Synthesis of Heterodimetallic Complexes by Reaction of a Terminal Phosphido Pt Complex with Metal Based Nucleophiles and Electrophiles

The complex trans-[PtCl(PCy2)(PHCy2)2] (1) possesses a terminal phosphanido group (PCy2) and a chloride ligand, which render it a good candidate for the synthesis of phosphanido- bridged heterodimetallic species (PHCy2)2Pt(μ- PCy2)M–L by reaction either with carbonyl metalates, as metal-based nucleophiles, or with metal-based electrophiles. The heterodinuclear complexes [(PHCy2)2Pt(μ-PCy2)Co- (CO)3](Pt–Co) (2), [(PHCy2)2Pt(μ-PCy2)Mo(CO)2Cp](Pt–Mo) (3), and [(PHCy2)2Pt(μ-PCy2)W(CO)2Cp](Pt–W) (4) are obtained by reaction of 1 with the carbonyl metalates Na[Co- (CO)4], Na[Mo(CO)3Cp] and Na[W(CO)3Cp], respectively. Although 2 is reluctant to react with carbon monoxide, 3 and 4 are promptly carbonylated under ambient conditions to afford mixtures of the cis and trans isomers of [(PHCy2)(CO)- Pt(μ-PCy2)M(CO)2Cp] (M = Mo or W), which interconvert through dissociation/reassociation of the CO ligand coordinated to the Pt centre. The reaction of 1 with AuCl(PPh3) leads to the formation of the trinuclear Pt2Au complexes cisand trans-[{Cl(PHCy2)2Pt(μ-PCy2)}2Au]Cl (cis- and trans- [8]Cl), in which a Au atom bridges two molecules of 1 through the originally terminal phosphanide ligands.