a
School of Chemistry, Beijing Institute of Technology and Key Laboratory of Cluster Science, Ministry of Education of China, Beijing, P. R. China
E-mail: cwhu@bit.edu.cn
;
Fax: (+)86 10 68912631
;
Tel: (+)86 10 68912631
b
College of Chemistry and Material Science, Hebei Normal University, Shijiazhuang, Hebei, P. R. China
c
Department of Chemistry, Capital Normal University, Beijing, P. R. China