1. State Key Laboratory of Rare Earth Resource Utilization; Changchun Institute of Applied Chemistry; Chinese Academy of Sciences; Changchun 130022 P.R. China
2. University of Chinese Academy of Sciences; Beijing 100049 P.R. China
3. Institut für Anorganische Chemie; KIT (Karlsruhe Institute of Technology); Engesserstr. 15 76131 Karlsruhe Germany