Where Is The Raman Optical Activity Heading, or Looking Back over Past 40 Years

Abstract

In this article we introduce Raman optical activity (ROA) and summarize its development over past 40 years and future prospects. ROA measures vibrational optical activity by means of a small difference in the intensity of Raman scattering from chiral molecules in right- and left-circularly polarized incident light or, equivalently, a small circularly polarized component in the scattered light. Thanks to new developments in instrumentation, ROA may be applied to a wide range of chiral molecular species. Application of ab initio methods to the analysis of experimental ROA spectra holds great promise for the determination of the three-dimensional structure and conformational distribution in unprecedented detail. Determination of absolute configuration of small and medium sized molecules in solution highlights the power of ROA. The many structure-sensitive bands in the ROA spectra of aqueous solutions of biomolecules provide detailed structural information including, in the case of proteins, the tertiary fold in addition to secondary structure elements such as helix and sheet. ROA studies of unfolded and partially folded proteins can provide new insight into the residual structure in denatured proteins and the abnormal behavior of proteins responsible for misfolding diseases. Hopefully this review will stimulate interest in this technique, and will open it up to the spectroscopic community in the Czech Republic.