利用太赫兹时域光谱(THz-TDS)技术对手性异构体D-酒石酸和外消旋体DL-酒石酸进行测量, 得到两种异构体在THz波段的特征吸收峰, 发现它们吸收光谱之间的差异十分明显。利用量子化学软件中密度泛函理论对酒石酸两种异构体的单分子和晶胞进行理论模拟计算, 得到酒石酸两种异构体模拟结果的吸收峰, 并对吸收峰进行指认。实验所测的结果与理论计算的结果对应的吸收峰位置基本吻合, 通过对吸收峰的指认, 深入分析出该类物质的异构体在THz波段吸收峰形成的机理。结果表明, THz-TDS技术可以鉴别酒石酸手性异构体及其外消旋体之间的微小差异。

The chiral isomers D- and DL-tartaric acid are measured by terahertz time-domain spectroscopy (THz-TDS), and characteristic absorption peaks of two isomers in the range of THz are obtained. The differences between them are obvious. The single molecular and unit cell of two isomers of tartaric acid are calculated by density functional theory in quantum chemistry software. The absorption peaks of two isomers of tartaric acid are obtained and identified. The results of the experiment are basically consistent with the calculated results at absorption peak. Through the identification of the absorption peak, the formation mechanism of the absorption peaks of such isomers in the range of THz is deeply analyzed. The results show that THz-TDS technology can identify small differences between tartaric acid chiral isomer and its racemate.