1. CIQ (UP), Department of Chemistry, Faculty of Sciences, University of Porto, R. Campo Alegre, 687, P-4169-007 Porto, Portugal, Instituto de Tecnologia Química e Biológica (ITQB/UNL), P-2781-901 Oeiras, Portugal, and “Petru Poni” Institute of Macromolecular Chemistry, Iasi, Romania