特丁基对苯二酚的密度泛函理论计算及红外光谱分析  

Density functional theory calculation and infrared spectral analysis of tert-butylhydroquinone

作　　者：张竺立 逯美红 高鹏慧 王志军 ZHANG Zhu-Li;LU Mei-Hong;GAO Peng-Hui;WANG Zhi-Jun(Department of Physics,Changzhi University,Changzhi 046011,China)

机构地区：[1]长治学院物理系,山西046011

出　　处：《原子与分子物理学报》2025年第2期33-40,共8页Journal of Atomic and Molecular Physics

基　　金：山西省高等学校教学改革创新项目(J20221074);山西省高等院校科技开发项目(2020L0622,2021L517)。

摘　　要：特丁基对苯二酚(Tert-butylhydroquinone,TBHQ)是一种常见的新型合成抗氧化剂,可以被用来延长食物的保质期,但过量使用会危害健康.目前的检测方法中振动光谱技术具有无损快速的优点,因此采用密度泛内涵理论与振动光谱技术相结合的研究方法可以为TBHQ的检测提供理论依据和参考.理论上,基于密度泛函理论DFT(RB3LYP)的三参数混合方法以及6-31G(d,p)和6-311++G(d,p)基组对TBHQ分子空间结构进行优化,给出了TBHQ的键长、键角和二面角等空间结构参数值,确定该分子空间构型为非平面结构.采Multiwfn和VMD程序计算并分析TBHQ分子的前线轨道和静电势,预测了该分子的反应活性位点,得出苯环和酚羟基的反应活性最强.TBHQ分子静电势最小值位于酚羟基的O原子附近,最大值位于酚羟基的H原子附近.亲电试剂和亲核试剂通过静电作用将与酚羟基发生作用.实验上,利用傅里叶变换红外光谱仪对TBHQ分子进行检测,然后在优化结构的基础上计算TBHQ分子的理论红外光谱.将得到的理论红外光谱与实验采集的数据进行对比,呈现出较好的一致性.理论计算结果可见TBHQ分子在0-2000 cm^(-1)和2000-4000 cm^(-1)范围两个区域有明显的红外活性,前者主要是指纹区的振动,后者是官能团的振动;从计算结果还可以明显看出943.9 cm^(-1)为叔丁基C-C伸缩振动以及C-H面外弯曲振动.由于-OH极性基团的取代,在1278.3 cm^(-1)、1307.1 cm^(-1)、1439.1 cm^(-1)、1587.5 cm^(-1)处出现了较强的骨架振动吸收峰和酚羟基-OH面内弯曲振动模式.这些均可作为TBHQ分子的特征峰.这为理解TBHQ的作用机理提供了重要信息,也为食品添加剂的检测研究提供了理论依据.Tert-butylhydroquinone(TBHQ)is a common new synthetic antioxidant that can be used to extend the shelf life of foods,but excessive use can be harmful to health.The vibration spectrum technology has the advantages of non-destructive and fast detection methods,so the research method combining the density universal connotation theory and vibration spectrum technology can provide theoretical basis and reference for the detection of TBHQ.In theory,the molecular structure of TBHQ was optimized based on the three-parameter mixing method of density functional theory DFT(RB3LYP)and the 6-31G(d,p)and 6-311++G(d,p)basis sets.The spatial structure parameters of TBHQ,such as bond length,bond angle and dihedral angle,were given,and the spatial configuration of TBHQ was determined to be non-planar.Multiwfn and VMD programs were used to calculate and analyze the front orbital and electrostatic potential of TBHQ molecule.The reactive sites of TBHQ molecule were predicted.It was concluded that benzene ring and phenolic hydroxyl group have the strongest reactive activity.The minimum electrostatic potential of TBHQ molecule is near the O atom of the phenol hydroxyl group,and the maximum is near the H atom of the phenol hydroxyl group.Electrophiles and nucleophiles will interact with phenolic hydroxyl groups by electrostatic interaction.In the experiment,the TBHQ molecule was detected by Fourier transform infrared spectrometer,and then the theoretical infrared spectrum of TBHQ molecule was calculated based on the optimization of the structure.The theoretical infrared spectra obtained are compared with the experimental data,showing a good agreement.The theoretical calculation results show that TBHQ molecule has obvious IR activity in the range of 0-2000 cm^(-1) and 2000-4000 cm^(-1).The former is mainly the vibration of fingerprint region,and the latter is the vibration of functional group.It is also obvious from the calculation results that 943.9 cm^(-1) is tert-butyl C-C stretching vibration and C-H out-of-plane bending vibration.Du

关 键 词：特丁基对苯二酚 红外光谱 密度泛函理论 静电势 前线分子轨道 

分 类 号：O657.33[理学—分析化学]