Photochemical process leading to an
isomerization of the substrate,
either by bond rotation, skeletal
rearrangement or atom- or group- transfer.
Notes:
- Typical examples are cis-trans photosomerization of alkenes,
polyenes and phototautomerization.
- Photochemical pathways have the advantage over thermal and catalytic methods
of giving isomer mixtures (photostationary states) rich in thermodynamically unstable isomers.
- Photoisomerization is the primary photochemical reaction of the chromophore
in several biological photoreceptors such as retinal proteins
(e.g., rhodopsin), phytochromes, and the photoactive yellow protein.
Source:
PAC, 2007, 79, 293
(Glossary of terms used in photochemistry, 3rd edition (IUPAC Recommendations 2006))
on page 393