A New Facial Homoleptic Tris-Cyclometalated Iridium(Iii) Complex With Oxygen-Bridged Triarylamine Units

A new facial homoleptic tris-cyclometalated phosphorescent iridium(III) complex Ir(ppyNO)(3) featuring three oxygen-bridged triarylamine units has been synthesized via an efficient Suzuki-Miyaura cross-coupling reaction of oxygen-bridged triarylamine unit based boron reagent 1-b with corresponding tribrominated iridium(III) complex Ir-Br. It can not only show an effective green light emission, but also display a narrower full width at half maximum (FWHM=57 nm) and better solubility than that of the classical complex fac-Ir(ppy)(3) (FWHM=82 nm, ppy=2-phenylpyridine). Furthermore, a longer emission lifetime (tau=1201 ns) of Ir(ppyNO)(3) in polystyrene (PS) film can be found than that (tau=45 ns) in CH2Cl2 solution. In addition, the lowest triplet state (T-1) of Ir(ppyNO)(3) can exhibit both metal-to-ligand charge transfer ((MLCT)-M-3) and intraligand charge transfer ((ILCT)-I-3) excited state character according to DFT calculations.