Poly oxoanions

Addendum predominant positive-valent element in a poly-oxoanion... 

Knowledge of the aluminium species present under alkaline conditions is of critical importance to industrial chemical operations such as the Bayer process in which the aluminium present in bauxite ores is dissolved in concentrated sodium hydroxide solution. Al NMR has been used to investigate the A1 coordination states in the resulting sodium aluminates after freeze drying (Bradley and Hanna 1994). At an OH Al ratio > 4.4, the predominant species is Na[Al(OH)4] (Q ) with a Al resonance at 86.6 ppm. A broader resonance at 71.3 ppm is probably composed of a variety of other poly-oxoanionic species such as [Al(OH2)(OAl)2] (Q ), [Al20(0H)6] (Q ) and... 

Iridium cluster mixtures in the size range of 1-4 nm, stabilized by poly-oxoanions and butylammonium cations, have very recently been described and used as catalysts. Hydrogen reduction of the polyoxoanion-supported... 

Finally, comparisons of the efficiencies of several Ni-substituted tungstophos-phates vis-a-vis the catalytic electroreduction of nitrate suggest that an increase of the Ni centers incorporated in stable sandwich-type poly oxoanions has a very beneficial effect. 

Dreyse P, Quezada D, Honores J, Aguirre MJ, Mendoza L, Matsuhiro B, Villagra D, Isaacs M (2012) Determination of S(1V) oxoanions at Poly[Ru(5-N02-Phen)2Cl] tetrapyridylpoiphyrin glassy carbon modified electrode. Electroanal 24(8) 1709-1718... 

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