Crystal structure of citric acid–acetonitrile (1/1), C8H11NO7

C8H11NO7, triclinic, P1̄ (no. 2), a = 5.5944(13) Å, b = 10.402(3) Å, c = 10.666(3) Å, α = 110.297(2) o , β = 101.342(3) o , γ = 104.701(2) o , V = 534.6(2) Å3, Z = 2, R gt(F) = 0.0318, wR ref(F 2) = 0.0833, T = 293(2) K.

High-temperature phase transitions, switchable dielectric behaviors and barocaloric effects in three new organic molecule-based crystals

Three new organic molecule-based compounds which undergo high-temperature phase transitions and display switchable dielectric behaviors.

Photoluminescent-dielectric duple switch in a perovskite-type high-temperature phase transition compound: [(CH3)3PCH2OCH3][PbBr3]

A perovskite-type high-temperature phase transition compound, ([(CH₃)₃PCH₂OCH₃][PbBr₃], 1), displays a remarkable bistable photoluminescent-dielectric duple switching behavior.

Two reversible ferroelectric phase transitions in diisopropylammonium perchlorate

Two reversible first-order phase transitions were found in an improper ferroelectric, diisopropylammonium perchlorate, as the crystal symmetry transforms from P2₁/c to P1 at 296 K, and subsequently to P2₁/c at 338 K in the heating process.

A one-dimensional ladder-like six-coordinate cadmium polymer: catena-poly[bis[(S)-2-methylpiperazine-1,4-diium] [bis[trichloridocadmium(II)]-di-μ3-chlorido]]

The crystal structure of the title compound {(C5H14N2)2[Cd2Cl8]}n, (I), consists of hydrogen-bonded 2-methylpiperazinediium (H2MPPA(2+)) cations in the presence of one-dimensional polymeric {[CdCl3(μ3-Cl)](2-)}n anions. The Cd(II) centres are hexacoordinated by three terminal chlorides and three bridging chlorides and have a slightly distorted octahedral CdCl3(μ3-Cl)3 arrangement. The alternating CdCl6 octahedra form four-membered Cd2Cl2 rings by the sharing of neighbouring Cd-Cl edges to give rise to extended one-dimensional ladder-like chains parallel to the b axis, with a Cd···Cd distance of 4.094 (2) Å and a Cd···Cd···Cd angle of 91.264 (8)°. The H2MPPA(2+) cations crosslink the [CdCl3(μ3-Cl)]n chains by the formation of two N-H···Cl hydrogen bonds to each chain, giving rise to one-dimensional ladder-like H2MPPA(2+)-Cl2 hydrogen-bonded chains [graph set R4(2)(14)]. The [CdCl3(μ3-Cl)]n chains are interwoven with the H2MPPA(2+)-Cl2 hydrogen-bonded chains, giving rise to a three-dimensional supramolecular network.

A one-dimensional ABX3-type coordination polymer: catena-poly[benzyltrimethylammonium [tri-μ-chlorido-cadmium(II)]]

The crystal structure of the title novel one-dimensional ABX3-type organic-inorganic hybrid complex {(C10H16N)[CdCl3]}n, (I), consists of benzyltrimethylammonium (Me3BzN(+)) cations and one-dimensional anionic {[Cd(μ-Cl)3](-)}∞ chains. Each Cd(II) centre is hexacoordinated by bridging chloride ligands, giving a slightly distorted octahedral Cd(μ-Cl)6 arrangement. The octahedra are linked by two opposite shared faces, giving rise to an almost perfectly linear anionic {[Cd(μ-Cl)3](-)}∞ chain in the a-axis direction. Me3BzN(+) cations located in the inter-chain spaces balance the charge. Noncovalent static attracting forces (Coulombic and van der Waals forces) and nonclassical C-H···Cl hydrogen-bond interactions stabilize the crystal structure.

Dimethyl-ammonium guanidinium naphthalene-1,5-disulfonate

The asymmetric unit of the title salt, CH₆N₃⁺·C₂H₈N⁺·C₁₀H₆O₆S₂²⁻, consists of one dimethyl­ammonium cation, one guanidinium cation, and two half naphthalene-1,5-disulfonate anions, which lie on inversion centers. N—H⋯O hydrogen bonds link the cations and anions into layers parallel to the ab plane. The layers have a sandwich-like structure, with the sulfonate groups and cations forming outer slices and the naphthalene ring systems inside.

Bis(2-hy-droxy-ethanaminium) terephthalate

The asymmetric unit of the title salt, 2C₂H₈NO⁺·C₈H₄O₄²⁻, comprises one crystallographically independent 2-hy­droxy­ethanaminium cation and one half terephthalate anion. In the crystal, hydrogen bonds involving the hy­droxy and ammonium groups of the cations and the carboxyl­ate O atoms of the terephthalate anions result in the formation of a three-dimensional network structure.

Methylammonium tetrafluoridoborate 18-crown-6 clathrate

In the title compound, CH₃NH₃⁺·BF₄⁻·C₁₂H₂₄O₆, the methyl­ammonium cation makes three N—H⋯O hydrogen bonds to the 18-crown-6 mol­ecule. The –NH₃⁺ and –CH₃ groups of the cation adopt a staggered conformation. The F atoms of the tetra­fluoridoborate anion are disordered over two sets of sites in a 0.519 (11):0.481 (11) ratio. Weak C—H⋯F inter­actions occur in the crystal, which possibly correlate with the anion disorder.

Bis(diisopropyl-ammonium) naphthalene-1,5-disulfonate

In the title compound, 2C₆H₁₆N⁺·C₁₀H₆O₆S₂²⁻, the cations and anions are associated via N—H⋯O and C—H⋯O hydrogen-bonding inter­actions.

Tetra-aqua-bis-(2-methyl-1H-imidazole-κN)cobalt(II) naphthalene-1,5-disulfonate

In the title complex, [Co(C₄H₆N₂)₂(H₂O)₄](C₁₀H₆O₆S₂), the cation and anion both reside on crystallographic inversion centers, such that the asymmetric unit comprises one half cation and one half anion. The central Co^II ion is coordinated by four water mol­ecules and two 2-methyl­imidazole ligands, resulting in a trans-octa­hedral coordination geometry. The existence of strong N—H⋯O and O—H⋯O hydrogen-bonding inter­actions gives rise to a three-dimensional structure.

Piperazine-1,4-diium naphthalene-1,5-disulfonate

The title molecular salt, C₄H₁₂N₂²⁺·C₁₀H₆O₆S₂²⁻, consists of a piperazinium cation and a 1,5-naphthalene­disulfonate anion. Crystallographic inversion centers are situated at the center of the ring of the dication as well as at the midpoint of the central carbon–carbon bond in the dianion. In the crystal, inter­molecular N—H⋯O hydrogen bonds link the cations and anions.

Dimeth-yl(4-methyl-phen-yl)ammonium naphthalene-1,5-disulfonate dihydrate

The asymmetric unit of the organic–inorganic hybrid salt, 2C₉H₁₄N⁺·C₁₀H₆O₆S₂²⁻·2H₂O, consists of one dimeth­yl(4-methyl­phen­yl)ammonium cation, one half of a naphthalene-1,5-disulfonate anion lying on a crystallographic centre of inversion, and one water mol­ecule. In the crystal, O—H⋯O(S) and N—H⋯OH₂ hydrogen bonds link the cations and anions forming ring motifs.

Diisopropyl-ammonium 4-meth-oxy-benzoate

In the crystal structure of the title compound, C(6)H(16)N(+)·C(8)H(7)O(3) (-), inter-molecular N-H⋯O hydrogen bonds link the cations and anions into arrangements consisting of two cations and two anions each.