Predicted ground-state dipole moment between the iridium metal center and the anion's center using basic chemical theory (µ = d • q; where d is distance between charges and q is the elementary charge) for Ir When considering the ligand framework of Ir[tBu] + , a ground-state dipole moment is expected on grounds of both symmetry and formal charge distribution. However, cyclometalation of Ir(III) with dF(CF) 3 ppy ligands produces a highly mixed HOMO (Ir d -dF(CF) 3 ppy) that lies relatively close to the metal. This bonding environment implies that the ground-state intramolecular dipole in Ir[tBu] + should be relatively small. In contrast, the apparent dipole moment resulting from a contact-ion pair interaction is expected to be large, due to the relatively large separation between the ionic charge centers and the fact that the ions rotate as a single unit in solution. Directly measured dipole moments of [Ir(C^N) 2 (N^N)] + complexes have never been reported to our knowledge, either in the ground or excited-states. Using the slope from ε" vs the concentration of Ir[tBu]-PF 6 in 1,4-dioxane (figure (a)), equation ( ), and a θ paired of 70.5 ps (calculated assuming contact-ion pairing as described in the Molecular Rotation section of the SI) we found the ground-state dipole moment of Ir[tBu]-PF 6 to be 10.7 D. If we assume loose or no ion pairing, the rotation time is modified to 68.26 ps and the calculated dipole moment is reduced to 10.6 D, only a small change occasioned by the very compact size of PF - 6 . In both cases, the magnitude of the ground-state dipole is substantially larger than what we would expect for the intramolecular ground-state dipole moment of just Ir[tBu] + (∼ 5.0 D, based on that of Ir(ppy) 3 (see SI section Non-ionic Iridium(III) Complex)). Yet, the calculated value is still smaller than we expect for a contact-ion pair Ir[tBu]-PF 6 (27.4 D). We posit three primary explanations: first, that the inter-and intra-molecular dipoles partially cancel in a contact-ion pair that self-organizes to minimize electrostatic energy, as depicted in Figure . Second, that the small PF - 6 anion may lie ∼ 2.5 Å closer to the positive charge center than expected (27.4-5.0 = 22.4 D, integer charge separation produces a dipole moment of 4.8 D/Å), interdigitating with the ligand shell. Third, that contact ion pair is likely to be in equilibrium with solvent-separated pairs, which would reduce the average dipole moment that we measure.