1. Max-Planck-Institut für Strahlenchemie, Postfach 101365, D-45413 Mülheim an der Ruhr, Germany, Department of Materials Chemistry, Faculty of Science and Technology, Ryukoku University, Otsu, Shiga, 520-2194, Japan, and Department of Bioscience and Biotechnology, Ritsumeikan University, Kusatsu, Shiga 525-8577, Japan