Definition of the Halogen Bond (IUPAC Recommendations 2013): A Revisit

Crystal Growth & Design, Journal Year: 2024, Volume and Issue: 24(13), P. 5494 - 5525

Published: June 24, 2024

This Article revisits the "Definition of Halogen Bond (IUPAC Recommendations 2013)" [Desiraju, G. R. Pure Appl. Chem. 2013, 85 (8), 1711–1713], recommendations that fail to include fundamental, underlying concept (electrophilic) σ- and p-/π-hole theory orbital-based charge transfer interactions accompany halogen bond formation. An electrophilic σ-hole, or p-/π-hole, is an electron-density-deficient region positive polarity (and potential) on electrostatic surface side along, orthogonal to, a covalently bonded in molecular entity leads development noncovalent interaction─a bond─when close proximity electron-density-rich nucleophilic same another identical different entity, with which it interacts. re-examines characteristic features lists wide variety donors acceptors participate bonding. We add caveats are essential for identifying bonding chemical systems, necessary appropriate use terminologies involved. Illustrative examples systems feature inter- intramolecular bonds other crystalline phase given, together case study some dimer using first-principles calculations. also point out π-hole/belt (or p-hole/belt) may develop derivative halogenated molecules be prone forming when nucleophiles similar entity.

Language: Английский

Halogen Bond via an Electrophilic π-Hole on Halogen in Molecules: Does It Exist?

International Journal of Molecular Sciences, Journal Year: 2024, Volume and Issue: 25(9), P. 4587 - 4587

Published: April 23, 2024

This study reveals a new non-covalent interaction called π-hole halogen bond, which is directional and potentially non-linear compared to its sister analog (σ-hole bond). A shown here be observed on the surface of in halogenated molecules, can tempered display aptness form bond with series electron density-rich sites (Lewis bases) hosted individually by 32 other partner molecules. The [MP2/aug-cc-pVTZ] level characteristics bonds 33 binary complexes obtained from charge density approaches (quantum theory intramolecular atoms, molecular electrostatic potential, independent gradient model (IGM-δginter)), intermolecular geometries energies, second-order hyperconjugative transfer analyses are discussed, similar interactions. That molecules substantiated experimentally reported crystals documented Cambridge Crystal Structure Database. importance design growth chemical systems synthetic chemistry, crystallography, crystal engineering yet fully explicated.

Language: Английский

Halogen Bonds Formed by Halogen’s p/π-Hole in Molecules Help Shape Crystalline Materials

Crystal Growth & Design, Journal Year: 2025, Volume and Issue: unknown

Published: April 24, 2025

Language: Английский