Abstract Circularly polarized luminescence (CPL) active materials with dynamically tunable properties are highly desirable for next‐generation photonics and encryption technologies, yet achieving this through predictable solid‐state structural transformations remains a formidable challenge. Herein, we demonstrate a novel dimensionality‐engineering strategy to realize stimuli‐responsive CPL in chiral hybrid Mn(II) halides. Employing a single chiral cation, R/S‐3‐methylmorpholine, we selectively synthesized two distinct phases: a red‐emissive 1D chain structure with octahedral Mn(II) centers and a green‐emissive 0D structure with tetrahedral coordination. Remarkably, the 0D phase undergoes a rapid and reversible ethanol‐assisted thermal transformation into the 1D phase, accompanied by a striking CPL color switch from green to red. This unique behavior stems from a stimulus‐induced recoordination of Mn–Cl units and reorganization of the hydrogen‐bonding network. Capitalizing on this reversible response and intrinsic chirality, we engineered a sophisticated multilevel photonic encryption platform, encompassing binary dot‐matrix coding, dual‐channel (photoluminescence/CPL) Morse code, and CPL‐based ASCII decryption. This work establishes structural dimensionality control as a powerful paradigm for creating intelligent, CPL‐active materials, opening new avenues for high‐security optical information technologies.
Li et al. (Wed,) studied this question.