Structures of 1,2-dimethyl- and 3-methyl-cyclopropenebis(triphenylphosphine)platinum(0)

Abstract

The crystal and molecular structures of the title compounds (I) 1,2-dimethyl- and (II) 3-methyl-cyclopropene-bis(triphenylphosphine)platinum(0) have been each determined from X-ray data collected by counter methods. The structures were determined by the heavy-atom method and refined by least-squares techniques to R 0.032 [(I), 2390 independent reflections] and 0.051 [(II), 905 independent reflections]. The parameters of the cyclopropene ring in (II) are inaccurate owing to disorder in the crystal used.

The compounds have the same overall molecular structure. On complex formation the cyclopropene ring remains intact, with CC 1.50 Å, and is co-ordinated to the platinum via a metal–olefin interaction with Pt–C 2.28 Å. In (II), the methyl group and the metal lie on opposite sides of the cyclopropene-ring plane.

Crystals are orthorhombic, space group P2₁/c with Z= 4 in unit cells of dimensions: (I), a= 12.49(1), b= 17.77(7), c= 16.38(7)Å, β= 109.42(5)°(II); a= 11.28(3), b= 20.74(4), c= 17.23(4)Å, β= 124.5(2)°.