Sodium ammonium bromide

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... 

Examples of other frequently used surfactants that able to form reversed micelles without the addition of cosurfactants are didodecyldimethyl ammonium bromide [17], do-decylammonium propionate, benzyldimethylhexadecyl ammonium chloride [18], lecithin [19], tetraethyleneglycol monododecylether (C12E4) [20], decaglycerol dioleate [21], do-decylpyridinium iodide [22], and sodium bis(2-ethylhexyl) phosphate [23],... 

Br HBr HBr NH Br KBr KBA UBr NaBr Hydnobromic acid Hydrogen bromide Ammonium bromide Potassium bromide Potassium bromate Lithtum bromide Sodium bromide HgC NaSa NaaHCaOg NiCjNj ZnCA CA KsFeCgNs FejCiaNij Ca... 

Surfactants employed for w/o-ME formation, listed in Table 1, are more lipophilic than those employed in aqueous systems, e.g., for micelles or oil-in-water emulsions, having a hydrophilic-lipophilic balance (HLB) value of around 8-11 [4-40]. The most commonly employed surfactant for w/o-ME formation is Aerosol-OT, or AOT [sodium bis(2-ethylhexyl) sulfosuccinate], containing an anionic sulfonate headgroup and two hydrocarbon tails. Common cationic surfactants, such as cetyl trimethyl ammonium bromide (CTAB) and trioctylmethyl ammonium bromide (TOMAC), have also fulfilled this purpose however, cosurfactants (e.g., fatty alcohols, such as 1-butanol or 1-octanol) must be added for a monophasic w/o-ME (Winsor IV) system to occur. Nonionic and mixed ionic-nonionic surfactant systems have received a great deal of attention recently because they are more biocompatible and they promote less inactivation of biomolecules compared to ionic surfactants. Surfactants with two or more hydrophobic tail groups of different lengths frequently form w/o-MEs more readily than one-tailed surfactants without the requirement of cosurfactant, perhaps because of their wedge-shaped molecular structure [17,41]. 

Note PEO = polyethylene oxide PVA = polyvinyl alcohol SDS = sodium dodecyl sulfate CTAB = cetyl trimethyl ammonium bromide. 

The surface active agents (surfactants) may be cationic, anionic or non-ionic. Surfactants commonly used are cetyltrimethyl ammonium bromide (CTABr), sodium lauryl sulphate (NaLS) and triton-X, etc. The surfactants help to lower the surface tension at the monomer-water interface and also facilitate emulsification of the monomer in water. Because of their low solubility surfactants get fully dissolved or molecularly dispersed only at low concentrations and at higher concentrations micelles are formed. The highest concentration where in all the molecules are in dispersed state is known as critical micelle concentration (CMC). The CMC values of some surfactants are listed in table below. 

Figure 6.14 Flow curves for sodium kaolinite at pH 4. The two systems are differ only by the addition of hexadecyl trimethyl ammonium bromide (HDTAB)...

Quaternary ammonium tribromides can also be produced in situ from the quaternary ammonium bromide, sodium hypochlorite and sodium bromide and can be used, for example, in electrophilic addition reactions reaction with alkenes and alkynes. 

The reaction of sodium azide with N-aryl chloroimines, obtained from benzanilides and thionyl chloride, to form 1,5-disubstituted tetrazoles is catalysed by tetra-n-butyl-ammonium bromide (Scheme 5.26, Table 5.40) [18] in variable yields, but generally <85%. 5-Butyl-2,3-diphenyltetrazolium salts have also been used as catalysts [18, 19]. 1,5-Disubstituted tetrazoles are also obtained from a one-pot sequential reaction of carbodimides with sodium azide and an aroyl chloride in the presence of tetra-n-butylammonium chloride [20]. 5-Chlorotetrazoles are obtained from the catalysed reaction of aryldichloroisocyanides with sodium azide (Scheme 5.26) [21],... 

It is liquid-liquid reactions involving phase transfer catalysts which generally benefit from the use of ultrasound. Sonication produces homogenisation - i. e. very fine emulsions - which greatly increase the reactive interfacial area and allows faster reaction at lower temperatures. Davidson has reported an example of this with the ultrasonically enhanced saponification of wool waxes by aqueous sodium hydroxide using tetra n-heptyl ammonium bromide as a PTC [124]. 

Eor univalent ionic surfactants, e.g., alkyl trimethyl-ammonium bromide and chloride, sodium alkyl sulfate, and sodium alkyl carboxylate. 

Contrary to hydrotropes, micelle-forming surfactants spontaneously self-aggregate cooperatively above the critical micelle concentration (cmc) even in the absence of solubilizate. Typical examples of micelle-forming surfactants include sodium dode-cylsulfate (SDS), dodecyltrimethylammonium bromide (DTAB), cetyltrimethyl-ammonium bromide (CTAB), and heptaoxyethylene dodecyl ether (C12E7) (Scheme 2). 

Arsine is produced by the reaction of arsenic trichloride, arsenic trioxide or any inorganic arsenic compound with zinc and sulfuric acid. It is also made by treating a solution of sodium arsenide or potassium arsenide in liquid ammonia with ammonium bromide ... 

Surfactants such as cetyl trimethyl ammonium bromide (CTAB), Triton X-100 (TX-lOO) and sodium dodecyl sulphate (SDS) are the most commonly used. CTAB forms large micelles [24-26] with aggregation number 61, cmc 9.2 X 10 M, and a positive micellar Stem layer TX-lOO has aggregation number 139 with neutral OH groups on the Stern layer, and SDS forms negative micelles with cmc 8.3 x 10 M and aggregation number 131. The... 

SDS sodium dodecyl sulphate CTAB cetyl trimethyl ammonium bromide TX-lOO Triton X-100 Mb myoglobin... 

Detergents. Under appropriate conditions of pH, ionic strength and temperature, detergents (ionic sodium lauiyl sulphate, sodium deoxycholate, sodium cholate and cetyldiethyl-ammonium bromide, or nonionic Tweens and Tritons), can be used to lyse cells. Detergents may however cause enzyme inactivation and may need to be removed before purification. 

The bromide may be obtained from the chloride by double decomposition with ammonium bromide, and by the action of sodium dithionate, the dithionate,... 

To a large bottle are added 470.0 gm (5.6 moles) of 2-methyl-3-butyne-2-ol, 1000 ml of 48 % technical grade hydrobromic acid, 200.0 gm (2.04 moles) of ammonium bromide, and 70.0 gm (0.71 mole) of cuprous chloride. The bottle is sealed, shaken at room temperature for 4J hr, opened, and the organic layer is separated. The organic layer is washed twice with sodium bicarbonate solution, once with a saturated sodium bisulfite solution, dried over calcium chloride, and fractionally distilled through a glass-helix-packed column to afford 500 gm (61 %) of almost pure product (ir 1956 cm-1 allene), b.p. 34°C (18 mm), d5 1.5163. The ir showed that the product contained a trace of l-bromo-3-methyl-1,3-butadiene (1580 and 1620 cm-1). 

Duynstee and Grunwald present some experimental data for Reaction (F) in the presence of hexadecyl trimethyl ammonium bromide (CTABr, C = cetyl) and sodium dodecyl sulfate (NaLS, L = lauryl). Sodium hydroxide was the source of OH" in all cases. A pseudo-first-order rate constant of 2.40 x 10-2 s-1 is observed for A CTABr. Use the following absorbance data to evaluate NaLS for this reaction ... 

The reaction of Problem 10 was studied at two different temperatures, and, from the temperature dependence of the rate constants, the authors determined AH% and ASJ, the enthalpy and entropy of activation, respectively. The following values of these parameters were obtained in pure water and in 0.01 M sodium dodecyl sulfate (NaLS) and 0.01 M hexadecyl trimethyl ammonium bromide (CTABr) ... 

The relative mol. compressibility of ammonium bromide in 700 mols. of solvent is 0973, and in 1500 mols. of the solvent, 0951—vide ammonium iodide. W. C. Rontgen and J. Schneider 9 also measured the surface tension of these soln. The viscosity of ammonium bromide at 25° decreases from 0 008867 dynes per sq. cm. for 0 216A-soln. to O 008254 for 2 646Ar-soln., and then increases from this minimum to 0 008560 with 4 920A-soln. The respective sp. gr. of these soln. are T0121, 1 1414, and 12605. The values for l 63A-soln. decrease from 0 0116 at 10°, to 00077 at 30°, to 0 0056 at 50°. The velocity of diffusion of ammonium bromide in aq. soln. is smaller than that of potassium bromide, and greater than sodium bromide.10... 

According to F. C. Franklin and C. A. Kraus,40 liquid ammonia readily dissolves sodium and potassium iodides. The partial press, of ammonia in soln. of potassium iodide at 25°, as measured by R. Abegg and H. Riesenfeld, is raised from 13 45 mm. of water to 13 28, and 14 88 mm. for 0 5W-, N-, and l 5Ar-soln. respectively. H. M. Dawson and J. McCrae have shown that the distribution of ammonia between water and chloroform is generally lowered by the addition of various salts of the alkali metals and ammonium which they tried—halides, nitrates, chlorates, oxalates, sulphates, carbonates, hydroxides this means that the solvent power of aq. soln. of the alkali salts is in general less than that of pure water—lithium chloride, ammonium bromide, and sodium iodide act in the opposite way. The other halide salts of lithium were not tried. The change produced in the partition coeff. by the halides, at 20°, is as follows ... 

ALUMINUM BROMIDE (m.p. 97.5) Ammonium bromide Silver bromide (m.p. 434) Sodium bromide (m.p. 755) Stannous bromide (m.p. 215. BaBr0,CaBr0,KBr,PbBr0,HgBr, TIBr ... 

Durrant, Pearson and Robinson, J. Ohem. Soc., 1934, p. 730. Por the preparation of arsine by the action of ammonium bromide on sodium arsenides in liquid ammonia, see Johnson and Pechukas, J. Amer. Ohem. Soc., 1937, 59, 2065. 

Thirty grams of the complex chloride are dissolved in 100ml of water at 65cC and 45g of sodium or ammonium bromide are stirred in, The product precipitates immediately and is recovered by cooling in ice to complete the crystallization, then filtering by suction. 

Potassium r-butoxide-Hexamethyl-phosphoric triamide, 252 Potassium r-butoxide-Xonotlite, 254 Potassium hydroxide, 258 Potassium hydroxide-18-Crown-6, 258 Potassium hydroxide-Tricaprylyl-methylammonium chloride, 258 Sodium hydroxide-Methyltrioctyl-ammonium chloride, 192 Sodium hydroxide-Triethyl(2-methyl-butyl)ammonium bromide, 239 Sodium hydroxide-N-(p-Trifluoro-methylbenzyl)cinchoninium bromide, 325... 

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