1. Department of Chemistry, School of Science, Kwansei-Gakuin University, Uegahara, Nishinomiya 662, Japan, Advanced Materials Research Laboratory, Matsushita Research Institute Tokyo, Inc., Higashimaita, Tama-ku, Kawasaki 214, Japan, and Institute of DNA Medicine, The Jikei University School of Medicine, Nishi-shinbashi, Minato-ku, Tokyo 105, Japan