Bimetallic platinum complexes containing linear tetraphosphine ligands

The meso and rac forms of the tetraphosphine ligand bis[(diphenylphosphinoethyl)phenylphosphino]methane, Ph2PCH2CH2PPhCH2PPhCH2CH2PPh2 (DPPEPM), have been separated and found to react with 2 equiv of [PtCl2(cod)] or [PtMe2(cod)] to generate bimetallic complexes of the form [Pt2X4(μ-DPPEPM)]. When [PtClMe(cod)] is treated with the tetraphosphine followed by TlPF6, the chloride-bridged species [Pt2Me2(μ-Cl)(μ-DPPEPM)]PF6 is obtained. The solid state structures of [Pt2X4(μ-meso-DPPEPM)] (X=Cl, Me) are reported, along with preliminary studies of some hydrogenation reactions catalyzed by the bimetallic derivatives.