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大量镇静催眠药的滥用给食品安全带来了严重负面影响,时刻威胁着人们的身体健康和生命安全。本文采用B3LYP/6-311+G**和MP2/6-311+G**方法,研究了苯二氮类药物替马西泮(TMZ)在中性和酸性甲醇溶液中的醇解反应机理。结果显示,无论从热力学还是动力学上分析,TMZ分子在中性和酸性甲醇溶液中N1—C2键断裂开环降解反应(Path 2和Path 3)都很难发生;而中性甲醇溶液中断裂C3—N4键醇解开环降解反应(Path 1)从动力学上分析是可行的,反应涉及1个或2个显性甲醇溶剂分子参与反应,通过质子的受体与给体的酸碱催化作用促进反应的进行,液相能垒(ΔG≠)分别为85.7k J/mol和81.6k J/mol,应该为TMZ分子在甲醇溶液中醇解的优势反应路径。研究结果与实验观察一致。
The abuse of a large number of sedatives and hypnotics has a serious negative impact on food safety, threatening people’s health and safety. In this paper, B3LYP / 6-311 + G ** and MP2 / 6-311 + G ** methods were used to study the alcoholysis mechanism of benzodiazepine TMZ in neutral and acidic methanolic solutions. The results showed that the open-loop degradation reaction of N1-C2 bond (Path 2 and Path 3) in both neutral and acidic methanol solution was very difficult for both TMZ molecules and neutral methanol solution, both in thermodynamics and kinetics. The kinetic analysis of the C3-N4 alcoholysis ring-opening degradation reaction (Path 1) is viable and the reaction involves one or two dominant methanol solvent molecules participating in the reaction that is facilitated by the acid-base catalysis of the proton acceptor with the donor The progress of the reaction, the liquid barrier (ΔG ≠) were 85.7k J / mol and 81.6k J / mol respectively, should be the dominant reaction pathway of TMZ molecules in methanol solution. The results are consistent with the experimental observations.