The Raman spectrum of sulphur dioxide in different states

Abstract

Abstract The influence of the state of matter on the three vibrations of sulphur dioxide has been studied. For that reason the Raman spectra of gaseous SO 2 at 12 atmospheres, of liquid SO 2 at 40° and 70°, of solutions of SO 2 in water and of mixtures of SO 2 with CCl 4 (and SO 3 ) were investigated. The difference between equation image gas and equation image liquid for the strongest Raman line of SO 2 , is equal to 6 cm −1 . This is to be ascribed to the action of the electrostatic fields of the dipole molecules in the liquid. For solutions in water (at 50°), the dissolved SO 2 is in a state comparable with the gaseous one. The concentration of H 2 SO 3 in the solution can only be small. For the mixtures only small displacements of the Raman lines have been The spectrum of the mixtures consists in first approximation of a superposition of the spectra of the two components. The experimental arrangement used, is described in detail.