THE INFRARED-ABSORPTION SPECTRA AND NORMAL COORDINATE ANALYSIS OF (CH3OH)-C-13, (CD3OH)-C-13 AND (CD3OD)-C-13

The infrared absorption spectra of the gas-phase 13C-methanol isotopomers, 13CH3OH, 13CD3OH, and 13CD3OD, were measured in the wavenumber region between 400 and 4000 cm-1, at instrumental resolutions of 4 and 0.12 cm-1. The fundamental vibrational wavenumbers were assigned from the spectra with the aid of a normal coordinate analysis using the valence force constants recently determined for the gas-phase 12C isotopomers. Using the fundamental wavenumbers of both 12C and 13C-methanol isotopomers, we obtained a new set of force constants for the methanol molecule by a simultaneous least-squares adjustment to a total of 67 observed wavenumbers. © 1992.