Role of Metal–Chloride Anions in Photoluminescence Regulations for Hybrid Metal Halides

Binbin Su, Gaomin Song, Maxim S. Molokeev, Nicolay N. Golovnev, Maxim K. Lesnikov, Zheshuai Lin, and Zhiguo Xia. JOURNAL OF PHYSICAL CHEMISTRY LETTERS

Organic–inorganic hybrid metal halides with emissive organic cations are of great interest due to their structural diversity and interesting photophysical properties. Here, we assemble emissive organic cations (EnrofloH22+) with different metal–chloride anions (Pb2Cl62– to Bi2Cl104– to SnCl62–) to form the new single crystal phases, and thus the photoluminescence properties of the metal halides, including Stokes shift, full width at half-maximum (FWHM), and photoluminescence quantum yield (PLQY) have been studied accordingly. (EnrofloH2)SnCl6·H2O, as an example, possesses narrow FWHM and high PLQY, which are caused by the strong π–π stacking and inter- and intramolecular hydrogen bonds interactions. Compared with EnrofloH22+ cation in solution, the interactions generate a restraining effect and increase the rigid degree of EnrofloH22+ cation in the bulk single crystals. Our work clarifies the photophysical properties of the EnrofloH22+ organic cations by constructing the inter- and intramolecular interactions and boosts the further study of organic–inorganic hybrid metal halides materials with different luminescence mechanisms.