CRYSTAL AND MOLECULAR-STRUCTURE OF TETRACARBONYL (6,6'-DIMETHYL-2,2'-BIPYRIDINE)MOLYBDENUM BENZENE SOLVATE

The crystal structure of the complex cis-[Mo(CO)4(6,6'-dimethyl-2,2'-bipyridine)].C6H6 has been determined by X-ray diffraction. The structure shows that repulsion between the methyl groups and the carbonyl ligands in the equatorial plane is principally responsible for the geometric distortion observed. Within the asymmetrically bound ligand the two pyridine rings suffer distortions in the same direction to pseudo-boat conformations so as to optimise molybdenum-nitrogen binding. The benzene solvent molecules are in narrow channels which lie between the axial carbonyl ligands. There are no significant short intermolecular contacts between the benzene and complex molecules.