disproportionation

Also contains definition of: radical disproportionation
https://doi.org/10.1351/goldbook.D01799
  1. Any chemical reaction of the type D01799-0.png, where A, A' and A'' are different chemical species. For example:
    D01799-1.png
    The reverse of disproportionation is called comproportionation. A special case of disproportionation (or 'dismutation') is 'radical disproportionation', exemplified by:
    D01799-2.png
    Reactions of the more general type:
    D01799-3.png
    are also loosely described as radical disproportionations.
    Source:
    PAC, 1994, 66, 1077. 'Glossary of terms used in physical organic chemistry (IUPAC Recommendations 1994)' on page 1107 (https://doi.org/10.1351/pac199466051077)
  2. A reversible or irreversible transition in which species with the same oxidation state combine to yield one of higher oxidation state and one of lower oxidation state. Example: D01799-4.png The term also applies to an internal oxidation-reduction process as occurs, for example, among the iron atoms of CaFeO3, where D01799-5.png, at Fe subarrays on lowering the temperature.
    Source:
    PAC, 1994, 66, 577. 'Definitions of terms relating to phase transitions of the solid state (IUPAC Recommendations 1994)' on page 581 (https://doi.org/10.1351/pac199466030577)