J/ApJ/777/120 cm to submm spectra of H2C=CH-CH2NC (Haykal+, 2013)
The cm-, mm-, and sub-mm-wave spectrum of allyl isocyanide and radioastronomical
observations in Orion KL and the SgrB2 line surveys.
Haykal I., Margules L., Huet T.R., Motyienko R.A., Ecija P., Cocinero E.J.,
Basterretxea F., Fernandez J.A., Castano F., Lesarri A., Guillemin J.C.,
Tercero B., Cernicharo J.
<Astrophys. J., 777, 120 (2013)>
=2013ApJ...777..120H 2013ApJ...777..120H
ADC_Keywords: Atomic physics
Keywords: ISM: molecules; line: identification; methods: laboratory: molecular
methods: observational; submillimeter: ISM
Abstract:
Organic isocyanides have an interesting astrochemistry and some of
these molecules have been detected in the interstellar medium (ISM).
However, rotational spectral data for this class of compounds are
still scarce. We provide laboratory spectra of the four-carbon allyl
isocyanide covering the full microwave region, thus allowing a
potential astrophysical identification in the ISM. We assigned the
rotational spectrum of the two cis (synperiplanar) and gauche
(anticlinal) conformations of allyl isocyanide in the centimeter-wave
region (4-18GHz), resolved its 14N nuclear quadrupole coupling (NQC)
hyperfine structure, and extended the measurements into the millimeter
and submillimeter-wave (150-900GHz) ranges for the title compound.
Rotational constants for all the monosubstituted 13C and 15N
isotopologues are additionally provided. Laboratory observations are
supplemented with initial radioastronomical observations. Following
analysis of an extensive dataset (>11000 rotational transitions),
accurate ground-state molecular parameters are reported for the cis
and gauche conformations of the molecule, including rotational
constants, NQC parameters, and centrifugal distortion terms up to
octic contributions. Molecular parameters have also been obtained for
the two first excited states of the cis conformation, with a dataset
of more than 3300 lines. The isotopic data allowed determining
substitution and effective structures for the title compound. We did
not detect allyl isocyanide either in the IRAM 30m line survey of
Orion KL or in the PRIMOS survey toward SgrB2.
Description:
Allyl isocyanide was synthesized on the gram scale, as recently
reported (Chrostowska et al. 2012, ChemPhysChem., 13, 226). The sample
was first analyzed in the 4-18GHz centimeter-wave region using a
supersonic jet Fourier-transform microwave spectrometer built at the
University of the Basque Country.
The millimeter- and submillimeter-wave spectra of allyl isocyanide
were recorded using the Lille spectrometer based on solid-state
sources. Spectra were recorded at room temperature (T=294K) in the
150-204, 225-315, 400-500, 500-600, and 780-905GHz regions with a
frequency step of 30, 36, 48, 54, and 76kHz, respectively, with an
acquisition time of 35ms.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 67 10719 Result of the fit for the ground state and the
excited vibrational states of cis allyl isocyanide
table3.dat 67 7193 Result of the fit for the ground state of gauche
allyl isocyanide
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See also:
J/A+A/572/A44 : Vibrationally excited vinyl cyanide in Orion-KL (Lopez+, 2014)
J/ApJ/768/81 : Ethyl cyanide, CH3CH2CN, vibrational states (Daly+, 2013)
J/A+A/553/A84 : (Sub)mm spectrum of deuterated methyl cyanides (Nguyen+, 2013)
J/A+A/549/A96 : mm and sub-mm spectra of 13C-glycolaldehydes (Haykal+, 2013)
J/A+A/544/A82 : Rotational spectrosc. of diisocyanomethane (Motiyenko+, 2012)
J/A+A/493/565 : Deuterated and 15N ethyl cyanides (Margules+, 2009)
J/ApJS/156/127 : 350µm molecular line survey of Orion KL (Comito+, 2005)
Byte-by-byte Description of file: table[23].dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- v" [0/2] Upper quantum number v"
4- 5 I2 --- J" [1/99] Upper quantum number J"
7- 8 I2 --- Ka" [0/39] Upper quantum number Ka"
10- 11 I2 --- Kc" [0/99] Upper quantum number Kc"
13- 14 I2 --- F" [0/6]? Upper quantum number F"
16- 17 I2 --- v' [0/2] Lower quantum number v'
19- 20 I2 --- J' [0/98] Lower quantum number J'
22- 23 I2 --- Ka' [0/39] Lower quantum number Ka'
25- 26 I2 --- Kc' [0/98] Lower quantum number Kc'
28- 29 I2 --- F' [0/5]? Lower quantum number F'
31- 42 F12.5 MHz Freq [4403.5/904305] Observed frequency
44- 51 F8.5 MHz O-C [-0.6/0.6] Residual; observed minus
calculated value
53- 57 F5.3 MHz e_Freq [0/0.1] Assumed experimental uncertainty
59- 67 E9.3 --- Iw [0.04/5.3] Intensity weighting for
blended lines (Iw=1.0 for non-blended lines)
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 09-Apr-2015