Reaction of O(2 1D 2) with halomethanes

Abstract

The reactions of O(2 1D 2) with the halomethanes CFCl 3, CF 2Cl 2, CF 3Cl, CF 2HCl, CFHCl 2 and CF 3Br have been studied using flash photolysis with kinetic spectroscopy (O(2 1D 2) atoms were generated by photolysis of O 3 or N 2O in the ultraviolet). Formation of ClO has been observed and lower limits for the branching ratio into the channel ▪ relative to the total cross section for removal of O(2 1D 2) were determined as 0.39, 0.47, 0.39, 0.27 and 0.36 for the molecules CF 3Cl, CF 2Cl 2, CFCl 3, CF 2HCl and CFHCl 2, respectively. The secondary yields of ClO following the reaction of CF x Cl 3− x radicals with O 2 are also reported. The reaction of O(2 1D 2) with CF 3Br is shown to yield BrO as a primary product. The photolysis of CCl 3Br in the presence of O 2 is also shown to yield BrO, but in this case via secondary reactions.