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Title: Reactions of Atomic Carbon with Butene Isomers: Implications for Molecular Growth in Carbon-Rich Environments

We carried out the product detection studies of C( 3P) atom reactions with butene (C 4H 8) isomers (but-1-ene, cis-but-2-ene, trans-but-2-ene) in a flow tube reactor at 353 K and 4 Torr under multiple collision conditions. Ground state carbon atoms are generated by 248 nm laser photolysis of tetrabromomethane, CBr 4, in a buffer of helium. Thermalized reaction products are detected using synchrotron tunable VUV photoionization and time-of-flight mass spectrometry. The temporal profiles of the detected ions are used to discriminate products from side or secondary reactions. Furthermore, for the C( 3P) + trans-but-2-ene and C( 3P) + cis-but-2-ene reactions, various isomers of C 4H 5 and C 5H 7 are identified as reaction products formed via CH 3 and H elimination. Assuming equal ionization cross sections for all C 4H 5 and C 5H 7 isomers, C 4H 5:C 5H 7 branching ratios of 0.63:1 and 0.60:1 are derived for the C( 3P) + trans-but-2-ene and the C( 3P) + cis-but-2-ene reactions, respectively. For the C( 3P) + but-1-ene reaction, two reaction channels are observed: the H-elimination channel, leading to the formation of the ethylpropargyl isomer, and the C 3H 3 + C 2H 5 channel. Assuming equal ionizationmore » cross sections for ethylpropargyl and C 3H 3 radicals, a branching ratio of 1:0.95 for the C 3H 3 + C 2H 5 and H + ethylpropargyl channels is derived. Finally, the experimental results are compared to previous H atom branching ratios and used to propose the most likely mechanisms for the reaction of ground state carbon atoms with butene isomers.« less
Authors:
 [1] ;  [2] ;  [3] ;  [2] ;  [1]
  1. Univ. of Rennes, Cedex (France). Inst. of Physics at Rennes
  2. West Virginia Univ., Morgantown, WV (United States). Dept. of Chemistry
  3. Sandia National Lab. (SNL-CA), Livermore, CA (United States). Combustion Research Facility
Publication Date:
Report Number(s):
SAND2016-10088J
Journal ID: ISSN 1089-5639; 649570
Grant/Contract Number:
AC04-94AL85000; AC02-05CH11231
Type:
Accepted Manuscript
Journal Name:
Journal of Physical Chemistry. A, Molecules, Spectroscopy, Kinetics, Environment, and General Theory
Additional Journal Information:
Journal Volume: 120; Journal Issue: 46; Journal ID: ISSN 1089-5639
Publisher:
American Chemical Society
Research Org:
Sandia National Lab. (SNL-CA), Livermore, CA (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:
1338711

Bourgalais, J., Spencer, Michael, Osborn, David L., Goulay, F., and Le Picard, S. D.. Reactions of Atomic Carbon with Butene Isomers: Implications for Molecular Growth in Carbon-Rich Environments. United States: N. p., Web. doi:10.1021/acs.jpca.6b09785.
Bourgalais, J., Spencer, Michael, Osborn, David L., Goulay, F., & Le Picard, S. D.. Reactions of Atomic Carbon with Butene Isomers: Implications for Molecular Growth in Carbon-Rich Environments. United States. doi:10.1021/acs.jpca.6b09785.
Bourgalais, J., Spencer, Michael, Osborn, David L., Goulay, F., and Le Picard, S. D.. 2016. "Reactions of Atomic Carbon with Butene Isomers: Implications for Molecular Growth in Carbon-Rich Environments". United States. doi:10.1021/acs.jpca.6b09785. https://www.osti.gov/servlets/purl/1338711.
@article{osti_1338711,
title = {Reactions of Atomic Carbon with Butene Isomers: Implications for Molecular Growth in Carbon-Rich Environments},
author = {Bourgalais, J. and Spencer, Michael and Osborn, David L. and Goulay, F. and Le Picard, S. D.},
abstractNote = {We carried out the product detection studies of C(3P) atom reactions with butene (C4H8) isomers (but-1-ene, cis-but-2-ene, trans-but-2-ene) in a flow tube reactor at 353 K and 4 Torr under multiple collision conditions. Ground state carbon atoms are generated by 248 nm laser photolysis of tetrabromomethane, CBr4, in a buffer of helium. Thermalized reaction products are detected using synchrotron tunable VUV photoionization and time-of-flight mass spectrometry. The temporal profiles of the detected ions are used to discriminate products from side or secondary reactions. Furthermore, for the C(3P) + trans-but-2-ene and C(3P) + cis-but-2-ene reactions, various isomers of C4H5 and C5H7 are identified as reaction products formed via CH3 and H elimination. Assuming equal ionization cross sections for all C4H5 and C5H7 isomers, C4H5:C5H7 branching ratios of 0.63:1 and 0.60:1 are derived for the C(3P) + trans-but-2-ene and the C(3P) + cis-but-2-ene reactions, respectively. For the C(3P) + but-1-ene reaction, two reaction channels are observed: the H-elimination channel, leading to the formation of the ethylpropargyl isomer, and the C3H3 + C2H5 channel. Assuming equal ionization cross sections for ethylpropargyl and C3H3 radicals, a branching ratio of 1:0.95 for the C3H3 + C2H5 and H + ethylpropargyl channels is derived. Finally, the experimental results are compared to previous H atom branching ratios and used to propose the most likely mechanisms for the reaction of ground state carbon atoms with butene isomers.},
doi = {10.1021/acs.jpca.6b09785},
journal = {Journal of Physical Chemistry. A, Molecules, Spectroscopy, Kinetics, Environment, and General Theory},
number = 46,
volume = 120,
place = {United States},
year = {2016},
month = {10}
}