Term: reorganization energy
https://doi.org/10.1351/goldbook.R05292

Definition:
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 (λ) is written as the sum of an inner contribution (λin) and an outer contribution (λout) attributed to nuclear reorganizations of the redox partners and their environment (solvent), respectively.

Note: Approximations have been proposed to calculate the value of λout taking into account the '@R05273@' of the solvent.

Related Terms:
1) relative permittivity (http://doi.org/10.1351/goldbook.R05273).
2) electron transfer (http://doi.org/10.1351/goldbook.E02011).
3) franck–condon principle (http://doi.org/10.1351/goldbook.F02510).

Source: PAC, 2007, 79, 293. 'Glossary of terms used in photochemistry, 3rd edition (IUPAC Recommendations 2006)' on page 414 (https://doi.org/10.1351/pac200779030293)

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. https://doi.org/10.1351/goldbook.R05292

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