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Authordc.contributor.authorNúñez Vergara, Luis es_CL
Authordc.contributor.authorBontá, M. es_CL
Authordc.contributor.authorSturm, J. C. 
Authordc.contributor.authorNavarrete Encina, Patricio 
Authordc.contributor.authorBollo Dragnic, Soledad 
Authordc.contributor.authorSquella Serrano, Juan
Admission datedc.date.accessioned2008-06-16T16:01:39Z
Available datedc.date.available2008-06-16T16:01:39Z
Publication datedc.date.issued2001-08-31
Cita de ítemdc.identifier.citationELECTROCHIMICA ACTA 46(28):4289-4300en
Identifierdc.identifier.issn0013-4686
Identifierdc.identifier.urihttps://repositorio.uchile.cl/handle/2250/120459
Abstractdc.description.abstractThis paper reports a comprehensive study by tast polarography, d.p.p., and cyclic voltammetry on the electrochemical reduction in different electrolytic media of ortho- and meta-nitrotoluene derivatives. Controlled potential electrolysis was used to generate the nitro radical anions and its detection by cyclic voltammetry and UV-Vis spectroscopy was performed. In protic media (30% ethanol/0.1 M. Britton-Robinson buffer pH 2-12) both derivatives gave a sharp irreversible well-defined peak in all the pH range on Hg in a reaction involving four electrons to give the hydroxylamine derivative. In this medium meta-nitrotoluene is easier reduced in approximately 80 mV than that of the ortho-nitrotoluene. In mixed aqueous organic media (0.015 M aqueous citrate/DMF: 60:40, 0.3 M KCI and 0. 1 M TBAI) at pH > 8, the isolation and the electrochemical characterization of the one-electron reduction product, the nitro radical anion was achieved. At a 1 mM of nitrotoluene concentration, the average dismutation second-order rate constant values, k(2), were: 11,000 +/- 170 and 6900 +/- 72 M (-1) s(-1) for ortho-and meta-nitrotoluene, respectively. In aprotic media (0.1 M TBAI in DMF), the nitro radical anions were more stable than that of mixed media, with the following dismutation second-order rate constant values, k(2): 5800 +/- 35 and 4700 +/- 42 M-1 s(-1) for ortho- and meta-nitrotoluene, respectively. Also, a comparison between nitrotoluene derivatives and some nitrocompounds of pharmacological relevance relating the effects of substituents on nitrobenzene and the electrolytic media composition on both the easiness of formation and stability of radicals is presented.en
Lenguagedc.language.isoenen
Publisherdc.publisherPERGAMON-ELSEVIER SCIENCEen
Keywordsdc.subjectnitrotoluene derivativesen
Títulodc.titleElectrochemical characterization of ortho and meta-nitrotoluene derivatives in different electrolytic media. Free radical formationen
Document typedc.typeArtículo de revista


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