Sodium periodate

Chemical compound From Wikipedia, the free encyclopedia

Sodium periodate

Sodium periodate is an inorganic salt, composed of a sodium cation and the periodate anion. It may also be regarded as the sodium salt of periodic acid. Like many periodates, it can exist in two different forms: sodium metaperiodate (formula‍ NaIO4) and sodium orthoperiodate (normally Na2H3IO6, but sometimes the fully reacted salt Na5IO6). Both salts are useful oxidising agents.[2]

Quick Facts Names, Identifiers ...
Sodium periodate
Thumb
Names
IUPAC name
Sodium periodate
Other names
Sodium metaperiodate
Identifiers
3D model (JSmol)
ChEBI
ChemSpider
ECHA InfoCard 100.029.270
EC Number
  • meta: 232-197-6
  • para: 237-720-1
  • trihydrogen: 239-681-6
RTECS number
  • meta: SD4550000
UNII
  • InChI=1S/HIO4.Na/c2-1(3,4)5;/h(H,2,3,4,5);/q;+1/p-1 Y
    Key: JQWHASGSAFIOCM-UHFFFAOYSA-M Y
  • meta: InChI=1/HIO4.Na/c2-1(3,4)5;/h(H,2,3,4,5);/q;+1/p-1
    Key: JQWHASGSAFIOCM-REWHXWOFAO
  • para: InChI=1S/H5IO6.3Na/c2-1(3,4,5,6)7;;;/h(H5,2,3,4,5,6,7);;;/q;3*+1/p-3
    Key: DSYMXPNUZLZKOA-UHFFFAOYSA-K
  • ortho: InChI=1S/H5IO6.5Na/c2-1(3,4,5,6)7;;;;;/h(H5,2,3,4,5,6,7);;;;;/q;5*+1/p-5
    Key: RAJUJHHGBPSUAC-UHFFFAOYSA-I
  • trihydrogen: InChI=1S/H5IO6.2Na/c2-1(3,4,5,6)7;;/h(H5,2,3,4,5,6,7);;/q;2*+1/p-2
    Key: PEPDKRLBEGSBRW-UHFFFAOYSA-L
  • meta: [O-]I(=O)(=O)=O.[Na+]
  • para: OI(=O)(O)([O-])([O-])[O-].[Na+].[Na+].[Na+]
  • ortho: [O-]I(=O)([O-])([O-])([O-])[O-].[Na+].[Na+].[Na+].[Na+].[Na+]
  • trihydrogen: OI(=O)(O)(O)([O-])[O-].[Na+].[Na+]
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
Other anions
sodium perchlorate, sodium perbromate
Other cations
potassium periodate, periodic acid
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N verify (what is YN ?)
Close

Preparation

Classically, periodate was produced in the form of sodium hydrogen periodate (Na3H2IO6).[3] This commercially available, but can also be produced by the oxidation of iodates with chlorine and sodium hydroxide.[3][4] Or, similarly, from iodides by oxidation with bromine and sodium hydroxide:

NaIO3 + Cl2 + 4 NaOH → Na3H2IO6 + 2NaCl + H2O
NaI + 4 Br2 + 10 NaOH → Na3H2IO6 + 8 NaBr + 4 H2O

Modern industrial scale production involves the electrochemical oxidation of iodates, on a lead dioxide (PbO2) anode, with the following standard electrode potential:

H5IO6 + H+ + 2e → IO3 + 3 H2O     E° = 1.6 V[5]

Sodium metaperiodate can be prepared by the dehydration of sodium hydrogen periodate with nitric acid.

Na3H2IO6 + 2 HNO3 → NaIO4 + 2 NaNO3 + 2 H2O

Structure

Sodium metaperiodate (NaIO4) forms tetragonal crystals (space group I41/a) consisting of slightly distorted IO
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) forms orthorhombic 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 the monoclinic system (space group C2/m).[8]

Uses

Sodium periodate can be used in solution to open saccharide rings between vicinal diols leaving two aldehyde groups. This process is often used in labeling saccharides with fluorescent molecules or other tags such as biotin. Because the process requires vicinal diols, periodate oxidation is often used to selectively label the 3′-ends of RNA (ribose has vicinal diols) instead of DNA as deoxyribose does not have vicinal diols.

NaIO4 is used in organic chemistry to cleave diols to produce two aldehydes.[9]

Thumb

In 2013 the US Army announced that it would replace environmentally harmful chemicals barium nitrate and potassium perchlorate with sodium metaperiodate for use in their tracer ammunition.[10]

See also

References

Loading related searches...

Wikiwand - on

Seamless Wikipedia browsing. On steroids.