Spiro structure-containing compound, electron transport material and organic electroluminescent device

Abstract

The invention discloses a spiro structure-containing compound, an electron transport material and an organic electroluminescent device, and belongs to the technical field of organic electroluminescence. The chemical structural formula of the compound is as follows: # imgabs0, benzonitrile group or pyridyl is introduced into the compound, nitrogen-containing six-membered heterocycles such as pyridine, pyrimidine or triazine and electron withdrawing groups such as quinoline are combined, and the groups have a synergistic effect, so that the electron mobility of the compound is increased. Moreover, benzonitrile groups and pyridyl groups contain lone pair electrons, intermolecular hydrogen bonds can be formed, and the stability of the compound can be improved by combining with indole spirofluorene groups. Due to the characteristics, the compound can be applied to an organic electronic electroluminescent device, particularly to an electron transport functional layer, so that the current efficiency and external quantum efficiency of the organic electroluminescent device are improved, the working voltage is reduced, and the service life of the device is prolonged.

Description

Technical Field

[0001] The present application relates to the technical field of organic electroluminescence, and in particular to a spiro-structure-containing compound, an electron transport material and an organic electroluminescent device. Background Art

[0002] Organic electroluminescent devices (OLEDs) are widely used in mobile phones, flat-panel displays, televisions, lighting, and automotive displays due to their advantages such as active luminescence, short response time, high color contrast, and low energy consumption.

[0003] The working principle of organic electroluminescent devices is that holes and electrons injected through the electrode recombine in the light-emitting layer to form excitons, and emit light when the excitons return to the ground state. Organic electroluminescent devices generally adopt a sandwich structure, that is, the organic layer is sandwiched between the anode and the cathode on both sides. The organic layer is divided into a hole transport layer, an electron transport layer, a light-emitting layer, a hole blocking layer and an electron blocking layer according to the different photoelectric properties of various materials. Among them, the electron transport material in the electron transport layer is a material that transfers electrons from the cathode to the light-emitting layer, and is an important component of the organic electroluminescent device. Since most organic compounds transfer holes faster than electrons, this makes the number of electrons and holes in the light-emitting layer unbalanced, resulting in luminescence quenching and affecting the performance of the device. Therefore, the development of organic compounds with high electron mobility has become a focus of research. Summary of the invention

[0004] The embodiments of the present application provide a spiro-structured compound, an electron transport material, and an organic electroluminescent device. The compound has a high electron mobility, can improve the current efficiency and external quantum efficiency of the organic electroluminescent device, reduce the operating voltage, and extend the service life of the device. The technical solution is as follows:

[0005] In one aspect, a spiro-containing compound is provided, wherein the compound is applied to an organic electroluminescent device, and the chemical structure of the compound is as follows:

[0006]

[0007] Among them, R1-R 13 Each independently represents one of the following: hydrogen, halogen, cyano, alkyl having 1 to 12 carbon atoms, alkoxy having 1 to 8 carbon atoms, substituted or unsubstituted aryl having 6 to 30 carbon atoms, substituted or unsubstituted heteroaryl having 3 to 30 carbon atoms, triarylamine, carbazolyl, triarylphosphinyl;

[0008] Ar1 represents one of the following: a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaryl group having 3 to 30 carbon atoms;

[0009] Ar2 represents one of the following: substituted or unsubstituted pyridyl, substituted or unsubstituted benzonitrile;

[0010] L1 represents a single bond or a phenylene group;

[0011] L2 represents one of the following: a substituted or unsubstituted arylene group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroarylene group having 3 to 30 carbon atoms;

[0012] n is 1, 2, 3, 4 or 5;

[0013] There is at least one nitrogen atom in Z1-Z3, and the rest are carbon atoms.

[0014] In one possible implementation, R1-R 13 Each independently represents one of the following: hydrogen, methyl, ethyl, propyl, isopropyl, tert-butyl, cyclohexyl, adamantyl, phenyl, tolyl, biphenyl.

[0015] In another possible implementation, Ar1 is represented by one of the following: a phenyl group having 6 to 30 carbon atoms, a naphthyl group having 6 to 30 carbon atoms, a fluorenyl group having 6 to 30 carbon atoms, a dibenzothiophenyl group having 6 to 30 carbon atoms, a dibenzofuranyl group having 6 to 30 carbon atoms, a phenanthryl group having 6 to 30 carbon atoms, a fluoranthene group having 6 to 30 carbon atoms, an anthracene group having 6 to 30 carbon atoms, a naphthyl group having 6 to 30 carbon atoms, a biphenyl group having 6 to 30 carbon atoms, or a pyridyl group having 5 to 30 carbon atoms.

[0016] In another possible implementation, Z1, Z2, and Z3 are all nitrogen atoms.

[0017] In another possible implementation, L1 is a single bond, and the connection site with the fluorenyl group is the second site or the third site.

[0018] In another possible implementation, L2 is a phenylene group.

[0019] In another possible implementation, n is 1 or 2.

[0020] In another aspect, an electron transport material is provided, wherein the electron transport material comprises any one of the compounds described above.

[0021] In another aspect, an organic electroluminescent device is provided, the organic electroluminescent device comprising: an anode, a cathode and an organic layer;

[0022] The organic layer includes a hole transport unit, a light emitting layer and an electron transport unit, wherein at least one of the hole transport unit, the light emitting layer and the electron transport unit contains any one of the above compounds.

[0023] In a possible implementation, the electron transport unit includes at least one of a hole blocking layer and an electron transport layer;

[0024] At least one of the hole blocking layer and the electron transporting layer contains the compound.

[0025] The present application embodiment provides a compound containing a spiro structure, which introduces a benzonitrile or pyridyl group, and then combines nitrogen-containing six-membered heterocycles such as pyridine, pyrimidine or triazine, and electron-withdrawing groups such as quinoline, and these groups work synergistically to increase the electron mobility of the compound. In addition, the benzonitrile and pyridyl groups contain lone pairs of electrons, which can form hydrogen bonds between molecules, and combined with the indole spirofluorene group, the stability of the compound can be increased. The above characteristics of the compound enable it to be applied to organic electronic electroluminescent devices, especially to electron transport functional layers, thereby improving the current efficiency and external quantum efficiency of organic electroluminescent devices, reducing the operating voltage, and extending the service life of the device.

[0026] It is to be understood that the foregoing general description and the following detailed description are exemplary only and are not restrictive of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the structure of an organic electroluminescent device provided in an embodiment of the present application.

[0028] The reference numerals represent:

[0029] 110-glass substrate, 120-anode, 130-hole injection layer, 140-hole transport layer, 150-electron blocking layer,

[0030] 160 - light-emitting layer, 170 - hole blocking layer, 180 - electron transport layer, 190 - electron injection layer, 200 - cathode. DETAILED DESCRIPTION

[0031] In order to make the technical solutions and advantages of the present application clearer, the implementation methods of the present application are described in further detail below.

[0032] In a first aspect, an embodiment of the present application provides a compound containing a spiro structure, which is applied to an organic electroluminescent device. The chemical structure of the compound is as follows:

[0033]

[0034] Among them, R1-R 13 Each independently represents one of the following: hydrogen, halogen, cyano, alkyl having 1 to 12 carbon atoms, alkoxy having 1 to 8 carbon atoms, substituted or unsubstituted aryl having 6 to 30 carbon atoms, substituted or unsubstituted heteroaryl having 3 to 30 carbon atoms, triarylamine, carbazolyl, triarylphosphinyl;

[0035] Ar1 represents one of the following: a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaryl group having 3 to 30 carbon atoms;

[0036] Ar2 represents one of the following: substituted or unsubstituted pyridyl, substituted or unsubstituted benzonitrile;

[0037] L1 represents a single bond or a phenylene group;

[0038] L2 represents one of the following: a substituted or unsubstituted arylene group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroarylene group having 3 to 30 carbon atoms;

[0039] n is 1, 2, 3, 4 or 5;

[0040] There is at least one nitrogen atom in Z1-Z3, and the rest are carbon atoms.

[0041] The present application embodiment provides a compound containing a spiro structure, which introduces a benzonitrile or pyridyl group, and then combines nitrogen-containing six-membered heterocycles such as pyridine, pyrimidine or triazine, and electron-withdrawing groups such as quinoline, and these groups work synergistically to increase the electron mobility of the compound. In addition, the benzonitrile and pyridyl groups contain lone pairs of electrons, which can form hydrogen bonds between molecules, and combined with the indole spirofluorene group, the stability of the compound can be increased. The above characteristics of the compound enable it to be applied to organic electronic electroluminescent devices, especially to electron transport functional layers, thereby improving the current efficiency and external quantum efficiency of organic electroluminescent devices, reducing the operating voltage, and extending the service life of the device.

[0042] For R1-R 13 , preferably, R1-R 13 Each of them can be independently represented by one of the following: hydrogen, methyl, ethyl, propyl, isopropyl, tert-butyl, cyclohexyl, adamantyl, phenyl, tolyl, biphenyl.

[0043] One thing that needs to be explained is that R1-R 13Each independently represents one of the following: hydrogen, methyl, ethyl, propyl, isopropyl, tert-butyl, cyclohexyl, adamantyl, phenyl, tolyl, biphenyl, means that R1 is one of the following: hydrogen, methyl, ethyl, propyl, isopropyl, tert-butyl, cyclohexyl, adamantyl, phenyl, tolyl, biphenyl, R2 is one of the following: hydrogen, methyl, ethyl, propyl, isopropyl, tert-butyl, cyclohexyl, adamantyl, phenyl, tolyl, biphenyl, R3 is one of the following: hydrogen, methyl, ethyl, propyl, isopropyl, tert-butyl, cyclohexyl, adamantyl, phenyl, tolyl, biphenyl, and so on, until R 13 The same is true for other similar expressions in this application and will not be repeated here.

[0044] In the embodiment of the present application, when R1~R 13 When each of them is the above substituent, the steric stability of the indole spirofluorene group can be increased, thereby increasing the stability of the compound and further extending the service life of the organic electroluminescent device.

[0045] For Ar1, preferably, Ar1 can be represented by one of the following: a substituted or unsubstituted phenyl group having 6 to 30 carbon atoms, a substituted or unsubstituted naphthyl group having 6 to 30 carbon atoms, a substituted or unsubstituted fluorenyl group having 6 to 30 carbon atoms, a substituted or unsubstituted dibenzothiophenyl group having 6 to 30 carbon atoms, a substituted or unsubstituted dibenzofuranyl group having 6 to 30 carbon atoms, a substituted or unsubstituted phenanthryl group having 6 to 30 carbon atoms, a substituted or unsubstituted fluoranthene group having 6 to 30 carbon atoms, anthracene group having 6 to 30 carbon atoms, a substituted or unsubstituted naphthyl group having 6 to 30 carbon atoms, a substituted or unsubstituted biphenyl group having 6 to 30 carbon atoms, or a substituted or unsubstituted pyridyl group having 5 to 30 carbon atoms.

[0046] In the embodiment of the present application, when Ar1 is the above-mentioned substituent, the steric stability of the nitrogen-containing six-membered heterocycle such as pyridine, pyrimidine or triazine can be increased, thereby increasing the stability of the compound and further extending the service life of the organic electroluminescent device.

[0047] As for Z1-Z3, preferably, Z1, Z2, and Z3 are all nitrogen atoms.

[0048] In the embodiment of the present application, when Z1, Z2, and Z3 are all nitrogen atoms, the group they belong to is a triazine group, which acts synergistically with other groups to increase the electron mobility of the compound, and can also reduce the LUMO (Lowest Unoccupied Molecular Orbital) energy level of the compound, thereby improving the charge injection capability, thereby reducing the operating voltage of the organic electroluminescent device and improving the current efficiency and external quantum efficiency.

[0049] As for L1, preferably, L1 is a single bond, and the connection site with the fluorenyl group is the second site or the third site.

[0050] In the embodiments of the present application, the nitrogen-containing six-membered heterocyclic ring such as pyridine, pyrimidine or triazine can be connected to any site on the fluorenyl group through a single bond, preferably the second site or the third site of the fluorenyl group. When the connection site is the second site or the third site of the fluorenyl group, the planarity of the compound can be more effectively increased, thereby improving the luminous efficiency of the organic electroluminescent device.

[0051] As for L2, preferably, L2 is a phenylene group.

[0052] In the embodiments of the present application, the benzonitrile group and the nitrogen-containing six-membered heterocyclic ring such as pyridine, pyrimidine or triazine are connected by a phenylene group, which can increase the electron mobility of the compound, reduce the LUMO energy level of the compound, and enhance the charge injection capability, thereby reducing the operating voltage of the organic electroluminescent device and improving the current efficiency and external quantum efficiency.

[0053] As for n, preferably, n is 1 or 2.

[0054] In the embodiments of the present application, when n is 1 or 2, the stability of the compound can be increased, thereby extending the service life of the organic electroluminescent device. When n is large, that is, the number of benzonitrile groups or pyridine groups is too large, the sublimation temperature of the compound will be increased, and long-term high-temperature sublimation will reduce the heat resistance of the compound, and the temperature is too high and is not suitable for production.

[0055] It should be noted that the hydrogen atoms in the embodiments of the present application and the hydrogen atoms contained in the aromatic groups include isotopes with different numbers of neutrons, namely protium, deuterium and tritium.

[0056] In the embodiments of the present application, the compound containing a spiro structure is any one of the following structural formulas 1-111.

[0057]

[0058]

[0059]

[0060]

[0061]

[0062]

[0063]

[0064] The compound of the above chemical formula provided in the present application can be prepared by the following method 1 or 2. Method 1:

[0065]

[0066] Method 2:

[0067]

[0068] Method 1 and Method 2 It can be prepared as follows:

[0069]

[0070] Among them, X, X1, X2 and X3 are all halogens, specifically chlorine, bromine and iodine; other substituents are the same as those in the chemical structural formula of the compound.

[0071] In the embodiments of the present application, both Method 1 and Method 2 are based on the Suzuki reaction to prepare compounds, wherein the specific preparation process of Method 1 can refer to the preparation process of compound 10 in the following Example 1, and the specific preparation process of Method 2 can refer to the preparation process of compound 52 in the following Example 6. For details, see Examples 1 and 6, which will not be repeated here.

[0072] In a second aspect, an embodiment of the present application provides an electron transport material, which includes the compound provided above.

[0073] Wherein, when the electron transport material includes the compound provided in the present application, it may be doped with an organic metal complex, and the doping amount of the organic metal complex is 20 wt % to 70 wt %.

[0074] The organic metal complex may be 8-hydroxyquinoline lithium or other compounds, which are not specifically limited.

[0075] The compound provided by the present application introduces a benzonitrile group or a pyridyl group, and then combines a nitrogen-containing six-membered heterocyclic ring such as pyridine, pyrimidine or triazine, and an electron-withdrawing group such as quinoline. These groups work synergistically to increase the electron mobility of the compound. Therefore, using the compound as an electron transport material can improve the efficiency of electron transport to the light-emitting layer, thereby improving the performance of the organic electroluminescent device.

[0076] The above electron transport material can be used to prepare an electron transport layer, and can also be used to prepare a hole blocking layer.

[0077] In a third aspect, an embodiment of the present application provides an organic electroluminescent device, the organic electroluminescent device comprising: an anode, a cathode and an organic layer;

[0078] The organic layer includes a hole transport unit, a light emitting layer and an electron transport unit, wherein at least one of the hole transport unit, the light emitting layer and the electron transport unit contains the compound provided above.

[0079] In the embodiment of the present application, when the hole transport unit in the organic layer contains the compound provided above, the compound can transport holes to the light-emitting layer, thereby improving the hole transport rate. When the electron transport unit in the organic layer contains the compound provided above, the compound can transport electrons to the light-emitting layer, thereby improving the electron transport rate. When the light-emitting layer in the organic layer contains the compound provided above, it is conducive to the recombination of electrons and holes to form excitons, thereby emitting light.

[0080] Among them, the hole transport unit is selected from at least one of a hole injection layer, a hole transport layer, and an electron blocking layer, and the electron transport unit is selected from at least one of a hole blocking layer, an electron transport layer, and an electron injection layer.

[0081] In a possible implementation, the electron transport unit includes a hole blocking layer, and the hole blocking layer contains the above compound.

[0082] In this implementation, when the hole blocking layer contains the above compound, the compound can block holes from entering the electron transport layer while transporting electrons, thereby improving the electron transport rate.

[0083] In a possible implementation, the electron transport unit includes an electron transport layer, and the electron transport layer contains the above compound.

[0084] In this implementation, when the electron transport layer contains the above compound, electrons are mainly transported through the compound, thereby improving the electron transport rate. In the embodiment of the present application, only the application of the compound to the electron transport layer is used as an example for description.

[0085] In a possible implementation, the organic layer includes a light-emitting layer, and the light-emitting layer includes a light-emitting main material and a light-emitting doping material. By changing the light-emitting main material, the emission of various required lights can be adjusted so that the light-emitting layer has good light-emitting characteristics.

[0086] Among them, the light-emitting layer may include one or more of the following compounds, such as: naphthalene compounds, pyrene compounds, fluorene compounds, phenanthrene compounds, chrysene compounds, fluoranthene compounds, anthracene compounds, pentacene compounds, perylene compounds, diarylethene compounds, triphenylamine vinyl compounds, amine compounds, carbazole compounds, benzimidazole compounds, furan compounds, metal organic fluorescent complexes, metal organic phosphorescent complexes (such as Ir, Pt, Os, Cu, Au), boron nitrogen compounds, polyvinyl carbazole, polysilicon compounds, polythiophene, etc. The light-emitting layer may also include other compounds, which are not specifically limited.

[0087] In a possible implementation, the total thickness of the organic layer is 1 to 1000 nm. Preferably, the total thickness of the organic layer is 50 to 500 nm.

[0088] In the embodiment of the present application, each layer of the organic layer can be prepared by vacuum evaporation, molecular beam evaporation, solvent dip coating, spin coating, rod coating or inkjet printing, and the metal electrode can be prepared by evaporation or sputtering.

[0089] The organic electronic materials containing the above compounds provided in the embodiments of the present application can be used not only in organic electroluminescent devices, but also in organic solar cells, organic thin film transistors, organic photodetectors, organic field effect transistors, organic integrated circuits and organic photoreceptors.

[0090] In order to make the technical solutions and advantages of the present application more clear, they will be described in detail through specific embodiments below.

[0091] In the following specific examples, the operations involved, if the conditions are not specified, are all carried out under conventional conditions or conditions recommended by the manufacturer. The raw materials used, if the manufacturers and specifications are not specified, are all conventional products that can be obtained from the market.

[0092] The intermediates or products synthesized in the following specific examples were separated by column chromatography and then analyzed by nuclear magnetic resonance ion mass spectrometry ( 1 HNMR), high resolution mass spectrometer ( 1 HRMS) was used for molecular structure characterization.

[0093] Example 1

[0094] Compound 10 was synthesized. The synthetic route is as follows:

[0095]

[0096] Step 1: Synthesis of intermediate 10-1

[0097] 2-Bromospiro[fluorene-9,10'-indole[1,2-a]indole] (10.0 g, 23.02 mmol), bipyraclostrobin (7.0 g, 27.57 mmol), potassium acetate (6.7 g, 68.27 mmol) and anhydrous toluene (100 mL) were added to a three-necked flask, and bis(triphenylphosphine)palladium chloride (0.2 g, 0.28 mmol) was added under nitrogen protection. After reflux reaction for 5 hours, the mixture was filtered while hot, concentrated to a viscous state, cooled and filtered, washed with ethanol, and dried to obtain 9.7 g of an off-white product with a yield of 87%.

[0098] The NMR data of intermediate 10-1 are as follows: 1HNMR (400MHz, CDCl3)d:7.83-7.85(m, 1H), 7.69-7.73(m, 2H), 7.49-7.51(m, 1H), 7.28-7.43(m, 10H), 7.00-7.02(m, 1H), 6.37-6.38(m, 1H), 1.27(s, 12H).

[0099] Step 2: Synthesis of compound 10

[0100] 3'-(4-chloro-6-phenyl-1,3,5-triazine-2-yl)-[1,1'-biphenyl]-4-carbonitrile (1.0 g, 2.71 mmol), intermediate 10-1 (1.37 g, 2.85 mmol) and potassium carbonate (0.56 g, 4.05 mmol) were added to a three-necked flask, and toluene (10 mL), tetrahydrofuran (5 mL) and deionized water (5 mL) were added. Di(triphenylphosphine)palladium chloride (0.02 g, 0.028 mmol) was added under nitrogen protection. After reflux reaction for 8 hours, the reaction was complete. The solid was cooled and precipitated, filtered, washed with ethanol, and the crude product was separated by column chromatography with PE / DCM=1 / 1 as the eluent. The product was concentrated to dryness and dried to obtain 1.3 g of a white solid with a yield of 70%.

[0101] The NMR data of compound 10 are as follows: 1 HNMR (400MHz, CDCl3)d:8.23-8.24(m, 1H), 8.17-8.21(m, 3H), 7.99-8.01(m, 1H), 7.89-7.91(m, 1H), 7.83-7.85(m, 2H ), 7.73-7.75(m, 2H), 7.66-7.70(m, 4H), 7.47-7.51(m, 2H), 7.27-7.44(m, 11H), 6.96-6.98(m, 1H), 6.28-6.29(m, 1H).

[0102] Mass spectral data are as follows: HRMS (ESI, m / z): [M+H] + :Theoretical value:C 49 H 30 N5, 688.2496, experimental value: 688.2499. Theoretical calculation of the mass fraction of each element (%): C, 85.57; H, 4.25; N, 10.18; actual analysis of the mass fraction of each element (%): C, 85.61; H, 4.20; N, 10.19.

[0103] Example 2

[0104] Compound 13 was synthesized. The synthetic route is as follows:

[0105]

[0106] The synthesis method was the same as compound 10, with a yield of 75%.

[0107] The NMR data of compound 13 are as follows: 1 HNMR(400MHz, CDCl3)d:8.17-8.20(m,2H),7.98-8.01(m,3H),7.89-7.91(m,1H),7.83-7.85(m,2H),7.73-7 .76(m, 2H), 7.64-7.69(m, 5H), 7.47-7.49(m, 1H), 7.27-7.43(m, 11H), 6.96-6.98(m, 1H), 6.29-6.30(m, 1H).

[0108] The mass spectrum data are as follows: HRMS (ESI, m / z): [M+H] + :Theoretical value:C 49 H 30 N5, 688.2496, experimental value: 688.2494. Theoretical calculation of the mass fraction of each element (%): C, 85.57; H, 4.25; N, 10.18; actual analysis of the mass fraction of each element (%): C, 85.46; H, 4.29; N, 10.25.

[0109] Example 3

[0110] Compound 28 was synthesized. The synthetic route is as follows:

[0111]

[0112] Step 1: Synthesis of intermediate 28-1

[0113] The synthesis method is the same as that of intermediate 10-1, with a yield of 89%.

[0114] The NMR data of intermediate 28-1 are as follows: 1 HNMR (400MHz, CDCl3)d:7.82-7.83(m, 1H), 7.67-7.71(m, 2H), 7.57-7.58(m, 1H), 7.50-7.51(m, 1H), 7.28-7.40(m, 8H), 7.17-7.18(m, 1H), 7.00-7.02(m, 1H), 6.44-6.45(m, 1H), 1.27(s, 12H).

[0115] Step 2: Synthesis of compound 28

[0116] The synthesis method was the same as compound 10, and the yield of compound 28 was 68%.

[0117] The NMR data of compound 28 are as follows: 1 HNMR (400MHz, CDCl3)d: 8.17-8.20 (m, 2H), 8.05-8.06 (m, 1H), 7.98-8.00 (m, 3H), 7.73-7.76 (m, 3H ), 7.64-7.69(m, 5H), 7.47-7.49(m, 1H), 7.27-7.44(m, 12H), 6.96-6.98(m, 1H), 6.23-6.24(m, 1H).

[0118] The mass spectrum data are as follows: HRMS (ESI, m / z): [M+H] + :Theoretical value:C 49 H 30 N5, 688.2496, experimental value: 688.2495. Theoretical calculation of the mass fraction of each element (%): C, 85.57; H, 4.25; N, 10.18; Actual analysis of the mass fraction of each element (%): C, 85.55; H, 4.30; N, 10.15.

[0119] Example 4

[0120] Compound 30 was synthesized. The synthetic route is as follows:

[0121]

[0122] The synthesis method was the same as compound 10, with a yield of 77%.

[0123] The NMR data of compound 30 are as follows: 1 HNMR (400MHz, CDCl3)d:8.17-8.24(m, 4H), 8.04-8.05(m, 1H), 7.98-8.00(m, 1H), 7.73-7.76(m, 3H ), 7.66-7.70 (m, 4H), 7.47-7.51 (m, 2H), 7.27-7.44 (m, 12H) 6.96-6.98 (m, 1H), 6.23-6.24 (m, 1H).

[0124] The mass spectrum data are as follows: HRMS (ESI, m / z): [M+H] + :Theoretical value:C 49 H 30 N5, 688.2496, experimental value: 688.2491. Theoretical calculation of the mass fraction of each element (%): C, 85.57; H, 4.25; N, 10.18; actual analysis of the mass fraction of each element (%): C, 85.68; H, 4.17; N, 10.15.

[0125] Example 5

[0126] Compound 37 was synthesized. The synthetic route is as follows:

[0127]

[0128] Step 1: Synthesis of intermediate 37-1

[0129] The synthesis method is the same as that of intermediate 10-1, with a yield of 89%.

[0130] The NMR data of intermediate 28-1 are as follows: 1 HNMR (400MHz, CDCl3)d:7.67-7.71(m, 2H), 7.50-7.51(m, 1H), 7.45-7.46(m, 1H), 7.34-7.41(m, 5H), 7.29 -7.32(m, 3H), 7.20-7.23(m, 1H), 6.97-6.98(m, 1H), 6.89-6.91(m, 1H), 6.37-6.38(m, 1H), 1.27(s, 12H).

[0131] Step 2: Synthesis of compound 37

[0132] The synthesis method was the same as compound 10, and the yield of compound 37 was 68%.

[0133] The NMR data of compound 37 are as follows: 1 HNMR (400MHz, CDCl3)d:8.17-8.20(m, 2H), 7.95-8.01(m, 3H), 7.73-7.75(m, 2H ), 7.62-7.69(m, 7H), 7.27-7.49(m, 12H), 7.07-7.09(m, 2H), 6.28-6.29(m, 1H).

[0134] Mass spectral data are as follows: HRMS (ESI, m / z): [M+H] + :Theoretical value: C 49 H 30 N5, 688.2496, experimental value: 688.2496. Theoretical calculation of the mass fraction of each element: C, 85.57; H, 4.25; N, 10.18; the actual analysis of the mass fraction of each element: C, 85.60; H, 4.33; N, 10.07.

[0135] Example 6

[0136] Compound 52 was synthesized. The synthetic route is as follows:

[0137]

[0138] Step 1: Synthesis of intermediate 52-1

[0139] The synthesis method was the same as compound 10, with a yield of 85%.

[0140] The NMR data of intermediate 52-1 are as follows: 1 HNMR (400MHz, CDCl3)d:8.17-8.21(m, 3H)), 7.99-8.01(m, 1H), 7.89-7.91(m, 1H), 7.83-7.85(m, 2H), 7.77-7 .78(m, 1H), 7.66-7.69(m, 1H), 7.54-7.57(m, 1H), 7.29-7.49(m, 13H), 6.96-6.98(m, 1H), 6.28-6.29(m, 1H).

[0141] Step 2: Synthesis of compound 52

[0142] Intermediate 52-1 (1.0 g, 1.61 mmol), 3-pyridineboronic acid (0.24 g, 1.95 mmol) and potassium carbonate (0.33 g, 2.39 mmol) were added to a three-necked flask, and then toluene (10 mL), tetrahydrofuran (5 mL) and deionized water (5 mL) were added. Palladium acetate (0.02 g, 0.089 mmol) and X-phos (0.04 g, 0.084 mmol) were added under nitrogen protection. After reflux reaction for 8 hours, the reaction was complete. The solid was cooled and precipitated, filtered, washed with ethanol, and the crude product was separated by column chromatography with EA / DCM=1 / 10 as the eluent. The product was concentrated to dryness and dried to obtain 0.85 g of a white solid with a yield of 79%.

[0143] The NMR data of compound 52 are as follows: 1 HNMR (400MHz, CDCl3)d: 8.98-8.99 (m, 1H), 8.63-8.64 (m, 1H), 8.24-8.28 (m, 2H), 8.17-8.20 (m, 2H), 7.99-8.02 (m, 2H), 7.89-7 .91 (m, 1H), 7.83-7.85 (m, 2H), 7.66-7.71 (m, 2H), 7.47-7.50 (m, 2H), 7.28-7.44 (m, 12H), 6.96-6.98 (m, 1H), 6.28-6.29 (m, 1H).

[0144] Mass spectral data are as follows: HRMS (ESI, m / z): [M+H] + :Theoretical value: C 47 H 30N5, 664.2496, experimental value: 664.2494. Theoretical calculation of the mass fraction of each element: C, 85.05; H, 4.40; N, 10.55; the actual analysis of the mass fraction of each element: C, 85.12; H, 4.34; N, 10.54.

[0145] Example 7

[0146] Compound 53 was synthesized. The synthetic route is as follows:

[0147]

[0148] The synthesis method was the same as compound 52, with a yield of 81%.

[0149] The NMR data of compound 53 are as follows: 1 HNMR (400MHz, CDCl3)d: 8.79-8.80 (m, 2H), 8.17-8.23 (m, 4H), 7.99-8.01 (m, 1H), 7.89-7.91m, 1H), 7.83-7.85 (m, 2H), 7.71-7. 74 (m, 3H), 7.66-7.69 (m, 1H), 7.55-7.57 (m, 1H), 7.47-7.49 (m, 1H), 7.28-7.44 (m, 11H), 6.96-6.98 (m, 1H), 6.29-6.30 (m, 1H).

[0150] Mass spectral data are as follows: HRMS (ESI, m / z): [M+H] + :Theoretical value: C 47 H 30 N5, 664.2496, experimental value: 664.2497. Theoretical calculation of the mass fraction of each element: C, 85.05; H, 4.40; N, 10.55; the actual analysis of the mass fraction of each element: C, 85.01; H, 4.38; N, 10.61.

[0151] Example 8

[0152] Compound 55 was synthesized. The synthetic route is as follows:

[0153]

[0154] The synthesis method was the same as compound 52, with a yield of 77%.

[0155] The NMR data of compound 55 are as follows: 1HNMR (400MHz, CDCl3)d: 8.67-8.68 (m, 1H), 8.27-8.31 (m, 2H), 8.19-8.22 (m, 2H), 7.99-8.01 (m, 1H), 7.89-7.91 (m, 1H), 7.83-7 .85 (m, 1H), 7.77-7.80 (m, 3H), 7.65-7.67 (m, 1H), 7.49-7.50 (m, 1H), 7.28-7.46 (m, 18H), 7.00-7.02 (m, 1H), 6.29-6.30 (m, 1H).

[0156] Mass spectral data are as follows: HRMS (ESI, m / z): [M+H] + :Theoretical value: C 53 H 34 N5, 740.2809, experimental value: 740.2811. Theoretical calculation of the mass fraction of each element: C, 86.04; H, 4.50; N, 9.46; actual analysis of the mass fraction of each element: C, 86.06; H, 4.45; N, 9.49.

[0157] Example 9

[0158] Compound 64 was synthesized. The synthetic route is as follows:

[0159]

[0160] Step 1: Synthesis of intermediate 64-1

[0161] The synthesis method was the same as compound 10, with a yield of 88%.

[0162] The NMR data of intermediate 64-1 are as follows: 1 HNMR (400MHz, CDCl3)d: 8.17-8.21 (m, 3H), 8.04-8.05 (m, 1H), 7.98-8.00 (m, 1H), 7.74-7.78 (m, 2H), 7.66-7 .69 (m, 1H), 7.54-7.57 (m, 1H), 7.47-7.49 (m, 1H), 7.29-7.46 (m, 13H), 6.96-6.98 (m, 1H), 6.23-6.24 (m, 1H).

[0163] Step 2: Synthesis of compound 64

[0164] The synthesis method was the same as compound 52, with a yield of 74%.

[0165] The NMR data of compound 64 are as follows: 1HNMR (400MHz, CDCl3)d: 8.98-8.99 (m, 1H), 8.63-8.64 (m, 1H), 8.24-8.28 (m, 2H), 8.17-8.20 (m, 2H), 7.98-8.05 (m, 3H ), 7.74-7.76(m, 1H), 7.66-7.71(m, 2H), 7.47-7.50(m, 2H), 7.28-7.44(m, 13H), 6.96-6.98(m, 1H), 6.23-6.24(m, 1H).

[0166] Mass spectral data are as follows: HRMS (ESI, m / z): [M+H] + :Theoretical value: C 47 H 30 N5, 664.2496, experimental value: 664.2498. Theoretically calculated mass fractions of each element: C, 85.05; H, 4.40; N, 10.55; actual analysis of the mass fractions of each element: C, 84.99; H, 4.44; N, 10.57.

[0167] Example 10

[0168] Compound 65 was synthesized. The synthetic route is as follows:

[0169]

[0170] The synthesis method was the same as compound 52, with a yield of 79%.

[0171] The NMR data of compound 65 are as follows: 1 HNMR (400MHz, CDCl3)d: 8.79-8.80 (m, 2H), 8.17-8.23 (m, 4H), 7.98-8.05 (m, 2H), 7.71-7.76 (m, 4H), 7.66-7 .69(m, 1H), 7.55-7.57(m, 1H), 7.47-7.49m, 1H), 7.28-7.44(m, 12H), 6.96-6.98(m, 1H), 6.23-6.24(m, 1H).

[0172] Mass spectral data are as follows: HRMS (ESI, m / z): [M+H] + :Theoretical value: C 47 H 30 N5, 664.2496, experimental value: 664.2492. Theoretical calculation of the mass fraction of each element: C, 85.05; H, 4.40; N, 10.55; actual analysis of the mass fraction of each element: C, 85.11; H, 4.41; N, 10.48.

[0173] Embodiment 11

[0174] Compound 72 was synthesized. The synthetic route is as follows:

[0175]

[0176] Step 1: Synthesis of intermediate 72-1

[0177] The synthesis method is the same as compound 10, with a yield of 80%.

[0178] The NMR data of intermediate 72-1 are as follows: 1 HNMR(400MHz, CDCl3)d:8.18-8.21(m,1H),8.05-8.06(m,1H),7.97-8.00(m,3H),7.74-7 .78(m, 2H), 7.54-7.69(m, 6H), 7.28-7.49(m, 14H), 6.96-6.98(m, 1H), 6.23-6.24(m, 1H).

[0179] Step 2: Synthesis of compound 72

[0180] The synthesis method was the same as compound 52, with a yield of 68%.

[0181] The NMR data of compound 72 are as follows: 1 HNMR (400MHz, CDCl3)d: 8.98-8.99 (m, 1H), 8.63-8.64 (m, 1H), 8.26-8.29 (m, 1H), 8.16-8.17 (m, 1H), 8.07-8.08 (m, 1H), 7.97-8.04 (m, 4H ), 7.74-7.76(m, 1H), 7.63-7.69(m, 4H), 7.57-7.60(m, 2H), 7.47-7.50(m, 2H), 7.28-7.43(m, 13H), 7.00-7.02(m, 1H), 6.29-6.30(m, 1H).

[0182] Mass spectral data are as follows: HRMS (ESI, m / z): [M+H] + :Theoretical value: C 53 H 34 N5, 740.2809, experimental value: 740.2810. Theoretical calculation of the mass fraction of each element: C, 86.03; H, 4.50; N, 9.47; actual analysis of the mass fraction of each element: C, 86.09; H, 4.42; N, 9.49.

[0183] Example 12

[0184] Compound 77 was synthesized. The synthetic route is as follows:

[0185]

[0186] Step 1: Synthesis of intermediate 77-1

[0187] The synthesis method was the same as compound 10, with a yield of 68%.

[0188] The NMR data of intermediate 77-1 are as follows: 1 HNMR (400MHz, CDCl3)d:8.68-8.69(m, 2H), 8.02-8.07(m, 3H), 7.87-7.89(m, 1H), 7.64-7.68(m, 3H ), 7.50-7.52(m, 1H), 7.30-7.41(m, 8H), 7.25-7.27(m, 1H), 7.02-7.03(m, 1H), 6.42-6.43(m, 1H).

[0189] Step 2: Synthesis of compound 77

[0190] The synthesis method was the same as compound 52, with a yield of 62%.

[0191] The NMR data of compound 77 are as follows: 1 HNMR (400MHz, CDCl3)d:8.79-8.80(m, 2H), 8.71-8.73(m, 2H), 8.33(s, 1H), 8.12-8.13(m, 1H), 8.05-8.06(m, 2H), 8.00-8.01(m, 1H), 7.80-7.82(m, 1H), 7.73-7.74(m, 2H), 7.63-7.69(m, 3H), 7.51-7.56(m, 2H), 7.47-7.49(m, 1H), 7.28-7.40(m, 8H), 7.25-7.27(m, 1H), 6.97-6.99(m, 1H), 6.23-6.24(m, 1H).

[0192] Mass spectral data are as follows: HRMS (ESI, m / z): [M+H] + :Theoretical value: C 47 H 30 N5, 664.2496, experimental value: 664.2495. Theoretical calculation of the mass fraction of each element: C, 85.05; H, 4.40; N, 10.55; the actual analysis of the mass fraction of each element: C, 85.09; H, 4.32; N, 10.59.

[0193] Embodiment 13

[0194] Compound 82 was synthesized. The synthetic route is as follows:

[0195]

[0196] Step 1: Synthesis of intermediate 82-1

[0197] The synthesis method was the same as compound 10, with a yield of 85%.

[0198] The NMR data of intermediate 82-1 are as follows: 1 HNMR (400MHz, CDCl3)d: 8.17-8.20 (m, 2H), 8.04-8.05 (m, 1H), 7.97-8.00 (m, 3H), 7.74-7.76 (m, 1H), 7.66-7 .69 (m, 1H), 7.47-7.49 (m, 1H), 7.28-7.44 (m, 12H), 7.23-7.24 (m, 1H), 6.96-6.98 (m, 1H), 6.23-6.24 (m, 1H).

[0199] Step 2: Synthesis of compound 82

[0200] The synthesis method was the same as compound 52, with a yield of 66%.

[0201] The NMR data of compound 82 are as follows: 1 HNMR (400MHz, CDCl3)d:8.78-8.80 (m, 2H), 8.38-8.39 (m, 2H), 8.24-8.25 (m, 1H), 8.19-8.22 (m, 2H), 8.07-8.08 (m, 1H), 7.98-8.01 (m, 1H), 7.81-7 .83(m, 2H), 7.70-7.73(m, 3H), 7.65-7.67(m, 1H), 7.48-7.50(m, 1H), 7.2 8-7.44(m, 12H), 7.24-7.26(m, 2H), 7.00-7.02(m, 1H), 6.28-6.29(m, 1H).

[0202] Mass spectral data are as follows: HRMS (ESI, m / z): [M+H] + :Theoretical value: C 52 H 33 N6, 741.2761, experimental value: 741.2764. Theoretical calculation of the mass fraction of each element: C, 84.31; H, 4.35; N, 11.34; actual analysis of the mass fraction of each element: C, 84.28; H, 4.42; N, 11.30.

[0203] Embodiment 14

[0204] Compound 84 was synthesized. The synthetic route is as follows:

[0205]

[0206] The synthesis method was the same as compound 52, with a yield of 72%.

[0207] The NMR data of compound 84 are as follows: 1 HNMR (400MHz, CDCl3)d: 8.79-8.80 (m, 4H), 8.25-8.26 (m, 2H), 8.19-8.22 (m, 2H), 8.07-8.08 (m, 1H), 7.98-8.01 (m, 1H) ), 7.74-7.76(m, 6H), 7.65-7.67(m, 1H), 7.48-7.50(m, 1H), 7.28-7.43(m, 12H), 7.00-7.02(m, 1H), 6.28-6.29(m, 1H).

[0208] Mass spectral data are as follows: HRMS (ESI, m / z): [M+H] + :Theoretical value: C 52 H 33 N6, 741.2761, experimental value: 741.2758. Theoretical calculation of the mass fraction of each element: C, 84.31; H, 4.35; N, 11.34; actual analysis of the mass fraction of each element: C, 84.34; H, 4.30; N, 11.36.

[0209] Embodiment 15

[0210] Compound 89 was synthesized. The synthetic route is as follows:

[0211]

[0212] Step 1: Synthesis of intermediate 89-1

[0213] The synthesis method was the same as compound 52, with a yield of 45%.

[0214] The NMR data of intermediate 89-1 are as follows: 1HNMR (400MHz, CDCl3)d: 8.34-8.35 (m, 1H), 8.19-8.22 (m, 2H), 8.08-8.09 (m, 1H), 7.97-8.02 (m, 3H), 7.87-7.89 (m, 1H) ), 7.74-7.76(m, 1H), 7.64-7.67(m, 2H), 7.49-7.56(m, 3H), 7.28-7.44(m, 12H), 7.00-7.02(m, 1H), 6.28-6.29(m, 1H).

[0215] Step 2: Synthesis of compound 89

[0216] The synthesis method was the same as compound 52, with a yield of 86%.

[0217] The NMR data of compound 89 are as follows: 1 HNMR (400MHz, CDCl3)d: 9.01-9.02 (m, 1H), 8.63-8.64 (m, 1H), 8.19-8.26 (m, 4H), 8.06-8.08 (m, 2H), 7.97-8.01 (m, 3H), 7.91-7 .93 (m, 1H), 7.74-7.76 (m, 1H), 7.64-7.67 (m, 2H), 7.48-7.55 (m, 2H), 7.26-7.44 (m, 13H), 7.00-7.02 (m, 1H), 6.28-6.29 (m, 1H).

[0218] Mass spectral data are as follows: HRMS (ESI, m / z): [M+H] + :Theoretical value: C 54 H 33 N6, 765.2761, experimental value: 765.2762. Theoretically calculated mass fractions of each element: C, 84.80; H, 4.21; N, 10.99; actual analysis of the mass fractions of each element: C, 84.79; H, 4.18; N, 11.03.

[0219] Example 16

[0220] Compound 98 was synthesized. The synthetic route is as follows:

[0221]

[0222] Step 1: Synthesis of intermediate 98-1

[0223] The synthesis method is the same as compound 10, with a yield of 80%.

[0224] The NMR data of intermediate 98-1 are as follows: 1HNMR (400MHz, CDCl3)d: 8.17-8.20 (m, 2H), 7.97-8.00 (m, 3H), 7.89-7.91 (m, 1H), 7.83-7.85 (m, 2H), 7.66-7 .69 (m, 1H), 7.47-7.49 (m, 1H), 7.28-7.44 (m, 11H), 7.23-7.24 (m, 1H), 6.96-6.98 (m, 1H), 6.23-6.24 (m, 1H).

[0225] Step 2: Synthesis of compound 98

[0226] The synthesis method was the same as compound 52, with a yield of 73%.

[0227] The NMR data of compound 98 are as follows: 1 HNMR (400MHz, CDCl3)d:8.78-8.80(m, 2H), 8.38-8.39(m, 2H), 8.24-8.25(m, 1 H), 8.19-8.22(m, 2H), 7.99-8.01(m, 1H), 7.89-7.91(m, 1H), 7.81-7.85(m, 3H ), 7.78-7.79(m, 1H), 7.70-7.74(m, 2H), 7.65-7.67(m, 1H), 7.48-7.50(m, 1H) , 7.28-7.44(m, 11H), 7.24-7.26(m, 2H), 7.00-7.02(m, 1H), 6.28-6.29(m, 1H).

[0228] Mass spectral data are as follows: HRMS (ESI, m / z): [M+H] + :Theoretical value: C 52 H 33 N6, 741.2761, experimental value: 741.2759. Theoretical calculation of the mass fraction of each element: C, 84.31; H, 4.35; N, 11.34; actual analysis of the mass fraction of each element: C, 84.23; H, 4.39; N, 11.38.

[0229] Embodiment 17

[0230] Compound 99 was synthesized. The synthetic route is as follows:

[0231]

[0232] The synthesis method was the same as compound 52, with a yield of 77%.

[0233] The NMR data of compound 99 are as follows: 1HNMR (400MHz, CDCl3)d: 8.79-8.80 (m, 4H), 8.19-8.22 (m, 4H), 7.99-8.01 (m, 1H), 7.89-7.91 (m, 1H), 7.83-7.85 (m, 1H), 7.78-7 .79 (m, 1H), 7.74-7.76 (m, 5H), 7.65-7.67 (m, 1H), 7.48-7.50 (m, 1H), 7.28-7.44 (m, 11H), 7.00-7.02 (m, 1H), 6.28-6.29 (m, 1H).

[0234] Mass spectral data are as follows: HRMS (ESI, m / z): [M+H] + :Theoretical value: C 52 H 33 N6, 741.2761, experimental value: 741.2757. Theoretical calculation of the mass fraction of each element: C, 84.31; H, 4.35; N, 11.34; the actual analysis of the mass fraction of each element: C, 84.38; H, 4.32; N, 11.30.

[0235] Embodiment 18

[0236] Compound 105 was synthesized. The synthetic route is as follows:

[0237]

[0238] Step 1: Synthesis of intermediate 105-1

[0239] The synthesis method was the same as compound 52, with a yield of 42%.

[0240] The NMR data of intermediate 105-1 are as follows: 1 HNMR (400MHz, CDCl3)d: 8.35-8.36 (m, 1H), 8.19-8.22 (m, 2H), 7.97-8.02 (m, 2H), 7.89-7.91 (m, 1H), 7.80-7.85 (m, 2H ), 7.74-7.76(m, 2H), 7.65-7.70(m, 3H), 7.49-7.51(m, 2H), 7.28-7.44(m, 11H), 7.00-7.02(m, 1H), 6.29-6.30(m, 1H).

[0241] Step 2: Synthesis of compound 105

[0242] The synthesis method was the same as compound 52, with a yield of 81%.

[0243] The NMR data of compound 105 are as follows: 1HNMR (400MHz, CDCl3)d: 8.79-8.80 (m, 2H), 8.16-8.22 (m, 4H), 7.99-8.01 (m, 1H), 7.89-7.91 (m, 1H), 7.83-7.85 (m, 1H), 7.78-7.79 (m, 1H) ), 7.73-7.76(m, 5H), 7.69-7.71(m, 2H), 7.65-7.67(m, 1H), 7.49-7.50(m, 1H), 7.26-7.42(m, 11H), 7.00-7.02(m, 1H), 6.29-6.30(m, 1H).

[0244] Mass spectral data are as follows: HRMS (ESI, m / z): [M+H] + :Theoretical value: C 54 H 33 N6, 765.2761, experimental value: 765.2766. Theoretical calculation of the mass fraction of each element: C, 84.79; H, 4.22; N, 10.99; the actual analysis of the mass fraction of each element: C, 84.77; H, 4.27; N, 10.96.

[0245] Embodiment 19

[0246] Compound 106 was synthesized. The synthetic route is as follows:

[0247]

[0248] The synthesis method was the same as compound 10, with a yield of 77%.

[0249] The NMR data of compound 106 are as follows: 1 HNMR (400MHz, CDCl3)d: 8.18-8.21 (m, 2H), 8.00-8.02 (m, 1H), 7.88-7.90 (m, 1H), 7.82-7.85 (m, 2H), 7.73- 7.75(m, 2H), 7.66-7.70(m, 4H), 7.47-7.51(m, 2H), 7.27-7.37(m, 8H), 6.96-6.98(m, 1H), 6.28-6.29m, 1H).

[0250] Mass spectral data are as follows: HRMS (ESI, m / z): [M+H] + :Theoretical value: C 49 H 25D5N5, 693.2810, experimental value: 693.2815. Theoretical calculation of the mass fraction of each element: C, 84.94; H, 4.95; N, 10.11; the actual analysis of the mass fraction of each element: C, 84.99; H, 4.88; N, 10.13.

[0251] Test Example 1

[0252] (1) Glass transition temperature

[0253] The glass transition temperatures (Tg) of Examples 1 to 19 and Comparative Examples 1 to 4 were tested using a differential scanning calorimeter Pyris Diamond (DSC2920) under nitrogen protection at a heating and cooling rate of 10°C / min. The results are shown in Table 1 below:

[0254] Table 1

[0255]

[0256] Among them, the materials corresponding to Comparative Examples 1 to 4 are:

[0257]

[0258] The glass transition temperature is an important indicator for measuring the thermal stability of materials. Materials with high glass transition temperatures are less likely to crystallize at high temperatures, thereby maintaining the stability and performance of the device. According to Table 1, it can be seen that compared with Comparative Examples 1 to 4, the compounds prepared in Examples 1 to 19 of the present application have a higher glass transition temperature. This is because the embodiments of the present application introduce benzonitrile or pyridine groups, which contain lone pairs of electrons and can form hydrogen bonds between molecules, which is beneficial to improving the thermal stability of the compound. Therefore, the organic electroluminescent device prepared by the embodiments of the present application also has better thermal stability and a longer service life of the device.

[0259] (2) HOMO (Highest Occupied Molecular Orbital) energy level and LUMO energy level

[0260] A Sunic Plus 200 vacuum coater was used to evaporate 50 nm of the compound on the silicon wafer at a rate of The HOMO energy level of the compound in a vacuum environment was measured using a photoelectron spectrometer AC-2, and the AC-2 test conditions were 50nW-step 0.05nW. Cyclic voltammetry (CV) was performed using a CH Instruments electrochemical workstation to determine the LUMO energy level of the compound. The results are shown in Table 2 below:

[0261] Table 2

[0262]

[0263]

[0264] The LUMO energy level determines the electron injection capability between the electron transport material and the electrode. A suitable LUMO energy level helps to reduce the barrier for electron injection into the light-emitting layer, helps to achieve more efficient electron-hole recombination, achieves low driving voltage and excellent luminescence performance, and thus improves the overall luminescence efficiency of the OLED device. The LUMO energy level of high-performance organic electron transport materials is usually in the range of -2.8 to -3.4 eV, which is more compatible with the interface work function (about 3.2 eV) of commonly used electrodes such as Yb / Al, thereby reducing the energy barrier for electron injection. It can be seen from Table 2 that the compounds prepared in the embodiments of the present application have a larger LUMO energy level. The embodiments of the present application introduce nitrogen-containing six-membered heterocycles such as pyridine, pyrimidine, and triazine, as well as electron-withdrawing groups such as quinoline to improve the electron mobility of the compound. These groups have the ability to lower the LUMO energy level of the molecule and enhance the n-type conductivity of the material. In addition, the LUMO energy level is also related to the chemical stability of the material. In the electron transport layer, if the energy in the excited state of the molecule is greater than the bond dissociation energy of a chemical bond in the molecule, it may lead to molecular degradation. Therefore, designing electron transport materials with appropriate LUMO energy levels can help improve the chemical stability of the device.

[0265] The structure and performance of the organic electroluminescent device prepared by the compound will be further described in detail below by applying Examples 1 to 19. The corresponding preparation method can also be used to prepare samples required for some subsequent test examples. In addition to the compounds provided in the examples of this application, the organic materials used can be obtained commercially or prepared and identified by referring to the methods of the compounds provided in the examples of this application.

[0266] Application Examples 1 to 19 use fluorenyl triazine compounds to prepare organic electroluminescent devices. Application Example 19 uses a compound containing deuterated phenylfluorene and a triazine group.

[0267] See the schematic diagram of the structure of the organic electroluminescent device. Figure 1 The organic electroluminescent device includes a glass substrate 110, an anode 120, a hole injection layer 130, a hole transport layer 140, an electron blocking layer 150, a light emitting layer 160, a hole blocking layer 170, an electron transport layer 180, an electron injection layer 190 and a cathode 200 which are stacked in sequence.

[0268] The more detailed structure of the organic electroluminescent device in each application embodiment is: glass / anode (ITO) / hole injection layer (HIL) / hole transport layer (HTL) / electron blocking layer (EBL) / light-emitting layer (EML, main material BH: blue light-emitting material BD) / hole blocking layer (HBL) / electron transport layer (ETL, electron transport material includes 8-hydroxyquinoline lithium (LiQ)) / electron injection layer (EIL) / cathode (Cathode).

[0269] Application Example 1

[0270] A transparent conductive ITO glass substrate 110 (with an anode 120 thereon) (China Southern Glass Group Co., Ltd.) was ultrasonically treated in a commercial cleaning agent, rinsed in deionized water, and then washed with ethanol, acetone and deionized water in sequence, baked in a clean environment until the water was completely removed, cleaned with ultraviolet photosynthetic ozone, and then treated with oxygen plasma for 30 seconds. The glass substrate with the anode was placed in a vacuum chamber and evacuated.

[0271] Hole injection layer: HIL (10 nm) was evaporated on the ITO as the hole injection layer 130, and the evaporation rate was 0.1 nm / s.

[0272] Hole transport layer: Compound HT is evaporated on the hole injection layer to form a hole transport layer 140 with a thickness of 100 nm, and the evaporation rate is 0.1 nm / s.

[0273] Electron blocking layer: EB is evaporated to form an electron blocking layer 150 with a thickness of 5 nm, and the evaporation rate is 0.1 nm / s.

[0274] Light-emitting layer: A 25 nm thick light-emitting layer 160 is evaporated on the electron blocking layer, wherein BH is the main light-emitting material and BD with a weight percentage of 3% is used as the doping guest material, and the evaporation rate is 0.1 nm / s.

[0275] HB is evaporated on the light-emitting layer to form a 5 nm thick hole blocking layer 170, with an evaporation rate of 0.1 nm / s.

[0276] Compound 10 and LiQ (weight ratio 5:5) were evaporated on the light-emitting layer to form an electron transport layer 180 with a thickness of 25 nm, and the evaporation rate was 0.1 nm / s.

[0277] As the electron injection layer 190 , LiQ was evaporated to a thickness of 1 nm.

[0278] Aluminum (Al) was evaporated to a thickness of 120 nm as the device cathode 200 .

[0279] The preparation methods of the devices of Application Examples 2 to 18 and Application Comparative Examples 1 to 6 are basically the same as those of Application Example 1, except that the electron transport materials used in the electron transport layer (ETL) of the device are different. The compounds used in the Application Examples and Application Comparative Examples are shown in Table 3. Among them, the structures of some compounds involved in Table 3 are shown below:

[0280]

[0281] In Table 3, the percentage ratio of the two raw materials in EML refers to the weight ratio, such as the weight ratio of BH and BD in Application Example 1 is 97%:3%. The percentage ratio of the two raw materials in ETL also refers to the weight ratio, such as the weight ratio of Compound 10 and LiQ in Application Example 1 is 50%:50%.

[0282] Table 3

[0283]

[0284]

[0285]

[0286] Performance testing of organic electroluminescent devices

[0287] The test was conducted using a Photo Research PR655 spectrometer and the measured value was 1000cd / cm 2 The operating voltage, turn-on voltage @1nit, current efficiency, external quantum efficiency EQE, and the brightness at 30mA / cm 2 The life span (T95) at which the brightness decays to 95% of the original brightness under the current density and room temperature environment is shown in Table 4 below:

[0288] Table 4

[0289]

[0290]

[0291] It can be seen from Table 4 that compared with the comparative examples 1 and 2, the device prepared in the present application has a lower operating voltage, higher current efficiency and external quantum efficiency, and a longer service life. Compared with compounds Ref-1 and Ref-2, the compound provided in the present application introduces a benzonitrile group or a pyridyl group. In some embodiments, the combination of a triazine group or a pyrimidine group can increase the electron mobility of the compound, and can reduce the LUMO energy level of the compound, improve the charge injection ability, reduce the operating voltage of the device, and improve the efficiency of the device prepared using the compound. The connection of the indole spirofluorene group can effectively increase the stability of the compound and extend the service life of the device.

[0292] The above description is only for the purpose of facilitating those skilled in the art to understand the technical solution of the present application and is not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A compound containing a spiro structure, characterized in that: The compound is applied to an organic electroluminescent device, and the chemical structural formula of the compound is shown below: Among them, R1-R 13 Each independently represents one of the following: hydrogen, halogen, cyano, alkyl having 1 to 12 carbon atoms, alkoxy having 1 to 8 carbon atoms, substituted or unsubstituted aryl having 6 to 30 carbon atoms, substituted or unsubstituted heteroaryl having 3 to 30 carbon atoms, triarylamine, carbazolyl, triarylphosphinyl; Ar1 represents one of the following: a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaryl group having 3 to 30 carbon atoms; Ar2 represents one of the following: substituted or unsubstituted pyridyl, substituted or unsubstituted benzonitrile; L1 represents a single bond or a phenylene group; L2 represents one of the following: a substituted or unsubstituted arylene group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroarylene group having 3 to 30 carbon atoms; n is 1, 2, 3, 4 or 5; There is at least one nitrogen atom in Z1-Z3, and the rest are carbon atoms.

2. The compound according to claim 1, characterized in that R1-R 13 Each independently represents one of the following: hydrogen, methyl, ethyl, propyl, isopropyl, tert-butyl, cyclohexyl, adamantyl, phenyl, tolyl, biphenyl.

3. The compound according to claim 1, characterized in that Ar1 represents one of the following: a substituted or unsubstituted phenyl group having 6 to 30 carbon atoms, a substituted or unsubstituted naphthyl group having 6 to 30 carbon atoms, a substituted or unsubstituted fluorenyl group having 6 to 30 carbon atoms, a substituted or unsubstituted dibenzothiophenyl group having 6 to 30 carbon atoms, a substituted or unsubstituted dibenzofuranyl group having 6 to 30 carbon atoms, a substituted or unsubstituted phenanthryl group having 6 to 30 carbon atoms, a substituted or unsubstituted fluoranthene group having 6 to 30 carbon atoms, anthracene group having 6 to 30 carbon atoms, a substituted or unsubstituted naphthyl group having 6 to 30 carbon atoms, a substituted or unsubstituted biphenyl group having 6 to 30 carbon atoms, or a substituted or unsubstituted pyridyl group having 5 to 30 carbon atoms.

4. The compound according to claim 1, characterized in that Z1, Z2 and Z3 are all nitrogen atoms.

5. The compound according to claim 1, characterized in that L1 is a single bond, and the connection site with the fluorenyl group is the second site or the third site.

6. The compound according to claim 1, characterized in that L2 is phenylene.

7. The compound according to claim 1, characterized in that n is 1 or 2.

8. An electron transport material, characterized in that The electron transport material comprises the compound according to any one of claims 1 to 7.

9. An organic electroluminescent device, characterized in that: The organic electroluminescent device comprises: an anode, a cathode and an organic layer; The organic layer comprises a hole transport unit, a light emitting layer and an electron transport unit, wherein at least one of the hole transport unit, the light emitting layer and the electron transport unit contains the compound according to any one of claims 1 to 7.

10. The organic electroluminescent device according to claim 9, characterized in that: The electron transport unit includes at least one of a hole blocking layer and an electron transport layer; At least one of the hole blocking layer and the electron transporting layer contains the compound.

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