1. Fullerene Development Group, Performance Products Division, Mitsubishi Chemical Corporation, 1-1 Kurosakishiroishi, Yahatanishi-ku, Kitakyushu 806-0004, Japan, Department of Chemistry, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan, and Mitsubishi Chemical Group Science and Technology Research Center, Inc., 1000 Kamoshida, Aoba-ku, Yokohama, Kanagawa, 227-8502, Japan