Strength of the Lewis–Brønsted Superacids Containing In, Sn, and Sb and the Electron Binding Energies of Their Corresponding Superhalogen Anions

Abstract

The HInnF3n+1, HSnnF4n+1, and HSbnF5n+1 (n = 1-3) compounds and their corresponding InnF3n+1(-), SnnF4n+1(-), SbnF5n+1(-) (n = 1-3) anions were investigated by employing the B3LYP, QCISD, and OVGF quantum chemistry methods and the LANL2DZ/6-311++G(d,p) basis sets. Our calculations revealed very strong acidity of all examined neutral compounds and large electronic stabilities (in the range 9.9-13.3 eV) of their corresponding anions. The gas phase acidities (manifested by small Gibbs free energies of deprotonation, ΔGacid) predicted for the HSn3F13 and HSb3F16 (ΔGacid of 243.5 and 230.3 kcal/mol at T = 298.15 K, respectively) suggest that these systems should actually act as even stronger acids than the F(SO3)4H and HSbF6 compounds (recognized thus far as the strongest superacids).