Absolute Intensities of the Infrared Bands of Gaseous Acrylonitrile

Khlifi, M.; Nollet, M.; Paillous, P.; Bruston, P.; Raulin, F.; Bénilan, Y.; Khanna, R. K.

doi:10.1006/jmsp.1998.7795

Cited by 27 publications

(29 citation statements)

References 18 publications

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“…Amorphous ices formed at 20 K Vibrational spectroscopy of acrylonitrile in rare-gas matrices has been studied earlier (Toumi et al, 2014). Here we present full infrared spectrum of pure solid acrylonitrile at different temperatures (20, 95, 130 K) along with the vibrational assignment by comparing with earlier studies (Dello Russo and Khanna, 1996;Khlifi et al, 1999). These comparisons are summarized in Table 2.…”

Section: Methodsmentioning

confidence: 94%

Acrylonitrile characterization and high energetic photochemistry at Titan temperatures

Toumi

Piétri

Chiavassa

et al. 2016

Icarus

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Section: Methodsmentioning

confidence: 94%

Acrylonitrile characterization and high energetic photochemistry at Titan temperatures

Toumi

Piétri

Chiavassa

et al. 2016

Icarus

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“…If the 695 cm −1 signature observed in limb spectra of March 2015 is due to acrylonitrile ice and if we assume that the retrieved ice mass mixing ratio near 0.1 mbar is the one near the top of the C 2 H 3 CN cloud (as the 695 cm −1 signature is not detected at higher altitude), then because of mass flux conservation, the gas volume mixing ratio at ∼ 0.1 mbar should be higher than ∼4 ×10 −8 , and also lower than the INMS values. There is currently no line list of the acrylonitrile gas in the mid-IR but Khlifi et al (1999) determined its IR spectrum, which displays many vibrational modes, and measured the corresponding integrated band intensities. In the mid-IR spectral region observed by CIRS, the three most intense acrylonitrile bands are located at 682, 953 and 972 cm −1 .…”

Section: The C 2 H 3 Cn Potential Candidatementioning

confidence: 99%

Study of Titan’s fall southern stratospheric polar cloud composition with Cassini/CIRS: Detection of benzene ice

Vinatier

Schmitt

Bézard

et al. 2018

Icarus

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We report the detection of a spectral signature observed at 682 cm −1 by the Cassini Composite Infrared Spectrometer (CIRS) in nadir and limb geometry observations of Titan's southern stratospheric polar region in the middle of southern fall, while stratospheric temperatures are the coldest since the beginning of the Cassini mission. In the same period, many gases observed in CIRS spectra (C 2 H 2 , HCN, C 4 H 2 , C 3 H 4 , HC 3 N and C 6 H 6 ) are highly enriched in the stratosphere at high southern latitude due to the air subsidence of the global atmospheric circulation and some of these molecules condense at much higher altitude than usually observed for other latitudes. The 682 cm −1 signature, which is only observed below an altitude of 300-km, is at least partly attributed to the benzene (C 6 H 6 ) ice ν 4 C-H bending mode. While we first observed it in CIRS nadir spectra of the southern polar region in early 2013, we focus here on the study of nadir data acquired in May 2013, which have a more favorable observation geometry. We derived the C 6 H 6 ice mass mixing ratio in 5 • latitude bins from the south pole to 65 • S and infer the C 6 H 6 cloud top altitude to be located deeper with increasing distance from the pole. We additionally analyzed limb data acquired in March 2015, which were the first limb dataset available after the May 2013 nadir observation, in order to infer a vertical profile of its mass mixing ratio in the 0.1 -1 1 mbar region (250 -170 km). We derive an upper limit of ∼1.5 µm for the equivalent radius of pure C 6 H 6 ice particles from the shape of the observed emission band, which is consistent with our estimation of the ice particle size from condensation growth and sedimentation timescales. We compared the ice mass mixing ratio with the haze mass mixing ratio inferred in the same region from the continuum emission of CIRS spectra, and derived that the haze mass mixing ratios are ∼30 times larger than the C 6 H 6 ice mass mixing ratios for all observations. Several other unidentified signatures are observed near 687 and 702 cm −1 and possibly 695 cm −1 , which could also be due to ice spectral signatures as they are observed in the deep stratosphere at pressure levels similar to the C 6 H 6 ice ones. We could not reproduce these signatures with pure nitrile ices (HCN, HC 3 N,CH 3 CN, C 2 H 5 CN and C 2 N 2 ) spectra available in the literature except the 695 cm −1 feature that could possibly be due to C 2 H 3 CN ice. From this tentative detection, we derive the corresponding C 2 H 3 CN ice mass mixing ratio profile and also inferred an upper limit of its gas volume mixing ratio of 2×10 −7 at 0.01 mbar at 79 • S in March 2015.

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“…In the case of CH 2 CHCN, there exists a large number of vibrational modes, the strongest of which are the bending modes ν 12 and ν 13 at 972 cm −1 (10.3 µm) and 954 cm −1 (10.5 µm) respectively (Cerceau et al 1985;Khlifi et al 1999). For CH 2 CN the only available experimental information concerns the ν 5 mode at 664 cm −1 (15.1 µm; Sumiyoshi et al 1996).…”

Section: Excitation Mechanism: Infrared Pumpingmentioning

confidence: 99%

Detection of circumstellar CH₂CHCN, CH₂CN, CH₃CCH, and H₂CS

Agúndez

Fonfría

Cernicharo

et al. 2008

A&A

132

135

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Aims. We report on the detection of vinyl cyanide (CH 2 CHCN), cyanomethyl radical (CH 2 CN), methylacetylene (CH 3 CCH), and thioformaldehyde (H 2 CS) in the C-rich star IRC +10216. These species, which are all known to exist in dark clouds, were detected for the first time in the circumstellar envelope around an AGB star. Methods. The four molecules were detected through pure rotational transitions in the course of a λ 3 mm line survey carried out with the IRAM 30-m telescope. The molecular column densities were derived by constructing rotational temperature diagrams. A detailed chemical model of the circumstellar envelope is used to analyze the formation of these molecular species. Results. We have found column densities in the range 5 × 10 12 −2 × 10 13 cm −2 , which translates to fractional abundances relative to H 2 of several 10 −9 . The chemical model is reasonably successful in explaining the derived abundances through gas phase synthesis in the cold outer envelope. We also find that some of these molecules, CH 2 CHCN and CH 2 CN, are most probably excited through infrared pumping to excited vibrational states. Conclusions. The detection of these species stresses the similarity between the molecular content of cold dark clouds and C-rich circumstellar envelopes. However, some differences in the chemistry are indicated by partially saturated carbon chains being present in IRC +10216 at a lower level than those that are highly unsaturated, while in TMC-1 both types of species have comparable abundances.

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Absolute Intensities of the Infrared Bands of Gaseous Acrylonitrile

Cited by 27 publications

References 18 publications

Acrylonitrile characterization and high energetic photochemistry at Titan temperatures

Acrylonitrile characterization and high energetic photochemistry at Titan temperatures

Study of Titan’s fall southern stratospheric polar cloud composition with Cassini/CIRS: Detection of benzene ice

Detection of circumstellar CH₂CHCN, CH₂CN, CH₃CCH, and H₂CS

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Absolute Intensities of the Infrared Bands of Gaseous Acrylonitrile

Cited by 27 publications

References 18 publications

Acrylonitrile characterization and high energetic photochemistry at Titan temperatures

Acrylonitrile characterization and high energetic photochemistry at Titan temperatures

Study of Titan’s fall southern stratospheric polar cloud composition with Cassini/CIRS: Detection of benzene ice

Detection of circumstellar CH2CHCN, CH2CN, CH3CCH, and H2CS

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Detection of circumstellar CH₂CHCN, CH₂CN, CH₃CCH, and H₂CS