1. Department of Chemistry, Graduate School of Science, University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113, Japan; Research Center for Spectrochemistry, Faculty of Science, University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113, Japan; National Institute for Material and Chemical Research, Higashi, Tsukuba, Ibaraki 305, Japan; and Department of Material Science, Faculty of Science, Osaka City University, Sugimoto, Sumiyoshi, Osaka 558, Japan