1. High Resolution NMR Centre (HNMR) and Department of General and Organic Chemistry of the Faculty of Applied Sciences (AOSC), Free University of Brussels (VUB), Pleinlaan 2, B-1050 Brussels, Belgium, INAN, Université Catholique de Louvain (UCL), Chemin du Cyclotron 2, B-1348 Louvain-la-Neuve, Belgium, and Department of Chemistry, The University of Adelaide, Adelaide, Australia