1. Dipartimento di Scienze Fisiche e Chimiche, University of L’Aquila, 67100 L’Aquila, Italy
2. Department of Chemistry, University of San Francisco, 2130 Fulton Street, San Francisco, California 94117-1080, United States
3. Institut für Physikalische Chemie II, Karlsruhe Institute of Technology (KIT), Fritz-Haber-Weg 2, 76131 Karlsruhe, Germany
4. Department of Chemistry, University of the Pacific, 3601 Pacific Avenue, Stockton, California 95211, United States
5. Laboratory for Femtochemistry and Synchrotron Radiation, Paul Scherrer Institut (PSI), 5232 Villigen, Switzerland