1. Department of Chemistry, Nara University of Education, Takabatake-cho, Nara 630-8528, Japan, Institute for Natural Science, Nara University, 1500 Misasagi-cho, Nara 631-8502, Japan, Department of Chemistry, Wayne State University, Detroit, Michigan 48202-3489, and Department of Chemistry, Faculty of Science, Saitama University, 255 Shimo-Ohkubo, Sakura-ku, Saitama 338-8570, Japan