Radiation chemistry of aqueous solutions of indole and its derivatives

Abstract

2,2-Bis-(3-indoly)indol-3(2H)-one and polymer are the major products derived by γ-irradiation of aqueous solutions of indole in argon, nitrous oxide, and oxygen. Small amounts of indoxyl, indoxyl red, indigo, and indirubin are also formed. Anthranilic acid appears to be produced in oxygen. A reaction pathway is discussed which accounts for the high G(–indole) values and the strong oxygen-dependence of these reactions. By use of pulse radiolysis, the absorption spectra were recorded for the transient hydroxyl radical adducts for indole, 2-, 3-, and 5-methylindole, 1,2- and 2,3-dimethylindole, and indoline. Rate constants for the reactions of hydroxyl radicals with a number of indoles were also measured.