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Title: Formaldehyde photodissociation: Dependence on total angular momentum and rotational alignment of the CO product

Abstract

Quasiclassical trajectory calculations are reported to investigate the effects of rotational excitation of formaldehyde on the branching ratios of the fragmentation products, H{sub 2}+CO and H+HCO. The results of tens of thousands of trajectories show that increased rotational excitation causes suppression of the radical channel and enhancement of the molecular channel. Decomposing the molecular channel into ''direct'' and ''roaming'' channels shows that increased rotation switches from suppressing to enhancing the roaming products across our chosen energy range. However, decomposition into these pathways is difficult because the difference between them does not appear to have a distinct boundary. A vector correlation investigation of the CO rotation shows different characteristics in the roaming versus direct channels and this difference is a potentially useful signature of the roaming mechanism, as first speculated by Kable and Houston in their experimental study of photodissociation of acetaldehyde [P. L. Houston and S. H. Kable, Proc. Nat. Acad. Sci. 103, 16079 (2006)].

Authors:
; ;  [1]
  1. Department of Chemistry, Emory University, Atlanta, Georgia 30322 and Cherry L. Emerson Center for Scientific Computation, Emory University, Atlanta, Georgia 30322 (United States)
Publication Date:
OSTI Identifier:
20991240
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Chemical Physics; Journal Volume: 126; Journal Issue: 13; Other Information: DOI: 10.1063/1.2715586; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; ACETALDEHYDE; BRANCHING RATIO; CARBON MONOXIDE; DISSOCIATION; EXCITATION; FORMALDEHYDE; PHOTOLYSIS; RADICALS; REACTION KINETICS

Citation Formats

Farnum, John D., Zhang, Xiubin, and Bowman, Joel M. Formaldehyde photodissociation: Dependence on total angular momentum and rotational alignment of the CO product. United States: N. p., 2007. Web. doi:10.1063/1.2715586.
Farnum, John D., Zhang, Xiubin, & Bowman, Joel M. Formaldehyde photodissociation: Dependence on total angular momentum and rotational alignment of the CO product. United States. doi:10.1063/1.2715586.
Farnum, John D., Zhang, Xiubin, and Bowman, Joel M. Sat . "Formaldehyde photodissociation: Dependence on total angular momentum and rotational alignment of the CO product". United States. doi:10.1063/1.2715586.
@article{osti_20991240,
title = {Formaldehyde photodissociation: Dependence on total angular momentum and rotational alignment of the CO product},
author = {Farnum, John D. and Zhang, Xiubin and Bowman, Joel M.},
abstractNote = {Quasiclassical trajectory calculations are reported to investigate the effects of rotational excitation of formaldehyde on the branching ratios of the fragmentation products, H{sub 2}+CO and H+HCO. The results of tens of thousands of trajectories show that increased rotational excitation causes suppression of the radical channel and enhancement of the molecular channel. Decomposing the molecular channel into ''direct'' and ''roaming'' channels shows that increased rotation switches from suppressing to enhancing the roaming products across our chosen energy range. However, decomposition into these pathways is difficult because the difference between them does not appear to have a distinct boundary. A vector correlation investigation of the CO rotation shows different characteristics in the roaming versus direct channels and this difference is a potentially useful signature of the roaming mechanism, as first speculated by Kable and Houston in their experimental study of photodissociation of acetaldehyde [P. L. Houston and S. H. Kable, Proc. Nat. Acad. Sci. 103, 16079 (2006)].},
doi = {10.1063/1.2715586},
journal = {Journal of Chemical Physics},
number = 13,
volume = 126,
place = {United States},
year = {Sat Apr 07 00:00:00 EDT 2007},
month = {Sat Apr 07 00:00:00 EDT 2007}
}