1. Department of Chemistry, School of Science, Kwansei-Gakuin University, Uegahara, Nishinomiya 662, Japan, Department of Physics, North-Eastern Hill University, Shillong-793022, India, Yokohama Research Center, Mitsubishi Chemical Corporation, Kamoshida-cho, Aoba-ku, Yokohama 227, Japan, Department of Chemistry, Faculty of Science and Engineering, University of Saga, Saga 840, Japan, Institute of DNA Medicine, The Jikei University School of Medicine, Nishi-shinbashi, Minato-ku, Tokyo 105, Japan