Investigation of superacidic behavior of hydrogenated FemFn (m = 1/2, n = 1–6/11) complexes and their abilities to form supersalts

The superacidic properties of HFe m F n ( m = 1/2, n = 1–6/11) are calculated by using the Density functional theory with Becke, 3-parameter, Lee–Yang–Parr (DFT/B3LYP) method. To improve accuracy, the Los Alamos National Laboratory 2 double-ζ (LAN2DZ) basis set is employed for Fe and 6-31G (d) basis set for H and F atoms in the calculations. The gas phase acidity of HFe m F n ( m = 1/2, n = 1–6/11) has been calculated by using Gibbs free energies of their deprotonation reactions. The calculated correlation factor ( R 2 = 0.97452) shows that the acidity of protonated superhalogens HFe m F n ( m = 1/2, n = 1–6/11) is directly related to the stability of their respective anionic superhalogens. HFeF 6 acid has comparable strength, while HFe 2 F 11 acid is stronger than the most acidic species HSbF 6 . The current study establishes a novel approach for modeling new superacids that are more acidic than the strongest superacid, HSbF 6 . We have also designed various supersalts using a combination of superacids HFeF 3 (odd n) HFeF 4 (even n), and superbase OLi 3 OH. The calculated dissociation energies through the neutral and ionic channels of supersalts are compared with the respective dissociation energies of traditional salt LiF. In supersalts, the computed nonlinear optical properties (NLO) are affected by whether the number of fluorine atoms is even or odd.