Chalcogenodiazoles have been intensively studied in recent years in the context of their supramolecular chemistry. In contrast, the newly discovered cationic 1,2,4-selenodiazole supramolecular building blocks, which can be obtained via coupling between 2-pyridylselenyl halides and nitriles, are virtually unexplored. A significant advantage of the latter is their facile structural tunability via the variation of nitriles, which could allow a fine tuning of their self-assembly in the solid state. Here, we explore the influence of the substituent (which derives from the nitrile) and counterions on the supramolecular assembly of cationic 1,2,4-selenodiazoles via chalcogen bonding.

The synthesis of 2-pyridyltellurenyl bromide via Br₂ oxidative cleavage of the Te–Te bond of dipyridylditelluride is reported. Single-crystal X-ray diffraction analysis of 2-pyridyltellurenyl bromide demonstrated that the Te atom of 2-pyridyltellurenyl bromide was involved in four different noncovalent contacts: Te⋯Te interactions, two Te⋯Br ChB, and one Te⋯N ChB contact forming 3D supramolecular symmetrical framework. In contrast to 2-pyridylselenenyl halides, the Te congener does not react with nitriles furnishing cyclization products. 2-Pyridylselenenyl chloride was demonstrated to easily form the corresponding adduct with benzonitrile. The cyclization product was studied by the single-crystal X-ray diffraction analysis, which revealed that in contrast to earlier studied cationic 1,2,4-selenadiazoles, here we observed that the adduct with benzonitrile formed supramolecular dimers via Se⋯Se interactions in the solid state, which were never observed before for 1,2,4-selenadiazoles.

Gold(I) isocyanide complexes featuring Au···Au interactions attract considerable attention because of their tunable photophysical properties. Although the synthetic exploration of isocyanide gold(I) complexes seems reasonable, their structural diversity is mainly limited to linear gold(I) derivatives. The synthesis and structural characterization of cationic three-coordinate gold(I) mixed 2,2′-bipyridyl/isocyanide complex are presented here for the first time. Cationic gold species form supramolecular dimers in the solid state via attractive Au···Au interactions. The nature and energies of aurophilic contacts, which are responsible for dimerization in the solid state, were studied by DFT calculations together with QTAIM, ELF, RDG, and NCI techniques and Hirshfeld surface analysis. The estimated energy of the aurophilic interactions was 6.3 kcal/mol.

The aim of the present study was to explore the transformations of heteroleptic and homoleptic Au( i ) complexes in detail and to systematically map their chemical evolutionary pathways.

In this manuscript, the synthesis and single crystal X-ray diffraction characterization of four N-substituted 1,3,5-triazinanes are reported along with a detailed analysis of the noncovalent interactions observed in the solid state architecture to these compounds, focusing on C–H···π and C–H···O H-bonding interactions. These noncovalent contacts have been characterized energetically by using DFT calculations and also by Hirshfeld surface analysis. In addition, the supramolecular assemblies have been characterized using the quantum theory of “atoms-in-molecules” (QTAIM) and molecular electrostatic potential (MEP) calculations. The XRD analysis revealed a never before observed feature of the crystalline structure of some molecules: symmetrically substituted 1,3,5-triazacyclohexanes possess two chemically identical sulfonamide nitrogen atoms in different sp² and sp³-hybridizations.

Au( i ) and Cu( i ) complexes bearing PPh ₃ or NHC ligands function as dynamic “cocktail”-type systems rather than single-species catalysts, with ligand effects being strongly reaction-dependent.