1. Department of Chemistry, Faculty of Science, Kyushu University, Hakozaki, Higashiku, Fukuoka 812-8581, Japan, Department of Chemistry, The University of Sheffield, Sheffield S3 7HF, U.K., and Procter and Gamble Far East Inc., Koyo-cho, Naka 1-17, Higashinada-ku, Kobe 658-0032, Japan