1. Department of Chemistry, Graduate School of Science, Tohoku University, Aoba-ku, Aramaki, Sendai 980-77, Japan, Division of Chemistry, Graduate School of Science, Hokkaido University, Kita-ku, Sapporo 060, Japan, Department of Chemistry, Faculty of Science, Nara Women's University, Nara 630, Japan, and Department of Applied Chemistry, Faculty of Engineering, Kumamoto University, Kurokami, Kumamoto 860, Japan