1. Key Laboratory of Polyoxometalate Science of the Ministry of Education
2. College of Chemistry
3. Northeast Normal University
4. Changchun 130024, P. R. China
5. College of Chemistry and Molecular Engineering
6. Peking University
7. Beijing 100871, P. R. China
8. State Key Laboratory of Inorganic Synthesis and Preparative Chemistry
9. Jilin University
10. Changchun, P. R. China