Compounds and organic electroluminescent devices and display devices

Abstract

The present application 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 shown in formula (I) to formula (III): The organic electroluminescent device using the material of the compound of the present application has a lower driving voltage and a higher current efficiency, and has a longer lifespan.

Description

Technical Field

[0001] The present application relates to the field of electroluminescence, and in particular to a compound and an organic electroluminescent device and a display device. Background Art

[0002] Currently, organic electroluminescent (OLED) display technology has been applied in smart phones, tablet computers and other fields, and will be further expanded to large-size application fields such as televisions. In the past 30 years of development, people have developed various OLED materials with excellent performance, and through different designs of device structures and optimization of device performance such as life and efficiency, the commercialization process of OLED has been accelerated, making OLED widely used in the display and lighting fields.

[0003] The selection of materials for the hole layer, light-emitting layer and other organic functional layers also has a significant impact on the current efficiency, driving voltage and life of the device. Currently, we are still exploring functional layer materials with higher performance.

[0004] Therefore, in order to meet people's higher requirements for OLED devices, the field is in urgent need of developing more types of OLED materials with higher performance. Summary of the invention

[0005] The present application discloses a compound, an organic electroluminescent device, and a display device. The organic electroluminescent device using the material of the compound of the present application has a lower driving voltage and a higher current efficiency. At the same time, the OLED device prepared by the compound provided by the present application has a longer lifespan.

[0006] In order to achieve the above objectives, this application provides the following technical solutions:

[0007] A compound, the structural formula of the compound is as shown in formula (I) to formula (III):

[0008]

[0009] wherein a, b, c, d, e, f, g are each independently selected from 0, 1, 2, 3 or 4; p is selected from 0 or 1; R1 to R7 are each independently selected from hydrogen, deuterium, F, CN, an alkyl group containing 1 to 6 carbon atoms, an alkoxy group containing 1 to 6 carbon atoms, and an aromatic group containing 6 to 13 carbon atoms; the hydrogen in the aromatic group containing 6 to 13 carbon atoms may be replaced by R;

[0010] R 11 , R 12 Each is independently selected from an alkyl group containing 1 to 6 carbon atoms and an aromatic group containing 6 to 13 carbon atoms, wherein the hydrogen in the aromatic group containing 6 to 13 carbon atoms may be replaced by R; R 11 , R12 They can be connected to form a ring through single bonds;

[0011] R 31 ~R 35 are independently selected from hydrogen, deuterium, F, CN, an alkyl group containing 1 to 6 carbon atoms, an alkoxy group containing 1 to 6 carbon atoms, an aromatic group containing 6 to 13 carbon atoms, or triphenylene, and R 31 ~R 35 At least one is selected from Ar1 or Ar2

[0012]

[0013] Where R 41 ~R 45 , R 51 ~R 55 independently selected from hydrogen, deuterium, F, CN, an alkyl group containing 1 to 6 carbon atoms, an alkoxy group containing 1 to 6 carbon atoms, an aromatic group containing 6 to 13 carbon atoms or triphenylene, and when R 31 ~R 35 When one of them is selected from Ar1, R 31 ~R 35 The remaining four and R 41 ~R 45 At least one of them is selected from deuterium, F, CN, an alkyl group containing 1 to 6 carbon atoms, an alkoxy group containing 1 to 6 carbon atoms, an aromatic group containing 6 to 13 carbon atoms, or triphenylene;

[0014] Ar is selected from an aromatic group containing 6 to 13 carbon atoms, and the hydrogen in the aromatic group containing 6 to 13 carbon atoms can be replaced by R;

[0015] R is selected from an alkyl group containing 1 to 6 carbon atoms, an alkoxy group containing 1 to 6 carbon atoms, or an aromatic group containing 6 to 13 carbon atoms;

[0016] Furthermore, the compound is selected from one of the following structures:

[0017]

[0018]

[0019] Furthermore, the sum of a, b, c, d, e, f and g is less than 3, and the sum of e, f and g is 1 or 0.

[0020] Furthermore, R 31 ~R 35 One of them is selected from Ar1.

[0021] Furthermore, R 11 , R 12Selected from methyl, ethyl or phenyl.

[0022] Furthermore, a, b and d are selected from 0, c is selected from 1, and R3 is selected from an alkoxy group containing 1 to 6 carbon atoms or an aromatic group containing 6 to 12 carbon atoms.

[0023] Further, in the six structures of Formula I-2, Formula II-2, Formula III-2, Formula I-3, Formula II-3, and Formula III-3, the sum of a, b, c, and d is equal to 1 or 0;

[0024] Furthermore, the sum of e, f, and g is equal to 1 or 0;

[0025] Furthermore, R 31 ~R 35 One of them is selected from Ar1, and R 31 ~R 35 The remaining four and R 51 ~R 55 At least one of them is selected from an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms or an aromatic group having 6 to 13 carbon atoms.

[0026] Furthermore, R 11 , R 12 is selected from methyl, ethyl, phenyl, and R 11 , R 12 They can be linked to form rings via single bonds.

[0027] Further, in the nine structures of Formula I, Formula II, Formula III, Formula I-2, Formula II-2, Formula III-2, Formula I-3, Formula II-3, and Formula III-3, Ar is selected from phenyl, biphenyl, naphthyl, 9,9-dialkyl substituted fluorenyl, triphenylene, and fluoranthene, and the hydrogen in Ar can be replaced by R.

[0028] Furthermore, in the nine structures of Formula I, Formula II, Formula III, Formula I-2, Formula II-2, Formula III-2, Formula I-3, Formula II-3, and Formula III-3, a, b, and d are selected from 0, c is selected from 1, and R3 is selected from an alkoxy group containing 1 to 6 carbon atoms or an aromatic group containing 6 to 12 carbon atoms.

[0029] Further, in the nine structures of Formula I, Formula II, Formula III, Formula I-2, Formula II-2, Formula III-2, Formula I-3, Formula II-3, and Formula III-3, a, b, d, e, f, and g are selected from 0, c is selected from 1, R3 is selected from an alkoxy group containing 1 to 6 carbon atoms or an aromatic group containing 6 to 12 carbon atoms, and R 31 ~R 35 Selected from H and benzene.

[0030] Further, in the nine structures of Formula I, Formula II, Formula III, Formula I-2, Formula II-2, Formula III-2, Formula I-3, Formula II-3, and Formula III-3, a, b, c, d, e, f, and g are selected from 0, R 31 ~R 35 One of them is selected from Ar1, and R 31 ~R 35 The remaining four and R 51 ~R 55 At least one of them is selected from an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms or an aromatic group having 6 to 13 carbon atoms.

[0031] Further, the compound is selected from one of the structures shown in P-1 to P-97 or one of the isomers of the structures shown in P-1 to P-97:

[0032]

[0033]

[0034]

[0035]

[0036]

[0037]

[0038]

[0039] The isomers of the above structure are: when p=1, the spirofluorene group and the diarylamine group are both connected to the fixed position of Ar, wherein any possible connection structure between the aromatic groups constituting Ar, and the structure formed by the connection of any Sp2 hybridized carbon atom on the Ar group with the spirofluorene and diarylamine groups are defined as isomers of the above structure, and are all included in the technical solution of the present application.

[0040] The following uses a specific compound as an example to explain its related isomers.

[0041] The structure of compound P-64 is as follows:

[0042]

[0043] Its isomers include but are not limited to the following structures:

[0044]

[0045] The structure of compound P-55 is as follows:

[0046]

[0047] Its isomers include but are not limited to the following structures:

[0048]

[0049] In addition, the isomers also include the following situations:

[0050] In the above specific structure, when R 31 ~R 35 When at least one Ar1 or Ar2 is present, a specific structure is obtained. The isomers described in this application include the nine structures of formula I, formula II, formula III, formula I-2, formula II-2, formula III-2, formula I-3, formula II-3, and formula III-3. The various possible connections of the various aromatic groups are illustrated as follows: Taking the structure of compound P-36 as an example, R 31 ~R 35 When four of them are selected from H and one is not selected from H but is selected from benzene.

[0051] The isomers of P-36 described in this application include but are not limited to the following structures:

[0052]

[0053] The isomers of other specific structural compounds can be understood by referring to the above explanations.

[0054] In a second aspect, the present application provides an organic electroluminescent device, wherein the organic electroluminescent device comprises the compound of the present application.

[0055] Furthermore, the material of the hole transport layer and / or the electron blocking layer of the organic electroluminescent device is the compound of the present application.

[0056] In a third aspect, the present application provides a display device, including the organic electroluminescent device provided by the present application.

[0057] The technical solution of this application produces the following beneficial effects:

[0058] The present application provides a compound shown in formula (I) to formula (III), with spirofluorene group as the parent core, and at the same time limits the specific position and N atom connection on the benzofluorene group in the general formula. The selection range of each substituent group is also limited, the material performance is improved, and the material is more improved than the existing material. At the same time, the structure of the compound is changed, the HOMO and LOMO energy levels of the material are improved, so that the material described in the present application has higher luminous efficiency, lower driving voltage and longer life when used as a hole transport layer (HTL) material in OLED devices. DETAILED DESCRIPTION

[0059] The following will be combined with the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0060] It should be noted that: in this application, if there is no special description, all the embodiments and preferred implementation methods mentioned herein can be combined with each other to form a new technical solution. In this application, if there is no special description, all the technical features and preferred features mentioned herein can be combined with each other to form a new technical solution. In this application, if there is no special description, percentage (%) or part refers to the weight percentage or weight part relative to the composition. In this application, if there is no special description, the components or their preferred components involved can be combined with each other to form a new technical solution. In this application, unless otherwise specified, the numerical range "a-b" represents an abbreviation of any real number combination between a and b, where a and b are both real numbers. For example, the numerical range "6-22" means that all real numbers between "6-22" have been listed in this article, and "6-22" is just an abbreviation of these numerical combinations. The "range" disclosed in this application can be one or more lower limits and one or more upper limits in the form of lower limits and upper limits. In this application, unless otherwise specified, each reaction or operation step can be carried out sequentially or not in sequence. Preferably, the reaction method in this article is carried out sequentially.

[0061] Unless otherwise specified, the professional and scientific terms used herein are the same as those familiar to those skilled in the art. In addition, any method or material similar or equivalent to the described content may also be applied to the present application.

[0062] Synthesis Example 1 Synthesis of Compound P-1

[0063] (1) Synthesis of intermediate M-1:

[0064]

[0065] In a 250 ml three-necked flask, under nitrogen protection, add 100 ml of dry toluene, 2.45 g (0.01 mol) of 4-aminoterphenyl, 3.23 g (0.01 mol) of 9-bromo-7,7-dimethyl-7H-benzo[c]fluorene, 0.0575 g (0.0001 mol) of Pd(dba)2 (bis(dibenzylideneacetonepalladium), 0.4 g (0.0002 mol) of a toluene solution containing 10% tri-tert-butylphosphine, and 1.44 g (0.015 mol) of sodium tert-butoxide. Heat to 60°C for 10 hours, cool, add water to separate, wash the organic layer with water until it is neutral, dry with magnesium sulfate, filter to remove the magnesium sulfate, concentrate to dryness, and recrystallize with methanol to obtain 2.8 g of the compound represented by formula M-1.

[0066] The compound represented by formula M-1 was subjected to mass spectrometry detection, and the m / z of the molecule was determined to be 487.

[0067] (2) Synthesis of P-1

[0068]

[0069] In a 500 ml three-necked flask, under nitrogen protection, add 250 ml of dry toluene, 4.88 g (0.01 mol) of the compound shown in M-1, 4.71 g (0.01 mol) of 2-(4-bromophenyl)-9,9'-spirobifluorene, 0.0575 g (0.0001 mol) of Pd(dba)2 (bis(dibenzylideneacetonepalladium), 0.4 g (0.0002 mol) of a toluene solution containing 10% tri-tert-butylphosphine, and 1.44 g (0.015 mol) of sodium tert-butoxide. Heat to reflux for 6 hours, cool, add water to separate, wash the organic layer with water until neutral, dry with magnesium sulfate, filter to remove magnesium sulfate, concentrate to dryness, separate by silica gel column chromatography, and elute with petroleum ether:ethyl acetate = 20:0.5 (volume ratio) to obtain 6.7 g of the compound shown in formula P-1.

[0070] The compound represented by formula P-1 was subjected to mass spectrometry detection, and the m / z of the molecule was determined to be 877.

[0071] Synthesis Example 2 Synthesis of Compound P-2

[0072] The synthesis method refers to the synthesis of P-1, except that 9-bromo-7,7-dimethyl-7H-benzo[c]fluorene is replaced with 2-bromo-11,11-dimethyl-11H-benzo[b]fluorene to obtain the compound shown in P-2.

[0073] The compound P-2 was detected by mass spectrometry, with m / z of 877.

[0074] Synthesis Example 3 Synthesis of Compound P-3

[0075] The synthesis method refers to the synthesis of P-1, except that the 9-bromo-7,7-dimethyl-7H-benzo[c]fluorene is replaced with 9-bromo-11,11-dimethyl-11H-benzo[a]fluorene to obtain the compound shown in P-3.

[0076] The compound P-3 was detected by mass spectrometry, with m / z of 877.

[0077] Synthesis Example 4 Synthesis of Compound P-7

[0078] The synthesis method refers to the synthesis of P-1, except that the 4-aminoterphenyl is replaced by 3,5-diphenylaniline to obtain the compound shown in P-7.

[0079] The compound P-7 was detected by mass spectrometry, with m / z of 877.

[0080] Synthesis Example 5 Synthesis of Compound P-25

[0081] The synthesis method is similar to that of P-1, except that 2-(4-bromophenyl)-9,9'-spirobifluorene is replaced with 2-bromo-9,9'-spirobifluorene to obtain the compound shown in P-25.

[0082] The compound P-25 was detected by mass spectrometry, with m / z of 801.

[0083] Synthesis Example 6 Synthesis of Compound P-55

[0084] The synthesis method refers to the synthesis of P-1, except that 2-(4-bromophenyl)-9,9'-spirobifluorene is replaced with 2-(4'-bromo-[1,1'-biphenyl]-4-yl)-9,9'-spirobifluorene to obtain the compound shown in P-55.

[0085] The compound P-55 was detected by mass spectrometry with m / z of 953.

[0086] Synthesis Example 7 Synthesis of Compound P-82

[0087] (1) Synthesis of 2-bromo-7-methoxy-9,9'-spirobifluorene

[0088]

[0089] In a 500 ml autoclave, add 100 ml DMF, 4.74 g (0.01 mol) 2,7-dibromo-9,9'-spirobifluorene, 0.1 g cuprous iodide, and 0.54 g (0.01 mol) sodium methoxide. After nitrogen replacement, seal the autoclave, heat to 200 ° C for 12 hours, cool to room temperature, add water and dichloromethane for separation, wash the organic layer with water until neutral, dry with magnesium sulfate, filter out magnesium sulfate, concentrate the organic layer to dryness, separate by silica gel column chromatography, and elute with petroleum ether: ethyl acetate: dichloromethane = 10: 0.5: 1 (volume ratio) to obtain 2.1 g 2-bromo-7-methoxy-9,9'-spirobifluorene.

[0090] The obtained 2-bromo-7-methoxy-9,9'-spirobifluorene was detected by mass spectrometry, and the two largest peaks were 424 and 426. The molecular formula of the product was determined to be: C 26 H 17 BrO.

[0091] (2) Synthesis of 2-(4-chlorophenyl)-7-methoxy-9,9'-spirobifluorene

[0092]

[0093] In a 250 ml three-necked flask, under nitrogen protection, add 80 ml of dioxane, 20 ml of water, and then add 4.25 g (0.01 mol) of 2-bromo-7-methoxy-9,9'-spirobifluorene, 1.56 g (0.01 mol) of 4-chlorophenylboronic acid, 2.12 g (0.02 mol) of sodium carbonate, and 0.115 g (0.0001 mol) of tetrakistriphenylphosphine palladium. Slowly raise the temperature to reflux for reaction for 8 hours, cool down, add water to separate, wash the organic layer with water, dry with magnesium sulfate, filter to remove magnesium sulfate, and remove the solvent under reduced pressure. The obtained solid is separated by column chromatography and eluted with petroleum ether: dichloromethane = 10:1 (volume ratio) to obtain 3.1 g of 2-(4-chlorophenyl)-7-methoxy-9,9'-spirobifluorene.

[0094] Mass spectrometry was performed on 2-(4-chlorophenyl)-7-methoxy-9,9'-spirobifluorene, and the m / z of the molecule was determined to be 456.

[0095] (3) Synthesis of P-82

[0096]

[0097] The synthesis method refers to the synthesis of P-1, except that 2-(4-bromophenyl)-9,9'-spirobifluorene is replaced with 2-(4-chlorophenyl)-7-methoxy-9,9'-spirobifluorene, and the reaction time is changed to 24 hours to obtain the compound shown in P-82.

[0098] The compound P-82 was detected by mass spectrometry with m / z of 907.

[0099] Synthesis Example 8 Synthesis of Compound P-85

[0100] (1) Synthesis of 2-(4-chlorophenyl)-7-phenyl-9,9'-spirobifluorene

[0101]

[0102] The synthesis method was similar to the synthesis of 2-(4-chlorophenyl)-7-methoxy-9,9'-spirobifluorene in Example 7 to obtain 2-(4-chlorophenyl)-7-phenyl-9,9'-spirobifluorene.

[0103] The obtained 2-(4-chlorophenyl)-7-phenyl-9,9'-spirobifluorene was detected by mass spectrometry, and the m / z was 502.

[0104] (2) Synthesis of P-58

[0105]

[0106] The synthesis method was similar to that of P-82 in Example 7 to obtain P-85.

[0107] The obtained P-85 was detected by mass spectrometry, and the m / z was 953.

[0108] The products not listed in the above synthesis examples can be synthesized by conventional methods known in the art.

[0109] Device Embodiment

[0110] The specific structures of several materials used in this application are as follows:

[0111]

[0112] Device Example 1

[0113] The examples use the compounds of the present application as hole transport materials in organic electroluminescent devices, and the comparative examples use HT-1, HT-2, HT-3, and HT-4 as hole transport materials in organic electroluminescent devices.

[0114] The structure of the organic electroluminescent device is: ITO / hole transport material (20nm) / GH1 (30nm): Ir(ppy)3[7%] / TPBI (10nm) / Alq3 (15nm) / LiF (0.5nm) / Al (150nm). "Ir(ppy)3[7%]" refers to the doping ratio of the green light dye, that is, the weight ratio of the green light host material GH1 to Ir(ppy)3 is 100:7.

[0115] The organic electroluminescent device was prepared as follows: a glass plate coated with an ITO transparent conductive layer was ultrasonically treated in a commercial cleaning agent, rinsed in deionized water, ultrasonically degreased in an acetone:ethanol mixed solvent, baked in a clean environment to completely remove water, cleaned with ultraviolet light and ozone, and bombarded with a low-energy cation beam;

[0116] Place the glass substrate with the anode in a vacuum chamber and evacuate to 1×10 -5 ~9×10 -3 Pa, vacuum evaporating the comparative material and the material of the present invention on the above anode layer as a hole transport layer, the evaporation rate is 0.1nm / s, and the evaporation film thickness is 20nm;

[0117] Green light host material GH1 and dye Ir(ppy)3 are vacuum evaporated on the hole transport layer as the light-emitting layer of the organic electroluminescent device, the evaporation rate is 0.1nm / s, the total evaporation film thickness is 30nm, and the weight ratio of green light host material GH1 to Ir(ppy)3 is 100:7;

[0118] The electron transport layer TPBI and Alq3 were vacuum-deposited on the light-emitting layer in sequence, with the evaporation rate of both being 0.1 nm / s and the thickness of the evaporated films being 10 nm and 15 nm respectively;

[0119] 0.5 nm of LiF and 150 nm of Al were vacuum-deposited on the electron transport layer as the electron injection layer and cathode.

[0120] All organic electroluminescent devices are prepared by the above method, and the only difference is the choice of hole transport materials, as shown in Table 1 below.

[0121] Performance Testing:

[0122] The OLED-1000 multi-channel accelerated aging life and light color performance analysis system produced by Hangzhou Yuanfang was used to test the brightness, driving voltage, current efficiency, and LT95 of the prepared organic electroluminescent device. The test results are shown in the following table. The life data LT95 refers to the current density at room temperature (25-27°C) at the initial brightness (here 1000cd / m 2 ), the time (hours) required for the brightness to decrease to 95% of the initial brightness.

[0123] Table 1

[0124]

[0125]

[0126] It can be seen from the above table that, compared with the comparative compounds, the compounds provided in the present application can improve the luminous efficiency, reduce the driving voltage, and increase the lifespan when used as hole material transport in organic electroluminescent devices.

[0127] Obviously, those skilled in the art can make various changes and modifications to the embodiments of the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims

1. A compound, characterized in that The compound is selected from one of the following structures:

2. An organic electroluminescent device, characterized in that: Comprising the compound as claimed in claim 1.

3. A display device, characterized in that: Comprising the organic electroluminescent device as claimed in claim 2.

Images