Thèse numérisée par la Direction des bibliothèques de l'Université de Montréal.

Thèse numérisée par la Division de la gestion de documents et des archives de l'Université de Montréal.

A autoxidação dos complexos de Ni(II) e Co(II) com tetra, penta e hexaglicina, em meio de tampão borato, é acelerada por espécies de enxofre (IV) (H2S0<SUB3, HS03-e SO32-). A formação dos complexos de Ni(III) e Co(III) foi acompanhada espectrofotometricamente em 325 e 265 nm, respectivamente. A velocidade da reação de autoxidação do complexo de Ni(II)/Gn aumenta com a concentração de S(IV) e é máxima em pH &#926;8,5. O processo é autocatalítico com Ni(III)ou Co(III)atuando como iniciadores, forma~os pela oxidação espontânea de Ni(II) ou Co(II) pelo oxigênio molecular. A dependência da constante de velocidade observada com a oncentração de S(IV) evidenciou possíveis reações paralelas com formação de um complexo com ligantes mistos antes da etapa da oxidação. A autoxidação dos complexos de Cu(II)com penta e hexaglicina em pH =9 é muito lenta, na presença e na ausência de S(IV).A presença de S(IV) e de traços de Ni(II)ou Co(II) aumenta significativamente a velocidade e a eficiência da reação (período de indução de 0,5 s). O mecanismo envolve uma cadeia de reações e um ciclo redox dos complexos. Acetaldeído e formaldeído inibem parcialmente a reação de autoxidação de Ni(II)/G4 na presença de S(IV) e luminol.O método quimiluminescente desenvolvido pode ser empregado para determinação de formaldeído [(5,0.10-5 - 1,0.10-2) mol L-1] e acetaldeído [(1,0.10-4 - 0,10) mol L-1], não sendo possível detectar separadamente cada um desses aldeídos. Na autoxidação de Ni(OH)2 induzida por S(IV) na presença de luminol ocorre emissão de radiação, possibilitando a detecção de S(IV) na faixa de 5,0.10-8 a 1,0.10-5 mol L-1, com limite de detecção estimado de 1,3.10-8 mol L-1. / The autoxidation of Ni(lI) and Co(lI) complexes with tetra, penta and hexaglycine, in borate medium, is accelerated by sulfur (IV) species (H2S03, HS03- and SO32-). The formation of Ni(llI) and Co(lIl) complexes was followed spectrophotometrically at 325 and 265 nm, respectively. The autoxidation rate of Ni(II)/Gn complex increases with S(IV) concentration and is maximum at pH ~ 8.5. The process is autocatalytic with Ni(lIl) or Co(llI) acting as initiators, formed by spontaneous oxidation by oxygen. The dependence of the observed rate constant with S(IV) concentration showed evidences of back or parallel reactions with formation of mixed ligand complex prior to the oxidation step. The autoxidation of Cu(II)/penta and hexaglycine complexes at pH = 9, in the presence and absence of S(IV), is very slow. The presence of S(IV) and of small amounts of Ni(lI) or Co(lI) increases significantly the effectiveness and reaction rate (induction period = 0.5 s). The mechanism involves a radical chain and redox cycling of the metal íon complexes. Acetaldehyde and formaldehyde partially inhibit the autoxidation reaction of Ni(II)/G4 in the presence of S(IV) and luminol. The developed chemiluminescent method can be used for determination of formaldehyde [(5.0.10-5 - 1.0.10-2) mol L-1] and acetaldehyde [(1.0.10-4 - 0.10) mol L-1), being not possible their isolated detection. The S(IV) induced autoxidation of Ni(OH)2 in the presence of luminol, occurs with radiation emission, allowing S(IV) detection in the range 5.0.10-8 to 1.0.10,-5 mol L-1, with detection limit of 1.3.10-8 mol L-1.

The late transition metal complexes containing sulfide ligands have trem- endous applications not only in biochemistry but also in industrial catalysis. We have successfully synthesized four different bidentate ligands, 2- (Benzylidene)benzenethiol(NS-1), 2-[2,6-(Dimethylbenzylidene)]benzenethi- ol(NS-2), 2-(2-Chloro-1-methylethylidene)benzenethiol(NS-3) and 2-(Diphe- nylphosphanyl)benzenethiol(PS), and five tridentate ligands, N-{N-[2-(Diph- enylphosphino)benzylidene]-2-sec-butylethylsulfide}(PNS-1), N-{N-[2-(Di- phenylphosphino)benzylamino]-2-sec-butylethylsulfide}(PNS-2), 2-[2-(Diph- enylphosphino)phenylsulfanylmethyl]pyridine(PSN-1), 2-[2-(Diphenylphos- phino)phenylsulfanyl]ethylamine(PSN-2) and 2-(Diphenylphosphino)phenyl- sulfanylacetonitrile(PSN-3). These ligands reacted with the late transition metal (Zn, Ag, Pd, and Ni) salts, and produced complexes 1-12. Besides their spectra, we also obtained crystal structures of complexes 3, 4, 5, 6, 7, 8, 9, 10, 11, and 12. We found that the PNS tridentate ligands had different bonding modes in zinc, silver, palladium, and nickel complexes. For examples, in zinc complexes 1 and 2 only P and S atoms were coordinated to the metal while all P, N, and S atoms were coordinated to the Pd metal in Pd complexes. It indicated that thiolether prefers to coordinate to palladium but not to zinc in our cases. When PNS-2 went through different reaction routes, two silver complexes 4 and 5 with different coordination modes a M2L2 type dinuclear complex and a ML2 type mononuclear complex were obtained.. When reacting PNS-2 with nickel, we obtained an unique tetranuclear nickel complex 6. PSN-1 showed two different coordinate modes in complexes 8-10 while PSN-2 and silver produced a dinuclear silver complex 11 that resembled complex 4. PSN-3 coordinated to Pd ion by phosphorus and sulfide atoms. As such, we demonstrated the various coordinated modes in PNS and PSN ligands. Finally PS bidentate ligand reacted with zinc salt produced complex 7 with one oxidized ligand. The variable temperature NMR experiment was also used to probe the structural change that occurred in solution state for 3.

Late transition metal complexes bearing nitrogen-containing ligands may act as catalyst in biotechnology or industrial catalysis. Imidazole is one of the most common biofunctional ligands that play critical roles in meta1loenzymes, since the imidazole moiety of the histidyl residues often constitutes all or part of the binding sites of various transition metal centers. In this work, some new zinc(II), copper(II) and nickel(II) complexes containing the imidazolate and pyridyl moieties incorporated in the imine (ImPyI) and amine (ImPyA) ligands were obtained. Different methods of crystallization yield crystals of complexes (2), (6), (8), (9), (10), (17) and (18). Subsequent structural analyses revealed their interesting structures. In zinc(II) and nickel(II) complexes, facial isomers were isolated while none of the meridional isomers were observed. Particularly interesting is the zinc(II) complexes where two facial complexes with different geometries were identified. The mixture of the different nitrogen donor groups in the same ligand provides handy comparison of these structural variations due to the different nature of these donor groups. One tridentate ligand with bromide substitution on the imidazolate and a tetradentate ligand with an additional pyridyl group were synthesized as an extension of this work. One crystal structure of each of the corresponding metal complex bearing these ligands is also discussed here. Most metal complexes are consolidated by extensive weak hydrogen bonds among them in the crystal lattices.

Thèse numérisée par la Division de la gestion de documents et des archives de l'Université de Montréal

A autoxidação dos complexos de Ni(II) e Co(II) com tetra, penta e hexaglicina, em meio de tampão borato, é acelerada por espécies de enxofre (IV) (H2S0<SUB3, HS03-e SO32-). A formação dos complexos de Ni(III) e Co(III) foi acompanhada espectrofotometricamente em 325 e 265 nm, respectivamente. A velocidade da reação de autoxidação do complexo de Ni(II)/Gn aumenta com a concentração de S(IV) e é máxima em pH &#926;8,5. O processo é autocatalítico com Ni(III)ou Co(III)atuando como iniciadores, forma~os pela oxidação espontânea de Ni(II) ou Co(II) pelo oxigênio molecular. A dependência da constante de velocidade observada com a oncentração de S(IV) evidenciou possíveis reações paralelas com formação de um complexo com ligantes mistos antes da etapa da oxidação. A autoxidação dos complexos de Cu(II)com penta e hexaglicina em pH =9 é muito lenta, na presença e na ausência de S(IV).A presença de S(IV) e de traços de Ni(II)ou Co(II) aumenta significativamente a velocidade e a eficiência da reação (período de indução de 0,5 s). O mecanismo envolve uma cadeia de reações e um ciclo redox dos complexos. Acetaldeído e formaldeído inibem parcialmente a reação de autoxidação de Ni(II)/G4 na presença de S(IV) e luminol.O método quimiluminescente desenvolvido pode ser empregado para determinação de formaldeído [(5,0.10-5 - 1,0.10-2) mol L-1] e acetaldeído [(1,0.10-4 - 0,10) mol L-1], não sendo possível detectar separadamente cada um desses aldeídos. Na autoxidação de Ni(OH)2 induzida por S(IV) na presença de luminol ocorre emissão de radiação, possibilitando a detecção de S(IV) na faixa de 5,0.10-8 a 1,0.10-5 mol L-1, com limite de detecção estimado de 1,3.10-8 mol L-1. / The autoxidation of Ni(lI) and Co(lI) complexes with tetra, penta and hexaglycine, in borate medium, is accelerated by sulfur (IV) species (H2S03, HS03- and SO32-). The formation of Ni(llI) and Co(lIl) complexes was followed spectrophotometrically at 325 and 265 nm, respectively. The autoxidation rate of Ni(II)/Gn complex increases with S(IV) concentration and is maximum at pH ~ 8.5. The process is autocatalytic with Ni(lIl) or Co(llI) acting as initiators, formed by spontaneous oxidation by oxygen. The dependence of the observed rate constant with S(IV) concentration showed evidences of back or parallel reactions with formation of mixed ligand complex prior to the oxidation step. The autoxidation of Cu(II)/penta and hexaglycine complexes at pH = 9, in the presence and absence of S(IV), is very slow. The presence of S(IV) and of small amounts of Ni(lI) or Co(lI) increases significantly the effectiveness and reaction rate (induction period = 0.5 s). The mechanism involves a radical chain and redox cycling of the metal íon complexes. Acetaldehyde and formaldehyde partially inhibit the autoxidation reaction of Ni(II)/G4 in the presence of S(IV) and luminol. The developed chemiluminescent method can be used for determination of formaldehyde [(5.0.10-5 - 1.0.10-2) mol L-1] and acetaldehyde [(1.0.10-4 - 0.10) mol L-1), being not possible their isolated detection. The S(IV) induced autoxidation of Ni(OH)2 in the presence of luminol, occurs with radiation emission, allowing S(IV) detection in the range 5.0.10-8 to 1.0.10,-5 mol L-1, with detection limit of 1.3.10-8 mol L-1.

京都大学 / 新制・課程博士 / 博士(工学) / 甲第24818号 / 工博第5161号 / 新制||工||1986(附属図書館) / 京都大学大学院工学研究科合成・生物化学専攻 / (主査)教授 浜地 格, 教授 森 泰生, 教授 生越 友樹 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

Le sujet de cette thèse porte sur la synthèse de ligands de type bis-NHC (carbène N-Hétérocyclique) et leur réactivité vis-À-Vis des complexes d’argent(I), de cuivre(I) et de nickel(II).Après avoir exploré les différentes méthodologies de synthèse des complexes de nickel(II) bis-NHC, le but était de tester leurs activités en catalyse d’oligomérisation de l’éthylène. Une série de nouveaux complexes d’argent(I) et de cuivre(I) fut synthétisée. Cinq voies furent testées pour la formation de complexes de nickel. Les résultats les plus probants furent obtenus par transmétallation à partir des complexes d’iodure ou de bromure d’argent(I). / The purpose of this work was the synthesis of bis-NHC (N-Heterocyclic carbene) ligands, theformation of the corresponding silver(I), copper(I) and nickel(II) complexes and the assessment ofthe catalytic activity of the bis-NHC nickel(II) complexes in ethylene oligomerization. A series of new bis-NHC silver(I) and copper(I) complexes was synthesized. Five different synthetic routes were tested for the formation of nickel(II) bis-NHC complexes. The most significant results were obtained by transmetalation from the silver(I) iodide or bromide complexes.

Thesis (MSc (Chemistry and Polymer Science))--Stellenbosch University, 2008. / N,N-dialkyl-N-acyl(aroyl)thiourea ligands form stable chelated complexes in a cis configuration with the platinum group metals. Such chelated complexes are generally considered substitutionally “inert” in solution, however, it was found that cis-bis(N,Ndialkyl- N-acyl(aroyl)thioureato)M(II) complexes (M = Ni(II), Pd(II) or Pt(II)) readily undergo facile chelate metathesis reactions in solution at room temperature. Upon mixing two different parent complexes, a mixed-ligand product formed in solution, with an equilibrium, or steady state, between the two parent complexes and the mixed-ligand product being attained after a period of time: M(LA)2 + M(LB)2 M(LA)(LB). All three complexes remained in solution even with a ten-fold excess of one parent complex. The presence of the mixed-ligand products in solution was confirmed by liquid chromatography-mass spectrometry (LC-MS), nuclear magnetic resonance (NMR) spectra and a crystal structure of the mixed-ligand complex cis-Pd(L3-S,O)(L4-S,O). Though a number of attempts were made, it was not possible to either isolate or synthesise the mixed-ligand complexes exclusively. The equilibrium distribution and the rate of the metathesis reaction were influenced by a number of factors, including the central metal ion, the substituents on the complexed ligands and the reaction medium. In addition to these, a number of other factors, some unexpected, also played a role in the rate of the reaction. Initial concentration of the parent complexes, the age of the solutions upon mixing and the presence of impurities or additives all contributed to the overall rate of reaction. The results from these rate studies highlighted the necessity for extensively purified compounds. In addition to chelate metathesis reactions, the exchange between a cis-Pd(L-S,O)2 complex and an unbound HL ligand in solution was also investigated. Again, even with an excess of unbound ligand, all three possible complexes were present in solution. It has been shown previously that these complexes undergo a photoinduced cis-trans isomerisation under intense light, and it has been proposed that the reverse trans-cis process, which occurs in the dark, may be a metathesis reaction. In light of this, the relationship between these chelate metathesis reactions and the reverse trans-cis reaction was briefly investigated. Though the metathesis reactions were a general phenomenon in the Ni(II), Pd(II) and Pt(II) complexes of the aforementioned ligands, the experiments focused mainly on the cis-Pd(L-S,O)2 complexes due to the favourable timescales of their metathesis reactions. The primary technique to observe these reactions was reversed-phase high-performance liquid chromatography (rp-HPLC). The timescales involved in the cis-Pd(L-S,O)2 metathesis reactions as well as the stability of the Pd(II) complexes under the HPLC conditions made this technique ideal.