The dithionate (or metabisulfate)

anion An ion () is an atom or molecule with a net electrical charge. The charge of an electron is considered to be negative by convention and this charge is equal and opposite to the charge of a proton, which is considered to be positive by conven ...

, , is a

sulfur Sulfur ( American spelling and the preferred IUPAC name) or sulphur ( Commonwealth spelling) is a chemical element; it has symbol S and atomic number 16. It is abundant, multivalent and nonmetallic. Under normal conditions, sulfur atoms ...

oxoanion An oxyanion, or oxoanion, is an ion with the generic formula (where A represents a chemical element and O represents an oxygen atom). Oxyanions are formed by a large majority of the chemical elements. The formulae of simple oxyanions are determined ...

derived from dithionic acid, H₂S₂O₆. Its

chemical formula A chemical formula is a way of presenting information about the chemical proportions of atoms that constitute a particular chemical compound or molecule, using chemical element symbols, numbers, and sometimes also other symbols, such as pare ...

is sometimes written in a semistructural format, as ₃SSO₃sup>2−. It is the first member of the polythionates. The sulfur atoms of the dithionate ion are in the +5

oxidation state In chemistry, the oxidation state, or oxidation number, is the hypothetical Electrical charge, charge of an atom if all of its Chemical bond, bonds to other atoms are fully Ionic bond, ionic. It describes the degree of oxidation (loss of electrons ...

due to the presence of the S–S bond. Generally, dithionates form stable compounds that are not readily oxidised or reduced. Strong oxidants oxidise them to

sulfate The sulfate or sulphate ion is a polyatomic anion with the empirical formula . Salts, acid derivatives, and peroxides of sulfate are widely used in industry. Sulfates occur widely in everyday life. Sulfates are salts of sulfuric acid and many ...

s and strong reducing agents reduce them to

sulfite Sulfites or sulphites are compounds that contain the sulfite ion (systematic name: sulfate(IV) ion), . The sulfite ion is the conjugate base of bisulfite. Although its acid (sulfurous acid) is elusive, its salts are widely used. Sulfites are ...

s and dithionites. Aqueous solutions of dithionates are quite stable and can be boiled without decomposition. The γ-irradiation of crystalline dithionates produces

radical Radical (from Latin: ', root) may refer to: Politics and ideology Politics *Classical radicalism, the Radical Movement that began in late 18th century Britain and spread to continental Europe and Latin America in the 19th century *Radical politics ...

ions. The unpaired electron in the radical can be detected with

electron paramagnetic resonance Electron paramagnetic resonance (EPR) or electron spin resonance (ESR) spectroscopy is a method for studying materials that have unpaired electrons. The basic concepts of EPR are analogous to those of nuclear magnetic resonance (NMR), but the spin ...

and barium dithionate has been proposed as the basis for a radiation

dosimeter A radiation dosimeter is a device that measures the equivalent dose, dose uptake of external ionizing radiation. It is worn by the person being monitored when used as a personal dosimeter, and is a record of the radiation dose received. Modern el ...

. The dithionate ion can act as a bidentate

ligand In coordination chemistry, a ligand is an ion or molecule with a functional group that binds to a central metal atom to form a coordination complex. The bonding with the metal generally involves formal donation of one or more of the ligand's el ...

.''Structures of Some Copper (II) Complexes Containing Ion'' Ishii M. ''Bulletin of the Yamagata University'' 5, 1,(2001), 7 The structure of the dithionate ion in the solid state is staggered in Na₂S₂O₆·2H₂O, whereas in the anhydrous potassium salt it is nearly eclipsed.

Compounds

Compounds containing the dithionate ion include: * sodium dithionate, Na₂S₂O₆ * potassium dithionate, K₂S₂O₆ * barium dithionate, BaS₂O₆

References

External links

{{commons category-inline, Dithionate ion Sulfur oxyanions