Photochemical process leading to an isomerization of the substrate, either by bond rotation, skeletal rearrangement or atom- or group- transfer.
  1. Typical examples are cis-@C01092@ photosomerization of @A00224@, polyenes and phototautomerization.
  2. Photochemical pathways have the advantage over thermal and catalytic methods of giving @I03289@ mixtures (photostationary states) rich in thermodynamically @U06569@ isomers.
  3. Photoisomerization is the primary @P04585@ of the @C01076@ in several biological photoreceptors such as retinal @P04898@ (e.g., rhodopsin), phytochromes, and the photoactive yellow protein.
PAC, 2007, 79, 293. 'Glossary of terms used in photochemistry, 3rd edition (IUPAC Recommendations 2006)' on page 393 (