Curved Anthracenes for Visible-Light Photon Energy Storage via Dewar Isomerization

We report the design of curved anthracene systems that undergo efficient Dewar isomerization upon visible light absorption and release heat through thermally triggered reverse isomerization, with high cyclability. These systems achieve remarkably high energy storage capacities-up to 170 kJ/mol and 0.65 MJ/kg-comparable to the best reported MOST materials, while offering the added capability of harnessing standard solar spectrum and presenting chemical robustness. Notably, these curved anthracenes can be fine-tuned to store energy in a neat liquid state, presenting a promising route toward solvent-free solar thermal energy storage devices. This report highlights the potential of fully carbon-based aromatic systems to store a large quantity of solar energy via photo-induced valence isomerization and dearomatization.