OLEDs iridium complexes

Cyclometallated iridium complexes, for OLEDs, 12, 145 Cyclometallated palladium(II) complexes from amines and pyridines, 8, 280 with C,C-chelating ligands, 8, 291 enantioselective synthesis, 8, 296 ferrocene-based palladacycles, 8, 292 four-membered palladacycles, 8, 297 imine- and oxime-based complexes, 8, 285 with N-N and N=N bonds, 8, 288 palladacycle catalysis, 8, 297... 

Keywords Iridium complexes Cyclometalating ligands Phosphorescence Electrochemistry Multicomponent arrays OLEDs Photoinduced processes... 

Keywords Emission quantum yields High-resolution spectroscopy Iridium complexes OLED emitters Organometallic compounds Phosphorescence Photophysics Platinum complexes Radiative rates Spin-orbit coupling Triplet emitters Zero-field splitting SOC ZFS SOC and geometry SOC paths... 

The EML with a multilayer structure for the lanthanide ions is very different from that of other phosphor materials such as iridium complexes. Multilayer structures with EMLs usually emit hybrid light which is used in white light emitting OLEDs [33]. For lanthanide complexes extremely pure light is achievable, because their emission is due to electronic transitions of... 

Three iridium complexes of formula [Ir(acac)(L)2] have been synthesized, [k(dpp)2 (acac)], [Ir(bpp)2(acac)j and [Ir(fpp)2(acac)j, where L is a substituted arylpyridine (dpp = 2,4-diphenylpyridine bpp = 2-(4-f-butylphenyl)-4-phenylpyridine fpp = 2-(4-fluoroph-enyl)-4-phenylpyridine). The OLEDs based on these materials, with structure ito/Ir com-plexipvk/F-tbb/Alqs/LiF/Al (F-tbb = l,3,5-tris(4-fiuorobiphenyl-4 -yl)benzene), showed maximum luminances of 8776, 8838 and 14180 cdm , and maximum external efficiencies of 11.5, 12.9 and 17.0 cdA, repectively ° . 

The introduction of rigid and bulky cycloalkene unit in these iridium complexes is expected to provide high device efficiencies as well as the suppressed triplet-triplet (T-T) annihilation in the OLED devices. These iridium complexes, lr(chpy)3 or Ir(mchpy)3, with cycloalkenylpyridines have higher HOMO and lower LUMO energy levels than iridium(III) complex, Ir(ppy)3. We synthesized 2-cycloalkenylpyridine substituted iridium complexes, Ir(chpy)3 or Ir(mchpy)3, in 44-74% yields and reported (Kang et al. 2008). 

Ruthenium complexes used to lead research in photochemistry of metal compounds, but rhodium complexes have recently overtaken them as the key target compounds due to their applications in OLEDs. This is a lively and ever-changing field for example, over 90% of luminescent iridum(III) complexes have been reported only in the six years to the beginning of 2009. With their luminescence tuneable through ligand choice, iridium complexes are firm candidates for optical display applications. 

Polystyrenes have also been used to support chromophores useful in organic light-emitting diodes (OLEDs). Week and coworkers have attached tris(2-phenylpyridine) iridium complexes to aminomethylated polystyrene using a Schiff base reaction, 4 [21]. There was no major diminution of the desirable luminescence properties of the iridium complexes (high emission quantum yields of 0.23 and lifetimes of about a microsecond). Similar results have been reported for aluminum and boron 8-hydroxy quinoline complexes tethered to polystyrene using Schiff base condensation [22]. 

Tsuboyama, A., Okada, S., and Ueno, K. 2008. Highly efficient red-phosphorescent iridium complexes. In Highly Efficient OLEDs with Phosphorescent Materials, H. Yersin (ed.), Wiley-VCH Verlag, Weinheim, Germany, pp. 163-183. 

Abstract Considerable studies have been made on iridium complexes during the past 10 years, due to their high quantum efficiency, color tenability, and potential applications in various areas. In this chapter, we review the synthesis, structure, and photophysical properties of luminescent Ir complexes, as well as their applications in organic light-emitting diodes (OLEDs), biological labeling, sensitizers of luminescence, and chemosensors. 

Fig. 5 OLEDs fabricated with iridium complexes bearing 6-fluoroquinoline-based ligands as emitters and TICCBI and TICNBI as donor-acceptor bipolar hosts...

The development of phosphorescent iridium organometallic complexes was another major breakthrough [8]. Such iridium complexes are triplet emitters and enhance the theoretical quantum efficiency of OLEDs from 25% for fluorescent... 

Ma et al. at PPG recently applied for patents on a series of iridium star-like bidentate complexes [300], Examples of two such green dopants are shown in Scheme 3.82 (254, 255). OLEDs fabricated using the dopants showed green emission with higher EQE and enhanced stability compared with a similar Ir(ppy)3-based device. 

Iridium(III) cyclometalated complexes are attracting widespread interest because of their unique photophysical properties and applications in organic fight-emitting diodes (OLEDs). Several groups have used extensively neu-... 

A series of facial homoleptic cyclometalated iridium(III) complexes has been synthesized and their photophysical properties investigated. The MLCT emission of the complexes in toluene 298 K occurred at 558-652nm (To = 0.74-4.7 J,s). An OLED device that used [Ir(l-phenylisoquinolinato)3] as a phosphorescent dopant produced pure-red emission with very high efficiency. 

In this review, the synthesis, properties, and applications in optoelectronic fields of polyfluorenes with on-chain metal centers have been briefly summarized. Metal complexes involving iridium(III), platinum(II), europium(III), rhenium(I), and ruthenium(II) complex coupled with polyfluorene are surveyed. Efficient energy transfer from polymer main-chain to metal-centers can occur in these host-guest systems. These kinds of novel polymers are usually applied in the fields of phosphorescent OLEDs, memory devices, and sensors. In particular, the realization of efficient energy transfer and phosphorescence offers a huge potential for future optoelectronic devices based on these kinds of materials. 

Forrest and Thompson have demonstrated high-efficiency, high-brightness red phosphorescent OLEDs employing cyclometalated benzothienylpyri-dine (btp) iridium and platinum complexes [43], such as in (2-(2 -benzo[4,5-a]thienyl)pyridinato-N,C3 )platinum(acetylacetonate), [Pt(btp)(acac)] 41. 

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