The Absorption Spectra of Gaseous Methylamine and Dimethylamine in the Photographic Infra-Red

The absorption spectra of gaseous methylamine and dimethylamine have been measured in the region from 6000 to 12,000A using a 105-foot stainless steel absorption tube and a 3-m grating spectrograph. Absorption bands were observed at 7940, 9100, 9940, 10,070, 10,330 and 11,800A in methylamine and at 7940, 8045, 9100, 10,360, 10,625 and 11,800A in dimethylamine. The only band showing resolvable fine structure was that at 9940A in methylamine. Wherever possible the observed bands have been assigned to overtones and combinations of the fundamental N–H and C–H valence vibrations.