New ferroelectrics based on divalent metal ion alum

4-Fluoro-anilinium tetra-chloridoferrate(III) 18-crown-6 clathrate

The reaction of 4-fluoro­aniline hydro­chloride, 18-crown-6 and ferric chloride in methano­lic solution yields the title compound, (C₆H₇FN)[FeCl₄]·C₁₂H₂₄O₆, which has an unusual supramolecular structure. N—H⋯O hydrogen-bonding inter­actions between the NH₃⁺ substituents of the 4-fluoro­anilinium cations and the O atoms of the crown ether mol­ecules result in a rotator–stator-like structure.

4-(Cyano-meth-yl)anilinium 4-methyl-benzene-sulfonate monohydrate

In the title salt, C₈H₉N₂⁺·C₇H₇O₃S⁻·H₂O, the dihedral angle between the cation and anion benzene rings is 50.1 (4)°. In the cation, the cyano­methyl group is twisted from the plane of the benzene ring [C—C—C—N = −86 (12)°]. In the crystal, the cations, anions and water mol­ecules are linked by N—H⋯O and O—H⋯O hydrogen bonds, forming a chain along the c axis.

Dimethyl-ammonium tetra-chloridoferrate(III) 18-crown-6 clathrate

The reaction of dimethyl­amine hydro­chloride, 18-crown-6 and ferric chloride in ethanol yields the title compound, (C₂H₈N)[FeCl₄]·C₁₂H₂₄O₆, which exhibits an unusual supramolecular structure. The protonated dimethyl­amine contains one NH₂⁺ group, resulting in a 1:1 supra­molecular rotator–stator structure (CH₃—NH₂⁺—CH₃)(18-crown-6), through N—H⋯O hydrogen-bonding inter­actions between the ammonium group of the cation and the O atoms of the crown ether. In the crystal, all three components lie on a common crystallographic mirror plane normal to [010].

Hexa-kis-(4-acetyl-pyridinium) octa-deca-chloridotetra-anti-monate(III)

The title compound, (C₇H₈NO)₆[Sb₄Cl₁₈], contains centrosymmetric hexa­anions built up from four vertex-sharing alternating SbCl₅ square-based pyramids and highly distorted SbCl₆ octa­hedra when long (<3.2 Å) ‘secondary’ Sb—Cl inter­actions are taken into account. The inter-polyhedral Sb—Cl bonds define a square-shape. In the crystal, the components are linked by N—H⋯Cl, C—H⋯Cl and C—H⋯O hydrogen bonds, generating a three-dimensional network.

4-Methyl-anilinium tetra-fluoro-borate 18-crown-6 clathrate

In the title compound, C(7)H(10)N(+)·BF(4) (-)·C(12)H(24)O(6), the proton-ated 4-methyl-anilinium cation inter-acts with 18-crown-6 forming a rotator-stator structure, (C(6)H(4)CH(3)NH(3) (+))(18-crown-6), through three bifurcated N-H⋯(O,O) hydrogen bonds between the ammonium groups of the cations (-NH(3)) and the O atoms of the crown ether mol-ecule. The BF(4) (-) anions, the methyl group and the protonated -NH(3) groups of the 4-methylanilinium lie on a dual axis of rotation. The 18-crown-6 unit is perpendicular to the dual axis of rotation and the mirror plane which contains the dual axis of rotation. The benzene ring of 4-methylanilinium is perpendicular to the mirror plane and parallel to the dual axis.

4-Ethoxy-anilinium hexa-fluoro-phosphate monohydrate

In the crystal of the title compound, C₈H₁₂NO⁺·PF₆⁻·H₂O, inter­molecular N—H⋯F, N—H⋯O and O—H⋯F hydrogen bonds link the mol­ecules into chains along the c axis and C—H⋯π contacts further stabilize the structure. The F atoms of one of the hexa­fluoro­phosphate anions are disordered over two sets of sites with site-occupancy factors of 0.27 (3) and 0.73 (3).

1-[Morpholino(phen-yl)meth-yl]-2-naphthol

There are two independent mol-ecules in the asymmetric unit of the title compound, C(21)H(21)NO(2), which was synthesized by the one-pot reaction of 2-naphthol, morpholine and benzaldehyde. The dihedral angles between the naphthalene ring systems and the benzene rings are 84.03 (7) and 75.76 (8)° in the two mol-ecules and an intra-molecular O-H⋯N hydrogen bond occurs in each independent mol-ecule.

4-Bromo-anilinium hexa-fluoro-phosphate monohydrate

In the title compound, C₆H₇BrN⁺·PF₆⁻·H₂O, N—H⋯F, N—H⋯O and O—H⋯F hydrogen-bonding inter­actions stabilize the crystal structure and give rise to to chains running parallel to the c axis. In the anion, four of the F atoms are disordered over two sets of sites of equal occupancy.

Bis(4-fluoro-anilinium) tetra-chloridocuprate(II)

The crystal structure of the title compound, (C(6)H(7)FN)(2)[CuCl(4)], consists of parallel two-dimensional perovskite-type layers of corner-sharing CuCl(6) octa-hedra. These are bonded together via N-H⋯Cl hydrogen bonds from the 4-fluoro-anilinium chains, which are almost perpendicular to the layers. The CuCl(4) dianions have two short Cu-Cl bonds [2.2657 (15) and 2.2884 (13) Å] and two longer bonds [2.8868 (15) Å], giving highly Jahn-Teller-distorted CuCl(6) octa-hedra. The Cu atoms are situated on crystallographic centers of inversion.

4-Iodo-anilinium nitrate

In the title compound, C₆H₇IN⁺·NO₃⁻, π–π stacking inter­actions [centroid–centroid distances = 4.014 (4) and 4.029 (4) Å] stabilize the crystal structure and strong N—H⋯O and N—H⋯N hydrogen bonds link the cations and anions into zigzag chains running parallel to the c axis. The asymmetric unit contains two unique cations and anions