Reaction of OsO4 with one equivalent of PPh3 in the presence of the tertiar
y diols, 2,3-dimethyl-2,3-butanediol (H(2)pin) and 1,1'-bicyclohexane-1,1'-
diol (H(2)bicy), afforded the new oxoosmium(VI) complexes [OsO(diol)(2)]. T
he molecular structures of [OsO(pin)(2)], [OsO(bicy)(2)] and its adduct [Os
O(bicy)(2)]. H(2)bicy . PPh3O were determined by X-ray crystallography.