Thesis (M.Sc.) - Carleton University, 2006. / Includes bibliographical references (p. 100-102). Also available in electronic format on the Internet.

Les travaux décris dans cette thèse rapportent la conception de Metal-Organic Frameworks (MOFs) photoactifs et leur immobilisation sur surface dans le but d’obtenir et d’étudier des SurMOFs (Surface anchored Metal-Organic Frameworks) propices aux processus photoinduits dans le cadre de la photosynthèse artificielle. Pour accomplir cela, nous avons synthétisé différents ligands photoactifs et réalisé leur immobilisation sur surface à l’aide de la croissance épitaxiale en phase liquide. Ainsi, différents SurMOFs à base de zinc(II), présentant tous une structure de type SurMOF-2, ont été préparés avec succès. Les premiers matériaux obtenus à base de ligands rylènes (naphtalène dimide : NDI et pérylène diimide : PDI) ont mis en avant de fortes interactions  entre les chromophores au sein du SURMOF, causant une perte de la luminescence. Une deuxième génération de ligands plus encombrés a été synthétisée. Ils ont conduit à des SurMOFs luminescents et siège de transferts d’énergie interligands. Ces premiers travaux ont mis en avant l’impact de la disposition des ligands dans le matériau sur les propriétés photoniques. Par ailleurs, des SurMOFs constitués de ligands dicétopyrrolopyrrole (DPP) et d’anthracène (ADP) ont été synthétisés. L’étude de leurs propriétés photoniques alliée à des calculs théoriques ont montré que le transfert d’énergie au sein de ce SurMOF ne se fait pas de manière isotrope. Enfin, un SurMOF à partir de ligand DPP portant des fonctions réactives (azoture) a été synthétisé et nous avons pu greffer différentes molécules par réaction de cyclo-addition de type Huisgen, dont un accepteur d’électron, à sa périphérie par modification post-synthétique. / The aim of this thesis was the development of photoactive Metal-Organic Frameworks (MOFs) and their immobilizations on surface to obtain and study SurMOFs (Surface anchored Metal-Organic Frameworks) to investigate photoinduced processes in the context of the artificial photosynthesis. Towards this goal, we have synthesized photoactive ligands and immobilized them on surfaces using liquid phase epitaxy (LPE) in a layer-by-layer (LbL) fashion. Thus, different zinc (II) based SurMOFs, featuring a SurMOF-2 structure, were successfully prepared. The first rylene- (naphthalene diimide: NDI and perylene diimide: PDI) based SurMOFs described in this thesis showed strong  interactions between the chromophores within the MOF, causing the quenching of the luminescence. A second generation of ligands, sterically hindered, was then synthesized. They lead to luminescent SurMOFs showing efficient ligand-to-ligand energy transfer. These first results highlight the impact of linker arrangement within the material on its photonic properties. Furthermore, diketopyrrolopyrrole (DPP) and anthracene (DPA) based SurMOFs were prepared. The study of their photonic properties coupled with theoretical calculations showed that energy transfers, occurring within SurMOF-2 type materials, were not isotropic. Finally, a SurMOF, made out of a DPP ligand bearing reactive moieties (azide), was synthesized and was functionalized with different kinds of molecules, including an electron acceptor, at the periphery by post-synthetic modification using the Huisgen cycloaddtion reaction.

Usando a técnica de decaimento do potencial de superfície e de correntes termo estimuladas, foi investigado em cristais de naftaleno, o movimento de cargas elétricas injetadas por uma descarga corona. Os resultados obtidos nas medidas de decaimento, foram explicados satisfatoriamente usando um modelo teórico de transporte de cargas, na presença de armadilhas rasas e profundas. A partir desse modelo foram calculadas: a mobilidade modulada dos portadores, o tempo de captura das armadilhas profundas e estimada a sua seção de captura. Nas medidas de corrente termo-estimuladas, foram identificadas as armadilhas rasas e profundas e determinada as suas profundidades energéticas. / Using the method of surface potential decay, and thermal stimulated currents, it was possible to study the motion of electrical charges, injected in naphthalene single crystals, by a negative corona discharge in the air. The results obtained in the measurements of the decay, were explained by using a theoretical model of transport of charges in the presence of shallow and deep traps. With the help of this model, the trap modulated mobility of the carriers, the trapping time of the deep traps, and the capture cross section were calculated. In the measurements of thermal stimulated currents, it was possible to identify the deep and shallow traps and also to calculate their activation energies.

Usando a técnica de decaimento do potencial de superfície e de correntes termo estimuladas, foi investigado em cristais de naftaleno, o movimento de cargas elétricas injetadas por uma descarga corona. Os resultados obtidos nas medidas de decaimento, foram explicados satisfatoriamente usando um modelo teórico de transporte de cargas, na presença de armadilhas rasas e profundas. A partir desse modelo foram calculadas: a mobilidade modulada dos portadores, o tempo de captura das armadilhas profundas e estimada a sua seção de captura. Nas medidas de corrente termo-estimuladas, foram identificadas as armadilhas rasas e profundas e determinada as suas profundidades energéticas. / Using the method of surface potential decay, and thermal stimulated currents, it was possible to study the motion of electrical charges, injected in naphthalene single crystals, by a negative corona discharge in the air. The results obtained in the measurements of the decay, were explained by using a theoretical model of transport of charges in the presence of shallow and deep traps. With the help of this model, the trap modulated mobility of the carriers, the trapping time of the deep traps, and the capture cross section were calculated. In the measurements of thermal stimulated currents, it was possible to identify the deep and shallow traps and also to calculate their activation energies.