Ionizing radiation induced reactions of 2,6-dichloroaniline in dilute aqueous solution

In pulse radiolysis investigations the hydroxyl radical formed in water radiolysis reacts with 2,6-dichloroaniline in radical addition to the ring forming hydroxy-cyclohexadienyl radical and also in hydrogen atom abstraction from the amino group resulting in anilino radical. The hydroxy-cyclohexadienyl radical in the absence of dissolved O2 partly transforms to anilino radical, when dissolved oxygen is present the radical transforms to peroxy radical. According to chemical oxygen demand measurements the reaction of one OH radical induces the incorporation of 0.6 O2 into the products. It is a typical value for chlorine atom substituted aromatic molecules, and smaller than found for molecules without chlorine atom (1.0–2.0).

► In reaction of OH with 2,6-dichloroaniline hydroxy-cyclohexadienyl and anilino radicals form.
► Reaction of one OH induces incorporation of ∼0.6 O2 molecule into the products.
► At 10−4 mmol dm−3 concentration ∼5 kGy dose is needed for discoloration.