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A series of lanthanide-doped polyoxometalate microtubes, Ln-SiW 12 (Ln=Nd, Dy and Yb), have been synthesized, and characterized by X-ray diffraction, elemental analysis and thermogravimetric analysis. In the microtubes, the lanthanide cations combine with polyanions through electrostatic interaction. Furthermore, the lanthanide-doped microtubes were chelated with 8-hydroxyquinoline (HQ) in a post-synthesis step (designed as LnQ-SiW 12 ). The LnQ-SiW 12 show characteristic near-infrared (NIR) luminescence, corresponding to Ln 3+ ions due to efficient energy transfer from Q to the Ln 3+ ions through antenna effect. [ABSTRACT FROM AUTHOR]

The rational self-assembly of mono-lacunary Keggin clusters with 4d and 4f metal salts via a conventional method has yielded two novel polyoxometalate-based 4d–4f heterometallic compounds containing lacunary Keggin anions connected to ten metal atoms: {[Ag{Ag2(H2O)4}{Ln(H2O)6}2H ⊂ {SiW11Ln(H2O)4O39}2]·nH2O (Ln = Ce and n = 7 for 1, Ln = Pr and n = 3 for 2). Their structures were determined by single crystal X-ray diffraction analyses and further characterized by elemental analyses, IR spectra, and thermogravimetric (TG) analyses. A structural feature in 1 and 2 is that each [SiW11O39]8− cluster (SiW11) is connected to ten metals (five Ag+ and five Ln3+ cations), representing the highest number of connected metal atoms to any mono-lacunary Keggin anion to date. This large connectivity leads to a structure with a purely inorganic 3D framework with two kinds of channels along the [100] and [010] directions. The magnetic properties of both compounds show the expected magnetic moments (0.8 and 1.6 amu K mol−1 per Ce3+ and Pr3+ ion, respectively) and confirm the presence of isolated Ce3+ and Pr3+ ions. [ABSTRACT FROM AUTHOR]

Two bisupporting Keggin-type polyoxoanion-based hybrids decorated by [Zn(phen) 2] 2+ complexes, [Zn(phen) 2] 2(PW 11VIW VO 40) ( 1) and K[Zn(phen) 2(H 2O)] 2(OH) (SiW 12O 40) ·H 2O ( 2) (phen = 1,10′-phenanthroline), have been hydrothermally synthesized, and characterized by elemental analysis, IR spectra, UV–Vis spectrum, X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis, and single-crystal X-ray diffraction. The structural analyses reveal that compound 1 consists of a 0D bisupporting Keggin-type heteropoly blue cluster obtained by using reductant glucose, which is grafted by two [Zn(phen) 2] 2+ fragments; compound 2 presents a 1D infinite chain, which is constructed from bisupporting [SiW 12O 40] 4− polyoxoanions decorated by [Zn(phen) 2(H 2O)] 2+ fragments and K + ions. Additionally, the electrochemical behaviors of two compounds were studied. [ABSTRACT FROM AUTHOR]

Three inorganic-organic hybrid complexes, [Cu(Hbiim)(OH)](SiWO)·2HO ( 1), [Cu(Hbiim)](SiWO)·2HO ( 2) and [Ag(Hbiim)](SiWO)·2HO ( 3) (Hbiim = 2, 2′-biimidazole), have been synthesized under hydrothermal conditions, and characterized by elemental analysis, IR, PXRD, TG and single-crystal X-ray diffraction. The crystallographic analysis reveals that in compounds 1- 3, the Keggin polyanions [ α-SiWO] act as inorganic building blocks, which are linked with the dinuclear metal-organic units via Cu-O bonds in compound 1, or through supramolecular interactions in compounds 2 and 3. Compound 1 shows a 3D supramolecular structure constructed by net-like layers. Compounds 2 and 3 display 2D layer structures which were composed of wave-like chains. In addition, these compounds show electrochemical activities, and photoluminescence properties are measured in the solid state. [ABSTRACT FROM AUTHOR]

Abstract: Two isostructural Keggin-templated compounds containing a chair-like heptanuclear silver complex, [{Ag7(Hbtz)2(btz)4}{PM12O40}]·H2O (M=W, 1; Mo, 2) (Hbtz=benzotriazolate), have been hydrothermally synthesized and characterized by routine methods and single crystal X-ray diffraction. In the compounds 1 and 2, the Hbtz ligands present two types of coordination modes. A pentameric silver chain with two kinds of Ag⋯Ag weak interactions exists in the heptanuclear silver complex. The heptanuclear silver cations connect the polyoxoanions PM12O40 3− to a two-dimensional layer, and the adjacent layers are fused together by the pseudo wave-like chains, H-bonds and AgI–π interactions, constructing a three-dimensional net. Furthermore, electrochemical properties have been studied for compounds 1 and 2 and the two compounds display excellent electrocatalytic activities to the reduction of nitrite. [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 couples of new compounds templated by the polyanion [SiW12O40]4−,[Hbix][CuI(bix)]3[SiW12O40]·4H2O (1) and [CuII(H2O)(Hbix)2(bix)]2[CuII(H2O)2(Hbix)2(bix)][SiW12O40]3·4H2O (2) (bix = 1,4-Bis(imidazol-1-ylmethyl)benzene), [CuI(bbi)]4[SiW12O40]·2H2O (3) and [CuII(bbi2)]2[SiW12O40] (4) (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. Compounds 1 and 2 were synthesized from the same reactants but exhibited distinct structures which could be ascribed to the different ratios of the reactant bix to CuII. In compound 1, the higher ratio of bix results in the transformation of the CuII to CuI, the [SiW12O40]4− templates direct the CuI–bix coordination polymers to form a 3D supramolecular framework with grid-like channels along two directions. The [SiW12O40]4− templates in compound 2 locate in the voids of the 3D supramolecular network constructed by CuII–bix coordination polymers, which exhibits the interdigitation fashion in both the formation of the 2D layer and the 3D framework. Compounds 3 and 4 were synthesized similar to 1 and 2, except for the change of bix to bbi. In compound 3, the CuI–bbi polymers form a supramolecular metal–organic host framework with rhombic channels in which the SiW12 templates reside. Compound 4 shows a framework with hexagonal channels constructed by CuII–bbi coordination polymers which accommodated the SiW12 templates. [Copyright &y& Elsevier]

Abstract: Two new compounds based on Weakley-sandwich-type polyanion (WSP), H2[Mn(en)2]2[Mn(en)2(H2O)]2[Mn4(H2O)2(PW9O34)2]·9H2O (1) and Na2[Co(en)2]2[{Co(en)2(H2O)]2[Co4(H2O)2(PW9O34)2]·9H2O (2) (en=ethylenediamine), have been synthesized by the hydrothermal reaction of the trivacant Keggin polyoxoanion [a-A-PW9O34]9− with transition metal ions and en, and structurally characterized by routine physical methods and single-crystal X-ray diffraction. Compound 1 represents a 1D chain structure made up of WSPs and [Mn(en)2]2+ ions. Compound 2 represents a 2D layer structure formed by the interconnection of WSPs, [Co(en)2]2+ and Na+ ions. Compounds 1 and 2 represent the first example of high-dimensional construction based on WSPs and transition metal complexes (TMCs), in which the water molecules located on the featured tetra-metal unit are still remained, and exhibit the property of sorption/desorption of water molecules. [Copyright &y& Elsevier]

Abstract: An inorganic–organic hybrid complex, {[Cu2(phen)2(OH)2(H2O)]2[α-SiW12O40]}·8H2O 1, (phen=1,10-phenanthroline), has been synthesized under mild reaction conditions and characterized by single-crystal X-ray diffraction, IR spectrum, thermal analyses (TG-DTA) and fluorescent measurement. The crystallographic analysis reveals that in the compound, the Keggin polyanion [α-SiW12O40]4− acts as the inorganic building block, two [Cu2(phen)2(OH)2(H2O)] units covalently bond to it via terminal oxygen atoms of the Keggin anion. An open framework is formed through supramolecular interactions with solvent accessible volume of 18% in the unit-cell. Dehydration and re-adsorption of water in 1 were investigated by X-ray powder diffraction (XRPD).The compound shows thermal stability and photoluminescence property in the solid state. [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 novel polyoxometalate(POM)-templated coordination polymers: [Cu2(phnz)3][M6O19] (M=Mo for 1, W for 2; phnz=phenazine), have been hydrothermally synthesized and characterized by routine physical methods and single crystal X-ray diffraction. In the compounds, Lindqvist POMs as templates induce the [Cu2(phnz)3] complexes to 2D hexagonal metal-organic framework (MOF), which represents 63 topologies of dimensions ca. 13.515×13.515×13.515Å. Furthermore, the 2D sheets are held together by Lindqvist POMs into 3D supramolecular networks with 1D channel, and Lindqvist POMs site in the channels. The successful syntheses and isolation of two compounds provide a novel example of the utility of POM clusters as templates for self-assembly extended framework with cavities. [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]

Abstract: Two new hexadecavanadate derivatives, (bpy)[Zn(4,4′-bpy)2]2[H4ClV16O38]·6H2O 1 and (bpy)[Co(4,4′-bpy)2]2[H4ClV16O38]·6H2O 2 (bpy=4,4′-bipyridine), were synthesized under the hydrothermal conditions and structurally characterized by IR, XPS and EPR spectroscopy, redox titration and single-crystal X-ray diffraction. The two compounds are isostructural and crystallize in the tetragonal non-centrosymmetric space group P-4n2 (No. 118) with a =17.124(2), b =17.124(2), c =14.724(3)Å, V =4317.5(12)Å3 and Z =1 for the compound 1, and a =17.038(2), b =17.038(2), c =14.754(3)Å, V =4282.9(12)Å3 and Z =1 for the compound 2. Compounds 1 and 2 were constructed from 4-connected {H4ClV16O38} clusters and 6-connected Zn(II) or Co(II) ions, extending in the three dimensions. Square channels with an opening of ca. 7.2×7.2Å were formed through the twining double left-handed helical chains composed of MII octahedral complexes bridged by bpy molecules, which were filled by water and free bpy molecules. Magnetic property was also studied. [Copyright &y& Elsevier]

Abstract: Three new dye-doped inorganic-organic hybrid microtubes, SiMW11-F (M = W, Mo and V; F = fluorescein), have been obtained and characterized by X-ray diffraction, ultraviolet/visible spectroscopy, elemental analysis, thermogravimetric analysis. Comparative studies have been carried out on fluorescent properties of the three SiMW11-F microtubes and fluorescein. These fluorescent hybrid microtubes exhibit luminescent emission properties which are different from raw material fluorescein in the blue spectral region, which is suggests that different luminescence centers may be formed in the hybrid microtubes. The SiW12-F and SiMoW11-F microtubes show more similar fluorescent properties than the SiVW11-F microtubes, due to the differences in ionic radius and oxidation state between W/Mo and V. Furthermore, the three polyoxometalate components in the microtubes exhibit an inhibiting effect on photobleaching of fluorescence dye in the reaction system. [Copyright &y& Elsevier]

Abstract: Two isostructural compounds based on Anderson polyoxoanions, [Cu(phen)]2[CrMo6H5O24] (1) and [Cu(phen)]2[AlMo6H5O24] (2) (phen=1,10-phenaanthroline), have been hydrothermally synthesized and characterized by IR, XPS, EPR spectra, TG analyses, magnetic susceptibility, and single-crystal X-ray diffraction. Compounds crystallize in the monoclinic space group P2(1)/n with a =5.66710(10)Å, b =21.3723(5)Å, c =14.7092(3)Å, β =98.10(10)°, V =1763.79(6)Å3, R 1 =0.0240, Z =2 and GOF =1.140 for 1, and in the monoclinic space group P2(1)/n with a =5.6641(3)Å, b =21.3346(13)Å, c =14.6909(9)Å, β =97.9120(10)°, V =1758.37(18)Å3, R 1 =0.0529, Z =2 and GOF =0.0994 for 2. Single crystal X-ray diffraction reveals that the compounds 1 and 2 are both built up of Anderson polyoxoanions and copper–phen complexes. The structural feature of 1 and 2 is that the Anderson polyoxoanions act as multidentate ligands linking copper–phen complex to form 1D chains. Compounds 1 and 2 not only represent new Anderson-type POM-supported transition metal organic–inorganic hybrid compounds with extend structure, but also verify the feasibility of constructing these compounds through hydrothermal methods. [Copyright &y& Elsevier]