Negative-ion photoelectron spectroscopy of (CS2)n−: coexistence of electronic isomers

Photoelectron spectra of (CS2)n− (1 ≤n≤6) are measured at the photon energy of 4.66 eV. From the photoelectron spectra, the vertical detachment energy of (CS2)n− is determined as a function of cluster size. The spectra for n ≥ 2 are found to consist of two different types of photoelectron bands which arise from isomers having different electronic structures. These ‘electronic’ isomers possess structures represented as CS2− ⋯ (CS2)n−1 and C2S4− ⋯ (CS2)n−2.