1. Department of Chemistry, Faculty of Science, Chiba University, 1-33 Yayoi, Inage, Chiba 263-8522, Japan, Institute of Carbon Science and Technology, Shinshu University, 4-17-1 Wakasato, Nagano 380-8553, Japan, and SORST, Japan Science and Technology Agency, NEC Corporation, 34 Miyukigaoka, Tsukuba 305-8501, Japan