CN107619406A - A kind of new carbazole analog derivative and preparation method thereof and application in the devices - Google Patents

Abstract

The invention provides a carbazole derivative. Compared with the prior art, different nitrogen-containing heterocyclic substituents are introduced into the carbazole derivative provided by the invention to form a new carbazole derivative effect. At the same time The performance of the carbazole derivatives can also be improved by adjusting the molecular weight and types of the substituents, so that the devices prepared by using the new carbazole derivatives of the present invention have the characteristics of long life and high efficiency.

Description

A new carbazole derivative and its preparation method and application in devices

technical field

The invention relates to the field of organic electroluminescent materials, in particular to a carbazole derivative and a preparation method and application thereof.

Background technique

Since Tang et al. successfully prepared low-voltage-driven small molecule light-emitting devices in 1987, organic light-emitting technology has made great progress and has begun to enter the process of industrialization; among them, organic electroluminescent materials play a very important role in the performance of organic light-emitting devices. role.

According to the molecular weight of organic electroluminescent materials, they can be divided into small molecule organic electroluminescent materials and high molecular organic electroluminescent materials. Among the currently disclosed luminescent materials, small molecule electroluminescent materials have high fluorescence quantum efficiency, are easy to purify, and have better luminous brightness and color purity than polymer materials. Therefore, small molecule electroluminescent materials are applied to light-emitting devices to begin to realize commercialize.

Organic light-emitting devices (OLEDs) are usually composed of a cathode, an anode, and an organic layer inserted between the cathode and anode, that is, the device is composed of a transparent ITO anode, a hole injection layer (TIL), a hole transport layer (HTL) , Light emitting layer (EL), hole blocking layer (HBL), electron transport layer (ETL), electron injection layer (EIL) and cathode formation, 1~2 organic layers can be omitted as required. The mechanism of action is that a voltage is formed between the two electrodes, while electrons are injected from the cathode, and holes are injected from the anode on the other side. The electrons and holes recombine in the light-emitting layer to form an excited state, and the excited state returns to a stable ground state.

Among them, the light-emitting materials in light-emitting devices are divided into fluorescent materials and phosphorescent materials. The formation methods of the light-emitting layer mainly include: 1) doping phosphorescent materials (organic metals) in fluorescent host materials, 2) doping fluorescent host materials (including nitrogen 3) Dopants (DCM, Rubrene, DCJTB, etc.) are used in the luminous body to achieve long wavelength; and the doped luminescent material has a great influence on the luminous wavelength, efficiency, driving voltage and life of the light-emitting device. big impact. Factors such as emission wavelength, efficiency, driving voltage, and lifetime are improved by such doping.

Generally, the material forming the light-emitting layer has central bodies such as benzene, naphthalene, fluorene, spirobifluorene, anthracene, pyrene, and carbazole, and ligands such as benzene, biphenyl, naphthalene, and heterocycles; the combination of para-position, meta-position, and ortho-position Position and replacement structure of amino group, cyano group, fluorine group, methyl group, tert-butyl group, etc.

With the development of large-scale OLED panels, materials with higher brightness and better heat resistance are required. On the other hand, the luminous efficiency and lifespan also need to be further improved. However, the currently disclosed luminescent materials have relatively poor luminous efficiency and lifetime.

Therefore, developing a luminescent material with high luminous efficiency and long lifespan has become an urgent technical problem to be solved by various production and application manufacturers in this field.

Contents of the invention

In view of this, the technical problem to be solved by the present invention is to provide a new carbazole derivative, a preparation method thereof, and an organic electroluminescent device. The compound has better luminous efficiency and long service life.

The invention provides a carbazole derivative, the carbazole derivative has a chemical formula 1 structure,

chemical formula 1

Wherein, R1 and R2 are hydrogen, substituted or unsubstituted C1~C20 alkyl, substituted or unsubstituted C6~C20 aryl;

R' and R'' are hydrogen, substituted or unsubstituted C1~C20 alkyl, substituted or unsubstituted C6~C20 aryl, substituted or substituted C5~C20 heterocyclic group;

Ar1 and Ar2 are substituted or unsubstituted C3~C30 cycloalkyl, substituted or unsubstituted C6~C30 aryl, substituted or substituted C8~C20 fused ring group, or when Ar1 and Ar2 are phenyl When , it connects with the connected nitrogen to form a carbazole structure.

A1~A10 may be the same or different, each independently selected from N.

The carbazole derivatives are shown in any one of Chemical Formula 2-1~Chemical Formula 2-4,

Chemical formula 2-1

Chemical formula 2-2

Chemical formula 2-3

Chemical formula 2-4

The A1~A10 can be the same or different, each independently selected from N;

The R1 and R2 are hydrogen, substituted or unsubstituted C1~C20 alkyl, substituted or unsubstituted C6~C20 aryl.

Preferably, said R1 or R2 is selected from hydrogen or phenyl.

The carbazole derivatives are shown in any one of structural formula 001-027,

.

The present invention also provides a method for preparing the carbazole derivatives described in any one of the above technical solutions, comprising the following steps:

After reacting the compound of formula (A) and the compound of formula (B), the compound of formula (C) is obtained,

(A), (B), (C);

Wherein, R1 and R2 are hydrogen, substituted or unsubstituted C1~C20 alkyl, substituted or unsubstituted C6~C20 aryl;

R' and R'' are hydrogen, substituted or unsubstituted C1~C20 alkyl, substituted or unsubstituted C6~C20 aryl, substituted or substituted C5~C20 heterocyclic group;

Ar1 and Ar2 are substituted or unsubstituted C3~C30 cycloalkyl, substituted or unsubstituted C6~C30 aryl, substituted or substituted C8~C20 fused ring group, or when Ar1 and Ar2 are phenyl When , connect with the connected nitrogen to form a carbazole structure;

Said X is independently selected from I, Br or Cl;

The selection range and optimization principles of the substituents or structures in the raw materials in the present invention are consistent with the selection ranges and optimization principles of the aforementioned carbazole derivatives, and will not be repeated here.

The present invention has no special requirements on the ratio of the raw materials, and the conventional ratio of this type of reaction known to those skilled in the art can be used, and those skilled in the art can select and adjust according to actual production conditions, product requirements or quality requirements. The present invention does not have special requirement to the condition of described reaction, get final product with the routine condition of this type of reaction well known to those skilled in the art, those skilled in the art can select and adjust according to actual production situation, product requirement or quality requirement, the present invention The solvent is preferably toluene.

In addition, the source of the compound of formula (A) and formula (B) is not particularly limited in the present invention, they can be prepared by well-known preparation methods in the art or purchased from the market.

The present invention also provides an organic electroluminescent device, including an electroluminescent material; the electroluminescent material includes the carbazole derivatives described in any one of the above technical solutions or the carbazole derivatives prepared by the above technical solutions derivative.

The organic electroluminescence device of the present invention preferably comprises:

The first electrode, the second electrode, and the organic layer placed between the two electrodes, wherein the organic layer contains a compound of the structure shown in Chemical Formula 1; the compound of the structure shown in Chemical Formula 1 can be in a single form or combined with Other substances are mixed in the organic layer.

Wherein, the organic layer at least includes a hole injection layer, a hole transport layer, a layer having both hole injection and hole transport capabilities, an electron blocking layer, a light-emitting layer, a hole blocking layer, an electron transport layer, and an electron injection layer. And one or more of the technical layers that have both electron transport and electron injection.

At least one of the hole injection layer, the hole transport layer, and the layer having both hole injection and hole transport skills is a conventional hole injection material, a hole transport material, or a hole injection material. It may also be a substance having a hole-transporting technology, or an electron-transporting substance.

In this patent, "organic layer" refers to the term of all layers arranged between the first electrode and the second electrode of the organic electronic device.

For example, the above-mentioned organic layer includes a light-emitting layer, and the above-mentioned organic layer includes more than one of a phosphorescent host, a fluorescent host, a phosphorescent dopant, and a fluorescent dopant, wherein the above-mentioned light-emitting layer includes a heterocyclic ligand with the structure of the above chemical formula 1, i) The above-mentioned fluorescent host can be a heterocyclic ligand with the structure of the above chemical formula 1 ii) the above-mentioned fluorescent dopant can be a heterocyclic ligand with the structure of the above chemical formula 1 iii) the above-mentioned fluorescent host and fluorescent dopant can be a heterocyclic ring with the structure of the above chemical formula 1 Ligand.

Specifically, when the compound of the chemical formula 1 exists in the light-emitting layer in the organic layer, the compound of the chemical formula 1 can be used as the light-emitting host of the electroluminescent material or doped in other fluorescent hosts; for example: the light-emitting layer Can be red, yellow or blue emitting layer. Doping the compound of chemical formula 1 on the blue host can improve the efficiency, brightness, resolution and long life of the light-emitting device.

When the compound of Chemical Formula 1 exists in the electron transport layer, the electron transport layer also includes a metal-containing compound.

When the organic layer includes a light emitting layer and an electron transport layer, the compound of the chemical formula 1 may exist in one or both layers.

The device prepared by the compound containing the chemical formula 1 described in the present invention can be used in organic light-emitting devices (OLED), organic solar cells (OSC), electronic paper (e-Paper), organic photoreceptors (OPC) or organic thin film transistors (OTFT).

The device of the present invention can form anodes by evaporating metals and conductive oxides and their alloys on the substrate by thin film evaporation, electron beam evaporation, physical vapor deposition, etc., or by using spin-coating (spin- coating) or strip head evaporation; also can use tape-casting, doctor-blading, screen-printing, inkjet printing or thermal imaging (Thermal-Imaging) and other methods Reduce the number of layers to manufacture.

The invention provides a carbazole derivative. Compared with the prior art, different nitrogen-containing heterocyclic substituents are introduced into the carbazole derivative provided by the invention to form a new carbazole derivative effect. At the same time The performance of the carbazole derivatives can also be improved by adjusting the molecular weight and types of the substituents, so that the devices prepared by using the new carbazole derivatives of the present invention have the characteristics of long life and high efficiency.

The following will clearly and completely describe the technical solutions of the embodiments of the present invention. Obviously, the described embodiments are only some of the embodiments of the present invention, but not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

detailed description

Synthesis of intermediate 1-1~intermediate 1-4:

Weigh 1 mmol of 1,3-dibromo-5-fluorobenzene, 1.2 mmol of 9H-carbazole, 1.2 mmol of 9H-carbazole, 0.2 mmol of cuprous chloride, 20 mmol of potassium carbonate, 40 ml of DMSO as the solvent, and heat to reflux for 8 hours. The reaction oil body was cooled to room temperature, and the precipitated crystals were recrystallized with methanol and separated by filtration. The resulting residue was subjected to silica gel column chromatography to obtain intermediate 1-1, yield = 50%. Intermediates 1-2 to 1-4 were synthesized according to the preparation method of intermediate 1-1 above, and Table 1 is a summary of the reaction substances, generated substances and yields of the present invention.

Table 1 Summary of reaction substances, produced substances and yields of intermediate 1-1~intermediate 1-4

Synthesis of intermediate 2-1~intermediate 2-4:

Dissolve 0.018mol of intermediate 1-1 in 100ml of dry THF, then add it to a dried 500ml three-neck flask, react at -78°C for 30min under the protection of _N2 , slowly add 0.027mol of n-butyllithium dropwise, and the dropwise addition ends After that, keep it at -78°C for 3 hours, then slowly add 0.02 mol of triisopropyl borate dropwise. After the dropwise addition, keep the reaction at -78°C for 2 hours, slowly warm up to room temperature, and react overnight. After the reaction is monitored by TLC, water The reaction solution was quenched slowly, extracted and evaporated to dryness to obtain 0.0144 mol of intermediate 2-1 with a yield of 80%. Intermediates 2-2 to 2-4 were synthesized according to the preparation method of intermediate 2-1 above, and Table 2 is a summary of the reaction substances, generated substances and yields of the present invention.

Table 2 Summary of reaction substances, produced substances and yields of intermediate 2-1~intermediate 2-4

Synthesis of intermediate 3-1~intermediate 3-4:

8.9mmol of 1-bromo-3-fluorobenzene, 9.8mmol of (3,5-bis(9H-carbazol-9-yl)phenyl)boronic acid, 0.3mmol of tetrakistriphenylphosphine palladium and 0.02mol of potassium carbonate were dissolved in 100ml Toluene:H2O=2:1 mixed solvent, stirred at 80°C for 5h, under nitrogen protection, after the reaction was monitored by TLC, cooled to room temperature, extracted with dichloromethane and water, and the organic phase was dried with anhydrous magnesium sulfate and evaporated Drying, evaporation to dryness and column chromatography of the product yielded 7.92 mmol of intermediate 3-1 with a yield of 89%. Intermediates 3-2 to 3-4 were synthesized according to the preparation method of intermediate 3-1 above, and Table 3 is a summary of the reaction substances, generated substances and yields of the present invention.

Table 3 Summary of reaction substances, produced substances and yields of intermediate 3-1~intermediate 3-4

Synthesis of intermediate 4-1~intermediate 4-11:

Intermediates 4-1 to 4-13 were synthesized according to the preparation method of intermediate 1-1 above, and Table 4 is a summary of the reaction substances, generated substances and yields of the present invention.

Table 4 Summary of reaction substances, produced substances and yields of intermediate 4-1~intermediate 4-13

Synthesis of intermediates 5-1~5-13:

Intermediates 5-1 to 5-13 were synthesized according to the preparation method of intermediate 2-1 above, and Table 5 is a summary of the reaction substances, generated substances and yields of the present invention.

Table 5 Summary of reaction substances, produced substances and yields of intermediate 5-1~intermediate 5-13

Synthesis of target products 001~027:

3'-Bromo-3,5-bis(9-carbazole)biphenyl 8.9mmol, 3,5-bis(2-pyridyl)phenylboronic acid 9.8mmol, tetrakistriphenylphosphine palladium 0.3mmol and potassium carbonate 0.02 mol was dissolved in 100ml of toluene:H ₂ O=2:1 mixed solvent, stirred at 80°C for 5h, under nitrogen protection, after the reaction was monitored by TLC, cooled to room temperature, extracted with dichloromethane and water, and the organic phase was washed with After being dried over magnesium sulfate, it was evaporated to dryness, and the column chromatography of the product after evaporation gave 7.83 mmol of the target product 001, with a yield of 88%. Mass spectrum: 714.89.

According to the preparation method of the above-mentioned target product 001, the target products 002-027 were synthesized, and Table 6 is a summary of the reaction substances, generated substances and yields of the present invention.

Table 6 Summary of reaction substances, generated substances and yields of target product 001~target product 027

After testing, the mass spectrum values of some products were obtained: Compound 007:716.91; Compound 022:770.96; Compound 027:766.97.

Device preparation embodiment:

Application Example 1 (Blue Phosphorescent Device)

The ITO glass substrate with a coating thickness of 1500Å from Fisher Company was cleaned twice in distilled water, ultrasonically washed for 30 minutes, washed twice with distilled water, ultrasonically washed for 10 minutes, after distilled water cleaning, isopropanol, acetone, Solvents such as methanol are sequentially ultrasonically washed, dried, transferred to a plasma cleaner, and the substrate is washed for 5 minutes before being sent to an evaporation machine. According to ITO (1000Å) / NPB (700Å) / mCP (150Å) / compound of chemical formula 11: FIrpic (92:8 weight, 300Å) / Bphen (250Å) / LiF (5Å) / Al (1000Å) for the synthesis of compound substances in the present invention Perform device testing.

Application Example 2 (Green Phosphorescent Device)

The ITO glass substrate with a coating thickness of 1500Å from Fisher Company was cleaned twice in distilled water, ultrasonically washed for 30 minutes, washed twice with distilled water, ultrasonically washed for 10 minutes, after distilled water cleaning, isopropanol, acetone, Solvents such as methanol are sequentially ultrasonically washed, dried, transferred to a plasma cleaner, and the substrate is washed for 5 minutes before being sent to an evaporation machine. According to ITO (1000Å) / NPB (700Å) / TCTA (100Å) / chemical formula: 11 Ir (ppy) 3 (93:7 mass ratio, 300Å) / Alq 3 (250Å) / LiF (5Å) / Al (1000Å ) Device tests were performed on the synthetic compound substances of the present invention.

Application Example 3 (White Phosphorescent Device)

The ITO glass substrate with a coating thickness of 1500Å from Fisher Company was cleaned twice in distilled water, ultrasonically washed for 30 minutes, washed twice with distilled water, ultrasonically washed for 10 minutes, after distilled water cleaning, isopropanol, acetone, Solvents such as methanol are sequentially ultrasonically washed, dried, transferred to a plasma cleaner, and the substrate is washed for 5 minutes before being sent to an evaporation machine. According to ITO(1000Å)/TCTA:WoO3(70:30 mass ratio, 600Å)/TCTA(100Å)/chemical formula 11:FIrpic:Ir(phq)2(acac):Ir(PPy)3(91:8:0.5 : 0.5 mass ratio, 150 Å) / BePP 2 (100 Å) / BePP 2 : Cs2CO 3 (90: 10 mass ratio, 200 Å) / LiF (5 Å) / Al (1000 Å) for the device test of the synthetic compound material of the present invention.

The light-emitting device prepared by the present invention is tested by using KEITHLEY 2400 type source measurement unit and CS-2000 spectroradiance luminance meter to evaluate the driving voltage, luminous brightness, luminous efficiency and luminous color of the light-emitting device; for the obtained device Table 7 shows the test results of light-emitting characteristics of some compounds prepared in the examples of the present invention and light-emitting devices prepared by comparison materials.

Table 7 Test results of light-emitting characteristics of some compound light-emitting devices prepared in the examples of the present invention

From the above results in Table 7, it can be seen that the luminous efficiency and lifetime characteristics of the organic electroluminescent device prepared by the new carbazole derivatives having the structure of Chemical Formula 1 provided by the present invention are significantly improved.

The organic light-emitting device using the carbazole derivatives of the present invention can obtain good results in luminous efficiency and service life, so it can be applied to the OLED industry with high practicability. The organic electroluminescent device of the present invention can be applied to flat panel displays, planar luminous bodies, surface-emitting OLED luminous bodies for lighting, flexible luminous bodies, copiers, printers, LCD backlights or light sources of measuring machines, display panels, signs, etc. .

The descriptions of the above embodiments are only used to help understand the method and core idea of the present invention. It should be pointed out that for those skilled in the art, without departing from the principle of the present invention, some improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims (6)

1. a kind of carbazole analog derivative, it is characterised in that the carbazoles derivative molecular formula is：

Chemical formula 1

Wherein, R₁And R₂For hydrogen, substituted or unsubstituted C1 ~ C20 alkyl, substituted or unsubstituted C6 ~ C20 aryl；

R ' and R ' ' is hydrogen, substituted or unsubstituted C1 ~ C20 alkyl, substituted or unsubstituted C6 ~ C20 aryl, substitution or For substituted C5 ~ C20 heterocyclic radical；

Ar₁And Ar₂For substituted or unsubstituted C3 ~ C30 cycloalkyl, substituted or unsubstituted C6 ~ C30 aryl, substitute or be Substituted C8 ~ C20 condensed ring radical, or work as Ar₁With Ar₂For phenyl when, be connected to form carbazole class formation with connected nitrogen；

A1 ~ A10 can be the same or different, and be independently selected from N.

2. carbazole analog derivative according to claim 1, it is characterised in that the carbazole analog derivative such as chemical formula 2-1 ~ In chemical formula 2-4 shown in any one,

Chemical formula 2-1

Chemical formula 2-2

Chemical formula 2-3

Chemical formula 2-4

A1 ~ the A10 can be the same or different, and be independently selected from N；

The R₁And R₂For hydrogen, substituted or unsubstituted C1 ~ C20 alkyl, substituted or unsubstituted C6 ~ C20 aryl.

3. carbazole analog derivative according to claim 2, it is characterised in that the R₁Or R₂Selected from hydrogen or phenyl.

4. carbazole analog derivative according to claim 1, it is characterised in that the carbazole analog derivative such as structural formula 001 ~ Shown in 027 any one,

。

A kind of 5. preparation method of carbazole analog derivative as described in claim 1 ~ 4 any one, it is characterised in that including with Lower step：

By formula（A）The compound and formula of structure（B）After the compound reaction of structure, formula is obtained（C）The compound of structure,

（A）,（B）,（C）；

Wherein, R₁And R₂For hydrogen, substituted or unsubstituted C1 ~ C20 alkyl, substituted or unsubstituted C6 ~ C20 aryl；

R ' and R ' ' is hydrogen, substituted or unsubstituted C1 ~ C20 alkyl, substituted or unsubstituted C6 ~ C20 aryl, substitution or For substituted C5 ~ C20 heterocyclic radical；

Ar₁And Ar₂For substituted or unsubstituted C3 ~ C30 cycloalkyl, substituted or unsubstituted C6 ~ C30 aryl, substitute or be Substituted C8 ~ C20 condensed ring radical, or work as Ar₁With Ar₂For phenyl when, be connected to form carbazole class formation with connected nitrogen；

The X independences are selected from I, Br or Cl.

6. a kind of organic electroluminescence device, it is characterised in that including electroluminescent material；The electroluminescent material includes power Profit requires the carbazole analog derivative prepared by carbazole analog derivative or claim 5 described in 1 ~ 4 any one.