Supramolecular Organization of Diaryliodonium Dicyanoargentates(I) Provided by Iodine(III)–Cyanide Halogen Bonding

Three diaryliodonium dicyanoargentates(I), [MesIAr][Ag(CN)2] (Ar = Ph 1, Mes 2, 4-MeC6H4 3; Mes = 2,4,6-Me3C6H2), were prepared by anion metathesis. The X-ray structural analyses for these crystals revealed C–IIII∙∙∙N≡C halogen bonds (abbreviated as XB) between I atoms of diaryliodonium cations and N atoms of cyano groups, which provide different supramolecular organization. The noncovalent nature of these interactions was studied by density functional theory (DFT) calculations and topological analysis of the electron density distribution in the framework of the quantum theory of atoms in molecules (QTAIM) at the PBE-D3/jorge-DZP-DKH level of theory both in gas phase and crystal models. The philicities of partners in these contacts were confirmed by electron localization function (ELF) projections, electron density/electrostatic potential (ED/ESP) profiles, and Hirshfeld surfaces analysis. An analysis of the available crystallographic data from the literature allows us to find other examples of σ-hole interactions including the dicyanoargentate(I) anion, and the C–X∙∙∙N≡C (X = Br, I, Te) bonding were also confirmed theoretically.