CRYSTAL AND MOLECULAR-STRUCTURES OF HEXAMETHYLTUNGSTEN AND HEXAMETHYLRHENIUM

The structure of hexamethyltungsten, W(CH3)(6), was determined by x-ra y single-crystal diffraction at -163 degrees C. The molecule has a str ongly distorted trigonal prismatic structure with C-3v symmetry. This irregular structure is not a result of intermolecular forces, but rath er represents its true molecular structure. A similar structure, which deviates less from the ideal trigonal prismatic structure, was determ ined for hexamethylrhenium, Re(CH3)(6). Although these structures viol ate the simplistic models used to predict the geometry of molecules, t hey are at least in part explainable by the molecular orbital model.