Emissive iridium(III) diimine complexes formed by double cyclometalation of coordinated triphenylphosphite
Journal
Inorganic Chemistry
Journal Volume
50
Journal Issue
11
Pages
5075-5084
Date Issued
2011
Author(s)
Chang, Yao-Yuan
Hung, Jui-Yi
Chi, Yun
Chyn, Jong-Pyng
Chung, Min-Wen
Lin, Chia-Li
Lee, Gene-Hsiang
Chang, Chih-Hao
Lin, Wei-Chieh
Abstract
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 (�b(ext)), a luminance efficiency (�b(l)), and a power efficiency (�b(p)) of 14.1%, 46.6 cd A(-1), and 39.9 lm W(-1), respectively.
Type
journal article