The novel framework [{Co(en) 2 } 2 Sb III 8 V IV 14 O 42 (H 2 O)]•6H 2 O is composed of two-dimensional arrays of {Sb III 8 V IV 14 O 42 (H 2 O)} clusters interlinked via {Co(en) 2 } bridging groups; such antimony-vanadium clusters with antimony and vanadium in low oxidation states were previously unknown.Keggin-type heteropolycomponds find application as heterogeneous catalysts in a variety of oxidation reactions. 1 However, the biggest drawback of heteropolycompounds, which limits their application as heterogeneous catalysts, is the structural decomposition, which occurs in air at temperatures close to 300 ЊC. 2 It is interesting that heteropolycompounds containing antimony oxide often play an important role in heterogeneous oxidation catalysis and antimony cations have a stabilizing effect on polyoxometalates at high (>450 ЊC) temperatures. 3 The reports of antimony-containing polyoxometalates are rather scarce. However, some polyoxometalates of antimonycontaining polyoxotungstates 4-9 and antimony-containing polyoxomolybdates 10 have been reported. Here we report the synthesis and X-ray crystal structure analysis of the first antimony-containing polyoxovanadium compound { [{Co-(en) 2 } 2 Sb III 8 V IV 14 O 42 (H 2 O)]ؒ6H 2 O} (1). Compound 1 was synthesized hydrothermally as black rhombus crystals in 46% yield (based on Sb). A mixture of Sb 2 and H 2 O (20 mL) in a molar ratio of 1 : 2 : 2 : 2 : 1292 was stirred for 120 min and then adjusted to pH = 9.0 using en. It was sealed in a 30 mL Teflon-lined reactor and kept at 160 ЊC for nine days. H 2 C 2 O 4 ؒ2H 2 O was used as a reducing agent and it was necessary to maintain the pH of the reaction. After being cooled to room temperature, black rhombus crystals were isolated. The elemental analysis, ICP and IR spectra † in combination with the X-ray single-crystal analysis ‡ confirmed the formula of 1, [{Co(enThe 2D extended structure (Fig. 1) of 1 consists of [Sb III 8 -V IV 14 O 42 (H 2 O)] 4Ϫ sphere-like clusters, each one of which is linked to four other neighbouring [Sb III 8 V IV 14 O 42 (H 2 O)] 4Ϫ units by four [Co(en) 2 ] 2ϩ bridges, generating a two-dimensional network of [-{Sb III 8 V IV 14 O 42 (H 2 O)}-µ-{Co(en) 2 }-{Sb III 8 V IV 14 O 42 -(H 2 O)}-] ∞ arrays. The octahedral geometry around each cobalt is completed by four nitrogen donors from two en molecules [Co-N = 2.125(7)-2.147(7) Å] and two trans-µ-oxo groups (O3, O20) [Co-O = 2.106(5), 2.121(5) Å]. The H 2 O molecules occupy the parallelogrammic cavities. The spherical structure (Fig. 2) of each [Sb III 8 V IV 14 O 42 -(H 2 O)] 4Ϫ cluster consists of 14 condensed vanadium oxygen square pyramids (VO 5 ) and 8 trigonal pyramids (SbO 3 ), and includes at its center a statistically disordered H 2 O molecule.

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Four zinc(II) or cadmium(II) supramolecular compounds, namely, [Zn(ox)(Him)] n (1), [Zn(bta) 2 ] n (2), [Zn(H 2 O) 4 (na) 2 ] n (3), and [Cd 2 (ox)(OH) 2 ] n (4) (ox ) oxalate anion, Him ) imidazole, bta ) benzotriazole anion, and na ) nicotinic anion), have been synthesized. Among them, 1 is constructed to be a 3-D supramolecular framework by covalent and noncovalent interactions, 2 containing two bta coordination modes displays a 2-D layer structure linked by covalent bonds, the 3-D network of 3 is mainly constructed by strong hydrogen bonds, while 4 exhibits a 3-D framework with 1-D channels only constructed by covalent interactions. The different metal centers and ligand dimensions result in the different structures although they were obtained from similar reaction systems. All of these compounds display strong fluorescence emissions in the blue region, which may be assigned to charge transfer between metal and ligand (for 1, 3, and 4) and the π f π* transition of bta (for 2).

The novel two-and three-dimensional solid materials [Cu(en) The design and synthesis of framework materials linked by well-defined building blocks is still a challenge for the solid-state inorganic and material chemist. Polyoxometalates (POMs) have received considerable attention due to their diverse structures and unusual properties, with potential applications in fields such as catalysis, magnetism, optics and medicine.[ 14Ϫ [3] and one-dimensional chains connected through VϪOϪV bonds.[4] Our group has recently reported the first transition metal coordination compound supported on a metal-oxygen cluster with a bicapped Keggin structure.[5] There has recently been increasing interest in the assembly of higher-dimensional networks comprised of POM clusters and various bridging groups, either inorganic or organometallic. capped by two additional {VO} 2ϩ units. The vanadium atoms in compound 2 display three different coordination environments, including a disordered VO 4 tetrahedron at the center, distorted VO 6 octahedra as the sphere shell com-