1. Institute of Chemistry, Federal University of Rio Grande do Sul (UFRGS), Av. Bento Gonçalves 9500, P.O. Box 15003, 91501-970, Porto Alegre, RS, Brazil
2. Department of Chemistry – CCET, Federal University of Sergipe, P.O. Box 353, 49000-000 São Cristovão, SE, Brazil
3. Department of Chemistry, Federal University of Agriculture, P.M.B. 2240, Abeokuta, Ogun State, Nigeria