Sb3+-Activated Near-Infrared Circularly Polarized Luminescence in Chiral Zero-Dimensional Hybrid Tin(IV) Chlorides.

Near-infrared circularly polarized luminescence (NIR-CPL) materials are promising for advanced photonic applications, yet simultaneously achieving pronounced chiroptical activity and efficient NIR emission remains challenging. Herein, we report a pair of enantiomeric zero-dimensional chiral tin(IV) chlorides, (R/S-APD)SnCl6 (R/S-APD: R/S-3-aminopiperidine), and activate broadband visible-to-NIR CPL through heterovalent Sb3+ incorporation. The chiral host lattice transfers molecular chirality to isolated [SnCl6]2- units through asymmetric N-H···Cl hydrogen bonding. Sb3+ doping introduces low-symmetry Sb-centered emissive centers, enabling ultrabroad 500-1000 nm emission. The R and S enantiomers exhibit mirror-image CPL with luminescence dissymmetry factor (glum) values of -2.6 × 10-3 and +3.3 × 10-3, respectively. Temperature-dependent photoluminescence reveals strong electron-phonon coupling and a high exciton binding energy, supporting robust self-trapped exciton emission. The material exhibits excellent stability, retaining 79% of its emission intensity after 120 days. This work establishes a host-dopant strategy that decouples chirality transmission from emissive-state engineering, providing a pathway toward stable chiral halide emitters for NIR photonics and imaging applications.