The influence of electron donating tendency on electrochemical oxidative behavior of hydroquinone: Experimental and theoretical investigations

The effect of electron donating tendency on the oxidative behavior of hydroquinone (HQ) on glassy carbon electrode (GCE) at room temperature was studied by means of cyclic voltammetry (CV), differential pulse voltammetry (DPV) and square wave voltammetry (SWV) techniques in aqueous acetonitrile solution. The oxidation potential of HQ shifted to increasingly more negative direction as electron donating tendency increased due to the presence of electron donating substituent's in the benzene ring of hydroquinone moiety. The study was further extended to observe their oxidative behavior with pH. The results showed that an easy oxidation of hydroquinone compounds with the rise in pH. In order to get a proper insight into to an oxidative behavior, the DFT quantum chemical calculation was performed for all hydroquinone molecules at the B3LYP level and by using 6-311++(d, p) basis set. The calculated quantum chemical and molecular reactivity parameters from optimized structures were good agreement with experimental findings.