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69-526: The city of Hazar , former Cheleken, is located in the peninsula, which administratively belongs to Turkmenistan's Balkan Province . The Cheleken Peninsula is about 40 km long and 22 km wide. It borders on the Caspian Sea in the west and with the Türkmenbaşy Gulf (former Krasnovodsk Bay) in the north. The peninsula has a continental dry climate with a precipitation of 150 mm/year. The area

138-547: A Captain by the name of Woodruff of a British merchant company remarked that 36 Ogurdjali families resided on the island. They had 26 large boats and some oil wells . Prior to 1917, the Moscow Society, Cheleken-Dagestan Society, Kuzmin and Co, Bostondjoglo, South Caucasian Mining Society, and Second Moscow Group were among the established Russian oil companies. By 1925, after the establishment of Soviet Turkmenistan , wells had been nationalized and oil production decreased. By

207-633: A Turkic people, the Khazars ( viz. ), who lived on the shores of the Caspian Sea and lent their tribal name to the body of water in several Turkic languages, including Turkmen . The current name of the city thus comes from the Turkmen name of the Caspian Sea. The former name, Çeleken (Cheleken), is the name of the former island, now peninsula, on which the city is located. The word comes from Persian chahar kan چهارکن, meaning "four wells" or "four riches", referring to

276-415: A by-product of potash . Apart from some minor medical applications, the first commercial use was the daguerreotype . In 1840, bromine was discovered to have some advantages over the previously used iodine vapor to create the light sensitive silver halide layer in daguerreotypy. By 1864, a 25% solution of liquid bromine in .75 molar aqueous potassium bromide was widely used to treat gangrene during

345-436: A face-centered orthorhombic structure. At 100 GPa it changes to a body centered orthorhombic monatomic form. Bromine has two stable isotopes , Br and Br. These are its only two natural isotopes, with Br making up 51% of natural bromine and Br making up the remaining 49%. Both have nuclear spin 3/2− and thus may be used for nuclear magnetic resonance , although Br is more favourable. The relatively 1:1 distribution of

414-496: A high first ionisation energy, very strong oxidisers such as peroxydisulfuryl fluoride (S 2 O 6 F 2 ) can oxidise it to form the cherry-red Br 2 cation. A few other bromine cations are known, namely the brown Br 3 and dark brown Br 5 . The tribromide anion, Br 3 , has also been characterised; it is analogous to triiodide . Bromine oxides are not as well-characterised as chlorine oxides or iodine oxides , as they are all fairly unstable: it

483-422: A major medical sedative, before replacement by shorter-acting drugs. They retain niche uses as antiepileptics . Bromine was discovered independently by two chemists, Carl Jacob Löwig and Antoine Balard , in 1825 and 1826, respectively. 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

552-430: A result of the increasing molecular weight of the halogens down the group, the density and heats of fusion and vaporisation of bromine are again intermediate between those of chlorine and iodine, although all their heats of vaporisation are fairly low (leading to high volatility) thanks to their diatomic molecular structure. The halogens darken in colour as the group is descended: fluorine is a very pale yellow gas, chlorine

621-611: A stronger one than iodine. Conversely, the bromide ion is a weaker reducing agent than iodide, but a stronger one than chloride. These similarities led to chlorine, bromine, and iodine together being classified as one of the original triads of Johann Wolfgang Döbereiner , whose work foreshadowed the periodic law for chemical elements. It is intermediate in atomic radius between chlorine and iodine, and this leads to many of its atomic properties being similarly intermediate in value between chlorine and iodine, such as first ionisation energy , electron affinity , enthalpy of dissociation of

690-419: Is Br ( t 1/2 = 57.04 h). The primary decay mode of isotopes lighter than Br is electron capture to isotopes of selenium ; that of isotopes heavier than Br is beta decay to isotopes of krypton ; and Br may decay by either mode to stable Se or Kr. Br isotopes from Br and heavier undergo beta decay with neutron emission and are of practical importance because they are fission products. Bromine

759-409: Is hydrogen bromide , HBr. It is mainly used in the production of inorganic bromides and alkyl bromides , and as a catalyst for many reactions in organic chemistry. Industrially, it is mainly produced by the reaction of hydrogen gas with bromine gas at 200–400 °C with a platinum catalyst. However, reduction of bromine with red phosphorus is a more practical way to produce hydrogen bromide in

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828-534: Is 331 pm within a layer and 399 pm between layers (compare the van der Waals radius of bromine, 195 pm). This structure means that bromine is a very poor conductor of electricity, with a conductivity of around 5 × 10  Ω  cm just below the melting point, although this is higher than the essentially undetectable conductivity of chlorine. At a pressure of 55  GPa (roughly 540,000 times atmospheric pressure) bromine undergoes an insulator-to-metal transition. At 75 GPa it changes to

897-463: Is a stub . You can help Misplaced Pages by expanding it . Bromine Bromine is a chemical element ; it has symbol Br and atomic number 35. It is a volatile red-brown liquid at room temperature that evaporates readily to form a similarly coloured vapour. Its properties are intermediate between those of chlorine and iodine . Isolated independently by two chemists, Carl Jacob Löwig (in 1825) and Antoine Jérôme Balard (in 1826), its name

966-441: Is a poor solvent, only able to dissolve small molecular compounds such as nitrosyl chloride and phenol , or salts with very low lattice energies such as tetraalkylammonium halides. Nearly all elements in the periodic table form binary bromides. The exceptions are decidedly in the minority and stem in each case from one of three causes: extreme inertness and reluctance to participate in chemical reactions (the noble gases , with

1035-526: Is a seaport town located on the Cheleken Peninsula of the Caspian Sea . It is directly subordinate to the city of Balkanabat in Balkan Province of western Turkmenistan . In November 2022, it was downgraded from city-with-district-status to a town, and alongside Gumdag , it became subordinate to City of Balkanabat . Hazar (also Khazar, a backformation of Russian: Хазар ) was the name of

1104-493: Is a straw-coloured liquid. It may be formed by directly fluorinating bromine at room temperature and is purified through distillation. It reacts violently with water and explodes on contact with flammable materials, but is a less powerful fluorinating reagent than chlorine trifluoride . It reacts vigorously with boron , carbon , silicon , arsenic , antimony , iodine, and sulfur to give fluorides, and will also convert most metals and many metal compounds to fluorides; as such, it

1173-399: Is beneficial for human eosinophils , and is an essential trace element for collagen development in all animals. Hundreds of known organobromine compounds are generated by terrestrial and marine plants and animals, and some serve important biological roles. As a pharmaceutical , the simple bromide ion (Br ) has inhibitory effects on the central nervous system, and bromide salts were once

1242-485: Is desert and the central part is elevated terrain averaging 100 m elevation, with 25 m high cliffs in the central part of the western shore, while the eastern shore is low and sandy. The Peninsula has two spits or bars at the end running meridionally from north to south; the northern or right spit is also known as the Kafaldja Peninsula, while the southern or left spit running towards Ogurja Ada (Ogurchinsky Island)

1311-543: Is difficult to work with as a solvent, because its boiling point is low, it has a small liquid range, its dielectric constant is low and it does not dissociate appreciably into H 2 Br and HBr 2 ions – the latter, in any case, are much less stable than the bifluoride ions ( HF 2 ) due to the very weak hydrogen bonding between hydrogen and bromine, though its salts with very large and weakly polarising cations such as Cs and NR 4 (R = Me , Et , Bu ) may still be isolated. Anhydrous hydrogen bromide

1380-542: Is fairly weak, which corresponds to the general reluctance of the 4p elements arsenic , selenium , and bromine to attain their group oxidation state, as they come after the scandide contraction characterised by the poor shielding afforded by the radial-nodeless 3d orbitals. Like the other carbon–halogen bonds, the C–Br bond is a common functional group that forms part of core organic chemistry . Formally, compounds with this functional group may be considered organic derivatives of

1449-432: Is greenish-yellow, and bromine is a reddish-brown volatile liquid that melts at −7.2 °C and boils at 58.8 °C. (Iodine is a shiny black solid.) This trend occurs because the wavelengths of visible light absorbed by the halogens increase down the group. Specifically, the colour of a halogen, such as bromine, results from the electron transition between the highest occupied antibonding π g molecular orbital and

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1518-569: Is halogen exchange in the presence of excess "halogenating reagent", for example: When a lower bromide is wanted, either a higher halide may be reduced using hydrogen or a metal as a reducing agent, or thermal decomposition or disproportionation may be used, as follows: Most metal bromides with the metal in low oxidation states (+1 to +3) are ionic. Nonmetals tend to form covalent molecular bromides, as do metals in high oxidation states from +3 and above. Both ionic and covalent bromides are known for metals in oxidation state +3 (e.g. scandium bromide

1587-721: Is intermediate in reactivity between chlorine and iodine, and is one of the most reactive elements. Bond energies to bromine tend to be lower than those to chlorine but higher than those to iodine, and bromine is a weaker oxidising agent than chlorine but a stronger one than iodine. This can be seen from the standard electrode potentials of the X 2 /X couples (F, +2.866 V; Cl, +1.395 V; Br, +1.087 V; I, +0.615 V; At, approximately +0.3 V). Bromination often leads to higher oxidation states than iodination but lower or equal oxidation states to chlorination. Bromine tends to react with compounds including M–M, M–H, or M–C bonds to form M–Br bonds. The simplest compound of bromine

1656-614: Is known as the Dervish Peninsula. From time to time, such as in 1995, the Cheleken Peninsula becomes an island again when the level of the waters of the Caspian rises. There are mud volcanoes in the Cheleken Peninsula. The Cheleken Peninsula was formerly an island . It was plotted on a rough map for the first time in 1715 by Alexander Bekovich-Cherkassky as 'Chereken Island'. The area was mapped by Fedor Ivanovich Soimonov during

1725-459: Is liquid under these conditions is mercury . At high temperatures, organobromine compounds readily dissociate to yield free bromine atoms, a process that stops free radical chemical chain reactions . This effect makes organobromine compounds useful as fire retardants , and more than half the bromine produced worldwide each year is put to this purpose. The same property causes ultraviolet sunlight to dissociate volatile organobromine compounds in

1794-783: Is mostly ionic, but aluminium bromide is not). Silver bromide is very insoluble in water and is thus often used as a qualitative test for bromine. The halogens form many binary, diamagnetic interhalogen compounds with stoichiometries XY, XY 3 , XY 5 , and XY 7 (where X is heavier than Y), and bromine is no exception. Bromine forms a monofluoride and monochloride, as well as a trifluoride and pentafluoride. Some cationic and anionic derivatives are also characterised, such as BrF 2 , BrCl 2 , BrF 2 , BrF 4 , and BrF 6 . Apart from these, some pseudohalides are also known, such as cyanogen bromide (BrCN), bromine thiocyanate (BrSCN), and bromine azide (BrN 3 ). The pale-brown bromine monofluoride (BrF)

1863-485: Is named as a bromide as it is analogous to the other nitrogen trihalides.) Bromination of metals with Br 2 tends to yield lower oxidation states than chlorination with Cl 2 when a variety of oxidation states is available. Bromides can be made by reaction of an element or its oxide, hydroxide, or carbonate with hydrobromic acid, and then dehydrated by mildly high temperatures combined with either low pressure or anhydrous hydrogen bromide gas. These methods work best when

1932-621: Is obtained by burning hydrogen in bromine. Brominated flame retardants represent a commodity of growing importance, and make up the largest commercial 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 radicals, oxygen radicals, and hydroxyl radicals react with hydrobromic acid to form less reactive bromine radicals (i.e., free bromine atoms). Bromine atoms may also react directly with other radicals to help terminate

2001-427: Is the third halogen , being a nonmetal in group 17 of the periodic table. Its properties are thus similar to those of fluorine , chlorine , and iodine , and tend to be intermediate between those of the two neighbouring halogens, chlorine, and iodine. Bromine has the electron configuration [Ar]4s 3d 4p , with the seven electrons in the fourth and outermost shell acting as its valence electrons . Like all halogens, it

2070-515: Is then condensed and purified. Today, bromine is transported in large-capacity metal drums or lead-lined tanks that can hold hundreds of kilograms or even tonnes of bromine. The bromine industry is about one-hundredth the size of the chlorine industry. Laboratory production is unnecessary because bromine is commercially available and has a long shelf life. A wide variety of organobromine compounds are used in industry . Some are prepared from bromine and others are prepared from hydrogen bromide , which

2139-416: Is thus one electron short of a full octet, and is hence a strong oxidising agent, reacting with many elements in order to complete its outer shell. Corresponding to periodic trends , it is intermediate in electronegativity between chlorine and iodine (F: 3.98, Cl: 3.16, Br: 2.96, I: 2.66), and is less reactive than chlorine and more reactive than iodine. It is also a weaker oxidising agent than chlorine, but

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2208-515: Is unstable at room temperature, disproportionating quickly and irreversibly into bromine, bromine trifluoride, and bromine pentafluoride. It thus cannot be obtained pure. It may be synthesised by the direct reaction of the elements, or by the comproportionation of bromine and bromine trifluoride at high temperatures. Bromine monochloride (BrCl), a red-brown gas, quite readily dissociates reversibly into bromine and chlorine at room temperature and thus also cannot be obtained pure, though it can be made by

2277-416: Is used to oxidise uranium to uranium hexafluoride in the nuclear power industry. Refractory oxides tend to be only partially fluorinated, but here the derivatives KBrF 4 and BrF 2 SbF 6 remain reactive. Bromine trifluoride is a useful nonaqueous ionising solvent, since it readily dissociates to form BrF 2 and BrF 4 and thus conducts electricity. Bromine pentafluoride (BrF 5 )

2346-400: Is used, either alone or in combination with silver chloride and silver iodide , as the light sensitive constituent of photographic emulsions . 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

2415-578: The Caspian Expedition , which surveyed the Caspian Sea from 1719 to 1727 and in some maps of the 18th to 19th centuries it appeared as 'Neftyanoy' or as 'Neftonia'. The island was also described later by G. S. Karelin in 1832. Karelin commented that there were four types of crude oil in the Cheleken Peninsula. The island merged with the mainland after 1937. Hazar, Turkmenistan Hazar (until 1999 known as Çeleken , also written Cheleken ; Russian : Челекен ; Persian : Chaharken چهارکن )

2484-451: The Dead Sea contains 0.4% bromide ions. It is from these sources that bromine extraction is mostly economically feasible. Bromine is the tenth most abundant element in seawater. The main sources of bromine production are Israel and Jordan . The element is liberated by halogen exchange, using chlorine gas to oxidise Br to Br 2 . This is then removed with a blast of steam or air, and

2553-612: The Latin word muria ("brine"). 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 . In his publication, Balard stated that he changed the name from muride to brôme on

2622-445: The atmosphere to yield free bromine atoms, causing ozone depletion . As a result, many organobromine compounds—such as the pesticide methyl bromide —are no longer used. Bromine compounds are still used in well drilling fluids , in photographic film , and as an intermediate in the manufacture of organic chemicals. Large amounts of bromide salts are toxic from the action of soluble bromide ions, causing bromism . However, bromine

2691-937: The hypobromite anion. So-called " bromine dioxide ", a pale yellow crystalline solid, may be better formulated as bromine perbromate , BrOBrO 3 . It is thermally unstable above −40 °C, violently decomposing to its elements at 0 °C. Dibromine trioxide , syn -BrOBrO 2 , is also known; it is the anhydride of hypobromous acid and bromic acid . It is an orange crystalline solid which decomposes above −40 °C; if heated too rapidly, it explodes around 0 °C. A few other unstable radical oxides are also known, as are some poorly characterised oxides, such as dibromine pentoxide , tribromine octoxide , and bromine trioxide. The four oxoacids , hypobromous acid (HOBr), bromous acid (HOBrO), bromic acid (HOBrO 2 ), and perbromic acid (HOBrO 3 ), are better studied due to their greater stability, though they are only so in aqueous solution. When bromine dissolves in aqueous solution,

2760-543: The American Civil War, before the publications of Joseph Lister and Pasteur . Potassium bromide and sodium bromide were used as anticonvulsants and sedatives in the late 19th and early 20th centuries, but were gradually superseded by chloral hydrate and then by the barbiturates . In the early years of the First World War , bromine compounds such as xylyl bromide were used as poison gas . Bromine

2829-513: The Earth's crust, the high solubility of the bromide ion (Br ) has caused its accumulation in the oceans. Commercially the element is easily extracted from brine evaporation ponds , mostly in the United States and Israel . The mass of bromine in the oceans is about one three-hundredth that of chlorine. At standard conditions for temperature and pressure it is a liquid; the only other element that

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2898-406: The Earth's crustal rocks, and then only as bromide salts. It is the 46th most abundant element in Earth's crust. It is significantly more abundant in the oceans, resulting from long-term leaching . There, it makes up 65 parts per million, corresponding to a ratio of about one bromine atom for every 660 chlorine atoms. Salt lakes and brine wells may have higher bromine concentrations: for example,

2967-461: The US. This application has declined since the 1970s due to environmental regulations (see below). Brominated vegetable oil (BVO), a complex mixture of plant-derived triglycerides that have been reacted to contain atoms of the element bromine bonded to the molecules, is used primarily to help emulsify citrus-flavored soft drinks, preventing them from separating during distribution. Poisonous bromomethane

3036-478: The X 2 molecule (X = Cl, Br, I), ionic radius, and X–X bond length. The volatility of bromine accentuates its very penetrating, choking, and unpleasant odour. All four stable halogens experience intermolecular van der Waals forces of attraction, and their strength increases together with the number of electrons among all homonuclear diatomic halogen molecules. Thus, the melting and boiling points of bromine are intermediate between those of chlorine and iodine. As

3105-478: The bromate anion is stable to disproportionation in both acidic and aqueous solutions. Bromic acid is a strong acid. Bromides and bromates may comproportionate to bromine as follows: There were many failed attempts to obtain perbromates and perbromic acid, leading to some rationalisations as to why they should not exist, until 1968 when the anion was first synthesised from the radioactive beta decay of unstable SeO 4 . Today, perbromates are produced by

3174-840: The bromide anion. Due to the difference of electronegativity between bromine (2.96) and carbon (2.55), the carbon atom in a C–Br bond is electron-deficient and thus electrophilic . The reactivity of organobromine compounds resembles but is intermediate between the reactivity of organochlorine and organoiodine compounds . For many applications, organobromides represent a compromise of reactivity and cost. Organobromides are typically produced by additive or substitutive bromination of other organic precursors. Bromine itself can be used, but due to its toxicity and volatility, safer brominating reagents are normally used, such as N -bromosuccinimide . The principal reactions for organobromides include dehydrobromination , Grignard reactions , reductive coupling , and nucleophilic substitution . Organobromides are

3243-440: The bromide product is stable to hydrolysis; otherwise, the possibilities include high-temperature oxidative bromination of the element with bromine or hydrogen bromide, high-temperature bromination of a metal oxide or other halide by bromine, a volatile metal bromide, carbon tetrabromide , or an organic bromide. For example, niobium(V) oxide reacts with carbon tetrabromide at 370 °C to form niobium(V) bromide . Another method

3312-459: The bromine with diethyl ether . After evaporation of the ether, a brown liquid remained. With this liquid as a sample of 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. Balard found bromine chemicals in the ash of seaweed from the salt marshes of Montpellier . The seaweed

3381-472: The exception of xenon in the very unstable XeBr 2 ); extreme nuclear instability hampering chemical investigation before decay and transmutation (many of the heaviest elements beyond bismuth ); and having an electronegativity higher than bromine's ( oxygen , nitrogen , fluorine , and chlorine ), so that the resultant binary compounds are formally not bromides but rather oxides, nitrides, fluorides, or chlorides of bromine. (Nonetheless, nitrogen tribromide

3450-737: The final polymers. A number of gaseous or highly volatile brominated halomethane compounds are non-toxic and make superior fire suppressant agents by this same mechanism, and are particularly effective in enclosed spaces such as submarines, airplanes, and spacecraft. However, they are expensive and their production and use has been greatly curtailed due to their effect as ozone-depleting agents. They are no longer used in routine fire extinguishers, but retain niche uses in aerospace and military automatic fire suppression applications. They include bromochloromethane (Halon 1011, CH 2 BrCl), bromochlorodifluoromethane (Halon 1211, CBrClF 2 ), and bromotrifluoromethane (Halon 1301, CBrF 3 ). Silver bromide

3519-521: The following reactions occur: Hypobromous acid is unstable to disproportionation. The hypobromite ions thus formed disproportionate readily to give bromide and bromate: Bromous acids and bromites are very unstable, although the strontium and barium bromites are known. More important are the bromates , which are prepared on a small scale by oxidation of bromide by aqueous hypochlorite , and are strong oxidising agents. Unlike chlorates, which very slowly disproportionate to chloride and perchlorate,

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3588-501: The free radical chain-reactions that characterise combustion. To make brominated polymers and plastics, bromine-containing compounds can be incorporated into the polymer during polymerisation . One method is to include a relatively small amount of brominated monomer during the polymerisation process. For example, vinyl bromide can be used in the production of polyethylene , polyvinyl chloride or polypropylene . Specific highly brominated molecules can also be added that participate in

3657-431: The laboratory: At room temperature, hydrogen bromide is a colourless gas, like all the hydrogen halides apart from hydrogen fluoride , since hydrogen cannot form strong hydrogen bonds to the large and only mildly electronegative bromine atom; however, weak hydrogen bonding is present in solid crystalline hydrogen bromide at low temperatures, similar to the hydrogen fluoride structure, before disorder begins to prevail as

3726-581: The late 1950s, oil production index went up again. Dragon Oil , a petroleum extraction firm owned by Emirates National Oil Company , is the major employer in Hazar and operates the oil loading terminal there. Following planned renovations and upgrades, the Hazar iodine plant will have a design capacity of 300 tonnes of iodine, plus 4500 tonnes of bromine per year. 39°26′42″N 53°06′54″E  /  39.445°N 53.115°E  / 39.445; 53.115 This Turkmenistan location article

3795-476: The lowest vacant antibonding σ u molecular orbital. The colour fades at low temperatures so that solid bromine at −195 °C is pale yellow. Like solid chlorine and iodine, solid bromine crystallises in the orthorhombic crystal system , in a layered arrangement of Br 2 molecules. The Br–Br distance is 227 pm (close to the gaseous Br–Br distance of 228 pm) and the Br···Br distance between molecules

3864-417: The most common organohalides in nature, even though the concentration of bromide is only 0.3% of that for chloride in sea water, because of the easy oxidation of bromide to the equivalent of Br , a potent electrophile. The enzyme bromoperoxidase catalyzes this reaction. The oceans are estimated to release 1–2 million tons of bromoform and 56,000 tons of bromomethane annually. An old qualitative test for

3933-473: The oxidation of alkaline bromate solutions by fluorine gas. Excess bromate and fluoride are precipitated as silver bromate and calcium fluoride , and the perbromic acid solution may be purified. The perbromate ion is fairly inert at room temperature but is thermodynamically extremely oxidising, with extremely strong oxidising agents needed to produce it, such as fluorine or xenon difluoride . The Br–O bond in BrO 4

4002-502: The polymerisation process. For example, tetrabromobisphenol A can be added to polyesters or epoxy resins, where it becomes part of the polymer. Epoxies used in printed circuit boards are normally made from such flame retardant resins , indicated by the FR in the abbreviation of the products ( FR-4 and FR-2 ). In some cases, the bromine-containing compound may be added after polymerisation. For example, decabromodiphenyl ether can be added to

4071-454: The presence of the alkene functional group is that alkenes turn brown aqueous bromine solutions colourless, forming a bromohydrin with some of the dibromoalkane also produced. The reaction passes through a short-lived strongly electrophilic bromonium intermediate. This is an example of a halogen addition reaction . Bromine is significantly less abundant in the crust than fluorine or chlorine, comprising only 2.5  parts per million of

4140-507: The proposal of M. Anglada. The name brôme (bromine) derives from the Greek βρῶμος ( brômos , "stench"). Other sources claim that the French chemist and physicist Joseph-Louis Gay-Lussac suggested the name brôme for the characteristic smell of the vapors. Bromine was not produced in large quantities until 1858, when the discovery of salt deposits in Stassfurt enabled its production as

4209-538: The reversible direct reaction of its elements in the gas phase or in carbon tetrachloride . Bromine monofluoride in ethanol readily leads to the monobromination of the aromatic compounds PhX ( para -bromination occurs for X = Me, Bu , OMe, Br; meta -bromination occurs for the deactivating X = –CO 2 Et, –CHO, –NO 2 ); this is due to heterolytic fission of the Br–F bond, leading to rapid electrophilic bromination by Br . At room temperature, bromine trifluoride (BrF 3 )

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4278-631: The temperature is raised. Aqueous hydrogen bromide is known as hydrobromic acid , which is a strong acid (p K a = −9) because the hydrogen bonds to bromine are too weak to inhibit dissociation. The HBr/H 2 O system also involves many hydrates HBr· n H 2 O for n = 1, 2, 3, 4, and 6, which are essentially salts of bromine anions and hydronium cations . Hydrobromic acid forms an azeotrope with boiling point 124.3 °C at 47.63 g HBr per 100 g solution; thus hydrobromic acid cannot be concentrated beyond this point by distillation. Unlike hydrogen fluoride , anhydrous liquid hydrogen bromide

4347-451: The two isotopes in nature is helpful in identification of bromine containing compounds using mass spectroscopy. Other bromine isotopes are all radioactive, with half-lives too short to occur in nature. Of these, the most important are Br ( t 1/2 = 17.7 min), Br ( t 1/2 = 4.421 h), and Br ( t 1/2 = 35.28 h), which may be produced from the neutron activation of natural bromine. The most stable bromine radioisotope

4416-506: The wealth of petroleum found on the peninsula. This city and area are rich in petroleum oil reserves. As far back as the 1st century, the Greek philosopher Strabo said, "They say, diggers opened oily springs near the Okh River. Indeed, if a country has alkaline, asphalt, sticky, sulfurous waters, it is most likely to have oily springs. Only, their scarceness makes this fact miraculous." In 1743,

4485-399: Was derived from Ancient Greek βρῶμος (bromos)  'stench', referring to its sharp and pungent smell. Elemental bromine is very reactive and thus does not occur as a free element in nature. Instead, it can be isolated from colourless soluble crystalline mineral halide salts analogous to table salt , a property it shares with the other halogens . While it is rather rare in

4554-414: Was first synthesised in 1930. It is produced on a large scale by direct reaction of bromine with excess fluorine at temperatures higher than 150 °C, and on a small scale by the fluorination of potassium bromide at 25 °C. It also reacts violently with water and is a very strong fluorinating agent, although chlorine trifluoride is still stronger. Although dibromine is a strong oxidising agent with

4623-430: Was once thought that they could not exist at all. Dibromine monoxide is a dark-brown solid which, while reasonably stable at −60 °C, decomposes at its melting point of −17.5 °C; it is useful in bromination reactions and may be made from the low-temperature decomposition of bromine dioxide in a vacuum. It oxidises iodine to iodine pentoxide and benzene to 1,4-benzoquinone ; in alkaline solutions, it gives

4692-418: 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 were intermediate between those of chlorine and iodine; thus 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

4761-573: Was widely used as pesticide to fumigate soil and to fumigate housing, by the tenting method. Ethylene bromide was similarly used. These volatile organobromine compounds are all now regulated as ozone depletion agents. The Montreal Protocol on Substances that Deplete the Ozone Layer scheduled the phase out for the ozone depleting chemical by 2005, and organobromide pesticides are no longer used (in housing fumigation they have been replaced by such compounds as sulfuryl fluoride , which contain neither

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