In chemistry

Chemistry

Chemistry is the science of matter, especially its chemical reactions, but also its composition, structure and properties. Chemistry is concerned with atoms and their interactions with other atoms, and particularly with the properties of chemical bonds....

, the perbromate ion is the anion

Ion

An ion is an atom or molecule in which the total number of electrons is not equal to the total number of protons, giving it a net positive or negative electrical charge. The name was given by physicist Michael Faraday for the substances that allow a current to pass between electrodes in a...

 having the chemical formula . It is an oxyanion

Oxyanion

An oxyanion or oxoanion is a chemical compound with the generic formula AxOyz− . Oxoanions are formed by a large majority of the chemical elements. The formulae of simple oxoanions are determined by the octet rule...

 of bromine

Bromine

Bromine ") is a chemical element with the symbol Br, an atomic number of 35, and an atomic mass of 79.904. It is in the halogen element group. The element was isolated independently by two chemists, Carl Jacob Löwig and Antoine Jerome Balard, in 1825–1826...

, the conjugate base of perbromic acid

Perbromic acid

The compound perbromic acid is the inorganic compound with the formula HBrO4. It is an oxoacid of bromine. Perbromic acid is unstable and cannot be formed by displacement of chlorine from perchlorate, as periodates are prepared. It can only be made by protonation of the perbromate ion.Perbromic...

, in which bromine has the oxidation state

Oxidation state

In chemistry, the oxidation state is an indicator of the degree of oxidation of an atom in a chemical compound. The formal oxidation state is the hypothetical charge that an atom would have if all bonds to atoms of different elements were 100% ionic. Oxidation states are typically represented by...

 +7. Unlike its chlorine

Chlorine

Chlorine is the chemical element with atomic number 17 and symbol Cl. It is the second lightest halogen, found in the periodic table in group 17. The element forms diatomic molecules under standard conditions, called dichlorine...

 and iodine

Iodine

Iodine is a chemical element with the symbol I and atomic number 53. The name is pronounced , , or . The name is from the , meaning violet or purple, due to the color of elemental iodine vapor....

 analogs (perchlorate

Perchlorate

Perchlorates are the salts derived from perchloric acid . They occur both naturally and through manufacturing. They have been used as a medicine for more than 50 years to treat thyroid gland disorders. They are used extensively within the pyrotechnics industry, and ammonium perchlorate is also a...

 and periodate

Periodate

Periodate is an anion composed of iodine and oxygen. Periodates include two forms. The metaperiodate ion is IO4−; the orthoperiodate ion is IO65−. Usually both forms are called periodates. Periodate is the conjugate base of periodic acid....

), it is difficult to synthesize. It has tetrahedral molecular geometry

Tetrahedral molecular geometry

In a tetrahedral molecular geometry a central atom is located at the center with four substituents that are located at the corners of a tetrahedron. The bond angles are cos−1 ≈ 109.5° when all four substituents are the same, as in CH4. This molecular geometry is common throughout the first...

.

The term perbromate also refers to a compound that contains the anion or the functional group

Functional group

In organic chemistry, functional groups are specific groups of atoms within molecules that are responsible for the characteristic chemical reactions of those molecules. The same functional group will undergo the same or similar chemical reaction regardless of the size of the molecule it is a part of...

.

The perbromate ion is a strong oxidizing agent. The reduction potential for the BrO₄⁻/Br⁻

Bromide

A bromide is a chemical compound containing bromide ion, that is bromine atom with effective charge of −1. The class name can include ionic compounds such as caesium bromide or covalent compounds such as sulfur dibromide.-Natural occurrence:...

 couple is +0.69 V at pH 14. This is comparable to selenite

Selenite

Selenite, satin spar, desert rose, and gypsum flower are four varieties of the mineral gypsum; all four varieties show obvious crystalline structure...

's reduction potential.

Synthesis

Attempted syntheses of perbromates were unsuccessful until 1968, when it was finally obtained by the beta decay

Beta decay

In nuclear physics, beta decay is a type of radioactive decay in which a beta particle is emitted from an atom. There are two types of beta decay: beta minus and beta plus. In the case of beta decay that produces an electron emission, it is referred to as beta minus , while in the case of a...

 of selenium-83

Selenium

Selenium is a chemical element with atomic number 34, chemical symbol Se, and an atomic mass of 78.96. It is a nonmetal, whose properties are intermediate between those of adjacent chalcogen elements sulfur and tellurium...

 in a selenate

Selenate

The selenate ion is SeO42–.Selenates are analogous to sulfates and have similar chemistry. They are highly soluble in aqueous solutions at ambient temperatures....

 salt:

⁸³SeO₄²⁻ → ⁸³BrO₄⁻ + β⁻

Subsequently, it was successfully synthesized again by the electrolysis

Electrolysis

In chemistry and manufacturing, electrolysis is a method of using a direct electric current to drive an otherwise non-spontaneous chemical reaction...

 of , although only in low yield. Later, it was obtained by the oxidation of bromate

Bromate

The bromate anion, BrO, is a bromine-based oxoanion. A bromate is a chemical compound that contains this ion. Examples of bromates include sodium bromate, , and potassium bromate, .Bromates are formed many different ways in municipal drinking water...

 with xenon difluoride

Xenon difluoride

Xenon difluoride is a powerful fluorinating agent with the chemical formula , and one of the most stable xenon compounds. Like most covalent inorganic fluorides it is moisture sensitive. It decomposes on contact with light or water vapour. Xenon difluoride is a dense, white crystalline solid. It...

. Once perbromates are obtained, perbromic acid

Perbromic acid

The compound perbromic acid is the inorganic compound with the formula HBrO4. It is an oxoacid of bromine. Perbromic acid is unstable and cannot be formed by displacement of chlorine from perchlorate, as periodates are prepared. It can only be made by protonation of the perbromate ion.Perbromic...

 can be produced by protonating .

The best method currently known of producing perbromate is by the oxidation of bromate

Bromate

The bromate anion, BrO, is a bromine-based oxoanion. A bromate is a chemical compound that contains this ion. Examples of bromates include sodium bromate, , and potassium bromate, .Bromates are formed many different ways in municipal drinking water...

 with fluorine

Fluorine

Fluorine is the chemical element with atomic number 9, represented by the symbol F. It is the lightest element of the halogen column of the periodic table and has a single stable isotope, fluorine-19. At standard pressure and temperature, fluorine is a pale yellow gas composed of diatomic...

under alkaline conditions:

+ + 2 → + 2 + 2

This synthesis is much easier to perform on a large scale than the electrolysis route or oxidation by xenon difluoride.