1. Department of Chemistry; University of Fribourg; Ch. du Musée 9 1700 Fribourg Switzerland
2. Department of Chemistry and Biochemistry; University of Bern; Freiestrasse 3 3012 Bern Switzerland
3. Institute of Chemistry and Biological Chemistry; Zurich University of Applied Sciences (ZHAW); 8820 Wädenswil Switzerland
4. Optical Additives GmbH; Flurweg 9 3073 Gümligen Switzerland