Organometallic Compounds for Storing Sunlight Energy

Certain organometallic molecules undergo a reaction upon exposure to light that is reversible with either a catalyst or heat. In some cases a considerable amount of energy can be stored, as was shown for example in the work of Vollhardt in 1996 for fulvalenes. In the Ru case shown in this figure, the Ru-Ru bond and the C-C bond are broken upon light exposure, and the molecule effectively “flips”. This stored chemical energy is highly stable, with a large back-reaction barrier, and can then be released in a very straightforward manner. 

We are at present using computation to understand how and why this reaction takes place, and also how to engineer the efficiency of the reaction in order to increase its ability to store energy. In addition, we are investigating a number of other such molecules that fall into the same class of sunlight-to-chemical energy storage. We’re also exploring pathways for utilizing such molecules on large scales, which involve appropriate matrix materials (which in turn impact its chemical properties).