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By using different organic ligands, six octamolybdate hybrid compounds with different dimensionalities, namely, [Ag 4 (dpz) 8 ( β -Mo 8 O 26 )] ( 1 ), [Cu 4 (dpz) 8 ( β -Mo 8 O 26 )] ( 2 ), [Co 2 (tbz) 4 (H 2 O) 2 ( β -Mo 8 O 26 )] ( 3 ), [Ni 2 (tbz) 4 (H 2 O) 2 ( β -Mo 8 O 26 )]·2H 2 O ( 4 ), [Cu(tbz) (H 2 O) ( β -Mo 8 O 26 ) 1/2 ] ( 5 ), [Cu(btp) 2 (H 2 O) ( β -Mo 8 O 26 ) 1/2 ]·2H 2 O ( 6 ) (dpz = 3,5-dimethyl-pyrazolidine, tbz = 2-(4-thiazolyl)benzimidazole, btp = 1,3-bis(1,2,4-triazol-1-yl)propane), have been synthesized under hydrothermal conditions and characterized by single crystal X-ray diffraction analyses, elemental analyses and IR spectra. By using a dpz ligand, two isostructural 0D compounds 1 and 2 were obtained, with four {M(dpz) 2 } fragments (M = Ag for 1 , Cu for 2 ) supporting one anion. When rigid tbz was used, 0D compounds 3 and 4 , and 1D structure of compound 5 was constructed. The tbz play a terminate chelate role in these compounds. By selecting a flexible bis(triazole) btp ligand with more N donors, a 2D hamburger-like layer is formed. Adjacent layers further interpenetrate with each other to construct a 3D interpenetrating framework of compound 6 , realizing dimensionality from 2D to 3D. Using different ligands to tune the dimensionality of POM-based structures is rational. The electrochemical and photocatalytic properties of compounds 1 – 6 were researched, in which the POM subunit is regarded as active component but not organic moiety. [ABSTRACT FROM AUTHOR]

Using the pendent organic ligand 1-butyl-1 H-(1,3,4)triazole (btz), two new polyoxometalate (POM)-based compounds, [Cu3(btz)6(H2O)4(H3P2W18O62)2]·6H2O ( 1) and [Cu2(btz)(tz)(H2O)2(SiMo12O40)]·5H2O ( 2) (tz=1 H-(1,3,4)triazole), have been synthesized under hydrothermal conditions. In compound 1, three CuII ions are fused by six btz ligands to form a linear tri-nuclear CuII cluster, with water as bridging molecules. Two Wells-Dawson anions offer two terminal O atoms to link two apical CuII atoms of this tri-nuclear cluster. In compound 2, the btz and tz molecules connect CuII ions to construct an infinite CuII chain still with water molecules as bridges. The adjacent chains are linked by one type of POM anions to build a 2D grid-like layer. Considering the long-range coordinative Cu-O bonds, the other types of POM anions connect adjacent layers to form a 3D framework. The electrochemical and photocatalytic properties of compounds 1 and 2 were also studied. [ABSTRACT FROM AUTHOR]

Two polyoxometalate-based compounds constructed by Keggin/Ag/L, namely [Ag10(L1)6(HL1)2][HPMo2 VMoVI 10O40] (1) and [Ag10(L2)8(H2SiMo12O40)] (2) (L1 = 1,2,4-1H-triazole and L2 = 1Htetrazole), were synthesized under hydrothermal conditions and characterized by single-crystal X-ray diffraction, elemental analyses, and IR spectroscopy. In compound 1, the tetra-nuclear Ag cycles constructed by four L1 ligands, two Ag1 ions, and two Ag2 ions. Com- pound 1 exhibits a two dimensional (2D) metal-organic layer containing adjacent tetra-nuclear Ag cycles. Furthermore, the adjacent 2D layers are further extended by Ag ions to form a three dimensional (3D) channel-like framework, with Keggin anions embedding in the channels. Compound 2 is isostructural with 1. Additionally, the electrochemical and photocatalytic properties of the title compounds were investigated. [ABSTRACT FROM AUTHOR]

By using two kinds of organic ligands (1-benzyl-1H-(1,2,4)triazole (2-btz) and 1-benzyl-1H-(1,3,4)triazole (3-btz)), six polyoxometalate (POM)-based compounds were hydrothermally synthesized and structurally characterized, [Ag4(2-btz)4(HPMo2VMo10VIO40)] (1), [Ag4(2-btz)4(SiW12O40)] (2), [Ag4(2-btz)5K(SiWVW11VIO40)]·13H2O (3), [Cu4(2-btz)16(Mo8O26)2] (4), [Cu3(3-btz)8(H2O)4](PMo12O40)2·4H2O (5) and [Cu7(3-btz)16(OH)2(H2O)4(P2W18O62)2]·16H2O (6). Compounds 1 and 2 are isostructural with two sets of Ag–(2-btz) chains linked by Keggin anions to construct a “ladder”. Adjacent “ladders” are further connected by Ag1–O13 bonds to build a 3D framework. In compound 3, the anion dimers are linked by Ag5–O9 bonds to form a 1D chain. The chains are fused by Ag3 and K ions and a 3D framework of 3 is built. In compound 4, the Mo8 anions are linked by [Cu(2-btz)4]2+ subunits to construct a 3D structure. By changing 2-btz to 3-btz, we obtained a linear tri-nuclear cluster [Cu3(3-btz)8(H2O)4]6+ in compound 5. The discrete PMo12 anions combine with tri-nuclear clusters through hydrogen bonding interactions to construct a 2D supramolecular layer. Compound 6 contains a cycle tri-nuclear cluster-supporting anion [Cu3(3-btz)6(OH)(H2O)2(P2W18O62)]−, which is further connected by one [Cu(3-btz)4]2+ subunit to construct a discrete anion dimer. The title compounds show good electrocatalytic activities for reducing nitrite, hydrogen peroxide and bromate. These compounds also exhibit excellent photocatalytic activities for the degradation of methylene blue (MB, 1–6 as catalysts) and Rhodamine B (RhB, 5 and 6 as catalysts). Additionally, the magnetic properties of compounds 5 and 6 have been investigated. [ABSTRACT FROM AUTHOR]

Through tuning the N-donor site of the pyridyl group in 5-(x-pyridyl)-1H-tetrazole ligands (x = 2, 4), four new Keggin-based compounds, [Cu7(2-ptz)8(OH)2(H2O)2(HPMoVI10MoV2O40)]·4H2O (1), [Cu5(2-ptz)6(HPMoVI10MoV2O40)(H2O)4]·4H2O (2), [Ag6(4-ptz)4(H2SiMo12O40)] (3) and [Ag5(4-ptz)4(H2PMo12O40)]·5H2O (4) (2-ptzH = 5-(2-pyridyl)-1H-tetrazole, 4-ptzH = 5-(4-pyridyl)-1H-tetrazole), were successfully synthesized under hydrothermal conditions and structurally characterized. Compound 1 possesses two kinds of CuII subunits: penta-nuclear clusters and mono-nuclear subunits, which connect with each other to form a one dimensional (1D) stair-like metal–organic chain. The adjacent 1D stair-like chains are further linked by tetradentate Keggin anions to construct a 2D layer. In compound 2, the tetra-nuclear CuII clusters and mono-nuclear CuII subunits construct a 2D metal–organic layer, which is further linked by bidentate Keggin anions to build a 3D framework. In compound 3, the 4-ptz ligand links AgI ions with tetrazole groups to form 1D infinite Ag–ptz chains, which are extended by the pyridyl group of 4-ptz and the tetrazole groups of other 4-ptz molecules to construct a 2D layer. The adjacent 2D layers are further linked by 6-connected Keggin anions to build a 3D framework. In compound 4, the 4-ptz ligands are linked by AgI ions to form 1D infinite Ag–ptz belts. The Keggin anions are linked by AgI ions to construct another infinite inorganic chain, in which each Keggin anion provides six oxygen atoms to coordinate with the AgI ions from adjacent Ag–ptz belts to construct a 2D layer. The roles of the ptz ligands with different N-donor sites in the construction of multinuclear clusters and 1D chains are discussed. The electrochemical and photocatalytic properties of the title compounds were investigated as well. [ABSTRACT FROM AUTHOR]

Three polyoxometalate supramolecular assemblies based on rigid 2-(4-thiazolyl)benzimidazole (L) and two types of polytungstate anions, [CuII2Cl(L)4(PW12O40)]·3H2O (1), [CuII(L)2(H2O)]2[P2W18O62]·(HL)2·6H2O (2), and [ZnII(L)3]4[H(KPW12O40)3] (3), have been synthesized and characterized by single-crystal X-ray diffraction, elemental analyses, and IR spectra. Compound1contains binuclear copper clusters {Cu2L4Cl}3+with Cl–as bridges. These binuclear clusters and [PW12O40]3–anions construct a supramolecular 2-D layer through hydrogen-bonding interactions. In2, the [CuL2(H2O)]2+subunits and Wells–Dawson anions build a 1-D supramolecular chain. In3, the [PW12O40]3–anions are covalently linked by K+to form an inorganic chain. These chains and discrete [ZnII(L)3]2+subunits construct a 3-D supramolecular structure. The electrochemical and photocatalytic properties of1–3have been studied. Three POM-based supramolecular compounds have been obtained under hydrothermal conditions. Compound1is a 2-D supramolecular layer, which is constructed from the binuclear copper clusters {Cu2L4Cl}3+and Keggin anions. Compound2exhibits a 1-D supramolecular chain built by Wells–Dawson anions and [CuL2(H2O)]2+subunits. In3, there exists an inorganic Keggin anion chain linked by K+ions and discrete [ZnII(L)3]2+subunits, which are connected by hydrogen bonding interactions to construct a 3-D supramolecular structure. [ABSTRACT FROM AUTHOR]

Two novel Wells-Dawson based coordination polymers, [Co(btb)(HO)][HXWO]· nHO (X = P for 1 and As for 2; n = 3 for 1 and 6 for 2) (btb = 1,4-bis(1,2,4-triazol-1-y1)butane), have been successfully isolated under hydrothermal conditions. Single crystal X-ray diffraction analyses reveal that isostructural compounds 1 and 2 exhibit 2D metal-organic layers, which are further linked by four-dentate [XWO] anions to form an unusual (4,4,6)-connected self-penetrating 3D framework with the Schläfli symbol of {3·5·6}{3·5·6·7·8}{5·6}. To the best of our knowledge, this kind of topological structure has not been reported yet. The electrochemical and photocatalytic properties of compounds 1 and 2 have been investigated. [ABSTRACT FROM AUTHOR]

Two new Keggin-based hybrid compounds, [Cu2(pdon)3][PMoVI11MoVO40]·3H2O (1) and [Mn2Cl(H2O)2(pdon)4][PMo12O40]·2H2O (2) (pdon = l, l0-phenanthroline-5,6-dione) (pdon), were synthesized under hydrothermal conditions. By using different metal ions and tuning the ratio of metal to ligand, pdon shows different coordination modes. In compound1, pdon with three kinds of coordination modes link CuIIions to form a 1D wave chain and Keggin-type polyanions [PMoVI11MoVO40]4−fringe this 1D chain; hydrogen bonding interactions extend these 1D chains into a 2D supramolecular network. Compound2exhibits a discrete structure, in which pdon shows a single chelating coordination. Electrochemical properties of the title compounds have been investigated. [ABSTRACT FROM AUTHOR]

Abstract: A polyoxometalate-based compound, (bix)[Cu(bix)][Cu2(bix)2(P2W18O62)]·2H2O (1) (bix=1,4-bis(imidazol-1-ylmethyl)benzene), was hydrothermally synthesized, and characterized by elemental analyses, IR spectroscopy, thermogravimetric analysis, and single X-ray diffraction. Compound 1 exhibits the 1D+1D polypseudo-rotaxane structure consists of two parts: the P2W18–Cu2–(bix)2 chain which contains 26-membered Cu2(bix)2 macrocycles and the 1D Cu-bix line. Remarkably, it represents the first polypseudo -rotaxane structure based on the Wells–Dawson polyoxometalate. [Copyright &y& Elsevier]

Abstract: In order to investigate the effect of polyoxometalate (POM) on the assembly of transition metal-bis(tetrazole) thioether complexes, three new complexes based on different Keggin anions and multinuclear CuI-cluster [CuI 12(bmtr)9(HSiMo12O40)4] (1), [CuI 3(bmtr)3(PM12O40)] (M=W for 2; Mo for 3) (bmtr=1,3-bis(1-methyl-5-mercapto-1,2,3,4-tetrazole)propane), have been hydrothermally synthesized and characterized by routine physical methods and single crystal X-ray diffraction. In compound 1, two kinds of nanometer-scale tetranuclear subunits linked by [SiMo12O40]4− polyanions assemble a (3, 4)-connected three-dimensional (3D) self-penetrating framework. Compounds 2 and 3 are isostructural, exhibiting a 1D chain with [PW12O40]3−/[PMo12O40]3− polyanions and trinuclear clusters arranging alternately. The distinct structural differences between these POM-based CuI-bmtr complexes of 1 and 2/3 maybe rest on the contrast of Keggin-type polyoxometalate with different central heteroatoms, which have been discussed in detail. In addition, the electrochemical properties of the title complexes have been investigated. [Copyright &y& Elsevier]

Abstract: Three compounds, [Na(bie)]2H[PW12O40] (1), [Cu(bie)]4[SiW12O40] (2) and [Cu(bie)]3H2[H3W12O40] (3) (bie=2,2′-bis(1H-imidazolyl)ether) have been hydrothermally synthesized by introducing different metal cations and polyanions, and characterized by routine physical methods. Their crystal structures have been established by single crystal X-ray diffraction. Compound 1 shows a 1D infinite chain which is composed of Na-bie coordination polymers and PW12 polyanions. By using the CuI cation, compounds 2 and 3 which show the 2D layer architectures were obtained. Due to the different polyanions of compounds 2 and 3, the topologies of the 2D layers are distinct. Further, the electrochemical properties of compounds 1–3 were studied. [ABSTRACT FROM AUTHOR]

Abstract: Two new supramolecular compounds based on the Wells–Dawson polyoxometalate, [Cu(Hpbi)2]4[P2W18O62]2 (1) and (H2bbi)4[Cu2(bbi)(Hbbi)2][P2W18O62]2 (2) (pbi=1,1′-(1,3-propanediyl)bis(imidazole), bbi=1,1′-(1,4-butanediyl)bis(imidazole)), were hydrothermally synthesized and characterized by elemental analyses, IR spectroscopy, thermogravimetric analyses, and single X-ray diffraction. The [P2W18O62]6− polyanions in both compounds play the template role inducing the metal–organic coordination polymers to array around them. The polymers form 3D supramolecular frameworks with different voids in which the polyanions reside. The difference should be attributed to the different lengths of the two organic ligands. In addition, the electrochemistry properties of the two compounds were studied, which indicates that the supramolecular compounds keep the redox properties of their parent polyanions and exhibit the electrocatalytic activities toward the reduction of bromate and nitrite. [Copyright &y& Elsevier]

Two interesting hybrids based on polyoxometalates (POMs)and silver-tetrazolatesubunits, H[Ag11(pytz)6(H2O)3(P2W18O62)]·H2O (1), and H[Ag17(pytz)12(H2O)6(PMo12O40)2] (2) (pytz = 5-(2-pyridyl)tetrazolate), have been synthesizedand structurally characterized. X-ray diffraction analysis revealsthat the periphery of the Wells–Dawson POMs contains 16 Ag-pytzsubunits in compound 1, which represents the highestconnection of the POMs up to now. In the crystal engineering pointof view, all subunits, Ag atoms, POMs, and ligands, exhibit rich andnovel coordination geometries, which facilitate the formation of thehighest coordination number of the POMs. Compound 2exhibitsa complicated (6,12) connecting network with (364653)(31843051563) topology and possesses close-packed structure due to the complementarycoordination mode of PMo12aand PMo12b. To the best of our knowledge, this is a scarce coordinationmode in one crystal. In addition, the luminescent properties and electrochemicalbehaviors of these compounds are discussed. [ABSTRACT FROM AUTHOR]

Abstract: A new two-dimensional (2D) polyoxometalate (POM)-based helical coordination polymer, [Cu3(μ2-OH)(pdon)3(pca)(H2O)3][SiW12O40]·6H2O (1) (pdon=1,10-phenanthroline-5,6-dione, Hpca=pyridine-4-carboxlic acid), has been synthesized by in situ generation of pyridine-4-carboxlic acid and 1,10-phenanthroline-5,6-dione from 2-(4-pyridine)imidazo[4,5-f]1,10-phenanthroline under hydrothermal condition, and characterized by elemental analysis, IR spectra, TGA and single-crystal X-ray diffraction. In complex 1, each [SiW12O40]4− (SiW12) cluster connects with three trinuclear [Cu3(μ2-OH)(pdon)3(pca)(H2O)3]4+ metal-organic fragments, meanwhile, each metal-organic fragment also links with three SiW12 polyoxoanions to form two types of one dimensional (1D) helical chains. The adjacent 1D chains with different spiral orientations are connected by the terminal oxygen atom of SiW12 polyoxoanions, leading to the formation of a 2D layer network. Moreover, the photochemical catalysis and electrochemical properties of complex 1 are also reported. [Copyright &y& Elsevier]

Abstract: A new compound, {[Cu2(DF)2H2O]2SiMo12O40} (1) (DF=4,5-diazafluoren-9-one), has been hydrothermally synthesized and characterized by routine methods and single crystal X-ray diffraction. In 1, all the DF only adopt the unusual bidentate coordination mode for the first time coordinating to Cu atoms to form copper-dimers which link [SiMo12O40]4− clusters obtaining an intertwined double chain. Furthermore, the luminescent and electrochemical properties of the title compound have been studied. [Copyright &y& Elsevier]

Abstract: A Ag-bridged V-centred tungstovanadate dimer capped by [Ag(phen)] unit, [Ag(phen)2]7{Ag[Ag(phen)(VW10V2O40)]2} (1) (phen=1,10-phenanthroline), has been hydrothermally synthesized, and characterized by IR, TG and single-crystal X-ray diffraction. Structural analysis reveals that the compound is composed of one dimeric {Ag[Ag(phen)(VW10V2O40)]2}7− anion and seven [Ag(phen)2]+ cations, which represents the first V-centred tungstovanadate grafted by transition metal coordination polymers. Furthermore, the electrochemical properties of 1 have been studied in the paper. [Copyright &y& Elsevier]

Abstract: Two new supramolecular assemblies based on Keggin-type polyoxometalates, [Ag3(4,4′-bipy)2(2,2′-bipy)2][Ag(2,2′-bipy)2][{Ag(2,2′-bipy)}HSiW11VO40] (1) and [Ag3(4,4′-bipy)2(2,2′-bipy)2][Ag(2,2′-bipy)2][{Ag(2,2′-bipy)}PW11VO40] (2) (4,4′-bipy=4,4′-bipyridine, 2,2′-bipy=2,2′-bipyridine), have been synthesized under the hydrothermal conditions and structurally characterized by IR, XPS, TG and single-crystal X-ray diffraction. Compound 1 has a 2D layer network structure via weak Ag...O interactions. Compound 2 is isostructural with compound 1. In addition, the fluorescence of compound 1 is reported. [Copyright &y& Elsevier]

Abstract: Two novel organic–inorganic hybrid polyoxometalates, (X=P, m =1 1; X=Si, m =2 2; 2,2′-bpy=2,2′-bpyridine), have been synthesized under hydrothermal conditions and structurally characterized by single-crystal X-ray diffraction. They are isostructural, possessing orthorhombic, and the parameters of unit cells for compound 1 are space group Pbca, a =17.317(4)Å, b =17.092(3)Å, c =20.587(4)Å, V =6445(2)Å3, Z =4; for compound 2 are space group Pcab, a =17.181(3)Å, b =18.198(4)Å, c =20.672(4)Å, V =6463(2)Å3, Z =4. The two compounds show a layer framework constructed from Keggin-polyoxoanion clusters and [Cu (2, 2′-bpy)2]2+ coordination polymer fragments via weak covalent interactions, resulting in a 3D network via supramolecular interactions. Their electrochemical properties are studied in detail. [Copyright &y& Elsevier]