Tunable circularly polarized luminescence behaviors caused by the structural symmetry of achiral pyrene-based emitters in chiral co-assembled systems.

We found that during the chiral co-assembly process, the structural symmetry of achiral Py-based emitters could cause different chiral co-assembly modes, leading to the tunable CPL emission behaviors of the resulting co-assemblies. Most importantly, this kind of chiral co-assembly (R / S -B) 1 -(Py-2) 7 can form highly ordered helical nanofiber through intermolecular layered packing mode, leading to the promoted chiral induction and amplification effects. [Display omitted] The regulation of circularly polarized luminescence (CPL) behavior is of great significance for practical applications. Herein, we deliberately designed three achiral pyrene derivatives (Py-1 , Py-2 , and Py-3) with different butoxy-phenyl substituents and the chiral binaphthyl-based inducer ( R/S -B) with anchored dihedral angle to construct chiral co-assemblies, and explored their induced CPL behaviors. Interestingly, the resulting co-assemblies demonstrate tunable CPL emission behaviors caused by the structural symmetry effect of achiral pyrene-based emitters during the chiral co-assembly process. And in spin-coated films, the dissymmetry factor (g em) values were 9.1 × 10-3 for (R/S- B) 1 -(Py-1) 10 , 5.6 × 10-2 for (R/S- B) 1 -(Py-2) 7 , and 8.6 × 10-4 for (R/S- B) 1 -(Py-3) 1 , respectively. The strongest CPL emission (| g em | = 5.6 × 10-2, λ em = 423 nm, QY = 34.8 %) was detected on (R/S- B) 1 -(Py-2) 7 due to the formation of regular and ordered helical nanofibers through the strong π-π stacking interaction between the R/S- B and the achiral Py-2 emitter. The strategy presented here provides a creative approach for progressively regulating CPL emission behaviors in the chiral co-assembly process. [ABSTRACT FROM AUTHOR]