Upon considering side path(s), the overall conclusion is no longer paradoxical. Here, the illustrative example is a study of visible-light-mediated activation of vinyl chlorides derived from α-chloro ethyl cinnamates via oxidative quenching of excited photocatalyst fac-Ir(ppy)3 (Figure ). Upon photoelectron transfer and chloride extrusion, the corresponding vinyl radical can be efficiently trapped by enol acetates, giving rise to 1,4-dicarbonyl compounds. In agreement with reduction potentials and bond dissociation energies (BDEs), the α-fluoro cinnamate substrate, which has the strongest vinyl-X bond (BDE = 123.7 kcal/mol), does not allow for the formation of a vinyl radical. However, the trend between the α-chloro cinnamate and the α-bromo cinnamate substrates is paradoxical under this mode of analysis. The data presented indicate that the Cvinyl-Cl bond is both significantly stronger and more challenging to be reduced than the corresponding Cvinyl-Br bond. Nevertheless, under the optimized conditions, the α-bromo cinnamate substrate resulted in a significantly lower product yield. The resolution to this paradox comes from taking another elementary step into consideration: photocatalyst degradation. Ethyl bromoacetate, formed as a byproduct upon the reaction of the vinyl bromide with the enol acetates, acts as an efficient catalyst poison for fac-Ir(ppy)3 due to acid-induced ppy ligand radical functionalization. In contrast, ethyl chloroacetate, formed in the reaction of the α-chloro cinnamate substrate, has not been found to have this effect. Consequently, in the case of the α-bromo substrate, the productive reaction halted at low conversion due to deactivation of the photocatalyst. An illustrative example comes from the study of the rotational barriers of biaryl compounds (Figure ). At first glance, single electron oxidation appears to contradict expectations; it shortens the biaryl C-C bond, seemingly increasing steric congestion at the transition state compared to the neutral counterpart, without involving dispersion forces. Paradoxically, despite this bond contraction, the rotational barrier decreases significantly upon oxidation. This paradox resolves upon considering an additional parameter besides bond length: the frontier orbitals. Initially, focusing on these orbitals might seem counterintuitive, especially in a context devoid of bond formation. However, removing an electron from the HOMO stabilizes the planar transition state to the point that it becomes an intermediate on the potential energy surface. This stabilization, alongside the bond shortening in radical cations-particularly noticeable in the rotational transition state and achiral minimum-is due to enhanced bonding character between the carbon atoms. Arene radical cations' greater preference for planarity relative to their neutral counterparts is another outcome of this stabilization, driven by the net bonding interaction between the naphthalene π-systems when the HOMO is partially unoccupied. In essence, while steric hindrance alone would suggest an increase in the rotational barrier, the inclusion of frontier orbital interactions offers a consistent explanation. In general, although the inclusion of the additional parameter appears to make the data no longer paradoxical, the analysis may still not fully encapsulate the complexity of a phenomenon. Other underlying factors might be overshadowed by the focused study of the two parameters for one specific molecule. In structurally similar molecules, different yet unstudied parameters could prove significant, suggesting a need for a broader, albeit still incomplete, understanding.