Theoretical and Experimental Studies on the Positional Impact of Hydroxyl Groups on the Electrochemical Oxidative Behavior of Dihydroxybenzenes

The impact of the position of the electron-donating hydroxyl groups on the oxidative behavior of dihydroxybenzenes were determined by using cyclic voltammetry (CV), differential pulse voltammetry (DPV) and square wave voltammetry (SWV) on the glassy carbon electrode (GCE) in aqueous phosphate buffer solution having neutral pH at room temperature. A pair of hydroxyl groups positions determines the oxidation potential of dihydroxybenzenes and the oxidation potentials associated with the location of a pair of hydroxyl groups follow a sequence para to each other < ortho to each other < meta to each other inside the benzene ring of dihydroxylbenzene molecule. In order to understand an oxidative behavior, all molecules were subjected to DFT quantum chemical computation at the B3LYP level and by using the basis set 6-311++(d,p). The estimated molecular reactivity and quantum chemical values derived from optimized structures were in excellent concordance with experimental results.