Photolysis of Chlorine Nitrate at 254 nm

Article abstract of DOI:10.1021/j100326a020

The photolysis of ClONO2 has been studied at 254 nm.The production of NO3, NO2, and ClONO and the removal of ClONO2 have been obseved directly, and the yield of O(3P) has been inferred from the production of O3.The production of Cl and NO3 was found to be the dominant photolysis pathway.For ClONO2 concentrations of <*>5*10¹³ molecules cm^-3, the values determined for the quantum yields for the removal of ClONO2, -ψ_ClONO2, and the production of NO3, ψ_NO3, were 0.99+/-0.1 and 1.04+/-0.04, respectively.However, these yields appear to be dependent on the ClONO2 concentration and decrease as ClONO2 concentration increases.For ClONO2 concentrations in the range (3-8)*10¹⁴ molecules cm^-3, the yields, obtained for the formation of O, NO2, and ClONO, are ψ_O=0.24, ψ_NO2=0.25, and ψ_ClONO<*>0.2.No evidence was found for a significant production of NO.The observed behavior may be explained by the production of a long-lived excited state of ClONO2.The results are discussed in relation to the stratospheric behavior of ClONO2.