The Nonoctahedral Structures of d0, d1, and d2 Hexamethyl Complexes

The unusual distorted trigonal-prismatic structure reported recently for hexamethyltungsten is only the tip of the iceberg. None of the d0, d1, and d2 hexamethyl complexes studied here with density functional theory has an octahedral structure. All of them prefer distorted or regular trigonal-prismatic structures (depicted below). The electronic factors which control the structures of these systems are discussed, and spectroscopic predictions are made to facilitate the experimental characterization of the, as yet unknown, d2 systems [Os(CH3)6] and [Ru(CH3)6].