Light-Driven Electron Accumulation in a Molecular Pentad.

Accumulation and temporary storage of redox equivalents with visible light as an energy input is of pivotal importance for artificial photosynthesis because key reactions, such as CO2 reduction or water oxidation, require the transfer of multiple redox equivalents. We report on the first purely molecular system, in which a long-lived charge-separated state (τ≈870 ns) with two electrons accumulated on a suitable acceptor unit can be observed after excitation with visible light. Importantly, no sacrificial reagents were employed.