Imaging photon-initiated reactions: A study of the Cl({sup 2}P{sub 3/2})+CH{sub 4}{yields}HCl+CH{sub 3} reaction

Journal Article · Thu Sep 01 04:00:00 EDT 2005 · Journal of Chemical Physics

DOI:https://doi.org/10.1063/1.2009737· OSTI ID:20723040

Bass, M J; Brouard, M; Cireasa, R; Clark, A P; Vallance, C ^[1]

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1. Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QZ (United Kingdom)

The hydrogen or deuterium atom abstraction reactions between Cl({sup 2}P{sub 3/2}) and methane, or its deuterated analogues CD{sub 4} and CH{sub 2}D{sub 2}, have been studied at mean collision energies around 0.34 eV. The experiments were performed in a coexpansion of molecular chlorine and methane in helium, with the atomic Cl reactants generated by polarized laser photodissociation of Cl{sub 2} at 308 nm. The Cl-atom reactants and the methyl radical products were detected using (2+1) resonantly enhanced multiphoton ionization, coupled with velocity-map ion imaging. Analysis of the ion images reveals that in single-beam experiments of this type, careful consideration must be given to the spread of reagent velocities and collision energies. Using the reactions of Cl with CH{sub 4}, CD{sub 4}, and CH{sub 2}D{sub 2}, as examples, it is shown that the data can be fitted well if the reagent motion is correctly described, and the angular scattering distributions can be obtained with confidence. New evidence is also provided that the CD{sub 3} radicals from the Cl+CD{sub 4} reaction possess significant rotational alignment under the conditions of the present study. The results are compared with previous experimental and theoretical works, where these are available.

• OSTI ID: 20723040
• Journal Information: Journal of Chemical Physics, Journal Name: Journal of Chemical Physics Journal Issue: 9 Vol. 123; ISSN JCPSA6; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
ATOM-MOLECULE COLLISIONS
ATOMIC BEAMS
CHLORINE
DEUTERIUM
DEUTERIUM COMPOUNDS
HELIUM
HYDROGEN
ISOTOPE EFFECTS
METHANE
METHYL RADICALS
MILLI EV RANGE
MOLECULAR BEAMS
MULTI-PHOTON PROCESSES
PHOTOIONIZATION
PHOTON-MOLECULE COLLISIONS
PHOTONS
REACTION KINETICS
SCATTERING