Synthesis and Characterization of [OsCl2(=C=CHR)(PPh3)2] and Related Complexes

Treatment of [OsCl2(PPh3)3] with HC≡CR (R = Ph, p‐tolyl, CMe3) in the presence of HCl gives the corresponding trichloro(carbyne) complexes [OsCl3(≡CCH2R)(PPh3)2] in good yields. The vinylidene complexes [OsCl2(=C=CHR)(PPh3)2] (R = Ph, p‐tolyl, CMe3) are, in turn, prepared from the reactions of the carbyne complexes [OsCl3(≡CCH2R)(PPh3)2] with NEt3. These new vinylidene complexes are hygroscopic and react with H2O to give (aqua)(vinylidene) complexes [OsCl2(H2O)(=C=CHR)(PPh3)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)