Polynuclear palladium phosphide and phosphineidene complexes: Synthesis and properties as catalysts for hydrogenation

Interaction of palladium bis(acetylacetonate) with alkali-metal diphenyl- and phenylphosphides was studied. The reaction of Pd(Acac)(2) with NaPPh2 was found to proceed through the step of formation of a binuclear [Pd(Acac)(PPh2)](2) complex to yield sodium tris(diphenylphosphido)palladate as a final product. It was shown that the interaction of Pd(Acac)(2) with Li2PPh is accompanied by the side redox processes resulting in the phenylphosphineidene complexes [Pd-4(PPh)(3)](n). The latter exhibit high activity for hydrogenation of unsaturated hydrocarbons.