Title: quenching
Long Title: IUPAC Gold Book - quenching
DOI: 10.1351/goldbook.Q05007
Status: current

Definition
Deactivation of an excited molecular entity intermolecularly by an external environmental influence (such as a quencher) or intramolecularly by a substituent through a non-radiative process.

Notes
1) When the external environmental influence (quencher) interferes with the behaviour of the excited state after its formation, the process is referred to as dynamic quenching. Common mechanisms include energy transfer, electron transfer, etc.
2) When the environmental influence inhibits the excited state formation the process is referred to as static quenching.

Related Terms
- Deactivation: https://goldbook.iupac.org//terms/view/D01528
- electron transfer: https://goldbook.iupac.org//terms/view/E02011
- excited state: https://goldbook.iupac.org//terms/view/E02257
- quencher: https://goldbook.iupac.org//terms/view/Q05006

Source
- PAC, 2007, 79, 293. 'Glossary of terms used in photochemistry, 3rd edition (IUPAC Recommendations 2006)' on page 407 (https://doi.org/10.1351/pac200779030293)

Other Outputs
- html: https://goldbook.iupac.org/terms/view/Q05007/html
- json: https://goldbook.iupac.org/terms/view/Q05007/json
- xml: https://goldbook.iupac.org/terms/view/Q05007/xml

Citation: Citation: 'quenching' 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.Q05007
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Accessed: 2026-05-09T08:30:32+00:00