Color tuning of iridium complexes - Part I: Substituted phenylisoquinoline-based iridium complexes as the triplet emitter

A series of new iridium complexes with isoquinoline derivative ligands were synthesized for application in organic light-emitting diodes (OLEDs). It is demonstrated that varying the substituents at the 2'- or 4'-positions of the isoquinoline ligand makes the color tuning possible. Because of the steric effect, the 6'-substituted complexes: bis[1-(6'-methyl)phenylisoquinolinato-N,C-2'] iridium(III) (acetylacetonate) (6b1), bis[1-(6'-trifluoromethyl)phenylisoquinolinato-N, C-2'] iridium(III) (acetylacetonate) (6b2), and bis[1-(6'-methoxy)phenylisoquinolinato-N C-2'] iridium(III) (acetylacetonate) (6b3) show red-shift effect with respect to the 4'-substituted complexes: bis[l-(4'-methyl)phenylisoquinolinato-N, C-2'] iridium(III) (acetylacetonate) (6a1), bis[l-(4-trifluoromethyl)phenylisoquinolinato-N C2'] iridium(III) (acetylacetonate) (6a2), and bis[l-(4'-methoxy)phenylisoquinlinato-N, C-2'] iridium(III) (acetylacetonate) (60). All of these complexes are suitable for the red phosphorescent materials in OLEDs. (c) 2005 Elsevier B.V. All rights reserved.