Diazocines: Photoswitches with Excellent Photophysical Properties and Inverted Stabilities

Diazocine was first synthesized more than 110 years ago; however, its photochemical properties were not investigated until 2009. Structurally, diazocines are related to azobenzenes. The two phenyl rings are bridged by a CH 2 CH 2 group in ortho position forming an 8-membered ring. The small structural variation gives rise to improved photophysical properties, such as bathochromically shifted switching wavelengths, very high quantum yields, superior photoconversion yields, and very high fatigue resistance. Within the last decade, new synthetic strategies were developed and a number of derivatives were synthesized. Diazocines found applications in material science such as photoactuators and mechanochromes, in biochemistry for light-induced protein and DNA structure switching, and particularly in photopharmocology.