1. Clausthal University of Technology, Institute of Organic Chemistry, Leibnizstrasse 6, D-38678 Clausthal-Zellerfeld, Germany
2. Helmholtz-Zentrum Dresden-Rossendorf, Helmholtz Institute Freiberg for Resource Technology, Chemnitzer Str. 40, D-09599 Freiberg, Germany
3. Clausthal University of Technology, Institute of Inorganic and Analytical Chemistry, Arnold-Sommerfeld-Str. 4, D-38678 Clausthal-Zellerfeld, Germany
4. Clausthal University of Technology, Institute of Particle Technology, Leibnizstrasse 19, D-38678 Clausthal-Zellerfeld, Germany
5. University of Helsinki, Department of Chemistry, P. O. Box 55, FIN-00014 Helsinki, Finland