Ab initio study of the energetics of photoinduced electron and proton transfer processes in a bio-inspired model of photochemical water splitting

The photochemical reaction mechanisms of a supramolecular model system consisting of a truncated chlorophyll, imidazole, and benzoquinone have been explored with ab initio electronic-structure methods. The calculations indicate that a photoinduced electron-driven proton-transfer process leads to the oxidation of imidazole and reduction of the quinone. The repeated photoinduced reduction of benzoquinone is a mechanism which can lead to the decomposition of water by sunlight.