1. Department of Chemistry, National Cheng Kung University, Tainan 701, Taiwan
2. Institute of Chemistry, Academia Sinica, Taipei 115, Taiwan
3. Instrumentation Center, College of Science, National Taiwan University, Taipei 106, Taiwan
4. Division of Applied Chemistry Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita 565-0871, Japan