04569 IUPAC Gold Book - phosphorescence 10.1351/goldbook.P04569 P04569 current 1 From a phenomenological point of view, the term has been used to describe long-lived luminescence. In mechanistic photochemistry, the term designates luminescence involving change in spin multiplicity, typically from triplet to singlet or vice versa. The luminescence from a quartet state to a doublet state is also phosphorescence. doublet state https://goldbook.iupac.org//terms/view/D01853 luminescence https://goldbook.iupac.org//terms/view/L03641 photochemistry https://goldbook.iupac.org//terms/view/P04588 quartet state https://goldbook.iupac.org//terms/view/Q04993 PAC, 1984, 56, 231. 'Nomenclature, symbols, units and their usage in spectrochemical analysis-Part VI: molecular luminescence spectroscopy' on page 233 (https://doi.org/10.1351/pac198456020231) PAC, 1996, 68, 2223. 'Glossary of terms used in photochemistry (IUPAC Recommendations 1996)' on page 2258 (https://doi.org/10.1351/pac199668122223) Orange Book, 2nd ed., p. 184 (https://media.iupac.org/publications/analytical_compendium/) https://goldbook.iupac.org/terms/view/P04569/html https://goldbook.iupac.org/terms/view/P04569/json https://goldbook.iupac.org/terms/view/P04569/plain Citation: 'phosphorescence' 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.P04569 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. 2026-05-06T19:09:30+00:00