Chiral Hydride and Dihydrogen Pincer-Type Complexes of Osmium

Reaction of [OsCl6]2- with a pincer-type ligand, (S)-But2PCH2CH(NMe2)C3H6PBut2, afforded a chiral square-pyramidal 16-electron carbene complex, OsCl(PGP) (1), PGP = [κ4-But2PCH2CH(N(Me)CH)CHC2H4PBut2], in excellent yield. Reactions of 1 with hydrogen under different conditions resulted in the hydride and dihydrogen species OsH2Cl(PGP), [Os(H2)2(PGP)]+, and OsH3(PGP), which have been characterized by a combination of spectroscopic and DFT computational techniques.