1. Department of Molecular Science and Technology, Doshisha University, Kyotanabe, Kyoto 610-0321, Japan, X-ray Laboratory, Rigaku-Denki, Akishima, Tokyo 196, Japan, Department of Chemistry, Saga University, Saga 840, Japan, and Department of Chemistry, Kyushu University, Hakozaki, Higashi-ku, Fukuoka 812, Japan