Photoelectron velocity-map imaging spectroscopy of nickel carbide: examination of the low-lying electronic states

Abstract

The photoelectron detachment of nickel carbide anions has been characterized using photoelectron velocity-map imaging spectroscopy, allowing for a precise assignment of the electron affinity, vibrational frequencies, energy spacing and ordering of the low-lying electronic states. Additional insight into the chemical bonding and electronic structure of ground-state NiC has been achieved by a range of quantum chemical calculations. It is found that the triple-bonded ¹Σ⁺ ground state probably mainly correlates with the Ni 3d⁹4s¹ state, so the triple bonds are better described as involving one electron-sharing σ bond, one electron-sharing π bond, and one Ni → C dative π bond.