Item – Thèses Canada

​
Numéro d'OCLC
1006674782
Auteur
Ma, Erin Shu Fen,1972-
Titre
Reactivity and coordination chemistry of ruthenium(II) aminophosphine complexes with H₂S, thiols, H₂O and other small molecules.
Diplôme
Ph. D. -- University of British Columbia, 1999
Éditeur
Ottawa : National Library of Canada = Bibliothèque nationale du Canada, [2000]
Description
4 microfiches
Notes
Includes bibliographical references.
Résumé
The coordination of small molecules (H2S, RSH, H2O, ROH, H2, NH3, N2 and N2O; R = alkyl) to the coordinatively unsaturated complexes RuX2(P-N)(PR 3) (X = Cl, Br, I; P-N = ['o'-('N,N'-dimethylamino)phenyl]diphenylphosphine; R = Ph, 'p'-tolyl), themselves prepared from RuX2(PR 3)3 and P-N, was investigated (see figure). The species containing the Ru(P-N) moiety were characterized spectroscopically, particularly by 1H and 31P{1H} NMR and in some cases in conjunction with X-ray crystallography* 'Cis'-RuX2(P-N)PPh3)(L) species (X = Cl, L = H2S, MeSH, EtSH, X = Br, L = H2S) were isolated from the reaction of RuX2(P-N)(PPh3) with excess L in acetone, and characterized crystallographically. The geometry of these complexes is pseudo-octahedral with the halogen atoms in mutual cis positions with the coordinated S-ligand cis to the P-atom of the P-N ligand and trans to a halogen atom; all H-atoms on the coordinated S-ligands were refined isotropically. The reaction of RuCl2(P-N)(PR3) with H2O gave 'trans'-RuCl2(P-N)(PR3)(OH 2), which was crystallographically characterized. The geometry is pseudo-octahedral with mutually trans Cl-atoms; the H2O ligand is trans to the P-atom of the P-N ligand. The thermodynamics for the reversible binding of H2S, thiols, H2 and H2O to RuCl2(P-N)(PPh3), in solution, were determined using UV-Vis and NMR spectroscopies. The low [Delta]H° values (-22 to -54 kJ/mol) imply relatively weak Ru-L bond energies and the negative [Delta]S° values (-32 to -140 J/mol K) are consistent with binding of a small molecule at a metal site. 'Cis'-RuX2(P-N)(PPh3)(SH2) (X = Cl, Br) reacted with NaSH or proton sponge (in the presence of added H2S) to give initially Ru(SH)Cl(P-N)(PPh3) and then Ru(SH)2(P-N)(PPh3). Reaction of 1 atm NH3 with RuX2(P-N)(PPh3 ) (X = Cl, Br) in the solid state led to the formation of 'trans '-RuX2(P-N)(PPh3)(NH3) which, when dissolved in solution, subsequently isomerized to 'cis'-RuX 2(P-N)(PPh3)(NH3). The formation of 'cis'-RuCl2(P-N)(PPh 3)(N2O) was observed by NMR spectroscopy at -40°C when RuCl2(P-N)(PPh3) was subjected to 6 atm N 2O in CD2Cl2. The coordination of N2O is of particular interest because of the rarity of such a reaction and because of the potential of discovering an effective catalytic oxidation system using N2O as an O-atom donor. RuCl2(P-N)(PPh3) also reacted with HCCPh to give the crystallographically characterized 'cis'-RuCl 2(P-N)(PPh3)(=C=CHPh). The carbene complex reacted with H 2S and H2O to give 'cis'-RuCl2(P-N)(PPh 3)(S=C(H)CH2Ph) and a mixture containing RuCl(P-N)(PPh 3)(CH2Ph)(CO) and RuCl2(P-N)(PPh3)(CO), respectively. The formulations of the products were based on 31P{ 1H} NMR and IR spectroscopic data. (Abstract shortened by UMI.) *Please refer to dissertation for diagram.
ISBN
0612463796
9780612463790