Élaboration de nouveaux polymères réticulables ou hyperbranchés pour l'optique non linéaire du second ordre

Les travaux décrits dans ce manuscrit concernent la conception et la synthèse de nouveaux polymères pour des applications en optique non linéaire du second ordre. Dans un premier volet, une nouvelle méthode de réticulation fondée sur la réaction thermique de Huisgen est développée. Des polymères de type méthacrylique comportant un chromophore analogue au DR1 substitué par une triple liaison ou un azide et un motif fonctionnalisé par un groupement complémentaire (azide ou triple liaison, respectivement) ont été synthétisés. Des films d épaisseurs allant jusqu à 2,7 m ont pu être caractérisés par un coefficient électrooptique r33 de l ordre de 16 pm/V à 1,064 m stable jusqu à 137C. Le deuxième volet porte sur la synthèse de polymères à haute température de transition vitreuse basée sur la post-fonctionnalisation du méthacrylate de propargyle par des chromophores DR1 et des groupements rigidifiants de type adamantyle dotés de fonctions azide via la réaction catalytique de Huisgen sous activation micro-ondes. Selon la concentration en chromophores, des coefficients électrooptiques allant jusqu à 31 pm/V ont pu être mesurés à 1,064 m. Cependant, la stabilité d orientation des chromophores n est pas conservée au-delà de 90C. Le troisième volet consiste à appliquer la réaction de Huisgen catalytique classique d abord à la synthèse d un polymère hyperbranché de type main-chain employant le chromophore DR1. Puis, la synthèse de polyimides hyperbranchés post-fonctionnalisés en périphérie par des chromophores DR1 ou porphyriniques a été réalisée. Leurs coefficients électrooptiques r33 mesurés à 1,064 m s élevant jusqu à 18 pm/V se sont révélés stables jusqu à 130CThis manuscript describes the development and the preparation of new polymers for second order nonlinear applications. In the first part, the synthesis of crosslinkable polymers based on the thermal Huisgen reaction is developped. Methacrylic like co-polymers containing DR1 derivative substituted with triple bond or azide group and another monomer functionnalized with a complementary group (azide or triple bond, respectively) were synthesized. Films of thickness up to 2.7 m have been prepared and they display electro-optic coefficients about 16 pm/V at 1.064 m stable up to 137C. The second part concerns the synthesis of polymers with high glass transition temperature based on the post-functionalization of a polypropargylic methacrylate polymer with azido derivatized chromophores and rigid azido functionnalized adamantyl units using the copper-catalyzed Huisgen reaction under microwave activation. Depending on the chromophores concentration, electro-optic coefficients up to 31 pm/V were measured at 1.064 m. However, electro-optic properties are not stable above 90C. The third section consists in the synthesis of main-chain hyperbranched polymers with DR1 chromophores. The synthesis of hyperbranched polyimides peripherically post-functionalized with DR1 or with porphyrinic chromophores was performed. Some polymers exhibit electro-optic coefficients r33 up to 18 pm/V at 1.064 m that are stable up to 130CNANTES-BU Sciences (441092104) / SudocSudocFranceF

Postfunctionalization of poly(propargyl methacrylate) using copper catalyzed 1,3-dipolar Huisgen cycloaddition: an easy route to electro-optic materials

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Postfunctionalization of poly(propargyl methacrylate) using copper catalyzed 1,3-dipolar Huisgen cycloaddition: An easy route to electro-optic materials

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From a molecule to an electro-optic antenna

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Charge transfer state and large first hyperpolarizability in a highly electronically coupled zinc and gold porphyrin dyad

We report the synthesis and the characterizations of a novel dyad composed of a zinc porphyrin (ZnP) linked to a gold porphyrin (AuP) through an ethynyl spacer. The UV/Vis absorption spectrum and the electrochemical properties clearly reveal that this dyad exhibits a strong electronic coupling in the ground state as evidenced by shifted redox potentials and the appearance of an intense charge-transfer band localized at lambda = 739 nm in dichloromethane. A spectroelectrochemical study of the dyad along with the parent homometallic system (i.e., ZnP-ZnP and AuP-AuP) was undertaken to determine the spectra of the reduced and oxidized porphyrin units. Femtosecond transient absorption spectroscopic analysis showed that the photoexcitation of the heterometallic dyad leads to an ultrafast formation of a charge-separated state (+ZnP-AuP center dot) that displays a particularly long lifetime (tau=4 ns in toluene) for such a short separation distance. The molecular orbitals of the dyad were determined by DFT quantum-chemical calculations. This theoretical study confirms that the observed intense band at lambda = 739 nm corresponds to an interporphyrin charge-transfer transition from the HOMO orbital localized on the zinc porphyrin to LUMO orbitals localized on the gold porphyrin. Finally, a Hyper-Rayleigh scattering study shows that the dyad possesses a large first molecular hyperpolarizability coefficient (beta = 2100 x 10(-30) esu at lambda = 1064 nm), thus highlighting the valuable nonlinear optical properties of this new type of push-pull porphyrin system

Effects of Dendronization on the Linear and Third-Order Nonlinear Optical Properties of Bis(thiopyrylium) Polymethine Dyes in Solution and the Solid State

Effects of the size and attachment position of benzyl aryl ether dendrons covalently attached to bis­(thiopyrylium) penta- and heptamethines on the optical properties of these dyes in solution and in solid films have been investigated. In dilute solution the low-energy absorption bands of some of the dendronized species differ from those of the parent compounds in having much smaller transition dipole moments, this effect possibly due to differences in ion pairing, while at higher concentrations, dye–dye interactions lead to a decrease in the transition dipole moments of the nondendronized species, but not of the dendronized ones. Consequently, in the high concentration range, dendronized and nondendronized species exhibit similar values of the real part of the microscopic third-order polarizability at 1550 nm. Solid-state film absorption spectra suggest that the dendrons significantly disrupt the chromophore–chromophore interactions seen for the nondendronized species, reducing, but not eliminating, linear absorption losses in the near-IR, and suppressing absorption peaks that are hypsochromically shifted from the solution spectra maximum: centrally placed dendrons have a larger effect than terminal dendronization, so that the corresponding thin-film spectra more closely resemble those seen in solution with increasing generations of dendronization. Z-scan measurements at 1550 nm indicate that the third-order susceptibility of dendronized heptamethine guest–host films depend approximately linearly on doping ratio of dyes and are in reasonable agreement with values extrapolated from solution-derived third-order polarizabilities; in contrast, the susceptibilities of films highly doped with an undendronized analogue fall short of values expected from solution polarizabilities