1. Division of Chemistry, Graduate School of Science, Hokkaido University, Kita-ku, Sapporo 060-0810, Japan, Department of Applied Chemistry, Faculty of Engineering, Nagasaki University, Bunkyo-machi, Nagasaki 852-8521, Japan, and Institute of Inorganic Chemistry, pr. Lavrentyeva 3, Novosibirsk 630090, Russia