A suitable model for computational study giving reliable estimation of the catalytic effect of σ-hole donating organocatalysts is suggested.

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–I^III∙∙∙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.

The nucleophilic properties of the isolated dicyanoaurate(I) anion in σ-hole interactions were investigated using theoretical calculations of models from 19 crystalline literature structures. The study focuses on the ability of [Au(CN)₂]⁻ to participate in various noncovalent interactions, including halogen, chalcogen, pnictogen, and tetrel bonds. The research reveals that both nitrogen atoms of the cyanide ligands and the gold(I) center exhibit nucleophilic behavior. The nature of all interactions and philicities of interacting atoms were confirmed using a set of theoretical methods, including QTAIM topological analysis, noncovalent interaction plots (NCIplot), electrostatic potential (ESP) surfaces, electron localization function (ELF), analysis of electron density (ED), and electrostatic potential (ESP) minima in their 1D profiles along the bond paths, BSSE corrected dimerization energies, and NBO charge-transfer analysis. The study demonstrates that the dicyanoaurate(I) anion can act as a versatile building block in supramolecular chemistry, participating in multiple types of noncovalent interactions through different sites, including first confirmed examples of gold(I)-involving intermolecular chalcogen bonds.