Vinylidene, Allenylidene, and Carbyne Complexes from the Reactions of [OsCl2(PPh3)3] with HC⋮CC(OH)Ph2

Treatment of [OsCl 2 (PPh 3 ) 3 ] with HC⋮CC(OH)Ph 2 in benzene at room temperature produces [(PPh 3 ) 2 ClOs(μ-Cl) 3 Os( C CHC(OH)Ph 2 )(PPh 3 ) 2 ], fac -[OsCl 3 (⋮C−CH CPh 2 )(PPh 3 ) 2 ], mer -[OsCl 3 (⋮C−CH CPh 2 )(PPh 3 ) 2 ], and [OsCl 2 ( C C CPh 2 )(CO)(PPh 3 ) 2 ]. The latter two complexes are the major products when the reaction is carried out in refluxing toluene. Treatment of [OsCl 2 (PPh 3 ) 3 ] with HC⋮CC(OH)Ph 2 in the presence of HCl produces fac -[OsCl 3 (⋮C−CH CPh 2 )(PPh 3 ) 2 ] and mer -[OsCl 3 (⋮C−CH CPh 2 )(PPh 3 ) 2 ]. Treatment of [OsCl 2 (PPh 3 ) 3 ] with HC⋮CC(OH)Ph 2 in the presence of HPPh 3 BF 4 produces [OsCl 2 (⋮C−CH CPh 2 )(H 2 O)(PPh 3 ) 2 ]BF 4 . The structures of all the new complexes have been confirmed by X-ray diffraction.