Circularly Polarized Luminescence in Achiral Tin-Based Perovskites via Structural Isomer-Driven Coordination Interaction

A chiral bidentate ligand, ( R )-(−)-1-amino-2-propanol (denoted as R 1 ) or ( R )-(−)-2-amino-1-propanol (denoted as R 2 ), was used to modify achiral 2D tin-based perovskite HDASnBr 4 (HDA: 1,6-hexamethylenediamine) to form R 1 -HDASnBr 4 or R 2 -HDASnBr 4 by an acid precipitation method. R 1 -HDASnBr 4 exhibits a near-unity photoluminescence quantum yield (PLQY) and strong yellow circularly polarized luminescence (CPL) with a luminescence asymmetry g-factor (| g lum |) of 8.3 × 10 –3, while R 2 -HDASnBr 4 shows a PLQY of 95% and | g lum | of 3.2 × 10 –3 . Both exhibit strong CPL activities, attributed to the significant centro-asymmetric distortion induced by the interaction between the chiral ligand and the inorganic lattice of 2D perovskites. The | g lum | of R 1- HDASnBr 4 is 2.6× that of R 2 -HDASnBr 4, resulting from the direct coordination of the hydroxyl group attached to the chiral carbons in R 1 with the [SnBr 6 ] 4– inorganic framework, which induces a higher degree of distortion than the amino group in R 2 . Furthermore, we explored the potential of R 1 -HDASnBr 4 as a chiral inducer and a CPL source to facilitate asymmetric polymerization. This work offers a simple strategy to introduce chirality to achiral perovskites.