Spectral Study of Active Nitrogen Flames Exhibiting CN ``Tail'' Bands

Flames of active nitrogen and simple chlorinated hydrocarbons which exhibit several zones defined by differences in intensity and spectra have been examined under a variety of conditions of flow rate, pressure, added impurities, and burner configuration. One of these zones exhibited strong emission arising from the CN ``tail'' bands, i.e., bands originating in high vibrational levels of the B 2Σ state. Qualitative spectral evidence is consistent with the assumption that the chemical processes responsible for the emission from the different zones all produce CN selectively in the A 2Π state but with different vibrational distributions, and that population of B 2Σ occurs through interaction of mutually perturbing rotational levels of A 2Π and B 2Σ and through collision-induced transfer from unperturbed levels in A 2Π. As an incidental aspect of the work it has been found that traces of air in the N2 supply were helpful for production of the ``pink'' nitrogen afterglow.