Term: carbenium centre
https://doi.org/10.1351/goldbook.C00811

Definition:
The three-coordinate carbon atom in a carbenium ion to which the excess positive charge of the ion (other than that located on heteroatoms) may be formally considered to be largely attributed, i.e. which has one vacant p-orbital. (N.B. It is not always possible to uniquely identify such an atom.) This formal attribution of charge often does not express the real charge distribution.

Related Terms:
1) carbenium ion (http://doi.org/10.1351/goldbook.C00812).
2) orbital (http://doi.org/10.1351/goldbook.O04317).

Source: PAC, 1994, 66, 1077. 'Glossary of terms used in physical organic chemistry (IUPAC Recommendations 1994)' on page 1092 (https://doi.org/10.1351/pac199466051077)

Citation: 'carbenium centre' 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.C00811

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.