Solvent-Regulated CPL Enhancement via Chiral Transfer in Efficient Luminescent Ionic Hydrogen-Bonded Frameworks for...

Circularly polarized luminescence (CPL) materials have garnered significant attention due to their broad application prospects in information-encryption and optical storage. However, chiral small-molecule systems face challenges such as intramolecular chiral-transfer confinement and low energy transfer efficiency, making it difficult to achieve breakthroughs in chiral optical properties using a single component. We propose a multistage chiral-transfer-strategy based on ionic hydrogen-bonded organic frameworks (iHOFs), utilizing (1R/1S,2R/2S)-1, 2-diphenylethylenediamine-(R/S-DPEN) as the chiral source and 4,4'-bis(2-sulfonatostyryl)biphenyl-(H₂CBS) as the chromophore to synthesize R/S-iHOF-40. Our study reveals that the introduction of an effective charge donor modulates the excited-state energy gap, which is the primary reason for R/S-iHOF-40's high quantum yield (QY) of 67.8% (compared to 5.41% for HOF-R/S-DPEN). Furthermore, the strong mirror cotton effect observed at 323 nm for R/S-iHOF-40 confirms effective intermolecular chiral-transfer, while the crystal structure clearly reveals a double-helix supramolecular assembly mechanism mediated by hydrogen-bond bridging. Interestingly, the interference of water molecule motion within the structure on the chiral coupling between ions demonstrates the crucial role of hydrogen-bond dynamics in regulating the chiral emission of the R/S-iHOF-40 excited state. This work deepens our understanding of the mechanisms of chiral-transfer and amplification, and provides new strategies for the application of solid-state chiral materials in information-encryption.