Examination of Metal−Silicon Bonding through Structural and Theoretical Studies of an Isostructural Set of Five-Coordinate Silyl Complexes, Os(SiR<sub>3</sub>)Cl(CO)(PPh<sub>3</sub>)<sub>2</sub> (R = F, Cl, OH, Me)
作者:Klaus Hübler、Patricia A. Hunt、Susan M. Maddock、Clifton E. F. Rickard、Warren R. Roper、David M. Salter、Peter Schwerdtfeger、L. James Wright
DOI:10.1021/om970580h
日期:1997.11.1
Os(SiCl3)Cl(CO)(PPh3)(2) is prepared by treatment of OsPhCl(CO)(PPh3)(2) with excess HSiCl3 and serves in turn as the starting material for the syntheses of three more five-coordinate silyl complexes Os(SiR3)Cl(CO)(PPh3)(2) (R = F, OH, Me) via substitution of the chloride groups on silicon. All four compounds were fully characterized, including a single-crystal solid-state structure of each derivative. Carbonyl stretching frequencies decrease and Os-Si bond lengths increase as R changes in the order from F to Cl to OH to Me. Ab initio calculations were performed on the model complexes Os(SiR3)Cl(CO)(PH3)(2) (R = F, Cl, OH, Me) to explain the trends observed in the IR and X-ray studies, and the importance of the pi-acceptor capacities of the silyl groups are discussed.