Organic electroluminescent compound as well as preparation method and application thereof

Abstract

The invention discloses an organic electroluminescent compound as well as a preparation method and application thereof. The organic electroluminescent compound has a structure as shown in a formula I, at least one of Ar3, Ar4 and Ar5 is selected from a structure as shown in a formula II, and Ar1 and Ar2 are respectively and independently selected from hydrogen, deuterium, tritium, C1-C39 alkyl, C2-C39 alkenyl and C2-C39 alkynyl; and # imgabs0 # represents a connection site. In the organic electroluminescent compound, due to the existence of the group with the structure as shown in the formula II, the organic electroluminescent compound has high mobility and proper conjugation, so that the material has the characteristic of wide band gap; the organic electroluminescent compound has proper electron donating ability and higher hole mobility by being connected with arylamine, so that the compound has lower working voltage, higher efficiency and lower power consumption after being used in an organic electroluminescent device. # imgabs1 #

Description

Technical Field

[0001] The present invention relates to the field of display technology, and more specifically, to an organic electroluminescent compound and a preparation method and application thereof. Background Art

[0002] With the development of science and technology, organic electroluminescent devices (OLEDs) have a series of advantages such as full solid state, fast response speed, and wide operating temperature range, and have attracted more and more attention from academia and industry. After years of continuous and active exploration, the structure and process of the device and the further optimization of related materials, organic electroluminescence has made great progress and has now been industrialized. Although many compounds for organic electroluminescent devices have been reported in the past, such as some related compounds containing spiro rings and aromatic amines in the disclosed structures, there is still a need for compounds that further improve the performance (such as efficiency and life) of organic electroluminescent devices. Summary of the invention

[0003] Based on the above facts, the object of the present invention is to provide an organic electroluminescent compound and a preparation method and application thereof.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions:

[0005] According to a first aspect of the present invention, there is provided an organic electroluminescent compound having a structure as shown in the following formula I:

[0006]

[0007] in:

[0008] The L1, L2 and L3 are each independently selected from a single bond, a substituted or unsubstituted C6-C30 arylene group, and a substituted or unsubstituted C5-C30 heteroarylene group;

[0009] Among Ar3, Ar4 and Ar5, at least one is selected from the structure shown in Formula II:

[0010]

[0011] wherein Ar1 and Ar2 are each independently selected from hydrogen, deuterium, tritium, C1-C39 alkyl, C2-C39 alkenyl, C2-C39 alkynyl;

[0012] represents the site of attachment; and

[0013] In Ar3, Ar4 and Ar5, the groups not having the structure shown in Formula II are independently selected from C1-C39 alkyl, C2-C39 alkenyl, C2-C39 alkynyl, C6-C39 aryl, C5-C60 heteroaryl, C6-C60 aryloxy, C1-C39 alkoxy, C6-C39 arylamine, C3-C39 heterocycloalkyl, C1-C39 alkylsilyl, C1-C39 alkylboryl, C6-C39 arylboryl, C6-C39 arylphosphino and C6-C39 arylsilyl, and H in the aforementioned groups may be substituted by D.

[0014] Furthermore, the C1-C39 alkyl group is selected from a C1-C39 straight-chain alkyl group, a C1-C39 branched-chain alkyl group or a C1-C39 cycloalkyl group.

[0015] Furthermore, L1, L2 and L3 are each independently selected from a single bond and a C6-C30 arylene group.

[0016] Furthermore, the arylene group is selected from phenylene and biphenylene.

[0017] Furthermore, among Ar3, Ar4 and Ar5, the aryl group is selected from phenyl, One of the following; wherein, “·” represents a connection site.

[0018] Further, among Ar3, Ar4 and Ar5, the heteroaryl group is selected from Wherein, “·” indicates a connection site.

[0019] Furthermore, one or two of Ar3, Ar4 and Ar5 are structures represented by Formula II.

[0020] Furthermore, the organic electroluminescent compound has a structure as described in one of the following formulae:

[0021]

[0022]

[0023]

[0024]

[0025]

[0026]

[0027]

[0028]

[0029]

[0030]

[0031]

[0032]

[0033]

[0034]

[0035]

[0036]

[0037]

[0038]

[0039]

[0040]

[0041]

[0042]

[0043]

[0044]

[0045]

[0046]

[0047]

[0048]

[0049]

[0050]

[0051]

[0052]

[0053]

[0054]

[0055]

[0056]

[0057]

[0058] In another aspect, the present invention provides a method for preparing the organic electroluminescent compound as described in the first aspect, the preparation method comprising the following steps:

[0059] In the presence of a catalyst and an alkaline substance, compound XL d -Ar d With compound Carry out a carbon-nitrogen coupling reaction to obtain the organic electroluminescent compound:

[0060]

[0061] Among them, the L b , L c and L d The definitions of are each independently the same as those of L1, L2 and L3 in the first aspect above;

[0062] The Ar b ,Ar c and Ar d In the embodiment, at least the Ar d The definition of the group selected from the structure represented by formula II and the remaining groups not having the structure represented by formula II is the same as the definition of Ar3, Ar4 and Ar5 not having the structure represented by formula II in the first aspect above.

[0063] In another aspect, the present invention provides an organic electroluminescent device, wherein the structure of the organic electroluminescent device includes an anode, a cathode, and one or more light-emitting units disposed between the anode and the cathode;

[0064] Each light-emitting unit includes: a light-emitting layer, a hole transport region, an electron blocking layer and an electron transport region;

[0065] Wherein, the hole transport region includes a hole injection layer and a hole transport layer; the electron transport region includes at least one of an electron transport layer, a hole blocking layer and an electron injection layer;

[0066] Wherein, the material of the hole transport layer and / or the electron blocking layer includes the organic electroluminescent compound as described in the first aspect above.

[0067] In yet another aspect, the present invention provides a display device, wherein the structure of the display device includes the organic electroluminescent device as described above.

[0068] The beneficial effects of the present invention are as follows:

[0069] In the organic electroluminescent compound provided by the present invention, the presence of the group of the structure shown in formula II enables the organic electroluminescent compound to have high mobility, suitable conjugation, and the material has the characteristics of a wide band gap; by connecting with aromatic amine, the organic electroluminescent compound has appropriate electron donating ability and faster hole mobility, so that after the compound is used in an organic electroluminescent device, it has a lower operating voltage, higher efficiency and lower power consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0070] The specific implementation modes of the present invention are further described in detail below in conjunction with the accompanying drawings.

[0071] Figure 1 The NMR spectrum of compound 3-109 obtained in Example 1-1 is shown. DETAILED DESCRIPTION

[0072] In order to more clearly illustrate the present invention, the present invention is further described below in conjunction with preferred embodiments and accompanying drawings. Similar components in the accompanying drawings are represented by the same reference numerals. It should be understood by those skilled in the art that the content specifically described below is illustrative rather than restrictive, and should not be used to limit the scope of protection of the present invention.

[0073] The structure of an organic electroluminescent device (OLED) includes an anode, a cathode, and one or more light-emitting units contained between the anode and the cathode. OLED is achieved by applying a current or voltage to the main surfaces of the two electrodes, the cathode and holes are injected into the organic material layer, and negative electrons are injected into the organic layer. When the injected holes and electrons meet, excitons are formed, and the excitons drop to the ground state and emit light. In this case, the materials used for the organic material layer can be classified according to their functions: hole injection materials, hole transport materials, auxiliary transport layers, light-emitting layers, charge transport materials, and charge injection materials.

[0074] Organic compounds are used in various layers as materials for organic electronic components due to the huge differences in properties brought about by their material structures. In particular, due to the differences in the number of rings and fused positions, the types and arrangements of heteroatoms in the structure of organic compounds, organic compounds have different characteristics such as band gap (HOMO, LUMO), electrical properties, chemical properties, and physical properties.

[0075] In order to further improve the luminous efficiency of organic electronic components, reduce the driving voltage and increase the life of the components, a specific embodiment of the present invention provides an organic electroluminescent compound that can be used for a hole transport layer and / or an electron blocking layer during organic electroluminescence, and the organic electroluminescent compound has a structure shown in the following formula I:

[0076]

[0077] in:

[0078] The L1, L2 and L3 are each independently selected from a single bond, a substituted or unsubstituted C6-C30 arylene group, and a substituted or unsubstituted C5-C30 heteroarylene group;

[0079] Among Ar3, Ar4 and Ar5, at least one is selected from the structure shown in Formula II:

[0080]

[0081] wherein Ar1 and Ar2 are each independently selected from hydrogen, deuterium, tritium, C1-C39 alkyl, C2-C39 alkenyl, C2-C39 alkynyl;

[0082] ~~~~ indicates a connection site; and

[0083] In Ar3, Ar4 and Ar5, the groups not having the structure shown in Formula II are independently selected from C1-C39 alkyl, C2-C39 alkenyl, C2-C39 alkynyl, C6-C39 aryl, C5-C60 heteroaryl, C6-C60 aryloxy, C1-C39 alkoxy, C6-C39 arylamine, C3-C39 heterocycloalkyl, C1-C39 alkylsilyl, C1-C39 alkylboryl, C6-C39 arylboryl, C6-C39 arylphosphino and C6-C39 arylsilyl, and H in the aforementioned groups may be substituted by D.

[0084] The organic electroluminescent compound provided in this embodiment has a unique condensed naphthalene fragment (i.e., a group of the structure shown in Formula II), and in the fragment, Ar1 and Ar2 are not five-membered or six-membered aromatic rings or heteroaromatic rings, and this fragment is conducive to improving the mobility of the compound. This fragment is a high T1 fragment, which can prevent the exciton from diffusing to the hole transport region, and effectively improve the efficiency and life of the device. By coordinating the alkyl substitution in the periphery of the compound, the solubility of the material can be increased, and it is easy to clean and handle later.

[0085] The organic electroluminescent compound is used as a hole transport layer or (and) an electron blocking layer (EBL) of an organic electroluminescent device, which can reduce the driving voltage of the device and improve the luminous efficiency, brightness, thermal stability, color purity and device life of the device.

[0086] The planarity of molecules is a very important structural feature of molecules, and many problems are closely related to planarity. For π-conjugated systems, since their planarity obviously affects the π electron conjugation ability, it is closely related to the carrier transport ability of the material. Moreover, planarity also affects the ability of molecules to interact with each other and form stacking structures. The method in Journal of Molecular Modeling, 27, 263 (2021) can be used to evaluate the planarity of molecules / fragments. First, a plane must be fitted to the entire molecule or the local area under investigation based on the coordinates of the atoms in it using the least squares method, and this plane is required to pass through the geometric center of these atoms. Then the root mean square deviation of each atom from the fitting plane is calculated (molecular planarity parameter, MPP), which reflects the overall planarity of the molecule.

[0087] Compared with the structure obtained by replacing Formula I with 9,9-2-phenylfluorene and a five-membered or six-membered aromatic ring or heteroaromatic ring, the organic electroluminescent compound provided in this embodiment has a smaller volume and a smaller MPP value, as shown in Table 1 below, which can make the stacking between molecules more compact. In addition, the higher planarity makes the material have a higher mobility, and the use of a smaller substituent is conducive to improving the life of the device.

[0088] Table 1

[0089]

[0090] In some examples, the unsubstituted C6-C30 arylene group refers to an aromatic ring having a total carbon number between 6 and 30 connected by a conjugated system.

[0091] In some examples, the unsubstituted C6-C30 arylene group is selected from phenylene, naphthylene, anthrylene, phenanthrylene, and the like.

[0092] In some examples, the substituted C6-C30 arylene group refers to a group containing at least one heteroatom in the aromatic ring. Exemplary substituted C6-C30 arylene groups include, but are not limited to, furanylene, thienylene, and the like.

[0093] In some examples, L1, L2 and L3 are each independently selected from a single bond, a C6-C30 arylene group.

[0094] In some specific examples, the C6-C30 arylene group is selected from phenylene and biphenylene. Etc., wherein “·” indicates a connection site.

[0095] In some examples, one, two or three of L1, L2 and L3 are single bonds.

[0096] In some examples, the C1-C39 alkyl group is selected from a C1-C39 straight chain alkyl group, a C1-C39 branched chain alkyl group, or a C3-C39 cycloalkyl group.

[0097] In some specific examples, the C1-C39 alkyl group is preferably a C1-C10 straight-chain alkyl group, a C1-C10 branched-chain alkyl group, or a C3-C10 cycloalkyl group, for example, a methyl group, an ethyl group, a propyl group, and the like.

[0098] In some examples, the C2-C39 alkenyl group is a C2-C10 alkenyl group.

[0099] In some examples, the C2-C39 alkynyl group is a C2-C10 alkynyl group.

[0100] In some examples, among Ar3, Ar4 and Ar5, the C6-C39 aryl group is selected from C6-C30 aryl groups. Preferably, the C6-C39 aryl group is selected from phenyl, One of the following; wherein, “·” represents a connection site.

[0101] In some examples, among Ar3, Ar4 and Ar5, the C5-C60 heteroaryl group is selected from Wherein, “·” indicates a connection site.

[0102] In some preferred examples, one or two of Ar3, Ar4 and Ar5 are structures shown in Formula II.

[0103] It can be understood that, illustratively, in the technical scheme of the implementation method of the present invention, if only Ar3 is the structure shown in Formula II, then Ar4 and Ar5 are different from the structure shown in Formula II, and Ar4 and Ar5 are each independently selected from C1-C39 alkyl, C2-C39 alkenyl, C2-C39 alkynyl, C6-C39 aryl, C5-C60 heteroaryl, C6-C60 aryloxy, C1-C39 alkoxy, C6-C39 aromatic amino, C3-C39 heterocycloalkyl, C1-C39 alkylsilyl, C1-C39 alkylboryl, C6-C39 arylboryl, C6-C39 arylphosphino, C6-C39 arylsilyl, and H in the aforementioned groups can be replaced by D.

[0104] In some examples, the organic electroluminescent compound has a structure as described in one of the following formulas:

[0105]

[0106]

[0107]

[0108]

[0109]

[0110]

[0111]

[0112]

[0113]

[0114]

[0115]

[0116]

[0117]

[0118]

[0119]

[0120]

[0121]

[0122]

[0123]

[0124]

[0125]

[0126]

[0127]

[0128]

[0129]

[0130]

[0131]

[0132]

[0133]

[0134]

[0135]

[0136]

[0137]

[0138]

[0139]

[0140]

[0141] According to another specific embodiment of the present invention, a method for preparing the organic electroluminescent compound as described above is provided, and the preparation method comprises the following steps:

[0142] In the presence of a catalyst and an alkaline substance, compound XL d -Ar d With compound Carry out a carbon-nitrogen coupling reaction to obtain the organic electroluminescent compound:

[0143]

[0144] Among them, the L b , L c and L d The definitions of L1, L2 and L3 are independently the same as those in claim 1;

[0145] The Ar b ,Ar c and Ar d In the embodiment, at least the Ar d The definition of the group selected from the structure represented by formula II and the remaining groups not having the structure represented by formula II is the same as the definition of Ar3, Ar4 and Ar5 not having the structure represented by formula II in claim 1.

[0146] That is, Ar b ,Arc and Ar d In the formula, the groups not having the structure shown in II are each independently selected from C1-C39 alkyl, C2-C39 alkenyl, C2-C39 alkynyl, C6-C39 aryl, C5-C60 heteroaryl, C6-C60 aryloxy, C1-C39 alkoxy, C6-C39 arylamine, C3-C39 heterocycloalkyl, C1-C39 alkylsilyl, C1-C39 alkylboryl, C6-C39 arylboryl, C6-C39 arylphosphino, C6-C39 arylsilyl, and H in the aforementioned groups may be substituted by D.

[0147] In some examples, the catalyst is selected from tris(dibenzylideneacetone)dipalladium and / or tri-tert-butylphosphine.

[0148] In some examples, the alkaline substance is selected from sodium tert-butoxide.

[0149] In this embodiment, the method for preparing the organic electroluminescent compound is preferably carried out in the presence of a solvent. Exemplarily, the solvent is toluene.

[0150] In some examples, during the preparation of the organic electroluminescent compound, the reaction equation is:

[0151]

[0152] Wherein, the above X is selected from Br or I; L b , L c , L d ,Ar b ,Ar c and Ar d The definitions of are as described above.

[0153] According to another specific embodiment of the present invention, an organic electroluminescent device is provided, wherein the structure of the organic electroluminescent device includes an anode, a cathode, and one or more light-emitting units disposed between the anode and the cathode;

[0154] Each light-emitting unit includes: a light-emitting layer, a hole transport region, an electron blocking layer and an electron transport region;

[0155] Wherein, the hole transport region includes a hole injection layer and a hole transport layer; the electron transport region includes at least one of an electron transport layer, a hole blocking layer and an electron injection layer;

[0156] Wherein, the material of the hole transport layer and / or the electron blocking layer includes the organic electroluminescent compound provided in the first specific embodiment above.

[0157] In some examples, the material of the light-emitting layer includes but is not limited to

[0158] wait.

[0159] Hole transport materials:

[0160]

[0161] wait.

[0162] Electronic transmission:

[0163] wait.

[0164] According to another specific embodiment of the present invention, a display device is provided, wherein the structure of the display device includes the organic electroluminescent device as described above.

[0165] The technical solution of the present invention is described below in conjunction with some specific embodiments:

[0166] Embodiments of the organic electroluminescent compound used for the electron blocking layer of a green organic electroluminescent device:

[0167] Example 1-1

[0168] An organic electroluminescent compound (Compound 3-109), the preparation process of which is as follows:

[0169]

[0170] The specific preparation method is as follows:

[0171] In a 2L three-necked flask, 45.0mmol of N-[1,1′-biphenyl]-4-yl[1,1′-biphenyl]-2-amine and 45.0mmol of di-3-(4-bromophenyl)-1,1-dimethyl-1H-cyclobuta[1,2,3-ij]naphthalene were added, and 400ml of dried and degassed toluene was added as a solvent, and nitrogen was passed through for 30 minutes;

[0172] Then, 4.97 g (51.72 mmol) of sodium tert-butoxide, 0.39 g (1% mol) of catalyst Pd2(dba)3 and 2 ml (2% mol) of toluene solution of P(t-bu)3 (m / v, 10%) were added, the temperature was raised to 110°C, and the reaction was carried out for 6 hours;

[0173] After the reaction was completed, the mixture was cooled to room temperature, filtered, dissolved with dichloromethane, passed through a silica gel short column, the solvent was removed by rotation, and recrystallized with toluene to obtain 22.3 g of compound 3-109 with a yield of 86%.

[0174] The mass-to-charge ratio of compound 3-109 is 563.26, and the proportion of each element content is: 91.61% C, 5.9% H, 9.30% N and 2.48% O. H-NMR: 8.03-8.04 (1H), 7.84-7.86 (1H), 7.64-7.67 (2H), 7.56-7.59 (4H), 7.53-7.55 (1H), 7.39-7.48 (11H), 7.34-7.39 (1H), 7.21-7.30 (7H), 1.63 (5H). Its specific NMR spectrum is as follows Figure 1 shown.

[0175] Example 1-2 to Example 1-10

[0176] The method for preparing the compounds is the same as that of Example 1-1, except that the raw materials are selected differently, and Compound 1-86, Compound 1-90, Compound 1-101, Compound 1-107, Compound 2-20, Compound 2-44, Compound 2-71, Compound 3-34, and Compound 3-80 are prepared respectively.

[0177] Preparation of the above organic electroluminescent device:

[0178] The device provided in this embodiment includes an anode, a hole injection layer HIL, a hole transport layer HTL, an electron blocking layer EBL, a light-emitting layer EML (including a host and a guest), a hole blocking layer HBL, an electron transport layer ETL, an electron injection layer EIL, and a cathode.

[0179] Among them, the specific device structure of the compound used in this embodiment is:

[0180] ITO / HT-1:PD(1nm,98%:2%) / HT-1(110nm) / HT-2(20nm) / EML: (GH-1:GH-2:GD-1)(30nm ,60%:40%:10%) / HBL(5nm) / ETL:LIQ(35nm(1:1)) / LIQ(10nm) / Mg:Ag(11nm,2:8) / CPL.

[0181] Among them, the selection of raw materials for each layer:

[0182] EML:

[0183]

[0184] Hole transport materials:

[0185]

[0186]

[0187] Electronic transmission:

[0188]

[0189] Materials of the electron blocking layer: the compounds of the above-mentioned embodiments or comparative examples.

[0190] Organic electroluminescent device performance test:

[0191] The test results of the performance of the above green light device are shown in Table 2 below.

[0192] Table 2

[0193] G-EBL V(％) Eff.(%) LT(%) Example 1-1 3-109 94.3 180.3 201.2 Example 1-2 1-86 97.2 142.6 214.1 Examples 1-3 1-90 96.7 140.4 176.3 Examples 1-4 1-101 98.2 155.4 180.1 Examples 1-5 1-107 97.3 166.1 195.9 Examples 1-6 2-20 95.2 158.6 234 Examples 1-7 2-44 98.4 159.2 191.1 Examples 1-8 2-71 97.3 154.2 186.8 Examples 1-9 3-34 98.3 168.5 208.3 Examples 1-10 3-80 97.5 154.7 180.6 Comparative Example 1 EB-1 100.0 100 100 Comparative Example 2 EB-2 95.7 148.6 154.1 Comparative Example 3 EB-3 96.7 157.4 163.1

[0194] According to the above test results, the organic electroluminescent compound provided by the present invention can reduce the voltage of the organic electroluminescent device after being used in the electron blocking layer, and improve the life and efficiency. The specific fragment of the organic electroluminescent compound provided in the present invention (the structure shown in Formula II) makes the HOMO energy level of the material at a suitable level, which is deeper than the comparative example EB-1, and can reduce the interface Gap with the EML, which is conducive to the injection of holes into the light-emitting layer, so that holes and electrons recombine with the highest efficiency, reducing charge accumulation; in addition, the fragment of the material of this scheme has better planarity, which can improve the mobility of the material and make the device have higher efficiency. In addition, the alkyl substituted group of the present invention has a smaller volume than the benzene substituted fragment, accompanied by higher thermodynamic stability. Through the comparative example, the device of the present invention has a longer life.

[0195] The physical property data table of some organic electroluminescent compounds in the present invention and some materials in comparative examples are shown in Table 3 below: (energy levels are calculated using Spartan (DFT, B3LYP, 6-31g**)).

[0196] Table 3

[0197] LUMO / eV HOMO / eV EB-1 -1.00 -4.74 EB-2 -1.06 -4.81 EB-3 -0.99 -4.84 1-74 -1.05 -4.82 1-86 -1.01 -4.79 1-107 -0.99 -4.80 1-154 -1.03 -4.88 1-201 -1.05 -4.89 2-33 -1.14 -4.80 2-76 -1.08 -4.90 3-21 -1.01 -4.88 3-86 -1.09 -4.85 3-109 -1.01 -4.78 3-122 -1.03 -4.83 4-23 -1.01 -4.89 4-83 -1.07 -4.92

[0198] Embodiments of the organic electroluminescent compound used for the electron blocking layer of a blue organic electroluminescent device:

[0199] Specific materials:

[0200] Luminous layer:

[0201]

[0202] The materials of other layers are the same as those of the above green light device.

[0203] The preparation method of the B-EBL organic electroluminescent compound used in the following Examples 2-1 to 2-4 is the same as the preparation method of the compound in the green light device.

[0204] After testing, the performance of the obtained organic electroluminescent device is shown in Table 4 below.

[0205] Table 4

[0206]

[0207]

[0208] It can be seen from Table 4 that the material designed in this scheme can also be used in the structure of the electron blocking layer EBL of a blue light device, and also has the effect of improving efficiency and lifespan.

[0209] Embodiments in which the organic electroluminescent compound is used for the hole transport layer of a blue organic electroluminescent device:

[0210] ET, HB, BH, BD, EB-2 are the same as above, EBL is EB-1, and HT is as shown in Table 5 below.

[0211] The preparation method of the HT organic electroluminescent compound used in Examples 3-1 to 3-9 is the same as the preparation method of the compound in the above green light device.

[0212] After testing, the performance of the obtained organic electroluminescent device is shown in Table 5 below.

[0213] Table 5

[0214] HT V(％) Eff.(%) LT(%) Example 3-1 1-74 98.7 157.3 222.8 Example 3-2 1-81 99.2 162.1 206.6 Example 3-3 1-98 98.3 167.2 191.4 Embodiment 3-4 2-11 99.3 173.3 196.0 Embodiment 3-5 2-34 97.3 161.2 257.5 Embodiment 3-6 2-48 97.2 172.3 201.6 Embodiment 3-7 3-54 99.6 163.0 205.4 Embodiment 3-8 3-62 97.4 155.1 193.3 Embodiment 3-9 3-72 95.8 161.4 216.1 Comparative Example 6 HT-1 100.0 100.0 100.0 Comparative Example 7 HT-2 98.2 157.9 167.8

[0215] It can be seen from Table 5 that the material designed in this scheme can also be used as a hole transport layer material in the structure of a blue light organic electroluminescent device, and has the effect of improving efficiency and lifespan.

[0216] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not limitations on the implementation methods of the present invention. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description. It is impossible to list all the implementation methods here. All obvious changes or modifications derived from the technical solution of the present invention are still within the protection scope of the present invention.

Claims

1. An organic electroluminescent compound, characterized in that: The organic electroluminescent compound has a structure shown in the following formula I: in: The L1, L2 and L3 are each independently selected from a single bond, a substituted or unsubstituted C6-C30 arylene group, and a substituted or unsubstituted C5-C30 heteroarylene group; Among Ar3, Ar4 and Ar5, at least one is selected from the structure shown in Formula II: wherein Ar1 and Ar2 are each independently selected from hydrogen, deuterium, tritium, C1-C39 alkyl, C2-C39 alkenyl, C2-C39 alkynyl; ~~~~ indicates a connection site; and In Ar3, Ar4 and Ar5, the groups not having the structure shown in Formula II are independently selected from C1-C39 alkyl, C2-C39 alkenyl, C2-C39 alkynyl, C6-C39 aryl, C5-C60 heteroaryl, C6-C60 aryloxy, C1-C39 alkoxy, C6-C39 arylamine, C3-C39 heterocycloalkyl, C1-C39 alkylsilyl, C1-C39 alkylboryl, C6-C39 arylboryl, C6-C39 arylphosphino and C6-C39 arylsilyl, and H in the aforementioned groups may be substituted by D.

2. The organic electroluminescent compound according to claim 1, characterized in that The C1-C39 alkyl group is selected from a C1-C39 straight-chain alkyl group, a C1-C39 branched-chain alkyl group or a C1-C39 cycloalkyl group.

3. The organic electroluminescent compound according to claim 1, characterized in that The L1, L2 and L3 are each independently selected from a single bond and a C6-C30 arylene group.

4. The organic electroluminescent compound according to claim 1 or 3, characterized in that: The arylene group is selected from phenylene and biphenylene.

5. The organic electroluminescent compound according to claim 1, characterized in that In Ar3, Ar4 and Ar5, the aryl group is selected from phenyl, wherein "·" represents a connection site.

6. The organic electroluminescent compound according to claim 1, characterized in that In Ar3, Ar4 and Ar5, the heteroaryl group is selected from Wherein, "·" indicates the connection site.

7. The organic electroluminescent compound according to claim 1, characterized in that One or two of Ar3, Ar4 and Ar5 are structures represented by Formula II.

8. The organic electroluminescent compound according to claim 1, 5, 6 or 7, characterized in that: The organic electroluminescent compound has a structure as described in one of the following formulas:

9. The method for preparing an organic electroluminescent compound according to any one of claims 1 to 8, characterized in that: The steps include: In the presence of a catalyst and an alkaline substance, compound XL d -Ar d With compound Carry out a carbon-nitrogen coupling reaction to obtain the organic electroluminescent compound: Among them, the L b , L c and L d The definitions of are independently the same as those of L1, L2 and L3 in claim 1; The Ar b ,Ar c and Ar d In the embodiment, at least the Ar d The definition of the group selected from the structure represented by formula II and the remaining groups not having the structure represented by formula II is the same as the definition of Ar3, Ar4 and Ar5 not having the structure represented by formula II in claim 1.

10. An organic electroluminescent device, characterized in that: The structure of the organic electroluminescent device includes an anode, a cathode, and one or more light-emitting units arranged between the anode and the cathode; Each light-emitting unit includes: a light-emitting layer, a hole transport region, an electron blocking layer and an electron transport region; Wherein, the hole transport region includes a hole injection layer and a hole transport layer; the electron transport region includes at least one of an electron transport layer, a hole blocking layer and an electron injection layer; Wherein, the material of the hole transport layer and / or the electron blocking layer comprises the organic electroluminescent compound as described in any one of claims 1-9.

11. A display device, characterized in that: The structure of the display device includes the organic electroluminescent device as claimed in claim 10.

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