Dielectric transition and relaxation in an imidazolium-based organic-inorganic hybrid crystal (HIm)6[(CdCl4)(CdCl6)]

Accessing One-Dimensional Chains of Halogenoindates(III) in Organic-Inorganic Hybrids

Organic-inorganic hybrids of halogenoindates(III) are typically represented by one of the zero-dimensional units: InX₄^-, InX₅^2-, InX₆^3-, or In₂X₁₁^5-. Higher dimensional anionic forms, although not forbidden, have remained almost elusive. Here we report for the first time In³⁺-based organic-inorganic hybrids, (C₄H₅N₂S)₂InCl₅ and (C₄H₅N₂S)₂InBr₅, with 1D anionic chains of trans-halide-bridged InX₆ octahedra whose formation is guided by 2-mercaptopyrimidinium cations (C₄H₅N₂S⁺). The chains are characterized by the significant ease of deformation, which is reflected in the elongation of the bridging bonds or the displacement of In³⁺ ions. The materials show a robust band gap predominantly governed by C₄H₅N₂S⁺ cations. Dielectric relaxation processes in (C₄H₅N₂S)₂InBr₅ arise from the cations' dynamics and suggest the ability of the brominated system to accommodate even larger cations. Our work represents a successful attempt to expand the structural diversity of halogenoindates(III) and opens a pathway to reach multifunctional 1D In³⁺-based hybrids.

High-temperature structural phase transition coupled with dielectric switching in an organic-inorganic hybrid crystal: [NH3(CH2)2Br]3CdBr5

Molecular bistable switches (electrical switches "ON" and "OFF") represent a class of highly desirable intelligent materials due to their sensitive switchable responses, simple and environmentally friendly processing, light weight, and mechanical flexibility. In particular, these switches above room temperature with potential practical application are rarely reported. In this work, a new zigzag chained organic-inorganic hybrid compound [NH₃(CH₂)₂Br]₃CdBr₅ (1), which displays rapidly sensitive dielectric switching reversibility and remarkable switching antifatigue, has been successfully synthesized. Systematic characterization including differential scanning calorimetry measurements (DSC), dielectric measurements, and variable-temperature structural analyses was performed to reveal the phase transition of 1. A couple of reversible heat anomaly peaks at 335.6/323.8 K with a large hysteresis (ca. 11.8 K) were observed in the DSC curve, indicating the first-order type of phase transition. 1 exhibits an obvious dielectric switching at around 327 K, which makes 1 a potential switchable dielectric material. Variable-temperature structural analyses show that the cationic order-disorder motion is the main attribution for the phase transition of 1.

Role of crystallization water molecules on hydrogen-bonded structures and dielectric phase transitions in amino trimethylene phosphonic acid-based crystals

Amino trimethylene phosphonic acid-based organic salts show crystallization water molecule-triggered dielectric transitions and relaxations.

Distinct room-temperature dielectric transition in a perchlorate-based organic–inorganic hybrid perovskite

Distinct room-temperature dielectric transition is realized in a perchlorate-based organic–inorganic hybrid perovskite with the introduction of a polar cationic guest.