Chalcogen Bond Mediated Enhancement of Cooperative Ion‐Pair Recognition

Abstract

A series of heteroditopic receptors containing halogen bond (XB) and unprecedented chalcogen bond (ChB) donors integrated into a 3,5‐bis‐triazole pyridine structure covalently linked to benzo‐15‐crown‐5 ether motifs exhibit remarkable cooperative recognition of halide anions. Multi‐nuclear 1H, 13C, 125Te and 19F NMR, ion pair binding investigations reveal sodium cation–benzo‐crown ether binding dramatically enhances the recognition of bromide and iodide halide anions, with the chalcogen bonding heteroditopic receptor notably displaying the largest enhancement of halide binding strength of over two hundred‐fold, in comparison to the halogen bonding and hydrogen bonding heteroditopic receptor analogues. DFT calculations suggest crown ether sodium cation complexation induces a polarisation of the sigma hole of ChB and XB heteroditopic receptor donors as a significant contribution to the origin of the unique cooperativity exhibited by these systems.

Benzothienoiodolium Cations Doubly Bonded to Anions via Halogen-Chalcogen and Halogen-Hydrogen Supramolecular Synthons

“…[9][10][11][12] HB is by far the most commonly studied and employed NCI. XB and ChB donors are broadly used in organic noncovalent catalysis, [13][14][15][16] drug design, [17][18][19][20][21] molecular recognition [22][23][24][25][26][27][28][29] and in various other applications. [30][31][32][33][34][35] They are relatively well studied in crystal engineering [36][37][38][39][40][41] as they provide, in contrast to HB, highly directional supramolecular assembly.…”

Strongσ‐Hole Activation on Icosahedral Carborane Derivatives for a Directional Halide Recognition

“…[10][11][12][13][14][15] Moreover,molecules involving two activated chalcogen atoms have been used to chelate aLewis base,inthe field of organocatalysis or anion recognition. [16][17][18][19][20] Despite those observations and discoveries,h arnessing the ChB for crystal engineering remains challenging due to the presence of two s-holes that can significantly deviate from the CÀCh bond axis, [21,22] in contrast to monotopic and directional XB.…”