1. Department of Organic Chemistry, Faculty of Natural Sciences, Comenius University, Mlynská dolina, SK-84215 Bratislava, Slovakia
2. Institut für Physikalische und Theoretische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, DE-97074 Würzburg, Germany
3. Institute of Inorganic Chemistry, Slovak Academy of Sciences, Dúbravská cesta 9, SK-84536 Bratislava, Slovakia
4. Department of Physics, University of Patras, GR-26504 Patras, Greece