Emergence of Chiral Defective Pores Through Chiral Linker Exchange in Nonchiral MOFs for Enantioselective Recognition.

Enantioselective recognition is vital for numerous chemical and biological applications, which, however, remains challenging due to the nearly indistinguishable physicochemical properties of enantiomers. In this study, we report a luminescent sensing strategy for enantioselective recognition based on metal-organic frameworks (MOFs) constructed through chiral linker exchange, which simultaneously introduces chirality and defective sites into the frameworks. The resulting chiral defective MOFs exhibit confined nanopore environments, resulting in distinct luminescence responses toward enantiomers. A pair of enantiomeric MOFs was constructed, exhibiting opposite selective recognition performance toward R- and S-substrates. The sensing behavior arises from the interplay of competitive absorption and electron transfer process, while disparities in binding affinities serve as the dominating factor dictating the enantioselectivity. Meanwhile, this system enables the quantitative detection of enantiomeric excess (ee) values in mixtures through differential luminescence responses. Due to its facile synthesis routes, selectivity, and ease of implementation, this strategy offers a practical approach for developing chiral luminescent sensing materials, while highlighting the significance of host-guest interactions in sensing.