Chalcogen Bonding Ion‐Pair Cryptand Host Discrimination of Potassium Halide Salts
Andrew Docker, Thanthapatra Bunchuay, Michael J. Ahrens, Antonio J. Martínez‐Martínez, Paul D. Beer
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 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.