1. Department of Organic ChemistryUniversity of Campinas, Chemistry Institute, C.P. 6154 CEP. 13083-970 Campinas São Paulo Brazil
2. Department of ChemistryQuaid-i-Azam University Islamabad 45320 Pakistan
3. Department of Fundamental ChemistryUniversity of São Paulo Avenida Lineu Prestes, 748, Bl. 05 sup. Sl 0552 Butantã São Paulo, SP Brazil