Pulse radiolysis and chemical analysis of azo dyes in aqueous solution I. p-phenylazoaniline

The spectroscopic and kinetic characteristics of transients produced by one electron reduced and by one electron oxidized p-phenylaniline (PAA) at var ious pHs are reported. In the presence of air at pH 4-10 the transient spec tra are very similar to those observed by the OH-attack on PAA at pH=4. Thi s indicates that in all cases the OH-radicals are the major reactive specie s towards PAA in addition to the specific e(aq)(-) reaction on the azo grou p. Steady-state radiolysis experiments were also performed under various co nditions and the major radiolytic products were identified by HPLC. (C) 200 0 Elsevier Science Ltd. All rights reserved.