1. Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of the Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi’an 710069, P. R. China
2. Shanghai Synchrotron Radiation Facility, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201204, P. R. China
3. Department of Chemistry, University of South Florida, Tampa, Florida 33620, United States
4. Department of Chemistry, University of Utah, Salt Lake City, Utah 84112, United States