Finally, we can analyze the effect of methylation in hydroxyquinones. Methyl groups are inductive electron-donating groups, and therefore, methylation enriches the electron density of hydroquinones making the system more nu-cleophilic and stabilizing the oxidized forms. As a result of the stabilization, oxidation and deprotonation reactions are less endergonic and their respective oxidation potentials less negative. This tendency, which clearly comes out in experimental data, is also qualitatively picked up in our calculations. Methylated hydroquinone exhibits shifts in the oxidation potentials with respect to the non-methylated case of +0.29 eV and +0.04 eV for the ET and PCET processes, respectively. These shifts are comparable with the experimental one of +0.20 eV.