Mg2Na2V10O28·20H2O and Mg3V10O28·28H2O

The crystal structures of dimagnesium disodium decavanadate icosahydrate, Mg₂Na₂V₁₀O₂₈·20H₂O, (I), and trimagnesium decavanadate octacosahydrate, Mg₃V₁₀O₂₈·28H₂O, (II), have been determined by single‐crystal X‐ray diffraction. They crystallize with monoclinic (C2/c) and triclinic () symmetry, respectively. All the Mg²⁺ cations in (I) and (II) are octahedrally coordinated by six water mol­ecules. The Na⁺ cations in (I) are coordinated by three water mol­ecules and three O atoms of the decavanadate anions, and link the latter into a three‐dimensional network. The decavanadate anions in (II) are not linked to one another.     

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.     

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.     

[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.     

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).     

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.     

Hexalithium hexadecahydrate decavanadate, [Li6(H2O)16V10O28]n

The novel title compound, poly­[octa‐μ‐aqua‐octa­aqua‐μ‐decavanadato‐hexalithium], contains [V₁₀O₂₈]⁶⁻ polyanions with 2/m symmetry linked by centrosymmetric [Li₆(H₂O)₁₆]⁶⁺ cation chains. The [V₁₀O₂₈]⁶⁻ polyanions form a two‐dimensional network with [Li₆(H₂O)₁₆]⁶⁺ chains via O‐polyanion–Li‐chain coordination, with Li—O bond lengths in the range 2.007 (5)–2.016 (5) Å. The hexalithium hexadecahydrate chain is composed of a centrosymmetric pair of LiO₆ octahedra and four distorted LiO₄ tetrahedra. Hydro­gen bonds occur between the polyanion and the Li‐based chains, and within the Li‐based chains.     

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).     

A novel zirconium polyoxometalate compound: (NH4)9[Zr2(μ‐OH)(H2O)2(AsOH)2(AsW7O28)(AsW10O36)]·26H2O

The crystal structure of the title compound, nona­ammonium (arsenic decatungstido)(arsenic heptatungstido)­di­aqua‐μ‐hydroxo‐(hydroxy­arsenido)­di­zir­conium hexa­cosa­hydrate, which was ob­tained from the reaction of [NaAs₄W₄₀O₁₄₀]²⁷⁻ with Zr^IV, has been determined. The anionic complex consists of two hydroxyl‐bridged seven‐coordinate capped trigonal‐prismatic zirconium ions, which are bonded to an [AsW₁₀O₃₆]⁹⁻ anion and to an [AsW₇O₂₈]¹¹⁻ anion that has two {AsOH}²⁺ capping units. The asymmetric unit contains half of the complex, with one crystallographically independent Zr atom. Crystallographic m symmetry imposed by the monoclinic C2/m space group gives rise to the asymmetric unit comprising half of the complex with one crystallographically independent Zr atom.     

(NH4)3[VO2(SO4)2(H2O)2]·1.5H2O

The title compound, tri­ammonium cis‐di­aqua‐cis‐dioxo‐trans‐disulfatovanadate 1.5‐hydrate, was obtained by oxidizing V^IV to V^V in a 2 M sulfuric acid solution of vanadyl­ sulfate and adding ammonium sulfate. Here, the V atom is sandwiched by two sulfate groups by corner‐sharing to form a discrete [VO₂(SO₄)₂(OH₂)₂]^3? anion. The water mol­ecules occupy cis positions in the equatorial plane of the vanadium octahedron.     

A three‐dimensional inorganic/organic hybrid material, [Ni2(4,4′‐bipy)3(H2O)2V4O12]·2.5H2O

The title compound, poly­[[[di­aqua(μ‐4,4′‐bipyridyl)­di­nickel(II)]‐bis(μ‐4,4′‐bipyridyl)‐di‐μ‐hexa­oxo­di­vana­date(2?)] 2.5‐hydrate], [Ni₂­(V₂O₆)₂­(C₁₀H₈N₂)₃­(H₂O)₂]·­2.5H₂O, has been prepared hydro­thermally and characterized by elemental analyses, IR spectroscopy and single‐crystal X‐ray diffraction. The structure consists of [V₂O₆], [Ni­(4,4′‐bipy)₄O₂] and [Ni­(H₂O)₂­(4,4′‐bipy)₂O₂] polyhedra, and water of crystallization. The Ni atoms and one bipyridyl group lie on centres of symmetry.     

Bis[(±)‐trans‐2‐amino­cyclo­hexyl­ammonium] tetra­thio­molybdate(VI) and trans‐cyclo­hexane‐1,4‐diammonium tetra­thio­molybdate(VI)

The structures of the title complexes, (C₆H₁₅N₂)₂[MoS₄], (I), and (C₆H₁₆N₂)[MoS₄], (II), can be described as consisting of discrete tetra­hedral [MoS₄]²⁻ dianions that are linked to the organic ammonium cations via weak hydrogen‐bonding inter­actions. The asymmetric unit of (I) consists of a single (±)‐trans‐2‐amino­cyclo­hexyl­ammonium cation in a general position and an [MoS₄]²⁻ anion located on a twofold axis, while in (II), two crystallographically independent trans‐cyclo­hexane‐1,4‐diammonium cations located on centres of inversion and one [MoS₄]²⁻ anion in a general position are found. The differing dispositions of the amine functionalities in the organic cations in the title complexes lead to different crystal packing arrangements in (I) and (II).     

The first X‐ray structure of a hexa­ammine­cobalt(III) salt with two different complex chloro­cadmium anions: synthesis,characterization and crystal structure of [Co(NH3)6]4[CdCl6][CdCl4(SCN)(H2O)]2Cl2·2H2O

In the title complex salt, tetra­kis[hexa­ammine­cobalt(III)] hexa­chloro­cadmate(II) bis­[aqua­tetra­chloro­thio­cyanato­cad­mate(II)] dichloride dihydrate, the discrete ions, i.e. [Co(NH₃)₆]³⁺, Cl⁻, [CdCl₆]⁴⁻ (located on an inversion centre) and [CdCl₄(SCN)(H₂O)]³⁻, together with cocrystallized water mol­ecules, are assembled by means of a network of hydrogen‐bonding inter­actions. This is the first X‐ray structure determination of a hexa­amminecobalt(III) salt with two different complex chloro­cadmium anions.     

Three different bonding modes of cyano groups in the coordination polymer [Cu(en)2(H2O)][Cu(en)2Ni2Cu2(CN)10]·2H2O (en is 1,2‐diaminoethane)

Partial reduction of the Cu^II ions in the aqueous system Cu^II–en–[Ni(CN)₄]^2? (1/1/1) (en is 1,2‐di­amino­ethane) yields a novel heterobimetallic mixed‐valence compound, poly­[[aqua­bis(1,2‐di­amino­ethane)copper(II)] [hexa‐μ‐cyano‐tetra­cyano­bis(1,2‐di­amino­ethane)­tricopper(I,II)­dinickel(II)] dihydrate], [Cu(C₂H₈N₂)₂(H₂O)][Ni₂Cu₃(CN)₁₀(C₂H₈N₂)₂]·2H₂O or [Cu(en)₂(H₂O)][Cu(en)₂Ni₂Cu₂(CN)₁₀]·2H₂O. The structure is formed by a negatively charged two‐dimensional array of the cyano complex [Cu(en)₂Ni₂Cu₂(CN)₁₀]_n^2n?, [Cu(en)₂(H₂O)]²⁺ complex cations and water mol­ecules of crystallization. These last are involved in a complicated hydrogen‐bonding system. The cyano groups act as terminal, μ₂‐bridging or μ₃‐bridging ligands.     

K2[Hg(SO3)2]·2.25H2O

The characteristic feature of the structure of the title compound, dipotassium bis(sulfito‐κS)mercurate(II) 2.25‐hydrate, is a layered arrangement parallel to (001) where each of the two independent [Hg(SO₃)₂]²⁻ anions are grouped into centrosymmetric pairs and are surrounded by two K⁺ cations to give the overall layer composition {K₂[Hg(SO₃)₂]₂}²⁻. The remaining cations and the uncoordinated water molecules are situated between these layers. Within the [Hg(SO₃)₂]²⁻ anions, the central Hg atoms are twofold coordinated by S atoms, with a mean Hg—S bond length of 2.384 (2) Å. The anions are slightly bent [174.26 (3) and 176.99 (3)°] due to intermolecular O...Hg interactions greater than 2.8 Å. All coordination polyhedra around the K⁺ cations are considerably distorted, with coordination numbers ranging from six to nine. Although the H atoms of the five water molecules (one with symmetry 2) could not be located, O...O separations between 2.80 and 2.95 Å suggest a system of medium to weak O—H...O hydrogen bonds which help to consolidate the structural set‐up. Differences and similarities between the bis(sulfito‐κS)mercurate(II) anions in the title compound and those in the related salts (NH₄)₂[Hg(SO₃)₂] and Na₂[Hg(SO₃)₂]·H₂O are discussed.     

Two Novel Compounds Built Up of Decavanadate Clusters and Transition-Metal Complexes: Synthesis and Structure

Two inorganic compounds entitled tetrasodium hexaaquacobalt decavanadate tetraco-sahydrate,(I), and diammonium bis[hexaaquamanganese] decavanadate tetrahydrate,(II), have been isolated by conventional solution method and structurally characterized by single-crystal X-ray diffraction methods, scanning electron microscopy, IR spectra, thermal analyses and cyclic voltammetry measurements. They crystallize with triclinic (P-1) symmetry and consists of a centrosymmetric [V₁₀O₂₈]^6? anion. The Co²⁺ and Mn²⁺ cations in (I) and (II) respectively are octahedrally coordinated by six water molecules. Compound (I) also contains a polymeric linear array of edge-sharing [Na(OH₂)₆]⁺ and [Co(OH2)₆]²⁺ octahedra and compound (II) exhibit a catenary structure consisting of [V₁₀O₂₈]^6? anions linked to [Mn(OH2)₆]²⁺ and NH₄ ⁺via hydrogen bonds.     

Supramolecular Networks Extended by N–H···O Interactions between Cu‐Benzimidazole Subunits and Keggin Anions

Three new 2D/3D supramolecular architectures derived from Cu‐organic subunits and Keggin anions, [Cu^II₂(biz)₈(HPMo^VI₁₀Mo^V₂O₄₀)(H₂O)₂] · 2H₂O ( 1 ), [Cu^I₄(biz)₈(SiW₁₂O₄₀)] · 2H₂O ( 2 ) and [Cu^I₂(dmbiz)₄(Hdmbiz)₂(SiW₁₂O₄₀)] ( 3 ) (biz = benzimidazole, dmbiz = 5, 6‐dimethyl benzimidazole), were obtained under hydrothermal conditions. Single crystal X‐ray diffraction analysis reveals that compound 1 has two kinds of [Cu^II(biz)₂]²⁺ cations, which are further extended by Keggin anions into a 2D (4, 8)‐connected supramolecular network by hydrogen bonding interactions. In compound 2 , four types of [Cu^I(biz)₂]⁺ subunits link the [SiW₁₂O₄₀]^4– anions to form a 3D (2, 6)‐connected supramolecular structure. Compound 3 shows a 3D supramolecular network with a NaCl‐type topology constructed by [Cu^I(dmbiz)₂]⁺ subunits, anions, and discrete [Hdmbiz]⁺ cations. Moreover, the electrochemical and photocatalytic properties of compounds 1 and 2 were investigated.     

Double complexes [Co(NH3)5(H2O)]2[Zr3F18]·6H2O and [Co(NH3)6]2[Zr3F18]·6H2O

The structures of orthorhombic bis[pentaammineaquacobalt(III)] tetra‐μ₂‐fluorido‐tetradecafluoridotrizirconium(IV) hexahydrate (space group Ibam), [Co(NH₃)₅(H₂O)]₂[Zr₃F₁₈]·6H₂O, (I), and bis[hexaamminecobalt(III)] tetra‐μ₂‐fluorido‐tetradecafluoridotrizirconium(IV) hexahydrate (space group Pnna), [Co(NH₃)₆]₂[Zr₃F₁₈]·6H₂O, (II), consist of complex [Co(NH₃)_x(H₂O)_y]³⁺ cations with either m [in (I)] or and 2 [in (II)] symmetry, [Zr₃F₁₈]⁶⁻ anionic chains located on sites with 222 [in (I)] or 2 [in (II)] symmetry, and water molecules.     

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.     

Second‐sphere coordination in anion binding: sodium hexa­ammine­cobalt(III) tetra­kis­(4‐fluoro­benzoate) monohydrate

In sodium hexa­amminecobalt(III) tetra­kis­(4‐fluoro­benzoate) monohydrate, Na[Co(NH₃)₆](C₇H₄FO₂)₄·H₂O, determined at 180 K, [Co(NH₃)₆]³⁺ cations lie on centres of inversion and form layers in which their C₄ axes lie perpendicular to the layer planes. 4‐Fluoro­benzoate anions lie on twofold axes and general positions and adopt near‐planar geometries. Na⁺ cations and water mol­ecules lie on twofold axes, forming [NaO₅] square pyramids that lie between the [Co(NH₃)₆]³⁺ cations. The second‐sphere inter­actions between [Co(NH₃)₆]³⁺ cations and 4‐fluorobenzoate anions comprise edge‐to‐face and vertex‐to‐face arrangements. The structure is closely comparable with that of the benzoic acid salt, demonstrating that fluorination of the anion in the para position has no significant influence on the second‐sphere inter­actions and minimal influence on the gross crystal structure.