High dielectric permittivity and relaxation-induced dielectric pulsing effect-like in [1,3-bis(1-methylimidazolium)propane][Pb2I6] crystal

Herein, a new hybrid, [1,3-bis(1-methylimidazolium)propane][Pb2I6] (1), was synthesized and thoroughly characterized using microanalysis, thermogravimetric analysis (TG), differential scanning calorimetry (DSC), and powdered X-ray diffraction (PXRD) techniques. The crystal structure of 1 reveals one-dimensional face -sharing PbI6 octahedral chains composed of Pb2+ and I- ions, with the disordered 1,3-bis(1-methylimidazolium)propane dications positioned between these inorganic chains. Remarkably, 1 exhibits high dielectric permittivity (-200) across a wide temperature range of 123-423 K. Moreover, it demonstrates a relaxation -induced dielectric pulsing effect -like, characterized by a broad and temperature -independent dielectric anomaly peak around 263 K in epsilon'- T plots. The mechanisms responsible for the high dielectric permittivity and the origin of the relaxation -induced dielectric pulsing effect -like are further discussed through a comprehensive analysis of the variabletemperature crystal structure.