Rotational spectroscopy, dipole moment and 14N nuclear hyperfine structure of iso-propyl cyanide

Müller, H. S. P.; Coutens, A.; Walters, A.; Grabow, Jens‐Uwe; Schlemmer, S.

doi:10.1016/j.jms.2011.02.011

Cited by 39 publications

(34 citation statements)

References 47 publications

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“…In addition to at least reasonable knowledge of the rotational and vibrational contributions to the partition function, one would need to know the dipole moment components accurately. In the case of monocyanides of alkanes or alkenes, the dipole vector is close to being aligned with the CN bond, as in the examples of either vinyl and ethyl cyanide (Kraśnicki & Kisiel 2011) or iso-propyl cyanide (Müller et al 2011), and the total dipole moments are almost the same. The estimates of the dipole moment components for the n-butyl cyanide conformers, obtained by rotating the CH 3 CN dipole vector such that it is parallel to the CN bond of the respective conformer (Bohn et al 1997), are hence probably quite good.…”

Section: Laboratory Spectroscopymentioning

confidence: 83%

The quest for complex molecules in space: laboratory spectroscopy ofn-butyl cyanide,n-C₄H₉CN, in the millimeter wave region and its astronomical search in Sagittarius B2(N)

Ordu

Müller

Walters

et al. 2012

A&A

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Context. The saturated n-propyl cyanide was recently detected in Sagittarius B2(N). The next largest unbranched alkyl cyanide is n-butyl cyanide. Aims. We provide accurate rest frequency predictions beyond the millimeter wave range to search for this molecule in the Galactic center source Sagittarius B2(N) and facilitate its detection in space. Methods. We investigated the laboratory rotational spectrum of n-butyl cyanide between 75 GHz and 348 GHz. We searched for emission lines produced by the molecule in our sensitive IRAM 30 m molecular line survey of Sagittarius B2(N). Results. We identified more than one thousand rotational transitions in the laboratory for each of the three conformers for which limited data had been obtained previously in a molecular beam microwave study. The quantum number range was greatly extended to J ≈ 120 or more and K a > 35, resulting in accurate spectroscopic parameters and accurate rest frequency calculations up to about 500 GHz for strong to moderately weak transitions of the two lower energy conformers. Upper limits to the column densities of N ≤ 3 × 10 15 cm −2 and 8 × 10 15 cm −2 were derived towards Sagittarius B2(N) for the two lower energy conformers, anti-anti and gauche-anti, respectively. Conclusions. Our present data will be helpful for identifying n-butyl cyanide at millimeter or longer wavelengths with radio telescope arrays such as ALMA, NOEMA, or EVLA. In particular, its detection in Sagittarius B2(N) with ALMA seems feasible.

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Section: Laboratory Spectroscopymentioning

confidence: 83%

The quest for complex molecules in space: laboratory spectroscopy ofn-butyl cyanide,n-C₄H₉CN, in the millimeter wave region and its astronomical search in Sagittarius B2(N)

Ordu

Müller

Walters

et al. 2012

A&A

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“…Both n-and i-propyl cyanide isomer are detected (spectroscopic data are provided by Demaison & Dreizler 1982;Vormann & Dreizler 1988;Wlodarczak et al 1988, for the n isomer and by Müller et al 2011, for the i isomer). We mainly detect them towards IRc7, IRc21, MF2, and MF10, with a tentative detection of the n isomer towards EGP (Figs.…”

Section: Propyl Cyanide C 3 H 7 Cnmentioning

confidence: 99%

The complexity of Orion: an ALMA view

Pagani

Favre

Goldsmith

et al. 2017

A&A

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Context. We wish to improve our understanding of the Orion central star formation region (Orion-KL) and disentangle its complexity. Aims. We collected data with ALMA during cycle 2 in 16 GHz of total bandwidth spread between 215.1 and 252.0 GHz with a typical sensitivity of 5 mJy/beam (2.3 mJy/beam from 233.4 to 234.4 GHz) and a typical beam size of 1 . 7 × 1 . 0 (average position angle of 89 • ). We produced a continuum map and studied the emission lines in nine remarkable infrared spots in the region including the hot core and the compact ridge, plus the recently discovered ethylene glycol peak. Methods. We present the data, and report the detection of several species not previously seen in Orion, including n-and i-propyl cyanide (C 3 H 7 CN), and the tentative detection of a number of other species including glycolaldehyde (CH 2 (OH)CHO). The first detections of gGg ethylene glycol (gGg (CH 2 OH) 2 ) and of acetic acid (CH 3 COOH) in Orion are presented in a companion paper. We also report the possible detection of several vibrationally excited states of cyanoacetylene (HC 3 N), and of its 13 C isotopologues. We were not able to detect the 16 O 18 O line predicted by our detection of O 2 with Herschel, due to blending with a nearby line of vibrationally excited ethyl cyanide. We do not confirm the tentative detection of hexatriynyl (C 6 H) and cyanohexatriyne (HC 7 N) reported previously, or of hydrogen peroxide (H 2 O 2 ) emission. Results. We report a complex velocity structure only partially revealed before. Components as extreme as −7 and +19 km s −1 are detected inside the hot region. Thanks to different opacities of various velocity components, in some cases we can position these components along the line of sight. We propose that the systematically redshifted and blueshifted wings of several species observed in the northern part of the region are linked to the explosion that occurred ∼500 yr ago. The compact ridge, noticeably farther south displays extremely narrow lines (∼1 km s −1 ) revealing a quiescent region that has not been affected by this explosion. This probably indicates that the compact ridge is either over 10 000 au in front of or behind the rest of the region. Conclusions. Many lines remain unidentified, and only a detailed modeling of all known species, including vibrational states of isotopologues combined with the detailed spatial analysis offered by ALMA enriched with zero-spacing data, will allow new species to be detected.

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“…One of the first results of EMoCA was the first detection in space of a branched alkyl molecule, iso-propyl cyanide, which is found to be nearly as abundant as its straight-chain isomer n-propyl cyanide (Belloche et al 2014). The laboratory spectroscopic investigation on iso-propyl cyanide (Müller et al 2011) was an A&A 590, A93 (2016) obvious prerequisite. The decrease in line confusion, however, was also important because this molecule was not detected in our previous single-dish survey of Sgr B2(N) (Belloche et al 2013;Müller et al 2011).…”

Section: Introductionmentioning

confidence: 99%

“…The laboratory spectroscopic investigation on iso-propyl cyanide (Müller et al 2011) was an A&A 590, A93 (2016) obvious prerequisite. The decrease in line confusion, however, was also important because this molecule was not detected in our previous single-dish survey of Sgr B2(N) (Belloche et al 2013;Müller et al 2011).…”

Section: Introductionmentioning

confidence: 99%

Spectroscopic study and astronomical detection of doubly¹³C-substituted ethyl cyanide

Margulès

Беллоче

Müller

et al. 2016

A&A

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Context. We have performed a spectral line survey called Exploring Molecular Complexity with ALMA (EMoCA) toward Sagittarius B2(N) between 84.1 and 114.4 GHz with the Atacama Large Millimeter/submillimeter Array (ALMA) in its Cycles 0 and 1. Line intensities of the main isotopic species of ethyl cyanide and its singly 13 C-substituted isotopomers observed toward the hot molecular core Sagittarius B2(N2) suggest that the doubly 13 C-substituted isotopomers should also be detectable. Aims. We want to determine the spectroscopic parameters of all three doubly 13 C-substituted isotopologues of ethyl cyanide to search for them in our ALMA data. Methods. We investigated the laboratory rotational spectra of the three species between 150 GHz and 990 GHz. We searched for emission lines produced by these species in the ALMA spectrum of Sagittarius B2(N2). We modeled their emission and the emission of the 12 C and singly 13 C-substituted isotopologues assuming local thermodynamic equilibrium. Results. We identified more than 5000 rotational transitions, pertaining to more than 3500 different transition frequencies, in the laboratory for each of the three doubly 13 C-substituted isotopomers. The quantum numbers reach J ≈ 115 and K a ≈ 35, resulting in accurate spectroscopic parameters and accurate rest frequency calculations beyond 1000 GHz for strong to moderately weak transitions of either isotopomer. All three species are unambiguously detected in our ALMA data. The 12 C/ 13 C column density ratio of the isotopomers with one 13 C atom to those with two 13 C atoms is about 25. Conclusions. Ethyl cyanide is the second molecule after methyl cyanide for which isotopologues containing two 13 C atoms have been securely detected in the interstellar medium. The model of our ethyl cyanide data suggests that we should be able to detect vibrational satellites of the main species up to at least 19 = 1 at ∼1130 K and up to 13 + 21 = 2 at ∼600 K for the isotopologues with one 13 C atom in our present ALMA data. Such satellites may be too weak to be identified unambiguously for isotopologues with two 13 C atoms.

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Rotational spectroscopy, dipole moment and 14N nuclear hyperfine structure of iso-propyl cyanide

Cited by 39 publications

References 47 publications

The quest for complex molecules in space: laboratory spectroscopy ofn-butyl cyanide,n-C₄H₉CN, in the millimeter wave region and its astronomical search in Sagittarius B2(N)

The quest for complex molecules in space: laboratory spectroscopy ofn-butyl cyanide,n-C₄H₉CN, in the millimeter wave region and its astronomical search in Sagittarius B2(N)

The complexity of Orion: an ALMA view

Spectroscopic study and astronomical detection of doubly¹³C-substituted ethyl cyanide

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Rotational spectroscopy, dipole moment and 14N nuclear hyperfine structure of iso-propyl cyanide

Cited by 39 publications

References 47 publications

The quest for complex molecules in space: laboratory spectroscopy ofn-butyl cyanide,n-C4H9CN, in the millimeter wave region and its astronomical search in Sagittarius B2(N)

The quest for complex molecules in space: laboratory spectroscopy ofn-butyl cyanide,n-C4H9CN, in the millimeter wave region and its astronomical search in Sagittarius B2(N)

The complexity of Orion: an ALMA view

Spectroscopic study and astronomical detection of doubly13C-substituted ethyl cyanide

Contact Info

Product

Resources

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The quest for complex molecules in space: laboratory spectroscopy ofn-butyl cyanide,n-C₄H₉CN, in the millimeter wave region and its astronomical search in Sagittarius B2(N)

The quest for complex molecules in space: laboratory spectroscopy ofn-butyl cyanide,n-C₄H₉CN, in the millimeter wave region and its astronomical search in Sagittarius B2(N)

Spectroscopic study and astronomical detection of doubly¹³C-substituted ethyl cyanide