Ultrastable Enantiomeric Tetrapod Cu(30) Clusters With Near-Infrared Circularly Polarized TADF.

The development of stable Cu(I) clusters exhibiting near-infrared circularly polarized luminescence (NIR CPL) presents a significant challenge. In addressing this challenge, we present the synthesis of ultrastable chiral R/S-Cu clusters through a dual-ligand strategy, which feature a tetrapod metal skeleton and represent the largest nuclearity Cu(I) cluster reported to exhibit NIR CPL. The R/S-Cu structure is self-assembled from five octahedral Cu units. R/S-Cu exhibits excellent NIR CPL with high quantum yields of 40% in solution, benefiting from the characteristic of stable structure and thermally activated delayed fluorescence (TADF), marking the first observation of NIR circularly polarized TADF within the Cu(I) cluster family. Due to the exceptional stability, solution processability and NIR CPL property of R/S-Cu, the NIR-CP light-emitting diodes were fabricated and exhibited g of +1.8/-2.1 × 10 and an EQE of 8% with an emission wavelength of 732 nm. This study not only presents an enantiomeric pair of tetrapod-like Cu(I) clusters but also successfully addresses the intertwined challenges of stability, efficient NIR emission, and chiral luminescence in the design of copper clusters.