Electronic circular dichroism and Raman optical activity: Principle and applications
Siyuan Zhu, Mengtao Sun
Abstract
This review briefly describes the principles, methods, and applications of electronic circular dichroism (ECD) and Raman optical activity (ROA) in practical cases. Researchers have always been interested in determining the absolute configuration of natural products. Due to the characteristics of high sensitivity and simple sample requirements, ECD is widely used in the configuration of rigid systems and flexible systems. Besides, the shortcomings in protein structure and the application of visual analysis of twisted bilayer graphene structure spectra will be explained. In recent years, the combination of ECD and other methods has significantly improved time-consuming and accuracy.With the development of spectrometers, the characteristics of low ROA scattering intensity have also been improved. The review summarized several technologies of surface-enhanced ROA, as well as new technologies related to ROA measurement. The uniqueness of ROA is mainly reflected in the biological structure. It analyzes the application in protein, nucleic acid and carbohydrate. The article uses examples to introduce a new visualization method of this experimental group combined with ECD and ROA spectroscopy to analyze the chiral structure of different molecules. The anisotropy on the dipole moment of the chromophore under a specific laser will affect the spectrum, and there is a relationship between the anisotropy and the chiral specific structure. In a broad sense, this theoretical method is a general analysis of the chirality of traditional molecules, clusters, and crystals method. Due to their early development, ECD and ROA have always been powerful "probing needles" for structure determination through chiral interactions.