Luminescent hybrid halides with various centering metal cations (Zn, Cd and Pb) and diverse structures.

Organic-inorganic hybrid metal halides have been extensively studied because of their great potential in optoelectronics. Herein, we report three hybrid metal halides (Bmpip) ₂ ZnBr ₄ , (Bmpip) ₂ CdBr ₄ , and (Bmpip) ₈ Pb ₁₁ Br ₃₀ (where Bmpip ⁺ is 1-butyl-1-methyl-piperidinium, C ₁₀ H ₂₂ N ⁺ ). (Bmpip) ₂ ZnBr ₄ and (Bmpip) ₂ CdBr ₄ crystallize in the P 2 ₁ / c space group with zero-dimensional crystal structures with [ M Br ₄ ] ^2- ( M = Zn, Cd) tetrahedra isolated by Bmpip ⁺ . (Bmpip) ₈ Pb ₁₁ Br ₃₀ crystallizes in the triclinic space group P 1̄ with one-dimensional corrugated chains constructed from face-sharing [PbBr ₆ ] ^4- octahedra. All of the compounds exhibit excellent ambient and thermal stability. Under UV excitation, all three compounds exhibit very broad emissions. Temperature-dependent photoluminescence measurements indicate that the broad emissions of (Bmpip) ₂ ZnBr ₄ and (Bmpip) ₂ CdBr ₄ can be attributed to both the organic cations and self-trapped excitons (STEs) and that the emission of (Bmpip) ₈ Pb ₁₁ Br ₃₀ is assigned to STEs. Density functional theory calculations reveal that the three compounds adopt a direct band gap. This work enriches our understanding of the structure types of hybrid metal halides while revealing their diverse emission mechanisms.