FAR-INFRARED SPECTROSCOPY OF THE H<sub>2</sub>-O<sub>2</sub>VAN DER WAALS COMPLEX

Bunn, Hayley; Bennett, Trystan; Karayilan, Aidan M.

doi:10.1088/0004-637x/799/1/65

Cited by 8 publications

(9 citation statements)

References 17 publications

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“…The far-infrared radiation generated from deflecting the (200 mA) electron beam is directed into a Bruker IFS 125 HR FTIR spectrometer that houses a room temperature glass sample cell containing a White cell (path length at 12 passes = 6.6 m) . Similar to what we previously used, − the instrument was equipped with a Mylar beamsplitter, polyethylene windows, and liquid helium cooled Si bolometer detector. This set up allowed for high spectral brightness around 350 cm –1 , wherein lies the ν 19 band of 2CE.…”

Section: Methodsmentioning

confidence: 99%

Far-Infrared Synchrotron Spectroscopy and Quantum Chemical Calculations of the Potentially Important Interstellar Molecule, 2-Chloroethanol

2019

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The high brightness of the Australian synchrotron allowed for detailed spectra to be collected at high resolution (0.00096 cm −1 ) in the vicinity of the a/b/c-type ν 19 band of 2-chloroethanol, which involves O−H torsional motion about the C−O bond. A rovibrational analysis was performed for both chlorine isotopologues in the ν 19 fundamental (centered at ∼344 cm −1 ) which involved the assignment of 7153 lines (J ≤ 90, K a ≤ 41). A global fit to these lines in addition to 119 microwave lines (J ≤ 29, K a ≤ 11) led to the determination of spectroscopic constants up to the sextic level in both the ground and excited states using Watson's A-reduction Hamiltonian. The constants agree well with those calculated at the anharmonic MP2/cc-pVTZ level and allow for spectroscopically accurate predictions of rotational transitions in the ground vibrational state to be made over a broad range of rotational energies (T R < 1000 K). We explored the role that 2-chloroethanol might play in interstellar molecular clouds by performing calculations on the substitution reaction between HCl and ethylene glycol, and the addition reaction between HCl and oxirane, all of which have been observed in Sagittarius B2(N) and are expected to play important roles in the chemistry that occurs on the icy mantles of interstellar dust grains. While both reactions have relatively high activation barriers, the HCl + oxirane reaction was found be much more exothermic; further calculations on it indicate that a water-like environment significantly reduces the barrier while slightly increasing its exothermicity. These results suggest that 2-chloroethanol could be efficiently produced from the cosmic ray bombardment of common interstellar ices.

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Section: Methodsmentioning

confidence: 99%

Far-Infrared Synchrotron Spectroscopy and Quantum Chemical Calculations of the Potentially Important Interstellar Molecule, 2-Chloroethanol

2019

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“…The setup of the spectrometer was similar to what we used previously . Briefly, the synchrotron radiation was coupled to a Bruker IFS 125 HR FTIR spectrometer equipped with a Mylar beam splitter and polyethylene windows.…”

Section: Methodsmentioning

confidence: 99%

“…The setup of the spectrometer was similar to what we used previously. 21 Briefly, the synchrotron radiation was coupled to a Bruker IFS 125 HR FTIR spectrometer equipped with a Mylar beam splitter and polyethylene windows. After the beam passed through the interferometer, it was directed into the gas cell and detected with a liquid-helium-cooled silicon bolometer.…”

Section: Methodsmentioning

confidence: 99%

Far-Infrared Synchrotron Spectroscopy and Torsional Analysis of the Important Interstellar Molecule, Vinyl Alcohol

Bunn

Hudson

Gentleman

2017

ACS Earth Space Chem.

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We report far-infrared spectra (100−600 cm −1 ) covering the torsional bands of the important interstellar molecule, vinyl alcohol. We observed the fundamental and first two hot bands of syn-vinyl alcohol and the fundamental and first hot band of anti-vinyl alcohol, whose infrared spectrum has not been previously reported. The hot bands for syn-vinyl alcohol were incrementally shifted by ∼40 cm −1 from the fundamental, implying a high degree of anharmonicity in the torsional potential in the vicinity of the global minimum. The opposite holds true for anti-vinyl alcohol, as evidenced by the relatively small red shift (∼2 cm −1 ) of the hot band with respect to the fundamental. These characteristics were captured by ab initio calculations of the torsional potential, which we fit a seven-term Fourier series expansion to, and used along with the calculated torsional inertias to solve for the energy levels and wave functions. The potential was empirically refined by fitting the three leading terms in the expansion to the observed torsional frequencies, which resulted in a 3-fold decrease in the root-mean-square deviation between theory and experiment. The resulting energy difference between the ground states of the two rotamers is 4.0 kJ/mol, which is approximately consistent with the measured intensity ratio of the two ground-state torsional bands and with microwave spectroscopic measurements (4.5 ± 0.6 kJ/mol) [

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“…32,34−40 The anisotropic interaction potentials reduce delocalization, however, thus hindering quantum exchanges and the appearance of nonclassical trends in the rotational moments of inertia. The use of homonuclear diatomics such as N 2 41 or O 2 42 would help out in this regard (since their interaction potentials with hydrogen are less anisotropic); however, it is difficult to study larger (N > 1) clusters. Interestingly, it was suggested over a decade ago 43 that CO would be a better probe for perpendicular superfluid response 44 than OCS because of its weaker interactions with pH 2 (the H 2 −CO well depth is 109.27 cm −1 45 ).…”

Section: Introductionmentioning

confidence: 99%

Rotational Spectroscopic Study of Quantum Solvation in Isotopologic (pH₂)_N–CO Clusters

Jäger

2017

J. Phys. Chem. A

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We report the Fourier transform microwave spectra of (pH)-CO, (pH)-CO, and (pH)-CO (N ≤ 8) clusters. We find that the frequencies of the a-type J = 1-0 transitions decrease to a minimum at N = 6 and then rapidly increase up to at least N = 8; this is similar to what was previously reported for (pH)-CO, for which the turnaround was found to correlate with an increase in the superfluid fraction of the pH component of the clusters [ Raston Phys. Rev. Lett. 2012 , 108 , 253402 ]. The data suggest that the turnaround in the transition frequency marks an abrupt decrease in the anisotropy of the potential (i.e., in going from N = 6 → 7 → 8), as evidenced from the isotopologic differences rapidly evolving from end-over-end to free-rotor character. Structurally, a more quantitative analysis of the anisotropy was hindered by the lack of accurate frequencies in the b-type series, and a simple Kraitchman analysis yielded unphysical results. In addition to comparing the transition frequencies of the different isotopologic clusters, we provide here more comprehensive details and further discussion of the initial measurements made on (pH)-CO.

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FAR-INFRARED SPECTROSCOPY OF THE H₂-O₂VAN DER WAALS COMPLEX

Cited by 8 publications

References 17 publications

Far-Infrared Synchrotron Spectroscopy and Quantum Chemical Calculations of the Potentially Important Interstellar Molecule, 2-Chloroethanol

Far-Infrared Synchrotron Spectroscopy and Quantum Chemical Calculations of the Potentially Important Interstellar Molecule, 2-Chloroethanol

Far-Infrared Synchrotron Spectroscopy and Torsional Analysis of the Important Interstellar Molecule, Vinyl Alcohol

Rotational Spectroscopic Study of Quantum Solvation in Isotopologic (pH₂)_N–CO Clusters

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FAR-INFRARED SPECTROSCOPY OF THE H2-O2VAN DER WAALS COMPLEX

Cited by 8 publications

References 17 publications

Far-Infrared Synchrotron Spectroscopy and Quantum Chemical Calculations of the Potentially Important Interstellar Molecule, 2-Chloroethanol

Far-Infrared Synchrotron Spectroscopy and Quantum Chemical Calculations of the Potentially Important Interstellar Molecule, 2-Chloroethanol

Far-Infrared Synchrotron Spectroscopy and Torsional Analysis of the Important Interstellar Molecule, Vinyl Alcohol

Rotational Spectroscopic Study of Quantum Solvation in Isotopologic (pH2)N–CO Clusters

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Product

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FAR-INFRARED SPECTROSCOPY OF THE H₂-O₂VAN DER WAALS COMPLEX

Rotational Spectroscopic Study of Quantum Solvation in Isotopologic (pH₂)_N–CO Clusters