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Title: Analyzing velocity map images to distinguish the primary methyl photofragments from those produced upon C-Cl bond photofission in chloroacetone at 193 nm

Abstract

We use a combination of crossed laser-molecular beam scattering experiments and velocity map imaging experiments to investigate the three primary photodissociation channels of chloroacetone at 193 nm: C-Cl bond photofission yielding CH{sub 3}C(O)CH{sub 2} radicals, C-C bond photofission yielding CH{sub 3}CO and CH{sub 2}Cl products, and C-CH{sub 3} bond photofission resulting in CH{sub 3} and C(O)CH{sub 2}Cl products. Improved analysis of data previously reported by our group quantitatively identifies the contribution of this latter photodissociation channel. We introduce a forward convolution procedure to identify the portion of the signal, derived from the methyl image, which results from a two-step process in which C-Cl bond photofission is followed by the dissociation of the vibrationally excited CH{sub 3}C(O)CH{sub 2} radicals to CH{sub 3}+ COCH{sub 2}. Subtracting this from the total methyl signal identifies the methyl photofragments that result from the CH{sub 3}+ C(O)CH{sub 2}Cl photofission channel. We find that about 89% of the chloroacetone molecules undergo C-Cl bond photofission to yield CH{sub 3}C(O)CH{sub 2} and Cl products; approximately 8% result in C-C bond photofission to yield CH{sub 3}CO and CH{sub 2}Cl products, and the remaining 2.6% undergo C-CH{sub 3} bond photofission to yield CH{sub 3} and C(O)CH{sub 2}Cl products.

Authors:
; ;  [1]
  1. James Franck Institute and Department of Chemistry, University of Chicago, Chicago, Illinois 60637 (United States)
Publication Date:
OSTI Identifier:
22038646
Resource Type:
Journal Article
Journal Name:
Journal of Chemical Physics
Additional Journal Information:
Journal Volume: 135; Journal Issue: 3; Other Information: (c) 2011 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0021-9606
Country of Publication:
United States
Language:
English
Subject:
74 ATOMIC AND MOLECULAR PHYSICS; 37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; CARBON COMPOUNDS; DISSOCIATION; MOLECULAR BEAMS; MULTI-PHOTON PROCESSES; ORGANIC COMPOUNDS; PHOTOFISSION; PHOTOLYSIS; PHOTON-MOLECULE COLLISIONS; VIBRATIONAL STATES

Citation Formats

Alligood, Bridget W., Straus, Daniel B., and Butler, Laurie J. Analyzing velocity map images to distinguish the primary methyl photofragments from those produced upon C-Cl bond photofission in chloroacetone at 193 nm. United States: N. p., 2011. Web. doi:10.1063/1.3609757.
Alligood, Bridget W., Straus, Daniel B., & Butler, Laurie J. Analyzing velocity map images to distinguish the primary methyl photofragments from those produced upon C-Cl bond photofission in chloroacetone at 193 nm. United States. doi:10.1063/1.3609757.
Alligood, Bridget W., Straus, Daniel B., and Butler, Laurie J. Thu . "Analyzing velocity map images to distinguish the primary methyl photofragments from those produced upon C-Cl bond photofission in chloroacetone at 193 nm". United States. doi:10.1063/1.3609757.
@article{osti_22038646,
title = {Analyzing velocity map images to distinguish the primary methyl photofragments from those produced upon C-Cl bond photofission in chloroacetone at 193 nm},
author = {Alligood, Bridget W. and Straus, Daniel B. and Butler, Laurie J.},
abstractNote = {We use a combination of crossed laser-molecular beam scattering experiments and velocity map imaging experiments to investigate the three primary photodissociation channels of chloroacetone at 193 nm: C-Cl bond photofission yielding CH{sub 3}C(O)CH{sub 2} radicals, C-C bond photofission yielding CH{sub 3}CO and CH{sub 2}Cl products, and C-CH{sub 3} bond photofission resulting in CH{sub 3} and C(O)CH{sub 2}Cl products. Improved analysis of data previously reported by our group quantitatively identifies the contribution of this latter photodissociation channel. We introduce a forward convolution procedure to identify the portion of the signal, derived from the methyl image, which results from a two-step process in which C-Cl bond photofission is followed by the dissociation of the vibrationally excited CH{sub 3}C(O)CH{sub 2} radicals to CH{sub 3}+ COCH{sub 2}. Subtracting this from the total methyl signal identifies the methyl photofragments that result from the CH{sub 3}+ C(O)CH{sub 2}Cl photofission channel. We find that about 89% of the chloroacetone molecules undergo C-Cl bond photofission to yield CH{sub 3}C(O)CH{sub 2} and Cl products; approximately 8% result in C-C bond photofission to yield CH{sub 3}CO and CH{sub 2}Cl products, and the remaining 2.6% undergo C-CH{sub 3} bond photofission to yield CH{sub 3} and C(O)CH{sub 2}Cl products.},
doi = {10.1063/1.3609757},
journal = {Journal of Chemical Physics},
issn = {0021-9606},
number = 3,
volume = 135,
place = {United States},
year = {2011},
month = {7}
}