Arylazopyrazoles: High Performance Photoswitches with Applications from Photopharmacology to Thermal Storage (RSC Awards Lecture)

Photoswitchable compounds, which can be reversibly switched between two isomers by light, continue to attract significant attention for a wide array of applications. Azoheteroarenes represent a relatively new but understudied type of photoswitch, where one or both of the aryl rings from the conventional azobenzene class has been replaced with a five-membered heteroaromatic ring. This talk will give an overview of our work in this area, particularly focusing on our discovery of the arylazopyrazoles, which offer quantitative photoswitching and high thermal stability of the Z isomer (half-lives of up to 46 years). Several examples will be presented of how we have applied the arylazopyrazoles to different optically addressable applications including photopharmacology and as molecular solar thermal (MOST) energy storage materials.