Polar solvent-induced self-assembly of organic cocrystal helixes based on achiral molecules

Abstract

Precise control over chirality in supramolecular structures has attracted significant attention in biology and optoelectronics. Herein, we report a novel helical cocrystal of organic donor−acceptor complex based on two achiral components. Depending on the solvent polarity, two red emissive cocrystals were self-assembled with different stacking manners. Notably, although the inversion symmetry of crystal lattice, strong solvent-solute interactions between polar crystal planes and acetonitrile governs the growth dynamics, to generate helical architectures. Furthermore, chiral additive tailoring was successfully established to regulate the supramolecular helix handedness which showed good circularly polarized luminescence performance, with an asymmetry factor (g_lum) of 0.005. This work demonstrates new pathway for chirality growth and tuning in circularly polarized optoelectronic devices and chiral recognition systems.