Classical trajectory studies of the reagent rotational energy dependence for the reactions X + ICH3→ XI + CH3(X = Na and F)

Abstract

The effect of reagent rotational excitation on the dynamics of the reactions Na + ICH₃ and F + ICH₃ has been investigated using classical trajectory methods. Both reactions have similar reagent mass ratios, but very different potential–energy surfaces. For Na + ICH₃ the surface has a small barrier, whereas the surface for F + ICH₃ has a hollow corresponding to the stable intermediate CH₃IF. For both reactions, it is found that as the CH₃I rotational energy increases the reaction cross-section initially remains constant and then either increases or decreases depending on whether the collision energy is high or low. The fraction of the reaction energy that is disposed into product translation. 〈F_T〉, essentially remains constant with changing CH₃I rotational energy, but there is an increased contribution to the product angular distribution from sideways scattering with increasing reagent rotational energy.