Ligand Design and Preparation, Photophysical Properties, and Device Performance of an Encapsulated-Type -Tris(heteroleptic) Iridium(III) Emitter.

The organic molecule 2-(1-phenyl-1-(pyridin-2-yl)ethyl)-6-(3-(1-phenyl-1-(pyridin-2-yl)ethyl)phenyl)pyridine () has been designed, prepared, and employed to synthesize the encapsulated-type -tris(heteroleptic) iridium(III) derivative Ir(κ-'L). Its formation takes place as a result of the coordination of the heterocycles to the iridium center and the -CH bond activation of the phenyl groups. Dimer [Ir(μ-Cl)(η-COD)] is suitable for the preparation of this compound of class [Ir(9h)] (9h = 9-electron donor hexadentate ligand), but Ir(acac) is a more appropriate starting material.

Alkynyl Ligands as Building Blocks for the Preparation of Phosphorescent Iridium(III) Emitters: Alternative Synthetic Precursors and Procedures.

Alkynyl ligands stabilize dimers [Ir(μ-X)(3b)] with a cis disposition of the heterocycles of the 3b ligands, in contrast to chloride. Thus, the complexes of this class─[Ir(μ-η-C≡CPh){κ-,-(CH-Isoqui)}] (Isoqui = isoquinoline) and [Ir(μ-η-C≡CR){κ-,-(MeCH-py)}] (R = Ph, Bu)─have been prepared in high yields, starting from the dihydroxo-bridged dimers [Ir(μ-OH){κ-,-(CH-Isoqui)}] and [Ir(μ-OH){κ-,-(MeCH-py)}] and terminal alkynes. Subsequently, the acetylide ligands have been employed as building blocks to prepare the orange and green iridium(III) phosphorescent emitters, Ir{κ-,-[C(CHPh)Npy]}{κ-,-(CH-Isoqui)} and Ir{κ-,-[C(CHR)Npy]}{κ-,-(MeCH-py)} (R = Ph, Bu), respectively, with an octahedral structure of carbon and nitrogen atoms.

-Tris(heteroleptic) Red Phosphorescent Iridium(III) Complexes Bearing a Dianionic ,,','-Tetradentate Ligand.

1-Phenyl-3-(1-phenyl-1-(pyridin-2-yl)ethyl)isoquinoline (HMeL) has been prepared by Pd(-XantPhos)-catalyzed "" to synthesize new phosphorescent red iridium(III) emitters (601-732 nm), including the carbonyl derivative Ir(κ--,'--,'-MeL)Cl(CO) and the acetylacetonate compound Ir(κ--,'--,'-MeL)(acac). The tetradentate 6e-donor ligand (6tt') of these complexes is formed by two different bidentate units, namely, an orthometalated 2-phenylisoquinoline and an orthometalated 2-benzylpyridine. The link between the bidentate units reduces the number of possible stereoisomers of the structures [6tt' + 3b] (3b = bidentate 3e-donor ligand), with respect to a [3b + 3b' + 3b″] emitter containing three free bidentate units, and it permits a noticeable stereocontrol.

Preparation of Tris-Heteroleptic Iridium(III) Complexes Containing a Cyclometalated Aryl-N-Heterocyclic Carbene Ligand.

A new class of phosphorescent tris-heteroleptic iridium(III) complexes has been discovered. The addition of PhMeImAgI (PhMeIm = 1-phenyl-3-methylimidazolylidene) to the dimer [Ir(μ-Cl)(COD)] (1; COD = 1,5-cyclooctadiene) affords IrCl(COD)(PhMeIm) (2), which reacts with 1-phenylisoquinoline, 2-phenylpyridine, and 2-(2,4-difluorophenyl)pyridine to give the respective dimers [Ir(μ-Cl){κ- C, C-(CH-ImMe)}{κ- C, N-(CH-isoqui)}] (3), [Ir(μ-Cl){κ- C, C-(CH-ImMe)}{κ- C, N-(CH-py)}] (4), and [Ir(μ-Cl){κ- C, C-(CH-ImMe)}{κ- C, N-(CFH-py)}] (5), as a result of the N-heterocyclic carbene (NHC)- and N-heterocycle-supported o-CH bond activation of the aryl substituents and the hydrogenation of a C-C double bond of the coordinated diene. In solution, these dimers exist as a mixture of isomers a (Im trans to N) and b (Im trans to Cl), which lie in a dynamic equilibrium.

[Developing the control criterion for continuous culture of microorganisms].

A short survey and critical analysis of previously proposed criteria for growth control of populations of microorganisms in the chemostat are presented. Based on the analysis of a mathematical model of the steady-state of a microbial population in the chemostat, an adequate control criterion is suggested, along with a method to identify the corresponding regulating factors. The new control criterion is expressed as a product of the factor transformation coefficient and the biomass sensitivity coefficient (SC) with respect to the change of the factor at the chemostat inlet (referred to in the sequel as the biomass SC).