有机磷类农药的密度泛函理论计算及拉曼光谱研究

发布时间：2018-08-16 12:19

【摘要】：有机磷类农药常被用于防治植物病、虫、害,但对人、畜的急性毒性很强,能抑制乙酰胆碱酯酶。三种有机磷类农药分子(乐果、敌百虫和伏杀硫磷)的分子构型用GaussView3.07构造,理论计算采用密度泛函理论(density functional theory,DFT)的B3LYP/6-31G(d,p)基组,并将实验拉曼光谱、理论计算拉曼光谱和表面增强拉曼光谱(SERS)进行比较。结果表明,三种有机磷类农药分子的实验值与理论方法计算值具有很好的匹配性,并对三种有机磷类农药分子(乐果、敌百虫和伏杀硫磷)在400~1 800cm-1范围内的振动频率进行了全面地归属,找到了这三种有机磷类农药的特征峰。有机磷类农药分子的振动峰中会出现相近的波数,P—O基团引起的波数在1 140~1 320cm-1之间,P迨S的伸缩振动的谱带在535~750cm-1范围,含有P—O—C基团的有机磷类农药在920~1 088cm-1范围产生一个谱带。对比分析三种农药的实验拉曼光谱和表面增强拉曼光谱,找到了这三种有机磷农药分子各自主要的表面增强拉曼特征峰,这些表明利用SERS技术可以用来鉴定有机磷农药。研究结果为有机磷农药的定性定量分析提供了理论基础。
[Abstract]:Organophosphorus pesticides are often used to control plant diseases, insects and pests, but the acute toxicity of organophosphorus pesticides to humans and animals is very strong, which can inhibit acetylcholinesterase. The molecular configurations of three organophosphorus pesticides (dimethoate, trichlorfon and thiophos) were constructed by GaussView3.07. The B3LYP/6-31G (dapp) basis set of the density functional theory (density functional) was calculated by using the density functional theory (DFT). The theoretical calculations of Raman spectra and surface-enhanced Raman spectra (SERS) were compared. The results show that the experimental values of the three organophosphorus pesticide molecules are in good agreement with the calculated values of the theoretical method, and the three organophosphorus pesticides molecules (dimethoate, etc.) The vibrational frequencies of trichlorfon and fenthion were assigned in the range of 400 ~ 1 800cm-1, and the characteristic peaks of these three organophosphorus pesticides were found. In the vibrational peak of organophosphorus pesticides, there will be similar wave-number P-O groups in the range of 1 140 ~ 1 320cm-1. The spectrum bands of the stretching vibration of S are in the range of 535~750cm-1. Organophosphorus pesticides containing P-O-C group produce a band in the range of 920 088cm-1. The experimental Raman spectra and surface-enhanced Raman spectra of the three pesticides were compared and the main surface-enhanced Raman peaks of the three organophosphorus pesticide molecules were found which indicated that the SERS technique could be used to identify the organophosphorus pesticides. The results provide a theoretical basis for qualitative and quantitative analysis of organophosphorus pesticides.
【作者单位】：江西农业大学工学院生物光电及应用重点实验室;江苏大学现代农业装备与技术教育部重点实验室;
【基金】：国家自然科学基金项目(31271612)资助
【分类号】：TQ450.7;O657.37

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