1. Laboratoire de Recherches sur la Reactivite des Solides, UMR 5613 du CNRS, Universite de Bourgogne, BP 47870, 21078 Dijon Cedex, France, Department of Chemistry, Norwegian University of Science and Technology, NO-7491 Trondheim, Norway, and Leiden Institute of Chemistry, PO Box 9502, 2300 RA Leiden University, Leiden, The Netherlands