A metal-organic framework with chiral nanochannels for enantioselective fluorescence switching of amino alcohols.

The origin of chirality in metal-organic frameworks (MOFs) from achiral linkers remains largely unpredictable, as it mainly stems from the intrinsic arrangement of structural components within the framework. To date, only a handful of reports have explored the achiral ligands for chiral MOF synthesis; their potential for chiral molecular recognition remains a fascinating area of research. Here, we have synthesised a 3-D Co-bpy MOF with chiral nanopores using an achiral linker, which undergoes spontaneous chirality induction through asymmetric crystallization. The MOF crystallizes in a 422 chiral space group, featuring distinctive 4-fold helical chains generating chiral nanochannels along the -axis. Remarkably, this structural arrangement enables Co-bpy to exhibit enantioselectivity among chiral amino alcohols by "turn-off" and "turn-off-on" type fluorescence responses for each, with a high enantioselectivity factor.