8-diazabicyclo [5.4.0]undec-7-ene (DBU) [269,270]. This method cannot be envisaged in our case, as a specific ABAB geometry is required for the two macrocycle.

Controlling the number and location of functional groups on the lanthanide bis(phthalocyanine) complexes requires the synthesis of asymmetrically substituted derivatives, in particular, complexes with ABAB type phthalocyanines. To the best of our knowledge, there have been no homoleptic lanthanide bis(phthalocyanine) complexes containing functionalized ABAB type phthalocyanines reported to date [271][272][273].

The synthetic procedures available for such compounds are based on the template complexation of a half-sandwich lanthanide compound with lithium phthalocyaninate, which usually give mixtures of products in comparatively low yields that are hard to separate [274].

Alternatively,reactions of Li 2 Pc or H 2 Pc in the presence of a lanthanide salt and an organic base in a highboiling solvent also lead to the formation of these homoleptic lanthanide sandwich complexes [275].The use of free phthalocyanines as the starting compounds was shown to be more efficient than the use of the corresponding phthalodinitriles, because the reaction time is shortened substantially, isolation and purification become simpler, and, in most cases, the yield of target products increases [276].

For instance, double decker crown bis(phthalocyanines) by thedirect interaction of tetra-15-crown-5-phthalocyanine (H 2 Pc) with a Y(OAc) 3 •4H 2 O in the presence of DBU as an organic base in1-chloronaphthalene under reflux (260 °C) was synthesizedwith high yield by Gorbunova and et. al. (Fig.3.7) [277].

Figure3.7Synthesis of bis(phthalocyaninato) Y(III) double-decker complexes

This method offers modularity in terms of ligand choice and forces the twophthalocyanine units to through space delocalization, both phthalocyanine planes are subjected to severe conformational twisting suitable for conjugation-dependent NLO applications [227]. Moreover, this method is synthetically quite easy and high yielding. Therefore, we initiated our work with this procedure [278].

This synthetic method allowed us to synthesizeselectively the double decker bis(phthalocyanine) molecules from free base ABAB type free phthalocyanine Figure3. [START_REF] Denus | [END_REF] The synthesize approach for octupolar Ln(Pc) 2

The reaction yield of lanthanide bis(phthalocyanine) complexes is the order: Y(ABAB) 2 : 60%, Nd(ABAB) 2 : 60%, Eu(ABAB) 2 : 63%, Dy(ABAB) 2 : 54%, Lu(ABAB) 2 : 60% Bian and et. al. suggested that the reaction yields of lanthanide bis(phthalocyanine) complexes aredependent the size of the metal centers. For the series of bis(phthalocyaninato)complexes, the yields are lower for those with a largermetal center [280].However, we didn't observe any relation between the reaction yield and size of metal centers. Ln(Pc) 2 complexes, which were synthesized during this thesis, were characterized by 1 HNMR, 13 C NMR, IR, mass spectrometry, elemental analyses., UV-NIR, X-Ray and second-order NLO properties were investigated by using the HRS techniques. The UV-NIR spectrum of neutral Lu(ABAB) 2 Bis(Phthalocyanine) (9) is given as example in Fig. 3.12 shows a relativily intense absorption at 682 nm with a vibronic band at 645 nm is due to the phthalocyanine Q band. The broad band at 400 The electronic absorption spectra of (ABAB) 2 Ln (Eu (7), Dy (8), Nd [START_REF] Verbiest | [END_REF] and Y ( 11)) are similarto Lu(ABAB) 2 ( 9) and the electronic spectral data summarised in Table 3 were investigated and compared for all double decker Pcs series.

All of Ln(ABAB) 2 (Lu, Dy, Eu, Y, Nd) were crystallized from concentrated chloroform solution by slow diffusion of methanol and the crystal structure was resolved by X-ray diffraction. Fig. 3.15 shows the molecular structure of Lu(ABAB) 2 ( 9) asselected examples to illustrate the structural features of the Ln(ABAB) 2 series of complexes, which are isostructural from each other. The 9)

The molecular central core of Lu(ABAB) 2 has a very similar structure to the previously reported unsubstituted ( 18)and hekzadeka-substituted [START_REF] Ashwell | Optical Materials for Non-linear Optics[END_REF] bis(phthalocyaninato)lutetium(III) complexes [291,292]. Moreover, the twist angles of the two macrocycles, φ T , indicate that the coordination polyhedral of the metals variety from a distorted cube to almosta square antiprism. The twist angle between the two cycles of φ T : 45.05° that creates a chiral non centrosymmetric molecule (Fig. 3.18) and also higher than the values reported 45° for unsubstituted (18) and 42° for octa-substituted (19,[START_REF] Ashwell | Optical Materials for Non-linear Optics[END_REF] (Fig. In the neutral radicalic form,Ln(Pc) 2 , the unpaired electron is delocalized over both rings and therefore no significant differences are found from both phthalocyanine rings. The first hyperpolarizability β values of the octupoles Ln(ABAB) 2 (7)[START_REF] Denus | [END_REF][START_REF] Stucky | Materials for Nonlinear Optics: Chemical Perspectives[END_REF][START_REF] Verbiest | [END_REF](11) were determined by Hyper-Rayleigh Scattering (HRS) method also named The error is estimated to be approximately ±15 %.

3.1.5.Hyper-Rayleigh

The instrumental setup of Hyper-Rayleigh Scattering (HRS), necessary formulas and details of the calculations of β are given in ANNEX 3.

The first hyperpolarizabiliy βobtained for the Ln(ABAB) 2 (7)[START_REF] Denus | [END_REF][START_REF] Stucky | Materials for Nonlinear Optics: Chemical Perspectives[END_REF][START_REF] Verbiest | [END_REF](11) in neutral forms are summarized in the Table 3.2.

Table 3.2

The second-order NLO data for the octupole Ln(ABAB) 2 (7)[START_REF] Denus | [END_REF][START_REF] Stucky | Materials for Nonlinear Optics: Chemical Perspectives[END_REF][START_REF] Verbiest | [END_REF](11) P ETV : Slope of ETV, P s : Slope of Sample, Corr. P S : Corrected slope for sample

The first hyperpolarizabiliy of Ln(ABAB) 2 are exceptionally large with a value of 5750x10 -30 esu for Lu(ABAB) 2 ( 9), 5622x10 -30 esu for Dy(ABAB) 2 ( 8), 5429x10 -30 esu for Eu(ABAB) 2 ( 7), 3251x10 -30 esu for Nd(ABAB) 2 [START_REF] Verbiest | [END_REF] and 3010x10 - 30 esu for Y(ABAB) 2 (11).

To the best of our knowledge these are one of the highest values reported for a non-dipolar compound and compares well with the very best octupolar chromophores described ever reported to dateand much larger than the paracyclophane derivative the closest example of the real cube described by Bazan (46x10 -30 esu) [297]. Moreover, this high NLO activity is roughly 10 times larger than those of octupole phthalocyanine derivatives described in the literature [297,298].

As already observed for the dipolar and octupolar rare-earth series, the NLO Compounds Form activity regularly increases from yttrium to lutetium along the f-element row, and called "metal-induced 300].

This "metal-induced NLO-enhancement" effect was observed in serious Ln (Lu, Eu, Dy, Nd and Y)(ABAB) 2 . For instance,although Lu (9) and Y (11) complexes are isostructural,the β 1907 value of Lu ( 9) complex is roughly 2 times larger than the one of Y ( 11) complex.

The NLO results of the yttrium complex Y(ABAB) 2 is particularly useful to rationalize the "metal-induced" NLO enhancement effect by comparing it with the dysprosium complex Dy(ABAB) 2 . Yttrium presents strong chemical similarities with the lanthanides, and its ionic radius (1.075 Å) is very close to that of dysprosium (1.083 Å). On the other hand, yttrium is not f-block element and therefore has a 4f 0 electronic configuration. Experimentally, the first hyperpolarizability of yttrium, (β 1907 :3010x10 -30 esu) is significantly lower than that of dysprosium (β 1907 :5622x10 - 30 esu), even if these two complexes are isostructural and has roughly same ionic The spectral changes due to chemical oxidation in the UV-NIR spectrum of Lu(ABAB) 2 Bis(Phthalocyanine) ( 9) is illustrated in Fig. 3.22as example. Arrows in spectra indicate the decrease and increase of bands.The oxidation of Lu(ABAB) 2 [START_REF] Stucky | Materials for Nonlinear Optics: Chemical Perspectives[END_REF] was carried out by adding bromine in CHCl 3 to a solution of Lu(ABAB) 2 ( 9) (10 -5 M). The strongest absorption Q band at 743 nm loses intensity and exhibits red shift. Fig. 3.22 also shows that intensity of band at 588 nm and 970 nm, corresponding to radical π-π * transition, significantly increase. In addition, because one electron, which causes the intermolecular transition that was prominent in the neutral form complex 9, is removed from complex, all bands corresponding to those transitions disappeared.

The electronic absorption spectra of oxidized form of (ABAB) 2 Ln (Eu (7), Dy [START_REF] Denus | [END_REF], Nd [START_REF] Verbiest | [END_REF] and Y ( 11)) are similarto oxidized form of Lu(ABAB) 2 ( 9) and the electronic spectral data summarised in The anionic complex (Pc electron by reduction. Moreover the bands at 933 nm and 550 nm, which are linked to the radical part of the complex, also disappeared by reduction of complex 9.

The electronic absorption spectra of reduced form of (ABAB) 2 Ln (Eu (7), Dy [START_REF] Denus | [END_REF], Nd [START_REF] Verbiest | [END_REF] and Y ( 11)) are similarto reduced form of Lu(ABAB) 2 ( 9) and the electronic spectral data summarised in Table 3.4 The first hyperpolarizabiliy βobtain for the Ln(ABAB) 2 (7)[START_REF] Denus | [END_REF][START_REF] Stucky | Materials for Nonlinear Optics: Chemical Perspectives[END_REF][START_REF] Verbiest | [END_REF](11) in oxidized forms are summarized in the The first hyperpolarizabiliy of the oxidized form of Ln(ABAB) 2 seems more complicated to explain than the one of neutral and reduced forms. The first hyperpolarizabiliy of the oxidized form of Ln(ABAB) 2 are still large with a value of 4722x10 -30 esu for Lu(ABAB) 2 ( 9), 4691x10 -30 esu for Dy(ABAB) 2 ( 8), 4548x10 -30 esu for Eu(ABAB) 2 ( 7), 2787x10 -30 esu for Nd(ABAB) 2 [START_REF] Verbiest | [END_REF], and 2801x10 -30 esu for Y(ABAB) 2 (11) (see Fig. 3.24). The first hyperpolarizabiliy of the oxidized form decreased for all Ln(ABAB) 2 (7)[START_REF] Denus | [END_REF][START_REF] Stucky | Materials for Nonlinear Optics: Chemical Perspectives[END_REF][START_REF] Verbiest | [END_REF](11) compare to the neutral form, regardless of the metal center involve in the complex. In comparison, the first hyperpolarisability of the oxidized form are lower than those of neutral form but higher than that of the reduced form values. The intervalence band at 970 nm, partially absorb the scattered light at the second harmonic (953 nm), it might be the reason of the higher NLO activity than the reduced forms, since this new band has substantial ε value (32000 M -1 cm -1 ), compare to reduced (0) forms, that might cause disruptive process resonance effects [307].

However, the first hyperpolarizability of the neutral form of octupolar Lu(ABAB) 2 is still higher than the oxidized one, although contribution of disruptive process resonance effects. These results seem to indicate that the resonance effect has small effect on the quadratic nonlinear response compareto ICT band contribution. It must be noted that a resonance-enhanced value does not represent the intrinsic value for a molecule. The NLO activity of the oxidized form of Ln(ABAB) 2 regularly increases from yttrium to lutetium with the only contribution of the "metal-induced NLOenhancement". The oxidized form of Ln(ABAB) 2 has disadvantages, particularly in terms of transparency/nonlinearity tradeoff , because improved neither NLO activity nor optical transparency compare to neutral form of Ln(ABAB) 2 .

The first hyperpolarizabiliy βobtain for the Ln(ABAB) 2 (7)[START_REF] Denus | [END_REF][START_REF] Stucky | Materials for Nonlinear Optics: Chemical Perspectives[END_REF][START_REF] Verbiest | [END_REF](11) in reduced forms are summarized in the Table 3.6. The reduced form of Ln(ABAB) 2

Bis(Phthalocyanine)was prepared by adding 3 mg of NaBH 4 to 10 mL of a solution of complexes (10 -5 M) in THF/CHCl 3 (1/10).

Table 3.6

The second-order NLO data for the octupole Ln(ABAB) 2 (7)[START_REF] Denus | [END_REF][START_REF] Stucky | Materials for Nonlinear Optics: Chemical Perspectives[END_REF][START_REF] Verbiest | [END_REF](11) P ETV : Slope of ETV, P s : Slope of Sample, Corr. P S : Corrected slope for sample

In the case of the reduced form of Ln(ABAB) 2 , because intermolecular transition is absent, the first hyperpolarizabiliy are still large with a value of 4587x10 -30 esu for Lu(ABAB) 2 ( 9), 4208x10 -30 esu for Dy(ABAB) 2 ( 8), 3693x10 -30 esu for Eu(ABAB) 2 ( 7), 2426x10 -30 esu for Nd(ABAB) 2 [START_REF] Verbiest | [END_REF], 2454x10 -30 esu for Y(ABAB) 2 (11) but quite lower than the values of neutral and oxidized form. The hyperpolarizability in function of the type of lanthanide ion is illustrated in Fig. 3.26.

These results also prove the contribution of the metal-induced NLO-enhancement and the lanthanide contraction to the NLO activity. In the case of the reduced form of Ln(ABAB) 2 , the addition second electron to the complexes, consequently the intermolecular transition and its corresponding bands that was prominent in the neutral form disappeared (see Fig. Although, the reduced form of Ln(ABAB) 2 has lower NLO activity than neutral and oxidized forms, it clearly show a much better transparency (see Fig.

Compounds Form

3.27).

This transparency of reduced of formofLn(ABAB) 2 provides an unique solution to suppress potential problems associated with the electronic transition at the second harmonic wavelength including the linear absorption of the generated 2ω light and the resonance enhancement that elevates the measured β value which artificially inflates the β value. Simply, the reduced Ln(ABAB) 2 allows us to defeat all potential disruptive processes. One can suggest that, even though βvalues of the reduced form is lower than that of neutral and oxidized forms, the resulting βvaluesare much more reliable.

Analyzes of nonoctupolarbis(phthalocyaninato) Ln(III)

double-decker complexes Ln(AB3) 2 (12)(13)(14)[START_REF] Yariv | Quantum Electronics[END_REF], Ln(A4) 2 [START_REF] Yariv | Quantum Electronics[END_REF][START_REF] Kajzar | [END_REF](18), Ln(B4) 2 (19)(20)[START_REF] Ashwell | Optical Materials for Non-linear Optics[END_REF][START_REF] Nalwa | Nonlinear Optics of Organic Molecules and[END_REF][START_REF] Blau | [END_REF], Ln(T4) 2 (24)(25)(26) In order to understand the contribution of octupolar cube structures to the first hyperpolarizability, the nonoctupolar series of lanthanidebis(phthalocyanines) complexes (Ln(AB3) 2 (12)(13)(14), Ln(A4) 2 [START_REF] Yariv | Quantum Electronics[END_REF][START_REF] Kajzar | [END_REF](18), Ln(B4) 2 (19)(20)[START_REF] Ashwell | Optical Materials for Non-linear Optics[END_REF], Ln(T4) 2 (24)(25)(26))were synthesized and the NLO activity measured.

Synthesis of nonoctupolarbis(phthalocyaninato) Ln(III)

double-decker complexes Ln(AB3) 2 (12)(13)(14)[START_REF] Yariv | Quantum Electronics[END_REF], Ln(A4) 2 [START_REF] Yariv | Quantum Electronics[END_REF][START_REF] Kajzar | [END_REF](18), Ln(B4) 2 (19)(20)[START_REF] Ashwell | Optical Materials for Non-linear Optics[END_REF][START_REF] Nalwa | Nonlinear Optics of Organic Molecules and[END_REF][START_REF] Blau | [END_REF], Ln(T4) 2 (24)(25)(26) The unsubstituted (A 4 ) and substituted (B 4, T 4 ) homoleptic bis(phthalocyaninato)lanthanide (III) complexes can be prepared by cyclic tetramerization of the corresponding phthalodinitrile with Ln(Ac) 3 .nH 2 0 either in the solid state or in solution, in the presence of a promoter [308].

In solid state approach, Ln(Pc) 2 are produced by heating (170-190 °C) the powder of unsubstituted or substituted phthalodinitrile with appropriate lanthanide salts (Fig. In the solution approach, the same reactants as in the mentioned procedure are heated in hexanol in the presence of a promoter DBU (1,8-diazabycyclo (5,5,0)undec-7-ene), a strong organic base which favors the formation of the macrocycle (Fig. 3.29) [310,311]. The yield of Ln(Pc) 2 complexes formed seems to be somehow better than in the former solid-state method.

Therefore, this method was preferred for synthesized aforementioned unsubstituted (A 4 ) and substituted (B 4, T 4 ) symmetric bis(phthalocyaninato)lanthanide (III) complexes. The method also gives small amounts of metal freephthalocyanines as side products that wereseparated readily from the sandwich complexes bycolumn chromatography.

CN CN R 2 N N N N N N N N R 1 R 2 R 2 R 2 R 1 R 1 R 1 R 2 N N N N N N N N R 2 R 1 R 1 R 2 R 2 R 1 R 1 R 2 Ln Ln(OAc) 3 .4H 2 O R 1 N N N N N N N N R 2 R 1 R 1 R 2 R 2 R 1 R 1 R 2 N N N N N N N N R 1 R 2 R 2 R 2 R 1 R 1 R 1 R 2 N N N N N N N N R 2 R 1 R 1 R 2 R 2 R 1 R 1 R 2 Ln Ln N NH N N N HN N N R 1 R 2 R 2 R 2 R 1 R 1 R 1 R 2 Figure 3.29.
The method in solution approach cyclic tetramerization for homoleptic bis-Pcs

The nonoctupolarLn(AB3) 2 was obtained from AB3 phthalocyanine with the same method described for octupole Ln(ABAB) 2 (Fig.

N N N R 1 R 2 R 2 R 2 R 1 R 1 R 1 R 2 N N N N N N N N R 2 R 1 R 1 R 2 R 2 R 1 R 1 R 2

Ln

Ln(OAc)

UV-NIR measurements of nonoctupolarbis(phthalocyaninato)

Ln(III) double-decker complexes Ln(AB3) 2 (12)(13)(14)[START_REF] Yariv | Quantum Electronics[END_REF], Ln(A4) 2 [START_REF] Yariv | Quantum Electronics[END_REF][START_REF] Kajzar | [END_REF](18), Ln(B4) 2 (19)(20)[START_REF] Ashwell | Optical Materials for Non-linear Optics[END_REF][START_REF] Nalwa | Nonlinear Optics of Organic Molecules and[END_REF][START_REF] Blau | [END_REF], Ln(T4) 2 (24)(25)(26) The UV-NIR measurements of non substituted (A 4 ) and substituted (AB 3 , B 4, T 4 ) homoleptic bis(phthalocyaninato)lanthanide (III) complexes were carried out in chloroform (1x10 -5 M). Fig. 3.31 shows the absorption spectra of AB3-H 2 Pc ( 6) in solutionin chloroform. AB3-H 2 Pc presents the classical spectrum of low symmetry free phthalocyanines with a B-band at 341 ( 6) and intense Q-band split in two with maxima at 690-723 nm [START_REF] Franken | [END_REF].A small bathochromic (red) shift is observed for the most intense absorption peaks Qx and Qy of AB3-H 2 Pc ( 6)compare to ABAB-H 2 Pc [START_REF] Butcher | The elements of nonlinear optics[END_REF] due to the substitution of the Pc ring by more electron donating thio(hexyl) groups. Ln(ABAB) 2 .All complexes show three (BV, RV, ICT) absorptions bands which all characteristic Pc *-bands related for bis(phthalocyanine) lanthanide (III) complex.

Since, the characteristic Ln(Pc) 2 related bands and effect of nature of the central metal ion were already explained, it wont be repeated for unsubstituted (A 4 ) and substituted (AB 3 , B 4, T 4 ) homoleptic bis(phthalocyaninato)lanthanide (III) complex in this chapter.

The addition of electro-donor substituents to the phthalocyanine core cause The position of the most intense absorption maximum (Q-band) for the bis(thiohexyl substituted phthalocyaninato)Lu(III) complexes depends directly on the electron-donating properties of substituted groups [312]. Due to the better electrondonating property of the alkylthio substituted bis(phthalocyanines) [START_REF] Stucky | Materials for Nonlinear Optics: Chemical Perspectives[END_REF]14,[START_REF] Ashwell | Optical Materials for Non-linear Optics[END_REF]27) all the bands in the electronic absorption spectra of these complexes were found to shift to longer wavelength in comparison substituted Lu(Pc) 2 (18). Between our compounds, we observed that the positions of Qx,y bands in the UV-NIR spectra significantly depend on the number of electron-donating groups for the Ln(Pc) 2 . The Q-band was found to shift to the red in the order Lu(B 4 ) 2 -705 nm> Lu(AB 3 ) 2 -693 nm> Lu(ABAB) 2 -688 nm> Lu(T 4 ) 2 -681 nm> Lu(A 4 ) 2 -662 nm. The total shift between the sixteen thiohexyl substituted Lu(B 4 ) 2 and the unsubstituted Lu(A 4 )

phthalocyanines is about 45 nm.

Lu(ABAB) 2 and Lu(T 4 ) 2 have the same number of hexyl thio substituted groups on the Pcs core. However the peripherally tetra substituted Lu(T 4 ) 2 show slightly different electronic absorption spectra, probably due to the mixture of isomers, compared with the Lu(ABAB) 2 . The total shift between the Lu(ABAB) 2 and the Lu(T 4 ) 2 phthalocyanines is about 9 nm. The addition of electron-donating alkylthio substituents to the phthalocyanine core doesn't cause a significant shift of the RV and ICT band (Fig. The electronic absorption spectra of neutral form of Lu(Pc) 2 are similar to neutral form of nonoctupolar complexes: Ln(AB3) 2 (12)(13)(14)[START_REF] Yariv | Quantum Electronics[END_REF], Ln(A4) 2 [START_REF] Yariv | Quantum Electronics[END_REF][START_REF] Kajzar | [END_REF](18), Ln(B4) 2 (19)(20)[START_REF] Ashwell | Optical Materials for Non-linear Optics[END_REF][START_REF] Nalwa | Nonlinear Optics of Organic Molecules and[END_REF][START_REF] Blau | [END_REF], Ln(T4) 2 (24)(25)(26) and the electronic spectral data summarised in Table 3.7.

Table 3.7UV-NIR spectral data of neutral forms ofLn(AB3) 2 (12)(13)(14), Ln(A4) 2 [START_REF] Yariv | Quantum Electronics[END_REF][START_REF] Kajzar | [END_REF](18), Ln(B4) 2 (19)(20)[START_REF] Ashwell | Optical Materials for Non-linear Optics[END_REF], Ln(T4) 2 (24)(25)(26) The oxidation of Lu(Pc) 2 (14,26,[START_REF] Ashwell | Optical Materials for Non-linear Optics[END_REF] were carried out by adding bromine in CHCl 3 to a solution of Lu(Pc) 2 (14,26,[START_REF] Ashwell | Optical Materials for Non-linear Optics[END_REF] The strongest absorption Q bands lose intensity and exhibits red shift.

Moreover, theintensity of bands (BV and RV) which corresponding to radical ππ * transition, significantly increase. In addition, because one electron, which causes the intermolecular transition that was prominent in the neutral form complexes, is removed from complex, all bands corresponding to those transitions disappeared.

The position of the Q and RV bands for the Lu(Pc) 2 (14,26,[START_REF] Ashwell | Optical Materials for Non-linear Optics[END_REF] complexes depends directly on electron-donating property of substituted groups. Due to the better electron-donating properties of the Lu(B4) 2 [START_REF] Ashwell | Optical Materials for Non-linear Optics[END_REF], the Q and RV bands in the electronic absorption spectra were found to shift to longer wavelength in comparison with those of Lu(Pc) 2 (14, 26). Fig. 3.34shows that the position of BV bands of complexes is not depend on electron-donating property of substituted groups.

However, the intensity of BV bands seems increase with electron donating groups.

The intensity of BV band of Lu(B4) 2 ( 21) is much higher than Lu(Pc) 2 (14, 26)

The electronic absorption spectra of oxidized form of Lu(Pc) 2 are similar to oxidized form of nonoctupolar Ln(AB3) 2 (12)(13)(14)[START_REF] Yariv | Quantum Electronics[END_REF], Ln(A4) 2 [START_REF] Yariv | Quantum Electronics[END_REF][START_REF] Kajzar | [END_REF](18), Ln(B4) 2 (19)(20)[START_REF] Ashwell | Optical Materials for Non-linear Optics[END_REF][START_REF] Nalwa | Nonlinear Optics of Organic Molecules and[END_REF][START_REF] Blau | [END_REF], Ln(T4) (24)(25)(26) and the electronic spectral data summarized in Table 3.8. (12)(13)(14), Ln(A4) 2 [START_REF] Yariv | Quantum Electronics[END_REF][START_REF] Kajzar | [END_REF](18), Ln(B4) 2 (19)(20)[START_REF] Ashwell | Optical Materials for Non-linear Optics[END_REF], Ln(T4) 2 (24)(25)(26) Bis-phthalocyanine (1 x 10 -5 M) B: Soret band, BVand RV: radical transition bands, ICT: Intramolecular charge transfer band

The reduced form of Lu(Pc) 2 bis(Phthalocyanine) (14,26,[START_REF] Ashwell | Optical Materials for Non-linear Optics[END_REF] The anionic complex (Pc 2 Lu -) displays a splitted Q band absorbing at 641 nm and 751 nm. The intervalence transition is absent due to addition of second electron by reduction. Moreover the bands at 933 nm and 550 nm, which are linked to the radical part of the complex, also disappeared by reduction of complex Lu(Pc) 2 (14,26,[START_REF] Ashwell | Optical Materials for Non-linear Optics[END_REF]. Moreover, contrast to neutral and oxidized form, the number of electro donating groups don't cause significant red-shift (Fig. The electronic absorption spectra of reduced form of Lu(Pc) 2 (14,26,[START_REF] Ashwell | Optical Materials for Non-linear Optics[END_REF] are similarto reduced form of nonoctupolar Ln(AB3) 2 (12)(13)(14)[START_REF] Yariv | Quantum Electronics[END_REF], Ln(A4) 2 [START_REF] Yariv | Quantum Electronics[END_REF][START_REF] Kajzar | [END_REF](18), Ln(B4) 2 (19)(20)[START_REF] Ashwell | Optical Materials for Non-linear Optics[END_REF][START_REF] Nalwa | Nonlinear Optics of Organic Molecules and[END_REF][START_REF] Blau | [END_REF], Ln(T4) 2 (24)(25)(26) and the electronic spectral data summarized in Table 3.9 A bs orba nc e W a veleng ht (nm) Table 3.9. UV-NIR spectrums of reduced forms of Ln(AB3) 2 (12)(13)(14), Ln(A4) 2 [START_REF] Yariv | Quantum Electronics[END_REF][START_REF] Kajzar | [END_REF](18), Ln(B4) 2 (19)(20)[START_REF] Ashwell | Optical Materials for Non-linear Optics[END_REF], Ln(T4) 2 (24)(25)(26) Bis-phthalocyanine (1 x 10 The first hyperpolarizabiliy βobtain for the Ln(AB3) 2 (12)(13)(14), Ln(A4) 2 [START_REF] Yariv | Quantum Electronics[END_REF][START_REF] Kajzar | [END_REF](18), Ln(B4) 2 (19)(20)[START_REF] Ashwell | Optical Materials for Non-linear Optics[END_REF], Ln(T4) 2 (24)(25)(26) in neutral forms are summarized in the (12)(13)(14), Ln(A4) 2 [START_REF] Yariv | Quantum Electronics[END_REF][START_REF] Kajzar | [END_REF](18), Ln(B4) 2 (19)(20)[START_REF] Ashwell | Optical Materials for Non-linear Optics[END_REF], Ln(T4) 2 (24)(25)(26) P ETV : Slope of ETV, P s : Slope of Sample, Corr. P S : Corrected slope for sample

The conclusions, which we came out with these NLO measurements, are that metal-induced NLO-enhancement and lanthanide contraction, also applies for the series of nonoctupolar complexes Ln(AB3) 2 (12)(13)(14), Ln(A4) 2 [START_REF] Yariv | Quantum Electronics[END_REF][START_REF] Kajzar | [END_REF](18), Ln(B4) 2 (19)(20)[START_REF] Ashwell | Optical Materials for Non-linear Optics[END_REF], Ln(T4) 2 (24)(25)(26) as described previous chapter.

Thereafter only the first hyperpolarizabiliy of nonoctupolar Lutetium complexes Ln(Pc) 2 will be compared. The first hyperpolarizability values4630x10 - 30 esu for Lu(B4) 2 ( 21), 4592x10 -30 esu for Lu(AB3) 2 ( 14), 4116x10 -30 esu for Lu(A4) 2 (18), 4011x10 -30 esu for Lu(T4) 2 (26) were obtained.

Ifthe firsthyperpolarizabiliy versus Lu(Pc) 2 is plotted (See Fig. The effect of the contribution of the octupolar structure on the first hyperpolarizabiliy can be highlight comparing the NLO activity between the octupole Lu(ABAB) 2 [START_REF] Stucky | Materials for Nonlinear Optics: Chemical Perspectives[END_REF] and the nonoctupole Lu(T 4 ) 2 (26). In both case, the metal center and the number of thiohexyl substituent are identical, allowing us to eliminate the metal-induced NLO-enhancement, the lanthanide contraction effect and the influence of the number of substituent. Lu(ABAB) 2 and Lu(T 4 ) 2 have 5756 x10 - 30 esu and 4011 x10 -30 esu βhyperpolarizability values respectively. Only the octupolar structure contribution can explain this huge difference of NLO activity.

If the first hyperpolarizabiliy of the nonoctupole Lutetium complexes Lu(B4) 2 [START_REF] Ashwell | Optical Materials for Non-linear Optics[END_REF], Lu(AB3) 2 (14), Lu(A4) 2 (18), Lu(T4) 2 (26) are confronted, the influence of the number of electron-donating groups on the NLO activity can be observed. The order of β is as follow: Lu(T 4 ) 2 < Lu(A 4 ) 2 < Lu(AB 3 ) 2 < Lu(B 4 ) 2 . Like these complexes have the same metal center but not the same number of thiohexyl substituent, we can deduce that the number of electron-donating groups is the reason of the differences of NLO activity between nonoctupolar compounds. The first hyperpolarizabiliy βobtain for the Ln(AB3) 2 (12)(13)(14), Ln(A4) 2 [START_REF] Yariv | Quantum Electronics[END_REF][START_REF] Kajzar | [END_REF](18), Ln(B4) 2 (19)(20)[START_REF] Ashwell | Optical Materials for Non-linear Optics[END_REF], Ln(T4) 2 (24)(25)(26) in oxidized forms are summarized in the Thereafter only the first hyperpolarizabiliy of nonoctupolar lutetium complexes Lu(Pc) 2 (Lu(B4) 2 [START_REF] Ashwell | Optical Materials for Non-linear Optics[END_REF], Lu(AB3) 2 (14), Lu(A4) 2 (18), Lu(T4) 2 ( 26) )will be compared as example.

Table 3.11 The second-order NLO data for the Ln(AB3) 2 (12)(13)(14), Ln(A4) 2 [START_REF] Yariv | Quantum Electronics[END_REF][START_REF] Kajzar | [END_REF](18), Ln(B4) 2 (19)(20)[START_REF] Ashwell | Optical Materials for Non-linear Optics[END_REF], Ln(T4) 2 (24)(25)(26) P ETV : Slope of ETV, P s : Slope of Sample, Corr. P S : Corrected slope for sample

It is important to note that, NLO activities of reduced and oxidized Ln(A4) 2

and Ln(AB3) 2 are oddly high and incoherent according to previous results. The origin of this enhancement is unclear. Therefore, we consider that these results come from uncertainty of HLS measurement (15-20 %). We are aware that these experiments will need to be repeating in order to clarify this discrepancy. (Ln(AB3) 2 (12)(13)(14), Ln(A4) 2 [START_REF] Yariv | Quantum Electronics[END_REF][START_REF] Kajzar | [END_REF](18), Ln(B4) 2 (19)(20)[START_REF] Ashwell | Optical Materials for Non-linear Optics[END_REF], Ln(T4) 2 (24)(25)(26)))

Compounds

The first hyperpolarizabiliy βobtain for the Ln(AB3) 2 (12)(13)(14), Ln(A4) 2 [START_REF] Yariv | Quantum Electronics[END_REF][START_REF] Kajzar | [END_REF](18), Ln(B4) 2 (19)(20)[START_REF] Ashwell | Optical Materials for Non-linear Optics[END_REF], Ln(T4) 2 (24)(25)(26) in reduced forms are summarized in the Table 3.12.The reduced form of Ln(Pc) 2 Bis(Phthalocyanine)were prepared by adding 3 mg of NaBH 4 to 10 mL of a solution of complexes (10 -5 M) in THF/CHCl 3 (1/10).

The first hyperpolarizabiliy of the reduced form of nonoctupolar Ln(Pc) 2

(Ln(AB3) 2 (12)(13)(14), Ln(A4) 2 [START_REF] Yariv | Quantum Electronics[END_REF][START_REF] Kajzar | [END_REF](18), Ln(B4) 2 (19)(20)[START_REF] Ashwell | Optical Materials for Non-linear Optics[END_REF], Ln(T4) 2 (24)(25)(26)) are still large but quite lower than the values of neutral and oxidized form.

Table 3. 12 The second-order NLO data for the nonoctupole Ln(AB3) 2 (12)(13)(14), Ln(A4) 2 [START_REF] Yariv | Quantum Electronics[END_REF][START_REF] Kajzar | [END_REF](18), Ln(B4) 2 (19)(20)[START_REF] Ashwell | Optical Materials for Non-linear Optics[END_REF], Ln(T4) Dy (25) Red. 0.005 0.014 0.0415 0.043 0.0442 2875 Lu(26) Red. 0.008 0.015 0.0434 0.047 0.0495 2979

When thenonoctupolar Ln(Pc) 2 is reduced, the intramolecular charge transfer (ICT) band is absent due to addition of second electron. And it seems that the decrease of the hyperpolarizability values is directly related to the vanishing of this band.

As mentioned before, although the reduced form of nonoctupolar Ln(Pc) 2 has lower NLO activity than neutral and oxidized forms, theypossess better transparency. IR (KBr) ν (cm -1 ):2970 (s), 2950 (br,w), 2860 (s), 2240 (s), 1560 (s), 1450 (s), 1350 (s), 1280 (s), 1260 (s) 1 H NMR (CDCl 3 ):δ7. 63 (dd, 1H),7.55 (d, 1H), 7.49 (dd, 1H), 3.00 (t, J: 5.6 Hz,2H), 1.46 (m, 2H), 1.29 (b, 6H), 0.87 (t,J: 6.6 Hz, 3H) .

EXPERIMENTAL PART

13 C NMR (CDCl 3 ): δ 14.05, 22.59, 28.15, 28.77, 31.70, 31.87,110.57, 115.1, 115.56, 116.19, 129.82, 129.94, 133.12, 147.53.

(ESI-MS) m/z: 267.10 [M+Na]

EA: Calculated: C 68.81, H 6.60, N 11.46, S 13.12 Found: C 68.46, H 6.41, N 11.76, S 13,60

4,5-Bis(hexylthio)-1,2-dicyanobenzene (2)

4,5-Dichloro-1,2-dicyanobenzene (10 g, 50.8 mmol) and pulverized K 2 CO 3 (30 g, 21.7 mmol) are stirred in DMF (70 mL), then 1-hexanethiol (14.76 g, 101.6 mmol) was added drop by drop. The reaction mixture was vigorously stirred under argon atmosphere at room temperature overnight. After addition of water, the solution was extracted by DCM.Thecombined organic phase were washed with water (3 x50 mL) and dried over sodium sulfate. The solvent was removed under reduced pressure, and the residue was recrystallized from ethanol to give pure 4,5bis(hexylthio)-1,2-dicyanobenzene (2) [314]. 83,134.32, 116, 109.55, 34.21, 31.64, 28.95, 28.50, 22.71, 14 13 C NMR (CDCl 3 ):δ 167. 83, 141.32, 131.81, 118.77, 33.36, 28.95, 28.50, 22. 71, 14.22

ESI-MS (m/z): 378 [M+H] + .

EA: Calculated: C 63.61, H 8.27, N 11.13, S 16.98 Found: C 63.44, H 8.48, N 11.46, S 16.

hexa(hexylthio)phthalocyanine (6)

A mixture of anhydrous triethylamine (0.72 mL, 5.2 mmol, 2 eq) and 1,3,3trichloroisoindolenine (4) (2.9 g, 13 mmol, 5 eq) in anhydrous THF (400 mL) under argon was cooled to approximately 0°C with and ice/salt bath. A solution of 4,5bis(hexylthio)isoindoline 1,3-diimine (3) (1 g, 2.65 mmol, 1 eq) in anhydrous THF (400 mL) was then added over a period of 12 hours. The mixture was reheated slowly to room temperature overnight.

After filtration under argon to remove the triethylammonium chloride, hydroquinone (0,286 g, 2.65 mmol, 1 eq) and sodium methoxide (0,421 g, 7.8 mmol, 3 eq) were added to the filtrate and the resulting mixture was heated at 65°C under argon overnight to obtain a green solution. The solvent was removed under reduced pressure and the crude product extractedin aSoxhlet with ethanol and acetone to take away the organic impurities and the B 4 phthalocyanine, followed by CH 2 Cl 2 to obtain a solution containing a mixture of ABAB and AB 3 phthalocyanines. The two compounds were separated by preparative thin layer chromatography on silica eluting with n-hexane/dichloromethane (5:2, v/v). Obtained: 65 mg (2 %) of AB 3 (2,3,9,10,16,17 hexa(hexylthio)phthalocyanine) as the first eluting compound and 206mg (8 %) of the desired ABAB phthalocyanine as the second eluting compound.

ABAB-5:

206mg, Yield (8 %) C 56 H 66 N 8 S 4 Mw: 979.44 IR (KBr) ν(cm -1 ): 3307 (s), 3070(br, w), 2850-2919 (w), 1603 (s), 1537 (s). 1 H NMR (CDCl 3 ):δ. 7.96 (s, 4H),7.56 (d, 4H), 7.48 (d, 4H), 3.07(t, J: 7 Hz, 8H), 1.96 (m, 8H), 1.72 (m,J 1 : 14 Hz,J 2 : 7.2 Hz,8H), 1.54 (m, 16H), 1.08 (t, J: 6.3 Hz,12 H), -5.30 (s, 2H).

13 C NMR (CDCl 3 ): 138.4, 134.9, 131.04, 128.08, 121.27, 118.20, 33.29, 31.80, 29.20, 28.67, 22. 81, 14 9, 138.04, 135.55, 132.27, 131.9, 131.176, 128.48, 121.85, 119.51, 118.8, 117.98, 33.88, 33.66, 33.33, 31.85, 29.31, 29.23, 29.18, 28.66, 22.80 MALDI-TOF MS: m/z 1212 [M] + .

4.2.6.General method for the synthesisof ABAB and AB3homoleptic bis(phthalocyaninato) lanthanide(III)complexes ((Ln(ABAB) 2 ) (7-11), (Ln(AB3) 2 ) (12-15))

A mixture of dry Ln(OAc) 3 .4H 2 O powder (0,1mmol), DBU (1 mL) and a solution of free phthalocyanine (0.21 mmol) in 1-chloronapthalene (3 mL) was refluxed for 4 h under nitrogen to give dark-green solution. The solution was cooled to room temperature and hexane (100 mL) was slowly added. The precipitated product was filtered off. The filtrate was concentrated and purified by column chromatography on silica gel eluting (Ln(ABAB)

4.2.6.1.ABAB bis(phthalocyaninato) europium(III) complex (Eu(ABAB) 2 )(7)

Green product was prepared according to the general protocol as described the synthesis method above. Green product was prepared according to the general protocol as described the synthesis method above.

4.2.6.7.AB3bis(phthalocyaninato) dyprosium(III) complex (Dy(AB 3 ) 2 )(13)

Green product was prepared according to the general protocol as described the synthesis method above. Green product was prepared according to the general protocol as described the synthesis method above. Green product was prepared according to the general protocol as described the synthesis method above. Green product was prepared according to the general protocol as described the synthesis method by using related dinitrile derivative, above. Green product was prepared according to the general protocol as described the synthesis method by using related dinitrile derivative, above. Green product was prepared according to the general protocol as described the synthesis method by using related dinitrile derivative, above. Green product was prepared according to the general protocol as described the synthesis method by using related dinitrile derivative, above. Green product was prepared according to the general protocol as described the synthesis method by using related dinitrile derivative, above. Green product was prepared according to the general protocol as described the synthesis method by using related dinitrile derivative, above. Green product was prepared according to the general protocol as described the synthesis method by using related dinitrile derivative, above.

N N N N N N N N R 1 R 2 R 2 R 2 R 1 R 1 R 1 R 2 N N N N N N N N R 2 R 1 R 1 R 2 R 2 R 1 R 1 R 2

GENERAL CONCLUSION

Recently, a new class of materials based on octupolar symmetries has been proposed for NLO applications by Zyss and coworkers. Octupolar molecules lack permanent dipole moments and have better chances to adopt noncentrosymmetric packing. Another significant advantage of octupolar systems is that their hyperpolarizability (β) increases steadily as the extent of charge transfer increases, whereas theβof dipolar molecules increases to a maximum value and then decreases as the length of the conjugation increases.

Moreover, it has been shown that the basic template for octupolar molecules is a cube with eight alternated charges at the corner and delocalization of the charges between the higher and lower plans. Despite all the various of 2D and 3D octupolar molecule structures, which were deduced from this basic cubic point charge template by projecting the charges, reported, no molecules actually representing the "real" cube have been achieved so far.

Our initial goalin this thesiswas to develop a categorized strategy for thesynthesis of cubic octupoles. So, we foreseen that real octupolar cube can be demonstrated by designing a bis(phthalocyaninato)Ln-(III) double-decker complex with a crosswise ABAB phthalocyanine bearing alternating electron-donor and electron-acceptor groups. And these cubic systems are expected to show high nonlinearities and improve nonlinearity/transparency tradeoff.

The crosswise ABAB phthalocyanine was synthesized by regioselective approach. Finally, the real octupolar cube bis(phthalocyanine) complexes were obtained in good yield from the ABAB phthalocyanine and lanthanide acetate in refluxing 1-chloronaphthalene using DBU as an organic base. The results of β values undoubtedly shows that the octupole Ln(ABAB) 2 has higher first hyperpolarizabiliy than the corresponding nonoctupole Ln(Pc) 2 (Ln(AB3) 2 , Ln(A4) 2 , Ln(B4) 2 , Ln(T4) 2 ) complexes as we expected. The number of electron-donating groups have significant influence on the first hyperpolarizabiliy of the nonoctupole complexes Ln(Pc) 2 and the order of β is as follow: Lu(T 4 ) 2 <

Lu(A 4 ) 2 < Lu(AB 3 ) 2 < Lu(B 4 ) 2 . While, the electron-donating groups increase NLO activity, clearly cost optical transparency because of red shift.

Finally, we have predicted and achieved the closest structured reported so far for the "true" octupolar cube. And these cubic octupolar bis(phthalocyanines) exhibits the highest quadratic hyperpolarizability ever reported for an octupolar molecule. To obtain the β values, it was necessary to work in three steps. First, the second-order intensity of the octupolar ethyl violet as reference only was measured.

The same experiment was then carried out with the solution of the complex and measurement of reference was repeated in order to have more acquired results. In these two cases, I 2w (intensity of the second-harmonic) versus I w (the square of the intensity of harmonic light) was plotted (Fig. ANNEX3.2). Knowing the βrefvalue, βwas determined by calculating the ratio of the two slopes. To obtain the most precise results as possible, around 3 slopes for both reference and solution of complex were plotted for each compound. And then, average of these slopes were used for calculation of theβvalues.

I 5 . 3 . 1 . 6 . 3 . 1 . 6 . 1

 53163161 express my profound thanks to the French Embassy in Ankara for having given me an opportunity to carry out my doctoral work by PHD co-tutelle fellowship. I cannot express my gratitude in mere words to my parents for their affectionate encouragement and support throughout. complexes (Ln(ABAB) 2 (Lu, Dy, Eu, Y, Nd)) Hyper-Rayleigh Scattering (HRS) Measurements of Neutral Form of octupolar bis(phthalocyaninato) Ln(III) double-decker complexes (Ln(ABAB) 2 (Lu, Dy, Eu, Y, Nd)) Analyzes of oxidized and reduced form of octupolar bis(phthalocyaninato) Ln(III) double-decker complexes (Ln(ABAB) 2 (Lu, Dy, Eu, Y, Nd)) UV-NIR measurements of oxidized and reduced form of octupolar bis(phthalocyaninato) Ln(III) double-decker complexes (Ln(ABAB) 2 (Lu, Dy, Eu, Y, Nd))

1 . 2 . 2 . 2 . 3 . 2 . 4 . 5 . 2 . 6 . 2 . 7 . 2 . 8 . 2 . 9 . 2 . 10 . 2 . 11 . 2 . 12 . 2 . 14 . 2 . 15 . 2 . 16 . 2 . 17 .Selected ferrocenyl complexes 2 . 18 . 2 . 22 . 2 . 23 . 2 . 24 . 2 . 25 . 2 . 26 . 2 . 27 . 2 . 28 . 2 . 29 . 2 . 31 . 2 . 32 . 2 . 33 . 2 . 34 . 2 . 35 . 2 . 36 . 2 . 38 . 2 . 39 . 2 . 40 . 2 . 41 . 2 . 42 . 2 . 43 .

 1222324526272829210211212214215216217218222223224225226227228229231232233234235236238239240241242243 ABBREVIATIONS

2. 45 . 2 . 46 . 2 . 48 . 2 . 49 . 2 . 50 . 2 . 51 . 2 . 54 . 63 3. 1 . 3 . 2 . 3 . 3 . 3 . 4 . 3 . 5 . 3 . 6 . 3 . 7 . 3 . 8 . 2 3. 9 . 3 . 10 . 3 3. 13 . 14 . 3 . 15 . 3 . 16 . 3 . 17 . 3 . 18 . 3 . 19 . 3 . 21 . 2 3. 22 . 3 . 23 . 3 . 24 . 2 3. 25 . 3 . 26 . 2 3. 27 . 3 . 28 . 3 . 29 . 3 . 30 . 2 3. 31 . 3 . 32 .+Br 2 36 . 2 3. 37 . 3 . 38 .

 45246248249250251254631323334353637382931031314315316317318319321222323324225326227328329330231332236237338 The structures of 3D octupolar bipyridine metal complexes Octupolar aryl trisphthalocyanine phosphonium salt 2.47.3D octupolarPcbased compounds and their Second-Order NLO Properties Schematic representation of HRS process in bulk liquid Benchmark materials for HRS experiment Schematic representation of general octupolar distribution and pCP template (a) Schematic representation of a molecule with square geometry (b) A cubic octupole template (c) A disordered cubic octupole template 2.52.Sandwiches phthalocyanines and porphyrins as a octupole template 2.53.The structures of crosswise ABAB type free Pc and octupolar double decker lanthanides bis(phthalocyanines) The structures of non-octupolar AB 3 , A 4 , B 4 , T 4 type double decker lanthanide homoleptic bis(phthalocyanines) (a) Schematic of a molecule with square geometry (b) A cubic octupole template (c) A disordered cubic octupole template The statistical condensation approach for synthesize ABAB type pc The statistical condensation approach for steric hinderance Pc The first regioselective approach for crosswise-Pc The regioselective approach for crosswise-Pc Synthetic route of crosswise ABAB type Pc by regioselective approach. Synthesis of bis(phthalocyaninato) Y(III) double-decker complexes The synthesize approach for octupolar Ln(Pc) Absorption spectra of free phthalocyanine (i) and metallo phthalocyanine (ii) and Electronic transitions accounting for B and Q bands of phthalocyanines UV-Vis Spectrum of ABAB (5) type free phthalocyanines 3.11. UV-NIR spectrum of a neutral Ln(Pc) 2 bisphthalocyanine and scmatic representation of the MO levels 3.12. UV-NIR spectrum of Lu(ABAB) 2 Bis-phthalocyanine (1 x 10 -5 M) in CHCl The UV-NIR spectrum of neutral Ln(Eu, Dy, Lu, Y, Nd)(Pc(ABAB) Plot of the interplane distances vslanthanide ionic radius Crystallographic structure of Lu(ABAB) 2 (9) The interplane distance (d N4-N4 ) of Ln(ABAB) (Lu, Eu, Dy, Nd , Y) The interplane distance (d N4-N4 ) of Ln(ABAB) 2 vs lanthanide contraction The twist angles φ T of Ln(ABAB) 2 (Lu, Eu, Dy, Y, Nd) Plot of the hyperpolarisability β vs Ln(ABAB) 2 (a) and f-orbital filling (b) 3.20. The UV-NIR spectrum of neutral Ln (Eu, Dy, Lu, Y, Nd)(ABAB) 2 in CHCl 3 (1x10 -5 M) (b) Plot of the interplane distances vslanthanide ionic radius Neutral, oxidized, and reduced forms of Ln(Pc) UV-NIR spectrum of Lu(ABAB) 2 Bis-phthalocyanine (1 x 10 -5 M) in CHCl 3 +Br 2 (oxidized) UV-NIR spectrum of reduced form ofLu(ABAB) 2 Bis-phthalocyanine (1 x 10 -5 M) in (1/10 -THF/CHCl 3 + 3 mg NaBH 4 ) Plot of the hyperpolarisability coefficient β vs oxidized form of Ln(ABAB) UV-NIR spectra of Eu(ABAB) 2 bis(Phthalocyanine) (7) (1 x 10 -5 M) Plot of the hyperpolarisability coefficient β vs reduced form of Ln(ABAB) UV-NIR spectrum of Eu(ABAB) 2 Bis(Phthalocyanine) (7) (1 x 10 -5 M) Tetramerization Solid-state approachfor homoleptic bis(Pcs) The method in solution approach cyclic tetramerization for homoleptic bis-Pcs The synthesize approach for Ln(AB3) UV-Vis spectra of AB3 (6) type free phthalocyanine The UV-NIR spectra of neutral Lu(Pc(SC 6 ) n:0-8 ) 2 in CHCl 3 (1x10 -5 M) 3.33. The UV-NIR spectra of neutral Lu(Pc(SC 6 ) n:0-8 ) 2 in CHCl 3 (1x10 -5 M) 3.34. UV-NIR spectra of Lu(Pc) 2 Bis(phthalocyanine) (1 x 10 -5 M) in CHCl 3 Plot of the hyperpolarisability coefficient β vs Lu(Pc) The UV-NIR spectra of neutral Lu(Pc(SC 6 ) n:0-8 ) 2 in CHCl 3 (1x10 -5 M) Plot of the hyperpolarisability coefficient β vs (a) octupolar Lu(ABAB) 2 (b) nonoctupolar Lu(B4) 2

Figure 2 . 1 .

 21 Figure 2.1.Induced polarisation as a function of time.(a) Linear and represention as a function of applied field.

Figure 2 . 2 .

 22 Figure 2.2.Induced polarisation as a function of time.(b) nonlinear and represention as a function of applied field.

Figure 2 . 3 .

 23 Figure 2.3.The process of second-harmonic generation.

Figure 2 . 4 .

 24 Figure 2.4. Plots of the electric field of (a) an applied electromagnetic wave and (b)

Figure 2 . 5 .

 25 Figure 2.5. Plots of the electric field of (a) an applied electromagnetic wave and (b)

  of second-order NLO materials is now quite developed andessential criteria for exhibition of large hyperpolarizabilities have been discovered. The basic rules are as follows: v Polarisable material v Asymmetric charge distribution v A pathway of π-conjugated electrons v Asymmetric crystal packing Moreover, for optical applications, a nonlinear material should posses the subsequent features [22]. v Wide optical transparency area v High laser damage threshold v Ability to process into crystals, thin films, etc. v Easy of fabrication v Nontoxicity and good environmental stability v High mechanical strength and thermal stability v Fast optical response time.

  ) Metal-based systems can possess metal-to-ligand (MLCT) or ligand-to-metal (LMCT) charge transfer bands in the visible region of the spectrum. These optical absorption bands are usually associated with large second-order activity (although, they can also lead to "transparency" problems). b) Chromophores, such as phthalocyanines and its analogs, containing metal ions are between the most strongly colored materials known. The strength of the optical absorption band (related to its transition dipole moment) is also related with large NLO. c) Metal-based compounds have low-energy excited states with excited-state dipole moments considerably different from their respective ground-state dipole moments. Most of these excited states involve transfer of electron density between the central metal and one or more of the associated ligands and have large oscillator strength. d) Metal-based compounds also have significant benefits in the range and mix of non-aromatic ligands that can be attached to the metals. These ligands can shift the occupied and unoccupied metal d orbitals that interact with the πelectron orbitals of the conjugated ligand system. This provides a mechanism for fine-tuning and optimizing β or the crystallographic factors that control the bulk susceptibility. The only predictable drawback is the low energy d-d transitions present in nearly all metal-based compounds, normally observed in the visible light region. This

Figure 2 . 7 .

 27 Figure 2.7. Various methods for preparing metal-free phthalocyanine

Figure 2 . 8 .

 28 Figure 2.8. Various methods for preparing metallo phthalocyanine

Figure 2 . 9 .

 29 Figure 2.9. Proposition of a reaction mechanism for a MPc.

2 .

 2 Nomenclature of phthalocyaninesAn unambiguous system for compound nomenclature is required to distinguish the many phthalocyanine derivatives. The phthalocyanines is named with base on the formula a-(L)n-n&p-S-Pc M(Fig.2.10)[START_REF] Mckeown | Phthalocyanine Materials: Synthesis, Structure, Function[END_REF].

Figure 2 . 11 .

 211 Figure 2.11. Structure of different type of Pcsa)porphyrinb)subPcc) double decker

Figure 2

 2 Figure 2.12 Charge transfer in metallophthalocyanines

πFigure 2 .

 2 Figure 2.13.a-The prototypical dipolar D-π-A p-nitroaniline molecule, b-Dipolar charge distribution in protypical dipolar systems

2 . 14 )

 214 [109].

Figure 2 . 14

 214 Figure 2.14 Typical push-pull type benchmarks

Figure 2 . 15 .

 215 Figure 2.15. The second order optical nonlinearity in a donor or acceptor substituted benzene.

Figure 2 . 16 .

 216 Figure 2.16.Values of β for para, meta and ortho nitroaniline [111]

  possess intense, low energy metal-to-ligand charge transfer (MLCT), ligand-to metal charge transfer (LMCT), or intraligand charge transfer (ILCT) excitations. Nonlinear optic metal complexes are relatively new and unexplored compare to organic nonlinear optic materials. Metal complexes have good potential as second-order NLO materials. Moreover, in the D-π-A (Push-pull) systems metal complexes are able to act as donor or acceptor groups, or as polarisable bridge[127][128][129][130].Since the Green et al. who, reporteda powder SHG efficiency 62 times that of urea for cis-1-ferrocenyl-2-(4-nitrophenyl) ethylene, metal-based moleculeswere intensely investigated as donor groups, and especially ferrocenyl compounds had special interest among the metal-based complexes for NLO[131,132]. The ferrocenyl compoundscan act as a reasonable donor group and their second-order NLO properties are similar with those of related methoxyphenyl organic materials[133,134]. The βvalues are smaller than expected; correspond to donor strength estimatedfrom binding energy and redox potential. This result is indicate that electronic coupling between the metal d-orbitals and the π-network of the substituent is quite poor.

Fig 2 . 17

 217 Fig 2.17 Selected ferrocenyl complexes

2 . 18 )

 218 [137,138]. And because ruthenium has the higher ionization energy compare to iron. The substituting iron with ruthenium in the complex cause a blue shift in the absorption bands and decreases the β values.

Fig. 2 .

 2 Fig. 2.18 Selected ferrocenyl and ruthenocenyl complexes

Fig. 2 . 19 .

 219 Fig. 2.19. Selected Ruthenium(II) amine complexes

Fig. 2 .

 2 Fig. 2.20 Stilbazole and bis(stilbazole) metal complexes

Fig. 2 . 2 . 6 . 1 . 3 .

 22613 Fig. 2.21 Donor and/or bridge role of the metal centre in Schiff base complexes on passing from unsubstituted to D/A substituted. Adapted from ref. [150]

2 . 22 )

 222 [159,160]. The measurements were consummate by the EFISHG technique, but no sign of relevant βwas found[161].In these studies, both the donor and acceptor functional groups were directly attached to the Pc core[162][163][164][165].

Figure 2 . 22

 222 Figure 2.22 Structures of tetra substituted push-pull phthalocyanines

  synthesized for studying the electronic character of the substituents and influence of the position, as well as the role of the central metal atom, on the second-order NLO properties of push-pull phthalocyanines with extended conjugation (Fig.2.23).

Figure 2 . 23 .

 223 Figure 2.23.Structure of extended π-conjugation length push-pull phthalocyanines

2 . 24 ) 10 Figure 2 . 24 .

 22410224 Figure 2.24.Structures of 11a and 11bpush-pull phthalocynines

Figure 2 . 25 Figure2. 26 .

 22526 Figure 2.25 Structures of 12a-cpush-pull porphyrines

Figure 2 . 27

 227 Figure 2.27 Structures of phthalocyanine-triazolehemiporphyrazine dimers

  The β values of the octupoles are assumed to increase as the Charge Transfer energy decreas and with the transition moment's increase -The β value of octupoles increases gradually with the extent of intramolecular charge transfer (ICT) -The β value of octupoles increases gradually with increasing the donor-acceptor strength, π orbital energy, and the conjugation length Appropiately, various derivatives of octupolar molecules were synthesized and their structure-property relationship have been investigated [198-205]. At a structural level, it can be shown that the most general template for octupolar molecules originates to a cube with alternating charges (donor and acceptor groups) at the edges (Fig. 2.28) [190].

Figure 2 . 28 .

 228 Figure 2.28. Cubic octupolar archetype template.

Figure2. 29 .

 29 Figure2.29. Schematic representation of 2D-octupolar symmetries. Adapted from ref.[206]

Figure2. 30 .

 30 Figure2.30.The structures of 2D octupolara-TATB, b-triazine, c-boroxine molecules

Figure2. 31 .

 31 Figure2.31. The structures of 1,3,5-trisubstituted benzenederivatives

Fig. 2 .Fig. 2 .

 22 Fig. 2.32The structures of 1,3,5-trimethoxybenzene derivatives

  NLO properties of two-dimensional (2D) octupolar metal complexes were first verified by Zyss et al. for tris(bipyridine) (21a) complexes [219]. These complexes possess D 3 symmetry and show intense multidirectional [d π (Ru II )--π*(bpy or phen)] MLCT excitations accountable for their fairly good second-order NLO response. Moreover, very large NLO value was afterward accomplished with substitution of the bipyridine ligands byp-dibutylaminostyryl donor groups (21b) [219].

Figure2. 34 .Fig. 2 .

 342 Figure2.34. The structures of tris(bipyridine) complexes

Figure 2 . 35 . 22 Figure2. 36 .

 2352236 Figure 2.35. The structures of 1,3,5-substituted with Ru II σ-acetylide complexes

Figure 2 . 37 38 .

 23738 Figure 2.37 The structure oftris(dipicolinato)lanthanide(III) series complexes

  )-1,3,5-triazine 23d werepreliminary synthesizedand studied their NLO (Fig. 2.39) [226].

Figure 2 . 39 .

 239 Figure 2.39. Structures of octupolar 1,3,5-trisubstituted benzene -triazinemolecules and their Second-Order NLO Properties

Figure 2 . 40 .Figure2. 41 .

 24041 Figure 2.40. Structures of subphthalocyanines and Second-Order NLO Properties

Figure2. 43 .

 43 Figure2.43. Schematic representation of general octupolar distribution and pCP template. Adapted from ref.[232]

Figure2. 45 . 3 .

 453 Figure2.45. The structures of 3D octupolar bipyridine metal complexes

Figure 2 . 46 .

 246 Figure 2.46. Octupolar aryl trisphthalocyanine phosphonium salt

Figure 2 .

 2 Figure 2.47.3D octupolarPcbased compounds and their Second-Order NLO Properties

  HRS measures the amount of light incoherently scattered at exactly twice the frequency of an powerfull laser beam [248]. Basic HRS process representation is showed in Figure 2.48.

Figure 2 . 48 .

 248 Figure 2.48.Schematic representation of HRS process in bulk liquid.

  , ionic chromophores, conductive materials, polymers and proteins, to which the EFISH can't[249][250][251][252]. The HRS technique is related with changing in the chromophore concentration and orientation. When intense laser beam at ω frequency is concentrate into NLO material containing solution, local density and orientation changing of the material raise frequency scattering of light from ω to 2ω in all directions. And latter frequency is proportional to total average of β 2 tensor shown on the polarization directions of the incident and scattered light. Thus, βvalue and several component of βtensor of nonlinear molecules are accessible straightforwardly. HRS experiment uses internal and external reference methods in order to extract reliable first molecular hyperpolarizability data.

Figure 2 . 49 .

 249 Figure 2.49. Benchmark materials for HRS experiment

Figure 2 . 50 .

 250 Figure 2.50. Schematic representation of general octupolar distribution and pCP template. Adapted from ref. [233]

Fig. 2 .

 2 Fig. 2.51.b,c. The square unit represented by a substituted crosswise ABAB phthalocyanine (A: acceptor; B: donor) in Fig. 2.51.a.

Figure 2 . 51 .FigFigure2. 52 .

 25152 Figure 2.51. (a) Schematic representation of a molecule with square geometry (b) A cubic octupole template (c) A disordered cubic octupole template

Figure2. 53 .Fig. 2 . 1 .Figure3. 1 Figure3. 2 .

 532112 Figure2.53.The structures of crosswise ABAB type free Pc and octupolar double decker lanthanide bis(phthalocyanines)

Figure3. 3 .

 3 Figure3.3.The statistical condensation approach for steric hinderance Pc

3 . 4 )

 34 [265]. They successfully increased the regioselectivity and yieldof the synthesis of crosswise ABAB phthalocyanine. And they suggested that this method allow obtaining only ABAB type phthalocyanine[265].

  research ofHanack and et. al. showed that the regioselective method also allow to produce AB3 type phthalocyanine and trace amount of B4 type phthalocyanine beside of ABAB type phthalocyanine in contrast to theYound and Onyebuagu results. The yield of ABAB type phthalocyanine (15.3%) is about 10 times higher than AB3 type phthalocyanine (1.3 %) (Fig. 3.5)[266].

Figure3. 6Synthetic

 6Synthetic Figure3.6Synthetic route of crosswise ABAB type Pc by regioselective approach.

(H 2

 2 Pc), which represent the cubic octupole as shown in Figure 3.8. unsymmetrical bis(phthalocyanine) complexs were obtained in good yield from the ABAB type phthalocyanine and lanthanide acetate (Ln(OAc) 3 -Ln: Lu, Eu, Dy, Nd and Y) in refluxing 1-chloronaphthalene using DBU as a base as shown in Fig. 3.8[279]. Bis(phthalocyanines) obtained by this approach could lead to noncentrosymmetric and octupolar conformation as shown in Fig. 3.1 c.

  scheme of its electronic energy levels. In accordance with their electronic structure, Pcs present intense π-π bands in the visible (Q band) and UV (B or Soret band) spectral regions [281]. Fig. 3.9represents a typical UV-vis spectra and electronic transitions accounting for B and Q bands of unsubstituted Pcs.

Figure 3 . 9 .Fig. 3 .

 393 Figure 3.9. Absorption spectra of free phthalocyanine (i) and metallo phthalocyanine (ii)and Electronic transitions accounting for B and Q bands of phthalocyanines

Figure3. 10 .Fig. 3 .

 103 Figure3.10. UV-Vis Spectrum of ABAB (5) type free phthalocyanine

Fig. 3 .

 3 Fig.3.11.shows a UV-NIR spectrum of a neutral Ln(Pc) 2 bisphthalocyanine and scmatic representation of the MO levels [286]. The intense Q band in the electronic absorption spectrum of Ln(Pc 2-)(Pc *-) can be considered as the sum of the overlapping Q bands of each species. The band at 469 nm (BV) is attributed to transitions into the SOMO a 1u orbital and is specific for the Pc *-radical. And the band between 1220 and 1600 nm is ascribed to HOMO-LUMO transitionand connected to an intramolecular charge transfer (ICT) between two Pc rings: the dianion Pc 2-behaves as an electron donor and the Pc -• radical as an electron acceptor.The weak band at 943 nm (RV) with a vibronic component at 820 nm attributed to.

Figure3

  Figure3.11.UV-NIR spectrum of a neutral Ln(Pc) 2 bisphthalocyanine and scmatic representation of the MO levels, Adapted from [287]

  at 443 nm is attributed to the phthalocyanine Soret band.In addition, the intramolecular charge transfer (ICT) between two Pc ringsof neutral Lu(ABAB) 2 bis(Phthalocyanine)[START_REF] Stucky | Materials for Nonlinear Optics: Chemical Perspectives[END_REF] shows broad and intense absorption regions in the infrared region appearing between 1075 and 1705nm.And the two n-radical anion bands appeared at 550 (BV) and 933 nm (RV).

Figure 3 . 12 .

 312 Figure 3.12.UV-NIR spectrum of a neutral Lu(ABAB) 2 bisphthalocyanine in CHCl 3

  ht (nm ) central rare earths[288].These results indicate that the interaction between the two rings becomes stronger as the ring-to-ring separation decreases along with the lanthanide contraction (Fig.3.13). More accurately, the blue-shiftis due to the decreased distance between the Pc rings..

Figure 3 .

 3 Figure 3.13The UV-NIR spectrum of neutral Ln(Eu, Dy, Lu, Y, Nd)(Pc(ABAB) 2 in CHCl 3 (1x10 -5 M) The UV-NIR spectrumsand the ICT bandsof (ABAB) 2 Ln (Lu, Eu, Dy, Nd and Y)complexes in chloroform are given as example in Figure 3.13.The ionic radii of the lanthanides and Y are in the order Lu -100.8 pm < Y-104 pm < Dy -105.2 pm < Eu-108.7 pm < Nd-112.3 pm [289].

  structure refinement parameters and selected distances data of Ln(ABAB) 2(Lu, Eu, Dy, Y, Nd) and Eu(B4) 2 are listed in ANNEX 2, respectively.

Figure 3 .

 3 Figure 3.15The molecular structure of Lu(ABAB) 2[START_REF] Stucky | Materials for Nonlinear Optics: Chemical Perspectives[END_REF]

Figure 3 . 16 .Fig. 3 .

 3163 Figure 3.16. The interplane distance (d N4-N4 ) of Ln(ABAB) (Lu, Eu, Dy, Nd and Y)

Fig. 3 .

 3 Fig. 3.17The interplane distance (d N4-N4 ) of Ln(ABAB) 2 vs lanthanide contraction

Figure3. 18

 18 Figure3.18 The twist angles φ T of Ln(ABAB) 2(Lu, Eu, Dy, Y, Nd) According toKoike et al. the value of the twist angles φ T is related to the strength of the π-π interaction between two Pc rings, which is related to interplane distance (d N4-N4 ) [293]. However, Fig 3.17 and Fig. 3.18 show that though the interplanar distance from Eu to Lu decrease following the same variations as the ionic radii of the metal cations, significant changing on the twist angles wasn't observed. Darovskikh et al. suggested that the diversity of twist angles is the result of a fine equilibrium between steric repulsion in the solid state, lattice energy and aromaticity of the Pc macrocycles [294]. And this theory seems more appropriate for our observations.

  Nonpolarized harmonic light scattering method (HLS). The HRS technique involves the detection of the incoherently scattered second harmonic generated by a solution of the molecule irradiated by a laser of wavelength λ, leading to the measurement of the mean value of the βproduct.All HRS measurements were carried out at the Ecole Normale Superieure de Cachan at the same concentration to avoid concentration effects. It has to be notice that the neutral form of lanthanide double-decker complexes Ln(Pc) 2 have absorption bands at λ/2, in order to minimize the interferences of these bands, all measurements were carried out at very low concentration (1x10 -5 M) and HRS data were corrected for chromophore absorption before determining β 1907 . HRS measurements were carried outwith a low-energy nonresonant incident radiation of at 1.907 nm,where multi-photon fluorescence (MPF) cannot interfere, thereby avoiding any multiphoton fluorescence contribution to the HRS signal[295].It must be noted that most classical organic solvents are not transparent at 1.907 nm, which cause interferences with theβ values. Chlorinated solvents are an exception, so chloroform was chosen to perform the HRS measurements. And the ethyl violet was used as a reference in order to accurate of our setup on the determination of β[296].

Figure 3 . 19 .Figure 3 . 5 Figure 3 . 2 Pc

 3193532 Figure 3.19. Plot of the hyperpolarisability β vs Ln(ABAB) 2 (a) and f-orbital filling (b)

Figure 3 .

 3 Figure 3.22UV-NIR spectrum of Lu(ABAB) 2 Bis-phthalocyanine (1 x 10 -5 M) in CHCl 3 +Br 2 (oxidized)

  band, BVand RV: radical transition bands, ICT: Intramolecular charge transfer band The reduced form of Lu(ABAB) 2 Bis(Phthalocyanine)was prepared by adding 3 mg of NaBH 4 to 10 mL of a solution of 9 (10 -5 M) in THF/CHCl 3 (1/10). The UV-NIR spectrum of reduced form of 9is given as example in Fig. 3.23.

Figure 3 .

 3 Figure 3.23UV-NIR spectra of reduced form ofLu(ABAB) 2 Bis-phthalocyanine (1 x 10 -5 M) in (1/10 -THF/CHCl 3 + 3 mg NaBH 4 )

. Tablo 3 .

 3 4UV-NIR spectra of reduced forms ofLn(Eu, Dy, Lu, Nd, Y)(ABAB) 2 Bisphthalocyanine (1 x 10 -5 M) B: Soret band, BVand RV: radical transition bands, ICT: Intramolecular charge transfer band

Figure 3 . 24 .

 324 Figure 3.24. Plot of the hyperpolarisability coefficient β vs oxidized form of Ln(ABAB) 2

Figure 3 . 25 .

 325 Figure 3.25. UV-NIR spectra of Eu(ABAB) 2 Bis(Phthalocyanine) (7) (1 x 10 -5 M)

Figure 3 . 26 .

 326 Figure 3.26. Plot of the hyperpolarisability coefficient β vs reduced form of Ln(ABAB) 2

  3.27).The decrease of the hyperpolarizability values is directly related to the vanishing of this band.

Figure 3 . 27 .

 327 Figure 3.27. UV-NIR spectra of Eu(ABAB) 2 bis(Phthalocyanine) (7) (1 x 10 -5 M)

3 . 28 ).

 328 This method is quite simple, however has some important disadvantages. It certainly produces several by products mono-decker, triple-decker derivatives and metal free compounds. Consequently, the yield of corresponding to double decker lanthanide Pc complexes and their purity are low[309].

Figure 3 . 28 .

 328 Figure 3.28. Tetramerization solid-state approachfor homoleptic bis(Pcs)

  3.30). Detailed synthetic procedures are given in the Experimental Part.

Figure 3 . 30 .

 330 Figure 3.30.The synthesize approach for Ln(AB3) 2

Figure 3 . 31 .

 331 Figure 3.31. UV-Vis Spectra of AB3 (6) type free phthalocyanine

a 32 Figure 3 . 32 .

 32332 Figure 3.32. The UV-NIR spectra of neutral Lu(Pc(SC 6 ) n:0-8 ) 2 in CHCl 3 (1x10 -5 M)

Figure 3 . 33 .

 333 Figure 3.33. The UV-NIR spectrum of neutral Lu(Pc(SC 6 ) n:0-8 ) 2 in CHCl 3 (1x10 -5 M)

  Lu(III) bis(phthalocyanines), regardless of the number of alkylthio substituted, red-shifted about 40 nm compare with unsubstituted Lu(

  Bis(phthalocyanine) (1 x 10 -5 M) B: Soret band, BVand RV: radical transition bands, ICT: Intramolecular charge transfer band The spectral changes due to chemical oxidation in the UV-NIR spectrum of Lu(Pc) 2 Bis(Phthalocyanine) (14, 26, 21) is illustrated in Figure 3.34 as example.

  were prepared by adding 3 mg of NaBH 4 to 10 mL of a solution of Lu(Pc) 2 (14, 26, 21) (10 -5 M) in THF/CHCl 3 (1/10). The UV-NIR spectra of reduced form of Lu(Pc) 2 (14, 26, 21)are given as example in Fig. 3.35.

NeutralFig. 3 .

 3 Fig.3.37), the most intense absorption maximum (Q-band) shifts to longer wavelength due to the number of electron-donating groups. This phenomenon is characteristic of the substituted alkylthio substituent.

Figure 3 . 37 .

 337 Figure 3.37. The UV-NIR spectrum of neutral Lu(Pc(SC 6 ) n:0-8 ) 2 in CHCl 3 (1x10 -5 M)

Figure 3 . 38

 338 Fig 3.38).

58

 58

  g, 0,2 mol) and PCl 5 (130 g) were stirred in 1,2dichlorobenzene (250 mL) at 120 °C during 1 week, then cooled to room temperature. The product was distillated undervacuum (bp 125 °C at 0.05 Torr)[315]. mp: 107 °C, ref. mp: 106 °C 30 g,Yield( 80%) C 8 H 4 Cl 3 N Mw: 220.48 IR (KBr) ν(cm -1 ): 3200 (br, w), 3062 (w), 2717 (s) 1744 (s), 1609 (s)

  ) ν(cm -1 ): 2955 (s), 2923 (s), 2845 (s), 2580 (b, w), 2200 (b, w), 1586 (s), 1496 (s), 1444 (s), 1308 (s).MALDI-TOF MS:m/z 2108 [M+H] +4.2.6.2.ABAB bis(phthalocyaninato) dysprosium(III) complex (Dy(ABAB) 2 )(8)Green product was prepared according to the general protocol as described the synthesis method above. 130 mg, Yield (54 %) C 112 H 128 DyN 16 S 8 Mw: 2117.34 IR (KBr) ν(cm -1 ): 2955 (s), 2923 (s), 2845 (s), 2580 (b, w), 2200 (b, w), 1586 (s), 1496 (s), 1444 (s), 1308 (s). MALDI-TOF MS: m/z 2118 [M+H] + 4.2.6.3.ABAB bis(phthalocyaninato) lutetium(III) complex (Lu(ABAB) 2 ) (9)

  ) ν(cm -1 ): 2955 (s), 2923 (s), 2845 (s), 2580 (b, w), 2200 (b, w), 1586 (s), 1496 (s), 1444 (s), 1308 (s). MALDI-TOF MS: m/z 2128 [M+H] + .

  55 mg, Yield (62 %) C 136 H 176 DyN 16 S 12 , Mw: 2581.24 IR (KBr) ν(cm -1 ): 2955 (s), 2923 (s), 2845 (s), 2580 (b, w), 2200 (b, w), 1586 (s), 1496 (s), 1444 (s), 1308 (s). MALDI-TOF MS: m/z 2582 [M+H] + 4.2.6.8.AB3bis(phthalocyaninato) lutetium(III) complex (Lu(AB 3 ) 2 )(14)

  40 mg, Yield (42 %) C 136 H 176 LuN 16 S 12 , Mw: 2592.71 IR (KBr) ν(cm -1 ): 2955 (s), 2923 (s), 2845 (s), 2580 (b, w), 2200 (b, w), 1586 (s), 1496 (s), 1444 (s), 1308 (s).MALDI-TOF MS: m/z 2593 [M+H] +4.2.6.9.AB3bis(phthalocyaninato) yttrium(III) complex (Y(AB 3 ) 2 )[START_REF] Yariv | Quantum Electronics[END_REF]

  ) ν(cm -1 ): 2955 (s), 2923 (s), 2845 (s), 2580 (b, w), 2200 (b, w), 1586 (s), 1496 (s), 1444 (s), 1308 (s). MALDI-TOF MS: m/z 2507 [M+H] + bottomed flask fitted with a condenser was degassed and flamedried under dry argon. The flask was charged under argon with dinitrile derivative (1.56 mmol), anhydrous Ln(OAc) 3 .4H2O ( 0,195mmol), DBU (600 µL, 4 mmol), and 16 mL of hexan-1-ol. The mixture was refluxed under argon for 48 h. Evaporation of the hexan-1-ol under reduced pressure left a greenish waxy residue. It was precipitated by hexane, and filtered. The residue was washed with ethanol and acetone several times. Then thiscompound was solved in dichloromethan and concentrated.

  ) ν(cm -1 ): 2955 (s), 2923 (s), 2845 (s), 2580 (b, w), 2200 (b, w), 1586 (s), 1496 (s), 1444 (s), 1308 (s). MALDI-TOF MS: m/z 1202 [M+4H] + .

  110 mg, Yield (10 %) C 160 H 224 EuN 16 S 16 Mw: 3034.0 IR (KBr) ν(cm -1 ): 2955 (s), 2923 (s), 2845 (s), 2580 (b, w), 2200 (b, w), 1586 (s), 1496 (s), 1444 (s), 1308 (s).

  ) ν(cm -1 ): 2955 (s), 2923 (s), 2845 (s), 2580 (b, w), 2200 (b, w), 1586 (s), 1496 (s), 1444 (s), 1308 (s). MALDI-TOF MS: m/z 3059 [M+H] + 4.2.7.7.The octahexylthia substituted (B4) bis(phthalocyaninato) yttrium(

  100 mg, Yield (12 %) C 160 H 224 YN 16 S 16 Mw: 2970.04 IR (KBr) ν(cm -1 ): 2955 (s), 2923 (s), 2845 (s), 2580 (b, w), 2200 (b, w), 1586 (s), 1496 (s), 1444 (s), 1308 (s).

  ) ν(cm -1 ): 2955 (s), 2923 (s), 2845 (s), 2580 (b, w), 2200 (b, w), 1586 (s), 1496 (s), 1444 (s), 1308 (s). MALDI-TOF MS: m/z 3030 [M+H] + .

  140 mg, Yield (13 %) C 112 H 128 EuN 16 S 8 Mw: 2106.81 IR (KBr) ν(cm -1 ): 3020 (s), 2955 (s), 2923 (s), 2845 (s), 2580 (b, w), 2200 (b, w), 1586 (s), 1496 (s), 1444 (s), 1308 (s). MALDI-TOF MS:m/z 2108 [M+H] + .

  The homoleptic double-decker ABAB bis(Phthalocaynines) are characterized by X-Ray and UV-NIR. And the results show that the homoleptic double-decker ABAB bis(Phthalocaynine) structure provide octupolar structure requirements such as multidirectional charge transfer and noncentrosymettry.Then we extended this work in order to understand better of efficiency of octupolar structure, various non-octupolar AB 3 , A 4 , B 4 , T 4 type double decker lanthanide homoleptic bisphthalocyanines are synthesized by cyclic tetramerization of the corresponding phthalodinitrile in the presence of a lanthanide salt and DBU.In summary, a series of octupole and nonoctupole double decker rare-earth bis(Phthalocyanine) complexes have been synthesized, and their linear optical and nonlinear optical properties (first molecular hyperpolarizability β) have been investigated.The first molecular hyperpolarizability (β) measurement shows that coordination chemistry of lanthanide ions is a powerful instrument for the design of efficient octupole structure and that the molecular quadratic hyperpolarizability (β) values are strongly influenced by the nature of the lanthanide ion. For each series, the NLO activity regularly increases from yttrium to lutetium along the f-element row and this effect iscalled "metal-induced NLO-enhancement". Moreover, the Lu(Pc) 2 complexes exhibits the highest hyperpolarizability over the lanthanide series, even if for other ions the 1907 nm laser wavelength comes into resonance with the intervalence band. This seems to indicate that the intervalence transition has small influence on the quadratic nonlinear response. This conclusion is particularly attractive in terms of transparency/nonlinearity tradeoff because NLO activity is significantly improved without any cost of optical transparency.However, in the case of the reduced form of Ln(Pc) 2 , we observed that the NLO activity of Ln(Pc) 2 is intensely influenced not only by the nature of the lanthanide ion but also by the intermolecular charge transfer (ICT). In this case, the contribution of the intermolecular charge transfer (ICT) to the hyperpolarizability vanishes and cause lower NLO activity than in the neutral form. Unfortunately NLO activities of oxidized form of both octupole and nonoctupole bis(Phthalocyanines) are falsely disrupt by resonance effects, which is caused by the radical π-π * transition band.

Figure ANNEX1. 2 .Figure ANNEX1. 3 .Figure ANNEX1. 4 .Figure ANNEX1. 6 .Figure ANNEX1. 8 .Figure ANNEX1. 9 .Figure ANNEX1. 10 .Figure ANNEX1. 14 .FigureFigure ANNEX1. 18 .

 234689101418 Figure ANNEX1.2. UV-NIR spectra of ABAB bis(phthalocyaninato) dysprosium(III) complex (Dy(ABAB) 2 )(8) (1x 10 -5 M)

Formula

Figure ANNEX3. 1 . 2 =

 12 Figure ANNEX3.1.Schematic representation of HLS at 1.907 µm. F: Filter; M: Mirrors; A: Attenuator; GP: Glassplate; L: Lens; P: Polarizer; λ/2: Half wave plate; PMT: Photomultiplier tube; NPP: Reference material; PC: Personal computer, MC: Micro controller.

Figure ANNEX3. 2 .

 2 Figure ANNEX3.2. Plotthe intensity of the second-harmonic (I 2w ) of sample vs reference materialNPP = (frequency doubler N-4-nitrophenyle-L-prolinol).

FigureANNEX4FigureANNEX4FigureANNEX4

  FigureANNEX4.4 13 C-NMR spectrum of 2,3,9,10,16,17hexa(hexylthio)phthalocyanine (AB3)[START_REF] Franken | [END_REF]

FigureANNEX4FigureANNEX4

  FigureANNEX4.18.Maldi-TOFspectrum of unsubstituted (A4) bis(phthalocyaninato) lutetium(III) complex (Lu(A 4 ) 2 )(18) [M+ : 1202]

Table 2 .1. Static

 2 hyperpolarizability for a series of conjugated donor-acceptor compounds containing heterocyclic rings. Data taken from refs.

Table 2 . 2

 22

. Static hyperpolarizability and decomposition temperature (Td) of a number of thermally stable chromophores with good nonlinearity. Data taken from refs.

[120, 125, 126]

electron-donating group electron-withdrawing group conjugating system Figure2

.44. The

(4,7,12,[START_REF] Yariv | Quantum Electronics[END_REF]

tetra-substitution pattern for

[2.2]

p-cyclophane(pCp) as a point-charge template for an octupole

.1. Tablo 3.1UV-NIR spectral

	Compound	Form	B	BV	Q	RV	ICT
		Eu(7) Neutral	322	557	609,686	920	118-1911
	ABAB (7-11)	Dy(8) Neutral Lu(9) Neutral Nd(10) Neutral	336 340 328	554 533 562	680 621,671 610,694	985 925 910	1165-1865 1075-1705 1451-2000
		Y(11) Neutral	328	550	610,682	946	1205-1733

data of neutral forms ofLn(Eu, Dy, Lu, Nd, Y)(ABAB) 2 Bis(phthalocyanine) (1 x 10 -5 M) B: Soret band, BVand RV: radical transition bands, ICT: Intramolecular charge transfer band The position of the ICT band for the Ln(ABAB) 2 are dependent on the size of λmax (nm)

2 Dy(ABAB) 2 Y(ABAB) 2 Eu(ABAB) 2 Nd(ABAB) 2

									d N4-N4
	d N4-N4 (Å) 2.656			2.773		2.747		2.841	2.953
		114
	2
	N4--N4 ) of L n(A B A B )	108 110 112				E u			N d
	inte rpla ne dis ta nc e (d	100 102 104 106	L u		D y
			2.65	2.70	2.75	2.80	2.85	2.90	2.95	3.00
					ionic ra dius (pm )

Y

Lu(ABAB)

Table 3 .3 Tablo

 3

3.3UV-NIR spectra of oxidized forms ofLn(Eu, Dy, Lu, Nd, Y)(ABAB) 2 Bis-

Table 3 . 5 .

 35 The oxidation of Ln(ABAB) 2 was carried out by adding bromine in CHCl 3 to a solution of Ln(ABAB) 2 (10 -5 M).

	λmax (nm)

Table 3 . 5

 35 The second-order NLO data for the octupole Ln(ABAB) 2(7)[START_REF] Denus | [END_REF][START_REF] Stucky | Materials for Nonlinear Optics: Chemical Perspectives[END_REF][START_REF] Verbiest | [END_REF](11) P

ETV : Slope of ETV, P s : Slope of Sample, Corr. P S : Corrected slope for sample

3 .4H 2 O Hexanol, DBU Ln: Dy, Eu, Lu A4: R 1 : H, R 2 : H B4: R 1 : C 6 H 13 , R 2 : C 6 H 13 T4: R 1 : H, R 2 : C 6 H 13 R 1 Ln: Dy, Eu, Lu Ln: Dy, Eu, Lu, Y, Nd

947 1401-2000 Dy(20) Neutral 315 560 640,711 944 1320-1879 Lu(21) Neutral 323 544 632,710 931 1235-1710 Nd(22) Neutral 322 580 628,718 953 1550-2000 Y(23) Neutral 322 562 640,706 953 1325-1847 T4 (24-26) Eu(24) Neutral 334 505 632,688 925 1368-2000 Dy(25) Neutral 315 483 615,686 939 1264-1859 Lu(26) Neutral 315 483 635,686 1006 1158-1711

						λmax (nm)
	Compound	Form	B	BV	Q	RV	ICT
		Eu(12) Neutral 322	566	616,699 942 1373-2000
	AB3	Dy(13) Neutral 321	548	620,696 924 1250-1890
	(12-15) A4 (16-18) 632,710 Figure3.34. UV-NIR spectra of Lu(Pc) 2 Bis(phthalocyanine) (1 x 10 -5 M) in CHCl Lu(14) Neutral 329 533 616,693 950 1174-1690 Y(15) Neutral 328 556 628,694 941 1230-1841 Eu(16) Neutral 310 477 635,670 910 1407-1883 Dy(17) Neutral 318 575 632,64 911 1250-1800 Lu(18) Neutral 316 570 626,658 914 1150-1650 Eu(19) Neutral 329 561 +Br 2 (oxidized)
	B4
	(19-23)
				(10 -5 M).

Table 3 .

 3 8UV-NIR spectrums of oxidized forms ofLn(AB3) 2

.2.3.Hyper-Rayleigh Scattering (HRS)measurements of nonoctupolarbis(phthalocyaninato) Ln(III) double-decker complexes (Ln(AB3) 2 (12-15), Ln(A4) 2 (16-18), Ln(B4) 2 (19-23), Ln(T4) 2 (24-26))

	-5 M)
	B: Soret band, BVand RV: radical transition bands, ICT: Intramolecular charge transfer band
	3

Table 3 .

 3

	10.

Table 3 .

 3 [START_REF] Verbiest | [END_REF] The second-order NLO data for the nonoctupole Ln(AB3) 2

  Plot of the hyperpolarisability coefficient β vs Lu(Pc) 2

	Compounds	Absorbance Form λ 1907 λ 955	P ETV	P S	Av. Corr. Corr.P S βx10 --30 esu
		Eu(12) N.	0.078 0.071 0.087	0.092 0.1196 3622
	AB3 Dy(13) N.	0.021 0.062 0.067	0.097 0.1099 3949
	(12--15) Lu(14) N.	0	0.047 0.12	0.252 0.266	4591
	A4	Eu(16) N.	0.037 0.027 0.0968 0.13	0.1462 3790
	(16--18) Dy(17) N.	0.012 0.067 0.0648 0.103 0.1048 3923
		Lu(18) N.	0	0.05 0.108	0.18	0.1906 4116
		Eu(19) N.	0.105 0.052 0.081	0.13	0.1462 3790
	B4 (19--23) Figure 3.36. Dy(20) N. Lu(21) N.	0.026 0.06 0.076 0 0.1 0.095	0.114 0.1298 4037 0.195 0.2187 4680
	T4	Eu(24) N.	0.058 0.019 0.0208 0.028 0.0332 3700
	(24--26) Dy(25) N.	0.011 0.035 0.023	0.036 0.0393 3915
		Lu(26) N.	0	0.061 0.028	0.049 0.0525 4011
						3.36), it
	undoubtedly shows that the octupolar Lu(ABAB) 2 has higher first hyperpolarizabiliy
	than the corresponding nonoctupolar Lu(Pc) 2 complexes.

Table 3 .

 3 11.The oxidation of Ln(P) 2 was carried out by adding bromine in CHCl 3 to a solution of Ln(Pc) 2 (10 -5 M).

(12--14) Dy(13) Red. 0 0.015 0.051 0.098 0.0997 3544 Lu(14) Red. 0.019 0.024 0.069 0.226 0.2439 3600 A4 (16--18) Eu(16) Red. 0 0 0.0719 0.15 0.15 3692

	Compounds	Absorbance Form λ 1907 λ 955	P ETV	P S	Av. Corr. Corr.P S βx10 --30 esu
	AB3	Eu(12) Red. 0	0.02 0.058	0.11	0.1125 3527
		Dy(17) Red. 0	0	0.058	0.133 0.133	3876
		Lu(18) Red. 0	0.005 0.070	0.168 0.1689 3932
		Eu(19) Red. 0	0.025 0.06	0.096 0.098	3271
	B4 (19--21)	Dy(20) Red. 0	0.025 0.098	0.159 0.1636 3319
		Lu(21) Red. 0.026 0.169 0.07	0.17	0.1884 3432
		Eu(24) Red. 0.01	0.017 0.0412 0.036 0.0379 2676
	T4
	(24--26)

2

(24)(25)(26)

P ETV : Slope of ETV, P s : Slope of Sample, Corr. P S : Corrected slope for sample

NMR (CDCl 3 ):140.1, 138.

	.27
	MALDI-TOF MS: m/z 980 [M+H] + .
	AB 3 -6:
	65 mg, Yield(2 %)
	C 68 H 90 N 8 S 6 Mw: 1211.89
	IR (KBr) ν(cm -1 ): 3307 (s), 3070(br, w), 2850-2919 (w), 1603 (s), 1537 (s).
	1 H NMR (CDCl 3 ):δ. 8.36 (s, 2H),7.77 (m, 6H), 7.63 (d, 2H), 3.13(t, J: 7 Hz12H),
	1.95 (m, 12H), 1.69 (m,J 1 : 14.8 Hz, J 2 : 7.1 Hz 12H), 1.44 (m, 24H), 1.00 (t, 18 H), -
	5.30 (s, 2H). ).

13 C

6 (AB3--H 2 Pc) --SC 6 H 13 Ln(AB3) 2 12 13 14 15 Eu Dy Lu Y --SC 6 H 13 --SC 6 H 13 --SC 6 H 13 --SC 6 H 13

	Cmpd. No	R	Cmpd. No	Ln	R
				7	Eu	--H
	5 (ABAB--H 2 Pc)	--H	Ln(ABAB) 2	8 9 10	Dy Lu Y	--H --H --H
				11	Nd	--H
				2 :(CH 2 Cl 2 /n-hexane, 2:3
	(v/v)[316], Ln(AB3) 2 : CH 2 Cl 2 /n-hexane, 1:1 (v/v) [317]).

6 H 13 --SC 6 H 13 --SC 6 H 13 --SC 6 H 13 --SC 6 H 13 --SC 6 H 13 --SC 6 H 13 --SC 6 H 13 --SC 6 H 13 --SC 6 H 13 Ln(B4) 2 19 20 21 22 23 Eu Dy Lu Y Nd --SC 6 H 13 --SC 6 H 13 --SC 6 H 13 --SC 6 H 13 --SC 6 H 13 --SC 6 H 13 --SC 6 H 13 --SC 6 H 13 --SC 6 H 13 --SC 6 H 13 1 1 1 --SC 6 H 13 --SC 6 H 13 --SC 6 H 13 H H H Ln(T4) 2 24 25 26 Eu Dy Nd --SC 6 H 13 --SC 6 H 13 --SC 6 H 13 H H H CN CN R 2

  The residue was purified by column chromatography on silica gel

	Cmpd. No	R1	R2		Cmpd. No Ln	R1	R2
		H	H		16	Eu	H	H
	Commercial	H H	H H	Ln(A4) 2	17 18	Dy Lu	H H	H H
	2	--SC
	2
	2
	2
	2

11The tetrahexylthia substituted (T4) bis(phthalocyaninato) lutetium(III) complex (Lu(T 4 ) 2 ) (26)

	4.2.7.Green product was prepared according to the general protocol as described
	the synthesis method by using related dinitrile derivative, above.
	110 mg, Yield (10 %)
	C 112 H 128 LuN 16 S 8 Mw: 2126.81
	IR (KBr) ν(cm -1 ):3020 (s), 2955 (s), 2923 (s), 2845 (s), 2580 (b, w), 2200 (b, w),
	1586 (s), 1496 (s), 1444 (s), 1308 (s).
	125 mg, Yield (12 %)
	C 112 H 128 DyN 16 S 8 Mw: 2117.34
	IR (KBr) ν(cm -1 ): 3020 (s), 2955 (s), 2923 (s), 2845 (s), 2580 (b, w), 2200 (b, w),
	1586 (s), 1496 (s), 1444 (s), 1308 (s).
	MALDI-TOF MS: m/z 2118 [M+H] +

MALDI-TOF MS

: m/z 2128 [M+H] + .

étudiés pour l'ONL. Cependant les molécules dipolaires diverses limitations telles que leur transparence optique, leur faible stabilité thermique et leur tendance à adopter un alignement antiparallèle à l'état solide. Récemment, une nouvelle classe de matériaux est apparue basé sur des symétries octupolaire qui ne possède pas de dipôle permanent, pour les applications ONL. Au niveau structural, la structure générique idéale pour des molécules tridimensionnelles avec une distribution de charges octupolaire est un cube avec des charges opposées alternées à chaque angle. À ce jour, aucune molécule représentant le cube vrai (déformé) avec huit charges alternées aux sommets et délocalisation des charges complètes entre les plans supérieurs et inférieurs n'a été décrite. Dans le cadre de cette thèse, des complexes de lanthanides III à partir de phthalocyanines de type ABAB présentant en alternance des groupes donneurs et accepteurs d'électrons ont été synthétisés représentant le premier réel octupole. Ces structures ont été caractérisé par UV-NIR, X-Ray et présentent les plus élevés hyperpolarisabilité quadratique jamais enregistré pour des molécules octupolaires. En outre, ce travail a été étendu à divers type de double-decker de lanthanides homoleptiques non-octupolaire basé sur des phthalocyanines AB3, A4, B4, T4. Il a été observé que ces complexes présentent aussi des mesures d'hyperpolarisabilité quadratique élevés, mais inferieur a celles trouvé pour la série de complexes Ln (ABAB) 2 octupolaire, comme prévu.

21a, b, c, d, 21abcd-

H and13 C NMR Spectra were recorded on Bruker AC

(500 MHz), spectrometer. All spectrawere measured at room temperature.13 C NMR spectra were recorded with complete proton decoupling.The chemical shifts (δ) are given in ppm.The coupling constants J are listed in Hz. For proton, the multiplicity of the signals isindicated by s (singlet), d (doublet), t (triplet), q (quartet) and m (multiplet).All spectra were measured using CDCl 3 as solvents.

LIST OF FIGURES

4.2.6.4.ABAB bis(phthalocyaninato) yttrium(III) complex (Y(ABAB) 2 )(10)

Green product was prepared according to the general protocol as described the synthesis method above. Green product was prepared according to the general protocol as described the synthesis method above.

MALDI-TOF MS: m/z 2099 [M+H] +

4.2.6.6.AB3bis(phthalocyaninato) europium(III) complex (Eu(AB 3 ) 2 )(12)

Green product was prepared according to the general protocol as described the synthesis method above. Green product was prepared according to the general protocol as described the synthesis method by using related dinitrile derivative, above. Green product was prepared according to the general protocol as described the synthesis method by using related dinitrile derivative, above. Green product was prepared according to the general protocol as described the synthesis method by using related dinitrile derivative, above.

BIBLIOGAPHIC REFERENCES ANNEX-1

The UV-NIR spectra of all complexes were carried out by SHIMADZU UV-VIS-NIR Spectrophotometer UV-3600.

Since, most classical organic solvents are not transparent at near-IR, chloroform was used as solvent for the UV-NIR measurements. The measurements were carried out in same concentration (1x10 -5 M) to avoid concentrationeffects.

While, the oxidized forms were carried out by adding bromine in CHCl 3 to mL of a CHCl 3 solution of complexes, the reduced forms were prepared by adding mg of NaBH 4 to 10 mL of a solution of complexes in THF/CHCl 3 (1/10).

UV-NIR Spectra of Ln(Pc) 2 ANNEX 2

Single-crystal X-ray structure determination

A Suitable crystal was selected and mounted on a Gemini kappa-geometry diffractometer (Agilent Technologies UK Ltd) equipped with an Atlas CCD detector and using Mo radiation (l = 0.71073 Å).

Intensities were collected at 100 K by means of the CrysalisPro software [1].

Reflection indexing, unit-cell parameters refinement, Lorentz-polarization correction, peak integration and background determination were carried out with the CrysalisPro software [1]. An analytical absorption correction was applied using the modeled faces of the crystal [2]. The structures were solved by direct methods with SIR97 and the least-square refinement on F 2 was achieved with the CRYSTALS software [3,4].

All non-hydrogen atoms were refined anisotropically. The hydrogen atoms were all located in a difference map, but those attached to carbon atoms were repositioned geometrically. The H atoms were initially refined with soft restraints on the bond lengths and angles to regularize their geometry (C---H in the range 0.93--0.98 Å) and U iso (H) (in the range 1.2-1.5 times U eq of the parent atom), after which the positions were refined with riding constraints. List and number of the molecules described in the manuscript