Investigating photoluminescence and electroluminescence of iridium(III)-based blue-emitting phosphors

Thiphenylmethane based structural fragments as building blocks towards solution-processable heteroleptic iridium(iii) complexes for OLED use

Functionalization with 1,1,1-triphenylmethylpentane groups can be used for heteroleptic iridium(iii) complexes in order to obtain solution-processable OLED emitters.

The crystal structure of bis-{3,5-di-fluoro-2-[4-(2,4,6-tri-methyl-phen-yl)pyridin-2-yl]phen-yl}(picolinato)iridium(III) and its 4-tert-butyl-pyridin-2-yl analogue

The crystal structures of bis-{3,5-di-fluoro-2-[4-(2,4,6-tri-methyl-phen-yl)pyridin-2-yl]phenyl-κ2 N,C 1}(picolinato-κ2 N,O)iridium(III), [Ir(C20H16F2N)2(C6H4NO2)], 1, and bis-[2-(4-tert-butyl-pyridin-2-yl)-3,5-di-fluoro-phenyl-κ2 N,C 1](picolinato-κ2 N,O)iridium(III), [Ir(C15H14F2N)2(C6H4NO2)], 2, are presented herein. These phospho-rescent cyclo-metallated iridium(III) compounds have been structurally investigated in order to better understand the nature of their blue-shifted emssions while maintaining high quantum yields. Compound 1 exhibits substantial twisting of the mesitylene rings out of the plane of the attached pyridine ring, with dihedral angles of 67.0 (1) and 78.7 (1)° between the best mean planes. For both compounds, the contribution of disordered solvent mol-ecule(s) was removed using the SQUEEZE [Spek (2015 ▸). Acta Cryst. C71, 9-18] routine in PLATON [Spek (2015 ▸). Acta Cryst. C71, 9-18]. These solvent mol-ecules are not considered in the given chemical formula and other crystal data.

Novel Design of Iridium Phosphors with Pyridinylphosphinate Ligands for High-Efficiency Blue Organic Light-emitting Diodes

Due to the high quantum efficiency and wide scope of emission colors, iridium (Ir) (III) complexes have been widely applied as guest materials for OLEDs (organic light-emitting diodes). Contrary to well-developed Ir(III)-based red and green phosphorescent complexes, the efficient blue emitters are rare reported. Like the development of the LED, the absence of efficient and stable blue materials hinders the widely practical application of the OLEDs. Inspired by this, we designed two novel ancillary ligands of phenyl(pyridin-2-yl)phosphinate (ppp) and dipyridinylphosphinate (dpp) for efficient blue phosphorescent iridium complexes (dfppy)₂Ir(ppp) and (dfppy)₂Ir(dpp) (dfppy = 2-(2,4-difluorophenyl)pyridine) with good electron transport property. The devices using the new iridium phosphors display excellent electroluminescence (EL) performances with a peak current efficiency of 58.78 cd/A, a maximum external quantum efficiency of 28.3%, a peak power efficiency of 52.74 lm/W and negligible efficiency roll-off ratios. The results demonstrated that iridium complexes with pyridinylphosphinate ligands are potential blue phosphorescent materials for OLEDs.

Design of C^NN type iridium(iii) complexes towards short-wavelength emission for high efficiency organic light-emitting diodes

The first blue-emitting C^NN based Ir-complex was synthesized and applied to PhOLEDs, with efficiencies of 20.1% and 41.6 cd A⁻¹.

Tuning the electronic and phosphorescence properties of blue-emitting iridium(iii) complexes through different cyclometalated ligand substituents: a theoretical investigation

A DFT/TDDFT investigation was performed to estimate the OLED performance of six reported and seven newly designed iridium(iii) complexes.

Cyclometalated Ir(III) Complexes Containing Pyrazole/Pyrazine Carboxylate Ligands

Two cyclometalated Ir(iii) complexes using 2-phenylpyridine (ppy-H) as the cyclometalating ligand, and pyrazole-3-carboxylic acid (prca-H) and pyrazine 3,5-dicarboxylic acid (pzdca-H2) as ancillary ligands; were synthesized from the chloro-bridged dimer precursor [{(ppy)2Ir}2(μ-Cl)2]. The title compounds [Ir(ppy)2(prca)] (1) and [{Ir(ppy)2}2(pzdca)] (2) are monomeric and dimeric neutral Ir(iii) complexes, respectively. Their electrochemical and photophysical properties were examined. They exhibit metal-based oxidations and ligand-based reductions. These complexes exhibit emission in the blue-green region with lifetimes in the micro-second range at room temperature. The nature of the emission spectra indicates differences in the origin of emission in these two compounds.