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A series of blue phosphorescent heteroleptic cyclometalated Ir (III) complexes with mesitylphenyl‐imidazole ligands for organic light‐emitting devices are investigated theoretically to explore their electronic structures, spectroscopic properties, and application value for organic light‐emitting devices. FCNIr, (FCN)2Ir(tpip), (FCN)2Ir(acac), (CN)2Ir(tpip), (CN)2Ir(acac), and CNIr are investigated with density functional theory approaches, where, for (FCN)2Ir(acac), FCN denotes 2,4‐difluorobiphenyl3‐carbonitrile and acac denotes acetylacetonate; for (FCN)2Ir(tpip), tpip denotes tetraphenylimido‐diphosphonate); and for (CN)2Ir(acac) and (CN)2Ir(tpip), CN denotes biphenyl‐3‐carbonitrile. [ABSTRACT FROM AUTHOR]

A series of heterocyclic Ir(III) complexes used in organic light‐emitting diode (OLED) materials with low‐efficiency roll‐off performance have been studied theoretically. Their electronic structures, spectral properties, and their application value in OLEDs are discussed. The geometries, electronic structures, lowest‐lying singlet absorptions, and triplet emissions of (dmdppr‐dmp)2Ir(dibm), and the theoretically designed models of (dmdppr‐dmp)2Ir(acac), (dmdppr‐dmp)2Ir(tpip), (dmdppr‐Fdmp)2Ir(dibm), (dmdppr‐Fdmp)2Ir(acac), and (dmdppr‐Fdmp)2Ir(tpip) were investigated with density‐functional‐theory‐based approaches, where dibm denotes 2,6‐dimethy‐3,5‐heptanedionato‐κ2‐O,O′, acac denotes acetylacetonate, and tpip denotes tetraphenylimido‐diphosphinate. [ABSTRACT FROM AUTHOR]

A series of heteroleptic cyclometalated Ir (III) complexes with low‐color‐temperature and low‐efficiency roll‐off properties, which cause a fast reduction in efficiency when the drive current increases, for organic light‐emitting devices are investigated theoretically to explore their electronic structures and spectroscopic properties. The geometries, electronic structures, lowest‐lying singlet absorptions and triplet emissions of (ptpy)2Ir(acac), and the theoretically designed models (ptpy)2Ir(tpip), (F‐ptpy)2Ir(acac), (F‐ptpy)2Ir(tpip), (F2‐ptpy)2Ir(acac) and (F2‐ptpy)2Ir(tpip), are investigated with density functional theory approaches, where ptpy denotes 4‐phenylthieno [3,2‐c] pyridine, acac denotes acetylacetonate, tpip denotes tetraphenylimido‐diphosphinate, F‐ptpy denotes 4‐(3‐fluorophenyl) thieno [3,2‐c] pyridine, and F2‐ptpy denotes 4‐(2,4‐difluorophenyl) thieno [3,2‐c] pyridine. A series of heteroleptic cyclometalated Ir (III) complexes, which are used for OLED application, were investigated by DFT and TD‐DFT method. The frontier molecular orbital character and charge transfer character show that they have the advantages of low‐efficiency roll‐off and low‐color‐temperature properties, which is a 'stumbling block' in the process of OLED solid‐lighting's development. This means that the materials play an important role in the development of OLED. [ABSTRACT FROM AUTHOR]

Abstract A series of blue and green-emitting phosphorescent heteroleptic cyclometalated Ir(III) complexes with mesityl-phenyl-imidazole Ligand for organic light-emitting devices are investigated theoretically to explore their electronic structures, spectroscopic properties and the application value for organic light emitting devices. The geometries, electronic structures, lowest-lying singlet absorptions, and triplet emissions of Ir(mpim) 3 , and the theoretically designed models Ir(F-mpim) 3 , Ir(F 2 -mpim) 3 , (mpim) 2 Ir(acac), (F-mpim) 2 Ir(acac), (F 2 -mpim) 2 Ir(acac), (mpim) 2 Ir(tpip), (F-mpim) 2 Ir(tpip), (F 2 -mpim) 2 Ir(tpip), are investigated with Density Functional Theory (DFT) approaches, where mpim denotes 1-mesityl-2-phenyl-1 H -imidazole, F-mpim denotes 2-(4-fluorophenyl)-1-mesityl-1 H -imidazole, F 2 -mpim denotes 2-(2,4-difluorophenyl)-1-mesityl-1 H -imidazole, acac denotes acetylacetonate, and tpip denotes tetraphenylimido-diphosphinate. Graphical abstract A series of heteroleptic cyclometalated Ir (III) complexes, which are used for OLED application,were investigated by DFT and TD-DFT method. The frontier molecular orbital character and charge transfer charactershown that they have theadvantagesof low efficiency roll-offproperties, which is a "stumbling block"in the process of OLED solid-lighting's development. Namely, means the materials will play animportant role in the journey development of OLED. Image 1 Highlights • Cyclometalated iridium (III) complexes have received special attention as dopants for harvesting the otherwise nonemissive triplet states formed in OLEDs, but now, most of them cannot satisfy to be used for the applications, especially for blue and green, since that a fast reduction in efficiency known as roll-off, however, occurs when the drive current increases, this leads to a much lower luminance and more power consumption. • Thus in this paper, in order to find a series of blue and green OLED materials with low efficiency roll-off properties, we theoretical design and investigate a series of Iridium complexes. • The geometries, electronic structures, the lowest-lying singlet absorptions, triplet emissions properties and the application value for organic light emitting devices were all analysed by theory in this article. [ABSTRACT FROM AUTHOR]