An inorganic-organic hybrid compound with face-sharing bromoplumbate chain: Synthesis, crystal structure, Hirshfeld surface analysis, ferroelectric and dielectric properties

A new hybrid ferroelectric compound, [40-nitrobenzylidene-1-aminopyridinium][PbBr3](1) has been synthesized and characterized structurally. The compound 1 crystallizes in the monoclinic crystal system with the space group Cc. The unit cell parameters are a = 12.1611(14) angstrom, b = 18.230(2) angstrom, c = 7.6899 (7) angstrom, beta = 94.661(10)degrees and V = 1699.2(3) angstrom(3). The structure exhibits face-sharing PbBr6 octahedral chains in inorganic components. The intermolecular interactions were quantified and analyzed using Hirshfeld surface analysis, indicating the frequent contacts are mainly ascribed to H center dot center dot center dot Br, O center dot center dot center dot H and Pb...Br contacts. The compound 1 shows two dielectric anomalies around 90 degrees C and 140 degrees C, as well as huge dielectric constant above 90 degrees C. The macroscopic polarization reversal of the hybrid crystal probably arises from the dipole reversal of the polar PbBr6 octahedral by means of the relative displacement of Pb2+ ion along one Pb-Br bond. (C) 2020 Elsevier Ltd. All rights reserved.