Abstract:A hydrido platinum(II) complex with a dihydrosilyl ligand, [cis-PtH(SiH 2 Trip)(PPh 3 ) 2 ] (2) was prepared by oxidative addition of an overcrowded primary silane, TripSiH 3 (1, Trip = 9-triptycyl) with [Pt(η 2 -C 2 H 4 )(PPh 3 ) 2 ] in toluene. The ligand-exchange reactions of complex 2 with free phosphine ligands resulted in the formation of a series of (hydrido)(dihydrosilyl) complexes (3-5). Thus, the replacement of two PPh 3 ligands in 2 with a bidentate bis(phosphine) ligand such asIn contrast, the ligand-exchange reaction of 2 with an excess amount of PMe 3 in toluene quantitatively produced [PtH(SiH 2 Trip)(PMe 3 )(PPh 3 )] (5), where the PMe 3 ligand is adopting trans to the hydrido ligand. The structures of complexes 2-5 were fully determined on the basis of their NMR and IR spectra, and elemental analyses. Moreover, the low-temperature X-ray crystallography of 2, 3, and 5 revealed that the platinum center has a distorted square planar environment, which is probably due to the steric requirement of the cis-coordinated phosphine ligands and the bulky 9-triptycyl group on the silicon atom.

Hydride-abstraction reactions of hydrido(dihydrogermyl) complexes [MH(GeH2Trip)(dcpe)] [M = Pt, Pd, Trip = 9-triptycyl, dcpe = 1,2-bis(dicyclohexylphosphino)ethane] with B(C6F5)3 led to the unexpected formation of new cationic (μ-germyl)(μ-hydrido) dinuclear platinum and palladium complexes, [{M(dcpe)}2(μ-GeHTrip)(μ-H)](+).