for individual spectra). The Sm(II) analogs of these complexes were not studied as the intense absorption features spanning the visible region fully quenches emission from f-d charge transfer electronic transitions through non-radiative decay. The intra 4f luminescent transitions of Ln(III) complexes are well-understood and do not vary significantly with the ligand field due to the radially contracted 4f orbitals. By contrast, the energies of the f-d luminescent transitions of Ln(II) complexes tend to vary to a much greater extent and are more vibrationally broadened. Here, the local crystal field and solvent stabilization effects in the excited state, in combination with the relatively more stabilized d-orbitals, enable other competitive nonradiative relaxation pathways.