Effect of Temperature on the OH-Stretching Bands of the Methanol Dimer
Research output: Contribution to journal › Journal article › Research › peer-review
We present a conceptually simple model for understanding the significant spectral changes that occur with the temperature in the infrared spectra of hydrogen-bound complexes. We have measured room-temperature spectra of the methanol dimer and two deuterated isotopologues in the OH(D)-stretching region. We correctly predict spectral changes observed in the gas phase for the bound OH stretch in the methanol dimer from jet-cooled to room temperature and corroborate this with experimental and theoretical results for deuterated isotopologues. The origin of the observed spectral features is explained based on a reduced-dimensional vibrational model, which includes the two high-frequency OH stretches, the two methyl torsions, and the six intermolecular low-frequency vibrations. Key to the success of the model is a new coordinate definition to describe the intrinsic large-amplitude curvilinear motion of low-frequency vibrations. Despite the deceivingly simple appearance of the room temperature bound OH-stretching fundamental band, it consists of ∼107 vibrational transitions.
Original language | English |
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Journal | Journal of Physical Chemistry A |
Volume | 128 |
Issue number | 2 |
Pages (from-to) | 392-400 |
Number of pages | 9 |
ISSN | 1089-5639 |
DOIs | |
Publication status | Published - 2023 |
Bibliographical note
Funding Information:
We are grateful for funding from the Independent Research Fund Denmark (grant no. 9040-00142B) and the Novo Nordisk Foundation (grant nos. NNF19OC0057374 and NNF220C0080193) and for computer time from the High Performance Computer Centre at University of Copenhagen.
Publisher Copyright:
© 2024 American Chemical Society.
ID: 381233493