High-Temperature Switchable Dielectric of an Organic–Inorganic Hybrid Metal Halide with Four-fold Cross-Linking Inorganic Anion Spiral Chains

The understanding of structure–property relationship and exploration of novel physical properties are current research topics of molecular switchable dielectric materials. In this paper, an organic metal halide {[ClCH2CH2(OH)CH2N(CH3)3][PbBr3], PbBr2-3-Cl} was obtained by the reaction of 3-chloro-2-hydroxypropyltrimethyl ammonium chloride and lead bromide in HBr aqueous solution. The structural analysis reveals that PbBr2-3-Cl consists of an organic ammonium cation and a four-fold cross-linking spiral inorganic anion chain, in which the Pb atom is five-coordinated with Br atoms adopting a square-pyramidal geometry, which is further connected with four neighboring square-pyramids by sharing four Br atoms at the vertices of the square-pyramid bottom. PbBr2-3-Cl can be used as a dielectric switch at a very high temperature (435 K), and a semiconductor and broadband red fluorescent material.