The spectrum of mono-deuteromethane in the photographic infra-red. I. Preparation of the gas, and measurements of a simple band at 9021 cm. -1

Abstract

An investigation of the infra-red spectra of the deutero substituted methanes is necessary for the complete spectroscopic determination of the structure of the methane molecule, for it was early recognized that for highly symmetrical molecules the normal frequencies are insufficient to determine uniquely the molecular parameters. In the case of methane the rotation structure is much influenced by interaction phenomena, and here again the spectra of the deuteromethanes can provide valuable material for the elucidation of the effects. We have recently completed the examination of the absorption spectrum of mono-deuteromethane in the photographic infra-red, from 8400 to 13,000 cm. -1 (7600-12,000 A), and we propose here to give an account of the preparation of the gas, of which we required the relatively large amount of 40 l., and to present the measurements of a band at 9021 cm. -1 having a simple rotation structure.