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Title: Infrared Spectroscopy of the Entrance Channel Complex Formed Between the Hydroxyl Radical and Methane in Helium Nanodroplets

Here, the entrance channel complex in the exothermic OH + CH 4 → H 2O + CH 3 reaction has been isolated in helium nanodroplets following the sequential pick-up of the hydroxyl radical and methane. The a-type OH stretching band was probed with infrared depletion spectroscopy, revealing a spectrum qualitatively similar to that previously reported in the gas phase, but with additional substructure that is due to the different internal rotation states of methane (j CH4 = 0, 1, or 2) in the complex. We fit the spectra by assuming the rotational constants of the complex are the same for all internal rotation states; however, subband origins are found to decrease with increasing j CH4. Measurements of deuterated complexes have also been made (OD–CH 4, OH–CD 4, and OD–CD 4), the relative linewidths of which provide information about the flow of vibrational energy in the complexes; vibrational lifetime broadening is prominent for OH–CH 4 and OD–CD 4, for which the excited OX stretching state has a nearby CY 4 stretching fundamental (X, Y = H or D).
Authors:
ORCiD logo [1] ;  [2] ; ORCiD logo [2]
  1. James Madison Univ., Harrisonburg, VA (United States)
  2. Univ. of Georgia, Athens, GA (United States)
Publication Date:
Grant/Contract Number:
SC0008086
Type:
Accepted Manuscript
Journal Name:
Journal of Physical Chemistry. A, Molecules, Spectroscopy, Kinetics, Environment, and General Theory
Additional Journal Information:
Journal Volume: 121; Journal Issue: 40; Journal ID: ISSN 1089-5639
Publisher:
American Chemical Society
Research Org:
Univ. of Georgia Research Foundation, Athens, GA (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
OSTI Identifier:
1409064

Raston, Paul L., Obi, Emmanuel I., and Douberly, Gary E.. Infrared Spectroscopy of the Entrance Channel Complex Formed Between the Hydroxyl Radical and Methane in Helium Nanodroplets. United States: N. p., Web. doi:10.1021/acs.jpca.7b07906.
Raston, Paul L., Obi, Emmanuel I., & Douberly, Gary E.. Infrared Spectroscopy of the Entrance Channel Complex Formed Between the Hydroxyl Radical and Methane in Helium Nanodroplets. United States. doi:10.1021/acs.jpca.7b07906.
Raston, Paul L., Obi, Emmanuel I., and Douberly, Gary E.. 2017. "Infrared Spectroscopy of the Entrance Channel Complex Formed Between the Hydroxyl Radical and Methane in Helium Nanodroplets". United States. doi:10.1021/acs.jpca.7b07906. https://www.osti.gov/servlets/purl/1409064.
@article{osti_1409064,
title = {Infrared Spectroscopy of the Entrance Channel Complex Formed Between the Hydroxyl Radical and Methane in Helium Nanodroplets},
author = {Raston, Paul L. and Obi, Emmanuel I. and Douberly, Gary E.},
abstractNote = {Here, the entrance channel complex in the exothermic OH + CH4 → H2O + CH3 reaction has been isolated in helium nanodroplets following the sequential pick-up of the hydroxyl radical and methane. The a-type OH stretching band was probed with infrared depletion spectroscopy, revealing a spectrum qualitatively similar to that previously reported in the gas phase, but with additional substructure that is due to the different internal rotation states of methane (jCH4 = 0, 1, or 2) in the complex. We fit the spectra by assuming the rotational constants of the complex are the same for all internal rotation states; however, subband origins are found to decrease with increasing jCH4. Measurements of deuterated complexes have also been made (OD–CH4, OH–CD4, and OD–CD4), the relative linewidths of which provide information about the flow of vibrational energy in the complexes; vibrational lifetime broadening is prominent for OH–CH4 and OD–CD4, for which the excited OX stretching state has a nearby CY4 stretching fundamental (X, Y = H or D).},
doi = {10.1021/acs.jpca.7b07906},
journal = {Journal of Physical Chemistry. A, Molecules, Spectroscopy, Kinetics, Environment, and General Theory},
number = 40,
volume = 121,
place = {United States},
year = {2017},
month = {9}
}