Aurones: Unexplored, Highly Efficient Visible-Light Photoswitches for Aqueous Medium

The development of synthetically accessible photoswitches showing an efficient performance in aqueous medium has recently become an urgent task due to the rapid development of photopharmacology and novel biomedical applications. In response to this challenge, in this work, aurone derivatives are introduced for the first time as highly efficient visible-light photoswitches for aqueous medium. In general, aurones exhibit superior performance in water, including significantly higher quantum yields, compared with other indigoid photoswitches (hemithioindigo and hemiindigo). Especially remarkable are the half-lifes of the photoinduced E-isomers of aurones in water, reaching up to 7 years. Further modification of the aurone scaffold with substituents that increase water solubility does not affect most of the photoswitching characteristics and even improves some them. The highly advantageous property profile of the aurone photoswitches in water make them a perfect novel platform for the design of light-controllable molecules for bioapplications.