ISSN:
1040-0397
Keywords:
Benzoquinone
;
Naphthoquinone
;
Cyclic voltammetry
;
Hammett equation
;
Solvent dependence
;
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Potentials for the one-electron reduction of a series of substituted benzo- and naphthoquinones were measured in 10 aprotic solvents by cyclic voltammetry and used to construct Hammett plots. Hammett reaction constants, ρ, were determined in each solvent and used as indicators of the solvent-mediated stabilization of the charged radical-anion product of the reduction reaction. Correlations of Hammett ρ values with solvent parameters suggest that the Lewis acidity of the solvent, in particular the solvent's ability to donate a partially positive proton, is a consistent predictor of the degree of charge stabilization of the quinone radical anion. Other mechanisms of charge stabilization, including solvent-solute charge transfer complexes and dipole-dipole interactions involving the molecular dipole moment (or an induced dipole moment) of the solvent, were found to be inconsistent predictors of the effect of solvent on one-electron quinone reduction in aprotic media.
Additional Material:
4 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/elan.1140090810
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