Note: Single-ultraviolet-photon dissociation dynamics of ${\rm CS}_{\rm 2}^ + (\tilde X{}^2\Pi _g)$ CS 2+(X̃2Πg) in 227–243 nm revealed by time-sliced velocity map imaging

Abstract

The single-UV-photon (227–243 nm) dissociation of ${\rm CS}_2^ + (\tilde X{}^2\Pi _{g,3/2,1/2})$ CS 2+(X̃2Πg,3/2,1/2) into the S+(4S)CS(X1)Σ+ channel was investigated by means of time-sliced velocity map imaging technique. In the high-energy region of the $\tilde B{}^2\Sigma _u^ +$B̃2Σu+ state, a rather subtle photodissociation dynamics was observed, i.e., a slight variation in the excitation photon energy may lead to a drastic change in the vibronic distributions of the CS(X1Σ+) fragments originating from the two spin-orbit $\tilde X{}^{\rm 2}\Pi _g$X̃2Πg states. The photodissociation mechanisms involved here may be interpreted as being due to the complex interplay among various vibronic and spin-orbit interactions in this energy region of ${\rm CS}_{\rm 2}^ +$ CS 2+. It is quite impressive that, for such a simple triatomic cation species, ${\rm CS}_{\rm 2}^ +$ CS 2+, there exhibits such complexity and subtlety in its photodissociation dynamics.