Transition metal silyl complexes.: Part 63. Influence of the phosphane ligands and the metal complex geometry on the silyl group exchange between L 2Pt(SiMe 2Ph) 2 (L 2=R 2PCH 2CH 2PR 2 or 2PR 3) and HSiR′ 3

Abstract

The exchange of the silyl ligands upon reaction of [(κ 2-P,P)-R 2PCH 2CH 2PR 2]Pt(SiMe 2Ph) 2 (R=Ph, Me, cyclohexyl) with HSi(OMe) 3 or 1,2-bis(dimethylsilyl)benzene was investigated by NMR spectroscopy. The exchange rate is considerably lower than in the complexes cis-(R 3P) 2Pt(SiMe 2Ph) 2, and decreases in the order R=Ph>Me>cyclohexyl. No exchange was observed in the analogous reactions of trans-(R 3P) 2Pt(SiMe 2Ph) 2. The isomerization of cis-(PhMe 2P) 2Pt(SiMe 2Ph) 2 into trans-(PhMe 2P) 2Pt(SiMe 2Ph) 2 is catalyzed by di- and oligosilanes.