1. Chemistry Laboratory, Kochi Gakuen College, 292 Asahi Tenjin-cho, Kochi 780-0955, Japan, Department of Pharmaceutical Sciences, Tokushima Bunri University, 180 Boji, Nishihama, Ymashiro-cho, Tokushima 770-8055, Japan, Department of Material Sciences, Faculty of Sciences, Kochi University, 2-1-5 Akebono-cho, Kochi 780-8520, Japan, and Christopher Ingold Laboratory, Department of Chemistry, University College London, 20 Gordon Street, London WC1H OAJ, U.K.