Crystal Structure, Phase Transition and Dielectric Behaviors of One‐dimensional Organic‐inorganic Bromoargentate Hybrids of [Et‐dabco]2Ag2Br4

Abstract

AbstractA new haloargentate hybrid, [Et‐dabco]₂Ag₂Br₄ (1) (Et‐dabco+=1‐Ethyl‐1,4‐diazabicyclo[2.2.2]octan‐1‐ium), has been successfully synthesized by a solution diffusion method and characterized using microanalysis, single crystal X‐ray diffraction, variable‐temperature powder X‐ray diffraction (PXRD), differential scanning calorimetry (DSC), and dielectric spectra. The crystal structure of 1 at 273 K contains one‐dimensional (1D) anionic [Ag₂Br₄]2− chains, with the [Et‐dabco]+ cations embedded in the gaps between the inorganic chains. Hybrid 1 underwent a reversible structural phase transition (SPT) at around 464.5 K on heating, and the Pawley refinement revealed similar crystal structures in the low‐ and high‐temperature phases. The SPT endows 1 with switchable and bistable dielectric properties. Combined with previous studies, it was revealed that the self‐assembly of silver halide (AgX) with the lower rotational energy barrier of 1‐alkyl‐1,4‐diazabicyclo[2.2.2]octan‐1‐ium in solution probably achieves new phase transition materials.