Four inorganic-organic hybrid compounds, [Cu(I)(4)(bte)(4)(SiW(12)O(40))] (1), [Cu(II)(2)(bte)(4)(SiW(12)O(40))].4H(2)O (2) [bte = 1,2-bis(1,2,4-triazol-1-yl)ethane], [Cu(I)(4)(btb)(2)(SiW(12)O(40))].2H(2)O (3), and [Cu(II)(2)(btb)(4)(SiW(12)O(40))].2H(2)O (4) [btb = 1,4-bis(1,2,4-triazol-1-yl)butane], were hydrothermally synthesized through use of the same Keggin polyoxometalate as the template and tuning the molar ratio of the bis(triazole) ligand to the Cu(II) ion. The ratio of the bis(triazole) ligand to Cu(II) has a crucial influence on the structures of this series. Single-crystal X-ray diffraction analyses indicate that compound 1 is constructed by tetranuclear ring-connecting chains and polymerized [Cu(bte)](+) chains, between which SiW(12) anions are inserted to form a three-dimensional (3D) structure. Compound 2 shows a (4(4).6(2)) two-dimensional grid sheet. The discrete SiW(12) anions are sandwiched by the sheets, just like "hamburgers". Compound 3 presents channel-like [Cu(2)(btb)](2+) polymerized chains, which are further connected by SiW(12) anions to construct a 3D framework. Compound 4 exhibits a (6(6)) 3D Cu-btb framework with hexagonal channels, into which the tetradentate SiW(12) anions are incorporated. The thermal stabilities of the compounds are discussed.

Three inorganic-organic hybrids based on polyoxometalate (POM), [Cu 6 (bbtz) 6 (HPM 12 O 40 )] 3 2H 2 O (M = Mo, 1; W, 2) and [Cu 6 (trz) 2 (bbtz) 2 (SiW 12 O 40 )] (3) (trz=1-H-1,2,4-triazole, bbtz=1,4-bis(1,2,4-triazol-1-ylmethyl)benzene), were synthesized under hydrothermal conditions, and structurally characterized. Through the use of the flexible ligand bbtz, isostructural compounds 1 and 2 with interpenetrating structures were obtained. In compound 1, ladder-like chains exist, in which the PMo 12 anions act as "middle rails". These chains are linked by wave-like [Cu(bbtz)] n nþ lines to construct a threedimensional (3D) framework. Two such frameworks penetrate each other to construct a 2-fold interpenetrating structure. By introducing the rigid ligand trz, compound 3 with an un-interpenetrating structure is obtained. In compound 3, two-dimensional (2D) (6 3 ) 2 metal organic framework (MOF) layers exist, which are linked by Keggin anions to construct a 3D (4 4 3 6 2 )(6 3 ) 2 framework. The differences between these compounds should be ascribed to the introduction of the rigid molecule trz that plays a role in restraining the formation of interpenetrating structures.

By introducing the unprecedented and flexible isomeric bis(pyridyl-tetrazole) ligands into a polyoxometalates (POMs) system, three POM-based compounds, {Ag2(4-bptzb)2(H2O)2[H2PMo12O40]2}·4-bptzb·5H2O (1), [Ag4(3-bptzb)2(PMo(V)Mo(VI)11O40)]·2H2O (2), and Ag3(3-bptzb)2.5(H2O)2[H3P2W18O62] (3) [4-bptzb = 1,4-bis(5-(4-pyridyl)tetrazolyl)butane and 3-bptzb =1,4-bis(5-(3-pyridyl)tetrazolyl)butane], were synthesized under hydrothermal conditions and structurally characterized by single-crystal X-ray diffraction analyses. Compound 1 exhibits a dimeric structure constructed from two Keggin [PMo12O40](3-) anions and a binuclear [Ag2(trans-4-bptzb)2](2+) subunit in which the trans-4-bptzb acts as a bidentate bridging ligand with one tetrazolyl group. In 2, the 3-bptzb acts as a tetradentate bridging ligand with the tetrazolyl and pyridyl groups linking Ag(I) ions to generate a 3D metal-organic framework (MOF), which contains charming meso-helix chains. The Keggin anions acting as bidentate inorganic ligands reside in the distorted tetragonal channels of the MOF. In compound 3, the 3-bptzb adopts versatile coordination modes linking Ag(I) ions to first construct loop connecting loop 1D chains, which are linked by {Ag[P2W18O62]}n zigzag chains to form a scarce hamburger-style 2D sheet. These adjacent sheets are further fused by 3-bptzb ligands to construct a 3D framework. The influences of isomeric bptzb ligands and POMs on the construction of Ag-bptzb subunits and the whole structures of the title compounds are discussed. The electrochemical behaviors and electrocatalytic activities of compounds 2 and 3 and their corresponding parent POMs as well as the fluorescent properties of the title compounds have been studied in detail. In addition, the photocatalytic activities of compounds 2 and 3 and their corresponding parent POMs for decomposition of methylene blue, rhodamine B, and methyl orange under UV irradiation have also been investigated.

Four SiMo12O40 4– (SiMo12)-based compounds, namely, [Ag6Cl2(mmt)4(H4SiMo12O40)(H2O)2] (1), [Ag4(bmte)2(H2O)2(SiMo12O40)] (2), [Ag4(bmtr)2(H2O)2(SiMo12O40)] (3), and [Ag4(bmtb)3(SiMo12O40)] (4) (mmt = 1-methyl-5-mercapto-1,2,3,4-tetrazole, bmte = 1,2-bis(1-methyl-5-mercapto-1,2,3,4-tetrazole)ethane, bmtr = 1,3-bis(1-methyl-5-mercapto-1,2,3,4-tetrazole)propane, bmtb = 1,4-bis(1-methyl-5-mercapto-1,2,3,4-tetrazole)butane), have been synthesized under hydrothermal conditions. Single crystal X-ray diffraction analyses reveal that insertion of -(CH2) n - spacers into the reactant mmt ligand plays important roles in constructing multinuclear AgI clusters in the title compounds and tuning the formation of different multinuclear AgI clusters. In compound 1, the mmt ligands link AgI ions forming a three-dimensional non-multinuclear self-penetrating framework with large dimension channels occupied by SiMo12 polyanions. In 2, a tetranuclear [Ag4(bmte)2(H2O)2]4+ and SiMo12 anions arrange alternately forming a one-dimensional (1D) chain. The structure of compound 3 is similar to that of 2, except for different coordination modes of AgI ions in tetranuclear clusters and SiMo12 polyanions owing to the longer -(CH2)3- alkyl skeleton of bmtr ligand. Compound 4 exhibits a two-dimensional grid layer formed by a 1D AgI “ribbon” based on binuclear AgI clusters and bridging bmtb ligands with the longest -(CH2)4- alkyl skeleton. The SiMo12 polyanions as tetradentate inorganic linkages reside in the grids. The influences of -(CH2) n - spacers on forming and tuning different multinuclear AgI clusters have been discussed. Furthermore, the photochemical catalysis and electrochemical properties of the title compounds have been studied.

Two novel Anderson-type polyoxometalates (POMs)-based metal-organic frameworks (MOFs), namely, H{Cu2(μ2-OH)2L(1)[CrMo6(OH)6O18]}·4H2O (), {Cu2L(2)[CrMo(VI)5Mo(V)(OH)6O18](H2O)4}·4H2O () (L(1) = N,N'-bis(3-pyridinecarboxamide)-piperazine, L(2) = N,N'-bis(4-pyridinecarboxamide)-piperazine), are hydrothermally synthesized and structurally characterized by single-crystal X-ray diffraction, IR spectra, powder X-ray diffraction (PXRD) and thermogravimetric analyses (TGA). In complex , the hexadentate [CrMo6(OH)6O18](3-) polyoxoanion bridges the Cu(II) ions to generate a 2D Cu-POM inorganic layer, which is further extended by the μ2-bridging L(1) ligands (via ligation of pyridyl nitrogen atoms) to form a 3D MOF with a 4,6-connected {4(4)·6(10)·8}{4(4)·6(2)} topology. Complex is also a 3D POM-based MOF exhibiting a {4(2)·8(4)} topology, which is constructed from the quadridentate [CrMo(VI)5Mo(V)(OH)6O18](4-) polyoxoanions and μ4-bridging L(2) ligands (via ligation of pyridyl nitrogen and carbonyl oxygen atoms). The different coordination modes of POM polyanions and the isomeric bis(pyridylformyl)piperazine ligands play key roles in the construction of the title complexes. In addition, the photocatalytic activities of the title complexes on the degradation of methylene blue (MB) under UV, visible light and sunlight irradiation have been investigated in detail.

The design and construction of a series of metalorganic coordination polymers based on two isomeric semi-rigid bis-pyridyl-bis-amide ligands and three aromatic polycarboxylates †

b S Supporting Information ' INTRODUCTIONPolyoxometalates (POMs), as an outstanding class of inorganic metal-oxide clusters, have attracted extensive attention owing to not only their controllable shape, size, composition, and structural diversity but also their promising properties, such as photochemical activity, magnetism, and catalytic activity. 1 In recent years, the introduction of transition-metal complexes (TMCs) to POMs has become an appealing field, aiming for construction of high dimensional frameworks with novel topology and some potential properties. Thus, a series of these compounds have been reported. 2À4 In these compounds, POMs usually act as two kinds of roles: linkages and templates. First, as is well-known, POMs comprise abundant terminal/bridging oxygen atoms acting as potential coordination sites to link TMCs, which lend itself to play the linkage role, and many POM-based compounds with high dimensionality and connectivity have been obtained. 3 Second, POMs act as only inorganic templates, without utilizing the coordination ability of terminal/bridging oxygen atoms. 4,5 As inorganic templates, POMs have their obvious merits: (a) They have high negative charges, which can assemble the cationic metalÀorganic subunits and conduce to construct different interesting frameworks. 4b (b) They exhibit controllable shapes and sizes, such as , Keggin (10.45 Â 10.45 Å), Anderson (9.07 Â 9.07 Å), which result in the construction of different metalÀorganic structures. 4d,6 Thus, POMs acting as inorganic templates bring an appealing route to obtain fascinating metalÀ organic frameworks. However, the reports on POMs-templated

Two interesting hybrids based on polyoxometalates (POMs) and silver-tetrazolate subunits, 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 synthesized and structurally characterized. X-ray diffraction analysis reveals that the periphery of the Wells–Dawson POMs contains 16 Ag-pytz subunits in compound 1, which represents the highest connection of the POMs up to now. In the crystal engineering point of view, all subunits, Ag atoms, POMs, and ligands, exhibit rich and novel coordination geometries, which facilitate the formation of the highest coordination number of the POMs. Compound 2 exhibits a complicated (6,12) connecting network with (364653)­(31843051563) topology and possesses close-packed structure due to the complementary coordination mode of PMo12 a and PMo12 b. To the best of our knowledge, this is a scarce coordination mode in one crystal. In addition, the luminescent properties and electrochemical behaviors of these compounds are discussed.