Term: electron-transfer catalysis
https://doi.org/10.1351/goldbook.E02012

Definition:
The term indicates a sequence of reactions such as shown in equations (1)–(3), leading from A to B :    \[\text{A} + \text{e}^{-} \rightarrow \text{A}^{\cdot- }\]  (1)    \[\text{A}^{\cdot- } \rightarrow \text{B}^{\cdot- }\]  (2)    \[\text{B}^{\cdot- } + \text{A} \rightarrow \text{B} + \text{A}^{\cdot- }\]  (3)   An analogous sequence involving radical cations (A+·, B+·) is also observed. The most notable example of electron-transfer catalysis is the S RN 1 (or T + D N + A N) reaction of aromatic halides. The term has its origin in a suggested analogy to acid-base catalysis, with the electron instead of the proton. However, there is a difference between the two catalytic mechanisms, since the electron is not a true catalyst, but rather behaves as the initiator of a chain reaction. 'Electron-transfer induced chain reaction' is a more appropriate term for the situation described by equations (1)–(3).

Related Terms:
1) sequence (http://doi.org/10.1351/goldbook.ST06775).
2) catalysis (http://doi.org/10.1351/goldbook.C00874).
3) proton (http://doi.org/10.1351/goldbook.P04906).
4) catalyst (http://doi.org/10.1351/goldbook.C00876).
5) initiator (http://doi.org/10.1351/goldbook.I03043).
6) chain reaction (http://doi.org/10.1351/goldbook.C00960).

Source: PAC, 1994, 66, 1077. 'Glossary of terms used in physical organic chemistry (IUPAC Recommendations 1994)' on page 1110 (https://doi.org/10.1351/pac199466051077)

Citation: 'electron-transfer catalysis' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. https://doi.org/10.1351/goldbook.E02012

License: The IUPAC Gold Book is licensed under Creative Commons Attribution-ShareAlike CC BY-SA 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/) for individual terms.

Disclaimer: The International Union of Pure and Applied Chemistry (IUPAC) is continuously reviewing and, where needed, updating terms in the Compendium of Chemical Terminology (the IUPAC Gold Book). Users of these terms are encouraged to include the version of a term with its use and to check regularly for updates to term definitions that you are using.