Velocity-map imaging study of the photodissociation of acetaldehyde

Journal Article · Tue Mar 22 04:00:00 EST 2005 · Journal of Chemical Physics

DOI:https://doi.org/10.1063/1.1861886· OSTI ID:20662326

Cruse, H A; Softley, T P ^[1]

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1. Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Mansfield Road, Oxford OX1 3TA (United Kingdom)

Velocity-map imaging studies are reported for the photodissociation of acetaldehyde over a range of photolysis wavelengths (317.5-282.5 nm). Images are obtained for both the HCO and CH{sub 3} fragments. The mean rotational energy of both fragments increases with photodissociation energy, with a lesser degree of excitation in the CH{sub 3} fragment. The CH{sub 3} images demonstrate that the CH{sub 3} fragments are rotationally aligned with respect to the recoil direction and this is interpreted, and well modeled, on the basis of a propensity for forming CH{sub 3} fragments with M{approx}K, where M is the projection of the rotational angular momentum along the recoil direction. The origin of the CH{sub 3} rotation is conserved motion from the torsional and methyl-rocking modes of the parent molecule. Nonstatistical vibrational distributions for the CH{sub 3} fragment are obtained at higher energies.

• OSTI ID: 20662326
• Journal Information: Journal of Chemical Physics, Journal Name: Journal of Chemical Physics Journal Issue: 12 Vol. 122; ISSN JCPSA6; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
ACETALDEHYDE
ANGULAR MOMENTUM
METHYL RADICALS
PHOTOCHEMISTRY
PHOTOLYSIS
PHOTON-MOLECULE COLLISIONS
REACTION KINETICS
ROTATIONAL STATES
VIBRATIONAL STATES