A complimentary combination of Density Functional Theory (DFT) methodology and Electrospray Ionization-Mass Spectrometry (ESI-MS) has been utilized to increase our limited understanding of the first nucleation steps in the formation of the [XM(12)O(40)](n-) Keggin polyoxometalates (POMs) (where addenda metal atom M = W or Mo, and the heteroatom X = P or As). We postulate that the first key step...

Four hybrid polyoxometalate–porphyrin copolymer films were obtained by the electrooxidation of zinc-β-octaethylporphyrin (ZnOEP) or 5,15-ditolylporphyrin (H2T2P) in presence organosilyl functionalized Keggin-type POMs TBA3[PW11Si2O40C26H16N2] (abbreviated Py-PW11Si2-Py) and Dawson-type TBA6[P2W17Si2O62C26H16N2] Py-P2W17Si2-Py) bearing two remote pyridyl groups. The electropolymerization process...

A tetra-n-butylammonium (TBA) salt of a γ-Keggin -6-charged germanodecatungstate, [γ-H(2)GeW(10)O(36)](6-) (I), could act as an efficient homogeneous catalyst for Knoevenagel condensation of active methylene compounds with carbonyl compounds.

Epoxides are an important class of industrial chemicals that have been used as chemical intermediates. Catalytic epoxidation of olefins affords an interesting production technology. We found a widely usable green route to the production of epoxides: A silicotungstate compound, [gamma-SiW10O34(H2O)2]4-, is synthesized by protonation of a divacant, lacunary, Keggin-type polyoxometalate of [gamma-...

A novel method for constructing supramolecular hybrids composed of polyoxometalates and photofunctional metal complexes was developed. A Ru(II) complex with phosphonate groups (RuP) strongly interacted with Zn(II) to afford a 2 : 1 trinuclear metal complex ([(RuP)2Zn](3+)). In dimethylsulfoxide, [(RuP)2Zn](3+) strongly interacted with a Keggin-type heteropolyoxometalate (Si-WPOM) to form a 1 : ...

In the asymmetric unit of the title salt, (C(5)H(12)NO)(6)[PMo(12)O(40)](2)·5C(5)H(11)NO, there are two independent α-Keggin-type [PMo(12)O(40)](3-) polyoxidoanions, which show characteristic features with respect to bond lengths and angles. One of the [CH(3)CH(2)C(=OH)N(CH(3))(2)](+) cations is hydrogen bonded to the neighboring polyoxidoanion through a C=O-H⋯O(bridge) hydrogen bond. The organ...

By using mixed rigid and flexible organic ligands, three Keggin based compounds, [Ag6(tbz)4(bmz)2(H3PW12O40)]·4H2O (1), [Ag(H2bdpm)2(H2PMo12O40)]·7.5H2O (2), and [Ag4(tbz)2(H2bdpm)2(HPMo12O40)]·2H2O (3) (Htbz = thiabendazole, Hbmz = benzimidazole, H2bdpm = 1,1'-bis(3,5-dimethyl-1H-pyrazolate)methane), were hydrothermally synthesized and structurally characterized. Through adopting rigid Htbz li...

The acidity and its effects on reactivity of Keggin-type heteropolycompounds were examined by catalytic probe reactions, microcalorimetry of ammonia sorption, and density functional quantum chemical calculations. Phosphotungstic, phosphomolybdic, silicotungstic, and silicomolybdic acids were used as model compounds. The specific rates of double-bond isomerization of both 1-butene and cis-2-bute...

We report examples of crystal surface modification of polyoxometalate open frameworks whereby the use of pyrrole or aniline as monomers leads to the formation of the corresponding polymers via an oxidative polymerization process initiated by the redox active POM scaffolds. Guest-exchange experiments demonstrate that the polymers can finely tune the guest exchange rate and their structural integ...