Chloride capture using a C-H hydrogen-bonding cage.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 31123106.
- Also identified by DOI 10.1126/science.aaw5145.
- No licence information is recorded for this record.
- Because redistribution is not established, this page shows the abstract only. Follow the links below for the full text.
Abstract
Tight binding and high selectivity are hallmarks of biomolecular recognition. Achieving these behaviors with synthetic receptors has usually been associated with OH and NH hydrogen bonding. Contrary to this conventional wisdom, we designed a chloride-selective receptor in the form of a cryptand-like cage using only CH hydrogen bonding. Crystallography showed chloride stabilized by six short 2.7-angstrom hydrogen bonds originating from the cage's six 1,2,3-triazoles. Attomolar affinity (10<sup>17</sup> M<sup>-1</sup>) was determined using liquid-liquid extractions of chloride from water into nonpolar dichloromethane solvents. Controls verified the additional role of triazoles in rigidifying the three-dimensional structure to effect recognition affinity and selectivity: Cl<sup>-</sup> > Br<sup>-</sup> > NO<sub>3</sub> <sup>-</sup> > I<sup>-</sup> This cage shows anti-Hofmeister salt extraction and corrosion inhibition.