Theoretical Study On The Spectrum Property And The Hydrolysis Mechanism Of Sulfonylurea Herbicides

Sulfonylurea herbicides have become one of fascinating areas of researches in recent years. In the paper, the spectrum property and the hydrolysis mechanism of sulfonylurea herbicides in different acidity conditions have been studied by HF method and B3LYP method at the level of 6-31G(d) of the quantum-chemical calculation program GAUSSIAN98.Besidese, the alcoholysis and hydrolysis reaction mechanisms and kinetics of benzothiadiazole which was separated from sulfonylurea herbicides were studied in the paper.We chose a serial of sulfonylurea herbicides N-(4'-methyl pyrimidine-2'-radical)-N-substitude-2-nitrobenzene sulfonylurea to study their spectrum properties. Firstly the geometric configuration have been optimized and vibrational analysis has been preformed to confirm at the level of HF/6-31G(d). The IR spectrum data of compounds are essentially consistent with experimental values. Secondly, the NMR spectrum have been calculated by GIAO method at the level of B3LYP/6-31G(d) and the relative error is 0.9%—12%.The chemical hydrolysis of sulfonylurea herbicides undergoes easily in the environment, and the hydrolysis paths have been repoted largely. The pH is one of the most important influencing factor. The hydrolysis mechanisms of three sulfonylurea herbicides in acidic and neutral conditions have been studied at the level of...