采用傅里叶变换红外光谱技术(FTIR)和密度泛函理论(DFT)研究了常温环境下生物素和吡哆素两种维生素的太赫兹光谱特性, 测量和理论分析的结果显示在太赫兹范围内, 维生素分子内存在较强的分子内和分子间相互作用力。 实验中样品与聚乙烯粉末按照不同的比例进行混合, 结果表明样品所含比例越大, 其在高频段的吸收谱重复性越差, 这证实了维生素样品的吸收率随着频率升高逐渐增加。 采用密度泛函理论(DFT)分析了生物素和吡哆素的单分子、 二分子、 三分子、 以及晶胞分子的太赫兹光谱, 指证了对应的吸收峰, 阐明了分子内和分子间相互作用力的振动和转动机制。

Terahertz (THz) absorption spectra of the biotin and pyridoxine were studied using Fourier transform infrared spectroscopy (FTIR) at room temperature. These spectra exhibit enhanced absorption in THz range because of strong intramolecular and intermolecular vibration modes. In the experiment, the samples were mixed with high density polyethylene powder, which was used as spectrophotometric grid. The absorption spectra show worse consistency at higher frequencies for the high ratio of the samples to polyethylene. It indicates that the absorbance of the biotin and pyridoxine increased with frequency. Molecular vibrational spectral calculations based on density functional theory (DFT) show strong correlation with the experiment. We investigated the absorption spectra of isolated molecules (single molecule, two molecules, three molecules) and unit cell of crystal to clarify the mechanism of the spectra change due to intramolecular and intermolecular vibration and rotation.