A compound containing carbazole and carbazole derivatives and an organic electroluminescent device

Abstract

The application discloses a compound containing carbazole and carbazole derivatives and an organic electroluminescent device, and relates to the technical field of organic electroluminescence, wherein the structural formula of the compound is shown in the following formula 1. The compound is applied to the organic electroluminescent device, the luminous efficiency of the device is greatly improved under the same current density, the starting voltage is lowered, the power consumption is relatively reduced, and the service life is correspondingly improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of organic electroluminescence, in particular to a compound containing carbazole and carbazole derivatives and an organic electroluminescence device. BACKGROUND

[0002] Organic Light-emitting Devices (OLED) are self-luminescent devices that use the following principle: when an electric field is applied, a fluorescent substance emits light through the recombination of holes injected from the anode and electrons injected from the cathode. Such self-luminescent devices have low voltage, high brightness, wide viewing angle, fast response, good temperature adaptability, and are ultra-thin, can be made on flexible panels, and have other advantages, and are widely used in mobile phones, tablets, televisions, lighting, and other fields.

[0003] Compared with the crystal layer of LED (light-emitting diode) or LCD (liquid crystal display), the organic plastic layer of OLED is thinner, lighter and more flexible; OLED is brighter than LED, the organic layer of OLED is much thinner than the corresponding inorganic crystal layer in LED, so the conductive layer and the emission layer of OLED can adopt a multi-layer structure, in addition, LED and LCD need to use glass as a support, but glass will absorb part of the light, and OLED does not need to use glass.

[0004] At present, the OLED device is composed of a substrate, a cathode, an anode, a hole injection layer (HIL), an electron injection layer (EIL), a hole transport layer (HTL), an electron transport layer (ETL), an electron blocking layer (EBL), a hole blocking layer (HBL), an emission layer (EML), etc. When a voltage is applied to the two end electrodes of the OLED device, positive and negative charges are generated in the organic layer functional material film layer by the action of the electric field, and the positive and negative charges are further recombined in the emission layer to produce light.

[0005] The viewing range of OLED is very wide, up to about 170 degrees, while LCD blocks light when working, so there is a natural observation obstacle at some angles. OLED itself can emit light, so the viewing range is also much wider.

[0006] In terms of the actual needs of the current organic electroluminescence industry, the development of organic electroluminescence materials is still far from enough, far behind the requirements of panel manufacturing enterprises. SUMMARY

[0007] The purpose of the present application is to solve the above technical problems, and to provide a compound containing carbazole and carbazole derivatives that can emit light.

[0008] Another purpose of the present application is to provide an organic electroluminescence device containing the above compound.

[0009] The object of the present application can be achieved by the following measures:

[0010] A compound containing a carbazole and carbazole derivatives, the structural formula is shown as formula 1:

[0011]

[0012] wherein,

[0013] Ra is hydrogen or deuterium;

[0014] R1-R6 are each independently hydrogen, deuterium or a substituted or unsubstituted C 6-20 aromatic group, the substituents of which are selected from one or more of deuterium, phenyl, C 1-6 alkyl or halogen;

[0015] R7-R 18 are each independently hydrogen, deuterium or a substituted or unsubstituted phenyl, the substituents of which are selected from one or more of deuterium, C 1-6 alkyl, halogen or phenyl;

[0016] Ar1 is a substituted or unsubstituted C 6-20 aromatic group, the substituents of which are selected from one or more of deuterium, phenyl, C 1-6 alkyl or halogen.

[0017] In a preferred embodiment, R1-R6 are each independently hydrogen, deuterium or a substituted or unsubstituted phenyl, biphenyl, terphenyl, anthryl, naphthyl, phenanthryl, fluorenyl, dibenzofuranyl or dibenzothiophenyl, the substituents of which are selected from one or more of deuterium, C 1-6 alkyl or phenyl.

[0018] In another preferred embodiment, R1-R6 are each independently hydrogen, deuterium, phenyl, deuterated phenyl, biphenyl, deuterated biphenyl, terphenyl, deuterated terphenyl, anthryl, deuterated anthryl, naphthyl, deuterated naphthyl or 9,9-dimethylfluorenyl.

[0019] In a preferred embodiment, R7-R 18 are each independently hydrogen, deuterium or a substituted or unsubstituted phenyl, the substituents of which are selected from one or more of deuterium or phenyl.

[0020] In another preferred embodiment, R7-R 18 are each independently hydrogen, deuterium, phenyl or deuterated phenyl.

[0021] In a preferred embodiment, Ar1 is a substituted or unsubstituted phenyl, biphenyl, terphenyl, anthryl, naphthyl, phenanthryl, fluorenyl, dibenzofuranyl or dibenzothiophenyl, the substituents of which are selected from one or more of deuterium, C1-6 One or more of alkyl or phenyl groups.

[0022] In another preferred embodiment, Ar1 is phenyl, deuterated phenyl, biphenyl, deuterated biphenyl, terphenyl, deuterated terphenyl, anthracene, deuterated anthracene, naphthyl, deuterated naphthyl, phenanthryl, deuterated phenanthryl, fluorenyl, deuterated fluorenyl, dibenzofuranyl, deuterated dibenzofuranyl, dibenzothiophenyl, deuterated dibenzothiophenyl, 9,9-dimethylfluorenyl, or deuterated 9,9-dimethylfluorenyl.

[0023] In another preferred embodiment, Ar1 is one of the following groups:

[0024]

[0025] In another preferred embodiment, R1 is hydrogen or deuterium.

[0026] In another preferred embodiment, R2 is hydrogen, deuterium, phenyl, or deuterated phenyl.

[0027] In another preferred embodiment, R3-R6 are each independently hydrogen or deuterium.

[0028] In another preferred embodiment, R7-R 10 Each is either hydrogen or deuterium.

[0029] In another preferred embodiment, R 11 -R 14 Each is either hydrogen or deuterium.

[0030] In another preferred embodiment, R 15 -R 18 Each can be independently hydrogen, deuterium, phenyl, or deuterated phenyl.

[0031] In another preferred embodiment, Ar1 is phenyl, deuterated phenyl, biphenyl, deuterated biphenyl, naphthyl, or deuterated naphthyl.

[0032] Furthermore, it is any one of the following compounds:

[0033]

[0034]

[0035]

[0036]

[0037]

[0038]

[0039]

[0040]

[0041]

[0042]

[0043]

[0044]

[0045]

[0046]

[0047]

[0048]

[0049]

[0050]

[0051]

[0052] The compound containing carbazole and carbazole derivatives of formula 1 of the present application can be prepared by the following reaction route, wherein the definition of each group is described above:

[0053]

[0054] The compound of the present application has excellent thermal stability, which can meet the requirements of the use of organic electroluminescent material. Compared with the similar compounds, the compound of the present application has the advantages of high luminous efficiency, low power consumption, long service life and the like. We found that when specific groups are used at Ra, R2, R 15 -R 18 And Ar1, the compound can have more excellent effect, the luminous efficiency can be greatly improved, the power consumption of the light emitting device is lower, and the service life is greatly improved.

[0055] An organic electroluminescent device, which comprises a first electrode, a second electrode and an organic layer formed between the first electrode and the second electrode, wherein the organic layer contains the compound of formula 1 of the present application.

[0056] Further, the organic layer of the organic electroluminescent device comprises a hole injection layer, a first hole transport layer, a second hole transport layer, a light-emitting layer, a hole blocking layer, an electron transport layer, an electron injection layer; at least one of the hole injection layer, the first hole transport layer, the second hole transport layer, the light-emitting layer, the hole blocking layer, the electron transport layer, the electron injection layer contains the compound of formula 1 according to the present application.

[0057] Further, the light-emitting layer of the organic electroluminescent device contains the compound of formula 1 according to the present application.

[0058] Further, the light-emitting layer of the organic electroluminescent device contains at least one of the following compounds G1-G56:

[0059]

[0060]

[0061]

[0062] The present application also provides an electronic display device containing the organic electroluminescent device described above.

[0063] The present application also provides an OLED lighting device containing the organic electroluminescent device described above.

[0064] The following terms used in the claims and the specification have the following meanings unless otherwise indicated.

[0065] "H", refers to protium (1H), which is the primary stable isotope of the element hydrogen.

[0066] "Deuterium", refers to a stable form of isotope of hydrogen, also known as heavy hydrogen, with the element symbol D.

[0067] "Halogen", refers to a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom.

[0068] "Aromatic group", abbreviated as "aryl", refers to a monocyclic, fused or condensed polycyclic group containing multiple carbon atoms, or also containing one or more ring heteroatoms (such as N, O or S), all or part of which have a fully conjugated pi-electron system. The number of carbon ring atoms in the aromatic group can be represented by C6-20 or the like, for example, C 6-20 The aromatic group refers to the number of carbon ring atoms in the aromatic group can be 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, and so on, up to 20. The aromatic group can be represented by C 6-20 The aromatic group, C 6-16 The aromatic group, C 6-12 The aromatic group, C6-10 Aromatic groups, C 6-9 Aromatic groups, C 6-8 Aromatic groups, C 6-7 Aromatic groups, C 8-16 Aromatic groups, etc. Non-limiting examples of aromatic groups include phenyl, biphenyl, terphenyl, anthryl, naphthyl, phenanthryl, fluorenyl, dibenzofuranyl, dibenzothiophene, 9,9-dimethylfluorenyl, benzimidazolyl, quinolinyl, isoquinolinyl, etc.

[0069] "Substituted or unsubstituted" means that the following group may or may not have substituents. As used herein, in "substituted" or "unsubstituted," the term "substituted" means that at least one hydrogen in the group is recoordinated with a hydrocarbon group, hydrocarbon derivative group, halogen, cyano (-CN), or other substituent. The term "unsubstituted" means that none of the hydrogens in the group are recoordinated with a hydrocarbon group, hydrocarbon derivative group, halogen, cyano (-CN), or other substituents. Examples of hydrocarbon groups or hydrocarbon derivative groups may include, but are not limited to, C1 to C20 alkyl, C2 to C20 alkenyl, C2 to C20 alkynyl, C6 to C20 aryl, C5 to C20 heteroaryl, C1 to C20 alkylamino, C6 to C20 aromaticamino, C6 to C20 heteroarylamino, C6 to C20 arylheteroarylamino, etc.

[0070] "The substituent is selected from one or more of..." means that the group can have one, two, or more substituents. When there are multiple substituents, they can be multiple identical substituents or multiple different substituents. Taking "The substituent is selected from one or more of deuterium or phenyl" as an example, when there is one substituent, it can be either deuterium or phenyl; when there are multiple substituents, they can all be deuterium, all be phenyl, or some can be deuterium and some are phenyl.

[0071] "Alkyl" refers to a saturated aliphatic hydrocarbon group with 1-10 carbon atoms, including straight-chain and branched groups (the numerical range mentioned in this application, such as "1-10", refers to the group, which is an alkyl group and can contain 1, 2, 3, etc., up to 10 carbon atoms). The alkyl group can be C10 or C20. 1-6 Alkyl, C 1-5 Alkyl, C 1-4 Alkyl, C 1-3 Alkyl, C 1-2 Alkyl, C 2-3 Alkyl, C 2-4 Alkyl groups, etc. Specific alkyl groups include, but are not limited to, methyl, ethyl, propyl, 2-propyl, n-butyl, isobutyl, or tert-butyl.

[0072] The "*" in the group refers to the connection site of the group to other groups or parent rings. When there are multiple connection sites of a group to other groups or parent rings, if not specifically mentioned, it refers to multiple connection sites of the group. Taking biphenyl as an example, the connection site of the biphenyl to other groups or parent rings can be on the para position, meta position or ortho position of one benzene ring.

[0073] Advantages of the present application:

[0074] The present application designs a new class of organic electroluminescent materials. The compounds are formed by connecting and combining carbazole and carbazole derivatives, triazine and triazine derivatives, and dibenzofuran and dibenzofuran derivatives in a specific way. The 1 position of dibenzofuran is the active position, which is protected by a benzene ring or a deuterated benzene ring and connected to a triazine group. The dibenzofuran, phenyl or deuterated phenyl forms an ortho relationship with the triazine. This connection relationship has the following advantages:

[0075] 1. The spatial steric hindrance of the material molecule is improved, thereby improving the triplet energy level of the material molecule, effectively avoiding the reverse transfer of energy from the doped material to the host material;

[0076] 2. The torque of the material can be improved, the planarity of the material molecule is reduced, thereby reducing the crystallinity, improving the film-forming property, improving the stability of the device, and thereby improving the service life and efficiency of the device;

[0077] 3. The conjugation degree of the material is reduced, the rigidity of the material molecule is reduced, thereby improving the solubility of the material, reducing the preparation difficulty and cost of the material.

[0078] The compound of the present application forms a new parent ring structure through reasonable connection and combination of carbazole, triazine, dibenzofuran and benzene. With the cooperation of other groups, the compound has the advantages of high luminous efficiency, low power consumption and long service life.

[0079] Through device verification, the organic electroluminescent device prepared using the compound designed in the present application has better luminous efficiency and service life. BRIEF DESCRIPTION OF DRAWINGS

[0080] Figure 1 The figure is a structural schematic diagram of the organic electroluminescent device of the present application;

[0081] The labels in the figure respectively represent: 1-anode, 2-hole injection layer, 3-first hole transport layer, 4-second hole transport layer, 5-emitting layer, 6-hole blocking layer, 7-electron transport layer, 8-electron injection layer, 9-cathode.

[0082] Figure 2 The figure is a HPLC chart of the compound 1 prepared in Example 1 of the present application.

[0083] Figure 3 The DSC pattern of compound 1 prepared in Example 1 of the present application is shown in the following table. Figure 3 It can be seen that the Tm value of compound 1 is 245.00°C.

[0084] Figure 4 The TGA pattern of compound 1 prepared in Example 1 of the present application is shown in the following table. Figure 4 It can be seen that the thermal weight loss temperature Td value is 433.06°C.

[0085] Figure 5 The lifetime pattern of the organic electroluminescent device prepared in Application Example 1 and Comparative Example 1 of the present application is shown in the following table. Figure 5 It can be seen that the T97% lifetime of the organic electroluminescent device prepared in Application Example 1 and Comparative Example 1 of the present application is 601 h and 434 h, respectively. DETAILED DESCRIPTION

[0086] Embodiments of the various aspects are further illustrated and described below. It is to be understood that the description herein is not intended to limit the claims to the particular aspects described. Rather, the intention is to cover any alternatives, modifications, and equivalents that can be included within the spirit and scope of the patent disclosure as defined by the claims.

[0087] Unless otherwise indicated, conventional methods or those described in the literature were used in the examples. Unless otherwise indicated, the reagents or instruments used were conventional products available on the market.

[0088] Example 1:

[0089]

[0090] The synthesis method of compound 1 is as follows:

[0091]

[0092] Under nitrogen protection, compound 1-a (1.1 eq, 11.41 g, 370.25 g / mol, 30.83 mmol), compound 1-b (1 eq, 10 g, 356.81 g / mol, 28.03 mmol) were dissolved in 200 mL of toluene, palladium acetate (0.31 g, 224.51 g / mol, 1.40 mmol), X-phos (0.26 g, 476.72 g / mol, 1.40 mmol), potassium carbonate (11.62 g, 138.21 g / mol, 84.08 mmol) were added, and then 100 mL of ethanol and 50 mL of water were added. The reaction was stirred at 82°C overnight, and the reaction progress was monitored by HPLC.

[0093] After the reaction of compound 1-b was completed, the reaction was stopped, the reaction solution was cooled to room temperature, 60 mL of water was added, stirred for 20 min, suction filtered to obtain a filter cake, the filter cake was washed twice with water and ethanol, and then dried in vacuum at 80°C for 6 hours. The dried filter cake was added to a 250 mL three-necked flask, 100 mL of o-dichlorobenzene was added, heated to 120°C until the solid was completely dissolved. After complete dissolution, the hot solution was passed through a silica gel and activated carbon funnel to obtain a filtrate. The filtrate was naturally cooled to room temperature, and white solid was precipitated. The filtrate was suction filtered to obtain a filter cake. The filter cake was subjected to two more recrystallization operations to obtain the final target product compound 1, with a yield of 38.5%, ESI-MS (m / z) (M+): theoretical value 564.63, found value 564.02, elemental analysis results (molecular formula C39H24N4O): theoretical value C, 82.96; H, 4.28; N, 9.92; O, 2.83; found value C, 82.91; H, 4.34; N, 9.87; O, 2.88.

[0094] The following compounds in Table 1 were obtained in a similar manner:

[0095] Table 1

[0096]

[0097]

[0098]

[0099]

[0100]

[0101]

[0102]

[0103] The synthesis identification results of the compounds prepared above are shown in Table 2 below:

[0104] Table 2

[0105]

[0106]

[0107] Material property test:

[0108] The thermal weight loss temperature Td and the melting point Tm of the compounds 1, 6, 7, 12, 20, 32, 36, 40, 78, 83, 88, 90, 91, 95, 101, 121, 132, 174, 180, 182, 190, 219, 222, 230, 238, 250, 261, 272, 307, 315, 327 of the present application were tested, and the test results are shown in Table 3.

[0109] Note: The thermal weight loss temperature Td is the temperature at which 5% weight loss occurs in a nitrogen atmosphere, and is measured on a TGA N-1000 thermal gravimetric analyzer at a nitrogen flow rate of 10 mL / min. The melting point Tm is measured by differential scanning calorimetry (DSC, Shinco DSC N-650) at a temperature increase rate of 10°C / min.

[0110] Table 3:

[0111]

[0112]

[0113] From the above data, it can be seen that the thermal stability of the compounds synthesized in the present application is excellent, which indicates that the compounds conforming to the structural general formula of the present application all have excellent thermal stability, and can meet the requirements for use of organic electroluminescent materials.

[0114] Device performance test:

[0115] Application Example 1:

[0116] ITO is used as the reflective layer anode substrate material, and the surface is treated with water, acetone, N2 plasma in sequence;

[0117] On the ITO anode substrate, 10 nm of HT-1 doped with 2% NDP-9 (mass percentage) is deposited to form a hole injection layer (HIL);

[0118] On the hole injection layer (HIL), 100 nm of HT-1 is evaporated to form a first hole transport layer (HTL);

[0119] On the first hole transport layer (HTL), GP is vacuum evaporated to form a second hole transport layer (GPL) with a thickness of 30 nm;

[0120] The compound 1 designed in the present application and G1 are co-evaporated as green host materials in a mass ratio of 5:5, and GD-1 is evaporated on the second hole transport layer (GPL) as a dopant material (the amount of GD-1 is 8% of the total mass of compound 1 and G1) to form a light-emitting layer with a thickness of 30 nm;

[0121] HB-1 was evaporated onto the light-emitting layer to obtain a hole blocking layer (HBL) with a thickness of 20 nm;

[0122] ET-1 and LiQ were co-evaporated onto the hole blocking layer (HBL) in a ratio of 5:5 to obtain an electron transport layer (ETL) with a thickness of 30 nm;

[0123] Magnesium (Mg) and silver (Ag) were mixed and evaporated onto the electron transport layer (ETL) in a mass ratio of 9:1 to form an electron injection layer (EIL) with a thickness of 50 nm;

[0124] Thereafter, silver (Ag) was evaporated onto the electron injection layer to form a cathode with a thickness of 100 nm, and a DNTPD with a thickness of 50 nm was deposited on the cathode sealing layer. In addition, the cathode surface was sealed with a UV-hardened adhesive and a seal cap containing a moisture absorbent to protect the organic electroluminescent device from the influence of oxygen or moisture in the atmosphere. Thus, an organic electroluminescent device was prepared.

[0125]

[0126]

[0127] Example 2-31

[0128] The compounds 6, 7, 12, 20, 32, 36, 40, 78, 83, 88, 90, 91, 95, 101, 121, 132, 174, 180, 182, 190, 219, 222, 230, 238, 250, 261, 272, 307, 315, 327 in Example 2-31 of the present application were used as green light host materials, respectively, and the other parts were the same as in Example 1. Accordingly, the organic electroluminescent device of Example 2-31 was produced.

[0129] Comparative Example 1-6:

[0130] The difference from Example 1 is that GH-1, GH-2, GH-3, GH-4, GH-5, GH-6 in CN110540536A were used instead of compound 1 as green light host materials, respectively, and the rest was the same as in Example 1.

[0131] The properties of the organic electroluminescent devices produced in the above examples and the organic electroluminescent devices produced in the comparative examples were measured under the condition of a current density of 10 mA / cm 2 , and the results are shown in Table 4.

[0132] Table 4:

[0133]

[0134]

[0135]

[0136] As can be seen from Table 2 above, the compound of the present application is applied to the organic electroluminescent device, the luminous efficiency is greatly improved under the same current density, the starting voltage of the device is decreased, the power consumption of the device is relatively reduced, and the service life of the device is correspondingly improved.

[0137] The organic electroluminescent devices prepared in Comparative Examples 1-6 and Application Examples 1-10 are respectively subjected to luminous life test to obtain the luminous life T97% data (time for luminous intensity to reduce to 97% of initial luminous intensity), and the test equipment is TEO luminous device life test system. The results are shown in Table 5:

[0138] Table 5:

[0139]

[0140] As can be seen from Table 5 above, the compound of the present application is applied to the organic electroluminescent device, the service life is greatly improved under the same current density, and has broad application prospects.

Claims

1. A compound containing carbazole and carbazole derivatives, characterized in that, The compound is selected from:

2. An organic electroluminescent device, characterized in that, It includes a first electrode, a second electrode, and an organic layer formed between the first electrode and the second electrode, the organic layer containing the compound as described in claim 1.

3. The organic electroluminescent device as described in claim 2, characterized in that, The organic layer comprises a hole injection layer, a first hole transport layer, a second hole transport layer, a light-emitting layer, a hole blocking layer, an electron transport layer, and an electron injection layer; at least one of the hole injection layer, the first hole transport layer, the second hole transport layer, the light-emitting layer, the hole blocking layer, the electron transport layer, and the electron injection layer contains the compound of claim 1.

4. The organic electroluminescent device as described in claim 3, characterized in that, The light-emitting layer also contains at least one of the following compounds G1-G56:

5. An electronic display device, characterized in that, It contains the organic electroluminescent device as described in claim 2.

6. An OLED lighting device, characterized in that, It contains the organic electroluminescent device as described in claim 2.

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