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Zinc dichromate

The oxidation of alcohols with metal dichromates, other than sodium or potassium dichromate, has been little explored. Hydrated zinc dichromate (ZnCr207 3H20)367 368a and ferric dichromate [Fe2(Cr207)3],368b—which are very easy to prepare as stable solids—are able to oxidize alcohols in organic solvents.368 Zinc dichromate is particularly efficient in the transformation of a-hydroxyphosphonates into a-ketophosphonates.369... [Pg.87]

Zinc Dichromate, ZnCrgO. SHjO, is obtained by evaporation of a solution of zinc carbonate in cold aqueous chromic acid. It yields, when pure, orange-red crystals, but the colour is usually dark red. The crystals are hygroscopic and readily dissolve in water, by which the diehromate is decomposed on boiling. [Pg.72]

Tungsten hexafluoride, WF (mp 2.5 °C, bp 17 °C) [529], resembles M0F5 and M0OCI3 in its oxidative properties. However, less exotic reagents such as ozone, ammonium cerium sulfate, or zinc dichromate may be used for a similar purpose. [Pg.21]

Zinc dichromate tiihydrate, ZnCr207<3H20, is obtained as an orange-red solid by adding zinc carbonate to a cold solution of chromium trioxide in dilute sulfuric acid [660]. The applications are oxidations of acetylenes lo a-diketones, of aromatic hydrocarbons to quinones, of alcohols to aldehydes, and of ethers to esters and the oxidative regeneration of carbonyl compounds from their oximes [660]. [Pg.25]

Diarylacetylenes are converted in 55-90% yields into a-diketones by refluxing for 2-7 h with thallium trinitrate in glyme solutions containing perchloric acid [413. Other oxidants capable of achieving the same oxidation are ozone [84], selenium dioxide [509], zinc dichromate [660], molybdenum peroxo complex with HMPA [534], potassium permanganate in buffered solutions [848, 856, 864,1117], zinc permanganate [898], osmium tetroxide with potassium chlorate [717], ruthenium tetroxide and sodium hypochlorite or periodate [938], dimethyl sulfoxide and iV-bromosuccin-imide [997], and iodosobenzene in the presence of a ruthenium catalyst [787] (equation 143). [Pg.91]

Not very many other chromium compounds are suitable for the preparation of carboxylic acids from alcohols. One such compound is zinc dichromate, which oxidizes benzyl alcohol to benzoic acid in 90% yield in dichloromethane solution at room temperature [660]. [Pg.128]

By far the most important oxidation of ethers is their conversion into esters and lactones. Only a few reagents are capable of such a transformation ozone [110], chromium trioxide [539, 586], zinc dichromate [660], potassium permanganate [855], zinc permanganate [898], benzyltriethylam-monium permanganate [902], and ruthenium tetroxide (which gives the best yields) [774, 940] (equations 324 and 325). [Pg.169]

Firouzabadi, H., Iranpoor, N., Sobhani, S., and Sardarian, A.R., High yield preparation of a-keto-phosphonates by oxidation of a-hydroxyphosphonates with zinc dichromate trihydrate (ZnCr2O7 SHjO) under solvent-free conditions. Tetrahedron Lett., 42, 4369, 2001. [Pg.391]

ZINC DICHROMATE (14018-95-2) An oxidizer. Reacts with reducing agents, alcohols, combustible materials, ethers, hydrazines, organic substances, metal powders. [Pg.1249]

Both alcohols and aldehydes can be oxidised to carboxylic acids using ruthenium tetroxide an efficient, two-phase (CCl4-aq.NaCl) electro-oxidation method has been developed for the generation of RuO which could be especially useful for oxidations of carbohydrate derivatives, partly protected as acetonides.5 Zinc dichromate... [Pg.89]

What is wrong with the chemical formula for each of the following compounds (a) (NH3)2C03 (ammonium carbonate), (b) CaOH (calcium hydroxide), (c) CdS03 (cadmium sulfide), and (d) ZnCr04 (zinc dichromate) ... [Pg.66]

Zinc chromates group Zinc oxides and hydroxides group Zinc sulfides group Aurichalcite Cadmium zinc sulfide Claraite Cobalt zinc oxide Copper zinc carbonate, rosasite type Franklinite Iron zinc oxide Iron zinc oxide Lead antimony zinc oxide Matraite Rosasite Smithsonite Sphalerite Wurtzite Zinc carbonate Zinc carbonate hydroxide Zinc dichromate hydrate Zinc hexacyanoferrate(II) Zinc oxide Zinc oxide sulfide Zinc phosphate Zinc potassium chromate Zinc potassium chromate hydrate Zinc sulfate Zinc sulfide Zinc sulfide hydrate Zinc titanate Zincite Blende Mosaic gold Murexide Bieganska et al. (1988) Merck Index (1996)... [Pg.405]

Copper chromate oxide hydrate Cobalt chromate Iron dichromate Iron chromate hydroxide Manganese chromate hydrate Silver chromate Thallium chromate Titanium chromate Cadmium chromate Cadmium chromate hydroxide Mercury chromate Zinc dichromate hydrate Zinc chromate(VI) hydroxide Zinc sodium chromate Zinc potassium chromate... [Pg.422]

See other pages where Zinc dichromate is mentioned: [Pg.788]    [Pg.93]    [Pg.265]    [Pg.236]    [Pg.236]    [Pg.991]    [Pg.1720]    [Pg.1345]    [Pg.1092]    [Pg.43]    [Pg.220]    [Pg.230]    [Pg.236]    [Pg.69]    [Pg.817]    [Pg.74]    [Pg.97]    [Pg.101]    [Pg.101]    [Pg.404]    [Pg.404]    [Pg.405]    [Pg.282]   


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Dichromate

Dichromism

Zinc dichromate ethers

Zinc dichromate oxidation

Zinc dichromate, alcohol oxidant

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