Effect of Oxygen in the Surface-Catalyzed Excitation of Nitrogen

The emission of the nitrogen first positive bands which follows the recombination of nitrogen atoms at certain surfaces (surface-catalyzed excitation) requires the presence of a small amount of electrically discharged oxygen. We find that the oxygen interacts in the gas phase to produce the emitting N2(B 3Πg) from the vibrationally excited N2(A 3Σu+) which had been formed by N-atom recombination at the surface. This interaction is very rapid, with a rate coefficient estimated at 5 × 10−12 cm3 sec−1. The species of oxygen which is involved is most likely an excited molecule. These results imply that N2(A 3Σu+) can be formed in high concentrations by the surface-catalyzed excitation of nitrogen, provided that care is taken to insure an oxygen-free system.