00804 IUPAC Gold Book - carbanion 10.1351/goldbook.C00804 C00804 current 1 Generic name for anions containing an even number of electrons and having an unshared pair of electrons on a tervalent carbon atom (e.g. $\ce{Cl3C^{−}}$ or $\ce{HC#C^{−}}$) or — if the ion is mesomeric (see mesomerism) — having at least one significant contributing structure with an unshared pair of electrons on a tervalent carbon atom, for example: contributing structure https://goldbook.iupac.org/terms/view/C01309 mesomerism https://goldbook.iupac.org/terms/view/M03845 radical ion https://goldbook.iupac.org/terms/view/R05073 PAC, 1994, 66, 1077. 'Glossary of terms used in physical organic chemistry (IUPAC Recommendations 1994)' on page 1092 (https://doi.org/10.1351/pac199466051077) PAC, 1995, 67, 1307. 'Glossary of class names of organic compounds and reactivity intermediates based on structure (IUPAC Recommendations 1995)' on page 1324 (https://doi.org/10.1351/pac199567081307) https://goldbook.iupac.org/terms/view/C00804/html https://goldbook.iupac.org/terms/view/C00804/json https://goldbook.iupac.org/terms/view/C00804/plain Citation: 'carbanion' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. 10.1351/goldbook.C00804 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. If you are interested in licensing the Gold Book for commercial use, please contact the IUPAC Executive Director at executivedirector@iupac.org . 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. 2026-05-14T03:48:16+00:00