||Luminescent Ir(III) complexes bearing benzothiazole or benzoxazole-based pincer ligand
Kuwabara, Junpei ,
Namekawa, Tomomi ,
Sakabe, Eiko ,
Haga, Masa-akiKanbara, Takaki
Journal of organometallic chemistry
195 , 2017-09 , Elsevier
Ir complexes bearing pincer ligands are expected to be efficient phosphorescent materials. This work investigated the solid-state structures and photophysical properties of Ir(III) complexes that contain different NCN pincer ligands (NCN = 1,3-bis(2-benzothiazolyl)benzene, 1,3-bis(2-benzoxazoyl)benzene, or 1,3-bis(2-benzimidazoyl)benzene derivatives), bidentate cyclometalating NC ligands (NC = 2-phenylpyridine or 2-phenylbenzothiazole), and anionic ancillary ligands. The structure of the NCN pincer ligands is a dominant factor for determining the emission wavelength, rather than the bidentate NC and ancillary ligands. The organic light emitting diodes (OLEDs) with an Ir(III) complex show electroluminescence with 14% external quantum efficiency at 1 mAcm−2. Modification of the device structure improved the efficiency at the high current density region.