A density functional theory and ab initio study of the hydrolysis of dinitrogen pentoxide

The density functional theory and ab initio methods are used to study two minimum energy pathways for the hydrolysis of N2O5 to form nitric acid, one involving a single water molecule and the other involving two water molecules. Both of the reactions are initiated by the nucleophilic attack on N2O5 by water while the additional water in the two-water reaction acts as a polar solvent to stabilize the ion pair resulted from the nucleophilic attack. The activation energy is 20 kcal/mol for the one-water reaction and it is reduced by half for the two-water reaction. The study suggests that the heterogeneous hydrolysis of N2O5 is likely more favorable than the homogeneous process.