Dissociative-electron-attachment cross sections: A comparative study of ${\mathrm{NO}}_2$ and ${\mathrm{O}}_3$

Absolute cross sections for dissociative electron attachment (DEA) to ${\mathrm{NO}}_2$ have been measured and compared with that of ${\mathrm{O}}_3.$ A striking similarity is observed in the dissociation channels and the relative cross sections between the two molecules. This similarity is interpreted in terms of a common mechanism for electron capture to the two molecules and is exploited to characterize the nature of the ${\mathrm{NO}}_2$ resonances in analogy with ${\mathrm{O}}_3,$ using specific quantum chemical calculations as well as experimental data. This experimental observation and its interpretation seeks to direct attention to a previously uncommented on aspect of the DEA phenomenon in relation to molecules that are isoelectronically unrelated. The observation also tends to highlight the dominance of electronic polarizability in the electron-molecule scattering potential leading to capture.