Ab initio Study on the Reaction Kinetics of IO+ClO and IO+BrO

Abstract

Ab initio calculations have been performed to investigate various geometries, vibrational frequencies and reaction kinetics of the reactions IO with ClO and IO with BrO, which play a crucial role in atmospheric ozone depletion. Geometries and frequencies have been obtained at the MP2 using SDB(Stuttgart-Dresden-Bonn)TZ basis set for bromine, iodine and cc-pVTZ basis sets for chlorine and oxygen along with (s,p) diffuse functions for all the atoms. The energetics have been studied at the QCISD(T) level of theory at the MP2 optimized geometries. We obtained consistent heat of reactions of the various channels for both the reactions. Calculated heat of formations of the different species are in good agreement with the available data and may serve as future references.