Reactivity of {(Ph 3P)Pt[μ-η 2-HSiH(Ar)]} 2 (Ar=2-isopropyl-6-methylphenyl) with phosphines. X-ray crystal structure of trans-{(dppe)Pt[μ-SiH(Ar)]} 2

Abstract

The dinuclear PtSi complex {(Ph 3P)Pt{μ-η 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 (PMe 2Ph) to afford different dinuclear PtSi complexes with loss of H 2, {(P) 2Pt[μ-SiH(IMP)]} 2 [P=dppe, trans- 2a (major), cis -2b (trace); PMe 2Ph, 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 (PCy 3) afforded {(Cy 3P)Pt{μ-η 2-HSiH(IMP)]} 2 ( trans- 4a– cis- 4b 2:1) analogous to 1a, b where the central Pt 2Si 2(μ-H) 2 core remains intact but the PPh 3 ligands have been replaced by PCy 3. Complexes 4a and 4b was characterized by multinuclear NMR and IR spectroscopies.