Study on THz Spectra and Vibrational Modes of Benzoic Acid and Sodium Benzoate
ZHENG Zhuan-ping, FAN Wen-hui*, YAN Hui, LIU Jia, XU Li-min
State Key Laboratory of Transient Optics and Photonics, Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi’an 710119, China
Abstract：Terahertz time-domain spectroscopy was employed to measure the terahertz absorption spectra of benzoic acid and sodium benzoate at room temperature. The origins of the measured features of benzoic acid were summarized based on previous study. Density functional theory was used to compute and analyze the molecular structure and vibrational modes of sodium benzoate in monomer. Based on the obtained results, the authors found that the THz spectral features can be used to distinguish benzoic acid and sodium benzoate totally; the essential reason for the THz spectral difference between benzoic acid and sodium benzoate is that the electrovalent bond of sodium benzoate affects the values of covalent bond lengths and bond angles, as well as the molecular interactions and arrangement in unit cell; the measured features of benzoic acid and sodium benzoate come from the collective vibrations except the peaks located at 107 cm-1 of benzoic acid and 54 cm-1 of sodium benzoate.
Key words：Terahertz time-domain spectroscopy (THz-TDS);Density functional theory (DFT);Benzoic acid;Sodium benzoate
郑转平，范文慧*，闫 慧，刘 佳，徐利民 . 苯甲酸与苯甲酸钠的太赫兹光谱和振动模式分析 [J]. 光谱学与光谱分析, 2013, 33(03): 582-585.
ZHENG Zhuan-ping, FAN Wen-hui*, YAN Hui, LIU Jia, XU Li-min . Study on THz Spectra and Vibrational Modes of Benzoic Acid and Sodium Benzoate . SPECTROSCOPY AND SPECTRAL ANALYSIS, 2013, 33(03): 582-585.
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