A chromate ester is a chemical structure that contains a chromium atom (symbol Cr) in a +6 oxidation state that is connected via an oxygen (O) linkage to a carbon (C) atom. The Cr itself is in its chromate form, with several oxygens attached, and the Cr–O–C attachment makes this chemical group structurally similar to other ester functional groups. They can be synthesized from various chromium(VI) metal compounds, such as CrO3, chromium chloride complexes, and aqueous chromate ions, and tend to react via redox reactions to liberate chromium(IV).
Chromate esters are the key reactive intermediates in the Jones oxidation, the mechanistically related oxidations using pyridinium dichromate or pyridinium chlorochromate. Chromate esters of allyl alcohols may isomerize via formal [3,3]-sigmatropic shift to give rearranged enone products.[1]
An example of an isolable chromate ester is ((CH3)3CO)2CrO2.[2]
^Carruthers, W.; Coldham, I. (2004). Modern Methods of Organic Synthesis (4th ed.). p. 381. ISBN 978-0-521-77097-2.
^Fillmore Freeman, "Di-tert-butyl Chromate" Encyclopedia of Reagents for Organic Synthesis, 2001, John Wiley & Sons, Ltd. doi:10.1002/047084289X.rd059m
A chromateester is a chemical structure that contains a chromium atom (symbol Cr) in a +6 oxidation state that is connected via an oxygen (O) linkage...
Chromate salts contain the chromate anion, CrO2− 4. Dichromate salts contain the dichromate anion, Cr 2O2− 7. They are oxyanions of chromium in the +6...
Potassium chromate is the inorganic compound with the formula K2CrO4. This yellow solid is the potassium salt of the chromate anion. It is a common laboratory...
formation of a mixed chromateester: These esters have the formula CrO3(OCH2R)− CrO3(OH)− + RCH2OH → CrO3(OCH2R)− + H2O Like conventional esters, the formation...
Zinc chromate, ZnCrO4, is a chemical compound, a salt containing the chromate anion, appearing as odorless yellow powder or yellow-green crystals, but...
acid forms di-tert-butyl chromate (((CH3)3C−O−)2Cr(=O)2) Inorganic acids that exist as tautomers form two or more types of esters. Thiosulfuric acid forms...
Sodium chromate is the inorganic compound with the formula Na2CrO4. It exists as a yellow hygroscopic solid, which can form tetra-, hexa-, and decahydrates...
through the formation of a chromateester (1) from nucleophilic attack of the chlorochromate by the allylic alcohol. The ester then undergoes a [3,3]-sigmatropic...
triterpene lupeol was oxidized to lupenone: With tertiary alcohols, the chromateester formed from PCC can isomerize via a [3,3]-sigmatropic reaction and following...
Silver chromate is an inorganic compound with formula Ag2CrO4 which appears as distinctively coloured brown-red crystals. The compound is insoluble and...
Strontium chromate is an inorganic compound with the formula SrCrO4. Strontium chromate is prepared from strontium chloride and sodium chromate, or from...
sodium dichromate. Alternatively, it can be also obtained from potassium chromate by roasting chromite ore with potassium hydroxide. It is soluble in water...
Barium chromate, is a yellow sand like powder with the formula BaCrO4. It is a known oxidizing agent and produces a green flame when heated, a result of...
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the catalytic mechanism. The active catalyst is often depicted as a chromateester bound to the silica surface. The mechanism for the polymerization process...
Cadmium chromate is the inorganic compound with the formula CdCrO4. It is relevant to chromate conversion coating, which is used to passivate common metal...
Calcium chromate is an inorganic compound with the formula CaCrO4, i.e. the chromate salt of calcium. It is a bright yellow solid which is normally found...
Magnesium chromate is a chemical compound, with the formula MgCrO4. It is a yellow, odorless, water-soluble salt with several important industrial uses...
material. It is crystallised around 30 to 35 degrees C Dichromate and chromate salts are oxidizing agents. For the tanning of leather, sodium dichromate...
In organic chemistry, organophosphates (also known as phosphate esters, phosphorates(V) or OPEs) are a class of organophosphorus compounds with the general...
traditional method is by the ignition of copper chromate: 2 CuCrO 4 → 2 CuCrO 3 + O 2 Copper barium ammonium chromate is the most commonly used substance for...
Caesium chromate or cesium chromate is an inorganic compound with the formula Cs2CrO4. It is a yellow crystalline solid that is the caesium salt of chromic...
inorganic compound with the formula (NH4)2Cr2O7. In this compound, as in all chromates and dichromates, chromium is in a +6 oxidation state, commonly known as...