Monovalent currency metal complex and preparation and application thereof

Abstract

The application discloses a monovalent currency metal complex and preparation and application thereof, and belongs to the technical field of electroluminescent materials. The monovalent currency metal complex has a carbene-metal-arylamines structure, has a thermal activation delayed fluorescence property, and has the advantages of high photo-induced quantum yield, short exciton lifetime and high level of directional transition dipole orientation distribution, so that the external quantum efficiency of a device can be improved and the efficiency roll-off of the device can be inhibited, and a new scheme for constructing an organic electroluminescent device with high efficiency and long service life is provided.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electroluminescent materials, and particularly relates to a monovalent currency metal complex and preparation and application thereof. BACKGROUND

[0002] Organic light-emitting diodes (OLEDs) have been industrialized in many fields such as high-definition display and solid-state lighting due to their advantages of high efficiency, ultra-thin, self-luminescence and flexible display, and continue to attract the research interest of panel manufacturers and scientists worldwide.

[0003] External quantum efficiency and device stability are the most important performance indicators for evaluating OLED devices. In the multi-layer structure commonly used in OLED devices, the light-emitting layer material plays a crucial role in these performance indicators. So far, the light-emitting layer materials of commercial OLED devices can be divided into three categories: traditional fluorescent materials, heavy metal phosphorescent materials and organic thermally activated delayed fluorescence materials. Traditional fluorescent materials have an external quantum efficiency of no more than 5% because only singlet excitons are involved in light emission. However, due to the fast rate of singlet radiation transition, the device stability is good. In comparison, heavy metal phosphorescent materials and organic thermally activated delayed fluorescence materials can utilize triplet excitons, significantly improving device efficiency. Heavy metal phosphorescent materials enhance the spin-orbit coupling (SOC) between singlet and triplet states by introducing noble metal elements such as iridium and platinum, thereby achieving the utilization of triplet excitons. Organic thermally activated delayed fluorescence materials can achieve the reverse intersystem crossing (RISC) process from triplet excitons to singlet excitons through environmental thermal energy, also achieving the utilization of triplet excitons. However, the exciton lifetime of these two materials is relatively long, and exciton annihilation occurs to different degrees under electrical conditions, leading to a decrease in device stability. Therefore, it is of great theoretical significance and practical value to develop a light-emitting material with high exciton utilization rate and short exciton lifetime.

[0004] Compared with iridium and platinum elements, currency metal elements such as gold, silver and copper have higher natural abundance, lower price and less environmental hazards. In view of the high reactivity and strong spin-orbit coupling effect of monovalent currency metal complexes, they also have great development potential in the field of organic light-emitting materials. In 2017, Credgington et al. (D. Credgington, Science, Vol 356, 159, 2017) reported a series of carbene-metal-arylamines (CMA) complexes based on monovalent currency metals. Due to its unique linear coplanar molecular configuration, separated front-line orbital distribution and strong SOC, CMA complexes exhibit high photoluminescence quantum yield and short TADF lifetime. In recent years, CMA complexes with monovalent currency metal as the core have become a new generation of OLED light-emitting layer materials with great development prospects. However, the external quantum efficiency of the current monovalent currency metal CMA complex is still relatively low compared with heavy metal phosphorescent materials and organic TADF materials, usually less than 30%, and the delayed fluorescence lifetime of many materials in the thin film state is longer than 1 μs, which can easily cause serious device efficiency roll-off. Therefore, the external quantum efficiency, device roll-off and device stability of OLED devices based on such materials still need to be improved.

[0005] Based on the above background, the existing technology, especially the solution related to material design, still needs to be improved and broken through. SUMMARY

[0006] In view of the above defects of the prior art, in the first aspect of the present application, a monovalent currency metal complex is provided, which has a monovalent currency metal as the core, includes a heterocyclic carbene ligand and a carbazole ligand, and the structure formula of the monovalent currency metal complex is as follows:

[0007]

[0008] In structure formula I, X represents a monovalent currency metal, Y represents a heterocyclic carbene ligand, and B represents a carbazole ligand.

[0009] Preferably, in structure formula I, the monovalent currency metal is one of monovalent copper, silver and gold, which corresponds to the following structure formula II, structure formula III and structure formula IV respectively:

[0010]

[0011] Preferably, in structure formula I, the carbazole ligand is one of an unsubstituted carbazole ligand, a substituted carbazole ligand, a carbazole ligand fused with at least one hydrogen heterocycle, and a carbazole ligand fused with at least one deuterium heterocycle.

[0012] Further preferably, the carbazole ligand includes one of the following structures:

[0013]

[0014] wherein Z1and Z2are each independently one of an oxygen atom, a nitrogen atom, a sulfur atom, a selenium atom, and a tellurium atom;

[0015] each of the substituents R1, R2, R3is independently hydrogen, deuterium, fluorine, chlorine, bromine, iodine, methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, t-butyl, methoxy, dimethylamino, cyano, trifluoromethyl, trimethylsilyl, vinyl, allyl, benzyl, phenyl, naphthyl, anthryl, benzoanthryl, phenanthryl, benzophenanthryl, adamantyl, silafluorenyl, triphenylenyl, pyrenyl, chrysenyl, coronenyl, fluoranthenyl, tetracene, pentacene, benzopyrenyl, biphenyl, biphenylyl, terphenyl, trinaphthyl, quaterphenyl, fluorenyl, spirobifluorenyl, dihydrophenanthryl, dihydropyrenyl, tetrahydropyrenyl, cis-indenofluorenyl, trans-indenofluorenyl, trindene, isotrindene, spirotrindene, spiroisotrindene, furanyl, benzofuranyl, isobenzofuranyl, dibenzofuranyl, thienyl, benzothienyl, isobenzothienyl, dibenzothienyl, pyrrolyl, isoindolyl, carbazolyl, indenocarbazolyl, pyridyl, quinolyl, isoquinolyl, acridyl, phenanthridyl, benzo-5,6-quinolyl, benzo-6,7-quinolyl, benzo-7,8-quinolyl, pyrazolyl, indazolyl, imidazolyl, benzoimidazolyl, naphthoimidazolyl, phenanthroimidazolyl, pyridinoimidazolyl, pyrazinoimidazolyl, quinoxalinoimidazolyl, oxazolyl, benzoxazolyl, naphthoxazolyl, anthroxazolyl, phenanthroxazolyl, 1,2-thiazolyl, 1,3-thiazolyl, benzothiazolyl, pyridazinyl, benzopyridazinyl, pyrimidinyl, benzopyrimidinyl, quinoxalinyl, 1,5-diazanthrenyl, 2,7-diazapyrenyl, 2,3-diazapyrenyl, 1,6-diazapyrenyl, 1,8-diazapyrenyl, 4,5-diazapyrenyl, 4,5,9,10-tetraazachrysenyl, pyrazinyl, phenoxazinyl, phenothiazinyl, naphthidinyl, azacarbazolyl, benzocarbolinyl, phenanthrolinyl, 1,2,3-triazolyl, 1,2,4-triazolyl, benzotriazolyl, 1,2,3-oxadiazolyl, 1,2,4-oxadiazolyl, 1,2,5-oxadiazolyl, 1,2,3-thiadiazolyl, 1,2,4-thiadiazolyl, 1,2,5-thiadiazolyl, 1,3,4-thiadiazolyl, 1,3,5-triazinyl, 1,2,4-triazinyl, 1,2,3-triazinyl, tetrazolyl, 1,2,4,5-tetrazinyl, 1,2,3,4-tetrazinyl, 1,2,3,5-tetrazinyl, purinyl, pteridinyl, indolizinyl, benzothiadiazolyl, 9,9-dimethylacridinyl, triarylaminyl, fluorophenyl, methylphenyl, trimethylphenyl, cyanophenyl.

[0016] Preferably, in the structural formula I, the heterocyclic carbene ligand is a five- or six-membered heterocyclic carbene ligand.

[0017] Further preferably, the heterocyclic carbene ligand comprises one of the following structures:

[0018]

[0019] wherein, the substituents P1 and P2 are each independently one of phenyl, 2,6-diisopropylphenyl, 2,4,6-trimethylphenyl, adamantyl, methyl, ethyl, isopropyl, tert-butyl.

[0020] According to the technical principle of the first aspect of the present application, the monovalent currency metal complex has the thermal activation delayed fluorescence (TADF) property. According to the principle of the carbene-metal-arylamines (CMA) TADF material, when the difference (ΔE ST ) between the singlet state and the triplet state of the complex is small enough, the triplet exciton of the compound can be converted into the singlet exciton through the reverse intersystem crossing (RISC), so as to realize the high-efficiency luminescence. Generally, the carbene ligand and the arylamine ligand of the CMA complex have the electron acceptor (acceptor) and electron donor (donor) properties, respectively, and the special connection mode thereof is referred to as the D-A structure. In addition, the electron is transferred from the donor to the acceptor through the monovalent currency metal center, and the process is referred to as the ligand-ligand charge transfer (LLCT). In addition, the CMA has the linear and planar geometric structure, and thus is more conducive to the improvement of the oscillator strength and the coupling of the electron. The monovalent currency metal complex has the CMA and D-A characteristic structures, and has the obvious LLCT and small ΔE ST .

[0021] In the second aspect of the present application, a preparation method of the monovalent currency metal complex with simple process is provided, comprising the following steps:

[0022] (1) reacting the heterocyclic carbene ligand raw material with the monovalent currency metal source to obtain a coordination intermediate of the heterocyclic carbene ligand and the monovalent currency metal;

[0023] (2) further reacting the coordination intermediate with the carbazole ligand raw material under the nucleophilic reaction condition to obtain the monovalent currency metal complex.

[0024] Preferably, in the step (1), the heterocyclic carbene ligand raw material is a quaternary ammonium salt of the heterocyclic carbene ligand or a chloride salt of the heterocyclic carbene ligand; and the monovalent currency metal source is a halide or an oxide of the monovalent currency metal.

[0025] Preferably, in the step (1), the reaction temperature is -78-25 ℃, and the reaction time is 12-72 h.

[0026] Preferably, in the step (2), the carbazole ligand raw material is a hydrogen substitute of the carbazole ligand, and the structure is B-H.

[0027] Preferably, in the step (2), the reaction temperature is 25-50°C, and the reaction time is 12-72h.

[0028] Preferably, the preparation method of the monovalent copper complex comprises the following steps:

[0029] (1) uniformly dispersing the heterocyclic carbene ligand raw material and the monovalent copper source into a proper amount of tetrahydrofuran, adding an organic strong base, and performing a reaction under the protection of inert gas and in the dark, to obtain a coordination intermediate through separation and purification;

[0030] (2) dissolving the coordination intermediate and the carbazole ligand raw material in a proper amount of acetone, adding anhydrous carbonate, and performing a reaction under the protection of inert gas, to obtain a monovalent copper complex through separation and purification.

[0031] Further preferably, in the step (1), the monovalent copper source is cuprous chloride or cuprous bromide dimethyl sulfide.

[0032] Further preferably, in the step (1), the molar ratio of the heterocyclic carbene ligand raw material to the monovalent copper source is 1:1-3, and the molar ratio of the heterocyclic carbene ligand raw material to the organic strong base is 1:1-4.

[0033] Further preferably, in the step (2), the molar ratio of the coordination intermediate to the carbazole ligand raw material is 1:1-3, and the molar ratio of the coordination intermediate to the anhydrous carbonate is 1:2-3.

[0034] Preferably, the preparation method of the monovalent silver complex comprises the following steps:

[0035] (1) uniformly dispersing the heterocyclic carbene ligand raw material and the monovalent silver source into a proper amount of tetrahydrofuran or dichloromethane, performing a reaction under the protection of inert gas and in the dark, to obtain a coordination intermediate through separation and purification;

[0036] (2) dissolving the coordination intermediate and the carbazole ligand raw material in a proper amount of tetrahydrofuran, adding an organic strong base, and performing a reaction under the protection of inert gas, to obtain a monovalent silver complex through separation and purification.

[0037] Further preferably, in the step (1), the molar ratio of the heterocyclic carbene ligand raw material to the monovalent silver source is 1:0.5-2.

[0038] Further preferably, in the step (2), the molar ratio of the coordination intermediate to the carbazole ligand raw material is 1:1-3, and the molar ratio of the coordination intermediate to the organic strong base is 1:1-3.

[0039] Preferably, the preparation method of the monovalent silver complex comprises the following steps:

[0040] (1) uniformly dispersing a heterocyclic carbene ligand raw material and a monovalent silver source into a proper amount of tetrahydrofuran, adding an organic strong base and performing a reaction under inert gas protection and in the dark, and then separating and purifying to obtain a coordination intermediate;

[0041] (2) dissolving the coordination intermediate and a carbazole ligand raw material in a proper amount of tetrahydrofuran, adding an organic strong base and performing a reaction under inert gas protection, and then separating and purifying to obtain a monovalent silver complex.

[0042] Further preferably, in the step (1), the molar ratio of the heterocyclic carbene ligand raw material to the monovalent silver source is 1:0.5-2, and the molar ratio of the heterocyclic carbene ligand raw material to the organic strong base is 1:2-3.

[0043] Further preferably, in the step (2), the molar ratio of the coordination intermediate to the carbazole ligand raw material is 1:1-3, and the molar ratio of the coordination intermediate to the organic strong base is 1:1-3.

[0044] In the preparation method of the monovalent silver complex, the monovalent silver source is silver oxide.

[0045] Preferably, the preparation method of the monovalent gold complex comprises the following steps:

[0046] (1) uniformly dispersing a heterocyclic carbene ligand raw material and a monovalent gold source into a proper amount of tetrahydrofuran, adding an organic strong base and performing a reaction under inert gas protection and in the dark, and then separating and purifying to obtain a coordination intermediate;

[0047] (2) dissolving the coordination intermediate and a carbazole ligand raw material in a proper amount of tetrahydrofuran, adding an organic strong base and performing a reaction under inert gas protection, and then separating and purifying to obtain a monovalent silver complex.

[0048] Further preferably, in the step (1), the monovalent gold source is gold dichloride dimethyl sulfide or gold chloride tetrahydrothiophene.

[0049] Further preferably, in the step (1), the molar ratio of the heterocyclic carbene ligand raw material to the monovalent gold source is 1:1-3, and the molar ratio of the heterocyclic carbene ligand raw material to the organic strong base is 1:1-4.

[0050] Further preferably, in the step (2), the molar ratio of the coordination intermediate to the carbazole ligand raw material is 1:1-3, and the molar ratio of the coordination intermediate to the anhydrous carbonate salt is 1:2-3.

[0051] In the above preparation method, the strong organic base is one of lithium bis(trimethylsilyl)amide, sodium bis(trimethylsilyl)amide, potassium bis(trimethylsilyl)amide, lithium diisopropylamide, n-butyllithium, and sodium tert-butoxide.

[0052] In a third aspect of the present application, there is provided the use of the monovalent currency metal complex of the first aspect of the present application and the monovalent currency metal complex prepared by the preparation method of the second aspect of the present application in the preparation of an electroluminescent device.

[0053] The specific application method comprises the following steps:

[0054] The monovalent currency metal complex or the composition of the monovalent currency metal complex and the OLED host material is used as the light-emitting layer material of the electroluminescent device to prepare a light-emitting layer; and the light-emitting layer is combined with a functional layer to prepare an electroluminescent device.

[0055] Preferably, the electroluminescent device comprises an evaporation device prepared by an evaporation process or a spin-coating device prepared by a spin-coating process.

[0056] Further preferably, the structure of the evaporation device is, from bottom to top, a glass substrate, an anode, a hole injection layer, a hole transport layer, an electron blocking layer, a light-emitting layer, a hole blocking layer, an electron transport layer, an electron injection layer, and a cathode.

[0057] Further preferably, the structure of the spin-coating device is, from bottom to top, a glass substrate, an anode, a hole injection layer, a light-emitting layer, a hole blocking layer, an electron transport layer, an electron injection layer, and a cathode.

[0058] According to the technical principle described in the first aspect of the present application, the monovalent currency metal complex has the characteristics of thermally activated delayed fluorescence (TADF). Due to the decrease in the reorganization energy of the excited state after fusion, the photo-induced quantum yield is improved; due to the heavy atom in the fusion, the SOC between the singlet and the triplet is increased, and the TADF lifetime is shortened. In addition, due to the planar molecular structure and the large and long fused ring plane, the organic compound according to the present application has a high proportion of horizontally oriented transition dipole moments, which has a certain gain effect on the light coupling output in the electroluminescent device. The monovalent currency metal complex of the present application can be used as a light-emitting layer material in OLEDs, and by matching with appropriate host materials, the light-emitting efficiency of the electroluminescent device can be improved, providing a low-cost, high-efficiency, and low-rolloff light-emitting device solution.

[0059] For practical applications in electroluminescent devices, monovalent monetary metal complexes possess high photoinduced quantum yield, short excited-state lifetime, and horizontally oriented transition dipole orientation. High photoinduced quantum yield is beneficial for improving the quantum efficiency within OLED devices. Short excited-state lifetime helps suppress efficiency roll-off and improve device stability. A high horizontally oriented transition dipole orientation provides a certain gain in optical coupling output, thereby achieving higher external quantum efficiency without increasing device structural complexity. Generally, the orientation of the transient transition dipole moment (TDM) is related to the molecular structure and the orientation of the molecules themselves, i.e., it has good molecular packing orientation, thus achieving a higher proportion of horizontal TDM orientation.

[0060] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0061] This invention provides a monovalent monetary metal complex that exhibits thermally activated delayed fluorescence properties, high photoinduced quantum yield, short excited-state lifetime, and horizontally oriented transition dipole orientation.

[0062] This invention provides a method for preparing monovalent monetary metal complexes. The method is simple, has a wide range of raw materials, and can prepare different types of monovalent monetary metal complexes according to actual needs.

[0063] This invention combines a monovalent monetary metal complex with the OLED host material as the light-emitting layer, providing an application of monovalent monetary metal complexes in the fabrication of electroluminescent devices, and solving the technical problems of low efficiency and material scarcity in existing electroluminescent devices. Attached Figure Description

[0064] Figure 1 This is the general structural formula for vapor-deposited electroluminescent devices;

[0065] Figure 2 This is the general structural formula for spin-coated electroluminescent devices;

[0066] Figure 3 This is a comparison spectrum of transient luminescence lifetimes of materials 4, 6, and 7 in Examples and comparative substances 1-3;

[0067] Figure 4 This is the transient transition dipole moment (TDM) orientation distribution pattern of the monovalent currency metal complex synthesized in Example 1 in a 2,8-bis(diphenylphospho)dibenzo[b,d]furan (PPF) doped film. Detailed Implementation

[0068] The present invention is further illustrated below by way of embodiments, but the invention is not limited to the scope of the embodiments described herein. Experimental methods in the following embodiments that do not specify specific conditions were performed according to conventional methods and conditions, or as selected according to the product instructions.

[0069] In the following embodiments:

[0070] HAT-CN: 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazabenzophenanthrene;

[0071] PEDOT: PSS: Poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid;

[0072] TAPC: 4,4'-cyclohexylenebis[N,N-di(p-tolyl)aniline];

[0073] TCTA: 4,4,4-tris(carbazole-9-yl)triphenylamine;

[0074] mCBP: 3,3'-bis(N-carbazole)-1,1'-biphenyl;

[0075] mCP: 1,3-bis(carbazole-9-yl)benzene;

[0076] o-CzOXD: 2,5-Bis(2-(9H-carbazole-9-yl)phenyl)-1,3,4-oxadiazole;

[0077] PPF: 2,8-bis(diphenylphospho)dibenzo[b,d]furan;

[0078] DPEPO: Di[2-((oxo)diphenylphosphino)phenyl] ether;

[0079] ANT-BIZ: (1-(4-(10-([1,1'-biphenyl]-4-yl)anthracene-9-yl)phenyl)-2-ethyl-1H-benzo[d]-imidazolium);

[0080] TmPyPB: 1,3,5-Tris[(3-pyridyl)-3-phenyl]benzene.

[0081] Example 1

[0082] Preparation:

[0083]

[0084]

[0085] (1) Synthesis of [(1,3-bis(2',6'-diisopropylphenyl)-5,5-dimethyl-4-oxohexahydropyrimidine-2-carbene]cuprous chloride (I):

[0086] 4.83 g (10 mmol) of 1,3-bis(2,6-diisopropylphenyl)-5,5-dimethyl-4-oxo-3,4,5,6-tetrahydropyrimidine onium salt and 1.49 g (15 mmol) of cuprous chloride were added to a 100 mL Scheranck flask, followed by 50 mL of anhydrous tetrahydrofuran. The mixture was thoroughly mixed to obtain a suspension. Under ice bath and argon protection, 12 mL of a 1 mol / L aqueous solution of bis(trimethylsilyl)amino potassium was added dropwise to the suspension. The reaction was then carried out in the dark for 24 hours. After quenching the reaction with ice water, the product was extracted, subjected to column chromatography, and recrystallized to obtain 4.54 g of a white crystalline powder. The mass spectrometry result of this product was: MS (EI): m / z 545.2 [M + The test results match the theoretical molecular weight of the molecule.

[0087] (2) Synthesis of (benzo[3,2-c]furancarbazole-5-yl)[1,3-bis(2,6-diisopropylphenyl)-5,5-dimethyl-4-oxohexahydropyrimidine-2-carbene]copper(I):

[0088] 543 mg (1 mmol) of [(1,3-bis(2',6'-diisopropylphenyl)-5,5-dimethyl-4-oxohexahydropyrimidine-2-carbene]cuprous chloride (I), 257 mg (1 mmol) of 5H-benzofuran[3,2-c]carbazole and 276 mg (2 mmol) of potassium carbonate were dispersed in 20 mL of anhydrous acetone and reacted at 50 °C for 48 h. After the reaction was completed, the mixture was filtered and recrystallized several times with dichloromethane and n-hexane to obtain 390 mg of a bright yellow crystalline powder. The mass spectrometry result of this product was: MS (EI): m / z 766.3 [M + The test results match the theoretical molecular weight of the molecule.

[0089] Example 2

[0090] Preparation:

[0091]

[0092]

[0093] (1) In this embodiment, the synthesis steps of [(1,3-bis(2',6'-diisopropylphenyl)-5,5-dimethyl-4-oxohexahydropyrimidine-2-carbene]cuprous chloride (I) are the same as in Example 1;

[0094] (2) Synthesis of (benzo[2,3-a]furancarbazole-12yl)[(1,3-bis(2',6'-diisopropylphenyl)-5,5-dimethyl-4-oxohexahydropyrimidine-2-carbene]copper(I):

[0095] 543 mg (1 mmol) of [(1,3-bis(2',6'-diisopropylphenyl)-5,5-dimethyl-4-oxohexahydropyrimidine-2-carbene]cuprous chloride (I), 257 mg (1 mmol) of 12H-benzo[2,3-a]furancarbazole and 276 mg (2 mmol) of potassium carbonate were dispersed in 20 mL of anhydrous acetone and reacted at 50 °C for 48 h. After the reaction was completed, the mixture was filtered and recrystallized several times with dichloromethane and n-hexane to obtain 435 mg of a bright yellow crystalline powder. The mass spectrometry result of this product was: MS (EI): m / z 766.3 [M + The test results match the theoretical molecular weight of the molecule.

[0096] Example 3

[0097] Preparation:

[0098]

[0099] (1) In this embodiment, the synthesis steps of [(1,3-bis(2',6'-diisopropylphenyl)-5,5-dimethyl-4-oxohexahydropyrimidine-2-carbene]cuprous chloride (I) are the same as in Example 1;

[0100] (2) Synthesis of (thiophene[2,3-a]carbazole-10-yl)[(1,3-bis(2',6'-diisopropylphenyl)-5,5-dimethyl-4-oxohexahydropyrimidine-2-carbene]copper(I):

[0101] 543 mg (1 mmol), [(1,3-bis(2',6'-diisopropylphenyl)-5,5-dimethyl-4-oxohexahydropyrimidine-2-carbene]cuprous chloride (I), 223 mg (1 mmol) 10H-thiophene[2,3-a]carbazole, and 276 mg (2 mmol) potassium carbonate were dispersed in 20 mL of anhydrous acetone and reacted at 50 °C for 48 h. After the reaction was completed, the mixture was filtered and recrystallized several times with dichloromethane and n-hexane to obtain 401 mg of a bright yellow crystalline powder. The mass spectrometry results of this product were: MS (EI): m / z 731.3 [M + The test results match the theoretical molecular weight of the molecule.

[0102] Example 4

[0103] Preparation:

[0104]

[0105] (1) In this embodiment, the synthesis steps of [(1,3-bis(2',6'-diisopropylphenyl)-5,5-dimethyl-4-oxohexahydropyrimidine-2-carbene]cuprous chloride (I) are the same as in Example 1;

[0106] (2) Synthesis of (benzo[2,3-a]thiophene-12-yl)[1,3-bis(2',6'-diisopropylphenyl)-5,5-dimethyl-4-oxohexahydropyrimidine-2-carbene]copper(I):

[0107] 543 mg (1 mmol) of [(1,3-bis(2',6'-diisopropylphenyl)-5,5-dimethyl-4-oxohexahydropyrimidine-2-carbene]cuprous chloride (I), 273 mg (1 mmol) of 12H-benzo[2,3-a]thiophenecarbazole and 276 mg (2 mmol) of potassium carbonate were dispersed in 20 mL of anhydrous acetone and reacted at 50 °C for 48 h. After the reaction was completed, the mixture was filtered and recrystallized several times with dichloromethane and n-hexane to obtain 422 mg of a bright yellow crystalline powder. The mass spectrometry result of this product was: MS (EI): m / z 782.3 [M + The test results match the theoretical molecular weight of the molecule.

[0108] Example 5

[0109] Preparation:

[0110]

[0111] (1) In this embodiment, the synthesis steps of [(1,3-bis(2',6'-diisopropylphenyl)-5,5-dimethyl-4-oxohexahydropyrimidine-2-carbene]cuprous chloride (I) are the same as in Example 1;

[0112] (2) Synthesis of (3-trifluoromethyl-5H-benzo[3,2-c]furancarbazole-5-yl)[1,3-bis(2',6'-diisopropylphenyl)-5,5-dimethyl-4-oxohexahydropyrimidine-2-carbene]copper(I):

[0113] 543 mg (1 mmol) of [(1,3-bis(2',6'-diisopropylphenyl)-5,5-dimethyl-4-oxohexahydropyrimidine-2-carbene]cuprous chloride (I), 273 mg (1 mmol) of 3-trifluoromethyl-5H-benzo[3,2-c]furancarbazole and 276 mg (2 mmol) of potassium carbonate were dispersed in 20 mL of anhydrous acetone and reacted at 50 °C for 48 h. After the reaction was completed, the mixture was filtered and recrystallized several times with dichloromethane and n-hexane to obtain 516 mg of a bright yellow crystalline powder. The mass spectrometry result of the product was: MS (EI): m / z 833.3 [M + The test results match the theoretical molecular weight of the molecule.

[0114] Example 6

[0115] Preparation:

[0116]

[0117] (1) Synthesis of 1-[(2',6'-diisopropylphenyl)-5,5-dimethyl(adamantane-2,3-pyrrolidine)-2-carbene)]cuprous chloride(I):

[0118] 4.49 g (10 mmol) of 1-[(2',6'-diisopropylphenyl)-5,5-dimethyl(adamantane-2,3-pyrrole)] hydrochloride and 1.49 g (15 mmol) of cuprous chloride were weighed into a 100 mL Scheranck flask, and 50 mL of anhydrous tetrahydrofuran was added. The mixture was thoroughly mixed to obtain a suspension. Under a -78°C cryogenic bath and argon protection, 12 mL of a 1 mol / L aqueous solution of bis(trimethylsilyl)amino potassium was added dropwise to the suspension. The reaction was then carried out in the dark for 24 hours. After quenching the reaction with ice water, the product was extracted, subjected to column chromatography, and recrystallized to obtain 3.98 g of white crystalline powder. The mass spectrometry results of the product were: MS (EI): m / z 475.2 [M + The test results match the theoretical molecular weight of the molecule.

[0119] (2) Synthesis of (benzo[2,3-a]thiophenecarbazo-12-yl)[1-(2,6-diisopropylphenyl)-5,5-dimethyl(adamantane-2,3-pyrrolidine)-2-carbene]copper(I):

[0120] 475 mg (1 mmol) of 1-[(2',6'-diisopropylphenyl)-5,5-dimethyl(adamantane-2,3-pyrrolidine)-2-carbene)]cuprous chloride (I), 273 mg (1 mmol) of 12H-benzo[2,3-a]thiophenecarbazole and 276 mg (2 mmol) of potassium carbonate were dispersed in 20 mL of anhydrous acetone and reacted at 50 °C for 48 h. After the reaction was completed, the mixture was filtered and recrystallized several times with dichloromethane and n-hexane to obtain 402 mg of a bright yellow crystalline powder. The mass spectrometry result of this product was: MS (EI): m / z 713.2 [M + The test results match the theoretical molecular weight of the molecule.

[0121] Example 7

[0122] Preparation:

[0123]

[0124] (1) Synthesis of [2-(2',6'-diisopropylphenyl)-3,3-diphenylisoindoline carbene]cuprous bromide (I):

[0125] 5.79 g (10 mmol) of 2-(2',6'-diisopropylphenyl)-3,3-diphenylisoindoline trifluoromethanesulfonate and 1.49 g (15 mmol) of cuprous dimethyl sulfide bromide were weighed into a 100 mL Scheranck flask, and 50 mL of anhydrous tetrahydrofuran was added. The mixture was thoroughly mixed to obtain a suspension. Under a -78°C cryogenic bath and argon protection, 12 mL of a 1 mol / L aqueous solution of bis(trimethylsilyl)amino potassium was added dropwise to the suspension. The reaction was carried out in the dark for 24 hours. After the reaction was completed, the reaction was quenched with ice water, filtered, and recrystallized several times to obtain 3.98 g of a yellow crystalline powder. The mass spectrometry results of this product were: MS (EI): m / z 572.1 [M + The test results match the theoretical molecular weight of the molecule.

[0126] (2) Synthesis of (benzo[4,5]thiophene[2,3-a]carbazole-12-yl)[2-(2',6'-diisopropylphenyl)-3,3-diphenylisoindolinecarbene]copper(I):

[0127] 572 mg (1 mmol) of [2-(2',6'-diisopropylphenyl)-3,3-diphenylisoindoline carbene]cuprous bromide (I), 273 mg (1 mmol) of 12H-benzo[2,3-a]thiophene carbazole and 276 mg (2 mmol) of potassium carbonate were dispersed in 20 mL of anhydrous acetone and reacted at 50 °C for 24 h. After the reaction was completed, the mixture was filtered and recrystallized several times with dichloromethane and n-hexane to obtain 311 mg of a bright yellow crystalline powder. The mass spectrometry result of this product was: MS (EI): m / z 764.2 [M + The test results match the theoretical molecular weight of the molecule.

[0128] Example 8

[0129] Preparation:

[0130]

[0131] (1) Synthesis of [1,3-bis(2',6'-diisopropylphenyl)-5,5-dimethyl-4-oxohexahydropyrimidine-2-carbene]silver(I):

[0132] 4.83 g (10 mmol) of 1,3-bis(2,6-diisopropylphenyl)-5,5-dimethyl-4-oxo-3,4,5,6-tetrahydropyrimidine onium salt and 1.39 g (6 mmol) of silver oxide in 100 mL were weighed into a Scheranck flask, and 50 mL of anhydrous dichloromethane was added. After mixing thoroughly, the mixture was reacted at room temperature under argon protection in the dark for 24 hours. After the reaction was completed, the mixture was filtered to remove the solvent from the filtrate, and then recrystallized once with tetrahydrofuran and n-hexane to obtain 5.32 g of white crystalline powder. The mass spectrometry result of this product was: MS (EI): m / z 588.2 [M + The test results match the theoretical molecular weight of the molecule.

[0133] (2) Synthesis of (benzo[4,5]thiophene[2,3-a]carbazole-12-yl)[1,3-bis(2',6'-diisopropylphenyl)-5,5-dimethyl-4-oxohexahydropyrimidine-2-carbene]silver(I):

[0134] 588 mg (1 mmol) of [1,3-bis(2',6'-diisopropylphenyl)-5,5-dimethyl-4-oxohexahydropyrimidine-2-carbene]silver (I), 273 mg (1 mmol) of 12H-benzo[4,5]thiophene[2,3-a]carbazole and 115 mg (1.2 mmol) of sodium tert-butoxide were weighed into a 100 mL Scheranck flask, and 20 mL of anhydrous tetrahydrofuran was added. After reacting at room temperature under argon protection for 24 hours, the mixture was filtered, recrystallized several times with dichloromethane and n-hexane, and 201 mg of bright yellow crystalline powder was obtained. The mass spectrometry results of this product were: MS (EI): m / z 825.3 [M + The test results match the theoretical molecular weight of the molecule.

[0135] Example 9

[0136] Preparation:

[0137]

[0138]

[0139] (1) Synthesis of 1-[(2',6'-diisopropylphenyl)-5,5-dimethyl(adamantane-2,3-pyrrolidine)-2-carbene)]silver chloride (I):

[0140] 4.49 g (10 mmol) of 1-[(2',6'-diisopropylphenyl)-5,5-dimethyl(adamantane-2,3-pyrrole)] hydrochloride and 1.38 g (6 mmol) of silver oxide were added to a 100 mL Scheranck flask, followed by 50 mL of anhydrous tetrahydrofuran. The mixture was thoroughly mixed to obtain a suspension. Under -78°C cryogenic bath and argon protection, 8 mL of a 2.5 mol / L diisopropylaminolithium aqueous solution was added dropwise to the suspension. The reaction was carried out in the dark for 24 hours. After quenching the reaction with ice water, the silver oxide solid was removed by filtration. The filtrate was evaporated to dryness and recrystallized to obtain 2.01 g of white crystalline powder. The mass spectrometry results of this product were: MS (EI): m / z 519.2 [M + The test results match the theoretical molecular weight of the molecule.

[0141] (2) Synthesis of (benzo[2,3-b]furancarbazole-7-yl)[1-(2',6'-diisopropylphenyl)-5,5-dimethyl(adamantane-2,3-pyrrolidine)-2-carbene)]silver(I):

[0142] 519 mg (1 mmol) of 1-[(2',6'-diisopropylphenyl)-5,5-dimethyl(adamantane-2,3-pyrrolidine)-2-carbene)]silver chloride (I), 271 mg (1 mmol) of 4-methyl-5H-benzofuran[3,2-c]carbazole and 115 mg (1.2 mmol) of sodium tert-butoxide were dispersed in 20 mL of anhydrous tetrahydrofuran and reacted at room temperature for 24 hours. After filtration, the product was recrystallized several times with dichloromethane and n-hexane to obtain 435 mg of a bright yellow crystalline powder. The mass spectrometry results of this product were: MS (EI): m / z 754.3 [M + The test results match the theoretical molecular weight of the molecule.

[0143] Example 10

[0144] Preparation:

[0145]

[0146]

[0147] (1) In this embodiment, the synthesis steps of [(1,3-bis(2',6'-diisopropylphenyl)-5,5-dimethyl-4-oxohexahydropyrimidine-2-carbene]cuprous chloride (I) are the same as in Example 1;

[0148] (2) Synthesis of (benzo[2,3-b]furancarbazole-7-yl)[(1,3-bis(2',6'-diisopropylphenyl)-5,5-dimethyl-4-oxohexahydropyrimidine-2-carbene]copper(I):

[0149] 543 mg (1 mmol) of [(1,3-bis(2',6'-diisopropylphenyl)-5,5-dimethyl-4-oxohexahydropyrimidine-2-carbene]cuprous chloride (I), 257 mg (1 mmol) of 7H-benzo[2,3-b]furancarbazole and 276 mg (2 mmol) of potassium carbonate were dispersed in 20 mL of anhydrous acetone and reacted at 50 °C for 48 hours. After filtration, the product was recrystallized several times with dichloromethane and n-hexane to obtain 472 mg of a bright yellow crystalline powder. The mass spectrometry results of this product were: MS (EI): m / z 766.3 [M + The test results match the theoretical molecular weight of the molecule.

[0150] Example 11

[0151] Preparation:

[0152]

[0153] (1) In this embodiment, the synthesis steps of [(1,3-bis(2',6'-diisopropylphenyl)-5,5-dimethyl-4-oxohexahydropyrimidine-2-carbene]cuprous chloride (I) are the same as in Example 1;

[0154] (2) Synthesis of (furan[2,3-a]carbazole-10-yl)[(1,3-bis(2',6'-diisopropylphenyl)-5,5-dimethyl-4-oxohexahydropyrimidine-2-carbene]copper(I):

[0155] 543 mg (1 mmol) of [(1,3-bis(2',6'-diisopropylphenyl)-5,5-dimethyl-4-oxohexahydropyrimidine-2-carbene]cuprous chloride (I), 198 mg (1 mmol) of 10H-furan[2,3-a]carbazole, and 276 mg (2 mmol) of potassium carbonate were dispersed in 20 mL of anhydrous acetone and reacted at 50 °C for 48 hours. The mixture was filtered, recrystallized several times with dichloromethane and n-hexane to obtain 401 mg of a bright yellow crystalline powder. The mass spectrometry results of this product were: MS (EI): m / z 707.4 [M + The test results match the theoretical molecular weight of the molecule.

[0156] Example 12

[0157] Preparation:

[0158]

[0159] (1) In this embodiment, the synthesis steps of [(1,3-bis(2',6'-diisopropylphenyl)-5,5-dimethyl-4-oxohexahydropyrimidine-2-carbene]cuprous chloride (I) are the same as in Example 1;

[0160] (2) Synthesis of (3-cyano-5H-benzo[3,2-c]furancarbazole-5-yl)[1,3-bis(2',6'-diisopropylphenyl)-5,5-dimethyl-4-oxohexahydropyrimidine-2-carbene]copper(I):

[0161] 543 mg (1 mmol) of [(1,3-bis(2',6'-diisopropylphenyl)-5,5-dimethyl-4-oxohexahydropyrimidine-2-carbene]cuprous chloride (I), 230 mg (1 mmol) of 3-cyano-5H-benzo[3,2-c]furancarbazole and 276 mg (2 mmol) of potassium carbonate were dispersed in 20 mL of anhydrous acetone and reacted at 50 °C for 48 hours. After filtration, the product was recrystallized several times with dichloromethane and n-hexane to obtain 481 mg of a bright yellow crystalline powder. The mass spectrometry results of this product were: MS (EI): m / z 790.4 [M +The test results match the theoretical molecular weight of the molecule.

[0162] Example 13

[0163] Preparation:

[0164]

[0165] (1) In this embodiment, the synthesis steps of [1,3-bis(2',6'-diisopropylphenyl)-5,5-dimethyl-4-oxohexahydropyrimidine-2-carbene]silver (I) are the same as in Example 8;

[0166] (2) Synthesis of (3-cyano-benzo[4,5]thiophene[2,3-a]carbazole-12-yl)[1,3-bis(2',6'-diisopropylphenyl)-5,5-dimethyl-4-oxohexahydropyrimidine-2-carbene]silver(I):

[0167] 588 mg (1 mmol) of [1,3-bis(2',6'-diisopropylphenyl)-5,5-dimethyl-4-oxohexahydropyrimidine-2-carbene]silver (I), 298 mg (1 mmol) of 12H-3-cyano-benzo[4,5]thiophene[2,3-a]carbazole and 115 mg (1.2 mmol) of sodium tert-butoxide were weighed into a 100 mL Scheranck flask, and 20 mL of anhydrous tetrahydrofuran was added. After reacting at room temperature under argon protection for 24 hours, the mixture was filtered, recrystallized several times with dichloromethane and n-hexane, and 220 mg of bright yellow crystalline powder was obtained. The mass spectrometry results of this product were: MS (EI): m / z 850.3 [M + The test results match the theoretical molecular weight of the molecule.

[0168] Example 14

[0169] Preparation:

[0170]

[0171] (1) In this embodiment, the synthesis steps of [1,3-bis(2',6'-diisopropylphenyl)-5,5-dimethyl-4-oxohexahydropyrimidine-2-carbene]silver (I) are the same as in Example 8;

[0172] (2) Synthesis of (3-methoxy-benzo[4,5]thiophene[2,3-a]carbazole-12-yl)[1,3-bis(2',6'-diisopropylphenyl)-5,5-dimethyl-4-oxohexahydropyrimidine-2-carbene]silver(I):

[0173] 588 mg (1 mmol) of [1,3-bis(2',6'-diisopropylphenyl)-5,5-dimethyl-4-oxohexahydropyrimidine-2-carbene]silver (I), 303 mg (1 mmol) of 12H-3-methoxy-benzo[4,5]thiophene[2,3-a]carbazole and 115 mg (1.2 mmol) of sodium tert-butoxide were weighed into a 100 mL Scheranck flask, and 20 mL of anhydrous tetrahydrofuran was added. After reacting at room temperature under argon protection for 24 hours, the mixture was filtered, recrystallized several times with dichloromethane and n-hexane, and 154 mg of bright yellow crystalline powder was obtained. The mass spectrometry results of this product were: MS (EI): m / z 856.9 [M + The test results match the theoretical molecular weight of the molecule.

[0174] Example 15

[0175] Preparation

[0176]

[0177]

[0178] (1) In this embodiment, the synthesis steps of [1,3-bis(2',6'-diisopropylphenyl)-5,5-dimethyl-4-oxohexahydropyrimidine-2-carbene]silver (I) are the same as in Example 8;

[0179] (2) Synthesis of (benzo[3,2-c]furancarbazole-5-yl)[1,3-bis(2,6-diisopropylphenyl)-5,5-dimethyl-4-oxohexahydropyrimidine-2-carbene]silver(I):

[0180] 588 mg (1 mmol) of [1,3-bis(2',6'-diisopropylphenyl)-5,5-dimethyl-4-oxohexahydropyrimidine-2-carbene]silver (I), 257 mg (1 mmol) of 5H-benzofuran[3,2-c]carbazole and 115 mg (1.2 mmol) of sodium tert-butoxide were weighed into a 100 mL Scheranck flask, and 20 mL of anhydrous tetrahydrofuran was added. After reacting at room temperature under argon protection for 24 hours, the mixture was filtered, recrystallized several times with dichloromethane and n-hexane, and 302 mg of bright yellow crystalline powder was obtained. The mass spectrometry results of this product were: MS (EI): m / z 819.0 [M + The test results match the theoretical molecular weight of the molecule.

[0181] Example 16

[0182] Preparation:

[0183]

[0184] (1) In this embodiment, the synthesis steps of [1,3-bis(2',6'-diisopropylphenyl)-5,5-dimethyl-4-oxohexahydropyrimidine-2-carbene]silver (I) are the same as in Example 8;

[0185] (2) Synthesis of (benzo[2,3-b]furancarbazole-7-yl)[1,3-bis(2,6-diisopropylphenyl)-5,5-dimethyl-4-oxohexahydropyrimidine-2-carbene]silver(I):

[0186] 588 mg (1 mmol) of [1,3-bis(2',6'-diisopropylphenyl)-5,5-dimethyl-4-oxohexahydropyrimidine-2-carbene]silver (I), 257 mg (1 mmol) of 7H-benzofuran[2,3-b]carbazole and 115 mg (1.2 mmol) of sodium tert-butoxide were weighed into a 100 mL Scheranck flask, and 20 mL of anhydrous tetrahydrofuran was added. After reacting at room temperature for 24 hours under argon protection, the mixture was filtered, recrystallized several times with dichloromethane and n-hexane, and 411 mg of bright yellow crystalline powder was obtained. The mass spectrometry results of this product were: MS (EI): m / z 819.2 [M + The test results match the theoretical molecular weight of the molecule.

[0187] Example 17

[0188] Preparation:

[0189]

[0190] (1) In this embodiment, the synthesis steps of [1,3-bis(2',6'-diisopropylphenyl)-5,5-dimethyl-4-oxohexahydropyrimidine-2-carbene]silver (I) are the same as in Example 8;

[0191] (2) Synthesis of (benzo[2,3-a]furancarbazole-12yl)[1,3-bis(2,6-diisopropylphenyl)-5,5-dimethyl-4-oxohexahydropyrimidine-2-carbene]silver(I):

[0192] 588 mg (1 mmol) of [1,3-bis(2',6'-diisopropylphenyl)-5,5-dimethyl-4-oxohexahydropyrimidine-2-carbene]silver (I), 257 mg (1 mmol) of 12H-benzofuran[2,3-a]carbazole, and 115 mg (1.2 mmol) of sodium tert-butoxide were weighed into a 100 mL Scheranck flask, and 20 mL of anhydrous tetrahydrofuran was added. After reacting at room temperature for 24 hours under argon protection, the mixture was filtered, recrystallized several times with dichloromethane and n-hexane, and 321 mg of bright yellow crystalline powder was obtained. The mass spectrometry results of this product were: MS (EI): m / z 819.1 [M+ The test results match the theoretical molecular weight of the molecule.

[0193] Example 18

[0194] Fabrication of green thermoactive delayed fluorescence vapor-deposited organic electroluminescent devices:

[0195] The glass plate with a 150nm thick ITO transparent conductive layer was wiped with cotton soaked in acetone and ethanol respectively, rinsed with deionized water, and then ultrasonically cleaned with acetone and ethanol for 10 minutes respectively. It was then baked in a clean environment until all moisture was removed, and cleaned with ultraviolet light and ozone for 20 minutes.

[0196] The treated ITO glass substrate was placed in a vacuum chamber, and after evacuation, the functional layers were vacuum-deposited onto the anode layer film. The structure of the thermally activated delayed fluorescence device is as follows: Figure 1 As shown, the layers are, in order, a glass substrate, an anode layer, a hole injection layer, a hole transport layer, a hole transport layer, an electron blocking layer, a light-emitting layer, a hole blocking layer, an electron transport layer, an electron injection layer, and a metal aluminum cathode; the evaporation rate of the functional layers is 0.4 Å / s, and the evaporation rate of the metal cathode is 4 Å / s.

[0197] In the green thermoactive delayed fluorescence vapor deposition organic electroluminescent device, the glass substrate is ITO conductive glass, covered with an anode layer film; the hole injection layer is 5 nm thick and made of HAT-CN; the hole transport layer is 30 nm thick and made of TAPC; the hole transport layer is 15 nm thick and made of TCTA; the electron blocking layer is 10 nm thick and made of mCBP; the light-emitting layer is 20 nm thick and made of a composition formed by PPF and the complex obtained in Example 1 at a mass ratio of 96:4; the hole blocking layer is 10 nm thick and made of PPF; the electron transport layer is 40 nm thick and made of ANT-BIZ; the electron injection layer is 1.5 nm thick and made of Liq; and the aluminum cathode layer is 100 nm thick.

[0198] Electroluminescence spectra were obtained using a PR735 spectrometer. Current-luminosity-voltage characteristics were obtained using a Keithley 2400 testing system with an LS-110 luminometer. All tests were conducted in atmospheric conditions.

[0199] In this embodiment, a vapor-deposited green photoluminescent device was prepared using the complex synthesized in Example 1 as the host material. The maximum external quantum efficiency was 33.0%, and the CIE values ​​of color coordinates were x = 0.30 and y = 0.49.

[0200] Example 19

[0201] In this embodiment, the preparation method of the green light evaporation-type thermoactive delayed fluorescence organic light-emitting device is basically the same as that in Example 18, the only difference being that the material composition of the functional layer of the evaporation-type organic light-emitting device in this embodiment is as follows:

[0202] The glass substrate is ITO conductive glass, covered with an anode layer film; the hole injection layer is 5 nm thick and made of HAT-CN; the hole transport layer is 30 nm thick and made of TAPC; the hole transport layer is 15 nm thick and made of TCTA; the electron blocking layer is 10 nm thick and made of mCBP; the light-emitting layer is 20 nm thick and made of mCBP; and the composition is formed by combining mCBP with the complex obtained in Example 2 at a mass ratio of 96:4; the hole blocking layer is 10 nm thick and made of DPEPO; the electron transport layer is 40 nm thick and made of ANT-BIZ; the electron injection layer is 1.5 nm thick and made of Liq; and the aluminum cathode layer is 100 nm thick.

[0203] Electroluminescence spectra were obtained using a PR735 spectrometer. Current-luminosity-voltage characteristics were obtained using a Keithley 2400 testing system with an LS-110 luminometer. All tests were conducted in atmospheric conditions.

[0204] In this embodiment, a vapor-deposited green photoluminescent device was prepared using the complex synthesized in Example 2 as the host material. The maximum external quantum efficiency was 30.8%, and the CIE values ​​of color coordinates were x = 0.30 and y = 0.49.

[0205] Example 20

[0206] In this embodiment, the preparation method of the green light evaporation-type thermoactive delayed fluorescence organic light-emitting device is basically the same as that in Example 18, the only difference being that the material composition of the functional layer of the evaporation-type organic light-emitting device in this embodiment is as follows:

[0207] The glass substrate is ITO conductive glass, covered with an anode layer film; the hole injection layer is 5 nm thick and made of HAT-CN; the hole transport layer is 30 nm thick and made of TAPC; the hole transport layer is 15 nm thick and made of TCTA; the electron blocking layer is 10 nm thick and made of mCBP; the light-emitting layer is 20 nm thick and made of mCBP; and the composition is formed by combining mCBP with the complex obtained in Example 3 at a mass ratio of 90:10; the hole blocking layer is 10 nm thick and made of DPEPO; the electron transport layer is 40 nm thick and made of ANT-BIZ; the electron injection layer is 1.5 nm thick and made of Liq; and the aluminum cathode layer is 100 nm thick.

[0208] Electroluminescence spectra were obtained using a PR735 spectrometer. Current-luminosity-voltage characteristics were obtained using a Keithley 2400 testing system with an LS-110 luminometer. All tests were conducted in atmospheric conditions.

[0209] In this embodiment, a vapor-deposited green photoluminescent device was prepared using the complex synthesized in Example 3 as the host material. The maximum external quantum efficiency was 16.0%, and the CIE values ​​of color coordinates were x = 0.35 and y = 0.52.

[0210] Example 21

[0211] Fabrication of green spin-coated thermoactive delayed fluorescence organic light-emitting devices:

[0212] The glass plate with a 150nm thick ITO transparent conductive layer was wiped with cotton soaked in acetone and ethanol respectively, rinsed with deionized water, and then ultrasonically cleaned with acetone and ethanol for 10 minutes respectively. It was then baked in a clean environment until all moisture was removed, and cleaned with ultraviolet light and ozone for 20 minutes.

[0213] After ultraviolet light and ozone cleaning, according to Figure 2 The structure shown involves spin-coating PEDOT:PSS onto an ITO glass substrate coated with an anode film to form a hole injection layer, followed by annealing at 120°C for 10 minutes in a glove box. Then, the light-emitting layer material is dissolved in an appropriate amount of chlorobenzene and spin-coated onto the substrate, and annealed at 50°C for 10 minutes to form the light-emitting layer. The ITO glass substrate after the above treatment is placed in a vacuum chamber, evacuated, and the remaining functional layers are vacuum-deposited.

[0214] The material composition and thickness of the functional layer of the spin-coated organic electroluminescent device in this embodiment are as follows:

[0215] The glass substrate is ITO conductive glass, covered with an anode layer; the hole injection layer is 50 nm thick and made of PEDOT:PSS; the light-emitting layer is 40 nm thick and made of the complex synthesized in Example 4; the hole blocking layer is 10 nm thick and made of DPEPO; the electron transport layer is 40 nm thick and made of TmPyPB; the electron injection layer is 1 nm thick and made of Liq; and the aluminum cathode layer is 100 nm thick.

[0216] The evaporation rates of the functional layer and metal electrodes, as well as the test conditions for the electroluminescent device, were the same as in Example 18.

[0217] In this embodiment, a spin-coated green photoluminescent device was prepared using the complex synthesized in Example 4 as the host material. The maximum external quantum efficiency was 26.6%, and the CIE values ​​of color coordinates were x = 0.42 and y = 0.53.

[0218] Example 22

[0219] In this embodiment, the fabrication method of the blue light evaporation-type thermoactive delayed fluorescence organic light-emitting device is basically the same as that in Example 18, except that the material composition of the functional layer of the evaporation-type organic light-emitting device in this embodiment is as follows:

[0220] The glass substrate is ITO conductive glass, covered with an anode layer film; the hole injection layer is 5 nm thick and made of HAT-CN; the hole transport layer is 30 nm thick and made of TAPC; the hole transport layer is 15 nm thick and made of TCTA; the electron blocking layer is 10 nm thick and made of mCBP; the light-emitting layer is 20 nm thick and made of a composition formed by PPF and the complex obtained in Example 5 at a mass ratio of 96:4; the hole blocking layer is 10 nm thick and made of PPF; the electron transport layer is 40 nm thick and made of ANT-BIZ; the electron injection layer is 1.5 nm thick and made of Liq; the aluminum cathode layer is 100 nm thick.

[0221] Electroluminescence spectra were obtained using a PR735 spectrometer. Current-luminosity-voltage characteristics were obtained using a Keithley 2400 testing system with an LS-110 luminometer. All tests were conducted in atmospheric conditions.

[0222] In this embodiment, a vapor-deposited blue photoluminescent device was prepared using the complex synthesized in Example 5 as the host material. The maximum external quantum efficiency was 28.0%, and the CIE values ​​of color coordinates were x = 0.21 and y = 0.31.

[0223] Example 23

[0224] In this embodiment, the fabrication method of the red spin-coated thermoactive delayed fluorescence organic light-emitting device is basically the same as that in Example 21, except that the material composition of the functional layer of the spin-coated organic light-emitting device in this embodiment is as follows:

[0225] The glass substrate is ITO conductive glass, covered with an anode layer film; the hole injection layer is 50 nm thick and made of PEDOT:PSS; the light-emitting layer is 40 nm thick and made of a composition formed by mCP and the complex synthesized in Example 7 at a mass ratio of 80:20; the hole blocking layer is 10 nm thick and made of DPEPO; the electron transport layer is 40 nm thick and made of TmPyPB; the electron injection layer is 1 nm thick and made of Liq; and the aluminum cathode layer is 100 nm thick.

[0226] In this embodiment, a vapor-deposited red photoluminescent device was prepared using the complex synthesized in Example 7 as the host material. The maximum external quantum efficiency was 7.4%, and the CIE values ​​of color coordinates were x = 0.61 and y = 0.39.

[0227] Example 24

[0228] In this embodiment, the fabrication method of the green spin-coated thermoactive delayed fluorescence organic light-emitting device is basically the same as that in Example 21, except that the material composition of the functional layer of the spin-coated organic light-emitting device in this embodiment is as follows:

[0229] The glass substrate is ITO conductive glass, covered with an anode layer film; the hole injection layer is 50 nm thick and made of PEDOT:PSS; the light-emitting layer is 40 nm thick and made of a composition formed by mCP and the complex synthesized in Example 8 at a mass ratio of 70:30; the hole blocking layer is 10 nm thick and made of PPF; the electron transport layer is 50 nm thick and made of TmPyPB; the electron injection layer is 1.5 nm thick and made of Liq; the aluminum cathode layer is 100 nm thick.

[0230] In this embodiment, a vapor-deposited green photoluminescent device was prepared using the complex synthesized in Example 8 as the host material. The maximum external quantum efficiency was 16.4%, and the CIE values ​​of color coordinates were x = 0.34 and y = 0.53.

[0231] Example 25

[0232] Fabrication of a spin-coated thermoactive delayed-fluorescence organic light-emitting device:

[0233] The glass plate with a 150nm thick ITO transparent conductive layer was wiped with cotton soaked in acetone and ethanol respectively, rinsed with deionized water, and then ultrasonically cleaned with acetone and ethanol for 10 minutes respectively. It was then baked in a clean environment until all moisture was removed, and cleaned with ultraviolet light and ozone for 20 minutes.

[0234] After ultraviolet light and ozone cleaning, according to Figure 2 The structure shown involves spin-coating PEDOT:PSS onto an ITO glass substrate coated with an anode film to form a hole injection layer, followed by annealing at 120°C for 10 minutes in a glove box. Then, the light-emitting layer material is dissolved in an appropriate amount of chlorobenzene and spin-coated onto the substrate, and annealed at 50°C for 10 minutes to form the light-emitting layer. The ITO glass substrate after the above treatment is placed in a vacuum chamber, evacuated, and the remaining functional layers are vacuum-deposited.

[0235] The material composition and thickness of the functional layer of the spin-coated organic electroluminescent device in this embodiment are as follows:

[0236] The glass substrate is ITO conductive glass, covered with an anode layer film; the hole injection layer is 50 nm thick and made of PEDOT:PSS; the light-emitting layer is 40 nm thick and made of a composition of mCP, o-CzOXD, the complex synthesized in Example 4, and BN3 in a mass ratio of 40:39:20:1; the hole blocking layer is 10 nm thick and made of DPEPO; the electron transport layer is 50 nm thick and made of TmPyPB; the electron injection layer is 1 nm thick and made of Liq; and the aluminum cathode layer is 100 nm thick.

[0237] The evaporation rates of the functional layer and metal electrodes, as well as the test conditions for the electroluminescent device, were the same as in Example 18.

[0238] In this embodiment, the complex synthesized in Example 4 was used as a sensitizer, and BN3 was used as the guest to prepare a spin-coated yellow photoluminescent device with a maximum external quantum efficiency of 20.7% and color coordinate CIE values ​​of x = 0.45 and y = 0.53.

[0239] Example 26

[0240] In this embodiment, the fabrication method of the green spin-coated thermoactive delayed fluorescence organic light-emitting device is basically the same as that in Example 21, except that the material composition of the functional layer of the spin-coated organic light-emitting device in this embodiment is as follows:

[0241] The glass substrate is ITO conductive glass, covered with an anode layer film; the hole injection layer is 50 nm thick and made of PEDOT:PSS; the light-emitting layer is 40 nm thick and made of a composition formed by mCP and the complex synthesized in Example 13 at a mass ratio of 70:30; the hole blocking layer is 10 nm thick and made of PPF; the electron transport layer is 50 nm thick and made of TmPyPB; the electron injection layer is 1.5 nm thick and made of Liq; the aluminum cathode layer is 100 nm thick.

[0242] In this embodiment, a vapor-deposited green photoluminescent device was prepared using the complex synthesized in Example 13 as the host material. The maximum external quantum efficiency was 12.5%, and the CIE values ​​of color coordinates were x = 0.26 and y = 0.46.

[0243] Example 27

[0244] In this embodiment, the fabrication method of the green spin-coated thermoactive delayed fluorescence organic light-emitting device is basically the same as that in Example 21, except that the material composition of the functional layer of the spin-coated organic light-emitting device in this embodiment is as follows:

[0245] The glass substrate is ITO conductive glass, covered with an anode layer film; the hole injection layer is 50 nm thick and made of PEDOT:PSS; the light-emitting layer is 40 nm thick and made of a composition formed by mCP and the complex synthesized in Example 15 at a mass ratio of 70:30; the hole blocking layer is 10 nm thick and made of DPEPO; the electron transport layer is 50 nm thick and made of TmPyPB; the electron injection layer is 1.5 nm thick and made of Liq; the aluminum cathode layer is 100 nm thick.

[0246] In this embodiment, a vapor-deposited green photoluminescent device was prepared using the complex synthesized in Example 15 as the host material. The maximum external quantum efficiency was 24.0%, and the CIE values ​​of color coordinates were x = 0.33 and y = 0.50.

[0247] Example 28

[0248] In this embodiment, the fabrication method of the green spin-coated thermoactive delayed fluorescence organic light-emitting device is basically the same as that in Example 21, except that the material composition of the functional layer of the spin-coated organic light-emitting device in this embodiment is as follows:

[0249] The glass substrate is ITO conductive glass, covered with an anode layer film; the hole injection layer is 50 nm thick and made of PEDOT:PSS; the light-emitting layer is 40 nm thick and made of a composition of mCP and the complex synthesized in Example 16 at a mass ratio of 70:30; the hole blocking layer is 10 nm thick and made of DPEPO; the electron transport layer is 50 nm thick and made of TmPyPB; the electron injection layer is 1.5 nm thick and made of Liq; the aluminum cathode layer is 100 nm thick.

[0250] In this embodiment, a vapor-deposited green photoluminescent device was prepared using the complex synthesized in Example 16 as the host material. The maximum external quantum efficiency was 20.5%, and the CIE values ​​of color coordinates were x = 0.38 and y = 0.53.

[0251] Example 29

[0252] In this embodiment, the fabrication method of the green spin-coated thermoactive delayed fluorescence organic light-emitting device is basically the same as that in Example 21, except that the material composition of the functional layer of the spin-coated organic light-emitting device in this embodiment is as follows:

[0253] The glass substrate is ITO conductive glass, covered with an anode layer film; the hole injection layer is 50 nm thick and made of PEDOT:PSS; the light-emitting layer is 40 nm thick and made of a composition of mCP and the complex synthesized in Example 17 at a mass ratio of 70:30; the hole blocking layer is 10 nm thick and made of DPEPO; the electron transport layer is 50 nm thick and made of TmPyPB; the electron injection layer is 1.5 nm thick and made of Liq; the aluminum cathode layer is 100 nm thick.

[0254] In this embodiment, a vapor-deposited green photoluminescent device was prepared using the complex synthesized in Example 17 as the host material. The maximum external quantum efficiency was 19.0%, and the CIE values ​​of color coordinates were x = 0.31 and y = 0.48.

[0255] Example 30

[0256] The radiative transition efficiency of monovalent monetary metal complexes can be evaluated by the ratio (kr) of the photoinduced quantum yield (PLQY) to the exciton lifetime (τ). To evaluate the radiative transition efficiency of this series of monovalent monetary metal complexes, the PLQY and τ of the complexes obtained in Examples 1-8 were first tested, and the radiative and nonradiative transition rates (knr) were calculated based on these results. Meanwhile, to further compare the advantages of introducing heterocyclic fused carbazole ligands, the radiative transition rates of three comparative substances were tested and evaluated in this embodiment: (carbazole-9-yl)[1,3-bis(2,6-diisopropylphenyl)-5,5-dimethyl-4-oxohexahydropyrimidine-2-carbene]copper(I) (abbreviated as MAC-Cu-Cz, denoted as comparative substance 1), (carbazole-9-yl)[1-(2',6'-diisopropylphenyl)-5,5-dimethyl(adamantane-2,3-pyrrolidine)-2-carbene)]copper(I) (abbreviated as CAAC-Cu-Cz, denoted as comparative substance 2), and (carbazole-9-yl)[2-(2',6'-diisopropylphenyl)-3,3-diphenylisoindolinecarbene]copper(I) (abbreviated as CAArC-Cu-Cz, denoted as comparative substance 3). The test was performed in toluene solution. The test results are shown in Table 1. Figure 3 The transient luminescence lifetimes of Examples 4, 6, and 7 are compared with those of Comparative Substances 1–3. The orientation distribution of the transient transition dipole moment (TDM) of the complexes can be obtained by analyzing the angular distribution excitation spectra. Figure 4 The transient transition dipole moment (TDM) orientation distribution of the complex synthesized in Example 1 in the 2,8-bis(diphenylphospho)dibenzo[b,d]furan (PPF) doped film in the light-emitting layer of the electroluminescent device of Example 18 is given.

[0257] Table 1:

[0258] Name Carbene ligand Metal center PLQY [%] τ [μs] k r [10 6 s -1 ]]]> k nr [10 6 s -1 ]]]> Example 1 MAC Cu 95 0.65 1.46 0.08 Example 2 MAC Cu 91 1.08 0.84 0.11 Example 3 MAC Cu 72 0.73 0.99 0.39 Example 4 MAC Cu 93 0.65 1.43 0.11 Example 5 MAC Cu 87 0.80 1.09 0.16 Example 6 CAAC Cu 85 0.95 0.89 0.16 Example 7 CAArC Cu 59 0.18 3.28 2.27 Example 8 MAC Ag 62 0.56 1.11 0.68 Comparative substance 1 MAC Cu 80 1.40 0.57 0.14 Comparative substance 2 CAAC Cu 78 3.97 0.20 0.06 Comparative substance 3 CAArC Cu 50 0.35 1.43 1.43

[0259] Compared to the comparative materials, Examples 1-8, which are fused with heterocyclic rings, exhibit higher PLQY, shorter τ, and significantly higher kr. Therefore, through the present invention, CMA thermoactive delayed-fluorescence monovalent currency metal complexes with higher luminescent efficacy can be obtained.

[0260] like Figure 3 As shown, under the same test conditions, the materials listed in the examples all exhibited shorter exciton lifetimes compared to the comparative materials, with lifetimes on the sub-microsecond scale. This is beneficial for improving the radiative transition rate of the materials and the stability of the devices, and suppressing efficiency roll-off.

[0261] like Figure 4 As shown, the horizontal TDM ratio obtained by inverse fitting is 83%, which is significantly higher than the horizontal TDM ratio of 67% for isotropic random distribution. According to the principle of optical coupling output, this characteristic will improve the optical coupling output efficiency of electroluminescent devices by about 10%, thereby improving the external quantum efficiency of the devices.

[0262] In summary, the monovalent monetary metal complex of the present invention exhibits thermoactive delayed fluorescence (TADF) characteristics. Due to the heavy atom effect of heteroatoms, the exciton lifetime of the molecule is shortened. Furthermore, the fused rings increase the planarity and rigidity of the molecule, resulting in a higher photoinduced quantum yield and thus a significantly higher radiative transition rate compared to traditional carbazole-based CMA complexes. Additionally, due to the unique molecular configuration and radiative transition mode, the complex of the present invention has a high planar transition dipole moment ratio, which provides a certain gain effect on the optical coupling output in devices. The complex of the present invention can be used as a light-emitting layer material or sensitizer in OLEDs. By combining it with appropriate host materials, its luminous efficiency in electroluminescent devices can be improved, providing a low-cost, high-efficiency light-emitting device solution that can be widely applied in the field of organic electroluminescence. The preferred embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make many modifications and variations based on the concept of the present invention without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning, or limited experimentation on the basis of existing technology should be within the scope of protection defined by the claims.

Claims

1. A monovalent monetary metal complex, characterized in that, This complex is centered around a monovalent monetary metal and includes heterocyclic carbene ligands and carbazole ligands. The monovalent monetary metal complex has one of the following structural formulas: 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 。 2. A method for preparing the monovalent monetary metal complex as described in claim 1, characterized in that, Includes the following steps: (1) React the heterocyclic carbene ligand raw material with a monovalent monetary metal source to obtain a coordination intermediate between the heterocyclic carbene ligand and the monovalent monetary metal; (2) The coordination intermediate is further reacted with carbazole ligand raw material under nucleophilic reaction conditions to obtain a monovalent currency metal complex.

3. The preparation method according to claim 2, characterized in that: In step (1), the heterocyclic carbene ligand raw material is a quaternary ammonium salt or a chloride ion salt of a heterocyclic carbene ligand, and the monovalent monetary metal source is a halide or oxide of a monovalent monetary metal; the reaction temperature is -78~25℃, and the reaction time is 12~72h.

4. The preparation method according to claim 2, characterized in that: In step (2), the carbazole ligand raw material is a hydrogen-substituted carbazole ligand; the reaction temperature is 25~50℃ and the reaction time is 12~72h.

5. The application of a monovalent monetary metal complex according to claim 1 or a monovalent monetary metal complex prepared by any one of claims 2 to 4 in the preparation of electroluminescent devices.

6. The application according to claim 5, characterized in that, The specific application method includes the following steps: A monovalent monetary metal complex or a composition formed by a monovalent monetary metal complex and an OLED host material is used as the light-emitting layer material for an electroluminescent device to obtain the light-emitting layer; the light-emitting layer is then combined with a functional layer to prepare the electroluminescent device.

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