Inorganic Chemistry, Vol.59, No.17, 12286-12294, 2020
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 (H2L) has been designed and its reactions with [Ir(mu-Cl)(eta(4)-COD)](2) (1, COD = 1,5-cyclooctadiene) have been studied. The products obtained depend on the refluxing temperature of the solvent. Thus, complexes Ir(kappa(4)-C,C',N,N'-L)Cl(CO) (2), [Ir(eta(4)-COD)(kappa(2)-N,N'-H2L)][IrCl2(eta(4)-COD)] (3), and [Ir(mu-Cl)(kappa(4)-C,C',N,N'-L)](2) (4) have been formed in 2-ethoxyethanol, propan-2-ol, and 1-phenylethanol, respectively. Complex 4 reacts with K(acac) to give the acetylacetonate derivative Ir(kappa(4)-C,C',N,N'-L)(acac) (5). Complexes 2 and 5 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 mu s and high quantum yields (0.54-0.87) in both PMMA films and 2-MeTHF at room temperature.