A metaphosphate ion is an

oxyanion 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 determine ...

that has the empirical formula . It was first postulated in 1955 but was not observed until 1979, when it was detected by mass spectrometry. Metaphosphate is an intermediate in the hydrolysis of

phosphate ester In organic chemistry, organophosphates (also known as phosphate esters, or OPEs) are a class of organophosphorus compounds with the general structure , a central phosphate molecule with alkyl or Aryl, aromatic substituents. They can be conside ...

s but it is difficult to isolate, as it readily hydrolyses to from a

dihydrogen phosphate Dihydrogen phosphate or dihydrogenphosphate ion is an inorganic ion with the formula 2PO4sup>−. Phosphates occur widely in natural systems. These sodium phosphates are artificially used in food processing and packaging as emulsifying agents, ...

ion () and tends to self-react in the absence of water to form rings or infinite chains: These species are also called metaphosphates and are generally stable, with some such as

sodium trimetaphosphate Sodium trimetaphosphate (also STMP), with formula Na3P3O9, is one of the metaphosphates of sodium. It has the formula but the hexahydrate is also well known. It is the sodium salt of trimetaphosphoric acid. It is a colourless solid that finds ...

being produced on an industrial scale. Metaphosphates can be used as an alternative of white phosphorus in organic syntheses.

References

{{reflist Metaphosphates Phosphorus oxyanions

See also

References