WO2019128896A1

WO2019128896A1 - Organic electroluminescent device containing tetradentate platinum (ii) complex

Info

Publication number: WO2019128896A1
Application number: PCT/CN2018/122966
Authority: WO
Inventors: 康健; 戴雷; 蔡丽菲
Original assignee: 广东阿格蕾雅光电材料有限公司
Priority date: 2017-12-28
Filing date: 2018-12-23
Publication date: 2019-07-04
Also published as: TW201930331A; CN109980111B; TWI695008B; CN109980111A

Abstract

An organic electroluminescent device containing a tetradentate platinum (II) complex, comprising an anode, a cathode and an intermediate organic layer, wherein the intermediate organic layer at least comprises a light-emitting layer, and the light-emitting layer contains a tetradentate platinum (II) complex having the structure as shown in formula (3) as a phosphorescent doping material. Since the platinum (II) complex has a high fluorescence quantum efficiency, good heat stability and a low quenching constant, an OLED device, emitting orange light, having high light emission efficiency and low roll-off can be fabricated.

Description

Organic electroluminescent device containing tetradentate platinum (II) complex

Technical field

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

Background technique

Since its discovery, organic light-emitting diode (OLED) display technology has been widely concerned and researched for its unique performance such as low energy consumption, large viewing angle, and flexibility. In recent years, it has been on mobile phones. , TV, notebook computers and other electronic products are gradually applied. However, compared with the traditional display technology, OLED has shortcomings such as short service life, poor color purity, and easy aging, which leads to high cost, which hinders the promotion and development of OLED technology. Therefore, how to design a new type of OLED material is the focus and difficulty of research in the field of OLED.

In the field of OLED materials, phosphorescent OLED materials are developing rapidly and maturely. Phosphorescent OLED materials are mainly based on some heavy metal organic complexes such as ruthenium, platinum, rhodium, iridium and the like. Phosphorescent materials can make full use of the energy of singlet and triplet excitons in the luminescence process, so theoretically the quantum efficiency can reach 100%, which greatly improves the luminous efficiency of OLED devices, and is a widely used luminescent material in the industry.

Among them, platinum (II)-based phosphorescent OLED materials have been gradually developed and achieved good research results in recent years. Platinum (II) is generally a tetracoordinated site, and thus a metal organoplatinum (II) complex having a unique configuration can be formed 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 tetradentate platinum (II) complexes are mainly Schiff bases, which are relatively common, but the stability is relatively poor; O^N^C^O tetradentate platinum (II) The complex is relatively stable, but the performance needs to be improved.

Summary of the invention

In view of the defects in the above-mentioned fields, the organic electroluminescent device containing the tetradentate platinum (II) complex of the invention has good luminescent properties and good stability.

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

Wherein, 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 the group consisting of hydrogen, deuterium, halogen, hydroxy, acyl, alkoxy, acyloxy, amino, nitro, acylamino, cyano, carboxy, styryl, aminocarbonyl, urethane Acyl, benzylcarbonyl, aryloxy, diarylamino, saturated alkyl having 1 to 30 C atoms, unsaturated alkyl having 1 to 20 C atoms, substituted with 5 to 30 C atoms or An unsubstituted aryl group, a substituted or unsubstituted heteroaryl group having 5 to 30 C atoms, or an adjacent R _{1 to} R ₁₇ are bonded to each other by a covalent bond; wherein X ₁ -X ₂₇ is carbon, The halogen is F, Cl, Br.

Preferably, wherein R _{1 to} R _{17 are} independently selected from the group consisting of hydrogen, halogen, amino, nitro, cyano, diarylamino, saturated alkyl having 1 to 10 C atoms, and having 5 to 20 C atoms Halogen or one or more C1-C4 alkyl-substituted or unsubstituted aryl groups, 5-20 C atoms substituted by halogen or one or more C1-C4 alkyl groups or unsubstituted heteroaryl groups, or phases The adjacent R ₁ -R ₁₇ are bonded to each other by a covalent bond, and the halogen is F, Cl.

Preferred: for the following structure

Wherein R ₁ '-R ₅ ' is independently selected from the group consisting of hydrogen, halogen, diarylamine, saturated alkyl having 1-10 C atoms, halogen containing 5-10 C atoms or one or more C1- a C4 alkyl-substituted or unsubstituted aryl group, a 5- to 10-C atom-substituted or unsubstituted heteroaryl group substituted by a halogen or one or more C1-C4 alkyl groups, or adjacent R ₁ -R ₁₇ Covalent bonds are joined into a ring.

Preferably, of the 5 groups of R ₁ '-R ₅ ', wherein 0-3 groups are independently represented by a diarylamine group, 5-10 C atoms are halogen or one to three C1-C4 alkanes a substituted or unsubstituted aryl group, a halogen-containing or one to three C1-C4 alkyl-substituted or unsubstituted heteroaryl group having 5 to 10 C atoms; the other groups are independently represented as hydrogen or A saturated alkyl group of 1-8 C atoms, said halogen being F.

Preferably, among the 5 groups of R ₁ '-R ₅ ', 0-3 of the groups are independently represented by diphenylamino, benzene, pyridine or carbazolyl, and the other groups are independently represented by hydrogen or different. Propyl or tert-butyl.

For the purposes of this application, the terms halogen, alkyl, alkenyl, aryl, acyl, alkoxy and heterocyclic aromatic or heterocyclic aromatic groups may have the following meanings, unless otherwise indicated:

The above halogen or halogen includes fluorine, chlorine, bromine and iodine, preferably F, Cl, Br, particularly preferably F or Cl, most preferably F.

The above-mentioned ring-bonding, aryl-based, heteroaryl group by covalent bond includes having 5 to 30 carbon atoms, preferably 5 to 20 carbon atoms, more preferably 5 to 10 carbon atoms, and consisting of one aromatic ring or a plurality of The aromatic ring consists of an aryl group. Suitable aryl groups are, for example, phenyl, naphthyl, acenaphthenyl, acenaphthenyl, fluorenyl, fluorenyl, phenalenyl. The aryl group may be unsubstituted (i.e., all carbon atoms capable of substituting a hydrogen atom) 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 groups, preferably having from 1 to 20, from 1 to 10 or from 1 to 8 carbon atoms, particularly preferably methyl, ethyl or isopropyl Or a tert-butyl group; an aryl group, preferably a re-substituted or unsubstituted C ₅ , C ₆ aryl or anthracenyl group; a heteroaryl group, preferably a heteroaryl group containing at least one nitrogen atom, particularly preferably a pyridyl group; The aryl group particularly preferably has a substituent selected from the group consisting of F and a tert-butyl group, preferably an aryl group which is a given aryl group or a C ₅ ,C ₆ aryl group optionally substituted by at least one of the above substituents, C ₅ , C ₆ aryl is particularly preferably having 0, 1 or 2 of the above substituents, and C ₅ , C ₆ aryl is particularly preferably unsubstituted phenyl or substituted phenyl, such as biphenyl, by two uncles The butyl group is preferably a phenyl group substituted at the meta position.

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

The above alkyl group includes an alkyl group 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 may be cyclic, and may be interrupted by one or more heteroatoms, preferably N, O or S. Moreover, the alkyl group may be substituted by one or more halogens or the above-mentioned substituents with respect to the aryl group. Likewise, it is possible for the alkyl group to have one or more aryl groups, all of which are suitable for this purpose, the alkyl group being particularly preferred from methyl, ethyl, isopropyl, n-propyl, Isobutyl, n-butyl, tert-butyl, sec-butyl, isopentyl, cyclopropyl, cyclopentyl, cyclohexyl.

The above acyl group is an alkyl group which is bonded to a CO group by a single bond, as used herein.

The above alkoxy group is directly bonded to oxygen as a single bond, as used herein.

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

In certain embodiments, a heteroaryl group can be a five or six membered aromatic heterocyclic ring system containing the above independent zero, one or two substituents. Typical examples of heteroaryl groups include, but are not limited to, unsubstituted furan, benzofuran, thiophene, benzothiophene, pyrrole, pyridine, hydrazine, oxazole, benzoxazole, isoxazole, benzisoxazole, thiazole, benzo. Thiazole, isothiazole, imidazole, benzimidazole, pyrazole, oxazole, tetrazole, quinoline, isoquinoline, pyridazine, pyrimidine, purine and pyrazine, furan, 1,2,3-diazole, 1, 2,3-thiadiazole, 1,2,4-thiadiazole, triazole, benzotriazole, acridine, benzoxazole, diazole, benzopyrazole, quinolizine, porphyrin, pyridazine, Quinazole 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 are shown below, including but not limited to the following structures:

The preparation method of the above complex comprises the following steps:

As shown below, the carbazole derivative S1 is subjected to bromination reaction to obtain a substrate S2, S2 is reacted with a boronic acid pinacol ester to obtain a corresponding pinacol ester derivative S3, and S3 is reacted with a pyridine derivative S4 by Suzuki reaction. S5, S5 and the pyridine derivative S6 are subjected to Suzuki reaction to obtain S7, and S7 is demethylated to obtain the corresponding ligand S8, and S8 is reacted with K ₂ PtCl ₄ to obtain the target product P.

Wherein R' ₁ to R' ₅ are aromatic or non-aromatic substituents.

The N^N^N^O tetradentate platinum (II) complex can be used in an OLED light-emitting device as a phosphorescent dopant material for photon emission in the light-emitting layer. The doping amount of the tetradentate platinum (II) complex is from 1% to 12%. It is preferably 4% to 8%.

A thermally deposited and solution treated OLED device can be fabricated using the platinum (II) complex having the above structure.

Organic light-emitting devices comprising one or more complexes are included.

The complex is applied in layers in the device by thermal deposition.

The complex is applied in layers in the device by spin coating.

The complex is applied in layers in the device by ink jet printing.

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

The platinum (II) complex of the present invention has high fluorescence quantum efficiency, good thermal stability and low quenching constant, and can produce a red-emitting OLED device with high luminous efficiency and low roll-off.

DRAWINGS

1 is a schematic structural view of an organic electroluminescent device of the present invention,

Detailed ways

The present invention will be further described in detail below with reference to the embodiments.

Example 1:

synthetic route:

Synthesis of Compound 2: 6.50 g (20.0 mmol) of Compound 1, 12.70 g of diboronic acid pinacol ester (2.5 eq., 50.0 mmol), potassium carbonate 5.18 g (2.5 eq., 50.0 mmol) and Pd(dppf)Cl ₂ 292 mg (0.02 eq., 0.4 mmol) was placed in a three-necked flask, vacuum-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, the mixture was cooled to room temperature, and the solvent was evaporated to remove the solvent. The mixture was evaporated to ethyl ether. The organic phase was collected, dried over anhydrous magnesium sulfate, and then evaporated. Column chromatography on ethyl acetate afforded 7.12 g of white solid.

Synthesis of Compound 3: 11.85 g (50.0 mmol) of compound 2,6-dibromopyridine, 2.70 g of 2-methoxyphenylboronic acid (1.0 eq., 50.0 mmol), potassium carbonate 6.48 g (1.25 eq., 62.5 mmol) And Pd(OAc) ₂ 224 mg (0.02 eq., 1 mmol), PPh ₃ 1.31 g (0.1 eq., 5 mmol) was added to a three-necked flask, vacuum-replaced with nitrogen for several times, and then 150 mL of acetonitrile and 50 mL of methanol were injected. , heated to 60 ° C. After reacting under nitrogen for 12 hr, the mixture was cooled to room temperature, and the solvent was evaporated to remove the solvent. The mixture was evaporated to ethyl ether. The organic phase was collected, dried over anhydrous magnesium sulfate, and then evaporated. Column chromatography on an ethyl acetate system gave 9.90 g of a white solid.

Synthesis of Compound 4: 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 ( 0.02 eq., 0.3 mmol), which was placed in a three-necked flask, was evacuated and purged with nitrogen several times, then 100 mL of acetonitrile and 50 mL of methanol were poured and heated to 60 °C. After reacting under nitrogen for 12 hr, the mixture was cooled to room temperature, and the solvent was evaporated to remove the solvent. The mixture was evaporated to ethyl ether. The organic phase was collected, dried over anhydrous magnesium sulfate, and then evaporated. Column chromatography on an ethyl acetate system gave 4.28 g of a white solid.

Synthesis of Compound 5: 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 (0.02 eq., 0.16 mmol), which was placed in a three-necked flask, was evacuated and purged with nitrogen several times, and then 60 mL of acetonitrile and 30 mL of methanol were poured and heated to 60 °C. After reacting under nitrogen for 12 hr, the mixture was cooled to room temperature, and the solvent was evaporated to remove the solvent. The mixture was evaporated to ethyl ether. The organic phase was collected, dried over anhydrous magnesium sulfate, and then evaporated. Column chromatography on an ethyl acetate system gave 3.07 g of a white solid.

Synthesis of compound 6: 2.14 g (4.0 mmol) of compound 5, pyridine hydrochloride 30 g (PyHCl), added to a three-necked flask, vacuumed and replaced with nitrogen several times, heated to 190 ° C under nitrogen atmosphere, reaction After 4 hr, it was cooled to room temperature, and then extracted with water and ethyl acetate. The organic phase was collected, dried over anhydrous magnesium sulfate, and then filtered. White solid 1.32 g, yield 80%, purity 99.9%. Mass spectrum ^{(ESI -) ([MH]} -) C 28 H 18 N 3 O Calculated: 412.15; Found: 412.13.

Synthesis of Compound P1: 826 mg (2.0 mmol) of Compound 5 and 328 mg of anhydrous sodium acetate (2.0 eq., 4.0 mmol) were dissolved in 25 mL of DMSO, stirred, heated to 80 ° C, then added potassium chloroplatinate 830 mg (1.0 Eq., 2.0 mmol), vacuumed several times with nitrogen, and heated to 120 ° C for 5 hr. After completion of the reaction, 100 ml of water was added while hot, and the solid was collected, washed with an appropriate amount of water and methanol, and the obtained solid was recrystallized from toluene, and then sublimated in vacuo to give 788 mg of a dark red solid, yield 65%, purity 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: 16.72 g of carbazole (0.10 mol) and 655 mg of anhydrous aluminum trichloride (5 mmol) were placed in a three-necked flask, vacuum-replaced with nitrogen for several times, and then chloro-tert-butane 27.77 g was added dropwise. (3.0 eq., 0.30 mmol) and 250 mL of dry dichloromethane, stirred for 12 hr under nitrogen atmosphere, and then extracted with an appropriate amount of water, and the organic phase was collected, and the solvent was removed by rotary evaporation, and the obtained solid was recrystallized from ethanol. White solid 23.20 g, yield 83%, purity 99.5%.

Synthesis of Compound 8: 13.97 g (50.0 mmol) of Compound 7 was dissolved in 750 mL of acetic acid, and then 19.98 g (2.5 eq., 125.0 mmol) of liquid bromine was added dropwise, and the reaction was blocked. After stirring at room temperature for about 4 hr, the solvent is removed by rotary evaporation, and then water and sodium bisulfite solution is added, and ethyl acetate is extracted, and the organic phase is collected. After drying over anhydrous magnesium sulfate, an appropriate amount of silica gel is added, and the solvent is removed by rotary evaporation using n-hexane. Column chromatography with ethyl acetate system gave 20.77 g of white solid.

Synthesis of compound 9: 10.93 g (25.0 mmol) of compound 8, borax acid pinacol ester 15.88 g (2.5 eq., 62.5 mmol), potassium carbonate 8.64 g (2.5 eq., 62.5 mmol) and Pd(dppf)Cl. ₂ 366 mg (0.02 eq., 0.5 mmol) was placed in a three-necked flask, vacuum-replaced with nitrogen for several times, and then injected with 300 mL of dioxane and heated to 85 °C. After reacting under nitrogen for 12 hr, the mixture was cooled to room temperature, and the solvent was evaporated to remove the solvent. The mixture was evaporated to ethyl ether. The organic phase was collected, dried over anhydrous magnesium sulfate, and then evaporated. Column chromatography on ethyl acetate gave a white solid, 9.56 g, yield 72%, purity 99.9%.

Synthesis of Compound 10: 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 ( 0.02 eq., 0.3 mmol), which was placed in a three-necked flask, was evacuated and purged with nitrogen several times, then 100 mL of acetonitrile and 50 mL of methanol were poured and heated to 60 °C. After reacting under nitrogen for 12 hr, the mixture was cooled to room temperature, and the solvent was evaporated to remove the solvent. The mixture was evaporated to ethyl ether. The organic phase was collected, dried over anhydrous magnesium sulfate, and then evaporated. Column chromatography on ethyl acetate gave a white solid 5.74 g, yield 65%, purity 99.9%.

Synthesis of Compound 11: 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 (0.02 eq., 0.16 mmol), which was placed in a three-necked flask, was evacuated and purged with nitrogen several times, and then 60 mL of acetonitrile and 30 mL of methanol were poured and heated to 60 °C. After reacting under nitrogen for 12 hr, the mixture was cooled to room temperature, and the solvent was evaporated to remove the solvent. The mixture was evaporated to ethyl ether. The organic phase was collected, dried over anhydrous magnesium sulfate, and then evaporated. Column chromatography on an ethyl acetate system gave 3.67 g of a white solid.

Synthesis of compound 12: 2.16 g (4.0 mmol) of compound 11 and pyridine hydrochloride 30 g (PyHCl) were added to a three-necked flask, vacuum-passed and purged several times with nitrogen, and heated to 190 ° C under nitrogen atmosphere. After 4 hr, it was cooled to room temperature, and then extracted with water and ethyl acetate. The organic phase was collected, dried over anhydrous magnesium sulfate, and then filtered. The white solid was 1.79 g, the yield was 85%, and the purity was 99.9%. Mass spectrum ^{(ESI -) ([MH]} -) C 36 H 34 N 3 O Calculated: 524.27; Found: 524.24.

Synthesis of Compound P2: 1.06 g (2.0 mmol) of Compound 5 and 328 mg of anhydrous sodium acetate (2.0 eq., 4.0 mmol) were dissolved in 25 mL of DMSO, stirred, heated to 80 ° C, then 830 mg of potassium tetrachloroplatinate ( 1.0 eq., 2.0 mmol), vacuumed several times with nitrogen, and heated to 120 ° C for 5 hr. After the completion of the reaction, 100 ml of water was added while hot, and the solid was collected, washed with water and methanol, and the obtained solid was recrystallized from toluene, and then sublimated in vacuo to give a dark red solid, 1.01 g, yield 70%, 99.9%. Mass spectrum ^{(ESI -) ([MH]} -) C 36 H 33 N 3 OPt Calculated: 717.23; Found 717.20 ::.

Example 3:

synthetic route:

Synthesis of Compound 14: 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 ( 0.02 eq., 0.3 mmol), which was placed in a three-necked flask, was evacuated and purged with nitrogen several times, then 100 mL of acetonitrile and 50 mL of methanol were poured and heated to 60 °C. After reacting under nitrogen for 12 hr, the mixture was cooled to room temperature, and the solvent was evaporated to remove the solvent. The mixture was evaporated to ethyl ether. The organic phase was collected, dried over anhydrous magnesium sulfate, and then evaporated. Column chromatography on ethyl acetate gave a white solid 7.50 g, yield 60%, purity 99.5%.

Synthesis of compound 15: 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 (0.02 eq., 0.16 mmol), which was placed in a three-necked flask, was evacuated and purged with nitrogen several times, and then 60 mL of acetonitrile and 30 mL of methanol were poured and heated to 60 °C. After reacting under nitrogen for 12 hr, the mixture was cooled to room temperature, and the solvent was evaporated to remove the solvent. The mixture was evaporated to ethyl ether. The organic phase was collected, dried over anhydrous magnesium sulfate, and then evaporated. Column chromatography on an ethyl acetate system gave 6.27 g of white solid.

Synthesis of compound 16: 3.14 g (4.0 mmol) of compound 15 and pyridine hydrochloride 30 g (PyHCl) were added to a three-necked flask, vacuum-passed and purged several times with nitrogen, and heated to 190 ° C under nitrogen atmosphere. After 4 hr, it was cooled to room temperature, and then extracted with water and ethyl acetate. The organic phase was collected, dried over anhydrous magnesium sulfate, and then filtered. The white solid was 2.77 g, the yield was 90%, and the purity was 99.9%. Mass spectrum ^{(ESI -) ([MH]} -) C 54 H 62 N 3 O Calculated: 768.50; Found: 768.47.

Synthesis of compound P105: 1.54 g (2.0 mmol) of compound 16 and 328 mg of anhydrous sodium acetate (2.0 eq., 4.0 mmol) were dissolved in 25 mL of DMSO, stirred, heated to 80 ° C, then 830 mg of potassium tetrachloroplatinate ( 1.0 eq., 2.0 mmol), vacuumed several times with nitrogen, and heated to 120 ° C for 5 hr. After the reaction was completed, 100 ml of water was added while hot, and the solid was collected, washed with an appropriate amount of water and methanol, and the obtained solid was recrystallized from toluene, and then sublimated in vacuo to give 1.25 g of a dark red solid, 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) complex of the examples exhibited significant orange-red light emission in a solution of dichloromethane solution, as shown in the following table:

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

Device preparation method:

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

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

The ITO substrate was then mounted on a substrate holder of a vacuum vapor deposition apparatus. In the evaporation equipment, the control system pressure is 10 ^-6 torr.

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

The luminescent layer 40 material EML-1 having a thickness of 40 nm is then evaporated, wherein different mass fractions of platinum (II) complex dopant are doped.

Then, the electron transport layer 50 material ETL-1 having a thickness of 30 nm was evaporated.

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

Finally, Al having a thickness of 80 nm was evaporated as the cathode 70 and the device package was completed. See Figure 3.

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

Device comparison results are shown in the table below:

The above ITO/HTL-1 (60 nm)/EML-1:Pt(II) (40 nm)/ETL- under the conditions of the tetradentate platinum (II) complex doping concentration of 4 wt%, 8 wt%, and 12 wt%, respectively. 1 (30 nm) / LiF (1 nm) / Al (80 nm) device basic structure preparation device. Based on the performance of Pt0-based devices, the devices with four-tooth platinum (II) complexes Pt1, Pt2, and Pt105 have different degrees of reduction in the startup voltage V _on compared to Pt0 devices, especially the startup voltage of Pt105-based devices. Dropped to 3.0V. At the same time, under the condition of 1000cd/A, the devices based on Pt1, Pt2 and Pt105 have different degrees of improvement in current efficiency (CE), power efficiency (PE) and external quantum efficiency (EQE) compared to Pt-0 based devices. Especially for 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 increases little or even the efficiency decreases to some extent, but Pt105 has better efficiency, and its current efficiency is improved from 73.5 cd/A. At 78.5 cd/A, the power efficiency increased from 67.8 lm/W to 78.5 lm/W, and the external quantum efficiency increased from 17.8% to 18.7%. Pt105 has a larger sterically hindered group than Pt0, Pt1 and Pt2, which can effectively reduce the aggregation between molecules, avoid the formation of exciplex and improve the luminous efficiency. At the same time, Pt1, Pt2 have different degrees of performance improvement relative to Pt0.

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

Claims

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

Wherein, A1-A5 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 as shown in the formula (4):

Wherein R 1 -R 17 are independently selected from the group consisting of hydrogen, deuterium, halogen, hydroxy, acyl, alkoxy, acyloxy, amino, nitro, acylamino, cyano, carboxy, styryl, aminocarbonyl, urethane Acyl, benzylcarbonyl, aryloxy, diarylamino, saturated alkyl having 1 to 30 C atoms, unsaturated alkyl having 1 to 20 C atoms, substituted with 5 to 30 C atoms or An unsubstituted aryl group, a substituted or unsubstituted heteroaryl group having 5 to 30 C atoms, or an adjacent R 1 to R 17 are bonded to each other by a covalent bond; wherein X 1 -X 27 is carbon, The halogen is F, Cl, Br.
The organic electroluminescent device according to claim 2, wherein R 1 to R 17 are independently selected from the group consisting of hydrogen, halogen, amino, nitro, cyano, diarylamine, and saturated alkane having 1 to 10 C atoms. a halogen-containing or one or more C1-C4 alkyl groups having 5 to 20 C atoms substituted by halogen or one or more C1-C4 alkyl groups, having 5 to 20 C atoms The substituted or unsubstituted heteroaryl group, or the adjacent R 1 -R 17 are bonded to each other by a covalent bond, 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 ' is independently selected from the group consisting of hydrogen, halogen, diarylamine, saturated alkyl having 1-10 C atoms, halogen containing 5-10 C atoms or one or more C1- a C4 alkyl-substituted or unsubstituted aryl group, a 5- to 10-C atom-substituted or unsubstituted heteroaryl group substituted by a halogen or one or more C1-C4 alkyl groups, or adjacent R 1 -R 17 Covalent bonds are joined into a ring.
The organic electroluminescent device according to claim 4, wherein among the 5 groups of R 1 '-R 5 ', 0-3 of the groups are independently represented by a diarylamine group, and 5 to 10 a C atom substituted by halogen or one to three C1-C4 alkyl groups or unsubstituted aryl groups, 5-10 C atoms substituted by halogen or one to three C1-C4 alkyl groups or unsubstituted heteroaryl groups Other groups are independently represented by hydrogen or a saturated alkyl group having 1-8 C atoms, which is F.
The organic electroluminescent device according to claim 5, wherein among the five groups of R 1 '-R 5 ', 0-3 of the groups are independently represented by diphenylamine, benzene, pyridine or carbazole. The other groups are independently represented by 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 tetradentate platinum (II) complex has a doping amount of from 1% to 12%.
The organic electroluminescent device according to claim 7, wherein the tetradentate platinum (II) complex has a doping amount of 4% to 8%, and the tetradentate platinum (II) complex is formed by thermal deposition and spinning. Coating, inkjet printing is applied in layers to the device.