Patent Application
20170294605
The present invention relates to novel organic compounds that may be advantageously used in organic light emitting devices. More particularly, the invention relates to iridium complexes and their use in OLEDs.
Opto-electronic devices that make use of organic materials are becoming increasingly desirable for a number of reasons. Many of the materials used to make such devices are relatively inexpensive, so organic opto-electronic devices have the potential for cost advantages over inorganic devices. In addition, the inherent properties of organic materials, such as their flexibility, may make them well suited for particular applications such as fabrication on a flexible substrate. Examples of organic opto-electronic devices include organic light emitting devices (OLEDs), organic phototransistors, organic photovoltaic cells, and organic photodetectors. For OLEDs, the organic materials may have performance advantages over conventional materials. For example, the wavelength at which an organic emissive layer emits light may generally be readily tuned with appropriate dopants.
OLEDs make use of thin organic films that emit light when voltage is applied across the device. OLEDs are becoming an increasingly interesting technology for use in applications such as flat panel displays, illumination, and backlighting. Several OLED materials and configurations are described in U.S. Pat. Nos. 5,844,363, 6,303,238, and 5,707,745, which are incorporated herein by reference in their entirety.
One application for phosphorescent emissive molecules is a full color display. Industry standards for such a display call for pixels adapted to emit particular colors, referred to as “saturated” colors. In particular, these standards call for saturated red, green, and blue pixels. Color may be measured using CIE, coordinates, which are well known to the art.
In recent years, many researches indicate that the iridium complex is regarded as the most ideal selection of OLEDs phosphor materials among many heavy metal element complexes. After forming +3 cation, the Iridium atoms with 5d76 s2 outer electron structure owns the 5d6 electron configuration and the stable hexa-coordinate octahedral structure, which lets the materials own higher chemical stability and heat stability. Meanwhile, Ir(III) owns larger spin-orbit coupling constants (ξ=3909 cm-1), which is conductive to improving the quantum yield of complexes and reducing the luminescence Lifetime, thus improving the whole performance of illuminator.
As the phosphor materials, in general, the iridium complex easily causes in the microsecond phosphorescence quenching between triplet-triplet of iridium complex and triplet-polaron. In addition, in the current common materials, the hole mobility of hole-transport material is far higher than the electronic mobility of electron transport material, and the common host materials give priority to the hole transport, which would cause that many redundant electron holes gather on the luminescent layer and electron transfer layer surface. All these factors would result the efficiency reduction and the severe efficiency roll-off. It's indicated in the research that: in case of owning higher electronic transmission ability, the iridium complex could effectively increase the transmission and distribution of electron in luminescent layer, expand the area of electron-hole and balance the quantity of electron-hole pairs, which greatly improves the efficiency of device and reduces the efficiency roll-off.
Thereof, it is necessary to disclose and provide improved Iridium complex to overcome the above-mentioned disadvantages.
The present disclosure will hereinafter be described in detail with reference to an exemplary embodiment. To make the technical problems to be solved, technical solutions and beneficial effects of the present disclosure more apparent, the present disclosure is described in further detail together with the figure and the embodiment. It should be understood the specific embodiment described hereby is only to explain the disclosure, not intended to limit the disclosure.
In the synthetic process of iridium complex in the invention, the Iridium trichloride, 4,6-difluoromethyl and trifluoromethyl pyridine-3 boracic acid, 4,6-difluoromethyl and trifluoromethyl pyridine-4-boracic acid, 2-Bromide pyridine derivatives, 2-Bromine pyrimidine derivatives, 2-Bromine pyrazine derivatives and 2-Bromine triazine derivatives with the similar synthesis methods. Mix iridium dimerization bridging complex containing two main ligands and the 2-(5-phenyl-1,3,4-oxadiazole-2-) phenol auxiliary ligand and sodium carbonate; The mentioned main ligands are any one of the follows: 2-(4,6-difluoromethyl and trifluoromethyl pyridine-3-) butypyridine, 2-(4,6-difluoromethyl and trifluoromethyl pyridine-4-) butypyridine, 2-(4,6-difluoromethyl and trifluoromethyl pyridine-3-) butypyrimidine, 2-(4,6-difluoromethyl and trifluoromethyl pyridine-4-) butypyrimidine, 2-(4,6-difluoromethyl and trifluoromethyl pyridine-3-) butypyrazine, 2-(4,6-difluoromethyl and trifluoromethyl pyridine-4-) butypyrazine, and 2-(4,6-difluoromethyl and trifluoromethyl pyridine-3-) butytriazine and 2-(4,6-difluoromethyl and trifluoromethyl pyridine-4-) butytriazine the derivatives. 2-ethoxyethanol solution is added for the heating reaction at 120-140° C. for 12-48 h, then cool down to the room temperature, remove the solvent by decompression and distillation, then extract and concentrate with dichloromethane, finally gain the crude product of complexes by column chromatography isolation, and gain pure iridium complex through sublimation. Among them, the mentioned iridium dimerization bridging complex includes 2-(4,6-difluoromethyl and trifluoromethyl pyridine-3-) butypyridine, 2-(4,6-difluoromethyl and trifluoromethyl pyridine-4-) butypyridine, 2-(4,6-difluoromethyl and trifluoromethyl pyridine-3-) butypyrimidine, 2-(4,6-difluoromethyl and trifluoromethyl pyridine-4-) butypyrimidine, 2-(4,6-difluoromethyl and trifluoromethyl pyridine-3-) butypyrazine, 2-(4,6-difluoromethyl and trifluoromethyl pyridine-4-) butypyrazine, and the derivatives of 2-(4,6-difluoromethyl and trifluoromethyl pyridine-3-) butytriazine and 2-(4,6-difluoromethyl and trifluoromethyl pyridine-4-) butytriazine the derivatives. The mole ratio of Iridium dimer bridging complexes, ligand and sodium carbonate is 1:2:5.
The mentioned iridium complex owns the one of the following structures:
Based on one following example, the complexes GIr8-001 is used to specially describe the invention content, which would be conducted to further undertaking the invention, but isn't limited to the invention content.
Manufacturing method of complex GIr8-001
2-Bromine pyridine (26.39 mmol), 4,6-difluoromethyl and trifluoromethyl pyridine-3-boracic acid (31.66 mmol), (beta-4)-platinum (0.79 mmol) and sodium carbonate (60.00 mmol are dissolved in 100 mL butylene oxide with 65° C. reaction for 24 hours, then cool down and add water and dichloromethane. Finally, the main ligand (productivity is 52.24%) is gained from the organic horizon concentrating column by chromatography. Dissolve main ligand (13.08 mmol) and Iridium trichloride (6.23 mmol) in 15 mL 2-ethoxyethanol with mixture 130° C. reaction for 12 h, then add 2-(5-phenyl-1,3,4-oxadiazole-2-) phenol (12.46 mmol) and sodium carbonate (31.15 mmol), and continue the 130° C. reaction for 24 h. After the system cools down, add water and dichloromethane, then gain yellow solid GIr8-001 from the organic horizon concentrating column by chromatography with the productivity of 44%.
Nuclear magnetism and mass spectrometric characterization: 1H NMR (500 MHz, CDCl3) δ 9.09 (d, J=5.6 Hz, 2H), 8.29 (d, J=8.4 Hz, 2H), 7.66 (t, J=8.0 Hz, 2H), 7.16 (t, J=7.4 Hz, 2H), 7.32 (t, J=6.6 Hz, 1H), 7.18-7.14 (m, 3H), 6.83 (t, J=6.5 Hz, 2H), 6.59 (d, J=8.6 Hz, 2H), 6.49 (t, J=7.4 Hz, 1H), 6.42 (s, 1H), 6.28 (s, 1H). ESI-MS: m/z 1012.10 [M]+, found: 1011.79 [M]+.
A serial of iridium complexes with green-ray were designed in this invention with each of 2-(4, 6-bistrifluoromethylpyridyl-3-) pyridine, 2-(4, 6-bistrifluoromethylpyridyl-4-) pyridine, 2-(4,6-bistrifluoromethylpyridine-3-) pyrimidine 2-(4, 6-bistrifluoromethylpyridine-4-) pyrimidine, 2-(4, 6-bistrifluoromethylpyridine-3-) tetramethypyrazine, 2-(4,6-bistrifluoromethylpyridine-4-) tetramethypyrazine and 2-(4, 6-dibtrifluoromethylpyridine-3-) triazine derivatives, 2-(4, 6-dibtrifluoromethylpyridine-4-) triazine derivatives as main ligand and 2-(5-phenyl-1, 3, 4-oxadiazol-2-) as auxiliary ligand. It reaches the purpose for control of complexes shining and electronic mobility by designing ligand or complexes structure and embellishing the simple chemical substituent group on ligand.
All mentioned Nitrogen heterocycles are the group with stronger electronic transmission, which is conductive to balancing the injection and transmission of current carrier.
The mentioned iridium complex owns higher luminous efficiency and electronic mobility. After the optimization verification, it has simple preparation method with higher productivity.
Preparation of Organic Light-Emitting Device
Based on the following example that GIr8-001 (luminescent materials) is used to prepare the organic light-emitting device, the preparation of the organic light-emitting device in the invention is described. The structure of OLEDs device includes: Substrate, anode, hole transport layer, organic light emitting layer and electron transfer layer/cathode.
The substrate for the manufacturing the device in the invention is glass, and its anode materials are indium tin oxide (ITO); Hole transport layer uses the 4,4′-Cyclohexyl 2 [N,N (4-methyl phenyl) aniline (TAPC), the material in electronic transport layer uses 3,3′-(5′-(3-(pyridine-3-buty) phenyl)-[1,1′:3′,1″-triphenyl]-3,3″-hydroxyl) bipyridine (TmPyPB) with the thickness and evaporation rate of 60 nm and 0.05 nm/s respectively; The cathode uses LiF/Al, their thicknesses are 1 nm and 100 nm respectively, and their evaporation rates are 0.01 nm/s and 0.2 nm/s respectively. Organic light emitting layer is adopted the doping structure, main body material is 1,3-bi (9H-carbazole-9-buty) benzene (mCP), and the luminescent materials selected is GIr1-001. The thickness of luminescent layer is 40 nm, the evaporation rate is 0.05 nm/s, and the GIr8-001 mass fraction is 8%.
The structure of several materials used in the invention is as follows:
The green-ray complex is selected in the invention to prepare the organic light-emitting device. Please refer to
The phosphor materials in the invention could be applied in emission layer of phosphorescence OLEDs as the luminescence center. And the invention could control the emitting color and efficiency of complexes by designing ligand or complexes structure and embellishing the chemical substituent group on mentioned ligand.
It is to be understood, however, that even though numerous characteristics and advantages of the present exemplary embodiment have been set forth in the foregoing description, together with details of the structures and functions of the embodiment, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms where the appended claims are expressed.
| Number | Date | Country | Kind |
|---|---|---|---|
| 201610213735.1 | Apr 2016 | CN | national |
