1. Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, D-45470 Mülheim an der Ruhr, Germany
2. Institute of Chemistry, University of Campinas—UNICAMP, 13083-970 Campinas, São Paulo, Brazil
3. Department of Chemistry, Federal Rural University of Pernambuco−UFRPE, 52171-900 Recife, Pernambuco, Brazil
4. Department of Chemistry, Federal University of Sergipe−UFS, 49100-000 São Cristóvão, Sergipe, Brazil