Hierarchical Chirality Memory Governs Dual Chiroptical Inversion in Mesoscopic Helical Covalent Organic Frameworks.

Constructing crystalline chiral covalent organic frameworks (CCOFs) with programmable chiroptical properties from a single chiral source remains highly challenging. Herein, we report a dynamic covalent evolution strategy that transforms supramolecular-induced helical covalent organic polymers into mesoscopic helical CCOFs through thermodynamic self-crystallization as well as single-step and stepwise monomer exchange. Remarkably, two distinct chiroptical inversion modes are preserved during framework evolution: a conventional inversion accompanied by opposite helical sense and a second inversion displaying opposite chiroptical activity despite identical mesoscopic helicity, originating from different sub-nanometer chiral packing arrangements. Time-dependent experiments and theoretical calculations reveal persistent chirality- and packing-memory effects throughout dynamic reconstruction. Using a single chiral template system, this strategy affords 24 mesoscopic helical CCOFs with diverse linkage chemistries and programmable chiroptical responses. Furthermore, pore-confined incorporation of aggregation-induced emissive guests extends both inversion modes into flexible circularly polarized luminescence films.