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 a structure as shown in a formula I. By designing the structure of the compound containing boron and nitrogen, the obtained compound containing boron and nitrogen has excellent performance, and the organic electroluminescent device prepared by using the compound containing boron and nitrogen as a luminescent layer material has relatively low driving voltage and relatively high current efficiency.

Description

Technical Field

[0001] The present invention belongs to the technical field of organic optoelectronic display, and particularly relates to a boron-nitrogen-containing compound and its application. Background Art

[0002] An organic light emitting diode (OLED) is a display component that utilizes the self-luminescence phenomenon. It has a large viewing angle. Compared with liquid crystal display components, OLED components are thinner, lighter, have a faster response speed, and can achieve flexible display. Therefore, it is highly anticipated as an application for full-color display components or lighting devices.

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

[0004] Among them, in order to improve the efficiency and stability of the organic light emitting element, the organic layer is in most cases composed of a multi-layer structure formed by different substances respectively. 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, holes in the anode will be injected into the organic layer, and 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 an organic light emitting element is widely recognized as having characteristics such as self-luminescence, high brightness, high efficiency, low driving voltage, wide viewing angle, high contrast, and high-speed responsiveness.

[0005] Currently, the research on organic electroluminescent materials has been widely carried out in the academic and industrial fields. Among them, blue light materials are an important part of organic electroluminescent devices. The transport performance and light emitting efficiency of blue light materials restrict the industrialization of light emitting devices. Therefore, designing and finding a compound as a new type of OLED material to overcome the deficiencies that occur in the actual application process is the focus and future research and development trend in the research work of OLED materials. Summary of the Invention

[0006] Aiming at the deficiencies of the prior art, the purpose of the present invention is to provide a boron-nitrogen-containing compound and its application. Through the design of the structure of the boron-nitrogen-containing compound, the obtained boron-nitrogen-containing compound has excellent properties and is suitable for use as a light emitting layer material in organic electroluminescent devices.

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

[0008] In a first aspect, the present invention provides a boron-nitrogen-containing compound having a structure represented by Formula I:

[0009]

[0010] In Formula I, R 1 , R 2 , R 3 , R 4 , R 5 are the same as or different from each other and are each independently selected from hydrogen, deuterium, substituted or unsubstituted C 1 -C 12 alkyl groups, substituted or unsubstituted C 6 -C 30 aryl groups, or substituted or unsubstituted C 3 -C 30 heteroaryl groups;

[0011] When the substituted or unsubstituted group contains a substituent, the substituent is selected from deuterium, F, CN, C 1 -C 12 alkyl groups, C 6 -C 30 aryl groups, or C 3 -C 30 heteroaryl groups.

[0012] And all hydrogen atoms in Formula I may each independently be substituted by deuterium, F, CN, C 1 -C 12 alkyl groups, C 6 -C 30 aryl groups, or C 3 -C 30 heteroaryl groups;

[0013] n1, n2, n3 are selected from integers from 0 to 4, and n4 is selected from integers from 0 to 3;

[0014] m1 is selected from 0 or 1;

[0015] If m1 is 0, then n5 is selected from integers from 0 to 5;

[0016] If m1 is 1, then n5 is selected from integers from 0 to 4;

[0017] And when n1, n2, n3, n4, n5 are 2 or greater, two or more substituents in the parentheses are the same as or different from each other.

[0018] Preferably, the C 1 -C 12 alkyl group is selected from methyl, ethyl, propyl, isopropyl, butyl, tert-butyl, pentyl, pivalyl, n-hexyl or cyclohexyl.

[0019] More preferably, the C 1 ~C 12 alkyl group is selected from methyl, ethyl, isopropyl or tert-butyl.

[0020] Preferably, the C 6 ~C 30 aryl group refers to the general name of the monovalent group remaining after removing one hydrogen atom from the aromatic nucleus carbon of an aromatic hydrocarbon molecule; the C 6 ~C 30 aryl group includes a monocyclic aryl group or a fused-ring aryl group.

[0021] Preferably, the C 6 ~C 30 aryl group is selected from phenyl, biphenyl, terphenyl, naphthyl, anthracenyl, indenyl, perylenyl, phenanthryl, pyrenyl, fluoranthenyl, fluorenyl, spirobifluorenyl or benzophenanthryl.

[0022] More preferably, the C 6 ~C 30 aryl group is selected from phenyl, biphenyl, naphthyl.

[0023] Preferably, the C 3 ~C 30 heteroaryl group refers to the general name of the group obtained by replacing one or more aromatic nucleus carbons in the aryl group with heteroatoms; the heteroatoms of the C 3 ~C 30 heteroaryl group are selected from oxygen, sulfur, nitrogen or silicon; the C 3 ~C 30 heteroaryl group includes a monocyclic heteroaryl group or a fused-ring heteroaryl group.

[0024] Preferably, the C 3 ~C 30 heteroaryl group is selected from pyridyl, benzofuranyl, benzothiophenyl, dibenzofuranyl, dibenzothiophenyl, carbazolyl, diarylamino, benzofurancarbazolyl, benzofuranthiophenyl or triazinyl.

[0025] More preferably, the C 3 ~C 30 heteroaryl group is selected from pyridyl, dibenzofuranyl, dibenzothiophenyl or carbazolyl.

[0026] Preferably, the boron and nitrogen-containing compound is selected from any one of Compounds 1 to 48:

[0027]

[0028]

[0029] The present invention lists some specific structural forms of the boron-nitrogen-containing compound, but the boron-nitrogen-containing compound described in the present invention is not limited to these chemical structures listed. Any structure based on the structure shown in Formula I, where R 1 、R 2 、R 3 、R 4 、R 5 、n1, n2, n3, n4, n5, m1 meet the above-defined conditions should be included.

[0030] In a second aspect, the present invention provides an organic electroluminescent device, which includes the boron-nitrogen-containing compound as described in the first aspect.

[0031] Preferably, the organic electroluminescent device includes a first electrode, a second electrode, and an organic layer disposed between the first electrode and the second electrode.

[0032] The material of the organic layer includes the boron-nitrogen-containing compound as described in the first aspect.

[0033] Preferably, the organic layer includes a light-emitting layer.

[0034] The material of the light-emitting layer includes the boron-nitrogen-containing compound as described in the first aspect.

[0035] Furthermore, the light-emitting layer is prepared by a vapor deposition method.

[0036] In a third aspect, the present invention provides a display device, which includes the organic electroluminescent device as described in the second aspect.

[0037] Compared with the prior art, the present invention has the following beneficial effects:

[0038] By designing the structure of the boron-nitrogen-containing compound, the obtained boron-nitrogen-containing compound has good light-emitting properties and can be used to prepare an organic electroluminescent device. Especially as the material of the light-emitting layer in the organic electroluminescent device, it can effectively reduce the driving voltage of the organic electroluminescent device and improve the current efficiency of the organic electroluminescent device. Detailed Embodiments

[0039] To facilitate the understanding of the present invention, preparation examples and embodiments are listed below. Those skilled in the art should understand that the synthesis examples and device examples are only to help understand the present invention and should not be regarded as specific limitations on the present invention.

[0040] Synthesis Example 1

[0041] This example provides a method for synthesizing Compound 1 as follows:

[0042]

[0043] (1) Synthesis of intermediate 1-1

[0044] Under nitrogen protection, add 200 mL of dry toluene, 0.1 mol of bromide-1, 0.1 mol of amine-1, and 0.001 mol of Pd(dba) into a 500 mL three-necked flask. 2 (bis(dibenzylideneacetonepalladium), 4g of a 10% tri-tert-butylphosphine toluene solution (the amount of tri-tert-butylphosphine is 0.002mol) and 0.3mol of sodium tert-butoxide, heated to reflux reaction for 12h, cooled to room temperature, added water to separate, then the organic layer was washed with water until neutral, dried with magnesium sulfate, filtered to remove magnesium sulfate, concentrated to dryness, and crystallized with ethanol to obtain intermediate 1-1;

[0045] The mass spectrometry of intermediate 1-1 revealed a mass-to-charge ratio (m / z) of 702.2.

[0046] (2) Synthesis of Compound 1

[0047] Under nitrogen protection, the reaction flask containing 0.01 mol of intermediate 1-1 and 100 ml of toluene was cooled to 0°C, and then 0.3 mol of 1.7 M tert-butyl lithium pentane solution (35 ml) was added dropwise to the reaction system. After the addition was completed, the temperature was raised to 70°C and stirred for 3 hours. Then the system was cooled to -40°C, 0.012 mol of boron tribromide was added dropwise, and after the addition was completed, the temperature was raised to 25°C and stirred for 4 hours. When the reaction was completed, saturated Na 2 S 2 O 3 Aqueous solution and saturated NaHCO 3 The organic layer was washed with water until neutral, dried over magnesium sulfate, filtered to remove the magnesium sulfate, concentrated to dryness, and separated by silica gel column chromatography with petroleum ether: ethyl acetate = 10: 1 (volume ratio) to obtain compound 1.

[0048] The obtained compound 1 was subjected to mass spectrometry detection, and the mass-to-charge ratio (m / z) was measured to be 676.3.

[0049] Synthesis Example 2

[0050] This embodiment provides a method for synthesizing compound 3, as described below:

[0051]

[0052] (1) Synthesis of bromide-2

[0053] Under sufficient nitrogen protection, 400 ml of tetrahydrofuran and 0.1 mol of 5-chloro-5-phenyl-9H-9-silafluorene were added to the reaction flask. After complete dissolution, the temperature was lowered to -78 °C. Then, 0.1 mol of tert-butyllithium (tert-butyllithium is a 1.7 M pentane solution) was added dropwise at -78 °C. After the addition was completed, the mixture was kept at -78 °C for 0.5 hour. Then, a tetrahydrofuran solution of 0.1 mol of 2,5-dibromotert-butylbenzene (dissolved in 100 ml of THF) was added dropwise at -78 °C. After the addition was completed, the temperature was allowed to rise to room temperature naturally. The mixture was poured into 2000 ml of water and stirred for 1 hour. The crude solid was obtained by filtration using a Buchner funnel. The crude solid was recrystallized with toluene and ethanol to obtain bromide-2.

[0054] The bromide-2 was subjected to mass spectrometry, and the measured mass-to-charge ratio (m / z) was 468.1.

[0055] (2) Referring to the synthesis method of Synthesis Example 1, bromide-2 in an equimolar amount was used to replace bromide-1 in Synthesis Example 1, and Compound 3 could be obtained under the same other conditions.

[0056] Compound 3 was subjected to mass spectrometry: the measured mass spectrum (m / z) was 732.3.

[0057] Synthesis Example 3

[0058] This example provides a method for synthesizing Compound 4, which is as follows:

[0059]

[0060] Referring to the synthesis method of Synthesis Example 2, 1,3-di-tert-butyl-2,5-dibromobenzene was used to replace 2,5-dibromotert-butylbenzene in Synthesis Example 2, and bromide-3 could be synthesized;

[0061] The bromide-3 was subjected to mass spectrometry: the measured mass-to-charge ratio (m / z) was 524.2.

[0062] Referring to the synthesis method of Synthesis Example 2, bromide-3 in an equimolar amount was used to replace bromide-2 in Synthesis Example 2, and Compound 4 could be obtained under the same other conditions.

[0063] Compound 4 was subjected to mass spectrometry: the measured mass-to-charge ratio (m / z) was 788.4.

[0064] Synthesis Example 4

[0065] This example provides a method for synthesizing Compound 9, which is as follows:

[0066]

[0067] Referring to the synthesis method of Synthesis Example 3, replacing amine-1 in Synthesis Example 3 with an equimolar amount of amine-2, and keeping other conditions unchanged, compound 9 can be obtained.

[0068] Compound 9 was subjected to mass spectrometry detection, and the measured mass-to-charge ratio (m / z): 1012.6.

[0069] Referring to the synthesis methods of the above compounds and combining common organic synthesis means, compounds 10, 12, 13, 14, 24, 33, 34, and 43 were prepared and subjected to mass spectrometry detection. The test results are shown in Table 1 below.

[0070] Table 1

[0071]

[0072]

[0073] For compounds without specifying the specific synthesis steps, they can be prepared by combining the above examples with common general knowledge in the art.

[0074] The specific structures of the compounds used in the following device examples and device comparative examples are as follows:

[0075]

[0076] In the following device examples, the boron-nitrogen-containing compound provided by the present invention is selected as the luminescent layer doping material in the organic electroluminescent device, and in the device comparative examples, the above BD-1, BD-2, and BD-3 are selected as the luminescent layer doping materials in the organic electroluminescent device.

[0077] Device Example 1

[0078] This device example provides an organic electroluminescent device, using compound 1 provided by Synthesis Example 1 of the present invention as the luminescent layer doping material; and in this example, the luminescent layer is prepared by evaporation.

[0079] The structure of the organic electroluminescent device is:

[0080] ITO / HT(40nm) / BH: Compound 1 3% / TPBI(30nm) / LiF(0.5nm) / Al(150nm).

[0081] The preparation method of the above organic electroluminescent device is as follows:

[0082] The glass substrate coated with an ITO transparent conductive layer (as the 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 completely dehydrated, cleaned with ultraviolet light and ozone, and bombarded with a low-energy cation beam on the surface to improve the surface properties and enhance the bonding ability with the hole injection layer;

[0083] Place the above-mentioned glass substrate in a vacuum chamber, evacuate to 1×10 -5 ~9×10 -6 Pa, and vacuum deposit HT as the hole transport layer on the anode at a deposition rate of 0.1 nm / s and a deposited film thickness of 40 nm;

[0084] Vacuum deposit the light-emitting layer on the hole transport layer at a deposition rate of 0.1 nm / s and a total deposited film thickness of 30 nm. The main material of the light-emitting layer is BH, and the doping material is Compound 1 provided by the present invention. 3% refers to the doping ratio of the doping material, that is, the volume ratio of the main material of the light-emitting layer to the doping material is 97:3.

[0085] Transfer the glass substrate on which the light-emitting layer has been deposited in the previous step to the vacuum chamber, and vacuum deposit TPBI as the electron transport layer of the device on the light-emitting layer at a deposition rate of 0.1 nm / s and a total deposited film thickness of 30 nm;

[0086] Vacuum deposit 0.5 nm of LiF and 150 nm of Al as the electron injection layer and the cathode on the electron transport layer.

[0087] The brightness, driving voltage, current efficiency, and lifetime of the fabricated organic light-emitting device were measured (see Table 2 for details).

[0088] Device Examples 2 - 12

[0089] Device Examples 2 - 12 respectively provide an organic light-emitting device, which is only different from Device Example 1 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 in Device Example 1.

[0090] Device Comparative Examples 1 - 3

[0091] Device Comparative Examples 1 - 3 respectively provide an organic light-emitting device, which is only different from Device Example 1 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 in Device Example 1.

[0092] Performance Test

[0093] Test the driving voltage, current efficiency, and LT90 of the OLED device provided above; where LT90 refers to the time required for the current density to remain unchanged while maintaining the initial brightness of 1000 nit and the brightness drops to 90% of the original brightness. 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 relative values at a brightness of 1000 cd / m 2 (based on the test data of BD-1). The performance test results of the organic electroluminescent device are shown in Table 2 below.

[0094] Table 2

[0095]

[0096]

[0097] As can be seen from the above, through structural design, the present invention obtains a compound suitable as a doping material for the light-emitting layer. The organic electroluminescent device prepared therefrom has a lower driving voltage, a higher current efficiency, and a longer service life.

[0098] The present invention uses the above embodiments to illustrate the detailed process flow of the present invention, but the present invention is not limited to the above detailed process flow, that is, it does not mean that the present invention must rely on the above detailed process flow to be implemented. Those skilled in the art should understand that any improvement to the present invention, the equivalent replacement of each raw material of the product of the present invention, the addition of auxiliary components, and the selection of specific methods, etc., all fall within the protection scope and the 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: In Formula I, R1, R2, R3, R4, and R5 are the same or different from each other and are each independently selected from hydrogen, deuterium, substituted or unsubstituted C1 to C 12 Alkyl, substituted or unsubstituted C6~C 30 Aryl, substituted or unsubstituted C3~C 30 heteroaryl; When the substituted or unsubstituted group contains a substituent, the substituent is selected from deuterium, F, CN, C1-C 12 Alkyl, C6~C 30 Aryl or C3~C 30 heteroaryl; All hydrogen atoms in Formula I can be independently replaced by deuterium, F, CN, C1-C 12 Alkyl, C6~C 30 Aryl or C3~C 30 is substituted with a heteroaryl group; n1, n2, n3 are selected from integers of 0 to 4, and n4 is selected from integers of 0 to 3; m1 is selected from 0 or 1; If m1 is 0, n5 is selected from an integer from 0 to 5; If m1 is 1, n5 is selected from an integer of 0 to 4; Furthermore, when n1, n2, n3, n4, and n5 are 2 or more, two or more substituents in brackets may be the same as or different from each other.

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.

3. The boron-nitrogen-containing compound according to claim 1, characterized in that C6~C 30 The aryl group of is selected from phenyl, biphenyl, terphenyl, naphthyl, anthracenyl, indenyl, perylenyl, phenanthryl, pyrenyl, fluoranthenyl, fluorenyl, spirobifluorenyl or triphenylenyl.

4. The boron-nitrogen-containing compound according to claim 1, characterized in that C3~C 30 The heteroatom in the heteroaryl group is selected from oxygen, sulfur, nitrogen or silicon.

5. The boron-nitrogen-containing compound according to claim 1, characterized in that C3~C 30 The heteroaryl group is selected from pyridyl, benzofuranyl, benzothiophenyl, dibenzofuranyl, dibenzothiophenyl, carbazolyl, diarylideneamine, benzofuranocarbazolyl, benzofuranothiophenyl or triazine.

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 48:

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 organic layer comprises a light-emitting layer; and the light-emitting layer comprises the boron-nitrogen-containing compound according to any one of claims 1 to 6.

9. The organic electroluminescent device according to claim 8, characterized in that: The light-emitting layer is prepared by evaporation method.

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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