Potassium peroxymonosulfate explained

Potassium peroxymonosulfate is widely used as an oxidizing agent, for example, in pools and spas (usually referred to as monopersulfate or "MPS"). It is the potassium salt of peroxymonosulfuric acid. Potassium peroxymonosulfate per se is rarely encountered. It is often confused with the triple salt, known as Oxone.

The standard electrode potential for potassium peroxymonosulfate is +1.81 V with a half reaction generating the hydrogen sulfate :[1]

Oxone

Potassium peroxymonosulfate per se is a relatively obscure salt, but its derivative called Oxone is of commercial value. Oxone refers to the triple salt . As such about one third by weight is potassium peroxymonosulfate. Oxone has a longer shelf life than does potassium peroxymonosulfate. A white, water-soluble solid, Oxone loses <1% of its oxidizing power per month.[2]

Oxone, which is commercially available, is produced from peroxysulfuric acid, which is generated in situ by combining oleum and hydrogen peroxide. Careful neutralization of this solution with potassium hydroxide allows the crystallization of the triple salt.

Uses

Cleaning

Oxone is used widely for cleaning. It whitens dentures, oxidizes organic contaminants in swimming pools,[3] and cleans chips for the manufacture of microelectronics.[4] [5]

Organic oxidations

Oxone is a versatile oxidant in organic synthesis. It oxidizes aldehydes to carboxylic acids; in the presence of alcoholic solvents, the esters may be obtained.[6] Internal alkenes may be cleaved to two carboxylic acids (see below), while terminal alkenes may be epoxidized. Sulfides give sulfones, tertiary amines give amine oxides, and phosphines give phosphine oxides.

Further illustrative of the oxidative power of this salt is the conversion of an acridine derivative to the corresponding acridine-N-oxide.

Oxone oxidizes sulfides to sulfoxides and then to sulfones.

Oxone converts ketones to dioxiranes, which are used for diverse oxidations in organic synthesis. The dominant reagent dimethyldioxirane (DMDO) forms upon treatment of acetone with oxone. Dioxiranes are versatile, especially for the epoxidation of olefins.[7] Dioxiranes are also oxidize other unsaturated functionality, heteroatoms, and alkane C-H bonds.[8]

Other uses

Oxone has been investigated for the delignification of wood.[9]

Ammonium, sodium, and potassium salts of are used in the plastics industry as radical initiators for polymerization. They are also used as etchants, oxidative desizing agents for textile fabrics, and for decolorizing and deodorizing oils.

Notes and References

  1. M.. Spiro. The standard potential of the peroxosulphate/sulphate couple. Electrochimica Acta. 0013-4686. 313–314. 24. 3. 10.1016/0013-4686(79)85051-3. 1979.
  2. Book: Encyclopedia of Reagents for Organic Synthesis. Crandall. Jack K.. Shi. Yian. Burke. Christopher P.. Buckley. Benjamin R.. 2001. John Wiley & Sons, Ltd. 978-0-470-84289-8. en. 10.1002/047084289x.rp246.pub3.
  3. Book: Pool School . Trouble Free Pool . PT4 . November 30, 2018.
  4. United States Environmental Protection Agency . 2020-03-11 . Peroxy Compounds Human Health and Ecological Draft Risk Assessment DP 455445, 455446 . 9-10 . 2021-09-24.
  5. Stanisław . Wacławek . Holger V. . Lutze . Klaudiusz . Grübel . Vinod V.T. . Padil . Miroslav . Černík . Dionysios. D. . Dionysiou . Peroxy Compounds Human Health and Ecological Draft Risk Assessment DP 455445, 455446 . Chemical Engineering Journal . 330 . 44–62 . 10.1016/j.cej.2017.07.132. 2017-12-15 .
  6. 10.1021/ol0340078 . Benjamin R. Travis . Meenakshi Sivakumar . G. Olatunji Hollist . Babak Borhan . amp . Facile Oxidation of Aldehydes to Acids and Esters with Oxone . 2003 . Organic Letters . 5 . 1031–4 . 12659566 . 7.
  7. Dioxirane Epoxidation of Alkenes. Adam. W.. Saha-Moller. C.. Zhao. C.-G.. Org. React.. 2004. 61. 219. 10.1002/0471264180.or061.02.
  8. Dioxirane Oxidations of Compounds other than Alkenes. Adam. W.. Zhao. C.-G.. Jakka. K.. Org. Reactions. 2007. 69. 1. 10.1002/0471264180.or069.01.
  9. Treatment of softwood kraft pulps with peroxymonosulfate before oxygen delignification . Springer . E. L. . McSweeny . J. D. . TAPPI Journal . 1993 . 76 . 8 . 194–199 . 0734-1415 . 2011-05-14 . https://web.archive.org/web/20110929012348/http://www.tappi.org/Bookstore/Technical-Papers/Journal-Articles/TAPPI-JOURNAL/Archives/1993/August/Treatment-of-softwood-kraft-pulps-with-peroxymonosulfate-before-oxygen-delignification-TAPPI-JOURNA.aspx . 2011-09-29 . dead .