阅读说明：本技术 一种化合物、用于有机电致发光器件的材料及其应用 (Compound, material for organic electroluminescent device and application thereof ) 是由 翟露 高威 代文朋 张磊 冉佺 于 2021-04-23 设计创作，主要内容包括：本发明涉及一种化合物、用于有机电致发光器件的材料及其应用,所述化合物具有式(1)所示的结构。本发明提供的化合物具有较高的折射率,当用于有机电致发光器件中,特别是作为盖帽层材料时,可以有效提高有机光电装置的光取出效率,提高外量子效率,在可见光区域(400-750nm)具有较高的折射率,有利于提升发光效率。在紫外区域(小于400nm)具有较大的消光系数,有利于吸收有害光色,保护视力,同时,在蓝光区域(400-450nm)具有较小的消光系数,对蓝光几乎没有吸收,利于提升发光效率。(The invention relates to a compound, a material for an organic electroluminescent device and application thereof, wherein the compound has a structure shown in a formula (1). The compound provided by the invention has a higher refractive index, can effectively improve the light extraction efficiency of an organic photoelectric device and the external quantum efficiency when being used in an organic electroluminescent device, particularly as a capping layer material, and has a higher refractive index in a visible light region (400-750nm), thereby being beneficial to improving the luminous efficiency. The material has a larger extinction coefficient in an ultraviolet region (less than 400nm), is favorable for absorbing harmful light color and protecting eyesight, and has a smaller extinction coefficient in a blue light region (400-450nm), almost no blue light is absorbed, and the material is favorable for improving the luminous efficiency.)

1. A compound having a structure represented by formula (1);

in the formula (1), R is₁And R₂Each independently selected from benzoxazole-or benzothiazole-containing groups

In the formula (1), Y and Z are eachIndependently selected from O, S, NR₃Or CR₄R₅Any one of (1), the R₃Selected from substituted or unsubstituted C6-C60 aryl or substituted or unsubstituted C3-C60 heteroaryl, wherein R is₄And R₅Each independently selected from any one of a hydrogen atom, a substituted or unsubstituted C6-C60 aryl group, and a substituted or unsubstituted C3-C60 heteroaryl group;

R₃、R₄and R₅Wherein each of the substituted groups is independently selected from any one or at least two combinations of protium, deuterium, tritium, cyano, halogen, C1-C10 alkyl, C1-C10 haloalkyl, C1-C10 alkoxy, C6-C60 aryl, and C3-C60 heteroaryl.

2. A compound of claim 1, wherein R is₁And R₂Each independently has a structure represented by formula (2) or formula (3);

wherein the wavy line indicates the bond of the group;

n and m are each independently 0 or 1, L₁And L₂Each independently selected from substituted or unsubstituted C6-C60 arylene, wherein R is₆Selected from substituted or unsubstituted C6-C60 aryl or substituted or unsubstituted C3-C60 heteroaryl, wherein X is selected from O or S;

L₁、L₂and R₆Wherein each of the substituted groups is independently selected from any one or at least two combinations of protium, deuterium, tritium, cyano, halogen, C1-C10 alkyl, C1-C10 haloalkyl, C1-C10 alkoxy, C6-C60 aryl, and C3-C60 heteroaryl.

3. A compound of claim 2, wherein R is₁And R₂At least one of them has a structure represented by formula (3).

4. A compound of claim 2, wherein R is₁And R₂Are all selected from the structures shown in formula (3).

5. The compound of claim 2, wherein n and m are both 1.

6. The compound of claim 2, wherein L is₁And L₂Each independently selected from substituted or unsubstituted phenylene.

7. A compound of claim 2, wherein R is₆Selected from the group consisting of substituted or unsubstituted phenyl, substituted or unsubstituted biphenyl, substituted or unsubstituted terphenyl, substituted or unsubstituted quaterphenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted phenanthryl, substituted or unsubstituted fluorenyl, substituted or unsubstituted carbazolyl, substituted or unsubstituted dibenzofuranyl, substituted or unsubstituted dibenzothiophenyl, substituted or unsubstituted pyrimidinyl, substituted or unsubstituted triazinyl, substituted or unsubstituted indolocarbazolyl, substituted or unsubstituted indolocarbafuranyl, substituted or unsubstituted indolocarbaphthenyl, substituted or unsubstituted benzofuranylpyrimidinyl, substituted or unsubstituted benzothiophenyl, substituted or unsubstituted anthracenyl, substituted or unsubstituted pyrenyl, substituted or unsubstituted pyrrolyl, substituted or unsubstituted furanyl, substituted or unsubstituted thienyl, A substituted or unsubstituted indolyl group, a substituted or unsubstituted indenocarbazolyl group, a substituted or unsubstituted pyridyl group, a substituted or unsubstituted pyrazinyl group, a substituted or unsubstituted pyridazinyl group, or a group in which at least two of these groups are linked.

8. A compound of claim 2, wherein R is₆Is selected fromSaid L₂M and X have the same defined ranges as in formula (3);

wherein the wavy line indicates the bond of the group.

9. The compound of claim 1, wherein the compound has any one of the following structures M1-M45:

10. a material for an organic electroluminescent device, characterized in that the material for an organic electroluminescent device comprises any one or at least two combinations of the compounds of any one of claims 1 to 9.

11. An organic electroluminescent device is characterized by comprising a first electrode layer, an organic functional layer and a second electrode layer which are sequentially stacked;

the organic functional layer comprising the material according to claim 10.

12. The organic electroluminescent device is characterized by comprising a first cap layer, a first electrode layer, an organic functional layer and a second electrode layer which are sequentially stacked;

the first cap layer contains the material of claim 10.

13. The organic electroluminescent device as claimed in claim 12, further comprising a second cap layer disposed on a side of the first cap layer away from the first electrode layer, wherein the second cap layer contains a material comprising lithium fluoride and/or small organic molecules having a refractive index of 1.40-1.65.

14. A display panel characterized in that the display panel comprises the organic electroluminescent device according to any one of claims 11 to 13.

15. The display panel of claim 14, wherein the display panel is a foldable display panel.

16. A display device characterized in that it comprises a display panel according to claim 14 or 15.

Technical Field

The invention relates to the technical field of organic electroluminescence, in particular to a compound, a material for an organic electroluminescent device and application thereof.

Background

Organic electroluminescence (OLED) has made significant progress over decades of development. Although the internal quantum efficiency is close to 100%, the external quantum efficiency is only about 20%. Most of the light is confined inside the light emitting device due to factors such as substrate mode loss, surface plasmon loss, and waveguide effect, resulting in a large amount of energy loss.

In the top emission device, an organic Coating (CPL) is evaporated on a semitransparent metal electrode Al, so that the optical interference distance is adjusted, the external light reflection is inhibited, and the extinction caused by the movement of surface plasma is inhibited, thereby improving the light extraction efficiency and the luminous efficiency.

The performance requirements for CPL materials are high: no absorption in the visible wavelength region (400nm-700 nm); high refractive index (generally, n >2.1), low extinction coefficient (k ≦ 0.00) in the wavelength range of 400nm to 600 nm; high glass transition temperature and molecular thermal stability, and at the same time, can be deposited without thermal decomposition.

The CPL materials in the prior art have many problems, such as: (1) the refractive index is generally below 1.9, and cannot meet the requirement of high refractive index; (2) under the condition that the refractive index meets the requirement, the visible light region has stronger absorption or larger extinction coefficient; (3) amine derivatives having a specific structure with a high refractive index and using a material satisfying specific parameters improve light extraction efficiency, but do not solve the problems of luminous efficiency and chromaticity at the same time, particularly in a blue light emitting element; (4) in order to increase the density of molecules and achieve high thermal stability, the molecular structure is designed to be large and loose, and tight accumulation among molecules cannot be achieved, so that too many molecular gel holes are formed during evaporation and the molecules cannot be completely covered; (5) the electronic type covering layer material is designed purely, the effects of electronic transmission and light extraction are achieved, the preparation cost of the device is saved to a certain extent, multiple effects are achieved, light extraction is not facilitated, the luminous efficiency is only weakly improved, and the chromaticity is not solved.

Therefore, there is a need in the art to develop a wider variety of higher performance CPL materials.

Disclosure of Invention

In view of the disadvantages of the prior art, it is an object of the present invention to provide a compound, especially to provide an organic electroluminescent material, especially to provide a capping layer material. The compound has a high refractive index, can effectively improve the External Quantum Efficiency (EQE) of the organic photoelectric device when being used as a capping layer material, and meanwhile has a small extinction coefficient in a blue light region (400-450nm), almost does not absorb blue light, and is beneficial to improving the luminous efficiency.

In order to achieve the purpose, the invention adopts the following technical scheme:

the invention provides a compound, which has a structure shown in a formula (1);

in the formula (1), R is₁And R₂Each independently selected from benzoxazole-or benzothiazole-containing groups

In the formula (1), Y and Z are each independently selected from O, S, NR₃Or CR₄R₅Any one of (1), the R₃Selected from substituted or unsubstituted C6-C60 aryl or substituted or unsubstituted C3-C60 heteroaryl, wherein R is₄And R₅Each independently selected from a hydrogen atom, substituted or unsubstitutedAny one of C6-C60 aryl, substituted or unsubstituted C3-C60 heteroaryl;

R₃、R₄and R₅Wherein each of the substituted groups is independently selected from any one or at least two combinations of protium, deuterium, tritium, cyano, halogen, C1-C10 alkyl, C1-C10 haloalkyl, C1-C10 alkoxy, C6-C60 aryl, and C3-C60 heteroaryl.

It is a second object of the present invention to provide a material for an organic electroluminescent device comprising any one or at least two combinations of the compounds described in the first object.

The organic electroluminescent device comprises a first electrode layer, an organic functional layer and a second electrode layer which are sequentially stacked;

the organic functional layer contains the material of the second aspect.

The fourth purpose of the invention is to provide an organic electroluminescent device, which comprises a first cap layer, a first electrode layer, an organic functional layer and a second electrode layer which are sequentially stacked;

the first cap layer contains the second material.

The fifth object of the present invention is to provide a display panel including the organic electroluminescent device of the fourth object.

The sixth object of the present invention is to provide a display device including the display panel of the fifth object.

Compared with the prior art, the invention has the following beneficial effects:

the compound provided by the invention has higher refractive index, has higher refractive index in a visible light region (400-750nm), is favorable for improving luminous efficiency, has higher extinction coefficient in an ultraviolet region (less than 400nm), is favorable for absorbing harmful light color and protecting eyesight, and has lower extinction coefficient in a blue light region (400-450nm), almost no absorption to blue light and is favorable for improving luminous efficiency.

Drawings

Fig. 1 is a schematic structural view of an organic electroluminescent device according to an embodiment of the present invention;

FIG. 2 is a schematic structural diagram of an organic electroluminescent device according to still another embodiment of the present invention;

the light-emitting diode comprises a substrate 1, an anode 2, a hole injection layer 3, a first hole transport layer 4, a second hole transport layer 5, a light-emitting layer 6, a first electron transport layer 7, a second electron transport layer 8, a cathode 9, a first capping layer 10 and a second capping layer 11.

Detailed Description

For the purpose of facilitating an understanding of the present invention, the present invention will now be described by way of examples. It should be understood by those skilled in the art that the examples are only for the understanding of the present invention and should not be construed as the specific limitations of the present invention.

An object of the present invention is to provide a compound having a structure represented by formula (1);

in the formula (1), R is₁And R₂Each independently selected from benzoxazole-or benzothiazole-containing groups

In the formula (1), Y and Z are each independently selected from O, S, NR₃Or CR₄R₅Any one of (1), the R₃Selected from substituted or unsubstituted C-C (e.g., C, etc.) aryl or substituted or unsubstituted C-C (e.g., C, etc.) heteroaryl, wherein R is selected from the group consisting of₄And R₅Each independently selected from hydrogen atom, substituted or unsubstituted C6-C60 (e.g. C8, C10, C12, C14. Any one of C, etc.) aryl, substituted or unsubstituted C-C (e.g., C, etc.) heteroaryl;

R₃、R₄and R₅In the above formula, the substituted groups are each independently selected from protium, deuterium, tritium, cyano, halogen, C1-C10 (e.g., C2, C3, C4, C5, C6, C7, C8, C9, etc.) alkyl, C1-C10 (e.g., C2, etc.) alkyl, C2-C2 (e.g., C2, etc.) haloalkyl, C2-C2 (e.g., C2, C2, 36, C58, etc.), an aryl group, C3-C60 (e.g., C4, C5, C6, C7, C8, C10, C12, C14, C16, C18, C20, C22, C24, C26, C28, C30, C32, C34, C36, C38, C40, C42, C44, C46, C48, C50, C52, C54, C56, C58, etc.), a heteroaryl group.

The present invention provides a novel compound toThe organic electroluminescent device is a mother nucleus, benzene rings at two ends of the mother nucleus are substituted with groups containing benzoxazole or benzothiazole, the organic electroluminescent device has a high refractive index in a visible light region, and when the organic electroluminescent device is applied to an organic electroluminescent device, particularly as a capping layer material, the light extraction efficiency of the organic electroluminescent device can be effectively improved, and the external quantum efficiency is improved. Meanwhile, the compound of the invention has larger extinction coefficient in an ultraviolet region (less than 400nm), is favorable for absorbing harmful light color and protecting eyesight, and has smaller extinction coefficient in a blue light region (400-450nm)The extinction coefficient of the LED lamp almost does not absorb blue light, and the luminous efficiency is improved.

In one embodiment, the compound has any one of the following structures:

R₁、R₂、R₃、R₄and R₅All having the same selection ranges as above.

In one embodiment, said R is₁And R₂Each independently has a structure represented by formula (2) or formula (3);

wherein the wavy line indicates the bond of the group;

n and m are each independently 0 or 1, L₁And L₂Each independently selected from substituted or unsubstituted C6-C60 arylene, wherein R is₆Selected from substituted or unsubstituted C6-C60 aryl or substituted or unsubstituted C3-C60 heteroaryl, wherein X is selected from O or S;

L₁、L₂and R₆Wherein each of the substituted groups is independently selected from any one or at least two combinations of protium, deuterium, tritium, cyano, halogen, C1-C10 alkyl, C1-C10 haloalkyl, C1-C10 alkoxy, C6-C60 aryl, and C3-C60 heteroaryl.

In one embodiment, said R is₁And R₂At least one of them has a structure represented by formula (3).

In the preferred technical scheme of the invention, at least one end of the mother nucleus is grafted with benzoxazole or benzothiazole through an arylamine group, and the structure increases the conjugation degree and obtains higher refractive index.

In one embodiment, said R is₁And R₂Are all selected from the structures shown in formula (3).

In the invention, benzoxazole or benzothiazole at two ends of a mother nucleus is preferably grafted through an arylamine group, and compared with the structure of unilateral arylamine, the conjugated length is increased, so that the refractive index can be further improved, and the synthesis difficulty is reduced.

In one embodiment, n and m are both 1.

Preference is given according to the invention to the presence of a linking group L between benzoxazole or benzothiazole and the parent nucleus or the N atom₁Or L₂Such a structure increases the degree of conjugation, resulting in a higher refractive index.

In one embodiment, said L is₁And L₂Each independently selected from substituted or unsubstituted phenylene.

In one embodiment, said R is₆Selected from the group consisting of substituted or unsubstituted phenyl, substituted or unsubstituted biphenyl, substituted or unsubstituted terphenyl, substituted or unsubstituted quaterphenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted phenanthryl, substituted or unsubstituted fluorenyl, substituted or unsubstituted carbazolyl, substituted or unsubstituted dibenzofuranyl, substituted or unsubstituted dibenzothiophenyl, substituted or unsubstituted pyrimidinyl, substituted or unsubstituted triazinyl, substituted or unsubstituted indolocarbazolyl, substituted or unsubstituted indolocarbafuranyl, substituted or unsubstituted indolocarbaphthenyl, substituted or unsubstituted benzofuranylpyrimidinyl, substituted or unsubstituted benzothiophenyl, substituted or unsubstituted anthracenyl, substituted or unsubstituted pyrenyl, substituted or unsubstituted pyrrolyl, substituted or unsubstituted furanyl, substituted or unsubstituted thienyl, A substituted or unsubstituted indolyl group, a substituted or unsubstituted indenocarbazolyl group, a substituted or unsubstituted pyridyl group, a substituted or unsubstituted pyrazinyl group, a substituted or unsubstituted pyridazinyl group, or a group in which at least two of these groups are linked.

In one embodiment, said R is₆Is selected fromSaid L₂M and X have the same defined ranges as in formula (3);

wherein the wavy line indicates the bond of the group.

In one embodiment, the compound has any one of the structures shown as M1-M45 below:

it is a second object of the present invention to provide a material for an organic electroluminescent device comprising any one or at least two combinations of the compounds described in the first object.

The organic electroluminescent device comprises a first electrode layer, an organic functional layer and a second electrode layer which are sequentially stacked;

the organic functional layer contains the material of the second aspect.

In the present invention, one of the first electrode layer and the second electrode layer is an anode layer, and the other is a cathode layer, and specifically, the first electrode layer and the second electrode layer may be: the first electrode layer is an anode layer and the second electrode layer is a cathode layer, or the first electrode layer is the cathode layer and the second electrode layer is the anode layer.

The fourth purpose of the invention is to provide an organic electroluminescent device, which comprises a first cap layer, a first electrode layer, an organic functional layer and a second electrode layer which are sequentially stacked;

the first cap layer contains the second material.

When the device is a top emission device, the first electrode layer is a cathode layer, and the second electrode layer is an anode layer; when the device is a bottom-emitting device, the first electrode layer is an anode layer and the second electrode layer is a cathode layer.

In one embodiment, the present invention provides an organic electroluminescent device as shown in fig. 1, which includes: the organic electroluminescent device comprises a substrate 1, an anode 2, a hole injection layer 3, a first hole transport layer 4, a second hole transport layer 5, a light-emitting layer 6, a first electron transport layer 7, a second electron transport layer 8, a cathode 9 and a first cap layer 10.

In one embodiment, the organic electroluminescent device further comprises a second capping layer arranged on the side of the first capping layer far away from the first electrode layer, wherein the second capping layer contains a material containing lithium fluoride and/or organic small molecules with a refractive index of 1.40-1.65 (such as 1.41, 1.42, 1.43, 1.44, 1.45, 1.46, 1.47, 1.48, 1.49, 1.50, 1.51, 1.52, 1.53, 1.54, 1.55, 1.56, 1.57, 1.58, 1.59, 1.60, 1.61, 1.62, 1.63, 1.64 and the like).

In the organic electroluminescent device provided by the invention, two cap layers are preferably contained, and the compound provided by the invention is matched with lithium fluoride and/or organic micromolecule materials with the refractive index of 1.40-1.65, so that the total reflection of the packaging glass to light can be slowed down, the visible light can be favorably transmitted through the glass, and the light extraction effect is improved.

In one embodiment, the present invention provides an organic photoelectric device as shown in fig. 2, including: the organic electroluminescent device comprises a substrate 1, an anode 2, a hole injection layer 3, a first hole transport layer 4, a second hole transport layer 5, a light-emitting layer 6, a first electron transport layer 7, a second electron transport layer 8, a cathode 9, a first cap layer 10 and a second cap layer 11.

In one embodiment, the material of the organic small molecule with the refractive index of 1.40-1.65 comprises any one or at least two of polyfluorocarbon, boron-containing compound, silicon-containing compound, oxygen-containing silicon compound or adamantane-containing alkane compound.

The fifth object of the present invention is to provide a display panel including the organic electroluminescent device of the fourth object.

In one embodiment, the display panel is a foldable display panel.

The compound provided by the invention is used in a foldable display panel, and when the compound is displayed in multiple angles, the extraction delta n of RGB light color light is smaller, so that the color cast can be effectively reduced.

The sixth object of the present invention is to provide a display device including the display panel of the fifth object.

The preparation method of the compound provided by the invention belongs to the prior art, and a person skilled in the art can select a specific synthetic method according to the conventional technical knowledge, and the invention only provides a synthetic route in an exemplary way, but is not limited to the following synthetic route.

The invention provides a representative synthetic route of the compound of formula (1) as follows:

the following examples exemplarily provide a series of methods for synthesizing specific compounds, and compounds that are not mentioned in the specific methods can be synthesized by similar methods, or can be synthesized by other existing methods, which is not specifically limited in the present invention.

Example 1

Synthesis of compound M1:

the preparation method specifically comprises the following steps:

compound 1(0.5mmol), compound 2(0.5mmol), compound 3(1.5mmol), KO (t-Bu) (0.75mmol) and [ Pd (cinnamyl) Cl]₂(0.2mmol) was added to a 3 mL-solution of toluene, mixed, placed in a 50 mL-flask, and reacted at 80 ℃ for 12 hours. Cooled to room temperature, and then saturated MgSO was slowly added to the solution₄Aqueous solution and acetic acidThe ethyl ester was extracted three times, and then the organic layer was subjected to column chromatography by removing the solvent through a rotary evaporator to obtain a crude product M1.

The structure of the target product M1 was tested: MALDI-TOF MS (m/z) is obtained by matrix-assisted laser desorption ionization time-of-flight mass spectrometry: 826.9, test values are: 826.7.

elemental analysis: the theoretical values C:81.34, H:4.14, N: 6.78; actual values are 81.35 for C, 4.15 for H and 6.78 for N.

Example 2

Synthesis of compound M7:

the preparation method specifically comprises the following steps:

compound 3(0.5mmol), compound 4(0.5mmol), compound 5(1.5mmol), KO (t-Bu) (0.75mmol) and [ Pd (cinnamyl) Cl]₂(0.2mmol) was added to a 3 mL-solution of toluene, mixed, placed in a 50 mL-flask, and reacted at 80 ℃ for 12 hours. Cooled to room temperature, and then saturated MgSO was slowly added to the solution₄The aqueous solution and ethyl acetate were extracted three times, and then the organic layer was subjected to column chromatography by removing the solvent through a rotary evaporator to obtain a crude product M7.

The structure of the target product M7 was tested: MALDI-TOF MS (m/z) is obtained by matrix-assisted laser desorption ionization time-of-flight mass spectrometry: calculated value 959.1; the actual value is 959.0.

Elemental analysis: theoretical values of C80.14, H3.99, N5.84; the test values C:80.15, H:3.98 and N: 5.85.

Example 3

Synthesis of compound M11:

the preparation method specifically comprises the following steps:

reacting a mixture of (0.5mmol) of the compound 6, (0.5mmol) of the compound 3, (1.5mmol) of the compound 7, KO (t-Bu) (0.75mmol),[Pd(cinnamyl)Cl]₂(0.2mmol) was added to a 3 mL-solution of toluene, mixed, placed in a 50 mL-flask, and reacted at 80 ℃ for 12 hours. Cooled to room temperature, and then saturated MgSO was slowly added to the solution₄The aqueous solution and ethyl acetate were extracted three times, and then the organic layer was subjected to column chromatography by removing the solvent through a rotary evaporator to obtain a crude product M11.

The structure of the target product M11 was tested: MALDI-TOF MS (m/z) is obtained by matrix-assisted laser desorption ionization time-of-flight mass spectrometry: a theoretical value of 1173.3; the test value was 1173.1.

Elemental analysis: the theoretical values C:81.89, H:4.12, N: 7.16; test values C:81.87, H:4.10, N: 7.15.

Example 4

Synthesis of compound M13:

the preparation method specifically comprises the following steps:

mixing compound 1(0.5mmol), compound 8(0.75mmol), and K₂CO₃(0.5mmol)、PdCl₂(5×10^-4mmol)、Pd(pph₃)₄(5×10^-4mmol) was added to 3mL of toluene, and the mixture was placed in a 50mL flask and reacted at 100 ℃ for 24 hours. Cooled to room temperature, and then saturated MgSO was slowly added to the solution₄The aqueous solution and ethyl acetate were extracted three times, and then the organic layer was subjected to column chromatography by removing the solvent through a rotary evaporator to obtain a crude product M13.

The structure of the target product M13 was tested: MALDI-TOF MS (m/z) is obtained by matrix-assisted laser desorption ionization time-of-flight mass spectrometry: theoretical value is 492.5; the test value was 492.3.

Elemental analysis: theoretical values C:78.04, H:3.27, N: 5.69; the test values C:78.03, H:3.25 and N: 7.13.

Example 5

Synthesis of compound M20:

the preparation method specifically comprises the following steps:

(1) compound 9(0.5mmol), compound 10(4.5mmol), KO (t-Bu) (0.75mmol) and [ Pd (cinnamyl) Cl]₂(0.2mmol) was added to a 3 mL-solution of toluene, mixed, placed in a 50 mL-flask, and reacted at 80 ℃ for 12 hours. Cooled to room temperature, and then saturated MgSO was slowly added to the solution₄The aqueous solution and ethyl acetate were extracted three times, and then the organic layer was subjected to column chromatography by removing the solvent through a rotary evaporator to obtain a crude product 11.

(2) Compound 11(0.5mmol), compound 6(4.5mmol), KO (t-Bu) (0.75mmol) and [ Pd (cinnamyl) Cl]₂(0.2mmol) was added to a 3 mL-solution of toluene, mixed, placed in a 50 mL-flask, and reacted at 80 ℃ for 12 hours. Cooled to room temperature, and then saturated MgSO was slowly added to the solution₄The aqueous solution and ethyl acetate were extracted three times, and then the organic layer was subjected to column chromatography by removing the solvent through a rotary evaporator to obtain a crude product 12.

(3) Mixing compound 12(0.5mmol), compound 8(0.75mmol), and K₂CO₃(0.5mmol)、PdCl₂(5×10^{- 4}mmol)、Pd(pph₃)₄(5×10^-4mmol) was added to 3mL of toluene, mixed, placed in a 50mL flask, and reacted at 100 ℃ for 24 hours. Cooled to room temperature, and then saturated MgSO was slowly added to the solution₄The aqueous solution and ethyl acetate were extracted three times, and then the organic layer was subjected to column chromatography by removing the solvent through a rotary evaporator to obtain a crude product M20.

The structure of the target product M20 was tested: MALDI-TOF MS (m/z) is obtained by matrix-assisted laser desorption ionization time-of-flight mass spectrometry: the calculated value was 807.15 and the test value was 807.13.

Elemental analysis: theoretical value C77.30, H3.62, N5.20; test values C:77.29, H:3.64, N: 5.19.

Example 6

Synthesis of compound M41:

the preparation method specifically comprises the following steps:

compound 13(0.5mmol), compound 3(4.5mmol), KO (t-Bu) (0.75mmol) and [ Pd (cinnamyl) Cl]₂(mmol) was added to a solution of toluene (3 mL) and mixed, and the mixture was placed in a 50mL flask and reacted at 80 ℃ for 12 hours. After cooling to room temperature, the solution was slowly extracted three times with saturated aqueous MgSO4 solution and ethyl acetate, and then the organic layer was subjected to solvent removal by a rotary evaporator and column chromatography to give crude product M41.

The structure of the target product M41 was tested: MALDI-TOF MS (m/z) is obtained by matrix-assisted laser desorption ionization time-of-flight mass spectrometry: the calculated value was 1060.10 and the test value was 1060.00.

Elemental analysis: the theoretical value C is 79.23, H is 3.80, and N is 7.92; the test values C:79.22, H:3.80 and N: 7.91.

Example 7

Synthesis of compound M42:

the preparation method specifically comprises the following steps:

mixing compound 1(0.5mmol), compound 14(0.75mmol), and K₂CO₃(0.5mmol)、PdCl₂(5×10^{- 4}mmol)、Pd(pph₃)₄(5×10^-4mmol) was added to a 3mL toluene solution, mixed, placed in a 50mL flask, and reacted at 100 ℃ for 24 hours. After cooling to room temperature, the solution was slowly extracted three times with saturated aqueous MgSO4 solution and ethyl acetate, and then the organic layer was subjected to solvent removal by a rotary evaporator and column chromatography to give crude product M42.

The structure of the target product M42 was tested: MALDI-TOF MS (m/z) is obtained by matrix-assisted laser desorption ionization time-of-flight mass spectrometry: the calculated value was 492.48 and the test value was 492.46.

Elemental analysis: theoretical values C:78.04, H:3.27, N: 5.69; the test values C:78.03, H:3.25 and N: 5.58.

Example 8

Synthesis of compound M43:

the preparation method specifically comprises the following steps:

mixing compound 15(0.5mmol), compound 16(0.75mmol), and K₂CO₃(0.5mmol)、PdCl₂(5×10^{- 4}mmol)、Pd(pph₃)₄(5×10^-4mmol) was added to a 3mL toluene solution, mixed, placed in a 50mL flask, and reacted at 100 ℃ for 24 hours. After cooling to room temperature, the solution was slowly extracted three times with saturated aqueous MgSO4 solution and ethyl acetate, and then the organic layer was subjected to solvent removal by a rotary evaporator and column chromatography to give crude product M43.

The structure of the target product M43 was tested: MALDI-TOF MS (m/z) is obtained by matrix-assisted laser desorption ionization time-of-flight mass spectrometry: the calculated value was 719.78 and the test value was 719.77.

Elemental analysis: the theoretical values C:83.43, H:4.06, N: 5.84; test values C:83.42, H:4.05, N: 5.83.

Example 9

Synthesis of compound M44:

the preparation method specifically comprises the following steps:

mixing compound 17(0.5mmol), compound 16(0.75mmol), and K₂CO₃(0.5mmol)、PdCl₂(5×10^{- 4}mmol)、Pd(pph₃)₄(5×10^-4mmol) was added to a 3mL toluene solution, mixed, placed in a 50mL flask, and reacted at 100 ℃ for 24 hours. Cooled to room temperature, and then saturated aqueous MgSO4 solution and ethyl acetate are slowly added to the solution to extract trisNext, the organic layer was subjected to solvent removal by a rotary evaporator and column chromatography to give crude product M44.

The structure of the target product M44 was tested: MALDI-TOF MS (m/z) calculated value obtained by matrix-assisted laser desorption ionization time-of-flight mass spectrometry is 810.96, and test value is 810.95.

Elemental analysis: the theoretical values C:84.42, H:4.23, N: 3.45; test values C:84.41, H:4.21, N: 3.44.

Example 10

Synthesis of compound M45:

the preparation method specifically comprises the following steps:

mixing compound 18(0.5mmol), compound 16(0.75mmol), and K₂CO₃(0.5mmol)、PdCl₂(5×10^{- 4}mmol)、Pd(pph₃)₄(5×10^-4mmol) was added to a 3mL toluene solution, mixed, placed in a 50mL flask, and reacted at 100 ℃ for 24 hours. Cooled to room temperature, and then saturated MgSO was slowly added to the solution₄The aqueous solution and ethyl acetate were extracted three times, and then the organic layer was subjected to column chromatography by removing the solvent through a rotary evaporator to obtain a crude product M45.

The structure of the target product M45 was tested: MALDI-TOF MS (m/z) is obtained by matrix-assisted laser desorption ionization time-of-flight mass spectrometry: the calculated value was 810.96 and the test value was 810.95.

Elemental analysis: theoretical values C:86.97, H:4.52, N: 4.83; the test values C:86.96, H:4.51 and N: 4.82.

Performance test-characterization of refractive index of Material

The refractive index of the compound at 460nm, 530nm and 620nm was measured by an ellipsometer, and the difference Δ n between the refractive index at 460nm and the refractive index at 530nm was calculated₁The difference Deltan between the refractive index at 530nm and 620nm₂And refractive index at 460nm wavelength and at 620nm wavelengthRefractive index difference Deltan of₃。

The test results are shown in table 1.

TABLE 1

Wherein the structures of comparative compounds C1 and C2 are as follows:

as can be seen from Table 1, the compound provided by the present invention has a high refractive index in the visible light region, and satisfies the requirements that the difference between the refractive index at a wavelength of 460nm and the refractive index at a wavelength of 530nm is 0.10 to 0.17, the difference between the refractive index at a wavelength of 530nm and the refractive index at a wavelength of 620nm is 0.03 to 0.10, and the difference between the refractive index at a wavelength of 460nm and the refractive index at a wavelength of 620nm is 0.15 to 0.40, and can effectively improve color shift when multi-angle display is realized. However, the compounds C1 and C2 cannot satisfy the above refractive index conditions, and thus multi-angle display cannot be achieved.

For the purpose of understanding the present invention, the following are exemplified as applications of the compounds of the present invention. It should be understood by those skilled in the art that the examples are only for the understanding of the present invention and should not be construed as the specific limitations of the present invention.

Application example 1

The application example provides an organic electroluminescent device, the structure of which is shown in fig. 1, and the specific preparation steps are as follows:

1) cutting a glass substrate with an Indium Tin Oxide (ITO) anode layer 2 (thickness 15nm) into sizes of 50mm x 0.7mm, sonicating in isopropanol and deionized water for 30 minutes, respectively, and then exposing to ozone for about 10 minutes for cleaning, mounting the cleaned substrate 1 on a vacuum deposition apparatus;

2) evaporating a hole injection layer material compound 2 and a p-doped material compound 1 on the ITO anode layer 2 in a vacuum evaporation mode, wherein the doping proportion is 3 percent (mass ratio); a thickness of 5nm as a hole injection layer 3;

3) vacuum evaporating a hole transport layer material compound 2 on the hole injection layer 3, wherein the thickness of the hole transport layer material compound 2 is 100nm and is used as a first hole transport layer 4;

4) vacuum evaporating a hole-transport type material compound 3 on the first hole-transport layer 4, wherein the thickness of the hole-transport type material compound 3 is 5nm and is used as a second hole-transport layer 5;

5) a luminescent layer 6 is vacuum-evaporated on the second hole transport layer 5, wherein the compound 4 is used as a main material, the compound 5 is used as a doping material, the doping proportion is 3% (mass ratio), and the thickness is 30 nm;

6) an electron transport material compound 6 is vacuum-evaporated on the luminescent layer 6, the thickness of the compound is 30nm, and the compound is used as a first electron transport layer 7;

7) an electron transport material compound 7 and an n-doped material compound 8 are vacuum evaporated on the first electron transport layer 7, and the doping mass ratio is 1: 1; a thickness of 5nm as a second electron transport layer 8;

8) a magnesium silver electrode is evaporated on the second electron transport layer 8 in vacuum, wherein the ratio of Mg to Ag is 9:1, the thickness is 10nm, and the magnesium silver electrode is used as a cathode 9;

9) compound M1 of the present invention was vacuum-deposited on cathode 9 to a thickness of 100nm, and used as cap layer 10.

The compound used in the above step has the following structure:

application examples 2 to 10 and comparative application examples 1 to 2 differ from application example 1 only in that the cap layer was prepared by replacing compound M1 in step 9) with compounds M7, M11, M13, M20, M41, M42, M43, M44, M45, C1 and C2, respectively, and the remaining preparation steps were the same, and are specifically described in table 2.

Performance test two-device performance characterization

The following performance tests were performed on the organic electroluminescent devices provided in the above application examples 1 to 10 and comparative application examples 1 to 2:

the current at different voltages according to the organic electroluminescent device was measured using a Keithley 2365A digital nanovoltmeter, and then the current density at different voltages of the organic photoelectric device was obtained by dividing the current by the light emitting area. The luminance and radiant energy flux density of the organic electroluminescent devices manufactured according to the application examples and comparative application proportions were measured at different voltages using a Konicaminolta CS-2000 spectroradiometer. According to the current density and the brightness of the organic electroluminescent device under different voltages, the same current density (10 mA/cm) is obtained²) Operating voltage V below_on(V), current efficiency CE (cd/A), external quantum efficiency EQE_(max)Color shift JNCD (30 ℃/45/60 ℃) and lifetime LT95 (lifetime LT95 (at 50 mA/cm) was obtained by measuring the time when the luminance of the organic electroluminescent device reached 95% of the initial luminance²Test conditions)), the results are shown in table 2.

TABLE 2

As can be seen from table 2, when the compound provided by the present invention is used as a cap layer material of an organic electroluminescent device, the color shift of the device can be effectively reduced, and the current efficiency and external quantum efficiency can be improved, and the compound has a longer lifetime.

Application example 11

The application example provides an organic electroluminescent device, the structure of which is shown in fig. 2, and the specific preparation steps are as follows:

1) cutting a glass substrate with an Indium Tin Oxide (ITO) anode layer 2 (thickness 15nm) into sizes of 50mm x 0.7mm, sonicating in isopropanol and deionized water for 30 minutes, respectively, and then exposing to ozone for about 10 minutes for cleaning, mounting the cleaned substrate 1 on a vacuum deposition apparatus;

2) evaporating a hole injection layer material compound 2 and a p-doped material compound 1 on the ITO anode layer 2 in a vacuum evaporation mode, wherein the doping proportion is 3 percent (mass ratio); a thickness of 5nm as a hole injection layer 3;

3) vacuum evaporating a hole transport layer material compound 2 on the hole injection layer 3, wherein the thickness of the hole transport layer material compound 2 is 100nm and is used as a first hole transport layer 4;

4) vacuum evaporating a hole-transport type material compound 3 on the first hole-transport layer 4, wherein the thickness of the hole-transport type material compound 3 is 5nm and is used as a second hole-transport layer 5;

5) a luminescent layer 6 is vacuum-evaporated on the second hole transport layer 5, wherein the compound 4 is used as a main material, the compound 5 is used as a doping material, the doping proportion is 3% (mass ratio), and the thickness is 30 nm;

6) an electron transport material compound 6 is vacuum-evaporated on the luminescent layer 6, the thickness of the compound is 30nm, and the compound is used as a first electron transport layer 7;

7) an electron transport material compound 7 and an n-doped material compound 8 are evaporated on the first electron transport layer 7 in a vacuum manner together, and the doping mass ratio is 1: 1; a thickness of 5nm as a second electron transport layer 8;

8) a magnesium silver electrode is evaporated on the second electron transport layer 8 in vacuum, wherein the ratio of Mg to Ag is 9:1, the thickness of the Mg to Ag is 10nm, and the Mg to Ag is used as a cathode 9;

9) compound M1 of the present invention was vacuum-deposited on cathode 9 to a thickness of 100nm, and used as first cap layer 10.

10) The organic small molecule D1 with a low refractive index was vacuum-deposited on the first cap layer 10 to a thickness of 20nm, and used as the second cap layer 11.

The low refractive index organic small molecule structure is as follows:

application examples 12 to 21 differ from application example 15 only in that the organic small molecule D1 in step 10) is replaced with D2, D3, D4, D5, D6, D7, D8, D9, D10 and D11 to prepare a second cap layer, and the rest of the manufacturing steps are the same; application examples 22 to 24, comparative applications 3 to 4 and application example 15 differ only in that the first cap layer was prepared by replacing compound M1 in step 9) with M7, M11, M13, C1 and C2, respectively, as specified in table 3.

The organic electroluminescent devices of application examples 11 to 25 and comparative application examples 3 to 4 were subjected to performance tests using the same test methods as described above, and the results are shown in table 3.

TABLE 3

As can be seen from table 3, the compound provided by the present invention is used as a material of the first cap layer to match with the second cap layer material containing the low refractive index organic small molecule, which is more beneficial to improving the device efficiency, especially significantly improving the external quantum efficiency, compared to the compounds C1 and C2 used to match with the second cap layer material containing the low refractive index organic small molecule.

The applicant states that the present invention is illustrated in detail by the above examples, but the present invention is not limited to the above detailed methods, i.e. it is not meant that the present invention must rely on the above detailed methods for its implementation. It should be understood by those skilled in the art that any modification of the present invention, equivalent substitutions of the raw materials of the product of the present invention, addition of auxiliary components, selection of specific modes, etc., are within the scope and disclosure of the present invention.