RsvH3 and O2 •-, 2PCET between RsvH3 and O2 •-, and concerted PCET between RsvH3 and HO2 • . To gain deeper insight into the PCET mechanism of O2 •-scavenging by RsvH3, the potentialenergy surfaces were investigated at the (U)B3LYP/PCM/6-311+G(d,p) level of theory combined with NBO calculations. Along the reaction in DMF solution, three elementary steps are assumed to proceed, i) formation of PRC via HBs from the free reactants, ii) PCET reaction forming product complex (PC) via a TS, and iii) dissociation of the PC yielding the free products.