1. Department of Chemistry; College of Chemistry and Chemical Engineering; Chongqing University; Daxuecheng South Rd. 55 401331 Chongqing P. R. China
2. Istituto per lo Studio dei Materiali Nanostrutturati (ISMN); Sezione di Bologna CNR; Via Gobetti 101 40129 Bologna Italy
3. Department of Chemistry; University of Bologna; Via Selmi 2 40126 Bologna Italy
4. Max Plank Institute for the Structure and Dynamics of Matter; The Hamburg Centre for Ultrafast Imaging at the Universität Hamburg; 22761 Hamburg Germany