Raman Spectrum of Carbon Disulphide

Abstract

The Raman spectrum of liquid carbon disulphide has been investigated with high dispersion. In addition to the lines already known, five very faint lines have been observed. The intensities of the stronger lines were measured and, with a spectrograph of low dispersion, the degrees of depolarization of the two principal bands were determined. The results are in accord with the assumption made by Fermi, Dennison and Placzek that large perturbations of some of the energy levels occur on account of the approximate coincidence of v 1 with 2v 2. The values Δ = —120 cm—1 and |P| = 17.8 cm—1 are obtained for the difference Δ = v 1 — 2v 2 and for the coupling constant P = βh ½/4π2μ1 ½μ 2(v 1+2v 2) 3 2 .