Electron binding motifs in the (CS₂)_n^- (n>4) cluster anions

Photoelectron imaging spectroscopy of (CS₂)_n ^-, n>4, reveals a new state with an electron binding energy smaller than that of any of the corresponding CS₂^- and C₂S₄^- states known to date. With support from ab initio calculations, two long-lived, metastable binding motifs with small electron binding energies are discussed for these clusters. The first is a solvent network permeating state, where the excess electron is delocalized over a number of linear CS₂ molecules. The second is an excited ₂B¹ state of the core CS₂^- anion stabilized at a slightly bent geometry by the solvation interactions. Based on the observed solvation-induced shifts in binding energy, the second motif is favored.