Structure of Hydridochlorobis(diphenylethylphosphine)platinum

The crystal and molecular structure of hydridochlorobis(diphenylethylphosphine)platinum, PtHCl[P(C₆H₅)₂C₂H₆]₂, has been determined from three-dimensional X-ray data. The material crystallizes in space group C_2h ⁵-P2₁/c of the monoclinic system, with four molecules in a cell of dimensions a = 11.80, b = 16.93, c = 14.31 Å., β = 108.4°. The individual monomeric molecules are well separated, the closest Pt-Pt distance being greater than 9 Å. The phosphorus atoms are trans to one another and with the chlorine lie at three of the four corners of an approximate square, with the platinum in the center. In agreement with results reported previously for a similar bromo compound, the Pt-P distances are shorter and the Pt-halogen distance longer than are calculated from the usual radii-sum rules. The Pt-halogen lengthening is consistent with the high lability of the halogen trans to a hydrogen. The platinum, phosphorus, and chlorine atoms deviate slightly, but significantly, from coplanarity.