An artificial selective binding pocket for multivalent anions

ABSTRACT

In the study, we designed and synthesised a V-shaped quadruple amide receptor R with a pocket of multiple hydrogen-bond network and characterised it through NMR, HRMS and single crystal X-ray diffraction. By the pre-organised hydrogen-bonding interactions, its pocket could accommodate some selected anions such as CF₃SO₃⁻, HSO₄⁻, H₂PO₄⁻, Cl⁻ and Br⁻. The binding constants of R to the guest anions span the order of magnitude from the first power of ten to the third power of ten, according to the ¹H NMR titration experiments. The recognition of R to the multivalent anions demonstrated high selectivity, reaching up to 258.8 between the complexes of R with H₂PO₄⁻ and Br⁻. The density functional theory calculations of these stable complexes illustrated that the origin of the high selectivity is the self-fitness of the shape of R’s binding pocket to the shape of guest anions.

Graphical abstract

KEYWORDS:

• Amide receptor
• binding pocket
• selective binding
• multivalent anions

Acknowledgments

This work was supported by the National Natural Science Foundation of China (51972179 and 52072189); and the Project for Shandong Provincial Natural Science Foundation (ZR2021QB196).

Disclosure statement

No potential conflict of interest was reported by the author(s).

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/10610278.2023.2300832.

Additional information

Funding

The work was supported by the National Natural Science Foundation of China [51972179]; Natural Science Foundation of Shandong Province [ZR2021QB196]; National Natural Science Foundation of China [52072189].