Reactions of Tp–Os nitrido complexes with the nucleophiles hydroxide and thiosulfate

Reaction of TpOs(N)(OAc)2 (2) with thiosulfate occurs at the nitrido ligand to yield TpOs(NS)(OAc)2 (4). Reaction with hydroxide, however, gives TpOs(N)(OH)2 (3) by a direct substitution of OH− for OAc−, as confirmed by 18O-labeling. The contrasting reactivity of hydroxide with TpOs(N)Cl2 (1), 2, 3, and 4, at the metal versus at a ligand, is described.