No description available.

We have successfully synthesized the zinc and cadmium complexes containing bis(3-trimethylsilyl-2-thiophenyl)phenylphosphine (SiPS2): [NEt4][(SiPS2)Cd(SC6H5)] (1) , [NEt4][(SiPS2)Cd(SC6H11)] (2) , [NEt4][(SiPS2)Cd(SCH2C6H5)] (3) , [NEt4][(SiPS2)Zn(SC6H5)] (4) , [NEt4][(SiPS2)Zn(SC6H11)] (5) and [NEt4][(SiPS2)Zn(SCH2C6H5)] (6) , and characterized them using 31P NMR and mass spectrum.1 and 2 were also characterized by X-ray diffraction methods. In the attemprs to get crystals of 4 and 6, we got the oxidized dimer complex 4* and 6* instead. In these complexes the two oxygen atoms of the oxidized ligands and the sulfur atom of the monodentate thiolate ligand bridge both the cadmium centers. Zinc complexes exhibit distorted tetrahedral structure. However, the cadmium ion tends to form five coordination oxidation dimeric complexes.

No description available.

Copper acetylides may be the intermediate of some carbon-carbon coupling reactions. Metal acetylides were studied extensively due to their variable coordination modes. In order to mimic the structure of the intermediate, we synthesized different thioaminophosphine copper(I) complexes and tested their reactivity toward alkynes in this thesis. We introduced steric effect by controlling the carbon-chain length between second and third donor atoms of ligands and electronic effect by altering substituent groups of pheneylacetylenes. Results showed that alkynylcopper complexes were dimmeric in which the two copper(I) centers were brideged by two £g2-£b1-acetylides. Since sulfur atom of thioaminophosphine ligand was not coordinated to copper center, there was no steric effect observed in alkynylcopper complexes. No significant structural difference among alkynylcopper complexes due to electronic effect was seen either. Finally we tested reactions of thioiminophosphine copper(I) complexes toward thiophenolate. The product was a dinuclear copper(I) complex brideged by a £g2-£b1-thiophenolate ligand. Both copper(I) centers were coordinated with phosphorus, nitrogen and sulfur atoms of thioiminophosphine ligand extremely distorted tetrahedron geometry.

Nitrous oxide is a greenhouse gas produced in large quantity by several industrial processes. Efficient means of eliminating N2O are therefore of interest. The denitrification enzyme nitrous oxide reductase (N2OR), which reduces N2O to N2 and water , has recently been shown to contain an unprecedented [Cu4-µ4S] active site. Multinuclear copper sulfide compounds are known but have not been studied in the context of modeling N2OR or as N2O reduction catalysts. The synthesis of new tetranuclear [Cu4-µ4S] compounds is proposed to model the N2OR active site.The purpose of our research is to synthesize [Cu2-µ2S] complex, which original compound of [Cu4-µ4S] complex. This can be groundwork for mimicking the copper protein active site.

Hemilabile ligands attracted much attention in past thirty years because they were effectively utilized in the field of coordination chemistry and homogenous catalysis. We have synthesized four tridentate iminophosphine ligands (o-Ph2P(C6H4)-C(H)=N-(CH2)n-R, n = 2, R = SnBu, LPNS1; n = 3, R = SMe, LPNS2; n = 3, R = OMe, LPNO3; and n = 3, R = NMe2, LPNN4) and one tridentate aminophosphine ligand (o-Ph2P(C6H4)CH2N(H)(CH2)3NMe2, LPNHN5) in this work. The structures of the iminophosphine copper(I) complexes were determined by the carbon-chain length between imino-nitrogen and third donor atom, the coordination ability of the third donor atom, and the nature of the anions (i.e. its donor ability and atomic radius). An unexpected tetranuclear copper(I) iodide complex [(CuI)2(LPNN4)]2 (16) was obtained due to the larger atomic radius of iodide ion. The ligand LPNN4 displayed versatile coordination behavior after complexing with some late transition metals such as Pd(II), Ag(I), Zn(II), Cd(II). These tridentate ligands may act as PN-chelator or PNE-chelator (E = S, N¡¦). Both chelating and bridging modes were observed at the same time in Cu(I) and Ag(I) complexes. In Zn(II) complex, however, chelating by LPNN4 chelated only occurred through its N donor atoms. In term of the reactivity study of these complexes, we found that the complex [Cu(LPNN4)(CH3CN)0.2](BF4) (17) would successful react with Na(SCN), NaN3, and PhCCH/KOH to generate corresponding substitution products. However when reacted with PhCCC(O)OH/KOH, copper complexes bearing LPNN4 could not give the corresponding substituted carboxylate copper(I) product and gave the complex [Cu(CCPh)(LPNN4)]2 (18) via auto-decarboxylation instead.

Late transition metal complexes bearing nitrogen-containing ligands have many applications in biotechnology or industrial catalysis. In this thesis, we react two nitrogen-containing tridentate ligands with some late transition metal salts to yield complexes (1)-(18). Besides spectroscopic characterization, complexes (3), (5)-(7), (8), (10), (12)-(16) yielded crystal structures analyzed using X-ray single crystal diffraction. From crystal structure of complexes (3), (5)- (7), we concluded that the reaction of ligand and Cu(£L£L) salts always gave the CuLX2 products. In Ni series, structures of different coordination types were obtained by using different crystal-growing methods. Crystals obtained using diffusion method take on the form of MLX2 while different structures of complexes (8), (10) were obtained using double layer method. Judging from the result of ESI-Mass analyses, complexes (8) and (10) were both of the dimeric form[NiL1Cl(£g-Cl)]2. However complex (10) was shown by X-ray single crystal to be [NiL 2(H2O)2 Cl]Cl. This could be the hydration product from [NiL1Cl(£g-Cl)]2.

Les α-oléfines jouent un rôle très important en tant qu'intermédiaires réactionnels dans l'industrie chimique et pétrochimique. Leur utilisation principale est la production de diverses qualités de polyéthylène dans lequel l'α-oléfine est engagée en tant que co-monomère (butène-1, hexène-1 et octène-1). Les systèmes capables de dimériser, trimériser voir tétramériser sélectivement l'éthylène en α-oléfines supérieures, utilisent principalement le titane et le chrome. Du fait de la toxicité potentielle du chrome, la recherche industrielle et académique s’oriente de plus en plus vers des systèmes à base de titane.Notre objectif dans ce contexte était d’étudier le potentiel des systèmes « phénoxy-tridente » du Ti(IV) pour la trimérisation sélective de l’éthylène en hexène-1. De nombreux systèmes de formules générales [(ArO-X-L)TiCl3] (X=O,P,N et L=O,P,N) ont ainsi été isolés et caractérisés. L’étude de leurs propriétés électroniques et stériques et ses conséquences sur leurs performances en oligomérisation/polymérisation de l’éthylène ont été discutées. Elles mettent en évidence la criticité de l’ensemble des paramètres à la fois électroniques et structuraux du ligand. Un seul système de cette famille est capable de produire sélectivement de l’hexène-1, les autres conduisant à la polymérisation de l’éthylène.Une étude DFT associée à une étude expérimentale des propriétés redox des précurseurs catalytiques ou encore du comportement hémilabile des ligands mis en jeu, nous a conduit à proposer un mécanisme identifiant la phase d’activation comme l’élément clé permettant d’orienter les systèmes étudiés vers la polymérisation ou la production sélective d’hexène-1. / Linear α-olefins (LAOs) are crucial importance for the chemical and petrochemical industry as they are highly valuable feedstock for a variety of process mainly as co-monomer for the production of different grade of polyethylene (1-butene, 1-hexene and 1-octene). Some systems and predominantly chromium and titanium systems have performed selective dimerization, trimerization and tetramerization of ethylene to higher α-olefins. For toxicity reasons, industrial and academic research focus more and more on titanium-based systems.Our objective in this context was the study of potential “tridentate phenoxy” systems of Ti(IV) for selective trimerization of ethylene to 1-hexene. Numerous systems with general formula [(ArO-X-L)TiCl3] (X=O,P,N and L=O,P,N) were described and characterized. The study of electronic and steric properties and their consequences on catalytic performances in oligomerization/polymerization of ethylene were discussed. They showed the criticity of all electronic and structural parameters of ligands. Only one system of this family is able to produce selectively 1-hexene, others give mainly polyethylene.DFT study associated with an experimental study of redox properties on catalytic precursors or the hemilabile behavior of ligands involved, led us to propose a mechanism identifying the activation phase as the key to switch between polymerization or selective trimerization of ethylene.

The class of ligands represented by [CpCo(P(O)(OR)2)3]-, L- , were first synthesized by W. Kläui in 1977. These ligands have been found to coordinate to a variety of low and high oxidation state metals through the use of its three P=O oxygen atoms as donors. The ligands act as mono-anionic six electron donors which make them similar to the more widely known cyclopentadienyl ligands, (C5H5-xRx)-, but have electronic properties like those of fluoride or oxide. Also, it has been found that the coordination chemistry of L- resembles the unsubstituted tris(pryrazolyl)hydroborato six electron ligand, (RB(pz)3)-. All three of these ligands can be modified by changing the substituent R. The Kläui ligand offers a good opportunity to synthesize a chiral derivative. In the process to obtain the chiral version, (cyclopentadienyl)tris(biphenyl-phosphito-P)cobaltate(1-), 18, was synthesized from 2,2'-biphenol. This was characterized through NMR, mass spectroscopy, and XPS. Next, a racemic version, (cyclopentadienyl)tris(biphenylphosphito-P)cobaltate(1-), 17, was synthesized from (±)1,1′-bi-2-naphthol. A one-pot synthesis for the rac-binaphthyl phosphite derivative was developed with an increased yield from the previously published synthesis. The racemic version of the ligand was characterized by NMR and mass spectroscopy. The chiral version has not yet been synthesized, however, by following the developed procedure for the non-chiral version, the ligand could be synthesized from optically active 1,1'-bi-2-naphthol. / Master of Science

The clean reaction of 5-lithio-6-diisopropylphosphinoacenaphthene (1') with dichlorophosphines, RPCl₂ (R = Ph, Fc, NMe₂, iPr), led to the formation of peri-substituted phosphino-phosphonium chloride salts 2-5. The synthetic utility of these salts was demonstrated in a range of reactions. Mixed tertiary/secondary bis(phosphines) (6 and 7) were prepared by the LiAlH₄ reduction of phenyl or ferrocenyl phosphino-phosphoniums (2 and 3), and the bis(borane) adduct of 6 was prepared by reduction of 2 with BH₃•SMe₂. Reaction of 2 and 3 with a large excess of MeOTf at elevated temperature gave 1,2-diphosphoniums (11 and 12), which were subjected to reduction and co-ordination to a molybdenum(0) centre. An investigation into the co-ordination chemistry of 2 revealed three distinct modes of reactivity. In the reaction with [(nor)Mo(CO)₄] the Mo(0) complex [(2)Mo(CO)₄Cl] (18) was isolated, in which monodentate co-ordination was observed. [PtCl₂(cod)] reacts with the chloride and triflate salts of 2 to form [(2Cl)PtCl₂] (19) and [((2Cl)PtCl)₂][TfO]₂ (21) respectively, both of which show co-ordination of 2 as a bidentate phosphine/chlorophosphine ligand. A palladium(II) dimer (22) in which 2 forms a chelating phosphine/phosphide ligand was isolated from the oxidative addition of 2 to a palladium(0) complex. The geminally bis(peri-substituted) tridentate phosphine (27) was prepared by reaction of 1' with half an equivalent of iPrPCl₂. 27 has a rather strained geometry, and displays restricted dynamics on an NMR timescale, which leads to anisochronicity of all three phosphorus nuclei at low temperatures. Strained bis and tris(sulfides) 28 and 29 and the bis(selenide) 30 have been isolated from the reaction of 27 with sulfur and selenium, respectively. A series of co-ordination complexes, [(27)Cu(MeCN)][BF₄] (32), [(27)PtCl][Cl] (33), [(27)FeCl₂] (34) and fac-[(27)Mo(CO)₃] (35), with tetrahedral, square planar, trigonal bipyramidal and octahedral geometries, respectively, were synthesised. In all of these complexes the tris(phosphine) backbone is distorted, but to a significantly smaller extent that in the chalcogenides 28-30.