Term: Förster cycle
https://doi.org/10.1351/goldbook.F02487

Definition:
An indirect method of determination of excited state equilibria, such as p K *,a values, based on ground state thermodynamics and electronic transition energies. This cycle considers only the difference in molar enthalpy change (Δ Δ H) of reaction of ground and excited states, neglecting the difference in molar entropy change of reaction of those states (Δ Δ S).

Related Terms:
1) excited state (http://doi.org/10.1351/goldbook.E02257).
2) ground state (http://doi.org/10.1351/goldbook.G02704).
3) enthalpy (http://doi.org/10.1351/goldbook.E02141).
4) entropy (http://doi.org/10.1351/goldbook.E02149).

Source: PAC, 1996, 68, 2223. 'Glossary of terms used in photochemistry (IUPAC Recommendations 1996)' on page 2243 (https://doi.org/10.1351/pac199668122223)

Citation: 'Förster cycle' 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.F02487

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