Heteropolyoxometallate compounds

It is known [41] that partial oxidation reactions in heterogeneous catalysis involves redox properties of the solid catalysts, allowing the well known Mars-van Krevelen mechanism [42] to occur, or at least to be facilitated. Acid-base properties are also an important feature, as they play a determining role in the activation of the reactants and in the desorption of the intermediate compounds, for instance, an acid surface will favor desorption of acid products, thus avoiding further over-oxidation, while a basic surface will favor desorption of basic products as olefins. It follows that heteropolyoxometallate compounds, in particular TMSP, appear as potential... 

SELECTIVE OXIDATION OF PROPANE ON Cs2 5H1.5PV1WxM011.xO40 HETEROPOLYOXOMETALLATE COMPOUNDS... 

Cysteic acid is obtained in nearly quantitative yield from cysteine with aqueous hydrogen peroxide in the presence of iron(II) ions.397 Molybdates and tungstates have also been used as effective catalysts for similar transformations.398 An excellent route for the oxidation of 2-thioethanol to isothionic acid has been developed.399 Heteropolyoxometallates supported on alumina400 can also be used to oxidize a range of organo-sulfur compounds. For example, alkyl monosulfides to sulfoxides and sulfones, and thiols to sulfonic acids are a few possibilities (Figure 3.98). 

OXIDATION OF ORGANIC COMPOUNDS WITH MOLECULAR OXYGEN CATALYZED BY HETEROPOLYOXOMETALLATES... 

It is increasing interested in the utilization of heteropoly compounds as catalysts for the oxidation of various organic compounds. Recently, we have found that the mixed addenda heteropolyoxometallates such as (NH4)5H4PV0Mo0O4o 6H2O (PV0MO0) was efficient catalysts for the aerobic oxidation of olefinic compounds in the presence of isobutyraldehyde. We now present here the direct oxidation of amines and hydrocarbons with molecular oxygen by PV0MO0 catalyst. 

Misono, M. 2001. Unique acid catalysisof heteropoly compounds(heteropolyoxometalates) in the solid state. Chemical Communications 1141-1142. 

Misono, M. (2001). Unique Acid Catalysis of Heteropoly Compounds (Heteropolyoxometalates) in the Solid State, Chem. Commun., 13, pp. 1141-1152. 

Fujibayashi, S., Nakayama, K. and Hamamoto, M. (1996). An Efficient Aerobic Oxidation of Various Organic Compounds Catalyzed by Mixed Addenda Heteropolyoxometalates Containing... 

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