手性分子2, 3-丁二醇的旋光拉曼光谱研究

本文从拉曼峰和旋光拉曼峰出发,通过键极化率和微分键极化率分析研究(2R, 3R)-2, 3-丁二醇. 通过分子C₁和C₂两种点群的优化结构,获得不依赖于这两种结构的结果 和有关这个手性系统物理图像的丰富信息.对分子拉曼键极化率分析,得出在拉曼弛豫过程中, 电荷主要从外围流向骨架结构.对分子微分键极化率的分析,显示在不对称C原子和与其相联系的H原子 两侧化学键, C-O和C-CH₃的微分键极化率的符号正好相反,意味着这个分子具有相当好的手性 不对称性质.对比对称和反对称的键极化率、微分键极化率,本文得到这样的结论: 对于(特别是键伸缩的)键极化率,(大体上是)对称的大于反对称的; 而对于微分键极化率则是反对称的大于对称的. 关键词： 旋光拉曼 键极化率 微分键极化率 2,3-丁二醇

The chiral asymmetry revealed by the Raman differential bond polarizability of (2R, 3R)-(-)- 2, 3-butanediol

The Raman optical activity (ROA) of (2R, 3R)-2, 3-butanediol is investigated through the intensities of Raman spectrum and ROA spectrum, bond polarizability and differential bond polarizability. In view of the two possible optimized structures, i.e., C₁ and C₂ group, we obtain the conclusion that ample information concerning the physical pictures of this chiral system does not depend on the two variant structures.Based on the analysis of bond polarizabilities, the charge moves from the periphery to the skeleton structure in the Raman relaxation process. The analysis of differential bond polarizabilities shows that the signs of differential bond polarizabilities on the both sides of the plane associated with the asymmetric C and H atoms are opposite. This means that the chiral asymmetry of this molecule is rather complete.Also, it is observed that bond polarizabilities for the symmetric modes are larger than for the antisymmetric modes, while for the differential bond polarizabilities, the situation is just reverse.