Interfacial solvothermal synthesis of superhydrophilic ionic salt-derived chiral helical COFs with strong chiroptical activity

Traditional chiral induction strategies for nonionic covalent organic frameworks (COFs) often produce disordered aggregates with low dissymmetry factors and weak chiroptical activity due to uncontrolled crystallization kinetics. Here, we report an interfacial solvothermal strategy that spatially separates superhydrophilic ionic amines in an aqueous phase from aldehyde monomers in an organic phase, enabling precise kinetic regulation and efficient molecular-to-mesoscale chiral amplification. This method yields highly ordered helical ionic COFs, including anionic, cationic, and zwitterionic frameworks, with outstanding chiroptical properties, featuring ellipticities exceeding 3600 millidegrees (mdeg) and |gabs| values up to 0.07. By tuning the acid concentration and chiral inducer stoichiometry, the dimensions of superhelical anionic COFs can be controlled from the nanoscale to the micrometer scale. Furthermore, oppositely charged aggregation-induced emission luminogens are incorporated into the COF channels through electrostatic interactions, generating blue, yellow, and green circularly polarized luminescence. This work establishes a versatile platform for constructing chiral COFs with amplified chiroptical responses for chiral optoelectronics, sensing, and asymmetric catalysis.