1. Department of Chemistry Rutgers University-Newark 73 Warren Street Newark NJ 07102 USA
2. Key Laboratory of Cluster Science Ministry of Education of China Beijing Key Laboratory of Photoelectronic/Electrophotonic, Conversion Materials School of Chemistry and Chemical Engineering Beijing Institute of Technology Beijing 102488 P. R. China
3. State Key Laboratory of Polymer Physics and Chemistry Changchun Institute of Applied Chemistry Chinese Academy of Sciences Changchun 130022 P. R. China