1. Molecular Materials Research Center, School of Chemical Engineering, Nanjing University of Science and Technology, Nanjing 210094, P. R. China
2. Research Center for Materials Science, Department of Chemistry, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan
3. China-Australia Joint Research Center for Functional Molecule Materials, Scientific Research Academy, School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013, P. R. China