Cu3V10O28·24H2O and CuNa4V10O28·23H2O

The crystal structures of tricopper decavanadate tetracosa­hydrate, (I), and copper tetra­sodium decavanadate tricosa­hydrate, (II), have been determined by single‐crystal X‐ray diffraction. Both compounds exhibit a catenary structure consisting of [V₁₀O₂₈]⁶⁻ anions linked by Cu²⁺ cations in (I) or by Na⁺ cations in (II). Compound (II) also contains a polymeric linear array of edge‐sharing [Na(OH₂)₆]⁺ and [Cu(OH₂)₆]²⁺ octahedra. In both compounds, the [V₁₀O₂₈]⁶⁻ ions lie about inversion centres and the Cu²⁺ ions in (I) also lie about inversion centers.     

Barium chlorite hydrate,Ba(ClO2)2·3.5H2O

The structure of barium chlorite hydrate, Ba(ClO₂)₂·3.5H₂O, has been determined by single‐crystal X‐ray analysis at 150 K. The structure is monoclinic, space group C2/c, with Z = 8. It contains layers of Ba²⁺ cations coordinated by ClO₂⁻ anions and water mol­ecules. There are also solvate water mol­ecules involved only in hydrogen bonding of the layers. Three solvate water O atoms are on sites of twofold symmetry, while all other atoms are in general positions. The full coordination environment of the Ba²⁺ cation consists of ten O atoms belonging to six chlorites and three water mol­ecules, forming a bicapped square antiprism.     

[Ni(H2O)6]2[Na(H2O)3]2[V10O28]·4H2O,bis(nickel hexahydrate) bis(sodium trihydrate) decavanadate tetrahydrate

Polyoxometallates are capable of including transition metals in their crystal structures as either discrete cations or heteroatoms. The title compound crystallizes with triclinic symmetry and consists of a centrosymmetric [V₁₀O₂₈]^6? anion, a trimeric {[Na(H₂O)₃][Ni(H₂O)₆][Na(H₂O)₃]}⁴⁺ cation, an [Ni(H₂O)₆]²⁺ cation and four water molecules of crystallization. The compound possesses two Ni atoms (each on independent inversion centres), one as a discrete cation and one in a disodium–nickel trimeric cation involved in the one‐dimensional polycation–polyanion hybrid polymer. The polymers are bound together via hydrogen bonds to the water mol­ecules and the nickel(II) hexahydrate cation. Several structures of decavanadate compounds having transition metal atoms, monovalent cations and [V₁₀O₂₈]^6? anions in the ratio 2:2:1 have been reported previously. However, the present compound differs from these in its arrangement of monovalent cations and transition metal atoms.     

Mg2Ru2Cl10O·16H2O

Mg₂Ru₂Cl₁₀O·16H₂O {dimagnesium μ‐oxo‐bis­[penta­chloro­ruthenate(IV)] hexa­deca­hydrate} crystallizes in the monoclinic system (space group P2₁/c). The structure consists of layers of [Ru₂Cl₁₀O]⁴⁻ anions, [Mg(H₂O)₆]²⁺ cations and water mol­ecules stacked along the a axis. Only the O atom bonded to Ru occupies the 2a site with symmetry. All the other atoms occupy general 4e sites. The crystal structure is stabilized by O—H⋯O and O—H⋯Cl inter­actions.     

{[Ba2(C2O4)(H2O)6](NCS)2}n: a layered mixed‐anion barium oxalate

We present the first example of a compound containing Ba²⁺, C₂O₄²⁻, water and some additional halide or pseudo‐halide anions, viz. hexa‐μ₂‐aqua‐μ₆‐oxalato‐dibarium(II) diiso­thio­cyanate, {[Ba₂(C₂O₄)(H₂O)₆](NCS)₂}_n. The structure consists of positively charged planar covalent layers of Ba²⁺ cations, oxalate anions and water mol­ecules. The first coordination sphere of the Ba²⁺ cation contains six water mol­ecules and four O atoms from two planar oxalate anions. The oxalate anion lies on an inversion centre and is coordinated to six Ba²⁺ cations, each donor O atom being bonded to two cations. Pairs of water mol­ecules are coordinated by two Ba²⁺ cations. The layers are interspersed with non‐coordinated NCS⁻ anions.     

Na6(H2O)20(V10O28)·4H2O,a novel polyvanadate(V) with a three‐dimensional framework

The novel title polyvanadate(V), poly[[octa‐μ‐aqua‐dodecaaqua‐μ₄‐octacosaoxidodecavanadato‐hexasodium] tetrahydrate], [Na₆(H₂O)₂₀(V₁₀O₂₈)·4H₂O]_n, contains [V₁₀O₂₈]⁶⁻ anions which lie about inversion centres and have approximate 2/m symmetry and which are linked to [Na₃(H₂O)₁₀]³⁺ cations through two terminal and two μ₂‐bridging O atoms. The structure contains three inequivalent Na⁺ cations, two of which form [Na₂(H₂O)₈]_n chains, which are linked via NaO₆ octahedra involving the third Na⁺ ion, thus forming a three‐dimensional framework.     

Bis(ethyl­ene­di­ammonium) decaaqua­disodium decavanadate, (C2H10N2)2[Na2(H2O)10][V10O28]

In the title compound, the decavanadate anion, [V₁₀O₂₈]⁶⁻, and the bridged [Na₂(H₂O)₁₀]²⁺ dication lie across inversion centers. The charge balance is achieved by ethyl­ene­di­ammonium cations, H₃NCH₂CH₂NH₃²⁺, which are disordered. The decavanadate anions are surrounded by the [Na₂(H₂O)₁₀]²⁺ dications, thus forming layers, and the ethyl­ene­diammonium cations are located between these layers.     

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).     

[Cu{C2(COO)2}(H2O)3]·H2O,the first copper complex of acetyl­ene­dicarboxyl­ic acid

In the title compound, catena‐poly­[[[tri­aqua­copper(II)]‐μ‐acetyl­enedi­carboxyl­ato‐κ²O:O′′] hydrate], {[Cu(C₄O₄)(H₂O)₃]·H₂O}_n, the Cu^II ion is coordinated by two monodentate carboxyl­ate groups in trans positions and three water mol­ecules, thus forming a fivefold coordination polyhedron that can be described as a distorted square pyramid. All atoms are located on general sites. The polyhedra are connected by bifunctional acetyl­ene­di­carboxyl­ate ligands, to form almost linear chains parallel to [001]. Hydro­gen bonds involving the non‐coordinated water mol­ecule connect these chains to form a three‐dimensional framework.     

[Cd{C2(COO)2}(H2O)3]·H2O,the first cadmium salt of acetylenedicarboxylic acid

In catena‐poly­[[[tri­aqua­cadmium(II)]‐μ‐acetyl­enedi­carboxyl­ato‐κ⁴O,O′:O′′,O′′′] hydrate], {[Cd(C₄O₄)(H₂O)₃]·­H₂O}_n, the Cd^II atom is coordinated by two bidentate carboxyl­ate groups and three water mol­ecules, thus forming a sevenfold coordination polyhedron with all atoms located on general sites. These polyhedra are connected by the bifunctional acetyl­enedi­carboxyl­ate ligands, forming zigzag chains running parallel to [120]. Hydro­gen bonds, which involve the non‐coordinated water mol­ecule, connect these chains to form a three‐dimensional framework.     

Na10(glycine)2[H2W12O42]·28H2O

The title compound, decasodium diglycine di­hydro­geno­do­tetra­conta­do­deca­tung­state(10?) octa­cosa­hydrate, consists of a centrosymmetric paratungstate [H₂W₁₂O₄₂]^10? anion, ten Na⁺ cations, two zwitterionic glycine molecules and 28 water molecules of crystallization. Two glycine carboxylate O atoms coordinate three different Na⁺ cations, while the amino N atom forms hydrogen bonds with the paratungstate anion through both terminal and bridging O atoms.     

NEt4OH·5H2O containing hydro­xide–water layers

In the title compound, tetraethyl­ammonium hydro­xide pentahydrate, C₈H₂₀N⁺·OH^?·5H₂O, layers of approximately hexagonally close‐packed NEt₄⁺ cations and anionic layers of hydro­xide and water mol­ecules are stacked alternately along the b axis. All hydro­xide and water H atoms are in ordered positions, giving rise to a network of hydrogen bonds [O?O 2.633 (1)–2.947 (2) Å] with four‐ and six‐membered rings. The hydro­xide ion accepts four hydrogen bonds from four water mol­ecules but does not act as a proton donor.     

K2M(H2P2O7)2·2H2O (M = Ni,Cu, Zn): ortho­rhom­bic forms and Raman spectra

The crystal structures of three isotypic ortho­rhom­bic dihydrogendiphosphates, namely dipotassium copper(II)/nickel(II)/zinc(II) bis­(dihydrogendiphosphate) dihydrate, K₂M(H₂P₂O₇)₂·2H₂O (M = Cu, Ni and Zn), have been refined from single‐crystal data. The M²⁺ and K⁺ cations are located at sites of m symmetry, and the P atoms occupy general positions. These compounds also exist in triclinic forms with very similar structural features. The structures of both forms are compared, as well as the geometry of the MO₆ octa­hedron, which is considerably elongated towards the water mol­ecules for M = Ni and Cu. Such elongation has not been observed among the other representatives of the family. A Raman study of the whole series K₂M(H₂P₂O₇)₂·2H₂O (M = Mn, Co, Ni, Cu, Zn and Mg) is reported.     

The hydrogen‐bonded adduct 7,16‐diazonia‐18‐crown‐6–4‐aminobenzenesulfonate–water (1/2/2)

In the title hydrated adduct, 1,4,10,13‐tetraoxa‐7,16‐diazo­nia­cyclo­octa­decane bis(4‐amino­benzene­sulfonate) dihydrate, C₁₂H₂₈N₂O₄²⁺·2C₆H₆NO₃S⁻·2H₂O, formed between 7,16‐di­aza‐18‐crown‐6 and the dihydrate of 4‐amino­benzene­sulfonic acid, the macrocyclic cations lie across centres of inversion in the orthorhombic space group Pbca. The anions alone form zigzag chains, and the cations and anions together form sheets that are linked via water mol­ecules and anions to form a three‐dimensional grid.     

RbCrIII(C2O4)2·2H2O,Cs2Mg(C2O4)2·4H2O and Rb2CuII(C2O4)2·2H2O: three new complex oxalate hydrates

Rubidium chromium(III) dioxalate dihydrate [di­aqua­bis(μ‐oxalato)­chromium(III)­rubidium(I)], [RbCr(C₂O₄)₂(H₂O)₂], (I), and dicaesium magnesium dioxalate tetrahydrate [tetra­aqua­bis(μ‐oxalato)­magnesium(II)­dicaesium(I)], [Cs₂Mg(C₂­O₄)₂(H₂O)₄], (II), have layered structures which are new among double‐metal oxalates. In (I), the Rb and Cr atoms lie on sites with imposed 2/m symmetry and the unique water molecule lies on a mirror plane; in (II), the Mg atom lies on a twofold axis. The two non‐equivalent Cr and Mg atoms both show octahedral coordination, with a mean Cr—O distance of 1.966 Å and a mean Mg—O distance of 2.066 Å. Dirubid­ium copper(II) dioxalate dihydrate [di­aqua­bis(μ‐oxalato)­copper(II)­dirubidium(I)], [Rb₂Cu(C₂O₄)₂(H₂O)₂], (III), is also layered and is isotypic with the previously described K₂‐ and (NH₄)₂Cu^II(C₂O₄)₂·2H₂O compounds. The two non‐equivalent Cu atoms lie on inversion centres and are both (4+2)‐coordinated. Hydro­gen bonds are medium‐strong to weak in the three compounds. The oxalate groups are slightly non‐planar only in the Cs–Mg compound, (II), and are more distinctly non‐planar in the K–Cu compound, (III).     

9‐(2,6‐Dichloro­phen­oxycarbonyl)‐10‐methyl­acridinium trifluoro­methane­sulfonate and its precursor 2,6‐dichloro­phenyl acridine‐9‐carboxyl­ate

The title compounds, C₂₁H₁₄Cl₂NO₂⁺·CF₃O₃S⁻, (I), and C₂₀H₁₁Cl₂NO₂, (II), form triclinic crystals. Adjacent cations of (I) are oriented either parallel or antiparallel; in the latter case, they are related by a centre of symmetry. Together with the CF₃SO₃⁻ anions, the antiparallel‐oriented cations of (I) form layers in which the mol­ecules are linked via a network of C—H·O and π–π inter­actions (between the benzene rings). These layers, in turn, are linked via a network of multidirectional π–π inter­actions between the acridine rings, and the whole lattice is stabilized by electrostatic inter­actions between ions. Adjacent mol­ecules of (II) are oriented either parallel or antiparallel; in the latter case, they are related by a centre of symmetry. Parallel‐oriented mol­ecules are arranged in chains stabilized via C—H·Cl inter­actions. These chains are oriented either parallel or antiparallel and are stabilized, in the latter case, via multidirectional π–π inter­actions and more generally via dispersive inter­actions. Acridine and independent benzene moieties lie parallel in the lattices of (I) and (II), and are mutually oriented at an angle of 33.4 (2)° in (I) and 9.3 (2)° in (II).     

NEt4OH·4H2O containing infinite hydro­xide–water ribbons

In tetraethyl­ammonium hydro­xide tetrahydrate, C₈H₂₀N⁺·­OH^?·­4H₂O, the array of mirror symmetric NEt₄⁺ cations gives rise to a system of parallel channels which are filled with hydrogen‐bonded anionic ribbons. The central part of each ribbon is constituted by a [OH^?(HOH)_4/2] spiro‐chain, with each hydro­xide ion accepting four strong linear hydrogen bonds [d(O?O) between 2.692 (1) and 2.727 (1) Å] but donating none. Additional (two‐coordinate) H₂O mol­ecules bridge between the (four‐coordinate) H₂O mol­ecules of the spiro‐chain [d(O?O) between 2.831 (1) and 2.835 (1) Å].     

2‐Pyridone–tartronic acid (1/1), 3‐hydroxy­pyridinium hydrogen tartronate and 4‐hydroxy­pyridinium hydrogen tartronate

Tartronic acid forms a hydrogen‐bonded complex, C₅H₅NO·C₃H₄O₅, (I), with 2‐pyridone, while it forms acid salts, namely 3‐hydroxy­pyridinium hydrogen tartronate, (II), and 4‐hy­droxy­pyridinium hydrogen tartronate, (III), both C₅H₆NO⁺·C₃H₃O₅⁻, with 3‐hydroxy­pyridine and 4‐hydroxy­pyridine, respectively. In (I), the pyridone mol­ecules and the acid mol­ecules form R(8) and R(10) hydrogen‐bonded rings, respectively, around the inversion centres. In (II) and (III), the cations and anions are linked by N—H⋯O and O—H⋯O hydrogen bonds to form a hydrogen‐bonded chain. In each of (I), (II) and (III), an intermolecular hydrogen bond is formed between a carboxyl group and the hydroxyl group attached to the central C atom, and in (I), the hydroxyl group participates in an intramolecular hydrogen bond with a carbonyl group. No intermolecular hydrogen bond is formed between the carboxyl groups in (I), or between the carboxyl and carboxyl­ate groups in (II) and (III).     

Orientational disorder of [Mg(H2O)6] octa­hedra in the novel magnesium selenite hydrate Mg(SeO3)·7.5H2O

The crystal structure of magnesium selenite 7.5‐hydrate, Mg(SeO₃)·7.5H₂O (space group P6₃/mmc), is characterized by two crystallographically distinct [Mg(H₂O)₆]²⁺ octa­hedra, one of which is disordered over two different orientations. The selenite groups and water mol­ecules (with partially disordered H atoms) bridge the octa­hedra via hydrogen bonds. All the atoms are located on special positions, except for one water mol­ecule.     

Di­aqua­bis­[μ‐(R,R)‐tartrato‐κ4O1,O2:O3,O4]­dinickel(II) trihydrate

In the crystal structure of the title compound, [Ni₂(C₄H₄O₆)₂(H₂O)₂]·3H₂O, two nickel cations, two tartrate anions and two water mol­ecules form the dimeric complex. Each nickel cation is in a distorted octahedral environment composed of four O atoms of two crystallographically independent tartrate anions, one water mol­ecule and one O atom of a symmetry‐equivalent tartrate anion. The asymmetric unit contains three additional water mol­ecules which are connected via hydrogen bonding.