Photochemical cleavage of individual stereoisomers of coumarin-5-fluorouracil crossdimers via single- and two-photon-absorption

- Isomer-dependent photochemical cyclobutane cleavage efficiency measured.
- Comparison of single-photon-absorption and two-photon-absorption photochemistry.
- Significant differences were found, in the range of one order of magnitude.
- Isolation of the most light-sensitive isomer is recommended for applications.
- Finding is in particular relevant for medical applications, e.g. intraocular lenses.