THE MOLECULAR-STRUCTURE OF WI2(CO)(NCPH)(ETA(2)-MEC(2)ME)(2)

The X-ray crystal structure of [WI2(CO)(NCPh)(eta(2)-MeC(2)Me)(2)], 1, is described. The coordination of the tungsten atom in 1 is best cons idered as octahedral. The complex is formally eight-coordinate, howeve r it is more convenient to consider the geometry as six-coordinate wit h the two but-2-yne ligands occupying one coordination site each. The two iodo-atoms are mutually cis to each other, and each one is trans t o a but-2-yne ligand. The benzonitrile and carbonyl groups are trans t o each other in the axial positions.