The role of water in N2O anion dissociation and reaction rates of N2O with hydrated electrons in high temperature water

Nitrous oxide (N2O) is known as an important "greenhouse gas" but also a scavenger of hydrated electron and a source of OH radical. While there has been considerable interesting research on the electron attachment to N2O in the gas phase, the presence of solvent molecules will significantly alter the electron affinity, molecular structure and chemical reactivity of N2O. Ab initio calculations of the N2O anion suggest that electron affinity of N2O in gas phase is negative, while a positive value of electron affinity is recommended in a handbook. The calculations also suggest a possible dissociation path of N2O anion in a gas phase and water. The reaction rate of hydrated electrons, (e)aq, with N2O can be fitted with an Arrhenius-type temperature dependence up to 300 C with an activation energy of 15.5 kJ/mol. At higher temperatures, the rate constant decreases to give a local minimum at 380 C.