A MODEL OF ROTATIONAL-TRANSLATIONAL ENERG Y-TRANSFER IN THE EXIT-CHANNEL OF A 3-ATOM UNIMOLECULAR REACTION

For a three-atom unimolecular reaction of the type ABC --> AB + C perf ormed in a supersonic molecular beam experiment, we propose an analyti cal 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 potent ial energy surface and the agreement found is very satisfying. Includi ng this model in a statistical treatment could possibly extend its abi lity to describe processes involving non-negligible exit-channel rotat ional-translational energy transfers. (C) Academie des Sciences/Elsevi er, Paris.