Keggin Structure, Quō Vādis?

A fluorophosphate-based inverse Keggin structure.

An unusual PFO(3)(2-)-templated "inverse Keggin" polyanion, [Mo(12)O(46)(PF)(4)](4-), has been isolated from the degradation reaction of an {Mo(132)}-type Keplerate to [PMo(12)O(40)](3-) by [Cu(MeCN)(4)](PF(6)) in acetonitrile. (31)P-NMR studies suggest a structure-directing role for [Cu(MeCN)(4)](+) in the formation of the highly unusual all-inorganic inverse Keggin structure.

Catalytic consequences of composition in polyoxometalate clusters with Keggin structure.

Keggin Structure and Surface Acidity of 12-Phosphotungstic Acid Grafted Zr-MCM-48 Mesoporous Molecular Sieves

A zirconium modified MCM-48 mesoporous material was synthesized by surfactant-templated method. Surface grafting Zr-MCM-48 with tungstophosphoric acid led to a great enhancement of both the number of the Brønsted acid sites and acidity strength in comparison with the bare support. At 100 ̊C, the 30 wt% H3PW12O40/Zr-MCM-48 contained 174 mol/g Brønsted acid sites which were 21.7 times greater tha...

Magneto-optical response of 3d-decorated polyoxomolybdates with ε-Keggin structure.

A family of virtually isostructural tetra-capped ε-Keggin-type polyoxomolybdate(V) cluster compounds, [Mo12(V)O28(μ(2)–OH)10(μ(3)–OH)2{M(II)(H2O)3}4]·nH2O ({M4(II)Mo12(V)}, M = Ni, Co), exhibits magnetic-field-dependent optical response in their electronic absorption spectra in the 0–33 T range. On the basis of Effective Hamiltonian Crystal Field calculations, we find that the observed field-in...

3D-transition metal mono-substituted Keggin polyoxotungstate with an antenna molecule: synthesis, structure and characterization.

Three new organic-inorganic hybrid complexes based on 3d-transition metal monosubstituted Keggin polyoxometalates (POMs) with imidazole (Im) as pendant ligands, formulated as (HIm)(6-)[SiW11O39NiIm]0.8[SiW11O39Ni(H2O)]0.2.7H2O (1), (Im)4Na6[SiW11O39MnIm]0.69[SiW11O39Mn(H2O)]0.31.7.5H2O (2) and (HIm)6[SiW11O39CoIm]0.63[SiW11O39Co(H2O)]0.37.7H2O (3), have been synthesized and characterized by IR ...