1. State Key Laboratory of Coal Conversion; Institute of Coal Chemistry; Chinese Academy of Sciences; 030001 Taiyuan China
2. Max Planck Institute for Polymer Research; Ackermannweg 10 55128 Mainz Germany
3. University of Chinese Academy of Sciences; 100049 Beijing China
4. Center for Advancing Electronics Dresden (cfaed) & Department of Chemistry and Food Chemistry; Technische Universität Dresden; 01062 Dresden Germany