1. Particle and Interfacial Technology Group, Faculty of Bioscience Engineering, Ghent University, Coupure links 653, B-9000 Gent, Belgium, NMR and Structure Analysis Unit, Department of Organic Chemistry, Faculty of Sciences, Ghent University, Krijgslaan 281 S4, B-9000 Gent, Belgium, and Physical Chemistry 1, Center for Chemistry and Chemical Engineering, Lund University, P.O. Box 124, SE-22100 Lund, Sweden