Ce travail porte sur la synthèse et l'étude photophysique des molécules fluorescentes, visant à construire de nouveaux capteurs chimiques pour la détection sélective des ions métalliques importants en biologie ou pour l’environnement. Une série de fluoroionophores contenant le motif triazole et différents fluorophores ont été utilisés pour étudier les fonctions du groupe triazole dans les senseurs chimiques. Nos études photophysiques de ces ligands complexants démontrent que le triazole pourrait contribuer dans le cadre de fluorophores conjugués, comme les sites de complexation de métal ou de linkers. Plusieurs senseurs chimiques sélectifs ont été successivement mis au point pour la détection du Cu2+ ou du Hg2+. En incorporant le fluorophore dansyle sur calix[4]bisazacrown, une nouvelle capteur chimique de potassium a été construit. Un sulfonate fluorescente calix [4] bisazacrown a été conçu et synthétisé pour la détection sélective et ratiométrique de l’aluminium dans une solution tampon de lutidine à pH 6,0 avec une sensibilité satisfaisante. Enfin, nous avon cherché à réaliser une modulation de la complexation de cation par la redistribution de charge photoinduite à l'état excité. Deux motifs de liaison sur la base de fullerène et de pyridinium bétaïne ont été conçus à cet effet. Les résultats préliminaires ont mis en évidence un effet de type PET dans les composés à base de fullerène et les composés à base de pyridinium betaine sont trés prometteur dans la translocation de cation. / This work deals with the synthesis and photophysical study of fluorescent molecules, aiming to construct new chemical sensors for the selective detection of environmentally or biologically important metal ions. A series of fluoroionophores consisting of triazole moiety and different fluorophores was utilized to investigate the functions of triazole group in chemosensors. Our comprehensively photophysical and complexing studies of these ligands demonstrated that triazole groups could contribute as part of conjugated fluorophores, as metal binding sites or linkers. Several selective chemosensors were successively developed for the detection of Cu2+ or Hg2+. By incorporating dansyl fluorophore into calix[4]bisazacrown, a new potassium chemosensor was constructed. A sulfonate fluorescent calix[4]bisazacrown was created for the selective and ratiometric detection of Al3+ in lutidine buffer solution at pH 6.0 with a satisfying sensitivity. Finally, we aim to realize modulation of cation binding through the photoinduced charge redistribution in the excited state. Two binding motifs based on fullerene and betaine pyridinium were designed for this purpose. Preliminary results demonstrated that PET in fullerene might be not suitable but pydinium betaine hold great potential in the cation translocations.

Because of the structural analogies between these compounds and several other physiologically active compounds, such as chloroamphenicol, 4,4'-diaminodiphenyl sulfone, and 2,2-bis-(p-aminophenyl)-1,1,1-trichloroethane, a more complete study of the reduction products and the sequence of catalytic reduction of N-(4-nitrophenacyl)-4-(1-hexyl)pyridinium bromide was made in this investigation.

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

An attempt is made in the work described in this paper to extend the series started by Hall and Platas by means of a Knoevenagel condensation between 3-hydroxy-1,4-naphtho-quinone-2-(4-methylpyridinium) anhydride and various aromatic aldehydes giving rise to a series of unsaturated substituents on the four position of the pyridine ring.

Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal.

Chloride, bromide, pyridinium and quinolinium homologues of 4-(N- hexadecylpyridinium-4-ylmethylidene-amino)-2,6-dichlorophenolate have been investigated in solution, Langmuir and Langmuir-Blodgett films. Techniques including spectroscopy, surface potential measurement, quartz crystal microbalance, surface plasmon resonance, atomic force microscopy, reectometry and X-ray diffraction have been used to characterise these molecular systems. In solution, solvatochroism was observed and Benisi-Hildebrand analysis revealed dimeric aggregation. Langmuir monolayers were compressed at the air/water interface and chromophore rotation was observed by surface potential measurement. Langmuir- Blodgett monolayers showed lm-thickness dependence on the deposition-pressure. Monolayer thicknesses between 6-24Ä were measured using SPR and molecular areas between 40-l25Ä2 were measured using a quartz crystal microbalance. Both the molecular/s/area)and monolayer thicknesses were deposition-pressure dependent. The high tilt phases were visually distinguishable from the low tilt phases using atomic force microscopy, The compounds showed phase behaviour that was predominantly alike for the bromide and chloride homologues but different for the pyridinium and quinolinum homologues. Multilayer Y-type films of the merocyanine dyes were analysed using reectometry and deposition-pressure dependent thicknesses were found. Alternate layer structures of NLO-active hemicyanine amphiphiles were used to achieve homogeneous. orientation ordering using active and inactive spacer layers. Ordering was achieved but the optical efficiency was reduced by high proportions of inactive material and interlayer dipole formation. Double chained hemicyanine molecules were used to form Z-type structures and subsequent layers were found to significantly interdigitate. Different chain lengths were found to interdigitate by the length of the shortest chain. Gas detection experiments were undertaken on the quinolinium, dichloro merocyanine using three optical geometries. The absorption method showed slow switching and poor sensitivity. The Kretschmann SPR geometry showed high sensitivity and rapid switching. The grating SPR geometry showed rapid switching but was less sensitive than the ATR method. Protonation of the monolayers was investigated using hydrochloric acid gas, acetic acid vapour and stearic acid immobilised within the lm.

Thesis advisor: T. Ross Kelly / Thesis (PhD) — Boston College, 2008. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Chemistry.

Melanoma incidence is increasing faster than any other cancer worldwide.1 Early detection is often curative, but metastatic melanoma is lethal (5-year survival <20%) due to the development of resistance to all approved drugs.1 However, emerging evidence suggests that differences in melanoma metabolism relative to non-malignant cells may provide a target to improve treatment.2-14 Specifically, melanoma cells have increased mitochondrial electron transport chain (ETC) activity, elevated levels of reactive oxygen species, and a simultaneous hyperpolarized mitochondrial membrane potential relative to non-malignant cells.4, 8, 11, 15-17 Furthermore, melanoma cells have upregulated glucose consumption and concurrent increased levels of glucose transporters (GLUTs) relative to non-malignant cells; the products of glycolysis (pyruvate and NADPH) aid in the detoxification reactive oxygen species (ROS), while the intermediates are utilized in energy production via increased oxidative metabolism.15, 18 Collectively, melanoma cells exhibit alterations in metabolic, mitochondrial, and cell-surface targets that can be potentially exploited for therapeutic strategies for selective cancer cell killing relative to non-malignant cells. The research presented here demonstrates the therapeutic potential for a new class of mitochondrial-targeted fluorescent lipophilic-cations: pyridinium derivatives (UIRF 17023.186PV1 U.S. Provisional Patent Application No. 62/268,980 Patent Pending). Importantly, the pyridinium derivatives presented in this study have not been previously investigated as a mitochondrial-targeted therapy.19-21 Furthermore, the research presented outlines the feasibility of improving melanoma cellular accumulation of these pyridinium derivatives by including a GLUT targeting moiety in the form of a hexosamine. The addition of a hexosamine molecule to pyridinium derivatives has the potential to increase melanoma cell accumulation by targeting upregulation of GLUT expression in melanoma cells relative to normal cells. Thus, the results of this study identified: (1) a triphenylvinylpyridine (TPVP) lipophilic cation derivative that increased melanoma oxidative metabolism and decreased melanoma cell viability; and (2) the targeting potential for GLUT-mediated melanoma cell specific delivery of glucosamine-modified TPVP derivatives. These findings support the hypothesis that TPVP-based therapies can be developed to exploit fundamental differences in glucose and mitochondrial metabolism to selectively kill melanoma cells relative to non-malignant cells.

In the first part of this thesis, the synthesis, characterization and investigation of ortho-phenyleneethynylenes containing heterocycles, are presented. These compounds display changes in absorption and emission spectra varying with their functionalization and size. These compounds also have the ability to coordinate with metals. The synthesis of coordination compounds and their crystallographic data are reported. The synthesis and characterization of tetraethynyl thiophene compounds containing pyridines are also presented. These compounds exhibit differences in absorption and emission spectra upon exposure to various metal salts. The final topic to be discussed is the synthesis and characterization of diphenyl amine polymers. These polymers could in principle be used in NLO applications or light emitting devices.