Dissociative electron attachment to electronically excited CS2

Abstract

Dissociative attachment of low-energy electrons to the electronically excited and bent 1B2 state of CS2 is studied. The measurements are carried out in a crossed three-beam geometry in which a laser beam is used to prepare the excited molecules. The absolute cross sections for the formation of S- and CS- by dissociative attachment to the 1B2 excited state are determined by a measurement of the relative number density in the excited state. Based on the earlier observation of the formation of S-2 from the linear symmetric ground state of CS2, an increase in the S-2 cross section was expected from the bent excited state. However, S-2 is found to be absent from this state. Possible mechanisms are proposed to explain this counterintuitive result.