CN112300177A

CN112300177A - Organic electroluminescent compound and organic electroluminescent device

Info

Publication number: CN112300177A
Application number: CN202011514121.XA
Authority: CN
Inventors: 钱超; 许军
Original assignee: Nanjing Topto Materials Co Ltd
Current assignee: Nanjing Topto Materials Co Ltd
Priority date: 2020-12-21
Filing date: 2020-12-21
Publication date: 2021-02-02

Abstract

The invention provides an organic electroluminescent compound and an organic electroluminescent device, which have a structural formula shown as a formula 1:

wherein each Z1-4 is independently CR 1; r1 is selected from hydrogen, phenyl, deuterated phenyl or a group shown in formula 2; at least one R1 in Z1-4 is a group represented by formula 2;

p1-8 is each independently CR 2; r2 is selected from the group consisting of hydrogen, substituted or unsubstituted phenyl, substituted phenyl is wherein at least one hydrogenA group obtained by substitution with deuterium, a C1-C4 alkyl group, phenyl, biphenyl, deuterated phenyl; y1-3 is each independently CH or N; the compound is applied to an organic electroluminescent device and used as a main material of a luminescent layer, so that the luminous efficiency of the organic electroluminescent device can be improved to a certain extent, the starting voltage is reduced, the power consumption is relatively reduced, and the service life is prolonged.

Description

Organic electroluminescent compound and organic electroluminescent device

Technical Field

The invention relates to the technical field of organic electroluminescence, in particular to an organic electroluminescent compound and an organic electroluminescent device.

Background

The main features of OLEDs, as a device for generating electroluminescence using a multilayer organic thin film structure, which is easy to fabricate and requires only low driving voltages, make OLEDs very prominent for applications satisfying flat panel displays. Compared with an LCD, the OLED display screen is thinner and lighter, has high brightness, low power consumption, quick response, high definition, good flexibility and high luminous efficiency, and can meet the new requirements of consumers on display technology. More and more display manufacturers worldwide are invested in research and development, and the industrialization process of the OLED is greatly promoted.

The OLED device comprises a substrate, a cathode, an anode, a Hole Injection Layer (HIL), an Electron Injection Layer (EIL), a Hole Transport Layer (HTL), an Electron Transport Layer (ETL), an Electron Blocking Layer (EBL), a Hole Blocking Layer (HBL), an emitting layer (EML) and the like, when voltage is applied to electrodes at two ends of the OLED device, positive and negative charges are generated in an organic layer functional material film layer through the action of an electric field, and the positive and negative charges are further compounded in the emitting layer to generate light.

Currently, research into improving the performance of OLED devices includes: the driving voltage of the device is reduced, the luminous efficiency of the device is improved, the service life of the device is prolonged, and the like. In order to realize the continuous improvement of the performance of the organic electroluminescent device, not only the innovation of the structure and the manufacturing process of the organic electroluminescent device is required, but also the continuous research and innovation of the organic electro-photoelectric functional material are required, and the organic electroluminescent functional material with higher performance is created.

In terms of the actual demand of the current organic electroluminescent industry, the development of the current organic electroluminescent materials is far from enough and lags behind the requirements of panel manufacturing enterprises.

Disclosure of Invention

The purpose of the invention is as follows: in view of the above technical problems, the present invention provides an organic electroluminescent compound and an organic electroluminescent device.

In order to achieve the purpose of the invention, the technical scheme adopted by the invention is as follows:

an organic electroluminescent compound having a structural formula as shown in formula 1 below:

wherein Ar is phenyl or deuterated phenyl;

z1, Z2, Z3, Z4 are each independently CR 1;

r1 is selected from hydrogen, phenyl, deuterated phenyl or a group shown in formula 2;

at least one R1 of Z1, Z2, Z3 and Z4 is a group represented by formula 2;

p1, P2, P3, P4, P5, P6, P7, P8 are each independently CR 2;

r2 is selected from hydrogen, substituted or unsubstituted phenyl;

said substituted or unsubstituted phenyl group being an unsubstituted phenyl group or a group obtained by substituting at least one hydrogen with deuterium, a C1-C4 alkyl group, a phenyl group, a biphenyl group, a deuterated phenyl group;

y1, Y2 and Y3 are respectively and independently CH or N, and at least two of Y1, Y2 and Y3 are N;

x is O or S.

Further, at least two of Z1, Z2, Z3, Z4 are CH.

Further, Z2 and Z3 are CH, Z1 is CR1, and R1 is a group shown in formula 2.

Further, at least three of P1, P2, P3, P4 are CH; at least three of P5, P6, P7 and P8 are CH, one or two of P1, P2, P3, P4, P5, P6, P7 and P8 are CR2, and R2 is the substituted or unsubstituted phenyl.

Further, the structural formula of the organic electroluminescent compound is shown as formula 3 or formula 4 below:

、

。

further, the organic electroluminescent compounds are specifically the following compounds:

an organic electroluminescent device comprises a first electrode, a second electrode and an organic layer formed between the first electrode and the second electrode, wherein the organic layer contains the organic electroluminescent compound.

Further, the organic layer comprises a hole injection layer, a hole transport layer, an electron blocking layer, a light emitting layer, a hole blocking layer, an electron transport layer and an electron injection layer; at least one of the hole injection layer, the hole transport layer, the electron blocking layer, the light emitting layer, the hole blocking layer, the electron transport layer and the electron injection layer contains the organic electroluminescent compound.

Further, the light-emitting layer contains the organic electroluminescent compound.

Furthermore, the organic electroluminescent compound is used as a host material in a light-emitting layer, and the light-emitting layer also contains a doping material which is any one or combination of compounds G1-G28:

the room temperature of the invention is 25 +/-5 ℃.

The invention has the beneficial effects that:

the invention designs an organic electroluminescent compound, because a large conjugated rigid group, namely indole (3,2,1-JK) carbazolyl is introduced into a compound structure, the group has good thermal stability, chemical stability and film forming property, the active No. 1 position of dibenzofuran is protected by using the group, the stability and the film forming property of the whole material molecule are improved, and the group is applied to an organic electroluminescent device and used as a main material of a luminous layer, so that the luminous efficiency of the organic electroluminescent device can be improved to a certain extent, the starting voltage is reduced, and the power consumption is relatively reduced.

Drawings

Fig. 1 is a schematic structural diagram of an organic electroluminescent device provided by the present invention;

the reference numbers in the figures represent respectively:

1-anode, 2-hole injection layer, 3-hole transport layer, 4-electron blocking layer, 5-luminescent layer, 6-hole blocking layer, 7-electron transport layer, 8-electron injection layer and 9-cathode.

FIG. 2 is a DSC chart of Compound 1 prepared in example 1 of the present invention, and from FIG. 2, the Tm of Compound 1 is 405.33 ℃.

Fig. 3 is a TGA spectrum of compound 1 prepared in example 1 of the present invention, and it can be seen from fig. 3 that the thermal weight loss temperature Td of compound 1 is 512.63 ℃.

FIG. 4 is a life chart of organic electroluminescent devices prepared in application example 1 and comparative example 1 of the present invention;

as can be seen from fig. 4, T97% lifetimes of the organic electroluminescent devices prepared in application example 1 and comparative example 1 of the present invention were 520h and 424h, respectively.

Detailed Description

Embodiments of the various aspects are further illustrated and described below. It should be understood that the description herein is not intended to limit the claims to the particular aspects described. On the contrary, it is intended to cover alternatives, modifications, and equivalents as may be included within the spirit and scope of the disclosure as defined by the appended claims.

As used herein, a "Ca to Cb" hydrocarbyl group is defined as a hydrocarbyl group having a carbon number of "a" (inclusive) to "b" (inclusive). As used herein, "a and/or b" means "a" or "b" or "a and b".

As used herein, in "substituted" or "unsubstituted," the term "substituted" means that at least one hydrogen in the group is re-coordinated to deuterium, a hydrocarbon group, a hydrocarbon derivative group, a halogen, or a cyano (-CN). The term "unsubstituted" means that at least one hydrogen in the group does not re-coordinate with deuterium, a hydrocarbon group, a hydrocarbon derivative group, a halogen, or a cyano (-CN) group. Examples of the hydrocarbon group or hydrocarbon derivative group may include C1 to C30 alkyl groups, C2 to C30 alkenyl groups, C2 to C30 alkynyl groups, C6 to C30 aryl groups, C5 to C30 heteroaryl groups, C1 to C30 alkylamino groups, C6 to C30 arylamino groups, C6 to C30 heteroarylamino groups, C6 to C30 arylheteroarylamino groups, and the like, but are not limited thereto.

The alkyl of C1-C4 in the invention refers to methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl and tert-butyl; deuterated alkyl of C1-C4 is a group obtained by replacing any number of hydrogens in methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, and tert-butyl with deuterium.

The examples, in which specific conditions are not specified, were conducted under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products available commercially.

Example 1:

the synthesis of compound 1 is as follows:

s1: under the protection of nitrogen, compound 1-a (100 g, 314.96g/mol, 317.5 mmol), compound 1-b (1.1 eq, 58.4g, 167.21g/mol, 349.25 mmol), sodium tert-butoxide (1.1 eq, 33.56g, 96.1g/mol, 349.25 mmol), tris (dibenzylideneacetone) dipalladium (0.05 eq, 14.53g, 915g/mol, 15.88 mmol), tri-tert-butylphosphine (0.05 eq, 3.21g, 202.32g/mol, 15.88 mmol), toluene (2000 ml) were added to a reaction flask, after the addition, the temperature is raised to reflux reaction for 5h, after the reaction is finished, the temperature is reduced to room temperature, water (2000 ml) is added, stirring is carried out for 15min, then filtration is carried out, filtrate is filtered through diatomite, liquid separation is carried out, an organic phase is obtained, the organic phase is dried through anhydrous magnesium sulfate and then is dried in a spinning mode, and after column chromatography purification, the compound 1-c (89.94 g, the yield is 70.6 percent), ESI-MS (M/z) (M +): theoretical 401.26, found 402.33, elemental analysis result (molecular formula C21H13BrN 4): theoretical C, 62.86, H, 3.27, Br, 19.91, N, 13.96; found C, 62.86, H, 3.27, Br, 19.90, N, 13.96.

S2: under the protection of nitrogen, adding compound 1-c (80 g, 401.26g/mol, 199.37 mmol), compound 1-d (1.1 eq, 98.97g, 451.28g/mol, 219.31 mmol) and sodium carbonate (2 eq, 42.26g, 105.99g/mol, 398.74 mmol) into toluene (1600 ml), ethanol (400 ml) and water (400 ml), stirring and mixing uniformly, adding tetrakistriphenylphosphine palladium (0.05 eq, 11.52g, 1155.58g/mol, 9.97 mmol), heating to reflux reaction for 10h, cooling to room temperature, adding water (1200 ml), stirring to separate out an aqueous phase, extracting the aqueous phase with dichloromethane, combining organic phases, drying the organic phase with anhydrous sodium sulfate, carrying out silica gel column chromatography, purifying to obtain compound 1 (9.44 g, yield 79.8%), ESI-MS (M/z) (M +): theoretical 727.81, found 727.93, elemental analysis result (molecular formula C51H29N 5O): theoretical value C, 84.16, H, 4.02, N, 9.62, O, 2.20; found C, 84.16, H, 4.02, N, 9.62, O, 2.20.

Example 2:

the synthesis method of the compound 3 is as follows:

the preparation was substantially the same as in example 1, except that the compound 1-b was replaced with the compound 2-b, the yield was 77.3%, ESI-MS (M/z) (M +): theoretical 803.90, found 803.98, elemental analysis result (molecular formula C57H33N 5O): theoretical C, 85.16, H, 4.14, N, 8.71, O, 1.99; found C, 85.16, H, 4.14, N, 8.71, O, 1.99.

Example 3:

the synthesis of compound 5 is as follows:

the preparation was substantially the same as in example 1, except that the compound 1-b was replaced with the compound 3-b, the yield was 76.6%, ESI-MS (M/z) (M +): theoretical 803.90, found 803.85, elemental analysis result (molecular formula C57H33N 5O): theoretical C, 85.16, H, 4.14, N, 8.71, O, 1.99; found C, 85.16, H, 4.14, N, 8.70, O, 1.99.

Example 4:

the synthesis of compound 9 is as follows:

the preparation was essentially the same as in example 1, except that the compound 1-d was replaced with the compound 4-d in 80.1% yield, ESI-MS (M/z) (M +): theoretical 803.90, found 803.50, elemental analysis result (molecular formula C57H33N 5O): theoretical C, 85.16, H, 4.14, N, 8.71, O, 1.99; found C, 85.16, H, 4.14, N, 8.71, O, 1.99.

Example 5:

the synthesis of compound 13 is as follows:

the preparation was essentially the same as in example 4, except that compound 4-b was replaced with compound 5-b in 78.2% yield, ESI-MS (M/z) (M +): theoretical 880.00, found 881.13, elemental analysis result (molecular formula C63H37N 5O): theoretical C, 85.99, H, 4.24, N, 7.96, O, 1.82; found C, 85.99, H, 4.24, N, 7.96, O, 1.82.

Example 6:

the synthesis of compound 17 is as follows:

the preparation was substantially the same as in example 1, except that the compound 1-a was replaced with the compound 6-a in a yield of 80.8%, ESI-MS (M/z) (M +): theoretical 732.84, found 733.07, elemental analysis result (molecular formula C51H24D5N 5O): theoretical C, 83.59, H, 4.68, N, 9.56, O, 2.18; found C, 83.59, H, 4.68, N, 9.56, O, 2.18.

Example 7:

the synthesis of compound 21 was as follows:

the preparation was substantially the same as in example 1, except that the compound 1-b was replaced with the compound 7-b, the yield was 77.5%, ESI-MS (M/z) (M +): theoretical 808.94, found 809.23, elemental analysis result (molecular formula C57H28D5N 5O): theoretical C, 84.63, H, 4.73, N, 8.66, O, 1.98; found C, 84.63, H, 4.73, N, 8.66, O, 1.98.

Example 8:

the synthesis of compound 25 is as follows:

the preparation was essentially the same as in example 1, except that the compound 1-d was replaced with the compound 8-d in a yield of 78.9%, ESI-MS (M/z) (M +): theoretical 808.94, found 809.17, elemental analysis result (molecular formula C57H28D5N 5O): theoretical C, 84.63, H, 4.73, N, 8.66, O, 1.98; found C, 84.63, H, 4.72, N, 8.66, O, 1.98.

Example 9:

the synthesis of compound 30 is as follows:

the preparation was substantially the same as in example 8, except that the compound 8-b was replaced with the compound 9-b, the yield was 76.1%, ESI-MS (M/z) (M +): theoretical 885.03, found 885.22, elemental analysis result (molecular formula C63H32D5N 5O): theoretical C, 85.50, H, 4.78, N, 7.91, O, 1.81; found C, 85.50, H, 4.78, N, 7.91, O, 1.81.

Example 10:

the synthesis of compound 39 is as follows:

the preparation was substantially the same as in example 7, except that the compound 7-d was replaced with the compound 10-d, the yield was 76.0%, ESI-MS (M/z) (M +): theoretical 885.03, found 885.17, elemental analysis result (molecular formula C63H32D5N 5O): theoretical C, 85.50, H, 4.78, N, 7.91, O, 1.81; found C, 85.50, H, 4.78, N, 7.91, O, 1.80.

Example 11:

the synthesis of compound 41 is as follows:

the preparation was substantially the same as in example 1, except that the compound 1-d was replaced with the compound 11-d in a yield of 79.3%, ESI-MS (M/z) (M +): theoretical 743.87, found 743.88, elemental analysis result (molecular formula C51H29N 5S): theoretical value C, 82.35, H, 3.93, N, 9.41, S, 4.31; found C, 82.35, H, 3.93, N, 9.41, S, 4.30.

Example 12:

the synthesis of compound 56 is as follows:

the preparation was carried out in substantially the same manner as in example 1 except that the compounds 1-b and 1-d were replaced with the compounds 12-b and 12-d in a yield of 70.8%, ESI-MS (M/z) (M +): theoretical 972.16, found 973.30, elemental analysis result (molecular formula C69H41N 5S): theoretical value C, 85.25, H, 4.25, N, 7.20, S, 3.30; found C, 85.25, H, 4.25, N, 7.20, S, 3.30.

Example 13:

the synthesis of compound 68 is as follows:

the preparation was carried out in substantially the same manner as in example 1 except that the compounds 1-b and 1-d were replaced with the compounds 13-b and 13-d in a yield of 76.9%, ESI-MS (M/z) (M +): theoretical 901.10, found 901.22, elemental analysis result (molecular formula C63H32D5N 5S): theoretical C, 83.97, H, 4.70, N, 7.77, S, 3.56; found C, 83.97, H, 4.70, N, 7.77, S, 3.56.

Example 14:

the synthesis of compound 84 was as follows:

the preparation was carried out in substantially the same manner as in example 1 except that the compounds 1-b and 1-d were replaced with the compounds 14-b and 14-d in a yield of 76.5%, ESI-MS (M/z) (M +): theoretical 961.13, found 961.46, elemental analysis result (molecular formula C69H36D5N 5O): theoretical C, 86.23, H, 4.82, N, 7.29, O, 1.66; found C, 86.23, H, 4.82, N, 7.29, O, 1.66.

Example 15:

the synthesis of compound 97 was as follows:

the preparation was essentially the same as in example 1, except that compound 1-b was replaced with compound 15-b in 78.2% yield, ESI-MS (M/z) (M +): theoretical 860.01, found 861.36, elemental analysis result (molecular formula C61H41N 5O): theoretical C, 85.19, H, 4.81, N, 8.14, O, 1.86; found C, 85.19, H, 4.80, N, 8.14, O, 1.86.

Testing the performance of the device:

compounds

1, 3, 5, 9, 13, 17, 21, 25, 30, 39, 41, 56, 68, 84, 97 of examples 1-15 of the present invention were tested for their temperature Td and melting point Tm, and the results are shown in table 1:

note: the thermogravimetric temperature Td, which is the temperature at which the weight loss is 5% in a nitrogen atmosphere, was measured on a TGA N-1000 thermogravimetric analyzer at a nitrogen flow rate of 10mL/min, a melting point Tm was determined by differential scanning calorimetry (DSC, New Zedoku DSC N-650), and a temperature rise rate of 10 ℃/min.

TABLE 1

As can be seen from table 1 above, the compound of the present invention has higher Td value and Tm value, which indicates that it has excellent thermal stability, and when it is applied to an organic electroluminescent device, the compound can effectively prolong the service life of the organic electroluminescent device, and can obtain better use effect.

Testing the performance of the device:

application example 1, ITO is adopted as the material of the reflecting layer anode substrate, and water, acetone and N are sequentially used₂Carrying out surface treatment on the glass substrate by plasma;

depositing 10nm HT-1 doped with 5% HAT-CN on the ITO anode substrate to form a Hole Injection Layer (HIL);

evaporating HT-1 with the thickness of 100nm above the Hole Injection Layer (HIL) to form a Hole Transport Layer (HTL);

evaporating EB-1 above the Hole Transport Layer (HTL) in vacuum to form an Electron Blocking Layer (EBL) with the thickness of 10 nm;

the compound 1 prepared in the invention example 1 and G1 are used as luminescent main materials to be co-evaporated according to the proportion of 5:5, GD-1 is used as a doping material (GD-1 is used as 8 percent of the total weight of the compound 1 and G1) to be evaporated on an Electron Blocking Layer (EBL) to form a luminescent layer with the thickness of 20 nm;

evaporating HB-1 onto the light-emitting layer to obtain a Hole Blocking Layer (HBL) with the thickness of 20 nm;

performing co-evaporation on ET-1 and LiQ to obtain an Electron Transport Layer (ETL) with the thickness of 30nm on a Hole Blocking Layer (HBL) according to the proportion of 5: 5;

mixing magnesium (Mg) and silver (Ag) at a ratio of 9:1, and evaporating to form an Electron Injection Layer (EIL) with a thickness of 50nm above the Electron Transport Layer (ETL);

thereafter, silver (Ag) was evaporated over the electron injection layer to form a cathode having a thickness of 100nm, DNTPD having a thickness of 50nm was deposited on the above-mentioned cathode sealing layer, and further, the surface of the cathode was sealed with a UV hardening adhesive and a sealing film (seal cap) containing a moisture scavenger to protect the organic electroluminescent device from oxygen or moisture in the atmosphere, thereby preparing an organic electroluminescent device.

Application examples 2 to 15

Organic electroluminescent devices of application examples 2 to 15 were produced by replacing compound 1 in application example 1 with

compounds

3, 5, 9, 13, 17, 21, 25, 30, 39, 41, 56, 68, 84 and 97 in examples 2 to 15 of the present invention, respectively, and the rest of the examples were the same as application example 1.

Comparative examples 1 to 3

Comparative examples 1 to 3 and application example 1 were different in that GH-1, GH-2 and GH-3 were used instead of Compound 1 in application example 1, respectively, and the rest was the same as in application example 1.

The organic electroluminescent devices prepared in application examples 1 to 15 and comparative examples 1, 2 and 3 were respectively tested, and the test results are shown in table 2.

TABLE 2

As can be seen from table 2 above, when the compound of the present invention is applied to an organic electroluminescent device and used as a host material of a light-emitting layer, the light-emitting efficiency of the organic electroluminescent device can be improved to a certain extent, and the start-up voltage is reduced and the power consumption is relatively reduced.

The organic electroluminescent devices prepared in comparative examples 1 to 3 and application examples 1 to 15 were subjected to a light emission life test to obtain data of light emission life T97% (time for which light emission luminance was reduced to 97% of initial luminance), and the test apparatus was a TEO light emitting device life test system. The results are shown in Table 3:

TABLE 3

As can be seen from table 3 above, the compound of the present invention is used as a host material of a light emitting layer, and is applied to an organic electroluminescent device, and the service life of the prepared organic electroluminescent device is greatly prolonged, so that the compound has a wide application prospect.

Claims

1. An organic electroluminescent compound, characterized in that its structural formula is shown in formula 1 below:

wherein Ar is phenyl or deuterated phenyl;

z1, Z2, Z3, Z4 are each independently CR 1;

at least one R1 of Z1, Z2, Z3 and Z4 is a group represented by formula 2;

p1, P2, P3, P4, P5, P6, P7, P8 are each independently CR 2;

r2 is selected from hydrogen, substituted or unsubstituted phenyl;

x is O or S.

2. The organic electroluminescent compound of claim 1, wherein at least two of Z1, Z2, Z3, and Z4 are CH.

3. The organic electroluminescent compound according to claim 2, wherein Z2 and Z3 are CH, Z1 is CR1, and R1 is a group represented by formula 2.

4. The organic electroluminescent compound of claim 1, wherein at least three of P1, P2, P3, P4 are CH; at least three of P5, P6, P7 and P8 are CH, one or two of P1, P2, P3, P4, P5, P6, P7 and P8 are CR2, and R2 is the substituted or unsubstituted phenyl.

5. The organic electroluminescent compound according to any one of claims 1 to 4, having a structural formula as shown in formula 3 or formula 4 below:

、

。

6. the organic electroluminescent compound according to any one of claims 1 to 4, which is in particular the following compound:

。

7. an organic electroluminescent device comprising a first electrode, a second electrode, and an organic layer formed between the first electrode and the second electrode, wherein the organic layer contains the organic electroluminescent compound according to any one of claims 1 to 4.

8. The organic electroluminescent device according to claim 7, wherein the organic layer comprises a hole injection layer, a hole transport layer, an electron blocking layer, a light emitting layer, a hole blocking layer, an electron transport layer, an electron injection layer; at least one of the hole injection layer, the hole transport layer, the electron blocking layer, the light emitting layer, the hole blocking layer, the electron transport layer, and the electron injection layer contains the organic electroluminescent compound according to any one of claims 1 to 6.

9. The organic electroluminescent element as claimed in claim 8, wherein the light-emitting layer contains the organic electroluminescent compound as claimed in any one of claims 1 to 6.

10. The organic electroluminescent device according to claim 9, wherein the organic electroluminescent compound according to any one of claims 1 to 6 is used as a host material in a light-emitting layer, and the light-emitting layer further contains a dopant material selected from any one or more of compounds G1 to G28:

。