H ₃ PO ₂ ‐Induced Dimensionality‐Dependent Photoluminescence in Hybrid Cuprous Halides with Reversible Transformation

ABSTRACT Hybrid organic‐inorganic metal halides with stimuli‐responsive photoluminescent activity hold significant promise for applications in security encoding, encrypted transmission, information storage, and beyond. However, effectively manipulating these stimuli‐responsive characteristics requires one to shed light on the composition‐structure‐property interconnections. Herein, we devised and synthesized two novel Cu(I)‐based organic‐inorganic metal halides with distinct structural topologies and dimensionality‐dependent photoluminescence, namely, a 1D and a 0D arrangement, but composed of identical organic ligands and inorganic building blocks: (C 12 H 14 N 2 ) 4 [(CuI 2 )] 4 [(Cu 4 I 8 )] and (C 12 H 14 N 2 ) 4 (H 2 PO 2 ) 6 Cu 4 I 6 . Through a combination of experimental investigations and theoretical calculations, we explored the influence of H 3 PO 2 ‐mediated structural dimensionality on inter‐convertible structural transformations, luminescent properties, and spatial charge distributions in these compounds. Additionally, we achieved decagram‐scale synthesis of the nano‐structured 0D topology, highlighting its potential for its large‐scale production in anti‐counterfeiting and encryption applications.