The quenching of the resonance radiation of sodium

Abstract

The effective cross-section for quenching of sodium resonance radiation by the saturated and unsaturated hydrocarbons, tertiary amines and several diatomic molecules has been measured. The results indicate that with regard to quenching ability the gases fall into two groups, one comprising the saturated hydrocarbons and the inert gases and the other the unsaturated hydrocarbons and the amines. The difference in behaviour is too pronounced to be explained in terms of the discrepancy between the amount of energy the sodium atom gives up and the quenching molecule can receive, but may be attributed to the presence of unsaturation in the molecule. Within any one series the number of atoms in the molecule apart from the unsaturated centre seems to have little influence on the quenching ability, and it has been concluded that the quenching ability may be regarded as proceeding from a centre of unsaturation. The results have been qualitatively considered in the light of Stearn and Eyring’s theory of non-adiabatic reactions, and in the terminology of the theory of the intermediate complex we may say that the presence of unsaturation manifests itself in a relatively large transmission coefficient.