1. Contribution from the Institute for Molecular Science, Okazaki 444, Japan, Department of Chemistry, Faculty of Science, Toho University, Funabashi, Chiba 274, Japan, Department of Chemistry, Faculty of Science, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113, Japan, Institute for Solid State Physics, The University of Tokyo, Roppong, Minatoku, Tokyo 106, Japan, Department of General Education, Tokyo University of Marine Science, Konan, Minato-ku, Tokyo 108, Japan, and Equipe Précurseurs Moléculaires...