Ammonium bromid

One prevalent strategy for this involves tire use of a phase transfer agent, such as tetraoctyl ammonium bromide, to bring gold and silver salts into an organic phase [12, and. Reduction of tire metal salts... 

Place 425 ml. of concentrated ammonia solution (sp. gr. 0-88) in a 500 ml. round-bottomed flask and add slowly 75 g. of a-bromocaproic acid (Section 111,126). Stopper the flask tightly and allow it to stand in a warm place (50-55°) for 30 hours. Filter the amino acid at the pump and keep the filtrate A) separately. Wash the amino acid (ca. 26 g.) well with methyl alcohol to remove the ammonium bromide present. Evaporate the aqueous filtrate (A) almost to dryness on a steam bath. 

To 200 ml of 48% hydrobromic acid was added 0.40 mol of phosphorus tribromide (note 1). The mixture was agitated vigorously, while the temperature was kept between 20 and 30 0 by cooling in a water-bath at 10-15 0. After about 1 h the lower layer had disappeared completely. The solution was cooled to 0°C, then 0.40 mol of ammonium bromide, 0.10 mol (note 2) of copper(I) bromide (commercial product),... 

Another method of aldehyde bromination, apart from Riehl s established method (432) from bromine at 20°C, is to use trimethylphenyl-ammonium bromide in tetrahydrofuran solution, prepared by Vorlander and Siebert s method (50). However, the yield of 5-phenylthiazole using this method with thioformamide dissolved in dioxane is only 8% (513). 

Yan and associates developed a method for the analysis of iron based on its formation of a fluorescent metal-ligand complex with the ligand 5-(4-methylphenylazo)-8-aminoquinoline. In the presence of the surfactant cetyltrimethyl ammonium bromide the analysis is carried out... 

Formulations of ammonium phosphates and ammonium bromide are sold for use on ceUulosic—synthetic fiber blends. Other ammonium phosphate formulations contain wetting and softening agents. A large-volume, ca 9000 t/yr ia 1991, use ia the United States (48) for ammonium phosphate is ia forest fire control, usuaUy by aerial appUcation (see also Ammonium compounds). 

Diphenylamine is manufactured by the self-condensation of aniline in the presence of a small amount of a mineral acid, such as anhydrous hydrogen chloride, or Lewis acids, such as ferrous chloride or ammonium bromide. 

Ammonium chloride [12125-02-9] NH Q, ammonium bromide [12124-97-9] NH Br, and ammonium iodide [12027-06-4] NH I, are crystalline, ionic compounds of formula wts 53.49, 97.94, and 144.94, respectively. Their densities d systematically foUow the increase in formula weight 1.53, 2.40, and 2.52. AH three exist in two crystal modifications (10) the chloride, bromide, and iodide have the CsQ stmcture below temperatures of 184.5, 137.8, and — 17.6°C, respectively each reversibly transforms to the NaQ. stmcture at higher temperatures. 

The heat of formation of ammonium chloride from the elements is 317 kJ /mol (75.8 kcal/mol) it is 175 kJ /mol (41.9 kcal/mol) from gaseous ammonia and gaseous hydrogen chloride. The heat of formation of ammonium bromide from the elements, bromine in the Hquid form, is 273 kJ /mol (65.3 kcal/mol) for ammonium iodide, the corresponding heat of formation is 206 kJ /mol (49.3 kcal/mol). Iodine is in the soHd state. 

Manufacture. Ammonium bromide and Ammonium iodide are manufactured either by the reaction of ammonia with the corresponding hydrohahc acid or, more economically, by the reaction of ammonia with elemental bromine or iodine. In the latter reaction, an excess of ammonia must be used. 

For ammonium bromide, another method involving reaction of an aqueous bromine solution and Hon filings has been used. The solution of ferrous and ferric bromide thus formed then reacts with ammonia to precipitate hydrated oxides of Hon. Ammonium bromide can be recovered by crystallization from the concentrated Hquor. 

Economic Aspects and Uses. Ammonium bromide is available as a dry technical grade or as 38 to 45% solutions. It is used to manufacture chemical Hitermediates, and Hi photographic chemicals it also has some flame retardant appHcations. In June 1991, its price was quoted as 2.66/kg. Ammonium iodide has limited use Hi photographic and pharmaceutical preparations. 

Arsine is formed when any inorganic arsenic-bearing material is brought in contact with zinc and sulfuric acid. The arsenides of the electropositive metals are decomposed with the formation of arsine by water or acid. Calcium arsenide [12255-53-7] Ca2As2, treated with water gives a 14% yield of arsine. Better yields (60—90%) are obtained by decomposing a solution of sodium arsenide [12044-25-6] Na As, in Hquid ammonia with ammonium bromide (14,15). Arsine may be accidentally formed by the reaction of arsenic impurities in commercial acids stored in metal tanks, so that a test should be made for... 

Ammonium bromide [12124-97-9] can be prepared by the direct reaction of bromine with aqueous ammonia ... 

Methyl bromide slowly hydrolyzes in water, forming methanol and hydrobromic acid. The bromine atom of methyl bromide is an excellent leaving group in nucleophilic substitution reactions and is displaced by a variety of nucleophiles. Thus methyl bromide is useful in a variety of methylation reactions, such as the syntheses of ethers, sulfides, esters, and amines. Tertiary amines are methylated by methyl bromide to form quaternary ammonium bromides, some of which are active as microbicides. 

About 10% is marketed ia elemental form. Eighteen percent is converted to ethylene dibromide [106-93 ] for use ia gasoline and 30% is used ia fire retardants. Fifteen percent is used as a soil fumigant methyl bromide [74-83-9]. Other commercial forms are alkaU metal bromides, ammonium bromide [12124-97-9] and hydrobromic acid [10035-10-6],... 

Acid Detergent Fiber. The ground sample is heated for 1 h under reflux in a solution of 2% cetyltrimethyl ammonium bromide [57-09-0] in IN sulfuric acid [7664-93-9]. The acid hydrolyzes and dissolves the nonceUulosic polysaccharides. The insoluble residue, relatively free of hemiceUuloses and containing aU the ceUulose and lignin, is filtered, dried, and corrected for ash to give the ADF value. 

Reaction of two or more gases to make a liquid or solid, for example, ammonia plus hydrogen bromide to form ammonium bromide. 

Electrolysis of dilute solutions of hydrogen cyanide in ammonium bromide to give cyanogen bromide. This is then dissolved in a solvent such as tetrahydrofuran and reacted with gaseous ammonia to produce cyanamide. The cyanamide is then heated in an autoclave at about 190-200°C in the presence of ammonia and the melamine, recovered by filtration. 

The 2,5-dialkoxy-2,5-dihydrofurans can be obtained by electrolytic oxidation of furan in alcoholic ammonium bromide or by bromine oxidation of furan in the appropriate alcohol. ... 

Some radioactive bromine (half-life 36 hours), in the form of ammonium bromide, was put into a brine stream as a radioactive tracer. At another plant 30 km away, the brine stream was electrolyzed to produce chlorine. Radioactive bromine entered the chlorine stream and subsequently concentrated in the base of a distillation column, which removed heavy ends. This column was fitted with a radioactive-level controller. The radioactive bromine affected the level controller, which registered a low level and closed the bottom valve on the column. The column became flooded. There was no injury, but production was interrupted. 

Ammonium acetate Ammonium adipate Ammonium benzoate Ammonium bicarbonate Ammonium biflluoride Ammonium binoxalate Ammonium bisulfate Ammonium bitartrate Ammonium tetraborate Ammonium bromide Ammonium carbonate Ammonium chloride Ammonium citrate Ammonium diclnomate Ammonium fluoride Ammonium fluorosilicate Ammonium gluconate Ammonium iodide Ammonium molybdate Ammonium nitrate Ammonium oxalate Ammonium perchlorate Ammonium picrate Ammonium polysulfide Ammonium salicylate Ammonium stearate Ammonium sulfate Ammonium sulfide (hydrosulfide) Ammonium tartrate Ammonium tliiocyanate Ammonium thiosulfate... 

---