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The structure-directing "key-to-lock" interaction of double σ-(I III )-hole donating iodonium cations with the O-flanked pseudo-lacune rims of [β-Mo 8 O 26 ] 4- gives halogen-bonded iodonium-beta-octamolybate supramolecular associates. In the occurrence of their tetragonal pyramidal motifs, deep and broad σ-(I III )-holes of a cation recognize the molybdate backbone, which provides an electronic pool localized around the two lacunae. The halogen-bonded I⋯O linkages in the structures were thoroughly studied computationally and classified as two-center, three-center bifurcated, and unconventional "orthogonal" I⋯O halogen bonds. In the latter, the O-atom approaches orthogonally the C-I III -C plane of an iodonium cation and this geometry diverge from the IUPAC criteria for the identification of the halogen bond., Competing Interests: There are no conflicts of interest to declare., (This journal is © The Royal Society of Chemistry.)

We designed 0D, 1D, and 2D supramolecular assemblies made of diaryliodonium salts (functioning as double σ-hole donors) and carboxylates (as σ-hole acceptors). The association was based on two charge-supported halogen bonds (XB), which occurred between I III sites of the iodonium cations and the carboxylate anions. The sequential introduction of the carboxylic groups in the aryl ring of the benzoic acid added a dimension to the 0D supramolecular organization of the benzoate, which furnished 1D-chained and 2D-layered structures when terephthalate and trimesate anions, correspondingly, were applied as XB acceptors. The structure-directing XB were studied using DFT calculations under periodic boundary conditions and were followed by the one-electron-potential analysis and the Bader atoms-in-molecules topological analysis of electron density. These theoretical methods confirmed the existence of the XB and verified the philicities of the interaction partners in the designed solid-state structures.

We developed an atom- and reaction mass efficient strategy for the preparation of diarylselenides using iodonium salts as reactants. The developed approach allows the obtaining of diarylselenides from the corresponding trimethoxyphenyl-substituted iodonium salts via a two-step one-pot reaction sequence. The proposed metal-free methodology is based on the involvement of both iodonium aryl groups for diarylation.

Five new copper(I) complexes─composed of the paired dibenzohalolium and [CuL 2 ] - (L = 1,2,4-oxadiazolate) counterions in which O,O-atoms of the anion are simultaneously linked to the halogen atom─were generated and isolated as the solid via the three-component reaction between [Cu(MeCN) 4 ](BF 4 ), sodium 1,2,4-oxadiazolates, and dibenzohalolium triflates (or trifluoroacetates). This reaction is different from the previously reported Cu I -catalyzed arylation of 1,2,4-oxadiazolones by diaryliodonium salts. Inspection of the solid-state X-ray structures of the complexes revealed the strong three-center X···O,O (X = Br, I) halogen bonding occurred between the oxadiazolate moieties and dibenzohalolium cation. According to performed theoretical calculations, this noncovalent interaction (or noncovalent chelation) was recognized as the main force in the stabilization of the copper(I) complexes. An explanation for the different behavior of complexes, which provide either chelate or nonchelate binding, is based on the occurrence of additional -CH 3 ···π interactions, which were also quantified.

The arylation of azaheterocycles can be considered as one of the most important processes for the preparation of various biologically active compounds. In the present work, we describe a method for the copper-catalyzed N -arylation of hindered oxazolidinones using diaryliodonium salts. The method succeeds in good to excellent yields for the arylation of 4-alkyloxazolidinones, including sterically hindered isopropyl- and tert -butyl-substituted. The efficiency of the method was demonstrated for a wide range of diaryliodonium salts - symmetric and unsymmetric as well as ortho -substituted derivatives. The developed approach will provide an important contribution in the development and preparation of novel drugs and bioactive molecules containing oxazolidinone moieties.

A single-crystal X-ray diffraction (XRD) study of diaryliodonium tetrachloroaurates (or, in the recent terminology, tetrachloridoaurates), [( p -XC 6 H 4 ) 2 I][AuCl 4 ] (X = Cl, 1 ; Br, 2 ), was performed for 1 (the structure is denoted as 1a to show similarity with the isomorphic structure 2a ) and two polymorphs─ 2a (obtained from MeOH) and 2b (from 1,2-C 2 H 4 Cl 2 ). Examination of the XRD data for these three structures revealed 2-center C-X···Au III (X = Cl and Br) and 3-center bifurcated C-Br···( Cl - Au ) halogen bonding (abbreviated as XB) between the p -Cl or p -Br atoms of the diaryliodonium cations and the gold(III) atom of [AuCl 4 ] - . The noncovalent nature of Au III -involving interactions, the nucleophilicity of the gold(III) atoms, and the electrophilic role of p -X atoms of the diaryliodonium cations in the XBs were studied by a set of complementary computational methods. Combined experimental and theoretical studies allowed the recognition of the d-nucleophilicity of the [d 8 Au III ] atom which, regardless of its rather substantial formal 3+ charge, can function as a d-nucleophilic partner of XB. This conclusion was also supported by theoretical calculations performed for the structures' refcodes BINXOM and ICSD 62511; the obtained data verified the nucleophilicity of Au III toward a K + ions or a σ-(Cl)-hole, respectively. All our results, together with consideration of relevant literature, indicate that gold atoms in the three oxidation states (0, I, and even III) exhibit nucleophilicity in XBs.

Porous architectures characterized by parallel channels arranged in honeycomb or rectangular patterns are identified in two polymorphic crystals of a zwitterionic 4-(aryliodonio)-benzenesulfonate. The channels are filled with disordered water molecules which can be reversibly removed on heating. Consistent with the remarkable strength and directionality of the halogen bonds (XBs) driving the crystal packing formation, the porous structure is stable and fully preserved on almost quantitative removal and readsorption of water. The porous systems described here are the first reported cases of one-component 3D organic frameworks whose assembly is driven by XB only (XOFs). These systems are a proof of concept for the ability of zwitterionic aryliodonium tectons in affording robust one-component 3D XOFs. The high directionality and strength of the XBs formed by these zwitterions and the geometrical constraints resulting from the tendency of their hypervalent iodine atoms to act as bidentate XB donors might be key factors in determining this ability., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Hypervalent iodine(iii)-derivatives display higher catalytic activity than other aliphatic and aromatic iodine(i)- or bromine(i)-containing substrates for a Knorr-type reaction of N -acetyl hydrazides with acetyl acetone to give N -acyl pyrazoles. The highest activity was observed for dibenziodolium triflate, for which 10 mol% resulted in the generation of N -acyl pyrazole from acyl hydrazide and acetyl acetone typically at 50 °C for 3.5-6 h with up to 99% isolated yields. 1 H NMR titration data and DFT calculations indicate that the catalytic activity of the iodine(iii) is caused by the binding with a ketone., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Plasmon-assisted transformations of organic compounds represent a novel opportunity for conversion of light to chemical energy at room temperature. However, the mechanistic insights of interaction between plasmon energy and organic molecules is still under debate. Herein, we proposed a comprehensive study of the plasmon-assisted reaction mechanism using unsymmetric iodonium salts (ISs) as an organic probe. The experimental and theoretical analysis allow us to exclude the possible thermal effect or hot electron transfer. We found that plasmon interaction with unsymmetrical ISs led to the intramolecular excitation of electron followed by the regioselective cleavage of C-I bond with the formation of electron-rich radical species, which cannot be explained by the hot electron excitation or thermal effects. The high regioselectivity is explained by the direct excitation of electron to LUMO with the formation of a dissociative excited state according to quantum-chemical modeling, which provides novel opportunities for the fine control of reactivity using plasmon energy.

Reactions of 2-carbonyl- and 2-hydroxy(or methoxy)alkylbenzimidazoles with arenes in the Brønsted superacid TfOH resulted in the formation of the corresponding Friedel-Crafts reaction products, 2-diarylmethyl and 2-arylmethyl-substituted benzimidazoles, in yields up to 90%. The reaction intermediates, protonated species derived from starting benzimidazoles in TfOH, were thoroughly studied by means of NMR and DFT calculations and plausible reaction mechanisms are discussed.

A ditriflate derivative of 2-iodoxybenzoic acid (IBX) was prepared by the reaction of IBX with trifluoromethanesulfonic acid and characterized by single crystal X-ray crystallography. IBX-ditriflate is the most powerful oxidant in a series of structurally similar IBX derivatives which is best illustrated by its ability to readily oxidize hydrocarbons and the oxidation resistant polyfluoroalcohols.