1. Hubei Province Engineering and Technology Research Center for Fluorinated Pharmaceuticals School of Pharmaceutical Sciences Wuhan University Wuhan 430071 People's Republic of China
2. State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics National Center for Magnetic Resonance in Wuhan Wuhan Institute of Physics and Mathematics Innovative Academy of Precision Measurement Science and Technology Chinese Academy of Sciences Wuhan 430071 People's Republic of China