Observation of dynamic solvent effect for electron tunneling in U-shaped molecules

The electron-transfer rate constant is measured in two U-shaped donor-bridge-acceptor molecules over a wide range of temperature in acetonitrile and N-methylacetamide (NMA). The electron-transfer rate at high temperature can be well described by a nonadiabatic model of the reaction but at low temperatures the rate in NMA becomes controlled by the solvent.