Global Fit of Torsion–Rotational Transitions in the First Three Torsional States of CH3OD

Millimeter-Wave Spectra and Global Torsion–Rotation Analysis for the CH3OD Isotopomer of Methanol

“…Earlier reported fits (17,19) were to a transition subset with J Յ 20 and K Յ 6, but included only K states from Ϫ3 to Ϫ6 for E subbands involving v t ϭ 1 levels. This previous data set, which was stated to contain 2348 lines in the 20 -350 cm Ϫ1 region, was archived as supplementary information and made available through both the British Library Document Supply Centre (17) and the JMS archive (19). (We note in passing, however, that the list from the former contains only 2306 entries, while the latter has 2348 transitions but includes around 50 wavenumbers below 20 cm Ϫ1 which are duplicates of MW and MMW lines already in the fit.…”

“…We also chose at this stage not to incorporate v t ϭ 2 a-type MMW lines, which had been included in one of the previous studies (19), in order to maintain consistency and comparability with the earlier global fits in our series (1)(2)(3)(4). To treat v t ϭ 2 data properly in a true v t ϭ 0-2 fit, one would look for ⌬K ϭ Ϯ1 b-type transitions more sensitive to the torsional potential and seek to include data covering a substantial range of J and K quantum numbers.…”

Microwave spectroscopic and computational analyses of the phenylacetylene⋯methanol complex: insights into intermolecular interactions

“…Specifically, the barrier height to internal rotation of CH 3 OH and CH 3 OH-containing complexes, including the CH 3 OH dimer, has been a topic of great interest and investigation. 14–34 In the case of CH 3 OH, it has been reported that this barrier height is 373 cm −1 , which is the result of the interactions between the internal rotation of the methyl group and the large amplitude motion of the OH group. 14 There are reports that suggest that the binding of CH 3 OH to another molecule can influence (change the barrier height of) the internal rotation of the methyl group in the methanol molecule.…”