1. Department of Chemistry and Biochemistry; University of Bern, Freiestrasse 3; Bern 3012 Switzerland
2. Department of Chemistry; University of Milan, via Golgi 19; Milano 20133 Italy
3. Swiss Light Source, Paul Scherrer Institute, WLGA/229; Villingen 5234 Switzerland
4. Faculty of Chemistry; Jagiellonian University, Gronostajowa 2; Krakow 30-387 Poland