1. Department of Chemistry and Biochemistry, National Chung Cheng University, 168 University Road, Min-Hsiung, Chiayi 62102, Taiwan
2. Department of Chemistry, National Dong Hwa University, Shoufeng, Hualien 97401, Taiwan
3. Department of Chemistry, National Taiwan University, 1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan