Platinum Participation in the Hydrogenation of Phenylacetylene by Ru₅(CO)₁₅(C)[Pt(PBu^t₃)]

The hydride and PhC2H complexes, Ru5(CO)14(μ6-C)[Pt(PBut3)](μ-H)2, 2, and Ru5(CO)13(μ5-C)(PhC2H)[Pt(PBut3)], 3, were obtained from the reactions of Ru5(CO)15(C)[Pt(PBut3)], 1, with hydrogen and PhC2H, respectively. Styrene was formed catalytically when hydrogen and PhC2H were allowed to react with 3 in combination, and the complex Ru5(CO)12(μ5-C)[PtPBut3](PhC2H)(μ-H)2, 4, containing both hydrides and a PhC2H ligand was formed. The catalysis is promoted by the presence of the platinum atom in the complexes.