Names | |
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Preferred IUPAC name Hexabromobenzene | |
Other names
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Identifiers | |
3D model (JSmol) | |
ChEMBL | |
ChemSpider | |
ECHA InfoCard | 100.001.613 |
EC Number |
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PubChem CID | |
UNII | |
UN number | 3077 |
CompTox Dashboard (EPA) | |
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Properties | |
C6Br6 | |
Molar mass | 551.490 g·mol−1 |
Appearance | Monoclinic needles or white powder. [1] |
Odor | Odorless [2] |
Melting point | 327 °C (621 °F; 600 K) [2] |
0.16x10−3 mg/L (insoluble) [1] | |
Solubility | Slightly soluble in Ethanol, Diethyl ether [3] |
Solubility in Acetic acid | Soluble [3] |
Solubility in Benzene | 10% [4] |
Solubility in Chloroform | 10% [4] |
Solubility in Petroleum ether | 10% [4] |
log P | 6.07 [1] |
Hazards | |
GHS labelling: [2] | |
Danger [2] | |
H302, H312, H315, H319, H332, H335, H413 [1] | |
P261, P264, P270, P271, P280, P301+P312, P302+P352, P304+P312, P304+P340, P305+P351+P338, P312, P321, P322, P330, P332+P313, P362, P363, P403+P233, P405, P501 [1] | |
NFPA 704 (fire diamond) | |
Safety data sheet (SDS) | LCSS 6905 |
Related compounds | |
Related compounds | Hexafluorobenzene Hexachlorobenzene Hexaiodobenzene |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). |
Hexabromobenzene (HBB) is an aryl bromide and a six-substituted bromobenzene in which all six positions of the central benzene ring are bonded to a bromine atom.
Hexabromobenzene has seen use in high voltage capacitors as a flame retardant. [5] It also has applications as a starting material in the formation of thin graphene-like films for low cost energy storage devices and capacitors. [6]
It can be prepared by reacting benzene (C6H6) with 6 equivalents of bromine (Br2) in the presence of heat and UV light. This reaction is known as the bromination of Benzene:
Apart from hexabromobenzene, the reaction produces six equivalents of Hydrogen Bromide (HBr).
The reaction to form Hexabromobenzene, known as Bromination of Benzene, involves substitution of hydrogens by bromides. Electrophilic aromatic substitution [7] is a general method of derivatizing hexabromobenzene. Benzene is sufficiently nucleophilic that it undergoes substitution by bromide ions to give the substituted derivatives, hexabromobenzene. [8]
Hexabromobenzene is a white powder in physical form. It's not soluble in water but is soluble in ethanol, ether, and benzene. Molecular weigh t is 551.7 g/mol. Melting point of 327 °C. Whiteness percent of 93.0. Its bromine content is above 86%, and it represents high efficacy. Incompatible with strong oxidizing agents. It has excellent integration flexibility with several resins and plastics due to its solubility in substances like ethanol, ether, and benzene. [9]
Hexabromobenzene poses significant dangers due to its toxicity profile as classified by the GHS (Globally Harmonized System of Classification and Labeling of Chemicals). Classified as GHS07, HBB exhibits acute toxicity via oral, dermal, and inhalation routes, categorizing it under category 4 for this hazard. Additionally, it induces skin and eye irritation, classified under category 2 for both. Moreover, HBB is known to cause skin sensitization (category 1) and specific target organ toxicity upon single exposure (category 3), with the respiratory system being the primary target organ. [10]
Notably, the acute toxicity of HBB is observed to decrease with an increase in the number of bromine atoms in the molecule. [11] However, the potential for necrotic changes varies based on the position of these bromine atoms within the molecule. There are severe health risks associated with HBB exposure, warranting careful handling and stringent safety measures in its use and management. [10]
Hexabromobenzene finds extensive use as a fire retardant additive in a range of materials including plastics, paper, and electrical goods, where it serves as a top-tier flame retardant. With an impressive melting point of 327 °C and a high bromide content of 86%, HBB significantly enhances the fire safety of these materials. [12] Its ability to suppress combustion effectively makes it a sought-after choice in industries concerned with fire prevention. However, its widespread application also leads to its dispersion in the environment. Additionally, HBB can undergo proto bromination reactions when treated with sodium methoxide in methanol and ethyl methyl ketone, yielding a mixture of tribromobenzene.Despite its efficacy in fire retardation, the environmental and health impacts of HBB underscore the importance of careful handling and monitoring in its utilization. [10]
The influences of five organic cosolvents (acetone, methanol, ethanol, THF, or DMSO) on hexabromobenzene degradation catalyzed by one typical reactive material montmorillonite-templated sub nanoscale zero-valent iron (CZVI) was investigated. The CZVI-catalyzed HBB degradation mechanism was proposed as the electron transfer between zero-valent iron and HBB, which led to formation of four debromination products. [11]
Hexabromobenzene also serves as one of the key polyhalogenated aromatic compounds used in the bottom-up synthesis process of graphene-like films. Through electrochemical reduction, HBB contributes to the formation of polyaromatic ring structures alongside other compounds such as hexafluorobenzene (HFB) and hexachlorobenzene (HCB). It facilitates the creation of graphene-like carbon films upon thermal annealing, offering a cost-effective approach without the need for sophisticated equipment. [6]
Hexabromobenzene was used in a study investigating its metabolic fate in female rats, wherein the substance was orally administered at doses of 16.6 mg/kg body weight every other day for a span of 2 weeks. Analysis of the rats' excreta revealed the presence of various metabolites, including unchanged HBB, pentabromobenzene, as well as oxygen- and sulfur-containing compounds. [13]
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 and Antoine Jérôme Balard, its name was derived from Ancient Greek βρῶμος (bromos) 'stench', referring to its sharp and pungent smell.
The halogens are a group in the periodic table consisting of six chemically related elements: fluorine (F), chlorine (Cl), bromine (Br), iodine (I), and the radioactive elements astatine (At) and tennessine (Ts), though some authors would exclude tennessine as its chemistry is unknown and is theoretically expected to be more like that of gallium. In the modern IUPAC nomenclature, this group is known as group 17.
Toluene, also known as toluol, is a substituted aromatic hydrocarbon with the chemical formula C6H5CH3, often abbreviated as PhCH3, where Ph stands for the phenyl group. It is a colorless, water-insoluble liquid with the odor associated with paint thinners. It is a mono-substituted benzene derivative, consisting of a methyl group (CH3) attached to a phenyl group by a single bond. As such, its systematic IUPAC name is methylbenzene. Toluene is predominantly used as an industrial feedstock and a solvent.
In organic chemistry, the phenyl group, or phenyl ring, is a cyclic group of atoms with the formula C6H5, and is often represented by the symbol Ph or Ø. The phenyl group is closely related to benzene and can be viewed as a benzene ring, minus a hydrogen, which may be replaced by some other element or compound to serve as a functional group. A phenyl group has six carbon atoms bonded together in a hexagonal planar ring, five of which are bonded to individual hydrogen atoms, with the remaining carbon bonded to a substituent. Phenyl groups are commonplace in organic chemistry. Although often depicted with alternating double and single bonds, the phenyl group is chemically aromatic and has equal bond lengths between carbon atoms in the ring.
In chemistry, halogenation is a chemical reaction which introduces one or more halogens into a chemical compound. Halide-containing compounds are pervasive, making this type of transformation important, e.g. in the production of polymers, drugs. This kind of conversion is in fact so common that a comprehensive overview is challenging. This article mainly deals with halogenation using elemental halogens. Halides are also commonly introduced using salts of the halides and halogen acids. Many specialized reagents exist for and introducing halogens into diverse substrates, e.g. thionyl chloride.
In organic chemistry, an aryl halide is an aromatic compound in which one or more hydrogen atoms, directly bonded to an aromatic ring are replaced by a halide. Haloarenes are different from haloalkanes because they exhibit many differences in methods of preparation and properties. The most important members are the aryl chlorides, but the class of compounds is so broad that there are many derivatives and applications.
Bromobenzene is an aryl bromide and the simplest of the bromobenzenes, consisting of a benzene ring substituted with one bromine atom. Its chemical formula is C6H5Br. It is a colourless liquid although older samples can appear yellow. It is a reagent in organic synthesis.
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. 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.
Carbon tetrabromide, CBr4, also known as tetrabromomethane, is a bromide of carbon. Both names are acceptable under IUPAC nomenclature.
Zinc bromide (ZnBr2) is an inorganic compound with the chemical formula ZnBr2. It is a colourless salt that shares many properties with zinc chloride (ZnCl2), namely a high solubility in water forming acidic solutions, and good solubility in organic solvents. It is hygroscopic and forms a dihydrate ZnBr2·2H2O.
Arsenic tribromide is an inorganic compound with the formula AsBr3, it is a bromide of arsenic. Arsenic is a chemical element that has the symbol As and atomic number 33. This pyramidal molecule is the only known binary arsenic bromide. AsBr3 is noteworthy for its very high refractive index of approximately 2.3. It also has a very high diamagnetic susceptibility. The compound exists as colourless deliquescent crystals that fume in moist air.
Vanadium(III) bromide, also known as vanadium tribromide, describes the inorganic compounds with the formula VBr3 and its hydrates. The anhydrous material is a green-black solid. In terms of its structure, the compound is polymeric with octahedral vanadium(III) surrounded by six bromide ligands.
Bromobenzenes are a group of aryl bromides/halobenzenes consisting of one or more bromine atoms as substituents on a benzene core. They have the formula C6H6–nBrn, where n = 1–6 is the number of bromine atoms. Depending on the number of bromine substituents, there may be several constitutional isomers possible.
Tin(II) bromide is a chemical compound of tin and bromine with a chemical formula of SnBr2. Tin is in the +2 oxidation state. The stability of tin compounds in this oxidation state is attributed to the inert pair effect.
Bromine compounds are compounds containing the element bromine (Br). These compounds usually form the -1, +1, +3 and +5 oxidation states. Bromine 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 X2/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.
Tetralin (1,2,3,4-tetrahydronaphthalene) is a hydrocarbon having the chemical formula C10H12. It is a partially hydrogenated derivative of naphthalene. It is a colorless liquid that is used as a hydrogen-donor solvent.
Dibromomethane or methylene bromide, or methylene dibromide is a halomethane with the formula CH2Br2. It is slightly soluble in water but very soluble in organic solvents. It is a colorless liquid.
Barium bromide is the chemical compound with the formula BaBr2. It is ionic and hygroscopic in nature.
Organobromine chemistry is the study of the synthesis and properties of organobromine compounds, also called organobromides, which are organic compounds that contain carbon bonded to bromine. The most pervasive is the naturally produced bromomethane.
Chromium(III) bromide is an inorganic compound with the chemical formula CrBr3. It is a dark colored solid that appears green in transmitted light but red with reflected light. It is used as a precursor to catalysts for the oligomerization of ethylene.