A model of rotational-translational energy transfer in the exit-channel of a three-atom unimolecular reaction.

For a three-atom unimolecular reaction of the type ABC --> AB + C performed in a supersonic molecular beam experiment, we propose an analytical model to describe how the rotational angular momentum of AB varies from the transition state onto the separated products. This model is compared with quasiclassical trajectory calculations on a model potential energy surface and the agreement found is very satisfying. Including this model in a statistical treatment could possibly extend its ability to describe processes involving non-negligible exit-channel rotational-translational energy transfers. (C) Academie des Sciences/Elsevier, Paris.