Control of Circularly Polarized Luminescence in Cholesteric Luminescent Liquid Crystals: From FRET to Exciton Coupling

Abstract

ABSTRACT Achieving circularly polarized luminescent (CPL) materials with tunable wavelength and high dissymmetry factor ( g lum ) still faces great challenges. Cholesteric luminescent liquid crystal (N*LLC) is one of the most promising chiral systems to solve the above challenges. In this work, a pair of luminescent chiral inducers R1/S1 were synthesized by incorporating a rhodamine luminophore to a binaphthyl chiral scaffold and were doped into 5CB to construct N*LLC. As the concentration of the doped achiral naphthalimide derivative (NIA) increased, the CPL wavelength sequentially blue‐shifted from red to yellow and then to green, the g lum also increased to 0.3, which is fundamentally different from the conventional regulation with red‐shifted chiral luminescence. Moreover, the introduction of trifluoroacetic acid enabled the emitted CPL was reversibly switched, allowing reversible control of wavelength and g lum . Theoretical calculations revealed that, FRET‐dominated process transforms into exciton coupling (EC)‐governed interactions with the NIA concentration increased. This work demonstrates a feasible strategy of achieving reversible control of CPL within a single supramolecular system, offering new insight into the development of adaptable chiral photonic devices.