Infrared Spectra of Methanol, Ethanol, and rz-Propanol

The infrared absorption spectra of methanol, ethanol, and n-propanol have been measured with prism instruments. Studies have been made of the vapors and of several dilute solutions. The methanol spectra, between 2 to 15 microns, prpvided a direct comparison with the other two alcohols and confirmed earlier work on the existence of a number of lowintensity bands. The two other alcohols were studied from 2 to 36 microns. The bands have been classified in relation to the O —H, C —H, C —O, and C —C vibrations within the molecules. The long-wave absorption, in the region beyond 30 microns, for each alcohol, is attributed to the hindered rotation of OH. The object of the present study was to confirm the assignments for methanol and to study and assign the vibrational spectra of ethanol and n-propanol.