1. Department of Chemistry University of Victoria P.O. Box 1700 STN CSC Victoria British Columbia V8W 2Y2 Canada
2. Max-Planck-Institut für Kohlenforschung Kaiser-Wilhelm-Platz 1 45470 Mülheim an der Ruhr Germany
3. X-ray Crystallography Laboratory Department of Chemistry University of Alberta Edmonton Alberta T6G 2G2 Canada