Sulfur and phosphorus heterocyclic acceptor and nitrogen-containing heterocyclic donor compound, synthesis method and application thereof

Abstract

The application provides a kind of based on sulfur phosphorus heterocyclic acceptor and nitrogen-containing heterocyclic donor compound, in the compound, sulfur phosphorus heterocyclic acceptor as parent, with nitrogen-containing heterocyclic substituent group.It has thermal excitation delayed fluorescence light emitting performance, the moderate electron-withdrawing ability of phosphine oxide group in the molecule is used to optimize the ICT effect of the system, improve RISC efficiency, while using the steric effect of phosphine oxide group inhibits the exciton quenching caused by excited state structure relaxation and intermolecular interaction, so as to improve the photoluminescence quantum yield, luminous efficiency and device stability of blue light TADF light emitting material.

Description

[0001] The present application is a divisional application of the application (2022111668919), the original application has an application date of (2022-09-23), an application number of (2022111668919), and an invention title of Sulfur and Phosphorus Heterocyclic Acceptors and Nitrogen-Containing Heterocyclic Donor Compounds, Synthesis Methods Thereof, and Applications. TECHNICAL FIELD

[0002] The present application belongs to the technical field of organic electroluminescent materials, and specifically relates to a kind of based on sulfur and phosphorus heterocyclic acceptor and nitrogen-containing heterocyclic donor compound, synthesis method and application. BACKGROUND

[0003] High-efficiency, low-voltage driven organic electroluminescence brings revolutionary innovation to the development of light-emitting diodes. Research on organic light-emitting materials and devices has attracted widespread attention and in-depth study. Since the first OLED device, OLED technology has developed from the first generation of fluorescence (FL) technology, the second generation of phosphorescence (PH) technology to the third generation of thermally activated delayed fluorescence (TADF) technology. Phosphorescent technology uses phosphorescent dyes to achieve electroluminescence. Such dyes are generally heavy metal complexes, which involve heavy metals that are not only expensive, but also have poor sustainability and pollute the environment. In contrast, the third generation of TADF technology is mainly based on pure organic molecules with push-pull electron system structure. Through the reverse intersystem crossing (RISC) process from the first triplet energy level (T1) to the first singlet energy level (S1) of the molecule, the non-emitting triplet exciton is converted into a radiative singlet exciton, thus achieving 100% theoretical internal quantum efficiency. Therefore, TADF technology not only retains the low cost, environmental friendliness and sustainability of fluorescent materials, but also has the high efficiency of phosphorescent technology. Since the Adachi group reported the first efficient TADF device in 2012, related research has rapidly developed into one of the hotspots in the field of organic optoelectronic materials and devices. In less than 10 years, the performance of single-color TADF devices has approached that of phosphorescent devices, showing excellent development and application potential.

[0004] At present, efficient high color purity thermally activated delayed fluorescence (TADF) light-emitting materials are still one of the key bottlenecks restricting the real application of TADF technology. TADF materials must reduce the singlet-triplet splitting (ΔE ST ) through strong intramolecular charge transfer (ICT) to promote TADF emission. The commonly used method is to reduce the electron-donating ability of the donor (D) or to strengthen the frontier orbital separation and RISC by controlling the configuration, but at the cost of reducing the luminous efficiency.

[0005] Therefore, how to design and prepare efficient high color purity thermally activated delayed fluorescence (TADF) light-emitting materials with high luminous efficiency is still one of the problems to be solved for TADF light-emitting materials. SUMMARY

[0006] To solve the above problems, the present application provides a kind of compound with sulfur phosphorus heterocycle as matrix, with nitrogen-containing heterocyclic substituent group, which has thermally activated delayed fluorescence (TADF) light-emitting performance, good light-emitting purity and high light-emitting efficiency. The moderate electron-withdrawing ability of phosphine oxide group is used to optimize the ICT effect of the system, improve the RISC efficiency, and at the same time, the steric effect of phosphine oxide group is used to inhibit the exciton quenching caused by excited state structure relaxation and intermolecular interaction, thereby improving the photoluminescence quantum yield (PLQY) of blue TADF light-emitting material, improving the device light-emitting efficiency and device stability.

[0007] The first aspect of the present application aims to provide a compound based on sulfur phosphorus heterocycle acceptor and nitrogen-containing heterocyclic donor, wherein the sulfur phosphorus heterocycle acceptor serves as the matrix and carries nitrogen-containing heterocyclic substituent groups.

[0008] The compound based on sulfur phosphorus heterocycle acceptor and nitrogen-containing heterocyclic donor has the following structure:

[0009]

[0010] wherein R1, R2 are selected from nitrogen-containing heterocyclic substituent groups or hydrogen, and the nitrogen-containing heterocyclic substituent groups are selected from 9,9-dimethylacridine-N-yl, 9,9-diphenylacridine-N-yl, N-phenothiazine group or N-phenoxazine group; R2 is selected from nitrogen-containing heterocyclic substituent groups, preferably selected from N-dimethylacridine group, N-diphenylacridine group, N-phenothiazine group or N-phenoxazine group.

[0011] The second aspect of the present application aims to provide a preparation method of a sulfur-phosphorus heterocyclic acceptor and a nitrogen-containing heterocyclic donor compound, wherein a carbon-nitrogen coupling reaction is carried out in the presence of a halogenated sulfur-phosphorus heterocyclic compound and a nitrogen-containing heterocyclic compound and a palladium catalyst in an alkaline environment to obtain the compound.

[0012] The method comprises the following steps:

[0013] Step 1, preparing a halogenated sulfur-phosphorus heterocyclic compound;

[0014] Step 2, adding the halogenated sulfur-phosphorus heterocyclic compound, the nitrogen-containing heterocyclic donor compound, the palladium catalyst and the alkaline substance into a reaction solvent, stirring the reaction to obtain a reaction solution;

[0015] Step 3, post-treating the reaction solution to obtain the sulfur-phosphorus heterocyclic acceptor and the nitrogen-containing heterocyclic donor compound.

[0016] The third aspect of the present application aims to provide the use of the sulfur-phosphorus heterocyclic acceptor and the nitrogen-containing heterocyclic donor compound as a light-emitting layer material for preparing an electroluminescent device.

[0017] The fourth aspect of the present application aims to provide an electroluminescent device, wherein the light-emitting layer material of the electroluminescent device comprises the sulfur-phosphorus heterocyclic acceptor and the nitrogen-containing heterocyclic donor compound.

[0018] The sulfur-phosphorus heterocyclic acceptor and the nitrogen-containing heterocyclic donor compound provided by the present application have the following beneficial effects:

[0019] (1) The sulfur-phosphorus heterocyclic acceptor and the nitrogen-containing heterocyclic donor compound in the present application are based on a binary D-A system composed of a sulfone group acceptor and a donor, and under the premise of not changing or weakly changing the light-emitting color, the phosphine oxide group is used to optimize the ICT effect of the system, improve the RISC efficiency, and at the same time, the steric effect of the phosphine oxide group is used to inhibit the exciton quenching caused by the relaxation of the excited state structure and the intermolecular interaction, thereby improving the PLQY of the blue TADF light-emitting material, improving the device efficiency and device stability.

[0020] (2) The sulfur-phosphorus heterocyclic acceptor and the nitrogen-containing heterocyclic donor compound in the present application can be controllably prepared by reasonable molecular structure design and synthesis route design.

[0021] (3) The cleavage temperature of the compound (I) and the compound (II) in the present application can reach above 360℃. Under the light-emitting peak position of about 505nm, the current efficiency reaches a maximum value of up to 64.5 cd·A -1 , the power efficiency reaches a maximum value of up to 75.1 lm·W -1 , and the maximum external quantum efficiency reaches 26.5%.

[0022] (4) The cleavage temperature of compound (III) and compound (IV) in the present application can reach above 410℃. Under the light emission peak at about 505nm, the current efficiency reaches the maximum of 89.9 cd·A -1 , the power efficiency reaches the maximum of 108.6 lm·W -1 , and the maximum external quantum efficiency reaches 27.2%.

[0023] (5) The cleavage temperature of compound (V) and compound (VI) in the present application can reach above 470℃. Under the light emission peak at 493-498, the current efficiency reaches the maximum of 65.9 cd·A -1 , the power efficiency reaches the maximum of 78.1 lm·W -1 , and the maximum external quantum efficiency reaches 22.7%.

[0024] (6) The cleavage temperature of compound (VII) and compound (VIII) in the present application can reach above 360℃. Under the light emission peak at 495-505nm, the current efficiency reaches the maximum of 66.9 cd·A -1 , the power efficiency reaches the maximum of 82.4 lm·W -1 , and the maximum external quantum efficiency reaches 22.1%. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 The ultraviolet, fluorescence and phosphorescence spectra of compound (I) in the present application are shown; Figure 2 The voltage-current density relationship curve of device 1 in the present application is shown; Figure 3 The ultraviolet, fluorescence and phosphorescence spectra of compound (II) in the present application are shown; Figure 4 The voltage-current density relationship curve of device 2 in the present application is shown; Figure 5 The ultraviolet, fluorescence and phosphorescence spectra of compound (III) in the present application are shown; Figure 6 The voltage-current density relationship curve of device 3 in the present application is shown; Figure 7 The ultraviolet, fluorescence and phosphorescence spectra of compound (IV) in the present application are shown; Figure 8 The voltage-current density relationship curve of device 4 in the present application is shown; Figure 9 The ultraviolet, fluorescence and phosphorescence spectra of compound (V) in the present application are shown; Figure 10 The voltage-current density relationship curve of device 5 in the present application is shown; Figure 11 The ultraviolet, fluorescence and phosphorescence spectra of compound (VI) in the present application are shown; Figure 12 The voltage-current density relationship curve of device 6 in the present application is shown; Figure 13 The ultraviolet, fluorescence and phosphorescence spectra of compound (VII) in the present application are shown; Figure 14A voltage-current density relationship curve of the inventive device 7 is shown. Figure 15 UV, fluorescence and phosphorescence spectra of the inventive compound (VIII) are shown. Figure 16 A voltage-current density relationship curve of the inventive device 8 is shown. DETAILED DESCRIPTION

[0026] The present application will be described in detail below through specific embodiments, and the features and advantages of the present application will become more apparent with these descriptions.

[0027] The present application provides a kind of based on sulfur phosphorus heterocyclic acceptor and nitrogen-containing heterocyclic donor compound, there is strong ICT between the sulfur phosphorus heterocyclic acceptor and nitrogen-containing heterocyclic donor in its molecule, improve RISC efficiency, inhibit excimer quenching using molecular structure, improve the photoluminescence quantum yield of the compound as TADF luminescent material, so as to realize the improvement of electroluminescent device performance.

[0028] The first aspect of the present application provides a kind of based on sulfur phosphorus heterocyclic acceptor and nitrogen-containing heterocyclic donor compound, in the compound, sulfur phosphorus heterocyclic acceptor as parent body, with nitrogen-containing heterocyclic substituent group.

[0029] The based on sulfur phosphorus heterocyclic acceptor and nitrogen-containing heterocyclic donor compound has the following structure:

[0030]

[0031] Wherein, R1, R2 Selected from nitrogen-containing heterocyclic substituent group or hydrogen, the nitrogen-containing heterocyclic substituent group is selected from 9,9-dimethyl acridine-N- group, 9,9-diphenyl acridine-N- group, N- phenothiazine group or N-phenoxazine group;R2 Selected from nitrogen-containing heterocyclic substituent group, preferably selected from N-dimethyl acridine group, N-diphenyl acridine group, N- phenothiazine group or N-phenoxazine group.

[0032] Preferably, the based on sulfur phosphorus heterocyclic acceptor and nitrogen-containing heterocyclic donor compound is selected from:

[0033]

[0034] The based on sulfur phosphorus heterocyclic acceptor and nitrogen-containing heterocyclic donor compound provided in the present application has good ICT ability, improves RISC efficiency, and can inhibit excimer quenching caused by excited state structure relaxation and intermolecular interaction using the steric effect of phosphine oxide group, improve the photoluminescence quantum yield of the compound as thermal excitation delayed fluorescence luminescent material, realize the improvement of device luminous efficiency.

[0035] In addition, the sulfur-phosphorus heterocyclic acceptor and nitrogen-containing heterocyclic donor compound provided in the present application also has good thermal stability, so that the stability of the device is also improved. As the guest material of the light-emitting layer, the current efficiency and power efficiency of the electroluminescent device are effectively improved.

[0036] The sulfur-phosphorus heterocyclic acceptor and nitrogen-containing heterocyclic donor compound is prepared by carbon-nitrogen coupling reaction of halogenated sulfur-phosphorus heterocyclic compound and nitrogen-containing heterocyclic compound under the action of palladium catalyst.

[0037] The halogenated sulfur-phosphorus heterocyclic compound is:

[0038]

[0039] X1 is independently selected from H, Cl, Br or I, preferably selected from H, Cl or Br, and more preferably H or Br; and X2 is selected from Cl, Br or I, preferably selected from Cl or Br, and more preferably Br.

[0040] The nitrogen-containing heterocyclic compound is selected from 9,9-dimethylacridine (DMAC), 9,9-diphenylacridine (DPAC), phenothiazine (PTZ) or phenoxazine (PXZ).

[0041] The second aspect of the present application provides a preparation method of a sulfur-phosphorus heterocyclic acceptor and nitrogen-containing heterocyclic donor compound, wherein the halogenated sulfur-phosphorus heterocyclic compound and the nitrogen-containing heterocyclic compound are subjected to carbon-nitrogen coupling reaction in the presence of a palladium catalyst under alkaline conditions.

[0042] The method comprises the following steps:

[0043] Step 1, preparation of halogenated sulfur-phosphorus heterocyclic compound. Specifically comprising the following steps:

[0044] Step 1-1, using diphenyl sulfide and phenyl dichlorophosphine as raw materials, in the presence of alkyl lithium, the following heterocyclic compound is prepared,

[0045]

[0046] The alkyl lithium is selected from n-butyllithium, methyllithium and phenyllithium, and preferably n-butyllithium.

[0047] The molar ratio of diphenyl sulfide to phenyl dichlorophosphine is 1: (1-1.5), and preferably 1: (1-1.2). The molar ratio of diphenyl sulfide to alkyl lithium is 1: (2-3.5), and preferably 1: (2-2.5).

[0048] In step 1-1, the reaction temperature is -10-5℃, and preferably -5-2℃, and the reaction time is 10-25h, and preferably 15-18h.

[0049] After the reaction, the reaction mixture is extracted with water and dichloromethane, the solid desiccant is dried, and the solvent is evaporated.

[0050] Step 1-2, oxidizing the heterocyclic compound obtained in Step 1-1 to obtain the following oxidized phosphathiazine compound,

[0051]

[0052] The oxidation is carried out by adding an oxidizing agent to a solvent in which the heterocyclic compound obtained in Step 1-1 is dissolved, and the oxidizing agent is selected from hydrogen peroxide or peracetic acid, preferably hydrogen peroxide, and more preferably a 25% to 35% hydrogen peroxide aqueous solution.

[0053] The reaction is carried out in a solvent selected from one or more of a halogenated hydrocarbon solvent, an aromatic hydrocarbon solvent, and an amide solvent, preferably a halogenated hydrocarbon solvent, and more preferably dichloromethane. The volume mole ratio of the dichloromethane to the diphenyl sulfide in Step 1-1 is (6-18) mL: 1 mol, preferably (8-15) mL: 1 mol, and more preferably (10-12) mL: 1 mol.

[0054] In Step 1-2, the reaction temperature is -10 to 5°C, preferably -5 to 2°C, and the reaction time is 3 to 8 hours, preferably 4 to 6 hours.

[0055] After the reaction, the reaction mixture is extracted with water and dichloromethane, the solid desiccant is dried, and the solvent is evaporated.

[0056] Step 1-3, halogenating the oxidized phosphathiazine compound obtained in Step 1-2 to obtain the following halogenated phosphathiazine compound,

[0057]

[0058] The halogenation is carried out in a solvent selected from an acidic organic solvent, preferably an alkyl acid, and more preferably glacial acetic acid. The volume mole ratio of the solvent to the oxidized phosphathiazine compound obtained in Step 1-2 is (2-12) mL: 1 mmol, preferably (3-9) mL: 1 mmol, and more preferably (4-6) mL: 1 mmol.

[0059] The reaction is carried out in the presence of 98 wt% concentrated sulfuric acid, and the volume mole ratio of the concentrated sulfuric acid to the oxidized phosphathiazine compound obtained in Step 1-2 is (0.8-2.1) mL: 1 mmol, preferably (1-1.8) mL: 1 mmol, and more preferably (1.2-1.5) mL: 1 mmol.

[0060] The halogenation is carried out in the presence of a halogenating agent in a molar ratio of (0.8-3): 1 or (3-10): 1, preferably (1-2.5): 1 or (4-6): 1, to the phosphathiacycle oxide obtained in step 1-2. The halogenating agent is preferably a brominating agent, such as N-bromosuccinimide (NBS).

[0061] After the reaction, the product is poured into an ice water bath, extracted with dichloromethane, dried over solid desiccant, spun dry, and purified by column chromatography using a mixture of ethyl acetate (EA) and petroleum ether (PE) (volume ratio EA: PE = 2: 1) as eluent to obtain the halogenated phosphathiacycle.

[0062] Step 2, the halogenated phosphathiacycle, the nitrogen-containing heterocycle donor compound, the palladium catalyst, and the basic substance are added to a reaction solvent, and the reaction is stirred to obtain a reaction solution.

[0063] The basic substance is selected from one or more of alkali metal hydroxides, potassium alcoholate, and sodium alcoholate, preferably one or more of NaOH, KOH, potassium tert-butoxide, and sodium tert-butoxide, more preferably potassium tert-butoxide and / or sodium tert-butoxide, such as potassium tert-butoxide.

[0064] The reaction solvent is selected from one or more of aromatic hydrocarbon solvents, amide solvents, and ketone solvents, preferably one or more of toluene, xylene, N,N-dimethylformamide, N,N-dimethylacetamide, cyclohexanone, methyl ethyl ketone, more preferably xylene.

[0065] The palladium catalyst is selected from palladium salts, such as palladium chloride or palladium acetate, palladium on carbon, inorganic oxide-supported palladium, such as Pd / Al2O3 or Pd / MgO, palladium complexes, such as Pd(AsPh3)4, bis(tri-tert-butylphosphine)palladium, tetrakis(triphenylphosphine)palladium, Pd((MeO)3P)4, preferably palladium salts or palladium complexes, more preferably palladium acetate and / or bis(tri-tert-butylphosphine)palladium.

[0066] The molar ratio of the halogenated phosphathiacycle to the nitrogen-containing heterocycle donor compound is 1: (1.5-7.5), preferably 1: (2.0-7.0), more preferably 1: (2.5-6.5), such as 1:6 or 1:3.

[0067] The molar ratio of the halogenated phosphathiacycle to the basic substance is 1: (3.5-8.5), preferably 1: (4.5-7.5), more preferably 1: (5.5-6.5).

[0068] The molar ratio of the halogenated phosphathiacycle to the palladium catalyst is 1: (0.006-0.035), preferably 1: (0.008-0.025), more preferably 1: (0.01-0.015).

[0069] The molar volume ratio of the halogenated phosphaspirocyclic compound to the reaction solvent is 1 mmol:(5-18) mL, preferably 1 mmol:(7-15) mL, more preferably 1 mmol:(8-12) mL.

[0070] The coupling reaction is carried out under a protective atmosphere, such as nitrogen or argon atmosphere. The reaction temperature is 115-150°C, preferably 120-140°C, more preferably 125-135°C, and the reaction time is 6-15 hours, preferably 8-12 hours, such as 10 hours.

[0071] Step 3, the reaction solution is treated to obtain the phosphaspirocyclic acceptor and nitrogen-containing heterocyclic donor compound.

[0072] After the reaction in Step 2 is completed, the obtained reaction solution is poured into ice water to quench the reaction. After standing and separating the layers, the organic layer is separated and dried with a solid desiccant, and then column chromatography is performed using a mixture of dichloromethane and petroleum ether as the eluent, preferably with a volume ratio of 2:1, to obtain the phosphaspirocyclic acceptor and nitrogen-containing heterocyclic donor compound.

[0073] The molecular synthesis route of the phosphaspirocyclic acceptor and nitrogen-containing heterocyclic donor compound in the present application is reasonable in design, the synthesis method is easy to perform, and the target product can be obtained.

[0074] The third aspect of the present application provides the use of the phosphaspirocyclic acceptor and nitrogen-containing heterocyclic donor compound of the first aspect as a light-emitting layer material for preparing an electroluminescent device.

[0075] The fourth aspect of the present application provides an electroluminescent device, wherein the light-emitting layer material of the electroluminescent device comprises the phosphaspirocyclic acceptor and nitrogen-containing heterocyclic donor compound.

[0076] The electroluminescent device further comprises a conductive anode layer, a hole injection layer, a hole transport layer, an electron transport layer, an electron injection layer, and a cathode conductive layer.

[0077] The present application provides a preparation method of a light-emitting device using the phosphaspirocyclic acceptor and nitrogen-containing heterocyclic donor compound as a light-emitting layer material, which specifically comprises the following steps:

[0078] I. Preparation of a conductive anode layer;

[0079] The conductive anode layer is prepared on a substrate layer. The conductive anode layer is selected from tin oxide conductive glass (ITO), transparent conductive polymers such as polyaniline, and semi-transparent metals such as Au, preferably ITO or semi-transparent metals, and more preferably ITO. Preferably, the conductive anode layer is deposited by vacuum evaporation.

[0080] Preferably, the vacuum evaporation vacuum degree is 1 x 10 -6 mbar, the evaporation rate is set to 0.1-0.3 nm / s, and the material for evaporating the anode conductive layer on the glass or plastic substrate is indium tin oxide, with a thickness of 6-40 nm, preferably 8-30 nm, and more preferably 10-20 nm.

[0081] Preferably, the following hole injection layer, hole transport layer, light-emitting layer, electron transport layer, electron injection layer, and cathode conductive layer are prepared by vacuum evaporation.

[0082] II. Preparation of the hole injection layer;

[0083] The hole injection layer is evaporated on the anode conductive layer, with an evaporation thickness of 4-35 nm, preferably 6-25 nm, and more preferably 8-15 nm, such as 10 nm.

[0084] The hole injection layer material is selected from oxides of molybdenum or poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS), preferably oxides of molybdenum, and more preferably molybdenum oxide, such as MoO3.

[0085] III. Preparation of the hole transport layer;

[0086] The hole transport layer is evaporated on the hole injection layer, with an evaporation thickness of 15-55 nm, preferably 20-45 nm, and more preferably 25-35 nm, such as 30 nm.

[0087] The hole transport layer material is selected from one or more of arylamine compounds and carbazole compounds, such as N,N'-diphenyl-N,N'-(1-naphthyl)-1,1'-biphenyl-4,4'-diamine (NPB), 9,9'-(1,3-phenyl)di-9H-carbazole (mCP), and preferably mCP.

[0088] IV. Preparation of the light-emitting layer;

[0089] The light-emitting layer is further evaporated on the hole transport layer, with an evaporation thickness of 35-75 nm, preferably 40-65 nm, and more preferably 45-55 nm, such as 50 nm.

[0090] The light-emitting layer material includes sulfur-phosphorus heterocyclic acceptors and nitrogen-containing heterocyclic donor compounds, and preferably also includes 4,6-diphenyl phosphine oxide dipheno furan (DBFDPO). The mass fraction of the sulfur-phosphorus heterocyclic acceptors and nitrogen-containing heterocyclic donor compounds in the light-emitting layer material is 10-30%, preferably 15-25%, and more preferably 20%.

[0091] V. Preparation of the electron transport layer;

[0092] The electron transport layer material is selected from one or more of tris(8-hydroxyquinoline) aluminum (Alq3), 1,3,5-tris(1-phenyl-1H-benzimidazol-2-yl)benzene (TPBi), 4,7-diphenyl-1,10-phenanthroline (Bphen), 3-(biphenyl-4-yl)-5-(4-tert-butylphenyl)-4-phenyl-4H-1,2,4-triazole (TAZ), di[2-((oxo)diphenylphosphino)phenyl]ether (DPEPO), and 4,6-diphenylphosphine oxide dipheno-furan (DBFDPO), preferably DBFDPO. The electron transport layer is deposited on the light-emitting layer, with a deposition thickness of 25-55 nm, more preferably 35-45 nm, such as 40 nm.

[0093] Six, preparing an electron injection layer;

[0094] The electron injection layer is deposited on the electron transport layer, with a deposition thickness of 4-18 nm, preferably 6-15 nm, more preferably 8-12 nm, such as 10 nm.

[0095] The electron injection layer material is selected from lithium boron tetra(8-hydroxyquinoline) (LiBq4) or LiF, preferably LiF.

[0096] Seven, preparing a cathode conductive layer, packaging, and obtaining a thermally activated delayed fluorescence electroluminescent device.

[0097] The cathode conductive layer is deposited on the electron injection layer, with a deposition thickness of 60-130 nm, preferably 70-120 nm, more preferably 80-110 nm, such as 100 nm.

[0098] The cathode conductive layer material is selected from a single metal cathode or an alloy cathode, such as metal Al.

[0099] In the present application, the cleavage temperature of compound (I) and compound (II) can reach above 360℃, preferably above 400℃. The electroluminescent device has a maximum current efficiency of 45-65 cd·A -1 , preferably 64.5 cd·A -1 , a maximum power efficiency of 50-80 lm·W -1 , preferably 75.1 lm·W -1 , a maximum external quantum efficiency of 20-28%, preferably 22-26.5%, and a turn-on voltage of less than 3V, preferably 2.7V.

[0100] In the present application, the cleavage temperature of compound (III) and compound (IV) can reach above 410℃, preferably above 440℃. The electroluminescent device has a maximum current efficiency of 70-90 cd·A-1 , preferably 89.9 cd-A -1 , the power efficiency reaches a maximum value of 80-109 lm-W -1 , preferably 108.6 lm-W -1 , the maximum external quantum efficiency reaches 20-28%, preferably 27.2%, and the turn-on voltage is lower than 3V, preferably 2.6V.

[0101] The cleavage temperature of compound (V) and compound (VI) in the present application can reach above 460°C, preferably above 480°C. The current efficiency of the electroluminescent device reaches a maximum value of 60-70 cd-A at the peak position of 490-500 nm -1 , preferably 65.9 cd-A -1 , the power efficiency reaches a maximum value of 70-80 lm-W -1 , preferably 78.1 lm-W -1 , the maximum external quantum efficiency reaches 18-25%, preferably 22.7%, and the turn-on voltage is lower than 3V, preferably 2.6V.

[0102] The cleavage temperature of compound (VII) and compound (VIII) in the present application can reach above 360°C, preferably above 420°C. The current efficiency of the electroluminescent device reaches a maximum value of 60-70 cd-A at the peak position of 495-505 nm -1 , preferably 66.9 cd-A -1 , the power efficiency reaches a maximum value of 75-85, preferably 82.4 lm-W -1 , the maximum external quantum efficiency reaches 18-25%, preferably 22.1%, and the turn-on voltage is lower than 3V, preferably 2.5V.

[0103] Examples

[0104] Example 1

[0105] (1) 1 mmol diphenyl sulfide (DPS), 2.4 mmol n-butyllithium, 1 mmol phenyl dichlorophosphine are mixed, and reacted for 16 hours in an ice water bath. After the reaction, 10 ml water and 10 ml dichloromethane are extracted, dried with anhydrous sodium sulfate, and the solvent is rotary evaporated.

[0106] The obtained solid is dissolved in 10 ml dichloromethane, 10-15 mmol hydrogen peroxide (concentration of 30 wt%) is added under the condition of ice water bath, and reacted for 4 hours. Then 10 ml water and 10 ml dichloromethane are extracted, dried with anhydrous sodium sulfate, and the solvent is rotary evaporated.

[0107] The obtained 1 mmol solid was placed in a single neck flask, 4 ml of glacial acetic acid, 1.2 ml of concentrated sulfuric acid (98 wt%), 6 mmol of N-bromosuccinimide (NBS) were added, and the reaction was carried out at 30°C for 10 hours. After the reaction, the product was poured into an ice water bath, extracted with dichloromethane, dried over anhydrous sodium sulfate, rotary evaporated, and purified by column chromatography using a mixed solvent of ethyl acetate and petroleum ether (volume ratio EA: PE = 2:1) as the eluent to obtain the following double-brominated phosphacycle compound.

[0108]

[0109] (2) 1 mmol of the double-brominated phosphacycle compound with the above structure, 6 mmol of 9,9-dimethylacridine (DMAC), 6 mmol of potassium tert-butoxide, 6 mmol of tri-tert-butylphosphine, 0.01 mmol of palladium acetate, and 10 ml of xylene were mixed, and the reaction was carried out for 10 hours. After the reaction, the product was poured into ice water, 10 ml of dichloromethane was added for extraction, and the organic layer was obtained. After drying the organic layer with anhydrous sodium sulfate, column chromatography was performed for purification using a mixed solvent of dichloromethane and petroleum ether as the eluent, and the volume ratio of dichloromethane and petroleum ether was 2:1, to obtain compound (I) (SOSPODMAC2), which is:

[0110]

[0111] The nuclear magnetic resonance test results of compound (I) are as follows:

[0112] 1 H NMR (TMS, CDCl3, 400 MHz): δ = 8.534-8.473 (m, 2H), 8.453-8.404 (m, 2H), 7.988-7.869 (m, 2H), 7.645-7.582 (m, 1H), 7.571-7.475 (m, 8H), 7.073-6.999 (m, 8H), 6.384-6.303 (m, 4H); 1.5 (s, 12H).

[0113] The laser desorption ionization time-of-flight mass spectrometry (LDI-TOF-MS) test results are as follows: m / z (%): 738.89 (100) [M + ].

[0114] The elemental analysis test results are as follows (%)(C 48 H 39 N2O2PS): C, 78.03; H, 5.32; N, 3.79; O, 4.33; P, 4.19; S, 4.34.

[0115] The ultraviolet, fluorescence, and phosphorescence spectrum tests were performed on compound (I), and the spectrum is shown in Figure 1 .

[0116] Thermogravimetric analysis of compound (I) shows that its cracking temperature is 407℃.

[0117] (3) Preparation of electroluminescent device by using compound (I):

[0118] I. Put the plastic substrate cleaned by deionized water into a vacuum evaporation instrument, the vacuum degree is 1x10 -6 mbar, the evaporation rate is set to 0.1 nm s -1 , and the evaporation material on the glass or plastic substrate is indium tin oxide (ITO) with a thickness of 10 nm anode conductive layer;

[0119] II. Evaporate the hole injection layer material MoO3 on the anode conductive layer to obtain a hole injection layer with a thickness of 10 nm;

[0120] III. Evaporate the hole transport layer material mCP on the hole injection layer to obtain a hole transport layer with a thickness of 30 nm;

[0121] V. Evaporate the light-emitting layer on the hole transport layer, the material is a mixture of compound (I) and DBFDPO, the mass fraction of compound (I) in the mixture is 20%, and the thickness is 50 nm;

[0122] VI. Continue to evaporate the electron transport layer DBFDPO on the light-emitting layer, the thickness of the electron transport layer is 40 nm;

[0123] VIII. Evaporate the electron injection layer material LiF on the electron transport layer to obtain an electron injection layer with a thickness of 10 nm;

[0124] IX. Evaporate aluminum on the electron injection layer to form a cathode conductive layer with a thickness of 100 nm, and obtain device 1.

[0125] The structure of device 1 is: ITO / MoO3(10 nm) / mCP(30 nm) / DBFDPO:(I)(20%)(50 nm) / DBFDPO(40 nm) / LiF(10 nm) / Al.

[0126] The voltage-current density relationship curve of device 1 is shown in Figure 2 , which shows that compound (I) has semiconductor characteristics, and the threshold voltage is 2.7 V.

[0127] The change trend of the brightness of device 1 with voltage shows that the turn-on voltage of the device is 2.7 V.

[0128] The change trend of the current efficiency of device 1 with brightness shows that the current efficiency of device 1 reaches the maximum value of 47 cd·A -2 when the brightness is 54.2 cd·m -1 .

[0129] The trend of the power efficiency of the device 1 with the change of the brightness shows that the device 1 reaches the maximum power efficiency of 55 lm·W -2 when the brightness is 130 cd·m -1 .

[0130] The trend of the external quantum efficiency of the device 1 with the change of the brightness shows that the device 1 reaches the maximum external quantum efficiency of 26.5% when the brightness is 11.6 cd·cm -2 .

[0131] The electroluminescence spectrum of the device 1 shows that the electroluminescence peak of the device 1 is 507 nm.

[0132] Example 2

[0133] (1) 1 mmol of diphenyl sulfide (DPS), 2.4 mmol of n-butyllithium, and 1 mmol of phenyl dichlorophosphine were mixed, and reacted for 16 hours in an ice water bath. After the reaction, 10 ml of water and 10 ml of dichloromethane were used for extraction, and anhydrous sodium sulfate was used for drying. The solvent was spin-dried.

[0134] The obtained solid was dissolved in 10 ml of dichloromethane, and 10-15 mmol of hydrogen peroxide was added under the condition of an ice water bath, and reacted for 4 hours. Then, 10 ml of water and 10 ml of dichloromethane were used for extraction, and anhydrous sodium sulfate was used for drying. The solvent was spin-dried.

[0135] 1 mmol of the obtained solid was placed in a single-neck flask, 4 ml of ice acetic acid, 1.2 ml of concentrated sulfuric acid, and 1 mmol of N-bromosuccinimide (NBS) were added, and reacted for 10 hours at 30°C. After the reaction, the product was poured into an ice water bath, dichloromethane was used for extraction, anhydrous sodium sulfate was used for drying, spin-drying was performed, and column chromatography was performed using EA:PE=2:1 as the eluent.

[0136]

[0137] (2) The compound (II) was prepared according to the method in Example 1, with the difference that the dibromophosphacyclic compound with the above structure was replaced by a monobromophosphacyclic compound with the above structure in an equimolar amount, and the amount of DMAC added was 3 mmol.

[0138]

[0139] The nuclear magnetic resonance test results of the compound (II) are as follows:

[0140] 1H NMR (TMS, CDCl3, 400MHz): δ = 8.529-8.423 (m, 2H), 8.372-8.303 (m, 1H), 8.219-8.157 (m, 1H), 7.917-7.859 (m, 1H), 7. 848-7.792(m,2H),7.580-7.524(m,1H),7.511-7.413(m,6H),7.010-6.946(m,4H),6.272-6.205(m,2H),1.5(s,6H).

[0141] Laser desorption ionization time-of-flight mass spectrometry (LDI-TOF-MS) test results are: m / z (%): 531.61 (100) [M + ].

[0142] The results of elemental analysis are (%) (C 33 H 26 NO2PS): C, 74.56; H, 4.93; N, 2.63; O, 6.02; P, 5.83; S, 6.03.

[0143] The UV, fluorescence and phosphorescence spectra of compound (II) were tested. Figure 3 shown.

[0144] Thermogravimetric analysis of compound (II) showed that its pyrolysis temperature was 366°C.

[0145] Device 2 was prepared according to the method in Example 1. The structure of device 2 was: ITO / MoO3 (10 nm) / mCP (30 nm) / DBFDPO: (II) (20%) (50 nm) / DBFDPO (40 nm) / LiF (10 nm) / Al.

[0146] The voltage-current density relationship curve of test device 2 is as follows: Figure 4 As shown, it can be seen that compound (II) has semiconductor characteristics and its threshold voltage is 2.6V.

[0147] The brightness of device 2 is tested and the voltage changes. It can be seen that the turn-on voltage of the device is 2.7V.

[0148] The variation trend of the current efficiency of device 2 with the brightness is tested. It can be seen that the device 2 has a brightness of 1.05 cd·m -2 When the current efficiency reaches the maximum value of 64.5cd·A -1 .

[0149] The power efficiency of device 2 changes with brightness. It can be seen that device 2 has a brightness of 1.05 cd·m -2 When the power efficiency reaches the maximum value of 75.1lm·W-1 .

[0150] The trend of external quantum efficiency of the testing device 2 with the change of luminance shows that the device 2 obtains the maximum external quantum efficiency 22.0% when the luminance is 1.05 cd·cm -2 .

[0151] The electroluminescent spectrum of the testing device 2 shows that the electroluminescent peak of the device 2 is 503 nm.

[0152] Example 3

[0153] The compound (III) is prepared according to the method in Example 1, with the difference that 6 mmol of 9,9-diphenylacridine (DPAC) is added to replace DMAC.

[0154]

[0155] The nuclear magnetic resonance test results of the compound (III) are as follows:

[0156] 1 H NMR (TMS, CDCl3, 400 MHz): δ = 8.254-8.174 (m, 4H), 7.579-7.539 (m, 3H), 7.483-7.402 (m, 4H), 7.276-7.259 (d, J = 6.8 Hz, 13H), 7.145-7.103 (m, 4H), 7.005-6.964 (q, J1= 1.6 Hz, J2= 7.2 Hz, 16H), 6.516-6.496 (d, J = 8.0 Hz, 3H).

[0157] The laser desorption ionization time-of-flight mass spectrometry (LDI-TOF-MS) test results are as follows: m / z (%): 987.17 (100) [M+].

[0158] The elemental analysis test results (%) are as follows: C 68 H 47 N2O2PS: C, 82.74; H, 4.80; N, 2.84; O, 3.24; P, 3.14; S, 3.254.

[0159] The ultraviolet, fluorescence and phosphorescence spectrum tests are performed on the compound (III), and the spectrum is shown in Figure 5 .

[0160] The thermogravimetric analysis is performed on the compound (III), and the cracking temperature thereof is 445℃.

[0161] Device 3 was prepared according to the method in Example 1. The structure of device 3 was: ITO / MoO3 (10 nm) / mCP (30 nm) / DBFDPO: (III) (20%) (50 nm) / DBFDPO (40 nm) / LiF (10 nm) / Al.

[0162] The voltage-current density relationship curve of test device 3 is as follows: Figure 6 As shown, it can be seen that compound (III) has semiconductor characteristics and its threshold voltage is 2.7V.

[0163] The brightness of device 3 is tested and the voltage changes. It can be seen that the turn-on voltage of the device is 2.7V.

[0164] The variation trend of the current efficiency of device 3 with the brightness is tested. It can be seen that the current efficiency of device 3 is 1.65 cd·m -2 When the current efficiency reaches the maximum value of 70.4cd·A -1 .

[0165] The power efficiency of device 3 is tested with the change of brightness. It can be seen that the power efficiency of device 3 is 1.65 cd·m -2 When the power efficiency reaches the maximum value of 81.2lm·W -1 .

[0166] The external quantum efficiency of device 3 is tested with the change of brightness. It can be seen that device 3 has a brightness of 1.75 cd·m -2 When , the maximum external quantum efficiency of 21.0% is obtained.

[0167] The electroluminescence spectrum of device 3 was tested, and it was found that the electroluminescence peak of device 3 was 506 nm.

[0168] Example 4

[0169] Compound (IV) was prepared according to the method of Example 2, except that an equal molar amount of DPAC was added instead of DMAC.

[0170]

[0171] The NMR test results of compound (IV) are as follows:

[0172] 1H-NMR (TMS, CDCl3, 400MHz): δ=8.479-8.227(m,1H),8.222-7.898(m,2H),7.879-7.557(m,2H),7.552-7.496(m,1H),7.4 92-7.280 (m, 5H), 7.276-7.101 (t, J = 5.6Hz, 7H), 7.095-7.009 (m, 2H), 7.004-6.946 (m, 8H), 6.451-6.431 (d, J = 8.0Hz, 2H).

[0173] Laser desorption ionization time-of-flight mass spectrometry (LDI-TOF-MS) test results are: m / z (%): 655.75 (100) [M + ].

[0174] Elemental analysis test results (%) C 43 H 30 NO2PS: C, 78.76; H, 4.61; N, 2.14; O, 4.88; P, 4.72; S, 4.89.

[0175] The UV, fluorescence and phosphorescence spectra of compound (Ⅳ) were tested. Figure 7 shown.

[0176] Thermogravimetric analysis of compound (Ⅳ) showed that its pyrolysis temperature was 410°C.

[0177] Device 4 was prepared according to the method in Example 3. The structure of device 4 was: ITO / MoO3 (10 nm) / mCP (30 nm) / DBFDPO: (IV) (20%) (50 nm) / DBFDPO (40 nm) / LiF (10 nm) / Al.

[0178] The voltage-current density relationship curve of the test device 4 is as follows: Figure 8 As shown, it can be seen that compound (IV) has semiconductor characteristics and its threshold voltage is 2.6V.

[0179] The brightness of device 4 was tested and the voltage changed. It can be seen that the turn-on voltage of the device is 2.6V.

[0180] The variation trend of the current efficiency of device 4 with the brightness is tested. It can be seen that the device 4 has a brightness of 1.48 cd·m -2 When the current efficiency reaches the maximum value of 89.9cd·A -1 .

[0181] The power efficiency of device 4 is tested with the change of brightness. It can be seen that the device has a brightness of 1.48 cd·m -2 When the power efficiency reaches the maximum value of 108.6lm·W-1 .

[0182] The trend of external quantum efficiency of the tested device 4 with the change of luminance shows that the device obtains the maximum external quantum efficiency 27.2% when the luminance is 1.48 cd·m -2

[0183] The electroluminescent spectrum of the tested device 4 shows that the electroluminescent peak of the device is at 505 nm.

[0184] Example 5

[0185] The compound (V) is prepared according to the method in Example 1, with the difference that the DMAC is replaced by equimolar amount of phenothiazine (PTZ).

[0186]

[0187] The nuclear magnetic resonance test results of the compound (V) are as follows:

[0188] 1 H NMR (TMS, CDCI3, 400 MHz): δ = 8.594 (d, J = 11.6 Hz, 4H), 7.848 (t, J = 11.6 Hz, 4H), 7.610-7.539 (m, 9H), 7.456 (t, J = 8.4 Hz, 5H), 7.345 ppm (d, J = 7.2 Hz, 5H).

[0189] The laser desorption ionization time-of-flight mass spectrometry (LDI-TOF-MS) test results are as follows: m / z (%): 718.84 (100) [M+].

[0190] The elemental analysis test results are as follows (%): C 42 H 27 N2O2PS3: C, 70.18; H, 3.79; N, 3.90; O, 4.45; P, 4.31; S, 13.38.

[0191] The ultraviolet, fluorescence and phosphorescence spectrum tests are performed on the compound (V), and the spectrum is shown in Figure 9 .

[0192] The thermogravimetric analysis is performed on the compound (V), and the cracking temperature thereof is 488°C.

[0193] The device 5 is prepared according to the method in Example 1: ITO / MoO3 (10 nm) / mCP (30 nm) / DBFDPO: (V) (20%) (50 nm) / DBFDPO (40 nm) / LiF (10 nm) / Al.

[0194] The voltage-current density relationship curve of the tested device 5 is as follows​Figure 10 As shown, compound (V) has semiconductor characteristics, and its threshold voltage is 2.6 V.

[0195] The trend of luminance of the device 5 versus voltage is tested, and it is found that the turn-on voltage of the device is 2.6 V.

[0196] The trend of current efficiency of the device 5 versus luminance is tested, and it is found that the current efficiency of the device reaches a maximum value of 65.8 cd·A -2 ·m -1 -1 at a luminance of 1.3 cd·m -2 -2 .

[0197] The trend of power efficiency of the device 5 versus luminance is tested, and it is found that the power efficiency of the device reaches a maximum value of 74.6 lm·W -1 -1 at a luminance of 1.3 cd·m -2 -2 .

[0198] The trend of external quantum efficiency of the device 5 versus luminance is tested, and it is found that the external quantum efficiency of the device reaches a maximum value of 19.9% at a luminance of 1.3 cd·m -2 -2 .

[0199] The electroluminescence spectrum of the device 5 is tested, and it is found that the electroluminescence peak of the device is at 498 nm.

[0200] Example 6

[0201] Compound (VI) is prepared according to the method in Example 2, except that equimolar phenothiazine (PTZ) is used to replace DMAC.

[0202]

[0203] The nuclear magnetic resonance test results of compound (VI) are as follows: 1 H-NMR (TMS, CDCl3, 400 MHz): δ = 7.055-6.969 (m, 7H), 6.855-6.838 (m, 4H), 6.799-6.765 (m, 4H), 6.281-6.262 (d, J = 7.6 Hz, 4H) 5.293 ppm (s, 1H).

[0204] The laser desorption ionization time-of-flight mass spectrometry (LDI-TOF-MS) test results are as follows: m / z (%): 521.07 (100) [M + ].

[0205] The elemental analysis test results (%) C 30 H 20 N02PS2: C, 69.08; H, 3.87; N, 2.69; O, 6.13; P, 5.94; S, 12.29.

[0206] UV, fluorescence and phosphorescence spectra of compound (VI) were tested, and the spectra are shown in Figure 11 .

[0207] Thermogravimetric analysis of compound (VI) showed that the cracking temperature thereof was 478°C.

[0208] Device 6 was prepared according to the method in Example 5: ITO / MoO3(10 nm) / mCP(30 nm) / DBFDPO:(VI)(20%)(50 nm) / DBFDPO(40 nm) / LiF(10 nm) / Al.

[0209] The voltage-current density relationship curve of device 6 was tested, as shown in Figure 12 , and it was found that compound (VI) had semiconductor characteristics, and the threshold voltage thereof was 2.6 V.

[0210] The brightness-voltage trend of device 6 was tested, and it was found that the turn-on voltage of the device was 2.6 V.

[0211] The current efficiency-brightness trend of device 6 was tested, and it was found that the brightness of the device was 1.42 cd·m -2 when the current efficiency reached a maximum value of 65.9 cd·A -1 .

[0212] The power efficiency-brightness trend of device 6 was tested, and it was found that the power efficiency of the device reached a maximum value of 78.1 lm·W -2 when the brightness was 1.42 cd·m -1 .

[0213] The external quantum efficiency-brightness trend of device 6 was tested, and it was found that the maximum external quantum efficiency of 22.7% was obtained when the brightness was 1.42 cd·m -2 .

[0214] The electroluminescence spectrum of device 6 was tested, and it was found that the electroluminescence peak of the device was at 493 nm.

[0215] Example 7

[0216] Compound (VII) was prepared according to the method in Example 1, except that equimolar amount of phenoxazine (PXZ) was added instead of DMAC.

[0217]

[0218] The nuclear magnetic resonance test results of compound (VII) are as follows:

[0219] 1H NMR (TMS, CDC13, 400 MHz): δ = 8.514-8.512 (d, J = 0.8 Hz, 2H), 8.374-8.342 (m, 2H), 7.899-7.879 (d, J = 8 Hz, 2H), 7.592-7.462 (m, 6H), 6.660-6.624 (m, 4H), 6.002-5.982 ppm (d, J = 8 Hz, 4H).

[0220] The result of LDI-TOF-MS test is: m / z (%): 686.72 (100) [M+].

[0221] The result of elemental analysis test (%) C 42 H 27 N2O4PS: C, 73.46; H, 3.96; N, 4.08; O, 9.32; P, 4.51; S, 4.67.

[0222] The UV, fluorescence and phosphorescence spectra of compound (VII) are shown in Figure 13 .

[0223] The thermal gravimetric analysis of compound (VII) shows that its cracking temperature is 429°C.

[0224] Device 7 was prepared according to the method in Example 1: ITO / MoO3 (10 nm) / mCP (30 nm) / DBFDPO: (VII) (20%) (50 nm) / DBFDPO (40 nm) / LiF (10 nm) / Al.

[0225] The voltage-current density relationship curve of device 7 is shown in Figure 14 , which shows that compound (VII) has semiconductor characteristics, and its threshold voltage is 2.5 V.

[0226] The trend of luminance change with voltage of device 7 is tested, which shows that the turn-on voltage of the device is 2.5 V.

[0227] The trend of current efficiency change with luminance of device 7 is tested, which shows that the current efficiency of the device reaches the maximum value of 66.9 cd·A -2 when the luminance is 1.15 cd·m -1 .

[0228] The trend of power efficiency change with luminance of device 7 is tested, which shows that the power efficiency of the device reaches the maximum value of 82.4 lm·W -2 when the luminance is 1.15 cd·m -1 .

[0229] The trend of external quantum efficiency of the testing device 7 with the change of luminance shows that the device obtains the maximum external quantum efficiency 22.1% when the luminance is 1.15 cd·m -2 .

[0230] The electroluminescent spectrum of the testing device 7 shows that the electroluminescent peak of the device is at 504 nm.

[0231] Example 8

[0232] The compound (VIII) is prepared according to the method in Example 2, with the exception that equimolar amount of phenoxazine (PXZ) is added instead of DMAC.

[0233]

[0234] The nuclear magnetic resonance test results of the compound (VIII) are as follows:

[0235] 1H-NMR (TMS, CDCI3, 400 MHz): δ = 8.475-8.424 (m, 2H), 8.333-8.282 (m, 1H), 8.180-8.151 (m, 1H), 7.893-7.813 (m, 3H), 7.683-7.630 (m, 1H), 7.553-7.540 (m, 1H), 7.480-7.429 (m, 3H), 6.792-6.595 (m, 5H), 6.055-6.036 (d, J = 7.6 Hz, 1H), 5.935-5.916 (d, J = 7.6 Hz, 1H), 5.297 ppm (s, 1H).

[0236] The laser desorption ionization time-of-flight mass spectrometry (LDI-TOF-MS) test results are as follows: m / z (%): 505.53 (100) [M + ].

[0237] The elemental analysis test results (%) C 30 H 20 NO3PS: C, 71.28; H, 3.99; N, 2.77; O, 9.49; P, 6.13; S, 6.34.

[0238] The ultraviolet, fluorescence and phosphorescence spectrum tests are performed on the compound (VIII), and the spectrum is shown in Figure 15 .

[0239] The thermogravimetric analysis is performed on the compound (VIII), and the cracking temperature thereof is 369°C.

[0240] Device 8 was prepared according to the method in Example 7: ITO / MoO3(10 nm) / mCP(30 nm) / DBFDPO:(VIII)(20%)(50 nm) / DBFDPO(40 nm) / LiF(10 nm) / Al.

[0241] The voltage-current density relationship curve of device 8 was tested as shown in Figure 16 Figure 6, which shows that compound (VIII) has semiconductor characteristics, and the threshold voltage is 2.5 V.

[0242] The voltage-luminance relationship curve of device 8 was tested, which shows that the turn-on voltage of the device is 2.5 V.

[0243] The current efficiency-luminance relationship curve of device 8 was tested, which shows that the current efficiency reaches the maximum value of 62.7 cd·A -2 when the luminance is 0.92 cd·m -1 .

[0244] The power efficiency-luminance relationship curve of device 8 was tested, which shows that the power efficiency reaches the maximum value of 77.2 lm·W -2 when the luminance is 0.92 cd·m -1 .

[0245] The external quantum efficiency-luminance relationship curve of device 8 was tested, which shows that the maximum external quantum efficiency of 19.3% is obtained when the luminance is 0.92 cd·m -2 .

[0246] The electroluminescence spectrum of device 8 was tested, which shows that the electroluminescence peak of the device is at 497 nm.

[0247] The above detailed description of the application is made in conjunction with specific embodiments and / or exemplary examples and the accompanying drawings, but these descriptions cannot be understood as limiting the application. Those skilled in the art understand that various equivalent substitutions, modifications or improvements can be made to the technical solutions and embodiments of the application without departing from the spirit and scope of the application, and these all fall within the scope of the application. The scope of protection of the application is subject to the appended claims.

Claims

1. A compound based on a sulfur-phosphorus heterocyclic receptor and a nitrogen-containing heterocyclic donor compound, wherein the compound based on a sulfur-phosphorus heterocyclic receptor and a nitrogen-containing heterocyclic donor compound is:

2. A method for preparing a sulfur-phosphorus heterocyclic acceptor and a nitrogen-containing heterocyclic donor compound according to claim 1, characterized in that: The sulfur-phosphorus heterocyclic acceptor and nitrogen-containing heterocyclic donor compound are prepared by carbon-nitrogen coupling reaction of halogenated sulfur-phosphorus heterocyclic compound and nitrogen-containing heterocyclic compound under the action of palladium catalyst. The halogenated sulfur-phosphorus heterocyclic compound is: wherein X1 is independently selected from H, Cl, Br or I; X2 is selected from Cl, Br or I; The nitrogen-containing heterocyclic compound is 9,9-diphenylacridine.

3. A method for preparing a sulfur-phosphorus heterocyclic acceptor and a nitrogen-containing heterocyclic donor compound according to claim 2, characterized in that: X1 is independently selected from H, Cl or Br; X2 is selected from Cl or Br.

4. A method for preparing a sulfur-phosphorus heterocyclic acceptor and a nitrogen-containing heterocyclic donor compound according to claim 2, characterized in that: X1 is each independently selected from H or Br; X2 is selected from Br.

5. A method for preparing the compound according to claim 2, characterized in that: In the method, a halogenated sulfur-phosphorus heterocyclic compound and a nitrogen-containing heterocyclic compound are subjected to a carbon-nitrogen coupling reaction in the presence of a palladium catalyst under an alkaline environment to prepare the compound, wherein the nitrogen-containing heterocyclic compound is 9,9-dimethylacridine.

6. The method according to claim 5, characterized in that The method comprises the following steps: Step 1, preparing a halogenated sulfur-phosphorus heterocyclic compound; Step 2: adding a halogenated sulfur-phosphorus heterocyclic compound, a nitrogen-containing heterocyclic donor compound, a palladium catalyst and an alkaline substance to a reaction solvent, stirring and reacting to obtain a reaction solution; Step 3: post-treating the reaction solution to obtain a sulfur-phosphorus heterocyclic acceptor and a nitrogen-containing heterocyclic donor compound.

7. The method according to claim 6, characterized in that In step 2, The molar ratio of the halogenated sulfur-phosphorus heterocyclic compound to the nitrogen-containing heterocyclic donor compound is 1:(1.5-7.5).

8. The method according to claim 7, characterized in that In step 2, The molar ratio of the halogenated sulfur-phosphorus heterocyclic compound to the nitrogen-containing heterocyclic donor compound is 1:(2.0-7.0).

9. The method according to claim 7, characterized in that In step 2, The molar ratio of the halogenated sulfur-phosphorus heterocyclic compound to the nitrogen-containing heterocyclic donor compound is 1:(2.5-6.5).

10. The method according to claim 6, characterized in that In step 2, the molar ratio of the halogenated sulfur-phosphorus heterocyclic compound to the nitrogen-containing heterocyclic donor compound is 1:6 or 1:

3.

11. The method according to claim 6, characterized in that In step 2, the palladium catalyst is selected from palladium salts, palladium carbon, inorganic oxide-supported palladium, and palladium complexes.

12. The method according to claim 11, characterized in that In step 2, the palladium salt is palladium chloride or palladium acetate, the inorganic oxide-supported palladium is Pd / Al2O3 or Pd / MgO, and the palladium complex is Pd(AsPh3)4, di(tri-tert-butylphosphine)palladium, tetrakis(triphenylphosphine)palladium or Pd((MeO)3P)4.

13. The method according to claim 11, characterized in that In step 2, the palladium catalyst is selected from a palladium salt or a palladium complex.

14. The method according to claim 11, characterized in that In step 2, the palladium catalyst is selected from palladium acetate and / or di(tri-tert-butylphosphine)palladium.

15. The method according to claim 6, characterized in that In step 2, the alkaline substance is selected from one or more of alkali metal hydroxides, potassium alcoholates and sodium alcoholates.

16. The method according to claim 15, characterized in that In step 2, the alkaline substance is selected from one or more of NaOH, KOH, potassium tert-butoxide and sodium tert-butoxide.

17. The method according to claim 6, characterized in that In step 2, the alkaline substance is selected from potassium tert-butoxide and / or sodium tert-butoxide.

18. A use of a sulfur-phosphorus heterocyclic acceptor and a nitrogen-containing heterocyclic donor compound according to any one of claims 1 to 3, characterized in that: It is used as a light-emitting layer material to prepare electroluminescent devices. The current efficiency of the electroluminescent device reaches a maximum of 70-90 cd·A at the luminescence peak of 500-510 nm. -1 , the power efficiency reaches a maximum of 80-109lm·W -1 , the maximum external quantum efficiency reaches 20-28%, and the turn-on voltage is lower than 3V.

19. The use according to claim 18, characterized in that The start voltage is 2.6V.

20. An electroluminescent device, characterized in that: The light-emitting layer material of the electroluminescent device comprises the sulfur-phosphorus heterocyclic acceptor and nitrogen-containing heterocyclic donor compound according to any one of claims 1 to 3.

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