TY  - JOUR
AU  - Stevic, Milica C.
AU  - Ćirić-Marjanović, Gordana
AU  - Marjanovic, Budimir
AU  - Ignjatovic, Ljubisa M.
AU  - Manojlović, Dragan D.
PY  - 2012
UR  - https://cherry.chem.bg.ac.rs/handle/123456789/1534
AB  - The theoretical study of the 6-aminoquinoline (6-QNH(2)) electrochemical oxidation mechanism, based on the semi-empirical quantum chemical computations of the heat of formation, ionization energy, and spin density of reaction intermediates, taking into account the influence of pH and solvation effects, has been conducted. Two possible 6-QNH(2) electro-oxidation pathways are investigated, namely, the initial single-electron oxidation of 6-QNH(2) at lower electrode potentials, leading to the formation of cation radicals [6-QNH(2)](center dot+) in acidic solutions and neutral radicals [6-QNH](center dot) in alkaline solutions, as well as the two-electron oxidation of 6-QNH(2) leading to the initial formation of nitrenium cations [6-QNH](+) at higher electrode potentials. The regioselectivity of 6-QNH(2) dimerization reactions, which follow both the single- and two-electron transfer reactions, is computationally studied. Cyclic voltammetry experiments, conducted at a glassy carbon paste electrode in Britton-Robinson buffer/methanol media, are correlated with the computationally predicted 6-QNH(2) electro-oxidation mechanism. Differential pulse voltammetric and adsorptive stripping differential pulse voltammetric analyses of 6-QNH(2) oxidation have also been performed. (C) 2012 The Electrochemical Society. [DOI: 10.1149/2.004212jes] All rights reserved.
PB  - Electrochemical Soc Inc, Pennington
T2  - Journal of the Electrochemical Society
T1  - The Electrochemical Oxidation of 6-Aminoquinoline: Computational and Voltammetric Study
VL  - 159
IS  - 11
DO  - 10.1149/2.004212jes
ER  - 

@article{
author = "Stevic, Milica C. and Ćirić-Marjanović, Gordana and Marjanovic, Budimir and Ignjatovic, Ljubisa M. and Manojlović, Dragan D.",
year = "2012",
abstract = "The theoretical study of the 6-aminoquinoline (6-QNH(2)) electrochemical oxidation mechanism, based on the semi-empirical quantum chemical computations of the heat of formation, ionization energy, and spin density of reaction intermediates, taking into account the influence of pH and solvation effects, has been conducted. Two possible 6-QNH(2) electro-oxidation pathways are investigated, namely, the initial single-electron oxidation of 6-QNH(2) at lower electrode potentials, leading to the formation of cation radicals [6-QNH(2)](center dot+) in acidic solutions and neutral radicals [6-QNH](center dot) in alkaline solutions, as well as the two-electron oxidation of 6-QNH(2) leading to the initial formation of nitrenium cations [6-QNH](+) at higher electrode potentials. The regioselectivity of 6-QNH(2) dimerization reactions, which follow both the single- and two-electron transfer reactions, is computationally studied. Cyclic voltammetry experiments, conducted at a glassy carbon paste electrode in Britton-Robinson buffer/methanol media, are correlated with the computationally predicted 6-QNH(2) electro-oxidation mechanism. Differential pulse voltammetric and adsorptive stripping differential pulse voltammetric analyses of 6-QNH(2) oxidation have also been performed. (C) 2012 The Electrochemical Society. [DOI: 10.1149/2.004212jes] All rights reserved.",
publisher = "Electrochemical Soc Inc, Pennington",
journal = "Journal of the Electrochemical Society",
title = "The Electrochemical Oxidation of 6-Aminoquinoline: Computational and Voltammetric Study",
volume = "159",
number = "11",
doi = "10.1149/2.004212jes"
}

Stevic, M. C., Ćirić-Marjanović, G., Marjanovic, B., Ignjatovic, L. M.,& Manojlović, D. D.. (2012). The Electrochemical Oxidation of 6-Aminoquinoline: Computational and Voltammetric Study. in Journal of the Electrochemical Society
Electrochemical Soc Inc, Pennington., 159(11).
https://doi.org/10.1149/2.004212jes

Stevic MC, Ćirić-Marjanović G, Marjanovic B, Ignjatovic LM, Manojlović DD. The Electrochemical Oxidation of 6-Aminoquinoline: Computational and Voltammetric Study. in Journal of the Electrochemical Society. 2012;159(11).
doi:10.1149/2.004212jes .

Stevic, Milica C., Ćirić-Marjanović, Gordana, Marjanovic, Budimir, Ignjatovic, Ljubisa M., Manojlović, Dragan D., "The Electrochemical Oxidation of 6-Aminoquinoline: Computational and Voltammetric Study" in Journal of the Electrochemical Society, 159, no. 11 (2012),
https://doi.org/10.1149/2.004212jes . .

TY  - JOUR
AU  - Stevic, Milica C.
AU  - Ignjatovic, Ljubisa M.
AU  - Ćirić-Marjanović, Gordana
AU  - Stanišić, Svetlana M.
AU  - Stanković, Dalibor
AU  - Zima, Jiri
PY  - 2011
UR  - https://cherry.chem.bg.ac.rs/handle/123456789/1171
AB  - The 8-Hydroxyquinoline (8HQ) oxidation process has been investigated by Cyclic Voltammetry using a Glassy Carbon Paste Electrode (GCPE) as a working electrode. The theoretical study of the mechanism of electrochemical oxidation of 8HQ has been based on the AM1 semi-empirical quantum chemical computations of the heats of formation of the reaction intermediates, taking into account the influence of pH and solvation effects. We proposed that a two-electron irreversible process, controlled by diffusion of electroactive species, is responsible for an oxidation peak of 8HQ that appears in all cyclic voltammograms recorded on a clean electrode in the solutions of pH in the range 2-12 with a supporting electrolyte of Britton-Robinson Buffer/methanol. A single-electron oxidation of 8HQ leads, depending on pH, to the formation of various free radical species that combine to make dimers which, after being oxidized once more, give quinonoid-type compounds. Recording continuous cyclic voltammograms on the GCPE, pre-peaks appear as a consequence of dimer and quinonoid compounds formation. By applying Differential Pulse Voltammetry for 8HQ determination it was calculated that the limit of detection was 5.2x10(-8) mol/L. For more sensitive quantitative determination of the investigated substance Adsorptive Stripping Differential Pulse Voltammery can be used since it was found that after 300s-deposition time at 0.0 V vs. Saturated Calomel Electrode, a 2.1 times higher peak current than without deposition was obtained.
PB  - Electrochemical Science Group, Belgrade
T2  - International Journal of Electrochemical Science
T1  - Voltammetric Behaviour and Determination of 8-Hydroxyquinoline Using a Glassy Carbon Paste Electrode and the Theoretical Study of its Electrochemical Oxidation Mechanism
VL  - 6
IS  - 7
SP  - 2509
EP  - 2525
UR  - https://hdl.handle.net/21.15107/rcub_cherry_1171
ER  - 

@article{
author = "Stevic, Milica C. and Ignjatovic, Ljubisa M. and Ćirić-Marjanović, Gordana and Stanišić, Svetlana M. and Stanković, Dalibor and Zima, Jiri",
year = "2011",
abstract = "The 8-Hydroxyquinoline (8HQ) oxidation process has been investigated by Cyclic Voltammetry using a Glassy Carbon Paste Electrode (GCPE) as a working electrode. The theoretical study of the mechanism of electrochemical oxidation of 8HQ has been based on the AM1 semi-empirical quantum chemical computations of the heats of formation of the reaction intermediates, taking into account the influence of pH and solvation effects. We proposed that a two-electron irreversible process, controlled by diffusion of electroactive species, is responsible for an oxidation peak of 8HQ that appears in all cyclic voltammograms recorded on a clean electrode in the solutions of pH in the range 2-12 with a supporting electrolyte of Britton-Robinson Buffer/methanol. A single-electron oxidation of 8HQ leads, depending on pH, to the formation of various free radical species that combine to make dimers which, after being oxidized once more, give quinonoid-type compounds. Recording continuous cyclic voltammograms on the GCPE, pre-peaks appear as a consequence of dimer and quinonoid compounds formation. By applying Differential Pulse Voltammetry for 8HQ determination it was calculated that the limit of detection was 5.2x10(-8) mol/L. For more sensitive quantitative determination of the investigated substance Adsorptive Stripping Differential Pulse Voltammery can be used since it was found that after 300s-deposition time at 0.0 V vs. Saturated Calomel Electrode, a 2.1 times higher peak current than without deposition was obtained.",
publisher = "Electrochemical Science Group, Belgrade",
journal = "International Journal of Electrochemical Science",
title = "Voltammetric Behaviour and Determination of 8-Hydroxyquinoline Using a Glassy Carbon Paste Electrode and the Theoretical Study of its Electrochemical Oxidation Mechanism",
volume = "6",
number = "7",
pages = "2509-2525",
url = "https://hdl.handle.net/21.15107/rcub_cherry_1171"
}

Stevic, M. C., Ignjatovic, L. M., Ćirić-Marjanović, G., Stanišić, S. M., Stanković, D.,& Zima, J.. (2011). Voltammetric Behaviour and Determination of 8-Hydroxyquinoline Using a Glassy Carbon Paste Electrode and the Theoretical Study of its Electrochemical Oxidation Mechanism. in International Journal of Electrochemical Science
Electrochemical Science Group, Belgrade., 6(7), 2509-2525.
https://hdl.handle.net/21.15107/rcub_cherry_1171

Stevic MC, Ignjatovic LM, Ćirić-Marjanović G, Stanišić SM, Stanković D, Zima J. Voltammetric Behaviour and Determination of 8-Hydroxyquinoline Using a Glassy Carbon Paste Electrode and the Theoretical Study of its Electrochemical Oxidation Mechanism. in International Journal of Electrochemical Science. 2011;6(7):2509-2525.
https://hdl.handle.net/21.15107/rcub_cherry_1171 .

Stevic, Milica C., Ignjatovic, Ljubisa M., Ćirić-Marjanović, Gordana, Stanišić, Svetlana M., Stanković, Dalibor, Zima, Jiri, "Voltammetric Behaviour and Determination of 8-Hydroxyquinoline Using a Glassy Carbon Paste Electrode and the Theoretical Study of its Electrochemical Oxidation Mechanism" in International Journal of Electrochemical Science, 6, no. 7 (2011):2509-2525,
https://hdl.handle.net/21.15107/rcub_cherry_1171 .