The Application of Pulse Radiolysis to the Radiation Chemistry of Organic Dyes

Pulse radiolysis studies have shown that many organic dyes are highly reactive toward the products of water radiolysis. Dyes with quinonoid structures are reduced by e - aq to the semiquinone in encounter-limited reactions. Hydroxyl radicals react by oxidation and addition processes. In general, reductive bleaching takes place via semiquinone dismutation, while oxidative decoloration is a complex process involving several OH radicals. The complexing of dyes to high molecular weight substrates leads to a marked change of e - aq reactivity. Some oxidized dye intermediates and triplet states react with e - aq in chemiluminescent processes.