Quantum chemical study of the electronic structures of MnC2-/0 clusters and interpretation of the anion photoelectron spectra

Cyclic and linear MnC 2 - / 0 clusters have been theoretically studied. The 7 A 1 and 6 A 1 states of the cyclic isomer are calculated to be the ground states of the anionic and neutral cluster, respectively. All observed bands in the experimental photoelectron spectra of MnC 2 - could be assigned to the cyclic isomer. The X band is ascribed to an ionization during which an electron is detached from a nonbonding 4s4p hybrid orbital. The higher bands in the spectra are the result of ionization processes in which an electron from the nonbonding HOMO of the C 2 2 - ligand is removed.