ISSN:
1040-0397
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Anodic reactions of two stable nitroxide radicals, 4-hydroxyimino-2,2,6,6-tetramethylpiperidine-1-oxyl (1) and 4-[(aminocarbonyl)-hydrazone]-2.2,6,6-tetramethylpiperidine-1-oxyl (2) were studied in aqueous solutions over the pH range 5.33-8.04 using the cyclic voltammetry technique. They show one-electron oxidation processes of reversible and quasi-reversible natures, depending on scan rate conditions at pH 5.33. The diffusion coefficients, the observed standard rate constants (ks), and the oxidation potentials for the redox reaction nitroxyl radical ⇌ oxoammonium salt have been determined. A one-electron transfer process, followed by an irreversible chemical reaction, is observed at pH ≥ 5.71, and the rates of this reaction at pH 5.71 and 6.71 are 0.11 and 0.080 s-1, respectively. Controlled-potential electrolysis at 0.8 V (vs. SCE) confirms a one-electron electrode reaction.
Additional Material:
4 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/elan.1140030316
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