The reduction potential for the'COT radical anion has been determined by equilibration of formate with sulfhydryl radicals of@-mercaptoethanol, penicillamine, and lipamide in aqueous solutions at pH 3-6. The reaction'CO,+ e-+ H+= HCOT yields the value Eo9= 1.49 V with an uncertainty of i0. 06 V. On the basis of this value and the known free energies of C02 (aq) and HC0,-(aq), EO19 for C02+ e-= TO2-was found to be-1.85 V.
[Kessler, David P.; Ghebre-Sellassie, Isaac; Knevel, Adelbert M.; Hem, Stanley L. Journal of the Chemical Society, Perkin Transactions 2: Physical Organic Chemistry (1972-1999), 1981 , p. 1247 - 1251]
