engleski

THE EFFECT OF INERT ELECTROLYTE ON OXIDO- REDUCTION PROPERTIES OF ZINC COMPLEX WITH DIPICOLINIC ACID HYDRAZIDE DERIVATIVE

Hydrazide derivatives of dipicolinic acid contain a large number of potential donor atoms which are capable of coordinating to the metal center in diverse arrangements [1]. Previous studies have shown that Zn dipicolinic acid complexes exhibit effective insulin-mimetic activity [2]. The main goal of this study was to examine the effect of three different inert electrolytes (LiCl, KNO3 and KCl) on the oxido- reduction properties of zinc complex with dipicolinic acid hydrazide derivative (Zn2L2), with two voltammetric techniques (cyclic and differential pulse voltammetry). The measurements were performed using the three electrode system which included a working glassy carbon electrode, counter electrode platinum wire and Ag/AgCl reference electrode. Before each measurement, the surface of the working electrode was polished with α-Al2O3 suspension. The system was purged with high purity argon Ar 5 (φAr = 99.999 %) to accomplish the inert atmosphere. Cyclic voltammograms of the studied zinc complex showed one oxidation peak in all three investigated electrolytes indicating an irreversible oxidation process. The oxidation peak current increased with the increase of scan rate and the highest oxidation peak current was observed for KCl. Differential pulse voltammograms also revealed one oxidation peak, in all three electrolytes. The oxidation peak decreased with successive scans, which confirmes adsorption of the zinc complex oxidation product on the surface of the glassy carbon electrode.

inert electrolyte, voltammetry, metal complexes

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