Association reactions of oxygen atoms

A predissociation, which may or may not be related to the one just discussed, is observed in hot flames147 and in cool atomic flames148. For rotationless states the predissociating curve appears to cross the bound 2E+ state very near v = 2. The corresponding inverse predissociation has been proposed149,150 as an explanation for the observed overpopulation of the first and second vibrational levels of OH(2E+) in flames where there is a considerable excess population (over thermodynamic equilibrium) of O and H atoms. This process may produce a population inversion in nozzle expansion of a dissociated gas 15 x. 

The two-body radiative recombination of N+O has been observed by Tanaka152, and by Young and Sharpless153 in nitrogen afterglows partially titrated with NO. The fast reaction 

The emission intensity in the (0,0) band of the C(2IJ)-X(2I1) system is independent of pressure, 0.2 P 10 torr153, indicating that no third body is involved in the inverse predissociation 

Furthermore, the emission is not strongly quenched by N20 or C02153, or by N2 (half quenching pressure = 22 torr)154 so this association reaction seems to be particularly simple (cf. the halogens, where a third body appears to be involved in three distinct ways). 

Callear and Smith154 have made a careful study of the fluorescence and predissociation of the C state, and agree that the a417 state is involved. NO (C, v = 0) 

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The associative reaction of oxygen atoms with nitric oxide produces the yellow-green chemiluminescence in the air afterglow, easily seen by the naked eye. The reaction has long been used to measure the concentrations of O atoms in kinetics experiments [49-51] and is so bright that it has been used to visualize... 

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