Evaluation of kinetic parameters and redox mechanism of quinoxaline at glassy carbon electrode
Određivanje kinetičkih parametara i ispitivanje redoks mehanizma hinoksalina na elektrodi od staklastog ugljenika
Apstrakt
The electrochemical behavior of a biologically important heterocyclic compound quinoxaline (QUI) was investigated by cyclic voltammetry (CV) in solutions of differing pH, using a glassy carbon electrode (GCE). The reduction of QUI occurs as a quasi-reversible reaction in acid medium, reaching reversibility in alkaline solutions. The kinetic parameters of the electrode process such as αnα, diffusion coefficient (D) and heterogeneous rate constant (ks), were evaluated and discussed. Redox mechanism of QUI was proposed on the basis of experimental results. Reduction process involves a transfer of two electrons and two protons at the pyrazine ring of QUI forming a dihydro-derivative. In acid solutions, the product of QUI reduction undergoes irreversible oxidation in a one-electron process. The electrode processes was found to be diffusion controlled.
Elektrohemijsko ponašanje biološki značajnog heterocikličnog jedinjenja hinoksalina (QUI) ispitivano je cikličnom voltametrijom (CV) u rastvorima različitih pH vrednosti, korišćenjem electrode odstaklastog ugljenika. Redukcija QUI u kiseloj sredini se odigrava kao kvazi-reverzibilna reakcija, koja u baznoj sredini postaje reverzibilna. Određeni su i razmatrani kinetički parametric elektrodnog procesa kao što su koeficijent αnα, difuzioni koeficijent (D) i konstanta brzine (ks). Na osnovu eksperimentalnih rezultata predložen je mehanizam elektrodne reakcije. U procesu redukcije adiraju se dva elektrona i dva protona na pirazinski prsten hinoksalina i nastaje njegov dihidro derivat. Proizvod redukcije hinoksalina u kiseloj sredini se dalje oksiduje. Ovaj process oksidacije je difuziono kontrolisan, ireverzibilan i odigrava se uz učešće jednog elektrona i jednog protona.
Ključne reči:
Quinoxaline / cyclic voltammetry / glassy carbon electrode / redox mechanism / kinetic parameters / Hinoksalin / ciklična voltametrija / elektroda od staklastog ugljenika / redoks mehanizam / kinetički parametriIzvor:
Facta universitatis - series: Physics, Chemistry and Technology, 2014, 12, 1, 55-63Izdavač:
- Univerzitet u Nišu, Niš
Finansiranje / projekti:
Institucija/grupa
PharmacyTY - JOUR AU - Aleksić, Mara AU - Pantić, Jelena AU - Kapetanović, Vera PY - 2014 UR - https://farfar.pharmacy.bg.ac.rs/handle/123456789/2295 AB - The electrochemical behavior of a biologically important heterocyclic compound quinoxaline (QUI) was investigated by cyclic voltammetry (CV) in solutions of differing pH, using a glassy carbon electrode (GCE). The reduction of QUI occurs as a quasi-reversible reaction in acid medium, reaching reversibility in alkaline solutions. The kinetic parameters of the electrode process such as αnα, diffusion coefficient (D) and heterogeneous rate constant (ks), were evaluated and discussed. Redox mechanism of QUI was proposed on the basis of experimental results. Reduction process involves a transfer of two electrons and two protons at the pyrazine ring of QUI forming a dihydro-derivative. In acid solutions, the product of QUI reduction undergoes irreversible oxidation in a one-electron process. The electrode processes was found to be diffusion controlled. AB - Elektrohemijsko ponašanje biološki značajnog heterocikličnog jedinjenja hinoksalina (QUI) ispitivano je cikličnom voltametrijom (CV) u rastvorima različitih pH vrednosti, korišćenjem electrode odstaklastog ugljenika. Redukcija QUI u kiseloj sredini se odigrava kao kvazi-reverzibilna reakcija, koja u baznoj sredini postaje reverzibilna. Određeni su i razmatrani kinetički parametric elektrodnog procesa kao što su koeficijent αnα, difuzioni koeficijent (D) i konstanta brzine (ks). Na osnovu eksperimentalnih rezultata predložen je mehanizam elektrodne reakcije. U procesu redukcije adiraju se dva elektrona i dva protona na pirazinski prsten hinoksalina i nastaje njegov dihidro derivat. Proizvod redukcije hinoksalina u kiseloj sredini se dalje oksiduje. Ovaj process oksidacije je difuziono kontrolisan, ireverzibilan i odigrava se uz učešće jednog elektrona i jednog protona. PB - Univerzitet u Nišu, Niš T2 - Facta universitatis - series: Physics, Chemistry and Technology T1 - Evaluation of kinetic parameters and redox mechanism of quinoxaline at glassy carbon electrode T1 - Određivanje kinetičkih parametara i ispitivanje redoks mehanizma hinoksalina na elektrodi od staklastog ugljenika VL - 12 IS - 1 SP - 55 EP - 63 DO - 10.2298/FUPCT1401055A ER -
@article{ author = "Aleksić, Mara and Pantić, Jelena and Kapetanović, Vera", year = "2014", abstract = "The electrochemical behavior of a biologically important heterocyclic compound quinoxaline (QUI) was investigated by cyclic voltammetry (CV) in solutions of differing pH, using a glassy carbon electrode (GCE). The reduction of QUI occurs as a quasi-reversible reaction in acid medium, reaching reversibility in alkaline solutions. The kinetic parameters of the electrode process such as αnα, diffusion coefficient (D) and heterogeneous rate constant (ks), were evaluated and discussed. Redox mechanism of QUI was proposed on the basis of experimental results. Reduction process involves a transfer of two electrons and two protons at the pyrazine ring of QUI forming a dihydro-derivative. In acid solutions, the product of QUI reduction undergoes irreversible oxidation in a one-electron process. The electrode processes was found to be diffusion controlled., Elektrohemijsko ponašanje biološki značajnog heterocikličnog jedinjenja hinoksalina (QUI) ispitivano je cikličnom voltametrijom (CV) u rastvorima različitih pH vrednosti, korišćenjem electrode odstaklastog ugljenika. Redukcija QUI u kiseloj sredini se odigrava kao kvazi-reverzibilna reakcija, koja u baznoj sredini postaje reverzibilna. Određeni su i razmatrani kinetički parametric elektrodnog procesa kao što su koeficijent αnα, difuzioni koeficijent (D) i konstanta brzine (ks). Na osnovu eksperimentalnih rezultata predložen je mehanizam elektrodne reakcije. U procesu redukcije adiraju se dva elektrona i dva protona na pirazinski prsten hinoksalina i nastaje njegov dihidro derivat. Proizvod redukcije hinoksalina u kiseloj sredini se dalje oksiduje. Ovaj process oksidacije je difuziono kontrolisan, ireverzibilan i odigrava se uz učešće jednog elektrona i jednog protona.", publisher = "Univerzitet u Nišu, Niš", journal = "Facta universitatis - series: Physics, Chemistry and Technology", title = "Evaluation of kinetic parameters and redox mechanism of quinoxaline at glassy carbon electrode, Određivanje kinetičkih parametara i ispitivanje redoks mehanizma hinoksalina na elektrodi od staklastog ugljenika", volume = "12", number = "1", pages = "55-63", doi = "10.2298/FUPCT1401055A" }
Aleksić, M., Pantić, J.,& Kapetanović, V.. (2014). Evaluation of kinetic parameters and redox mechanism of quinoxaline at glassy carbon electrode. in Facta universitatis - series: Physics, Chemistry and Technology Univerzitet u Nišu, Niš., 12(1), 55-63. https://doi.org/10.2298/FUPCT1401055A
Aleksić M, Pantić J, Kapetanović V. Evaluation of kinetic parameters and redox mechanism of quinoxaline at glassy carbon electrode. in Facta universitatis - series: Physics, Chemistry and Technology. 2014;12(1):55-63. doi:10.2298/FUPCT1401055A .
Aleksić, Mara, Pantić, Jelena, Kapetanović, Vera, "Evaluation of kinetic parameters and redox mechanism of quinoxaline at glassy carbon electrode" in Facta universitatis - series: Physics, Chemistry and Technology, 12, no. 1 (2014):55-63, https://doi.org/10.2298/FUPCT1401055A . .