Solubilised bright blue-emitting iridium complexes for solution processed OLEDs

J Mater Chem C Mater. 2016 May 7;4(17):3726-3737. doi: 10.1039/c6tc00151c. Epub 2016 Feb 11.

Abstract

Combining a sterically bulky, electron-deficient 2-(2,4-difluorophenyl)-4-(2,4,6-trimethylphenyl)pyridine (dFMesppy) cyclometalating CN ligand with an electron rich, highly rigidified 1,1'-(α,α'-o-xylylene)-2,2'-biimidazole (o-xylbiim) NN ligand gives an iridium complex, [Ir(dFMesppy)2(o-xylbiim)](PF6), that achieves extraordinarily bright blue emission (ΦPL = 90%; λmax = 459 nm in MeCN) for a cationic iridium complex. This complex is compared with two reference complexes bearing 4,4'-di-tert-butyl-2,2'-bipyridine, and solution-processed organic light emitting diodes (OLEDs) have been fabricated from these materials.