利用太赫兹时域光谱(THz-TDS)技术和密度泛函理论(DFT)模拟相结合的方法,研究了阿拉伯糖手性异构体在太赫兹波段的光谱特性。THz-TDS测试发现L-,D-和DL-阿拉伯糖在0.4~1.8 THz有效频谱范围内表现出各自的特征吸收峰,且三者的吸收谱有明显差异。运用Gaussian09软件中密度泛函理论计算了L-,D-和DL-阿拉伯糖的吸收谱,并对其特征吸收峰进行了指认。研究结果表明:理论与实验得到的特征吸收峰的一些峰位有一定程度的吻合,太赫兹时域光谱能够鉴别阿拉伯糖手性异构体和它们的外消旋化合物,即利用太赫兹时域光谱能够揭示手性异构体结构差异与其太赫兹光谱之间的相关性,这为研究手性异构体和它们的外消旋体的检测和分析提供了新方法。

Terahertz time-domain spectroscopy (THz-TDS) and density functional theory (DFT) simulation are adopted to study the spectral properties of arabinose chiral isomers in the terahertz band. It is found that L-, D- and DL-arabinose show their characteristic absorption peaks in the effective spectrum range of 0.4-1.8 THz, and the absorption spectra of the three arabinoses are obviously different. The absorption spectra of L-, D- and DL-arabinose are calculated with the use of density functional theory in Gaussian09 software, and the characteristic absorption peaks are identified. The results show that the theoretical simulation is consistent with the experimental result and terahertz time-domain spectra can be used to identify the arabinose chiral isomers and their racemic compounds. This indicates that the correlation between chiral isomers and their terahertz spectra can be revealed by terahertz time-domain spectra. So terahertz time-domain spectra provide a new method for studying the detection and analysis of chiral isomers and their racemic compounds.