Adaptive host-guest chiral recognition in nanoarchitectonics with biomimetic MOF mimicking DNA

Biomimetic chiral metal organic frameworks (BioMOFs) act as chiral selectors to recognize and sense chiral molecules mimicking biological functional systems, providing a novel perspective for chiral recognition in natural processes. Here, a biological chiral metal-organic framework has been successfully prepared, namely ZnBTCHx (BTC = 1,3,5-benzenetricarboxylic acid, Hx = hypoxanthine), which has periodic large and small grooves similar to the double helix structure of DNA. The adaptability of the local shape of ZnBTCHx can facilitate specific recognition of the chiral guest. The tryptophan (Trp) enantiomer enters the main groove of ZnBTCHx as a guest, and the ZnBTCHx groove selectively recognizes L- and D-Trp because the size and shape of the Trp enantiomer match the groove of ZnBTCHx and it fits snugly into the primary groove. The way in which L-/D-Trp binds to ZnBTCHx reveals key molecular interactions that confer host-guest binding specificity, including pi-pi interactions as well as hydrogen bonding between chiral host and guest molecules, and spatial adaptation.