Computational results for the surface impact of (CH3I)(n) clusters are presented, and the dynamics of formation of molecular products is examined. The mechanism is compared to the high energy bimolecular CH3I + CH3I collision and to other reactions in impact-heated clusters, in particular, the burning of air. The results are discussed in reference to the experimentally: observed formation of molecular iodine (as I-2(-)) in surface collisions of (CH3I)(n)(-) clusters.