Lodaya et al. previously found that cationic nitrogen in GCCs can act as ortho-para activators for O2 binding, which is in line with the active site locations observed in this work. 36 Unlike the other ORR intermediates in this study, the O intermediate in catalyst C is unique in that it bonds directly to two carbons to form an epoxide intermediate. We discovered this epoxide intermediate when we placed the O atom at the ortho active site and optimized the geometry of the system, which caused the O atom to spontaneously transition into epoxide intermediate (Figure ). We calculated the energy of the epoxide structure relative to the single-site bound O atom at the ortho active site and found the epoxide structure is 0.06 eV lower in energy. Using the freezing string method, we calculated the activation energy for the transition between the two states to be 0.17 eV to transition from the single-site to epoxide structure. This energy difference is small enough that interconversion between both these binding modes would be possible during catalysis. We found that although the para active site can similarly form an epoxide structure by binding to the the same meta carbon as the ortho epoxide, this epoxide structure would not form spontaneously during DFT optimization from the single site O intermediate initial geometry. The specificity of where O2 will bind, as well as whether an epoxide intermediate will form for the R-O intermediate, can be explained by oxygen's tendency to bind to carbons that are not part of rings in Clar structures. The premise behind Clar structures is that not all carbon atoms in polyaromatic systems are equally stable, and unstable carbons can be identified based on the resonance structures of the system. Clar structures predict that the most stable resonance structure is the one with the maximum number of nonadjacent aromatic rings. Further, any aromatic carbon atoms that are not part of rings in the most stable Clar structure will be more reactive. The formalism of Clar structures also introduces an arrow notation that summarizes multiple resonance structures with the same number of total aromatic rings; the carbons in these rings are considered more stable than ones that are not in any ring.