1. Department of Chemistry, College of Science and Engineering, Aoyama Gakuin University, 6-16-1 Chitosedai, Setagaya, Tokyo, 157, Japan, Department of Chemistry, University of Hawaii at Manoa, 2545 The Mall, Honolulu, Hawaii 96822-2275, and The Natural History Museum, Cromwell Road, London SW7 5BD, U.K.