Photochemistry of Herbicide 2,4,5-Trichlorophenoxyacetic Acid in Aqueous Solutions in the Presence of Cyclodextrins
Photodegradation of herbicide 2,4,5-trichlorophenoxyacetic acid (2,4,5-Т) in aqueous solutions was studied by means of steady and nanosecond laser pulsed photolysis. It was shown that the primary photochemical act involves one- and two-photon ionization of the herbicide and the formation of the pair: hydrated electrone - cation radical. In oxygen-free solutions, hydrated electron disappears captured by the initial compound, while the cation radical gets hydrolyzed with water to form a long-living phenoxyl radical. We also studied the formation of complexes of 2,4,5-Т with β- and γ-cyclodextrins (2,4,5-Т-β(γ)-CD) and the effect of this process on the rate of steady photolysis of the herbicide.