What does dismutation mean?
Dismutation is a noun used in chemistry to describe a reaction in which a single chemical species acts as both oxidising agent and reducing agent at the same time, converting itself into two products that occupy different oxidation states. The everyday example is hydrogen peroxide, which spontaneously breaks down into water and oxygen through exactly this kind of self-oxidising, self-reducing process. In most chemistry contexts the word functions as a synonym for disproportionation, though it survives especially in biochemistry: enzymes called superoxide dismutases take their name from the dismutation they perform, transforming destructive superoxide radicals into benign oxygen and hydrogen peroxide and thereby protecting cells from oxidative damage. Because it belongs to specialist vocabulary, dismutation carries no emotional connotation and appears almost entirely in textbooks, research papers, and technical discussion rather than general conversation. Its value lies in precision — it names a specific and important class of redox behaviour.
nounA chemical reaction in which a single compound or element simultaneously undergoes both oxidation and reduction, splitting into two species with different oxidation states. It is the technical term for what is more commonly called a disproportionation reaction.
- (chemistry) A redox reaction in which one species is simultaneously oxidised and reduced, producing two different species with different oxidation states; also known as disproportionation.
- (biochemistry) The enzymatic conversion of superoxide radicals into oxygen and hydrogen peroxide, as catalysed by superoxide dismutase.
"The dismutation of hydrogen peroxide yields water and oxygen gas."
"Copper(I) ions are unstable in aqueous solution because they readily undergo dismutation into copper metal and copper(II) ions."
"The enzyme catalyses the dismutation of the superoxide anion, forming molecular oxygen and hydrogen peroxide."
Used when referring to multiple such reactions or instances of the process.
"Several dismutations occur during the decomposition of the reaction mixture."
Enzymes named after it — superoxide dismutases — protect nearly every oxygen-breathing organism by forcing a single reactive molecule to fight itself, turning one harmful ion into two harmless products.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of dismutation
Dismutation derives from Latin roots: the prefix 'dis-' indicating separation or apart, combined with 'mutare', meaning to change. The word entered scientific English in the nineteenth century as chemists sought a precise label for reactions in which one substance splits itself into two differently oxidised forms. It shares its Latin root with a wide family of English words including mutate, transmute, permutation, and commutation.
How dismutation is actually used
Dismutation is a technical term used almost exclusively in chemistry and biochemistry; in general chemistry writing, 'disproportionation' is the preferred and far more frequent synonym.
Easily confused with dismutation
Disproportionation is the far more common term for the same process; 'dismutation' is largely confined to biochemistry (e.g. superoxide dismutase) and some European chemistry traditions.
A mutation is a change in genetic material, whereas a dismutation is a redox reaction in which one substance is simultaneously oxidised and reduced.