Emissive iridium(III) diimine complexes formed by double cyclometalation of coordinated triphenylphosphite.

We report on the synthesis of a new series of iridium(III) complexes functionalized with various diimine chromophores, together with a facially coordinated dicyclometalated phosphite chelate and a monodentate anionic ancillary. This conceptual design presents a novel strategy in obtaining a new class of iridium(III) diimine complexes without employment of traditional nitrogen-containing polyaromatic cyclometalates. Additionally, we discuss the basic charactersistics of the ground and lower-lying excited states involved, as documented by crystal structural, photophysical studies, and density functional theory calculations. Fabrication of the green-emitting organic light-emitting diodes with one such dopant, [Ir(dbbpy)(tpit)NCS] (2b), where dbbpy and tpit represent di-tert-butyl-2,2′-bipyridine and dicyclometalated triphenylphosphite, respectively, was successfully made, attaining a peak external quantum efficiency (ηext), a luminance efficiency (ηl), and a power efficiency (ηp) of 14.1%, 46.6 cd A–1, and 3...