Synthesis of heterometallic species with (Ph2P)3CH or (Ph2P)3C–. Crystal structures of [Mo(CO)4{(PPh2)2CHPPh2AuCl}], [Mo(CO)4{(PPh2)2CHPPh2Au(C6F5)}] and [NBu]4[Mo(CO)4{(PPh2)2CPPh2Au(C6F5)}

Abstract

Treatment of [M(CO)4{(PPh2)2CHPPh2}](M = Cr a, Mo b or W c) with 1 equivalent of [AuX(tht)] or [Au(tht)(PPh3)]ClO4(tht = tetrahydrothiophene) afforded the neutral binuclear complexes [M(CO)4{(PPh2)2CHPPh2AuX}](X = Cl 1a–1c or C6F52a-2c), or the cationic derivatives [M(CO)4{(PPh2)2CHPPh2Au(PPh3)}]ClO43a-3c. Complexes 2 and 3 are readily deprotonated by [NBu4][acac](acac = acetylacetonate) to give the tris(diphenylphosphino)methanide species [NBu4]-[M(CO)4{(PPh2)2CPPh2Au(C6F5)}]4a–4c and [M(CO)4{(PPh2)2CPPh2Au(PPh3)}](5a–5c). Tri-nuclear compounds of the type [NBu4][{M(CO)4[(PPh2)2CPPh2]}2Au]6a–6c were obtained by reaction of [M(CO)4{(PPh2)2CHPPh2] with [NBu4][Au(acac)2] in the ratio 2:1. Single-crystal structure determinations were performed for compounds 1b, 2b and 4b. In the neutral complexes 1b and 2b the atoms C(2)(carbonyl), Mo, P(1)(co-ordinated to Au) and Au are essentially coplanar; the principal structural differences between the neutral and anionic (4b) complexes are the shorter P–C bonds and a rotation about the C–P(1) bond in the latter complex.