Polyoxometalate Chemistry for Nano-Composite Design

Polyoxometalates are discrete early transition metal-oxide cluster anions and comprise a class of inorganic complexes of unrivaled versatility and structural variation in both symmetry and size, with applications in many fields of science. Recent findings of both electron-transfer processes and magnetic exchange-interactions in polyoxometalates with increasing nuclearities, topologies, and dimensionalities, and with combinations of different magnetic metal ions and/or organic moieties in the same lattice attract strong attention towards the design of nano-composites, since the assemblies of metal-oxide lattices ranging from insulators to superconductors form the basis of electronic devices and machines in present-day industries. The editors organized the symposium, Polyoxometalate Chemistry for Nano-Composite Design at the Pacifichem 2000 Congress, held in Honolulu on December 17 19, 2000. Chemists from several international polyoxometalate research groups discussed recent results, including: controlled self-organization processes for the preparation of nano-composites; electronic interactions in magnetic mixed-valence cryptands and coronands; synthesis of the novel polyoxometalates with topological or biological significance; systematic investigations in acid-base and/or redox catalysis for organic transformations; and electronic properties in materials science. It became evident during the symposium that the rapidly growing field of polyoxometalates has important properties pertinent to nano-composites. It is therefore easy for polyoxometalate chemists to envisage a bottom-up approach for their design starting from individual small-size molecules and moieties which possess their own functionalities relevant to electronic/magnetic devices (ferromagnetism, semiconductivity, prot- conductivity, and display), medicine (antitumoral, antiviral, and antimicrobacterial activities), and catalysis.

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The remarkable range of stoichiometries, structures, and acid-base and redox properties of the polyoxoanions of the early transition metals has lead to their use in areas as diverse as catalysis, imaging, and medicine. Recent progress in polyoxometalate chemistry has opened up the possibility of developing a nanotechnology via a bottom-up approach, starting from molecular (polyoxometalate) subunits which incorporate functionalities that are appropriate for electronic/magnetic devices, and other applications. This book provides an overview of recent progress in polyoxometalate chemistry from leading international research groups. Topics include the formation of large multi-subunit assemblies of polyoxometalates, and their functionalization, magnetic and electron-transfer properties, and biological interactions.

Contenu
Self-Assembly and Nanostructures.- Chemistry with Nanoparticles: Linking of Ring-and Ball-Shaped Species.- Prospects for Rational Assembly of Composite Polyoxometalates.- Composite Materials Derived from Oxovanadium Sulfates.- Solid State Coordination Chemistry: Bimetallic Organophosphonate Oxide Phases of the M/Cu/O/RPO32? Family (M=V, Mo).- Polyoxothiomolybdates Derived from the {Mo2O2S2(H2O)6}2+ Building Unit.- Lanthanide Polyoxometalates: Building Blocks for New Materials.- Organometallic Oxides and Solution Chemistry.- Dynamics of Organometallic Oxides: From Synthesis and Reactivity to DFT Calculations.- An Organorhodium Tungsten Oxide Cluster with a Windmill-Like Skeleton: Synthesis of [(Cp*Rh)4W4O16] and Direct Observation by ESI-MS of an Unstable Intermediate [Cp*RhClWO4].- Role of Alkali-Metal Cation Size in Electron Transfer to Solvent-Separated 1:1 [(M+)(POM)] (M+=Li+, Na+, K+) Ion Pairs.- New Classes of Functionalized Polyoxometalates: Organo-Nitrogen Derivatives of Lindqvist Systems.- Polyoxometalate Speciation Ionic Medium Dependence and Complexation to Medium Ions.- Some Smaller Polyoxoanions. Their Synthesis and Characterization in Solution.- Magnetic, Biological, and Catalytic Interactions.- Polyoxometalates: From Magnetic Models to Multifunctional Materials.- Magnetic Exchange Coupling and Potent Antiviral Activity of [(VO)3(SbW9O33)2]12?.- Tetravanadate, Decavanadate, Keggin and Dawson Oxotungstates Inhibit Growth of S. cerevisiae.- Selective Oxidation of Hydrocarbons with Molecular Oxygen Catalyzed by Transition-Metal-Substituted Silicotungstates.- Transition-Metal-Substituted Heteropoly Anions in Nonpolar Solvents Structures and Interaction with Carbon Dioxide.- Polyoxometalates and Solid State Reactions at Low Heating Temperatures.-Structure Determination of Polyoxotungstates Using High-Energy Synchrotron Radiation.