Selective Potassium Chloride Recognition, Sensing, Extraction, and Transport Using a Chalcogen-Bonding Heteroditopic Receptor

• DOI: 10.1021/jacs.2c05333
• Publication Date: 2022-08-05T16:48:03Z
• Authors: Andrew Docker; Igor Marques; Heike Kuhn; Zongyao Zhang; Vítor Félix; Paul D. Beer
• Keywords: Chalcogen

Chalcogen bonding (ChB) is rapidly rising to prominence in supramolecular chemistry as a powerful sigma (σ)-hole-based noncovalent interaction, especially for applications the field of molecular recognition. Recent studies have demonstrated ChB donor strength and potency be remarkably sensitive local electronic environments, including redox-switchable on/off anion binding sensing capability. Influencing unique geometric environment sensitivity interactions through simultaneous cobound metal cation recognition, herein, we present first potassium chloride-selective heteroditopic ion-pair receptor. The direct conjugation benzo-15-crown-5 ether (B15C5) appendages Te centers bis-tellurotriazole framework facilitates alkali halide (MX) formation cofacial intramolecular bis-B15C5 M+ (M+ = K+, Rb+, Cs+) sandwich complex bidentate ChB···X- formation. Extensive quantitative 1H NMR affinity titration experiments, solid-liquid liquid-liquid extraction, U-tube transport all demonstrate unprecedented KCl selectivity over other group 1 chlorides. It that origin receptor's cooperativity arises from an polarization donors induced by cation. Importantly, magnitude this switch on Te-centered electrophilicity, therefore anion-binding affinity, shown correlate with inherent Lewis acidity computational DFT investigations corroborated experimental cation-anion observations halides oxoanions.