Chalcogen bond (ChB)–based heteroditopic receptors integrating neutral or positively charged thiazole motifs as anion binding sites and glycol chains as cation binding sites into a host framework were synthesized. 1 H NMR titration experiments revealed that the neutral receptors showed stronger binding ability for cations than for anions, whereas the protonated receptors demonstrated significantly enhanced anion binding but largely diminished cation association. In solution, the charge–neutral receptors displayed ion‐pair binding due to the allosteric effect from the bound cation and anion. Single–crystal X–ray analysis demonstrated the ion pairs are stabilized by the thiazoles through ChB interactions, the glycol chain through ion–dipole interactions, and cation–anion interactions.
Zhu et al. (Wed,) studied this question.