1. Department of Biology and Chemistry City University of Hong Kong Tat Che Avenue, Kowloon Tong, Hong Kong, China, Fax: (+852) 27887406
2. Department of Chemistry, University of Hong Kong Pokfulam Road, Hong Kong, China
3. State Key Laboratory of Rare Earth Materials Chemistry and Applications and PKU‐HKU Joint Laboratory on Rare Earth Materials and Bioinorganic Chemistry Peking University, Beijing 100871, China, Fax: (+86) 10‐62751708