REACTIVITY OF A PLATINUM ETA(1)-FORMYLKETENYL COMPLEX SYNTHESIS OF A PLATINUM ALPHA-PYRONE DERIVATIVE VIA GENERATION AND TRAPPING OF A C3H2O2 SPECIES .20.

The formylketenyl platinum complex, osphine)(eta1-formylketenyl)(hydri de)platinum(II), trans-(PCy3)2(H)Pt[eta1-C(CHO)CO] (1), reacts with ac ids causing the cleavage of the Pt-C bond and generating the species C 3H2O2 which is trapped by an excess of 1. The reaction gives rise to t he formation of the addition product trans-(PCy3)2(H)Pt(C6H3O4), where C6H3O4 is an alpha-pyrone ligand sigma-bonded to Pt. The crystal stru cture of the Pt alpha-pyrone derivative has been determined. The cryst als are monoclinic, space group P2(1)/a, with a = 19.404(9), b = 11.88 9(6), c = 18.534(9), beta = 91.3(l)-degrees, Z = 4. The plane of the a lpha-pyrone ligand is almost orthogonal to the coordination plane of P t. IR, H-1 and P-31 NMR and mass spectra also support the structure.