Ruthenium Silyl Complexes Containing the Cp(PMe3)2Ru Moiety: Preparation, Substituent Effects, and Silylene Character in the Ru−Si Bond

Abstract

The preparation and characterization of new ruthenium(II) silyl complexes containing the Cp(PM3)2Ru moiety are described. The ruthenium(II) hydride Cp(PMe3)2RuH reacts with a variety of chlorosilanes to produce the ruthenium(II) silyl complexes Cp(PMe3)2RuSiR3 [SiR3 = SiCl3 (1), SiHCl2 (2), SiH2Cl (3), SiMeCl2 (4), SiMeHCl (5), SiMe2Cl (6)] and the ruthenium(IV) dihydride [Cp(PMe3)2RuH2]Cl. Silyl complexes 1−6 undergo chloride/hydride exchange with LiAlH4 to give the corresponding ruthenium(II) hydrosilyl complexes Cp(PMe3)2RuSiHR2 [SiHR2 = SiH3 (7), SiMeH2 (8), SiMe2H (9)]. Methylation of 6 with AlMe3 produces Cp(PMe3)2RuSiMe3 (10). A method for recovering the Cp(PMe3)2Ru moiety is described. The structure of 1 was determined by X-ray crystallography. Complexes 1−10 represent the first complete set of metal silicon compounds that contain every possible combination of H, Cl, and Me groups on silicon. The effects of the substituents on the spectroscopic properties of 1−10 were examined as a function of Tol...