J/A+A/665/A9 2-iminopropanenitrile millimetre-wave spectra (Lukova+, 2022)
Decoding millimetre-wave spectra of 2-iminopropanenitrile, a candidate for
astronomical observations.
Lukova K., Kolesnikova L., Koucky J., Vavra K., Kania P., Guillemin J.-C.,
Urban S.
<Astron. Astrophys. 665, A9 (2022)>
=2022A&A...665A...9L 2022A&A...665A...9L (SIMBAD/NED BibCode)
ADC_Keywords: Interstellar medium ; Spectroscopy ; Atomic physics
Keywords: astrochemistry - molecular data - methods: laboratory: molecular -
techniques: spectroscopic - ISM: molecules
Abstract:
The recent detection of cyanomethanimine in the interstellar medium
makes its methyl derivative 2-iminopropanenitrile (CH3C(CN)NH) a
promising candidate for an interstellar detection. The aim of this
work is to extend the current knowledge of the laboratory rotational
spectrum to higher frequencies, which is an essential prerequisite for
an identification of the molecular species in the interstellar medium
by millimetre-wave astronomy.
The room-temperature rotational spectrum of 2-iminopropanenitrile has
been measured in several frequency regions between 128 and 329GHz.
The A-E splittings of the rotational transitions arising from the
methyl top internal rotation were analysed employing the ERHAM and
XIAM programs.
A data set of approximately 900 newly assigned rotational transitions
in the ground state of the Z isomer and a set of refined molecular
constants including the internal rotation parameters are reported.
Moreover, this work provides the first spectral characterisation of
three lowest-lying vibrationally excited states v21=1, v14=1, and
v20=1 of the Z isomer as well as of the less stable E isomer ground
state. This comprehensive spectroscopic study will allow to search for
2-iminopropanenitrile in the millimetre-wave surveys of interstellar
sources such as those recorded by the Atacama Large
Millimeter/submillimeter Array.
Description:
Observed rotational transitions of Z and E form of 2-iminopropanenitrile.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea3.dat 120 1960 List of the measured transitions of
Z-2-iminopropanenitrile
tablea4.dat 120 446 List of the measured transitions of
E-2-iminopropanenitrile
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Byte-by-byte Description of file: tablea3.dat tablea4.dat
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Bytes Format Units Label Explanations
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1- 12 A12 --- State Vibrational state
17 A1 --- Symmetry Symmetry
21- 23 I3 --- J' Upper state J quantum number
25- 27 I3 --- Ka' Upper state Ka quantum number
29- 31 I3 --- Kc' Upper state Kc quantum number
35- 37 I3 --- J" Lower state J quantum number
39- 41 I3 --- Ka" Lower state Ka quantum number
43- 45 I3 --- Kc" Lower state Kc quantum number
51- 61 F11.4 MHz FreqObs Observed transition frequency
69- 75 F7.4 MHz O-C Observed minus calculated frequency
79- 83 F5.3 MHz Unc Experimental uncertainty
91- 97 F7.4 MHz (O-C)b ? Observed minus calculated frequency for blends
102-105 F4.2 --- Weightb ? Weight of the components of the blends
111-120 A10 --- Notes Source of the data, notes (1)
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Note (1): Source of data as follows:
(1) = Groner et al. (1987 J. Chem. Phys., 107, 4483)
(2) = This work
Excl. = Excluded from the fit
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Acknowledgements:
Katerina Lukova, Katerina.Lukova(at)vscht.cz
(End) Patricia Vannier [CDS] 06-Jun-2022