An organic compound and its application, and an organic electroluminescent device containing the same

Abstract

The present invention provides an organic compound and its application, and an organic electroluminescent device containing the organic compound. The organic compound has a structure of formula I, and the organic compound is applied as a luminescent dye or a luminescent sensitizer in a luminescent layer of the organic electroluminescent device. The organic electroluminescent device comprises a first electrode, a second electrode, and an organic layer between the first electrode and the second electrode, and the organic layer contains the organic compound. When the organic compound is used as a luminescent material of the organic electroluminescent device, it exhibits excellent device performance and stability.

Description

Technical Field

[0001] The present invention relates to the technical field of organic electroluminescence, and in particular to an organic compound and application thereof, and an organic electroluminescence device containing the organic compound. Background Art

[0002] In recent years, optoelectronic devices based on organic materials have become increasingly popular. The inherent flexibility of organic materials makes them very suitable for manufacturing on flexible substrates. Beautiful and cool optoelectronic products can be designed and produced according to demand, gaining unparalleled advantages over inorganic materials. Examples of such organic optoelectronic devices include organic light-emitting diodes (OLEDs), organic field-effect transistors, organic photovoltaic cells, organic sensors, etc. Among them, OLED has developed particularly rapidly and has achieved commercial success in the field of information display. OLED can provide highly saturated red, green, and blue colors. Full-color display devices made of OLEDs do not require additional backlight sources and have the advantages of brilliant colors, lightness, thinness, and softness.

[0003] The core of OLED devices is a thin film structure containing a variety of organic functional materials. Common functionalized organic materials include: hole injection materials, hole transport materials, hole blocking materials, electron injection materials, electron transport materials, electron blocking materials, luminescent host materials and luminescent guest (dyes), etc. When power is turned on, electrons and holes are injected and transported to the luminescent area respectively and recombine there, thereby generating excitons and emitting light.

[0004] In the structure of organic electroluminescent devices in the field of display and lighting, blue fluorescence is generally used in combination with red and green phosphorescent materials. Due to the low exciton utilization rate of fluorescent materials, the efficiency problem of blue light OLED has become a bottleneck in the development of OLED. Recently, a class of TADF (Thermally Activated Delayed Fluorescence) fluorescent dye compounds has been reported in the literature. This class of compounds is composed of electron acceptor groups such as benzonitrile and triazine and electron donor groups such as carbazole and indolecarbazole. The HOMO and LUMO orbitals are distributed on the donor and acceptor groups, respectively, and are clearly separated in space. Since the energy difference between the first singlet state and the first triplet state of this type of material is very small, it has a very fast reverse intersystem crossing rate, so that triplet excitons can be used for luminescence. The structure of this type of material is as follows:

[0005]

[0006] This type of material uses carbazole as the electron-donating group and introduces a tert-butyl group, which is beneficial to prevent Dexter energy transfer and inhibit exciton quenching. However, on the one hand, the emission peak of this type of material 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. When tert-butyl and other groups are used as protective groups, the TADF properties of the material are weak and the luminescence efficiency is low. Due to these factors, it is difficult to achieve mass production and application of this type of material.

[0007] Therefore, higher performance TADF materials need to be developed urgently. Summary of the invention

[0008] In view of the deficiencies of the prior art, the object of the present invention is to provide an organic compound having a structure of Formula I:

[0009]

[0010] In Formula I, R 1 and R 2 Each is independently selected from any one of a substituted or unsubstituted C1-C10 chain alkyl group, a substituted or unsubstituted C3-C10 cycloalkyl group, a substituted or unsubstituted C1-C10 alkoxy group, a substituted or unsubstituted C1-C10 silyl group, and a substituted or unsubstituted C6-C30 aryl group;

[0011] In Formula I, D 1 and D 2 Each independently selected from

[0012] Among them, X 1 , X 2 , X 3 , X 4 , X 5 , X 6 , X 7 and X 8 Each independently selected from CR 3 , CR 4 or any one of N, and X 1 , X 2 , X 3 , X 4 , X 5 , X 6 , X 7 and X 8 At least one of the items is CR 4 ,

[0013] R 3Any one independently selected from hydrogen, substituted or unsubstituted C3-C10 chain alkyl, substituted or unsubstituted C3-C10 cycloalkyl, substituted or unsubstituted C1-C10 alkoxy, halogen, cyano, nitro, hydroxyl, substituted or unsubstituted C1-C10 silyl, amino, substituted or unsubstituted C6-C30 arylamino, substituted or unsubstituted C3-C30 heteroarylamino, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C3-C30 heteroaryl;

[0014] R 4 independently selected from methyl or ethyl;

[0015] In Formula I, D 3 Any one selected from the group (Hy-1):

[0016]

[0017] Among them, Ar 1 and Ar 2 Each is independently selected from any one of a substituted or unsubstituted C6-C30 aryl group and a substituted or unsubstituted C3-C30 heteroaryl group;

[0018] Ar 1 and Ar 2 Connected into a ring or not connected into a ring;

[0019] R 1 , R 2 , R 3 ,Ar 1 ,Ar 2 wherein the substituted group is selected from any one or a combination of at least two of halogen, cyano, nitro, hydroxyl, amino, C1-C10 chain alkyl, C3-C10 cycloalkyl, C1-C10 alkoxy, C1-C10 silyl, C6-C30 arylamino, C3-C30 heteroarylamino, C6-C30 monocyclic aromatic hydrocarbon or condensed aromatic hydrocarbon group, C3-C30 monocyclic heteroaromatic hydrocarbon or condensed heteroaromatic hydrocarbon group;

[0020] “*” represents the attachment site to the parent nucleus.

[0021] 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 the substituents is as shown above, and will not be repeated one by one.

[0022] In the present specification, the expression of Ca to Cb represents that the number of carbon atoms in the group is a to b. Unless otherwise specified, the number of carbon atoms generally does not include the number of carbon atoms in the substituent.

[0023] In the present 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.

[0024] In the present specification, “each independently” means that when there are multiple subjects, they may be the same as or different from each other.

[0025] In the present invention, the expression of chemical elements, unless otherwise specified, generally includes the concept of isotopes thereof. For example, the expression "hydrogen (H)" includes its isotopes. 1 H (hydrogen or H), 2 The concept of H (deuterium or D); carbon (C) includes 12 C. 13 C, etc., no further details.

[0026] The heteroatom in the present invention generally refers to an atom or an atom group selected from N, O, S, P, Si and Se, preferably selected from N, O and S.

[0027] In the present specification, examples of halogen include fluorine, chlorine, bromine, and iodine.

[0028] In the present invention, the monocyclic aromatic group refers to a molecule containing one or at least two phenyl groups. 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.; a condensed aromatic group 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.; a monocyclic heteroaryl group refers to a molecule containing at least one heteroaryl group. When the molecule contains one heteroaryl group and other groups (such as aromatic groups, heteroaryl groups, alkyl groups, etc.), the heteroaryl group and other groups are independent of each other and connected by a single bond, such as pyridine, furan, thiophene, etc.; a condensed heteroaryl group refers to a molecule composed of at least one phenyl group and at least one heteroaryl group fused together, or a molecule composed of at least two heteroaryl rings fused together, such as quinoline, isoquinoline, benzofuran, dibenzofuran, benzothiophene, dibenzothiophene, etc.

[0029] In the present invention, unless otherwise specified, aryl and heteroaryl include both monocyclic and condensed ring forms.

[0030] In the present invention, unless otherwise specified, a substituent is not fused to the group in which it is located.

[0031] In the present invention, the substituted or unsubstituted C6-C30 aryl group includes a monocyclic aryl group and a condensed ring aryl group, and a C6-C20 aryl group is further preferred. Preferably, the aryl group is 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-diethylfluorenyl, 9,9-dipropylfluorenyl, 9,9-dibutylfluorenyl, 9,9-dipentylfluorenyl, 9,9-dihexylfluorenyl, 9,9-diphenylfluorenyl, 9,9-dinaphthylfluorenyl, 9,9'-spirobifluorene and benzofluorene; the pyrenyl is selected from the group consisting of 1-pyrenyl, 2-pyrenyl and 4-pyrenyl; the naphthyl tetraphenyl is selected from the group consisting of 1-naphthyl tetraphenyl, 2-naphthyl tetraphenyl and 9-naphthyl tetraphenyl.

[0032] In the present invention, the substituted or unsubstituted C3-C30 heteroaryl group is further preferably a C4-C20 heteroaryl group, and the heteroaryl group is preferably a furyl group, a thienyl group, a pyrrolyl group, a pyridyl group, a benzofuranyl group, a benzothienyl group, an isobenzofuranyl group, an indolyl group, a dibenzofuranyl group, a dibenzothienyl group, an acridinyl group, an isobenzofuranyl group, an isobenzothienyl group, an azacarbazole group, a phenothiazine group, a phenazine group, a carbazole group and derivatives thereof, wherein the carbazole group derivative is preferably a 9-phenylcarbazole group, a 9-naphthylcarbazole group, a benzocarbazole group, a dibenzocarbazole group, or an indolecarbazole group.

[0033] Specific examples of the arylene group in the present invention include divalent groups obtained by removing one hydrogen atom from the above-mentioned aryl groups. Specific examples of the heteroarylene group in the present invention include divalent groups obtained by removing one hydrogen atom from the above-mentioned heteroaryl groups.

[0034] The aryloxy group in the present invention includes a monovalent group composed of the above-mentioned aryl group and heteroaryl group and oxygen.

[0035] Examples of the C6-C30 arylamino group mentioned in the present invention include phenylamino, methylphenylamino, naphthylamino, anthracenylamino, phenanthrenylamino, and biphenylamino.

[0036] Examples of the C3-C30 heteroarylamino group mentioned in the present invention include pyridylamino, pyrimidinylamino, dibenzofuranylamino and the like.

[0037] Examples of the C1-C10 alkyl group mentioned in the present invention include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, neopentyl, n-hexyl, n-octyl and n-nonyl.

[0038] In the present specification, the C3-C10 cycloalkyl group includes a monocyclic alkyl group and a polycyclic alkyl group, and examples thereof include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, and a cyclodecyl group.

[0039] In the above substituents, the carbon number of the C1-C10 chain alkyl group may be C1, C2, C3, C4, C5, C6, C7, C8, C9, C10; the carbon number of the C3-C10 cycloalkyl group may be C3, C4, C5, C6, C7, C8, C9, C10; the carbon number of the C1-C10 alkoxy group may be C1, C2, C3, C4, C5, C6, C7, C8, C9, C10; the carbon number of the C6-C30 monocyclic aromatic group may be C6, C10, C12, C14, C16, C1 The carbon number of the C10-C30 condensed ring aromatic group may be C10, C12, C14, C16, C18, C20, C26, C28, etc.; the carbon number of the C3-C30 monocyclic heteroaromatic group may be C3, C4, C6, C8, C10, C12, C14, C16, C18, C20, C26, C28, etc.; the carbon number of the C6-C30 condensed ring heteroaromatic group may be C6, C10, C12, C14, C16, C18, C20, C26, C28, etc.

[0040] The organic compound provided by the present invention has benzonitrile as the acceptor group, and the carbazole group D 1 and D 2 , and carbazole or aromatic amine groups D 3 As the donor group, and by introducing R 1 and R 2 The donor and acceptor groups are twisted to form a structure, so that the HOMO and LUMO orbitals of the organic compound are separated in space, and the compound has a stronger TADF property.

[0041] The organic compound provided by the invention is used in an organic electroluminescent device, and can improve the luminous efficiency of the device and reduce the starting voltage of the device.

[0042] Preferably, the R 1 and R 2 Each is independently selected from a substituted or unsubstituted C6-C30 aryl group.

[0043] Preferably, the R 1 and R 2 Each is independently selected from substituted or unsubstituted phenyl groups; more preferably substituted phenyl groups.

[0044] Preferably, the R 1 and R 2 Each is independently selected from any one of the following groups:

[0045]

[0046] As a further preferred technical solution, the R 1 and R 2 Each is independently selected from any one of the following groups: More preferably

[0047] Preferably, the R 1 and R 2 same.

[0048] Preferably, the R 4 It is methyl.

[0049] Preferably, the X 1 , X 2 , X 3 , X 4 , X 5 , X 6 , X 7 and X 8 1-4 (e.g. 1, 2, 3 or 4) of the items are CR 4 .

[0050] Preferably, the X 1 , X 2 , X 3 , X 4 1-2 items are CR 4 , and X 5 , X 6 , X 7 and X 8 0-2 items (e.g. 0, 1 or 2) are CR 4 .

[0051] Preferably, the X 3 and X 6 All CR 4 .

[0052] Preferably, the D 1 and D 2 Each independently selected from

[0053] Among them, X 1 , X 2 , X 4 , X 5 , X 7 and X 8 All have the same limited scope as above;

[0054] Preferably, the D 1 and D 2 Each is independently selected from any one of the groups (a-1) to (a-3):

[0055]

[0056] Preferably, the D 1 and D 2 All selected

[0057] Preferably, the D 1 and D 2 same.

[0058] Preferably, the D 3 Any one selected from the group (Hy-2) or (Hy-3):

[0059]

[0060] In (Hy-2), Y 1 , Y 2 , Y 3 , Y 4 , Y 5 , Y 6 , Y 7 , Y 8 , Y 9 and Y 10 Each independently selected from CR 5 or any one of N;

[0061] In (Hy-3), Z 1 , Z 2 , Z 3 , Z 4 , Z 5 , Z 6 , Z 7 and Z 8 Each independently selected from CR 5 or any one of N;

[0062] R 5independently 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, substituted or unsubstituted C1-C10 silyl, amino, substituted or unsubstituted C6-C30 arylamino, substituted or unsubstituted C3-C30 heteroarylamino, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C3-C30 Any one of the heteroaryl groups, wherein the substituted group is selected from any one or a combination of at least two of halogen, cyano, nitro, hydroxyl, amino, C1-C10 chain alkyl, C3-C10 cycloalkyl, C1-C10 alkoxy, C1-C10 silyl, C6-C30 arylamino, C3-C30 heteroarylamino, C6-C30 monocyclic aromatic hydrocarbon or condensed aromatic hydrocarbon group, C3-C30 monocyclic heteroaromatic hydrocarbon or condensed heteroaromatic hydrocarbon group; adjacent R 5 They are not connected to each other or are connected to form a ring through chemical bonds.

[0063] Preferably, in (Hy-2), Y 1 , Y 2 , Y 3 , Y 4 , Y 5 , Y 6 , Y 7 , Y 8 , Y 9 and Y 10 8-10 (e.g. 8, 9 or 10) of the following are selected from CR 5 , more preferably all selected from CR 5 .

[0064] Preferably, in (Hy-3), Z 1 , Z 2 , Z 3 , Z 4 , Z 5 , Z 6 , Z 7 and Z 8 6-8 (e.g. 6, 7 or 8) of the following are selected from CR 5 , more preferably all selected from CR 5 .

[0065] Preferably, the D3 is selected from any one of the following groups:

[0066]

[0067]

[0068] Preferably, the D3 is selected from any one of the following groups:

[0069]

[0070] Preferably, the organic compound has the following S1-S145 structure:

[0071]

[0072]

[0073]

[0074]

[0075]

[0076]

[0077]

[0078] A second object of the present invention is to provide an application of the organic compound described in the first object, wherein the application is that the organic compound described in the first object is used as a luminescent dye or a luminescent sensitizer in the light-emitting layer of an organic electroluminescent device.

[0079] The third object of the present invention is to provide an organic electroluminescent device, which includes a first electrode, a second electrode and an organic layer located between the first electrode and the second electrode, and the organic layer includes any one or a combination of at least two of the organic compounds described in one of the objects.

[0080] The organic electroluminescent device provided by the present invention includes a first electrode and a second electrode, and a plurality of organic material layers located between the electrodes. The organic material layer 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.

[0081] 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.

[0082] 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), magnesium-indium (Mg-In), magnesium-silver (Mg-Ag) and any combination thereof can be used.

[0083] 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.

[0084] The hole transport region is located between the anode and the light-emitting layer. The hole transport region can be a hole transport layer (HTL) of a single-layer structure, 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 multi-layer structure including at least one layer of a hole injection layer (HIL), a hole transport layer (HTL), and an electron blocking layer (EBL).

[0085] 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.

[0086]

[0087]

[0088]

[0089] 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-51 above, or one or more compounds of HI1-HI3 below; or one or more compounds of HT-1 to HT-51 can be doped with one or more compounds of HI1-HI3 below.

[0090]

[0091] The light-emitting layer includes a light-emitting dye (i.e., dopant) that can emit different wavelength spectra, and may also include a host material (Host). The light-emitting layer can 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 can be arranged in a plane according to a pixel pattern, or they can be stacked together to form a color light-emitting layer. When light-emitting layers of different colors are stacked together, they can be separated from each other or connected to each other. The light-emitting layer can also be a single color light-emitting layer that can simultaneously emit different colors such as red, green, and blue.

[0092] 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.

[0093] In one aspect of the present invention, the light-emitting layer adopts the technology of thermally activated delayed fluorescence luminescence. The main material of the light-emitting layer is selected from, but not limited to, one or more combinations of the above PH-1 to PH-85.

[0094]

[0095]

[0096]

[0097]

[0098] In one aspect of the present invention, the light-emitting layer adopts fluorescent electroluminescence technology. The fluorescent dopant of the light-emitting layer can be selected from, but not limited to, one or more combinations of BFD-1 to BFD-24 listed below.

[0099]

[0100]

[0101] 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.

[0102] 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).

[0103] 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.

[0104]

[0105]

[0106]

[0107] 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.

[0108] 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.

[0109] LiQ, LiF, NaCl, CsF, Li2O, Cs2CO3, BaO, Na, Li, Ca, Yb, Mg.

[0110] Compared with the prior art, the present invention has the following beneficial effects:

[0111] The organic compound provided by the present invention uses benzonitrile as an acceptor group, connects a donor group at a specific site, and introduces a specific substituent to make the donor and acceptor groups present a twisted structure, so that the HOMO and LUMO orbits of the organic compound are completely separated in space, and has a strong TADF property. The organic compound is used in an organic electroluminescent device to improve the luminous efficiency of the device and reduce the starting voltage of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0112] Figure 1 It is the molecular transient fluorescence spectrum of organic compound S1;

[0113] Figure 2It is the molecular transient fluorescence spectrum of organic compound S9;

[0114] Figure 3 It is the molecular transient fluorescence spectrum of the comparative compound C1. DETAILED DESCRIPTION

[0115] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0116] The compounds of the synthesis methods not mentioned in the present invention are all raw materials obtained through commercial channels. The solvents and reagents used in the present invention, such as chemical reagents such as dichloromethane, petroleum ether, ethanol, tetrahydrofuran, N, N-dimethylacetamide, anhydrous magnesium sulfate, carbazole, benzimidazole, etc., 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.

[0117] The analysis and detection of the intermediates and organic compounds in the present invention were performed using an ABSCIEX mass spectrometer (4000QTRAP).

[0118] The following will be described in detail with reference to a number of specific embodiments. The organic compound of the formula I structure of the present invention can be prepared by referring to the following general synthesis formula:

[0119]

[0120] Among them, D 1 , D 2 , D 3 , R 1 and R 2 With the defined range as shown above.

[0121] The specific preparation method of the novel organic compound of the present invention will be described in detail below by taking a plurality of preparation examples as examples, but the preparation method of the present invention is not limited to these preparation examples.

[0122] Preparation Example 1

[0123]

[0124] (1) Preparation of compound S1-1:

[0125] Add the raw materials 1,3,5-trifluoro-2,4,6-triiodobenzene (30 g, 58.85 mmol), phenylboric acid (17.94 g, 147.12 mmol), Pd(PPh3)4 (3.4 g, 2.94 mmol), potassium carbonate (24.4 g, 176.55 mmol) into a 1000 ml single-necked flask, add 300 ml 1,4-dioxane, 50 ml water, and react at 110°C overnight under nitrogen protection. Stop the reaction, evaporate the solvent, and purify by column chromatography. Obtain 7 g of white solid. The molecular ion mass determined by mass spectrometry is 410.18 (theoretical value: 410.18).

[0126] (2) Preparation of compound S1-2:

[0127] The intermediate S1-1 (7 g, 15.97 mmol) was added to a 500 ml single-mouth bottle, and ultra-dry THF was added. Under nitrogen protection at -20 ° C, n-butyl lithium (10 ml, 2.5 M, 25 mmol) was slowly added, and stirred for 15 min after returning to room temperature, and ultra-dry DMF (32 g, 13.24 mmol) was added. After stirring at room temperature for 0.5 h, water was added to quench, the solvent was evaporated, and it was directly put into the next step of the experiment. The molecular ion mass determined by mass spectrometry analysis was 312.28 (theoretical value: 312.29).

[0128] (3) Preparation of compound S1-3:

[0129] The intermediate S1-2 was added to a 500 ml single-mouth bottle, sodium acetate (6.7 g, 31.14 mmol), hydroxylamine hydrochloride (1.62 g, 23.36 mmol), and 300 ml toluene. The mixture was refluxed for 2 h. After no more water was evaporated, the mixture was restored to room temperature, cooled to -20 °C, and thionyl chloride (4.7 g, 38.93 mmol) was slowly added. The mixture was heated and stirred at 60 °C for 3 h. Water was added to quench the mixture, and the washed liquid was dried. After drying, the mixture was evaporated to dryness, and purified by column chromatography to obtain 3.8 g of pure product. The molecular ion mass determined by mass spectrometry was 309.29 (theoretical value: 309.29).

[0130] (4) Preparation of organic compound S1

[0131] Add intermediate S1-3 (2.7 g, 8.73 mmol), cesium carbonate (17.08 g, 52.38 mmol), 3,6-dimethylcarbazole (6.9 g, 34.92 mmol) to a 500 ml single-mouth bottle, add 200 ml of ultra-dry DMF, and heat at 70 ° C under nitrogen protection to react overnight. Add 300 ml of water, filter, wash with ethanol, filter, and purify by solid column chromatography. Obtain 3.41 g of yellow-green solid. The molecular ion mass determined by mass spectrometry is 835.07 (theoretical value: 835.07).

[0132] Preparation Example 2

[0133]

[0134]

[0135] The preparation method of organic compound S2 differs from that of S1 only in that phenylboronic acid in step (1) is replaced by 2-methylphenylboronic acid. 2.35 g of the final product is obtained, and the molecular ion mass determined by mass spectrometry is 863.12 (theoretical value 863.12).

[0136] Preparation Example 3

[0137]

[0138] (1) Preparation of compound S13-1:

[0139] Add intermediate S2-3 (2.5 g, 8.08 mmol), cesium carbonate (7.90 g, 19.40 mmol), 3,6-dimethylcarbazole (3.78 g, 19.40 mmol) into a 500 ml single-mouth bottle, add 200 ml of ultra-dry DMF, and heat at 70 ° C under nitrogen protection to react overnight. Add 300 ml of water, filter, wash with ethanol, filter, and purify by solid column chromatography. Obtain 3.27 g of yellow-green solid. The molecular ion mass determined by mass spectrometry is 659.81 (theoretical value: 659.81).

[0140] (2) Preparation of organic compound S13

[0141] Add intermediate S13-1 (3 g, 4.55 mmol), cesium carbonate (2.22 g, 6.82 mmol), 3,6-diphenylcarbazole (1.74 g, 5.46 mmol) to a 500 ml single-mouth bottle, add 200 ml of ultra-dry DMF, and heat at 70 ° C under nitrogen protection to react overnight. Add 300 ml of water, filter, wash with ethanol, filter, and purify by solid column chromatography. Obtain 2.44 g of yellow-green solid. The molecular ion mass determined by mass spectrometry is: 959.21 (theoretical value: 959.21).

[0142] Preparation Example 4

[0143]

[0144] The preparation method of organic compound S9 differs from that of S13 only in that 3,6-diphenylcarbazole in step (2) is replaced by 3,6-di-tert-butylcarbazole. Finally, 14.25 g of the product is obtained, and the mass of the molecular ion determined by mass spectrometry is 918.47 (theoretical value 918.47).

[0145] Preparation Example 5

[0146]

[0147] (1) Preparation of intermediate S33-1

[0148] Add 2,6-difluoro-3,5-diphenyl-4-bromobenzonitrile (20g, 54.03mmol), cesium carbonate (52.81g, 162.08mmol), 3,6-dimethylcarbazole (21.10g, 108.05mmol) into a 1000ml single-mouth bottle, add 400ml of ultra-dry DMF, heat at 70℃ under nitrogen protection and react overnight. Add 300ml of water, filter, wash with ethanol, filter, and purify by solid column chromatography. Obtain 30.14g of yellow-green solid. The molecular ion mass determined by mass spectrometry is: 720.71 (theoretical value: 720.71).

[0149] (2) Preparation of organic compound S33

[0150] The intermediate S33-1 (20 g, 27.75 mmol), diphenylamine (4.7 g, 27.75 mmol), cuprous iodide (1.06 g, 5.55 mmol), 1,10-phenanthroline (1.00 g, 5.55 mmol), cesium carbonate (18.08 g, 55.50 mmol) were added to a 1000 ml flask, and 400 ml of DMF was added, and the mixture was heated to 140° C. under nitrogen protection and reacted overnight. The solvent was dried, and the sample was mixed with silica gel column chromatography to obtain 20.01 g of yellow-green solid, and the molecular ion mass determined by mass spectrometry was 919.23 (theoretical value: 919.23).

[0151] Preparation Example 6

[0152]

[0153] The preparation method of organic compound S69 differs from that of S13 only in that S2-3 in step (1) is replaced by 2,4,6-trifluoro-3,5-dimethylbenzonitrile. The final product is 18.37 g, and the molecular weight determined by mass spectrometry is 834.37 (theoretical value 834.37).

[0154] Preparation Example 7

[0155]

[0156] The preparation method of organic compound S121 differs from that of S9 only in that 3,6-diphenylcarbazole in step (1) is replaced by 1,3,6,8-tetramethylcarbazole. Finally, 14.25 g of the product is obtained, and the mass of the molecular ion determined by mass spectrometry is 974.53 (theoretical value 974.53).

[0157] Preparation Example 8

[0158]

[0159] (1) Preparation of compound S114-1

[0160] Add intermediate S2-3 (10 g, 29.64 mmol), cesium carbonate (14.49 g, 44.46 mmol), 3,6-dimethyl α-carboline (5.82 g, 29.64 mmol) to a 500 ml single-mouth bottle, add 200 ml of ultra-dry DMF, and react at room temperature overnight under nitrogen protection. Add 300 ml of water, filter, wash with ethanol, filter, and purify by solid column chromatography. Obtain 5.13 g of yellow-green solid. The molecular ion mass determined by mass spectrometry is 512.60 (theoretical value: 512.60).

[0161] (2) Preparation of organic compound S114

[0162] Add intermediate S114-1 (5 g, 9.75 mmol), cesium carbonate (9.53 g, 29.26 mmol), 3,6-dimethylcarbazole (3.81 g, 19.51 mmol) to a 500 ml single-mouth bottle, add 200 ml of ultra-dry DMF, and react overnight at room temperature under nitrogen protection. Add 300 ml of water, filter, wash with ethanol, filter, and purify by solid column chromatography. Obtain 4.76 g of yellow-green solid. The molecular ion mass determined by mass spectrometry is 864.11 (theoretical value: 864.11).

[0163] (1) Computational chemistry: theoretical calculation of molecular excited state energy levels

[0164] The present invention uses Gaussian03 to perform quantum chemical calculations on the compounds, and uses the time-dependent density functional method (B3LYP / 6-31d) to perform theoretical calculations on the first singlet energy level and the first triplet energy level of the organic compounds listed in Table 1, respectively. The calculation results are shown in Table 1. The structural formulas of the comparative compounds C2 and C3 are as follows:

[0165]

[0166] Table 1

[0167] Compound No. First singlet energy level (eV) First triplet energy level (eV) C2 2.63 2.59 C3 2.41 2.33 S1 2.71 2.68 S2 2.71 2.67 S11 2.70 2.66 S13 2.69 2.65 S33 2.67 2.59 S57 2.76 2.63 S69 2.72 2.65

[0168] As can be seen from Table 1, from the theoretical calculation results, the organic compound provided by the present invention has a higher first singlet energy level and a higher first singlet energy level than the comparative compounds C2 and C3, and the fluorescence emission wavelength of the material is related to the first singlet energy level. The higher the energy level, the shorter the fluorescence emission wavelength of the material, and the bluer the emission. The phosphorescence emission wavelength of the material is related to the first triplet energy level. The higher the energy level, the shorter the phosphorescence emission wavelength of the material, and the bluer the emission. From the calculation results of Table 1, it can be seen that the embodiment of the organic compound of the present invention has a higher singlet energy than the comparative compounds C2 and C3, and it can be expected that its emission wavelength is shorter and more suitable as a light-emitting material for a blue light OLED device. This may be because the substituent on the carbazole ortho-cyano in the organic compound of the present invention is methyl, while the substituent on the carbazole ortho-cyano on C2 is phenyl. Relatively speaking, the methyl group has a weaker electron-donating ability and a smaller conjugation effect with carbazole, resulting in a blue-shifted luminescence. Compared with C3, since there is only one cyano group in the organic compound of the present invention, the electron-withdrawing effect is weaker than that of C3, resulting in a bluer luminescence.

[0169] (2) Molecular transient fluorescence spectroscopy (test instrument model: FLS920) test:

[0170] The present invention uses FLS920 to perform molecular transient fluorescence spectroscopy test on organic compounds S1, S9 and C1, wherein the structural formula of the comparative compound C1 is as follows:

[0171]

[0172] Figure 1 This is the molecular transient fluorescence spectrum of organic compound S1. Figure 2 This is the molecular transient fluorescence spectrum of the organic compound S2. Figure 3 To compare the molecular transient fluorescence spectrum of compound C1, Figure 1 , Figure 2 and Figure 3 It can be seen that the organic compounds S1 and S9 provided by the present invention have obvious delayed fluorescence emission, while the transient spectrum of C1 is mainly instantaneous luminescence without obvious delayed luminescence, indicating that the TADF properties of S1 and S9 are stronger than that of C1.

[0173] The test results for compounds S1, S9, S11, S13, S33, S69, C1, C4, and C5 are shown in Table 2:

[0174] Table 2

[0175] Compound No. Delayed light ratio Photoluminescence efficiency PLQY C1 10.0％ 20％ C4 9％ 17％ C5 13％ 20％ S1 34.1％ 70％ S9 70.0％ 62％ S11 53.0％ 68％ S13 46.4％ 65％ S33 41.2％ 58％ S69 56.7％ 67％

[0176] It can be seen from Table 2 that in the transient fluorescence spectra of the comparative compounds C1, C4, and C5, no obvious delayed fluorescence emission is shown, and the delayed luminescence accounts for less than 15%, while the delayed luminescence accounts for more than 30% of the organic compounds in the present invention, proving that when the cyano group is ortho-dimethylcarbazole, the compound has stronger TADF properties than when the cyano group is ortho-di-tert-butylcarbazole. In addition, the photoluminescence efficiencies of C1, C4, and C5 are all 20% or less, while the photoluminescence efficiencies PLQY of the organic compounds provided by the present invention are all above 50%. In comparison, the organic compounds of the present invention have higher photoluminescence efficiency, which may be due to the fact that dimethylcarbazole has stronger rigidity than di-tert-butylcarbazole and diisopropylcarbazole, and the methyl group can protect the active site of carbazole to prevent quenching.

[0177] Device Example:

[0178] The manufacturing process of device embodiment 1 is as follows:

[0179] Example 1

[0180] This embodiment provides an organic electroluminescent device, and the preparation process thereof is as follows:

[0181] A glass plate coated with a transparent conductive layer of ITO (150 nm) 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 until the water was completely removed, cleaned with ultraviolet light and ozone, and bombarded with a low-energy cation beam;

[0182] Place the glass substrate with the anode in a vacuum chamber and evacuate to 1×10 -5 ~1×10 -4 Pa, vacuum evaporating 10 nm of HT-4:HI-3 (97 / 3, w / w) mixture as a hole injection layer, 60 nm of compound HT-4 as a hole transport layer, and 5 nm of compound HT-51 as an electron blocking layer on the above anode layer film;

[0183] 40 nm of PH-54:S1 (100 / 40, w / w) was vacuum-deposited on the hole transport layer as the light-emitting layer of the organic electroluminescent device;

[0184] On the light-emitting layer, 5nm of ET-23 was vacuum-deposited as a hole blocking layer, 25nm of a mixture of compounds ET-69:ET-57 (50 / 50, w / w) was used as an electron transport layer, 1nm of LiF was used as an electron injection layer, and 150nm of metal aluminum was used 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.

[0185] Example 2-13

[0186] The difference from Example 1 is that S1 is replaced by S2, S9, S11, S13, S16, S33, S69, S113, S129, S137, S144, and S145 in sequence, forming Example 2, Example 3, Example 4, Example 5, Example 6, Example 7, Example 8, Example 9, Example 10, Example 11, Example 12, and Example 13 respectively.

[0187] Comparative Examples 1-3

[0188] The difference from Example 1 is that S1 is replaced by compounds C1, C4, and C5, correspondingly forming Comparative Examples 1-3.

[0189] Performance Testing

[0190] At the same brightness, a digital source meter and a brightness meter were used to measure the driving voltage and current efficiency of the organic electroluminescent devices prepared in Examples 1 to 13 and Comparative Example 1. 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 this time 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 EQE (%).

[0191] The performance test results are shown in Table 3:

[0192] Table 3

[0193] Compound No. <![CDATA[Required luminance cd / m 2 > EQE% Comparative Example 1 C1 1000.00 12.2 Comparative Example 2 C4 1000.00 11.5 Comparative Example 3 C5 1000.00 11.0 Example 1 S1 1000.00 21.5 Example 2 S2 1000.00 20.7 Example 3 S9 1000.00 22.0 Example 4 S11 1000.00 21.4 Example 5 S13 1000.00 21.8 Example 6 S16 1000.00 22.0 Example 7 S33 1000.00 18.7 Example 8 S69 1000.00 19.3 Example 9 S113 1000.00 19.7 Example 10 S129 1000.00 20.3 Embodiment 11 S137 1000.00 20.4 Example 12 S144 1000.00 19.3 Embodiment 13 S145 1000.00 19.8

[0194] Embodiment 14

[0195] The device was prepared according to the method described in Example 1, vacuum evaporating 10 nm of a mixture of HT-4:HI-3 (97 / 3, w / w) as a hole injection layer, 60 nm of compound HT-4 as a hole transport layer, and 5 nm of compound HT-51 as an electron blocking layer;

[0196] Vacuum evaporation of "PH-54:S1:BFD-16 (100:40:1, w / w / w) (40 nm)" on the hole transport layer as the light-emitting layer of the organic electroluminescent device;

[0197] On the light-emitting layer, 5nm of ET-23 was vacuum-deposited as a hole blocking layer, 25nm of a mixture of compounds ET-69:ET-57 (50 / 50, w / w) was used as an electron transport layer, 1nm of LiF was used as an electron injection layer, and 150nm of metal aluminum was used 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.

[0198] Examples 15-26

[0199] The difference from Example 14 is that S1 is replaced by S2, S9, S11, S13, S16, S33, S69, S113, S129, S137, S144, and S145 in sequence, forming Example 15, Example 16, Example 17, Example 18, Example 19, Example 20, Example 21, Example 22, Example 23, Example 24, Example 25, and Example 26 respectively.

[0200] Comparative Examples 4-6

[0201] The only difference from Example 14 is that S1 is replaced by C1, C4, and C5.

[0202] Performance test results Table 4:

[0203] Table 4

[0204] Compound No. <![CDATA[Required luminance cd / m 2 > EQE% Comparative Example 4 C1 1000.00 13.5 Comparative Example 5 C4 1000.00 12.8 Comparative Example 6 C5 1000.00 11.9 Embodiment 14 S1 1000.00 22.9 Embodiment 15 S2 1000.00 21.8 Example 16 S9 1000.00 23.2 Embodiment 17 S11 1000.00 22.5 Embodiment 18 S13 1000.00 23.0 Embodiment 19 S16 1000.00 23.3 Embodiment 20 S33 1000.00 18.7 Embodiment 21 S69 1000.00 20.1 Embodiment 22 S113 1000.00 19.9 Embodiment 23 S129 1000.00 20.1 Embodiment 24 S137 1000.00 21.5 Embodiment 25 S144 1000.00 20.4 Embodiment 26 S145 1000.00 20.7

[0205] It can be seen from Tables 3 and 4 that when the organic compound of the present invention is used as a dye, compared with the comparative example compounds C1, C4, and C5, the efficiency is improved and excellent device performance is shown. This is because the organic compound provided by the present invention uses dimethylcarbazole at the ortho-cyano position, which has stronger TADF properties and higher luminous efficiency than compounds C1, C4, and C5, thereby improving device performance.

[0206] The applicant declares that the above is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention shall fall within the protection scope and disclosure scope of the present invention.

Claims

1. An organic compound, characterized in that The organic compound has a structure of Formula I: In Formula I, R 1 and R 2 Each is independently selected from any one of a C1-C10 chain alkyl group, a substituted or unsubstituted phenyl group; In Formula I, D 1 and D 2 Each independently selected from Among them, X 1 , X 2 , X 3 , X 4 , X 5 , X 6 , X 7 and X 8 Each independently selected from CR 3 , CR 4 or any one of N, and X 1 , X 2 , X 3 , X 4 , X 5 , X 6 , X 7 and X 8 At least one of the items is CR 4 , R 3 Any one independently selected from hydrogen, C3-C10 chain alkyl, C3-C10 cycloalkyl, C1-C10 alkoxy, halogen, C6-C20 aryl, C3-C20 heteroaryl; R 4 independently selected from methyl or ethyl; In Formula I, D 3 Any one selected from the group (Hy-2) or (Hy-3): In (Hy-2), Y 1 , Y 2 , Y 3 , Y 4 , Y 5 , Y 6 , Y 7 , Y 8 , Y 9 and Y 10 Each independently selected from CR 5 Any one of or N, and 8-10 of them are selected from CR 5 ; In (Hy-3), Z 1 , Z 2 , Z 3 , Z 4 , Z 5 , Z 6 , Z 7 and Z 8 Each independently selected from CR 5 Any one of N, and 6-8 of them are selected from CR 5 ; R 5 Any one of hydrogen, C1-C10 chain alkyl, C3-C10 cycloalkyl, C1-C10 alkoxy, halogen, C6-C30 aryl, and C3-C30 heteroaryl is independently selected; the adjacent R 5 There is no connection between them; R 1 , R 2 In the above, the substituted group is selected from any one of halogen, C1-C10 chain alkyl, C3-C10 cycloalkyl, C1-C10 alkoxy, C6-C30 monocyclic aromatic hydrocarbon or condensed aromatic hydrocarbon group, C3-C30 monocyclic heteroaromatic hydrocarbon or condensed heteroaromatic hydrocarbon group; "*" represents the attachment site to the parent nucleus.

2. The organic compound according to claim 1, characterized in that The R 1 and R 2 Each is independently selected from any one of the following groups:

3. The organic compound according to claim 1, characterized in that The R 1 and R 2 same.

4. The organic compound according to claim 1, characterized in that The R 4 It is methyl.

5. The organic compound according to claim 1, characterized in that The X 1 , X 2 , X 3 , X 4 , X 5 , X 6 , X 7 and X 8 1-4 items are CR 4 .

6. The organic compound according to claim 1, characterized in that The X 1 , X 2 , X 3 , X 4 1-2 items are CR 4 , and X 5 , X 6 , X 7 and X 8 0-2 items are CR 4 .

7. The organic compound according to claim 1, characterized in that The X 3 and X 6 All CR 4 .

8. The organic compound according to claim 5, characterized in that The D 1 and D 2 Each independently selected from Among them, X 1 , X 2 , X 4 , X 5 , X 7 and X 8 All have the same definition as claim 1.

9. The organic compound according to claim 1, characterized in that The D 1 and D 2 Each is independently selected from any one of the groups (a-1) to (a-3):

10. The organic compound according to claim 1, characterized in that The D 1 and D 2 All selected 11. The organic compound according to claim 1, characterized in that The D 1 and D 2 same.

12. The organic compound according to claim 1, characterized in that (Hy-2), Y 1 , Y 2 , Y 3 , Y 4 , Y 5 , Y 6 , Y 7 , Y 8 , Y 9 and Y 10 are all selected from CR 5 .

13. The organic compound according to claim 1, characterized in that In (Hy-3), Z 1 , Z 2 , Z 3 , Z 4 , Z 5 , Z 6 , Z 7 and Z 8 All selected from CR 5 .

14. The organic compound according to claim 1, characterized in that The D3 is selected from any one of the following groups:

15. The organic compound according to claim 1, characterized in that The D3 is selected from any one of the following groups:

16. The organic compound according to claim 1, characterized in that The organic compound has the following S1-S145 structure:

17. Use of an organic compound according to any one of claims 1 to 16, characterized in that: The organic compound is used as a luminescent dye or a luminescent sensitizer in the luminescent layer of an organic electroluminescent device.

18. An organic electroluminescent device, characterized in that: The organic electroluminescent device comprises a first electrode, a second electrode and an organic layer located between the first electrode and the second electrode, wherein the organic layer comprises the organic compound according to any one of claims 1 to 16.

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