No description available.

No description available.

O gás carbônico é a fonte primária de carbono ideal para se obter novos compostos, devido principalmente à sua abundância, atoxidade e ao fato de ser renovável. Desta forma, novos métodos de introduzir o CO2 em rotas sintéticas se fazem necessários. Dentre os possíveis métodos, nesta tese foram estudadas duas rotas diferentes de utilização do gás carbônico: uma, empregando complexos bimetálicos como catalisadores da inserção do CO2 em alcenos e alcanos e outra utilizando enzimas imobilizadas em partículas magnéticas, atuantes no ciclo de redução do CO2 ao metanol. Os complexos bimetálicos foram construídos a partir do ligante de ponte, bispirrolidyl- fenil (BPP) incorporando grupos difenilmetanol e difenilfosfino em suas arquiteturas moleculares. Sua inspiração partiu de sistemas biomiméticos para a redução do CO2, e foi direcionada para a carboxilação de hidrocarbonetos. Nas reações de acoplamento carbono-carbono, observou-se que com o iodeto de metila, os complexos foram capazes de transformar o gás carbônico e produzir acetato de metila. Já nas reações com 1-deceno, isobutano e iso-octano, apenas três complexos se mostraram eficientes: BPP(ONi,ONi), BPP(OZn,OPPh2Pd) e BPP(OPPh2Pd,OPPh2Pd). Na rota enzimática, fez-se uso de enzimas imobilizadas do tipo desidrogenase e três tipos de nanopartículas magnéticas (MagNP) como suporte (MagNP-APTS, MagNP@SiO2-APTS e MagNP-APTS/Glioxil-Agarose, APTS = aminopropiltrimetoxissilano). Observou-se que para a imobilização da álcool desidrogenase e da formaldeído desidrogenase, o melhor suporte foi a MagNP@SiO2- APTS, enquanto para a formato desidrogenase, o melhor suporte de imobilização foi a MagNP-APTS. Para a glutamato desidrogenase, um sistema com imobilização via múltiplos pontos, como na MagNP-APTS/Glioxil-Agarose, conduziu a um melhor desempenho, . Os melhores sistemas enzima-suporte foram utilizados em uma reação multi-enzimática com CO2, NADH e glutamato para a obtenção de formaldeído e metanol. Os dois métodos de redução do gás carbônico se mostraram capazes de realizar o objetivo da tese, que é a transformação do CO2 em produtos de maior valor agregado / CO2 is a primary world carbon source readily available for the production of new compounds, under sustainable conditions due to its great abundance and non-toxic, renewable characteristics. Hence, there is a compulsive interest to develop new methodologies capable of introducing carbon dioxide in the chemical synthetic routes. Among the many possible alternatives, two different strategies were pursued this thesis: one using bimetallic complexes as catalysts, and the other one using enzymes supported on superparamagnetic nanoparticles. The bimetallic complexes were based on the bridging bis-pyrrolidyl-phenol (BPP) architecture encompassing diphenylmethanol and diphenylphosphino groups. They were inspired in biomimetic systems for the chemical reduction of CO2 and employed in the carboxylation of hydrocarbons. In such carbon-carbon coupling reactions, the bimetallic complexes were able to catalyse the reaction between CO2 and methyl iodide in order to obtain methyl acetate. However, in the reaction with 1- decene, isobutene and iso-octane, only three of them were efficient: BPP(ONi,ONi), BPP(OZn,OPPh2Pd) and BPP(OPPh2Pd,OPPh2Pd). In the studies focusing on immobilized enzymes, dehydrogenase-like enzymes and three different kind of magnetic particles (MagNP) were employed (MagNP-APTS, MagNP@SiO2-APTS and MagNP-APTS/Glioxyl-Agarose, APTS = aminopropyltrimethoxisylane). The best immobilization support for alcohol dehydrogenase and formaldehyde dehydrogenase was MagNP@SiO2-APTS, while for formate dehydrogenase the best immobilization support was MagNP-APTS. For glutamate dehydrogenase a multi-point immobilization was required, turning MagNPAPTS/ Glioxyl-Agarose the best catalytic support. These enzyme-support systems were used in a multi-enzymatic reaction using CO2, NADH and glutamate in order to obtain methanol and formaldehyde. Both CO2 redution methods were successful explored, and the results fulfilled the major objective of this thesis, which is the conversion of CO2 into higher value products.

O gás carbônico é a fonte primária de carbono ideal para se obter novos compostos, devido principalmente à sua abundância, atoxidade e ao fato de ser renovável. Desta forma, novos métodos de introduzir o CO2 em rotas sintéticas se fazem necessários. Dentre os possíveis métodos, nesta tese foram estudadas duas rotas diferentes de utilização do gás carbônico: uma, empregando complexos bimetálicos como catalisadores da inserção do CO2 em alcenos e alcanos e outra utilizando enzimas imobilizadas em partículas magnéticas, atuantes no ciclo de redução do CO2 ao metanol. Os complexos bimetálicos foram construídos a partir do ligante de ponte, bispirrolidyl- fenil (BPP) incorporando grupos difenilmetanol e difenilfosfino em suas arquiteturas moleculares. Sua inspiração partiu de sistemas biomiméticos para a redução do CO2, e foi direcionada para a carboxilação de hidrocarbonetos. Nas reações de acoplamento carbono-carbono, observou-se que com o iodeto de metila, os complexos foram capazes de transformar o gás carbônico e produzir acetato de metila. Já nas reações com 1-deceno, isobutano e iso-octano, apenas três complexos se mostraram eficientes: BPP(ONi,ONi), BPP(OZn,OPPh2Pd) e BPP(OPPh2Pd,OPPh2Pd). Na rota enzimática, fez-se uso de enzimas imobilizadas do tipo desidrogenase e três tipos de nanopartículas magnéticas (MagNP) como suporte (MagNP-APTS, MagNP@SiO2-APTS e MagNP-APTS/Glioxil-Agarose, APTS = aminopropiltrimetoxissilano). Observou-se que para a imobilização da álcool desidrogenase e da formaldeído desidrogenase, o melhor suporte foi a MagNP@SiO2- APTS, enquanto para a formato desidrogenase, o melhor suporte de imobilização foi a MagNP-APTS. Para a glutamato desidrogenase, um sistema com imobilização via múltiplos pontos, como na MagNP-APTS/Glioxil-Agarose, conduziu a um melhor desempenho, . Os melhores sistemas enzima-suporte foram utilizados em uma reação multi-enzimática com CO2, NADH e glutamato para a obtenção de formaldeído e metanol. Os dois métodos de redução do gás carbônico se mostraram capazes de realizar o objetivo da tese, que é a transformação do CO2 em produtos de maior valor agregado / CO2 is a primary world carbon source readily available for the production of new compounds, under sustainable conditions due to its great abundance and non-toxic, renewable characteristics. Hence, there is a compulsive interest to develop new methodologies capable of introducing carbon dioxide in the chemical synthetic routes. Among the many possible alternatives, two different strategies were pursued this thesis: one using bimetallic complexes as catalysts, and the other one using enzymes supported on superparamagnetic nanoparticles. The bimetallic complexes were based on the bridging bis-pyrrolidyl-phenol (BPP) architecture encompassing diphenylmethanol and diphenylphosphino groups. They were inspired in biomimetic systems for the chemical reduction of CO2 and employed in the carboxylation of hydrocarbons. In such carbon-carbon coupling reactions, the bimetallic complexes were able to catalyse the reaction between CO2 and methyl iodide in order to obtain methyl acetate. However, in the reaction with 1- decene, isobutene and iso-octane, only three of them were efficient: BPP(ONi,ONi), BPP(OZn,OPPh2Pd) and BPP(OPPh2Pd,OPPh2Pd). In the studies focusing on immobilized enzymes, dehydrogenase-like enzymes and three different kind of magnetic particles (MagNP) were employed (MagNP-APTS, MagNP@SiO2-APTS and MagNP-APTS/Glioxyl-Agarose, APTS = aminopropyltrimethoxisylane). The best immobilization support for alcohol dehydrogenase and formaldehyde dehydrogenase was MagNP@SiO2-APTS, while for formate dehydrogenase the best immobilization support was MagNP-APTS. For glutamate dehydrogenase a multi-point immobilization was required, turning MagNPAPTS/ Glioxyl-Agarose the best catalytic support. These enzyme-support systems were used in a multi-enzymatic reaction using CO2, NADH and glutamate in order to obtain methanol and formaldehyde. Both CO2 redution methods were successful explored, and the results fulfilled the major objective of this thesis, which is the conversion of CO2 into higher value products.

No description available.

Le sujet de cette thèse porte sur l’étude de ligands hybrides incorporant un donneur carbène N-hétérocyclique (NHC). Les ligands phosphine-NHC construits sur le motif m-phénylène ont conduit à des complexes di- ou tétranucléaires d’Ag, Cu, Au et Ir, et à des complexes bimétalliques Ag/Cu et Ag/Ir par transmétallation sélective du site NHC. Dans le cas des ligands phosphino-picoline-NHC (PNC), la transmétallation des sels de Li ou K correspondants a permis d’isoler des complexes « pinceurs » dé-aromatisés du Cr, Fe et Co. La déprotonation du ligand bis(phosphinométhyl)pyridine (PNP) a été examinée, et les ligands dé-aromatisés mono- et bis-anioniques correspondants ont été utilisés dans des réactions de transmétallation vers le Cr(II) et Zr(IV). Différents modes de coordination des ligands dé-aromatisés, notamment une métallation de la position alpha-CHP, ont été observés. La substitution de la phosphine dans PNC par une fonction imine conduit à un ligand hybride « rédox non-innocent ». / The purpose of this work is the synthesis and study of hybrid and potentially “pincer” ligands featuring an N-heterocyclic carbene (NHC) donor. The phosphine-NHC ligands based on the m-phenylene framework led to di- or tetranuclear Ag, Cu, Au and Ir complexes, and to bimetallic Ag/Cu and Ag/Ir complexes by selective transmetallation of the NHC. With the phosphino-picoline-NHC (PNC) ligands, transmetallation from the corresponding Li or K salts led to dearomatised Cr, Fe and Co “pincer” complexes. Deprotonation of the bis(phosphinomethyl)pyridine (PNP) ligand was also examined. The corresponding dearomatised mono- and bis-anionic ligands were isolated as Li or K salts and further used in transmetallation reactions towards Cr(II) and Zr(IV). Different coordination modes of the dearomatised ligands, including side-arm metallation, were observed. Substitution of the phosphine group in PNC by an imine donor led to a hybrid and “redox non-innocent” ligand.

Un axe de recherche particulièrement développé en chimie organométallique moderneconcerne la recherche d’agents chimiothérapeutiques alternatifs au cisplatine dans lestraitements contre le cancer. Dans ce domaine, plusieurs stratégies ont été développées depuisplusieurs dizaines d’années, parmi lesquelles nous pouvons citer la multinucléarité, consistanten la création d’édifices polymétalliques. L’objectif de la première partie de ce manuscrits’inscrit dans cette thématique, par la conception, l’obtention et l’étude des propriétésbiologiques de complexes hétérobimétalliques "early-late" (Ti-Ru, Ti-Au, Ti-Pt, Ti-Os, Ti-Rh, Ti-Ir) et "late-late" (Pt-Au). Un deuxième concept développé au cours de ce manuscritconsiste en la génération de nouvelles espèces théranostiques, par association au sein d’unmême complexe d’un fragment métallique à activité thérapeutique et d’une sonde fluorescentepermettant de visualiser le trajet et les cibles biologiques de ce premier. Dans ce cadre, deuxséries parallèles de complexes bimétalliques ont été synthétisées à partir des squelettesRu(bipy)32+ et Ru(bipy)2(dipy)2+ dont les propriétés de luminescence ont été largementdécrites et utilisées pour diverses applications. Ces composés bimétalliques ont pu fairel’objet de mesures sur les deux fronts, à savoir leur activité cytotoxique envers des lignéescellulaires cancéreuses et leurs propriétés photophysiques. / A research theme especially developed in modern organometallic chemistry deals withnew chemotherapeutic agents as alternatives to cisplatin for the treatments against cancer. Inthis area, several strategies have been considered since decades, among which one can citemultinuclearity, meaning the creation of polymetallic structures. The objective of the first partof this manuscript deals with this theme, with the design, synthesis and study of the biologicalproperties of "early-late" hetero-bimetallic complexes (Ti-Ru, Ti-Au, Ti-Pt, Ti-Os, Ti-Rh, Ti-Ir) and "late-late" (Pt-Au). A second concept developed in this thesis consists in thegeneration of new theranostic agents by association inside a same unit of a metal fragmentwith therapeutic activity, and of a fluorescent probe allowing the visualization of thebiological targets. In this field, two parallel series of bimetallic compounds have beenobtained based on the skeletons Ru(bipy)32+ and Ru(bipy)2(dipy)2+, whose luminescenceproperties have been widely described and used for several applications. These bimetalliccomplexes have been tested both for their cytotoxic activity against cancer cells lines andtheir photophysical properties.

No description available.

Dirhodium complexes have been known for their catalytic reactivities toward C-H bond activation for nearly two decades. However, both experimental and theoretical studies have not given a clear explanation on the roles of each metal in the reactivities, largely due to the limited number of available bimetallic species. To study the system systematically, we set our goal to synthesize bimetallic complexes from two independent approaches. In the first approach, five N, N’ -diarylformamidines with symmetric or asymmetric substituents on the phenyl groups were synthesized and fully characterized. Formamidines without bulky substituents exhibited fluxionality in solution, which was proved by a single set of signal in 1 H NMR. In contrast, two sets of signals were observed for formamidines with bulky substituents in the ortho positions, indicating two major stereoisomers ( E and Z conformers) co-existing in solution. In solid state, strong stability for E conformers was gained from a pair of H bonds between two ligands facing each other. The phenomenon was observed for all ligands but N, N’ -bis(2,6-dimethylphenyl)formamidine ( L2 ), in which ligands in Z conformation were connected through H bonds from both sides of a ligand and an infinite chain structure formed in solid state. Metallation of the formamidines with diethylzinc and mesitylmagnesium bromide produced ten complexes in a variety of geometries, indicating a rich diversity in geometry for the formamidine family as coordination ligands. Among these complexes, three bimetallic complexes, with metal atoms close in distance, are potential candidates for the formation of complexes with metal-metal bonds. In each dizinc complex, two formamidinates (deprotonated formamidines) spanned over the two Zn atoms and brought them together, while in the dimagnesium complex, the two Mg atoms were bridged by two bromides, resulting in a Mg 2 Br 2 cubic core. In the other approach, two newly designed tripodal ligands were obtained at relatively high yields. Each of the ligands contains three branches built up from a central atom C or N. Lone pairs on the three branches of a deprotonated ligand working together could behave like a three-prong clamp and secure two metal centers closely in the pocket. A dichromium complex with a geometry matching our initial design was successfully synthesized. Meanwhile, two monometallic complexes, potential candidates as precursors to heterobimetallic complexes, were obtained.

No description available.