Bromide
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Names | |||
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Systematic IUPAC name
Bromide[1] | |||
Identifiers | |||
3D model (
JSmol ) |
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3587179 | |||
ChEBI | |||
ChEMBL | |||
ChemSpider | |||
14908 | |||
KEGG | |||
PubChem CID
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UNII | |||
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Properties | |||
Br− | |||
Molar mass | 79.904 g·mol−1 | ||
Conjugate acid
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Hydrogen bromide | ||
Thermochemistry | |||
Std molar
entropy (S⦵298) |
82 J·mol−1·K−1[2] | ||
Std enthalpy of (ΔfH⦵298)formation |
−121 kJ·mol−1[2] | ||
Pharmacology | |||
N05CM11 (WHO) | |||
Pharmacokinetics: | |||
12 d | |||
Related compounds | |||
Other anions
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Fluoride | ||
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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A bromide ion is the negatively charged form (Br−) of the element bromine, a member of the halogens group on the periodic table. Most bromides are colorless. Bromides have many practical roles, being found in anticonvulsants, flame-retardant materials, and cell stains.[3] Although uncommon, chronic toxicity from bromide can result in bromism, a syndrome with multiple neurological symptoms. Bromide toxicity can also cause a type of skin eruption, see potassium bromide. The bromide ion has an ionic radius of 196 pm.[4]
Natural occurrence
Bromide is present in typical seawater (35 PSU) with a concentration of around 65 mg/L, which is about 0.2% of all dissolved salts. Seafood and deep sea plants generally have higher levels than land-derived foods. Bromargyrite—natural, crystalline silver bromide—is the most common bromide mineral known but is still very rare. In addition to silver, bromine is also in minerals combined with mercury and copper.[5]
Formation and reactions of bromide
Dissociation of bromide salts
Bromide salts of alkali metal, alkaline earth metals, and many other metals dissolve in water (and even some alcohols and a few ethers) to give bromide ions. The classic case is sodium bromide, which fully dissociates in water:
- NaBr → Na+ + Br−
Hydrogen bromide, which is a diatomic molecule, takes on salt-like properties upon contact with water to give an ionic solution called hydrobromic acid. The process is often described simplistically as involving formation of the hydronium salt of bromide:
- HBr + H2O → H3O+ + Br−
Hydrolysis of bromine
Bromine readily reacts with water, i.e. it undergoes hydrolysis:
- Br2 + H2O → HOBr + HBr
This forms hypobromous acid (HOBr), and hydrobromic acid (HBr in water). The solution is called "bromine water". The hydrolysis of bromine is more favorable in the presence of base, for example sodium hydroxide:
- Br2 + NaOH → NaOBr + NaBr
This reaction is analogous to the production of bleach, where chlorine is dissolved in the presence of sodium hydroxide.[6]
Oxidation of bromide
One can test for a bromide ion by adding an oxidizer. One method uses dilute HNO3.
Balard and Löwig's method can be used to extract bromine from seawater and certain brines. For samples testing for sufficient bromide concentration, addition of chlorine produces bromine (Br2):[7]
- Cl2 + 2 Br− → 2 Cl− + Br2
Applications
Bromide's main commercial value is its use in producing
Many metal bromides are produced commercially, including
Medicinal and veterinary uses
Folk and passé medicine
From 1954 - 1977, the Australian
Bromide compounds, especially potassium bromide, were frequently used as sedatives in the 19th and early 20th centuries. Their use in over-the-counter sedatives and headache remedies (such as Bromo-Seltzer) in the United States extended to 1975 when bromides were withdrawn as ingredients due to chronic toxicity.[14] This use gave the word "bromide" its colloquial connotation of a comforting cliché.[15]
It has been said that during World War I, British soldiers were given bromide to curb their sexual urges.[16] Lord Dunsany mentions a soldier being given bromide as a sedative for nervous exhaustion and overwork in his play Fame and the Poet (1919).[17]
Bromide salts are used in
The bromide ion is
Since bromide is still used in veterinary medicine in the United States, veterinary diagnostic labs can routinely measure blood bromide levels. However, this is not a conventional test in human medicine in the US since there are no FDA-approved uses for the bromide. Therapeutic bromide levels are measured in European countries like Germany, where bromide is still used therapeutically in human epilepsy.
Biochemistry
Bromide is rarely mentioned in the biochemical context. Some enzymes use bromide as substrate or as a cofactor.
Substrate
Cofactor
In one specialized report, bromide is an essential cofactor in the peroxidising catalysis of sulfonimine crosslinks in collagen IV. This post-translational modification occurs in all animals and bromine is an essential trace element for humans.[20]
The average concentration of bromide in human blood in Queensland, Australia, is 5.3±1.4 mg/L and varies with age and gender.[22] Much higher levels may indicate exposure to brominated chemicals. It is also found in seafood.
Further reading
Encyclopedia articles and books
- Christe, K., and S. Schneider (2020), Bromine, Encyclopædia Britannica.
- Emerson, S., and J. Hedges (2011), Chemical Oceanography and the Marine Carbon Cycle, Cambridge University Press, Cambridge.
- Glasow, R. von, and C. Hughes (2014), Biogeochemical Cycles: Bromine, Encyclopedia of Atmospheric Sciences (Second Edition).
- Knight, J., and N. Schlager (2002), Real-life chemistry, Gale Group, Detroit, MI.
- Millero, F. J. (2013), Chemical oceanography, Taylor & Francis, Boca Raton.
- Newton D. E. (2010), Bromine (Revised), Chemical Elements: From Carbon to Krypton.
- Riley, J. P., G. Skirrow, and R. Chester (1975), Chemical Oceanography, Academic Press, London
- Ross, R. (2017), Facts About Bromine, LiveScience.
- Steele, J. H., S. A. Thorpe, and K. K. Turekian (2001), Encyclopedia of Ocean Sciences, Academic Press, San Diego.
- Steele, J. H., S. A. Thorpe, and K. K. Turekian (2009), Encyclopedia of Ocean Sciences, Academic Press, Boston.
- Watkins, T. (2011), Bromine, Environmental Encyclopedia.
Peer-reviewed journal articles for bromine (Br)
- Wisniak, J. (2002), The history of bromine from discovery to commodity, NOPR.
Peer-reviewed journal articles for bromide (Br−)
- Anbar, A. D., Y. L. Yung, and F. P. Chavez (1996), Methyl bromide: Ocean sources, ocean sinks, and climate sensitivity, AGU Journals.
- Foti, S. C., and Naval Ordnance Lab White Oak Md (1972), Concentration of Bromide Ions in Seawater by Isotopic Exchange with Mercurous Bromide, DTIC.
- Gribble, G. W. (2000), The natural production of organobromine compounds, Environmental Science and Pollution Research, 7(1), 37–49, .
- Leri A. (2012), The Chemistry of Bromine in Terrestrial and Marine Environments, Science Highlight.
- Magazinovic, R. S., B. C. Nicholson, D. E. Mulcahy, and D. E. Davey (2004), Bromide levels in natural waters: its relationship to levels of both chloride and total dissolved solids and the implications for water treatment, Chemosphere, 57(4), 329–335, .
- Pilinis, C., D. B. King, and E. S. Saltzman (1996), The oceans: A source or a sink of methyl bromide?, Geophysical Research Letters, 23(8), 817–820, .
- Stemmler, I., I. Hense, and B. Quack (2015), Marine sources of bromoform in the global open ocean – global patterns and emissions, Biogeosciences, 12(6), 1967–1981, .
- Suzuki, A., Lim, L., Hiroi, T., & Takeuchi, T. (2006, March 20). Rapid determination of bromide in seawater samples by capillary ion chromatography using monolithic silica columns modified with cetyltrimethylammonium ion.
References
- ^ "Bromide – PubChem Public Chemical Database". The PubChem Project. USA: National Center for Biotechnology Information. Archived from the original on 2012-11-03.
- ^ ISBN 978-0-618-94690-7.
- PMID 22614389.
- .
- ^ "Mindat.org - Mines, Minerals and More". www.mindat.org. Archived from the original on 2 March 2001. Retrieved 29 April 2018.
- ^ Chemistry of the Elements, N. N. Greenwood, A. Earnshaw, Elsevier, 2012, pp 789
- from the original on 2021-05-25. Retrieved 2021-03-07.
- ^ "Polybrominated Diphenyl Ethers (PBDEs) Action Plan Summary | Existing Chemicals | OPPT | US EPA". Archived from the original on 2015-09-01. Retrieved 2012-12-03.
- ^ "Brominated Flame Retardants in the Environment" (PDF). Columbia Environmental Research Center. Archived (PDF) from the original on 2016-05-08. Retrieved 2012-12-03.
- ^ Weaver, Gawain (2008). "A Guide to Fiber-Base Gelatin Silver Print Condition and Deterioration" (PDF). George Eastman House, International Museum of Photography and Film. Retrieved 30 October 2009.
- ^ Bipolar disorder Archived 2022-02-24 at the Wayback Machine. webmd.com
- ^ "Papers of Shirley Andrews". Trove. Retrieved 2022-10-26.
- ^ Adams, Samuel Hopkins (1905). The Great American fraud. Press of the American Medical Association..
- ^ "the definition of bromide". Dictionary.com. Archived from the original on 24 December 2016. Retrieved 21 December 2016.
- ISBN 0415194008.
- ^ Lord Dunsany (August 1919). "Fame and the Poet". The Atlantic Monthly: 175–183.
- ^ Goodman, L. S.; Gilman, A., eds. (1970). "10. Hypnotics and Sedatives". The Biological Basis of Therapeutics (4th ed.). London: Macmillan. p. 121.
- doi:10.1039/a900201d.
- PMID 24906154.
- ^
Mayeno, Arthur N.; Curran, A. Jane; Roberts, Robert L.; Foote, Christopher S. (1989-04-05). "Eosinophils Preferentially Use Bromide to Generate Halogenating Agents". Journal of Biological Chemistry. 264 (10): 5660–5668. PMID 2538427.
- PMID 9602940.