JOURNAL of the Tunisian Chemical Society

The electrochemical behavior of 4-chloroguaiacol (4-CG) on pre-treated gold electrodes was investigated by cyclic voltammetry. Electrolytic solutions are water-acetone mixtures with 0 - 40 vol % acetone and containing 0.5 mol dm^-3 of sulfuric acid. The cyclic voltammogram shows one irreversible anodic peak and a pre-peak. The effect of experimental conditions on the ratio of these two peaks was examined. The proposed mechanism is based on the hypothesis of a two-electron discharge leading to three phenoxonium cation mesomers, which hydrolysis would lead to 4-chlorocatechol, methoxyhydroquinone and 5-chloro-3-methoxycatechol. The process of electrode passivation during 4-CG electrooxidation at the gold electrode was studied with respect to 4-CG concentration and for different conditions of the electrode pre-treatment. Preliminary study shows that 4-CG is quantitatively oxidized by electrolysis at PbO₂ anode in sulfuric acid aqueous solutions (pH = 2). Maleic, fumaric, formic and oxalic acids are among the formed products.

Y. Samet, R. Abdelhedi, A. Savall

4-chloroguaiacol, electrochemical oxidation, gold electrode, PbO₂ anode

Pages 1615-1624