Peroxydisulfate

Ion containing sulfur and oxygen with a charge of 2-

Peroxydisulfate
Names


Other names Peroxodisulfate Persulfate^[1]
Identifiers
CAS Number	15092-81-6
3D model (JSmol)	Interactive image
ChEBI	CHEBI:29267
ChemSpider	97014
PubChem CID	107879
UNII	1SQ1481FEQ
InChI InChI=1S/H2O8S2/c1-9(2,3)7-8-10(4,5)6/h(H,1,2,3)(H,4,5,6)/p-2 Key: JRKICGRDRMAZLK-UHFFFAOYSA-L
SMILES [O-]S(=O)(=O)OOS([O-])(=O)=O
Properties
Chemical formula	O₈S₂⁻²
Molar mass	192.11 g·mol⁻¹
Conjugate acid	Peroxydisulfuric acid
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Chemical compound

The peroxydisulfate ion, S
₂O²⁻
₈, is an oxyanion, the anion of peroxydisulfuric acid. It is commonly referred to as persulfate, but this term also refers to the peroxomonosulfate ion, SO²⁻
₅. It is also called peroxodisulfate.^[2] Approximately 500,000 tons of salts containing this anion are produced annually. Important salts include sodium persulfate (Na₂S₂O₈), potassium persulfate (K₂S₂O₈), and ammonium persulfate ((NH₄)₂S₂O₈). These salts are colourless, water-soluble solids that are strong oxidants.^[3]

Applications

Salts of peroxydisulfate are mainly used to initiate the polymerization of various alkenes, including styrene, acrylonitrile, and fluoroalkenes. Polymerization is initiated by the homolysis of the peroxydisulfate:

[O₃SO–OSO₃]²⁻ ⇌ 2 [SO₄]^•−

Moreover, sodium peroxydisulfate can be used for soil and groundwater remediation, water and wastewater treatment, and etching of copper on circuit boards.^[4]^[2]

It has also been used to produce hair lighteners and bleaches, medical drugs, cellophane, rubber, soaps, detergents, adhesive papers, dyes for textiles, and in photography.^[2]

In addition to its major commercial applications, peroxydisulfate participates in reactions of interest in the laboratory:

Elbs persulfate oxidation
Oxidation of Ag⁺ to Ag²⁺, such as the preparation of tetrakis(pyridine)silver(II) peroxydisulfate

Structure

Peroxydisulfate is a centrosymmetric anion. The O-O distance is 1.48 Å. The sulfur centers are tetrahedral.^[5]

References

^ Ambiguous—see persulfate
^ ^a ^b ^c Shafiee, Saiful Arifin; Aarons, Jolyon; Hamzah, Hairul Hisham (2018). "Electroreduction of Peroxodisulfate: A Review of a Complicated Reaction". Journal of the Electrochemical Society. 165 (13): H785–H798. doi:10.1149/2.1161811jes. S2CID 106396614.
^ Harald Jakob, Stefan Leininger, Thomas Lehmann, Sylvia Jacobi, Sven Gutewort. "Peroxo Compounds, Inorganic". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a19_177.pub2. ISBN 978-3527306732.{{cite encyclopedia}}: CS1 maint: multiple names: authors list (link)
^ Wacławek, Stanisław; Lutze, Holger V.; Grübel, Klaudiusz; Padil, Vinod V.T.; Černík, Miroslav; Dionysiou, Dionysios.D. (2017). "Chemistry of persulfates in water and wastewater treatment: A review". Chemical Engineering Journal. 330: 44–62. doi:10.1016/j.cej.2017.07.132.
^ Allan, David R. (2006). "Sodium Peroxodisulfate". Acta Crystallographica Section E. 62 (3): i44–i46. doi:10.1107/S1600536806004302.