Chirality-Controlled Mercapto-β-cyclodextrin Covalent Organic Frameworks for Selective Adsorption and Chromatographic Enantioseparation

Abstract

Chiral covalent organic frameworks (CCOFs) benefit from superior stability, abundant chiral environment, and homogeneous pore configuration. In its constructive tactics, only the post-modification method allows for the integration of supramolecular chiral selectors into achiral COFs. Here, the finding utilizes 6-deoxy-6-mercapto-β-cyclodextrin (SH-β-CD) as chiral subunits and 2,5-dihydroxy-1,4-benzenedicarboxaldehyde (DVA) as the platform molecule to synthesize chiral functional monomers through thiol-ene click reactions and directly establish ternary “pendant-type” SH-β-CD COFs. The chiral site density on SH-β-CD COFs was regulated by changing the proportion of chiral monomers to obtain an optimal construction strategy and remarkably improve the ability of chiral separation. SH-β-CD COFs were coated on the inner wall of the capillary in a covalently bound manner. The prepared open tubular capillary was achieved for the separation of six chiral drugs. By combining the outcomes of selective adsorption and chromatographic separation, we observed the higher density of chiral sites in the CCOFs, and poorer results were achieved. From the perspective of spatial conformational distribution, we interpret the variation in the performance of these chirality-controlled CCOFs for selective adsorption and chiral separation.

Nanocrystalline Porous Materials for Chiral Separation: Synthesis, Mechanisms, and Applications

“…Reproduced from Wu, J.; Li, L.; Cao, L.; Liu, X.; Li, R.; Ji, Y. Chirality-Controlled Mercapto-β-Cyclodextrin Covalent Organic Frameworks for Selective Adsorption and Chromatographic Enantioseparation. ACS Appl Mater Interfaces 2023 , 15 , 27214–27222 (ref ). Copyright 2023 American Chemical Society.…”

“…The efficacy of this point is excellently demonstrated in the recent study conducted by Ji et al, where they successfully synthesized chiral functional monomers by the sulfhydryl click reaction employing 6-deoxy-6-mercapto-β-cyclodextrin (SH-β-CD) as a chiral substituent and 2,5-dihydroxy-1,4-benzenedicarboxylic acid (DVA) as the platform molecule (Figure ). Ternary [SH-β-CD] x COFs ( x is the ratio of chiral functional monomers) were directly established . The modulation of chiral site density on the COF was achieved by adjusting the value of x , which resulted in precise control of chirality.…”