01059 IUPAC Gold Book - chirality axis 10.1351/goldbook.C01059 C01059 current synonym: axis of chirality 1 An axis about which a set of ligands is held so that it results in a spatial arrangement which is not superposable on its mirror image. For example with an allene $\ce{abC=C=Ccd}$ the chiral axis is defined by the $\ce{C=C=C}$ bonds; and with an ortho-substituted biphenyl the atoms $\ce{C-1}$, $\ce{C-1'}$, $\ce{C-4}$ and $\ce{C-4'}$ lie on the chiral axis. chiral https://goldbook.iupac.org//terms/view/C01057 ligands https://goldbook.iupac.org//terms/view/L03518 PAC, 1996, 68, 2193. 'Basic terminology of stereochemistry (IUPAC Recommendations 1996)' on page 2203 (https://doi.org/10.1351/pac199668122193) https://goldbook.iupac.org/terms/view/C01059/html https://goldbook.iupac.org/terms/view/C01059/json https://goldbook.iupac.org/terms/view/C01059/plain Citation: 'chirality axis' 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.C01059 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. 2026-06-27T22:15:23+00:00