A path to design stronger superacids by using superhalogens

作者：Srivastava Ambrish Kumar; Kumar Abhishek; Misra Neeraj

来源：Journal of Fluorine Chemistry, 2017, 197: 59-62.

DOI：10.1016/j.jfluchem.2017.03.001

• Superhalogen
• Superacid
• Gas phase acidity
• Vertical detachment energy
• DFT calculations

Conjugate superacids consist of Bronsted/Lewis acid components, which can be designed by the protonation of superhalogen anions, the anions with larger vertical detachment energy (VDE) than halogens. The most stable superhalogen anions are composed of central electropositive atoms with halogen ligands such as BF4-, AlF4-. Using DFT computation at omega B97xD/6-311++G(d,p) level, we design complex superhalogen anions B(BF4)(4)(-), B(AlF4)(4)(-), Al(BF4)(4)(-) and Al(AlF4)(4)(-) by replacing all F by BF4 and AIF(4) moieties in BF4- and AlF4-, whose VDEs exceed to 10 eV. We propose new superacids by protonation of these complex superhalogen anions such that the acidic strengths of HB(BF4)(4) and HAl(AlF4)(4) are comparable to that of HSbF6, the strongest superacid reported so far. Moreover, the acidic strength of HAI (BF4)(4) is larger than that of HSbF6. All the proposed superacids are expected to be thermodynamically more stable than HBF4, an experimentally observed superacid.

• 出版日期2017-5