Electrode Reactions of Aromatic Compounds in Strong Acid Solutions

Five distinct anodic chronopotentiometric waves are found for solutions of p-hydroquinone in 10-16F sulfuric acid. Reverse-current chronopotentiometry shows only two oxidation products although the reverse-current transition time equals one-third the anodic electrolysis time. All chemical species represented by these waves have been identified by means of UV and NMR spectra and comparison with electrochemical properties of compounds synthesized according to the literature. The pK2 of hydroquinone and several rates of sulfonation have been approximately evaluated. The electrochemical properties of durohydroquinone and ferrocene in sulfuric and other acid solutions were briefly investigated.