Periodate

The periodate ion is IO4&minus; or IO65&minus;. It comes from periodic acid.

A periodate is a compound that contains this group. Note that the pronunciation is per-iodate, not period-ate.

Examples

 * sodium periodate, NaIO4
 * potassium periodate, KIO4

See category for a bigger list.

Discussion
Periodates include two forms. The metaperiodate ion is IO4&minus;; the orthoperiodate ion is IO65&minus;.

Periodate compounds include metaperiodates and orthoperiodates. Usually both are called periodates.

In neutral or weak acid conditions, IO4&minus; is most common, in equilibrium with a smaller amount of H4IO6&minus;. In basic conditions, H3IO62&minus; is formed, plus some other ions.

Like its neighbor, tellurium, and unlike lighter halogens, iodine tends to be hexacoordinate, and the units HnIO6(5&minus;n)- are quite common; but in the case of iodine, tetracoordinate units, such as IO4&minus;, are also quite common.

Uses
Periodates can cleave carbon-carbon bonds when both carbon atoms bear an oxygen atom, either in the form of a hydroxyl or a carbonyl group. This property is often utilized in molecular biochemistry for the purposes of modifying saccharide rings, as many five- and six-membered sugars often have vicinal diols.

Периодаты