Quasiclassical trajectory study of the F + ICI system. Effect of the triplet energy of CIF

Abstract

Three-dimensional quasiclassical trajectory calculations have been carried out for the reaction of F atoms with ICI molecules at initial collisional energies of 3.35 and 33.9 kJ mol^–1, using several LEPS potential-energy surfaces, differing in the long-range forces of the triplet energy of CIF. The surfaces have a well that corresponds to the intermediate trihalogen and do not have any barrier in any channel, with the exception of one surface used in previous work that possesses a small barrier for the formation of CIF. It has been found that when the long-range repulsion forces between CI and F decrease, the cross-sections of both channels increase appreciably, the distribution of the population in the vibrational levels of IF becoming broader. For surfaces with small long-range repulsion forces the distribution of the translational energy for the formation of IF does not change with the collisional energy, in close agreement with the experimental results. Besides, the angular distribution of IF is determined by the disposal of angular momentum, and the distributions obtained at high collisional energy are in agreement with the experimental results. Lastly, the role played by the migratory trajectories has been worked out, and it has been found that the migratory formation of IF increases when the long-range repulsion between CI and F decreases.