Effect of a single solvent atom on bimolecular reactions: Collisions of O(³P) with hydrocarbon-argon clusters

The reaction between an O(³P) atom and a hydrocarbon molecule weakly bound to an argon atom was studied by classical trajectory simulations. The results are compared to those obtained for the reaction of a free hydrocarbon. A simplistic model system was constructed in which the hydrocarbon was represented as a pseudodiatomic molecule. Although simple, the model reproduced correctly the internal energy distribution in the OH produced in the reaction of the free species. It was found that the OH, produced from the reaction of the van der Waals complex, emerges with less internal energy and less translational energy than the OH from the monomeric process. In the case of the complexed reagents, the collision complex lifetime is longer and the oxygen explores portions of the potential energy surface that are not available in the monomeric reaction.