To clarify the mechanism of the PCET between RsvH3 and O2 •-in DMF, we performed DFT calculations using the B3LYP hybrid functional employing the PCM method. First, the stable structures of RsvH3 (Supporting Information, Table ) and the conformers of its deprotonated anions ( a RsvH2 -, b RsvH2 -, and c RsvH2 -) along the initial PT route were obtained from energy scanning of the dihedral angle around the stilbene moiety and three OHs. Figure shows the optimized structures along with their calculated standard Gibbs free energy changes (ΔG°/kJ mol -1 , 298.15 K) along the PT route (Supporting Information, Table ). The distributed charges on the OH protons of RsvH3 were obtained in an NBO analysis. and c RsvH2 -(39.70), because of the resonance effects of para-OH as is previously reported. According to these calculation results, PT is initiated at the 4'OH, forming a RsvH2 -. However, each of the three OH protons can be transferred to O2 •-along the dynamic behavior provoked by the alternation of HB formation and breaking between RsvH3 and O2 •-in DMF solutions.