Reactivity of a platinum η1-formylketenyl complex synthesis of a platinum α-pyrone derivative via generation and trapping of a C3H2O2 species. 20

The formylketenyl platinum complex, trans-bis(tricyclohexylphosphine)(η1-formylketenyl)(hydride)platinum(II), trans-(PCy3)2(H)Pt[η1-C(CHO)CO] (1), reacts with acids causing the cleavage of the Pt-C bond and generating the species C3H2O2 which is trapped by an excess of 1. The reaction gives rise to the formation of the addition product trans-(PCy3)2(H)Pt(C6H3O4), where C6H3O4 is an α-pyrone ligand σ-bonded to Pt. The crystal structure of the Pt α-pyrone derivative has been determined. The crystal are monoclinic, space group P21/a, with a = 19.404(9), b = 11.889(6), c = 18.534(9), β = 91.3(1)°, Z = 4. The plane of the α-pyrone ligand is almost orthogonal to the coordination plane of Pt. IR, 1H and 31P NMR and mass spectra also support the structure.