Raman Spectroscopy, Group Theory, and Computational Chemistry: A Physical Chemistry Laboratory Experiment on para -Difluorobenzene
Raman Spectroscopy, Group Theory, and Computational Chemistry: A Physical Chemistry Laboratory Experiment on para -Difluorobenzene
复制标题
拉曼光谱、群论和计算化学：对二氟苯的物理化学实验室实验
DOI：
10.1021/acs.jchemed.2c00095
复制
发表时间：
2022
影响因子：
3
通讯作者：
Varberg, Thomas D.
中科院分区：
文献类型：
--
作者：
Varberg, Thomas D.
描述了本科生物理化学实验室的一个实验，其中记录并指定了液体对二氟苯的拉曼光谱。使用计算化学软件对分子的 30 种简正模式进行密度泛函理论 (DFT) 计算。学生使用群论来确定哪些模式是拉曼活跃的。在这些结果的指导下，他们能够识别拉曼光谱中 15 个允许对称的基带中的 13 个。通过根据 DFT 计算的缩放结果估计对称允许跃迁的波数，将其余 17 个观察到的频带分配为泛音或组合频带。该实验展示了使用群论和计算化学来分配有机化合物的密集拉曼光谱的强大方法。
An experiment for the undergraduate physical chemistry laboratory is described in which the Raman spectrum of liquidpara-difluorobenzene is recorded and assigned. A density functional theory (DFT) calculation of the 30 normal modes of the molecule is undertaken using computational chemistry software. Students use group theory to determine which of the modes are Raman active. Guided by these results, they are able to identify 13 of the 15 symmetry-allowed fundamental bands in their Raman spectrum. The remaining 17 observed bands are assigned as either overtone or combination bands, by estimating the wavenumbers of symmetry-allowed transitions from the scaled results of their DFT calculation. The experiment demonstrates the powerful way in which group theory and computational chemistry can be used to assign a dense Raman spectrum of an organic compound.