Circularly Polarized Luminescence in Chiral Antimony(III) Chloride [Sb₂Cl₁₀]^4- Dimers Induced by Asymmetric Hydrogen...

Metal halide species with multimeric anionic frameworks exhibit outstanding coordination chiralities and intriguing photophysical properties, making them highly promising for emerging photonic applications. However, their chiroptical activities remain largely unexplored to date. Herein, lead-free chiral hybrid 0D materials composed of edge-sharing [Sb₂Cl₁₀]^4- dimers were synthesized via a natural cooling crystallization. The 0D chiral crystals R/S-1 [(R/S-MBA)₄Sb₂Cl₁₀] show broad yellow photoluminescence stemming from self-trapped exciton states with a PL peak at 596 nm. R/S-1 exhibits strong circular dichroism (|g_CD| ≈ 7 × 10^-3) and efficient circularly polarized luminescence (|g_lum| ≈ 5 × 10^-3). This is attributed to the chiral organic cations inducing inorganic sublattice chirality through asymmetric hydrogen-bonding interactions, while the inorganic lattice components adopt a helical arrangement following a 2₁ symmetry operation. Density functional theory calculations verify a Rashba-type band splitting for R/S-1, confirming the noncentrosymmetric structural distortion and substantial spin-orbit interaction induced by chiral organic cations. Furthermore, we applied chiral scintillators R/S-1 to achieve X-ray-driven asymmetric photopolymerization using circularly polarized emission. This study offers a pathway for the exploration and development of novel lead-free chiral metal halides.