Unconventional Type III Halogen···Halogen Interactions: A Quantum Mechanical Elucidation of σ-Hole···σ-Hole and Di-σ-Hole Interactions

Abstract

Herein, two unconventional type III halogen···halogen interactions, namely, σ-hole···σ-hole and di-σ-hole interactions, were reported in a series of halogenated complexes. In type III, the A-halogen···halogen angles are typically equal to 180°, and the occurrence of σ-hole on halogen atoms is mandatory. Using diverse quantum mechanical calculations, it was demonstrated that the occurrence of such interactions with binding energies varied from −0.35 to −1.30 kcal/mol. Symmetry-adapted perturbation theory-based energy decomposition analysis (SAPT-EDA) revealed that type III interactions are dominated by dispersion forces, while electrostatic forces are unfavorable. Cambridge Structure Database (CSD) survey unveiled the experimental evidence for the manifestation of σ-hole···σ-hole interactions in crystal structures. This work might be deemed as a foundation for a vast number of forthcoming crystal engineering and materials science studies.

External electric field effects on the σ-hole and lone-pair hole interactions of group V elements: a comparative investigation

“…30 In the PoC calculations, molecular stabilization energies for the optimized monomers were computed under the EEF inuence and the eld-free conditions in the presence of À0.25, À0.50, À0.75, and À1.00 au PoCs at an N/P/PoC distance ranging from 2.5 to 6.0 A with a step size of 0.1 A. The molecular stabilization energies were computed as follows: [64][65][66][67]…”

Comparison of ±σ-hole and ±R˙-hole interactions formed by tetrel-containing complexes: a computational study

“…The employed PoC values were set to AE0.10, AE0.25, AE0.50, and AE1.00 au. The strength of the AE s-hole and AE Rc-hole interactions was estimated at MP2/aug-cc-pVTZ(PP) level of theory in terms of the molecular stabilization energy (E stablization ) according to the following equation: 30,49,50,[52][53][54][55][56]…”

“…The point-of-charge (PoC) approach was utilized to precisely determine the Rc-hole location and elucidate the AE s-hole and AE Rc-hole interactions from the electrostatic perspective. 30,49,[52][53][54][55][56] The interaction energies for cTF 3 / and W-T-F 3 /B/Rc/ A complexes (where T ¼ C, Si, and Ge, and W ¼ H and F) were calculated at the MP2/aug-cc-pVTZ(PP) and CCSD(T)/CBS levels of theory. The symmetry adapted perturbation theory (SAPT) and reduced density gradient-noncovalent interaction (RDG-NCI) index calculations were executed to reconnoiter the characteristics and nature of such interactions.…”

C−H•••F−C Interactions: A Guide for Designing Fluorous Monodentate Ligands for the Highly Linear-Selective Hydroformylation at Near-Ambient Pressure

“…Several reported studies aimed at understanding the nature of these interactions, including approaches based on statistical analysis 14 , energy calculations 14 , crystal structure analysis 15 and charge-density analysis 16 . The different statisticalanalysis-based surface area correction approaches 17 have been applied to C-H•••F-C and C-F•••F-C interactions, revealing that the lighter uorine halogen favors the C-H•••F-C interactions 18,19 . The nature of C-H•••F-C interactions in molecular crystals has been exhaustively investigated, and it behaves as a weak hydrogen bond that is dominated by electrostatic and dispersion components when the two fragments are neutral 15,20 .…”