Paper
Mechanism of the Electrochemical Reduction of 3,5-Di-tert-butyl-1,2-benzoquinone. Evidence for a Concerted Electron and Proton Transfer Reaction Involving a Hydrogen-Bonded Complex as Reactant†
Published Jun 23, 2001 · Mark W. Lehmann and, Dennis H. Evans
Journal of Physical Chemistry B
56
Citations
0
Influential Citations
Abstract
The electrochemical reduction of 3,5-di-tert-butyl-1,2-benzoquinone (Q) has been investigated in acetonitrile with glassy carbon electrodes in the absence and presence of the hydrogen-bond and proton donating additives, water and 2,2,2-trifluoroethanol (TFE). Under nominally anhydrous conditions, the first step of the reduction is the reversible formation of the persistent radical anion, Q-·. However, in long-term experiments such as controlled potential electrolysis, the radical anion disappears slowly with the rate being enhanced by the addition of water. This reaction was shown to be the water-promoted disproportionation of the radical anion giving neutral quinone (Q), the protonated dianion (HQ-), and hydroxide. This reaction is too slow to affect the voltammetric experiments. Variation of the standard potential for the first step with the addition of water was explained by the formation of hydrogen-bonded complexes between Q-· and water. The 1:1 complex, (Q-·)(H2O), is proposed to be the reactant in ...
The electrochemical reduction of 3,5-di-tert-butyl-1,2-benzoquinone involves a concerted electron and proton transfer reaction involving a hydrogen-bonded complex as reactant.
Full text analysis coming soon...