05292 IUPAC Gold Book - reorganization energy 10.1351/goldbook.R05292 R05292 current 1 Gibbs energy dissipated when a system that has undergone 'vertical' electron transfer (i.e., electron transfer obeying the Franck–Condon principle) relaxes to the equilibrium state for its new charge distribution. Commonly the total reorganization energy (\(\lambda\)) is written as the sum of an inner contribution (\(\lambda_{\rm{in}}\)) and an outer contribution (\(\lambda_{\rm{out}}\)) attributed to nuclear reorganizations of the redox partners and their environment (solvent), respectively. Approximations have been proposed to calculate the value of \(\lambda_{\rm{out}}\) taking into account the 'relative permittivity' of the solvent. Franck–Condon principle https://goldbook.iupac.org/terms/view/F02510 electron transfer https://goldbook.iupac.org/terms/view/E02011 relative permittivity https://goldbook.iupac.org/terms/view/R05273 PAC, 2007, 79, 293. 'Glossary of terms used in photochemistry, 3rd edition (IUPAC Recommendations 2006)' on page 414 (https://doi.org/10.1351/pac200779030293) https://goldbook.iupac.org/terms/view/R05292/html https://goldbook.iupac.org/terms/view/R05292/json https://goldbook.iupac.org/terms/view/R05292/plain Citation: 'reorganization energy' 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.R05292 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. 2026-07-01T00:49:12+00:00