1. Beijing
National Laboratory for Molecular Science, Key Laboratory of Organic
Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
2. Department
of Chemistry, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
3. Tianjin
Key Laboratory of Molecular Optoelectronic Sciences, Department of
Chemistry, School of Science, Tianjin University and Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin 300072, China