The title heteropolyoxidotungstate-based inorganic-organic hybrid material, (C(6)H(12)N(5)O)(3)[W(12)(PO(4))O(36)]·6H(2)O, consists of one α-Keggin-type [W(12)(PO(4))O(36)](3-) polyoxidometalate anion (POM), three crystallographically independent 4-[(2H-tetra-zol-5-yl)meth-yl]morpholinium cations and six water mol-ecules of crystallization. The morpholine ring of the cation adopts a chair confo...

Competitive reactions between C-labeled dimethyl ether (C-DME) and unlabeled alkenes have been used to examine the mechanistic details of chain growth and termination pathways leading to the selective formation of triptane and isobutane by means of the homologation of DME or methanol (Scheme 1). These studies have also provided specific and quantitative evidence for the ubiquitous role of carbe...

A Keggin-type POM is attached to gold or glassy carbon surfaces by electro(chemical) or peptidic coupling. In addition to demonstrating the robust attachment of the POMs (by electrochemistry, XPS, and IRRAS), the surface concentration, layer thickness, and rate constant for electron transfer from the surface to the POMs have been measured. The use of such complementary techniques is mandatory t...

The selective oxidation of methoxy/methyl-substituted arenes to the corresponding benzoquinones has been first realized using aqueous hydrogen peroxide as a green oxidant, acid tetrabutylammonium salts of the γ-Keggin divanadium-substituted phosphotungstate [γ-PW10O38V2(μ-O)2]5- (I) as a catalyst, and MeCN as a solvent. The presence of the dioxovanadium core in the catalyst is crucial for the c...

The title compound, (C(10)H(10)N(2))(2)[SiW(12)O(40)]·C(10)H(8)N(2)·6H(2)O or (4,4'-bipyH(2))(2)[SiW(12)O(40)].(4,4'-bipy)·6H(2)O (4,4'-bipy is 4,4'-bipyridine), was prepared under hydro-thermal conditions. The asymmetric unit contains a discrete Keggin-type [SiW(12)O(40)](4-) anion (located on a twofold axis), one 4,4'-bipy (located on a twofold axis), two (4,4'-bipyH(2))(2+) cations and six u...

Biodiesel synthesis from rice bran fatty acids (RBFA) was carried out using cesium exchanged 12-tungstophosphoric acid (TPA) catalysts. The physico-chemical properties of the catalysts were derived from X-ray diffraction (XRD), Fourier transform infrared (FTIR), temperature programmed desorption (TPD) of NH(3) and scanning electron microscopy (SEM). The characterization techniques revealed that...

Reported here are both STM images and spatially resolved tunneling spectra of four different polyoxometalate (POM) structural class members: Keggin structure, H(3)[PW(12)O(40)] (spherical); Finke-Droege (FD) structure, Na(16)[Cu(4)(H(2)O)(2)(P(2)W(15)O(56))(2)] (prolate spheroidal); Wells-Dawson (WD) structure, H(7)[P(2)Mo(17)VO(62)] (prolate spheroidal); and Pope-Jeannin-Preyssler (PJP) struct...

Within the ever-growing field of (hetero)polyoxometalates, the molybdophosphate system occupies a special place as being one of the most extensively studied and quite well understood systems. Its speciation in aqueous solution as a function of pH and phosphate concentration has been established precisely by various methods such as potentiometric, NMR, Raman, and cyclic voltammetry measurements....

A novel capillary electrophoretic (CE) method, based on in-capillary complexation with [PW(11)O(39)](7-), was developed for the determination of cadmium(II) in natural water samples. When a sample solution is injected into a capillary containing 0.20 mM [PW(11)O(39)](7-) and 0.10 M malonate buffer (pH 3.0), the ternary Keggin-type complex, [P(Cd(II)W(11))O(39)](5-), which possesses high molar a...

The unusual behaviour of smectites, the ability to change volume when wetted (swelling) or dried (shrinking), make soil containing smectites very unstable and hazardous for the building industry due to foundation movement and poor slope stability. These macroscopic properties are dominated by the structural arrangement of its finest fraction. In this work we show utilisation of a new technique ...