The effect of reagent translational energy on the dynamics of the reaction O(P-3)+CS(X(1)Sigma(+))->CO(X(1)Sigma(+))+S(P-3)

D Summerfield*, ML Costen, GAD Ritchie, G Hancock, TWR Hancock, AJ OrrEwing

*Corresponding author for this work

Research output: Contribution to journalArticle (Academic Journal)peer-review

Abstract

Two different regimes of collision energy are used to explore the role of additional translational energy on the dynamics of the reaction O(P-3)+CS(X (1) Sigma(+))-->CO(X (1) Sigma(+))+S(P-3). Product CO rotational quantum-state population distributions for CO(upsilon'=12, 13, and 14) are used as an indicator of the reaction dynamics, and these rotational distributions are presented for reaction of thermal reagents (at 298 K) and for translationally hot oxygen atoms formed by the 355 nn photolysis of NO2. The experimental measurements are compared with the results of quasiclassicai trajectory calculations performed on an empirical London-Eyring-Polanyi-Sato potential energy surface tailored to model the observed dynamics for thermal reagents. Efficient conversion of the extra translational energy into product rotation is seen for all vibrational levels studied. The data are found to fit a simple model in which the fraction of the extra kinetic energy which appears as product rotation varies linearly with kinetic energy, and becomes unity for the fastest oxygen atoms produced by photolysis. The experimental results are interpreted in terms of an increasingly bent transition state for the reaction at higher collision energies, with the possibility of reagent reorientation towards a more Linear transition state as the kinetic energy is decreased. (C) 1997 American Institute of Physics.

Original languageEnglish
Pages (from-to)1391-1401
Number of pages11
JournalJournal of Chemical Physics
Volume106
Issue number4
Publication statusPublished - 22 Jan 1997

Keywords

  • DIFFERENTIAL-CROSS-SECTIONS
  • TRIATOMIC PHOTOFRAGMENT SPECTRA
  • INFRARED CHEMILUMINESCENCE
  • NO2 PHOTODISSOCIATION
  • BIMOLECULAR REACTIONS
  • CHLORINE ATOMS
  • STATE
  • EXCITATION
  • PRODUCT
  • DISTRIBUTIONS

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