1. State Key Laboratory of Eco‐functional Polymer Materials of the Ministry of Education College of Chemistry and Chemical Engineering Northwest Normal University Lanzhou 730070 P. R. China
2. State Key Laboratory of Applied Organic Chemistry Key Laboratory of Nonferrous Metal Chemistry and Resources Utilization of Gansu Province College of Chemistry and Chemical Engineering Lanzhou University Lanzhou 730000 P. R. China
3. State Key Laboratory of Inorganic Synthesis and Preparative Chemistry College of Chemistry Jilin University Changchun 130012 P. R. China