α-乳糖一水合物太赫兹动力学研究

Terahertz kinetic study ofα-lactose monohydrate

α-乳糖一水合物是一种重要的水合物,其结合水对乳糖分子结构的影响一直是相关领域的研究热点之一。利用太赫兹时域光谱技术通过设置温度梯度对α-乳糖一水合物进行低温下的太赫兹动力学研究,发现α-乳糖一水合物在1.2 THz、1.3 THz的2个吸收峰随温度变化而红移。为进一步探究其吸收峰的产生机理,基于密度泛函理论对α-乳糖一水合物分别进行了单分子和晶胞理论计算并分析了α-乳糖一水合物的吸收峰振动模式。结果表明,α-乳糖一水合物的吸收峰来源于水分子和乳糖分子间的相互作用以及乳糖分子骨架振动,晶胞计算比单分子计算对于太赫兹波段内振动模式的预测更加准确。

α-lactose hydrate is an important hydrate,and the effect of its bound water on the structure of lactose molecule has been one of the hot topics in the related fields.By setting the temperature step,the terahertz kinetics ofα-lactose monohydrate at low temperatures was investigated using terahertz time-domain spectroscopy technique,and the temperature dependence of the two characteristic absorption peaks ofα-lactose monohydrate at 1.2 THz and 1.3 THz was found.In order to further investigate the generation mechanism of the three absorption peaks ofα-lactose monohydrate,the vibrational analysis of the absorption peaks was carried out based on density functional theory for single-molecule and unit cell theory calculations,respectively.The results show that the absorption peaks ofα-lactose hydrate originate from intermolecular interactions between water molecules and lactose molecules and the vibrations of lactose molecular skeleton,and it is also shown that unit cell calculations are more accurate in predicting the vibrational modes than single-molecule calculations.