Quartz‐Like Structure, Optical Activity, and High Stability in the First Chiral Cation‐Coordinated Perovskite Semiconductor

Abstract Poor stability is a significant challenge to organic–inorganic hybrid perovskites for practical optoelectronic applications, which results from their inherent ionic nature and soft structures. The coordination bonding strategy is supposed to be a valid approach by enhancing the interaction between the cations and inorganic frameworks. Herein, the first pair of cation‐coordinated perovskites with high stability, achieved through coordination bonds between the cations and [PbX_n] anions instead of the weak hydrogen bonds and van der Waals force presented in conventional ionic perovskites, is reported. In L/R‐(4HOPD)PbBr₃ (4HOPD = 4‐hydroxypiperidine cation) (L/R=Left/Right–handed), one of the six halogen atoms is replaced by an oxygen atom from the cation. The PbO bond contributes to the high stability under a double 85 test. L/R‐(4HOPD)PbBr₃ crystallizes in the tetragonal system, belonging to one of 11 enantiomorphic space group types, P4₁2₁2 and P4₃2₁2. Similar to quartz, the chirality originates from the helical assembly of achiral units. The chirality‐induced optical rotatory power is 16.84° mm⁻¹ at 404 nm. Moreover, the uniaxial negative birefringent property with a comparable Δn value makes it a good alternative to quartz. The remarkable stability of this new perovskite presents significant potential for further investigation into stable perovskites and their applications in optical rotation and polarizing optics.