Solvent-controlled acceleration of electron transfer reaction

Summary form only given. Liquid phase electron transfer is one of the key reactions in nature and has been extensively studied. In his pioneering work, Marcus (1985) modelled electron transfer (ET) as thermally activated barrier hopping. Subsequent improvements of the theory that incorporated the influence of solvent dynamics on the ET process, led to the central conclusion that the inverse ET rate is linearly proportional to the longitudinal relaxation time of the solvent. We present the first, to the best of our knowledge, experimental evidence of the solvent-controlled rate of the intermolecular ET reaction. The key virtue of the study is the use of binary mixtures, which allows us to vary continuously the relaxation properties of the solvent. We demonstrate that the ET reaction rate can be increased by more than a factor of 5, which signifies the change from solvent-controlled ET to a non-adiabatic ET.