1. Department of Chemistry and Department of Physics, Faculty of Science, Kumamoto University, Kurokami 2-39-1, Kumamoto 860-8555, Japan, Department of Chemistry, Faculty of Science, Okayama University, Tsushima-naka 3-1-1, Okayama 700-8530, Japan, and Facolta di Farmacia, Università degli Studi “G. D'Annunzio”, Chieti, Italy