Organic electronic light-emitting device containing thermally activated delayed fluorescent material

Abstract

The present invention provides an organic compound and its application. The compound has a structure shown in formula (1). When the compound of the present invention is used in an organic electroluminescent device, especially as a luminescent dye material, the device driving voltage can be effectively reduced, the device luminescence efficiency can be improved, and the best effect can be achieved.

Description

Technical Field

[0001] The invention relates to the technical field of organic electroluminescent materials, and in particular to a compound, a thermally activated delayed fluorescent material, an organic electronic light-emitting device containing the same and applications thereof. Background Art

[0002] Optoelectronic devices using organic materials are becoming increasingly popular for a number of reasons. Many of the materials used to make such devices are relatively cheap, and optoelectronic devices have potential cost advantages over inorganic devices. In the structure of organic electroluminescent devices in the display and lighting fields, blue fluorescence is generally used in combination with red and green phosphorescent materials. Recently, there have been reports of TADF (Thermally Activated Delayed Fluorescence) fluorescent dye compounds based on benzonitrile carbazole. This type of compound is based on benzonitrile as an electron acceptor and multiple carbazoles are attached to the benzene ring as electron donors, with clearly separated HOMO and LUMO orbitals. For example:

[0003]

[0004] This type of material uses carbazole as an electron-donating group and introduces a large steric protective group at the carbazole active site, which is beneficial to prevent Dexter energy transfer and inhibit exciton quenching. Summary of the invention

[0005] Problem that the invention aims to solve

[0006] However, the luminescence peak of such materials in the prior art is difficult to reach the deep blue light region, and it is often difficult to achieve high efficiency when used in deep blue light devices. In addition, the life of such materials is still short. Due to these factors, it is difficult to achieve mass production and application of such materials.

[0007] The object of the present invention is to provide an organic compound which is a thermally activated delayed fluorescent material with excellent performance. An organic electronic light-emitting device comprising the organic compound can achieve higher current efficiency, lower starting voltage and longer life in the deep blue light field, and can solve the above-mentioned technical problems.

[0008] Solutions to the problem

[0009] The inventor of the present application has proposed an ingenious molecular design scheme after intensive research, and obtained a luminescent dye material with high product efficiency. The compound disclosed in the present invention is very suitable for use in OLED and can improve the performance of the device, and is particularly suitable for use as a deep blue light luminescent dye and / or sensitizer.

[0010] Specifically, the present invention provides an organic compound, characterized in that it has a structure as shown in formula (1):

[0011]

[0012] In the general formula (1):

[0013] R is selected from one of hydrogen, substituted or unsubstituted C1-C20 chain alkyl, substituted or unsubstituted C3-C20 cycloalkyl, substituted or unsubstituted C1-C20 alkoxy, halogen, nitro, hydroxy, amino, substituted or unsubstituted C1-C20 silyl, substituted or unsubstituted C6-C60 arylamino, substituted or unsubstituted C3-C60 heteroarylamino, substituted or unsubstituted C6-C60 aryl, and substituted or unsubstituted C3-C60 heteroaryl;

[0014] D 1 and D 2 Each independently has a structure as shown in formula (2):

[0015]

[0016] * represents the connection end with formula (1);

[0017] X 1 -X 4 Independently selected from N or CR 1 , R 1 are each independently selected from hydrogen, substituted or unsubstituted C1-C20 chain alkyl, substituted or unsubstituted C3-C20 cycloalkyl, substituted or unsubstituted C1-C20 alkoxy, halogen, cyano, nitro, hydroxyl, amino, substituted or unsubstituted C1-C20 silyl, substituted or unsubstituted C6-C60 arylamino, substituted or unsubstituted C3-C60 heteroarylamino, substituted or unsubstituted C6-C60 aryl, substituted or unsubstituted C3-C60 heteroaryl, and X 1 -X 4 At least one CR 1 At the same time, the R 1 is methyl; preferably X 1 -X 4 Independently selected from N, CH or CR 1 , and X 1 -X 4 There is only one CR 1 , the R 1 is methyl;

[0018] X 5 -X 8 Independently selected from N or CR 2 , R 2Each independently selected from hydrogen, substituted or unsubstituted C2-C20 chain alkyl, substituted or unsubstituted C3-C20 cycloalkyl, substituted or unsubstituted C1-C20 alkoxy, halogen, nitro, hydroxyl, amino, substituted or unsubstituted C1-C20 silyl, substituted or unsubstituted C6-C60 arylamino, substituted or unsubstituted C3-C60 heteroarylamino, substituted or unsubstituted C6-C60 aryl, substituted or unsubstituted C3-C60 heteroaryl, preferably X 5 -X 8 At least one CR 2 At the same time, the R 2 Not hydrogen;

[0019] D 3 and D 4 Each independently has a structure as shown in formula (3):

[0020]

[0021] * represents the connection end with formula (1);

[0022] X 11 -X 18 Independently selected from N or CR 3 , R 3 Each is independently selected from hydrogen, substituted or unsubstituted C1-C20 chain alkyl, substituted or unsubstituted C3-C20 cycloalkyl, substituted or unsubstituted C1-C20 alkoxy, halogen, cyano, nitro, hydroxyl, amino, substituted or unsubstituted C1-C20 silyl, substituted or unsubstituted C6-C60 arylamino, substituted or unsubstituted C3-C60 heteroarylamino, substituted or unsubstituted C6-C60 aryl, substituted or unsubstituted C3-C60 heteroaryl, and the adjacent R 3 They are connected to form a ring or not connected to form a ring;

[0023] When the above-mentioned substituted or unsubstituted group has a substituent, the substituent is selected from one or a combination of two or more of halogen, C1-C20 chain alkyl, C3-C20 cycloalkyl, C1-C20 alkoxy, C1-C20 silyl, cyano, nitro, hydroxyl, amino, C6-C60 arylamino, C3-C60 heteroarylamino, C6-C60 aryl, and C3-C60 heteroaryl.

[0024] It should be noted that in this specification, the expression of Ca to Cb means that the number of carbon atoms in the group is a to b. Unless otherwise specified, the number of carbon atoms does not include the number of carbon atoms in the substituent. In the present invention, the expression of chemical elements, unless otherwise specified, usually includes the concept of isotopes with the same chemical properties. For example, the expression of "hydrogen" also includes the concept of "deuterium" and "tritium" with the same chemical properties. Carbon (C) includes 12 C. 13 C, etc., no further details.

[0025] In the structural formula disclosed in this specification, the expression of a ring structure crossed by “—” indicates that the connection site is any position on the ring structure that can form a bond.

[0026] In this specification, unless otherwise specified, aryl and heteroaryl include both monocyclic and condensed ring situations. The so-called monocyclic aryl refers to a molecule containing at least one phenyl group. When the molecule contains at least two phenyl groups, the phenyl groups are independent of each other and connected by a single bond, such as phenyl, biphenyl, terphenyl, etc.; condensed ring aryl refers to a molecule containing at least two benzene rings, but the benzene rings are not independent of each other, but condensed to each other by sharing the ring edge, such as naphthyl, anthracenyl, etc.; monocyclic heteroaryl refers to a molecule containing at least one heteroaryl group. When the molecule contains one heteroaryl group and other groups (such as aryl, heteroaryl, alkyl, etc.), the heteroaryl group and other groups are independent of each other and connected by a single bond, such as pyridine, furan, thiophene, etc.; condensed ring heteroaryl refers to a molecule composed of at least one phenyl group and at least one heteroaryl group fused together, or, composed of at least two heteroaryl rings fused together, such as quinoline, isoquinoline, benzofuran, dibenzofuran, benzothiophene, dibenzothiophene, etc.

[0027] In the present specification, the substituted or unsubstituted C6-C60 aromatic group is preferably a C6-C30 aromatic group, and more preferably a group selected from the group consisting of phenyl, naphthyl, anthracenyl, benzanthryl, phenanthryl, triphenylenyl, pyrene, chrysene, peryl, fluoranthene, naphthyl, pentacene, benzopyrene, biphenyl, isophenyl, terphenyl, triphenyl, tetraphenyl, fluorenyl, spirobifluorenyl, dihydrophenanthryl, dihydropyrenyl, tetrahydropyrenyl, cis- or trans-indenofluorenyl, trimerized indenyl, isotrimerized indenyl, spirotrimerized indenyl, and spiroisotrimerized indenyl. Specifically, the biphenyl group is selected from 2-biphenyl, 3-biphenyl and 4-biphenyl; the terphenyl group includes p-terphenyl-4-yl, p-terphenyl-3-yl, p-terphenyl-2-yl, m-terphenyl-4-yl, m-terphenyl-3-yl and m-terphenyl-2-yl; the naphthyl group includes 1-naphthyl or 2-naphthyl; the anthracenyl group is selected from 1-anthracenyl, 2-anthracenyl and 9-anthracenyl; the fluorenyl group is selected from 1-fluorenyl, 2-fluorenyl, 3-fluorenyl, 4-fluorenyl and 9-fluorenyl; the pyrenyl group is selected from 1-pyrenyl, 2-pyrenyl and 4-pyrenyl; the tetraphenyl group is selected from 1-tetraphenyl, 2-tetraphenyl and 9-tetraphenyl. Preferred examples of the aryl group in the present invention include phenyl, biphenyl, terphenyl, naphthyl, anthracenyl, phenanthrenyl, indenyl, fluorenyl and its derivatives, fluoranthenyl, triphenylene, pyrenyl, peryl, The biphenyl group is selected from the group consisting of 2-biphenyl, 3-biphenyl and 4-biphenyl; the terphenyl group includes p-terphenyl-4-yl, p-terphenyl-3-yl, p-terphenyl-2-yl, m-terphenyl-4-yl, m-terphenyl-3-yl and m-terphenyl-2-yl; the naphthyl group includes 1-naphthyl or 2-naphthyl; the anthracenyl group is selected from the group consisting of 1-anthracenyl, 2-anthracenyl and 9-anthracenyl. The fluorenyl group is selected from the group consisting of 1-fluorenyl, 2-fluorenyl, 3-fluorenyl, 4-fluorenyl and 9-fluorenyl; the fluorenyl derivative is selected from the group consisting of 9,9-dimethylfluorene, 9,9-spirobifluorene and benzofluorene; the pyrenyl group is selected from the group consisting of 1-pyrenyl, 2-pyrenyl and 4-pyrenyl; the naphthyl group is selected from the group consisting of 1-naphthyl, 2-naphthyl and 9-naphthyl.

[0028] The heteroatom in the present invention is generally selected from N, O, S, P, Si and Se, preferably selected from N, O and S.

[0029] In the present specification, the substituted or unsubstituted C3-C60 heteroaryl group is preferably a C3-C30 heteroaryl group, more preferably a nitrogen-containing heteroaryl group, an oxygen-containing heteroaryl group, a sulfur-containing heteroaryl group, etc. Specific examples include: furyl, thienyl, pyrrolyl, pyridyl, benzofuranyl, benzothienyl, isobenzofuranyl, isobenzothienyl, indolyl, isoindolyl, dibenzofuranyl, dibenzothienyl, carbazolyl and its derivatives, quinolyl, isoquinolyl, acridinyl, phenanthridine yl, benzo-5,6-quinolyl, benzo-6,7-quinolyl, benzo-7,8-quinolyl, phenothiazinyl, phenazinyl, pyrazolyl, indazolyl, imidazolyl, benzimidazolyl, naphthoimidazolyl, phenanthroimidazolyl, pyridoimidazolyl, pyrazinoimidazolyl, quinoxalinoimidazolyl, oxazolyl, benzoxazolyl, naphthoxazolyl, anthrazolyl, phenanthroxazolyl, 1,2-thiazolyl, 1,3-thiazolyl, benzothiazolyl, pyridazinyl, benzopyridazinyl, pyrimidazinyl, pyridinyl, benzopyrimidinyl, quinoxalinyl, 1,5-diazaanthryl, 2,7-diazapyrenyl, 2,3-diazapyrenyl, 1,6-diazapyrenyl, 1,8-diazapyrenyl, 4,5-diazapyrenyl, 4,5,9,10-tetraazaperyl, pyrazinyl, phenazinyl, phenothiazinyl, naphthyridinyl, azacarbazolyl, benzocarbolinyl, phenanthrolinyl, 1,2,3-triazolyl, 1,2,4-triazolyl, benzotriazolyl, 1,2,3-oxadiazolyl, oxadiazole, 1,2,4-oxadiazole, 1,2,5-oxadiazole, 1,2,3-thiadiazolyl, 1,2,4-thiadiazolyl, 1,2,5-thiadiazolyl, 1,3,4-thiadiazolyl, 1,3,5-triazine, 1,2,4-triazine, 1,2,3-triazine, tetrazolyl, 1,2,4,5-tetrazine, 1,2,3,4-tetrazine, 1,2,3,5-tetrazine, purinyl, pteridinyl, indolizine, benzothiadiazole and the like. Preferred examples of heteroaryl groups in the present invention include furyl, thienyl, pyrrolyl, benzofuranyl, benzothienyl, isobenzofuranyl, indolyl, dibenzofuranyl, dibenzothienyl, carbazolyl and derivatives thereof, wherein the carbazolyl derivative is preferably 9-phenylcarbazole, 9-naphthylcarbazole, benzocarbazole, dibenzocarbazole or indolecarbazole.

[0030] In the present specification, examples of the C1-C20 alkyl group include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, 2-methylbutyl, n-pentyl, sec-pentyl, cyclopentyl, n-hexyl, cyclohexyl, adamantyl, n-heptyl, cycloheptyl, n-octyl, cyclooctyl, 2-ethylhexyl, trifluoromethyl, pentafluoroethyl, and 2,2,2-trifluoroethyl.

[0031] In the present specification, the cycloalkyl group includes a monocyclic alkyl group and a polycyclic alkyl group, and examples thereof include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl and the like.

[0032] In the present specification, examples of C1-C20 alkoxy groups include methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, sec-butoxy, isobutoxy, pentyloxy, isopentyloxy, hexyloxy, heptyloxy, octyloxy, nonyloxy, decyloxy, undecyloxy, dodecyloxy, etc., among which methoxy, ethoxy, n-propoxy, isopropoxy, tert-butoxy, sec-butoxy, isobutoxy, isopentyloxy, and methoxy is more preferred.

[0033] In the present specification, examples of C1-C20 silyl groups include silyl groups substituted with the groups listed in the above C1-C20 alkyl groups, specifically including methylsilyl, dimethylsilyl, trimethylsilyl, ethylsilyl, diethylsilyl, triethylsilyl, tert-butyldimethylsilyl, tert-butyldiphenylsilyl and the like.

[0034] In the present specification, examples of halogen include fluorine, chlorine, bromine, and iodine.

[0035] In the present invention, the "substituted or unsubstituted" group may be substituted with one substituent or with multiple substituents. When there are multiple substituents, they may be selected from different substituents. When the same expressions are involved in the present invention, they all have the same meaning, and the selection range of substituents is as shown above and will not be repeated one by one.

[0036] The inventors of the present application comprehensively considered the inductive effect, conjugation effect and volume of common substituents in the system to design the molecule, and found through experimental verification that: in the above formula (1), D 1 , D 2 Each independently selected from the group shown in formula (2), that is, the ortho-substituent D of the cyano group in the parent core 1 , D 2 All of them are carbazolyl or N-heterocarbazolyl with specific substituents. Specifically, the substituent of the aromatic ring on one side of the above-mentioned carbazolyl or N-heterocarbazolyl has and only has one methyl group, while the other side cannot have a methyl substituent, and preferably has at least one non-methyl substituent (that is, the other side is preferably not in an unsubstituted state). The inventors found that if such a group is selected, the luminescence efficiency can be improved and the excitation voltage can be reduced accordingly. The specific reasons why these compounds can achieve excellent technical effects are still unclear. The following is the inventor's speculation: when the two ortho positions of the cyano group simultaneously use the above-mentioned carbazolyl or N-heterocarbazolyl with specific substituents, the conformation of the molecule is more conducive to accumulation into a state with high carrier transport performance during film formation, thereby improving the corresponding transport efficiency and also reducing the starting voltage. At the same time, the strong rigidity of the methyl group can improve the luminescence efficiency of the molecule. The above reasons are only speculations, but these speculations do not limit the scope of protection of the present invention.

[0037] The organic compound of the present invention preferably has a structure as shown in formula (4):

[0038]

[0039] In general formula (4):

[0040] D 1 and D 2 Each independently has a structure as shown in formula (2):

[0041]

[0042] * represents the connection end with formula (4);

[0043] X 1 -X 4 Independently selected from N or CR 1 , R 1 are each independently selected from hydrogen, substituted or unsubstituted C1-C10 chain alkyl, substituted or unsubstituted C3-C10 cycloalkyl, substituted or unsubstituted C1-C10 alkoxy, halogen, cyano, nitro, hydroxyl, amino, substituted or unsubstituted C1-C10 silyl, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C3-C30 heteroaryl, and X 1 -X 4 At least one CR 1 And R 1 is methyl; preferably X 1 -X 4 Independently selected from N, CH or CR 1 , and X 1 -X 4 There is only one CR 1 , the R 1 is methyl;

[0044] X 5 -X 8 Independently selected from N or CR 2 , R 2 Each is independently selected from hydrogen, substituted or unsubstituted C2-C10 chain alkyl, substituted or unsubstituted C3-C10 cycloalkyl, substituted or unsubstituted C1-C10 alkoxy, halogen, nitro, hydroxyl, amino, substituted or unsubstituted C1-C10 silyl, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C3-C30 heteroaryl; preferably X 5 -X 8 At least one CR 2 At the same time, the R 2 Not hydrogen;

[0045] D 3and D 4 Each independently has a structure as shown in formula (3):

[0046]

[0047] * represents the connection end with formula (4);

[0048] X 11 -X 18 Independently selected from N or CR 3 , R 3 Each is independently selected from hydrogen, substituted or unsubstituted C1-C10 chain alkyl, substituted or unsubstituted C3-C10 cycloalkyl, substituted or unsubstituted C1-C10 alkoxy, halogen, cyano, nitro, hydroxyl, amino, substituted or unsubstituted C1-C10 silyl, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C3-C30 heteroaryl, and the adjacent R 3 They are connected to form a ring or not connected to form a ring;

[0049] When the above-mentioned substituted or unsubstituted group has a substituent, the substituent is selected from one or a combination of two or more of halogen, C1-C10 chain alkyl, C3-C10 cycloalkyl, C1-C10 alkoxy, C1-C10 silyl, cyano, nitro, hydroxyl, amino, C6-C30 arylamino, C3-C30 heteroarylamino, C6-C30 aryl, and C3-C30 heteroaryl.

[0050] In the technical solution of the present invention, it is very important to set D 3 and D 4 They are located at the two meta positions of the cyanide group of the parent nucleus respectively. Such substitution positions are more conducive to the spatial separation of the HOMO and LUMO orbitals of the molecule, which is beneficial to enhancing the TADF properties of the molecule.

[0051] In the organic compound of the present invention, D1 and D2 are the same, and D3 and D4 are the same. The molecular conformation formed by such a symmetrical structure is more conducive to accumulation into a state with high carrier transport performance during film formation, thereby further improving the transport efficiency and further reducing the starting voltage.

[0052] As mentioned above, D is very important in the present invention. 1 , D 2 For X 5 -X 8 Independently selected from N or CR 2 , as one of the R 2 , preferably a group that can slightly increase the electron cloud on the carbazole group and provide appropriate steric hindrance. Specifically, R 2Each is independently selected from hydrogen, substituted or unsubstituted C2-C10 chain alkyl, substituted or unsubstituted C3-C10 cycloalkyl, substituted or unsubstituted C1-C10 alkoxy, halogen, nitro, hydroxyl, amino, substituted or unsubstituted C1-C10 silane, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C3-C30 heteroaryl. It should be noted that X 5 -X 8 Preferably at least one is CR 2 At the same time, the R 2 It is not hydrogen, otherwise the steric hindrance is small and the transmission efficiency may be affected by the molecular conformation.

[0053] More specifically, the organic compound of the present invention is preferably D 1 and D 2 Each is independently selected from one of the following structures:

[0054]

[0055] More preferably D 1 and D 2 Each is independently selected from one of the following structures:

[0056]

[0057] In addition, the organic compound of the present invention is preferably R 1 and R 2 Each is independently selected from one of H, C1-C12 chain alkyl, C3-C12 cycloalkyl, and substituted or unsubstituted C6-C30 aryl, and more preferably each is independently selected from H.

[0058] Among the above organic compounds of the present invention, X 1 -X 8 At most one of them is N, X 11 -X 18 At most one of them is N; more preferably X 1 -X 8 , X 11 -X 18 Neither is N.

[0059] In the above organic compound of the present invention, X 3 Preferably CCH3;

[0060] X 1 , X 2 , X 4 , X 5 , X 7 , X 8 , X 11 , X 12 , X14 , X 15 , X 17 , X 18 Preferably CH;

[0061] X 6 Preferably CR 2 , the R 2 Selected from one of the following groups:

[0062] Ethyl, isopropyl, tert-butyl, cyclopentyl, cyclohexyl, phenyl, methoxy, isopropoxy, tert-butoxy, phenoxy,

[0063] The R 2 More preferably, it is selected from one of the following groups:

[0064] Isopropyl, tert-butyl, phenyl,

[0065] The R 2 Further preferred are tert-butyl and phenyl;

[0066] X 13 , X 16 Preferably CR 3 , the R 3 Each is independently selected from one of the following groups:

[0067] hydrogen, methyl, ethyl, isopropyl, tert-butyl, cyclopentyl, cyclohexyl, phenyl, methoxy, isopropoxy, tert-butoxy, phenoxy,

[0068] More preferably, each is independently selected from one of the following groups:

[0069] hydrogen, methyl, isopropyl, tert-butyl, phenyl;

[0070] More specifically, the organic compound of the present invention is preferably D 3 and D 4 Each is independently selected from one of the following structures:

[0071] It is speculated that the above-mentioned substitution position is more conducive to ensuring the appropriate electron cloud density of the carbazole group, and the luminescence efficiency is more outstanding. At the same time, it is more conducive to forming a suitable stacking structure during film formation, thereby improving the carrier transport performance.

[0072] In the organic compound of the present invention, R is preferably H.

[0073] Furthermore, the general formula compound of the present invention is preferably the following specific compound, but the present invention is not limited to the specific compounds shown below:

[0074]

[0075]

[0076]

[0077]

[0078] The present invention also discloses an application of the compound as described above in an organic electroluminescent device, preferably an application as a light-emitting layer in the organic electroluminescent device, and more preferably an application as a light-emitting dye and / or sensitizer in the light-emitting layer of the organic electroluminescent device.

[0079] The invention also discloses a thermally activated delayed fluorescent material, which contains the compound as mentioned above.

[0080] The present invention also discloses an application of the thermally activated delayed fluorescent material as described above in an organic electroluminescent device, preferably as a light-emitting layer in the organic electroluminescent device, and more preferably as a light-emitting dye and sensitizer in the light-emitting layer of the organic electroluminescent device.

[0081] The present invention also discloses an organic electroluminescent device, which comprises a first electrode, a second electrode and one or more organic layers inserted between the first electrode and the second electrode, wherein the organic layer comprises at least one compound as described above.

[0082] The present invention further discloses a display screen or a display panel, wherein the organic electroluminescent device as described above is adopted in the display screen or the display panel; preferably, the display screen or the display panel is an OLED display.

[0083] The present invention also discloses an electronic device, wherein the electronic device has a display screen or a display panel, and the display screen or the display panel adopts the organic electroluminescent device as described above.

[0084] Effects of the Invention

[0085] According to the present invention, an organic compound can be provided, which is a thermally activated delayed fluorescent material with excellent performance. An organic electronic light-emitting device containing the organic compound can achieve higher current efficiency, lower starting voltage and longer life in the deep blue light field, and can meet the current industry requirements for high-performance light-emitting materials. DETAILED DESCRIPTION

[0086] The present invention will be described in detail below with reference to a number of specific embodiments. The compounds of the embodiments of the present invention can be synthesized with reference to the specific synthesis examples shown below, but it should be noted that obtaining the compound is not limited to the synthesis method and raw materials used in the present invention, and those skilled in the art can also select other methods or routes to obtain the novel compounds proposed in the present invention. The compounds for which the synthesis method is not mentioned in the present invention are raw materials obtained from commercial channels, or are prepared by these raw materials according to known methods.

[0087]

[0088] The solvents and reagents used in the synthesis examples, such as dichloromethane, petroleum ether, ethanol, tetrahydrofuran, N, N-dimethylacetamide, anhydrous magnesium sulfate, carbazole, benzimidazole and other chemical reagents, can be purchased from the domestic chemical product market, such as Sinopharm Group Reagent Company, TCI Company, Shanghai Bid Pharmaceutical Company, Bailingwei Reagent Company, etc. In addition, those skilled in the art can also synthesize by known methods.

[0089] The analysis and detection of the intermediates and compounds in the synthesis examples were performed using an ABSCIEX mass spectrometer (4000QTRAP).

[0090] Synthesis Example

[0091] The following are methods for synthesizing representative compounds of the present invention.

[0092] Synthesis Example 1: Synthesis of P11

[0093]

[0094] Synthesis of intermediate P11-1:

[0095] Add 3-tert-butyl-6-methylcarbazole (20 g, 84.27 mmol), 2,3,5,6-tetrafluorobenzonitrile (7.38 g, 42.13 mmol), potassium carbonate (17.47 g, 126.40 mmol), and 200 ml of DMF to a 1000 mL three-necked flask. Stir overnight at 30 ° C under nitrogen protection. Pour the reaction solution into 500 ml of water and filter to obtain a yellow crude product. Silica gel mixed sample column chromatography (PE: DCM = 10: 1) to obtain 20.65 g of light yellow solid. The molecular ion mass determined by mass spectrometry is 609.76 (theoretical value: 609.76).

[0096] Synthesis of compound P11:

[0097] In a 1000ml three-necked flask, add P11-1 (20g, 32.880mmol), 3,6-di-tert-butylcarbazole (20.16g, 72.16mmol), potassium carbonate (13.60g, 98.40mmol), DMF 200ml, replace nitrogen, stir and heat to 80°C, react overnight, stop heating, cool the reaction solution, pour the reaction solution into 500ml water, filter to obtain a yellow crude product, and silica gel column chromatography (PE:DCM=5:1) to obtain 30.17g of yellow solid. The molecular particle mass determined by mass spectrometry is: 1128.60 (theoretical value: 1128.61).

[0098] Synthesis Example 2: Synthesis of P23

[0099]

[0100] Synthesis of compound P23:

[0101] In a 1000ml three-necked flask, add P11-1 (20g, 32.880mmol), 3-phenylcarbazole (17.56g, 72.16mmol), potassium carbonate (13.60g, 98.40mmol), 200ml DMF, replace nitrogen, stir and heat to 80°C, react overnight, stop heating, cool the reaction solution, pour the reaction solution into 500ml water, filter to obtain a yellow crude product, and perform silica gel column chromatography (PE:DCM=5:1) to obtain 28.53g of yellow solid. The molecular particle mass determined by mass spectrometry is: 1056.37 (theoretical value: 1056.37).

[0102] Synthesis Example 3: Synthesis of P35

[0103]

[0104] Synthesis of compound P35:

[0105] Add 3-tert-butyl-6-methylcarbazole (20 g, 84.27 mmol), 2,3,5,6-tetrafluorobenzonitrile (3.25 g, 18.54 mmol), potassium carbonate (17.47 g, 126.40 mmol), and 200 ml of DMF to a 1000 mL three-necked flask. Stir overnight at 30 ° C under nitrogen protection. Pour the reaction solution into 500 ml of water and filter to obtain a yellow crude product. Silica gel mixed sample column chromatography (PE: DCM = 5: 1) to obtain 18.37 g of light yellow solid. The molecular ion mass determined by mass spectrometry is: 1044.44 (theoretical value: 1044.44).

[0106] Device Embodiment

[0107] Next, the organic electroluminescent device will be described in detail.

[0108] OLED includes a first electrode, a second electrode, and an organic material layer between the electrodes. The organic material can be divided into multiple regions. For example, the organic material layer can include a hole transport region, a light emitting layer, and an electron transport region.

[0109] In a specific embodiment, a substrate may be used below the first electrode or above the second electrode. The substrate is a glass or polymer material with excellent mechanical strength, thermal stability, water resistance, and transparency. In addition, a thin film transistor (TFT) may also be provided on the substrate used as a display.

[0110] The first electrode can be formed by sputtering or depositing the material used as the first electrode on the substrate. When the first electrode is used as an anode, an oxide transparent conductive material such as indium tin oxide (ITO), indium zinc oxide (IZO), tin dioxide (SnO2), zinc oxide (ZnO) and any combination thereof can be used. When the first electrode is used as a cathode, a metal or alloy such as magnesium (Mg), silver (Ag), aluminum (Al), aluminum-lithium (Al-Li), calcium (Ca), ytterbium (Yb), ytterbium (Yb), magnesium-indium (Mg-In), magnesium-silver (Mg-Ag) and any combination thereof can be used.

[0111] The organic material layer can be formed on the electrode by vacuum thermal evaporation, spin coating, printing, etc. The compound used as the organic material layer can be organic small molecules, organic macromolecules and polymers, and combinations thereof.

[0112] The hole transport region is located between the anode and the light-emitting layer. The hole transport region can be a single-layer hole transport layer (HTL), including a single-layer hole transport layer containing only one compound and a single-layer hole transport layer containing multiple compounds. The hole transport region can also be a multilayer structure including at least one layer of a hole injection layer (HIL), a hole transport layer (HTL), and an electron blocking layer (EBL); wherein the HIL is located between the anode and the HTL, and the EBL is located between the HTL and the light-emitting layer.

[0113] The material of the hole transport region can be selected from, but not limited to, phthalocyanine derivatives such as CuPc, conductive polymers or polymers containing conductive dopants such as polyphenylene ethylene, polyaniline / dodecylbenzenesulfonic acid (Pani / DBSA), poly(3,4-ethylenedioxythiophene) / poly(4-styrenesulfonate) (PEDOT / PSS), polyaniline / camphorsulfonic acid (Pani / CSA), polyaniline / poly(4-styrenesulfonate) (Pani / PSS), aromatic amine derivatives such as the compounds shown in HT-1 to HT-51 below; or any combination thereof.

[0114]

[0115]

[0116]

[0117] The hole injection layer is located between the anode and the hole transport layer. The hole injection layer can be a single compound material or a combination of multiple compounds. For example, the hole injection layer can use one or more compounds of HT-1 to HT-50 mentioned above, or one or more compounds of HI-1 to HI-3 below; or one or more compounds of HT-1 to HT-51 can be doped with one or more compounds of HI-1 to HI-3 below.

[0118]

[0119] The light-emitting layer includes a light-emitting dye (i.e., dopant) that can emit light of different wavelength spectra, and may also include a host material (Host). The light-emitting layer may be a monochrome light-emitting layer that emits a single color such as red, green, and blue. A plurality of monochrome light-emitting layers of different colors may be arranged in a plane according to a pixel pattern, or may be stacked together to form a color light-emitting layer. When light-emitting layers of different colors are stacked together, they may be separated from each other or may be connected to each other. The light-emitting layer may also be a single color light-emitting layer that can simultaneously emit different colors such as red, green, and blue.

[0120] According to different technologies, the light-emitting layer material can be made of different materials such as fluorescent electroluminescent materials, phosphorescent electroluminescent materials, and thermally activated delayed fluorescent materials. In an OLED device, a single light-emitting technology can be used, or a combination of multiple different light-emitting technologies can be used. These different light-emitting materials classified by technology can emit light of the same color or different colors.

[0121] In one aspect of the present invention, the light-emitting layer adopts the technology of thermally activated delayed fluorescence luminescence, and the main material of the light-emitting layer is selected from, but not limited to, one or more combinations of PH-1 to PH-85.

[0122]

[0123]

[0124]

[0125]

[0126] In one aspect of the present invention, an electron blocking layer (EBL) is located between the hole transport layer and the light emitting layer. The electron blocking layer may be, but not limited to, one or more of the compounds HT-1 to HT-51 described above, or one or more of the compounds PH-47 to PH-77 described above; or a mixture of, but not limited to, one or more of the compounds HT-1 to HT-51 and one or more of the compounds PH-47 to PH-77.

[0127] The OLED organic material layer may further include an electron transport region between the light emitting layer and the cathode. The electron transport region may be a single-layer electron transport layer (ETL), including a single-layer electron transport layer containing only one compound and a single-layer electron transport layer containing multiple compounds. The electron transport region may also be a multilayer structure including at least one layer of an electron injection layer (EIL), an electron transport layer (ETL), and a hole blocking layer (HBL).

[0128] In one aspect of the present invention, the electron transport layer material can be selected from, but not limited to, one or more combinations of ET-1 to ET-73 listed below.

[0129]

[0130]

[0131]

[0132]

[0133] In one aspect of the present invention, a hole blocking layer (HBL) is located between the electron transport layer and the light emitting layer. The hole blocking layer may be, but not limited to, one or more compounds of ET-1 to ET-73, or one or more compounds of PH-1 to PH-46; or a mixture of one or more compounds of ET-1 to ET-73 and one or more compounds of PH-1 to PH-46.

[0134] The device may further include an electron injection layer located between the electron transport layer and the cathode. Materials for the electron injection layer include, but are not limited to, one or more combinations of the following.

[0135] LiQ, LiF, NaCl, CsF, Li2O, Cs2CO3, BaO, Na, Li, Ca, Yb, Mg, Yb.

[0136] The technical effects and advantages of the present invention are demonstrated and verified by applying the compound of the present invention to an organic electroluminescent device to test the actual performance.

[0137] The preparation process of the organic electroluminescent device of Example 1 is as follows:

[0138] The glass plate coated with the ITO transparent conductive layer was ultrasonically treated in a commercial cleaning agent, rinsed in deionized water, ultrasonically degreased in a mixed solvent of acetone:ethanol, baked in a clean environment to completely remove the water, cleaned with ultraviolet light and ozone, and bombarded with a low-energy cation beam;

[0139] Place the glass substrate with the anode in a vacuum chamber and evacuate to a vacuum of <1×10 -5 Pa, on the above anode layer film, vacuum thermal evaporation was performed in sequence of 10nm of HT-4:HI-3 (97 / 3, w / w) mixture as a hole injection layer, 60nm of compound HT-4 as a hole transport layer, 5nm of compound HT-51 as an electron blocking layer; 40nm of compound PH54:P3 (100:40, w / w) binary mixture as a light-emitting layer; 5nm of PH-28 as a hole blocking layer, 25nm of compound ET-69:ET-57 (50 / 50, w / w) mixture as an electron transport layer, 1nm of LiF as an electron injection layer, and 150nm of metal aluminum as a cathode. The total evaporation rate of all organic layers and LiF was controlled at 0.1nm / sec, and the evaporation rate of the metal electrode was controlled at 1nm / sec.

[0140] The preparation process of device examples 2-15 and comparative examples 1-2 is the same as that of device example 1, except that P3 in the light-emitting layer is replaced with the structure listed in Table 1.

[0141] The structures of compounds C1 and C2 are as follows:

[0142]

[0143] The organic electroluminescent device prepared by the above process was subjected to the following performance tests:

[0144] At the same brightness, the driving voltage and current efficiency of the organic electroluminescent device prepared from the compound and the comparative material, as well as the life of the device, were measured using a digital source meter and a brightness meter. Specifically, the voltage was increased at a rate of 0.1 V per second, and the brightness of the organic electroluminescent device was measured when it reached 1000 cd / m 2 The voltage at which the light is on is the driving voltage, and the current density at this time is measured at the same time; the ratio of brightness to current density is the current efficiency; the life test of LT95 is as follows: use a brightness meter at 1000cd / m 2 At the same brightness, the current is kept constant and the brightness of the organic electroluminescent device is measured to drop to 950cd / m 2 The unit is hours. The life of the device comparative example 1 is set to 1.0, and the life performance of other materials are all ratios to it.

[0145] The performance test results are shown in Table 1.

[0146] Table 1

[0147]

[0148]

[0149] As can be seen from Table 1, when the compound of the present invention is used as a dye, its voltage is lower than that of the comparative compound C1, showing excellent device performance. This may be due to the reduction of steric hindrance of the substituent group, which is beneficial to carrier transmission and can reduce voltage.

[0150] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. An organic compound, characterized in that It has the structure shown in formula (4): In the general formula (4): R is hydrogen; D 1 and D 2 Each is independently selected from one of the following structures and connected to the parent core at the N of carbazole: D 1 With D 2 same; D 3 and D 4 Each independently has a structure as shown in formula (3): * represents the connection end with formula (4); X 13 , X 16 CR 3 , the R 3 Each is independently selected from the following groups: hydrogen, methyl, ethyl, isopropyl, tert-butyl, cyclopentyl, cyclohexyl, phenyl, methoxy, isopropoxy, tert-butoxy, phenoxy, X 11 , X 18 is CH or N; X 12 , X 14 , X 15 , X 17 For CH.

2. The organic compound according to claim 1, characterized in that In the general formula (4), X 11 -X 18 At most one of them is N.

3. The organic compound according to claim 1 or 2, characterized in that D 1 and D 2 Each is independently selected from one of the following structures:

4. The organic compound according to claim 1 or 2, characterized in that R 3 Each is independently selected from one of the following groups: Hydrogen, methyl, isopropyl, tert-butyl, phenyl.

5. The organic compound according to claim 1 or 2, characterized in that D 3 and D 4 Each is independently selected from one of the following structures:

6. The organic compound according to claim 1, characterized in that D3 is the same as D4.

7. The organic compound according to claim 1, characterized in that The organic compound has the structures shown in P1 to P81:

8. Use of the organic compound according to any one of claims 1 to 7 as a light-emitting layer material in an organic electroluminescent device, and use of the organic compound as a light-emitting dye and / or a sensitizer in the light-emitting layer of the organic electroluminescent device.

9. An organic electroluminescent device comprising a first electrode, a second electrode and one or more organic functional layers inserted between the first electrode and the second electrode, characterized in that: The organic layer comprises at least one organic compound according to any one of claims 1 to 7, The organic functional layer includes a hole injection layer, a hole transport layer, a light-emitting layer, and an electron transport layer, wherein the hole injection layer is formed on the first electrode layer, the hole transport layer is formed on the hole injection layer, and the second electrode layer is formed on the electron transport layer, and a light-emitting layer is provided between the hole transport layer and the electron transport layer, wherein the light-emitting layer contains the organic compound described in any one of claims 1 to 7.

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