Haloplumbate-based perovskites display promising functionalities for advanced photovoltaic, optoelectronic and other applications with high performances and low costs. Herein, we present a study of variable-temperature crystal structures, dielectrics and conductance at 153-513 K, and luminescence at ambient temperature for a one-dimensional organic-inorganic perovskite, [N-methyldabconium]PbI3 (1). Hybrid 1 shows extra thermo- and water-stability (thermal decomposition at ca. 653 K), switchable dielectric behaviour and conductance at around 348 K, owing to symmetry-breaking structure phase transition from the hexagonal space group P63/mmc in the high-temperature phase to the orthogonal space group Pcba in the low-temperature phase, and bright yellow-green emission at room temperature, originating from the electron transition within the semiconducting {PbI3}∞ chains. This study will broaden the scope of lead halide-based hybrid materials for practical application in optical and electrical devices.

The emerging organic ion plastic crystals (OIPCs) are the most promising candidates used as solid-state electrolytes in a range of ionic devices. To endow an OIPC with additional functionality may create a new type of material for multifunctional devices. Herein, we present an ion plastic crystal, [EMIm]­[Ni­(mnt)2] (1; [EMIm]+ = 1-ethyl-3-methylimidazolium and mnt2– = maleonitriledithiolate), and its crystal consists of twin dimeric chains of [Ni­(mnt)2]− anions, embraced by [EMIm]+ cations. A crystal-to-plastic crystal transformation with a large latent heat that occurred at ∼367/337 K on heating/cooling is confirmed by the differential scanning calorimetry (DSC) technique. The plastic crystal phase in 1, characterized by variable temperature powder X-ray diffraction (PXRD) and optical microscopy images, spans a broad temperature range with ΔT ∼123/153 K on heating/cooling (DSC measurement), and the wide ΔT is relevant to an extra stable anion chain owing to the strong antiferromagnetic (AFM) interactions protecting the chain from collapse in the plastic crystal state. 1 is a single-component ion plastic crystal with a record high ion conductivity, 0.21 S·cm–1, at 453 K. The crystal-to-plastic crystal transformation in 1 is coupled to a bistable magnetic transition to give a multi-in-one multifunctional material. This study provides a creative thought for the design of OIPCs with striking thermal, electrical, and magnetic multifunctionality.

For the first time, a main-group metal complex is used as a template for the formation of hybrid crystal structures and isomorphic hybrid crystals are obtained using transition and main-group metal complexes.

Mixed ion−electron conductors have a wide range of important applications in devices relying on mixed ion−electron transport, mainly including conducting polymer composites and ceramics. Herein, we present a new type of mixed ion−electron conductor, an open-framework chalcogenide, (H 3 O)KCu 6 Ge 2 S 8 •nH 2 O (1), with a three-dimensional (3D) framework and two types of one-dimensional (1D) channels, occupied by hydronium ions and potassium ions, respectively. Thermogravimetric (TG) and powder X-ray diffraction (PXRD) measurements suggest that the hydrated proton species in the channels of 1 are in the form of H 2n+1 O n + (n > 1). The impedance measurements reveal that 1 is an intrinsic mixed proton− electron conductor. In the N 2 atmosphere, the conductivity (σ) of 1 increases with release of water molecules and increasing temperature with σ = 0.71 S cm −1 at 123 K and 1.61 S cm −1 at 473 K in the first cooling run, and in this case, the electron conduction is much higher than the ion conduction. At 98% relative humidity (RH), however, the situation is opposite, and the proton conductivity of 1 is higher than its electron conduction with an ion conductivity (σ i )/electron conductivity (σ e ), σ i /σ e , of 1.99 × 10 −3 /6.31 × 10 −4 S cm −1 at 298 K and 2.49 × 10 −2 /2.52 × 10 −3 S cm −1 at 343 K. To the best of our knowledge, 1 is the first example of an open-framework material with mixed proton−electron conduction, and this study demonstrates that open-framework materials, including chalcogenides, MOFs, and COFs, are good candidates for mixed proton− electron conductors.

An organometallic supramolecular crystal of {K(18-crown-6)(ηn-C6H5B(C6H5)3)} (n = 1–6) has a half-sandwich structure and exhibits a reversible breaking-symmetry phase transition and switchable dielectric behavior.