Concerted effects in the reaction of •OH radicals with aromatics:: radiolytic oxidation of salicylic acid

Liquid chromatographic and capillary electrophoretic studies have been used to resolve the products produced in the radiolytic oxidation of salicylic acid in aqueous solution. These studies have shown that, as in the case of phenol, (OH)-O-. radicals preferentially add to the positions ortho and para to the OH substituent. However, in contrast to its reaction with phenol, addition at the ortho position is favored over addition at the para position. Because (OH)-O-. radical is a strong electrophile this difference suggests that the electron population at the ortho position in the salicylate anion is enhanced as a result of the hydrogen bonding in salicylic acid. (C) 2003 Elsevier Science Ltd. All rights reserved.