Structural Origin of Enhanced Circularly Polarized Luminescence in Hybrid Manganese Bromides

Abstract Chiral hybrid metal halides with a high dissymmetry factor ( g lum ) and a superior photoluminescence quantum yield (PLQY) are promising candidates for circularly polarized luminescence (CPL) light sources. Here, we report eight new chiral hybrid manganese halides, crystallizing in the non‐centrosymmetric space group P 2 1 2 1 2 1 and showing intense CPL emissions. Oppositely‐signed circular dichroism (CD) and CPL signals are detected according to the R ‐ and S ‐configurations of the chiral alkanolammonium cations. Time‐resolved PL spectra show long averaged decay lifetimes up to 1 ms for ( R ‐3‐quinuclidinol)MnBr 3 ( R ‐ 1 ). The g lum of polycrystalline samples for coordinated structures (23×10 −3 ) is more than doubled compared with the non‐coordinated ones (8.5×10 −3 ), due to the structural variations. R ‐ 1 exhibit both a high g lum and a high PLQY (50.2 %). The effective chirality transfer mechanism through coordination bonds, with strongly emissive Mn II centers, enables a new class of high‐performance CPL materials.