Supramolecular architectures featuring Se⋯N secondary-bonding interactions in crystals of selenium-rich molecules: a comparison with their congeners

Abstract

Supramolecular aggregates featuring Se···N contacts have been identified in 88 crystals containing, two, three or four selenium atoms, corresponding to 9% of crystals where Se···N contacts have the potential to...

Dispersion in Crystal Structures of 1-Chloro-3-aryl-5-trihalomethyl-1λ4,2,4,6-thiatriazines: Towards an Understanding of the Supramolecular Organization of Covalent Thiazyl Chlorides

“…Yields were reasonable (>65%) considering the high sensitivity to hydrolysis. 1 H NMR spectra confirmed the condensation reactions by the complete absence of the prominent NH peaks of 1 or 2. Electron impact mass spectrometry confirmed the parent ions, which is rare for thiazyl halides since the chlorine attached to S is usually lost on ionization, but combustion analysis could not be obtained due to hydrolytic instability.…”

“…There is a strong current interest in supramolecular interactions between heterocyclic thiazyls (i.e., compounds containing unsaturated S-N bonds) and their heavier chalcogen (Se,Te) analogues. [1][2][3][4][5][6][7][8][9][10][11][12] A very common motif in all thiazyl intermolecular contacts is an approximately parallelepiped 'double S•••N' interaction (Figure 1, A-C). 13 This motif, which will be designated here as { + S•••N − } 2 , has re-ceived special attention in thiazyl radicals and triplet diradicals, many of which also form 'pancake bonded' dimers, as commonly but not exclusively observed for 1,2,3,5-dithiadiazolyls, A, [3][4][5][6][7][8][9][10][11] and for all known exemplars of 1,3,2,4,6-dithiatriazines, B.…”

“…The motif is also extremely common for simple diamagnetic thiazyls such as the 1,2,5-thiadiazoles, C. 2 For this case, the interactions have been accorded definitive supramolecular synthon status and have received intense interest in connection with -hole type chalcogen bonding, especially for the heavier Se and Te congeners. 1,2,15 A number of approaches have been used to rationalize the observed { + S•••N − } 2 interactions, ranging from simple geometric parameters (distances, angles, interplanar separations), 7,11,16 electrostatic interactions using molecular electrostatic potentials (MEP), 9,10 and formal computation of -holes. [2][3][4][5]7,8 By contrast, very little interest has been shown in the supramolecular structures of thiazyl halides, even though especially the chlorides are by far the most common precursors to many of the above-mentioned neutral thiazyls.…”

Carbon-based Biradicals: Structural and Magnetic Switching

“…In crystals of the yellow folded form, a sheet-like network is formed through an interheteroatom interaction between S and CN groups − (Scheme b), which is now known as a “chalcogen bond”, − and this facilitates the crystallization of the folded form in the pristine crystal. The observed network is similar to that in the planar tetracyanoquinodimethane derivative 13 fused with two thiadiazole rings exhibiting a two-dimensional network with chalcogen bonds (Scheme c). − On the other hand, the violet twisted form of 12 was isolated as a solvate, in which the chalcogen-bonded network is partially broken, so that it can incorporate solvent molecules.…”

Substituent Effect on Chalcogen Bonding in 5-Substituted Benzo[c][1,2,5]selenadiazoles and Their Copper(II) Complexes: Experimental and Theoretical Study

“…Similarly to the other weak interactions, the chalcogen bond (ChB) has attracted considerable attention due to its diverse applications in synthesis, catalysis, crystal engineering, molecular recognition, biochemical processes, functional materials, etc. − Both common di- or tetravalent chalcogen atoms in organic as well as in coordination compounds can potentially act as mono-, bifurcated, or trifurcated ChB donor centers in intermolecular interactions (Scheme a). There are several tactics for regulation/improvement of the strength and directionality of ChB at R–Ch ··· Nu.…”