Engineering Efficient Circularly Polarized Luminescence in Copper(I) Iodides through Supramolecular Chirality Control

Chiral hybrid metal halides are emerging as promising optoelectronic materials due to their tunable chirality and superior optoelectronic properties. However, the current synthesis predominantly relies on chiral organic cations to induce chirality, which constrains their structural diversity and design flexibility. Herein, we report a supramolecular assembly strategy based on the coassembly of 18-crown-6 (18C6) or its chiral methyl-modified derivatives (S/R-18C6) with chiral 4-substituted phenethylammonium groups. This coassembly strategy yields two types of Cu(I) halides, each incorporating a distinct inorganic polyhedral anion: the dimeric [Cu2I4]2– or the tetrameric [Cu4I6]2–. Structural analyses reveal that the stacking modes of the supermolecule influence inorganic anion architecture. Furthermore, the [Cu4I6]2– clusters exhibit broad yellow emission with near-unity PLQYs. The interaction between R/S-18C6 and chiral organic ammonium cations generates a highly asymmetric local chiral environment that induces distortion of the [Cu4I6]2– geometry (angular variance σ2 of up to 27.50 deg2), leading to remarkable circularly polarized luminescence (CPL) signal with a dissymmetry factor (glum) of up to +7.9 ± 0.4 × 10–3/–6.5 ± 0.1 × 10–3. A CPL-active white light-emitting diode (WLED) is fabricated using these materials, demonstrating high-quality white light with a significant CPL signal. This work establishes a supramolecular dual-chirality synergy strategy for the rational design of chiral metal halides, offering an effective strategy for the development of high-performance chiroptical materials.