Organic-inorganic hybrid supramolecular architecture constructed from Keggin-type [PMo<Subscript>12</Subscript>O<Subscript>40</Subscript>]<Superscript>3−</Superscript> clusters and transition metal complexes

A Keggin organic-inorganic hybrid polyoxometalate combined with nickel complex [Ni (Dmf)₃(H₂O)][HPMo₁₂O₄₀] · (Dmf) · 2H₂O (I) has been synthesized and structurally characterized by elemental analysis, IR spectrum, TG analysis, cyclic voltammetry, and single-crystal X-ray diffraction. Interestingly, a two-dimensional supramolecular network is constructed by the [PMo₁₂O₄₀]³⁻ polyanions, [Ni(Dmf)₃(H₂O)]²⁺ cations, and water molecules via hydrogen-bonding interactions. The cyclic voltammetric measurements illustrate that the [PMo₁₂O₄₀]³⁻ polyanion is the electrochemical redox active center of I in the solution.     

Hydrothermal syntheses, crystal structures, and properties of two polyoxometalates [Cd(2,2′-bpy)3]2[PMoVMoVI 11O40] and [H3PMo12O40]·3(4,4′-bpy)·4H2O

Two Keggin-type phosphododecamolybdate compounds [Cd(2,2′-bpy)₃]₂[PMo^VMo^VI ₁₁O₄₀] (1) and [H₃PMo₁₂O₄₀]·3(4,4′-bpy)·4H₂O (2) (bpy=bipyridine) were prepared by the hydrothermal method for the first time and characterized by elemental analyses, X-ray single-crystal diffraction, ESR spectra, and IR spectra, showing that compound 1 consists of a mixed valence Keggin polyanion [PMo^VMo^VI ₁₁O₄₀]⁴⁻ and two isolated coordinated cations [Cd(2,2′-bpy)₃]²⁺, while compound 2 is an intermolecular compound based on organic substrate 4,4′-bpy and heteropoly acid unit H₃PMo₁₂O₄₀. Furthermore, both the compounds show strong photoluminescence properties in the solid state at room temperature. The catalytic activities of the two compounds were also determined by the oxidation of benzaldehyde to benzoic acid using H₂O₂ as oxidant in a liquid–solid triphase system.     

Hydrothermal Synthesis and Crystal Structure of Two New α-Keggin Derivatives Decorated by Transition Metal Complexes

Two new neutral Keggin-polyoxometalate derivatives: [{Co(2,2′-bipy)₂(H₂O)}₂]–[PMo^VI₇Mo^V₅O₄₀(V^IVO)₂] (1) and [{Ni(phen)₂(H₂O)}₂](H₃O) [PMo^VI₁₀Mo^V₂O₄₀] · 4H₂O (2) have been synthesized under hydrothermal conditions and characterized by i.r., t.g. analysis, x.p.s. spectra and single-crystal X-ray diffraction. In the case of (1), the polyoxoanion cluster [PMo₁₂O₄₀]⁸⁻ is capped by two vanadium atoms via four bridging oxo groups on two opposite {Mo₄O₄} pits of the Keggin polyoxoanion. Two {Co (2,2′-bipy)₂(H₂O)} fragments are supported on the two vanadium atoms through two terminal oxygen atoms from two vanadium atoms. In (2), two {Ni(phen)₂(H₂O)}²⁺ moieties are linked to the molybdophosphate cluster [PMo₁₂O₄₀] core to form a neutral bimetallic cluster. Furthermore, through the linkages of π – π stacking interactions and hydrogen bond contacts, extended three-dimensional supramolecular networks in the solid of (1) and (2) were formed.     

Synthesis,structures and electrochemical properties of four organic–inorganic hybrid polyoxometalates constructed from polyoxotungstate clusters and transition metal complexes

Four novel organic–inorganic hybrid compounds [Cu₅ ^I(4,4′-bpy)₃(2,2′-bpy)₄][BW₁₂O₄₀] · H₂O (1), [Ni_0.5(2,2′-bpy)_1.25][Ni(2,2′-bpy)₃][Ni(2,2′-bpy)₂(H₂O)(SiW₁₁^VIW^VO₄₀)] · 0.5H₂O (2), [H₂bpy]₂[Zn(2,2′-bpy)₃]₂[Si₂W₁₈O₆₂] · 1.5H₂O (3) and [Cu^II(2,2′-bpy)₂]₂[SiW₁₂O₄₀] · 2H₂O (4) (2,2′-bpy = 2,2′-bipyridine, 4,4′-bpy = 4,4′-bipyridine) have been synthesized under hydrothermal conditions and characterized by elemental analysis, IR spectroscopy, thermal gravimetric analysis, electrochemical measurements and single-crystal X-ray diffraction. Compound (1) is a novel [BW₁₂O₄₀]⁵⁻ polyoxoanion bisupported by copper(I) coordination cations with mixed 2,2′-bpy and 4,4′-bpy ligands. Compound (2) is constructed from the [SiW₁₁^VIW^VO₄₀]⁵⁻ polyoxoanions supported by [Ni(2,2′–bpy)₂]²⁺. Compound (3) is composed of a novel [Si₂W₁₈O₆₂]⁸⁻ cluster and [Zn(2,2′–bpy)₃]²⁺ complexes, which held together into a three-dimensional (3D) supramolecular network through hydrogen-bonding interactions. Compound (4) shows a 2D layer framework constructed from a bisupporting Keggin polyoxoanion cluster and [Cu(2,2′–bpy)₂]²⁺ coordination polymer fragments, resulting in 3D networks via supramolecular interactions. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Two New 2D and 1D Ni(II) Coordination Polymers Bridged by Vanadium-Substituted Keggin Polyoxotungstophosphates: Hydrothermal Synthesis and Crystal Structure

Two coordination polymers based on vanadium-substituted Keggin polyoxotungstophosphates as bridging ligands, {[Ni(4,4′-bipy)_1.5(OH)(H₂O)]₂[H₃PW₁₀V₂O₄₀]}·4H₂O (4,4′-bpy = 4,4′-bipyridine) 1 and {[Ni(dpa)₂][Ni(dpa)(H₂O)₃]₂[PW₉V₃O₄₀]}·4H₂O (dpa = 2,2′-dipyridylamine) 2, have been obtained by hydrothermal reactions and characterized by elemental analysis, IR, XRD, TGA and single-crystal X-ray Diffraction analysis. Compound 1 is a 2D layered structure built from 1D infinite zigzag {Ni₂(4,4′-bipy)₃(OH)₂(H₂O)₂}_n²⁺ chains bridged via [H₃PW₁₀V₂O₄₀]²⁻ anions. Compound 2 exhibits a one-dimensional chain-like structure constructed from [Ni(dpa)₂]²⁺ fragments bridged via bis-supported Keggin polyoxoanions [Ni(dpa)(H₂O)₃]₂[PW₉V₃O₄₀]²⁻. The two examples demonstrate that vanadium-substituted Keggin polyoxometalates have greater coordination capability.     

Hydrothermal synthesis and crystal structure of [Ni(Bptc)<Subscript>2</Subscript>(Bimb)<Subscript>2</Subscript>(H<Subscript>2</Subscript>O)<Subscript>2</Subscript>]

In the compound [Ni(Bptc)₂(Bimb)₂(H₂O)₂] (I), where H₄Bptc is 3,3′,4,4′-biphenyltetracarboxylic acid; Bimb is 4,4′-bis(1-imidazolyl)biphenyl), Ni(II) has a distorted octahedral coordination geometry, which was bonded with two N atoms from two Bimb ligands, two O atoms from two H₂Bptc²⁻ ligands and two water O atoms. The crystal structure of compound I is stabilized by the π-π-stacking and hydrogen bonds interaction.     

Novel Hybrids Constructed from Keggin-Polyoxometalate and Mixed Copper Complex

Abstract  Two new Keggin-polyoxometalate hybrids, {[Cu₂(4,4′-bpy)₂][PW₁₀^VIW₂^VO₄₀]}[Cu₂(obpy)₂]₄ · 2 H₂O (1) and {[Cu₄(2,2′-bpy)₄(4,4′-bpy)₃][SiW₁₂O₄₀]} · 2H₂O (2) (4,4′-/2,2′-bpy = 4,4′-/2,2′-bipyridyl, Hobpy = 6-hydroxy-2,2′-bipyridyl), were hydrothermally synthesized and structurally characterized. Gillard type hydration of 2,2′-bipy is observed during the synthesis of 1, resulting in a new obpy ligand in situ. X-ray structural analyses show that 1 consists of 1D hybrid chain {[Cu₂(4,4′-bpy)₂][PW₁₀^VIW₂^VO₄₀]}_∞ and [Cu₂(obpy)₂] dimer, whereas 2 possesses 1D hybrid structure based on Keggin-type [SiW₁₂O₄₀]⁴⁻ anions and tetra-nuclear copper complexes [Cu₄(2,2′-bpy)₄(4,4′-bpy)₃]⁴⁺. Both compounds present interesting supramolecular architectures based on π–π stacking and hydrogen bonds. Graphical Abstract  Compounds {[Cu₂(4,4′-bpy)₂][PW₁₂O₄₀]}[Cu₂(obpy)₂]₄ · 2H₂O (1) and [Cu₄(2,2′-bpy)₄(4,4′-bpy)₃][SiW₁₂O₄₀] · 2H₂O (2) were hydrothermally synthesized. 1 features that the [Cu₂(obpy)₂] dimers based on in situ generated obpy ligands are stumped between the layers where 1D hybrid chain {[Cu₂(4,4′-bpy)₂][PW₁₂O₄₀]}_∞ locates, while 2 exhibits 1D chain-like structure based on anions [SiW₁₂O₄₀]⁴⁻ and tetra-copper complexes [Cu₄(2,2′-bpy)₄(4,4′-bpy)₃]⁴⁺.      

Two Novel Organic–Inorganic Hybrid Compounds Constructed from Anderson-type Clusters and Transition-Metal Complexes

Abstract  Two organic–inorganic hybrid compounds based on the Anderson-type clusters [TeMo₆O₂₄]⁶⁻, [(H₂O)₂Co(TeMo₆O₂₄)][(C₁₀N₂H₁₀)₂] · 9.5H₂O (1), [(C₁₀N₂H₉)Ni(H₂O)₃]₂[TeMo₆O₂₄] · 8.5H₂O (2), have been synthesized by hydrothermal reactions and characterized by elemental analyses, IR spectra, thermal stability analyses, and single-crystal X-ray diffraction. Compound 1 displays a 1D chain structure constructed from alternating [TeMo₆O₂₄]⁶⁻clusters and Co²⁺ along the a axis with two pendant ligands 4,4′-bpy (4,4′-bipyridine). Compound 2 is composed of [TeMo₆O₂₄]⁶⁻ clusters coordinated by [Ni(bpy)(H₂O)₃]²⁺ moieties, and a supramolecular architecture is further formed through extensive hydrogen bonds interactions. Graphical Abstract  Two organic–inorganic hybrid compounds based on the Anderson-type clusters [TeMo₆O₂₄]⁶⁻and the unit [M(4,4′-bpy)] have been synthesized under the hydrothermal conditions. Compound 1 displays a 1D chain structure constructed covalently from alternating polyoxoanions [TeMo₆O₂₄]⁶⁻ and Co²⁺ along the a axis with two pendant ligands 4,4′-bipyridine. Compound 2 is composed of [TeMo₆O₂₄]⁶⁻ polyoxoanion coordinated by [Ni(bpy)(H₂O)₃]²⁺ moieties and shows a 1D chain structure through the hydrogen bonds interactions. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Syntheses and characterization of three hybrid materials based on polymeric copper complexes and saturated Keggin polyoxoanions

Three novel heteropolytungstates, [Cu(phen)₂]₄[α-SiW₁₂O₄₀] (1), [Cu₄(4,4′-bpy)₃(2,2′-bpy)₄][α-SiW₁₂O₄₀] · H₂O (2) and [Cu(4,4′-bpy)(4,4′-Hbpy)_0.5]₂[PW₁₂O₄₀] (3) (phen = 1,10-phenanthroline, 4,4′-bpy = 4,4′-bipyridine, 2,2′-bpy = 2,2′-bipyridine), have been synthesized and characterized by elemental analyses, IR, TG analyses and single-crystal X-ray diffraction. Compound (1) exhibits interesting chiral layer constructed from interperpendicular helical chains running along a crystallographic 2₁ axis in the c and a directions. Furthermore, the chiral layers are connected by the [α-SiW₁₂O₄₀]⁴⁻ anions via hydrogen bonding interactions to form a 3D superamolecular structure. The [Cu₄(4,4′-bpy)₃(2,2′-bpy)₄]⁴⁺ coordinated complexes in compound (2) are packed together via the aromatic π–π stacking interactions and exhibit an interesting 3D sandglasslike “host” network with 1D channels, in which [α-SiW₁₂O₄₀]⁴⁻ anions “guests” reside. Compound (3) has a unique 2D superamolecular network, which is composed of cationic Cu^I coordination polymer chains and discrete [PW₁₂O₄₀]³⁻ polyoxoanions as linkers. It is noteworthy that the monprotonated 4,4′-bpy ligands of (3) act as arms and connect the adjacent 2D network, generating a 3D interpenetrating superamolecular structure.     

A New 2D Layered Co(II) Complex Based on Monosubstituted Keggin Anions and its Electrocatalytic O2 Evolution

A new complex based on monosubstituted Keggin anions, formulated as [Hpy]₂{[Co(4,4′-Hbpy)₂(H₂O)₂][SiCoW₁₁O₃₉]} 1, was hydrothermally synthesized and structurally characterized by elemental analysis, single-crystal X-ray diffraction, IR, XRD and TG. Complex 1 exhibits a 2D layered structure constructed by bridging {SiCoW₁₁O₃₉}_n⁶ⁿ⁻ chains via [Co(4,4′-Hbpy)₂(H₂O)₂]⁴⁺ fragments. The electrocatalysis of 1-CPEs (carbon paste electrodes) was performed in 0.5 M sodium acetate buffer (pH 4.5) containing 1 mM [Ru(bpy)₃]²⁺ solution. It is found that 1-CPEs are active to the electrocatalytic redox of [Ru(bpy)₃]³⁺/[Ru(bpy)₃]²⁺ and the electrocatalytic oxidation of H₂O into O₂.     

Assembly of a new circle connecting circle chain through exerting the template role of a Keggin polyoxometalate

By using the flexible bis(triazole) ligand 1,2-bis(1,2,4-triazol-1-yl)ethane (bte), a polyoxometalate-templated compound, [Zn₂(bte)₄(SiW₁₂O₄₀)]·2H₂O (1), was synthesized under hydrothermal conditions. The compound was characterized by single-crystal X-ray diffraction, elemental analyses, IR spectroscopy, photoluminescence spectroscopy, and cyclic voltammetry. Compound 1 is constructed from two motifs: the [SiW₁₂O₄₀]^4? polyanion and a bi-nuclear metal-organic circle [Zn₂(bte)₂]⁴⁺. The polyanion exerts a template role, inducing the formation of the bi-nuclear circle. The circles build a 1-D circle connecting circle chain through sharing the same Zn ions. Adjacent circles in the chain are vertical with each other. The template polyanion is surrounded by four circles from four different 1-D chains, forming a 3-D supramolecular structure.     

Assembly of two new polyoxometalate-templated supramolecular compounds by utilizing flexible 1,4-bis(pyrazol-1-ylmethyl)benzene ligand

Two new polyoxometalate-templated supramolecular compounds, [Cu^I₄(bpmb)₄][PMo^VI₁₁Mo^VO₄₀] (1) and [Cu^I₄(bpmb)₄SiW₁₂O₄₀] (2) (bpmb = 1,4-bis(pyrazol-1-ylmethyl)benzene), have been synthesized under hydrothermal conditions and characterized by routine methods. Structural analysis shows that in 1, there exist crown-like [Cu^I₄(bpmb)₄] coordination macrocycles, and the Keggin polyanions [PMo ^VI₁₁Mo^VO₄₀]^4? (abbr. as PMo₁₂), which direct the crown-like macrocycle to form a 3-D supramolecular framework. In 2, there exist unusual meso-helix chains, and these chains are mutually interlaced in a wave–trough pattern, but without intersection resulting in a multi-cavity layer, in which the [SiW₁₂O₄₀]^4? (abbr. as SiW₁₂) clusters as guest molecules occupy the cavities of the layers. The distinct structural features of the two compounds suggest that Keggin polyanions should play a significant role in the process of assembly. Electrocatalytic properties of 1 and 2 were investigated.     

Hydrothermal synthesis and crystal structure of a new 2D metal-organic framework: [Gd(Oba)(Ox)0.5(H2O)2]n (H2Oba = 4,4′-oxybis(benzoic acid); H2Ox = oxalic acid)

A new coordination polymer [Gd(Oba)(Ox)_0.5(H₂O)₂] _n (I) (H₂Oba = 4,4′-oxybis(benzoic acid), H₂Ox = oxalic acid) has been synthesized by hydrothermal reactions and characterized by elemental analysis and single-crystal X-ray diffraction. In I, two Gd³⁺ ions are bridged by Oba ligands to form 1D ribbon chains, which are further connected by Ox ligands, generating a 2D layer structure.     

Polyoxometalates–Directed Assembly of Inorganic–Organic Hybrid Compounds with Copper Multinuclear Nano-cluster Based on Flexible Double Tetrazole-based Thioether

Two new inorganic–organic hybrid compounds constructed from different polyoxometalates (POMs) and copper multinuclear clusters, [Cu(bmte)(H₂Mo₈O₂₆)_0.5]·3H₂O (1) and [Cu₃(bmte)₃(HSiMo₁₂O₄₀)]·H₂O (2) (bmte = 1,2-bis(1-methyl-5-mercapto-1,2,3,4-tetrazole)ethane), have been synthesized under hydrothermal conditions with a flexible double tetrazole-based thioether and characterized by IR, TG and single-crystal X-ray diffraction analyses. In compound 1, two bmte ligands chelate two Cu^I ions with three N atoms to form a binuclear nano-scale subunit [Cu₂(bmte)₂]²⁺, then the binuclear Cu^I subunits are connected by [Mo₈O₂₆]⁴⁻ anions to build a one dimensional (1D) chain. In compound 2, a trinuclear nano-scale subunit [Cu₃(bmte)₃]³⁺ constructed from three Cu^I ions and three bmte ligands has been obtained, and the adjacent trinuclear subunits are linked by [SiMo₁₂O₄₀]⁴⁻ anions to form a “zipper” 1D chain. The adjacent chains of the title compounds are ultimately extended into 2D layers by hydrogen bonds between bmte and POMs. The structural difference of the two compounds indicates that the POMs play an important structure-directed role on the final networks. In addition, the electrochemical behavior of 2-modified carbon paste electrode (2-CPE) and its electrocatalytic reduction of nitrite have been discussed.     

The assembly of POM-induced inorganic–organic hybrids based on copper ions and mixed ligands

Three inorganic–organic hybrid materials based on Keggin-type polyoxometalates (POMs), [Cu^II₂(phen)₂(4,4′-bipy)(H4,4′-bipy)₂(H₂O)₂][PMo₁₂O₄₀]₂·2H₂O (1), [Cu^II(phen)₂(H4,4′bipy)][PW₁₂O₄₀]·H₂O (2), and [Cu^II₂(phen)₂(4,4′-bipy)(BW₁₂O₄₀)(H₂O)₂](H₂4,4′-bipy)_0.5·3H₂O (3) (phen = 1,10-phenanthroline, 4,4′-bipy = 4,4′-bipyridine), were synthesized using different POMs in the hydrothermal conditions. Compounds 1–3 were characterized by single-crystal X-ray diffraction, IR spectra, elemental analyses, powder X-ray diffraction analyses, and thermogravimetric analyses. Compound 1 presents a two-dimensional (2-D) network containing the Keggin-type [PMo₁₂O₄₀]^3? anion and dinuclear metal–organic units [Cu^II₂(phen)₂(4,4′-bipy)(H4,4′-bipy)₂(H₂O)₂]³⁺. Compound 2 is a 2-D architecture constructed from a [PW₁₂O₄₀]^3? and mononuclear metal–organic units [Cu^II(phen)₂(H4,4′-bipy)]³⁺. In 3, the [BW₁₂O₄₀]^5? anions link [Cu^II₂(phen)₂(4,4′-bipy)] units to form a one-dimensional (1-D) chain [Cu^II₂(phen)₂(4,4′-bipy)(BW₁₂O₄₀)(H₂O)₂]; the 1-D chain connects with protonated 4,4′-bipy ligands and lattice waters, yielding a 2-D layer. Fluorescence spectra, UV–vis spectra, and electrochemical properties of 1–3 have been investigated.     

A new organic-inorganic composite sandwich-type phosphotungstate: Synthesis, crystal structure and properties of [Ni(phen)3]2H6[Ni4(H2O)2(B-α-PW9O34)2] · 4H2O

A new organic-inorganic composite sandwich-type phosphotungstate [Ni(phen)₃]₂H₆[Ni₄(H₂O)₂(B-α-PW₉O₃₄)₂] · 4H₂O (I) (phen = 1,10-phenanthroline) has been synthesized by hydrothermal method and characterized by elemental analysis, IR spectrum, thermogravimetry (TG) analysis, X-ray photoelectron spectroscopy (XPS) and X-ray single crystal diffraction. The structural analysis indicates that each structure unit of the compound III consists of two isolated [Ni(phen)₃]²⁺ cations, six protons, one tetra-Ni^II-substituted sandwich-type [Ni₄(H₂O)₂(B-α-PW₉O₃₄)₂]¹⁰⁻ anion and four crystallization water molecules. In the compound III the cations and the polyanion were linked together through electrostatic interactions and intermolecular forces. XPS measurement indicates that the oxidation state of W and Ni atoms in the compound III are +6 and +2, respectively. TG analysis of the compound III shows two steps of weight loss.     

A rubidium organic-inorganic hybrid complex with channels hosting decorated polyanion chains

A rubidium organic-inorganic hybrid complex, {H₂[Rb(PMo₁₂O₄₀)(CH₃CN)₃](dpdo)₂(H₂O)₂} _n (1), (where dpdo is 4,4′-bipyridine-N,N′-dioxide) with special channels for the chainlike assembly of decorated Keggin-type anions was synthesized and structurally characterized. The crystal structure was determined by single-crystal X-ray diffraction. The crystal is Orthorhombic space group Cmcm with a = 20.4713(18) ?, b = 17.0529(15) ?, c = 16.1968(14) ?, V = 5654.2(9) ?³, Z = 4, C₂₆H₃₁N₇O₄₆RbMo₁₂P, M = 2445.30, D _c = 2.873 Mg m⁻³, μ = 3.570 mm⁻¹, F(000) = 4640, the final R = 0.0438 and wR = 0.1350 for 2065 observed reflections with I > 2σ(I). Compound 1 exhibits a 3D network with large channels hosting decorated polyanion chains as guests.     

含磷钼酸及2,2’-联吡啶-3,3’-二羧酸配体的铜配位聚合物的合成、晶体结构与电化学性质

在水热条件下合成了一个新的化合物{[Cu₄(PMo₁₂O₄₀)(H₂O)₅(H₂bpdc)(Hbpdc)(bpdc)₂]·6H₂O}_n(H₂bpdc=2, 2’-联吡啶-3, 3’-二羧酸), 并用元素分析、IR、TG和X-射线衍射等手段进行了表征。结果表明本化合物的晶体结构中, 最小不对称单元包含1个 [Cu₄(H₂O)₅(H₂bpdc)(Hbpdc)(bpdc)₂]³⁺阳离子, 1个[PMo₁₂O₄₀]^3-阴离子和6个结晶水分子。Cu(Ⅱ)与相邻[PMo₁₂O₄₀]^3-的桥氧原子配位, 形成一维链状结构。电化学研究表明, 化合物存在三步氧化还原过程。     

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.     

Syntheses,Structures and Properties of Three Heteonuclear Complexes Containing [V<Subscript>10</Subscript>O<Subscript>28</Subscript>]<Superscript>6−</Superscript> Units

Three heteonuclear complexes containing [V₁₀O₂₈]⁶⁻ units, {[Cu(pyr)(H₂O)₄]₂(H₃O)₂[V₁₀O₂₈] · 13.5H₂O}_n (1), {[Ni(pyr)(H₂O)₄]₂(H₃O)₂[V₁₀O₂₈] · 9.5H₂O}_n (2) and [Zn₂(H₂O)₁₄(V₁₀O₂₈)] · H₂PPZ (3) are synthesized and characterized by elemental analyses, IR, single crystal X-ray analyses. The complex 1 and 2 have the similar structures which are composed of the [V₁₀O₂₈]⁶⁻ cluster anion and 1D chain {[M (pyr)(H₂O)₄]²⁺}_n (M = Cu Ni) cations bridged by pyrazine. In the complex 3, Zn²⁺ with two coordination modes is bridged by water molecules to build 1D zigzag chains, and then is linked to the bridging oxygen atoms from [V₁₀O₂₈]⁶⁻ to generate a 2D grid architecture filled with the protoned piperazine (PPZ) molecules. In this paper, the magnetic properties of complex 2 are characterized.