SciELO - Scientific Electronic Library Online

 
vol.21 número4Isolation, X-ray crystal structure and theoretical calculations of the new compound 8-Eepicordatin and identification of others terpenes and steroids from the bark and leaves of Croton palanostigma KlotzschDifferential metabolic and biological profiles of Lychnophora ericoides mart. (Asteraceae) from different localities in the Brazilian "campos rupestres" índice de autoresíndice de materiabúsqueda de artículos
Home Pagelista alfabética de revistas  

Journal of the Brazilian Chemical Society

versión impresa ISSN 0103-5053

Resumen

PAULA, Fávero R. et al. Theoretical and voltammetric studies of 5-Nitro-heterocyclic derivatives with potential trypanocidal activities. J. Braz. Chem. Soc. [online]. 2010, vol.21, n.4, pp. 740-749. ISSN 0103-5053.  http://dx.doi.org/10.1590/S0103-50532010000400022.

Stereoelectronic properties of nitro-heterocyclic bioisosteric congeners were investigated using theory-level quantum chemistry and cyclic voltammetry with the goal of determining physico-chemical properties that affect the redox potential of the nitro group. Molecular geometry, physicochemical properties and stereoelectronic surfaces, such as molecular electrostatic potential, and HOMO and LUMO orbitalar distributions, were calculated using the AM1 semiempirical method. The redox potential of nitro-heterocyclic compounds, which corresponds to the (Ar-NO2/Ar-NO2•- ) redox couple, was measured in aprotic media (DMSO and 0.1 mol L-1 Bu4NH4BF4) using glassy carbon as working electrode, Pt wire, Ag/AgCl, KCl(sat) as counter and reference electrodes, respectively. Analysis of minimal energy conformers of all derivatives indicated a break in structural planarity located between the hydrazine nitrogen and benzamide moiety. No statistical correlation was obtained using the PLS regression method, taking in account all physicochemical properties and the redox potential, which might result from the lack of coplanarity effect in the molecular structure of the compounds.

Palabras llave : 5-nitro-heterocyclic; stereoelectronic properties; redox potential.

        · resumen en Portugués     · texto en Inglés     · pdf en Inglés