1. Institute of Physics of the Czech Academy of Sciences, Cukrovarnická 10/112, 162 00 Praha 6, Czech Republic
2. Department of Analytical Chemistry, University of Chemistry and Technology Prague, Technická 5, 166 28 Praha 6, Czech Republic
3. Charles University, Faculty of Mathematics and Physics, V Holešovičkách 2, 180 00 Praha 8, Czech Republic
4. Department of Chemistry, Johannes Gutenberg University Mainz, Duesbergweg 10-14, D-55128 Mainz, Germany
5. Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo náměstí 542/2, 160 00 Praha 6, Czech Republic
6. Fachbereich Chemie, TU Kaiserslautern, Erwin-Schrödinger-Str. 54, 67663 Kaiserslautern, Germany