Along the plausible sequential-pathway for all compounds shown in Table , the sum of the ΔG°s of PT1-ET2 was endergonic, in case of using each of the three functionals. Conversely, since PT4 after PT1-ET2 is strongly exergonic for all the compounds, two concerted pathways (PT1-concerted PCET and 2PCET) driven by the second PT are feasible, as shown in the case of RsvH3 (Figure ). However, both the ΔG° values of the two concerted reactions (concerted and total in Table ) for pinosylvin (-37.4, -0.1, obtained using B3LYP) and p-coumaric acid (-29.2, -21.9) are not so larger than those for RsvH3 (-38.5, 0.3) and PtsH (-27.7, 4.2), which is inconsistent with the electrochemical results. Here, the ΔG° values for PtsH were calculated along a 2:1 PCET mechanism that occurs between two molecules of PtsH and O2 •-(Supporting Information, Figure ) similar to that of other mono phenol involving α-tocopherol. These ΔG° values for RsvH3 and PtsH are consistent with the CV results showing a successful PCET.