CN109970714B

CN109970714B - Tetradentate platinum (II) complex and application thereof

Info

Publication number: CN109970714B
Application number: CN201811567623.1A
Authority: CN
Inventors: 康健; 戴雷; 蔡丽菲
Original assignee: Guangdong Aglaia Optoelectronic Materials Co Ltd
Current assignee: Guangdong Aglaia Optoelectronic Materials Co Ltd
Priority date: 2017-12-28
Filing date: 2018-12-21
Publication date: 2021-04-13
Anticipated expiration: 2038-12-21
Also published as: CN109970714A; WO2019128897A1; TWI695007B; TW201930330A

Abstract

The invention relates to a tetradentate platinum (II) complex and application thereof, wherein the complex has an N ^ N ^ O configuration, and the structure of the complex is shown as a formula (3), wherein A1-A5 is a substituted or unsubstituted five-membered ring, six-membered ring or condensed ring structure. The complex can be used as a phosphorescent doped material to be applied to the field of OLED. The platinum (II) complex has high fluorescence quantum efficiency, good thermal stability and low quenching constant, and can be used for manufacturing orange red light OLED devices with high luminous efficiency and low roll-off.

Description

Tetradentate platinum (II) complex and application thereof

Technical Field

The invention relates to a novel N ^ N ^ N ^ O tetradentate platinum (II) complex metal organic material, in particular to a phosphorescence doped material which is used for a light-emitting layer of an OLED light-emitting device and plays a role in photon emission.

Background

Since the discovery of Organic Light-Emitting Diode (OLED) display technology, the OLED display technology has been widely focused and researched due to its unique properties of low energy consumption, large viewing angle, flexibility, etc., and is more gradually applied to electronic products such as mobile phones, televisions, notebook computers, etc. in recent years. However, compared with the conventional display technology, the cost of the OLED is high due to the defects of short service life, poor color purity, easy aging and the like, and the popularization and development of the OLED technology are hindered. Therefore, how to design new OLED materials is a major and difficult point of research in the OLED field.

In the field of OLED materials, phosphorescent OLED materials are rapidly and mature. Phosphorescent OLED materials are mainly based on some heavy metal organic complexes, such as iridium, platinum, europium, osmium, etc. The phosphorescent material can fully utilize the energy of singlet excitons and triplet excitons in the light emitting process, so that the quantum efficiency can reach 100% theoretically, the light emitting efficiency of the OLED device is greatly improved, and the phosphorescent material is a wide light emitting material used in the industry at present.

Among them, phosphorescent OLED materials based on platinum (II) have been gradually developed and have achieved better research results in recent years. Platinum (II) is generally tetradentate, and thus a metalorganic platinum (II) complex having a unique configuration can be formed by designing a tetradentate ligand. In general, the most common tetradentate ligands are of the type O ^ N ^ N ^ O (formula (1)), O ^ N ^ C ^ O (formula (2)),

wherein, the O ^ N ^ N ^ O type tetradentate platinum (II) complex is mainly Schiff base (Schiff base) type, is relatively common, but has relatively poor stability; the O ^ N ^ C ^ O type tetradentate platinum (II) complex is relatively stable, but the performance needs to be improved.

Disclosure of Invention

The invention designs a novel N ^ N ^ O-configuration tetradentate platinum (II) complex, which can be used as a phosphorescent doped material to be applied to the field of OLED, is a novel coordination mode, and shows better stability and luminous performance.

An N ^ N ^ N ^ O-configured tetradentate platinum (II) complex, which has a basic structure shown as a formula (3):

wherein A1-A5 is substituted or unsubstituted five-membered ring, six-membered ring or condensed ring structure.

The invention also provides a preparation method of the novel N ^ N ^ N ^ O configuration tetradentate platinum (II) complex.

Preferably: a structure represented by formula (4):

wherein R is₁－R₁₇Independently selected from hydrogen, deuterium, halogen, hydroxyl, acyl, alkoxy, acyloxy, amino, nitro, acylamino, cyano, carboxyl, styryl, aminocarbonyl, carbamoyl, benzylcarbonyl, aryloxy, diarylamino, saturated alkyl containing 1 to 30C atoms, unsaturated alkyl containing 1 to 20C atoms, substituted or unsubstituted aryl containing 5 to 30C atoms, substituted or unsubstituted heteroaryl containing 5 to 30C atoms, or adjacent R₁－R₁₇Are connected to each other through a covalent bond to form a ring; wherein, X₁－X₂₇Is carbon, and the halogen is F, Cl or Br.

Preferably: wherein R is₁－R₁₇Independently selected from hydrogen, halogen, amino, nitro, cyano, diarylamine, saturated alkyl containing 1-10C atoms, aryl substituted or unsubstituted with halogen or one or more C1-C4 alkyl containing 5-20C atoms, heteroaryl substituted or unsubstituted with halogen or one or more C1-C4 alkyl containing 5-20C atoms, or adjacent R₁－R₁₇The halogen is F and Cl.

Preferably: is of the following structure

Wherein R is₁’－R₅' is independently selected from hydrogen, halogen, diarylamine, saturated alkyl containing 1-10C atoms, aryl containing 5-10C atoms substituted with halogen or one or more C1-C4 alkyl groups or unsubstituted heteroaryl containing 5-10C atoms substituted with halogen or one or more C1-C4 alkyl groups or adjacent R₁－R₁₇Are linked to each other by covalent bonds to form a ring.

Preferably: r₁’－R₅' of the 5 groups, 0 to 3 of which are independently represented by a diarylamineA group, aryl substituted or unsubstituted with 5 to 10C atoms by halogen or one to three C1-C4 alkyl groups, heteroaryl substituted or unsubstituted with 5 to 10C atoms by halogen or one to three C1-C4 alkyl groups; the other groups are independently represented by hydrogen or saturated alkyl containing 1 to 8C atoms, and the halogen is F.

Preferably: r₁’－R₅Of the 5 groups of' 0 to 3 are independently represented by a dianilino group, a benzene, a pyridine, a carbazolyl group, and the others are independently represented by a hydrogen group, an isopropyl group or a tert-butyl group.

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

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

The above-mentioned cyclic, aryl and heteroaryl groups linked by a covalent bond include aryl groups 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 fused aromatic rings. Suitable aryl radicals are, for example, phenyl, naphthyl, acenaphthenyl, anthryl, fluorenyl, phenanthryl (phenalenyl). The aryl group may be unsubstituted (i.e., all carbon atoms capable of substitution carry 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, preferably having 1 to 20, 1 to 10 or 1 to 8 carbon atoms, particularly preferably methyl, ethyl, isopropyl or tert-butyl; aryl, preferably unsubstituted or substituted C₅，C₆Aryl or fluorenyl; heteroaryl, preferably heteroaryl containing at least one nitrogen atom, particularly preferably pyridyl; aryl particularly preferably bears substituents selected from F and tert-butyl, and preferably may be a given aryl or optionally substituted by at least one of the abovementioned substituents is C₅，C₆Aryl of aryl radical, C₅，C₆Aryl particularly preferably carries 0, 1 or 2 of the abovementioned substituentsBase, C₅，C₆Aryl is particularly preferably unsubstituted phenyl or substituted phenyl, such as biphenyl, phenyl which is substituted by two tert-butyl groups, preferably in the meta position.

Unsaturated alkyl groups having 1 to 20 carbon atoms, preferably alkenyl groups, more preferably alkenyl groups having one double bond, particularly preferably alkenyl groups 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 straight chain 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 halogen or the above-mentioned substituents for the aryl group. Likewise, it is possible for the alkyl group to bear one or more aryl groups, all of which are suitable for this purpose, the alkyl group being particularly preferably selected from the group consisting of methyl, ethyl, isopropyl, n-propyl, isobutyl, n-butyl, tert-butyl, sec-butyl, isopentyl, cyclopropyl, cyclopentyl, cyclohexyl.

The acyl group is singly bonded to a CO group, such as alkyl as used herein.

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

The aforementioned heteroaryl groups are understood to be aromatic, C₃－C₈Cyclic groups are related and also contain one oxygen or sulfur atom or 1 to 4 nitrogen atoms or a combination of one oxygen or sulfur atom and up to two nitrogen atoms, and their substituted and benzo-and pyrido-fused derivatives, for example, linked via one of the ring-forming carbon atoms, which heteroaryl group may be substituted with one or more of the substituents mentioned for aryl.

In certain embodiments, heteroaryl groups can be five or six membered aromatic heterocyclic ring systems bearing 0, 1 or 2 substituents independently as above. Typical examples of heteroaryl groups include, but are not limited to, unsubstituted furan, benzofuran, thiophene, benzothiophene, pyrrole, pyridine, indole, oxazole, benzoxazole, isoxazole, benzisoxazole, thiazole, benzothiazole, isothiazole, imidazole, benzimidazole, substituted heteroaryl, and substituted heteroarylOxazole, pyrazole, indazole, tetrazole, quinoline, isoquinoline, pyridazine, pyrimidine, purine and pyrazine, furan, 1,2, 3-oxadiazole, 1,2, 3-thiadiazole, 1,2, 4-thiadiazole, triazole, benzotriazole, pteridine, benzoxazole, oxadiazole, benzopyrazole, quinolizine, cinnoline, phthalazine, quinazol and quinoxaline, and mono-or di-substituted derivatives thereof. In certain embodiments, the substituents are halo, hydroxy, cyano, O-C_1～6Alkyl radical, C_1～6Alkyl, hydroxy C_1～6Alkyl and amino-C_1～6An alkyl group.

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

the preparation method of the complex comprises the following steps:

as shown in the following, a carbazole derivative S1 is subjected to bromination reaction to obtain a substrate S2, S2 is subjected to reaction with pinacol ester diboron to obtain a corresponding pinacol ester derivative S3, S3 is subjected to Suzuki reaction with a pyridine derivative S4 to obtain S5, S5 is subjected to Suzuki reaction with the pyridine derivative S6 to obtain S7, S7 is subjected to demethylation to obtain a corresponding ligand S8, and S8 and K are subjected to bromination reaction to obtain a corresponding ligand S6332₂PtCl₄The target product P is obtained after the reaction.

Wherein R'₁～R'₅Is an aromatic or non-aromatic substituent.

The N ^ N ^ N ^ O tetradentate platinum (II) complex can be used for a phosphorescent doped material which plays a role in photon emission in an OLED light-emitting device.

With the platinum (II) complex having the above structure, a heat sink and solution processed OLED device can be manufactured.

Including organic light emitting devices that include one or more complexes.

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

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

Wherein the complex is applied in the form of a layer in the device by ink jet printing.

The organic light emitting device emits orange-red color when current is applied thereto.

The platinum (II) complex has high fluorescence quantum efficiency, good thermal stability and low quenching constant, and can be used for manufacturing orange red light OLED devices with high luminous efficiency and low roll-off.

Drawings

FIG. 1 is a schematic view of the structure of an organic electroluminescent device according to the present invention,

Detailed Description

The present invention will be described in further detail with reference to examples.

Example 1:

the synthetic route is as follows:

synthesis of Compound 2: 6.50g (20.0mmol) of Compound 1, Biboronic acid pinacol ester 12.70g (2.5eq.,50.0mmol), potassium carbonate 5.18g (2.5eq.,50.0mmol) and Pd (dppf) Cl were taken₂292mg (0.02eq.,0.4 mmol) was charged into a three-necked flask, and was evacuated and purged with nitrogen gas several times, then 150mL of acetonitrile dioxane was injected, and the mixture was heated to 85 ℃. Reacting for 12hr under the protection of nitrogen, cooling to room temperature, removing the solvent by rotary evaporation, adding a proper amount of water and ethyl acetate for extraction, collecting an organic phase, drying with anhydrous magnesium sulfate, adding a proper amount of silica gel, removing the solvent by rotary evaporation, and performing column chromatography by using a normal hexane/ethyl acetate system to obtain 7.12g of a white solid, wherein the yield is 85% and the purity is 99.0%.

Synthesis of Compound 3 11.85g (50.0mmol) of Compound 2, 6-dibromopyridine, 7.60 g (1.0eq.,50.0mmol) of 2-methoxyphenylboronic acid, 6.48g (1.25eq.,62.5mmol) of potassium carbonate and Pd (OAc)₂ 224mg(0.02 eq.,1mmol)，PPh₃1.31g (0.1eq.,5mmol) was charged into a three-necked flask, and nitrogen gas was introduced into the flask in vacuum to displace the flask several times, followed by introduction of 150mL of acetonitrile and 50mL of methanol and heating to 60 ℃. Reacting under nitrogen protection for 12hr, cooling to room temperature, removing solvent by rotary evaporation, adding appropriate amount of water and ethyl acetate, extracting, collecting organic phase, drying with anhydrous magnesium sulfate, adding appropriate amount of silica gel, and removing solvent by rotary evaporationThe solvent is subjected to column chromatography by using a normal hexane/ethyl acetate system to obtain 9.90g of white solid, the yield is 75 percent, and the purity is 99.5 percent.

Synthesis of Compound 4: 6.29g (15.0mmol) of Compound 2, 33.96 g (1.0eq.,15.0 mmol), 3.45g (1.25eq.,25.0mmol) of Potassium carbonate and Pd (PPh)₃)₄347mg (0.02eq.,0.3mmol) was charged into a three-necked flask, and was evacuated by introducing nitrogen gas and replaced with nitrogen gas several times, followed by charging 100mL of acetonitrile and 50mL of methanol and heating to 60 ℃. Reacting for 12hr under the protection of nitrogen, cooling to room temperature, removing the solvent by rotary evaporation, adding a proper amount of water and ethyl acetate for extraction, collecting an organic phase, drying with anhydrous magnesium sulfate, adding a proper amount of silica gel, removing the solvent by rotary evaporation, and performing column chromatography by using a normal hexane/ethyl acetate system to obtain 4.28g of a white solid, wherein the yield is 60% and the purity is 99.5%.

Synthesis of Compound 5: 3.81g (8.0mmol) of the compound 4, 2-bromopyridine 1.37g (1.1eq.,8.8mmol), potassium carbonate 1.38g (1.25eq.,10.0mmol) and Pd (PPh)₃)₄185mg (0.02eq.,0.16mmol) was charged into a three-necked flask, and was evacuated and purged with nitrogen gas several times, followed by injection of acetonitrile 60mL and 30mL of methanol and heating to 60 ℃. Reacting for 12hr under nitrogen protection, cooling to room temperature, removing solvent by rotary evaporation, adding appropriate amount of water and ethyl acetate for extraction, collecting organic phase, drying with anhydrous magnesium sulfate, adding appropriate amount of silica gel, removing solvent by rotary evaporation, and performing column chromatography with n-hexane/ethyl acetate system to obtain white solid 3.07g, yield 90%, and purity 99.9%.

Synthesis of Compound 6: taking 2.14g (4.0mmol) of the compound 5 and 30g of pyridine hydrochloride (PyHCl), adding the mixture into a three-necked flask, vacuumizing, introducing nitrogen for replacement for multiple times, heating to 190 ℃ under the protection of nitrogen, reacting for 4 hours, cooling to room temperature, adding a proper amount of water and ethyl acetate for extraction, collecting an organic phase, drying anhydrous magnesium sulfate, adding a proper amount of silica gel, removing the solvent by rotary evaporation, and performing column chromatography by using a normal hexane/ethyl acetate system to obtain 1.32g of a white solid, wherein the yield is 80% and the purity is 99.9%. Mass spectrometry (ESI)^-)([M-H]^-)C₂₈H₁₈N₃412.15 as theoretical value of O; found 412.13.

Of compound P1Synthesizing: 826mg (2.0mmol) of compound 5 and 328mg of anhydrous sodium acetate (2.0eq.,4.0 mmol) are dissolved in 25mL of DMSO, stirred, heated to 80 ℃, added with 830mg (1.0eq.,2.0 mmol) of potassium tetrachloroplatinate, vacuumized, introduced with nitrogen for replacement for several times, and heated to 120 ℃ for reaction for 5 hr. After the reaction is finished, 100ml of water is added while the reaction is hot, the mixture is filtered, solid is collected and washed by proper amount of water and methanol, the obtained solid is recrystallized by toluene, and then the solid is sublimated in vacuum to obtain dark red solid 788mg, the total yield is 65 percent, and the purity is 99.9 percent. Mass spectrometry (ESI)^-)([M-H]^-)C₂₈H₁₆N₃OPt theoretical value 605.10; found 605.08.

Example 2:

the synthetic route is as follows:

synthesis of compound 7: taking 16.72g of carbazole (0.10mol) and 655mg of anhydrous aluminum trichloride (5mmol) into a three-neck flask, vacuumizing, introducing nitrogen for replacing for multiple times, then dropwise adding 27.77g (3.0eq.,0.30mmol) of chloro-tert-butane and 250mL of dried dichloromethane, stirring and reacting for 12 hours under the protection of nitrogen, adding a proper amount of water for extraction, collecting an organic phase, removing the solvent by rotary evaporation, and recrystallizing the obtained solid by using ethanol to obtain 23.20g of white solid, wherein the yield is 83% and the purity is 99.5%.

Synthesis of compound 8: 13.97g (50.0mmol) of Compound 7 was dissolved in 750mL of acetic acid, and then 19.98g (2.5eq.,125.0mmol) of liquid bromine was added dropwise thereto, followed by a light-shielding reaction. Stirring at room temperature for about 4hr, removing solvent by rotary evaporation, adding appropriate amount of water and sodium bisulfite solution, washing, extracting with ethyl acetate, collecting organic phase, drying with anhydrous magnesium sulfate, adding appropriate amount of silica gel, removing solvent by rotary evaporation, and performing column chromatography with n-hexane/ethyl acetate system to obtain white solid 20.77g, with yield 95% and purity 99.9%.

Synthesis of compound 9: 10.93g (25.0mmol) of Compound 8, 15.88g (2.5eq.,62.5mmol) of Biboronic acid pinacol ester, 8.64g (2.5eq.,62.5mmol) of potassium carbonate and Pd (dppf) Cl were taken₂366mg (0.02eq.,0.5 mmol) was added to a three-necked flask, and the flask was evacuated and purged with nitrogen several times, then 300mL of dioxane was injected, and the flask was heated to 85 ℃. Reacting for 12hr under the protection of nitrogen, cooling to room temperature, removing the solvent by rotary evaporation, adding a proper amount of water and ethyl acetate for extraction, collecting an organic phase, drying with anhydrous magnesium sulfate, adding a proper amount of silica gel, removing the solvent by rotary evaporation, and performing column chromatography by using an n-hexane/ethyl acetate system to obtain 9.56g of a white solid, wherein the yield is 72 percent and the purity is 99.9 percent.

Synthesis of compound 10: 7.97g (15.0mmol) of the compound 9, 33.96 g (1.0eq.,15.0 mmol), 3.45g (1.25eq.,25.0mmol) of potassium carbonate and Pd (PPh) were taken₃)₄347mg (0.02eq.,0.3mmol) was charged into a three-necked flask, and was evacuated by introducing nitrogen gas and replaced with nitrogen gas several times, followed by charging 100mL of acetonitrile and 50mL of methanol and heating to 60 ℃. Reacting for 12hr under the protection of nitrogen, cooling to room temperature, performing rotary evaporation to remove the solvent, adding an appropriate amount of water and ethyl acetate for extraction, collecting an organic phase, drying with anhydrous magnesium sulfate, adding an appropriate amount of silica gel, performing rotary evaporation to remove the solvent, and performing column chromatography by using an n-hexane/ethyl acetate system to obtain 5.74g of a white solid, wherein the yield is 65% and the purity is 99.9%.

Synthesis of compound 11: 4.71g (8.0mmol) of the compound 10, 2-bromopyridine 1.37g (1.1eq.,8.8mmol), potassium carbonate 1.38g (1.25eq.,10.0mmol) and Pd (PPh)₃)₄185mg (0.02eq.,0.16mmol) was charged into a three-necked flask, and was evacuated and purged with nitrogen gas several times, followed by injection of acetonitrile 60mL and 30mL of methanol and heating to 60 ℃. Reacting for 12hr under the protection of nitrogen, cooling to room temperature, performing rotary evaporation to remove the solvent, adding an appropriate amount of water and ethyl acetate for extraction, collecting an organic phase, drying with anhydrous magnesium sulfate, adding an appropriate amount of silica gel, performing rotary evaporation to remove the solvent, and performing column chromatography by using an n-hexane/ethyl acetate system to obtain 3.67g of a white solid, wherein the yield is 85% and the purity is 99.9%.

Synthesis of compound 12: 2.16g (4.0mmol) of Compound 11 and 30g of pyridine hydrochloride (PyHCl) were taken and put into a three-necked flask, and vacuum-pumping was performedReplacing with nitrogen for several times, heating to 190 deg.C under nitrogen protection, reacting for 4hr, cooling to room temperature, adding appropriate amount of water and ethyl acetate, extracting, collecting organic phase, drying with anhydrous magnesium sulfate, adding appropriate amount of silica gel, rotary evaporating to remove solvent, and performing column chromatography with n-hexane/ethyl acetate system to obtain white solid 1.79g, yield 85%, and purity 99.9%. Mass spectrometry (ESI)^-)([M-H]^-)C₃₆H₃₄N₃524.27 as theoretical value of O; found 524.24.

Synthesis of compound P2: 1.06g (2.0mmol) of compound 5 and 328mg of anhydrous sodium acetate (2.0eq.,4.0 mmol) are dissolved in 25mL of DMSO, stirred, heated to 80 ℃, added with 830mg (1.0eq.,2.0 mmol) of potassium tetrachloroplatinate, vacuumized, introduced with nitrogen for replacement several times, and heated to 120 ℃ for reaction for 5 hr. After the reaction is finished, 100ml of water is added while the reaction is hot, the mixture is filtered, solid is collected and washed by proper amount of water and methanol, the obtained solid is recrystallized by toluene, and then the solid is sublimated in vacuum to obtain 1.01g of dark red solid, wherein the total yield is 70 percent and 99.9 percent. Mass spectrometry (ESI)^-)([M-H]^-)C₃₆H₃₃N₃OPt theoretical value 717.23; found 717.20.

Example 3:

the synthetic route is as follows:

synthesis of compound 14: 7.97g (15.0mmol) of the compound 9, 137.63 g (1.0eq.,15.0 mmol), 3.45g (1.25eq.,25.0mmol) of potassium carbonate and Pd (PPh) were taken₃)₄347mg (0.02eq.,0.3mmol) was charged into a three-necked flask, and was evacuated by introducing nitrogen gas and replaced with nitrogen gas several times, followed by charging 100mL of acetonitrile and 50mL of methanol and heating to 60 ℃. Reacting under nitrogen protection for 12hr, cooling to room temperature, removing solvent by rotary evaporation, adding appropriate amount of water and ethyl acetate, extracting, collecting organic phase, and collecting anhydrous sulfurAfter magnesium is dried, a proper amount of silica gel is added, the solvent is removed by rotary evaporation, and the white solid 7.50g, the yield of 60 percent and the purity of 99.5 percent are obtained by column chromatography of a normal hexane/ethyl acetate system.

Synthesis of compound 15: 6.66g (8.0mmol) of the compound 14, 1.37g (1.1eq.,8.8mmol) of 2-bromopyridine, 1.38g (1.25eq.,10.0mmol) of potassium carbonate and Pd (PPh)₃)₄185mg (0.02eq.,0.16mmol) was charged into a three-necked flask, and was evacuated and purged with nitrogen gas several times, followed by injection of acetonitrile 60mL and 30mL of methanol and heating to 60 ℃. Reacting for 12hr under the protection of nitrogen, cooling to room temperature, removing the solvent by rotary evaporation, adding a proper amount of water and ethyl acetate for extraction, collecting an organic phase, drying with anhydrous magnesium sulfate, adding a proper amount of silica gel, removing the solvent by rotary evaporation, and performing column chromatography by using an n-hexane/ethyl acetate system to obtain 6.27g of a white solid, wherein the yield is 80% and the purity is 99.9%.

Synthesis of compound 16: taking 3.14g (4.0mmol) of compound 15 and 30g of pyridine hydrochloride (PyHCl), adding the mixture into a three-necked flask, vacuumizing, introducing nitrogen for replacement for multiple times, heating to 190 ℃ under the protection of nitrogen, reacting for 4 hours, cooling to room temperature, adding a proper amount of water and ethyl acetate for extraction, collecting an organic phase, drying anhydrous magnesium sulfate, adding a proper amount of silica gel, performing rotary evaporation to remove a solvent, and performing column chromatography by using a normal hexane/ethyl acetate system to obtain 2.77g of a white solid with the yield of 90% and the purity of 99.9%. Mass spectrometry (ESI)^-)([M-H]^-)C₅₄H₆₂N₃768.50 as theoretical value of O; found 768.47.

Synthesis of compound P105: 1.54g (2.0mmol) of compound 16 and 328mg of anhydrous sodium acetate (2.0eq.,4.0 mmol) were dissolved in 25mL of DMSO, stirred, heated to 80 ℃, added with 830mg (1.0eq.,2.0 mmol) of potassium tetrachloroplatinate, evacuated, purged with nitrogen several times, and heated to 120 ℃ for 5 hr. After the reaction is finished, 100ml of water is added while the reaction is hot, the mixture is filtered, solid is collected and washed by proper amount of water and methanol, the obtained solid is recrystallized by toluene, and then the solid is sublimated in vacuum to obtain dark red solid 1.25g, the total yield is 65 percent, and the purity is 99.9 percent. Mass spectrometry (ESI)^-)([M-H]^-)C₅₄H₆₀N₃OPt theoretical value 961.44; found 961.42.

The pt (ii) complexes of the examples exhibited significant orange-red light emission in the dichloromethane solution as shown in the following table:

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

The preparation method of the device comprises the following steps:

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

The transparent anodic Indium Tin Oxide (ITO)20(10 Ω/sq) glass substrate 10 was subjected to ultrasonic cleaning using 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 system pressure is controlled at 10^-6torr.。

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

The light-emitting layer 40 material EML-1 was then evaporated to a thickness of 40nm, with different mass fractions of platinum (II) complex dopant doped.

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

Then, LiF with a thickness of 1nm was evaporated to form the electron injection layer 60.

Finally, Al with the thickness of 80nm is evaporated to be used as a cathode 70, and the device packaging is completed. As shown in fig. 1.

The structure and the manufacturing method of the test device are completely the same, except that the organic metal complexes Pt0, Pt1, Pt2 and Pt105 are sequentially used as a dopant and a doping concentration in the light-emitting layer. Wherein, the Pt0 is a classic red light material of O ^ N ^ N ^ O class.

Device comparison results the following table shows:

under the conditions that the doping concentrations of the tetradentate platinum (II) complex are respectively 4 wt%, 8 wt% and 12 wt%, the device is prepared by using the basic structure of the ITO/HTL-1(60nm)/EML-1: Pt (II) (40nm)/ETL-1(30nm)/LiF (1nm)/Al (80nm) device. Based on the device performance of Pt0, the devices of the tetradentate platinum (II) complexes Pt1, Pt2 and Pt105 have starting voltage V_onThe devices all had a different reduction in comparison to the Pt0 device, especially the Pt105 based device with a reduced actuation voltage to 3.0V. Meanwhile, under the condition of 1000cd/A, the Current Efficiency (CE), the Power Efficiency (PE) and the External Quantum Efficiency (EQE) of the devices based on Pt1, Pt2 and Pt105 are improved to different degrees compared with the devices based on Pt-0, and especially the Current Efficiency (CE), the Power Efficiency (PE) and the External Quantum Efficiency (EQE) of the devices based on Pt105 are obviously improved. When the doping concentration of the tetradentate platinum (II) complex is increased, the efficiency of Pt0 and Pt1 is improved slightly and even reduced to a certain extent, but Pt105 has better efficiency improvement, the current efficiency is improved to 78.5cd/A from 73.5cd/A, the power efficiency is improved to 78.5lm/W from 67.8lm/W, and the external quantum efficiency is improved to 18.7% from 17.8%. Pt105 has larger steric hindrance groups compared with Pt0, Pt1 and Pt2, so that intermolecular aggregation can be effectively reduced, exciplex formation is avoided, and luminous efficiency is improved. Meanwhile, the performances of Pt1 and Pt2 are improved to different degrees compared with Pt 0.

In conclusion, the performance of the organic electroluminescent device prepared by the invention is better improved compared with that of a reference device, and the related novel N ^ N ^ N ^ O tetradentate platinum (II) complex metal organic material has higher application value.

Claims

1. An N ^ N ^ N ^ O-configured tetradentate platinum (II) complex has a structure shown as a formula (4):

wherein R is₁－R₁₇Independently selected from hydrogen, deuterium, halogen, hydroxy, amino, nitro, cyano, carboxy, styryl, aminocarbonyl, carbamoyl, benzylcarbonyl, diphenylamino, saturated alkyl containing 1-10C atoms, unsaturated alkenyl containing 2-8C atoms, heteroaryl, aryl optionally substituted with one or more halogen, alkyl, aryl or heteroaryl, or adjacent R₁－R₁₇Are connected with each other through covalent bond to form a ring; wherein, X₁－X₂₇Is carbon, the halogen is F, Cl, Br, the aryl group is an aryl group which has 5 to 20 carbon atoms and consists of one aromatic ring or a plurality of fused aromatic rings, the heteroaryl group is a five-or six-membered aromatic heterocyclic ring system containing 0, 1 or 2 substituents, and the substituents of the heteroaryl group are selected from halogen, hydroxyl, cyano, O-C_1～6Alkyl radical, C_1～6Alkyl, hydroxy C_1～6Alkyl, amino-C_1～6Alkyl and aryl, the alkyl of the substituted aryl being an alkyl of 1 to 10 carbon atoms.

2. The complex of claim 1, wherein R₁－R₁₇Independently selected from hydrogen, halogen, amino, nitro, cyano, dianilino, saturated alkyl containing 1-10C atoms, heteroaryl, aryl optionally substituted by one or more halogen, alkyl, aryl or heteroaryl, or adjacent R₁－R₁₇The halogen is F and Cl; the aryl is selected from phenyl, naphthyl, acenaphthenyl, dihydroacenaphthenyl, anthracenyl, fluorenyl and phenanthryl, the heteroaryl is selected from pyridyl and carbazolyl, and the alkyl of the substituted aryl is alkyl with 1-10 carbon atoms.

3. The complex of claim 2 having the structure:

wherein R is₁’－R₅' is independently selected from hydrogen, halogen, diphenylamino, saturated alkyl containing 1-10C atoms, heteroaryl, aryl optionally substituted with one or more of halogen, alkyl, aryl or heteroaryl; the aryl is selected from phenyl, naphthyl, acenaphthenyl, dihydroacenaphthenyl, anthracenyl, fluorenyl and phenanthryl, the heteroaryl is selected from pyridyl and carbazolyl, and the alkyl of the substituted aryl is alkyl with 1-10 carbon atoms.

4. The complex of claim 3, wherein R₁’－R₅' of the 5 groups, 0 to 3 of which are independently represented by a dianilino group, an aryl group optionally substituted with halogen or one to three C1-C4 alkyl groups, a heteroaryl group optionally substituted with halogen or one to three C1-C4 alkyl groups; the aryl group is selected from phenyl and naphthyl, the heteroaryl group is selected from pyridyl and carbazolyl, the other groups are independently represented by hydrogen or saturated alkyl containing 1-8C atoms, and the halogen is F.

5. The complex according to claim 4, R₁’－R₅Of the 5 groups of' 0 to 3 groups are independently represented by a dianilino group, a phenyl group, a pyridyl group, a carbazolyl group, and the others are independently represented by hydrogen, an isopropyl group or a tert-butyl group.

6. The complex of claim 1 having one of the following structures:

7. the complex of claim 6, having the structure:

8. a precursor of the complex according to claim 1 or 2, having the following structure:

wherein X₁－X₂₇、R₁－R₁₇As defined in claim 1 or 2.

9. The precursor of claim 8, having the structure:

wherein R is₁’－R₅' as defined in claim 3, 4 or 5.

10. A process for preparing a complex as claimed in any one of claims 3 to 5, comprising the steps of:

bromination reaction is carried out on carbazole derivative S1 to obtain substrate S2, reaction between S2 and pinacol ester diboron is carried out to obtain corresponding pinacol ester derivative S3, Suzuki reaction is carried out on S3 and pyridine derivative S4 to obtain S5, Suzuki reaction is carried out on S5 and pyridine derivative S6 to obtain S7, demethylation is carried out on S7 to obtain corresponding ligand S8, and S8 and K are reacted to obtain corresponding ligand S8₂PtCl₄Reacting to obtain a target product P;

wherein R is₁’－R₅' as defined in claim 3, 4 or 5.

11. Use of a complex according to any one of claims 1 to 7 in an OLED light emitting device.

12. The use according to claim 11, wherein the complex of any one of claims 1 to 7 is a phosphorescent dopant material for photon emission in a light-emitting layer in an OLED light-emitting device.