Electronic absorption spectra of the halogenocyanoacetylene cations in neon matrices

Abstract

The optical absorption spectra of the B²Π_3/2â†�X²Π_3/2 electronic transitions of chloro-,bromo- and iodo-cyanoacetylene cations have been measured in neon matrices at 4.5 K. In the case of the chloro species, the òΣ⁺â†�X²Π_3/2 transition is also observed. The spectra are analysed vibrationally and yield some of the fundamental vibrational frequencies of these cations in their excited electronic states.