periodates

Periodates are salts that contain the periodate anion IO4−, derived from periodic acids. They feature iodine in a high oxidation state and are among the more selective and practical oxidants used in aqueous media. The best-known periodates are sodium periodate (NaIO4) and potassium periodate (KIO4); periodic acid (H5IO6) and related orthoperiodate and metaperiodate species are also discussed in the literature, depending on pH and condensation equilibria.

In organic and carbohydrate chemistry, periodates are valued for their ability to oxidize vicinal diols, cleaving 1,2-diols to carbonyl-containing fragments such as aldehydes and ketones. This periodate oxidation is widely used for structural analysis of carbohydrates, for selective deprotections, and for sequencing or fragmenting polyols. Periodates can also oxidize other functional groups under suitable conditions, and they are employed as mild oxidants in various synthetic transformations.

Preparation and handling of periodates typically involve oxidation of iodate-containing species under controlled conditions to form the IO4− ion, followed by isolation as water-soluble salts such as NaIO4 or KIO4. They are strong oxidizers and must be handled with care: they react exothermically with reducing agents and organic materials, can be moisture-sensitive in some forms, and are typically stored away from acids and heat. In analytical and preparative contexts, periodates are valued for their selectivity and the relatively mild conditions under which they can operate.