1. Beijing National Laboratory for Molecular Sciences; Organic Solids Laboratory; CAS Research/Education Center for Excellence in Molecular Sciences; Institute of Chemistry; Chinese Academy of Sciences; Beijing 100190 P. R. China
2. School of Chemical Sciences; University of Chinese Academy of Sciences; Beijing 100049 P. R. China
3. School of Materials Science and Engineering; University of Science and Technology Beijing; Beijing 100083 P. R. China