Collision energy dependence of the O(1D) + HCl -OH + Cl( 2P) reaction studied by crossed beam scattering and quasiclassical trajectory calculations on ab initio potential energy surfaces

Document Type

Article

Publication Date

2-7-2008

Abstract

The dynamics of the O(1D) + HCl → OH + Cl(2P) reaction are investigated by a crossed molecular beam ion-imaging method and quasiclassical trajectory calculations on the three ab initio potential energy surfaces, the ground 11A′ and two excited (1 1A″ and 21A′) states. The scattering experiment was carried out at collision energies of 4.2, 4.5, and 6.4 kcal/mol. The observed doubly differential cross sections (DCSs) for the Cl(2P) product exhibit almost no collision energy dependence over this inspected energy range. The nearly forward-backward symmetric DCS indicates that the reaction proceeds predominantly on the ground-state potential energy surface at these energies. Variation of the forward-backward asymmetry with collision energy is interpreted using an osculating complex model. Although the potential energy surfaces obtained by CASSCF-MRCI ab initio calculations exhibit relatively low potential barriers of 1.6 and 6.5 kcal/mol for 1 1A″ and 21A′, respectively, the dynamics calculations indicate that contributions of these excited states are small at the collision energies lower than 15.0 kcal/mol. Theoretical DCSs calculated for the ground-state reaction pathway agree well with the observed ones. These experimental and theoretical results suggest that the titled reaction at collision energies less than 6.5 kcal/mol is predominantly via the ground electronic state. © 2008 American Chemical Society.

Identifier

39649107998 (Scopus)

Publication Title

Journal of Physical Chemistry A

External Full Text Location

https://doi.org/10.1021/jp076581x

ISSN

10895639

First Page

818

Last Page

825

Issue

5

Volume

112

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