Torsion-vibration interaction in the CH{sub 3}-rocking and OH-bending fundamentals and the CO-stretch overtone band of {sup 13}CH{sub 3}OH
Conference
·
OSTI ID:456895
- Univ. of New Brunswick, Fredericton (Canada)
- Justus-Liebig-Universitaet Giessen (Germany); and others
The CH{sub 3}-rocking and OH-bending fundamental bands and the first CO-stretch overtone of C-13 methanol have been analyzed by means of high resolution FTIR spectroscopy. The aim of this study was to explore the interactions among these states and neighbouring vibrational modes. Numerous subbranches have been assigned for the three vibrational bands and linked together with the use of ground-state combination differences. The assigned subbands have been fitted as J(J+1) power-series expansions in order to determine the infrared subband origins and state-specific energy expansion coefficients. Least squares determination of the excited-state molecular parameters from the subband origins has been investigated, and substantial increases in the effective barrier heights to internal rotation are found for the CH{sub 3}-rock and OH-bend as compared to the ground vibrational state. Coriolis resonances occur between certain CO-stretching K level stacks and CH{sub 3}-rocking (K-1) stacks, while Fermi resonances between CH{sub 3}-rocking and torsionally excited ground state levels at the crossing points for states with the same torsional symmetry have also been observed in the spectrum. As well, strong Fermi interaction couples the OH-bend with the nearby first-excited torsional state of the CH{sub 3}-rock, leading to significant Fermi shifts and the appearance of extra forbidden subbranches in the spectrum due to substantial wavefunction mixing. With the new data, a much more complete picture of the torsion-vibration energy pattern for C-13 methanol is evolving.
- OSTI ID:
- 456895
- Report Number(s):
- CONF-9506113--
- Country of Publication:
- United States
- Language:
- English
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Sat Dec 30 23:00:00 EST 1995
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OSTI ID:456894
Torsion-vibration interactions in the CH{sub 3}-rocking and OH-bending fundamentals of C-13 methanol
Conference
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Mon Dec 30 23:00:00 EST 1996
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OSTI ID:437246
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Journal Article
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Mon Oct 31 23:00:00 EST 1994
· Journal of Molecular Spectroscopy; (United States)
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OSTI ID:6816862