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Title: The thermal decomposition of the benzyl radical in a heated micro-reactor. I. Experimental findings

The pyrolysis of the benzyl radical has been studied in a set of heated micro-reactors. A combination of photoionization mass spectrometry (PIMS) and matrix isolation infrared (IR) spectroscopy has been used to identify the decomposition products. Both benzyl bromide and ethyl benzene have been used as precursors of the parent species, C{sub 6}H{sub 5}CH{sub 2}, as well as a set of isotopically labeled radicals: C{sub 6}H{sub 5}CD{sub 2}, C{sub 6}D{sub 5}CH{sub 2}, and C{sub 6}H{sub 5}{sup 13}CH{sub 2}. The combination of PIMS and IR spectroscopy has been used to identify the earliest pyrolysis products from benzyl radical as: C{sub 5}H{sub 4}=C=CH{sub 2}, H atom, C{sub 5}H{sub 4}—C ≡ CH, C{sub 5}H{sub 5}, HCCCH{sub 2}, and HC ≡ CH. Pyrolysis of the C{sub 6}H{sub 5}CD{sub 2}, C{sub 6}D{sub 5}CH{sub 2}, and C{sub 6}H{sub 5}{sup 13}CH{sub 2} benzyl radicals produces a set of methyl radicals, cyclopentadienyl radicals, and benzynes that are not predicted by a fulvenallene pathway. Explicit PIMS searches for the cycloheptatrienyl radical were unsuccessful, there is no evidence for the isomerization of benzyl and cycloheptatrienyl radicals: C{sub 6}H{sub 5}CH{sub 2}⇋C{sub 7}H{sub 7}. These labeling studies suggest that there must be other thermal decomposition routes for the C{sub 6}H{sub 5}CH{sub 2}more » radical that differ from the fulvenallene pathway.« less
Authors:
;  [1] ;  [2] ; ;  [1] ;  [3] ; ;  [4] ; ;  [5] ;  [6]
  1. Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309-0215 (United States)
  2. (United States)
  3. Molecular Dynamics Group, Paul Scherrer Institut, CH-5232 Villigen-PSI (Switzerland)
  4. Chemical Sciences Division, Lawrence Berkeley National Laboratories, Berkeley, California 94720 (United States)
  5. National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, Colorado 80401 (United States)
  6. Department of Mechanical Engineering, Center for Combustion and Environmental Research,University of Colorado, Boulder, Colorado 80309-0427 (United States)
Publication Date:
OSTI Identifier:
22416049
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Chemical Physics; Journal Volume: 142; Journal Issue: 4; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; ATOMS; BENZENE; BENZYL RADICALS; BROMIDES; CHEMICAL REACTORS; INFRARED SPECTRA; ISOMERIZATION; MASS SPECTROSCOPY; MATRIX ISOLATION; METHYL RADICALS; PHOTOIONIZATION; PRECURSOR; PYROLYSIS; PYROLYSIS PRODUCTS