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Polyoxometalates (POMs) are anionic metal oxides and encompass a diverse family of nanosized compounds with an unmatched range of architectures and physical properties. The use of the pyramidal sulfite anion, with its numerous coordination modes, has introduced structural diversity into the POM-based chemical systems, giving rise to the formation of novel synthons for the construction of unprecedented architectures ranging from low-nuclearity, isolable secondary building units to POM-based molecular nanoparticles, open-framework and 3D coordination materials, and the emergence of novel properties. [ABSTRACT FROM AUTHOR]

Abstract: The organically templated compound (NH4)3(4,4′-Hbpy)[(VIVO)6(μ 4-O)2(μ 3-OH)2(μ 3-SO3)4(μ-SO3)]·15/2 H2O 1 is the first example of an extended structure in which a polyoxometalate anion, [H2V6 IVS4 IVO22]2–, is linked by the pyramidal μ 2-bridging sulfite group forming a linear polymeric {V6}η chain. Two such chains are linked into a ‘double-rung ladder’ assembly via two different hydrogen bonds provided by 4,4′-Hbpy+ cations. To cite this article: H.N. Miras et al., C. R. Chimie 8 (2005). [Copyright &y& Elsevier]

The influence of the pyramidal heteroanion, TeO32−in the self-assembly of mixed metal (Mo/V) systems, is demonstrated by the isolation of three novel mixed-metal, mixed-valence architectures, {Mo12V12Te3} (1), {Mo12V12Te2} (2) and {Mo17V8Te} (3) with the tellurium centres exhibiting the novel μ8-TeO4and μ9-TeO3coordination modes while compounds 1 and 2 were discovered utilizing ESI mass spectrometry. [ABSTRACT FROM AUTHOR]

The reaction of molybdate with vanadium(v) in the presence of sulfite anions is explored showing how, viacation control, stepwise assembly through the {Mo11V7} cluster yields a {M25} cluster-based compound, [MoVI11VV5VIV2O52(μ9-SO3)(MoVI6VVO22)]10−(1a), which was first discovered using cryospray mass spectrometry, whereas switching the cation away from ammonium allows the direct formation of the spherical ‘Keplerate’ {Mo72V30} cluster. [ABSTRACT FROM AUTHOR]

The reaction of molybdate with vanadium(v) in the presence of sulfite anions is explored showing how, viacation control, stepwise assembly through the {Mo11V7} cluster yields a {M25} cluster-based compound, [MoVI11VV5VIV2O52(μ9-SO3)(MoVI6VVO22)]10−(1a), which was first discovered using cryospray mass spectrometry, whereas switching the cation away from ammonium allows the direct formation of the spherical ‘Keplerate’ {Mo72V30} cluster. [ABSTRACT FROM AUTHOR]

The reaction of molybdate with vanadium(v) in the presence of sulfite anions is explored showing how, viacation control, stepwise assembly through the {Mo11V7} cluster yields a {M25} cluster-based compound, [MoVI11VV5VIV2O52(μ9-SO3)(MoVI6VVO22)]10−(1a), which was first discovered using cryospray mass spectrometry, whereas switching the cation away from ammonium allows the direct formation of the spherical ‘Keplerate’ {Mo72V30} cluster. [ABSTRACT FROM AUTHOR]

The Young Chemists Special Issue has been put together to celebrate the past winners of the European Young Chemist Award (EYCA), presented at the first four EuCheMS Congresses, and to highlight the great diversity of research currently being conducted by young chemists from all over the world. Nine manuscripts that highlight this diversity have been selected to feature in the cover picture. In the top row from left to right: T. Noël et al. (p. 10562 ff.), A. Mateo ‐ Alonso et al. (p. 10626 ff.), and M. Gingras, G. Bergamini et al. (p. 10661 ff.). In the middle row from left to right: D. Vione et al. (p. 10590 ff.), S. Carenco (p. 10616 ff.), and N. Cramer et al. (p. 10654 ff.). In the bottom row from left to right: H. N. Miras (p. 10554 ff.), A. Tavassoli et al. (p. 10608 ff.), and E. Coronado, G. Mínguez Espallargas et al. (p. 10695 ff.). [ABSTRACT FROM AUTHOR]

We investigate the assembly of small polyoxomolybdates using Car-Parrinello molecular dynamics simulations which show that there is an expansion of the coordination sphere of the Mo center from four to six in molybdate anions when the acidity of the solution is increased. With the help of complemesstory static density functional theory (DFT) calculations and electrospray ionization mass spectrometry experiments, we are able to postulate tentative mechanisms, with energy-cascade profiles, for the formation of the Lindqvist [Mo6O19]2- anion.Similar to the family of isopolytungstates, it can be proposed that the [Mo6O19]2- is formed by the aggregation of one molybdenum unit at a time; however, significant differences with respect to isopolytungstates are also found. The different behavior of chromates with respect to molybdates and tungstates is also considered. [ABSTRACT FROM AUTHOR]

Two polyoxometalate open framework (POMOF) materials have been synthesized using a secondary building unit (SBU) approach that facilitates the convergent assembly of multidimensional framework materials using a preassembled anionic SBU {P8W48}, with integrated "pore" 1 nm in diameter, and electrophilic manganese {Mn2+} linkers. This yields two new POMOFS with augmented hexagonal tiling (2 and 3), related to a known three-dimensional (3D) cubic array K18Li6[MnII8(H2O)48PsW48O184]∙108H2O (1), K12[MnII14(H2O)30P8W48O184]∙111H2O (2), and K8Li4[MnII14(H2O)26P8W48O184]∙105H2O (3). These frameworks have been crystallized from aqueous Li-buffered solutions of {P8W48} and MnII(ClO4)2∙6H2O via careful control of the synthetic strategy akin to a crystal engineering approach using cation and temperature control to isolate different material architectures shown by compounds 1-3. [ABSTRACT FROM AUTHOR]

The Dawson-like polyoxometalate clusters (TEAH)6[H2W18O57(SO3)] (1) and (DMAH)8[W18O56(SO3)2(H2O)2] (2) were synthesized under similar reaction conditions by employing triethanolammonium (TEAH) and dimethylammonium (DMAH+) as cations, respectively. Crystallographic studies revealed that compound 1 has a compressed, peanut-like (W18) cage containing a single sulfite anion where each cage metal atom supports one terminal oxo-based ligand whereas compound 2 also has a (W18) cage, but tour of the eighteen cage metal atoms support two terminal oxo-based ligands with two sulfite anions embedded in the cluster. [ABSTRACT FROM AUTHOR]

Precise control of the "one-pot" reaction conditions is employed for the assembly of a nanosized 2.8 nm cluster, [H34W119Se8Fe2O420]54 -(1a), which is templated using eight selenite units and two iron(III) centers. Not only is this cluster characterized structurally using X-ray crystallography, it is the largest polyoxotungstate to be observed intact in solution using ESI-MS, with a molecular mass of ca. 30 000 Da. [ABSTRACT FROM AUTHOR]