Energy disequilibrium in the flash photolysis of NO2

From measurements of the absolute concentrations of vibrationally excited oxygen produced in levels v" = 4 to v" = 13, it is concluded that ca. 20 % of the exothermicity of the reaction O(3P) + NO2 → NO + O+2(v" ≤11) (1) appears initially as vibrational energy in oxygen. Vibrationally excited nitric oxide (v" = 1, 2) is also observed and may be produced in this reaction or in the primary process NO2 + hv → NO (v" ≤ 2) + O(3P). More highly excited oxygen (v" ≤ 15), with energy exceeding the exothermicity of the reaction, is produced in reaction (1) when the NO2 is first excited by radiation above the dissociation limit near 400 nm. The excited NO2 thus produced can also transfer energy to nitric oxide. NO2* + NO(v" = 0) → NO2+ NO(v" = 1).