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 the Ancient Greek βρῶμος (bromos) meaning "stench", referring to its sharp and pungent smell.
Hydrogen bromide is the inorganic compound with the formula HBr. It is a hydrogen halide consisting of hydrogen and bromine. A colorless gas, it dissolves in water, forming hydrobromic acid, which is saturated at 68.85% HBr by weight at room temperature. Aqueous solutions that are 47.6% HBr by mass form a constant-boiling azeotrope mixture that boils at 124.3 °C (255.7 °F). Boiling less concentrated solutions releases H2O until the constant-boiling mixture composition is reached.
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.
Copper(II) bromide (CuBr2) is a chemical compound that forms an unstable tetrahydrate CuBr2·4H2O. It is used in photographic processing as an intensifier and as a brominating agent in organic synthesis.
Zirconium(IV) bromide is the inorganic compound with the formula ZrBr4. This colourless solid is the principal precursor to other Zr–Br compounds.
The hypobromite ion, also called alkaline bromine water, is BrO−. Bromine is in the +1 oxidation state. The Br–O bond length is 1.82 Å. Hypobromite is the bromine compound analogous to hypochlorites found in common bleaches, and in immune cells. In many ways, hypobromite functions in the same manner as hypochlorite, and is also used as a germicide and antiparasitic in both industrial applications, and in the immune system.
Gallium(III) bromide (GaBr3) is a chemical compound, and one of four gallium trihalides.
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.
Iron(II) bromide refers to inorganic compounds with the chemical formula FeBr2(H2O)x. The anhydrous compound (x = 0) is a yellow or brownish-colored paramagnetic solid. The tetrahydrate is also known, all being pale colored solids. They are common precursor to other iron compounds.
Copper(I) bromide is the chemical compound with the formula CuBr. This diamagnetic solid adopts a polymeric structure akin to that for zinc sulfide. The compound is widely used in the synthesis of organic compounds and as a lasing medium in copper bromide lasers.
Caesium bromide or cesium bromide is an ionic compound of caesium and bromine with the chemical formula CsBr. It is a white or transparent solid with melting point at 636 °C that readily dissolves in water. Its bulk crystals have the cubic CsCl structure, but the structure changes to the rocksalt type in nanometer-thin film grown on mica, LiF, KBr or NaCl substrates.
The thallium halides include monohalides, where thallium has oxidation state +1, trihalides in which thallium generally has oxidation state +3, and some intermediate halides containing thallium with mixed +1 and +3 oxidation states. These materials find use in specialized optical settings, such as focusing elements in research spectrophotometers. Compared to the more common zinc selenide-based optics, materials such as thallium bromoiodide enable transmission at longer wavelengths. In the infrared, this allows for measurements as low as 350 cm−1 (28 μm), whereas zinc selenide is opaque by 21.5 μm, and ZnSe optics are generally only usable to 650 cm−1 (15 μm).
There are three sets of Indium halides, the trihalides, the monohalides, and several intermediate halides. In the monohalides the oxidation state of indium is +1 and their proper names are indium(I) fluoride, indium(I) chloride, indium(I) bromide and indium(I) iodide.
Barium bromide is the chemical compound with the formula BaBr2. It is ionic and hygroscopic in nature.
Beryllium bromide is the chemical compound with the formula BeBr2. It is very hygroscopic and dissolves well in water. The compound is a polymer with tetrahedral coordinated Be centres.
Bromous acid is the inorganic compound with the formula of HBrO2. It is an unstable compound, although salts of its conjugate base – bromites – have been isolated. In acidic solution, bromites decompose to bromine.
Xylylene dibromide is an organic compound with the formula C6H4(CH2Br)2. It is an off-white solid that, like other benzyl halides, a strong lachrymator. It is a useful reagent owing to the convenient reactivity of the two C-Br bonds. Two other isomers are known, para- and meta-xylylene dibromide.
