Connecting Nanoscale Molecular Self‐Assembly to Macroscale Photophysical Property of Pyrene‐Based Liquid Crystal Mesogen

Understanding the relationship between material properties and supramolecular nanostructures is essential for elucidating how nanoscale molecular organizations govern macroscale photoluminescence (PL) properties. Here, we introduce a novel pyrene‐based liquid crystal mesogen (Py‐LCM) and systematically investigate how its molecular packing nanostructures and orientations influence photophysical material properties. Py‐LCM exhibits diverse molecular packing structures depending on solvent polarity and concentration in the solution state, leading to a variety of controllable photophysical emissions. Thermodynamic and structural analyses in the solid state reveal that the formation of metastable and stable nanostructures of Py‐LCM can be precisely controlled by modulating the kinetic pathway of nanoscale molecular self‐assembly. Furthermore, by inducing macroscale molecular orientation, we achieve polarization‐dependent photophysical emissions. Finally, we demonstrate the practical application of Py‐LCM in optically encrypted systems, taking advantage of its distinct PL characteristics in both solution and solid states.