1. Department of General, Organic and Biomedical Chemistry, NMR and Molecular Imaging Laboratory, University of Mons‐Hainaut, 7000 Mons, Belgium, Fax: +32‐65‐373520
2. Department of Chemistry, Katholieke Universiteit Leuven, Celestijnenlaan 200F, 3001 Leuven, Belgium, Fax: +32‐16‐327992