Hydrate isomerism in [Cu(en)2(H2O)1.935]2[Fe(CN)6]·4H2O

The title compound, bis[di­aqua­bis­(ethyl­enedi­amine‐κ²N,N′)copper(II)­] hexa­cyano­iron(II) tetrahydrate, [Cu(C₂H₈N₂)₂(H₂O)_1.935]₂[Fe(CN)₆]·4H₂O, was crystallized from an aqueous reaction mixture initially containing CuSO₄, K₃[Fe(CN)₆] and ethyl­enedi­amine (en) in a 3:2:6 molar ratio. Its structure is ionic and is built up of two crystallographically different cations, viz. [Cu(en)₂(H₂O)₂]²⁺ and [Cu(en)₂(H₂O)_1.87]²⁺, there being a deficiency of aqua ligands in the latter, [Fe(CN)₆]⁴⁻ anions and disordered solvent water mol­ecules. All the metal atoms lie on centres of inversion. The Cu atom is octahedrally coordinated by two chelate‐bonded en mol­ecules [mean Cu—N = 2.016 (2) Å] in the equatorial plane, and by axial aqua ligands, showing very long distances due to the Jahn–Teller effect [mean Cu—O = 2.611 (2) Å]. In one of the cations, significant underoccupation of the O‐atom site is observed, correlated with the appearance of a non‐coordinated water mol­ecule. This is interpreted as the partial contribution of a hydrate isomer. The [Fe(CN)₆]⁴⁻ anions form quite regular octahedra, with a mean Fe—C distance of 1.913 (2) Å. The dominant intermolecular interactions are cation–anion O—H⋯N hydrogen bonds and these inter­actions form layers parallel to (001).     

A new hydrated ammonium hydroxy­borate, (NH4)2[B10O14(OH)4]·H2O

The structure of a new synthetic compound, di­ammonium tetra­hydroxy­deca­borate monohydrate, has been determined by single‐crystal X‐ray diffraction. It crystallizes in triclinic space group and all atoms occupy general sites. The title compound is composed of [B₁₀O₁₅(OH)₄]⁴⁻ ions as the fundamental building blocks, and these are linked end‐to‐end by sharing two common O atoms, thus producing infinite chains of composition [B₁₀O₁₄(OH)₄]_n^2n–. These chains are linked by hydrogen bonds, thus forming borate sheets. Water mol­ecules and ammonium ions between these sheets connect adjacent sheets via hydrogen bonds.     

Adducts of 1,1,1‐tris(4‐hydroxyphenyl)ethane with diamines: three‐dimensional hydrogen‐bonded frameworks formed with 1,6‐diaminohexane and 2,2′‐bipyridyl

The adduct 1,6‐di­amino­hexane–1,1,1‐tris(4‐hydroxy­phenyl)­ethane (1/2) is a salt {hexane‐1,6‐diyldiammonium–4‐[1,1‐bis(4‐hydroxyphenyl)ethyl]phenolate (1/2)}, C₆H₁₈N₂²⁺·2C₂₀H₁₇O₃^?, in which the cation lies across a centre of inversion in space group P. The anions are linked by two short O—H?O hydrogen bonds [H?O 1.74 and 1.76 Å, O?O 2.5702 (12) and 2.5855 (12) Å, and O—H?O 168 and 169°] into a chain containing two types of R(24) ring. Each cation is linked to four different anion chains by three N—H?O hydrogen bonds [H?O 1.76–2.06 Å, N?O 2.6749 (14)–2.9159 (14) Å and N—H?O 156–172°]. In the adduct 2,2′‐bipyridyl–1,1,1‐tris(4‐hydroxy­phenyl)­ethane (1/2), C₁₀H₈N₂·2C₂₀H₁₈O₃, the neutral di­amine lies across a centre of inversion in space group P2₁/n. The tris­(phenol) mol­ecules are linked by two O—H?O hydrogen bonds [H?O both 1.90 Å, O?O 2.7303 (14) and 2.7415 (15) Å, and O—H?O 173 and 176°] into sheets built from R(38) rings. Pairs of tris­(phenol) sheets are linked via the di­amine by means of a single O—H?N hydrogen bond [H?N 1.97 Å, O?N 2.7833 (16) Å and O—H?N 163°].     

Hydrogen‐bonded bilayers in ­piperazinium(2+) bis(mandelate) bis(methanol) solvate

In the title compound, C₄H₁₂N₂²⁺·2C₈H₇O₃^?·2CH₄O, the cations lie across centres of inversion and are disordered over two orientations with equal occupancy; there are equal numbers of (R)‐ and (S)‐mandelate anions present (mandelate is α‐hydroxy­benzene­acetate). The anions and the neutral water mol­ecules are linked by O—H?O hydrogen bonds [O?O 2.658 (3) and 2.682 (3) Å, and O—H?O 176 and 166°] into deeply folded zigzag chains. Each orientation of the cation forms two symmetry‐related two‐centre N—H?O hydrogen bonds [N?O 2.588 (4) and 2.678 (4) Å, and N—H?O 177 and 171°] and two asymmetric, but planar, three‐centre N—H?(O)₂ hydrogen bonds [N?O 2.686 (4)–3.137 (4) Å and N—H?O 137–147°], and by means of these the cations link the anion/water chains into bilayers.     

Ammonium 4‐nitrophenylarsonate

In the crystal structure of the title compound, (NH₄)[AsO₂(OH)(C₆H₄NO₂)], the 4‐nitro­phenyl­arsonate anions and ammonium cations are linked through hydrogen bonds to form infinite chains along the b axis. The hydroxyl O atom of the 4‐nitro­phenyl­arsonate anion acts as both an acceptor and a donor of hydrogen bonds. All atoms are located in general positions.     

Bis­[tris(2,2′‐bi­pyridine‐κ2N,N′)­ruthenium(II)] hexa­cyano­ferrate(III) chloride octahydrate

In the title compound, [Ru^II(C₁₀H₈N₂)₃]₂[Fe^III(CN)₆]Cl·8H₂O, the [Ru(bpy)₃]²⁺ (bpy is 2,2′‐bi­pyridine) cations and water mol­ecules afford intriguing microporous honeycomb layers, while the [Fe(CN)₆]³⁻ anions and the remainder of the water mol­ecules form anionic sheets based on extensive hydrogen‐bonding networks. The cationic and anionic layers alternate along the c axis. The Fe atom in [Fe(CN)₆]³⁻ lies on an inversion centre and the axial cyano ligands are hydrogen bonded to the water mol­ecules encapsulated within the micropores [N⋯O = 2.788 (5) Å], giving an unusual interpenetration between the cationic and anionic layers. On the other hand, the in‐plane cyano ligands are relatively weakly hydrogen bonded to the water mol­ecules [N⋯O = 2.855 (7) and 2.881 (8) Å] within the anionic sheets.     

Hydrogen‐bonding motifs in 4‐carboxy­phenyl­ammonium nitrate and perchlorate monohydrate,and in bis(4‐carboxy­phenyl­ammonium) sulfate

In the title compounds, C₇H₈NO₂⁺·NO₃⁻, (I), C₇H₈NO₂⁺·ClO₄⁻·H₂O, (II), and 2C₇H₈NO₂⁺·SO₄²⁻, (III), the carboxyl planes of the 4‐carboxy­phenyl­ammonium cations are twisted from the aromatic plane. A homonuclear C(8) hydrogen‐bonding motif of 4‐carboxy­phenyl­ammonium cations is observed in both (I) and (II), leading to `head‐to‐tail' layers. The cations in (III) form carboxyl group dimers, making a graph‐set motif of R₂²(8). In all the structures, anions connect the cationic layers and an infinite chain running along the c axis is observed, having the C₂²(6) graph‐set motif. Inter­estingly, in (II), the anions are connected through weak hydrogen bonds involving the water mol­ecules, leading to a graph‐set motif of R₄⁴(12). Alternate hydro­phobic and hydro­philic layers are observed in all three compounds as a result of the column‐like arrangement of the aromatic rings of the cations and the anions. Furthermore, in (I), head‐to‐tail N—H⋯O inter­actions and inter­actions linking the cations and anions form an R₆⁴(16) hydrogen‐bonding motif, resulting in a pseudo‐inversion centre at (, , 0).     

Thia­mine tetra­phenyl­borate monohydrate: a two‐dimensional hydrogen‐bonded network with (4,4)‐topology

The title compound, 3‐[(4‐amino‐2‐methyl­pyrimidin‐5‐yl)­meth­yl]‐5‐(2‐hydroxy­eth­yl)‐4‐methyl­thia­zolium tetra­phenyl­borate monohydrate, C₁₂H₁₇N₄OS⁺·C₂₄H₂₀B⁻·H₂O, is a salt in which the thiamine cations are linked by hydrogen bonds into a two‐dimensional network having (4,4)‐topology. The stacked sheets form channels, which are occupied by the anions; the cations and anions are linked by C—H⋯π(arene) hydrogen bonds.     

2‐Amino‐5‐nitro‐4,6‐dipiperidinopyrimidinium hydrogen­sulfate monohydrate: hydrogen‐bonded sheets containing highly distorted cations

In the title compound, C₁₄H₂₃N₆O₂⁺·HSO₄⁻·H₂O, the pyrimidinium ring of the cation adopts a twist‐boat conformation, induced by steric clashes between adjacent ring substituents; the anions and the water mol­ecules are linked by three O—H⃛O hydrogen bonds [H⃛O = 1.70–1.78 Å, O⃛O = 2.548 (2)–2.761 (2) Å and O—H⃛O = 161–168°] into chains of edge‐fused R(12) rings, which are linked into sheets by the cations, via three N—H⃛O hydrogen bonds [H⃛O = 1.96–2.17 Å, N⃛O = 2.820 (2)–2.935 (2) Å and N—H⃛O = 145–173°].     

3,5‐Bis(4‐methoxy­benzyl­idene)‐1‐methyl‐4‐piperidone and 3,5‐bis(4‐methoxy­benzyl­idene)‐1‐methyl‐4‐oxopiperidinium chloride: potential biophotonic materials

In the title compound 3,5‐bis(4‐methoxy­benzyl­idene)‐1‐methyl‐4‐piperidone, C₂₂H₂₃NO₃, (I), the central heterocyclic ring adopts a flattened boat conformation, while in the related salt 3,5‐bis(4‐methoxy­benzyl­idene)‐1‐methyl‐4‐oxopiperidin­ium chloride, C₂₂H₂₄NO₃⁺·Cl⁻, (II), the ring exhibits a `sofa' conformation in which the N atom deviates from the planar fragment. The pendant benzene rings are twisted from the heterocyclic ring planes in both mol­ecules in the same direction, the range of dihedral angles between the ring planes being 24.5 (2)–32.7 (2)°. The dominant packing motif in (I) involves centrosymmetric dimers bound by weak intermolecular C—H⋯O hydrogen bonds. In (II), cations and anions are linked by strong N—H⋯Cl hydrogen bonds, while weak C—H⋯O and C—H⋯Cl hydrogen bonds link the cations and anions into a three‐dimensional framework.     

The three‐dimensional coordination polymer tetra­ethyl­ammonium (ethyl­ene­di­amine)­cadmium(II) hexa­cyano­ferrate(III), (Et4N){[Cd(en)]4[Fe(CN)6]3}

The title compound, tetra­ethyl­ammonium dodeca‐μ‐cyano‐hexa­cyano­tetrakis­(ethyl­ene­di­amine)­tetra­cadmium(II)­tri­fer­rate(III), (C₈H₂₀N)[Cd₄Fe₃(CN)₁₈(C₂H₈N₂)₄], was pre­pared from a reaction mixture containing CdCl₂, K₃[Fe(CN)₆], ethyl­ene­di­amine (en) and [Et₄N]Br in a 1:1:3:1 molar ratio. The crystal structure consists of a negatively charged three‐dimensional framework of {[Cd(en)]₄[Fe(CN)₆]₃} anions, with [Et₄N]⁺ cations located in the cavities of the framework. The Cd atom is octahedrally coordinated by one disordered chelating en mol­ecule [mean Cd—N = 2.35 (3) Å] and four N‐­bonded bridging cyano groups [Cd—N distances are in the range 2.283 (2)–2.441 (2) Å]. There are two crystallographically independent [Fe(CN)₆]³⁻ anions in the structure and in each the Fe atom lies on a twofold axis. In the first [mean Fe—C = 1.941 (5) Å], all the cyano groups are bridging ligands, while in the second [mean Fe—C = 1.945 (2) Å], there are two terminal cyano ligands in trans positions. The Cd—N—C angles range from 128.6 (2) to 172.8 (2)°.     

l‐Argininamidium bis­(hydrogen­squarate)

Cations and anions of the title compound {systematic name: 1‐[4‐(amino­carbonyl)butyl]guanidinium bis­(hydrogen­squarate)}, C₆H₁₇N₅O²⁺·2C₄HO₄⁻, are connected into a three‐dimensional network by inter­molecular N—H⋯O hydrogen bonds between the l ‐argininamidium ammonium, amide and guanidinium functions and the hydrogensquarate carbonyl O atoms. The independent hydrogensquarate monoanions are linked into dimers by pairs of O—H⋯O′ hydrogen bonds.     

Barium bis­[6‐amino‐3‐methyl‐5‐nitro­so­pyrimidine‐2,4(1H,3H)‐dionate] trihydrate: coordination polymer chains linked by hydrogen bonds

The title complex, catena‐poly[[triaquabarium(II)]‐di‐μ‐6‐amino‐3‐methyl‐5‐nitro­so­pyrimidine‐2,4(1H,3H)‐dionato], [Ba(C₅H₅N₄O₃)₂(H₂O)₃]_n, forms a coordination polymer chain in which the two distinct anions use different ligating atoms to bridge pairs of cations. Adjacent pairs of cations are also linked by pairs of bridging water mol­ecules. The chains are linked into a single three‐dimensional framework by an extensive series of hydrogen bonds.     

N,N′‐Di­methyl­piperazinium(2+) phos­phonoacetate: hydrogen‐bonded anion sheets containing cation‐templated R66(28) rings

In the title compound, C₆H₁₆N₂²⁺·2C₂H₄O₅P^?, the cations lie across centres of inversion; in the anions, two of the H‐atom sites have 0.50 occupancy. The anions are linked by short O—H?O hydrogen bonds [O?O 2.465 (3)–2.612 (3) Å and O—H?O 165–171°] into sheets of alternating R(12) and R(28) rings, both of which are centrosymmetric; the cations lie at the centres of the larger rings linked to the anion sheet by N—H?O hydrogen bonds [N?O 2.642 (2) Å and N—H?O 176°].     

Bis(ammonium) tris­(hexa­aqua­magnesium) tetra­kis(hydrogen phosphite)

The structure of the title compound, (NH₄)₂[Mg(H₂O)₆]₃(HPO₃)₄, consists of [Mg(H₂O)₆]²⁺ and (NH₄)⁺ cations and (HPO₃)²⁻ anions held together by an intricate network of hydrogen bonds involving all H atoms except for one linked directly to a P atom. The Mg²⁺ cations are octa­hedrally coordinated by six water mol­ecules. One of the Mg atoms is located on a site with 2/m symmetry, whereas the other Mg atom and the P and N atoms occupy sites with m symmetry.     

Bis­[bis­(diethyl­enetri­amine)­zinc(II)] hexa­cyano­ferrate tetrahydrate

In the crystal structure of the title compound, [Zn(C₄H₁₃N₃)₂]₂[Fe(CN)₆]·4H₂O, the asymmetric unit is formed by a [Zn(dien)₂]²⁺ cation (dien = diethyl­enetri­amine, NH₂CH₂CH₂NHCH₂CH₂NH₂), water mol­ecules and half of the [Fe(CN)₆]^4? anion which is related by inversion symmetry through the Fe atom. The geometry around the Zn and Fe atoms is distorted octahedral and octahedral, respectively. Intramolecular O—H?O hydrogen bonds involving the water mol­ecules, and intermolecular O—H?N hydrogen bonds involving the water mol­ecules and the anions, result in an infinite chain. Intramolecular O—H?O and N—H?N, and intermolecular O—H?N, N—H?O and N—H?N hydrogen bonds form a three‐dimensional framework.     

(Aceto­nitrile)­[2,6‐bis­(pyrazol‐1‐yl)­pyridine](isonicotin­amide)copper(II)–tetra­fluoro­borate–aceto­nitrile (1/2/2)

Molecules of the title compound, [Cu(C₂H₃N)(C₁₁H₉N₅)(C₆H₆N₂O)](BF₄)₂·2C₂H₃N, comprise (aceto­nitrile)[2,6‐bis(pyrazol‐1‐yl)­pyridine](isonicotin­amide)copper(II) cations, tetra­fluoro­borate anions and lattice aceto­nitrile mol­ecules. The cations have distorted square‐pyramidal geometries in which the N₃‐donor, viz. 2,6‐bis­(pyrazol‐1‐yl)­pyridine, and the N‐donor, viz. the isonicotin­amide ligand, occupy the four basal positions, with the coordinated aceto­nitrile N‐donor atom occupying the apical position. Pairs of cations are linked by N—H?F hydrogen bonds through tetra­fluoro­borate anions, forming centrosymmetric dimers, which are further linked by C—H?O hydrogen bonds into two‐dimensional undulating sheets, three of which interpenetrate to generate a two‐dimensional network.     

Ammonium hydrogen squarate–water (3/2)

In the title compound, NH₄⁺·C₄HO₄^?·H₂O, the hydrogen squarate anions and water molecules are arranged to form planes almost parallel to bc. The ammonium cations are located between these planes and cross‐link them in the a direction by means of an extensive network of hydrogen bonds. There are two symmetry‐independent sets of cations and anions. One of the hydrogen squarate anions and one of the ammonium cations are situated on a twofold axis and the H atoms of these moieties are disordered over the symmetry‐related sites.     

Tris(ethyl­ene­diamine)­nickel(II) bis­[2‐cyano‐2‐(oxidoimino)­acetamidato]­nickelate(II) monohydrate

The title compound, [Ni(C₂H₈N₂)₃][Ni(C₃HN₃O₂)₂]·H₂O, appears to be a modular associate consisting of two complex counter‐ions, containing bivalent nickel as the central atom in both cases, and a solvent water mol­ecule. The Ni^II ion in the complex cation lies on the C₂ crystallographic axis. Its coordination environment is formed by six N atoms of three ethyl­ene­diamine (en) mol­ecules, representing a distorted octa­hedral geometry. The Ni^II ion in the complex anion occupies a position at the center of inversion. It exhibits a distorted square‐planar coordination geometry formed by four N atoms belonging to the deprotonated oxidoimine and amide groups of the two doubly charged 2‐cyano‐2‐(oxidoimino)acetamidate anions, situated in trans positions with respect to each other. In the crystal packing, the complex anions are linked by water mol­ecules via hydrogen bonds between the amide O atoms and water H atoms, forming chains translated along the a direction. The [Ni(en)₃]²⁺ cations fill empty spaces between the translational chains, connecting them by hydrogen bonds between the oxime and amide O atoms of the anions and the amine H atoms of the cations, forming layers along the ac plane. The water mol­ecules provide connection between layers through N atoms of the cations, thus forming a three‐dimensional modular structure.     

Ni(bipy)2Ni(CN)4, a new type of one‐dimensional square tetra­cyano complex

The one‐dimensional structure of catena‐poly­[[bis(2,2′‐bi­pyri­dyl‐1κ²N,N′)‐μ‐cyano‐1:2κ²N:C‐di­cyano‐2κ²C‐di­nickel(II)]‐μ‐cyano‐C:N], [Ni₂(CN)₄(C₁₀H₈N₂)₂]_n, consists of infinite zigzag chains running parallel to the c axis. The chains are composed of paramagnetic [Ni(bipy)₂]²⁺ cations (bricks; nickel on a twofold axis) linked by diamagnetic [Ni(CN)₄]^2? anions (mortar; nickel on an inversion center) via bridging cyano groups. The bridging cyano groups occupy cis positions in the cation and trans positions in the anion, giving rise to a new previously unknown CT‐type chain (i.e. cis–trans‐type) among square tetra­cyano complexes. The coordination polyhedron of the paramagnetic Ni atom (twofold symmetry) is a slightly deformed octahedron with the two Ni—N(bipy) bonds in cis positions being somewhat longer [2.112 (3) Å] than the remaining four Ni—N bonds with a mean value of 2.065 (6) Å. The bond distances and angles in the anion have typical values.