Figure 11.

From Figure 10, the water and the O₂ molecules were eliminated and the remaining species contains a catechol moiety. Hence, a potential approach of another superoxide is able to sequester a H atom, d(O₂-H) = 0.998 Å, forming the O₂H species. This is the classical manner of scavenging radicals by polyphenols, (option a). Total charge is −1, due to O₂H. Interestingly, the O₂H⁻ species in turn can capture a proton to form H₂O₂.