Positional Effects of Amine-Induced Chiral Perturbation on Circularly Polarized Luminescence in Cyanoarene-Based TADF Emitters

Abstract

Circularly polarized luminescence (CPL) from thermally activated delayed fluorescence (TADF) emitters is commonly realized using dinaphthalene-based chiral units such as BINOL. Here, we examine a simpler chiral perturbation strategy, by introducing commercially available (R)- and (S)-N-(1-phenylethyl)aniline into the cyanoarene TADF core 4Cz-IPN. Four chiral derivatives were synthesized with substitution at the 5- or 6-positions of the isophthalonitrile scaffold. All compounds exhibited measurable CPL, whereas only the 6-substituted derivatives showed TADF behavior. In all cases, chiral substitution led to a significant reduction in fluorescence quantum yield compared to the parent emitter. These results provide a systematic assessment of how substitution position and donor structure influence TADF activity, emission efficiency, and chirality transfer in cyanoarene-based systems.