Novel 3D Cubic Topology in Hybrid Lead Halides with a Symmetric Aromatic Triammonium Exhibiting Water Stability

The limitations of three-dimensional (3D) perovskites are related to their narrow structural tunability of the organic cations and their moisture sensitivity. Herein, we report a new family of 3D cubic hybrid metal halides (T-Et₆)₃Pb₁₁X₃₁ (X = I, Br), where T is 1,3,5-tris-(4-aminophenyl)benzene. The materials are synthesized through an in situ N-alkylation of T and an efficient one-step solvothermal reaction containing ethanol, initiating a tunable synthetic avenue for the acquisition of structurally complex hybrid halides with luminophores. (T-Et₆)₃Pb₁₁X₃₁ consist of an unprecedented Ia3̅ framework of [Pb₁₁X₃₁]^9- one-dimensional (1D) chains embedded with (T-Et₆)³⁺ cations, affording an overall 3D topology. The constituent [Pb₁₁X₃₁]^9- chains include exclusively octahedral lead halide units with clusters of face- and edge-sharing connectivity, giving rise to weak broad emission centered at ∼660 nm observed at 78 K. (T-Et₆)₃Pb₁₁I₃₁ demonstrates water stability for at least 7 days. Synthesis through ambient pressure results in tunable structural variations of zero-dimensional (0D) structures rendering T₇Pb₃Br₂₇·DMF and T₂Sn₃Br₁₈·4H₂O·0.5Br₂, both of which feature blue PL emission at room temperature.