Cationic And Neutral Bis-cyclometalated Iridium(III) Complexes With Pure Blue Photoluminescence

Iridium complexes have been employed as dopants in organic light-emitting diodes mainly due to their high photostability, color tunability, and their ability to harvest both singlet and triplet excited states due to enhanced spin–orbit coupling. Taking advantage of these features, iridium complexes can be carefully designed and modified to produce highly phosphorescent compounds with high color purity. Dopants with high color purity are of high interest since they help to expand the color gamut, increasing the range of colors displayed by a screen or monitor; therefore, enhancing image quality. This dissertation presents eight cationic and nine charge-neutral iridium complexes which exhibit sky-blue to deep-blue phosphorescence in 2 wt% poly(methyl methacrylate) thin films at room temperature with moderate to good photoluminescence quantum yields. All complexes have triazole- or imidazole-based cyclometalating ligands combined with strong-field ancillary ligands, yielding to a large enough HOMO–LUMO gap which is a requirement for blue phosphorescence.