Computer-aided design of triazolo-cages as anion receptors

Abstract

Molecular cages with three-dimensional cavities have garnered significant interest due to their enhanced encapsulation abilities. In this study, we computationally investigate the binding behavior of a triazolo-cage receptor composed of alternating triazole and phenyl building blocks. With six different anions, including atomic (F⁻, Cl⁻, Br⁻, and I⁻), linear (SCN⁻), and trigonal planar (NO₃⁻) geometries, we analyze the binding selectivity of the parent cage with DFT calculations. The influence of solvation on binding strength is investigated by calculating binding free energies in both gas phase and six solvent environments of progressively increasing dielectric constants. Symmetry-Adapted Perturbation Theory (SAPT) analysis reveals that electrostatic interactions dominate the binding process. Additionally, we perform computer-aided design to generate a series of new cage receptors with diverse functionalities, and our findings highlight the tunable chloride affinity achieved by adjusting various cage properties. Overall, this study offers insights into the design of novel cage receptors with versatile functionalities and provides a strategic approach to the rational design of anion receptors.