Thermodynamic and kinetic investigations on the reaction of O( 3P) with HNO

Abstract

The reaction of O( 3P) radical with HNO has been studied using the B3LYP method at 6-31++g** level. The computation results reveal that the reaction of O( 3P) with HNO proceeds to the formation of an energy-rich intermediate IM1. Through isomerization or decomposition of IM1, three possible product channels have been found. For the three reaction channels, the geometries and the vibrational frequencies of all species have been calculated and the frequency modes analysis also have been given to elucidate the reaction mechanism. On the basis of geometries optimization, the thermodynamic data and equilibrium constant of the three reaction channels have been calculated using the statistical theory at 500–2500 K. Using Eyring transition state theory with Wigner correction, the activation thermodynamic data, rate constant and frequency factors for the three reaction channels also have been given ranging from 500 to 2500 K at standard pressure. The results show that the reaction channel (1) of producing OH+NO is the main reaction channel in the reaction of O( 3P) with HNO, and it is not only spontaneous but also easy to take place kinetically.