Phospho-rescent mono- and diiridium(III) complexes cyclo-metalated by fluorenyl- or phenyl-pyridino ligands with bulky substituents, as prospective OLED dopants.

The crystal structures of tris-[9,9-dihexyl-2-(5-meth-oxy-pyridin-2-yl-κ)-9-fluoren-3-yl-κ ]iridium pentane monosolvate, [Ir(CHNO)]·CH, (I), di-μ-chlorido-bis-{bis-[2-(5-fluoro-pyridin-2-yl)-9,9-dihexyl-9-fluoren-3-yl]iridium} pentane 0.3-solvate, [Ir(CHFN)Cl]·0.3CH, (II), di-μ-cyanato-bis-{bis-[9,9-dihexyl-2-(5-meth-oxy-pyridin-2-yl)-9-fluoren-1-yl]iridium} pentane monosolvate, [Ir(CHNO)(NCO)(NCO)]·CH, (III), and {μ-,'-bis-[3,5-bis-(tri-fluoro-meth-yl)phen-yl]oxamidato}bis(bis{2-[4-(2,4,6-trimethylphenyl)pyridin-2-yl]phenyl-κ ,'}iridium)-chloro-benzene-pentane (1/2.3/0.4), [Ir(CHN)(CHFNO)]·2.3CHCl·0.4CH, (IV), synthesized in the quest for organic light-emitting devices, were determined. The bis-μ-chloro and bis-μ-cyanato complexes have ΔΔ and ΛΛ configurations of the distorted octa-hedral Ir centres in racemic crystals, whereas the oxamido complex has a centrosymmetric () structure with the ΔΛ configuration. The bridging oxamido moiety has a nearly planar geometry. All structures show substantial disorder of both host mol-ecules and solvents of crystallization.