TWI695008B - An organic electroluminescent device containing tetradentate platinum (ii) complex - Google Patents

Abstract

The present invention relates to an organic electroluminescent device comprising a tetradentate platinum (II) complex, comprising an anode, a cathode and an intermediate organic layer, the organic layer includes at least one light-emitting layer, wherein the light-emitting layer contains a tetradentate platinum (II) complex having a structure represented by the formula (3) as a phosphorescent dopant material. Since the platinum (II) complex has high fluorescence quantum efficiency, good thermal stability and low quenching constant, and can manufacture an orange-red emitting OLED device with high luminous efficiency and low roll-off.

Description

Organic electroluminescent device containing tetradentate platinum (II) complex

The invention relates to an OLED light-emitting device containing a novel N^N^N^O tetradentate platinum (II) complex metal organic material.

Since its discovery, Organic Light-Emitting Diode (OLED) display technology has been widely concerned and researched for its unique properties such as low energy consumption, large viewing angle, and flexibility, especially in recent years. It is gradually applied to electronic products such as mobile phones, televisions, and notebook computers. However, compared with traditional display technology, OLED has shortcomings such as short service life, poor color purity, and easy aging. Its cost remains high, which hinders the promotion and development of OLED technology. Therefore, how to design new OLED materials is the focus and difficulty of OLED research.

In the field of OLED materials, the development of phosphorescent OLED materials is relatively rapid and mature. Phosphorescent OLED materials are mainly based on some heavy metal organic complexes, such as iridium, platinum, europium, osmium, etc. Phosphorescent materials can make full use of the energy of singlet and triplet excitons in the light-emitting process, so theoretically their quantum efficiency can reach 100%, which greatly improves the luminous efficiency of OLED devices and is currently widely used in the industry.

Among them, the phosphorescent OLED materials based on platinum (II) have been gradually developed in recent years and have achieved good research results. Platinum (II) is generally a four-coordinated site, so it is possible to design a metal-organic platinum (II) complex with a unique configuration by designing a tetradentate ligand. In general, the common tetradentate ligands are mainly O^N^N^O (as in formula (1)), O^N^C^O (as in formula (2)),

Among them, O^N^N^O-type tetradentate platinum (II) complexes are mainly Schiff bases, which are more common, but the stability is relatively poor; O^N^C^O-type tetradentate platinum ( II) The complex is relatively stable, but its performance needs to be improved.

In view of the defects in the above-mentioned fields, the present invention provides an organic electroluminescent device containing a tetradentate platinum (II) complex, which has good luminous performance and good stability.

An organic electroluminescent device containing a tetradentate platinum (II) complex includes an anode, a cathode and an intermediate organic layer, the organic layer includes at least a light-emitting layer, wherein the light-emitting layer contains a structure represented by formula (3) Tetradentate platinum (II) complex as a phosphorescent doped material,

Among them, A1-A5 is a substituted or unsubstituted five-membered ring, six-membered ring, or fused ring structure.

Preferably: the structure shown in formula (4):

Wherein R ₁ -R _{17 are} independently selected from hydrogen, deuterium, halogen, hydroxy, acetyl, alkoxy, acetyl, amino, nitro, acetylamino, cyano, carboxy, styrenyl, aminocarbonyl, Carbamate, benzylcarbonyl, aryloxy, diarylamino, saturated alkyl containing 1-30 C atoms, unsaturated alkyl containing 1-20 C atoms, containing 6-30 C atoms Substituted or unsubstituted aryl groups, substituted or unsubstituted heteroaryl groups containing 5-30 C atoms, or adjacent R ₁ -R ₁₇ are connected to each other through a covalent bond to form a ring; wherein, X ₁ -X ₂₇ Is carbon, the halogen is F, Cl, Br.

Preferably: wherein R ₁ -R _{17 are} independently selected from the group consisting of hydrogen, halogen, amino, nitro, cyano, diarylamino, saturated alkyl containing 1-10 C atoms, coatings containing 6-20 C atoms Halogen or one or more C1-C4 alkyl substituted or unsubstituted aryl groups, 5-20 C atoms substituted or halogen or one or more C1-C4 alkyl substituted or unsubstituted heteroaryl groups, or phase The o-R ₁ -R ₁₇ are connected to each other through a covalent bond to form a ring, and the halogen is F, Cl.

Preferred: for the following structure

Wherein R ₁ '-R _5' are independently selected from hydrogen, halogen, di-arylamino, saturated alkyl group containing 1-10 C atoms, having 6-10 C atoms or one or more halogen C1- C4 alkyl substituted or unsubstituted aryl, 5-10 C atoms substituted or unsubstituted heteroaryl substituted by halogen or one or more C1-C4 alkyl, or adjacent R ₁ -R ₁₇ pass each other Covalent bonds are connected to form a ring.

Preferably: R ₁ '-R _5' 5 groups, wherein there are 0-3 groups independently represent a diarylamino group containing 6-10 C atoms or by one to three halogen, C1-C4 alkoxy Aryl substituted or unsubstituted, heteroaryl containing 5-10 C atoms substituted with halogen or one to three C1-C4 alkyl or unsubstituted heteroaryl; other groups are independently indicated as hydrogen or containing Saturated alkyl group with 1-8 C atoms, the halogen is F.

Preferably: R ₁ '-R _5' 5 groups, wherein there are 0-3 groups independently represent as diphenylamino, phenyl, pyridyl, carbazolyl, other groups independently represent hydrogen, iso Propyl or tert-butyl.

For the purposes of this application, unless otherwise indicated, the terms halogen, alkyl, alkenyl, aryl, acetyl, alkoxy, and heterocyclic aromatic systems or heterocyclic aromatic groups may have the following meanings: halogen or Halo includes fluorine, chlorine, bromine and iodine, preferably F, Cl, Br, particularly preferably F or Cl, most preferably F.

The above-mentioned ring, aryl, and heteroaryl groups connected by a covalent bond include 6-30 carbon atoms, preferably 6-20 carbon atoms, more preferably 6-10 carbon atoms, and are fused by one aromatic ring or multiple Aryl group consisting of aromatic rings. Suitable aryl groups are, for example, phenyl, naphthyl, acenaphthenyl, acenaphthenyl, anthracenyl, fluorenyl, phenalenyl. The aryl group may be unsubstituted (ie, all carbon atoms that can be substituted carry hydrogen atoms) or substituted at one, more than one, or all substitutable positions of the aryl group. Suitable substituents are, for example, halogen, preferably F, Br or Cl; alkyl, preferably alkyl having 1-20, 1-10 or 1-8 carbon atoms, particularly preferably methyl, ethyl, isopropyl Group or tert-butyl group; aryl group, preferably re-substituted or unsubstituted C ₅ , C ₆ aryl group or fluorenyl group; heteroaryl group, preferably a heteroaryl group containing at least one nitrogen atom, particularly preferably pyridyl; The aryl group particularly particularly preferably carries a substituent selected from F and tert-butyl, preferably an aryl group which may be a given aryl group or optionally substituted by at least one of the above substituents is a C ₅ , C ₆ aryl group, C ₅ , C ₆ aryl group particularly preferably carries 0, 1 or 2 of the above substituents, C ₅ , C ₆ aryl group is particularly preferably unsubstituted phenyl or substituted phenyl, such as biphenyl, by two tertiary The butyl group is preferably a phenyl group substituted in the meta position.

The unsaturated alkyl group having 1 to 20 C atoms is preferably an alkenyl group, more preferably an alkenyl group having a double bond, and particularly preferably an alkenyl group having a double bond and 1 to 8 carbon atoms.

The above-mentioned alkyl group includes alkyl groups having 1 to 30 carbon atoms, preferably 1 to 10 carbon atoms, preferably 1 to 4 carbon atoms. The alkyl group may be branched or linear, or cyclic, and may be interrupted by one or more heteroatoms, preferably N, O, or S. Furthermore, the alkyl group may be substituted with one or more halogens or the above-mentioned substituents regarding aryl groups. Similarly, for alkyl groups, it is possible to carry one or more aryl groups, all of which are suitable for this purpose, alkyl groups are particularly preferably selected from methyl, ethyl, isopropyl, n-propyl, Isobutyl, n-butyl, tert-butyl, sec-butyl, isopentyl, cyclopropyl, cyclopentyl, cyclohexyl.

The above-mentioned acyl group is connected to the CO group with a single bond, such as an alkyl group as used herein.

The above-mentioned alkoxy group is directly connected to oxygen by a single bond, as used herein an alkyl group.

The above heteroaryl group is understood to be related to an aromatic, C ₃ -C ₈ cyclic group, and also contains an oxygen or sulfur atom or 1-4 nitrogen atoms or a combination of an oxygen or sulfur atom and up to two nitrogen atoms , And their substituted and benzo and pyrido fused derivatives, for example, through one of the ring-forming carbon atoms, the heteroaryl group may be substituted by one or more of the substituents mentioned for aryl Replaced by.

In certain embodiments, the heteroaryl group may be a five- or six-membered aromatic heterocyclic system carrying the above independent groups containing 0, 1, or 2 substituents. Typical examples of heteroaryl groups include, but are not limited to, unsubstituted furan, benzofuran, thiophene, benzothiophene, pyrrole, pyridine, indole, azole, benzoxazole, isoxazole, benzisoazole, thiazole, benzo Thiazole, isothiazole, imidazole, benzimidazole, pyrazole, indazole, tetrazole, quinoline, isoquinoline, pyridazine, pyrimidine, purine and pyrazine, furan, 1,2,3-diazole, 1, 2,3-thiadiazole, 1,2,4-thiadiazole, triazole, benzotriazole, pyridine, benzoxazole, diazole, benzopyrazole, quinazine, cinnoline, phthalazine, Quinazol and quinoxaline and their mono- or di-substituted derivatives. In certain embodiments, the substituents are halo, hydroxy, cyano, OC _1-6 alkyl, C _1-6 alkyl, hydroxy C _1-6 alkyl, and amino-C _1-6 alkyl.

Specific examples shown below include but are not limited to the following structures:

The preparation method of the above complex includes the following steps: as shown below, the carbazole derivative S1 is brominated to obtain the substrate S2 , and S2 is reacted with biboronic acid pinacol ester to obtain the corresponding pinacol ester derivative S3 , S3 and S4 pyridine derivatives via Suzuki reaction S5, S5 and S6 pyridine derivatives via Suzuki reaction S7, S7 after demethylation to yield the corresponding ligand S8, S8 K ₂ PtCl ₄ to obtain the target product is reacted with P .

其中，R'₁~R'₅為芳香基或非芳香取代基。

Wherein, R _'1 ~ R' ₅ is an aromatic or non-aromatic group substituent.

The N^N^N^O tetradentate platinum (II) complex can be used in an OLED light emitting device, a phosphorescent doped material that functions as a photon emission in the light emitting layer. The doping amount of the tetradentate platinum (II) complex is 1%-12%. Preferably 4%-8%.

Using the platinum (II) complex having the above structure, an OLED device of thermal deposition and solution treatment can be manufactured.

Includes organic light-emitting devices containing one or more complexes.

The complex is applied as a layer in the device by thermal deposition.

The complex is applied as a layer in the device by spin coating.

The complex is applied in the form of a layer in the device by inkjet printing.

In the above organic light-emitting device, the device emits orange-red when current is applied.

The platinum (II) complex in the invention has high fluorescence quantum efficiency, good thermal stability and low quenching constant, and can produce orange-red light OLED devices with high luminous efficiency and low roll-off.

10: Glass substrate

20: Transparent indium tin oxide (ITO)

30: hole transport layer

40: light emitting layer

50: electron transport layer

60: electron injection layer

70: cathode

FIG. 1 is a schematic structural diagram of an organic electroluminescent device of the present invention.

The present invention will be further described in detail below in conjunction with examples.

Example 1:

synthetic route:

Synthesis of Compound 2 : 6.50 g (20.0 mmol) of Compound 1 , 12.70 g (2.5 eq., 50.0 mmol) of pinacol biborate, 5.18 g (2.5 eq., 50.0 mmol) of potassium carbonate and Pd(dppf)Cl ₂ 292 mg (0.02 eq., 0.4 mmol) was added to a three-necked flask, and the vacuum was replaced with nitrogen for several times, and then 150 mL of acetonitrile dioxane was injected and heated to 85°C. After reacting under nitrogen for 12 hr, cool to room temperature, spin-evaporate to remove the solvent, then add appropriate amount of water and ethyl acetate for extraction, collect the organic phase, dry the anhydrous magnesium sulfate, add appropriate amount of silica gel, spin-evaporate to remove the solvent, use n-hexane/ Column chromatography with ethyl acetate system gave 7.12g white solid with 85% yield and 99.0% purity.

Synthesis of Compound 3 : 11.85g (50.0mmol) of compound 2,6-dibromopyridine, 2-methoxybenzeneboronic acid 7.60g (1.0eq., 50.0mmol), potassium carbonate 6.48g (1.25eq., 62.5mmol) ) And Pd(OAc) ₂ 224 mg (0.02 eq., 1 mmol), PPh ₃ 1.31 g (0.1 eq., 5 mmol) were added to a three-necked flask, vacuum was replaced with nitrogen for multiple times, then 150 mL of acetonitrile and 50 mL of methanol were injected , Heated to 60 ℃. After reacting under nitrogen for 12 hr, cool to room temperature, spin-evaporate to remove solvent, then add appropriate amount of water and ethyl acetate for extraction, collect organic phase, dry anhydrous magnesium sulfate, add appropriate amount of silica gel, spin-evaporate to remove solvent, use n-hexane/ Column chromatography with ethyl acetate system gave 9.90 g of white solid with 75% yield and 99.5% purity.

Synthesis of compound 4 : Take 6.29 g (15.0 mmol) of compound 2 , compound 3 3.96 g (1.0 eq., 15.0 mmol), potassium carbonate 3.45 g (1.25 eq., 25.0 mmol) and Pd(PPh ₃ ) ₄ 347 mg ( 0.02eq., 0.3mmol), added to a three-necked flask, evacuated and replaced with nitrogen for multiple times, and then injected 100mL and 50mL of acetonitrile methanol, heated to 60 ℃. After reacting under nitrogen for 12 hr, cool to room temperature, spin-evaporate to remove solvent, then add appropriate amount of water and ethyl acetate for extraction, collect organic phase, dry anhydrous magnesium sulfate, add appropriate amount of silica gel, spin-evaporate to remove solvent, use n-hexane/ Column chromatography with ethyl acetate system gave 4.28g white solid with 60% yield and 99.5% purity.

Synthesis of compound 5 : Take 3.81 g (8.0 mmol) of compound 4 , 2- bromopyridine 1.37 g (1.1 eq., 8.8 mmol), potassium carbonate 1.38 g (1.25 eq., 10.0 mmol) and Pd(PPh ₃ ) ₄ 185 mg (0.02eq., 0.16mmol), added to a three-necked flask, evacuated with nitrogen to replace multiple times, and then injected 60mL and 30mL of acetonitrile methanol, heated to 60 ℃. After reacting under nitrogen for 12 hr, cool to room temperature, spin-evaporate to remove solvent, then add appropriate amount of water and ethyl acetate for extraction, collect organic phase, dry anhydrous magnesium sulfate, add appropriate amount of silica gel, spin-evaporate to remove solvent, use n-hexane/ Column chromatography with ethyl acetate system gave 3.07g of white solid with 90% yield and 99.9% purity.

Synthesis of Compound 6 : Take 2.14g (4.0mmol) of Compound 5 and 30g of pyridine hydrochloride (PyHCl), add it to a three-necked flask, evacuate and introduce nitrogen for multiple replacements, heat to 190°C under the protection of nitrogen, and react After 4hr, cool to room temperature, then add appropriate amount of water and ethyl acetate for extraction, collect the organic phase, dry anhydrous magnesium sulfate, add appropriate amount of silica gel, spin-evaporate to remove the solvent, and use n-hexane/ethyl acetate system column chromatography to obtain White solid 1.32g, yield 80%, purity 99.9%. Mass spectrometry (ESI ^- )([MH] ^- ) C ₂₈ H ₁₈ N ₃ O theoretical value: 412.15; found value: 412.13.

Synthesis of Compound P1 : Take 826 mg (2.0 mmol) of Compound 5 and 328 mg of anhydrous sodium acetate (2.0 eq., 4.0 mmol) in 25 mL of DMSO, stir and heat to 80°C, then add 830 mg (1.0 eq) of potassium tetrachloroplatinate ., 2.0 mmol), replaced with nitrogen by evacuating several times, warming to 120 ℃ for 5hr. After the reaction was completed, 100 ml of water was added while hot, filtered, and the solid was collected, washed with an appropriate amount of water and methanol, and the obtained solid was recrystallized with toluene, and then sublimated in vacuo to obtain 788 mg of a dark red solid, with a total yield of 65% and a purity of 99.9%. Mass spectrum ^{(ESI -) ([MH]} -) C 28 H 16 N 3 OPt Calculated: 605.10; Found: 605.08.

Example 2:

synthetic route:

Synthesis of Compound 7 : Take 16.72g of carbazole (0.10mol) and 655mg of anhydrous aluminum trichloride (5mmol) in a three-necked flask, evacuate and introduce nitrogen for multiple replacements, then add 27.77g of chloro-tert-butane dropwise ( 3.0eq., 0.30mmol) and dry dichloromethane 250mL, after stirring the reaction under nitrogen protection for 12hr, then add an appropriate amount of water for extraction, collect the organic phase, remove the solvent by rotary evaporation, and recrystallize the resulting solid using ethanol to obtain white Solid 23.20g, yield 83%, purity 99.5%.

Synthesis of compound 8 : Take 13.97 g (50.0 mmol) of compound 7 and dissolve it in 750 mL of acetic acid, then drop into liquid bromine 19.98 g (2.5 eq., 125.0 mmol), and shield the reaction. After stirring at room temperature for about 4 hr, the solvent was removed by rotary evaporation, and then appropriate amount of water and sodium bisulfite solution were added for washing, ethyl acetate extraction, and the organic phase was collected. After drying over anhydrous magnesium sulfate, an appropriate amount of silica gel was added, and the appropriate amount of silicone was added to the rotary evaporation to remove the solvent. /Ethyl acetate system column chromatography to obtain 20.77g white solid, yield 95%, purity 99.9%.

Synthesis of Compound 9 : Take 10.93g (25.0mmol) of Compound 8 , 15.88g (2.5eq., 62.5mmol) of pinacol biborate, 8.64g (2.5eq., 62.5mmol) of potassium carbonate and Pd(dppf)Cl ₂ 366 mg (0.02 eq., 0.5 mmol) was added to the three-necked flask, and the vacuum was replaced with nitrogen gas for many times, and then 300 mL of dioxane was injected, and heated to 85°C. After reacting under nitrogen for 12 hr, cool to room temperature, spin-evaporate to remove solvent, then add appropriate amount of water and ethyl acetate for extraction, collect organic phase, dry anhydrous magnesium sulfate, add appropriate amount of silica gel, spin-evaporate to remove solvent, use n-hexane/ Column chromatography with ethyl acetate system gave 9.56 g of white solid with 72% yield and 99.9% purity.

Synthesis of compound 10 : Take 7.97 g (15.0 mmol) of compound 9 , compound 3 3.96 g (1.0 eq., 15.0 mmol), potassium carbonate 3.45 g (1.25 eq., 25.0 mmol) and Pd (PPh ₃ ) ₄ 347 mg ( 0.02eq., 0.3mmol), added to a three-necked flask, evacuated and replaced with nitrogen for multiple times, and then injected 100mL and 50mL of acetonitrile methanol, heated to 60 ℃. After reacting under nitrogen for 12 hr, cool to room temperature, spin-evaporate to remove solvent, then add appropriate amount of water and ethyl acetate for extraction, collect organic phase, dry anhydrous magnesium sulfate, add appropriate amount of silica gel, spin-evaporate to remove solvent, use n-hexane/ Column chromatography with ethyl acetate system yielded 5.74g of white solid in 65% yield and 99.9% purity.

Synthesis of compound 11 : Take 4.71 g (8.0 mmol) of compound 10 , 2-bromopyridine 1.37 g (1.1 eq., 8.8 mmol), potassium carbonate 1.38 g (1.25 eq., 10.0 mmol) and Pd(PPh ₃ ) ₄ 185 mg (0.02eq., 0.16mmol), added to a three-necked flask, evacuated with nitrogen to replace multiple times, and then injected 60mL and 30mL of acetonitrile methanol, heated to 60 ℃. After reacting under nitrogen for 12 hr, cool to room temperature, spin-evaporate to remove solvent, then add appropriate amount of water and ethyl acetate for extraction, collect organic phase, dry anhydrous magnesium sulfate, add appropriate amount of silica gel, spin-evaporate to remove solvent, use n-hexane/ Column chromatography with ethyl acetate system gave 3.67 g of white solid with a yield of 85% and a purity of 99.9%.

Synthesis of Compound 12 : Take 2.16g (4.0mmol) of Compound 11 and 30g of pyridine hydrochloride (PyHCl), add it to a three-necked flask, and evacuate with nitrogen for multiple replacements, heat to 190°C under the protection of nitrogen, and react After 4hr, cool to room temperature, then add appropriate amount of water and ethyl acetate for extraction, collect the organic phase, dry anhydrous magnesium sulfate, add appropriate amount of silica gel, spin-evaporate to remove the solvent, and use n-hexane/ethyl acetate system column chromatography to obtain White solid 1.79g, yield 85%, purity 99.9%. Mass spectrum ^{(ESI -) ([MH]} -) C 36 H 34 N 3 O Calculated: 524.27; Found: 524.24.

Synthesis of Compound P2 : Dissolve 1.06g (2.0mmol) of Compound 5 and 328mg of anhydrous sodium acetate (2.0eq., 4.0mmol) in 25mL of DMSO, stir and heat to 80°C, then add 830mg of potassium tetrachloroplatinate (1.0 eq., 2.0mmol), nitrogen was replaced by evacuation several times, the temperature was raised to 120 ℃ for 5hr. After the reaction was completed, 100 ml of water was added while hot, filtered, the solid was collected, washed with an appropriate amount of water and methanol, and the obtained solid was recrystallized with toluene, and then sublimated in vacuo to obtain a deep red solid 1.01 g, with a total yield of 70% and 99.9%. Mass spectrometry (ESI ^- )([MH] ^- ) C ₃₆ H ₃₃ N ₃ OPt theoretical value: 717.23; found value: 717.20.

Example 3:

synthetic route:

Synthesis of compound 14 : Take 7.97 g (15.0 mmol) of compound 9 , compound 13 7.63 g (1.0 eq., 15.0 mmol), potassium carbonate 3.45 g (1.25 eq., 25.0 mmol) and Pd(PPh ₃ ) ₄ 347 mg ( 0.02eq., 0.3mmol), added to a three-necked flask, evacuated and replaced with nitrogen for multiple times, and then injected 100mL and 50mL of acetonitrile methanol, heated to 60 ℃. After reacting under nitrogen for 12 hr, cool to room temperature, spin-evaporate to remove solvent, then add appropriate amount of water and ethyl acetate for extraction, collect organic phase, dry anhydrous magnesium sulfate, add appropriate amount of silica gel, spin-evaporate to remove solvent, use n-hexane/ Column chromatography with ethyl acetate system gave 7.50 g of white solid with 60% yield and 99.5% purity.

Synthesis of compound 15 : Take 6.66 g (8.0 mmol) of compound 14 , 2-bromopyridine 1.37 g (1.1 eq., 8.8 mmol), potassium carbonate 1.38 g (1.25 eq., 10.0 mmol) and Pd(PPh ₃ ) ₄ 185 mg (0.02eq., 0.16mmol), added to a three-necked flask, evacuated with nitrogen to replace multiple times, and then injected 60mL and 30mL of acetonitrile methanol, heated to 60 ℃. After reacting under nitrogen for 12 hr, cool to room temperature, spin-evaporate to remove solvent, then add appropriate amount of water and ethyl acetate for extraction, collect organic phase, dry anhydrous magnesium sulfate, add appropriate amount of silica gel, spin-evaporate to remove solvent, use n-hexane/ Column chromatography with ethyl acetate system gave 6.27 g of white solid with 80% yield and 99.9% purity.

Synthesis of compound 16 : Take 3.14g (4.0mmol) of compound 15 and pyridine hydrochloride 30g (PyHCl), add to a three-necked flask, evacuate and introduce nitrogen for multiple replacements, heat to 190°C under nitrogen, react After 4hr, cool to room temperature, then add appropriate amount of water and ethyl acetate for extraction, collect the organic phase, dry anhydrous magnesium sulfate, add appropriate amount of silica gel, spin-evaporate to remove the solvent, and use n-hexane/ethyl acetate system column chromatography to obtain White solid 2.77g, yield 90%, purity 99.9%. Mass spectrum ^{(ESI -) ([MH]} -) C 54 H 62 N 3 O Calculated: 768.50; Found: 768.47.

Synthesis of Compound P105 : Take 1.54 g (2.0 mmol) of Compound 16 and 328 mg of anhydrous sodium acetate (2.0 eq., 4.0 mmol) in 25 mL of DMSO, stir and heat to 80°C, then add 830 mg of potassium tetrachloroplatinate (1.0 eq., 2.0mmol), nitrogen was replaced by evacuation several times, the temperature was raised to 120 ℃ for 5hr. After the reaction, add 100ml of water while hot, filter, collect the solid, wash with appropriate amount of water and methanol, recrystallize the obtained solid with toluene, and then vacuum sublimate to obtain a dark red solid 1.25g, total yield 65%, purity 99.9% . Mass spectrum ^{(ESI -) ([MH]} -) C 54 H 60 N 3 OPt Calculated: 961.44; Found: 961.42.

The Pt(II) complexes of the examples showed obvious orange-red light emission in the dichloromethane solution, as shown in the following table:

The following are application examples of the compounds of the present invention.

Device preparation method:

The basic structure model of the device is: ITO/HTL-1 (60nm)/EML-1: Pt(II) (40nm)/ETL-1 (30nm)/LiF (1nm)/Al (80nm).

The transparent indium tin oxide (ITO) 20 (10Ω/sq) glass substrate 10 was ultrasonically cleaned using acetone, ethanol, and distilled water in this order, and then treated with oxygen plasma for 5 minutes.

Then, the ITO substrate is mounted on the substrate holder of the vacuum vapor deposition equipment. In the evaporation equipment, control the system pressure at 10 ^-6 torr.

Thereafter, the hole transport layer 30 material HTL-1 having a thickness of 60 nm is evaporated onto the ITO substrate.

Then, the material EML-1 of the light-emitting layer 40 with a thickness of 40 nm is evaporated, and doped with platinum (II) complex dopants of different mass fractions.

The electron transport layer 50 material ETL-1 with a thickness of 30 nm is then evaporated.

Then, LiF with a thickness of 1 nm is evaporated as the electron injection layer 60.

Finally, Al with a thickness of 80 nm is evaporated as the cathode 70 and the device packaging is completed. See Figure 1.

The structure and manufacturing method of the test device are identical, the difference is that the organometallic complexes Pt0, Pt1, Pt2, and Pt105 are used in sequence as the dopant and doping concentration in the light-emitting layer. Among them, Pt0 is a classic O^N^N^O type red light material.

The device comparison results are shown in the table below:

Under the condition that the doping concentration of the tetradentate platinum(II) complex is 4wt%, 8wt%, and 12wt%, the above ITO/HTL-1(60nm)/EML-1: Pt(II)(40nm)/ETL- 1(30nm)/LiF(1nm)/Al(80nm) device basic structure to prepare device. Taking the performance of Pt0-based devices as a reference, the starting voltage V _{on of the} four-tooth platinum (II) complexes Pt1, Pt2, and Pt105 devices is reduced to varying degrees compared to Pt0 devices, especially the starting voltage of Pt105-based devices. Down to 3.0V. At the same time, under the conditions of 1000cd/A, the current efficiency (CE), power efficiency (PE) and external quantum efficiency (EQE) of devices based on Pt1, Pt2 and Pt105 have different degrees of improvement compared with devices based on Pt-0 , Especially Pt105, the improvement in current efficiency (CE), power efficiency (PE) and external quantum efficiency (EQE) is more obvious. When the doping concentration of the tetradentate platinum (II) complex increases, the efficiency of Pt0 and Pt1 is small or even decreased to a certain extent, but Pt105 has a better efficiency, and its current efficiency is increased from 73.5cd/A to 78.5cd/A, power efficiency increased from 67.8 lm/W to 78.5 lm/W, external quantum efficiency increased from 17.8% to 18.7%. Compared with Pt0, Pt1 and Pt2, Pt105 has larger steric groups, which can effectively reduce the aggregation between molecules, avoid the formation of exciplex, and improve the luminous efficiency. At the same time, Pt1 and Pt2 have different levels of performance improvement over Pt0.

In summary, the performance of the organic electroluminescent device prepared by the present invention has better performance than the reference device, and the new N^N^N^O tetradentate platinum (II) complex metal organic material is involved Has greater application value.

Claims (10)

An organic electroluminescent device containing a tetradentate platinum (II) complex includes an anode, a cathode and an intermediate organic layer, the organic layer includes at least a light-emitting layer, wherein the light-emitting layer contains a structure represented by formula (3) Tetradentate platinum (II) complex as a phosphorescent doped material,

Among them, A ₁ -A ₅ is a substituted or unsubstituted five-membered ring, six-membered ring, or fused ring structure. The organic electroluminescent device according to claim 1, wherein the tetradentate platinum (II) complex has a structure shown in formula (4):

Wherein R ₁ -R _{17 are} independently selected from hydrogen, deuterium, halogen, hydroxyl, acetyl, alkoxy, acetyl, amino, nitro, acetylamino, cyano, carboxyl, styryl, aminocarbonyl , Carbamate, benzylcarbonyl, aryloxy, diarylamino, saturated alkyl containing 1-30 C atoms, unsaturated alkyl containing 1-20 C atoms, containing 6-30 C Atom-substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl containing 5-30 C atoms, or adjacent R ₁ -R ₁₇ are connected to each other through a covalent bond to form a ring; wherein, X ₁ -X ₂₇ is carbon, and the halogen is F, Cl, Br. The organic electroluminescent device as described in claim 2, wherein R ₁ -R _{17 are} independently selected from hydrogen, halogen, amino, nitro, cyano, diarylamino, and saturated alkyl containing 1-10 C atoms Group, 6-20 C atoms containing halogen or one or more C1-C4 alkyl substituted or unsubstituted aryl groups, 5-20 C atoms containing halogen or one or more C1-C4 alkyl The substituted or unsubstituted heteroaryl group, or adjacent R ₁ -R ₁₇ are connected to each other through a covalent bond to form a ring, and the halogen is F, Cl. The organic electroluminescent device according to claim 3, wherein the tetradentate platinum (II) complex has a structure as shown in formula P:

Wherein, R ₁ '-R _5' are independently selected from hydrogen, halogen, di-arylamino, saturated alkyl group containing 1-10 C atoms, having 6-10 C atoms or one or more halogen C1 -C4 alkyl substituted or unsubstituted aryl, 5-10 C atoms substituted or unsubstituted heteroaryl substituted with halogen or one or more C1-C4 alkyl, or adjacent R ₁ -R ₁₇ Linked by a covalent bond to form a ring. The organic electroluminescent device, wherein, R ₁ '-R _5' 5 groups, wherein there are 0-3 groups independently represent a diarylamino group containing 6-10 of the requested item 4 Aryl groups substituted or unsubstituted by C atoms with halogen or one to three C1-C4 alkyl groups, heteroaromatic groups containing 5 to 10 C atoms substituted or unsubstituted by halogen or one to three C1-C4 alkyl groups The other groups independently represent hydrogen or a saturated alkyl group containing 1-8 C atoms, and the halogen is F. The organic electroluminescent device according to claim 5, wherein among the 5 groups of R ₁ ′-R ₅ ′, 0-3 of which are independently represented as dianiline, benzene, pyridine, carbamide Zazolyl, other groups are independently represented as hydrogen, isopropyl or tert-butyl. The organic electroluminescent device according to claim 1, wherein the tetradentate platinum (II) complex has the following structure:

The organic electroluminescent device according to claim 7, wherein the tetradentate platinum (II) complex has the following structure:

The organic electroluminescent device according to claim 7, wherein the doping amount of the tetradentate platinum (II) complex is 1%-12%. The organic electroluminescent device according to claim 7, wherein the doping amount of the tetradentate platinum (II) complex is 4%-8%, and the tetradentate platinum (II) complex is adopted by thermal deposition , Spin coating, inkjet printing is applied in the form of layers in the device.

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