J/A+A/647/A179 Laboratory spectroscopy of isotopic c-H2C3O (Mueller+, 2021)
Rotational spectroscopy of isotopic cyclopropenone, c-H2C3O,
and determination of its equilibrium structure.
Mueller H.S.P., Brahmi M.A., Guillemin J.-C., Lewen F., Schlemmer S.
<Astron. Astrophys. 647, A179 (2021)>
=2021A&A...647A.179M 2021A&A...647A.179M (SIMBAD/NED BibCode)
ADC_Keywords: Interstellar medium ; Spectroscopy ; Molecular data
Keywords: molecular data - methods: laboratory: molecular -
techniques: spectroscopic - radio lines: ISM - ISM: molecules -
astrochemistry
Abstract:
Cyclopropenone was first detected in the cold and less dense envelope
of the giant molecular cloud Sagittarius B2(N). It was found later in
several cold dark clouds and it may be possible to detect its minor
isotopic species in these environments. In addition, the main species
may well be identified in warmer environments.
We aim to extend existing line lists of isotopologs of c-H2C3O
from the microwave to the millimeter region and create one for the
singly deuterated isotopolog to facilitate their detections in space.
Furthermore, we aim to extend the line list of the main isotopic
species to the submillimeter region and to evaluate an equilibrium
structure of the molecule.
Description:
We employed a cyclopropenone sample in natural isotopic composition to
investigate the rotational spectra of the main and 18O-containing
isotopologs as well as the two isotopomers containing one 13C atom.
Spectral recordings of the singly and doubly deuterated isotopic
species were obtained using a cyclopropenone sample highly enriched in
deuterium. We recorded rotational transitions in the 70-126GHz and
160-245GHz regions for all isotopologs and also in the 342-505GHz
range for the main species. Quantum-chemical calculations were carried
out to evaluate initial spectroscopic parameters and the differences
between ground-state and equilibrium rotational parameters in order to
derive semi-empirical equilibrium structural parameters.
We determined new or improved spectroscopic parameters for six
isotopologs and structural parameters according to different structure
models.
The spectroscopic parameters are accurate enough to identify minor
isotopic species at centimeter and millimeter wavelengths while those
of the main species are deemed to be reliable up to 1THz. Our
structural parameters differ from earlier ones. The deviations are
attributed to misassignments in the earlier spectrum of one isotopic
species.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
13c1.dat 80 116 Transitions included in the fit of 13C1 isotopolog
13c2.dat 80 106 Transitions included in the fit of 13C2 isotopolog
18o.dat 80 61 Transitions included in the fit of 18O isotopolog
c-h2c3o.dat 83 466 Transitions included in the fit of c-H2C3O
d2.dat 80 189 Transitions included in the fit of D2 isotopolog
hd.dat 66 130 Transitions included in the fit of HD isotopolog
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Byte-by-byte Description of file: *.dat
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Bytes Format Units Label Explanations
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2- 3 I2 --- J' Upper state J quantum number
5- 6 I2 --- Ka' Upper state Ka quantum number
8- 9 I2 --- Kc' Upper state Kc quantum number
13- 14 I2 --- J" Lower state J quantum number
16- 17 I2 --- Ka" Lower state Ka quantum number
19- 20 I2 --- Kc" Lower state Kc quantum number
23- 33 F11.4 MHz FreqObs Observed transition frequency
37- 43 F7.5 MHz e_FreqObs Experimental uncertainty
45- 52 F8.5 MHz (O-C) Observed minus calculated frequency
(for group of lines if they are at the same
frequency)
55- 60 F6.4 --- wb ? Weight of the component in group of lines
62- 83 A22 --- Notes Source of data (reference); Koeln are from
this work (1)
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Note (1): References as:
Benson et al., 1973, J. Am. Chem. Soc., 95, 2772
Guillemin et al., 1990, J. Mol. Spectr., 140, 190
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Acknowledgements:
Holger Mueller, hspm(at)ph1.uni-koeln.de
References:
Mueller et al., 2001A&A...370L..49M 2001A&A...370L..49M,
The Cologne Database for Molecular Spectroscopy, CDMS.
Endres et al., 2016JMoSp.327...95E 2016JMoSp.327...95E,
The Cologne Database for Molecular Spectroscopy, CDMS,
in the Virtual Atomic and Molecular Data Centre, VAMDC
(End) Patricia Vannier [CDS] 08-Feb-2021