Robust Crystalline Hybrid Solid with Multiple Channels Showing High Anhydrous Proton Conductivity and a Wide Performance Temperature Range.

A proton conductor displaying high anhydrous proton conductivity (≈10(-2) S cm(-1)) and good performance over a broad temperature range is presented. This hybrid material is produced via doping HCl into open-framework chalcogenide(C2N2H10)(C2N2H9)2 Cu8 Sn3S12, and has cubopolyhedral cavities and multiple channels.

Observation of hysteretic magnetic phase transitions coupled with orientation motion of ions and dielectric relaxation in a one-dimensional nickel-bis-dithiolene molecule solid.

The second polymorph, the ß-crystal, of the nickel-bis-dithiolene compound [4'-CF3bzPy][Ni(mnt)2], where 4'-CF3bzPy = 1-(4'-trifluoromethylbenzyl)pyridinium and mnt(2-) = maleonitriledithiolate, was obtained. The variable-temperature single crystal structures, magnetic behavior in 1.8-300 K and dielectric nature in 123-373 K have been investigated for the ß-crystal. This polymorph experiences two hysteretic magnetic phase transitions in a narrow temperature region (190-217 K) with the thermal hysteresis loops ca. 6 K and ca. 11 K. The two hysteretic magnetic phase transitions are coupled with two isostructural phase transitions (IPTs), respectively, which are driven by the novel step-wise dynamic orientation motion of the anion and cation in the ß-crystal. There is an absence of a dielectric anomaly in the structural transformation temperature interval. However, a dielectric relaxation, related to the dipole motion of polar CF3 groups in the cations under an ac electrical field, emerges in the high-temperature phase.

Two segregated columnar stack platinum-bis-dithiolene molecule solids showing spin-Peierls-type transition above room temperature.

Two new one-dimensional (1-D) compounds, [CH3-BzPy][Pt(mnt)2] (1) and [CH3-BzPy-d5][Pt(mnt)2] (2) (CH3-BzPy(+) = 1-N-(4-CH3-benzyl)pyridinium and the pyridine in CH3-BzPy(+) was replaced by pyridine-d5 to give the CH3-BzPy-d5(+); mnt(2-) = maleonitriledithiolate), were synthesized and characterized. 1 and 2 show similar magnetic behavior in 1.8-400 K; they experience a spin-Peierls-type transition around 320 K and show a uniform antiferromagnetic S = 1/2 chain behavior in high temperature (HT) phase, a spin gap feature in low temperature (LT) phase. A symmetry breaking structural phase transition is associated with the spin-Peierls-type transition. Two isostructural compounds crystallize in space group P2(1)/c in HT phase, with a = 12.3066(8) Å, b = 27.0522(18) Å, c = 7.4248(4) Å, ß = 104.204(6)° and V = 2396.3(3) Å(3) for 1 versus a = 12.3331(9) Å, b = 27.087(4) Å, c = 7.4501(9) Å, ß = 104.149(13)° and V = 2413.3(6) Å(3) for 2 at 353 K, while space group P1[combining macron] in LT phase, with a = 7.3203(10) Å, b = 12.2816(16) Å, c = 26.904(4) Å, α = 88.500(4)°, ß = 86.731(4)°, γ = 75.421(4)° and V = 2337.0(5) Å(3) for 1 versus a = 7.3308(8) Å, b = 12.2848(13) Å, c = 26.930(3) Å, α = 88.479(3)°, ß = 86.652(4)°, γ = 75.563(3)° and V = 2344.5(4) Å(3) for 2 at 296 K. DSC measurements revealed 1 and 2 showing almost the same T(C). This observation is distinction from the [Ni(mnt)2](-)-based spin-Peierls-type analogues [CH3-BzPy][Ni(mnt)2] and [CH3-BzPy-d5][Ni(mnt)2] where the deuteration leads to T(C) up shifting 2.3 K.

Bis(1-ethyl-4,4'-bipyridin-1-ium) bis-(1,2-di-cyano-ethene-1,2-di-thiol-ato-κ(2) S,S')nickelate(II).

In the anion of the title compound, (C12H13N2)[Ni(C4N2S2)2], the Ni(II) atom is coordinated by four S atoms from two 1,2-di-cyano-ethene-1,2-di-thiol-ate (mnt) ligands in a suqare-planar geometry. Weak C-H⋯N and C-H⋯S hydrogen bonds between the 1-ethyl-4,4'-bipyridin-1-ium cations and mnt anions and weak π-π inter-actions between the pyridine rings of the cations [centroid-centroid distances = 3.808 (3) and 3.972 (3) Å] lead to a two-dimensional network parallel to (010).

Comparative study of structures, thermal stabilities and dielectric properties for a ferroelectric MOF [Sr(µ-BDC)(DMF)]∞ with its solvent-free framework.

A ferroelectric MOF with a formula [Sr(µ-BDC)(DMF)]∞ (1) was transformed into [Sr(µ-BDC)(CH2Cl2)x]∞ (2) using a solvent exchange approach, where DMF = N,N-dimethylformamide and BDC(2-) = benzene-1,4-dicarboxylate. The lattice solvents, CH2Cl2 molecules, in 2 were removed by heating to give the solvent-free metal-organic framework [Sr(µ-BDC)]∞ (3) and the crystal-to-crystal transformation is reversible between 1 and 3. The release of DMF molecules from 1 results in the metal-organic framework of [Sr(µ-BDC)]∞ expanding a little along the a- and b-axes. The crystal structure optimizations for 1 and 3 disclosed that the lattice expansion is associated with the alternations of the bond distances and angles in the Sr(2+) ion coordination sphere along the a- and b-axes directions. The metal-organic framework 3 collapses at temperatures of more than 600 °C; such an extremely high thermal stability is related to the closed-shell electronic structure of the Sr(2+) ion, namely, the coordinate bond between the closed-shell Sr(2+) ion and the bridged BDC(2-) ligands does not have a preferred direction, which is favored for reducing lattice strains and is responsible for the higher thermal stability. The comparative investigations for the dielectric and ferroelectric behaviors of 1 and 3 confirmed that the motion of the polar DMF molecules, but not the [Sr(µ-BDC)]∞ framework, is responsible for the ferroelectric properties of 1.