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| Names | |
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| IUPAC name Sodium periodate | |
| Other names Sodium metaperiodate | |
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3D model (JSmol) |
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| ChemSpider | |
| ECHA InfoCard | 100.029.270 |
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| Properties | |
| NaIO4 | |
| Molar mass | 213.8918 g/mol |
| Appearance | white crystals |
| Density | 3.865 g/cm3 (anhydrous) 3.210 g/cm3 |
| Melting point | 300 °C (572 °F; 573 K) (anhydrous) 175 °C (347 °F; 448 K) (trihydrate) (decomposes) |
| 91 g/L[1] | |
| Solubility | soluble in acids |
| Structure | |
| tetragonal (anhydrous) trigonal (trihydrate) | |
| Hazards | |
| NFPA 704 (fire diamond) | |
| Related compounds | |
Otheranions | sodium perchlorate,sodium perbromate |
Othercations | potassium periodate,periodic acid |
Except where otherwise noted, data are given for materials in theirstandard state (at 25 °C [77 °F], 100 kPa). | |
Sodium periodate is aninorganic salt, composed of asodiumcation and theperiodateanion. It may also be regarded as the sodiumsalt ofperiodic acid. Like many periodates, it can exist in two different forms:sodiummetaperiodate (formula NaIO4) andsodiumorthoperiodate (normally Na2H3IO6, but sometimes the fully reacted salt Na5IO6). Both salts are useful oxidising agents.[2]
Classically, periodate was produced in the form of sodium hydrogen periodate (Na3H2IO6).[3] This commercially available, but can also be produced by the oxidation ofiodates withchlorine andsodium hydroxide.[3][4] Or, similarly, fromiodides by oxidation withbromine and sodium hydroxide:
Modern industrial scale production involves theelectrochemical oxidation of iodates, on alead dioxide (PbO2) anode, with the followingstandard electrode potential:
Sodium metaperiodate can be prepared by the dehydration of sodium hydrogen periodate withnitric acid.
Sodium metaperiodate (NaIO4) formstetragonal crystals (space groupI41/a) consisting of slightly distortedIO−
4 ions with average I–O bond distances of 1.775 Å; the Na+ ions are surrounded by 8 oxygen atoms at distances of 2.54 and 2.60 Å.[6]
Sodium hydrogen periodate (Na2H3IO6) formsorthorhombic crystals (space group Pnnm). Iodine and sodium atoms are both surrounded by an octahedral arrangement of 6 oxygen atoms; however the NaO6 octahedron is strongly distorted. IO6 and NaO6 groups are linked via common vertices and edges.[7]
Powder diffraction indicates that Na5IO6 crystallises in themonoclinic system (space group C2/m).[8]
Sodium periodate can be used in solution to open saccharide rings betweenvicinal diols leaving two aldehyde groups. This process is often used in labeling saccharides with fluorescent molecules or other tags such asbiotin. Because the process requires vicinal diols, periodate oxidation is often used to selectively label the 3′-ends ofRNA (ribose has vicinal diols) instead ofDNA asdeoxyribose does not have vicinal diols.
NaIO4 is used inorganic chemistry to cleavediols to produce twoaldehydes.[9]
In 2013 theUS Army announced that it would replace environmentally harmful chemicalsbarium nitrate andpotassium perchlorate with sodium metaperiodate for use in theirtracer ammunition.[10]
