00628 IUPAC Gold Book - Bell–Evans–Polanyi principle 10.1351/goldbook.B00628 B00628 current 1 The linear relation between energy of activation \((E_{\rm{a}})\) and enthalpy of reaction \((\Delta H_{\rm{r}})\) sometimes observed within a series of closely related reactions. \[E_{\rm{a}} = A + B\ \unicode[Times]{x394}H_{\rm{r}}\] energy of activation https://goldbook.iupac.org/terms/view/E02108 enthalpy https://goldbook.iupac.org/terms/view/E02141 PAC, 1994, 66, 1077. 'Glossary of terms used in physical organic chemistry (IUPAC Recommendations 1994)' on page 1088 (https://doi.org/10.1351/pac199466051077) https://goldbook.iupac.org/terms/view/B00628/html https://goldbook.iupac.org/terms/view/B00628/json https://goldbook.iupac.org/terms/view/B00628/plain Citation: 'Bell–Evans–Polanyi principle' 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.B00628 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. 2026-05-11T00:47:52+00:00