σ–Hole activation and structural changes upon perfluorination of aryl halides: direct evidence from gas phase rotational spectroscopy

Abstract

Enhancement of the σ-hole on the halogen atom of aryl halides due to perfluorination of the ring is demonstrated by use of the Extended Townes−Dailey (ETD) model coupled to a...

Highly‐Stable CsPbI3 Perovskite Solar Cells with an Efficiency of 21.11% via Fluorinated 4‐Amino‐Benzoate Cesium Bifacial Passivation

“…[ 41 ] The I 3d peaks are shifted to the lower binding energy after ATFC modification (Figure 3b), which is induced by the F···I non‐covalent interaction that is different from the halogen bond because the positively charged σ ‐hole center cannot be formed in ATFC. [ 42 ] The XPS experiments of O 1s, N 1s, and F 1s are performed to reveal the reason for the movement of Pb 2+ peaks. According to Figure 3c–e, with the addition of PbI 2 , the movement of O 1s (1.01 eV, from 530.42 to 531.43 eV) is far larger than that of F 1s (0.38 eV, from 687.38 to 687.76 eV) and N 1s (0.15 eV, from 399.65 to 399.80 eV), suggesting that the Lewis acid–base interaction between CO and undercoordinated Pb 2+ is stronger than that of the coordination interaction of NH 2 ···Pb and the electrostatic interaction of FPb.…”

Weak hydrogen bonding to halogens and chirality communication in propanols: Raman and microwave spectroscopy benchmark theory

“…Relativistic effects are likely to play a role for Br, while Cl should be largely unaffected as previous studies have shown. [82][83][84] To this end, relativistic calculations have been conducted using the Douglas-Kroll-Hess of second order (DKH2) [85][86][87] transformation. For these calculations, the finite nucleus model 88 and picture change effects 89 are included.…”

Rotational Spectroscopy Probes Lone Pair···π-Hole Interactions in Hexafluorobenzene-Tertiary Alkylamines Complexes

“…As regards the P -population anisotropy, two series of data are derived: one from the calculated χ (Δ P zz χ ) and the other from the NBO analysis of the p-orbitals population (Δ P zz NBO ). As already discussed, , the positive value of Δ P zz is a direct measure of the strong electron density along the z -axis, while a negative value indicates a deficiency of electron density (σ-hole) which could lead to interaction with a nucleophilic group. The value of Δ P zz decreases going from the monomer to the complex for C 6 F 6 –NH 3 .…”