The rate of destruction of O2 (1Δg) by atomic hydrogen

An analysis of the atmospheric observations of O₂(¹δg) in the dayglow and twilight confirms the crude experimental assessments of Brown [1] and the conclusions that can be made from recent work of Westenberg, Roscoe, and DeHaas [2] that the reaction is relatively slow, much slower than was expected or can be explained easily in theoretical terms. Using a value for the concentration of atomic hydrogen at 85 km, an upper limit rate of 3×10^?13 cm³ molecule^?1 sec^?1 would be compatible with current atmospheric models. An evaluation of the available data for the rates of several reactions involving ground state or electronically excited species, for which the values are reasonably well established, is included to better analyze the general effects of an electronically excited reactant. This further illustrates the unusual slowness of the H + O₂(¹Δg) reaction.