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

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 sigma‐hole 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.