1. Department of Chemistry University of Fribourg Chemin du Musée 7 1700 Fribourg Switzerland
2. Department of Chemistry and Biochemistry University of Bern Freiestrasse 3 3012 Bern Switzerland
3. UCIBIO-Requimte Departamento de Química Faculdade de Ciências e Tecnologia Universidade NOVA de Lisboa 2829-516 Caparica Portugal