Instrument for natural and magnetic Raman optical activity studies in right-angle scattering

A simple computer-controlled instrument for natural and magnetic incident circular polarization Raman optical activity (ICP ROA) measurements in right-angle scattering is described. The key spectral elements consist of a fast single-stage monochromator equipped with a holographic notch filter, a highly efficient holographic diffraction grating and a thinned back-illuminated, thermoelectrically cooled charge-coupled device (CCD) detector. A temperature-stabilized longitudinal electro-optic modulator is employed to switch between orthogonal circular polarization states in the incident laser radiation. A polaroid film together with a mica half-wave retardation plate are used to select particular linear polarization states in the Raman scattered radiation with the same instrumental response. High-quality depolarized and polarized Stokes and depolarized anti-Stokes ICP ROA spectra of (R)-(−) and (S)-(+)-phenyloxirane and depolarized magnetic resonance ICP ROA spectra of copper(II) tetrabromide are presented as typical examples of the excellent performane characteristics