Reactivity of {(Ph3P)Pt[μ-η2-H-SiH(Ar)]}2 (Ar=2-isopropyl-6-methylphenyl) with phosphines.: X-ray crystal structure of trans-{(dppe)Pt[μ-SiH(Ar)}2

The dinuclear Pt-Si complex (Ph3P)Pt{mu-eta(2)-H-SiH(IMP)]}(2) (trans-1a-cis-1b=3:1: IMP= 2-isopropyl-6-methylphenyl) reacted with basic phosphines such as 1,2-bis(diphenylphosphino)ethane (dppe) and dimethylphenylphosphine (PMe2Ph) to afford different dinuclear Pt-Si complexes with loss of H-2, {(P)(2)Pt[mu-SiH(IMP)]}(2) [P = dppe, trans-2a (major), cis-2b (trace): PMe2Ph, 3 (trans only]. Complexes 2 and 3 were characterized by multinuclear NMR spectroscopy and X-ray crystallography (2a). In contrast. the reaction of 1a,b with the sterically demanding tricyclohexylphosphine (PCy3) afforded {(Cy3P)Pt{mu-eta(2)-H-SiH(IMP)]}(2) 2 (trans 4a - cis 4b 2:1) analogous to 1a.b where the central Pt2Si2(mu-H)(2) core remains intact but the PPh3 ligands have been replaced by PCy3. Complexes 4a and 4b was characterized by multinuclear NMR and IR spectroscopies. (C) 2002 Elsevier Science B.V. All rights reserved.