阅读说明：本技术 一种新型空穴传输材料及其应用 (Novel hole transport material and application thereof ) 是由 孟鸿 王涛 贺耀武 胡钊 刘铭 缪景生 于 2019-09-23 设计创作，主要内容包括：本发明提供了一种新型空穴传输材料及其应用,涉及有机光电材料技术领域。本发明的空穴传输材料通过在不同的芳环母体结构上连接间位二取代芳胺的苯基配体,调节该空穴传输材料的分子量、π共轭程度和分子刚性。其载流子传输能力强,有利于空穴传输,且可以提高玻璃化转变温度,不易于结晶,成膜性优良。与现有技术相比,含有本发明新型空穴传输材料的有机电致发光器件,具有较高的发光效率和较高长的使用寿命。(The invention provides a novel hole transport material and application thereof, and relates to the technical field of organic photoelectric materials. The hole transport material of the invention adjusts the molecular weight, the pi conjugation degree and the molecular rigidity of the hole transport material by connecting the phenyl ligand of the meta-disubstituted arylamine on different aromatic ring parent structures. The carrier transport ability is strong, which is beneficial to hole transport, and can increase the glass transition temperature, and the crystallization is not easy, and the film forming ability is good. Compared with the prior art, the organic electroluminescent device containing the novel hole transport material has higher luminous efficiency and longer service life.)

1. A novel hole transport material is characterized in that the molecular structure general formula is as follows:

wherein Ar is selected from substituted or unsubstituted C6-C60 aryl, substituted or unsubstituted C10-C60 condensed ring group, substituted or unsubstituted C3-C60 spiro ring group and substituted or unsubstituted C3-C60 heterocyclic group;

R₁、R₂independently selected from substituted or unsubstituted C6-C60 aryl, substituted or unsubstituted C10-C60 condensed ring group.

2. The novel hole transport material according to claim 1, wherein Ar is selected from the group consisting of substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C10-C30 fused ring, substituted or unsubstituted C4-C30 spiro ring, substituted or unsubstituted C4-C30 heterocyclic group;

R₁、R₂independently selected from substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C10-C30 condensed ring group.

3. The novel hole transport material according to claim 2, wherein Ar is selected from any one of the following structures:

4. the hole transport material of claim 3, wherein the hole transport material is selected from any one of the following chemical structures:

5. an organic electroluminescent device, characterized in that the organic functional layer of the organic electroluminescent device comprises the novel hole transport material according to any one of claims 1 to 4.

6. The organic electroluminescent device according to claim 5, wherein the organic functional layer comprises a charge transport layer comprising a hole transport layer and an electron transport layer; the hole transport layer comprises the novel hole transport material according to any one of claims 1 to 4.

Technical Field

The invention relates to the technical field of organic photoelectric materials, in particular to a novel hole transport material and application thereof.

Background

Organic Light-Emitting diodes (OLEDs) are a new generation of display and lighting technology, and have the advantages of active Light emission, wide viewing angle, high contrast, fast response, Light weight, low energy consumption, low driving voltage, wide color gamut, simple manufacturing process, capability of realizing flexible display, and the like, and have wide application prospects in the fields of flat panel display, lighting, and the like. In recent years, the system has received worldwide attention, and gradually has more and more applications in smart phones, computers, wearable devices and the like.

The organic light emitting device structure generally includes an anode, a cathode, and an organic functional layer therebetween, wherein the organic functional layer mainly includes a light emitting layer, an electron injection layer and a hole injection layer for charge injection, and an electron transport layer and a hole transport layer for charge transport. At present, the large-scale application of OLEDs is greatly restricted because the performance of the organic functional layers is far from the practical requirements. For example, the efficiency and stability of the light-emitting layer directly affect the lifetime and efficiency of the OLED device, exciton quenching caused by a large difference in the transmission speed between the electron transport layer and the hole transport layer may also cause non-uniform light color of the device and reduce the efficiency of the device, and the interface condition between the functional layers is difficult to control, which limits mass production. With the gradual improvement of the requirements of the market on the OLED device, the development of a novel hole transport material is an important means for improving and optimizing the performance of the organic electroluminescent device, and has important significance for the popularization and application of the OLED device.

The currently widely used hole transport material alpha-NPB has a great improvement space in photoelectric properties, and has the main disadvantage that the Tg (glass transition temperature) is only 98 ℃, and crystallization is easy to occur in the preparation and use processes, so that the hole transport efficiency is influenced, and the service life of a device is shortened. Meanwhile, since the electron transport efficiency of the electron transport material is generally higher than that of the hole transport material, the photoelectric efficiency of the device can be significantly improved when the hole transport efficiency of the hole transport material is improved. Therefore, the development of a novel hole transport material with high glass transition temperature and high hole mobility has great significance for improving the photoelectric property and stability of the OLED device.

Disclosure of Invention

One of the technical problems to be solved by the present invention is: provides a novel hole transport material, which solves the problems of low glass transition temperature and insufficient hole transport efficiency of the existing hole transport material.

The second technical problem to be solved by the present invention is: the organic electroluminescent device using the novel hole transport material is provided, and the problems of insufficient luminous efficiency and short service life of the conventional organic electroluminescent device are solved.

The invention provides a novel hole transport material and an organic electroluminescent device based on an organic-inorganic composite hole transport material, and relates to the technical field of organic photoelectric materials. The invention adjusts the molecular weight, the pi conjugation degree and the molecular rigidity of the hole transport material by connecting the phenyl ligand of the meta-position disubstituted arylamine on different aromatic ring parent structures. The carrier transport ability is strong, which is beneficial to hole transport, and can increase the glass transition temperature, and the crystallization is not easy, and the film forming ability is good. Compared with the prior art, the organic electroluminescent device based on the novel hole transport material has higher luminous efficiency and longer service life.

The invention provides a novel hole transport material, the molecular structural general formula of which is shown as chemical formula I:

wherein Ar is selected from substituted or unsubstituted C6-C60 aryl, substituted or unsubstituted C10-C60 condensed ring group, substituted or unsubstituted C3-C60 spiro ring group and substituted or unsubstituted C3-C60 heterocyclic group. R1 and R2 are independently selected from substituted or unsubstituted C6-C60 aryl and substituted or unsubstituted C10-C60 condensed ring group.

Preferably, Ar is selected from substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C10-C30 condensed ring group, substituted or unsubstituted C4-C30 spiro ring group, and substituted or unsubstituted C4-C30 heterocyclic group. R1 and R2 are independently selected from substituted or unsubstituted C6-C30 aryl and substituted or unsubstituted C10-C30 condensed ring group.

Preferably, Ar is selected from any one of the following structures:

preferably, the hole transport material provided by the present invention is selected from any one of the following chemical structures:

the organic electroluminescent device comprises a plurality of organic functional layers such as a cathode, an anode, a charge transport layer, a charge blocking layer and a light emitting layer, wherein the organic functional layers at least contain the novel hole transport material.

Preferably, the organic electroluminescent material is used as a hole transport layer material in an electroluminescent device. For example, the organic functional layer includes a charge transport layer including a hole transport layer and an electron transport layer; the organic functional layer at least contains the novel hole transport material.

The implementation of the invention has the following beneficial effects:

the invention provides a novel hole transport material and an organic electroluminescent device based on the novel hole transport material, and relates to the technical field of organic photoelectric materials. The invention adjusts the molecular weight, the pi conjugation degree and the molecular rigidity of the hole transport material by connecting the phenyl ligand of the meta-position disubstituted arylamine on different aromatic ring parent structures. The carrier transport ability is strong, which is beneficial to hole transport, and can increase the glass transition temperature, and the crystallization is not easy, and the film forming ability is good. Compared with the prior art, the organic electroluminescent device containing the novel hole transport material has higher luminous efficiency and longer service life.

Detailed Description

The technical solution of the present invention is described in detail with reference to the following specific examples, but the description of the examples is only a part of the examples of the present invention, and most of them are not limited thereto.

The novel hole transport material can be prepared by the following reaction:

the novel hole transport material of formula (I) of the present invention can be prepared by Buchwald-Hartwig coupling and Suzuki coupling using conventional reaction conditions well known to those skilled in the art. The raw materials used in the above reactions are not particularly limited, and the present invention can be prepared by commercially available products or synthetic methods commonly used by researchers in the field.

The organic electroluminescent device provided by the invention can be applied to the fields of intelligent equipment display, indoor and outdoor illumination, photoelectric coupling devices, wearable equipment and the like.

Example 1: preparation of Compound 1

Step 1, 3-dibromo-5-chlorobenzene (19.85g, 73.4mmol), N-phenyl-1-naphthylamine (32.19g, 146.8mmol), sodium tert-butoxide (21.14g, 220.2mmol) were charged in a three-necked flask, toluene was added and nitrogen was purged for 20 min. The catalyst dichloro, di-tert-butyl- (4-dimethylaminophenyl) palladium (II) phosphate (0.52g, 0.734mmol) was then added to the three-necked flask and nitrogen was passed on for 20min and the reaction was carried out at reflux temperature for 24 h. After the reaction was completed, the organic phase was filtered, concentrated and the crude product was passed through a silica gel column to obtain compound 1-1(28.88g, yield 72%).

Step 2, taking the compound 1-1(27.35g, 50mmol), pinacol diboron (15.25g, 60mmol) and potassium acetate (4.91g, 150mmol), adding into a three-neck flask, adding dried 1, 4-dioxane, dissolving and introducing nitrogen for 20 min. Tris (dibenzylideneacetone) dipalladium (2.29g, 2.5mmol) and 2-dicyclohexylphosphonium-2 ', 4', 6 ' -triisopropylbiphenyl (2.39g, 5mmol) were added to a three-necked flask, nitrogen was continuously introduced for 20min, the temperature was raised to 120 ℃ and the reaction was carried out for 12 hours. After the reaction is finished, the mixture is washed three times by deionized water, filtered and dried. The crude product was passed through a silica gel column to obtain Compound 1-2(27.1g, yield 85%)

Step 3, compound 1-2(25.51g, 40mmol), 1, 4-dibromobenzene (4.718g, 20mmol) and tetratriphenylphosphine palladium (2.31g, 2mmol) were taken and added to a three-necked flask, 80mL of toluene was added and dissolved and nitrogen was introduced for 20 min. Another potassium carbonate (16.59g, 120mmol) was dissolved in 20mL deionized water, added to the three-necked flask and nitrogen continued for 20 min. The reaction was carried out at reflux temperature for 12 h. And after the reaction is finished, adding deionized water for washing, separating to obtain an organic phase, drying and concentrating. The crude product was passed through a silica gel column to give compound 1(19.13g, 87% yield) mass spectrum m/z: theoretical value: 1098.47, respectively; measured value: 1098.49. theoretical element content (%) C₈₂H₅₈N₄: c, 89.59; h, 5.32; n, 5.10; measured elemental content (%): c, 89.57; h, 5.35; and N, 5.08. The above results demonstrate that the product obtained is the target compound.

Example 2: preparation of Compound 2

The 1, 4-dibromobenzene in example 1 is replaced by 2, 4-dibromobiphenyl. The other steps are the same as in example 1. Mass spectrum m/z: theoretical value: 1174.50, respectively; measured value: 1175.50. theoretical element content (%) C₈₈H₆₂N₄: c, 89.92; h, 5.32; n, 4.77; measured elemental content (%): c, 89.93; h, 5.36; and N, 4.75. The above results demonstrate that the product obtained is the target compound.

Example 3: preparation of Compound 3

The 1, 4-dibromobenzene in example 1 was replaced by 1, 4-dibromo-2, 5-diphenylbenzene. The other steps are the same as in example 1. Mass spectrum m/z: theoretical value: 1250.53, respectively; measured value: 1250.53. theoretical element content (%) C₉₄H₆₂N₄: c, 90.21; h, 5.32; n, 4.48; measured elemental content (%): c, 90.24; h5.33; and N, 4.47. The above results demonstrate that the product obtained is the target compound.

Example 4: preparation of Compound 63

The 1, 4-dibromobenzene in example 1 was replaced with 2, 7-dibromo-9, 9-dimethylfluorene. The other steps are the same as in example 1. Mass spectrum m/z: theoretical value: 1214.53, respectively; measured value: 1215.53. theoretical element content (%) C₉₁H₆₆N₄: c, 89.92; h, 5.47; n, 4.61; measured elemental content (%): c, 89.93; h, 5.49; and N, 4.59. The above results demonstrate that the product obtained is the target compound.

Example 5: preparation of Compound 64

The 1, 4-dibromobenzene in example 1 was replaced with 2, 7-dibromo-9, 9' -spirobifluorene. The other steps are the same as in example 1. Mass spectrum m/z: theoretical value: 1214.53, respectively; measured value: 1215.53. theoretical element content (%) C₉₁H₆₆N₄: c, 89.92; h, 5.47; n, 4.61; measured elemental content (%): c, 89.93; h, 5.49; and N, 4.59. The above results demonstrate that the product obtained is the target compound.

Example 6: preparation of Compound 65

The 1, 4-dibromobenzene in example 1 was replaced with 2,2 '-dibromo-9, 9' -spirobifluorene. The other steps are the same as in example 1. Mass spectrum m/z: theoretical value: 1214.53, respectively; measured value: 1215.53. theoretical element content (%) C₉₁H₆₆N₄: c, 89.92; h, 5.47; n, 4.61; measured elemental content (%): c, 89.94; h, 5.45; and N, 4.59. The above results demonstrate that the product obtained is the target compound.

Example 7: preparation of Compound 69

The 1, 4-dibromobenzene in example 1 was replaced with 2, 7-dibromospiro [ fluorene-9, 9' -xanthene]. The other steps are the same as in example 1. Mass spectrum m/z: theoretical value: 1353.54, respectively; measured value: 1352.54. theoretical element content (%) C₁₀₁H₆₈N₄O: c, 89.62; h, 5.06; n, 4.14; o, 1.18. Measured elemental content (%): c, 89.63; h, 5.08; n, 4.16; o, 1.19. The above results demonstrate that the product obtained is the target compound.

Example 8: preparation of Compound 70

The 1, 4-dibromobenzene in example 1 was replaced with 2',7' -dibromospiro [ fluorene-9, 9' -xanthene]. The other steps are the same as in example 1. Mass spectrum m/z: theoretical value: 1353.54, respectively; measured value: 1352.54. theoretical element content (%) C₁₀₁H₆₈N₄O: c, 89.62; h, 5.06; n, 4.14; o, 1.18. Measured elemental content (%): c, 89.63; h, 5.08; n, 4.16; o, 1.19. The above results demonstrate that the product obtained is the target compound.

Example 9: preparation of Compound 78

The 1, 4-dibromobenzene in example 1 was replaced with 2, 7-dibromodibenzofuran. The other steps are the same as in example 1. Mass spectrum m/z: theoretical value: 1188.48, respectively; measured value: 1189.48. theoretical element content (%) C₈₈H₆₀N₄O: c, 88.86; h, 5.08; n, 4.71; o, 1.35. Measured elemental content (%): c, 88.89; h, 5.07; n, 4.71; o, 1.34. The above results demonstrate that the product obtained is the target compound.

Example 10: preparation of Compound 79

The 1, 4-dibromobenzene in example 1 is replaced by 2, 7-dibromodibenzothiophene. The other steps are the same as in example 1. Mass spectrum m/z: theoretical value: 1188.48, respectively; measured value: 1189.48. theoretical element content (%) C₈₈H₆₀N₄O: c, 88.86; h, 5.08; n, 4.71; o, 1.35. Measured elemental content (%): c, 88.88; h, 5.06; n, 4.72; o, 1.35. The above results demonstrate that the product obtained is the target compound.

Example 11: preparation of Compound 86

The 1, 4-dibromobenzene in example 1 is replaced by 4,4' -dibromodiphenyl ether. The other steps are the same as in example 1. Mass spectrum m/z: theoretical value: 1190.49, respectively; measured value: 1191.50. theoretical element content (%) C₈₈H₆₂N₄O: c, 88.71; h, 5.25; n, 4.70; o, 1.34. Measured elemental content (%): c, 88.72; h, 5.26; n, 4.69; o, 1.34. The above results demonstrate that the product obtained is the target compound.

Example 12: preparation of Compound 92

Will be as in example 1The 1, 4-dibromobenzene is replaced by 4,4' -dibromo diphenyl sulfide. The other steps are the same as in example 1. Mass spectrum m/z: theoretical value: 1206.47, respectively; measured value: 1207.47. theoretical element content (%) C₈₈H₆₀N₄S: c, 87.53; h, 5.18; n, 4.64; s, 2.66. Measured elemental content (%): c, 87.54; h, 5.19; n, 4.65; s, 2.67. The above results demonstrate that the product obtained is the target compound.

The examples of the present invention and all of the above examples are limited in the number of related compounds, and other similar compounds, including but not limited to the examples, can be prepared by chemical reactions as described in the detailed description. In the first step, primary amine containing substituent groups R1 and R2 which are not listed in the examples is used, and dibromo substituent containing aromatic nucleus Ar which is not listed in the examples in the third step, wherein although the substituent groups R1, R2 and Ar are different, the substituent groups are all conjugated structures formed by connecting or fusing aromatic ring structures, and the conjugated structures do not influence the specific functional group reaction adopted in the embodiment of the invention, so that the similar effects to the listed examples can be achieved, the same type of chemical reaction can be achieved, and the prepared substance has similar functions and advantages of high glass transition temperature, high stability, strong carrier transport capability and the like.

Comparative example 1

And ultrasonically cleaning the ITO glass substrate for 30min by using deionized water, isopropanol and acetone respectively in sequence, repeatedly cleaning for multiple times, blow-drying by using nitrogen, transferring to a plasma cleaning machine for cleaning for 5min, drying and vacuumizing. Firstly, a layer of 5nm HATCN is evaporated on an ITO glass substrate to be used as a hole injection layer, and the evaporation rate is 0.1 nm/s. Then, evaporating an organic hole transport material alpha-NPB with the thickness of 30nm and the evaporation rate of 0.1nm/s, and then respectively evaporating a light-emitting layer main body GH 1: doped Ir (dppy)₃10% mixing/30 nm, evaporation rate 0.1 nm/s. And then respectively evaporating 30nm TPBi on the luminescent layer as an electron transport layer, and evaporating the 30nm TPBi and the 2.0nm LiF as electron injection layers at the evaporation rate of 0.1 nm/s. And finally, vacuum evaporating 200nm of metal cathode Al on the electron injection layer at the evaporation rate of 0.2 nm/s.

Application example 1

The organic hole transport material α -NPB in the comparative application example was replaced with compound 1 of example 1.

Application example 2

The organic hole transport material α -NPB in the comparative application example was replaced with compound 2 of example 2.

Application example 3

The organic hole transport material α -NPB in the comparative application example was replaced with compound 3 of example 3.

Application example 4

The organic hole transport material α -NPB in the comparative application example was replaced with compound 63 of example 4.

Application example 5

The organic hole transport material α -NPB in the comparative application example was replaced with compound 79 of example 8.

Application example 6

The organic hole transport material α -NPB in the comparative application example was replaced with compound 92 of example 11.

The glass transition temperatures of the hole transport materials used in application examples 1 to 6 of the present invention, and the light emitting device prepared in application examples 1 to 6 and comparative example 1 thereof had the following test results of light emitting characteristics as shown in table 1 below.

TABLE 1 results of the experiment

The above results show that the novel hole transport material of the present invention is expected to have a very high glass transition temperature for commonly used α -NPB, to be less likely to crystallize, and to have excellent film-forming properties. The organic electroluminescent material is applied to an organic electroluminescent device to prepare a hole transport layer, the device shows lower driving voltage and higher current efficiency, and the organic electroluminescent material is an excellent OLED hole transport material.

The foregoing examples further illustrate the present invention but are not to be construed as limiting thereof. Modifications and substitutions to methods, procedures, or conditions of the invention may be made without departing from the spirit and substance of the invention. Unless otherwise specified, the technical means used in the examples are conventional means well known to those skilled in the art.