1. Department of Chemistry, Graduate School of Advanced Science and Engineering, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8526, Japan
2. Organic Electronics Materials Department, Electronics Materials Division, Shin-Etsu Chemical Co., Ltd., 4-1, Marunouchi 1-chome, Chiyoda-ku, Tokyo 100-0005, Japan
3. Department of Chemistry, Faculty of Science, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8526, Japan
4. Department of Materials Science, Natural Science Center for Basic Research and Development (N-BARD), Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8526, Japan