Showing papers on "Bromide published in 1980"
TL;DR: In this paper, peak tailing of tricyclic antidepressant amines was studied on a range of alkyl-bonded silicas in reversed-phase ion-pair chromatographic systems Mobile phases were mixtures of methanol and buffers containing phosphate or bromide as counter-ions.
220 citations
Journal Article•
TL;DR: A partially purified preparation of guinea pig eosinophil peroxidase was found to be bactericidal when combined with H2O2 and either iodide, bromide, chloride, or thiocyanate ions.
Abstract: A partially purified preparation of guinea pig eosinophil peroxidase was found to be bactericidal when combined with H2O2 and either iodide, bromide, chloride, or thiocyanate ions. The EPO-H2O2-halide bactericidal system had an acid pH optimum and was inhibited by the proteins albumin and gelatin and by the hemeprotein inhibitors azide, cyanide, and aminotriazole. When the EPO concentration of the reaction mixture was lowered, the bactericidal effect at pH 7.0 was lost first with chloride, then with bromide, and finally with iodide as the halide. Activity with physiologic concentrations of chloride was favored by a relatively high EPO level, a decrease in pH below neutrality and an absence of extraneous protein. These findings are discussed in relation to the potential role of the peroxidase system in the intracellular and extracellular toxic reactions of eosinophils.
137 citations
123 citations
TL;DR: In this article, the separation process of the bromine fused salt from the aqueous solution is represented as a partitioning of Bromine between two phases and is dependent upon electrolysis state of charge, quaternary ammonium bromide, bromides ion concentration, and temperature.
Abstract: Upon electrolysis of aqueous zinc bromide solutions containing unsymmetrically substituted, cyclic quaternary ammonium bromides, both zinc metal and a bromine‐rich liquid are produced. Data, reported for N‐ethyl, N‐methylmorpholinium (1), N‐methoxymethyl, N‐methylpiperidinium (2), and N‐chloromethyl, N‐methylpyrrolidinium (3) bromides suggest that the bromine‐rich liquid is a fused salt and separates from the aqueous solution because of insolubility and density differences. The separation process of the bromine fused salt from the aqueous solution is represented as a partitioning of bromine between two phases and is dependent upon electrolysis state‐of‐charge, quaternary ammonium bromide, bromide ion concentration, and temperature. The bromine‐fused salts have properties dependent on composition. Selected examples of densities, specific resistances, viscosities, and polarization are given. Bromine, in the form of a dense, stable, conductive liquid, is useful in circulating zinc‐bromine batteries.
122 citations
TL;DR: Aldehydes are easily converted to 1-bromoolefins or terminal acetylenes by the use of Wittig reaction of bromomethylenetriphenylphosphorane which is prepared from brommethyltriphenymethylphosphonium bromide with potassium tert-butoxide as discussed by the authors.
116 citations
115 citations
Patent•
01 May 1980TL;DR: The reaction of a polyfluorocarbonyl compound such as a poly-fluoroketone or poly-carboxylic acid fluoride with fluoride ion and polyfluoroallyl chloride, bromide or fluorosulfate produces a polyplastic compound which copolymerize with ethylenically unsaturated monomers such as tetrafluoroethylene or vinylidene fluoride to form polymers which are moldable, and in some cases electrically conducting or are waterwettable and dyeable.
Abstract: The reaction of a polyfluorocarbonyl compound such as a polyfluoroketone or polyfluorcarboxylic acid fluoride with fluoride ion and a polyfluoroallyl chloride, bromide or fluorosulfate produces a polyfluoroallyloxy carboxylic acid fluoride or sulfonyl fluoride, e.g., CF 2 ═CFCF 2 OCF 2 CF 2 SO 2 F. The polyfluoroallyloxy compounds copolymerize with ethylenically unsaturated monomers such as tetrafluoroethylene, chlorotrifluoroethylene or vinylidene fluoride to form polymers which are moldable, and in some cases electrically conducting or are water-wettable and dyeable.
87 citations
TL;DR: In this paper, the reaction of copper(II) chloride, bromide, nitrate and perchlorate with acid amide ligands derived from 2-amino and 2,6-diamino pyridine was investigated.
85 citations
TL;DR: In this article, the 13C-n.m.r. spectra of β- l -rhamnosides are compared with those of α anomers, based on the use of 4-O-acetyl-2,3 -O-carbonyl-α- l-rhamnopyranosyl bromide as glycosylating agent.
82 citations
TL;DR: In this paper, a study was made of the reactions of compounds of the type (Me3Si)3CSiR2X (e.g. with AgNO3i-PrOH-MeOH, a mixture of products, with Y = NO3, OMe or OPri is formed), while the compounds TsiSiR2I with R2 = Et2, PhMe, or EtMe give both rearranged products, (Me 3Si)2CH(SiMe2Y) and unrearranged
75 citations
TL;DR: In this paper, the crystal structure of (bpy)(CO)3Re(PO2F2) has been determined from X-ray diffraction data by the heavy-atom technique.
Abstract: The complexes Re(CO)5ClO4, Re(CO)5PO2F2, L2(CO)3Re(OClO3) and L2(CO)3Re(PO2F2), where L2 = 2,2?-bipyridyl (bpy), have been synthesized by bromide abstraction reactions from the respective rhenium carbonyl bromide precursors. The complexes were characterized by infrared and mass spectroscopy. The crystal structure of (bpy)(CO)3Re(PO2F2) has been determined from X-ray diffraction data by the heavy-atom technique. The crystals are triclinic, space group Pī with a 8.620(3), b 15.912(5), c 6.466(3) Ǻ, α 102.08(8), β 83.29(8), γ 95.08(4) and Z 2. The structure has been refined by full-matrix least-squares from 2829 reflections to R = 0.084, Rw = 0.088. The coordination geometry about rhenium is that of a distorted octahedron. Difluorophosphate coordinates to the metal centre by one of its oxygen atoms. Formation of the difluorophosphate by hydrolysis of hexafluorophosphate was shown by 31P n.m.r. spectra.
TL;DR: In this paper, the second-order rate constants in water have been estimated by analyzing the rate surfactant profiles using independently measured values of Ks, and the reaction rate depends upon the concentration of both reactants in the micellar pseudophase and the rate constants for both substrates are very similar to those in water.
Abstract: The oxidations of ferrocene (FcH) and n-butylferrocene (FcBu) by ferric salts (nitrate or bromide) are strongly inhibited by aqueous cetyltrimethylammonium bromide and nitrate (CTABr and CTANO3, respectively). The kinetics of inhibition fit a model in which the substrates are distributed between water, and the micelles and binding constants Ks to the micelle can be estimated. The oxidations are strongly catalyzed by micelles of sodium lauryl sulfate (NaLS), and the kinetics can be fitted to a model in which the reaction rate depends upon the concentration of both reactants in the micellar pseudophase and the rate constants in that pseudophase, which for both substrates are very similar to those in water. Some added salts reduce the micellar catalysis by excluding ferric ions from the micelle. The oxidations of FcH and FcBu by ferricyanide ions are too fast to be followed in water, but they are inhibited by anionic micelles of NaLS. By analyzing the rate surfactant profiles using independently measured values of Ks the second-order rate constants in water have been estimated.
01 Oct 1980
TL;DR: In this paper, the authors investigated the micelle formation in aqueous solutions of docosane-1,22-bis (trimethylammonium bromide), referred to as C22Me6, by means of conductivity, emf, density, light scattering, and fluorescence, as well as chemical relaxation.
Abstract: Micelle formation in aqueous solutions of docosane- 1,22-bis(trimethylammonium bromide), referred to as C22Me6, has been investigated by means of conductivity, emf (concentration cell and bromide ion and detergent ion specific electrodes), density, light scattering, and fluorescence, as well as chemical relaxation (p-jump, T-jump, shock tube, ultrasonic absorption). The CMC, micelle ionization degree, micelle aggregation number, and volume change upon micellization have been found to be 2.8 × 10−3M, 0.38, 14, and 6 ± 2 cm3/mole, respectively. The slope of the plot log CMC vs number m of carbon atoms in the alkyl chain of bolaforms of the CmMe6 type as well as several other results reveal that these bolaforms behave like detergents with two charged groups on the first carbon of the alkyl chain. The main conclusion of the equilibrium studies is that the bolaform alkyl chain may be somewhat folded both in aqueous solution and in the micellized state. This conclusion is supported by the results of chemical relaxation studies which reveal for C22Me6 solutions relaxation times orders of magnitude smaller than those of the singly charged homolog. Upper limit values for the rate constants k− and k+ for the dissociation and association of a bolaform to and from a micelle have been found to be 7 × 106 sec−1 and 2 × 109 M−1 sec−1. These values are not compatible with an extended conformation of the micellized bolaform alkyl chain.
TL;DR: In this paper, the self association of dodecane-α,ω-bis(trimethylammonium bromide) and hexadecane-1,16-bis (trimethyl bromides) (C 12 Bu 6 and C 16 Me 6, respectively) was investigated by means of density, conductivity, emf, T-jump, and ultrasonic absorption.
TL;DR: In this article, a method was described for the analysis of stevioside and rebaudioside A from Stevia rebaudiana Bert, which were hydrolyzed to steviolbioside, and reacted with p-bromophenacyl bromide and crown reagent to yield the corresponding chromophoric esters.
TL;DR: Fluorescence probe study with the use of the fluorophore pyrene has revealed that the presence of 1-butanol in a cetyltrimethylammonium bromide solution results in an increase of the micellar concentration as mentioned in this paper.
TL;DR: In this article, the determination of nitrate and bromide directly from aqueous extracts by high-performance liquid chromatography on an amino phase chemically bonded to silica gel is described.
TL;DR: Using measured binding of the substrates to micelles of CTABR, the second-order rate constants in the micellar pseudophase are almost the same as that in water.
Abstract: Cationic micelles speed addition of cyanide ion to the 4 position of N-alkyl-3-carbomoylpyridinium bromide (alkyl = N-C12H25, N-C14H29, N-C16H33). At high concentration of cetyltrimethylammonium cyanide (CTACN) the reaction rates become almost independent of (CTACN) as substrate binding approaches completion. The rates of these reactions in 0.005 M Cn/sup -/ go through maxima with increasing concentration of cetyltrimethylammonium bromide (CTABR). The rate-surfactant profiles in both surfactants fit a pseudophase model of micellar catalysis. Using measured binding of the substrates to micelles of CTABR, the second-order rate constants in the micellar pseudophase are almost the same as that in water. Thus, the entire rate enhancement is due to concentration of reactants in the micellar pseudophase. 34 references.
TL;DR: Bromoallenes are useful intermediates in organic synthesis and also occur in a few natural products as mentioned in this paper, they usually are prepared from propargylic alcohols by reaction with hydrobromic acid in the presence of cuprous bromide.
TL;DR: Preliminary pharmacological studies of urine and blood metabolite levels in rats and human patients anesthetized with halothane agree with existing results determined by other methods and indicate that bromide concentrations in human blood remain elevated for a much longer period of time than those in rat blood.
Abstract: A simple and rapid method is presented for the quantitative determination of bromide and trifluoroacetlc acid in urine, plasma or serum. The biological-fluid Is treated with dimethyl sulfate in an acidic medium, resulting in thi~ formation of the methyl estei; of trifluoroacetic acid and methyl bromide. The volatile derivatives are then isolated from the samples via a head-space technique, separated and resolved by gas chromotography, and detected by flame ionization. Detection of the two metabolites Is:linear within the sample concentrations studied. The method is reproducible and applicable to the determination of the two metabolites in biological fluids in the 0.1-10 mM concentration range. The method is comparable to previous techniques but is less time consuming, and both bromide and trifluoroacetic acid can be determined simultaneously. Preliminary pharmacological studies of: urine: and blood metabolite "levels in rats and human patients anesthetized with halothane agree with existing results determined by other methods. In addition, the results indicate that bromide concentrations in human blood remain elevated for a much longer period of time than those in rat blood. head-space GC technique with flame-ionization detection (FID). The method does not require extraction, separation, sample transfer, lyophilization or other isolation procedures which would result in losses of the two metabolites.
TL;DR: In this article, the formation of 2,4,6-tribromophenol was shown to result from the chlorination of water containing phenol and bromide ion at pH 7.4.
TL;DR: In this article, it was shown that cyclopentyl bromide is de- pendent on the first power of the organic halide concentration, the magnesium surface area, and the rate at which the solution is stirred, and is inversely dependent on the solution viscosity.
Abstract: Three observations indicate that the rate of reaction of cyclopentyl bromide wjith metallic magnesium in several ethe- real solvents is limited by the rate of its encounter with the metal. First, the rate of disappearance of cyclopentyl bromide is de- pendent on the first power of the organic halide concentration, the magnesium surface area, and rate at which the solution is stirred, and is inversely dependent on the solution viscosity (-d(RBr)/d?a (RBr)', A', @I, 7-l). Second, the activation energy for the reaction in diethyl ether (E, N 2.3 kcal/mol) is consistent with mixing and diffusion as rate limiting. Third, a number of representative alkyl halides react with magnesium in diethyl ether at very similar rates; no organic halides examined react faster than this rate. The dependence of the rate of reaction of neopentyl bromide on solution dielectric constant illustrates transition from transport-limited to non-transport-limited rates, and suggests appreciable charge separation in the chemical step which breaks the carbon-bromine bond.
TL;DR: Bromide partition coefficients for the first halite crystallized under natural conditions from evaporated modern seawater in the marine salt works at Secovlje (Yugoslavia) are presented in this article.
TL;DR: The effect of the cationic surfactant 1-carbethoxypentadecyltrimethylammonium bromide at above and below its critical micelle concentration on the absorption spectra and the values of the apparent dissociation constant pK(2) of the dyes Phenol Red, Bromophenol Blue and Bromocresol Green has been studied.
Patent•
21 Nov 1980
TL;DR: In this paper, a method for the effective bleaching of textile goods at temperatures at or below about 140° F. which consists essentially in exposing same to an aqueous solution, at said temperatures, containing an amount effective for bleaching a material capable of generating positive bromine ions (Br+) during the bleaving of said textile goods.
Abstract: A method for the effective bleaching of textile goods at temperatures at or below about 140° F. which consists essentially in exposing same to an aqueous solution, at said temperatures, containing an amount effective for bleaching of a material capable of generating positive bromine ions (Br+) during the bleaching of said textile goods. The material may be available from a wide variety of sources, including alkali metal hypobromites or alkali metal hypochlorites with a source of bromide ion or a material being selected from the group consisting of: (a) an organo-N-bromo compound selected from the group consisting of N-brominated-hydantoins; N-brominated isocyanurates; N-brominated melamines and N-brominated glycolurils; (b) an organo-N-chloro-N-bromo compound selected from the group consisting of N-chlorinated-N-brominated-5,5-dialkylhydantoins; N-chlorinated-N-brominated isocyanurates; N-chlorinated-N-brominated melamines and N-chlorinated-N-brominated glycolurils; and (c) an organo-N-chloro compound selected from the group consisting of N-chlorinated-5,5-dialkylhydantoins; N-chlorinated isocyanurates, N-chlorinated melamines and N-chlorinated glycolurils, in combination with an alkali metal or alkaline earth metal bromide salt, said alkyl containing up to 8 carbons.
TL;DR: The addition of a catalytic amount of Cp2TiCl2 to an ether solution of propylmagnesium bromide and 1,3-dienes brings about an exchange reaction forming allylic Grignard reagents as discussed by the authors.
TL;DR: In this article, hydrogenic acid and bromine monochloride were used for the decomposition of methylmercury(II) chloride and thiomersal.
TL;DR: In this paper, it was shown that in dilute solution in a selective solvent for polyelectrolytic polyvinylpyridinium moities, there is multimerization, i.e. presence of particles constituted by several macromolecules.
Abstract: Hydrophobic-hydrophilic polystyrene/poly(4-vinyl-N-ethylpyridinium bromide) (poly-(l-phenylethylene)/poly[l-(N-ethyl-4-pyridinio)ethylene bromide]) block or graft copolymers were synthesized. These copolymers are well defined products, and are homogeneous in mole- cular weight and composition. They were obtained by quaternization, with ethyl bromide, of the nitrogen atoms of pyridine units of polystyrene/poly(4-vinylpyridine) block or graft copolymers. In dilute solution in a selective solvent for polyelectrolytic polyvinylpyridinium moities (water + salt), there is multimerization, i. e. presence of particles constituted by several macromolecules. Light scattering and ultracentrifugation measurements show that this multimerization is not the expected “micellization”, i.e. an “association” phenomenon due to the amphiphilic character of the copolymer, but corresponds Lo an “aggregation” phenomenon, resulting from incomplete dissolution of the product at the molecular scale.
TL;DR: The results show that the affinity sequence for the chloride transport process is I > Br congruent to Cl, that Br is transported, but that I is not, and that thiocyanate is a potent inhibitor of chloride transport.
Abstract: We have measured the fluxes of 82Br or 131I across short-circuited dog tracheal epithelium following complete replacement of chloride in the bathing medium by either bromide or iodide. In addition, we have partly replaced the bathing chloride with bromide, iodide, or thiocyanate and studied the effects of these anions on 36Cl fluxes. Our results show that the affinity sequence for the chloride transport process is I > Br congruent to Cl, that Br is transported, but that I is not. Thiocyanate is a potent inhibitor of chloride transport, and its effects are greater than those predicted by a simple competitive interaction with chloride for transport sites.