1. Center for Chemistry of High-Performance & Novel Materials; Department of Chemistry; Zhejiang University; Hangzhou 310027 P. R. 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; Chinese Academy of Sciences; Wuhan 430071 P. R. China
3. Institute of Pharmaceutics; College of Pharmaceutical Sciences; Zhejiang University; 866 Yuhangtang Road Hangzhou 310058 P. R. China