An experimental manifestation of distinct electronic–structural properties of covalent dimer anions of CO2 and CS2

Photoelectron imaging is employed to examine the monomer and dimer anions of CO2 and CS2, either isolated or embedded in clusters. In both cases, photodetachment from the dimer anion is compared to the corresponding monomer. The comparison of CS2− and (CS2)2− images reveals dissimilar bands attributed to detachment from different orbitals/species. Yet the photoelectron angular distributions obtained from the monomer and dimer anion cores of (CO2)n− clusters are surprisingly similar. These findings are reconciled with the qualitatively different electronic–structural properties of (CS2)2− and (CO2)2−.