1. Key Laboratory of Green Chemistry and Technology (Ministry of Education)College of ChemistrySichuan University Chengdu 610064 P. R. China
2. State Key Laboratory of Rare Earth Resource UtilizationChangchun Institute of Applied ChemistryChinese Academy of Sciences Changchun 130022 P. R. China
3. Key Laboratory of Magnetic Resonance in Biological SystemsState Key Laboratory of Magnetic Resonance and Atomic and Molecular PhysicsWuhan Institute of Physics and MathematicsInnovation Academy of Precision Measurement Science and TechnologyChinese Academy of Sciences – Wuhan National Laboratory for OptoelectronicsHuazhong University of Science and Technology Wuhan 430071 P. R. China