Carbazole-containing compound and application thereof

Abstract

The invention provides a carbazole-containing compound and application thereof, and the carbazole-containing compound has a structure as shown in a formula I. The carbazole-containing compound obtained by structural design of the carbazole-containing compound has excellent performance, and can be used for preparing the carbazole-containing compound. The organic light-emitting device prepared by using the compound as a light-emitting 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 carbazole-containing compound and its application. Background Art

[0002] An organic light emitting diode (OLED) is a display component that utilizes the phenomenon of self-luminescence. 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 emitting phenomenon refers to the phenomenon of converting electrical energy into light energy using organic substances. An organic light emitting diode that utilizes the organic light emitting 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 diode, 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 diode, 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 diode 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, the transport performance and light emitting efficiency of the 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 carbazole-containing compound and its application. Through the structural design of the carbazole-containing compound, the obtained carbazole-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] On the one hand, the present invention provides a carbazole-containing compound, and the carbazole-containing compound has a structure shown in Formula I:

[0009]

[0010] In Formula I, X is selected from silicon or a carbon atom;

[0011] Y 1 and Y 2 are independently absent or selected from a single bond, oxygen or sulfur, and at least one of Y 1 and Y 2 is selected from a single bond, oxygen or sulfur;

[0012] R 1 is selected from hydrogen, deuterium, CN, a substituted or unsubstituted C 1 ~C 12 alkyl group, a substituted or unsubstituted C 6 ~C 30 aryl group, a substituted or unsubstituted C 3 ~C 30 heteroaryl group, a substituted or unsubstituted diarylamino group;

[0013] When the substituted or unsubstituted group contains a substituent, the substituent is selected from deuterium, F, CN, C 1 ~C 12 alkyl group, C 6 ~C 30 aryl group or C 3 ~C 30 heteroaryl group;

[0014] And all hydrogen atoms in Formula I can be independently replaced by deuterium, F, CN, C 1 ~C 12 alkyl group, C 6 ~C 30 aryl group or C 3 ~C 30 heteroaryl group;

[0015] And the carbazole-containing compound does not include the following structures:

[0016]

[0017] Examples illustrate the meaning of the sentence "Y 1 and Y 2 are independently absent or selected from a single bond, oxygen or sulfur, and at least one of Y 1 and Y 2 is selected from a single bond, oxygen or sulfur", and examples are as follows:

[0018] If Y 1 exists, Y2 If it does not exist, the structure is as follows:

[0019]

[0020] If Y 2 exists, Y 1 If it does not exist, the structure is as follows:

[0021]

[0022] Preferably, the C 1 ~C 12 alkyl group is selected from methyl, ethyl, propyl, isopropyl, butyl, tert-butyl, pentyl, pivalyl, n-hexyl or cyclohexyl.

[0023] More preferably, the C 1 ~C 12 alkyl group is selected from methyl, ethyl, isopropyl or tert-butyl.

[0024] Preferably, the C 6 ~C 30 aryl group refers to the general term of the monovalent group remaining after removing a hydrogen atom from the aromatic nucleus carbon of an aromatic hydrocarbon molecule; the C 6 ~C 30 aryl group includes monocyclic aryl groups or polycyclic aryl groups.

[0025] Preferably, the C 6 ~C 30 aryl group is selected from phenyl, biphenyl, terphenyl, naphthyl, anthryl, indenyl, fluorenyl, perylenyl, phenanthryl, pyrenyl, fluoranthenyl, fluorenyl, spirobifluorenyl or benzophenanthryl.

[0026] More preferably, the C 6 ~C 30 aryl group is selected from phenyl, biphenyl, naphthyl.

[0027] Preferably, the C 3 ~C 30 heteroaryl group refers to the general term 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 monocyclic heteroaryl groups or polycyclic heteroaryl groups.

[0028] Preferably, the C 3 ~C 30 heteroaryl group is selected from pyridyl, benzofuranyl, benzothiophenyl, dibenzofuranyl, dibenzothiophenyl, carbazolyl, benzofurocarbazolyl, benzofurothiophenyl or triazinyl.

[0029] More preferably, the C 3 ~C 30 heteroaryl is selected from pyridyl, dibenzofuranyl, dibenzothiophenyl or carbazolyl.

[0030] Preferably, R 1 is selected from hydrogen, CN, phenyl, naphthyl, biphenyl, benzofuranyl, where the wavy line represents the connection site of the group.

[0031] Preferably, the carbazole-containing compound is selected from any one of Compounds 1 to 100:

[0032]

[0033]

[0034]

[0035]

[0036]

[0037] The present invention lists some specific structural forms of the carbazole-containing compound, but the carbazole-containing compound described in the present invention is not limited to these listed chemical structures. Any structure based on the structure shown in Formula I, where X, Y 1 , Y 2 , R 1 meet the above-defined conditions should be included.

[0038] In a second aspect, the present invention provides an organic electroluminescent device, which includes the carbazole-containing compound as described in the first aspect.

[0039] 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, and the material of the organic layer includes the carbazole-containing compound as described in the first aspect.

[0040] Preferably, the organic layer includes a light-emitting layer, and the material of the light-emitting layer includes the carbazole-containing compound as described in the first aspect.

[0041] Furthermore, the light-emitting layer is prepared by a vapor deposition method.

[0042] In a third aspect, the present invention provides a display device, which includes the organic electroluminescent device as described in the second aspect.

[0043] Compared with the prior art, the present invention has the following beneficial effects:

[0044] By designing the structure of the carbazole-containing compound, the obtained carbazole-containing compound has good luminescence properties and can be used to prepare organic electroluminescent devices. In particular, as a luminescent layer material in organic electroluminescent devices, it can effectively reduce the driving voltage of organic electroluminescent devices and improve the current efficiency of organic electroluminescent devices. Specific Embodiments

[0045] The technical solutions of the present invention will be further described below through specific embodiments. Those skilled in the art should understand that the embodiments are only for helping to understand the present invention and should not be regarded as specific limitations on the present invention.

[0046] Preparation Example 1

[0047] This embodiment provides a synthesis method of Intermediate 1, and the method is as follows:

[0048] (1) Synthesis of Intermediate 1-1

[0049] Under nitrogen protection, add 200 mL of dry toluene, 100 mL of ethanol, 100 mL of water, 0.1 mol of dibromo compound-1, 0.1 mol of phenylboronic acid, 0.005 mol of tetrakis(triphenylphosphine)palladium, and 0.15 mol of potassium carbonate to a 1000 mL three-necked flask, heat to 78 °C and reflux for 6 h, then cool to room temperature, separate the liquid, dry the organic phase with sodium sulfate, perform column chromatography, concentrate the chromatography solution to dryness, and recrystallize with toluene and ethanol to obtain Intermediate 1-1;

[0050] Perform mass spectrometry detection on Intermediate 1-1, and the measured mass-to-charge ratio (m / z) is 562.1.

[0051] (2) Synthesis of Intermediate 1

[0052] Take 0.1 mol of Intermediate 1-1, dissolve it in 300 mL of tetrahydrofuran, cool to between -80 and -75 °C, dropwise add 0.11 mol of n-butyllithium (2.5 M), keep the temperature between -80 and -70 °C during the dropping process, after the dropping is completed, keep the temperature between -80 and -70 °C and continue stirring for 1 h, then dropwise add trimethyl borate, keep the temperature between -80 and -70 °C during the dropping process, stop heat preservation after the dropping is completed, and slowly raise the temperature. When the temperature rises to -10 °C, dropwise add 200 mL of 10% dilute hydrochloric acid aqueous solution, stir at room temperature for 1 h, then pour the reaction solution into 2 L of pure water to precipitate the product. The product is refluxed and slurried with 200 mL of n-heptane for 1 h, then cooled and filtered to obtain Intermediate 1.

[0053] Since Intermediate 1 is boric acid, the following simple and accessible operations were carried out and tested:

[0054] Take 0.01 g of Intermediate 1, add 0.01 g of pinacol and 3 ml of toluene, and ultrasonicate at 50 °C for 5 minutes. After complete dissolution and clarification, a toluene solution of the pinacol ester corresponding to Intermediate 1 is obtained.

[0055] The toluene solution of the pinacol ester prepared above was tested by gas chromatography-mass spectrometry. The mass-to-charge ratio (m / z) of the solute was measured to be 610.3, and Intermediate 1 was determined to be the target product.

[0056] Referring to Preparation Example 1, the following intermediates can be obtained. Referring to Preparation Example 1, the corresponding pinacol esters were prepared and tested by gas chromatography-mass spectrometry. The specific results are shown in Table 1.

[0057] Table 1

[0058]

[0059]

[0060]

[0061] Synthesis Example 1

[0062] This example provides a method for synthesizing Compound 9, and the method is as follows:

[0063]

[0064] Under nitrogen protection, add 400 mL of dry toluene, 200 ml of ethanol, 200 ml of water, 0.1 mol of 9,9-diphenyl-2-bromofluorene, 0.11 mol of Boric acid-1, 0.005 mol of tetrakis(triphenylphosphine)palladium, and 0.15 mol of potassium carbonate to a 2000 mL three-necked flask. Heat to 78 °C and reflux for 8 h, then cool to room temperature, separate the liquid, dry the organic phase with sodium sulfate, perform column chromatography, concentrate the chromatography solution to dryness, and recrystallize with toluene and ethanol to obtain Compound 9;

[0065] Compound 9 was detected by mass spectrometry, and the measured mass-to-charge ratio (m / z) was 724.3.

[0066] Synthesis Example 2

[0067] This example provides a method for synthesizing Compound 11, which is as follows:

[0068]

[0069] Referring to the synthesis method of Synthesis Example 1, replace 9,9-diphenyl-2-bromofluorene in Synthesis Example 1 with an equimolar amount of 2-bromospirobifluorene, and Compound 11 can be obtained under other unchanged conditions.

[0070] Perform mass spectrometry detection on Compound 11: The measured mass spectrometry (m / z): 722.3.

[0071] Synthesis Example 3

[0072] This example provides a synthesis method of Compound 15, and the method is as follows:

[0073]

[0074] Referring to the synthesis method of Synthesis Example 1, replace boric acid-1 in Synthesis Example 1 with an equimolar amount of Intermediate 1, and Compound 15 can be obtained under other unchanged conditions.

[0075] Perform mass spectrometry detection on Compound 15: The measured mass spectrometry (m / z): 800.3.

[0076] Synthesis Example 4

[0077] This example provides a synthesis method of Compound 17, and the method is as follows:

[0078]

[0079] Referring to the synthesis method of Synthesis Example 2, replace boric acid-1 in Synthesis Example 2 with an equimolar amount of Intermediate 1, and Compound 17 can be obtained under other unchanged conditions.

[0080] Perform mass spectrometry detection on Compound 17, and the measured mass-to-charge ratio (m / z): 798.3.

[0081] Synthesis Example 5

[0082] This example provides a synthesis method of Compound 21, and the method is as follows:

[0083]

[0084] Referring to the synthesis method of Synthesis Example 1, replace 9,9-diphenyl-2-bromofluorene in Synthesis Example 4 with an equimolar amount of Chloride-1, and Compound 21 can be obtained under other unchanged conditions.

[0085] Perform mass spectrometry detection on Compound 21, and the measured mass-to-charge ratio (m / z): 770.2.

[0086] Synthesis Example 6

[0087] This example provides a synthesis method of Compound 27, and the method is as follows:

[0088]

[0089] Referring to the synthesis method of Synthesis Example 1, replace 9,9-diphenyl-2-bromofluorene in Synthesis Example 1 with an equimolar amount of bromide-1, and compound 27 can be obtained under other unchanged conditions.

[0090] Compound 27 was subjected to mass spectrometry, and the measured mass-to-charge ratio (m / z): 754.2.

[0091] Synthesis Example 7

[0092] This example provides a method for synthesizing compound 29, which is as follows:

[0093]

[0094] Referring to the synthesis method of Synthesis Example 1, replace 9,9-diphenyl-2-bromofluorene in Synthesis Example 1 with an equimolar amount of 9,9-diphenyl-2-bromosilafluorene, and compound 29 can be obtained under other unchanged conditions.

[0095] Compound 29 was subjected to mass spectrometry, and the measured mass-to-charge ratio (m / z): 740.3.

[0096] Synthesis Example 8

[0097] This example provides a method for synthesizing compound 30, which is as follows:

[0098]

[0099] Referring to the synthesis method of Synthesis Example 1, replace 9,9-diphenyl-2-bromofluorene in Synthesis Example 1 with an equimolar amount of bromide-2, and compound 30 can be obtained under other unchanged conditions.

[0100] Compound 30 was subjected to mass spectrometry, and the measured mass-to-charge ratio (m / z): 740.3.

[0101] Synthesis Example 9

[0102] This example provides a method for synthesizing compound 35, and the method is as follows:

[0103]

[0104] Referring to the synthesis method of Synthesis Example 7, replace boric acid-1 in Synthesis Example 7 with an equimolar amount of intermediate 1, and compound 35 can be obtained under other unchanged conditions.

[0105] Compound 35 was subjected to mass spectrometry, and the measured mass-to-charge ratio (m / z): 816.3.

[0106] Synthesis Example 10

[0107] This example provides a method for synthesizing Compound 36, and the method is as follows:

[0108]

[0109] Referring to the synthesis method of Synthesis Example 8, replacing Boric Acid-1 in Synthesis Example 8 with an equimolar amount of Intermediate 1, and keeping other conditions unchanged, Compound 36 can be obtained.

[0110] Compound 36 was subjected to mass spectrometry detection, and the measured mass-to-charge ratio (m / z): 816.3 was obtained.

[0111] Referring to the synthesis methods of the above compounds and combining common organic synthesis means, Compounds 18, 20, 38, 39, 40, 57, 60, 81, 82, 83, 84, 88, 89, 90, 94, 96, and 98 were prepared and subjected to mass spectrometry detection. The test results are shown in Table 2 below.

[0112] Table 2

[0113]

[0114]

[0115]

[0116]

[0117]

[0118] For other compounds whose specific synthesis steps are not listed, they can be prepared by combining the above examples with common general knowledge in the art.

[0119] The specific structures of the compounds used in the following device examples and device comparative examples are as follows:

[0120]

[0121] In the following device examples, the carbazole-containing compound provided by the present invention is selected as the host material for the light-emitting layer in the organic electroluminescent device, and in the device comparative examples, the above HTH-1, HTH-2, and HTH-3 are selected as the host materials for the light-emitting layer in the organic electroluminescent device.

[0122] Device Example 1

[0123] This device example provides an organic electroluminescent device, using the Compound 1 provided by the synthesis example 1 of the present invention as the host material for the light-emitting layer; and in this example, the light-emitting layer is prepared by evaporation.

[0124] The structure of the organic electroluminescent device is as follows:

[0125] ITO / HT (40 nm) / Compound 1: D-1 (5%) / TPBI (30 nm) / LiF (0.5 nm) / Al (150 nm).

[0126] The preparation method of the above-mentioned organic electroluminescent device is as follows:

[0127] The glass substrate coated with the 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 transport layer;

[0128] The above-mentioned glass substrate is placed in a vacuum chamber, and the vacuum is pumped to 1×10 -5 ~9×10 -6 Pa, and HT is vacuum-evaporated on the anode as the hole transport layer at a deposition rate of 0.1 nm / s, and the deposited film thickness is 40 nm;

[0129] The light-emitting layer is vacuum-evaporated on the hole transport layer at a deposition rate of 0.1 nm / s, and the total deposited film thickness is 30 nm. The host material of the light-emitting layer is Compound 1 provided by the present invention, and the doping material is D-1. 5% refers to the doping ratio of the doping material, that is, the volume ratio of the host material to the doping material in the light-emitting layer is 95:5.

[0130] TPBI is vacuum-evaporated on the light-emitting layer as the electron transport layer of the device at a deposition rate of 0.1 nm / s, and the total deposited film thickness is 30 nm;

[0131] 0.5 nm of LiF and 150 nm of Al are vacuum-evaporated on the electron transport layer as the electron injection layer and the cathode.

[0132] The brightness, driving voltage, current efficiency and lifetime of the prepared organic electroluminescent device were measured, and the results are shown in Table 3.

[0133] Device Examples 2 to 27

[0134] Device Examples 2 to 27 respectively provide an organic electroluminescent device, which is only different from Device Example 1 in that the host material of the light-emitting layer is different (see Table 3 for details), and other conditions are the same as those in Device Example 1.

[0135] Device Comparative Examples 1 to 3

[0136] Device Comparative Examples 1 to 3 respectively provide an organic electroluminescent device, which is different from Device Example 1 only in that the host material of the light-emitting layer is different (see Table 3 for details), and other conditions are the same as those of Device Example 1.

[0137] Performance Test

[0138] Test the driving voltage, current efficiency and lifetime LT90 of the above-provided OLED devices; wherein, LT90 refers to the time required for the current density to remain unchanged while maintaining the initial brightness of 1000 nit and the brightness to drop to 90% of the original brightness. The test items include the brightness, driving voltage, and current efficiency of the organic electroluminescent device. The data of the driving voltage, current efficiency, and LT90 are all relative values at a brightness of 1000 cd / m 2 (based on the test data of HTH-3). The performance test results of the organic electroluminescent device are shown in Table 3 below.

[0139] Table 3

[0140]

[0141]

[0142] As can be seen from the above, through the structural design, the present invention obtains a compound suitable as the host material of the light-emitting layer, and the organic electroluminescent device prepared therefrom has a lower driving voltage, a higher current efficiency, and a longer service life.

[0143] The applicant declares that the present invention uses the above examples to illustrate the carbazole-containing compound and its application of the present invention, but the present invention is not limited to the above examples, that is, it does not mean that the present invention must rely on the above examples to be implemented. Those skilled in the art should understand that any improvement of the present invention, the equivalent substitution of each raw material of the product of the present invention, the addition of auxiliary components, the selection of specific methods, etc. all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A carbazole-containing compound, characterized in that The carbazole-containing compound has a structure as shown in Formula I: In formula I, X is selected from silicon or carbon atom; Y1 and Y2 are independently absent or selected from a single bond, oxygen or sulfur, and at least one of Y1 and Y2 is selected from a single bond, oxygen or sulfur; R1 is selected from hydrogen, deuterium, CN, substituted or unsubstituted C1-C 12 Alkyl, substituted or unsubstituted C6~C 30 Aryl, substituted or unsubstituted C3~C 30 a heteroaryl group, a substituted or unsubstituted diarylideneamine group; 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; The carbazole-containing compounds do not include the following structures:

2. The carbazole-containing compound according to claim 1, characterized in that The C1-C12 alkyl group is selected from methyl, ethyl, propyl, isopropyl, butyl, tert-butyl, pentyl, tert-pentyl, n-hexyl or cyclohexyl.

3. The carbazole-containing compound according to claim 1, characterized in that The C6-C30 aryl group is selected from phenyl, biphenyl, terphenyl, naphthyl, anthracenyl, indenyl, fluorenyl, perylenyl, phenanthryl, pyrenyl, fluoranthenyl, fluorenyl, spirobifluorenyl or triphenylenyl.

4. The carbazole-containing compound according to claim 1, characterized in that The heteroatom in the C3-C30 heteroaryl group is selected from oxygen, sulfur, nitrogen or silicon; Preferably, the C3-C30 heteroaromatic group is selected from benzofuranyl, benzothiophenyl, dibenzofuranyl, dibenzothiophenyl, carbazolyl, benzofuranocarbazolyl, benzofuranothiophenyl or triazine.

5. The carbazole-containing compound according to claim 1, characterized in that R1 is selected from hydrogen, CN, phenyl, naphthyl, biphenyl, benzofuranyl, The wavy lines represent the attachment sites of the groups.

6. The carbazole-containing compound according to any one of claims 1 to 5, characterized in that The carbazole-containing compound is selected from any one of compounds 1 to 100:

7. An organic electroluminescent device, characterized in that: The organic electroluminescent device comprises the carbazole-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 carbazole-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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