Polyoxo ions

C60H402M0132N42O504 —3OOFI2O, Molybdate, polyoxo-, spherical cluster with acetate ion, hydrate, 34 191... 

Hi36Moi54Na2i053oP7 -3OOH2O, Molybdatc, polyoxo-, wheel-shaped cluster with hypophosphite ion, hydrate, 34 199 H 52Mo 53Na 50528.5 400H20, Alolybdate, polyoxo-, wheel-shaped cluster, hydrate, 34 197... 

H372M0132N42O504P30 -300H20, Molybdate, polyoxo-, spherical cluster with hypopho-sphite ion, hydrate, 34 196 H402C6qMoi32N42O504 - 300H2O, Molybdate, polyoxo-, spherical cluster with acetate ion, hydrate, 34 191... 

An interesting general reaction of polyoxo anions that has been recently explored is with RNCO and ArNCO reagents. Thus, with the [M6019]2 ions, products such as [W6Oi8NAr]2 , [Mo6Oi8(NPh)2]2 , and Mo6015(NAr)4]2 have been obtained.13 Of course this type of reaction,... 

In aqueous solution many other types of polyoxo ligands effectively complex the Ln3+ ions, including polyphosphates, mixed phosphoryl-carbonyl species, and crown ethers. 

The high-yield syntheses of macrocyclic polyoxoethers are characterized by the strong template effects that arise from oxygen coordination by alkali metal ions during cyclization of polyoxo units (96, 106,157,... 

Tetraborate is the only species, among the polyoxo-anions used as pillars up to now, that can be stable in basic conditions (scheme 2). Since the hydrotalcite layers and tetraborate ions both are stable under basic conditions, pillared LDHs of high crystallinity can be obtained. Moreover, the resultant pillared compounds are relatively thermo-stable because of the similarity in the basic nature between the layer and the pillar. Therefore, we can conclude that a suitable pillaring agent for hydrotalcite-like LDHs is the one stable in mild basic condition (pH s 8-10). 

The compounds with two polyoxo macrocycles have reversible one-electron electrochemical oxidation-reduction cycles and the half-wave potential is quite sensitive to the presence of alkali metal ions. The thio-oxo coronand also undergoes reversible one electron redox reactions, but is insensitive to alkali metal cations. 

Brthet, J. C., Thuery, R, and Ephritikhine, M. 2005. Unprecedented reduction of the uranyl ion [U02] + into a polyoxo uranium(IV) cluster Synthesis and crystal structure of the first f-element oxide with a M6( i3-0)8 core. Chem. Commun. 3415-3417. 

Many polyoxo complexes have metal ions such as Mo, W, V in their highest possible oxidation states. This makes them candidates for potential selective epoxidation catalysts. A heteropolyoxo anion [y-SiW Oj was found to show high epoxidation activity as a precatalyst with 30% hydrogen peroxide as the oxidant. 

In a slightly modified catalytic system, the cation 8.43 has been ion-paired with the heteropolyoxo anion [H PV MOjqO q] . The ion pair is then used as the precatalyst. In this catalytic system, the polyoxo anion is believed to act both as a Br0nstead acid and as a catalyst for the oxidation of Pt " to Pt by dioxygen. 

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