Naslov
Cyclic voltammetry of the second order CE mechanism at the thin mercury film covered stationary planar electrode

Autori
Lovrić, Milivoj

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Book of abstracts / Ignacio González, Yunny Meas - Santiago de Querétaro : ISE Meksiko, 2013, 372-372

Skup
64th ISE meeting

Mjesto i datum
Querétaro, Meksiko, 08.09.2013. - 13.09.2013

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
cyclic voltammetry

Sažetak
A cyclic voltammogram (CV) of a certain metal-ligand complex ML depends on the stability constant and the dissociation rate constant of the complex. If the first constant is big and the second one is small, the complex is characterized as being stable and inert. In the opposite case the complex is labile. Generally, the formal potential of free metal ions Mn+ is higher than the half-wave potential of the complex. So, this electrode reaction is a CE mechanism, in which the dissociation of the complex is the preceding chemical reaction. This applies to both electro-inactive and electro-active complexes. In the later case two peaks appear in the cathodic branch of CV. In the anodic branch the current depends on the rate constant of complex formation and the concentration of free ligand Ln-. In the theory of CE mechanism it is usually assumed that chemical reaction is pseudo-first order. This is because in the experiment the concentration of one reactant can be adjusted to the great excess. However, in natural waters the concentrations of free ligands that form inert complexes with heavy metal ions are low and comparable with the total metal concentrations [1]. So, in pseudopolarography of metal complexes in traces, a single anodic stripping voltammetric cycle is the second order CE mechanism and the potential of the stripping peak should depend on the free ligand concentration. The purpose of this work is to investigate this hypothesis theoretically. ML Mn+ + Ln- ne- ↓ ↕ ± ne- Ln- + M(Hg) M(Hg) 1. G. Branica, M. Lovrić, Electrochim. Acta 42 (1997) 1247.

Izvorni jezik
Engleski

Znanstvena područja
Kemija

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