a
Department of Chemistry, Huaibei Normal University, Huaibei, Anhui 235000, P R China
E-mail: leiwang@chnu.edu.cn
;
Fax: +86-561-309-0518
;
Tel: +86-561-380-2069
b
State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 200032, P R China