Preparation, Characterization, and Reactivity of an Osmium Alkenyl Dihydrogen Complex

Treatment of OsCl 2 (PPh 3 )(PNP) (PNP = 2,6-(Ph 2 PCH 2 ) 2 C 5 H 3 N) with LiC⋮CPh produced OsCl(PPh 3 )(2-Ph 2 PCH(CPh CH)-6-Ph 2 PCH 2 C 5 H 3 N). The structure of the latter, unusual complex has been confirmed by an X-ray diffraction study. Reaction of OsCl(PPh 3 )(2-Ph 2 PCH(CPh CH)-6-Ph 2 PCH 2 C 5 H 3 N) with H 2 and K 2 CO 3 in the presence of NaBF 4 in methanol produced OsH(PPh 3 )(2-Ph 2 PCH(CPh CH)-6-Ph 2 PCH 2 C 5 H 3 N). Protonation of OsH(PPh 3 )(2-Ph 2 PCH(CPh CH)-6-Ph 2 PCH 2 C 5 H 3 N) with HBF 4 gave [Os(H 2 )(PPh 3 )(2-Ph 2 PCH(CPh CH)-6-Ph 2 PCH 2 C 5 H 3 N)]BF 4, which reacted with H 2 to give [OsH(H 2 )(PPh 3 )(2-Ph 2 PCH(CPh CH 2 )-6-Ph 2 PCH 2 C 5 H 3 N)]BF 4 .