PULSE-RADIOLYSIS STUDIES ON (OH)-O-. RADICAL-INDUCED REACTIONS WITH SUBSTITUTED IODOBENZENES IN AQUEOUS-SOLUTIONS

The transient optical absorption band formed on pulse radiolysis of N2 O saturated neutral aqueous solution of substituted iodobenzenes (C(6) H(4)XI, X = H, Br, CH3, CF3) has been assigned to hydroxy cyclohexadie nyl radical, which absorbs in the region of 320-325 nm. In acidic solu tions, the hydroxyl radicals react to form two transient optical absor ption bands (lambda(max) = 310-320, 640-650 nm). The bands are assigne d to solute radical cation formed on H+-catalyzed dehydration of OH-ad duct. SO4.-, specific one-electron oxidant, is found to react with sub stituted iodobenzenes and form transient optical absorption bands, sim ilar to those formed on reaction of OH radicals in acidic solutions an d are assigned to solute radical cations. Copyright (C) 1997 Elsevier Science Ltd