Carborane superhalide bases and their conjugate Brønsted-Lowry Superacids: Electron binding energies and Dyson orbitals

Abstract Superacidity in protonated carboranes arises from properties of conjugate anions: shallow, uniform electrostatic potentials, large electron detachment energies and nodal structure in Dyson orbitals. Vertical electron detachment energies (VEDEs) and Dyson orbitals of closo CHB 11 X 11 − (X = H, F, Cl) carboranes calculated with ab initio electron-propagator theory in the renormalized partial third order (P3+) and non-diagonal, renormalized, second-order (NR2) approximations are in close agreement with anion photoelectron spectra. Whereas first VEDEs to 2 E 2 final states of all three of these superhalide anions exceed 6 eV, a more promising strategy for enhancing superacidity is increasing the anionic base’s second VEDE to the lowest 2 E 1 final state.