Chirality Transfer from Polylactide to Achiral Fluorophore in Hierarchical Crystallization for Realizing Handedness-Tunable and Nonreciprocal Circularly Polarized Luminescence

Realizing chiral crystals from achiral compounds is an important but challenging issue. Here, a kebab-structured chiral supra-crystallization complex is constructed in accomplishing hierarchical chiral crystallization of achiral fluorescent compound (1,8-naphthalic anhydride, NA) employing synthetic chiral macromolecules (polylactide, PLA) as a template. Chirality transfer efficiently takes place from PLA to NA crystal during the co-crystallization process, endowing the initial achiral NA crystal with intense optical activity. More importantly, the obtained chiral supra-crystals show remarkable circularly polarized luminescence (CPL) properties, with the highest luminescence dissymmetric factor up to 5 × 10–2. Moreover, handedness-tunable and nonreciprocal CPL emissions are further realized in one single sample by simply flipping and rotating the supra-crystallization composite film, following a polarization mechanism. The work presents the first polymer-based hierarchical chiral supra-crystal with switchable CPL emissions and provides a simple and universal strategy for constructing nonreciprocal CPL materials.