Rate Coefficient Measurements of Hydrated Electrons and Hydroxyl Radicals with Chlorinated Ethanes in Aqueous Solutions

• Published in: The journal of physical chemistry. A, Molecules, spectroscopy, kinetics, environment, & general theory Molecules, spectroscopy, kinetics, environment, & general theory, 2005-09, Vol.109 (34), p.7751-7756
• Main Authors: Milosavljevic, Bratoljub H, LaVerne, Jay A, Pimblott, Simon M
• Format: Article
• Language: English
• ISSN: 1089-5639; 1520-5215
• DOI: 10.1021/jp051249b

Rate coefficients for the reactions of hydrated electrons and hydroxyl radicals with various chloroethanes were determined in aqueous solutions using pulse radiolysis techniques. The rate coefficients for the hydrated electron increase from 0.17 × 109 to 16.3 × 109 M-1 s-1 with increasing number of chlorine atoms from monochloroethane to hexachloroethane. Very little difference in rates is found between the isomers. Rate coefficients for the OH radicals range from 1 to 5 x 108 M-1s-1 and have very little variation with the number of chlorine atoms except when no H atom is available on a carbon atom. The use of competition kinetics with low concentrations of SCN- as a reference is reviewed and suitable model simulations proposed. Possible explanations for the discrepancies between the previously published rate coefficients and the present values are offered.