Compound containing boron and nitrogen and application thereof

Abstract

The invention provides a compound containing boron and nitrogen and application thereof.The compound containing boron and nitrogen has the structure shown in the formula I. The structure of the compound containing boron and nitrogen is designed, and the obtained compound containing boron and nitrogen has good light-emitting performance and can be used for preparing organic light-emitting devices. Particularly, as a luminescent layer material in the organic electroluminescent device, the compound can effectively reduce the driving voltage of the organic electroluminescent device and improve the current efficiency of the organic electroluminescent device.

Description

Technical Field

[0001] The invention belongs to the technical field of organic photoelectric display, and in particular relates to a boron-nitrogen-containing compound and application thereof. Background Art

[0002] Organic light emitting diodes (OLEDs) are display components that utilize the phenomenon of self-luminescence and have a wide viewing angle. Compared with liquid crystal display components, OLED components are thinner and lighter, have a faster response speed, and can achieve flexible displays. Therefore, their application as full-color display components or lighting equipment is highly anticipated.

[0003] Generally, organic light emitting phenomenon refers to the phenomenon of converting electrical energy into light energy using organic substances. An organic light emitting element using the organic light emitting phenomenon generally has a structure including an anode, a cathode, and an organic material layer interposed between the anode and the cathode.

[0004] Among them, the organic layer is composed of a multilayer structure composed of different substances in most cases in order to improve the efficiency and stability of the organic light-emitting element. For example, it can be composed of a hole injection layer, a hole transport layer, a light-emitting layer, an electron transport layer, an electron injection layer, etc. If a voltage is applied between the two electrodes in the structure of such an organic light-emitting element, the holes in the anode will be injected into the organic layer, and the electrons in the cathode will also be injected into the organic layer. When the injected holes and electrons meet, excitons are formed. When the excitons release energy and transition to the ground state, photons will be emitted, thereby generating light. Such organic light-emitting elements are widely recognized to have the characteristics of self-luminescence, high brightness, high efficiency, low driving voltage, wide viewing angle, high contrast, and high-speed responsiveness.

[0005] At present, the research on organic electroluminescent materials has been widely carried out in academia and industry. Among them, blue light materials are an important component of organic electroluminescent devices. The transmission performance and luminous efficiency of blue light materials restrict the industrialization of light-emitting devices. Therefore, designing and finding a compound as a new OLED material to overcome its shortcomings in practical applications is the focus of OLED material research and the future research and development trend. Summary of the invention

[0006] In view of the shortcomings of the prior art, the present invention aims to provide a boron-nitrogen-containing compound and its application. The present invention is designed through the structure of the boron-nitrogen-containing compound, and the obtained boron-nitrogen-containing compound has excellent performance and is suitable for the light-emitting layer material in the organic electroluminescent device.

[0007] To achieve this object, the present invention adopts the following technical solutions:

[0008] In one aspect, the present invention provides a boron-nitrogen-containing compound, wherein the boron-nitrogen-containing compound has a structure as shown in Formula I or Formula II:

[0009]

[0010] Where X is selected from O, S, Y is selected from O or S;

[0011] R1, R2, R3, R4, R5, R6, R7, R8, R9, R 10 , R 11 , R 12 , R 13 , R 14 , R 15 , R 16 , R 17 Each independently selected from substituted or unsubstituted C1 to C 12 Alkyl, substituted or unsubstituted C6~C 30 aryl or substituted or unsubstituted C3~C 30 heteroaryl;

[0012] R1, R2, R3, R4, R5, R6, R7, R8, R9, R 10 , R 11 , R 12 , R 13 , R 14 , R 15 , R 16 , R 17 The substituted substituent is selected from C1 to C 12 Alkyl or C6~C 30 Aryl or C3~C 30 At least one of the heteroaryl groups;

[0013] All hydrogen atoms in the compounds of formula I and formula II can be replaced independently by deuterium atoms, F, CN, C1-C 12 Alkyl or C6~C 30 Aryl or C3~C 30 At least one of the heteroaryl groups is substituted;

[0014] * indicates the attachment site of the group.

[0015] Preferably, the C1 to C 12 The alkyl radical of the present invention is selected from methyl, ethyl, propyl, isopropyl, butyl, tert-butyl, pentyl, tert-pentyl, n-hexyl or cyclohexyl, 1-methylcyclohexyl or adamantyl.

[0016] More preferably, the C1 to C 12 The alkyl group is selected from methyl, ethyl or tert-butyl.

[0017] In the present invention, the C6~C 30 The aryl group is the general term for the monovalent group left after removing a hydrogen atom from the aromatic carbon of the aromatic hydrocarbon molecule; 30 The aryl group includes a monocyclic aryl group or a condensed ring aryl group.

[0018] Preferably, the C6~C 30 The aryl group of is selected from phenyl, biphenyl, terphenyl, naphthyl, anthracenyl, indenyl, fluorenyl, perylenyl, phenanthryl, pyrenyl, fluoranthenyl, fluorenyl, spirobifluorenyl or triphenylenyl.

[0019] More preferably, the C6~C 30 The aromatic hydrocarbon group is selected from phenyl, biphenyl, naphthyl or terphenyl.

[0020] In the present invention, the C3 to C 30 The heteroaryl group is a general term for groups in which one or more aromatic carbon atoms in an aromatic group are replaced by heteroatoms; 30 The heteroatom of the heteroaryl is selected from oxygen, sulfur, nitrogen or silicon; the C3~C 30 The heteroaryl group includes a monocyclic heteroaryl group or a condensed-ring heteroaryl group.

[0021] Preferably, the C3 to C 30 The heteroaryl group is selected from pyridyl, benzofuranyl, benzothiophenyl, dibenzofuranyl, dibenzothiophenyl, carbazolyl, diarylideneamine, benzofuranocarbazolyl, benzofuranothiophenyl or triazine.

[0022] More preferably, the C3 to C 30 The aromatic heterocyclic group is selected from pyridyl, dibenzofuranyl, dibenzothienyl or carbazolyl.

[0023] Preferably, the boron-nitrogen-containing compound is selected from any one of compounds 1 to 56:

[0024]

[0025]

[0026] The present invention lists some specific structural forms of the boron-nitrogen-containing compounds, but the boron-nitrogen-containing compounds of the present invention are not limited to these chemical structures listed. As long as the structure shown in Formula I or Formula II is based on X, Y, R1, R2, R3, R4, R5, R6, R7, R8, R9, R 10 , R 11 , R 12 , R 13 , R 14 , R 15 , R16 , R 17 All structures that meet the above restrictions should be included.

[0027] In a second aspect, the present invention provides an organic electroluminescent device, wherein the organic electroluminescent device comprises the boron-nitrogen-containing compound as described in the first aspect.

[0028] Preferably, the organic electroluminescent device comprises a first electrode, a second electrode and an organic layer disposed between the first electrode and the second electrode; the material of the organic layer comprises the boron-nitrogen-containing compound as described in the first aspect.

[0029] Preferably, the organic layer includes a light-emitting layer, and the material of the light-emitting layer includes the boron-nitrogen-containing compound as described in the first aspect.

[0030] Furthermore, the light-emitting layer is prepared by a solution method.

[0031] In a third aspect, the present invention provides a display device, comprising the organic electroluminescent device as described in the second aspect.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] The present invention designs the structure of the boron-nitrogen-containing compound to obtain a boron-nitrogen-containing compound with good luminescence performance, which can be used to prepare an organic electroluminescent device, especially as a light-emitting layer material in an organic electroluminescent device, and can effectively reduce the driving voltage of the organic electroluminescent device and improve the current efficiency of the organic electroluminescent device. DETAILED DESCRIPTION

[0034] 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.

[0035] Synthesis Example 1

[0036] This synthesis example provides compound 1 and its synthesis method, and the synthesis method is as follows:

[0037]

[0038] (1) Synthesis of intermediate 1-1

[0039] Under nitrogen protection, 200 mL of dry toluene, 0.1 mol of 3-bromobenzofuran, 0.1 mol of 2-fluoro-9H-carbazole, 0.001 mol of Pd(dba)2 (bis(dibenzylideneacetonepalladium), 4 g of a 10% tri-tert-butylphosphine toluene solution (the amount of tri-tert-butylphosphine is 0.002 mol) and 0.3 mol of sodium tert-butoxide were added to a 500 mL three-necked flask, and the mixture was heated to reflux for 12 h, cooled to room temperature, and separated by adding water. The organic layer was then washed with water until neutral, dried with magnesium sulfate, filtered to remove the magnesium sulfate, concentrated to dryness, and crystallized with ethanol to obtain intermediate 1-1;

[0040] The intermediate 1-1 was subjected to mass spectrometry detection: the mass-to-charge ratio (m / z) was measured to be 301.1.

[0041] (2) Synthesis of intermediate 1-2

[0042] Under nitrogen protection, add 300 mL of dry DMF, 0.1 mol of intermediate 1-1, 0.3 mol of thiophenol, and 0.5 mol of potassium carbonate to a 500 mL three-necked flask, heat to 110 °C for 10 h, cool to room temperature, add water to separate, then wash the organic layer with water until neutral, dry with magnesium sulfate, filter to remove magnesium sulfate, concentrate to dryness, and crystallize with ethanol to obtain intermediate 1-2;

[0043] The intermediate 1-2 was subjected to mass spectrometry detection: the mass-to-charge ratio (m / z) was measured to be 391.1.

[0044] (3) Synthesis of Compound 1

[0045] Under nitrogen protection and oil bath heating, 200 mL of dry o-dichlorobenzene, 0.01 mol of intermediate 1-2, and 0.00 6 mol of anhydrous nickel chloride were added to a 500 mL three-necked flask, stirred evenly, the temperature was maintained at 20°C-25°C, 20 mL of 1.0 M BBr3 dichloromethane solution (containing BBr30.02 mol) was slowly added dropwise, and the temperature was slowly raised to 40°C for the oil bath temperature to react for 2 h, and then slowly raised to 100°C for the oil bath. During the process, dichloromethane in the reaction system was distilled out, and then the oil bath was maintained at 100°C for reaction for 4 h, and then raised to 140°C for reaction for 12 h, and then cooled to room temperature, and 0.05 mol of N-ethyldiisopropylamine was slowly added to terminate the reaction; water was then added to separate, the organic layer was washed with water until neutral, dried with magnesium sulfate, filtered to remove magnesium sulfate, concentrated to dryness, separated by silica gel column chromatography, and eluted with petroleum ether: ethyl acetate = 20:1 (volume ratio) to obtain compound 1.

[0046] The obtained compound 1 was subjected to mass spectrometry detection: the mass-to-charge ratio (m / z) was measured to be 399.1.

[0047] Synthesis Example 2

[0048] This synthesis example provides compound 3 and its synthesis method, and the synthesis method is as follows:

[0049]

[0050] Referring to the synthesis method of compound 1 provided in Synthesis Example 1, 3-bromobenzofuran was replaced with an equal amount of 3-bromobenzothiophene, and other conditions remained unchanged to obtain compound 3.

[0051] The obtained compound 3 was subjected to mass spectrometry detection: the mass-to-charge ratio (m / z) was measured to be 415.1.

[0052] Synthesis Example 3

[0053] This synthesis example provides compound 43 and its synthesis method, and the synthesis method is as follows:

[0054]

[0055] (1) Synthesis of Intermediate 43-1

[0056] Under nitrogen protection, add 200 mL of dry xylene, 0.15 mol of 4-tert-butylphenol, 0.1 mol of di-tert-butyl bromide carbazole-1, 0.001 mol of Pd(dba)2 (bis(dibenzylideneacetone palladium)), and 0.3 mol of sodium tert-butoxide to a 500 mL three-necked flask, heat to reflux for 12 h, cool to room temperature, add water to separate, then wash the organic layer with water until neutral, dry with magnesium sulfate, filter to remove magnesium sulfate, concentrate to dryness, and crystallize with ethanol to obtain intermediate 43-1;

[0057] The intermediate 43-1 was subjected to mass spectrometry detection: the mass-to-charge ratio (m / z) was measured to be 427.3.

[0058] (2) Synthesis of Intermediate 43-2

[0059] Under nitrogen protection, 200 mL of dry toluene, 0.1 mol of intermediate 43-1, 0.15 mol of tert-butyl brominated benzothiophene, 0.001 mol of Pd(dba)2 (bis(dibenzylideneacetonepalladium), 4 g of 10% tri-tert-butylphosphine toluene solution (the amount of tri-tert-butylphosphine is 0.002 mol) and 0.3 mol of sodium tert-butoxide were added to a 500 mL three-necked flask, and the mixture was heated to reflux for 12 h, cooled to room temperature, and separated by adding water. The organic layer was then washed with water until neutral, dried with magnesium sulfate, filtered to remove magnesium sulfate, concentrated to dryness, and crystallized with ethanol to obtain intermediate 43-2.

[0060] The intermediate 43-2 was subjected to mass spectrometry detection: the mass-to-charge ratio (m / z) was measured to be 615.4.

[0061] (3) Synthesis of Compound 43

[0062] Referring to the synthesis method of Synthesis Example 1, intermediate 43-2 was used to replace intermediate 1-2, and other conditions remained unchanged to obtain compound 43.

[0063] Compound 43 was subjected to mass spectrometry detection: the mass-to-charge ratio (m / z) was measured to be 623.3.

[0064] Synthesis Example 4

[0065] This synthesis example provides compound 47 and its synthesis method, and the synthesis method is as follows:

[0066]

[0067] Referring to the synthesis method of compound 1 in Synthesis Example 3, 4-tert-butylthiophenol was used instead of 4-tert-butylphenol, and other conditions remained unchanged to obtain compound 47.

[0068] Compound 47 was subjected to mass spectrometry detection: the mass-to-charge ratio (m / z) was measured to be 639.3.

[0069] Compounds 7, 13, 17, 40, 45 and 55 were prepared by a similar preparation method and subjected to mass spectrometry detection. The test results are shown in Table 1 below.

[0070] Table 1

[0071]

[0072] Other compounds for which specific synthesis steps are not listed can be prepared by common knowledge in the art in combination with conventional means in the art and the above synthesis examples.

[0073] The specific structures of the compounds used in the following device examples and device comparative examples are shown below:

[0074]

[0075] In the following device examples, the compound provided by the present invention is selected as the doping material of the light-emitting layer in the organic electroluminescent device, and in the device comparative example, the above-mentioned BD-1 is selected as the doping material of the light-emitting layer in the organic electroluminescent device.

[0076] Device Example 1

[0077] This device embodiment provides an organic electroluminescent device, using the compound 1 provided in Synthesis Example 1 of the present invention as a doping material for the light-emitting layer; and in this embodiment, the light-emitting layer is prepared by a solution method.

[0078] The structure of the organic electroluminescent device is:

[0079] ITO / HT (40 nm) / BH: Compound 1 3% / ET (30 nm) / LiF (0.5 nm) / Al (150 nm).

[0080] The preparation method of the organic electroluminescent device is as follows:

[0081] The glass substrate coated with an ITO transparent conductive layer (as an anode) is ultrasonically treated in a cleaning agent, then rinsed in deionized water, ultrasonically degreased in a mixed solvent of acetone and ethanol, baked in a clean environment until the water is completely removed, cleaned with ultraviolet light and ozone, and bombarded with a low-energy cation beam to improve the properties of the surface and enhance the binding ability with the hole injection layer;

[0082] The glass substrate was placed in a vacuum chamber and evacuated to 1×10 -5 ~9×10 -3 Pa, HT was vacuum evaporated on the anode as a hole transport layer, the evaporation rate was 0.1nm / s, and the evaporation film thickness was 40nm;

[0083] The glass substrate on which the hole transport layer has been evaporated was transferred to a glove box filled with nitrogen, and the light-emitting layer solution was spin-coated on the hole transport layer. The light-emitting layer solution included a solute and a solvent. The solute included BH and 5% by mass of compound 1, and the solvent was 4-cyclohexylbenzene and chlorobenzene, wherein 4-cyclohexylbenzene:chlorobenzene=3:1 (volume ratio); the spin coating speed was 1000 rpm for 60 seconds, and then the glass substrate was heated at 80° C. for 2 hours, and the solvent was removed in vacuo. By adjusting the concentrations of BH and compound 1 in the solvent, the thickness of the obtained light-emitting layer was 35 nm, as shown in Table 2 (the unit of the light-emitting layer thickness is nm).

[0084] The glass substrate on which the light-emitting layer has been spin-coated in the previous step is transferred into a vacuum chamber, and ET is vacuum-deposited on the light-emitting layer as the electron transport layer of the device. The evaporation rate is 0.1 nm / s, and the total evaporation film thickness is 30 nm.

[0085] 0.5 nm of LiF and 150 nm of Al were vacuum-deposited on the electron transport layer to serve as an electron injection layer and a cathode.

[0086] The brightness, driving voltage and current efficiency of the prepared organic electroluminescent device were measured.

[0087] Device Examples 2 to 10

[0088] Device Examples 2 to 10 respectively provide an organic electroluminescent device, which differs from Device Example 1 only in that the doping materials of the light-emitting layer are different (see Table 2 for details), and other conditions are the same as those of Device Example 1.

[0089] Device Comparative Example 1

[0090] Device Comparative Example 1 provides an organic electroluminescent device, which is different from Device Example 1 only in that the doping material of the light-emitting layer is different (see Table 2 for details), and other conditions are the same as those of Device Example 1.

[0091] Performance Testing

[0092] Test the driving voltage, current efficiency and life LT90 of the OLED devices provided above; LT90 refers to the time required for the brightness to drop to 90% of the original brightness while maintaining the current density at the initial brightness of 1000nit. The test items include the brightness, driving voltage and current efficiency of the organic electroluminescent device. The driving voltage, current efficiency and LT90 data are all based on a brightness of 1000cd / m 2 The relative value of the device performance test result is shown in Table 2 below.

[0093] Table 2

[0094] Doping materials <![CDATA[Required luminance / (cd / m 2 )]]> Driving voltage Current efficiency LT90 Life Device Comparison Example 1 BD-1 1000 1 1 1 Device Example 1 Compound 1 1000 0.85 1.28 1.31 Device Example 2 Compound 3 1000 0.76 1.33 1.24 Device Example 3 Compound 7 1000 0.81 1.29 1.31 Device Example 4 Compound 13 1000 0.59 1.26 1.33 Device Example 5 Compound 17 1000 0.84 1.34 1.86 Device Example 6 Compound 40 1000 0.76 1.28 1.21 Device Example 7 Compound 43 1000 0.77 1.29 1.41 Device Example 8 Compound 45 1000 0.77 1.39 1.55 Device Example 9 Compound 47 1000 0.79 1.86 1.38 Device Example 10 Compound 55 1000 0.76 1.31 1.61

[0095] From the above content, it can be seen that the present invention obtains a compound suitable for use as a doping material for the light-emitting layer through structural design, and the organic electroluminescent device prepared thereby has a lower driving voltage, a higher current efficiency and a longer service life.

[0096] The applicant declares that the present invention illustrates the boron-nitrogen-containing compounds and their applications through the above-mentioned embodiments, but the present invention is not limited to the above-mentioned embodiments, that is, it does not mean that the present invention must rely on the above-mentioned embodiments to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of the raw materials of the product of the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A boron-nitrogen-containing compound, characterized in that The boron-nitrogen-containing compound has a structure as shown in Formula I or Formula II: Where X is selected from O, S, Y is selected from O or S; R1, R2, R3, R4, R5, R6, R7, R8, R9, R 10 , R 11 , R 12 , R 13 , R 14 , R 15 , R 16 , R 17 Each independently selected from substituted or unsubstituted C1 to C 12 Alkyl, substituted or unsubstituted C6~C 30 aryl or substituted or unsubstituted C3~C 30 heteroaryl; R1, R2, R3, R4, R5, R6, R7, R8, R9, R 10 , R 11 , R 12 , R 13 , R 14 , R 15 , R 16 , R 17 The substituted substituent is selected from C1 to C 12 Alkyl or C6~C 30 Aryl or C3~C 30 At least one of the heteroaryl groups; All hydrogen atoms in the compounds of formula I and formula II can be replaced independently by deuterium atoms, F, CN, C1-C 12 Alkyl or C6~C 30 Aryl or C3~C 30 At least one of the heteroaryl groups is substituted; * indicates the attachment site of the group.

2. The boron-nitrogen-containing compound according to claim 1, characterized in that C1~C 12 The alkyl group is selected from methyl, ethyl, propyl, isopropyl, butyl, tert-butyl, pentyl, tert-pentyl, n-hexyl or cyclohexyl, 1-methylcyclohexyl or adamantyl; More preferably, the C1 to C 12 The alkyl group is selected from methyl, ethyl or tert-butyl.

3. The boron-nitrogen-containing compound according to claim 1 or 2, characterized in that C6~C 30 The aryl group includes a monocyclic aryl group or a condensed ring aryl group; Preferably, the C6~C 30 The aryl group is selected from phenyl, biphenyl, terphenyl, naphthyl, anthracenyl, indenyl, fluorenyl, perylenyl, phenanthryl, pyrenyl, fluoranthenyl, fluorenyl, spirobifluorenyl or triphenylenyl; More preferably, the C6~C 30 The aromatic hydrocarbon group is selected from phenyl, biphenyl, naphthyl or terphenyl.

4. The boron-nitrogen-containing compound according to any one of claims 1 to 3, characterized in that C3~C 30 The heteroatoms of the heteroaryl group are selected from oxygen, sulfur, nitrogen or silicon; Preferably, the C3-C30 heteroaryl group includes a monocyclic heteroaryl group or a condensed-ring heteroaryl group.

5. The boron-nitrogen-containing compound according to any one of claims 1 to 4, characterized in that C3~C 30 The heteroaryl group is selected from pyridyl, benzofuranyl, benzothiophenyl, dibenzofuranyl, dibenzothiophenyl, carbazolyl, diarylideneamine, benzofuranocarbazolyl, benzofuranothiophenyl or triazine; More preferably, the C3 to C 30 The aromatic heterocyclic group is selected from pyridyl, dibenzofuranyl, dibenzothienyl or carbazolyl.

6. The boron-nitrogen-containing compound according to any one of claims 1 to 5, characterized in that The boron-nitrogen-containing compound is selected from any one of compounds 1 to 56:

7. An organic electroluminescent device, characterized in that: The organic electroluminescent device comprises the boron-nitrogen-containing compound according to any one of claims 1 to 6.

8. The organic electroluminescent device according to claim 7, characterized in that: The organic electroluminescent device comprises a first electrode, a second electrode and an organic layer disposed between the first electrode and the second electrode; the material of the organic layer comprises the boron-nitrogen-containing compound as claimed in any one of claims 1 to 6.

9. The organic electroluminescent device according to claim 7 or 8, characterized in that: The organic layer comprises a light-emitting layer, and a material of the light-emitting layer comprises the boron-nitrogen-containing compound as claimed in any one of claims 1 to 6.

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

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