Synthesis, Charactrerization and photoswitching studies of extended π-conjugated azopyrazole and azoisoxazole derivatives

Abstract

Photoswitchable compounds in general, and azobenzene photoswitches in specific continue to attract significant attention for a wide array of applications. Azoheteroarenes represent a relatively new but less studied type of photoswitch, where one of the aryl rings from the conventional azobenzene has been replaced with a five-membered heteroaromatic ring. Considering their increasing importance in a variety of fields, tuning and understanding the structure-property relationships of them are quite useful. In this regard, we have synthesized azopyrazoles and azoisoxazoles with extended π-conjugation. The aims of this study include the effect of π-conjugation at different position of azopyrazole and azoisoxazole derivatives on the photoswitching, and the thermal stability of their cis-isomers. Through systematic studies, a comparison has been made and the results are presented in this contribution.