Reactivity of keteylidenetriphenylphosphorane (Ph3PC=C=O) with Pt(II) complexes. Evidences of formation of an up to now unknown bis-eta(1)-ketenyl derivative

Ketenylidenetriphenylphosphorane, Ph3PC=C=O, 1, has been used to synthesize some Pt(II) eta(1)-ketenyl derivatives, through reactions with dimeric and tetrameric chlorine-bridged compounds. Particularly it has been possible t o isolate and characterize [Pt(eta(3)-C3H5)Cl{eta(1)-C(PPh3)CO}], 2, and [P tCl2{eta(1)-C(PPh3)CO} (PPh3)]. 3, Moreover, the reaction of 2 with a furth er equivalent of 1, in the presence of AgBF4, lead to the formation of [Pt( eta(3)-C3H5){eta(1)-C(PPh3)CO}(2)], 4, the first bis-eta(1)-ketenyl derivat ive. Compound 4 is stable in solution only at low temperatures and its form ation has been inferred unequivocally by IR, H-1 and P-31-NMR measurements carried out at - 50 degrees C. (C) 1999 Elsevier Science S.A. All rights re served.