Exploring ortho -dianthrylbenzenes for molecular solar thermal energy storage.

Molecular solar thermal systems, which absorb light, store it, and release it as heat, have been extensively researched, yet many potential candidates remain unexplored. To expand this range, five specifically designed ortho -dianthrylbenzenes were investigated. Anthracene dimers have been underexplored due to issues like photooxidation and varying photodimerization efficiency. The presented systems address these challenges by aryl-linking two anthracene moieties, achieving photodimerization quantum yields ranging from 11.5% to 16% in mesitylene. The impact of donor or acceptor groups on energy storage time (9-37 years), energy storage density (0.14-0.2 MJ kg -1 ), and solar energy storage efficiency (0.38-0.66%) was evaluated. The experimental results, supported by density functional theory-based modeling, highlight the potential of anthracene-based photoswitches for molecular solar thermal applications and encourage further exploration of similar systems.