Structure and Bonding of Halonium Compounds

The geometry, strength, and physicalnature of the bondingin halonium cationic compounds have been comprehensively investigatedby means of a combined structural and computational analysis. The geometrical parametersand the bonding in [D center dot center dot center dot X center dot center dot center dot D](+) halonium compounds, where D is a Lewis base with N as thedonor atom and X is Cl, Br, or I, have been investigated through acombined structural and computational study. Cambridge StructuralDatabase (CSD) searches have revealed linear and symmetrical [D center dot center dot center dot X center dot center dot center dot D](+) frameworks with neutral donors. By means of density functionaltheory (DFT), molecular electrostatic potential (MEP), and energydecomposition analyses (EDA) calculations, we have studied the effectof various halogen atoms (X) on the [D center dot center dot center dot X center dot center dot center dot D](+) framework, the effect of different nitrogen-donor groups(D) attached to an iodonium cation (X = I), and the influence of theelectron density alteration on the [D center dot center dot center dot I center dot center dot center dot D](+) halonium bond by variation of the R substituents at the N-donorupon the symmetry, strength, and nature of the interaction. The physicalorigin of the interaction arises from a subtle interplay between electrostaticand orbital contributions (sigma-hole bond). Interaction energiesas high as 45 kcal/mol suggest that halonium bonds can be exploitedfor the development of novel halonium transfer agents, in asymmetrichalofunctionalization or as building blocks in supramolecular chemistry.

Automated summary

The geometry, strength, and physical nature of bonding in halonium cationic compounds have been comprehensively studied through a combined structural and computational analysis. The investigation focused on [D......X......D]+ halonium compounds, where D is a Lewis base and X is Cl, Br, or I. Various factors, including different halogen atoms (X) and nitrogen-donor groups (D) attached to an iodonium cation, were analyzed to understand their influence on the symmetry, strength, and nature of the interaction. The interaction arises from an interplay between electrostatic and orbital contributions, with potential applications in halofunctionalization and supramolecular chemistry.