Crystal structure and dielectric property of the first bromide/iodide heteroleptic haloplumbate-based lamellate inorganic–organic hybrid compound

A new heteroleptic haloplumbate-based inorganic–organic hybrid compound, with a formula [4′-chloro-1-aminopyridinium][Pb3Br5I2], has been synthesized and characterized. This hybrid compound crystallizes in orthorhombic space group Pcca, their inorganic and organic components form respectively layered arrangements. The inorganic anion lamellas (A) and the organic cation layers (C) alternate in the …ACAC… manner along b-axis direction, and the inorganic layer is constructed by the PbBr2I4 and PbBr4I2 octahedra as well as the very rare PbBr8 square antiprisms via sharing the Br–Br or I–I edges and Br–Br–Br triangular faces in the hybrid crystal. To the best of our knowledge, this is the first example that an inorganic layer contains bromide/iodide heteroleptic haloplumbate in a lamellate inorganic–organic hybrid compound. The dielectric property for the hybrid compound was further investigated in the temperature range of 20–150 °C and in the frequency region of 1–107 Hz, indicating the existence of the thermally assisted dynamical dipole motion under ac electric field, which probably originates from the ion hopping. This study will shed a light on the design and preparation of new heteroleptic haloplumbate-based hybrid materials.