High Luminescence Dissymmetry in Zero-Dimensional Chiral Hybrid Metal Halide With Inter-Octahedral Hydrogen Bonding

Hydrogen-bonding interactions between chiral organic and inorganic components have been widely utilized to induce and modulate circularly polarized luminescence (CPL) in chiral hybrid metal halides (CHMHs). Beyond these established strategies, incorporating inter-octahedral (inorganic-inorganic) hydrogen bonding offers significant yet underexplored potential for amplifying CPL through long-range chirality transfer. Here, we report the design and synthesis of (S/R-C₉H₂₀ON₂)In_0.93Sb_0.07Cl₅·H₂O (S/R-InSbCl₅·H₂O), in which three types of organic-inorganic, inter-octahedral, and inter-organic (organic-organic) hydrogen-bonding interactions are synergistically integrated within a zero-dimensional CHMH framework. These materials not only feature a near-unity photoluminescence quantum yield, but also, more importantly, exhibit a remarkable luminescence dissymmetry factor of 0.1. Structural and photophysical analyses reveal that inter-octahedral hydrogen bonding significantly enhances octahedral distortion and the coherence of chirality transfer across the lattice through inter-octahedral interactions, thereby significantly amplifying CPL activity. Combined crystallographic analyses and theoretical calculations further demonstrate that these interactions are governed by the electrostatic potential distribution of coordinated molecules and the inter-octahedral distance. This work highlights inter-octahedral hydrogen bonding as a novel key structural parameter for CPL amplification and provides a general strategy for designing high-performance chiral luminescent materials.