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Photodegradation of Pesticides: Photolysis of 2-Mercaptobnzothiaozle and 2-Mercaptobenzimidazole

1985; Elsevier BV; Volume: 23; Issue: 11 Linguagem: Inglês

10.3987/r-1985-11-2917

1881-0942

Abdou O. Abdelhamid, Cyril P�k�yi,

Inorganic and Organometallic Chemistry

Upon their application, organic pesticides are usually exposed to light under a variety of conditions.After some time, most of them undergo photodecomposition, especially in solution.and give degradation products with properties different from those of the original compounds.Thus, studies of the photochemistry of pesticides under controlled laboratory conditions are of interest.As an example, model studies of the photodegradation of 2arercaptobenzothiazole (1, used as fungicide, bactericide, and , % disinfectant) and of the n-iaoeleetronic, biologically active 2-mercaptobenzimidazole (i) have been carried out.Uv irradiation of 1 in the presence of air oxygen in a pyre* flask * yielded his-(2-benzathiazolyl) disulfide when dry benzene or toluene were used as the reaction mdium.With solutions of I in " methanol, ethanol, or acetonitrile, the corresponding bis-(2-benzothiazolyl) disulfone was obtained as the intermediate.with benzothiamle sulfate as the final reaction product.Similarly, photolysis of 2 in methanol, ethanol, or acetonitrile " yielded bis-(2-benzimidazolyl) disulfone and benzimidarole sulfate as the final product.