Ozone Ultraviolet Photolysis. II. Quantum Yield at Low Ozone Concentration

Abstract

The relative ultraviolet quantum yield was measured at low ozone concentration (∼ 0.2 torr) in order to identify contributing processes under conditions where the Norrish chain mechanism is not expected. The quantum yield in pure O3 and in O3–He mixtures exceeds that in O3–N2 mixtures by a component φx ≈ 2 which is attributed to the products of the O(1D) + O3 reaction. These products decompose ozone with a rate constant k ≤ 107liter/mole·sec and are not affected by a large excess of inert gas. This result tends to rule out O2(3Σu+) as the reactive product.