10.1021/ja052880t.s001 Youngmin You Youngmin You Soo Young Park Soo Young Park Inter-Ligand Energy Transfer and Related Emission Change in the Cyclometalated Heteroleptic Iridium Complex:  Facile and Efficient Color Tuning over the Whole Visible Range by the Ancillary Ligand Structure American Chemical Society 2005 novel color solvatochromic phenomena MLCT 3 state photoluminescence spectra LX 3 state Efficient Color Tuning electrophosphorescent iridium DFT calculations Related Emission Change Characteristic shapes ILET nm Ancillary Ligand Structure cyclometalating ligand Whole Visible Range 2005-09-14 00:00:00 Journal contribution https://acs.figshare.com/articles/journal_contribution/Inter_Ligand_Energy_Transfer_and_Related_Emission_Change_in_the_Cyclometalated_Heteroleptic_Iridium_Complex_Facile_and_Efficient_Color_Tuning_over_the_Whole_Visible_Range_by_the_Ancillary_Ligand_Structure/3268258 We report a novel color tuning methodology in the electrophosphorescent iridium complex by substituting one cyclometalating ligand to an ancillary ligand as an emitting center. Highly efficient exothermic inter-ligand energy transfer (ILET) from the MLCT<sup>3</sup> state produced between iridium and cyclometalating 2-(2,4-difluorophenyl)pyridine to LX<sup>3</sup> state of the ancillary ligand offers a chance to access a wider range of color from sky blue (478 nm) to red (666 nm). Characteristic shapes of photoluminescence spectra, strong solvatochromic phenomena as well as DFT calculations gave evidences for this exothermic ILET.