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

Abstract

ABSTRACT 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.