Cooperative switching events in azobenzene foldamer denaturation.

Insight into the mechanism of photoswitchable foldamer denaturation was gained by incorporating two azobenzene switching units (see figure; orange) into the helix backbone. Optimizing the location of the units leads to cooperative photoisomerization events, causing complete unfolding. The switching cooperativity coupled with the cooperative unfolding transition enables the design of highly photosensitive systems.