Chalcogen Bonding Ion‐Pair Cryptand Host Discrimination of Potassium Halide Salts

Abstract

A series of chalcogen, halogen and hydrogen bonding heteroditopic macrobicyclic cryptands are reported and their potassium halide ion-pair recognition properties investigated. Saliently, the co-bound potassium cation was determined to be crucial in switching on the bromide and iodide recognition properties of the respective cryptand receptor. Importantly, the nature of the sigmahole mediated interaction employed in the anion recognition component is demonstrated to significantly augment the ion-pair binding behaviour, markedly so for the halogen bonding analogue. Most notably the incorporation of a chelating chalcogen bonding donor motif significantly improves the selectivity towards KBr over KI, relative to halogen and hydrogen bonding analogues.

Halogen Bonding Tetraphenylethene Anion Receptors: Anion‐Induced Emissive Aggregates and Photoswitchable Recognition

“…Within the rapidly expanding field of supramolecular anion host‐guest chemistry, halogen bonding and chalcogen bonding intermolecular interactions have emerged as a valuable addition to the supramolecular toolbox. [ 24 , 25 , 26 , 27 ] These sigma hole interactions frequently confer enhanced anion affinity and unique selectivity profiles relative to hydrogen bonding (HB) interactions within anion receptors,[ 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 ] sensors[ 38 , 39 , 40 ] and transmembrane anion transporters. [ 41 , 42 , 43 , 44 ]…”

Modulating Chalcogen Bonding and Halogen Bonding Sigma‐Hole Donor Atom Potency and Selectivity for Halide Anion Recognition

“…Treatment of the proto‐alkyne with N ‐iodomorpholine hydroiodide in the presence of catalytic copper(I) iodide gave the bis‐iodoalkyne 2 in 81 % yield. Reaction of 1 with freshly pulverised AgNO 3 in NH 4 OH (aq) /MeOH mixtures facilitated precipitation and isolation of bis‐Ag I ‐acetylide 3 [25, 26] . Synthesis of the bis‐telluro alkynes was achieved by treatment of the appropriate dialkyl‐ or diaryl‐ ditelluride with a 1 M Br 2 CH 2 Cl 2 solution to afford the organo tellurium bromide which was reacted immediately with a THF suspension of 3 , affording the series of bis‐telluro functionalized alkynes 4 and 5 R after rapid chromatographic purification.…”

Anion recognition by halogen bonding and hydrogen bonding bis(triazole)-imidazolium [2]rotaxanes

“…[10][11][12] In more recent years, iodo-triazoles have emerged as synthetically accessible and highly potent XB donors, and accordingly have received intense interest in the field of anion recognition. [13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28] Herein we report a novel, potentially synergistic mixed XB/HB anion recognition motif, comprising of a central imidazolium unit with two adjacent iodotriazole groups (Figure 1). The receptor design exploits a bidentate XB donor array connected via flexible methylene linkers to a charge-assisted C--H HB donor.…”