Synthesis and Characterization of [OsCl 2 (=C=CHR)(PPh 3 ) 2 ] and Related Complexes

Treatment of [OsCl 2 (PPh 3 ) 3 ] with HC≡CR (R = Ph, p ‐tolyl, CMe 3 ) in the presence of HCl gives the corresponding trichloro(carbyne) complexes [OsCl 3 (≡CCH 2 R)(PPh 3 ) 2 ] in good yields. The vinylidene complexes [OsCl 2 (=C=CHR)(PPh 3 ) 2 ] (R = Ph, p ‐tolyl, CMe 3 ) are, in turn, prepared from the reactions of the carbyne complexes [OsCl 3 (≡CCH 2 R)(PPh 3 ) 2 ] with NEt 3 . These new vinylidene complexes are hygroscopic and react with H 2 O to give (aqua)(vinylidene) complexes [OsCl 2 (H 2 O)(=C=CHR)(PPh 3 ) 2 ]. The structures of several of these new complexes have been determined by X‐ray diffraction studies. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)