Electroreduction of Some Substituted Hydrazones on Platinum Electrode in Dimethylformamide

Ayça Demirel Özel,1,* Zehra Durmuş,1 Ibrahim Yılmaz,2 Alaaddin Çukurovalı3 and Esma Kılıç1

1 Department of Chemistry, Faculty of Science, Ankara University, Ankara, Turkey
2 Faculty of Science, Karamanoğlu Mehmetbey University, Karaman
3 Department of Chemistry, Faculty of Arts and Sciences, Fırat University, Elazığ, Turkey
* Corresponding author: E-mail: aycaozel@gmail.com;
Tel.: +90 312 2126720/1269; Fax: +90 312 2232395

The electrochemical behaviors of 4-(1-phenyl-1-methylcyclobutane-3-yl)-2-(2-hydroxybenzylidenehydrazino)thiazole (I), 4-(1-p-xylene-1-methylcyclobutane-3-yl)-2-(2- hydroxybenzylidenehydrazino)thiazole (II), 4-(1-mesytylene-1- methylcyclobutane-3-yl)-2-(2- hydroxybenzylidenehydrazino)thiazole (III), 4-(1-phenyl-1-methylcyclobutane-3-yl)-2- (2-hydroxy-5-bromobenzylidenehydrazino)thiazole (IV), 4-(1-phenyl-1-1-methylcyclobutane-3-yl)-2-(2-hydroxy-3- metoxybenzylidenehydrazino)thiazole (V), 4-(1-phenyl-1-methylcyclobutane-3-yl)-2-(2,4-dihydroxybenzylidenehydrazino) thiazole (VI) were investigated by cyclic voltammetry (CV), controlled potential electrolysis, and chronoamperometry (CA) techniques in the presence of 0.10 M tetrabutylammonium tetrafluoroborate (TBATFB) in dimethylformamide (DMF) at platinum electrode. Hydrazones display two cathodic peaks at about –1.60 V and –2.20 V. Diffusion coefficients and the number of electrons transferred were calculated by using an ultramicro electrode (UME). Standard heterogeneous rate constants for reduction were calculated by Klingler-Kochi technique. Electrochemical reduction mechanism of these hydrazones was also proposed that hydrazones seemed to follow an ECEC mechanism corresponding with irreversible electron transfer steps. Due to the widespread use of hydrazones in drug production, the redox properties of these hydrazones are thought to be useful for enlightening the metabolic fate of the drug containing hydrazones or its in vivo redox properties or pharmacological activity.

Keywords: Hydrazones, thiazoles, electrochemical behavior, voltammetry, dimethylformamide