RATE CONSTANTS FOR SOME REACTIONS OF OH RADICAL IN IRRADIATED AQUEOUS SOLUTIONS AT DIFFERENT PH VALUES

Air-saturated aqueous solutions of Safranine T,irradiated with 60Coγ-rays,have been used as a reference system for the determination, by the competition kinetics techniques, of relative rate constants for the reactions of the OH radical with HSO4-, Br- and I- ions at different pH values in the range 5.5 to0.4.Using benzene as a primary reference solute, the reaction OH+Safranine has T been found to be diffusion controlled and its rate constant has been established. Absolute rate constants calculated for the rest of the reactions agree with certain available literature values. A pH dependence of kOH+Safranme T observed has been attributed to protonation of the dye molecule at pH below 2, while the pH dependence of kOH+Bi- has also been confirmed. © 1969, Walter de Gruyter. All rights reserved.