Dynamically stable and amplified circularly polarized excimer emission regulated by solvation of chiral co-assembly process
Yuxia Zhang, Hang Li, Zhongxing Geng, Wen‐Hua Zheng, Yiwu Quan, Yixiang Cheng
Abstract
Abstract Chiral supramolecular assembly has been assigned to be one of the most favorable strategies for the development of excellent circularly polarized luminescent (CPL)-active materials. Herein, we report our study of an achiral boron-containing pyrene (Py)-based chromophore (PyBO) as a circularly polarized excimer emission (CPEE) dye induced by chiral co-assemblies containing chiral binaphthyl-based enantiomers ( R / S -M). Chiral co-assembly R / S -M-(PyBO) 4 fresh film spin-coated from toluene solution can exhibit orderly nanofibers and strong green CPEE (λ em = 512 nm, g em = ±0.45, Φ FL = 51.2 %) resulting from an achiral PyBO excimer. In contrast, only a very weak blue CPL was observed (λ em = 461 nm, g em = ± 0.0125, Φ FL = 19.0 %) after 187 h due to PyBO monomer emission as spherulite growth. Interestingly, this kind of chiral co-assembly R -M-(PyBO) 4 -T film from tetrahydrofuran (THF) solution retains uniform morphology and affords the most stable and strongest CPEE performance (λ em = 512 nm, g em = + 0.62, Φ FL = 53.3 %) after 10 days.