Regulating Circularly Polarized Luminescence Signals of Chiral Binaphthyl-Based Conjugated Polymers by Tuning Dihedral Angles of Binaphthyl Moieties

Abstract

A series of chiral binaphthyl-based conjugated polymers enantiomers incorporating boron dipyrromethene (BODIPY) chromophore in the main chain backbone were designed and synthesized by Pd-catalyzed Sonogashira cross-coupling reaction. All of them can exhibit strong Cotton effects and circularly polarized luminescence (CPL) emission signals in THF solution. The CD absorption dissymmetry factors (gabs) and the luminescence dissymmetry factors (glum) can be regulated by tuning the dihedral angles of binaphthyl arising from different substitutions of BINOL hydroxyls. Interestingly, the chiral polymers can exhibit the gradual increase of both gabs and glum as the decrease of dihedral angles of the chiral binaphthyl moiety. This work can provide a new strategy for the development of CPL emission materials.