J/A+A/615/A140 C4H9CN anti and gauche conformer data (Wehres+, 2018)
Rotational spectroscopy of the two conformers of 3 methylbutyronitrile
(C4H9CN) between 2 and 400 GHz.
Wehres N., Wilkins O.H., Borisov K., Lewen F., Grabow J.-U., Schlemmer S.,
Mueller H.S.P.
<Astron. Astrophys. 615, A140 (2018)>
=2018A&A...615A.140W 2018A&A...615A.140W (SIMBAD/NED BibCode)
ADC_Keywords: Atomic physics
Keywords: laboratory: molecular - techniques: spectroscopic - radio lines: ISM -
ISM: molecules - astrochemistry
Abstract:
We present high-resolution rotational spectroscopy of the two
conformers of 3-methylbutyronitrile (C4H9CN). Spectra were taken
between 2 and 24GHz by means of Fourier transform microwave
spectroscopy. Spectra between 36 and 403 GHz were recorded by means of
frequency modulated (FM) absorption spectroscopy. The analysis yields
precise rotational constants and higher order distortion constants, as
well as a set of 14N nuclear electric quadrupole coupling parameters
for each of the two conformers. In addition, quantum chemical
calculations were performed in order to assist the assignments.
Frequency calculations yield insight into the vibrational energy
structure of the two conformers, from which partition functions and
vibrational correction factors are determined. These factors are used
to determine experimentally and computationally the energy difference
between the two conformers, which is revealed to be negligible.
Overall, this study provides precise spectroscopic constants for the
search of 3-methylbutyronitrile in the interstellar medium. In
particular, this molecule is a perfect test case for our knowledge of
branched molecule formation in space.
Description:
fits output files: The files contain the fit files from SPFIT
for 3-methylbutyronitrile, anti and gauche conformer.
The quantum numbers are labelled as:
J', K_a', K_c', 0/1, F', J", K_a", K_c", 0/1, F
where 0 indicates hyperfine splitting is (partially) resolved,
and 1 is without hyperfine splitting being resolved.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
3MBN-anti-conformer-fit.txt 135 6714 3-methylbutyronitrile
anti conformer SPFIT data
3MBN-gauche-conformer-fit.txt 135 5383 3-methylbutyronitrile
gauche conformer SPFIT data
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Acknowledgements:
Nadine Wheres, wehres(at)ph1.uni-koeln.de
(End) Patricia Vannier [CDS] 13-Jun-2018