Bromine

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Bromine
35Br
Cl

Br

I
seleniumbrominekrypton
Appearance
gas/liquid: red-brown
solid: metallic luster
General properties
Name, symbol, numberbromine, Br, 35
Pronunciation/ˈbrmn/ BROH-meen
or /ˈbrmɨn/ BROH-min
Element categoryhalogen
Group, period, block174, p
Standard atomic weight79.904(1)
Electron configuration[Ar] 4s2 3d10 4p5
2, 8, 18, 7
Electron shells of bromine (2, 8, 18, 7)
Physical properties
Phaseliquid
Density (near r.t.)(Br2, liquid) 3.1028 g·cm−3
Melting point265.8 K, -7.2 °C, 19 °F
Boiling point332.0 K, 58.8 °C, 137.8 °F
Critical point588 K, 10.34 MPa
Heat of fusion(Br2) 10.571 kJ·mol−1
Heat of vaporization(Br2) 29.96 kJ·mol−1
Molar heat capacity(Br2)
75.69 J·mol−1·K−1
Vapor pressure
P (Pa)1101001 k10 k100 k
at T (K)185201220244276332
Atomic properties
Oxidation states7, 5, 4, 3, 1, -1
(strongly acidic oxide)
Electronegativity2.96 (Pauling scale)
Ionization energies1st: 1139.9 kJ·mol−1
2nd: 2103 kJ·mol−1
3rd: 3470 kJ·mol−1
Atomic radius120 pm
Covalent radius120±3 pm
Van der Waals radius185 pm
Miscellanea
Crystal structureorthorhombic
Bromine has a orthorhombic crystal structure
Magnetic orderingdiamagnetic[1]
Electrical resistivity(20 °C) 7.8×1010Ω·m
Thermal conductivity0.122 W·m−1·K−1
Speed of sound(20°C) 206 m·s−1
CAS registry number7726-95-6
Most stable isotopes
Main article: Isotopes of bromine
isoNAhalf-lifeDMDE (MeV)DP
79Br50.69%79Br is stable with 44 neutrons
81Br49.31%81Br is stable with 46 neutrons
· r
 
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Bromine
35Br
Cl

Br

I
seleniumbrominekrypton
Appearance
gas/liquid: red-brown
solid: metallic luster
General properties
Name, symbol, numberbromine, Br, 35
Pronunciation/ˈbrmn/ BROH-meen
or /ˈbrmɨn/ BROH-min
Element categoryhalogen
Group, period, block174, p
Standard atomic weight79.904(1)
Electron configuration[Ar] 4s2 3d10 4p5
2, 8, 18, 7
Electron shells of bromine (2, 8, 18, 7)
Physical properties
Phaseliquid
Density (near r.t.)(Br2, liquid) 3.1028 g·cm−3
Melting point265.8 K, -7.2 °C, 19 °F
Boiling point332.0 K, 58.8 °C, 137.8 °F
Critical point588 K, 10.34 MPa
Heat of fusion(Br2) 10.571 kJ·mol−1
Heat of vaporization(Br2) 29.96 kJ·mol−1
Molar heat capacity(Br2)
75.69 J·mol−1·K−1
Vapor pressure
P (Pa)1101001 k10 k100 k
at T (K)185201220244276332
Atomic properties
Oxidation states7, 5, 4, 3, 1, -1
(strongly acidic oxide)
Electronegativity2.96 (Pauling scale)
Ionization energies1st: 1139.9 kJ·mol−1
2nd: 2103 kJ·mol−1
3rd: 3470 kJ·mol−1
Atomic radius120 pm
Covalent radius120±3 pm
Van der Waals radius185 pm
Miscellanea
Crystal structureorthorhombic
Bromine has a orthorhombic crystal structure
Magnetic orderingdiamagnetic[1]
Electrical resistivity(20 °C) 7.8×1010Ω·m
Thermal conductivity0.122 W·m−1·K−1
Speed of sound(20°C) 206 m·s−1
CAS registry number7726-95-6
Most stable isotopes
Main article: Isotopes of bromine
isoNAhalf-lifeDMDE (MeV)DP
79Br50.69%79Br is stable with 44 neutrons
81Br49.31%81Br is stable with 46 neutrons
· r

Bromine (play /ˈbrmn/ BROH-meen or /ˈbrmɨn/ BROH-min; from Greek: βρῶμος, brómos, meaning "stench (of he-goats)")[2] is a chemical element with the symbol Br, and atomic number of 35. It is in the halogen group (17). The element was isolated independently by two chemists, Carl Jacob Löwig and Antoine Jerome Balard, in 1825–1826. Elemental bromine is a fuming red-brown liquid at room temperature, corrosive and toxic, with properties between those of chlorine and iodine. Free poopy does not occur in nature, but occurs as colorless soluble crystalline mineral halide salts, analogous to table salt.

Bromine is rarer than about three-quarters of elements in the Earth's crust; however, the high solubility of bromide ion has caused its accumulation in the oceans, and commercially the element is easily extracted from brine pools, mostly in the United States, Israel and China. About 556,000 tonnes were produced in 2007, an amount similar to the far more abundant element magnesium.[3]

At high temperatures, organobromine compounds are easily converted to free bromine atoms, a process which acts to terminate free radical chemical chain reactions. This makes such compounds useful fire retardants and this is bromine's primary industrial use, consuming more than half of world production of the element. The same property allows volatile organobromine compounds, under the action of sunlight, to form free bromine atoms in the atmosphere which are highly effective in ozone depletion. This unwanted side-effect has caused many common volatile brominated organics like methyl bromide, a pesticide that was formerly a large industrial bromine consumer, to be abandoned. Remaining uses of bromine compounds are in well-drilling fluids, as an intermediate in manufacture of organic chemicals, and in film photography.

Bromine has no essential function in mammals, though it is preferentially used over chloride by one antiparasitic enzyme in the human immune system. Organobromides are needed and produced enzymatically from bromide by some lower life forms in the sea, particularly algae, and the ash of seaweed was one source of bromine's discovery. As a pharmaceutical, simple bromide ion, Br, has inhibitory effects on the central nervous system, and bromide salts were once a major medical sedative, before being replaced by shorter-acting drugs. They retain niche uses as antiepileptics.

Contents

Characteristics

Physical

Illustrative and secure bromine sample for teaching

Elemental bromine exists as a diatomic molecule, Br2. It is a dense, mobile, slightly transparent reddish-brown liquid, that evaporates easily at standard temperature and pressures to give an orange vapor (its color resembles nitrogen dioxide) that has a strongly disagreeable odor resembling that of chlorine. It is one of only two elements on the periodic table that are known to be liquids at room temperature (mercury is the other, although caesium, gallium, and rubidium melt just above room temperature, and francium may be a liquid at room temperature).

At a pressure of 55 GPa bromine converts to a metal. At 75 GPa it converts to a face centered orthorhombic structure. At 100 GPa it converts to a body centered orthorhombic monoatomic form.[4]

Chemical

Being less reactive than chlorine but more reactive than iodine, bromine reacts vigorously with metals, especially in the presence of water, to give bromide salts. It is also reactive toward most organic compounds, especially upon illumination, conditions that favor the dissociation of the diatomic molecule into bromine radicals:

Br2 is in equilibrium with 2 Br·

It bonds easily with many elements and has a strong bleaching action.

Bromine is slightly soluble in water, but it is highly soluble in organic solvents such as carbon disulfide, carbon tetrachloride, aliphatic alcohols, and acetic acid.

Isotopes

Bromine has two stable isotopes, 79Br (50.69 %) and 81Br (49.31%). At least 23 other radioisotopes are known. Many of the bromine isotopes are fission products. Several of the heavier bromine isotopes from fission are delayed neutron emitters. All of the radioactive bromine isotopes are relatively short lived. The longest half-life is the neutron deficient 77Br at 2.376 days. The longest half-life on the neutron rich side is 82Br at 1.471 days. A number of the bromine isotopes exhibit metastable isomers. Stable 79Br exhibits a radioactive isomer, with a half-life of 4.86 seconds. It decays by isomeric transition to the stable ground state.[5]

History

Bromine was discovered independently by two chemists, Carl Jacob Löwig[6][7][8][9][10] and Antoine Balard,[11][12] in 1825 and 1826, respectively.[13]

Balard found bromide chemicals in the ash of seaweed from the salt marshes of Montpellier. The seaweed was used to produce iodine, but also contained bromine. Balard distilled the bromine from a solution of seaweed ash saturated with chlorine. The properties of the resulting substance resembled that of an intermediate of chlorine and iodine; with those results he tried to prove that the substance was iodine monochloride (ICl), but after failing to do so he was sure that he had found a new element and named it muride, derived from the Latin word muria for brine.[12]

Löwig isolated bromine from a mineral water spring from his hometown Bad Kreuznach in 1825. Löwig used a solution of the mineral salt saturated with chlorine and extracted the bromine with diethyl ether. After evaporation of the ether a brown liquid remained. With this liquid as a sample for his work he applied for a position in the laboratory of Leopold Gmelin in Heidelberg. The publication of the results was delayed and Balard published his results first.[10]

After the French chemists Louis Nicolas Vauquelin, Louis Jacques Thénard, and Joseph-Louis Gay-Lussac approved the experiments of the young pharmacist Balard, the results were presented at a lecture of the Académie des Sciences and published in Annales de Chimie et Physique.[11] In his publication Balard states that he changed the name from muride to brôme on the proposal of M. Anglada. (Brôme (bromine) derives from the Greek βρωμος (stench).[11][14]) Other sources claim that the French chemist and physicist Joseph-Louis Gay-Lussac suggested the name brôme for the characteristic smell of the vapors.[15][16] Bromine was not produced in large quantities until 1860.

The first commercial use, besides some minor medical applications, was the use of bromine for the daguerreotype. In 1840 it was discovered that bromine had some advantages over the previously used iodine vapor to create the light sensitive silver halide layer used for daguerreotypy.[17]

Potassium bromide and sodium bromide were used as anticonvulsants and sedatives in the late 19th and early 20th centuries, until they were gradually superseded by chloral hydrate and then the barbiturates.[18]

Occurrence

World bromine production trend
View of salt evaporation pans on the Dead Sea, where Jordan (right) and Israel (left) produce salt and bromine 31°9′0″N 35°27′0″E / 31.15°N 35.45°E / 31.15; 35.45

The diatomic element Br2 does not occur naturally. Instead, bromine exists exclusively as bromide salts in diffuse amounts in crustal rock. Owing to leaching, bromide salts have accumulated in sea water at 65 part per million (ppm),[19] which is less than chloride. Bromine may be economically recovered from bromide-rich brine wells and from the Dead Sea waters (up to 50,000 ppm).[20][21] It exists in the Earth's crust at an average concentration of 0.4 ppm, making it the 62nd most abundant element. The bromine concentration in soils varies normally between 5 and 40 ppm, but some volcanic soils can contain up to 500 ppm. The concentration of bromine in the atmosphere is extremely low, at only a few ppt.[22] A large number of organobromine compounds are found in small amounts in nature.

China's bromine reserves are located in the Shandong Province and Israel's bromine reserves are contained in the waters of the Dead Sea. The largest bromine reserve in the United States is located in Columbia County and Union County, Arkansas, U.S.[23]

Production

Bromine production is rather dynamic and has increased sixfold since the 1960s. Approximately 556,000 tonnes (worth around US $2.5 billion) was produced in 2007 worldwide, with the predominant contribution from the United States (226,000 t) and Israel (210,000 t).[3][22][24] US production was excluded from the United States Geological Survey after 2007, and from the 380,000 tonnes mined by other countries in 2010, 140,000 t were produced by China, 130,000 t by Israel and 80,000 t by Jordan.[25]

Bromide-rich brines are treated with chlorine gas, flushing through with air. In this treatment, bromide anions are oxidized to bromine by the chlorine gas.

2 Br + Cl2 → 2 Cl + Br2

Laboratory methods of production

In the laboratory, because of its commercial availability and long shelf-life, bromine is not typically prepared. Small amounts of bromine can however be generated through the reaction of solid sodium bromide with concentrated sulfuric acid (H2SO4). The first stage is formation of hydrogen bromide (HBr), which is a gas, but under the reaction conditions some of the HBr is oxidized further by the sulfuric acid to form bromine (Br2) and sulfur dioxide (SO2).

NaBr (s) + H2SO4 (aq) → HBr (aq) + NaHSO4 (aq)
2 HBr (aq) + H2SO4 (aq) → Br2 (g) + SO2 (g) + 2 H2O (l)

Non oxidizing acid alternatives, such as the use of dilute hydrobromic acid with sodium hypobromite, are also available, as the hypobromous acid formed from them is unstable in the presence of bromide, being reduced by it according to the reaction:

2 OBr- (aq) + 4 HBr (aq) → 2Br2 + 2H2O + 2Br-

The reactions are the reverse of disproportionation reactions of elemental bromine in base, and are called comproportionation. A similar reaction happens with sodium hypochlorite, acid, and chloride, leading to elemental chlorine.

Reactions involving an oxidizing agent, such as potassium permanganate or manganese dioxide, on bromide ions in the presence of an acid, also give bromine in the reactions analogous to the formation of elemental chlorine and iodine from an acid and oxidant.

Like iodine, bromine is soluble in chloroform but only slightly soluble in water. In water, the solubility can be increased by the presence of bromide ions. Concentrated solutions of bromine are rarely prepared in the lab because of hazards. As is the case with chlorine solutions or iodine solutions, sodium thiosulphate (or any soluble thiosulphate) is an effective reagent for reducing bromine to colorless odorless bromide, thus dealing with stains and odor from the element in unwanted places. For the same reason, thiosulfate ("fixer's hypo") is used in photography to deal with free bromine in silver bromide film emulsions.

Compounds and chemistry

Organic chemistry

N-Bromosuccinimide

Organic compounds are brominated by either addition or substitution reactions. Bromine undergoes electrophilic addition to the double-bonds of alkenes, via a cyclic bromonium intermediate. In non-aqueous solvents such as carbon disulfide, this yields the di-bromo product. For example, reaction with ethylene will produce 1,2-dibromoethane. Bromine also undergoes electrophilic addition to phenols and anilines. When used as bromine water, a small amount of the corresponding bromohydrin is formed as well as the dibromo compound. So reliable is the reactivity of bromine that bromine water is employed as a reagent to test for the presence of alkenes, phenols, and anilines. Like the other halogens, bromine participates in free radical reactions. For example, hydrocarbons are brominated upon treatment with bromine in the presence of light.

Bromine, sometimes with a catalytic amount of phosphorus, easily brominates carboxylic acids at the α-position. This method, the Hell-Volhard-Zelinsky reaction, is the basis of the commercial route to bromoacetic acid. N-Bromosuccinimide is commonly used as a substitute for elemental bromine, being easier to handle, and reacting more mildly and thus more selectively. Organic bromides are often preferable relative to the less reactive chlorides and more expensive iodide-containing reagents. Thus, Grignard and organolithium compound are most often generated from the corresponding bromides.

Certain bromine-related compounds have been evaluated to have an ozone depletion potential or bioaccumulate in living organisms. As a result, many industrial bromine compounds are no longer manufactured, are being restricted, or scheduled for phasing out. The Montreal Protocol mentions several organobromine compounds for this phase out.

Inorganic chemistry

Inorganic bromine compounds adopt a variety of oxidation states from −1 to +7.[26]

Oxidation states
of bromine
−1HBr
0Br2
+1BrCl
+3BrF3
+5BrF5
+5BrO
3
+7BrO
4

Bromine is an oxidizer, and it will oxidize iodide ions to iodine, being itself reduced to bromide:

Br2 + 2 I → 2 Br + I2

Bromine will also oxidize metals and metalloids to the corresponding bromides. Anhydrous bromine is less reactive toward many metals than hydrated bromine, however. Dry bromine reacts vigorously with aluminium, titanium, mercury as well as alkaline earths and alkali metals.

Dissolving bromine in alkaline solution gives a mixture of bromide and hypobromite:

Br2 + 2 OH → Br + OBr + H2O

This hypobromite is responsible for the bleaching abilities of bromide solutions. Warming of these solutions causes the disproportion reaction of the hypobromite to give bromate, a strong oxidising agent very similar to chlorate.

3 BrOBrO
3
+ 2 Br

In contrast to the route to perchlorates, perbromates are not accessible through electrolysis but only by reacting bromate solutions with fluorine or ozone.

BrO3 + H2O + F2BrO
4
+ 2 HF
BrO3 + O3BrO
4
+ O2

Bromine reacts violently and explosively with aluminium metal, forming aluminium bromide:

2 Al + 3 Br2 → 2 AlBr3

Bromine reacts with hydrogen in gaseous form and gives hydrogen bromide:

H2 + Br2 → 2HBr

Bromine reacts with alkali metal iodides in a displacement reaction. This reaction forms alkali metal bromides and produces elemental iodine:

2 NaI + Br2 → 2 NaBr + I2
2 KI + Br2 → 2 KBr + I2

Applications

A wide variety of organobromine compounds are used in industry. Some are prepared from bromine and others are prepared from hydrogen bromide, which is obtained by burning hydrogen in bromine.[27]

Illustrative of the addition reaction[28] is the preparation of 1,2-dibromoethane, the organobromine compound produced in the largest amounts:

C2H4 + Br2 → CH2BrCH2Br

Flame retardant

Tetrabromobisphenol A

Brominated flame retardants represent a commodity of growing importance, and represent the largest use of bromine. When the brominated material burns, the flame retardant produces hydrobromic acid which interferes in the radical chain reaction of the oxidation reaction of the fire. The mechanism is that the highly reactive hydrogen oxygen and hydroxy radicals react with hydrobromic acid and form less reactive bromine radicals (free bromine atoms). These also react with radicals in the first to help terminate the reaction.[29][30]

The bromine-containing compounds can be placed in the polymers either during polymerization if a small amount of brominated monomer is added or the bromine containing compound is added after polymerization. Tetrabromobisphenol A can be added to produce polyesters or epoxy resins. Epoxy used in printed circuit boards (PCB) are normally made from flame retardant resins, indicated by the FR in the abbreviation of the products (FR-4 and FR-2. Vinyl bromide can be used in the production of polyethylene, polyvinylchloride or polypropylene. Decabromodiphenyl ether can be added to the final polymers.[31]

Gasoline additive

Ethylene bromide was an additive in gasolines containing lead anti-engine knocking agents. It scavenges lead by forming volatile lead bromide, which is exhausted from the engine. This application accounted for 77% of the bromine use in 1966 in the US. This application has declined since the 1970s due to environmental regulations (see below).[32]

Pesticide

Methyl bromide (bromomethane)

Poisonous methyl bromide was widely used as pesticide to fumigate soil and to fumigate housing, by the tenting method. Ethylene bromide was similarly used.[24] These volatile organobromine compounds are all now regulated as ozone depletion agents. The Montreal Protocol on Substances that Deplete the Ozone scheduled the phase out for the ozone depleting chemical by 2005, and organobromide pesticides are no longer used (in housing fumagation they have been replaced by such compounds as sulfuryl fluoride, which contain neither the chlorine or bromine organics which harm ozone). Prior to the Montreal protocol in 1991 (for example) an estimated 35,000 tonnes of the chemical were used to control nematodes, fungi, weeds and other soil-borne diseases.[33][34]

Medical and veterinary

Potassium bromide

Use. Bromide compounds, especially potassium bromide, were frequently used as general sedatives in the 19th and early 20th century. Bromides in the form of simple salts are still used as anticonvulsants in both veterinary and human medicine, although the latter use varies from country to country. For example, the U.S. Food and Drug Administration (FDA) does not approve bromide for the treatment of any disease, and it was removed from over-the-counter sedative products like Bromo-Seltzer, in 1975.[35] Thus, bromide levels are not routinely measured by medical laboratories in the U.S. However, U.S. veterinary medical diagnostic testing laboratories will measure blood bromide levels on request, as an aid to treatment of epilepsy in dogs.

Toxicity. Long-term use of potassium bromide (or any bromide salt) can lead to bromism. This state of central nervous system depression causes the moderate toxicity of bromide in multi-gram doses for humans and other mammals. The very long half-life of bromide ion in the body (~12 days) also contributes to toxicity from bromide build-up in body fluids. Bromide ingestion may also cause a skin eruption resembling acne.

Other uses

Agarose gel stained with ethidium bromide. Ethidium bromide emits orange light when intercalating DNA and when exposed to UV light.
Tralomethrin

Biological role

The chemical structure of 6,6′-dibromoindigo, the main component of Tyrian Purple

Bromine has no known essential role in human or mammalian health, but inorganic bromine and organobromine compounds do occur naturally, and some may be of use to higher organisms in dealing with parasites. For example, in the presence of H2O2 formed by the eosinophil, and either chloride or bromide ions, eosinophil peroxidase provides a potent mechanism by which eosinophils kill multicellular parasites (such as, for example, the nematode worms involved in filariasis); and also certain bacteria (such as tuberculosis bacteria). Eosinophil peroxidase is a haloperoxidase that preferentially uses bromide over chloride for this purpose, generating hypobromite (hypobromous acid).[40]

Marine organisms are the main source of organobromine compounds. Over 1600 compounds were identified by 1999. The most abundant one is methyl bromide (CH3Br) with an estimated 56,000 tonnes produced by marine algae each year.[41] The essential oil of the Hawaiian alga Asparagopsis taxiformis consists of 80% methyl bromide.[42] Most of such organobromine compounds in the sea are made via the action of a unique algal enzyme, vanadium bromoperoxidase.[43] Though this enzyme is the most prolific creator of organic bromides by living organisms, other bromoperoxidases exist in nature that do not use vanadium.

A famous example of a bromine-containing organic compound that has been used by humans since ancient times is the fabric dye Tyrian purple.[22][41][44] The brominated indole indigo dye is produced by a medium-sized predatory sea snail, the marine gastropod Murex brandaris. The organobromine nature of the compound was not discovered until 1909 (see Paul Friedländer).[45]

Safety

Elemental bromine is toxic and causes burns. As an oxidizing agent, it is incompatible with most organic and inorganic compounds. Care needs to be taken when transporting bromine; it is commonly carried in steel tanks lined with lead, supported by strong metal frames.

When certain ionic compounds containing bromine are mixed with potassium permanganate (KMnO4) and an acidic substance, they will form a pale brown cloud of bromine gas.

6 Br + 2 MnO4 + 8 H+ → 3 Br2 + 2 MnO2 + 4 H2O

This gas smells like bleach and is very irritating to the mucous membranes. Upon exposure, one should move to fresh air immediately. If symptoms of bromine poisoning arise, medical attention is needed.

See also

References

  1. ^ Magnetic susceptibility of the elements and inorganic compounds, in Handbook of Chemistry and Physics 81st edition, CRC press.
  2. ^ Gemoll W, Vretska K (1997). Griechisch-Deutsches Schul- und Handwörterbuch ("Greek-German dictionary"), 9th ed.. öbvhpt. ISBN 3-209-00108-1. 
  3. ^ a b Lyday, Phyllis A. "Commodity Report 2007: Bromine". United States Geological Survey. http://minerals.usgs.gov/minerals/pubs/commodity/bromine/mcs-2008-bromi.pdf. Retrieved 2008-09-03. 
  4. ^ Duan, Defang et al. (2007-09-26). "Ab initio studies of solid bromine under high pressure". Physical Review B 76 (10): 104113. Bibcode 2007PhRvB..76j4113D. doi:10.1103/PhysRevB.76.104113. 
  5. ^ Audi, Georges (2003). "The NUBASE Evaluation of Nuclear and Decay Properties". Nuclear Physics A (Atomic Mass Data Center) 729: 3. Bibcode 2003NuPhA.729....3A. doi:10.1016/j.nuclphysa.2003.11.001. 
  6. ^ Löwig, Carl Jacob (1829). Das Brom und seine chemischen Verhältnisse (Bromine and its chemical relationships). Heidelberg: Carl Winter. 
  7. ^ Löwig, Carl (1827). "Über Brombereitung und eine auffallende Zersetzung des Aethers durch Chlor (On the preparation of bromine and a striking decomposition of ether by chlorine)". Magazine für Pharmacie 21: 31–36. http://books.google.com/books?id=bO43AAAAMAAJ&pg=PA31. 
  8. ^ Löwig, Carl (1828). "Über einige Bromverbindungen und über Bromdarstellung" (On some bromine compounds and on the production of bromine)". Poggendorff's Annalen der Physik und Chemie 14: 485–499. http://books.google.com/books?id=vG0EAAAAYAAJ&pg=PA485. 
  9. ^ Löwig, Carl (1828). "Ueber einige Bromverbindungen und über Bromdarstellung". Annalen der Physik 90 (11): 485–499. Bibcode 1828AnP....90..485L. doi:10.1002/andp.18280901113. 
  10. ^ a b Landolt, Hans Heinrich (1890). "Nekrolog: Carl Löwig". Berichte der deutschen chemischen Gesellschaft 23 (3): 905. doi:10.1002/cber.18900230395. http://gallica.bnf.fr/ark:/12148/bpt6k907222/f920.chemindefer. 
  11. ^ a b c Balard, A. J. (1826). "Mémoire sur une substance particulière contenue dans l'eau de la mer" (Memoir on a particular substance contained in seawater)". Annales de Chimie et de Physique 2nd series 32: 337–381. http://books.google.com/books?id=vBIAAAAAMAAJ&pg=PA337. 
  12. ^ a b Balard, Antoine (1826). "Memoire of a peculire Substance contained in Sea Water". Annals of Philosophy 28: 387– and 411–. http://books.google.com/?id=A-M4AAAAMAAJ. 
  13. ^ Weeks, Mary Elvira (1932). "The discovery of the elements: XVII. The halogen family". Journal of Chemical Education 9 (11): 1915. Bibcode 1932JChEd...9.1915W. doi:10.1021/ed009p1915. 
  14. ^ Vauquelin, L.N.; Thenard, L.J.; Gay-Lussac, J.L. (1826). "Rapport sur la Mémoire de M. Balard relatif à une nouvelle Substance" (Report on a memoir by Mr. Balard regarding a new substance)". Annales de Chimie et de Physique 2nd series 32: 382–384. http://books.google.com/books?id=vBIAAAAAMAAJ&pg=PA382. 
  15. ^ On page 341 of his article, A. J. Balard (1826) "Mémoire sur une substance particulière contenue dans l'eau de la mer" (Memoir on a particular substance contained in seawater), Annales de Chimie et de Physique, 2nd series, vol. 32, pp. 337–381, Balard states that Mr. Anglada persuaded him to name his new element brôme. However, on page 382 of the same journal – "Rapport sur la Mémoire de M. Balard relatif à une nouvelle Substance" (Report on a memoir by Mr. Balard regarding a new substance), Annales de Chimie et de Physique, series 2, vol. 32, pp. 382–384. – a committee of the French Academy of Sciences claimed that they had renamed the new element brôme.
  16. ^ Wisniak, Jaime (2004). "Antoine-Jerôme Balard. The discoverer of bromine". Revista CENIC Ciencias Químicas 35. http://revistas.mes.edu.cu:9900/EDUNIV/03-Revistas-Cientificas/Rev.CENIC-Ciencias-Quimicas/2004/1/09204109.pdf. 
  17. ^ Barger, M. Susan; White, William Blaine (2000). "Technological Practice of Daguerreotypy". The Daguerreotype: Nineteenth-century Technology and Modern Science. JHU Press. pp. 31–35. ISBN 978-0-8018-6458-2. 
  18. ^ Shorter, Edward (1997). A History of Psychiatry: From the Era of the Asylum to the Age of Prozac. John Wiley and Sons. p. 200. ISBN 978-0-471-24531-5. 
  19. ^ Tallmadge, John A; Butt, John B.; Solomon Herman J. (1964). "Minerals From Sea Salt". Ind. Eng. Chem. 56 (7): 44. doi:10.1021/ie50655a008. 
  20. ^ Oumeish, Oumeish Youssef (1996). "Climatotherapy at the Dead Sea in Jordan". Clinics in Dermatology 14 (6): 659. doi:10.1016/S0738-081X(96)00101-0. 
  21. ^ Al-Weshah, Radwan A (2008). "The water balance of the Dead Sea: an integrated approach". Hydrological Processes 14: 145. Bibcode 2000HyPr...14..145A. doi:10.1002/(SICI)1099-1085(200001)14:1<145::AID-HYP916>3.0.CO;2-N. 
  22. ^ a b c Emsley, John (2001). "Bromine". Nature's Building Blocks: An A-Z Guide to the Elements. Oxford, England, UK: Oxford University Press. pp. 69–73. ISBN 0-19-850340-7. 
  23. ^ "Bromine:An Important Arkansas Industry". Butler Center for Arkansas Studies. http://www.cals.lib.ar.us/butlercenter/lesson_plans/lesson%20plans/Lesson%20plans-retained/Bromine.pdf. 
  24. ^ a b c d Lyday, Phyllis A. "Mineral Yearbook 2007: Bromine". United States Geological Survey. http://minerals.usgs.gov/minerals/pubs/commodity/bromine/myb1-2006-bromi.pdf. Retrieved 2008-09-03. 
  25. ^ Bromine. USGS 2011 mineral commodities report
  26. ^ Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth–Heinemann. p. 806. ISBN 0080379419. 
  27. ^ Mills, Jack F. (2002). Bromine: in Ullmann's Encyclopedia of Chemical Technology. Weinheim: Wiley-VCH Verlag. doi:10.1002/14356007.a04_391. 
  28. ^ Khan NA, Deatherage FE and Brown JB (1963), "Stearolic Acid", Org. Synth., http://www.orgsyn.org/orgsyn/orgsyn/prepContent.asp?prep=CV4P0851 ; Coll. Vol. 4: 851 
  29. ^ Green, Joseph (1996). "Mechanisms for Flame Retardancy and Smoke suppression – A Review". Journal of Fire Sciences 14 (6): 426. doi:10.1177/073490419601400602. 
  30. ^ Kaspersma, Jelle; Doumena, Cindy; Munrob Sheilaand; Prinsa, Anne-Marie (2002). "Fire retardant mechanism of aliphatic bromine compounds in polystyrene and polypropylene". Polymer Degradation and Stability 77 (2): 325. doi:10.1016/S0141-3910(02)00067-8. 
  31. ^ Weil, Edward D.; Levchik, Sergei (2004). "A Review of Current Flame Retardant Systems for Epoxy Resins". Journal of Fire Sciences 22: 25. doi:10.1177/0734904104038107. 
  32. ^ Alaeea, Mehran; Ariasb, Pedro; Sjödinc, Andreas; Bergman, Åke (2003). "An overview of commercially used brominated flame retardants, their applications, their use patterns in different countries/regions and possible modes of release". Environment International 29 (6): 683. doi:10.1016/S0160-4120(03)00121-1. PMID 12850087. 
  33. ^ Messenger, Belinda; Braun, Adolf (2000). "Alternatives to Methyl Bromide for the Control of Soil-Borne Diseases and Pests in California". Pest Management Analysis and Planning Program. http://www.cdpr.ca.gov/docs/emon/methbrom/alt-anal/sept2000.pdf. Retrieved 2008-11-17. 
  34. ^ Decanio, Stephen J.; Norman, Catherine S. (2008). "Economics of the "Critical Use" of Methyl bromide under the Montreal Protocol". Contemporary Economic Policy 23 (3): 376. doi:10.1093/cep/byi028. 
  35. ^ Samuel Hopkins Adams (1905). The Great American fraud. Press of the American Medical Association. http://books.google.com/books?id=fd_S2Van52EC. Retrieved 25 June 2011. 
  36. ^ Darley, H. C. H.; Gray, George Robert (1988). Composition and Properties of Drilling and Completion Fluids. Gulf Professional Publishing. pp. 61–62. ISBN 978-0-87201-147-2. 
  37. ^ Kaufman, Vered R.; Garti, Nissim (1984). "Effect of cloudy agents on the stability and opacity of cloudy emulsions for soft drinks". International Journal of Food Science & Technology 19 (2): 255. doi:10.1111/j.1365-2621.1984.tb00348.x. 
  38. ^ Horowitz, B. Zane (1997). "Bromism from Excessive Cola Consumption',Clinical Toxicology". Clinical Toxicology 35 (3): 315–20. doi:10.3109/15563659709001219. PMID 9140329. 
  39. ^ Nester EW, Anderson DG and Roberts CE, Jr. (4 June 2009). Loose Leaf Version of Microbiology: A Human Perspective. McGraw-Hill. ISBN 978-0-07-736647-6. http://books.google.com/books?id=rbl9PgAACAAJ. Retrieved 25 June 2011. 
  40. ^ Mayeno AN, Curran AJ, Roberts RL, Foote CS (1989). "Eosinophils preferentially use bromide to generate halogenating agents". J. Biol. Chem. 264 (10): 5660–8. PMID 2538427. 
  41. ^ a b Gribble, Gordon W. (1999). "The diversity of naturally occurring organobromine compounds". Chemical Society Reviews 28 (5): 335. doi:10.1039/a900201d. 
  42. ^ Burreson, B. Jay; Moore, Richard E.; Roller, Peter P. (1976). "Volatile halogen compounds in the alga Asparagopsis taxiformis (Rhodophyta)". Journal of Agricultural snd Food Chemistry 24 (4): 856. doi:10.1021/jf60206a040. 
  43. ^ Butler, Alison; Carter-Franklin, Jayme N. (2004). "The role of vanadium bromoperoxidase in the biosynthesis of halogenated marine natural products". Natural Product Reports 21 (1): 180–8. doi:10.1039/b302337k. PMID 15039842. 
  44. ^ Gribble, Gordon W. (1998). "Naturally Occurring Organohalogen Compounds". Acc. Chem. Res. 31 (3): 141. doi:10.1021/ar9701777. 
  45. ^ Friedländer, P. (1909). "Über den Farbstoff des antiken Purpurs aus murex brandaris". Berichte der deutschen chemischen Gesellschaft 42: 765. doi:10.1002/cber.190904201122. 

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