Compound, organic electroluminescent device and display device

Abstract

The invention relates to the field of electroluminescence, and discloses a compound, an organic electroluminescent device and a display device. The structural formula of the compound is as shown in formula (I). The organic electroluminescent device using the material of the compound provided by the invention has lower driving voltage and higher current efficiency, and meanwhile, the compound provided by the invention can be used for preparing a transmission layer or an injection layer of the organic electroluminescent device by using a solution method.

Description

[0001] This application is a divisional application of patent application number 202311151516.1 (the original application was filed on April 27, 2021, and the invention was entitled "Compound and Organic Electroluminescent Device and Display Device"). Technical Field

[0002] This invention relates to the field of electroluminescence, and particularly to a compound and an organic electroluminescent device and display device. Background Technology

[0003] Currently, organic light-emitting diode (OLED) display technology has been applied in smartphones, tablets, and other fields, and will further expand to large-size applications such as televisions. Over the past 30 years, various high-performance OLED materials have been developed, and through different device structure designs and optimizations of device lifespan, efficiency, and other performance aspects, the commercialization of OLEDs has been accelerated, leading to their widespread application in display and lighting fields.

[0004] However, the significant gap between the external and internal quantum efficiencies of OLEDs severely restricts their development, with one of the most significant factors being the fact that device efficiency has not yet reached an ideal level. This is due to substrate mode loss, surface plasmon loss, and waveguide effects, which confine most of the light within the light-emitting device, thus reducing its luminous efficiency. Improving luminous efficiency through the use of light extraction materials is one effective method. Capping layers (CPLs) can effectively improve light extraction efficiency by reducing surface plasmon effects on metal electrodes and adjusting the light emission direction and efficiency, thereby enhancing the device's luminous efficiency. Currently, the types of light extraction materials are relatively limited, and their effectiveness is not ideal. Developing more effective light extraction materials remains one of the most serious challenges facing OLED researchers.

[0005] In addition, the selection of light-emitting layer and other organic functional layer materials also has a significant impact on the current efficiency and driving voltage of the device. Currently, we are still exploring functional layer materials with higher performance.

[0006] Therefore, in order to meet people's higher requirements for OLED devices, there is an urgent need in this field to develop more types and higher performance OLED materials. Summary of the Invention

[0007] To address the shortcomings of existing technologies, the present invention aims to provide a compound and an organic electroluminescent device and display device. Organic electroluminescent devices using the materials of the compound of this application exhibit lower driving voltage and higher current efficiency. Furthermore, the compound provided in this application allows for the preparation of the transport layer or injection layer of the organic electroluminescent device using a solution method.

[0008] To achieve this objective, the present invention adopts the following technical solution:

[0009] In a first aspect, the present invention provides a compound, the structural formula of which is shown in Figure (I).

[0010] ,

[0011] Where a, b, c, and d are each independently selected from 0, 1, 2, 3, or 4; p is selected from 0 or 1;

[0012] R1 to R4 are each independently selected from hydrogen, deuterium, F, CN, alkyl groups containing 1 to 20 carbon atoms, alkoxy groups containing 1 to 20 carbon atoms, and aromatic groups containing 6 to 40 carbon atoms; the hydrogen in the aromatic group containing 6 to 40 carbon atoms can be replaced by R; wherein R can form a ring with spirofluorene, and Ar can form a ring with Ar1 and Ar2;

[0013] Ar and Ar1 are each independently selected from aromatic groups containing 6 to 40 carbon atoms, wherein the hydrogen in the aromatic group containing 6 to 40 carbon atoms can be replaced by R;

[0014] Ar2 is selected from one of the structures shown in A-1 to A-8:

[0015]

[0016]

[0017] ,

[0018] Where * indicates the position where Ar2 and the N atom in formula (I) are connected;

[0019] R5~R 14 Each is independently selected from alkyl groups containing 1 to 20 carbon atoms and aromatic groups containing 6 to 40 carbon atoms; the hydrogen in the aromatic group containing 6 to 40 carbon atoms can be replaced by R;

[0020] e and f are each independently selected from 0 or 1, and e and f are not both 0 at the same time;

[0021] R is selected from alkyl groups containing 1 to 20 carbon atoms, alkoxy groups containing 1 to 20 carbon atoms, or aromatic groups containing 6 to 40 carbon atoms.

[0022] The following are preferred technical solutions of the present invention, but are not intended to limit the technical solutions provided by the present invention. The purpose and beneficial effects of the present invention can be better achieved and realized through the following preferred technical solutions.

[0023] As a preferred embodiment of the present invention, Ar1 is selected from one of B-1 to B-4:

[0024] R 21 ~R 22 Each is independently selected from alkyl groups containing 1 to 20 carbon atoms and aromatic groups containing 6 to 40 carbon atoms; the hydrogen in the aromatic group containing 6 to 40 carbon atoms can be replaced by R; R 21 ~R 22 They can be linked into a ring; Ar3 and Ar4 are each independently selected from aromatic groups containing 6 to 40 carbon atoms, and the hydrogen in the aromatic group containing 6 to 40 carbon atoms can be replaced by R; p and q are selected from 0 or 1;

[0025] Where * indicates the position where the N atoms in B-1 to B-4 and formula (Ⅰ) are connected.

[0026] Furthermore, when R1 to R4 are selected from aromatic groups containing 6 to 40 carbon atoms that are substituted with alkyl groups of 1 to 20 carbon atoms, the alkyl groups of 1 to 20 carbon atoms can form a ring with the spirofluorene group.

[0027] The present invention also provides a method for synthesizing the compound shown in formula (I):

[0028]

[0029] The present invention also provides another method for synthesizing the compound shown in formula (I):

[0030]

[0031] X is selected from Cl, Br, and I.

[0032] The present invention also provides the following intermediates for synthesizing the compound shown in formula (I):

[0033]

[0034]

[0035] X is selected from Cl, Br, and I.

[0036] As a preferred embodiment of the present invention, the structure of the compound is selected from one of the following structures:

[0037]

[0038] .

[0039] As a preferred embodiment of the present invention, in compounds II-1 to II-9, Ar1 and Ar are selected from benzene, biphenyl, naphthalene, phenanthrene, fluorene, carbazole, dibenzofuran, dibenzothiophene, triphenylene, fluoranthene or Ar2, and the hydrogen in Ar1 and Ar can be replaced by an alkyl group with 1 to 20 carbon atoms or an aromatic group with 6 to 40 carbon atoms.

[0040] When the hydrogen in Ar and Ar1 is replaced by an aromatic group containing 6 to 40 carbon atoms, Ar and Ar1 can form a ring with the aromatic group containing 6 to 40 carbon atoms through carbon atoms, or through NR, or through O and S. R is selected from alkyl groups with 1 to 20 carbon atoms and aromatic groups with 6 to 40 carbon atoms. Ar can form a ring with substituents and spirofluorene.

[0041] As a preferred embodiment of the present invention, in compounds II-1 to II-9:

[0042] p is selected from 1;

[0043] Ar1 is selected from benzene, biphenyl, naphthalene, phenanthrene, fluorene, carbazole, dibenzofuran, dibenzothiophene, triphenylene, and fluoranthene, and the hydrogen in Ar1 can be replaced by alkyl groups with 1 to 6 carbon atoms or aromatic groups with 6 to 12 carbon atoms;

[0044] Ar is selected from benzene, biphenyl, spirofluorene, naphthalene, phenanthrene, fluorene, carbazole, dibenzofuran, dibenzothiophene, triphenylene, and fluoranthene, and the hydrogen in Ar can be replaced by alkyl groups with 1 to 6 carbon atoms or aromatic groups with 6 to 12 carbon atoms.

[0045] As a preferred embodiment of the present invention, in compounds II-1 to II-9, p is selected from 0; Ar1 ​​is selected from benzene, biphenyl, naphthalene, phenanthrene, fluorene, carbazole, dibenzofuran, dibenzothiophene, triphenylene, fluoranthene, and the hydrogen in Ar1 can be replaced by an alkyl group with 1 to 6 carbon atoms or an aromatic group containing 6 to 12 carbon atoms.

[0046] As a preferred embodiment of the present invention, the compound is selected from any one of the following compounds:

[0047] .

[0048] In this application, the P-1 to P-132 structural isomers refer to the different connection modes between the aromatic rings constituting Ar, the different connection modes between the aromatic rings constituting Ar1, the position of the SP2 hybrid carbon atom connected to the N atom on Ar2, and the different connection positions of the substituents on Ar2 in the specific structures of P-1 to P-132.

[0049] For example:

[0050] For P-3, where N is attached to a biphenyl group and a tetramethyldihydrophenanthrene group, any structural isomer of P-3 is considered to be formed when the two benzene rings on the biphenyl group are connected in any manner and / or when any sp2 hybridized carbon atom on the tetramethyldihydrophenanthrene group is attached to the N atom. This includes, but is not limited to, the following structures:

[0051]

[0052] For the structural isomers P-1 to P-132, the explanation in P-3 above can be used as a reference for understanding.

[0053] In a second aspect, the present invention provides a compound intermediate selected from one of the following structures:

[0054] .

[0055] Thirdly, the present invention provides an organic electroluminescent device, the organic electroluminescent device comprising the compound as described in the first aspect.

[0056] Fourthly, the present invention provides a display device including an organic electroluminescent device as described in the third aspect.

[0057] Compared with the prior art, the present invention has the following beneficial effects:

[0058] This invention provides a compound of formula (I) with a spirofluorene group as the parent core and a limited selection range of substituents, improving the film-forming properties and transmittance of the material, resulting in a significant improvement over existing materials. Simultaneously, the altered compound structure changes the material's solubility in organic solvents. After dissolving in a solvent, this compound solution yields an organic solvent with good viscosity properties. After solvent evaporation, the remaining organic material exhibits excellent film-forming properties, making this material more suitable for solution-based fabrication of OLED devices. Furthermore, the structural change improves the HOMO and LOMO energy levels of the material, enabling it to exhibit high luminous efficiency and low driving voltage when used as a host material, hole injection layer (HIL) material, or hole transport layer (HTL) material in OLED devices. Attached Figure Description

[0059] Figure 1 The mass spectrometry chromatogram of compound P-5 provided in the embodiments of this application;

[0060] Figure 2 The mass spectrometry result of compound P-6 provided in the embodiments of this application is shown. Detailed Implementation

[0061] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be considered as specific limitations thereof.

[0062] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the embodiments of this application. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0063] It should be noted that, unless otherwise specified, all embodiments and preferred methods mentioned herein can be combined to form new technical solutions. In this application, unless otherwise stated, the numerical range "a~b" represents an abbreviation of any combination of real numbers between a and b, where a and b are both real numbers. For example, the numerical range "6~22" indicates that all real numbers between "6~22" have been listed herein; "6~22" is merely an abbreviation of these numerical combinations. The "range" disclosed in this application takes the form of a lower limit and an upper limit, and may consist of one or more lower limits and one or more upper limits. In this application, unless otherwise stated, the various reaction or operation steps may be performed sequentially or not in sequence. Preferably, the reaction methods described herein are performed sequentially.

[0064] Unless otherwise stated, the technical and scientific terms used herein have the same meanings as those familiar to a person skilled in the art. Furthermore, any methods or materials similar to or equivalent to those described herein may also be used in this application.

[0065] Synthesis Example 1

[0066] Synthesis of P-1

[0067] Step S1) Synthesis of 4-bromo-9,9,10,10-tetramethyl-9,10-dihydrophenanthrene and 2-bromo-9,9,10,10-tetramethyl-9,10-dihydrophenanthrene

[0068]

[0069] In a 250 mL three-necked flask, 0.01 mol (2.36 g) of 9,9,10,10-tetramethyl-9,10-dihydrophenanthrene, 30 mL of dichloromethane, 5 mL of glacial acetic acid, and 0.2 g of iron powder were added. The temperature was then controlled at 20–25 °C, and 0.012 mol (1.92 g) of liquid bromine in 5 mL of dichloromethane solution was slowly added dropwise. After the addition was complete, the reaction was maintained at 20–25 °C for 4 hours. Water was added and the mixture was stirred. The insoluble matter was filtered off, and the mother liquor was separated. The organic layer was washed with sodium bisulfite solution, then washed with water until neutral, concentrated to dryness, and separated by silica gel column chromatography. The product was eluted with petroleum ether to obtain 0.81 g of 4-bromo-9,9,10,10-tetramethyl-9,10-dihydrophenanthrene and 0.92 g of 2-bromo-9,9,10,10-tetramethyl-9,10-dihydrophenanthrene, with an overall yield of 54.9%.

[0070] Mass spectrometry analysis was performed on the obtained 4-bromo-9,9,10,10-tetramethyl-9,10-dihydrophenanthrene, determining the molecular m / z to be 314, 316, and the molecular formula of the product to be C. 18 H 19 Br.

[0071] The obtained 4-bromo-9,9,10,10-tetramethyl-9,10-dihydrophenanthrene was subjected to NMR analysis, and the data were interpreted as follows: 1H-NMR (Bruker, Switzerland, Avance II 400MHz NMR spectrometer, CDCl3), δ7.71 (m, 1H), δ7.66 (m, 1H), δ7.55 (m, 1H), δ7.48 (m, 1H), δ7.34~7.28 (m, 2H), δ7.21 (t, 1H), δ1.33 (s, 12H).

[0072] Mass spectrometry analysis was performed on the obtained 2-bromo-9,9,10,10-tetramethyl-9,10-dihydrophenanthrene, determining the molecular m / z to be 314, 316, and the molecular formula of the product to be C.18 H 19 Br.

[0073] The obtained 2-bromo-9,9,10,10-tetramethyl-9,10-dihydrophenanthrene was subjected to NMR analysis, and the data were analyzed as follows: 1H-NMR (Bruker, Switzerland, Avance II 400MHz NMR spectrometer, CDCl3), δ7.71 (m, 1H), δ7.67 (d, 1H), δ7.61~7.53 (m, 2H), δ7.46 (m, 1H), δ7.35~7.26 (m, 2H), δ1.33 (s, 12H).

[0074] Step S2) Synthesis of 2-(9,9,10,10-tetramethyl-9,10-dihydrophenanthrene-4-yl)-2-propanol

[0075]

[0076] In a 250 mL three-necked flask, add 0.01 mol (3.15 g) of 4-bromo-9,9,10,10-tetramethyl-9,10-dihydrophenanthrene and 100 mL of tetrahydrofuran. After purging with nitrogen, cool to -78 °C, then add dropwise 7.5 mL of a 1.6 M solution of 0.012 mol butyllithium in n-hexane. After the addition is complete, maintain the temperature at -70 to -78 °C for 30 min. Then add 0.02 mol (1.16 g) of acetone all at once, and slowly raise the temperature to 25 °C. Add ammonium chloride solution for hydrolysis, then add dichloromethane for separation. Wash the organic layer with water until neutral, then concentrate under reduced pressure to dryness to obtain a yellow oily substance. Do not separate the oil and proceed directly to the next reaction.

[0077] Step S3) Synthesis of 4,4,8,8,9,9-hexamethyl-8,9-dihydro-4H-cyclopentanophenanthrene

[0078]

[0079] Under nitrogen protection, 20 mL of dichloromethane was added to the unseparated 2-(9,9,10,10-tetramethyl-9,10-dihydrophenanthrene-4-yl)-2-propanol obtained in the previous step. After stirring and dissolving, 3 mL of glacial acetic acid was added, and then the temperature was lowered to 0 °C. 2 g of methanesulfonic acid was slowly added dropwise while maintaining the temperature at 0–5 °C. After the addition was complete, the temperature was raised to 25 °C and reacted for 4 hours. Then, 30 mL of methanol was added, and a solid precipitated. The solid was filtered, washed with methanol, and dried to obtain 1.88 g of a white solid, 4,4,8,8,9,9-hexamethyl-8,9-dihydro-4H-cyclopenta[def]phenanthrene. The overall yield from the previous step was 68%.

[0080] Mass spectrometry analysis was performed on 4,4,8,8,9,9-hexamethyl-8,9-dihydro-4H-cyclopentano[def]phenanthrene, and the molecular m / z was determined to be 276.

[0081] Step S4) Synthesis of 2-bromo-4,4,8,8,9,9-hexamethyl-8,9-dihydro-4H-cyclopentanophenanthrene

[0082]

[0083] In a 250 mL three-necked flask, add 0.01 mol (2.76 g) of 4,4,8,8,9,9-hexamethyl-8,9-dihydro-4H-cyclopentaphenanthrene, 40 mL of dichloromethane, 15 mL of glacial acetic acid, and 0.2 g of iron powder. Then, control the temperature at 20–25 °C and slowly add 5 mL of a 0.012 mol (1.92 g) solution of liquid bromine in dichloromethane. After the addition is complete, control the temperature at 35–40 °C and react for 4 hours. Add water and stir. Filter the insoluble matter. Separate the mother liquor. Wash the organic layer with sodium bisulfite solution, then wash with water until neutral. Concentrate to dryness, separate by silica gel column chromatography, and elute with petroleum ether to obtain 2.18 g of the product 2-bromo-4,4,8,8,9,9-hexamethyl-8,9-dihydro-4H-cyclopentaphenanthrene.

[0084] Mass spectrometry analysis was performed on 2-bromo-4,4,8,8,9,9-hexamethyl-8,9-dihydro-4H-cyclopentanophenanthrene, determining the molecular m / z to be 354, 356, and the product molecular formula to be C. 21 H 23 Br.

[0085] Step S5) Synthesis of P-1

[0086]

[0087] In a 250 mL three-necked flask under nitrogen protection, add 150 mL of dry toluene, 4.84 g (0.01 mol) N-([1,1'-biphenyl]-3-yl)-9,9'-spirodifluorene-2-amine, 3.91 g (0.011 mol) 2-bromo-4,4,8,8,9,9-hexamethyl-8,9-dihydro-4H-cyclopentaphenanthrene, 0.0575 g (0.0001 mol) Pd(dba)2 (bis(dibenzylacetone palladium)), 0.4 g (0.0002 mol) a toluene solution containing 10% tri-tert-butylphosphine, and 1.44 g (0.015 mol) [unclear text - likely a typo]. Sodium tert-butoxide (mol) was heated to reflux for 6 hours, cooled, and diluted with water. The organic layer was washed with water until neutral, dried with magnesium sulfate, filtered to remove magnesium sulfate, concentrated to dryness, dissolved in a mixture of chloroform and methanol, and recrystallized to give 6.12 g of the compound shown in P-1, with a yield of 80.74%.

[0088] Mass spectrometry was performed on the compound shown in P-1, and the molecular m / z was determined to be 757.

[0089] The compound shown in P-1 was subjected to NMR analysis, and the data are analyzed as follows: 1H-NMR (Bruker, Switzerland, Avance II 400MHz NMR spectrometer, CDCl3), δ7.93~7.84 (m, 4H), δ7.77 (m, 2H), δ7.65 (m, 2H), δ7.59~7.46 (m, 5H), δ7.45~7.31 (m, 7H), δ7.28~7.21 (m, 6H), δ7.20~7.13 (m, 3H), δ1.70 (s, 6H), δ1.34 (s, 12H).

[0090] Synthesis Example 2

[0091] P-5 Synthesis

[0092]

[0093] The synthesis method is the same as that of P-1, except that N-([1,1'-biphenyl]-3-yl)-9,9'-spirodifluorene-2-amine is replaced with N-([1,1'-biphenyl]-4-yl)-9,9'-spirodifluorene-2-amine, and 2-bromo-4,4,8,8,9,9-hexamethyl-8,9-dihydro-4H-cyclopenta[def]phenanthrene is replaced with 9-bromo-7,7-dimethyl-7H-benzo[c]fluorene, to obtain the compound shown in P-5.

[0094] Mass spectrometry analysis was performed on the compound shown in P-5, and the spectrum is attached. Figure 1 The molecular m / z was determined to be 725.

[0095] Synthesis Example 3

[0096] Synthesis of P-6

[0097]

[0098] The synthesis method is the same as that of P-1, except that N-([1,1'-biphenyl]-3-yl)-9,9'-spirodifluorene-2-amine is replaced with N-(9,9-dimethyl-9H-fluorene-2-yl)-9,9'-spirodifluorene-2-amine, and 2-bromo-4,4,8,8,9,9-hexamethyl-8,9-dihydro-4H-cyclopenta[def]phenanthrene is replaced with 9-bromo-7,7-dimethyl-7H-benzo[c]fluorene, to obtain the compound shown in P-6.

[0099] Mass spectrometry was performed on the compound shown in P-6, and the spectrum is attached. Figure 2 The molecular m / z was determined to be 765.

[0100] Synthesis Example 4

[0101] Synthesis of P-17

[0102]

[0103] The synthesis method is the same as that of P-1, except that N-([1,1'-biphenyl]-3-yl)-9,9'-spirodifluorene-2-amine is replaced with N-(4-fluorophenyl)-9,9'-spirodifluorene-2-amine, and 2-bromo-4,4,8,8,9,9-hexamethyl-8,9-dihydro-4H-cyclopentanophenanthrene is replaced with 3-bromo-7,7-dimethyl-7H-benzo[de]anthracene, to obtain the compound shown in P-17.

[0104] Mass spectrometry analysis was performed on the compound shown in P-17, and the molecular m / z was determined to be 667.

[0105] Synthesis Example 5

[0106] Synthesis of P-44

[0107]

[0108] 1) First, 9,9'-spirodifluorene-2-amine and 5-bromo-7,7-dimethyl-7H-benzo[c]fluorene were reacted to generate the compound shown in P-44-1.

[0109] The compound shown in P-44-1 was analyzed by mass spectrometry, and the molecular m / z was determined to be 573.

[0110]

[0111] 2) React the compound shown in P-44-1 with the compound shown in P-44-2 to generate the compound shown in P-44.

[0112] Mass spectrometry was performed on the compound shown in P-44, and the molecular m / z was determined to be 890.

[0113] Synthesis Example 6

[0114] Synthesis of P-79

[0115]

[0116] The compound shown in P-79 is generated by reacting the compound shown in P-79-1 with the compound shown in P-79-1 and 3-bromo-7,7-dimethyl-7H-benzo[de]anthracene.

[0117] Mass spectrometry was performed on the compound shown in P-79, and the molecular m / z was determined to be 801.

[0118] Synthesis Example 7

[0119] Synthesis of P-102

[0120] 1) Synthesis of P-102-1

[0121]

[0122] In a 250 mL three-necked flask, add 100 mL DMF, 2.48 g 3-bromodiphenylamine, 2.33 g 3-chloro-4-nitro-1,1'-biphenyl, and 1.3 g sodium carbonate. Slowly heat to 60 °C and react for 2 hours, then heat to 100 °C and react for 1 hour. Cool down, add water, filter the solid, and recrystallize from ethanol to obtain P-102-1, weighing 3.8 g.

[0123] Mass spectrometry analysis was performed on the compound shown in P-102-1. The two largest peaks had essentially the same height, with m / z values ​​of 446 and 444. The molecular formula of the product was determined to be C. 24 H 17 BrN2O2.

[0124] 2) Synthesis of P-102-2

[0125]

[0126] Under nitrogen protection, 4.45 g of the compound shown in P-102-1, 100 mL of o-dichlorobenzene, and 16 g of triethyl phosphite were added to 500 mL of water. The mixture was heated to reflux for 8 hours, cooled, and 100 mL of 10% sodium hydroxide solution was added. The mixture was stirred at room temperature for 8 hours, separated, the organic layer was washed with water, dried over magnesium sulfate, and the desiccant was filtered off. The mother liquor was concentrated to obtain crude P-102-2. The crude product was recrystallized from a mixed solvent of toluene and ethanol to obtain P-102-2 with a weight of 1.8 g.

[0127] Mass spectrometry analysis was performed on the compound shown in P-102-2. The two largest peaks had essentially the same height, with m / z values ​​of 414 and 412. The molecular formula of the product was determined to be C. 24 H 17 BrN2.

[0128] 3) Synthesis of 3-iodo-7,7-dimethyl-7H-benzo[de]anthracene

[0129]

[0130] In a 500 mL three-necked flask under nitrogen protection, 3.23 g of 3-bromo-7,7-dimethyl-7H-benzo[de]anthracene, 2 g of potassium iodide, 2.0 g of cuprous iodide, 0.1 g of tetrabutylammonium bromide, and 100 mL of DMSO were added. The mixture was heated to 150 °C and reacted for 48 hours. After cooling, water and dichloromethane were added and stirred. The mixture was filtered to remove insoluble matter, and the layers were separated. The organic layer was washed with water until neutral, concentrated to dryness, and separated by silica gel column chromatography. The solution was eluted with petroleum ether to give 2.8 g of 3-iodo-7,7-dimethyl-7H-benzo[de]anthracene.

[0131] Mass spectrometry was used to detect 3-iodo-7,7-dimethyl-7H-benzo[de]anthracene, with a m / z of 370.

[0132] 4) Synthesis of P-102-3

[0133]

[0134] In a 500 mL three-necked flask, add 4.13 g of P-102-2, 3.70 g of 3-iodo-7,7-dimethyl-7H-benzo[de]anthracene, 0.2 g of cuprous iodide, 0.2 g of o-phenoroline (CAS no. 66-71-7), 100 mL of chlorobenzene, and 1.2 g of sodium carbonate. Heat to reflux for 24 hours, cool, add water and stir. Filter to remove insoluble matter, separate the layers, wash the organic layer with water until neutral, concentrate to dryness, separate by silica gel column chromatography, and elute with petroleum ether to obtain 4.6 g of P-102-3.

[0135] Mass spectrometry analysis was performed on the compound shown in P-102-3. The two largest peaks had essentially the same height, with m / z values ​​of 656 and 654. The molecular formula of the product was determined to be C. 43 H 31 BrN2.

[0136] 5) Synthesis of P-102

[0137]

[0138] In a 250 mL three-necked flask under nitrogen protection, add 50 mL toluene, 30 mL ethanol, 20 mL water, 3.6 g 9,9'-spirodifluorene-2-boric acid, 6.55 g of the compound shown in P-102-3, 2.1 g sodium carbonate, and 0.23 g tetraphenylphosphine palladium. Heat to reflux for 8 hours, cool, and filter to obtain crude P-102. Separate the crude P-102 by silica gel column chromatography, eluting with petroleum ether:dichloromethane = 10:0.5 (v / v), to obtain 6.2 g of the compound shown in P-102.

[0139] The compound shown in P-102 was analyzed by mass spectrometry, with an m / z of 890.

[0140] Products not listed in the above synthetic examples can be synthesized using methods known in the art and conventional means.

[0141] Device Examples

[0142] The specific structures of the materials used in this application are shown below:

[0143]

[0144] Device Example 1

[0145] The embodiments use compounds from this application as hole transport materials in organic electroluminescent devices, while the comparative embodiments use HT-1 to HT-3 as hole transport materials in organic electroluminescent devices.

[0146] The structure of the organic electroluminescent device is: ITO / HIL02 (100nm) / hole transport material (40nm) / EM39 (30nm) / TPBI (30nm) / LiF (0.5nm) / Al (150nm).

[0147] The fabrication process of organic electroluminescent devices is as follows:

[0148] The glass substrate coated with an ITO transparent conductive layer (as the anode) was ultrasonically treated in a cleaning agent, then rinsed in deionized water, then ultrasonically degreased in a mixed solvent of acetone and ethanol, then baked in a clean environment until completely dehydrated, cleaned with ultraviolet light and ozone, and bombarded with a low-energy cation beam to improve the surface properties and enhance the bonding ability with the hole injection layer.

[0149] The glass substrate was placed inside a vacuum chamber, and the vacuum was evacuated to 1×10⁻⁶. -5 ~9×10 -3 Pa, HIL02 was vacuum-deposited on the anode as a hole injection layer at a deposition rate of 0.1 nm / s and a film thickness of 100 nm;

[0150] The compound of this application and the comparative material were vacuum-deposited as hole transport layers on the hole injection layer, respectively, at a deposition rate of 0.1 nm / s and a film thickness of 40 nm.

[0151] EM39 was vacuum-deposited on top of the hole transport layer as the organic light-emitting layer of the device at a deposition rate of 0.1 nm / s and a total film thickness of 30 nm.

[0152] TPBI was vacuum-deposited on top of the organic light-emitting layer as the electron transport layer of the organic electroluminescent device; the deposition rate was 0.1 nm / s and the total film thickness was 30 nm.

[0153] 0.5 nm LiF and 150 nm Al were vacuum-deposited on the electron transport layer as the electron injection layer and cathode, respectively.

[0154] The brightness, driving voltage, and current efficiency of the prepared organic electroluminescent device were measured.

[0155] The performance of organic electroluminescent devices is shown in Table 1 below. The tests were conducted using an OLED-1000 multi-channel accelerated aging lifetime and photochromic performance analysis system manufactured by Hangzhou Yuanfang.

[0156] Table 1

[0157]

[0158] Device Example 2

[0159] In this embodiment, the compound of this application is selected as the hole transport material in the organic electroluminescent device. In the comparative embodiment, HT-1 is used as the hole transport material in the organic electroluminescent device. In this embodiment, the hole transport layer is prepared by solution method.

[0160] The structure of the organic electroluminescent device is: ITO / HIL02 (100nm) / hole transport material / EM39 (30nm) / TPBI (30nm) / LiF (0.5nm) / Al (150nm).

[0161] The fabrication process of organic electroluminescent devices is as follows:

[0162] The glass substrate coated with an ITO transparent conductive layer (as the anode) was ultrasonically treated in a cleaning agent, then rinsed in deionized water, then ultrasonically degreased in a mixed solvent of acetone and ethanol, then baked in a clean environment until completely dehydrated, cleaned with ultraviolet light and ozone, and bombarded with a low-energy cation beam to improve the surface properties and enhance the bonding ability with the hole injection layer.

[0163] The glass substrate was placed inside a vacuum chamber, and the vacuum was evacuated to 1×10⁻⁶. -5 ~9×10 -3 Pa, HIL02 was vacuum-deposited on the anode as a hole injection layer at a deposition rate of 0.1 nm / s and a film thickness of 100 nm;

[0164] The glass substrate with the hole injection layer already deposited was transferred to a glove box filled with nitrogen. Chlorobenzene solutions of the compound of this application and the comparative compound were spin-coated onto the hole injection layer at a spin speed of 1000 rpm for 60 seconds. By adjusting the concentrations of the compound of this application and the comparative compound in the solvent, the thickness of the hole transport layer was made to be between 45 and 55 nm. The glass substrate was then heated at 80°C for 2 hours, and the solvent was removed under vacuum. The thickness of the hole transport layer on the spin-coated substrate was measured using a profilometer (Amibios XP-2 surface profiler) and is listed in the table below.

[0165] The glass substrate with the hole transport layer already spin-coated in the previous step is transferred to the vacuum chamber, and EM39 is vacuum-deposited on the hole transport layer as the organic light-emitting layer of the device. The deposition rate is 0.1 nm / s and the total film thickness is 30 nm.

[0166] TPBI was vacuum-deposited on top of the organic light-emitting layer as the electron transport layer of the organic electroluminescent device; the deposition rate was 0.1 nm / s and the total film thickness was 30 nm.

[0167] 0.5 nm LiF and 150 nm Al were vacuum-deposited on the electron transport layer as the electron injection layer and cathode, respectively.

[0168] The brightness, driving voltage, and current efficiency of the prepared organic electroluminescent device were measured.

[0169] The performance of the organic electroluminescent devices is shown in Table 2 below. The tests were conducted using the OLED-1000 multi-channel accelerated aging lifetime and photochromic performance analysis system manufactured by Hangzhou Yuanfang.

[0170] Table 2

[0171]

[0172] Device Example 3

[0173] The examples use compounds from this application as the green light host material in organic electroluminescent devices, while the comparative examples use GH-1 and GH-2 as the green light host materials in organic electroluminescent devices.

[0174] The structure of the organic electroluminescent device is as follows: ITO / NPB (20 nm) / green light host material (30 nm): Ir(ppy)3 [7%] / TPBI (10 nm) / Alq3 (15 nm) / LiF (0.5 nm) / Al (150 nm). Here, "Ir(ppy)3 [7%]" refers to the doping ratio of the green dye, i.e., the weight ratio of the green light host material to Ir(ppy)3 is 100:7.

[0175] The fabrication process of organic electroluminescent devices is as follows: a glass plate coated with an ITO transparent conductive layer is ultrasonically treated in a commercial cleaning agent, rinsed in deionized water, ultrasonically degreased in a acetone:ethanol mixed solvent, baked in a clean environment until all moisture is removed, cleaned with ultraviolet light and ozone, and bombarded with a low-energy cation beam;

[0176] The glass substrate with the anode was placed in a vacuum chamber and evacuated to a vacuum level of 1×10⁻⁶. -5 ~9×10 -3 Pa, a hole transport layer NPB is vacuum-deposited on the above-mentioned anodic layer film at a deposition rate of 0.1 nm / s and a film thickness of 20 nm.

[0177] Green light host material and dye Ir(ppy)3 were vacuum-deposited on the hole transport layer as the light-emitting layer of the organic electroluminescent device. The deposition rate was 0.1 nm / s and the total film thickness was 30 nm.

[0178] Electron transport layers TPBI and Alq3 were sequentially vacuum-deposited on top of the light-emitting layer at a deposition rate of 0.1 nm / s, with film thicknesses of 10 nm and 15 nm, respectively.

[0179] 0.5 nm of LiF was vacuum-deposited on the electron transport layer, and 150 nm of Al was used as the electron injection layer and cathode.

[0180] All organic electroluminescent devices were prepared using the above method, with the only difference being the choice of the green light host material, as detailed in Table 3 below.

[0181] Performance testing:

[0182] The brightness, driving voltage, and current efficiency of the prepared organic electroluminescent device were tested and measured using the OLED-1000 multi-channel accelerated aging lifetime and photoluminescence performance analysis system manufactured by Hangzhou Yuanfang. The test results are shown in the table below.

[0183] Table 3

[0184]

[0185] As shown in the table above, compared with the comparative compounds, the compounds provided in this application, as the green light host material of organic electroluminescent devices, can improve luminous efficiency and reduce driving voltage.

[0186] Obviously, those skilled in the art can make various modifications and variations to the embodiments of this application without departing from the spirit and scope of this application. Therefore, if these modifications and variations of this application fall within the scope of the claims of this application and their equivalents, this application also intends to include these modifications and variations.

Claims

1. A compound, characterized in that, The structural formula of the compound is shown in formula (I). ， Where a, b, c, and d are each independently selected from 0, 1, 2, 3, or 4; p is selected from 0 or 1; R1 to R4 are each independently selected from hydrogen, deuterium, F, CN, alkyl groups containing 1 to 20 carbon atoms, alkoxy groups containing 1 to 20 carbon atoms, and aromatic groups containing 6 to 40 carbon atoms; the hydrogen in the aromatic group containing 6 to 40 carbon atoms can be replaced by R; wherein R can form a ring with spirofluorene, and Ar can form a ring with Ar1 and Ar2; Ar and Ar1 are each independently selected from aromatic groups containing 6 to 40 carbon atoms, wherein the hydrogen in the aromatic group containing 6 to 40 carbon atoms can be replaced by R; Ar2 is selected from one of the structures shown in A-1 to A-8: ， Where * indicates the position where Ar2 and the N atom in formula (I) are connected; R5~R 14 Each is independently selected from alkyl groups containing 1 to 20 carbon atoms and aromatic groups containing 6 to 40 carbon atoms; the hydrogen in the aromatic group containing 6 to 40 carbon atoms can be replaced by R; e and f are each independently selected from 0 or 1, and e and f are not both 0 at the same time; R is selected from alkyl groups containing 1 to 20 carbon atoms, alkoxy groups containing 1 to 20 carbon atoms, or aromatic groups containing 6 to 40 carbon atoms.

2. The compound according to claim 1, characterized in that, Ar1 is selected from one of B-1 to B-4: R 21 ~R 22 Each is independently selected from alkyl groups containing 1 to 20 carbon atoms and aromatic groups containing 6 to 40 carbon atoms; the hydrogen in the aromatic group containing 6 to 40 carbon atoms can be replaced by R; R 21 ~R 22 They can be linked into a ring; Ar3 and Ar4 are each independently selected from aromatic groups containing 6 to 40 carbon atoms, and the hydrogen in the aromatic group containing 6 to 40 carbon atoms can be replaced by R; p and q are selected from 0 or 1; Where * indicates the position where the N atoms in B-1 to B-4 and formula (Ⅰ) are connected.

3. The compound according to claim 1 or 2, characterized in that, The structure of the compound is selected from one of the following structures: 。 4. The compound according to claim 3, characterized in that, In compounds II-1 to II-9, Ar1 and Ar are selected from benzene, biphenyl, naphthalene, phenanthrene, fluorene, carbazole, dibenzofuran, dibenzothiophene, triphenylene, fluoranthene, or Ar2, and the hydrogen in Ar1 and Ar can be replaced by an alkyl group with 1 to 20 carbon atoms or an aromatic group with 6 to 40 carbon atoms.

5. The compound according to claim 3, characterized in that, In compounds II-1 to II-9: p is selected from 1; Ar1 is selected from benzene, biphenyl, naphthalene, phenanthrene, fluorene, carbazole, dibenzofuran, dibenzothiophene, triphenylene, and fluoranthene, and the hydrogen in Ar1 can be replaced by alkyl groups with 1 to 6 carbon atoms or aromatic groups with 6 to 12 carbon atoms; Ar is selected from benzene, biphenyl, spirofluorene, naphthalene, phenanthrene, fluorene, carbazole, dibenzofuran, dibenzothiophene, triphenylene, and fluoranthene, and the hydrogen in Ar can be replaced by alkyl groups with 1 to 6 carbon atoms or aromatic groups with 6 to 12 carbon atoms.

6. The compound according to claim 3, characterized in that, In compounds II-1 to II-9, p is selected from 0; Ar1 ​​is selected from benzene, biphenyl, naphthalene, phenanthrene, fluorene, carbazole, dibenzofuran, dibenzothiophene, triphenylene, fluoranthene, and the hydrogen in Ar1 can be replaced by an alkyl group with 1 to 6 carbon atoms or an aromatic group with 6 to 12 carbon atoms.

7. The compound according to claim 1, characterized in that, The compound is selected from any one of the following compounds: 。 8. A compound intermediate, characterized in that, The compound intermediate is selected from one of the following structures: 。 9. An organic electroluminescent device, characterized in that, The organic electroluminescent device includes the compound as described in any one of claims 1-7.

10. A display device, characterized in that, Including the organic electroluminescent device as described in claim 9.

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