1. Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Republic of Singapore
2. Institute of Pharmaceutical Science and Technology, College of Chemistry, Fuzhou University, Fuzhou 350108, China
3. National University of Singapore (Chongqing) Research Institute, Chongqing 401120, China
4. Department of Chemical and Biomolecular Engineering, National University of Singapore, Singapore 117585, Republic of Singapore