1. Chemistry Department, University of Coimbra, 3004-535 Coimbra, Portugal, Centro de Investigação em Química, Department of Chemistry, University of Porto, Rua do Campo Alegre, n° 687, P-4169-007 Porto, Portugal, and Physical Chemistry 1, Center for Chemistry and Chemical Engineering, Lund University, P.O. Box 124, SE-221 00 Lund, Sweden