Synthesis of Cyclodextrin-based MOFs incorporating amino acid chiral ligands for chiral separation of naproxen enantiomers

Abstract

The design of adsorbent materials capable of efficiently separating chiral molecules were a promising way to achieve selective recognition and separation of racemic enantiomers. Here, a γ-Cyclodextrin (γ-CD) based metal–organic framework (MOF) with D-Histidine (D-His) as a chiral ligand was synthesized for the first time to construct a functional chiral adsorption separation material (D-His@γ-CD-MOF), which can be used as an adsorbent for Naproxen enantiomer (S-/R-Npx). D-His@γ-CD-MOF provided a large number of chiral recognition sites for the selective enrichment of S-Npx based on the realization of the spatial advantage of the MOF structure, and the e.e. % value of a single separation of Npx racemates could reach 20.0 %. Meanwhile, the intermolecular binding patterns were predicted by computer simulations, and the chiral adsorption was attributed to the difference in affinity due to the difference in π-lone pair miscellaneous and hydrogen bonding force capacities of D-His@γ-CD-MOF and S-/R-Npx. Therefore, considering the stereospecific structure of D-His@γ-CD-MOF as well as the lone pair electron and hydrogen bonding coordination ability, it has great prospects for application as a chiral resolution agent.