Acid/base and hydrogen bonding effects on the proton-coupled electron transfer of quinones and hydroquinones in acetonitrile: Mechanistic investigation by voltammetry, 1H NMR and computation

Towards a Further Generation of High‐Energy Carbon‐Based Capacitors by Using Redox‐Active Electrolytes

“…The electrochemical reactions of quinoid compounds have been widely characterized at various electrodes, such as platinum, [10] gold, [11] and glassy carbon, [12] and in different media. [13][14][15] It is generally accepted that the redox chemistry of these compounds involves elementary steps comprising 2 H + and 2 e À for the quinone/hydroquinone reaction.…”

Anthraquinones As Pharmacological Tools and Drugs

“…219,221,[227][228][229] It should, however, be emphasized that the redox potential of quinones is pH dependent and highly influenced by the substitution pattern. 24,[229][230][231][232][233] The exact role of semiquinone in the formation of hydroxyl radicals and in cytotoxicity has been demonstrated in one study describing the enzymatic reduction of anthraquinone-2-sulfonate. 234 In a system containing NADPH-cytochrome P450 reductase, anthraquinone-2-sulfonate, NADPH, and traces of a heavy metal, semiquinone formed from one-electron reduction of anthraquinone-2-sulfonate was found to reduce the metal, for example, Fe 3+ to Fe 2+ , which then decomposes H 2 O 2, generated from a superoxide radical anion, through catalytic reduction into a hydroxyl radical.…”

Electrochemical Capacitors Based on Carbon Electrodes in Aqueous Electrolytes

“…Because of the development of the quinone/hydroquinone redox reaction on the carbon surface [115], the positive electrode exhibits a battery-like behavior, whereas the negative electrode remains of the EDL type. A tremendous capacitance value of 5017 F g −1 was recorded by cyclic voltammetry (at 1 mV s −1 ) for the positive electrode, as compared to 477 F g −1 for the negative one.…”