Compound containing pyrimidine structure, organic electroluminescent device and display element

Abstract

The invention discloses a compound containing a pyrimidine structure, an organic electroluminescent device and a display element, and belongs to the technical field of semiconductor materials. The structure of the compound containing the pyrimidine structure is shown as a general formula (A): # imgabs0 #. The compound containing the pyrimidine structure is applied to an organic thin film layer of an organic electroluminescent device, and the organic thin film layer comprises a hole transmission region thin film layer, a light-emitting region thin film layer and an electron transmission region thin film layer, the electron transmission region thin film layer contains the compound containing the pyrimidine structure. The compound containing the pyrimidine structure has good stability and good hole blocking capacity, and when the compound containing the pyrimidine structure is used as a material of an organic electroluminescent device, the efficiency of the device is remarkably improved, and the service life of the device is remarkably prolonged.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor materials, and in particular to a compound containing a pyrimidine structure, an organic electroluminescent device and a display element. Background Art

[0002] Organic light-emitting diode (OLED) technology can be used to manufacture new display products as well as new lighting products. It is expected to replace existing liquid crystal displays and fluorescent lighting, and has a wide range of applications. Organic light-emitting diodes have a sandwich-like structure, including electrode material films and organic photoelectric functional materials sandwiched between different electrode material films. Various organic functional materials are superimposed on each other according to their uses to form organic light-emitting diodes. As a current device, when voltage is applied to the electrodes at both ends of the organic light-emitting diode and the electric field acts on the positive and negative charges in the organic photoelectric functional material film layer, the positive and negative charges further recombine in the light-emitting layer, generating organic electroluminescence.

[0003] Currently, organic electroluminescent device display technology has been applied in smart phones, tablet computers, TVs and other fields. However, compared with the actual product application requirements, the performance of organic electroluminescent devices such as luminous efficiency and service life needs to be further improved. In order to continuously improve the performance of organic electroluminescent devices, it is necessary to continuously research and innovate organic optoelectronic functional materials to create higher performance organic optoelectronic functional materials.

[0004] Organic optoelectronic functional materials used in organic electroluminescent devices can be divided into two categories based on their uses, namely charge injection and transport materials and luminescent materials. Furthermore, charge injection and transport materials can be divided into electron injection and transport materials, electron blocking materials, hole injection and transport materials, and hole blocking materials. For organic electroluminescent devices, holes are injected from the anode, electrons are injected from the cathode, and are transported in the organic functional layer, and finally meet in the luminescent layer to form excitons, which recombine and emit light. The hole blocking layer is located between the luminescent layer and the electron transport layer, which can block the diffusion or movement of holes to the electron transport layer, and can also reduce the energy loss of excitons, playing a role in interface modification and auxiliary regulation of electron injection / transport. Due to the poor electron regulation ability and hole and exciton blocking ability of the existing hole blocking layer materials, it is difficult to obtain an efficient electron-hole balance inside the light-emitting layer, and it is difficult to obtain high-efficiency and long-life devices. At the same time, the existing hole blocking layer materials also have a narrow heat resistance window and poor electron tolerance. Therefore, it is necessary to further improve the electron injection and transmission capabilities of the hole blocking layer materials, the hole and exciton blocking ability, improve the stability of the material, achieve an efficient balance of excitons, and improve the efficiency and life of the device. Summary of the invention

[0005] In view of the above problems existing in the prior art, the present invention provides a compound containing a pyrimidine structure, an organic electroluminescent device and a display element. The compound containing a pyrimidine structure of the present invention is bridged by a specific structure, and the substituent group is a pyrimidine structure at a specific site, so that the compound has excellent hole blocking ability and good material stability. When applied to an organic electroluminescent device, the luminous efficiency and service life of the device can be effectively improved.

[0006] A compound containing a pyrimidine structure, wherein the compound containing a pyrimidine structure is represented by general formula (A):

[0007]

[0008] In the general formula (A), X1, X2, and X3 are each independently CH or N, wherein only two of X1, X2, and X3 are N;

[0009] Ar1 and Ar2 are each independently substituted or unsubstituted phenyl, substituted or unsubstituted biphenyl, substituted or unsubstituted terphenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted phenanthrenyl;

[0010] L1 represents a single bond, a substituted or unsubstituted phenylene group, a substituted or unsubstituted naphthylene group, or a substituted or unsubstituted pyridylene group;

[0011] X4, X5, X6, X7, and X8 are each independently represented by CH, C-R3 or N;

[0012] R3 represents a hydrogen atom, a substituted or unsubstituted phenyl group, a substituted or unsubstituted biphenyl group, a substituted or unsubstituted terphenyl group, a substituted or unsubstituted naphthyl group, a substituted or unsubstituted phenanthrenyl group, a substituted or unsubstituted pyridyl group, or a substituted or unsubstituted pyrimidyl group;

[0013] When X4, X5, X6, X7, and X8 are all CH, R3 is not a hydrogen atom;

[0014] R1 is represented by the structure shown in general formula (a);

[0015] In the general formula (a), Y represents an oxygen atom, a sulfur atom or a dimethyl-substituted methylene group;

[0016] In the general formula (a), Ring A and Ring B are each independently represented by a substituted or unsubstituted phenyl group or a substituted or unsubstituted naphthyl group; at least one of Ring A and Ring B is represented by a substituted or unsubstituted naphthyl group;

[0017] Any unsubstituted carbon on the benzene ring or naphthalene ring in the general formula (a) can serve as a connection site with the general formula (A);

[0018] The substituents for the above substitutable groups are halogen, deuterium, phenyl, biphenyl, naphthyl, pyridyl, and phenanthryl.

[0019] Furthermore, the compound containing a pyrimidine structure is as shown in any one of the general formulas (A-1) to (A-3):

[0020]

[0021] In general formulae (A-1) to (A-3), the meanings of X1, X2, X4, X5, X6, X7, X8, Ar1, Ar2, L1, and R1 are the same as those defined above.

[0022] Furthermore, the compound containing a pyrimidine structure is represented by general formula (1) or general formula (2):

[0023]

[0024] In the general formula (1) and the general formula (2), X1, X2, and X3 are each independently CH or N, wherein only two of X1, X2, and X3 are N;

[0025] Ar1 and Ar2 are each independently substituted or unsubstituted phenyl, substituted or unsubstituted biphenyl, substituted or unsubstituted terphenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted phenanthrenyl;

[0026] L1 represents a single bond, a substituted or unsubstituted phenylene group, a substituted or unsubstituted naphthylene group, or a substituted or unsubstituted pyridylene group;

[0027] R1 represents the structure shown in general formula (a);

[0028] In the general formula (1), R2 represents a substituted or unsubstituted phenyl group, a substituted or unsubstituted biphenyl group, a substituted or unsubstituted terphenyl group, a substituted or unsubstituted naphthyl group, a substituted or unsubstituted phenanthryl group, a substituted or unsubstituted pyridyl group, or a substituted or unsubstituted pyrimidyl group; Ar1, Ar2, and R2 may be the same or different; * represents the connection position;

[0029] In the general formula (2), X4, X5, X6, X7, and X8 are each independently represented by C-R3 or N; at least one of X4, X5, X6, X7, and X8 is represented by N;

[0030] R3 represents a hydrogen atom, a substituted or unsubstituted phenyl group, a substituted or unsubstituted biphenyl group, a substituted or unsubstituted terphenyl group, a substituted or unsubstituted naphthyl group, a substituted or unsubstituted phenanthrenyl group, a substituted or unsubstituted pyridyl group, or a substituted or unsubstituted pyrimidyl group;

[0031] In the general formula (a), Y represents an oxygen atom, a sulfur atom or a dimethyl-substituted methylene group; any unsubstituted carbon on the benzene ring or naphthalene ring in the general formula (a) can serve as a connection site with the general formula (1) or the general formula (2);

[0032] Ring A and Ring B are each independently represented by a substituted or unsubstituted phenyl group, or a substituted or unsubstituted naphthyl group; at least one of Ring A and Ring B is represented by a substituted or unsubstituted naphthyl group;

[0033] The substituents for the above substitutable groups are halogen, deuterium, phenyl, biphenyl, naphthyl, pyridyl, and phenanthryl.

[0034] Furthermore, the structure of the compound containing a pyrimidine structure is shown in any one of the general formulas (2-1) to (2-6):

[0035]

[0036] In general formulae (2-1) to (2-6), the meanings of X1, X2, X3, Ar1, Ar2, L1, R1, and R2 are the same as those defined above.

[0037] Furthermore, the structure of the compound containing a pyrimidine structure is shown in any one of the general formulas (3-1) to (3-6):

[0038]

[0039] In general formulae (3-1) to (3-6), the meanings of X1, X2, X3, Ar1, Ar2, L1, R1, R2, and R3 are the same as those defined above.

[0040] Furthermore, the structure of R1 is shown in any one of the general formulas (4-1) to (4-12):

[0041]

[0042]

[0043] In general formula (4-1) to general formula (4-12), Y has the same meaning as defined in claim 1;

[0044] Preferably, the structure of R1 is as follows:

[0045]

[0046] Any one of the above; Y has the same meaning as defined in claim 1;

[0047] Preferably, the structure of R1 is as follows:

[0048]

[0049] Any one of the above; the meaning of Y is the same as that defined in claim 1.

[0050] Furthermore, the compound containing a pyrimidine structure is any one of the following structures:

[0051]

[0052]

[0053]

[0054]

[0055]

[0056]

[0057]

[0058]

[0059]

[0060]

[0061]

[0062]

[0063]

[0064]

[0065]

[0066]

[0067] The invention also discloses an organic electroluminescent device, comprising a substrate, a first electrode and a second electrode, wherein a plurality of organic thin film layers are provided between the first electrode and the second electrode, and the organic thin film layers contain the compound containing the pyrimidine structure of the invention.

[0068] Furthermore, the organic thin film layer includes a hole transport region thin film layer, a light emitting region thin film layer and an electron transport region thin film layer, and the electron transport region thin film layer contains the pyrimidine structure-containing compound of the present invention.

[0069] Furthermore, the electron transport region thin film layer comprises a hole blocking layer, and the hole blocking layer contains the compound containing the pyrimidine structure of the present invention.

[0070] Furthermore, the hole transport region thin film layer comprises a hole injection layer, a hole transport layer and an electron blocking layer, the electron transport region thin film layer comprises a hole blocking layer, an electron transport layer and an electron injection layer, and the hole blocking layer contains the compound containing the pyrimidine structure of the present invention.

[0071] The invention also discloses a display element, which contains the organic electroluminescent device of the invention.

[0072] The beneficial technical effects of the present invention are:

[0073] The compound of the present invention contains a pyrimidine structure which is bridged to a benzospirofluorene heteroanthracenyl group through an aromatic group or a heteroaromatic group, so that the compound containing a pyrimidine structure of the present invention has more excellent hole blocking and exciton blocking capabilities, can effectively block holes from diffusing or moving to the electron transport layer, so that the holes are better confined in the light-emitting area, ensuring that more excitons are formed by holes and electrons in the light-emitting layer, thereby increasing the exciton concentration and thus improving the light-emitting efficiency and device life.

[0074] The pyrimidine structure-containing compound of the present invention has a more excellent electron regulation ability, supplements the electron transport layer, enhances or delays electron injection and transmission according to the electron-hole balance inside the light-emitting layer, and improves the device luminescence efficiency and device life. BRIEF DESCRIPTION OF THE DRAWINGS

[0075] Figure 1 Schematic diagram of the structure of the organic electroluminescent device described in the embodiment.

[0076] In the figure, 1, transparent substrate layer; 2, anode layer; 3, hole injection layer; 4, hole transport layer; 5, electron blocking layer; 6, light-emitting layer; 7, hole blocking layer; 8, electron transport layer; 9, electron injection layer; 10, cathode layer; 11, light extraction layer. DETAILED DESCRIPTION

[0077] The specific implementation of the present invention is described in detail below. The present invention can be implemented in many other ways than those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention, so the present invention is not limited by the specific embodiments disclosed.

[0078] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which the present invention belongs. The terms used are only for describing specific embodiments and are not intended to limit the present invention.

[0079] In the present invention, unless otherwise specified, HOMO means the highest occupied orbital of a molecule, and LUMO means the lowest unoccupied orbital of a molecule. In addition, in the present invention, HOMO and LUMO energy levels are expressed in absolute values, and the comparison between energy levels is also a comparison of the magnitude of their absolute values. Those skilled in the art know that the greater the absolute value of an energy level, the lower the energy of the energy level.

[0080] In the drawings, the sizes of layers and regions may be exaggerated for clarity. It will also be understood that when a layer or element is referred to as being "on" another layer or substrate, the layer or element may be directly on the other layer or substrate, or intervening layers may also be present. In addition, it will be understood that when a layer is referred to as being "between" two layers, the layer may be the only layer between the two layers, or one or more intervening layers may also be present.

[0081] In the present invention, when describing electrodes and organic electroluminescent devices, as well as other structures, the words "upper" and "lower" used to indicate orientation only indicate orientation in a certain state, and do not mean that the related structure can only exist in the orientation described; on the contrary, if the structure can change its position, such as inverted, the orientation of the structure will be changed accordingly. Specifically, in the present invention, the "lower" side of the electrode refers to the side of the electrode close to the substrate during the preparation process, and the opposite side away from the substrate is the "upper" side.

[0082] The halogen mentioned in the present invention refers to a chlorine atom, a fluorine atom or a bromine atom.

[0083] Organic electroluminescent devices

[0084] The organic electroluminescent device of the present invention may be a bottom-emitting organic electroluminescent device, a top-emitting organic electroluminescent device or a stacked organic electroluminescent device, and there is no particular limitation on this.

[0085] The organic electroluminescent device of the present invention comprises a substrate, a first electrode, a multi-layer organic thin film layer and a second electrode. The multi-layer organic thin film layer comprises a hole transport region, a light-emitting layer and an electron transport region, the hole transport region comprises a hole injection layer, a hole transport layer and an electron blocking layer, the electron transport region comprises a hole blocking layer, an electron transport layer and an electron injection layer, and a covering layer may be provided on the second electrode.

[0086] The organic electroluminescent device of the present invention may include layers and the positional relationship of each layer is as follows: it may include a substrate, a first electrode, a hole injection layer, a hole transport layer, an electron blocking layer, a light-emitting layer, a hole blocking layer, an electron transport layer, an electron injection layer, a second electrode and a covering layer. If the above layers exist, the first electrode is above the substrate, the hole injection layer is above the first electrode, the hole transport layer is above the hole injection layer, the electron blocking layer is above the hole transport layer, the light-emitting layer is above the electron blocking layer, the hole blocking layer is above the light-emitting layer, the electron transport layer is above the hole blocking layer, the electron injection layer is above the electron transport layer, the second electrode is above the electron injection layer, and the covering layer is above the second electrode.

[0087] As the substrate of the organic electroluminescent device of the present invention, any substrate commonly used in organic electroluminescent devices can be used. Examples are transparent substrates, such as glass or transparent plastic substrates; opaque substrates, such as silicon substrates; flexible PI film substrates. Different substrates have different mechanical strengths, thermal stability, transparency, surface smoothness, and waterproofness. Depending on the properties of the substrate, its use direction is different. In the present invention, a transparent glass substrate is preferably used, and the thickness of the substrate is not particularly limited.

[0088] A first electrode is formed on a substrate, and the first electrode and the second electrode may be opposite to each other. The first electrode may be an anode or a cathode. In the present invention, the first electrode is used as an anode, and the anode material is preferably a material with a high work function so that holes are easily injected into the organic functional material layer. Non-limiting examples of anode materials include, but are not limited to, indium tin oxide (ITO), indium zinc oxide (IZO), tin oxide (SnO2), zinc oxide (ZnO), magnesium (Mg), aluminum (Al), silver (Ag), aluminum-lithium (Al-Li), calcium (Ca), magnesium-indium (Mg-In) and magnesium-silver (Mg-Ag). The first electrode may have a single-layer structure or a multilayer structure including two or more layers. In addition, the thickness of the anode depends on the material used, typically 50-500nm, preferably 70-300nm, and more preferably 100-200nm.

[0089] A hole injection layer, a hole transport layer, and an electron blocking layer may be disposed between the first electrode and the light emitting layer.

[0090] The hole injection layer may include a main material and a P-type doping material, wherein the main material may be selected from conventional hole transport materials in the prior art, preferably the same organic material as the hole transport layer, and the P-type doping material is selected from compounds with charge conductivity disclosed in the prior art, and may be selected from compounds disclosed in the following patent documents: WO2011073149A, EP1968131A1, EP2276085A1, EP2213662A1, EP1722602A1, EP2 045848A1, DE102007031220A1, US20100181555A1, US20100102709A1, WO2009003455A1, WO2010094378A1, WO2011120709A1, US20100096600A1, DE102012209523A1, CN101728485A and WO2012095143A1, but are not limited thereto.

[0091] For example, the compound shown below:

[0092]

[0093] According to the present invention, P1 is preferably used as the P-type doping material.

[0094] The thickness of the hole injection layer of the present invention may be 1-100 nm, preferably 2-50 nm and more preferably 5-20 nm.

[0095] The material of the hole transport layer is preferably a material having high hole mobility, which enables holes to be transferred from the anode or the hole injection layer to the light emitting layer.

[0096] Preferably, the hole transport layer material of the present invention may be selected from the following compounds disclosed in the prior art:

[0097]

[0098] The thickness of the hole transport layer of the present invention may be 5-200 nm, preferably 10-180 nm, and more preferably 20-150 nm.

[0099] The electron blocking layer requires that the triplet state (T1) energy level of the material is higher than the T1 energy level of the main material in the light-emitting layer, which can play a role in blocking the energy loss of the light-emitting layer material; the HOMO energy level of the electron blocking layer material is between the HOMO energy level of the hole transport layer material and the HOMO energy level of the main material of the light-emitting layer, which is conducive to the injection of holes from the positive electrode into the light-emitting layer. At the same time, the electron blocking layer material is required to have a high hole mobility, which is conducive to hole transport and reduces the power of the device; the LUMO energy level of the electron blocking layer material is higher than the LUMO energy level of the main material of the light-emitting layer, which plays a role in electron blocking, that is, the electron blocking layer material is required to have a wide bandgap width (Eg). The electron blocking layer materials that meet the above conditions can be triarylamine derivatives, fluorene derivatives, spirofluorene derivatives, dibenzofuran derivatives, carbazole derivatives, etc.

[0100] In one embodiment of the present invention, the electron blocking layer material of the present invention may be selected from the following compounds disclosed in the prior art:

[0101]

[0102]

[0103] According to the present invention, the thickness of the electron blocking layer may be 1-200 nm, preferably 5-150 nm, and more preferably 5-50 nm.

[0104] According to the present invention, the light-emitting layer is located between the electron blocking layer and the hole blocking layer, and the material of the light-emitting layer is a material that can emit visible light by receiving holes from the hole transport region and electrons from the electron transport region respectively, and combining the received holes and electrons. The light-emitting layer may include a host material and a doping material. As the host material and guest material of the light-emitting layer of the organic electroluminescent device of the present invention, the host material may be one or a combination of two of anthracene derivatives, quinoxaline derivatives, triazine derivatives, xanthone derivatives, diphenyl ketone derivatives, carbazole derivatives, pyridine derivatives or pyrimidine derivatives. The guest material may be a pyrene derivative, a boron derivative, a chrysene derivative, a spirofluorene derivative, an iridium complex or a platinum complex.

[0105] The thickness of the light-emitting layer of the present invention may be 5-60 nm, preferably 10-50 nm, and more preferably 20-45 nm.

[0106] The hole blocking layer of the hole blocking layer of the present invention can be arranged on the light-emitting layer. The triplet state (T1) energy level of the hole blocking layer material is higher than the T1 energy level of the main material of the light-emitting layer, which can play a role in blocking the energy loss of the light-emitting layer material; the HOMO energy level of the material is lower than the HOMO energy level of the main material of the light-emitting layer, which plays a role in hole blocking, and at the same time, the hole blocking layer material is required to have a high electron mobility, which is conducive to electron transmission and reduces the application power of the device; the hole blocking layer material that meets the above conditions is the compound described above in the present invention.

[0107] The thickness may be 2-200 nm, preferably 5-150 nm, and more preferably 5-50 nm, but the thickness is not limited to this range.

[0108] The electron transport layer may be disposed on the light-emitting layer or (if present) the hole blocking layer. The electron transport layer material is a material that easily receives electrons from the cathode and transfers the received electrons to the light-emitting layer. A material having a high electron mobility is preferred. As the electron transport layer of the organic electroluminescent device of the present invention, the following compounds disclosed in the prior art can be used as electron transport layer materials for organic electroluminescent devices:

[0109]

[0110]

[0111] In a preferred embodiment of the present invention, the electron transport layer further comprises other compounds conventionally used in electron transport layers, for example, Alq3, LiQ, preferably LiQ.

[0112] The thickness of the electron transport layer of the present invention may be 10-80 nm, preferably 20-60 nm, and more preferably 25-45 nm.

[0113] According to the present invention, the electron injection layer can be arranged between the electron transport layer and the cathode. The electron injection layer material is generally preferably a material with a low work function, so that electrons are easily injected into the organic functional material layer. Preferably, the electron injection layer material is an N-type metal material. As the electron injection layer material of the organic electroluminescent device of the present invention, the electron injection layer materials for organic electroluminescent devices disclosed in the following prior art can be used: LiF, Cs2CO3, CsF, Csq, NaF, MgF2, CaF2, Al2O3, Yb.

[0114] The thickness of the electron injection layer of the present invention may be 0.1-5 nm, preferably 0.5-3 nm, and more preferably 0.8-1.5 nm, but the thickness is not limited to this range.

[0115] According to the present invention, as mentioned above, the second electrode can be a cathode or an anode. In the present invention, the second electrode is used as a cathode. The material used to form the cathode can be a material with a low work function, such as a metal, an alloy, a conductive compound or a mixture thereof. Non-limiting examples of cathode materials can include lithium (Li), ytterbium (Yb), magnesium (Mg), aluminum (Al), calcium (Ca), and aluminum-lithium (Al-Li), magnesium-indium (Mg-In) and magnesium-silver (Mg-Ag). The thickness of the cathode depends on the material used, typically 5-100nm, preferably 7-50nm and more preferably 10-25nm.

[0116] Optionally, in order to improve the light extraction efficiency of the organic electroluminescent device, a light extraction layer (ie, CPL layer) may be added on the second electrode (ie, cathode) of the device. The following compounds disclosed in the prior art may be used as CPL layer materials.

[0117]

[0118]

[0119] The thickness of the CPL layer is generally 5-300 nm, preferably 20-100 nm, and more preferably 40-80 nm.

[0120] The organic electroluminescent device may further include an encapsulation structure. The encapsulation structure may be a protective structure that prevents foreign substances such as moisture and oxygen from entering the organic layer of the organic electroluminescent device. The encapsulation structure may be, for example, a can, such as a glass can or a metal can; or a thin film covering the entire surface of the organic layer.

[0121] Organic electroluminescent device preparation method

[0122] The present invention also relates to a method for preparing the above-mentioned organic electroluminescent device, which comprises laminating a first electrode, a multi-layer organic thin film layer and a second electrode on a substrate in sequence. The multi-layer organic thin film layer is formed by laminating a hole transport region, a light-emitting layer and a hole blocking region on the first electrode from bottom to top, and the hole transport region is formed by laminating a hole injection layer, a hole transport layer and an electron blocking layer on the first electrode in sequence from bottom to top, and the hole blocking region is formed by laminating a hole blocking layer, an electron transport layer and an electron injection layer on the light-emitting layer in sequence from bottom to top. In addition, optionally, a CPL layer can also be laminated on the second electrode to improve the light extraction efficiency of the organic electroluminescent device.

[0123] For lamination, vacuum deposition, vacuum evaporation, spin coating, casting, LB method, inkjet printing, laser printing or LITI methods may be used, but are not limited thereto. Vacuum evaporation means heating and coating a material onto a substrate in a vacuum environment.

[0124] In the present invention, the various layers are preferably formed by vacuum evaporation, wherein the layers can be formed at a temperature of about 100-500° C. and at a temperature of about 10 -8 -10 -2 Torr vacuum and approx. The vacuum evaporation is carried out at a rate of 10 -6 -10 -2 Torr, preferably 10 -5 -10 -3 Torr. The rate is about More preferably, about

[0125] In addition, it should be noted that the materials used to form each layer described in the present invention can be formed into a film alone and used as a single layer, or can be mixed with other materials to form a film and used as a single layer. It can also be a stacked structure between layers formed into films alone, a stacked structure between layers formed into films after mixing, or a stacked structure of layers formed into films alone and layers formed into films after mixing.

[0126] Display components

[0127] The present invention also relates to a display device including the above-mentioned organic electroluminescent device, in particular a flat panel display device. In a preferred embodiment, the display device may include one or more of the above-mentioned organic electroluminescent devices, and in the case of including a plurality of devices, the devices are stacked and combined laterally or longitudinally. The display device may also include at least one thin film transistor. The thin film transistor may include a gate electrode, a source electrode and a drain electrode, a gate insulating layer and an active layer, wherein one of the source electrode and the drain electrode may be electrically connected to the first electrode of the organic electroluminescent device. The active layer may include crystalline silicon, amorphous silicon, an organic semiconductor or an oxide semiconductor, but is not limited thereto.

[0128] The following examples are intended to better explain the present invention, but the scope of the present invention is not limited thereto.

[0129] Example

[0130] I. Compound Preparation Examples

[0131] The present invention is described in detail below in conjunction with the accompanying drawings and embodiments.

[0132] The raw materials involved in the synthesis examples of the present invention can be purchased from the market or prepared by conventional preparation methods in the art; Synthesis of intermediate B-1:

[0133]

[0134] Preparation of intermediate C-1: Dissolve the raw material A-17 (60mmol, 17g) in 200mL tetrahydrofuran solution, add n-butyl lithium (60mmol, 3.85g) in hexane solution at -78°C, and then stir for about 1 hour. Add raw material A-16 (50mmol, 11.53g) and stir at room temperature for 2.5 hours. After extraction with ethyl acetate, concentrate to prepare intermediate C-1. LC-MS: Measured value: 435.08 ([M+H]+); Exact mass: 434.11.

[0135] Preparation of intermediate D-1: Under nitrogen protection, in a round-bottom flask, intermediate C-1 (45 mmol, 19.57 g) was added to 200 mL of acetic acid, and 2 ml of concentrated sulfuric acid was added at 80 ° C and refluxed for 5 hours. After the temperature was lowered to room temperature and the reaction was terminated, it was filtered and the solid obtained by filtration was washed twice with THF and ethyl acetate to obtain intermediate D-1. LC-MS: Measured value: 417.23 ([M+H]+); accurate mass: 416.10.

[0136] Preparation of intermediate B-1: Under nitrogen protection, in a round-bottom flask, add intermediate D-1 (10mmol, 4.17g), diboronic acid pinacol ester (12mmol, 3.05g), KOAC (40mmol, 3.93g), dioxane (120ml), nitrogen was passed for 30min to replace the air, Pd(PPh3)4 (0.2mmol, 0.23g) was added, and heated under reflux for 12h under nitrogen protection. TLC detection of the reaction solution found that the intermediate D-1 reacted completely. After the reaction was completed, the reaction system was naturally cooled to room temperature, poured into a separating funnel, shaken, and then allowed to stand for stratification. After separation, the aqueous phase was extracted with dichloromethane (60ml*3), the organic phases were combined, anhydrous magnesium sulfate was added, dried, filtered, and the filtrate was evaporated to remove dichloromethane to obtain intermediate B-1.

[0137] Intermediates B-4, B-5, B-7 to B-9 were prepared by a synthetic method similar to that of intermediate B-1, and the raw materials and intermediates used are shown in Table 1;

[0138] Table 1

[0139]

[0140]

[0141] Synthesis of intermediate B-2:

[0142]

[0143] Preparation of intermediate B-2: Under nitrogen protection, in a round-bottom flask, add raw material A-13 (10mmol, 4.62g), diboric acid pinacol ester (12mmol, 3.05g), KOAC (40mmol, 3.93g), dioxane (120ml), nitrogen was passed for 40min to replace the air, Pd (PPh3) 4 (0.2mmol, 0.23g) was added, and heated under reflux for 12h under nitrogen protection. TLC detection of the reaction solution found that the raw material A-13 reacted completely. After the reaction was completed, the reaction system was naturally cooled to room temperature, poured into a separating funnel, shaken, and then allowed to stand for stratification. After separation, the aqueous phase was extracted with dichloromethane (50ml*3), the organic phases were combined, anhydrous magnesium sulfate was added, dried, filtered, and the filtrate was evaporated to remove dichloromethane to obtain intermediate B-2.

[0144] Intermediates B-3 and B-6 were prepared by a synthetic method similar to that of intermediate B-2. The raw materials and intermediates used are shown in Table 2.

[0145] Table 2

[0146]

[0147]

[0148] Example 1: Synthesis of Compound 4:

[0149]

[0150] Preparation of intermediate E-1: Under nitrogen protection, in a round-bottom flask, add raw material A-11 (20 mmol, 10.17 g), raw material A-3 (25 mmol, 7.86 g), K2CO3 (60 mmol, 8.29 g), tetrahydrofuran (100 mL), water (50 mL) in sequence, pass nitrogen for 30 minutes to replace the air, add palladium acetate (0.2 mmol, 0.05 g), 2-dicyclohexylphosphine-2',4',6'-triisopropylbiphenyl (0.40 mmol, 0.19 g), and heat under reflux for 18 hours under nitrogen protection. The reaction solution was taken for TLC detection and it was found that the raw material A-11 had reacted completely. After the reaction was completed, the reaction system was naturally cooled to room temperature, the solvent was removed by rotary evaporation, 150 ml of dichloromethane was added to the residue to dissolve, 150 ml of water was added to wash, poured into a separatory funnel and shaken, and then allowed to stand for stratification. After separation, the aqueous phase was extracted with dichloromethane (80 ml*3), the organic phases were combined and dried over anhydrous magnesium sulfate, filtered, and the filtrate was evaporated to remove dichloromethane to obtain a crude product. The crude product was purified by silica gel column chromatography to obtain intermediate E-1.

[0151] Preparation of compound 4: Under nitrogen protection, in a round-bottom flask, add intermediate E-1 (15mmol, 8.54g), raw material A-1 (17mmol, 4.7g), K2CO3 (45mmol, 6.22g), tetrahydrofuran (150mL), and water (50mL) in sequence, pass nitrogen for 30min to replace the air, add Pd(PPh3)4 (0.3mmol, 0.35g), and heat under reflux for 15h under nitrogen protection. The reaction solution was taken for TCL detection and it was found that the intermediate E-1 had reacted completely. After the reaction was completed, the reaction system was naturally cooled to room temperature, the solvent was removed by rotary evaporation, 200 ml of dichloromethane was added to the residue to dissolve, 100 ml of water was added to wash, poured into a separatory funnel and shaken, and then allowed to stand for stratification. After separation, the aqueous phase was extracted with dichloromethane (80 ml*3), the organic phases were combined and dried over anhydrous magnesium sulfate, filtered, and the filtrate was evaporated to remove dichloromethane to obtain a crude product. The crude product was purified by silica gel chromatography to obtain compound 4.

[0152] Examples 2 to 18 were prepared using a synthetic method similar to that of Example 1, and the raw materials and intermediates used are shown in Table 3;

[0153] Table 3

[0154]

[0155]

[0156]

[0157] Example 19: Synthesis of Compound 51:

[0158]

[0159] Preparation of intermediate E-19: Under nitrogen protection, in a round-bottom flask, add raw material A-4 (15mmol, 4.01g), raw material A-2 (17mmol, 4.69g), K2CO3 (45mmol, 6.22g), tetrahydrofuran (150mL), and water (50mL) in sequence, pass nitrogen for 30min to replace the air, add Pd(PPh3)4 (0.3mmol, 0.35g), and heat under reflux for 18h under nitrogen protection. The reaction solution was taken for TLC detection and it was found that the raw material A-4 had reacted completely. After the reaction was completed, the reaction system was naturally cooled to room temperature, the solvent was removed by rotary evaporation, 200 ml of dichloromethane was added to the residue to dissolve, 100 ml of water was added to wash, poured into a separatory funnel and shaken, and then allowed to stand for stratification. After separation, the aqueous phase was extracted with dichloromethane (60 ml*3), the organic phases were combined and dried with anhydrous magnesium sulfate, filtered, and the filtrate was evaporated to remove dichloromethane to obtain a crude product. The crude product was purified by silica gel chromatography to obtain intermediate E-19.

[0160] Preparation of compound 51: Under nitrogen protection, in a round-bottom flask, intermediate E-19 (20 mmol, 8.38 g), raw material A-11 (25 mmol, 12.71 g), K2CO3 (60 mmol, 8.29 g), tetrahydrofuran (100 mL), and water (50 mL) were added in sequence, and nitrogen was passed through for 30 min to replace the air. Palladium acetate (0.2 mmol, 0.05 g) and 2-dicyclohexylphosphino-2',4',6'-triisopropylbiphenyl (0.40 mmol, 0.19 g) were added, and the mixture was heated to reflux for 12 h under nitrogen protection. The reaction solution was taken for TLC detection, and it was found that the intermediate E-19 had reacted completely. After the reaction was completed, the reaction system was naturally cooled to room temperature, and the solvent was removed by rotary evaporation. The residue was dissolved in 150 ml of dichloromethane, washed with 150 ml of water, poured into a separatory funnel and shaken, and then allowed to stand for stratification. After separation, the aqueous phase was extracted with dichloromethane (60 ml*3), and the organic phases were combined and dried over anhydrous magnesium sulfate, filtered, and the filtrate was evaporated to remove dichloromethane to obtain a crude product. The crude product was purified by silica gel chromatography to obtain compound 51.

[0161] Example 20 and Example 21 were prepared by a synthetic method similar to that of Example 19, and the raw materials and intermediates used are shown in Table 4;

[0162] Table 4

[0163]

[0164] The structural characteristics of the compounds obtained in each example are shown in Table 5

[0165] Table 5

[0166]

[0167]

[0168] II. Device Preparation Example

[0169] The following describes in detail the application effect of the compound synthesized according to the present invention as a hole blocking layer material in the device through device examples 1-21 and device comparative examples 1-11. Compared with device comparative examples 1-11, device examples 1-21 have the same manufacturing process of the device, and use the same substrate material and electrode material, and the film thickness of the electrode material is also the same. The difference is that the hole blocking layer material in the device has changed. The device layer structure is shown in Table 6, and the performance test results of each device are shown in Table 7.

[0170] The molecular structure formula of the relevant materials is shown below:

[0171]

[0172]

[0173] The structures of comparative compounds HB-1 to HB-11 are shown above. The above materials were all commercially available.

[0174] Device Comparison Example 1

[0175] The specific preparation process is as follows:

[0176] like Figure 1 As shown, the transparent substrate layer 1 is transparent glass, and Ag (100nm) is evaporated as the anode layer 2. On the anode layer 2, a vacuum evaporation device is used to evaporate HT-1 and P-1 with a film thickness of 10nm as the hole injection layer 3, and the mass ratio of HT-1 and P-1 is 97:3. Then, HT-1 with a thickness of 130nm is evaporated as the hole transport layer 4. Then, EB-1 with a thickness of 5nm is evaporated as the electron blocking layer 5. After the above-mentioned electron blocking material is evaporated, the light-emitting layer 6 of the OLED light-emitting device is prepared, using BH-1 as the main material and BD-1 as the doping material. The doping ratio of the doping material is 3% by weight, and the film thickness of the light-emitting layer 6 is 20nm. After the above-mentioned light-emitting layer 6, HB-1 is continuously evaporated, and the film thickness is 5nm, as a hole blocking layer 7. On the above-mentioned hole blocking layer 7, ET-1 and LiQ are continuously evaporated, and the mass ratio of ET-1 and LiQ is 1:1. The vacuum-deposited film thickness of the material is 30 nm, and this layer is the electron transport layer 8. On the electron transport layer 8, a LiF layer with a film thickness of 1 nm is made by a vacuum evaporation device, and this layer is the electron injection layer 9. On the electron injection layer 9, a Mg:Ag electrode layer with a film thickness of 16 nm is made by a vacuum evaporation device, and the mass ratio of Mg to Ag is 1:9, and this layer is used as the cathode layer 10. On the cathode layer 10, 65 nm of CP-1 is vacuum-deposited as the light extraction layer 11.

[0177] Device Examples 1-21 and Device Comparative Examples 2-11 were prepared in a similar manner to Device Comparative Example 1, except that the hole blocking layer materials listed in Table 6 below were used.

[0178] Table 6

[0179]

[0180]

[0181]

[0182]

[0183] III. Device Testing Example

[0184] The device prepared in the device preparation example was tested for its current efficiency, CIEy and LT95 life. The current efficiency and CIEy were tested using an IVL (current-voltage-luminance) test system (Suzhou Fushida Scientific Instrument Co., Ltd.), and the current density during the test was 10 mA / cm 2 LT95 refers to the time it takes for the device brightness to decay to 95% of the initial brightness. The current density during the test is 30mA / cm 2 ; The life test system is the EAS-62C OLED device life tester produced by Japan System Engineering Co., Ltd.; The test results are shown in Table 7 below.

[0185] Table 7

[0186]

[0187]

[0188] It can be seen from the device test data results in Table 7 above that compared with the comparative devices using HB-1, HB-2, HB-3, HB-4, HB-5, HB-6, HB-7, HB-8, HB-9, HB-10 and HB-11 as hole blocking layer materials, the device current efficiency prepared using the compound of the present invention as the hole blocking layer material is improved and the device life is extended. For example, its life is basically more than 1.2 times that of the comparative devices 1-6.

[0189] The structural formulas of the comparative compounds HB-1, HB-2, HB-3, HB-4, HB-5, HB-6, HB-7, HB-8, HB-9, HB-10 and HB-11 used in the comparative examples are close to those of the present invention with only slight differences. However, unexpectedly, the compounds of the present invention achieved better technical effects as hole blocking layer materials than the comparative compounds.

[0190] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are exhaustively listed. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0191] For those skilled in the art, several modifications and improvements may be made without departing from the concept of the present invention, all of which belong to the protection scope of the present invention. The protection scope of the present invention shall be based on the attached claims.

Claims

1. A compound containing a pyrimidine structure, characterized in that: The compound containing a pyrimidine structure is shown in general formula (A): In the general formula (A), X1, X2, and X3 are each independently CH or N, wherein only two of X1, X2, and X3 are N; Ar1 and Ar2 are each independently substituted or unsubstituted phenyl, substituted or unsubstituted biphenyl, substituted or unsubstituted terphenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted phenanthrenyl; L1 represents a single bond, a substituted or unsubstituted phenylene group, a substituted or unsubstituted naphthylene group, or a substituted or unsubstituted pyridylene group; X4, X5, X6, X7, and X8 are each independently represented by CH, C-R3 or N; R3 represents a hydrogen atom, a substituted or unsubstituted phenyl group, a substituted or unsubstituted biphenyl group, a substituted or unsubstituted terphenyl group, a substituted or unsubstituted naphthyl group, a substituted or unsubstituted phenanthrenyl group, a substituted or unsubstituted pyridyl group, or a substituted or unsubstituted pyrimidyl group; When X4, X5, X6, X7, and X8 are all CH, R3 is not a hydrogen atom; R1 represents the structure shown in general formula (a); In the general formula (a), Y represents an oxygen atom, a sulfur atom or a dimethyl-substituted methylene group; In the general formula (a), Ring A and Ring B are each independently represented by a substituted or unsubstituted phenyl group or a substituted or unsubstituted naphthyl group; at least one of Ring A and Ring B is represented by a substituted or unsubstituted naphthyl group; Any unsubstituted carbon on the benzene ring or naphthalene ring in the general formula (a) can serve as a connection site with the general formula (A); The substituents for the above substitutable groups are halogen, deuterium, phenyl, biphenyl, naphthyl, pyridyl, and phenanthryl.

2. A compound containing a pyrimidine structure according to claim 1, characterized in that: The compound containing a pyrimidine structure is represented by general formula (1) or general formula (2): In the general formula (1) and the general formula (2), X1, X2, and X3 are each independently CH or N, wherein only two of X1, X2, and X3 are N; Ar1 and Ar2 are each independently substituted or unsubstituted phenyl, substituted or unsubstituted biphenyl, substituted or unsubstituted terphenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted phenanthrenyl; L1 represents a single bond, a substituted or unsubstituted phenylene group, a substituted or unsubstituted naphthylene group, or a substituted or unsubstituted pyridylene group; R1 represents the structure shown in general formula (a); In the general formula (1), R2 represents a substituted or unsubstituted phenyl group, a substituted or unsubstituted biphenyl group, a substituted or unsubstituted terphenyl group, a substituted or unsubstituted naphthyl group, a substituted or unsubstituted phenanthryl group, a substituted or unsubstituted pyridyl group, or a substituted or unsubstituted pyrimidyl group; Ar1, Ar2, and R2 may be the same or different; * represents the connection position; In the general formula (2), X4, X5, X6, X7, and X8 are each independently represented by C-R3 or N; at least one of X4, X5, X6, X7, and X8 is represented by N; R3 represents a hydrogen atom, a substituted or unsubstituted phenyl group, a substituted or unsubstituted biphenyl group, a substituted or unsubstituted terphenyl group, a substituted or unsubstituted naphthyl group, a substituted or unsubstituted phenanthrenyl group, a substituted or unsubstituted pyridyl group, or a substituted or unsubstituted pyrimidyl group; In the general formula (a), Y represents an oxygen atom, a sulfur atom or a dimethyl-substituted methylene group; any unsubstituted carbon on the benzene ring or naphthalene ring in the general formula (a) can serve as a connection site with the general formula (1) or the general formula (2); Ring A and Ring B are each independently represented by a substituted or unsubstituted phenyl group, or a substituted or unsubstituted naphthyl group; at least one of Ring A and Ring B is represented by a substituted or unsubstituted naphthyl group; The substituents for the above substitutable groups are halogen, deuterium, phenyl, biphenyl, naphthyl, pyridyl, and phenanthryl.

3. A compound containing a pyrimidine structure according to claim 2, characterized in that: The structure of the compound containing a pyrimidine structure is shown in any one of the general formulas (2-1) to (2-6): In general formula (2-1) to general formula (2-6), the meanings of X1, X2, X3, Ar1, Ar2, L1, R1, and R2 are the same as those defined in claim 2.

4. A compound containing a pyrimidine structure according to claim 1, characterized in that: The structure of the compound containing a pyrimidine structure is shown in any one of the general formulas (3-1) to (3-6): In general formula (3-1) to general formula (3-6), the meanings of X1, X2, X3, Ar1, Ar2, L1, R1, R2, and R3 are the same as those defined in claim 2.

5. The compound containing a pyrimidine structure according to claim 1, characterized in that: The structure of R1 is shown in any one of the general formulas (4-1) to (4-12): In general formula (4-1) to general formula (4-12), Y has the same meaning as defined in claim 1; Preferably, the structure of R1 is as follows: Any one of the above; Y has the same meaning as defined in claim 1; Preferably, the structure of R1 is as follows: Any of the following: Y has the same meaning as defined in claim 1.

6. The compound containing a pyrimidine structure according to claim 1, characterized in that: The compound containing a pyrimidine structure is any one of the following structures:

7. An organic electroluminescent device comprising a substrate, a first electrode and a second electrode, wherein a plurality of organic thin film layers are provided between the first electrode and the second electrode, wherein: The organic thin film layer contains the compound containing a pyrimidine structure according to any one of claims 1 to 6; Preferably, the organic thin film layer comprises a hole transport region thin film layer, a light emitting region thin film layer and an electron transport region thin film layer, and the electron transport region thin film layer contains the pyrimidine structure-containing compound according to any one of claims 1 to 6.

8. An organic electroluminescent device according to claim 7, characterized in that: The electron transport region thin film layer comprises a hole blocking layer, and the hole blocking layer contains the pyrimidine structure-containing compound according to any one of claims 1 to 6.

9. An organic electroluminescent device according to claim 7, characterized in that: The hole transport region thin film layer comprises a hole injection layer, a hole transport layer and an electron blocking layer, the electron transport region thin film layer comprises a hole blocking layer, an electron transport layer and an electron injection layer, and the hole blocking layer contains the pyrimidine structure-containing compound according to any one of claims 1 to 6.

10. A display element, characterized in that: The display element comprises the organic electroluminescent device according to any one of claims 7 to 9.

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