Oxidation osmium

Other examples are the use of osmium(VIII) oxide (osmium tetroxide) as catalyst in the titration of solutions of arsenic(III) oxide with cerium(IV) sulphate solution, and the use of molybdate(VI) ions to catalyse the formation of iodine by the reaction of iodide ions with hydrogen peroxide. Certain reactions of various organic compounds are catalysed by several naturally occurring proteins known as enzymes. 

Osmic Acid Anhydride Osmium Oxide Osmium Tetraoxide Osmium Tetroxide OU1 Dry Agent ... 

Figure2.17 Formal Os(lll)/Os(ll) redox potential as a function of the average fraction of oxidized osmium sites for Qai,= 1 mM (dashed lines) or 1.2 M (solid line). From the slope it is possible to predict the lateral interaction parameters in Brown and Anson model, Equation 2.8. Taken from Ref [120].

The [Os3(CO)io( t-H)( t-OSi)]surface catalyzes the isomerization and hydrogenation of olefins. When the hydrogenation of ethylene is carried out at 90 °C the trinuclear framework of the initial cluster remains intact in all the proposed elementary steps of the catalytic cycle [133]. However, at higher reaction temperatures the stability of the [Os3(CO)io( t-H)( t-OSi)]sujface depends on the nature of the reactant molecule. It is moderately active in the isomerization of 1-butene at 115 °C but decomposes under reaction conditions to form surface oxidized osmium species that have a higher activity [134]. 

Whereas hydrolysis of epoxides leads to the trans diaxial addition of water and the formation of trans glycols (1,2-diols), cis glycol formation involves the addition of osmium(VIII) oxide (osmium tetroxide, OsO ) or cold dilute aqueous potassium manganate(Vll) (potassium permanganate) to an alkene. 

Potassium permanganate. Dimethyl sulfide-Chlorine. Dimethyl sulfoxide. Dimethyl sulfoxide-Chlorine. Dimethylsulf-oxide Sulfur trioxide. Dipyridine chro-mium(VI) oxide. Iodine. Iodine-Potassium iodide. Iodine tris(trifluoroacetate). Iodosobenzene diacetate. Isoamyl nitrite. Lead tetraacetate. Manganese dioxide. Mercuric acetate. Mercuric oxide. Osmium tetroxide—Potassium chlorate. Ozone. Periodic acid. Pertrifluoroacetic acid. Potassium ferrate. Potassium ferricyanide. Potassium nitrosodisulfonate. Ruthenium tetroxide. Selenium dioxide. Silver carbonate. Silver carbonate-Celite. Silver nitrate. Silver oxide. Silver(II) oxide. Sodium hypochlorite. Sulfur trioxide. Thalli-um(III) nitrate. Thallium sulfate. Thalli-um(III) trifluoroacetate. Triphenyl phosphite ozonide. Triphenylphosphine dibromide. Trityl fluoroborate. 

OSmium(IV) oxide (osmium tetroxide OSO4) A volatile yellow crystalline solid with a penetrating odor, used as an oxidizing agent and, in aqueous solution, as a catalyst for organic reactions. 

New Reoxidants for Dihydroxylation. Backvall has introduced some well thought out reoxidants for the dihydroxylation and asymmetric dihydroxylation processes. Hydrogen peroxide is the terminal oxidant that oxidizes osmium(VI) back to os-mium(VIII) by first oxidizing flavin (the product flavin-OOH in turn oxidizes an amine to its A -oxide in situ this A -oxide then acts conventionally in the dihydroxylation reaction). Originally, A -methylmorpholine was the amine of choice and this additive could be added in catalytic amounts. Recent developments have... 

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