| Cite this article as: Zhang Zhu-Li,Lu Mei-Hong,Gao Peng-Hui,Wang Zhi-Jun. Density functional theory calculation and infrared spectral analysis of tert-butylhydroquinone [J]. J. At. Mol. Phys.(原子与分子物理学报), 2025, 42: 021005 (in Chinese) |
| Density functional theory calculation and infrared spectral analysis of tert-butylhydroquinone |
| Hits 172 Download times 262 Received:June 11, 2023 Revised:July 01, 2023 |
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| DOI
10.19855/j.1000-0364.2025.021005 |
| Key Words
tert-butylhydroquinone Infrared spectrum Density functional theory Electrostatic potential Frontier molecular orbital |
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| Abstract
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| 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 0-2000cm-1 and 2000-4000cm-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 943.9cm-1 is tert-butyl C-C stretching vibration and C-H out-of-plane bending vibration. Due to the substitution of polar groups of -OH, strong skeleton vibration absorption peaks and in-plane bending vibration modes of phenol hydroxy-OH appear at 1278.3cm-1, 1307.1cm-1, 1439.1cm-1 and 1587.5cm-1. These can be used as the characteristic peaks of TBHQ molecule. This provides important information for understanding the action mechanism of TBHQ, and also provides a theoretical basis for the detection of food additives. |
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