Abstract
In this project, we have designed and synthesized curved anthracene systems that undergo Dewar valence isomerization under visible light irradiation and release heat through thermally triggered reverse isomerization. The four derivatives reported shows remarkable high energy storage capabilities – up to 0.65 MJ/kg – comparable to state-of-the-art molecular solar thermal (MOST) energy storage materials. The synthesis of these derivatives, while straightforward in concept, is challenging and demands careful approach due to the inherent instability of some bulky 9-substituted anthracenes. This report highlights the optimization of the synthetic protocols as well as the thermal kinetic studies of the corresponding Dewar isomers. The cyclability of these derivatives has been showcased via irradiation-heating cycling studies. Overall, this project puts forward curved anthracenes as a promising MOST system with high energy density and discusses synthetic strategies and thermal kinetic studies of the same.