Light-driven controllable cis–trans isomerization in a cycloparaphenylene dimer bridged by 9,9′-bifluorenylidene

Abstract

This work reports the synthesis and distinct photoisomerization of configurationally stable isomers of a cycloparaphenylene (CPP) dimer, bridged by a 9,9′-bifluorenylidene linker. Bidirectional photo-switching is achieved: a synergistic photoacid-catalyzed process drives trans-to-cis conversion, while a light-induced electron-transfer pathway enables efficient cis-to-trans isomerization.