CN1441028A - Red-light organic electroluminescent compound and components and devices made of it - Google Patents

Abstract

A red organic electroluminescent compound and assembly and device made of it, this compound is to connect the benzene ring of upper phase on 5, 6 position of chromophore [2, 6-dimethyl-4- (2, 2-dicyanovinyl) p-benzonaphthalenone ] of electron-withdrawing group, and connect the conjugation to push electron group on 5 position, make the emission wavelength fall in the red light area, get the new red light compound with better red purity, this compound has advantages of easy to synthesize and high red color purity; the light emitting component made of the compound is an organic electroluminescent component conforming to the NTSC specification of a television.

Description

Red-light organic electroluminescent compound and components and devices made of it

technical field

The present invention relates to a red-light organic electroluminescent compound and components and devices made of it, in particular to a red-light-emitting organic electroluminescent composition.

Background technique

Since 1987, Kodak has developed the first high-efficiency organic electroluminescent component, which has attracted the attention of the industry. Due to the characteristics of high brightness, self-luminescence, low driving voltage, no viewing angle, and simple manufacturing process, the organic electroluminescent component has Therefore, it can be applied to a flat panel display.

The principle of electroluminescence is an organic semiconductor thin film component. Under the action of an external electric field, electrons and holes are injected from the cathode and anode respectively, and are transferred in this component. When the electrons and holes combine, light is emitted.

The general simple two-layer component structure is to evaporate a hole transport layer (hole transport layer) on the anode, and then evaporate a light-emitting layer on it. The light-emitting layer has the ability to transport electrons and emit light, and finally evaporate electrodes on the electron transport layer. as the cathode.

There are also some multi-layer structure components, which evaporate other organic materials between the electrode and the hole transport material or material electron transport material, as a hole injection layer (hole injection layer) or an electron injection layer (electron injection layer). Injection efficiency, thereby reducing the driving voltage and increasing the probability of carrier recombination.

The red light-emitting material is usually made of doping components, and the host emits light through energy transfer. However, general red light materials require cumbersome organic synthesis steps, which have the disadvantages of low yield, high production cost and impure color purity.

In addition, in terms of existing red light-emitting material technology, such as disclosed in US Patent No. 5935720 (ChemicalPhysicsLetter1998, 287, pp.455-460; Macromol.symp.1997, 125, pp.49-58), these materials The emission wavelength and CIE coordinates of the TV are very different from the existing NTSC specification, so it is not suitable for current TV equipment.

Contents of the invention

The purpose of the present invention is to provide a red light organic electroluminescent compound, which overcomes the disadvantages of the prior art and achieves the purpose of easy synthesis and high color purity

Another object of the present invention is to provide a red light organic electroluminescent compound and components and devices made of it, and apply the novel red light organic electroluminescent compound to the red organic electroluminescent component to overcome the existing technology disadvantages, to achieve the purpose of the manufactured light-emitting component conforming to the organic electroluminescence component of the TV NTSC standard.

The object of the present invention is achieved like this: the red organic electroluminescence compound of the present invention is in the chromophoric group [2,6-dimethyl-4-(2,2-dicyanovinyl) pair of electron-withdrawing group The 5 and 6 positions of benzonaphthone] are connected with a parallel benzene ring, and a conjugated electron-pushing group is connected at the 5 position, so that the emission wavelength falls in the red light region, and a novel red light compound with excellent color purity is obtained .

The novel compound provided by the present invention has a chemical structural formula as follows:

Wherein, R ₁ and R ₂ are respectively at least one selected from alkyl, aryl, cycloalkyl or other heterocyclic groups with 1-20 carbon numbers;

R ₃ and R ₄ are respectively at least one selected from hydrogen, an alkyl group with a carbon number of 1-10, five or six rings and heterocycles with or without side chains connecting R ₁ and R ₂ .

The above compound, wherein R ₁ and R ₂ are respectively selected from methyl, ethyl, propyl, n-butyl, -(CH ₂ ) ₄ -, -(CH ₂ ) ₅ -; aryl, such as phenyl, Furyl, thienyl, pyridyl or other heterocyclic groups;

R ₃ and R ₄ are respectively selected from hydrogen, methyl, ethyl, propyl, n-butyl, isopropyl, second butyl, third butyl;

Or R ₁ , R ₃ =R ₂ , R ₄ =-(CH ₂ ) ₂ -, -(CH ₂ ) ₃ -, -(CH ₂ ) ₂ C(CH ₃ ) ₂ -;

R ₅ is selected from hydrogen, methyl, ethyl, propyl, n-butyl, isopropyl, second butyl, third butyl and -(CH ₂ ) ₃ -, -( CH ₂ ) ₄ -, pentacyclic or hexacyclic and furyl, thienyl, pyridyl or other heterocyclic groups.

The synthetic method of above-mentioned compound is as follows:

The electron-withdrawing chromophore 2-methyl-4-(2,2-dicyanomethenyl)benzo-p-benzonaphthone (2-dimethyl-4-(2,2-dicyanomethylene)chromone), Toluene, acetic acid, piperdine and compounds used as conjugated electron-pushing groups were heated and refluxed for 18-20 hours. After the reaction is completed, the reaction solution is cooled to room temperature, filtered, washed with a small amount of toluene, and purified by sublimation.

The above-mentioned conjugated electron-pushing group is selected from, for example, 9-formyl-julolidine (9-formyl-julolidine), 9-formyl-1-(1,1,7,7-tetramethyl)julolidine Compounds such as (9-formyl-1-1,1,7,7-tetramethyl)julolidine), 4-(N,N-dimethyl)anilinealdehyde (4-(N,N-dimethyl)anilinealdehyde).

Further description will be given below in conjunction with preferred embodiments and accompanying drawings.

Description of drawings

Fig. 1 is the luminance/voltage curve graph of the organic electroluminescent component made of compound A of the present invention.

Fig. 2 is an intensity/wavelength graph of an organic electroluminescent component made of Compound A of the present invention.

Detailed ways

Synthesis Example 1

The synthetic method of organic electroluminescent compound A of the present invention is as follows:

With 5 grams of 2-methyl-4-(2,2-dicyanomethenyl)benzo-p-benzonaphthone, 20ml of toluene, 1.5ml of acetic acid, 1.5ml of piperidine and 6.5 grams of 9- Aldehyde-julolidine was placed in a 150ml reaction bottle, and heated to reflux for 18 hours. The reaction was easily cooled to room temperature, filtered, and washed with a small amount of toluene. The yield was 68%. Then purify in sublimation mode, make compound A, the test result of compound A is as follows:

The melting point is 236°C.

¹ H-NMR: 8.88 (1H, d, J = 8.2Hz), 7.73 (1H, t, J = 8.6Hz), 7.43-7.40 (3H, m), 6.77 (2H, br), 3.26 (4H, t , J=5.8Hz), 2.75 (4H, t, J=4.6Hz), 1.96 (4H, t, J=5.4Hz) ppm.

Mass: 393 (M+2).

IR: 2205, 1623, 1588, 1552, 1478, 1312, 1156, 769 cm ^-1 .

The chemical formula of this compound A is:

Synthetic Example 2:

The synthetic method of organic electroluminescent compound B of the present invention is as follows:

With 5 grams of 2-methyl-4-(2,2-dicyanomethenyl)benzo-p-benzonaphthone, 20ml of toluene, 1.5ml of acetic acid, 1.5ml of piperidine and 5 grams of 4- (N,N-dimethyl)anilinealdehyde (4-(N,N-dimethyl)anilinealdehyde) was placed in a 150ml reaction bottle, and heated to reflux for 20 hours. The reaction was easily cooled to room temperature, filtered, and washed with a small amount of toluene. The yield was 78%. Then purify by sublimation, make compound B, the test result of compound B is as follows:

The melting point is 270°C.

¹ H-NMR: 8.89 (1H, d, J = 4.8Hz), 7.72 (1H, t, J = 7.6Hz), 7.68-7.39 (6H, m), 7.03 (1H, br), 6.67 (1H, S ), 6.62 (1H, d, J=15.6Hz), 3.08 (6H, s) ppm.

Mass: 393 (M ₊ ).

IR: 2199, 1627, 1591, 1552, 1166, 979, 811 ^{cm -1} .

The compound B chemical formula is:

Synthetic Example 3:

The synthetic method of organic electroluminescence compound C of the present invention is as follows:

With 5 grams of 2-methyl-4-(2,2-dicyanomethenyl)benzo-p-benzonaphthone, 20ml of toluene, 1.5ml of acetic acid, 1.5ml of piperidine and 7.8 grams of 9-aldehyde Base-1-(1,1,7,7-tetramethyl)julolidine (9-formyl-1-1,1,7,7-tetramethyl)julolidine) is placed in a 150ml reaction bottle, heated to reflux React for 20 hours. The reaction was easily cooled to room temperature, filtered, and washed with a small amount of toluene. The yield was 68%. Then purified by sublimation to obtain compound C, the test results of compound C are as follows:

The melting point is 252°C.

¹ H-NMR: 8.88 (1H, d, J = 8.2Hz), 7.73 (1H, t, J = 8.6Hz), 7.43-7.40 (3H, m), 6.77 (2H, br), 3.26 (4H, t , J=5.8Hz), 1.76-1.61 (4H, S), 1.25 (12H, s) ppm.

Mass: 449 (M ₊₂ ).

IR2203, 1624, 1585, 1550, 1476, 13120, 1153, ^{769 cm -1} .

The compound C chemical formula is:

Comparative Synthesis Example 1

Manufacture of DCM-1 [4-(2,2-Dicyanomethenyl)-2-methyl-6-(p-dimethylammonium vinylphenyl)-4H-p-benzonaphthone]

224 mg of 2,5-dimethyl-4-(2,2-dicyanomethenyl)-4H-p-benzonaphthone, 15 ml of toluene, 0.2 ml of acetic acid, 0.2 ml of piperidine and 236 Milligrams of 4-(N,N-dimethyl)anilinium aldehyde were placed in a 50ml reaction bottle, and heated to reflux for 20 hours. The reaction was easily cooled to room temperature, filtered, and washed with a small amount of toluene. The yield was 74%. It is then purified by sublimation. Obtain compound DCM-1, the structural formula of DCM-1 is as follows:

Comparative Synthesis Example 2

Manufacture of DCM-2[4-(2,2-Dicyanomethenyl)-2-methyl-6-(julolidinylstyryl)-4H-p-benzonaphthone]

224 mg of 2,5-dimethyl-4-(2,2-dicyanomethenyl)-4H-p-benzonaphthone, 15 ml of toluene, 0.2 ml of acetic acid, 0.2 ml of piperidine and 315 Milligrams of 9-formyl-julolidine (9-formyl-julolidine) were placed in a 50ml reaction bottle, and heated to reflux for 20 hours. The reaction was easily cooled to room temperature, filtered, and washed with a small amount of toluene. The yield was 58%. Then purified by sublimation to obtain compound DCM-2. The structural formula of DCM-2 is as follows:

Comparative Synthesis Example 3

Manufacture of DCJTB[4-(2,2-dicyanomethenyl)-2-quaternary butyl-6-(p-(1,1,7,7-tetramethyl)julolidinyl styryl )-4H-p-benzonaphthone]

224 mg of 2-methyl-5-tert-butyl-4-(2,2-dicyanomethenyl)-4H-p-benzonaphthone, 15 ml of toluene, 0.2 ml of acetic acid, 0.2 ml of Piperidine and 348 mg of 9-formyl-1-(1,1,7,7-tetramethyl)julolidine [9-formyl-1-(1,1,7,7-tetramethyl)-julolidine] Place in a 150ml reaction bottle, and heat to reflux for 18 hours. The reaction was easily cooled to room temperature, filtered, and washed with a small amount of toluene. The yield was 79%. Then purified by sublimation to obtain the compound DCJTB. The structural formula of DCJTB is as follows:

The compound synthesized by the present invention is applied to the operation examples of preparing organic light-emitting devices below, and the organic light-emitting devices cited below all include: hole injection layer (hole-Injection layer), hole transport layer (hole-transport layer) ), light emitting layer (light emitting layer) and electron transport layer (electron-transport layer) and other multi-layer organic electroluminescent components (ELelement).

Preparation Example 1 :

Indium tin oxide (Indium-tin-oxide) glass is used as the anode substrate, which is firstly cleaned with a commercially available glass cleaning agent, then cleaned with deionized water, and dried. Select copperphthalocyanine as the hole injection layer material (150 mm), and vapor-deposit it on the ITO glass. Nitrogen, nitrogen-di-(1-? base)-nitrogen, nitrogen biphenyl (600_) is evaporated on the hole injection layer. On the hole transfer layer, the main luminous body (host) tri-8-hydroxyquinoline aluminum complex (alumium-tris-8-hydroxyquinoline) and the guest luminous body (guest) are plated by co-evaporation. The synthesized compound B 2% (v/v) (150_) was used as light emitting layer (light emitting layer).

An electron transport layer, three-8-hydroxyquinoline aluminum complex (aluminum-tris-8-hydroxyquinoline) (350_) was vapor-deposited on the light-emitting layer. A magnesium-silver alloy is vapor-deposited on the electron transfer layer as a cathode. Package the assembly in a dry glove box filled with nitrogen.

Similarly, the compound A synthesized by the present invention is selected and prepared into an organic electroluminescent device according to the above-mentioned steps. The measured wavelength max=670nm of its EL spectrum, CIE coordinates (coordinate) x=0.66, y=0.33 (EL, B-V ), it can be seen that its wavelength, CIE coordinates are very close to red light wavelength 650nm and NTSCCIE coordinates x=0.67, y=0.33, and the luminance/voltage curve of this EL component is shown in Figure 1, and the intensity/wavelength is shown in Figure 2 .

Preparation Example 2 :

Indium tin oxide glass is used as the anode substrate, which is firstly cleaned with a commercially available glass cleaning agent, then cleaned with deionized water, and dried. Select copperphthalocyanine as the hole injection layer material (150 mm), and vapor-deposit it on the ITO glass. Evaporate hole transport layer material nitrogen, nitrogen-two-(1-naphthyl)-nitrogen, nitrogen biphenyl (600_) on the hole injection layer. On the hole transfer layer, the main luminous body (host) tri-8-hydroxyquinoline aluminum complex (aluminum-tris-8-hydroxyquinoline) and the guest luminous body (guest) are plated by co-evaporation. The synthesized compound A 2% (v/v) (150_) was used as a light emitting layer (light emitting layer).

An electron transport layer, three-8-hydroxyquinoline aluminum complex (aluminum-tris-8-hydroxyquinoline) (350_) was vapor-deposited on the light-emitting layer. A magnesium-silver alloy is vapor-deposited on the electron transfer layer as a cathode. Package the assembly in a dry glove box filled with nitrogen.

Preparation Example 3 :

Indium tin oxide glass is used as the anode substrate, which is first cleaned with a commercially available glass cleaning agent, then cleaned with deionized water, and dried. Select copperphthalocyanine as the hole injection layer material (150 mm), and vapor-deposit it on the ITO glass. Nitrogen, nitrogen-di-(1-? base)-nitrogen, nitrogen biphenyl (600_) is evaporated on the hole injection layer. On the hole transfer layer, the main luminous body (host) tri-8-hydroxyquinoline aluminum complex (aluminum-tris-8-hydroxyquinoline) and the guest luminous body (guest) are plated by co-evaporation. The synthesized compound C 2% (v/v) (150_) was used as the light-emitting layer.

Evaporate the electron transport layer and three-8-hydroxyquinoline aluminum complex (350_) on the light-emitting layer. A magnesium-silver alloy is vapor-deposited on the electron transfer layer as a cathode. Package the assembly in a dry glove box filled with nitrogen.

Preparation of Comparative Example 1 :

Indium tin oxide (Indium-tin-oxide) glass is used as the anode substrate, which is firstly cleaned with a commercially available glass cleaning agent, then cleaned with deionized water, and dried. Select copperphthalocyanine as the hole injection layer material (150 mm), and vapor-deposit it on the ITO glass. Nitrogen, nitrogen-di-(1-? base)-nitrogen, nitrogen biphenyl (600_) is evaporated on the hole injection layer. On the hole transport layer, the main luminous body (host) tri-8-hydroxyquinoline aluminum complex (aluminum-tris-8-hydroxyquinoline) and the guest luminous body (guest) comparison compound were deposited by co-evaporation DCM-1 1% (v/v) (150_) as light emitting layer (light emitting layer).

Evaporate the electron transport layer and three-8-hydroxyquinoline aluminum complex (350_) on the light-emitting layer. A magnesium-silver alloy is vapor-deposited on the electron transfer layer as a cathode. Package the assembly in a dry glove box filled with nitrogen.

Preparation of Comparative Example 2 :

Indium tin oxide (Indium-tin-oxide) glass is used as the anode substrate, which is firstly cleaned with a commercially available glass cleaning agent, then cleaned with deionized water, and dried. Select copperphthalocyanine as the hole injection layer material (150 mm), and vapor-deposit it on the ITO glass. Nitrogen, nitrogen-di-(1-? base)-nitrogen, nitrogen biphenyl (600_) is evaporated on the hole injection layer. On the hole transport layer, the main luminous body (host) tri-8-hydroxyquinoline aluminum complex and the guest luminous body (guest) comparative compound DCM-2 1% (v/v) are plated by co-evaporation. ) (150_) as a light emitting layer (light emitting layer).

Evaporate the electron transport layer and three-8-hydroxyquinoline aluminum complex (350_) on the light-emitting layer. A magnesium-silver alloy is vapor-deposited on the electron transfer layer as a cathode. Package the assembly in a dry glove box filled with nitrogen.

Preparation of Comparative Example 3 :

Indium tin oxide glass is used as the anode substrate, which is first cleaned with a commercially available glass cleaning agent, then cleaned with deionized water, and dried. Select flower bronze (copperphthalocyanine) as the hole injection layer material (150 mm), and vapor-deposit it on the ITO glass. Evaporate hole transport layer material nitrogen, nitrogen-two-(1-naphthyl)-nitrogen, nitrogen biphenyl (600_) on the hole injection layer. On the hole transport layer, the main luminous body (host) tri-8-hydroxyquinoline aluminum complex and the guest luminous body (guest) comparative compound DCJTB 0.5% (v/v) ( 150_) as the light-emitting layer.

An electron transport layer, three-8-hydroxyquinoline aluminum complex (350_) was vapor-deposited on the light-emitting layer. A magnesium-silver alloy is vapor-deposited on the electron transfer layer as a cathode. Package the assembly in a dry glove box filled with nitrogen.

Finally, according to the results of the above-mentioned preparation examples, it is calculated that the organic electroluminescent device made of the red organic electroluminescent compound synthesized by the present invention is different from the organic electroluminescent device made of the traditional red fluorescent compound (DCM-1, DCM-2, DCJTB). Table 1 shows the luminous efficiency, wavelength and CIE coordinate data of the organic electroluminescent device.

Table 1 Compounds Compound name Luminous maximum wavelength (nm) CIE(x,y) this invention Compound A 670 0.66, 0.33 Compound B 630 0.66, 0.36 Compound C 660 0.66, 0.34 Tradition DCM-1 610 0.62, 0.36 DCM-2 640 0.64, 0.36 DCJTB 620 0.62, 0.37

From the data in Table 1, it can be clearly seen that compared with the traditional technology, the red organic electroluminescent compound of the present invention has a significant improvement in efficiency. In addition, the wavelength and CIE coordinates are fully consistent with the red wavelength of 650nm and the NTSCCIE coordinates The criterion of x=0.67, y=0.33. In addition, the synthesis steps of the present invention are simple, so both the yield and the production cost are economical.

Although the present invention has been disclosed as above with preferred embodiments, it is not intended to limit the present invention. Any modifications and modifications made by those skilled in the art without departing from the spirit and scope of the present invention belong to the present invention. within the scope of protection.

Claims (8)

1. A red organic electroluminescence compound, characterized in that it is a compound of the following chemical structural formula: Wherein, R ₁ and R ₂ are alkyl, aryl, cycloalkyl or other heterocyclic groups with 1-20 carbon numbers respectively; R ₃ and R ₄ are respectively hydrogen, an alkyl group with 1-10 carbon numbers, five or six rings and heterocyclic groups connecting R ₁ and R ₂ with or without side chains; R ₅ is hydrogen, an alkyl group with a carbon number of 1-10, or a -(CH ₂ ) ₃ -, -(CH ₂ ) ₄ -, pentacyclic, hexacyclic or heterocyclic group connected to a benzene ring. 2. The compound according to claim 1, characterized in that: the R ₁ and R ₂ are respectively methyl, ethyl, propyl, n-butyl, -(CH ₂ ) ₄ -, -(CH ₂ ) ₅ -. 3. The compound according to claim 1, characterized in that: R ₃ and R ₄ are respectively hydrogen, methyl, ethyl, propyl, n-butyl, isopropyl, second butyl or third butyl base. 4. The compound according to claim 1, characterized in that: R ₁ , R ₃ =R ₂ , R ₄ =-(CH ₂ ) ₂ -, -(CH ₂ ) ₃ -, -(CH ₂ ) ₂ C(CH ₃ ) ₂ -. 5. The compound according to claim 1, characterized in that: the R ₅ is hydrogen, methyl, ethyl, propyl, n-butyl, isopropyl, second butyl, third butyl or benzene Ring-connected -(CH ₂ ) ₃ -, -(CH ₂ ) ₄ -, pentacyclic or hexacyclic and furyl, thienyl, pyridyl or other heterocyclic groups. 6. The compound according to claim 1, wherein the aryl group comprises phenyl, furyl, thienyl, pyridyl or other heterocyclic groups. 7. A red light organic electroluminescent component made of the compound according to any one of claims 1-6, characterized in that it is a red light organic electroluminescent component made of a compound of the following structural formula: Wherein, R ₁ and R ₂ are alkyl, aryl, cycloalkyl or other heterocyclic groups with 1-20 carbon numbers respectively; R ₃ and R ₄ are respectively hydrogen, an alkyl group with 1-10 carbon numbers, five or six rings and heterocyclic groups connecting R ₁ and R ₂ with or without side chains; R ₅ is hydrogen, an alkyl group with a carbon number of 1-10, or -(CH ₂ ) ₃ -, -(CH ₂ ) ₄ -, a pentacyclic or hexacyclic ring, or a heterocyclic group connected to a benzene ring. 8. The red light organic electroluminescent device composed of light-emitting components according to claim 7, characterized in that: the red light organic electroluminescent device comprises an anode, a cathode and a red organic electroluminescent device sandwiched therebetween. Optical component, the red light organic electroluminescence component is manufactured by the compound of the following structural formula:

Wherein, R ₁ and R ₂ are alkyl, aryl, cycloalkyl or other heterocyclic groups with 1-20 carbon numbers respectively; R ₃ and R ₄ are respectively hydrogen, an alkyl group with a carbon number of 1-10, five or six rings or heterocyclic groups connecting R ₁ and R ₂ with or without side chains; R ₅ is hydrogen, an alkyl group with a carbon number of 1-10, or -(CH ₂ ) ₃ -, -(CH ₂ ) ₄ -, a pentacyclic or hexacyclic ring, or a heterocyclic group connected to a benzene ring.