Analysis of the torsional splitting in the ⱱ8 band of propane near 870.4 cm−1caused by fermi resonance with the 2v14+2ν27 level

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https://hdl.handle.net/2142/91292

Author(s)

Groner, Peter

Contributor(s)

Issue Date

2016-06-21

Keyword(s)

Spectroscopy of Large Amplitude Motions

Abstract

Torsional splitting has been observed in the \nub{8} and \nub{21} IR bands of propane near 870.4 and 921.4 \wn, respectively, recorded at the AILES Beamline at the SOLEIL synchrotron.\footnote{A. Perrin et al., J. Mol. Spectrosc. 315 (2015), 55-62
A. Perrin et al., ISMS15, presentation TG04.} Over 4000 individual transitions of the \nub{8} band were assigned and analyzed with an expanded version of the effective rotational Hamiltonian for molecules with two symmetric internal rotors (ERHAM).\footnote{P. Groner, J. Chem. Phys. 107 (1997) 4483–4498
P. Groner, J. Mol. Spectrosc. 278 (2012) 52–67.} A least-squares fit approximated a large portion of the assigned transitions with a model of an isolated \nub{8} state with acceptable precision. However, this model was unable to reproduce many systematic deviations and local resonances. A torsional analysis of existing experimental data and ab initio predictions allows the conclusion that Fermi resonance between \nub{8} and the torsional combination state 2\nub{14}+2\nub{27} most likely caused the failure of the isolated state model. Additional modifications to ERHAM that include Fermi resonance with another state support the conclusion that most of the observed torsional splitting in \nub{8} is caused by the 2\nub{14}+2\nub{27} state. The continuing detailed analysis is expected to yield more definitive results by the time of this meeting.

Publisher

International Symposium on Molecular Spectroscopy

Type of Resource

text

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http://hdl.handle.net/2142/91292

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