1. Department of chemistry University of Science and Technology of China 96 Jinzhai Road Hefei Anhui 230026 P. R. China
2. Department of chemistry Huaibei Normal University 100 Dongshan Road Huaibei Anhui 235000 P. R. China
3. Information College Huaibei Normal University 100 Dongshan Road Huaibei Anhui 235000 P. R. China