SYNTHESIS AND A CRYSTAL STRUCTURE ANALYSIS OF MIXED BIS(PHOSPHINO)METHANIDE/PHOSPHONIUM BIS(METHYLIDE) COMPLEXES OF NICKEL, PALLADIUM, AND PLATINUM

From bis(diphenylphosphino)methanide complexes of the type {[(C6H5)2P]2CH}2M (M = Ni, Pd, Pt), and an equivalent amount of an ylide R2(CH3)P CH2 (R = CH3, C2H5), the three title complexes {[(C6H5)2P]2CH}M[(CH2)2PR2] (5a – c) have been prepared. CH2[P(C6H5)2]2 is the by-product of the reaction. An X-ray diffraction study of the platinum compound 5c revealed a mixed chelate structure with a planar bis(phosphino)methanide and a folded ylide ring. The central carbon of the bis(phosphino)methanide is not in close contact with the metal. Its distances to the phosphorus atoms indicate significant double bond character, some of which is also retained in the phosphonium bis(methylide) group.