1. State Key Laboratory of Applied Organic Chemistry & College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, P. R. China
2. Department
of Chemistry, Center of Novel Functional Molecules and State Key Laboratory
of Synthetic Chemistry, The Chinese University of Hong Kong, Shatin, Hong Kong
3. Department
of Chemistry and Center for Molecular Materials (CM2), Bielefeld University, 33615 Bielefeld, Germany