Reaction between the thiocarbonyl complex, Os(CS)(CO)(PPh3)3, and propyne: crystal structure of a new sulfur-substituted osmabenzene

Reaction between Os(CS)(CO)(PPh3)3 and propyne gives a complex mixture of products from which can be isolated the simple oxidative addition product Os(CCMe)H(CS)(CO)(PPh3)2 (1) and the osmabenzene Me)(CO)(PPh3)2 (2), where the two propyne molecules in the osmabenzene ring have linked tail-to-tail. Treatment of 1 with HCl gives, as the ultimate product, the propenylthioacyl complex, Os(η2-C[S]CHCHMe)Cl(CO)(PPh3)2 (3). The crystal structures of compounds 1–3 have been determined.