کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
6452423 | 1417597 | 2017 | 9 صفحه PDF | دانلود رایگان |
- OH/eaqâ exhibits appreciable reactivity towards the insecticide thiacloprid.
- The majority of OH attack the key cyanoiminothiazolidine pharmacophore.
- α-aminoalkyl, N-centred, α-(alkylthio)alkyl and >S-OH radicals form on this moiety.
- One-electron reduction occurs at the pyridyl function yielding pyridinyl radicals.
- Destruction of pharmacologically important substructures is anticipated.
Free radical induced oxidation/reduction mechanisms of the hazardous water contaminant thiacloprid have been unravelled using pulse radiolysis techniques involving transient spectral analysis and redox titration experiments. The OH-induced oxidation of thiacloprid proceeds with appreciable rate, the reaction rate constant has been determined to be kOH = 4.8 Ã 109 molâ1 L sâ1. The OH attack leaves behind a rather complex free radical system consisting of â¼9% α-aminoalkyl radicals, â¼31% aminyl + aminium nitrogen centred radicals, â¼46% radicals at the sulfur and â¼14% hydroxycyclohexadienyl radical of the pyridyl moiety. Since â¼86% of radicals are formed on the key cyanoiminothiazolidine pharmacophore, OH is anticipated to be an appropriate candidate for inactivation of this biologically active pollutant. The one-electron reduction exerted by eaqâ occurs at a diffusion controlled rate. As a result of the eaqâ attack pyridinyl radical forms that takes part in subsequent protonation and dechlorination processes. The course of events is anticipated to lead to the destruction of another important part of the molecule in respect to insecticidal activity.
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Journal: Journal of Photochemistry and Photobiology A: Chemistry - Volume 343, 15 June 2017, Pages 17-25