The Switching Mechanisms of Dihydroazulene/ Vinylheptafulvene Photo-/Thermoswitches

Abstract

We have investigated the switching mechanisms of photochromic systems that are relevant for harvesting, storing, and releasing solar energy. We consider storage of solar energy in the form of energetic chemical bonds via light-induced isomerization reactions. The approach concerns photoswitches that upon irradiation isomerize to high-energy metastable isomers and through the corresponding backreaction will release the stored energy. Thereby, we have considered molecular closed-cycle energy storage systems that do not involve the release of CO2. We present potential energy surfaces for ground states and excited states and discuss the roles that these states play when harvesting, storing, and releasing solar energy. Furthermore, we have illustrated new approaches for obtaining synergy between theoretical modeling and future experimental work.