Dynamics of the reaction of methyl radicals with iodine molecules

The CH3 + I2 reaction is studied by classical trajectory procedures. The majority of reactive collisions occur on a subpicosecond scale near the collinear configuration of CţdI-I, showing an anisotropic dependence on the initial orientation of I2 and significant excitation of the H3CI vibration. The collision involves two periods: the period from the start of collision to the impact (0.2–0.4 ps), where the early release of the exoergicity and energy buildup in the I2 vibration occur: and the period from the impact to the end of collision (0.3–0.5 ps), during which the C⋯I interaction converts the exoergicity into the H3CI vibration.