One‐Dimensional Chiral Copper Iodide Chain‐Like Structure Cu 4 I 4 ( R / S ‐3‐quinuclidinol) 3 with Near‐Unity Photoluminescence Quantum Yield and Efficient Circularly Polarized Luminescence

Abstract Chiral organic−inorganic hybrid metal halide materials have shown great potential for circularly polarized luminescence (CPL) related applications for their tunable structures and efficient emissions. Here, this work combines the highly emissive Cu 4 I 4 cubane cluster with chiral organic ligand R / S ‐3‐quinuclidinol, to construct a new type of 1D Cu‐I chains, namely Cu 4 I 4 ( R / S ‐3‐quinuclidinol) 3 , crystallizing in noncentrosymmetric monoclinic P 2 1 space group. These enantiomorphic hybrids exhibit long‐term stability and show bright yellow emission with a photoluminescence quantum yield (PLQY) close to 100%. Due to the successful chirality transfer from the chiral ligands to the inorganic backbone, the enantiomers show intriguing chiroptical properties, such as circular dichroism (CD) and CPL. The CPL dissymmetry factor ( g lum ) is measured to be ≈4 × 10 −3 . Time‐resolved photoluminescence (PL) measurements show long averaged decay lifetime up to 10 µs. The structural details within the Cu 4 I 4 reveal the chiral nature of these basic building units, which are significantly different than in the achiral case. This discovery provides new structural insights for the design of high performance CPL materials and their applications in light emitting devices.