Investigations in the infra-red region of the spectrum. Part VIII.—The application of the grating spectrometer to certain bands in the spectra of triatomic molecules (Sulphur dioxide, and carbon disulphide)

Abstract

In Part VI of the present series the spectroscopic similarity of the dioxides of sulphur and chlorine was demonstrated. The molecular structure of the two substances was left an open question, since the evidence then available gave contradictory results. The selection rules for the Raman spectrum demanded the obtuse-angled form, while, if complete resolution had been achieved in the infra-red bands, selection rules required the acute-angled modification. The present paper describes the reinvestigation of the bands in question using the grating spectrometer described in Part VII, and the results show that both sulphur and chlorine dioxides are obtuse angled triangles with a vertical angle of approximately 120°.