Chromium oxide chloride

Synonyms Chromium dioxychloride chromium dioxide dichloride chromium oxychloride chromium chloride oxide... 

SYNS CHLORURE de CHROMYLE (FRENCH) CHROMIC OXYCHLORIDE CHROMIUM CHLORIDE OXIDE CHROMIUM DICHLORIDE DIOXIDE CHROMIUM DIOXIDE DICHLORIDE CHROMIUM(VI) DIOXYCHLORIDE CHROMIUM OXYCHLORIDE CHROMOXYCHLORID (GERMAN) CHROMYLCHLOR-ID (GERMAN) CHROOMOXYLCHLORIDE (DUTCH) CROMILE, CLORURO di (ITALIAN) CROMO, OSSICLO-RURO di (ITALIAN) DICHLORODIOXOCHROMIUM DIOXODICHLOROCHROMIUM OXYCHLORURE CHROMIQUE (FRENCH)... 

CHROMIUM CHLORIDE OXIDE (14977-61-8) A powerful oxidizer. Violent reaction with water, producing hydrochloric and chromic acids, and chlorine gas. Potentially violent and explosive reaction with reducing agents, acetone, alcohols, calcium sulfide, combustible materials, gaseous or liquid ammonia, ethers, nonmetal halides, fuels, nonmetal hydrides, fluorine, organic matter, organic solvents, phosphorus, phosphorus trichloride, sodium azide, elemental sulfur, sulfur monochloride, turpentine, urea. Decomposes slowly in light. 

Synonyms/Trade Names Chlorochromic anhydride. Chromic oxychloride. Chromium chloride oxide. Chromium dichloride dioxide. Chromium dioxide dichloride. Chromium dioxychloride. Chromium oxychloride. Dichlorodioxochromium... 

Ammonia, anhydrous Mercury, halogens, hypochlorites, chlorites, chlorine(I) oxide, hydrofluoric acid (anhydrous), hydrogen peroxide, chromium(VI) oxide, nitrogen dioxide, chromyl(VI) chloride, sulflnyl chloride, magnesium perchlorate, peroxodisul-fates, phosphorus pentoxide, acetaldehyde, ethylene oxide, acrolein, gold(III) chloride... 

Cr-ZSM-5 catalysts prepared by solid-state reaction from different chromium precursors (acetate, chloride, nitrate, sulphate and ammonium dichromate) were studied in the selective ammoxidation of ethylene to acetonitrile. Cr-ZSM-5 catalysts were characterized by chemical analysis, X-ray powder diffraction, FTIR (1500-400 cm 1), N2 physisorption (BET), 27A1 MAS NMR, UV-Visible spectroscopy, NH3-TPD and H2-TPR. For all samples, UV-Visible spectroscopy and H2-TPR results confirmed that both Cr(VI) ions and Cr(III) oxide coexist. TPD of ammonia showed that from the chromium incorporation, it results strong Lewis acid sites formation at the detriment of the initial Bronsted acid sites. The catalyst issued from chromium chloride showed higher activity and selectivity toward acetonitrile. This activity can be assigned to the nature of chromium species formed using this precursor. In general, C r6+ species seem to play a key role in the ammoxidation reaction but Cr203 oxide enhances the deep oxidation. 

Aluminium, 0048 Ammonium phosphinate, 4554 Barium phosphinate, 0210 f Benzaldehyde, 2731 1,4-Benzenediol, 2333 Bis(hydrazine)tin(II) chloride, 4070 Calcium acetylide, 0585 Calcium phosphinate, 3931 Chromium(II) chloride, 4052 Chromium(II) oxide, 4241 Chromium(II) sulfate, 4244 Copper(I) bromide, 0265 Diacetatotetraaquocobalt, 1780 Diisobutylaluminium hydride, 3082 f 1,2-Dimethylhydrazine, 0955... 

The synthesis of the smaller fragment methyl esters 144-147 was completed as depicted in Scheme 20. Chelation-controlled allylation of aldehydes 135-138 prepared by chromium(VI) oxidation of alcohols 122,123,133, and 134 with allyltrimethylsilane (139) in the presence of titanium(IV) chloride proceeded... 

B. General Oxidation Procedure for Alcohols. A sufficient quantity of a 5% solution of dipyridine chromium (VI) oxide (Note 1) in anhydrous dichloromethane (Note 7) is prepared to provide a sixfold molar ratio of complex to alcohol. This excess is usually required for complete oxidation to the aldehyde. The freshly prepared, pure complex dissolves completely in dichloromethane at 25° at 5% concentration to give a deep red solution, but solutions usually contain small amounts of brown, insoluble material when prepared from crude complex (Note 8). The alcohol, either pure or as a solution in anhydrous methylene chloride, is added to the red solution in one portion with stirring at room temperature or lower. The oxidation of unhindered primary (and secondary) alcohols proceeds to completion within 5 minutes to 15 minutes at 25° with deposition of brownish-black, polymeric, reduced chromium-pyridine products (Note 9). When deposition of reduced chromium compounds is complete (monitoring the reaction by gas chromatography or thin-layer chromatography analysis is helpful), the supernatant liquid is decanted from the (usually tarry) precipitate and the precipitate is rinsed thoroughly with dichloromethane (Note 10). 

I )ipyridine chromium(VI) oxide is available from East-imni (Irganic Chemicals. To be an effective reagent, it must be ttnliydi oiis. It should form a red solution on dissolution in mdiydroiis methylene chloride. 

Piroxicam Piroxicam, 1,1 -dioxid-4-hydroxy-2-methyl-iV-2-pyradyl-2//-1,2-benzothiazine-3-carboxamide (3.2.78), is synthesized from saccharin (3.2.70). Two methods for saccharin synthesis are described. It usually comes from toluene, which is sulfonated by chlorosulfonic acid, forming isomeric 4- and 2-toluenesulfonyl chlorides. The isomeric products are separated by freezing (chilling). The liquid part, 2-toluenesulfonyl chloride (3.2.68) is separated from the crystallized 4-toluenesulfochloride and reacted with ammonia, giving 2-toluenesul-fonylamide (3.2.69). Oxidation of the product with sodium permanganate or chromium (VI) oxide in sulfuric acid gives saccharin—o-sulfobenzoic acid imide (3.2.70) [123-126]. 

Peroxyacids oxidize the imine group in (236) and related compounds to the nitrone. The 1,4-benzodiazepine (178) and its 4,5-dihydro analogue can be oxidized to the 2-oxo derivatives with chromium(VI) oxide. The benzodiazepinone (236) can be hydroxylated at the 3-position via a two-step process firstly reaction with LTA gives the 3-acetoxy derivative and this can then be hydrolyzed in high yield using sodium methoxide in methanol/methylene chloride. The 3-acetoxy derivative may also be prepared via bromina-tion with NBS and reaction with sodium acetate in situ (79JHC1449). 

All of the usual chromium-based oxidation reagents that have been used for the oxidation of cyclobutanols to cyclobutanones, for example, chromium(VI) oxide (Jones reagent),302 pyri-dinium chlorochromate,304 pyridinium dichromate,307 and chromium(YI) oxide/pyridine (Collins),303 are reported to do so without any serious problems. Alternatively, tetrapropylam-monium perruthenate in the presence of A-methylmorpholine A -oxide. oxalyl chloride in the presence of triethylamine in dimethyl sulfoxide (Swern),158,309,310 or phenyl dichlorophos-phate in the presence of triethylamine and dimethyl sulfoxide in dichloromethane (Pfitzner-Moffatt),308 can be used. The Pfitzner-Moffatt oxidation procedure is found to be more convenient than the Swern oxidation procedure, especially with respect to the strict temperature control that is necessary to achieve good yields in the latter, e.g. oxidation of 1 to give 2.308... 

Prepare a chromite solution using for this purpose the smallest possible amount of a sodium hydroxide solution, and boil it. What happens Which salt hydrolyzes more—one of chromium(III) oxide or sodium chromite Why How can the hydrolysis of chromium(IH) chloride be brought to the end ... 

Preparation of Anhydrous Chromium(III) Chloride. Perform the experiment in a fume cupboard Grind 5 g of charcoal into a fine powder in a mortar, mix it with 12.5 g of chromium(III) oxide, add a thick starch size or a dextrin solution in cold water, and make beads about 5 mm in diameter from the mixture. Put the beads onto a clay dish and dry them in a drying cabinet at 110-120 °C. Next put them into an iron crucible, cover them with the charcoal powder and a lid, and roast them. 

Chromium oxides with a minimal sulfur content are preferred for metallurgical applications. These are obtained by reacting sodium dichromate with ammonium chloride or sulfate in a deficiency of 10 mol% [3.51]. Chromium (III) oxides with a low sulfur content can also be obtained by thermal aftertreatment [3.52], Thermal decomposition of chromic acid anhydride (Cr03) yields high-purity chromium(III) oxide [3.53],... 

No hydrogen chloride or hydrogen fluoride elimination is found in the disproportionation of chlorotetralluoroethane (C2F4C1H, mixture of the isomers) over chromium(III) oxide between 220 and 240CC, whereby pentafluoroethane and 1,l-dichloro-2,2,2-trifluoroethane are produced.33... 

Using chromium-based oxidants 2,4-Dimethylpentane-2,4-diol chromate(VI) diester, 122 Trimethylsilyl chlorochromate, 327 Using other oxidizing agents Bis(tributyltin) oxide, 41 Hydrogen hexachloroplatinate(IV)-Copper(II) chloride, 145 4-Methoxy-2,2,6,6-tetramethyl-1 -oxopiperidinium chloride, 183 Osmium tetroxide, 222 Potassium nitrosodisulfonate, 258 Samarium(II) iodide, 270 From alkenes by addition or cleavage reactions... 

Chromium carbene complexes, 82 Chromium carbonyl, 51 Chromium(II) chloride, 84 Chromium(III) chloride-Lithium aluminum hydride, 84 Chromium(VI) oxide, 338... 

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