Synthesis, Crystal Structure, and Optical Properties of Two Lead Iodide Hybrid Compounds Based on the 4‐(Ammonioethyl)‐Tetrahydropyran Cation

Bifunctional ammonium cations have attracted interest in hybrid organic–inorganic metal halide research due to their ability to modulate structural connectivity and enhance material properties. Herein, 4‐(ammonioethyl)‐tetrahydropyran (HAETP + ) is used to construct two novel hybrid lead iodide materials: (HAETP) 4 Pb 5 I 14 ( 1 ) and (HAETP)PbI 3 ·H 2 O ( 2 ). Single‐crystal X‐ray diffraction reveals that (HAETP) 4 Pb 5 I 14 exhibits an unprecedented anion motif, where {PbI 6 } octahedra form an extended layer through both face‐ and edge‐sharing, while (HAETP)PbI 3 ·H 2 O features a simple band‐like anion motif. In both compounds, NH···O interactions allow for the formation of an extended, hydrogen‐bonded cationic aggregate. Thermal analysis shows that the compounds are stable above 200 °C, and in the case of 2 , this is after a dehydration step at 80 °C. Both compounds display an onset of absorption at ≈2.70 eV and broad low‐temperature emission centered at 1.88 and 2.05 eV, respectively.