Bromide salts, solubility

In an extension of this work, the reuse of the polymeric catalyst was addressed and several new PE-poly(alkene) glycol copolymers were prepared [68]. Commercially available oxidized polyethylene (CO2H terminated, both high and low molecular weight) was converted to the acid chloride and reacted with Jeffamine D or Jeffamine EDR, and subsequently converted to the tributylammonium bromide salt with butyl bromide. These new quaternary salts were shown to catalyze the nucleophihc substitution of 1,6-dibromohexane with sodium cyanide or sodium iodide. While none of the polymeric quaternary salts catalyzed the reaction as well as tetrabutylammonium bromide, the temperature-dependent solubility of the polymers allowed removal of the polymer by simple filtration. 

Hydrolysis of cis-Cr(en)2(H20)(0H)2+ probably gives a mixture of racemic (A,A and A,A) and meso (A,A) isomers (Fig. 2). Both forms are known but only the meso isomer has been isolated from the reaction mixture as the sparingly soluble bromide salt (33, 35). The bromide salt of the racemic form is very soluble, and it has been prepared as described in Section IV,D. 

Bromates.—The bromates are white salts soluble in water they do not, however, decompose into bromide and perbromate when heated the perbromate is unstable, and bromide and oxygen are the only products. Bromic acid, too, when warmed changes to water, hydrobromic acid, bromine, and oxygen as no compound analogous to C102 is produced, bromous acid is unknown. 

The characteristics of the experimental aquifer were independently determined from appropriate flowthrough column experiments or obtained directly from the literature. The dry bulk density of the sand ph= 1.61 kg/1, and the aquifer porosity 0=0.415 were evaluated by gravimetric procedures. The dimensionless retardation factor, R= 1.31, of the aqueous-phase TCE was determined from a column flowthrough experiment. The tortuosity coefficient for the aquifer sand was considered to be x =1.43 [75]. The molecular diffusion coefficient for the aqueous-phase TCE is D=0.0303 cm2/h [76]. The pool radius is r=3.8 cm. Bromide ion in the form of the moderately soluble potassium bromide salt was the tracer of choice [77 ] for the tracer experiment conducted in order to determine the longitudinal and transverse aquifer dispersivities a =0.259 cm and a-,— 0.019 cm, respectively. The experimental pool contained approximately 12 ml of certified ACS grade (Fisher Scientific) TCE with solubility of Cs=1100 mg/1 [78]. 

The compounds are prepared by a metathesis reaction from the corresponding iodide or bromide salt. The compounds are typically low melting point salts (in many cases molten at room temperature), which range from being quite hydrophobic (TFSA, PF ) to completely water soluble and hygroscopic (DCA, BF4). The purity of the samples is established via solution NMR, electrospray mass spectroscopy, and chemical analytical analysis. 

Filtrate B-1, containing the more-soluble diastereomer, is stirred at 60° and 5.0 g of NH4Br is added, whereupon crystallization of (-)s89-[Co(C204)(en)2]-Br H20 begins. After the NH4Br dissolves, the mixture is cooled in ice to 30° and then filtered. The red crystals are washed with 80% methanol, pure methanol, and diethyl ether and dried by suction on the filter. The yield (Aes2o = -1.99) is 8.4 g. The bromide salt is then stirred in 165 mL of water at 75° for about 10 minutes, allowed to cool in ice to 15°, and filtered and washed as before. The yield (Aejao = -2.61, [a]p = 820°)is 6.5 g or 71% of theoretical. 

Because oxidations with oxygen are free-radical reactions, free radicals should be good initiators. Indeed, in the presence of hydrogen bromide at high enough temperatures, lower molecular weight alkanes are oxidized to alcohols, ketones, or acids [5 7]. Much more practical are oxidations catalyzed by transition metals, such as platinum [5, 6, 55, 56], or, more often, metal oxides and salts, especially salts soluble in organic solvents (acetates, acetylacetonates, etc.). The favored catalysts are vanadium pent-oxide [3] and chlorides or acetates of copper [2, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66], iron [67], cobalt [68, 69], palladium [60, 70], rhodium [10], iridium [10], and platinum [5, 6, 56, 57]. 

Relative solubilities of salts in liquid ammonia can differ significantly from those in water. Thus, silver bromide is soluble in ammonia, but barium bromide is not (the reverse of the situation in water). 

The isolation of labile complex anions is often facilitated by combination with bulky cations to give organic-soluble salts. These salts are often more stable and more easily crystallized than those with simple metallic cations. One of the most convenient cations has been the p-nitrido-bis(triphenylphosphorus)(l+) ion, first isolated by Appel1 as its bromide salt in a complicated four-step... 

Bromide salt of sodium Bromnatrium Caswell No. 750A EINECS 231-599-9 EPA Pesticide Chemical Code 013907 HSDB 5039 NSC 77384 Sedoneural Sodium bromide Sodium bromide (NaBr) Trisodium tribromide. Used for preparation of bromides and in photography. Registered by EPA as an antimicrobial, fungicide, herbicide, insecticide and molluscicide. Used to control bacterial slimes in paper and pulp mills. Sedative/hypnotic anticonvulsant Used in veterinary medicine as a sedative and to control convulsions. Crystals mp = 755° d = 3.21 soluble in H2O (0.9 g/ml), less soluble in organic solvents crystallizes as a dihydrate LDso (rat ori) = 3.5 g/kg. Ethyl Corp. Great Lakes Fine Chem. Hawks Chem Co Ltd Morton tntn t... 

List the formulas of three soluble bromide salts and three insoluble bromide salts. Do the same exercise for sulfate salts, hydroxide salts, and phosphate salts (list three soluble salts and three insoluble salts). List the formulas for six insoluble Pb " salts and one soluble Pb salt. 

Quaternary ammonium polymers were first discovered by Butler and Bunch (13) in 1949. In that investigation, tri- and tetraallyl quaternary ammonium salts were polymerized to form highly cross-linked water-insoluble polymers. In 1951, Butler and Ingley (14) reacted diallyl quaternary bromide salt to produce a polymer that was water-soluble and did not form a gel. Later, Butler (15) showed that the chloride ion form of diallylammonium monomers gave more useful polymers because of their higher molecular weights. 

Due to heterogeneity of reaction mixtures containing PbO, the catalyst performance was affected by the order of mixing, temperature, and time of the catalyst preparation [55]. PbO is very soluble in molten phenol (up to 20wt%), and evaporation of phenol from such solution produces lead phenolate Pb(OPh)2. Study of the interactions between catalyst components in molten phenol showed that the phase composition of resulting mixtures depends on the temperature and the QBr PbO ratio (Scheme 12.3). Below 140 °C, a precipitate formed in this reaction contains phases of PbBr2 and Pb(OH)Br (minor component). Pd(acac)2 is unstable in PhOH solution in the presence of a bromide salt and decomposes with the formation of bromide Pd clusters (Pd Br = 6 1) and Pd- -Pd distance... 

Linear 1-olefins are oligomerized to dimers, trimers, and tetramers by the Lewis-acidic [C4GiIm]AlGl4 (excess of 0.1 mol. equiv. AIGI3) IL, without the presence of transition metal catalyst precursor. Notwithstanding, classical nickel complexes such as [ 7 -allylnickel bromide] are soluble in organoaluminate ILs, whereas alkenes possess only limited solubility. These properties have been used to develop a two-phase propene catalytic dimerization process. The catalytic system was prepared by dissolution of the nickel catalyst precursor in the molten salt... 

Whereas the presence in solution of an ion in common with a sparingly soluble salt can significantly decrease the salt solubility, the presence of an ion not in common with any of those of the solute can increase the solute solubility on account of the increase in ionic strength. For example, the solubility of silver bromide in water is increased by around 30% in a 0.1 mol L sodium nitrate aqueous solution, as can be seen in the following rough calculation. 

The principle of extraction method used to separate PTC and product is based on solubility of quaternary ammonium salt in alkaline aqueous solution. " For example, tetrabutylammonium bromide is soluble to the extent of 27% in dilute (1% NaOH) aqueous solutions, but when the solution is made more concentrated (15% NaOH), the solubility of Bu4N Br decreases to 0.07%. When the products are obtained in PTC system, they can be usually separated from PTC by distillation method. PTC catalyst in the distillation residue may sometimes be reusable. With quaternary ammonium salts as catalysts, temperatures above 100-120 C usually result in partial or total decomposition of the quaternary salts to trialkylamines and other products. Mieczynska et al. and Monflier et al. investigated the hydrogenation and hydroformylation under phase transfer catalytic conditions. They found that the yield of aldehydes obtained in hydroformylation of 1-hexene strongly depends on solvent 24% in toluene, 53-86% in toluene-water-ethanol mixture and 77-94% in water-ethanol solution. The mixture of water-ethanol as a solvent was also found to be the best for hydrogenation of 1-hexene (96% of hexane). Conversion of Ph2PCH(CH3)(COOH) phosphine into sodium salt Ph2PCH(CH3)(COONa) yields aldehyde in toluene, 92% in toluene-water and 94% in toluene-water-ethanol mixture. 

The hexamminenickel(II) bromide and iodide separate in the form of face-centered cubic crystals that are isomor-phous with ammonium hexachloropIatinate(IV). Depending upon particle size, the color of the crystals varies from pale lavender to deep blue. The bromide is soluble in hot water and may be recrystallized from concentrated aqueous ammonia. These salts should be stored in tightly stop-... 

The bromide salt of the cis aquabromo ion is much less soluble than the corresponding trans salt. For the dithionate salts the converse is true. The cis complex is violet and the trans is grey green. As is usual for cis and trans isomers, the visible absorption spectra are quite distinct. The first Ugand field band for the trans ion is weaker, and it appears at lower energies = 91.0, 1 = 19.0... 

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