SYNTHESIS OF [M(ETA(2)-C2PH2)(CO)(P(I)PR3)2] (M=OS OR RU) AND X-RAY CRYSTAL-STRUCTURE OF THE OSMIUM DERIVATIVE

The tetrahydrido complex [OsH4(CO)(PiPr3)2] (1) reacts with diphenylac etylene to give cis- and trans-stilbene and [Os(eta2-C2Ph2)(CO)(PiPr3) 2] (5). The X-ray crystal structure of 5 has been determined. 5 reacts with CO to give [Os(eta2-C2Ph2)(CO)2(PiPr3)2](6). The related rutheni um complex [Ru(eta2-C2Ph2)(CO)(PiPr3)2](7) was obtained by reaction of [RuH(eta2-H2BH2)(CO)PiPr3)2] (8) with diphenylacetylene. 7 reacts wit h CO to give [Ru(CO)3(PiPr3)2] (9) and diphenylacetylene. The synthesi s of the hydridovinyl complex [OsH(C(COOEt)=C(H)CO2Et)(CO)(P(i)Pr3)2] (10) is also reported.