HK1228369A - Organic electronic material - Google Patents

Description

Organic electronic material

Technical Field

The invention relates to a novel organic electroluminescent material, which is deposited into a film through vacuum evaporation and transition and is applied to an organic electroluminescent diode as a blue electroluminescent material, belonging to the technical field of organic electroluminescent device display.

Background

The organic electroluminescent device as a novel display technology has the unique advantages of self luminescence, wide viewing angle, low energy consumption, high efficiency, thinness, rich colors, high response speed, wide applicable temperature range, low driving voltage, capability of manufacturing flexible, bendable and transparent display panels, environmental friendliness and the like, so the organic electroluminescent device technology can be applied to flat panel displays and new generation illumination and can also be used as a backlight source of LCDs.

An organic electroluminescent device is a device prepared by spin-coating or depositing a layer of organic material between two metal electrodes, and a typical three-layer organic electroluminescent device includes a hole transport layer, a light emitting layer, and an electron transport layer. Holes generated by the anode are combined with electrons generated by the cathode through the hole transport layer and the electron transport layer to form excitons in the light emitting layer, and then the excitons emit light. The organic electroluminescent device can emit red, green and blue light by changing the material of the light emitting layer. Therefore, the stable, efficient and color-pure organic electroluminescent material has an important role in the application and popularization of organic electroluminescent devices, and is also an urgent need for the application and popularization of large-area panel display of OLEDs.

Among the three primary colors (red, blue, green), the red and green materials have recently been developed to meet the market demand of the panel. For blue light materials, there are also a series of commercial materials, among which the Distyrylbiphenyl (DPVBi) compounds which are used relatively early in the art (Idemitsu Kosan co., Ltd) are more popular, and devices prepared from such compounds have higher efficiency, but these materials tend to have poorer stability, and even more so, the color of light emitted from such compounds belongs to the sky blue light, and the y in the CIE value is often greater than 0.15. The use of such compounds in full color display devices is largely limited due to their poor temperature properties and impure color. Another class of blue-emitting materials is ADN and tetra-tert-butylperylene available from kodak corporation, but these compounds have poor luminous efficiency and poor stability, and thus cannot be used in large quantities.

Disclosure of Invention

The invention overcomes the defects of the compounds and provides a series of organic blue electroluminescent materials with better thermal stability, high luminous efficiency and high luminous purity, and an organic electroluminescent device prepared from the materials has the advantages of good electroluminescent efficiency, excellent color purity and long service life.

The organic electronic material has a structural formula shown in a formula (I):

wherein R is₁-R₁₇Independently represent hydrogen, deuterium atom, halogen, cyano, nitro, C1-C8 alkyl, C1-C8 alkoxy, substituted or unsubstituted aryl of C6-C30, substituted or unsubstituted aryl of C3-C30 containing one or more heteroatoms, C2-C8 substituted or unsubstituted alkylene, C2-C8 substituted or unsubstituted alkynylalkyl, wherein Ar is Ar₁-Ar₃Independently represent a C6-C60 substituted or unsubstituted aryl group, a C3-C60 substituted or unsubstituted heteroaryl group with one or more heteroatoms, and a tri-aromatic (C6-C30) amine group.

Preferably: wherein R is₁-R₁₇Independently represent hydrogen, halogen, cyano, nitro, C1-C8 alkyl, C1-C8 alkoxy, C2-C8 substituted or unsubstituted alkenylalkyl, C2-C8 substituted or unsubstituted alkynylalkyl, C1-C4 alkyl substituted or unsubstituted phenyl, C1-C4 alkyl substituted or unsubstituted naphthyl, or fluorenyl combined to form C1-C4 alkyl substituted or unsubstituted fluorenyl; ar (Ar)₁-Ar₃Independently represent C1-C4 alkyl or C6-C30 aryl substituted phenyl, C1-C4 alkyl or C6-C30 aryl substituted naphthyl, phenyl, naphthyl, pyridyl, N-C6-C30 aryl or C1-C4 alkyl substituted carbazolyl, dibenzothienyl, dibenzofuranyl, anthryl, phenanthryl, pyrenyl, perylenyl, anthryl, (9, 9-dialkyl) fluorenyl, (9, 9-dialkyl substituted or unsubstituted aryl) fluorenyl, 9, 9-spirofluorenyl.

Preferably: wherein R is₁-R₂May independently preferably represent hydrogen, halogen, C1-C4 alkyl, C1-C4 alkyl substituted or unsubstituted phenyl, C1-C4 alkyl substituted or unsubstituted naphthyl, or fluorenyl substituted or unsubstituted with C1-C4 alkyl combined; wherein R is₃-R₁₇May independently preferably represent hydrogen, halogen, C1-C4 alkyl, C1-C4 alkyl substituted or unsubstitutedPhenyl, C1-C4 alkyl substituted or unsubstituted naphthyl, preferably Ar₁-Ar₃Independently represent phenyl, tolyl, xylyl, tert-butylphenyl, naphthyl, pyridyl, methylnaphthalene, biphenyl, diphenylphenyl, naphthylphenyl, diphenylbiphenyl, diarylaminophenyl, N-phenylcarbazolyl, (9, 9-dialkyl) fluorenyl, (9, 9-dialkyl substituted or unsubstituted phenyl) fluorenyl, 9, 9-spirofluorenyl.

Preferably: wherein R is₃-R₁₇Preferably hydrogen, R₁，R₂May independently preferably be represented by hydrogen, methyl, ethyl, propyl, isopropyl, tert-butyl, phenyl, biphenyl, naphthyl, or combined to form a fluorenyl group; ar (Ar)₁-Ar₃Independently represent phenyl, pyridyl, tolyl, xylyl, naphthyl, methylnaphthyl, biphenyl, diphenylphenyl, naphthylphenyl, diphenylbiphenyl, (9, 9-dialkyl) fluorenyl, (9, 9-dimethyl substituted or unsubstituted phenyl) fluorenyl, 9, 9-spirofluorenyl.

Preferably: r₃-R₁₇Preferably hydrogen; r₁，R₂Independently represent hydrogen, methyl, or combine to form fluorenyl; ar (Ar)₁，Ar₂，Ar₃Independently represent phenyl, naphthyl.

Preferably:

the organic electronic material is applied to the fields of organic electroluminescent devices, organic solar cells, organic thin film transistors or organic photoreceptors.

As mentioned above, specific embodiments of the present invention are as follows, but are not limited to the enumerated structures:

the organic electronic material provided by the invention can be prepared into an organic electroluminescent device which comprises an anode, a cathode and one or more organic layers, wherein at least one of the organic layers contains the organic electronic material shown in the structural formula I.

The organic layers are a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer or/and an electron injection layer, and it is particularly noted that the organic layers may be present as needed, and the organic layers do not need to be present in every layer.

The hole transport layer, the electron transport layer and the light-emitting layer contain organic materials as shown in a structural formula 1.

The hole transport layer and the hole injection layer in the invention have good hole transport performance of the required materials, and can effectively transport holes from the anode to the organic light-emitting layer. May include small molecules and high molecular organic materials, and may include, but is not limited to, triarylamine compounds, biphenyldiamine compounds, thiazole compounds, oxazole compounds, imidazole compounds, fluorene compounds, phthalocyanine compounds, hexacyano hexaazatriphenylene (hexanitrile hexaazatriphenylene), 2,3,5, 6-tetrafluoro-7, 7',8,8' -tetracyanodimethyl-p-benzoquinone (F4-TCNQ), polyvinylcarbazole, polythiophene, polyethylene, and polyphenylsulfonic acid.

The organic electroluminescent layer of the present invention may contain, in addition to the compound of the formula (I) of the present invention, but is not limited thereto, naphthalene compounds, pyrene compounds, fluorene compounds, phenanthrene compounds, anthracene compounds, pentacene compounds, perylene compounds, diarylethene compounds, triphenylamine ethene compounds, amine compounds, benzimidazole compounds, furan compounds, and organic metal chelate compounds.

The organic electron transport material used in the organic electronic device of the present invention is required to have excellent electron transport performance, and to be capable of efficiently transporting electrons from the cathode to the light-emitting layer, and the following compounds may be selected, but not limited thereto, oxazaoles, thiazole compounds, triazole compounds, triazine compounds, quinoxaline compounds, diazananthracene compounds, silicon-containing heterocyclic compounds, quinoline compounds, phenanthroline compounds, metal chelates, and fluorine-substituted benzene compounds.

The organic electronic device of the present invention may be incorporated with an electron injection layer which can efficiently inject electrons from the cathode into the organic layer, and is selected from compounds mainly of alkali metals or compounds of alkaline earth metals or alkaline earth metals, and the following compounds may be selected, but not limited thereto, lithium fluoride, lithium oxide, lithium nitride, 8-hydroxyquinoline lithium, cesium carbonate, 8-hydroxyquinoline cesium, calcium fluoride, calcium oxide, magnesium fluoride, magnesium carbonate, magnesium oxide.

Device experiments show that the organic electronic material disclosed by the formula (I) has the advantages of good thermal stability, high luminous efficiency and high luminous purity. The organic electroluminescent device made of the organic luminescent material has the advantages of good electroluminescent efficiency, excellent color purity and long service life.

Drawings

Figure 1 is a diagram of the structure of a device of the present invention,

wherein 10 is represented by a glass substrate, 20 is represented by an anode, 30 is represented by a hole injection layer, 40 is represented by a hole transport layer, 50 is represented by a light emitting layer, 60 is represented by an electron transport layer, 70 is represented by an electron injection layer, and 80 is represented by a cathode.

FIG. 2 is a drawing of Compound 89¹H NMR chart.

FIG. 3 is a drawing of Compound 89¹³C NMR chart.

Figure 4 is an HPLC profile of compound 89.

Figure 5 is a TGA profile of compound 89.

FIG. 6 is a graph of voltage-current density curves of example 4, example 5 and comparative example 1

FIG. 7 is a graph of luminance versus CIEy for example 4, example 5, and comparative example 1

FIG. 8 shows the electroluminescence spectra of example 4, example 5 and comparative example 1

FIG. 9 is a graph of current density versus current efficiency for example 4, example 5 and comparative example 1

Detailed Description

In order to describe the present invention in more detail, the following examples are given, but not limited thereto.

(wherein the following compounds 1a, 1b, 1e, 1h, 3a and 89a are commercially available materials in common use)

Example 1

Synthesis of intermediate 1c

To a reaction flask was added 1a (240.00g,0.88mol),1b (496.32g,1.76mol), Pd (PPh)₃)₄(20.35g,17.60mmol), potassium carbonate (302.52g,2.20mol), toluene (2400mL), pure water (1200 mL). And pumping nitrogen for three times, starting heating, keeping the temperature of the reaction liquid to be 95-105 ℃, reacting for 8-12h, sampling TLC and HPLC, and completely reacting the raw materials. Stopping heating, cooling to 20-30 deg.C, vacuum filtering, separating organic layer from filtrate, extracting water layer with ethyl acetate, mixing organic layers, washing with water, drying with anhydrous magnesium sulfate, vacuum filtering, and concentrating filtrate to obtain dark yellow solid crude product. Recrystallizing with petroleum ether to obtain the off-white solid product with the yield of 90 percent and the purity of 95 percent.

Synthesis of intermediate 1d

To the reaction flask was added 1c (302g,0.78mol), B (OEt) in the corresponding proportions₃(142g,0.97mol), n-BuLi/THF (1.6M,600mL) and anhydrous THF (3000mL), pumping nitrogen for three times, cooling to the temperature of the reaction solution to-75-65 ℃, slowly dropwise adding the n-BuLi/THF solution, controlling the temperature of the reaction solution to-75-65 ℃, and continuously keeping the temperature after dropwise adding for reaction for 0.5-1 h. Then adding a certain amount of B (OEt)₃Dropwise adding the mixture, controlling the temperature of the reaction solution to be-75 to-65 ℃, continuously keeping the temperature for reacting for 0.5 to 1 hour after the dropwise adding is finished, then moving the reaction solution to room temperature for naturally heating and reacting for 4 to 6 hours, then adding 2M dilute hydrochloric acid, adjusting the pH value to 2 to 3, stirring for about 1 hour, and stopping the reaction. Adding ethyl acetate for extraction, extracting a water layer with EA, combining organic layers, drying with anhydrous magnesium sulfate, performing suction filtration, and concentrating a filtrate to obtain an off-white solid product with the purity of 95% and the yield of 62.5%.

Synthesis of intermediate 1f

To a reaction flask was added 1d (150g,0.43mol),1e (500g,0.86mol), Pd (PPh)₃)₄(5.0g,0.44mmol), potassium carbonate (130g,0.92mol), toluene (1000mL), pure water (500mL), nitrogen gas was purged three times and heating was started,keeping the temperature of the reaction solution at 95-105 ℃, reacting for 8-12h, sampling TLC and HPLC, and completely reacting the raw materials. Stopping heating, cooling to 20-30 deg.C, vacuum filtering, separating organic layer from filtrate, extracting water layer with ethyl acetate, mixing organic layers, drying with anhydrous magnesium sulfate, vacuum filtering, and concentrating filtrate to obtain dark yellow solid crude product with purity of 80% and yield of 78.1%.

Synthesis of intermediate 1g

1f (210g,0.42mol), NBS (135g,0.71mol), DMF (5L) was added to the reaction flask. And pumping nitrogen for three times, starting heating, keeping the temperature of the reaction liquid to be 60-65 ℃, reacting for 6-8h, sampling TLC and HPLC, and completely reacting the raw materials. Stopping heating, cooling to 20-30 ℃, pouring the reaction liquid into ice water, separating out dark yellow solid, performing suction filtration to obtain yellow solid, and drying to obtain 1g of crude product. Adding DCM/MeOH into the crude product until the solution becomes slightly turbid, stirring for about 30min to precipitate a large amount of solid, and vacuum filtering to obtain light yellow solid product with yield of about 54.05% and purity of 98.5%

¹H NMR(300MHz,CDCl₃)8.64(d,J＝8.8Hz,2H),7.99–7.90(m,4H),7.87(t,J＝1.6Hz,1H),7.78(dd,J＝9.3,2.3Hz,6H),7.61(ddd,J＝8.8,6.5,1.1Hz,2H),7.56–7.48(m,6H),7.46–7.38(m,4H).

¹³C NMR(76MHz,CDCl₃)142.67(s),142.03(s),141.26(s),140.69(s),137.83(s),137.52(s),131.87(s),131.24(s),130.44(s),129.09(s),128.80(s),128.38–127.40(m),127.18(s),126.05–125.21(m),123.08(s),77.74(s),77.31(s),76.89(s),30.10(s).

Synthesis of Compound 1

Into a 500ml three-necked flask were charged 1g (9.5g,16.92mmol),1h (6.41g,30.51mmol), Pd (PPh) in that order₃)₄(1.5g,1.3mmol), potassium carbonate (5.84g,42.3mmol), toluene (150mL), and pure water (75 mL). After nitrogen was purged three times, the reaction was carried out at 105 ℃. The reaction time is about 12h by liquid phase detection. The reaction solution is earthy yellow of the catalyst at the beginning of the reaction, then slowly becomes yellow solution, and the upper layer is light yellow after the reaction is stoppedColor, the lower layer is water. And after the reaction is stopped, filtering, washing filter residues by using ethyl acetate until no product exists in the filter residues, collecting filtrate, spin-drying, separating out a large amount of off-white solid, collecting the filter residues, and drying to obtain the target product with the purity of 98%. Sublimation in vacuo gave an off-white solid powder with a purity of 99.5%.

¹H-NMR(300MHz,CDCl₃)8.10–8.21(d，2H)，7.96–7.98(dd，3H)，7.87–7.89(m，2H)，7.81–7.86(m，4H)，7.78–7.81(d，4H),7.62–7.65(m，2H)，7.59(s，1H)，7.51–7.57(m，5H)，7.45–7.48(m，2H)，7.36–7.43(m，7H)，3.88(s，2H).

Example 2

Synthesis of Compound 3

Into a 500ml three-necked flask were charged 1g (9.5g,16.92mmol),3a (7.25g,30.46mmol), Pd (PPh) in that order₃)₄(1.5g,1.3mmol), potassium carbonate (5.84g,42.3mmol), toluene (150mL), and pure water (75 mL). After nitrogen was purged three times, the reaction was carried out at 105 ℃. The reaction time is about 12h by liquid phase detection. The reaction solution was made to be a yellowish-earthy catalyst at the beginning of the reaction, and then slowly changed to a yellow solution, and after the reaction was stopped, the upper layer was a clear pale yellow and the lower layer was water. And after the reaction is stopped, filtering, washing filter residues by using ethyl acetate until no product exists in the filter residues, collecting filtrate, spin-drying, separating out a large amount of off-white solid, collecting the filter residues, and drying to obtain the target product with the purity of 98%. Sublimation in vacuo gave an off-white solid powder with a purity of 99.7%.

¹H-NMR(300MHz,CDCl₃)8.1–8.2(d，2H)，7.96–7.99(dd，3H)，7.88–7.89(m，2H)，7.81–7.86(m，4H)，7.78–7.81(d，4H),7.61–7.65(m，2H)，7.59(s，1H)，7.51–7.56(m，5H)，7.46–7.48(m，2H)，7.35–7.43(m，7H)，1.61(s，6H).

Example 3

Synthesis of Compound 89

To the reaction vessel were added 1g (10.0g,17.8mmol),89a (7.1g,19.6mmol), Pd (PPh) in that order₃)₄(432.2mg,0.35mmol),K₂CO₃(6.14g,44.5mmol), toluene (300mL) and water (150mL), the apparatus was deoxygenated, purged with nitrogen, and then heated to 100 deg.C for reaction overnight. With DCM: the PE is a ratio of 1:5, the product point emits strong blue light under an ultraviolet lamp with the wavelength of 365nm, and the Rf value is about 0.2. The reaction solution was filtered by suction through silica gel, and the filter cake was washed twice with ethyl acetate (100mL), separated, the aqueous layer was extracted once with ethyl acetate (100mL), the organic layers were combined, and the organic phase was washed once with water (200 mL). The solvent was removed by spin-drying. The crude product was recrystallized from 120ml DCM/MeOH and filtered off with suction to give 13.1g of a yellow solid powder with a purity of 98.7% in 92.2% yield. Sublimation in vacuo gave a pale yellow solid powder with a purity of 99.7%. And m/z is 797.

From fig. 2 and 3, it can be seen that the hydrogen spectrum and the carbon spectrum of compound 89 are completely consistent with the structure. It can be seen from the high performance liquid chromatogram of compound 89 of fig. 4 that the product prepared according to the synthesis method of the present invention has high purity. From the thermogravimetric analysis of compound 89 of fig. 5, it can be seen that this type of compound has a decomposition temperature above 400 degrees celsius, indicating a very high thermal stability.

Example 4

Preparation of organic electroluminescent device 1

Preparation of OLEDs Using the organic electronic Material of the invention

First, a transparent conductive ITO glass substrate 10 (with an anode 20 thereon) is sequentially passed through: washing with detergent solution, deionized water, ethanol, acetone and deionized water, and treating with oxygen plasma for 30 s.

Then, HAT-CN was evaporated on the ITO to a thickness of 10nm₆As the hole injection layer 30.

Then, NPB was evaporated to form a hole transport layer 40 having a thickness of 30 nm.

Then, compound 3 was evaporated to a thickness of 30nm on the hole transport layer as a light-emitting layer 50.

Then, TPBi having a thickness of 15nm was deposited on the light-emitting layer as an electron transporting layer 60.

Finally, a 15nm BPhen is evaporated, Li is an electron injection layer 70, and 150nm Al is used as a device cathode 80.

The voltage of the prepared device is 3.58V under the working current density of 20mA/cm2, the current efficiency reaches 3.21cd/A and is 1000cd/m²CIEy coordinate at luminance is 0.0853, emitting blue light.

Structural formula in device

Example 5

Preparation of organic electroluminescent device 2

In the same manner as in example 4, compound 3 was replaced with compound 89 to fabricate an organic electroluminescent device.

The voltage of the prepared device is 3.84V under the working current density of 20mA/cm2, the current efficiency reaches 2.83cd/A and is 1000cd/m²CIEy coordinate at brightness is 0.0888, emitting blue light.

Comparative example 1

In the same manner as in example 4, Compound 3 was replaced with TAT, which is the following compound, to prepare an organic electroluminescent device for comparison.

TAT structural formula

The voltage of the prepared device is 4.00V under the working current density of 20mA/cm2, the current efficiency reaches 2.46cd/A and is 1000cd/m²CIEy coordinate at luminance is 0.0952, emitting blue light.

Examples 4 and 5 are specific applications of the materials of the present invention, resulting in devices that emit blue light with higher efficiency and brightness than the comparative examples. As described above, the material of the present invention has high stability, and the organic electroluminescent device prepared by the present invention has high efficiency and optical purity.

Claims (8)

1. The organic electronic material has a structural formula described by formula (I):

wherein R is₁-R₁₇Independently represent hydrogen, deuterium atom, halogen, cyano, nitro, C1-C8 alkyl, C1-C8 alkoxy, substituted or unsubstituted aryl of C6-C30, substituted or unsubstituted aryl of C3-C30 containing one or more heteroatoms, C2-C8 substituted or unsubstitutedSubstituted alkenylalkyl, C2-C8 substituted or unsubstituted alkynylalkyl, wherein Ar is₁-Ar₃Independently represent a C6-C60 substituted or unsubstituted aryl group, a C3-C60 substituted or unsubstituted heteroaryl group with one or more heteroatoms, and a tri-aromatic (C6-C30) amine group.

2. The organic electronic material of claim 1, wherein R₁-R₁₇Independently represent hydrogen, halogen, cyano, nitro, C1-C8 alkyl, C1-C8 alkoxy, C2-C8 substituted or unsubstituted alkenylalkyl, C2-C8 substituted or unsubstituted alkynylalkyl, C1-C4 alkyl substituted or unsubstituted phenyl, C1-C4 alkyl substituted or unsubstituted naphthyl, or fluorenyl combined to form C1-C4 alkyl substituted or unsubstituted fluorenyl; ar (Ar)₁-Ar₃Independently represent C1-C4 alkyl or C6-C30 aryl substituted phenyl, C1-C4 alkyl or C6-C30 aryl substituted naphthyl, phenyl, naphthyl, pyridyl, N-C6-C30 aryl or C1-C4 alkyl substituted carbazolyl, dibenzothienyl, dibenzofuranyl, anthryl, phenanthryl, pyrenyl, perylenyl, anthryl, (9, 9-dialkyl) fluorenyl, (9, 9-dialkyl substituted or unsubstituted aryl) fluorenyl, 9, 9-spirofluorenyl.

3. The organic electronic material of claim 2, wherein R₁-R₂May independently preferably represent hydrogen, halogen, C1-C4 alkyl, C1-C4 alkyl substituted or unsubstituted phenyl, C1-C4 alkyl substituted or unsubstituted naphthyl, or fluorenyl substituted or unsubstituted with C1-C4 alkyl combined; wherein R is₃-R₁₇May independently preferably represent hydrogen, halogen, C1-C4 alkyl, C1-C4 alkyl substituted or unsubstituted phenyl, C1-C4 alkyl substituted or unsubstituted naphthyl, Ar₁-Ar₃Independently represent phenyl, tolyl, tert-butylphenyl, naphthyl, pyridyl, methylnaphthyl, biphenyl, diphenylphenyl, naphthylphenyl, diphenylbiphenyl, diarylaminophenyl, N-phenylcarbazolyl, (9, 9-dialkyl) fluorenyl, (9, 9-dialkyl substituted or unsubstituted phenyl) fluorenyl, 9, 9-spirofluorenyl.

4. The organic electronic material of claim 3, wherein R₃-R₁₇Preferably hydrogen, R₁，R₂May independently preferably be represented by hydrogen, methyl, ethyl, propyl, isopropyl, tert-butyl, phenyl, naphthyl, or combined to form a fluorenyl group; ar (Ar)₁-Ar₃Independently represent phenyl, pyridyl, tolyl, naphthyl, methylnaphthalene, biphenyl, diphenylphenyl, naphthylphenyl, diphenylbiphenyl, (9, 9-dialkyl) fluorenyl, (9, 9-dimethyl substituted or unsubstituted phenyl) fluorenyl, 9, 9-spirofluorenyl.

5. The organic electronic material of claim 4, R₃-R₁₇Preferably hydrogen; r₁，R₂Independently represent hydrogen, methyl, or combine to form fluorenyl; ar (Ar)₁，Ar₂，Ar₃Independently represent phenyl, naphthyl.

6. The organic electronic material of claim 1, being a compound of the following structure:

7. the organic electronic material according to claim 6, which is a compound of the following structure,

8. use of the organic electronic material of any one of claims 1 to 7 in the field of organic electroluminescent devices, organic solar cells, organic thin film transistors or organic photoreceptors.