1. Department of Chemistry, Faculty of Science Kanazawa University, Kakuma-machi Kanazawa 920-11, Japan Department of Applied Chemistry, Faculty of Engineering Nagoya Institute of Technology Showa-ku, Nagoya 466, Japan X-ray Research Institute, Rigaku Corporation Akishima-shi, Tokyo 196, Japan Institute for Molecular Science Myodaiji, Okazaki 444, Japan Department of Chemistry, Faculty of Science Kyushu University, Hakozaki, Higasiku, Fukuoka 812, Japan