【作者】 邓嘉莉；

【导师】 廖显威；

【作者基本信息】 四川师范大学 ， 材料学， 2006， 硕士

【摘要】 磺酰脲类除草剂是当前研究的热点课题之一。鉴于研究体系比较大,本文用量子化学计算程序GAUSSIAN98中的从头算HF方法和密度泛函B3LYP方法,在6-31G(d)基组水平上,研究了磺酰脲类除草剂的谱学性质以及在不同酸碱性环境中水解反应的机理,同时对合成磺酰脲类除草剂时分离得到的植物激活剂苯并噻二唑(BTH)醇解和水解反应的机理也进行了理论研究。我们选取N-(4’-甲基嘧啶-2’-基)-N-取代基-2-硝基苯磺酰脲这一系列磺酰脲类除草剂,对其谱学性质进行理论计算。首先在HF/6-31G(d)基组水平上对其进行了结构优化,并通过振动分析确定其稳定构型,同时将理论计算所得的红外光谱峰值数据与实验所得的谱图加以比较,发现二者较为吻合;然后再用密度泛函B3LYP方法在相同基组水平上,用GAUSSIAN98程序提供的GIAO方法计算其核磁共振谱,计算结果与实验值之间的相对误差为0.9%—12%。磺酰脲类除草剂在环境中易于发生化学水解,且水解途径已有许多报道,且PH值是影响其水解的一个重要环境因子。我们在B3LYP/6-31G(d)//HF/6-31G(d)水平上对三种磺酰脲类除草剂的在酸性和中性条件下水解反应机理进行理论研究;同时在B3LYP/6-31G(d)//HF/6-31G(d)和B3LYP/6-31G(d)基组水平上对单嘧磺隆在碱性、中性和酸性条件下的水解机理进行理论研究。分别优化了各反应途径中反应物、过渡态、中间体以及产物的几何构型,并通过振动分析确定反应的过渡态和中间体的真实性。此外,还考虑了溶剂效应对水解反应的影响。计算结果表明:水解反应在酸性条件下易进行,在中性更多还原

【Abstract】 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更多还原