An Extensive Set of Accurate Fluoride Ion Affinities for p‐Block Element Lewis Acids and Basic Design Principles for Strong Fluoride Ion Acceptors

Abstract

The computed fluoride ion affinity (FIA) is a valuable descriptor to assess the Lewis acidity of a compound. Despite its widespread use, the varying accuracy of applied computational models hampers the broad comparability of literature data. Herein, we evaluate the performance of selected methods (like DLPNO-CCSD(T)) in FIA computations against CCSD(T)/CBS data and guide for the choice of suitable density functionals that allow the treatment of larger Lewis acids. Based on the benchmarked methods, we computed an extensive set of gas-phase and solvation corrected FIA, that is covering group 13-16 elements featuring moderate to strong electron-withdrawing substituents (190 entries). It permits an unbiased comparison of FIA over a significant fraction of the periodic table, serves as a source of reference for future synthetic or theoretical studies, and allows to derive some simple design principles for strong fluoride ion acceptors. Finally, the manuscript includes a tutorial section for the computation of FIA with and without the consideration of solvation.

σ‐Hole Interactions in Catalysis

“…Similarly, Menjón and colleagues concluded based on their calculated fluoride anion affinities (FIAs) that Sb(C 6 Cl 5 ) 3 is a mild Lewis acid . Recently, Greb and colleagues computationally determined the FIAs of a large variety of different Lewis acids at the DLPNO‐CCSD(T)/aug‐cc‐pVQZ (Table ) . Based on these values, antimony(III) compounds are considerably weaker Lewis acids than AlCl 3 or BCl 3 .…”

A Highly Lewis Acidic Strontium ansa‐Arene Complex for Lewis Acid Catalysis and Isobutylene Polymerization

“…To evaluate the Lewis acidity of 5 , the fluoride and hydride ion affinities (FIA/HIA) were calculated in the gas phase and in the condensed phase in dichloromethane DCM ( ϵ (DCM)=9.08 [25] ). The DCM‐values were shown to successfully level the influence of the charges upon comparing Lewis acidities [26, 27] . FIA and HIA values were referenced to SiMe 3 + calculated at the CCDS(T)/CBS [27] level and G3 level [28] respectively (Table 1).…”

Chemistry of Dicationic Diboranes

“…The quantum-chemically calculated (B3LYP+D3/def2-SVP, singlepoint calculation, CH 2 Cl 2 solution) FIA of the resulting dication equals 448 kJ mol -1 with respect to the COF 3 -/COF 2 Lewis pair (Scheme 13) and 852 kJ mol -1 relatively to the TMSF/TMS + anchor system, implying a strong Lewis acid. [62] Scheme 13. Isodesmic reaction for fluoride ion affinity (FIA) computation of [B 2 (hpp) 2 ] 2+ and the COF 3 -/COF 2 anchor in CH 2 Cl 2 (ε = 8.93).…”