Self-Assembly of Supramolecular Architectures Driven by σ-Hole Interactions: A Halogen-Bonded 2D Network Based on a Diiminedibromido Gold(III) Complex and Tribromide Building Blocks

Abstract

The reaction of the complex [Au(phen)Br2](PF6) (phen = 1,10-phenanthroline) with molecular dibromine afforded {[Au(phen)Br2](Br3)}∞ (1). Single crystal diffraction analysis showed that the [Au(phen)Br2]+ complex cations were bridged by asymmetric tribromide anions to form infinite zig-zag chains featuring the motif ···Au–Br···Br–Br–Br···Au–Br···Br–Br–Br···. The complex cation played an unprecedented halogen bonding (XB) donor role engaging type-I and type-II XB noncovalent interactions of comparable strength with symmetry related [Br3]− anions. A network of hydrogen bonds connects parallel chains in an infinite 2D network, contributing to the layered supramolecular architecture. DFT calculations allowed clarification of the nature of the XB interactions, showing the interplay between orbital mixing, analyzed at the NBO level, and electrostatic contribution, explored based on the molecular potential energy (MEP) maps of the interacting synthons.

An Experimental and Theoretical Insight into I2/Br2 Oxidation of Bis(pyridin‐2‐yl)Diselane and Ditellane

“…A comparison of optimized and structural data, available for compounds L1 , [23,55,56] L2 , [26] 2 , [25] 3 , 4 , [28] 5 , and 6 showed an excellent agreement at the selected level of theory (Table S6 and Figure S6). In particular, the optimized chalcogen‐chalcogen bond lengths in L1 and L2 were calculated to be 2.349 (average structural distance in the two known polymorphs, 2.30 Å) [23–56] and 2.723 Å (structural distance, 2.656 Å) [26] for Ch =Se and Te, respectively. The potential energy surface (PES) of compounds L1 and L2 was investigated to verify the preferential conformations of the two compounds.…”

“…[28] During the past decades, our research group has been studying the reactivity of pnictogen [30,31] and chalcogen donors [18,32,33] with dihalogens, with the aim of investigating the nature of the reaction products, [34,35] their formation mechanism, [36] and the use of vibrational spectroscopy to investigate three-body systems of the type ChÀ XÀ Ch, ChÀ XÀ X, and XÀ ChÀ X. [37] In addition, we have investigated the supramolecular assemblies formed by means of noncovalent interactions, such as halogen bond (XB) [37,38] and chalcogen bond (ChB). [39] In this paper, we present an in-depth structural, spectroscopic, and theoretical investigation on the products obtained by reacting compounds L1 and L2 with I 2 and Br 2 .…”

Unveiling the significance of adduct formation between thiocarbonyl Lewis donors and diiodine for the structural organization of rhodanine-based small molecule semiconductors

“…31 Cationic products can be counterbalanced by discrete or extended (poly)iodides with the general formula [I 2m+n ] nÀ (n, m 4 0), such as [I 4 ] 2À , [I 5 ] À , and [I 7 ] À , with the largest reported so far being the ferrocenium salt of [I 29 ] 3À . 36,37 To investigate the potential scenarios involving rhodanine-containing thiophene derivatives, BTR and I 2 were made to react under various reaction conditions, systematically changing both the solvents and the molar ratios of reactants. Single crystals of BTR were grown by slow evaporation of an ethanol solution (Table S1, ESI †).…”

Synthesis, X-ray characterization and DFT analysis of dicyanidoaurate telluronium salts: on the importance of charge assisted chalcogen bonds

“…This underscores the importance of interaction directionality and appropriate counterion geometry in establishing robust metallophilic interactions. 55 The δ Ch⋯A values for the Te⋯N and Te⋯C chalcogen bonding interactions in compounds 1 and 2 were derived using the equation proposed by Aragoni et al 56 and are given in Table 1. These values shed light on the relative shortening 1 and referencing the literature scale, 56 we deduce that both compounds presented feature one medium-strong ChB (Te1⋯N1 contact) and two weaker interactions (Te1⋯N2 and Te1⋯C2).…”