Phosphorescent Iridium(III) Complexes with a Dianionic C,C',N,N'-Tetradentate Ligand.

To prepare new phosphorescent iridium(III) emitters, 2-phenyl-6-(1-phenyl-1-(pyridin-2-yl)ethyl)pyridine (HL) has been designed and its reactions with [Ir(μ-Cl)(η-COD)] (, COD = 1,5-cyclooctadiene) have been studied. The products obtained depend on the refluxing temperature of the solvent. Thus, complexes Ir(κ-'-L)Cl(CO) (), [Ir(η-COD)(κ-HL)][IrCl(η-COD)] (), and [Ir(μ-Cl)(κL)] () have been formed in 2-ethoxyethanol, propan-2-ol, and 1-phenylethanol, respectively. Complex reacts with K(acac) to give the acetylacetonate derivative Ir(κL)(acac) (). Complexes and are efficient blue-green and green emitters of classes [6tt+1m+2m] and [6tt+3b], respectively. They display lifetimes in the range of 1.1-4.5 μs and high quantum yields (0.54-0.87) in both PMMA films and 2-MeTHF at room temperature.