1. Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, PR China
2. Center for the Physics of Materials and Department of Physics, McGill University, Montreal, Quebec H3A 2T8, Canada
3. Center for Molecular Systems and Organic Devices, Key Laboratory for Organic Electronics & Information Displays and Institute of Advanced Materials, Nanjing University of Posts & Telecommunications, Nanjing 210023, PR China
4. Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, PR China
5. Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, United States