Diplatinum complexes with bridging silyl ligands.: Si-H bond activation of μ-silyl ligand leading to a new platinum complex with bridging silylene and silane ligands

A diplatinum complex with bridging diethylsilyl ligands, [{Pt(PCy3)}(2)(mu-eta(2)-HSiEt2)(2)] (1), reacted with an excess of H2SiPh2 to yield [{Pt(PCy3)}(2)(mu-eta(2)-HSiPh2)(2)] (2) via exchange of the bridging SiHEt2 ligands with SiHPh2 groups. An equimolar reaction of H2SiPh2 with 1 afforded a mixture of the dinuclear complexes [{Pt(PCy3)}(2)(mu-eta(2)-HSiEt2)(mu-eta(2)-HSiPh2)] (3) and [{Pt(PCy3)}(2)(mu-eta(2):eta(2)-H2SiEt2)(mu-SiPh2)] (4). X-ray crystallographic structure determination of 4 showed bridging coordination of the H2SiEt2 ligand to two Pt centers via two Pt-H-Si three-center two-electron bonds (Pt-Si = 2.375(8) and 2.39(1) A).