Chiroptical isomerization in chiral covalent organic frameworks with identical mesoscopic helicity.

ABSTRACT: Chirality amplification and transfer strategies enable covalent organic polymers (COPs) to adopt supramolecular helicity with diverse structural and functional possibilities. Although helicity and chiroptical response typically correlate, we reveal a distinct chiroptical isomerization in helical COPs, where polymers with identical mesoscopic helicity exhibit opposite chiroptical activities. Using a supramolecular templating method, we prepared helical polyimines that maintain uniform helicity yet display reversed Cotton effects upon subtle variations in a single polymerization parameter, such as monomer structures, good-solvent identity, or good/poor solvent ratios. This inversion likely originates from opposite chiral packing of sub-nanometer building units while preserving overall helici

SUBMITTER: Zha X 

PROVIDER: S-EPMC12828032 | biostudies-literature | 2025 Dec

REPOSITORIES: biostudies-literature