Nanotubular chiral hyper-crosslinked polymers with ultrafast adsorption rate for enantioselective separation

The separation of racemic mixtures remains a great challenge due to the similar physicochemical properties of enantiomers in achiral environment. In this work, three novel chiral hyper-crosslinked polymers (CHCPs), i.e., D 0-CHCP, D 1-CHCP and D 2-CHCP, were synthesized by tuning the D -phenylalanine ( D -Phe)/benzidine (BZD) ratios. Results show that all three CHCPs exhibit typically hollow cylindrical nanotube. D 1-CHCP and D 2-CHCP achieve ultrafast enantioselective adsorption of D - and L -Phe within 2 min, attributed to ultrathin-walled nanotubes having hierarchically porous structures. More importantly, D 2-CHCP has a high enantiomeric excess ( e.e. ) value of up to 56.01 %, likely due to the cooperative interplay between D 0-CHCP and the implanted chiral recognition unit, as evidenced by the control experiment that D 0-CHCP exhibits chiral separation capability to some extent. In addition, these CHCPs display excellent recyclability and generality for chiral small-molecule drugs. These findings demonstrate that nanotubular CHCPs with ultrathin wall thickness and hierarchically porous structures possess both superior enantioselectivity and ultrafast adsorption rates, thus offering significant potential for practical applications in enantioselective adsorption separation.