Exploration of Superacidic Properties of HMnF_n (n = 1–6) Using Density Functional Theory

Abstract

Superacids play a key role as catalysts in various processes, such as acylation, esterification, and protonation of diverse chemical compounds. In the present investigation, HMnF n (n = 1-6) superacid series are studied within the quantum chemical framework using density functional theory with the B3LYP functional. The new superacid series is created through protonation of MnF n superhalogen complexes. Various molecular geometries, for example, HMnF, HMnF 2 , HMnF 3 , HMnF 4 , HMnF 5 , and HMnF 6 , are optimized to their respective global energy minimum and molecular properties are analyzed. First, the normal mode frequencies are analyzed in order to verify that the geometries are associated with their respective global minimum. Second, the Gibbs free energy of deprotonation G acid is computed to estimate acidity of the molecules in gas phase. A compound is classified as a superacid if G acid value is below 300 kcal mol −1 . The HMnF n superacid series is found to have G acid values well below this threshold of 300 kcal mol −1 and strength is comparable with fluoroantimonic acid (HSbF 6 ), which is the strongest superacid known having G acid value of 255.5 kcal mol −1 .

Insights into the catalytic activity of boron-doped thiazoles in the Diels–Alder reaction

“…Superhalogen can also act as a superacid. [26][27][28][29] Here, we have taken boron-doped thiazole superhalogen, 30 which is also known as a super-Lewis acid as it has high fluorine ion affinity. 31 Very recently, the dimer of the boron-doped thiazole system has been experimentally synthesized.…”