Chromic trioxide

The primary Cr—O bonded species is cbromium (VT) oxide, CrO, which is better known as chromic acid [1115-74-5], the commercial and common name. This compound also has the aliases chromic trioxide and chromic acid anhydride and shows some similarity to SO. The crystals consist of infinite chains of vertex-shared CrO tetrahedra and are obtained as an orange-red precipitate from the addition of sulfuric acid to the potassium or sodium dichromate(VI). Completely dry CrO is very dark red to red purple, but the compound is deflquescent and even traces of water give the normal mby red color. Cbromium (VT) oxide is a very powerful oxidi2er and contact with oxidi2able organic compounds may cause fires or explosions. 

The most widely employed transition metal oxidants for alcohols are based on Cr(VI). The specific reagents are generally prepared from chromic trioxide, Cr03, or a dichromate salt, [Cr207]2-. The form of Cr(VI) in aqueous solution depends upon concentration and pH the pKx and pK2 of H2Cr04 are 0.74 and 6.49, respectively. In dilute solution, the monomeric acid chromate ion [HCr03] is the main species present as concentration increases, the dichromate ion dominates. 

Chromic acid is produced in situ by the reaction of sodium dichromate (Na2Cr207) or chromic trioxide (CrOs), sulphuric acid and water. 

CHROMIC ANHYDRIDE Chromic Oxide, Chromic Trioxide, Chromic Add Oxidizing Material, 1 (S) 3 (1 1 ... 

Analogously, the key intermediates in the above synthesis, the hydroxyaldehyde 236 and glycol 235, were also converted to the depyrrole analogs of methyl lysergate 240 and isolysergate 241 (56). An unstable and inseparable mixture of epimeric hydroxyaldehydes 236 was dissolved in methanol - acetone and treated with chromic trioxide in sulfuric acid to give a 1 1 mixture... 

Osmylation afforded a mixture of two cis glycols 255, which was cleaved into the corresponding hydroxyaldehydes 256. Subsequent oxidation with chromic trioxide in methanol afforded a mixture of two hydroxy esters 257 and 258 that were separated. Contrary to the result in the model compounds (56), dehydration of both hydroxy esters 257 and 258 afforded the identical... 

SYNS ANHYDRIDE CHROMIQUE (FRENCH) ANIDRIDE CROMICA (ITALIAN) CHROME (TRIOXYDE de) (FRENCH) CHROMIC ACID CHROMIC(VI) ACID CHROMIC ACID, soKd (NA 1463) (DOT) CHROMIC ACID, solution (UN 1755) pOT) CHROMIC ANHYDRIDE CHROMIC TRIOXIDE CHROMIUxM OXIDE CHROMIUM(VI) OXIDE CHROMIUM TRIOXIDE CHROMIUM(6+) TRIOXIDE CHROMIUM TRIOXIDE, anhydrous pOT) CHROMIUM TRIOXIDE, anhydrous pN 1463) pOp CHROMO (TRIOSSIDO di) (ITALIAN) CHROMS-AEUREANHYDRID (GERMAN) CHROMTRIOXID (GERMAN) CHROOMTRIOXYDE pUTCH) CHROOMZUURANHYDRIDE pUTCH) MONO-CHROAQUM OXIDE D MONOCHROMIUM TRIOXIDE O PURATRONIC CHROMIUM TRIOXIDE... 

ACIDO CLOROSULFONICO (Spanish) (7790-94-5) see chlorosulfonic acid. ACIDO CROMICO (Spanish) (1333-82-0) see chromic trioxide. 

ANHYDRIDE ARSENIEUX (French) (1327-53-3) see arsenic trioxide. ANHYDRIDE ARSENIQUE (French) (1303-28-2) see arsenic pentaoxide. ANHYDRIDE CARBONIQUE (French) (124-38-9) see carbon dioxide. ANHYDRIDE CHROMIQUE (French) (1333-82-0) see chromic trioxide. ANHYDRIDE PHTALIQUE (French) (85-44-9) see phthalic anhydride. (nes)ANHYDRIDE PROPIONIQUE (French) (123-62-6) see propionic anhydride. ANHIDRIDO ACETICO (Spanish) (108-24-7) see acetic anhydride. 

ACETIC ACID, ANHYDRIDE (108-24-7) Forms explosive mixture with air (flash point 126°F/52°C). Reacts with water, forming acetic acid and liberating a large amount of heat. Reacts with alcohol, forming ethyl acetate. Reacts violently with alkaline materials (e.g., potassium hydroxide or sodium hydroxide), barium peroxide, boric acid, chromic trioxide,... 

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