Emission Band Spectra of Nitrogen: A Study of Some Singlet Systems

Abstract

Ten bands of Gaydon's and Herman's singlet systems and eight new bands have been photographed under high resolution and analyzed in detail. Two of the new transitions were shown to be '22-a 'II,, the upper state being in one case identical with Watson's and ICoontz's state g, and one new transition to be ' Ao-w ' A, in type. I t is proposed that the new state 'A, has the same electron configuration as the x '2; state. Two bands in the red and one band in the ultraviolet could not be assigned with certainty. Local perturbations in the p' ' Z;state were observed and shown to be caused by the u = 1 level of the b' ' Z: state. Observed pecularities in the rotatior~al structure of most of the upper states are proposed to be indicative of a transition from case b' to d' coupling. In some cases pronounced decreases in branch intensities were observed, indicating predissociations probably caused by "forbidden" intercombination processes. Identification of the electronic strrict~~re of the higher singlet states in terms of Rydberg orbitals is discussed. Rotational and vibrational constants and excitation energies are presented.

Highly excited states of gerade symmetry in molecular nitrogen

“…40 Finally, the sixth identified singlet gerade state is the z 1 ⌬ g state. This state was observed by Lofthus in 1957 41 in emission. Although this is the only reported observation up to our knowledge, the state is also found in the ab initio calculations of Michels.…”

The spectrum of molecular nitrogen

“…Lofthus [423] observed a new band, degraded to longer wavelengths, at 2498. 6 A, the analysis of which showed that it was due to a transition from an upper level tI:u-l-to v=O of (LlII g • The pusitiu1l of the J. Phys.…”

“…by J anin (m, b' and d) and by J anin and Crozet [347], who added three new systems to this group (0, ~, and d"). Lofthus [423] remeasured most of the bands at higher resolution, and added two new transitions (g and k).…”

“…Lofthus [423] also analyzed the 0-0 band, but at higher resolution. The perturbation in the p' level was readily observed, maximum perturbation lying between J=10 and 11.…”

“…Lofthus [423] analyzed the first of these bands under higher resolution. The predissociation showed up very clearly as a cutting-off of all branches above J' = 11; at least the intensities had decreased so much that the branches could not be followed after this point.…”