Potassium peroxymonosulfate

Potassium peroxymonosulfate, KHSO5, is widely used as an oxidizing agent. It is the potassium acid salt of peroxymonosulfuric acid.

The potassium salt is marketed by two companies: Evonik (formerly Degussa) under the tradename Caroat and DuPont under the tradename Oxone, tradenames which are now part of standard chemistry vocabulary. It is a component of a triple salt with the formula 2KHSO5·KHSO4·K2SO4. The standard electrode potential for this compound is -1.44 V with a half reaction generating the hydrogen sulfate.


 * HSO4- +  H2O  →  HSO5- +  2 H+  +  2 e-

Illustrative of the oxidation power of this salt is the conversion of an acridine to the corresponding acridine-N-oxide.


 * [[Image:Acridine oxone oxidation.gif|left|acridine to acridine-N-oxide oxidation by Oxone]]

It will also oxidize a thioether to a sulfone with 2 equivalents. With one equivalent the reaction converting sulfide to sulfoxide is much faster than that of sulfoxide to sulfone, so the reaction can conveniently be stopped at that stage if so desired.


 * [[Image:Sulfide oxone oxidation.gif|left|sulfide to sulfone oxidation by oxone]]