These assignments are supported by subtle differences in absorbance and steady-state emission spectra we observe for Ir[tBu]-PF 6 vs Ir[tBu]-BAr F 4 (See SI sections: Absorption and emission spectroscopy and [Ir(C^N) 2 (N^N)]X Electronic Structure). The dipole moment values we obtain are also broadly consistent with prior solvatochromism measurements for [Ir(C^N) 2 (N^N)]Cl complexes where (C^N)= ppy or benzo[h]quinoline (bzq), and (N^N)= bpy or 1,10-phenanthroline (bpy)). In this study, the ground and excited-state dipole moments were determined from absorption and emission solvatochromism data in 17 solvents spanning the polarity spectrum, but neglecting to account for ion pairing behavior. Thus, in low dielectric solvents, the dipole moment they observed should be characteristic of the ion-paired species [Ir(C^N) 2 (N^N)]Cl, whilst in high dielectric solvents it most likely represents that of the unpaired species. We conjecture that their measured value (µ Lit =6.7 D), represents an average of these two extremes, and compares favorably with an average of the dipole moments we find for Ir[tBu]-PF 6 and Ir[tBu]-BAr F 4 (µ Avg =7.7 D). Figure illustrates the ion-pairing behavior we propose for the ground-state without contact-ion pairing (5(a)) and with contact-ion pairing (5(b)). If the ion pair is not in contact, the overall dipole moment measured using dielectric-loss will be equal to just the intramolecular dipole moment (purple). However, in the presence of contact-ion pairing, the overall dipole moment measured using dielectric-loss will be equal to the vector sum (equation ( )) of the intramolecular dipole moment (purple) and the intermolecular dipole moment (yellow). Dielectric-loss can only measure ion pairs that are bound sufficiently tightly for the pair to tumble as a single molecular unit in solution. In any situation where each complex can tumble separately the measured dipole moment will revert to the intramolecular component depicted in Fig. , even if the ions remain paired in a looser solvent-separated fashion. ). The data obtained were collected and separated into their complex permittivity components as detailed in the Fitting COMSOL Models to Data and the Complex K-Factor section of the SI. Both complex's kinetics were fit with a global two-Species sequential kinetic model similar to that used for DMABN. Here, however, there is less of a clear a-priori basis for assigning the identity of these kinetically identified Species from TRDL measurements. We simply designate the fast, early-time component as Species A and the slower, later-time component as Species B for now. The rate constants from the kinetic fits and the absolute dipole moments are summarized in table . mechanism where the ion pair reorients to cancel the intramolecular dipole moment of the MLCT state, as inferred for the ground-state in the preceding section. Indeed, contact-ion pairing combined with this sort of excited-state reorganization will always result in an overall negative change in the dipole moment. Simply by virtue of the fact that the counter-ion must remain further from the molecular center than the ligand shell, it is impossible for the intramolecular dipole moment to exceed that associated with the intermolecular dipole moment. The fact that we do not see this negative change in the B Species of the Ir[tBu]-BAr F 4 complex is confirmation that the negative transient dipole moment is most likely due to ion-pair reorganization. As described previously on similar complexes, ion-pairing imposes an electrostatic restriction on the spatial geometry of the complex. This description agrees well with the differences we observe in the ground-state dipole moments and absorption spectra of Ir[tBu]-BAr F 4 vs Ir[tBu]-PF 6 (See SI, Absorbance and emission spectroscopy). However, the ion-pair rearrangement in the excited-state alters the geometry of the coordination sphere to accommodate the charge redistribution. This rearrangement results in a slight stabilization of the emitting states. This stabilizing effect is evidenced by small bathochromic shifts in the emission bands, differences in the population of the 3 MLCT dF(CF 3 )ppy/dtbpy (See Supplementary Fig. and Supplementary Table ), and a reduction of the excited-state lifetime. The observed shifts in emission profile and reduction in the lifetime for Ir[tBu]-PF 6 vs Ir[tBu]-BAr F 4 also agree well with previous literature results. In both complexes, ∆ε shows a much larger charge delocalization for Species A over Species B, as inferred from the large polarizability volume. This makes sense in light of the highly mixed nature of the Frank-Condon and high-lying excited-states that result in LLCT. This could be important to understanding and improving the efficiency of a photoredox catalyst since the charges in Species A are more dispersed than in Species B. Extending the lifetime of Species A or chemically pre-associating the photoredox catalyst with target substrate could enhance the likelihood of charge transfer due to Species A having a larger dispersion of charge and thus improve the overall reaction.