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Bromide

About: Bromide is a research topic. Over the lifetime, 24584 publications have been published within this topic receiving 349777 citations. The topic is also known as: bromide salt & bromides.


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Journal ArticleDOI
TL;DR: In this article, 1-alkyl-3-methylimidazolium tetrafluoroborate (TFLB) is described as an isotropic ionic liquid with an enantiotropic smectic A mesophase.
Abstract: Air- and water-stable 1-alkyl-3-methylimidazolium tetrafluoroborate salts with the general formula [Cn-mim][BF4] (n = 0–18) have been prepared by metathesis from the corresponding chloride or bromide salts. The salts have been characterised by 1H NMR and IR spectroscopy, microanalysis, polarising optical microscopy and differential scanning calorimetry. Those with short alkyl chains (n = 2–10) are isotropic ionic liquids at room temperature and exhibit a wide liquid range, whereas the longer chain analogues are low melting mesomorphic crystalline solids which display an enantiotropic smectic A mesophase. The thermal range of the mesophase increases with increasing chain length and in the case of the longest chain salt prepared, [C18-mim][BF4], the mesophase range is ca. 150 °C.

1,169 citations

Book ChapterDOI
TL;DR: The reaction is applied in a number of ways, such as in the structural elucidation of peptides and proteins, the detection of multiple forms of enzymes and of oxidized residues of methionine, the preparation of physiologically active peptide fragments, the location of newly introduced cross-linkages in enzymes, and the identification and characterization of fragments from enzyme active sites.
Abstract: Publisher Summary This chapter discusses the applications of the cyanogens bromide reaction Cyanogen bromide is capable of cleaving thioethers The action of cyanogen bromide upon proteins is unique in its selective attack on methionine The reaction of methionine with cyanogen bromide is greatly facilitated by the strong neighboring group effect exerted by the carboxyl group Cyanogen bromide is synthesized from bromine and potassium cyanide The selectivity of the reaction of cyanogen bromide with amino acids depends on pH The selectivity of the cyanogen bromide reaction is demonstrated by exposure to cyanogen bromide of a standard mixture of amino acids, as is used for calibration purposes in automated amino acid analyzer systems A number of applications to the general structural elucidation of peptides and proteins are: ribonuclease, rabbit γ-globulin, and chymotrypsin The reaction is applied in many other instances and is useful in a number of ways, such as in the structural elucidation of peptides and proteins, the detection of multiple forms of enzymes and of oxidized residues of methionine, the preparation of physiologically active peptide fragments, the location of newly introduced cross-linkages in enzymes,and the identification and characterization of fragments from enzyme active sites

743 citations

Journal ArticleDOI
TL;DR: In this paper, the reduction of metal salts which are dissolved in the water pools of microemulsions with hydrogen or hydrazine has been used to produce modispere particles.

719 citations

Journal ArticleDOI
TL;DR: Lithium salts enjoyed their hey-day in the latter half of last century when they were vaunted as curative in gout, and so doubtless in a multitude of other so-called gouty manifestations, but now it is not surprising that lithium salts have fallen into desuetude.
Abstract: LITHIUM SALTS enjoyed their hey-day in the latter half of last century when, commencing with their introduction by Garrod, they. were vaunted as curative in gout, and so doubtless in a multitude of other so-called gouty manifestations. This followed the demonstration that lithium urate was the most soluble of the urates. It was shown that if pieces of cartilage with urate deposits were immersed in solutions of sodium, potassium and lithium carbonate, the urate was dissolved first from that piece immersed in the lithium carbonate solution. As time went on and lithia tablets were consumed on an ever-increasing scale for an ever-increasing range of ailments, the toxic and depressant effects were more and more commonly seen. Garrod (1859) wrote of lithium carbonate: "When given internally in doses of from one to four grains dissolved in water, two to three times a day, it produces no direct physiological symptom ... their use does not appear to be attended with any injurious consequences." And certainly, in that dosage, there should never be any toxic symptoms. But about fifty years later cases are reported "of cardiac depression and even dilatation, as a result of excessive and continued consumption of lithia tablets" (The Practitioner, 1907). "Cardiac depression and even dilatation" was perhaps very vague physiology, but the note of warning was clear, also the statement in Squires's "Companion to the British Pharmacopoeia" that "lithia salts upset the stomach very easily" (The Practitioner, 1909). What with the hypothetical cardiac depression and the actual mental depression, nausea and giddiness, the uselessness of lithium in most of the conditions for which it was prescribed, and the fact that there was other, more efficacious treatment in the only disease in which it had been shown to be of some value, it is not surprising that lithium salts have fallen into desuetude. Culbreth (1927) says of lithium bromide that it is the most hypnotic of all bromides. The dosage stated there is the relatively enormous one of 10 to 30 grains. It is not stated how often this huge dose might be repeated each day, but one presumes the traditional two to three times. Squires, too, states that "in epilepsy it is the best of all bromides" and gives the dose more conservatively as five to 15 grains. It is worth noting that the hypnotic action of lithium bromide was thought to be due to the fact that, the atomic weight of lithium being so small, weight for weight, lithium bromide must contain more bromide ion than any other bromide. There is no evidence that the lithium ion was recognized as having a marked sedative action superior in some respects to that of the bromide. But 15 grains of lithium bromide repeated three times a day would soon lead, not to bromide, but to far more dangerous lithium, intoxication, and it is little wonder that it has never found favour in the treatment of epilepsy. It is a pity, because properly used, lithium salts might well be an important addition to the anti-convulsant armamentarium. In the course of some investigations by the writer into the toxicity of urea when injected intraperitoneally into guinea-pigs, it appeared desirable to ascertain whether uric acid enhanced this toxicity. The great difficulty was the insolubility of uric acid in water, so the most soluble urate was chosen--the lithium salt. When an aqueous solution of 8% urea, saturated with lithium urate, was injected, the toxicity was far less than was expected. It looked as if the lithium ion might have been exerting a protective effect. To determine this, more observations were made, lithium carbonate being used instead of lithium urate. An 8% aqueous solution of urea kills five out of ten guinea-pigs when injected intraperitoneally in doses of 1-25 millilitres per ounce of body weight. When 0.5% lithium carbonate in an 8% urea solution was injected in the same dosage, all ten animals survived; and this argued a strong protective function for the lithium ion against the convulsant mode of death caused by toxic doses of urea. …

632 citations

Journal ArticleDOI
TL;DR: In natural ground water systems, both chlorine and bromine occur primarily as monovalent anions, chloride and Bromide Although dissolution or precipitation of halite, biological activity in the root zone, anion sorption, and exchange can affect chloride/bromide ratios in some settings, movement of the ions in potable ground water is most often conservative Atmospheric precipitation will generally have mass ratios between 50 and 150; shallow ground water, between 100 and 200; domestic sewage, between 300 and 600; water affected by dissolution of Halite, between 1,000 and
Abstract: In natural ground water systems, both chlorine and bromine occur primarily as monovalent anions, chloride and bromide Although dissolution or precipitation of halite, biological activity in the root zone, anion sorption, and exchange can affect chloride/bromide ratios in some settings, movement of the ions in potable ground water is most often conservative Atmospheric precipitation will generally have mass ratios between 50 and 150; shallow ground water, between 100 and 200; domestic sewage, between 300 and 600; water affected by dissolution of halite, between 1,000 and 10,000; and summer runoff from urban streets, between 10 and 100 These, and other distinctive elemental ratios, are useful in the reconstruction of the origin and movement of ground water, as illustrated by case studies investigating sources of salinity in ground water from Alberta, Kansas, and Arizona, and infiltration rates and pathways at Yucca Mountain, Nevada

592 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
2023555
20221,171
2021377
2020439
2019493
2018475