1. Beijing Key Laboratory of Function Materials for Molecule and Structure Construction; School of Materials Science and Engineering; University of Science and Technology Beijing; Beijing 100083 P. R. China
2. MOE Laboratory of Bioinorganic and Synthetic Chemistry; Lehn Institute of Functional Materials; School of Chemistry; Sun Yat-Sen University; Guangzhou 510275 P. R. China
3. Guangdong Research Institute of Rare Metals; Guangzhou 510651 China
4. Guangdong Province Key Laboratory of Rare Earth Development and Application; Guangzhou 510651 China