Recent mechanistic studies have disclosed spectroscopic evidence for energy transfer from highly reducing PCs (i.e. Ir(ppy)3 and a phenoxazine (PhenO) PC; ppy = 2-phenylpyridine and PhenO = 3,7-di([1,1'-biphenyl]-4-yl)-10-(naphthalen-1-yl)-10H-phenoxazine) to a Ni complex to generate a Ni centered excited state that was crucial for catalysis (Fig. ). Based on these reports, we hypothesized that energy transfer would also be the mode of activation of Ni in our unified C─heteroatom coupling system as these same PCs are used. However, the reduction of Ni(II) to Ni(I) by the excited state PC (either Ir(ppy)3 or PhenO; Ered* = -1.66 and -1.73 V vs SCE respectively) is thermodynamically feasible based on reported cyclic voltammetry data of relevant nickel bipyridine complexes (Ered[Ni(II)/Ni(I)] = -1.0-1.3 V vs SCE). Furthermore, in our study with SCF3 nucleophiles, product yield was found to increase as the excited state reduction potential of the PC became more negative, while the triplet energy of the PCs was found to have no correlation with yield. These considerations taken together suggest that the alternate hypothesis of an oxidative quenching cycle (Fig. ) should be considered seriously in these systems, motivating a mechanistic study to distinguish between electron transfer and energy transfer as the mode of quenching of the Ir(ppy)3 excited state.