Theory of natural Raman optical activity

Abstract

A complete theory of natural circular polarization Raman optical activity (ROA) is presented that, for the first time, includes explicit dependence on the polarization and propagation vectors of the incident and scattered photons. The general theory directly yields Raman and ROA intensity expressions for incident, scattered and dual circular polarization (ICP, SCP and DCP) ROA measurements depending analytically on the polar and azimuthal scattering angles and on the orientation angle of an analysing or incident linear polarizer. For the case of chiral molecules, randomly oriented in an optically isotropic phase, two distinct sets of Cartesian Raman and ROA tensors are employed: the isotropic and anisotropic tensor invariants and the set first introduced in the original formulation of (ICP) ROA. In the general theory ten complex ROA invariants are present in any complete tensor set. It is found, however, that only the imaginary parts of six independent invariant combinations may be obtained by natural cir...