Table of Contents
Laser Chemistry
Volume 9 (1988), Issue 1-3, Pages 171-193
http://dx.doi.org/10.1155/LC.9.171

Laser Stimulation and Observation of Simple Gas Phase Radical Reactions

Physikalisch-Chemisches Institut, Universität Heidelberg, Im Neuenheimer Feld 253, Heidelberg D-6900, Germany

Received 19 January 1988; Accepted 29 March 1988

Copyright © 1988 Hindawi Publishing Corporation. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Experiments on the effect of Selective vibrational, translational and orientations excitation of reactants in bimolecular reactions can give important insights into the microscopic dynamics of elementary chemical reactions. The information obtained in such experiments can be compared with the results of theoretical calculations of the reaction dynamics based on ab initio potential energy surfaces and is also of basic interest to improve the kinetic data used in detailed chemical kinetic modelling.

Rotational and vibrational energy transfer between H2 and H0 has been studied directly using Raman excitation combined with time resolved CARS spectroscopy. The competition between reactive and inelastic channels was investigated for reactions of atoms with vibrationally excited H2 and HCl molecules. Selective vibrational excitation was achieved by using infrared laser or Raman-pumping. The reaction products were detected by time resolved atomic line resonance absorption mass-spectrometry and CARS-spectroscopy. In some cases information on the contributions of adiabatic and non-adiabatic reactive pathways could be obtained. The reaction H + O2 OH + O has been studied using translationally hot H atoms at various energies. Absolute total reactive cross-sections, nascent rotational state distributions and information on the distribution of orientations of the OH angular momentum vector using polarized dissociation and analysis laser sources have been obtained.