Surface-up constructed tandem-inverted bilayer cyclodextrins for enhanced enantioseparation and adsorption.

A new generation of triazole-bridged bilayer cyclodextrins (CDs) chiral stationary phase (CSP) material was constructed via a surface-up 'click' approach. The synergistic effect of the tandem-inverted duplex CDs was evidenced by the superior enantioresolution ability toward selected chiral compounds and the enhanced adsorption ability toward hesperetin. The enantioselectivities of dansyl amino acids and aryl carboxylic acids were promoted by 10-20%, while the resolutions of some aryl carboxylic acids were significantly increased from 0 to 3.5 and beyond. Adsorption experiments of hesperetin reveal that the binding ability of the target bilayer CDCSP is nearly 2.8 times than that of the single layer CDCSP. The current work provides a simple and practical approach to design and synthesize novel functional materials with cooperative CD dimers on surfaces.