1. MOE Key Laboratory of Bioinorganic and Synthetic ChemistrySchool of ChemistrySun Yat-sen University Guangzhou 510275 P.R. China
2. Berzelii Center EXSELENT on Porous MaterialsDepartment of Materials and Environmental ChemistryStockholm University 106 91 Stockholm Sweden
3. State Key Laboratory of Inorganic Synthesis and Preparative ChemistryCollege of ChemistryJilin University Changchun 130012 P. R. China
4. State Key Laboratory of Magnetic Resonance and Atomic and Molecular PhysicsNational center for Magnetic Resonance in WuhanWuhan Institute of Physics and MathematicsChinese Academy of Sciences Wuhan 430071 P. R. China