Vanadium-Containing Keggin-Type Polyoxometalates, [VMO] and [VVMO] (M = Mo, W): Structural Characterization and Voltammetric, NMR, and EPR Studies Related to Electrochemical Reduction at Framework and Central Vanadium Sites.

Vanadium is accommodated in both the framework (V) and central positions (V) in the Keggin-type polyoxometalates (POMs) [VVMO] (M = Mo, W; VVM) and in the central position in [VMO] (VM). The structures of the VVM class have been determined by X-ray crystallography and compared to those of VM reported previously. A major feature of interest with POMs is their capacity for very extensive reduction, particularly when protonation accompanies the electron transfer step.

Polyoxometalates in Imidazolim-based Ionic Liquids: Acceptor Number and Polarity Estimated from Their Voltammetric Behaviour.

The selection of an appropriate solvent is essential for achieving high yields and selectivity in chemical reactions. The chemical and physical parameters of organic solvents have been classified into several groups, and solvents can be compared with each other with respect to these properties. The acceptor number (A), donor number (D) and polarity (E) have been widely accepted and used for theoretically and quantitatively evaluating the properties of organic solvents.

Metal-substituted tungstosulfates with Keggin structure: synthesis and characterization.

Simple synthetic procedures for accessing novel metal-substituted tungstosulfates [SMW11O39]4- with Keggin-type structures were developed based on the reaction of metal ions (M = Mn2+, Co2+, Ni2+, and Cu2+) with lacunary tungstosulfate, [SW11O39]6-, which was obtained by treating [SW12O40]2- with a weak base in acetone. All metal-substituted tungstosulfates were characterized by elemental analysis, X-ray crystallography, ESI-MS, IR, Raman, UV-Vis and cyclic voltammetry analyses.

Prospects for 3D imaging of dopant atoms in ceramic interfaces.

Expanding upon recent experimental results for a Y-doped Sigma13 alpha-Al(2)O(3) grain boundary, we explore through simulation the extent to which plan-view imaging of buried interfaces may be possible (cf. the more usual cross-section imaging). As we show in detail, that case was significantly aided by the normal to the interface plane being a high-order zone axis orientation, giving the visibility of the Y atoms a remarkable insensitivity to the specimen thickness and the depth of the interface plane.