The reaction between atomic chromium and neat 2-vinylpyridine leads to the polymerization of the monomer, forming a polymer glass. The product of the rapid polymerization of neat monomer is atactic poly(2-vinylpyridine) in which the chromium has been incorporated as a complex. From cyclic voltammetry and electronic absorption studies, it was proposed that the chromium forms a neutral complex with a severely distorted octahedral geometry and consists of a formally Cr2+ metal center. The metal would then form an organometallic complex that is also bound via the nitrogen atom to pendant pyridine rings. / The polymerization of 2-vinylpyridine in 2-methyltetrahydrofuran at -78°C after reaction with chromium atoms leads to the formation of isotactic poly(2-vinylpyridine) with 50% mmm isotactic content from the 13C NMR spectrum. A coordination polymerization mechanism at a chromium metal center is proposed to occur during this reaction. Semicrystalline poly(2-vinylpyridine) was formed by annealing the isotactic polymer. The highest melting temperature reported for this polymer by differential scanning calorimetry was that observed with our sample at 217°C. The atactic polymer from the rapid polymerization of neat monomer displayed a glass transition at 95°C at a heating rate of 20°C/minute, but did not melt. The morphology of the crystalline portions of the isotactic polymer after annealing consisted of spherulites displaying both "Maltese Cross" and banding under cross polarizers. / Bis(eta6-1-methylnaphthalene)chromium was synthesized by the metal atom route. This complex was reacted with 2-vinylpyridine producing an atactic polymer glass from the resulting rapid polymerization of the monomer. This rapid polymerization was not inhibited by CO2 (g), but was quenched upon addition of hydroquinone. These results support a radical propagation mechanism that forms the polymer glass. / A cryogenic vacuum station was designed and constructed for the low-temperature (15 K) electron paramagnetic resonance characterization of the reaction products from the cocondensation of atomic vanadium with 2-vinylpyridine. The cocondensation of benzene with vanadium atoms produced bis(eta6-benzene)vanadium that displayed the characteristic axial spectrum. No signal was observed for reactions between vanadium atoms and nitrogen heterocycles including 2,6-dimethylpyridine and 2-vinylpyridine. / The incorporation of atomic iron and cobalt into 2-vinylpyridine following the addition of atomic chromium leads to a rapid polymerization reaction forming a polymer composite consisting of magnetic metal particles embedded in poly(2-vinylpyridine). The particle sizes were measured by transmission electron microscopy to be 1.5--22 nm in diameter. Magnetometry studies indicated the additional presence of smaller particles not identified by microscopy. The observation of a ferromagnetic resonance spectrum from the cobalt sample at X-band frequency is consistent with the cobalt particles having undergone an allotropic phase transition to the face-centered cubic phase. The addition of atomic Ni to the monomer did not yield metal particles, but instead, a nickel complex with the polymer matrix is formed. The electron paramagnetic resonance spectra of this polymeric material below 40 K are consistent with the Ni metal being present as an organometallic formally Ni1+ center in an octahedral complex bound to the polymer.

Several types of catalytic and stoichiometric reactions of titanocenes and chiral ansa-titanocenes were studied. / Dimethyltitanocene (DMT) and rac- (EBTHI) TiMe$ sb2$ (EBTHI = ethylene-1,2-bis (4,5,6,7-tetrahydro-1-indenyl)) are effective catalyst precursors for hydrosilation of a variety of ketones when using in conjunction with secondary silanes. A catalyst generated by in situ reaction of enantiomerically pure S- (EBTHI) TiX$ sb2$ (X = Cl, 1/2(S-1,1$ sp prime$-binaphthyl-2,2$ sp prime$-diolate)) with MeLi catalyzes hydrosilation of dialkyl ketones to give, after hydrolysis, the enantioenriched secondary alcohols in up to 70% ee. This result compares favorably with the best chiral-phosphine/Rh catalysts for asymmetric hydrosilation of dialkyl ketones. DMT and rac-(EBTHI) TiMe$ sb2$ are also very active catalyst precursors for cross dehydrocoupling/co-intramolecular hydrosilation of allylic and homoallylic alcohols with secondary silanes. This is the first time such reactions catalyzed by group 4 metallocenes have been reported. / Photochemical stoichiometric reactions of DMT and rac-(EBTHI) TiMe$ sb2$ with hydrosiloxanes in the presence of pyridine produce two novel Ti(III)-pyridine complexes Cp$ sb2$Ti(Me)(Py) and rac-(EBTHI) Ti(Me)(Py). Their structures were characterized by X-ray crystallography and EPR spectroscopy. Stoichiometric reaction of rac-(EBTHI) TiMe$ sb2$ with phenylmethylsilane gives a Ti(III) hydride dimer, rac-((EBTHI)Ti($ mu$-H)) $ sb2$, which is the first structurally characterized Ti(III) hydride dimer without a bridging organic ligand. EPR spectroscopic study revealed that the dimer exists in equilibrium with its monomer in solution. Reaction of this hydride dimer in the presence of excess phenylphosphine produces a Ti(IV) diphosphanediyl complex, rac-(EBTHI) Ti(PPh)$ sb2$, in quantitative yield. The structure of rac-(EBTHI) Ti(PPh)$ sb2$ was also characterized by X-ray crystallography.

The thesis is divided into two parts. In part I, the monomeric and dimeric metal carbonyl complexes, M(CO)$ sb6$ (M = Cr, Mo, W), CpMn(CO)$ sb3$ (Cp = $ eta sp5$-C$ sb5$H$ sb5$), ($ eta sp6$-C$ sb6$H$ sb6$)Cr(CO)$ sb3$, (CpFe(CO)$ sb2$) $ sb2$, (CpMo(CO)$ sb3$) $ sb2$, Mn$ sb2$(CO)$ sb{10}$ and trans-Ir(CO)Cl(PPh$ sb3$)$ sb2$, have been embedded into polystyrene (PS), poly(methylmethacrylate) (PMMA) and poly(styreneacrylonitrile) (PSAN) polymer film matrices. The environments experienced by the metal complexes as a function of the polymer type have been characterized by vibrational spectroscopy and have been compared with those of the structurally-related solvents toluene, ethyl acetate and acetonitrile, respectively. Several of films have been subjected to UV irradiation in order to study the solid-state photochemistry of metal carbonyls in donor and non-donor polymer matrices and the effect of the polymer microstructure on the photodecomposition of the complexes. Iodine oxidation of the dimeric complexes in different polymer films and the chemical reactivity of Vaska's complex in PS upon exposure to the simple molecular gases, H$ sb2$, O$ sb2$, CO, SO$ sb2$ and I$ sb2$ have also been examined. / In part II, treatment of an electrically-nonconducting copolymer of 3-methyl- and 3-hexylthiophene with (CpFe(CO)$ sb2$(H$ sb2$C = CMe$ sb2$)) BF$ sb4$ gave an electrically-conducting material ($ sigma$ = 10$ sp{-3}$-10$ sp{-4}$ $ Omega sp{-1}$ cm$ sp{-1}$). The IR, UV and NMR spectra of this material and of model complexes suggest that (CpFe(CO)$ sb2$)) $ sp+$ residues, which are attached to the sulfur atoms of the thiophene rings of the copolymer backbone, induce the improved conductivity.

A new divergent methodology to prepare a variety of dendritic polymers containing dimethylsilyl-linked-3,5-dihydroxybenzyl alcohol units in the backbone is reported. This simple and versatile synthetic route is based on the acid-base hydrolytic chemistry of 3,5-dihydroxybenzyl alcohol (DHBA) and dimethyldiaminosilane Me2Si(NMe2)2. Controlled sequential addition of reactants was used to prepare dendrimer generations 1--5. The dendritic growth was found to be dictated by a preferential attack of the benzylic hydroxyl group of DHBA on the aminosilane, as no traces of residual benzylic OH groups were observed using 1H NMR spectroscopy. By a continuation of this divergent route, these dendrimers were functionalized with a variety of terminal units, including trimethylsilyl, n-octanoate, organic dye disperse red 1, and hydroxypropyldiphenylphosphine. Uncontrolled reaction protocols using the same reacting partners were also investigated to prepare the corresponding hyperbranched polymers. Resulting macromolecules showed structural fragments ranging from that of dendrimer generation 1 to that of dendrimer generation 2 in their MALDI-TOF mass spectra. Addition of more reactants did not seem to increase the size of these hyperbranched polymers. / Determination of some of the structure-property relationships in these dendrimers was carried out to obtain a better understanding of their potential applications. Hydrolytic stability of the dendrimers was examined using dendrimer generations 1--3 solvated in wet DMSO. Their resistance towards hydrolysis was found to increase with an increase in generation number. Intrinsic viscosities were determined for dendrimer generations 1--5. A non-linear relationship was found between the generation number and the intrinsic viscosity, as it reached a maximum for dendrimer generation 4, followed by a decrease. 3,5-dihydroxybenzyl alcohol based dendrimers were found to self-assemble via hydrogen bonding between terminally situated hydroxyl groups. This phenomenon was found to be dependent on their concentration in solution, and a critical aggregation concentration was determined at 3.7 mg mL-1 for dendrimer generations 1--3. Higher generation dendrimers showed aggregate formation at low concentrations as the number of peripheral OH groups was significantly increased. / By functionalizing dendrimers and hyperbranched polymers with hydroxypropyldiphenylphosphine ligands, followed by coordination with [Rh(COD)Cl], we were able to synthesize metallodendrimers and organometallic hyperbranched polymers, in which active organometallic fragments are present at the periphery. Their catalytic activity was assessed in hydrogenation of 1-decene. Conversion rates of decene into decane for metallodendrimers were found to be dependent on the time of reaction and the generation number. Maximum conversion rates were found after 5 h reaction time in each case.

The interactions of ligand-capped gold nanoparticles with lipid bilayers are investigated. The properties determining the mechanism of nanoparticle interaction using synthetic membrane models are explored. First, a specific interaction, incorporation of nanoparticles into the bilayers, is examined using novel imaging and nanoparticle synthesis techniques. Mixed ligand capped gold nanoparticles are synthesized with assorted ligand arrangements in order to relate ligand composition and structure to interaction mechanism using a dye leakage assay. Finally, in vivo experiments are conducted using peptide labeled fluorescent gold nanoparticles in live HeLa cells. It was found that gold nanoparticles are capable of crossing lipid bilayers, implying energy-independent cellular uptake mechanisms may occur. It is concluded that the structure and composition of the protecting ligands are critical in determining the magnitude of bilayer disruption. / L'interaction des nanoparticules d'or avec les bicouches lipidiques est présentée dans ce mémoire. Les facteurs influençant cette interaction ont été explorés en utilisant des bicouches lipidiques synthétiques. L'interaction due à l'incorporation des nanoparticules au sein des bicouches a été étudiée par des techniques d'imagerie. Un test de fuite de fluorophore a été employé afin de déterminer l'influence de la composition et de la structure des ligands protégeant les nanoparticules sur leur incorporation dans les bicouches de lipides. Pour cela, nous avons développer une synthèse de nanoparticules protégées par deux types de ligands. Des expériences in vivo ont été réalises avec des nanoparticules d'or fonctionnalisées avec des peptides ainsi que des fluorophores, mis en contact avec des cellules vivantes de type HeLa. Nous avons constaté que les nanoparticules d'or sont capables de franchir les bicouches lipidiques en utilisant des mécanismes indépendants d'énergie. Nous concluons que la structure et la composition des ligands protégeant les nanoparticules ont une grande influence sur la perturbation qu'elles induisent dans la structure des bicouches lipidiques.

ABSTRACT The Sequential Insertion of Carbon Monoxide and Imines into Nickel-Carbon Sigma-Bonds and Kinetic Analysis of Imine Insertion into Palladium-Acyl Sigma-Bonds The coupling of imines and carbon monoxide mediated by late transition metals has been previously reported in the Arndtsen laboratory. The fundamental properties of 2,1-migratory insertion of imines into nickel- and palladium-acyl bonds are presented in this text. This study investigates the use of neutral eta2-N,O-salicylaldiminato nickel (II) systems (Chapter 2) as potential complexes to mediate the sequential insertion of carbon monoxide and imines. These complexes undergo rapid carbon monoxide insertion. Subsequent imine insertion is permitted when the imine substrate is sterically unencumbered. The coupling product disproportionates leading to the formation of 1,2-diamides. In our laboratory, kinetic and thermodynamic studies on the coordination and 2,1-migratory insertion of imines into palladium-carbon sigma-bonds were the focus of former student Rania Dghaym, Ph.D. Chapter 3 completes these studies, and offers a mechanistic picture of the pathway by which 2,1-migratory insertion into palladium-acyl bonds proceeds. Our mechanistic data suggest that imine insertion is distinct from olefin insertion and involves the concerted migratory attack of the sigma-coordinated imine to the electrophilic acyl ligand. / RÉSUMÉ L'insertion séquentielle de monoxyde de carbone et d'imines dans des liens sigma nickel-carbone ainsi que l'analyse cinétique de l'insertion d'imines dans le lien palladium-acétyle Le couplage d'imines et de monoxyde de carbone médié par des métaux de transition a été récemment publié par le laboratoire du Professeur Arndtsen. Les propriétés fondamentales de l'insertion migratoire-2,1 d'imines dans les liens nickel- et palladium-acétyle sont présentées dans le texte ci-présent. Les complexes neutres eta2-N,O-salicylaldiminato de nickel (II) sont le sujet de recherche dans le chapitre 2 pour leur potentiel de médier l'insertion séquentielle de monoxyde de carbone et d'imine. L'insertion de monoxyde de carbone dans le lien nickel-méthyle est rapide. Par contre, l'insertion d'imine subséquente est seulement observée dans les cas où l'encombrement stérique de celle-ci est minime. Le produit du couplage mène à la formation de 1,2-diamides. Dans notre laboratoire, la cinétique et thermodynamique de l'insertion migratoire-2,1 dans les liens sigma palladium-carbone était le sujet d'étude de Rania Dghaym, Ph.D., une étudiante précédente du laboratoire. Au chapitre 3 nous présentons la suite de ses études et offrons un portrait global du mécanisme par lequel l'insertion migratoire-2,1 dans les liens palladium-acétyle se produit. Nos résultats suggèrent que le mécanisme d'insertion d'imines est distinct de celui d'insertion d'oléfines et implique une attaque migratoire concertée de l'imine sigma-coordonnée au ligand acétyle électrophilique.

The complexes CpRu(CO)$ sb2$SR(Cp = $ eta sp5$-cyclopentadienyl; R = 4-C$ sb6 rm H sb4$Me, C$ rm sb6H sb5, CH sb2C sb6H sb5$) insert sulfur from S$ sb8$ to give CpRu(CO)$ rm sb2S sb{x}$R (x = 1-3) and undergo ligand exchange with R$ rm sp prime sb2S sb{y}$ (y = 2,3) to give CpRu(CO)$ sb2 rm S sb{x}R sp prime$ (x = 1-3). The mechanisms of these reactions are discussed. Treatment of CpRu(CO)$ sb2$SH with the appropriate phthalimide sulfur transfer reagents REphth (phth = phthalimide; E = SS, SS(O); R = 4-C$ rm sb6H sb4Me, C sb6H sb5, CH sb2C sb6H sb5$) gave CpRu(CO)$ sb2$ER. The complexes CpRu(CO)$ sb2$SSR undergo sulfur redistribution in solution to give CpRu(CO)$ rm sb2S sb{x}$R (x = 1-3) and insert sulfur from S$ sb8$ to give CpRu(CO)$ sb2$SSSR. The complexes CpRu(CO)$ sb2$SS(O)R undergo spontaneous oxygen transfer in solution to form CpRu(CO)$ sb2$SSR and CpRu(CO)$ sb2$SS(O)$ sb2$R. The reaction of CpRu(CO)$ sb2$ER (E = S, SS, SS(O)) with PPh$ sb3$ in ambient light gave CpRu(PPh$ sb3$)(CO)SR. The complexes CpRu(L)(CO)SS(O)$ sb2$R were prepared by oxidation of CpRu(PPh$ sb3$)(CO)SS(O)CHMe$ sb2$ with NaIO$ sb4$ (L = PPh$ sb3$) and reaction of CpRu(CO)$ sb2$SH with RS(O)$ sb2$Cl (L = CO; R = 4-C$ rm sb6H sb4Me, C sb6H sb5$). The reaction of CpRu(CO)$ sb2$SS(O)$ sb2$R with PPh$ sb3$ gave CpRu(PPh$ sb3$)(CO)SS(O)$ sb2$R. The x-ray structures of CpRu(CO)$ sb2$SS(O)C$ rm sb6H sb5 and CpRu(CO) sb2SS(O) sb2C sb6H sb5$ were determined. Oxidation of CpRu(PPh$ sb3$)(CO)SS(O)-4-C$ rm sb6H sb4$Me by dimethyldioxirane (DMDO) gave CpRu(PPh$ sb3$)(CO)S(O)$ sb2$S(O)$ sb2$-4-C$ rm sb6H sb4$Me which was immediately hydrolyzed by trace amounts of H$ sb2$O to give CpRu(PPh$ sb3$)(CO)S(O)$ sb3$H. Cyclic voltammetry (CV) studies of CpRu(CO)$ sb2$ER (E = S, SS, SS(O), SS(O)$ sb2$) were performed. All of these complexes undergo irreversible sulfur-based oxidations.

Infecting an estimated 350 to 500 million people and associated with more than 1 million deaths yearly, malaria remains one of the most devastating infectious diseases. Among the different drug targets, figures the malaria pigment. Its production is non-mutagenic and essential to the parasite survival. Its pro-inflammatory properties also place it as a potential agent in the elaboration of a malaria vaccine. These black prismatic microcrystals, also named hemozoin, result from hemoglobin catabolism by the parasites as they invade the red blood cells. As the natural compound is difficult to harvest, two synthetic routes were investigated. The acid-catalyzed method utilises accessible material and common laboratory procedures. It has been optimized to produce hematin anhydride microcrystals of about 1 μm long in a reproducible manner. Another method, the anhydrous base-annealing procedure, was also studied with the goal to produce crystals of a size which would enable single crystal XRD as well as biomimetics crystals. All of the reactive components have been varied: the source of the initial material, the solvents used, and the incubating temperature. The crystallization pathway appeared to be an equilibrium process where smaller crystals were obtained at room temperature, from methanol rich solvent systems and high concentration of hemin. Conditions were optimized to obtain single domain parallelepipeds of 1.4 μm, close to hemozoin size. Suggestions are given from these results for new starting point to make larger crystals enabling single crystal XRD. Unit cell orientation within the crystalline lattice has been ascertained theoretically by previous autho / Infectant entre 350 et 500 millions d'humains et associé avec plus d'un million de décès par année, le paludisme se trouve parmi les maladies infectieuses, les plus dévastatrices. Parmi les différents vecteurs de médication, se trouve le pigment malarique présentant une biochimie unique et essentielle au parasite ainsi qu'une production non-mutagène. Ses propriétés pro-inflammatoires en font également un agent potentiel dans l'élaboration d'un éventuel vaccin. Ces petits cristaux, également appelés hémozoïne résultent du catabolisme de l'hémoglobine par le parasite infectant les globules rouges. Due aux difficultés rencontrées dans l'isolation du matériel naturel, deux méthodes de synthèse on été étudiées. La précipitation de l'hémine catalysée par un acide organique représente une méthode de synthèse accessible utilisant des produits communs ainsi qu'une procédure adaptée à des conditions usuelles de laboratoire. Elle a été optimisée produisant à son tour de petits cristaux d'anhydride d'hématine d'environ 1 μm de long de façon reproductible. Une méthode plus élaborée, la déhydrohalogénation de l'hémine en présence d'une base anhydre, a également fait partie de l'étude dans le but de synthétiser des cristaux permettant la diffraction à rayons X de monocristaux ainsi que des biomimétiques. Les différents composés entrant dans le procédé ont tous été étudiés à partir des matériaux de départ, des solvants utilisés et la température d'incubation. La cristallisation du matériau semble sous l'influence d'un équilibre et de petits cristaux ont été observés à température ambiante avec une c

The complexes CpRu(PPh$ sb3)$(L)SR (Cp=$ eta sp5$-cyclopentadienyl; R=CMe$ sb3,$ CHMe$ sb2,$ 4-$ rm C sb6H sb4Me)$ reacted with NOBF$ sb4$ to give either (CpRu(PPh$ sb3)$(NO)SR) BF$ sb4$ (L=PPh$ sb3)$ or complexes containing disulfide ligands (L=CO). The bisphosphine complexes, CpRu(PPh$ sb3) sb2$SR, reacted with HBF$ sb4$ to give the corresponding thiol complex salts (CpRu(PPh$ sb3) sb2$(HSR)) BF$ sb4$ and with (MeSSME$ rm sb2 rbrack BF sb4$ to give (CpRu(PPh$ sb3) sb2$(SMe$ sb2)$) BF$ sb4$ regardless of the starting thiolates. The complexes CpRu(PPh$ sb3) sb2$SR reacted with the sulfur transfer agent MeSphth (phth=phthalimido) to give CpRu (PPh$ sb3) sb2$(phth) and the dimers ($ mu$-SMe)($ mu$-SR) (CpRu(phth)) $ sb2$ for R=CMe$ sb3$ or CHMe$ sb2,$ while for R=4-$ rm C sb6H sb4Me$ the same reaction gave CpRu(PPh$ sb3)$(phth)(MeSS-4-$ rm C sb6H sb4Me)$ and ($ mu$-SMe)($ mu$-S-4-$ rm C sb6H sb4$Me) (CpRu(S-4-$ rm C sb6H sb4Me) rbrack sb2.$ The complex CpRu(PPh$ sb3) sb2$ SCH$ sb2$CH=CH$ sb2,$ prepared from the reaction of CpRu(PPh$ sb3) sb2$Cl and LiSCH$ sb2$CH=CH$ sb2,$ reacted with CO and CS$ sb2$ to give CpRu(PPh$ sb3)$(CO)SCH$ sb2$CH=CH$ sb2$ and CpRu(PPh$ sb3)$S$ sb2$CSCH$ sb2$CH=CH$ sb2,$ respectively. Refluxing a toluene solution of CpRu(PPh$ sb3) sb2$SCH$ sb2$CH=CH$ sb2$ gave ($ mu sb3$-S)$ sb2( mu$-SCH$ sb2$CH=CH$ sb2$) (CpRu) $ sb3$ in which the C-S bond has been cleaved. / The complexes (PPh$ sb3) sb2$Pt(SR)$ sb2$ (R=H, $ rm CMe sb3, CHMe sb2,$ 4-$ rm C sb6H sb4Me)$ were treated with SO$ sb2$ as models for the Claus process. These reactions produced adducts of formula (PPh$ sb3) sb2$Pt(S(SO$ sb2)$R)$ sb2,$ which have a labile thiolate-bound SO$ sb2$ molecule, for R=CMe$ sb3,$ 4-$ rm C sb6H sb4Me$ and CHMe$ sb2.$ The reaction of cis-(PPh$ sb3) sb2$Pt(SH)$ sb2$ with SO$ sb2$ gave (PPh$ sb3) sb2$Pt(S$ sb3$O) and H$ sb2$O, a reaction which mimics Claus chemistry. The complexes cis-(PPh$ sb3) sb2$Pt(SH)$ sb2,$ (PPh$ sb3) sb2$Pt(S$ sb3$O) and (PPh$ sb3) sb2$Pt(SR)$ sb2$ catalyze the Claus reaction (2H$ sb2$S + SO$ rm sb2 to3/8S sb8+2H sb2O).$ / The complexes (PPh$ sb3) sb2$Pt(SR)$ sb2$ reacted with CS$ sb2$ to form the mixed thiolato-thioxanthato complexes (PPh$ sb3)$Pt(SR)(S$ sb2$CSR) wherein CS$ sb2$ had inserted into one of the Pt-S bonds. The complex cis-(PPh$ sb3) sb2$Pt(SH)$ sb2$ reacted with CS$ sb2$ to give the known complex, (PPh$ sb3) sb2$Pt(S$ sb2$CS), which contains a trithiocarbonate group. / The structures of (CpRu(PPh$ sb3)$(NO)SCMe$ rm sb3 rbrack BF sb4, ( mu$-SMe)($ mu$-S-4-$ rm C sb6H sb4Me)$ (CpRu(S-4-$ rm C sb6H sb4Me) rbrack sb2, ( mu sb3$-S)$ sb2( mu$-SCH$ sb2$CH=CH$ sb2)$ (CpRu) $ sb3,$ (PPh$ sb3) sb2$Pt(S$ sb3$O) and (PPh$ sb3)$Pt(S-4-$ rm C sb6H sb4Me)$(S$ sb2$CS-4-$ rm C sb6H sb4Me)$ were determined by x-ray crystallography.

Ionic liquids (ILs) have gained considerable research attention as potential replacements for volatile organic chemicals (VOCs) based solvents due to their low vapour pressures and ability to be easily recovered and recycled. Research on ILs has revealed such novel properties as: high chemical and thermal stabilities, good gas solubilites, wide windows of electrochemical stability, good electrical conductivities, high ionic mobilities and immiscibilities with some organic solvents and water. The exploitation of these IL properties has expanded the application scope to include: analytics, catalysis, electrochemistry, nanotechnology, synthesis and separations. This thesis examined the use of ILs in the synthesis of metal nanoparticles (NPs) and molecular complexes, with their application in biphasic catalysis. Metal NPs were synthesized directly in imidazolium or phosphonium ILs, which act as a reaction solvent and an electrostatic NP stabilizer. ILs functionalized with a metal binding moiety (i.e. thiolate or phosphine), otherwise known as functionalized ILs (FILs), were also employed for the synthesis of NPs to enhance their stability by direct attachment of the IL moiety to the metal surface. Transition metal NPs embedded in an IL solvent provided highly effective and recyclable biphasic hydrogenation catalysts for the reduction of alkene and arene substrates. FILs were also employed as stabilizing species of molecular complexes used as biphasic hydroformylation catalysts of long-chain olefins. Important to all of these studies was the influence of the IL parameters (i.e. cationic headgroup, alkyl chain length, counter anion) on the properties of the metal NPs and molecular complexes (i.e. NP size, surface plasmon band, stability under catalytic conditions, catalytic activity and selectivity). ILs are shown to be a highly tunable class of compounds, which allow for control of the properties of metal species stabilized within an IL. / Les liquides ioniques (LIs) ont fait l'objet d'une attention considérable en tant qu'alternatives potentielles aux solvants à base de composés organiques volatiles du fait de leur faible pression de vapeur saturante et de la facilité avec laquelle on peut les récupérer et les recycler. La recherche sur les LIs a par ailleurs révélé de nombreuses propriétés telles que : une grande stabilité chimique et thermique, de bonnes solubilités pour les gaz, une large fenêtre de stabilité électrochimique, une bonne conductivité électrique, une bonne mobilité ionique et une immiscibilité avec certains solvants organiques et l'eau. L'exploitation de ces propriétés ont étendues le champ des applications pour comprendre : la chimie analytique, la catalyse, l'électrochimie, la nanotechnologie, la synthèse et la purification. Cette thèse traite de l'utilisation des LIs pour la synthèse de nanoparticules (NPs) métalliques et de complexes, ainsi que de leur utilisation en catalyse biphasique. Des NPs métalliques ont été synthétisées directement dans les LIs à base de cations imidazolium ou phosphonium. Ces LIs jouent le rôle de solvant et de stabilisants électrostatiques pour les NPs. Des LIs fonctionnalisés avec une espèce ligante (i.e. un thiolate ou une phosphine), appelés LIs fonctionnalisés (LIFs), ont été employés pour la synthèse de NPs pour améliorer leur stabilité par attachement direct du LI à la surface métallique. Les NPs de métaux de transition ainsi obtenues sont très actives en catalyse biphasique d'hydrogénation des alcènes et des arènes et recyclables. Les LIFs ont également été employés comme ligands pour des complexes moléculaires utilisés en catalyse biphasique d'hydroformylation des oléfines à longue chaine. Au centre de cette étude, les paramètres moléculaires des LIs (i.e. le groupement cationique, la longueur de la chaine alkyle, le contre-ion) se sont révélés influer sur les propriétés des NPs métalliques et des complexes moléculaires (i.e. la taille des NPs, leur bande plasmon, leur stabilité en condition catalytique, leur activité catalytique et leur sélectivité). Les LIs constituent une classe de composés hautement versatiles, qui permettent le contrôle des propriétés des espèces métalliques qu'ils stabilisent.