1. Equipe mixte CEA-RP, RHODIA, 93308 Aubervilliers Cedex, France; Research School of Chemistry, Institue of Advanced Studies, Australian National University, Acton, ACT 0200, Australia; Laboratoire PMMH, ESPCI, 10 rue Vauquelin, 75231 Paris Cedex 05, France; and CNRS UMR 5503, Laboratoire de Génie Chimique, Université Paul Sabatier, 31062 Toulouse Cedex 4, France