Dynamic Circularly Polarized Luminescence with Tunable Handedness and Intensity Enabled by Achiral Dichroic Dyes in Cholesteric Liquid Crystal Medium

Abstract Cholesteric liquid crystals (CLCs) are chiral supramolecular systems that self‐assemble into a highly regular helical arrangement in a liquid crystal (LC) medium. Such an arrangement is highly beneficial for the chiral enlargement effect on circularly polarized luminescence (CPL) signals. Dichroic dyes with rod‐like molecular structures can exhibit fluorescence anisotropy along both the long and short molecular axes owing to their transition dipole moment (TDM) vectors. In this work, a pair of donor–accepter (D–A) achiral dichroic dyes is prepared, namely, 3,4‐ethylenedioxythiophene derivative (P1, whose TDM vector is parallel to the long axis of the molecule, i.e., F || > F ⊥ ) and anthraquinone derivative (N1, whose TDM vector is perpendicular to the long axis of the molecule, i.e., F || < F ⊥ ). CLCs can be fabricated by doping P1 or N1 together with chiral 1,1′‐binaphthyl‐derived inducers into SLC1717 medium. Dynamic CPL with tunable handedness and intensity is achieved by changing the N1:P1 mass ratio, and the luminescence dissymmetry factor ( g em ) value reaches |0.71|. This work describes the first observation of dynamic CPL with tunable handedness and intensity enabled by TDM regulation of achiral dichroic dyes in a CLC medium.