Relaxation, collisional quenching vibrational

It appears that direct population of high vibrational levels of the ground state is not primarily responsible for the initial distribution of vibrational energy in the NOg molecule formed. Evidence has been presented that vibrationally excited NOg is mainly produced by radiation or collisional quenching of electronically excited NOg. Data on the effects on vibrational relaxation rates of Ng, NOg and COg have also been reported. ... 

Observable effects in the quenching of fluorescence are usually the result of competition between radiation and bimolecular collisional deactivation of electronic energy, since vibrational relaxation is normally so rapid, especially in condensed phases, that emission derives almost entirely from the ground vibrational level of the upper electronic state. The simplest excitation-deactivation scheme, which does not allow for intramolecular radiationless... 

The efficient quenching of the atomic and molecular fluorescence by collisions has been observed in early studies of the luminescence of gaseous compounds (for a review of early work see Ref. 2). In a large number of cases these processes have been explained by the electronic-to-vibrational energy transfer, charge transfer or excited-complex (excimer or exciplex) formation. There remains, however, an important class of collisional processes corresponding to the essentially intramolecular relaxation induced (or assisted) by collisions with chemically inert partners. In such... 

On the basis of all the then available data, Campbell and Thrush proposed the following mechanism for the nitrogen afterglow. The A SJ state is populated by three body combination. Measurements of absolute afterglow intensities were combined with quenching data, as described for O - - NO H- M, to show that formation of A SJt by three body recombination accounted for about 50% of the total rate of recombination of N atoms. The vibrational energy distribution in A SJ is governed by the population process, by collisional redissociation, and by vibrational relaxation. Several types of collision-induced... 

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