The process by which a photochemical or photophysical alteration occurs in one molecular entity as a result of initial absorption of radiation by another molecular entity called a photosensitizer. In mechanistic photochemistry the term is limited to cases in which the photosensitizer is not consumed in the reaction.
See: energy transfer (in photochemistry)
PAC, 1981, 53, 753. 'Symbolism and Terminology in Chemical Kinetics' on page 762 (https://doi.org/10.1351/pac198153030753)
PAC, 1996, 68, 2223. 'Glossary of terms used in photochemistry (IUPAC Recommendations 1996)' on page 2265 (https://doi.org/10.1351/pac199668122223)