753009-64-2Relevant academic research and scientific papers
Nucleophilic substitution reactions at the Si-Cl bonds of the dichloro(methyl)silyl ligand in five- and six-coordinate complexes of ruthenium(II) and osmium(II)
Kwok, Wai-Him,Lu, Guo-Liang,Rickard, Clifton E.F.,Roper, Warren R.,Wright, L. James
, p. 2511 - 2522 (2007/10/03)
Treatment of either RuHCl(CO)(PPh3)3 or MPhCl(CO) (PPh3)2 with HSiMeCl2 produces the five-coordinate dichloro(methyl)silyl complexes, M(SiMeCl2) Cl(CO)(PPh3)2 (1a, M = Ru; 1b, M = Os). 1a and 1b react readily with hydroxide ions and with ethanol to give M(SiMe[OH]2)Cl(CO)(PPh3)2 (2a, M = Ru; 2b, M = Os) and M(SiMe[OEt]2)Cl(CO)(PPh3) 2 (3a, M = Ru; 3b, M = Os, respectively. 3b adds CO to form the six-coordinate complex, Os(SiMe[OEt]2)Cl(CO)2 (PPh3)2 (4b) and crystal structure determinations of 3b and 4b reveal very different Os-Si distances in the five-coordinate complex (2.3196(11) ?) and in the six-coordinate complex (2.4901(8) ?). Reaction between 1a and 1b and 8-aminoquinoline results in displacement of a triphenylphosphine ligand and formation of the six-coordinate chelate complexes M(SiMeCl 2)Cl(CO)(PPh3)(K2(N,N)-NC9 H6NH2-8) (5a), M = Ru; 5b, M = Os), respectively. Crystal structure determination of 5a reveals that the amino function of the chelating chelating 8-aminoquinoline ligand is located adjacent to the reactive Si-Cl bonds of the dichloro(methyl)silyl ligand but no reaction between these functions is observed. However, 5a and 5b react readily with ethanol to give ultimately M(SiMe[OEt]2)Cl(CO) (PPh3)(K2(N,N-NC9H6 NH2-8) (6a, M = Ru; 6b, M = Os). In the case of ruthenium only, the intermediate ethanolysis product Ru(SiMeCl[OEt])Cl(CO) (PPh3)(K2(N,N-NC9H6 NH2-8) (6c) was also isolated. The crystal structure of 6c was determined. Reaction between 1b 2-aminopyridine results in condensation between the Si-Cl bonds and the N-H bonds with formation of a novel tridentate "NSiN" ligand in the complex Os(K3(Si,N,N)-SiMe[NH(2-C5H4N)] 2)Cl(CO)(PPh3) (7b). Crystal structure determination of 7b shows that the "NSiN" ligand coordinates to osmium with a "facial" arrangement and with chloride trans to the silyl ligand.
