THE $A^{1}\Sigma^{-}_u$ AND $B^{1}\Delta_u$ ELECTRONIC STATES OF $C_{2}N_{2}$

Abstract

Absorption, emission and CN fragment yield spectra of ethanedinitrile $(C_{2}N_{2}$) have been measured between 225 and 206 nm. Even below the dissociation limit, emission is much stronger form the $A^{1}\Sigma^{-}_u$ electronic state than the $B^{1}\Delta_u$ electronic state. Conversely, the dissociation yield is higher from the $B^{1}\Delta_u$ state than from the $A^{1}\Sigma^{-}_u$ state. This allows us to distinguish between the two states. Absorption spectra have been taken for hot and cold samples which allows us to distinguish hot band absorptions. A tentative assignment for the region between 225 and 180 nm will be given.