1. Department of Material and Life Chemistry, Kanagawa University, 3‐27‐1 Rokkakubashi, Kanagawa‐ku, Yokohama 221‐8686, Japan, Fax: +81‐45‐413‐9770
2. Chemical Resources Laboratory, Tokyo Institute of Technology, 4259 Nagatsuta, Midori‐ku, Yokohama 226‐8503, Japan
3. Department of Chemistry and Material Engineering, Ibaraki National College of Technology, 866 Nakane, Hitachinaka, Ibaraki 312‐8508, Japan