1. Department of Chemistry, University of Antwerp, Universiteitsplein 1, B-2610 Wilrijk, Belgium; Department of Chemistry, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerpen, Belgium; Department of Chemistry, Katholieke Universiteit Leuven, Celestijnenlaan 200F, B-3001 Heverlee, Belgium; Department of Chemistry, University of Antwerp, Middelheimlaan 1, B-2020 Antwerpen, Belgium; and DUBBLE-CRG/ESRF, Rue des Martyrs 156, B.P. 220, F-38043 Grenoble Cedex, France