Molecular Dynamics Study of the Photodissociation of ICN in Ethanol: Effect of Solvent Polarity

In this work the photodissociation process for ICN in ethanol, a moderately polar solvent, was simulated using semi-classical molecular dynamics. Comparisons of the results with previous simulations of the photodissociation of ICN in highly polar and nonpolar solvents were made. The results that were compared include the probabilities for recombination as ICN or the isomer INC, or cage escape as I + CN or I* + CN, as well as the different kinetic and potential energy properties that allow further insight into the influence of the solvent on energy dissipation of the photoproducts. In excellent agreement with experiment, we observed a 59% recombination probability in ethanol, significantly lower than in water. The energy dissipation of the translational, rotational, and vibrational kinetic energy of the photofragments was found to be slower in ethanol than in water primarily due to a weaker caging effect exerted by ethanol.