Dispersion leading potential energy surface of N2·NbN12−: Anion photoelectron spectroscopy and theoretical studies.

In order to understand the dispersion interactions between molecules and to provide information about the potential energy surface of geometry evolutions, NbN12− and N2·NbN12− complexes were investigated by using photoelectron spectroscopy and ab initio calculations. The experimental adiabatic detachment energy (ADE) and vertical detachment energy (VDE) of NbN12− were both measured to be 2.129 ± 0.030 eV. The experimental ADE and VDE of N2·NbN12− were measured to be 2.17 ± 0.05 and 2.23 ± 0.05 eV, respectively, which are slightly higher than those of NbN12−. The structures of NbN12−/0 were confirmed to be hexacoordinated octahedrons. The investigation of N2·NbN12− structures shows that it is stable for N2 to bind to the face or vertex site of octahedron NbN12−; the face-side-on structure has the lowest energy. The calculations based on symmetry-adapted perturbation theory suggest that the dispersion term is predominant and leads to the stability of N2·NbN12− complexes. [ABSTRACT FROM AUTHOR]