In Situ Observation of Degradation by Ligand Substitution in Small-Molecule Phosphorescent Organic Light-Emitting Diodes
摘要:
Solutions of facial-tris(1-phenylpyrazole)Ir(III) (fac-Ir(ppz)(3)), when dissolved in either tert-butyl isocyanide or in solid films of 2-naphthylisocyanide, undergo replacement of a ppz ligand by the isocyanide molecules after irradiation with UV light as demonstrated by liquid chromatograph mass spectrometer analysis. Similarly, solutions of Ir(ppz)(3) and bathophenanthroline (BPhen) in CH2Cl2 or acetone-d(6) form a brightly emissive species, [Ir(ppz)(2)(Bphen)](+) when irradiated with UV light as established by optical, mass, and H-1 nuclear magnetic resonance spectroscopy. Electroluminescent data from blocked organic light-emitting diode (OLED) devices demonstrate that both mer- and fac-(Ir(ppz)(3)) dissociate a ligand and coordinate a neighboring BPhen molecule when the device is operated at moderate to high current levels. These experiments offer direct evidence of the dissociation of a metalligand bond and subsequent ligand substitution as a degradation pathway in active OLED devices during operation and provide a route to assay in situ the stability of future dopants.
A Synthesis and Luminescence Study of Ir(ppz)<sub>3</sub>for Organic Light-Emitting Devices
作者:Eun Jeong Nam、Jun Ho Kim、Bong-Ok Kim、Sung Min Kim、No Gill Park、Young Sik Kim、Young Kwan Kim、Yunkyoung Ha
DOI:10.1246/bcsj.77.751
日期:2004.4
Tris(1-phenyl-κC1-pyrazolato-κN2)iridium (Ir(ppz)3) was prepared and its luminescence properties were investigated for the application to organic light-emitting devices (OLEDs). The photoluminescence (PL) spectra of Ir(ppz)3 in dichloromethane showed a peak at 437 nm at room temperature. The luminescent lifetime of an Ir(ppz)3 film doped in CBP was found to be 218 ns, which indicated that its emission is phosphorescent. OLEDs were fabricated with doped films of Ir(ppz)3 in several hosts, and the electroluminescence (EL) peak was observed at 450 nm. The luminance of OLEDs was pure blue, with the CIE coordinates of x = 0.158, y = 0.139 at 100 cd/m2, but luminous efficiencies were low since the LUMO of Ir(ppz)3 is higher than those of the hosts used.
METHOD FOR PRODUCING CYCLOMETALATED IRIDIUM COMPLEX
申请人:TANAKA KIKINZOKU KOGYO K.K.
公开号:US20180362565A1
公开(公告)日:2018-12-20
The present invention provides a method for producing a cyclometalated iridium complex by use of a non-chlorine iridium raw material. The method for producing a cyclometalated iridium complex includes producing a cyclometalated iridium complex by reacting a raw material including an iridium compound with an aromatic heterocyclic bidentate ligand capable of forming an iridium-carbon bond, the raw material being non-halogenated iridium having a conjugated base of a strong acid as a ligand. Here, the non-halogenated iridium is preferably one containing a conjugated base of a strong acid having a pKa of 3 or less as a ligand.
A compound including a ligand L
1
of Formula I,
is described. In Formula I: rings A and B each independently represent a 5-membered or 6-membered carbocyclic or heterocyclic ring; X, Y, Z, and W are either carbon or nitrogen; R
1
to R
6
are selected from a variety of substituents, where adjacent substituents can be joined to form a fused ring; ligand L
1
is coordinated to a metal M by X-M and Y-M bonds; and ligand L
1
is optionally linked with other ligands to produce a tridentate, tetradentate, pentadentate or hexadentate ligand. Formulations and devices, such as an OLEDs, that include the compound that include a ligand L
1
of Formula I are also described.
Synthesis and Characterization of Facial and Meridional Tris-cyclometalated Iridium(III) Complexes
作者:Arnold B. Tamayo、Bert D. Alleyne、Peter I. Djurovich、Sergey Lamansky、Irina Tsyba、Nam N. Ho、Robert Bau、Mark E. Thompson
DOI:10.1021/ja034537z
日期:2003.6.1
tris-cyclometalates exhibit intense emission both at room temperature and at 77 K, whereas the phenylpyrazolyl-based derivatives emit strongly only at 77 K. The emission energies and lifetimes of the phenylpyridyl-based complexes (450-550 nm, 2-6 micros) and phenylpyrazolyl-based compounds (390-440 nm, 14-33 micros) are characteristic for a mixed ligand-centered/MLCT excited state. The meridional isomers
High efficiency single dopant white electrophosphorescent light emitting diodesElectronic supplementary information (ESI) available: emission spectra as a function of doping concentration for 3 in CBP, as well as the absorption and emission spectra of Irppz, CBP and mCP. See http://www.rsc.org/suppdata/nj/b2/b204301g/
作者:Vadim Adamovich、Jason Brooks、Arnold Tamayo、Alex M. Alexander、Peter I. Djurovich、Brian W. D'Andrade、Chihaya Adachi、Stephen R. Forrest、Mark E. Thompson
DOI:10.1039/b204301g
日期:2002.8.22
for an EBL in these devices was fac-tris(1-phenylpyrazolato-N,C2′)iridium(III). The EBL material effectively prevents electrons and excitons from passing through the emissive layer into the hole transporting NPD layer. CBP baseddevices gave a peak external quantum efficiency of 3.3±0.3% (7.3±0.7 lm W−1) at 1 cd m−2, and 2.3±0.2% (5.2±0.3 lm W−1) at 500 cd m−2. mCP baseddevices gave a peak external