CN107879984B

CN107879984B - Organic blue light micromolecule based on triplet-triplet annihilation mechanism and application thereof

Info

Publication number: CN107879984B
Application number: CN201711154506.8A
Authority: CN
Inventors: 路萍; 唐向阳
Original assignee: Jilin University
Current assignee: Jilin University
Priority date: 2017-11-20
Filing date: 2017-11-20
Publication date: 2021-01-05
Anticipated expiration: 2037-11-20
Also published as: CN107879984A

Abstract

A blue fluorescent micromolecule of a phenanthroimidazole-anthracene derivative based on a triplet-triplet annihilation mechanism and application thereof in preparing a high-efficiency non-doped electroluminescent device belong to the technical field of organic electroluminescence. In particular to a phenanthroimidazole raw material prepared by a one-pot method from phenanthrenequinone and a phenanthroimidazole and anthracene connected by Suzuki coupling. Phenanthroimidazole and anthracene groups are connected in a proper mode, triplet excitons are effectively utilized to emit light through triplet-triplet annihilation, and cyano groups are introduced to enhance intermolecular interaction, so that triplet-triplet annihilation efficiency is further improved, and overall performance of the device is improved. The brightness of the undoped blue light device in the invention is 1000cd m^‑2The time-out quantum efficiency is 9.44%, the efficiency roll-off is small, the starting voltage is low, the high efficiency is realized under high brightness, and the high-efficiency blue-ray quantum efficiency is an international leading level of blue-ray devices. The compound has important significance for filling the gap of the prior high-efficiency non-doped blue light device, and has important application prospect in full color display and white light illumination.

Description

Organic blue light micromolecule based on triplet-triplet annihilation mechanism and application thereof

Technical Field

The invention belongs to the technical field of organic electroluminescence, and particularly relates to a blue fluorescent small molecule of a phenanthroimidazole-anthracene derivative based on a triplet-triplet annihilation mechanism and application thereof in preparation of a high-efficiency non-doped OLEDs (organic light emitting diodes).

Background

In 1987, Organic electroluminescent devices with high efficiency were invented by Kodak company Deng Qing cloud Bo et al (Organic electroluminescent diodes, C.W.Tang and S.A.VanSlyke, appl.Phys.Lett.,1987, 51913-915.) and the research trend of OLEDs materials and devices was raised worldwide. Over the last three decades, OLEDs have evolved dramatically and have been commercialized accordingly for use in displays and lighting. There are still many problems in this field that have yet to be solved and further commercialization of OLEDs is hindered. In OLEDs devices, the ratio of singlet and triplet exciton generation is 1: 3, the traditional organic fluorescent micromolecules can only utilize 25% of singlet stateExcitons, the remaining 75% being triplet excitons, result in lower device efficiency due to transition forbidden resistance. The metal complex phosphorescent material based on iridium (Ir) or platinum (Pt) can directly emit triplet state of spin forbidden resistance, and realize 100% exciton utilization. Recently Thermally Activated Delayed Fluorescence (TADF) materials (high y fluorescence organic light-emitting diodes from a fluorescent phosphor ", H.UOyama, K.Goushi, K.Shizu, H.Nomura, C.Adachi, Nature,2012,492,234-_ST) The effective reverse intersystem crossing (RISC) from the triplet state to the singlet state is realized, and the aim of 100 percent utilization of excitons can also be achieved. However, both the metal complex phosphorescent material and the TADF material have a problem that the efficiency of the device is seriously deteriorated at high luminance. Due to triplet-to-singlet spin forbidden resistance, for metal complex phosphorescent materials, the rate of triplet radiation transition to singlet ground state is very slow; for TADF materials, the rate of triplet-reverse intersystem crossing to a singlet excited state is slow. This results in a long lifetime of the triplet state. In the actual working process of the device, as the current density is increased, the generated triplet excitons have no time to rapidly and radiatively jump to the ground state or the reverse system to pass through to the singlet excited state, so that a large amount of triplet excitons in the device are accumulated, and the triplet excitons can be annihilated by various non-radiative interactions, so that the serious efficiency roll-off under high brightness is caused, and the practical application of the material is not facilitated. And just because the spin-over speed from the triplet state to the singlet state is very slow, the metal complex phosphorescent material and the TADF material need to be doped into a proper matrix to relieve the problem of triplet state quenching caused by self aggregation. This requires selecting appropriate host materials and finely adjusting the doping concentration, which makes the device structure more complicated and increases the cost of practical application. Blue light is essential in full color display and white light illumination, and both the metal complex phosphorescent material and the TADF material have respective limitations in realizing blue light emission. Therefore, the development of organic fluorescent small molecular materials which are suitable for non-doped devices and can keep high efficiency under high brightness is significant, and the organic fluorescent small molecular materials have an important promotion effect on the further popularization of the OLEDs technology.

Triplet-triplet (TTA) annihilation is based on a mechanism in which two triplet excitons collide with each other to generate a singlet state, and can effectively convert the triplet excitons into the singlet state for light emission and overcome the problem of efficiency roll-off caused by an excessively high concentration of the triplet excitons, because theoretically the higher the concentration of the triplet excitons is, the higher the probability of collision of the two triplet excitons with each other is, and the more effective the triplet excitons are utilized through the TTA mechanism. Phenanthroimidazole and anthracene are both blue chromophores with high luminous efficiency and both can efficiently utilize triplet excitons through TTA mechanisms. Phenanthroimidazole and anthracene are connected in a reasonable mode, and Cyano (CN) is introduced to enhance intermolecular interaction, so that TTA efficiency is further improved, and the overall performance of the device is improved.

Disclosure of Invention

The invention aims to provide a high-efficiency organic blue light micromolecule suitable for non-doped devices, which can realize the effective utilization of triplet excitons through an effective TTA mechanism, can realize high efficiency under high brightness, and overcomes the defects that a metal complex phosphorescent material and a TADF material need to be doped, the efficiency of the device is seriously attenuated under high brightness and the like.

The invention also aims to provide application of the material as a light-emitting layer in preparing non-doped blue light OLEDs.

The structural formula of the organic blue light micromolecule based on the phenanthroimidazole-anthracene derivative is shown as P1n or P2 n:

wherein Ar represents an aromatic group represented by the following structural formula:

preferably, the organic blue light small molecule based on the phenanthroimidazole-anthracene derivative has a structural formula shown as P₁-P₈One of them is as follows:

the organic blue light micromolecule based on the phenanthroimidazole-anthracene derivative is prepared by preparing a phenanthroimidazole raw material by a phenanthrenequinone one-pot method and connecting phenanthroimidazole and anthracene by Suzuki coupling.

An organic electroluminescent device prepared based on the organic blue light micromolecules is composed of a glass substrate, an ITO anode, a hole transport layer, a luminescent layer, an electron transport layer and a cathode, and is characterized in that: the light-emitting layer at least contains one organic blue light small molecule.

The principle of the invention is as follows: phenanthroimidazole and anthracene are blue light chromophores with high efficiency, and can effectively utilize triplet excitons through a TTA mechanism, and break through exciton statistics of 25% singlet state generation rate of traditional organic fluorescent micromolecules. The TTA mechanism is based on that two triplet states collide to generate a singlet state, and the higher the triplet state concentration is in a certain triplet state concentration range, the more effective the TTA is, so that the high device efficiency can still be kept under high brightness, the TTA can be used for a non-doped device, the structure of the device can be simplified, the manufacturing cost of the device can be reduced, and the problem of serious efficiency roll-off of a metal complex phosphorescent material and a TADF material under high brightness can be solved. In addition, the introduction of the cyano group can enhance the interaction between molecules, and is beneficial to improving the efficiency of TTA, thereby further improving the overall performance of the undoped device. Finally, through a proper chemical synthesis method, the phenanthroimidazole can have a plurality of different reaction sites, and the diversification of the material structure is facilitated.

The organic blue light micromolecule luminescent material and the organic electroluminescent device have the following advantages and beneficial effects:

(1) the organic fluorescent micromolecule has the advantages of single and definite structure, simple synthesis, convenient purification, convenient research on the relationship between the structure and the performance and contribution to industrial amplification production.

(2) The organic fluorescent micromolecules have good thermal stability, the evaporated film is flat and uniform, no obvious phase separation exists, and the organic fluorescent micromolecules are suitable for non-doped OLEDs based on the evaporation technology.

(3) The organic fluorescent micromolecules have higher HOMO energy level and lower LUMO energy level, and are beneficial to balanced injection and transmission of current carriers.

(4) The undoped blue light OLEDs prepared by the organic fluorescent micromolecules have small efficiency roll-off and low starting voltage, and show higher device efficiency under high brightness. Is the international leading level of blue light devices. The compound has important significance for filling the gap of the prior high-efficiency non-doped blue light device, and has important application prospect in full color display and white light illumination.

Drawings

FIG. 1 is a differential scanning calorimetry curve, melting point (T), of P1_m) At 344 ℃, no phase transition or glass transition temperature was observed;

FIG. 2 is a graph of the thermogravimetric curve, glass transition temperature (T), of P1_g) 483 ℃ is adopted;

fig. 3 is a solvation emission spectrum. The compound is shown as local state emission, no obvious solvation effect appears, and a main luminescence peak is red-shifted from 434nm in non-polar solvent n-hexane to 446nm in polar solvent acetonitrile;

FIG. 4 is an absorption and emission spectrum of an undoped evaporated film. The main peak positions of the absorption spectrum are respectively positioned as follows: 265nm, 326nm, 365nm, 381nm and 404 nm; the main peak position of the emission spectrum is 463 nm;

FIG. 5 is a current density-voltage-luminance curve for an undoped electroluminescent device, which can function properly; maximum luminance 57787cd m^-2The starting voltage is 3.0V;

fig. 6 is an external quantum efficiency curve for an undoped electroluminescent device with a maximum external quantum efficiency of 9.44%. Illustration is shown: an electroluminescence spectrum under a 7V driving voltage, wherein a main peak of the spectrum is positioned at 470 nm;

FIG. 7 shows the electroluminescence spectra of the undoped electroluminescent device under different voltages, the main peak of the spectrum is at 470nm, and the electroluminescence spectra are stable under different driving voltages.

Detailed Description

Example 1

This example P₁The preparation method comprises the following preparation steps:

M₁the synthesis of (2): m₁Prepared by Suzuki coupling. In a 100mL round-bottom flask, 9, 10-dibromoanthracene (5mmol,1.67g), 4-cyanophenylboronic acid (5mmol,735mg), palladium tetrakistriphenylphosphine (0.1mmol, 115mg) were dissolved in 40mL of toluene and 20mL of an aqueous potassium carbonate solution (2.0mol L)^-1) And stirring and refluxing at 90 ℃ for 24 hours under the protection of nitrogen. After completion of the reaction, the reaction mixture was extracted with dichloromethane, the extract was concentrated by rotary evaporation, and column chromatography was performed (petroleum ether: dichloromethane: 3: 1, volume ratio) to obtain a pale yellow-green solid (710mg, yield: 40%). Mass Spectrometry MALDI-TOF (M/z) [ M⁺]: the test value was 357.87, and the theoretical value was 357.02.

M₂The synthesis of (2): m₂Is prepared by a one-pot method. In a 250mL round bottom flask, 9, 10-phenanthrenequinone (20mmol, 4.16g), 4-bromobenzaldehyde (20mmol, 3.68g), aniline (100mmol, 9.5mL), ammonium acetate (80mmol, 6.16g) were dissolved in 150mL glacial acetic acid and stirred at 120 ℃ under nitrogen for 4 hours under reflux. After the reaction, the reaction system was poured into 100mL of ice water, and a large amount of precipitate was instantaneously precipitated. The solid was filtered with suction and purified by column chromatography (petroleum ether: dichloromethane: 1, volume ratio) to give a white brown solid (8.05g, yield: 90%). Mass Spectrometry MALDI-TOF (M/z) [ M⁺]: the test value was 448.67, and the theoretical value was 448.06.

M₃The synthesis of (2): m₃Prepared by Suzuki coupling. In a 100mL round-bottom flask, M is added₂(5mmol, 2.24g), pinacol diboron (10mmol, 2.54g), potassium acetate (15mmol, 1.47g), [1,1' -bis (diphenylphosphino) ferrocene]Palladium dichloride (0.1mmol, 73mg)Dissolved in 60mL dioxane and stirred under reflux at 90 ℃ for 24 hours under nitrogen. After completion of the reaction, the reaction mixture was extracted with dichloromethane, the extract was concentrated by rotary evaporation, and column chromatography was performed (petroleum ether: dichloromethane: 1: 2, volume ratio) to obtain a white brown solid (1.48g, yield: 60%). Mass Spectrometry MALDI-TOF (M/z) [ M⁺]: the test value was 497.03, and the theoretical value was 496.23.

P₁The synthesis of (2): p₁Prepared by Suzuki coupling. In a 100mL round-bottom flask, M is added₁(5mmol，1.78g)，M₃(5mmol, 2.48g), Tetratriphenylphosphine palladium (0.1mmol, 115mg) was dissolved in 40mL of toluene and 20mL of aqueous potassium carbonate solution (2.0mol L)^-1) And stirring and refluxing at 90 ℃ for 24 hours under the protection of nitrogen. After completion of the reaction, the reaction mixture was extracted with dichloromethane, the extract was concentrated by rotary evaporation, and column chromatography was performed (petroleum ether: dichloromethane: 1: 2, volume ratio) to obtain a pale green solid (2.26g, yield: 70%). The product is further extracted by sublimation. Mass Spectrometry MALDI-TOF (M/z) [ M⁺]: the test value was 648.11, and the theoretical value was 647.24. Elemental analysis (%) C48H29N3 theoretical values C89.00, H4.51, N6.49; test values C89.03, H4.49, N6.48.

Example 2

This example P₂The preparation method comprises the following preparation steps:

M₄the synthesis of (2): m₄Is prepared by a one-pot method. In a 250mL round-bottom flask, 9, 10-phenanthrenequinone (20mmol, 4.16g), p-tert-butylbenzaldehyde (20mmol, 3.34mL), 4-bromoaniline (100mmol, 17.20g), ammonium acetate (80mmol, 6.16g) were dissolved in 150mL glacial acetic acid, and stirred at 120 ℃ under nitrogen for 4 hours under reflux. After the reaction, the reaction system was poured into 100mL of ice water, and a large amount of precipitate was instantaneously precipitated. Suction filtering, separating and purifying the obtained solid by column chromatography(petroleum ether: dichloromethane: 1 by volume) gave a tan solid (9.05g, yield: 90%). Mass Spectrometry MALDI-TOF (M/z) [ M⁺]: the test value was 505.08, and the theoretical value was 504.12.

M₅The synthesis of (2): m₅Prepared by Suzuki coupling. In a 100mL round-bottom flask, M is added₄(5mmol, 2.52g), pinacol diboron (10mmol, 2.54g), potassium acetate (15mmol, 1.47g), [1,1' -bis (diphenylphosphino) ferrocene]Palladium dichloride (0.1mmol, 73mg) was dissolved in 60mL dioxane and stirred under reflux at 90 ℃ for 24 hours under nitrogen. After completion of the reaction, the reaction mixture was extracted with dichloromethane, the extract was concentrated by rotary evaporation, and column chromatography was performed (petroleum ether: dichloromethane: 1: 2, volume ratio) to obtain a white brown solid (1.65g, yield: 60%). Mass Spectrometry MALDI-TOF (M/z) [ M⁺]: the test value was 552.93, and the theoretical value was 552.29.

P₂The synthesis of (2): p₂Prepared by Suzuki coupling. In a 100mL round-bottom flask, M is added₁(5mmol，1.78g)，M₅(5mmol, 2.76g), Tetratriphenylphosphine palladium (0.1mmol, 115mg) was dissolved in 40mL of toluene and 20mL of aqueous potassium carbonate solution (2.0mol L)^-1) And stirring and refluxing at 90 ℃ for 24 hours under the protection of nitrogen. After completion of the reaction, the reaction mixture was extracted with dichloromethane, the extract was concentrated by rotary evaporation, and column chromatography was performed (petroleum ether: dichloromethane: 1: 2, volume ratio) to obtain a pale green solid (2.46g, yield: 70%). The product is further extracted by sublimation. Mass Spectrometry MALDI-TOF (M/z) [ M⁺]: the test value was 704.22, and the theoretical value was 703.30. Elemental analysis (%) C48H29N3 theoretical values C88.73, H5.30, N5.97; test values C88.75, H5.29, N5.96

Example 3

This example P₃The preparation method comprises the following preparation steps:

M₆the synthesis of (2): m₆Is prepared by a one-pot method. In a 250mL round-bottom flask, 9, 10-phenanthrenequinone (20mmol, 4.16g), 4-bromobenzaldehyde (20mmol, 3.68g), 4-bromoaniline (100mmol, 17.20g), ammonium acetate (80mmol, 6.16g) were dissolved in 150mL glacial acetic acid and stirred at 120 ℃ under nitrogen for 4 hours under reflux. After the reaction, the reaction system was poured into 100mL of ice water, and a large amount of precipitate was instantaneously precipitated. The solid was filtered with suction and purified by column chromatography (petroleum ether: dichloromethane: 1, volume ratio) to give a white brown solid (9.47g, yield: 90%). Mass Spectrometry MALDI-TOF (M/z) [ M⁺]: the test value was 526.54, and the theoretical value was 525.97.

M₇The synthesis of (2): m₇Prepared by Suzuki coupling. In a 100mL round-bottom flask, M is added₆(5mmol, 2.63g), pinacol diboron (10mmol, 2.54g), potassium acetate (15mmol, 1.47g), [1,1' -bis (diphenylphosphino) ferrocene]Palladium dichloride (0.1mmol, 73mg) was dissolved in 60mL dioxane and stirred under reflux at 90 ℃ for 24 hours under nitrogen. After completion of the reaction, the reaction mixture was extracted with dichloromethane, the extract was concentrated by rotary evaporation, and column chromatography was performed (petroleum ether: dichloromethane: 1: 2, volume ratio) to obtain a white brown solid (1.25g, yield: 40%). Mass Spectrometry MALDI-TOF (M/z) [ M⁺]: the test value was 623.77, and the theoretical value was 622.32.

P₃The synthesis of (2): p₃Prepared by Suzuki coupling. In a 100mL round-bottom flask, M is added₁(5mmol，1.78g)，M₇(5mmol, 3.11g), Tetratriphenylphosphine palladium (0.1mmol, 115mg)) Dissolved in 40mL of toluene and 20mL of an aqueous potassium carbonate solution (2.0mol L)^-1) And stirring and refluxing at 90 ℃ for 24 hours under the protection of nitrogen. After completion of the reaction, the reaction mixture was extracted with dichloromethane, the extract was concentrated by rotary evaporation, and column chromatography was performed (petroleum ether: dichloromethane: 1: 2, volume ratio) to obtain a pale green solid (3.23g, yield: 70%). The product is further extracted by sublimation. Mass Spectrometry MALDI-TOF (M/z) [ M⁺]: the test value was 925.08, and the theoretical value was 924.33. Elemental analysis (%) C48H29N3 theoretical values C89.59, H4.36, N6.06; test values C89.61, H4.34, N6.05

Example 4

This example P₄The preparation method comprises the following preparation steps:

M₈the synthesis of (2): m₈Is prepared by a one-pot method. In a 250mL round-bottom flask, 2, 7-dibromophenanthrenequinone (20mmol, 7.28g), p-tert-butylbenzaldehyde (20mmol, 3.34mL), aniline (100mmol, 9.5mL), ammonium acetate (80mmol, 6.16g) were dissolved in 150mL glacial acetic acid and stirred at 120 ℃ under nitrogen for 4 hours under reflux. After the reaction, the reaction system was poured into 100mL of ice water, and a large amount of precipitate was instantaneously precipitated. The solid was filtered with suction and purified by column chromatography (petroleum ether: dichloromethane: 1, volume ratio) to give a white brown solid (10.48g, yield: 90%). Mass Spectrometry MALDI-TOF (M/z) [ M⁺]: the test value was 583.15, and the theoretical value was 582.03.

M₉The synthesis of (2): m₉Prepared by Suzuki coupling. In a 100mL round-bottom flask, M is added₈(5mmol, 2.91g), pinacol diboron (10mmol, 2.54g), potassium acetate (15mmol, 1.47g), [1,1' -bis (diphenylphosphino) ferrocene]Palladium dichloride (0.1mmol, 73mg) was dissolved in 60mL dioxane and stirred under reflux at 90 ℃ for 24 hours under nitrogen. After the reaction is finished, the second step is usedExtraction with methyl chloride, concentration of the extract by rotary evaporation, and column chromatography (petroleum ether: dichloromethane: 1: 2, vol.%) gave a white brown solid (1.36g, yield: 40%). Mass Spectrometry MALDI-TOF (M/z) [ M⁺]: the test value was 678.92, and the theoretical value was 678.38.

P₄The synthesis of (2): p₄Prepared by Suzuki coupling. In a 100mL round-bottom flask, M is added₁(5mmol，1.78g)，M₉(5mmol, 3.39g), Tetratriphenylphosphine palladium (0.1mmol, 115mg) was dissolved in 40mL of toluene and 20mL of aqueous potassium carbonate solution (2.0mol L)^-1) And stirring and refluxing at 90 ℃ for 24 hours under the protection of nitrogen. After completion of the reaction, the reaction mixture was extracted with dichloromethane, the extract was concentrated by rotary evaporation, and column chromatography was performed (petroleum ether: dichloromethane: 1: 2, volume ratio) to obtain a pale green solid (3.43g, yield: 70%). The product is further extracted by sublimation. Mass Spectrometry MALDI-TOF (M/z) [ M⁺]: the test value was 981.43, and the theoretical value was 980.39. Elemental analysis (%) C48H29N3 theoretical values C89.36, H4.93, N5.71; test values C89.33, H4.95, N5.72

Example 5

This example P₅The preparation method comprises the following preparation steps:

M₁₀the synthesis of (2): m₈Is prepared by a one-pot method. In a 250mL round-bottom flask, 3, 6-dibromophenanthrenequinone (20mmol, 7.28g), p-tert-butylbenzaldehyde (20mmol, 3.34mL), aniline (100mmol, 9.5mL), ammonium acetate (80mmol, 6.16g) were dissolved in 150mL glacial acetic acid and stirred at 120 ℃ under nitrogen for 4 hours under reflux. After the reaction, the reaction system was poured into 100mL of ice water, and a large amount of precipitate was instantaneously precipitated. The solid was filtered with suction and purified by column chromatography (petroleum ether: dichloromethane: 1, volume ratio) to give a white brown solid (10.48g, yield: 90%). Mass spectrometryMALDI-TOF(m/z)[M⁺]: the test value was 583.74, and the theoretical value was 582.03.

M₁₁The synthesis of (2): m₁₁Prepared by Suzuki coupling. In a 100mL round-bottom flask, M is added₁₀(5mmol, 2.91g), pinacol diboron (10mmol, 2.54g), potassium acetate (15mmol, 1.47g), [1,1' -bis (diphenylphosphino) ferrocene]Palladium dichloride (0.1mmol, 73mg) was dissolved in 60mL dioxane and stirred under reflux at 90 ℃ for 24 hours under nitrogen. After completion of the reaction, the reaction mixture was extracted with dichloromethane, the extract was concentrated by rotary evaporation, and column chromatography was performed (petroleum ether: dichloromethane: 1: 2, volume ratio) to obtain a white brown solid (1.36g, yield: 40%). Mass Spectrometry MALDI-TOF (M/z) [ M⁺]: the test value was 679.21, and the theoretical value was 678.38.

P₅The synthesis of (2): p₅Prepared by Suzuki coupling. In a 100mL round-bottom flask, M is added₁(5mmol，1.78g)，M₁₁(5mmol, 3.39g), Tetratriphenylphosphine palladium (0.1mmol, 115mg) was dissolved in 40mL of toluene and 20mL of aqueous potassium carbonate solution (2.0mol L)^-1) And stirring and refluxing at 90 ℃ for 24 hours under the protection of nitrogen. After completion of the reaction, the reaction mixture was extracted with dichloromethane, the extract was concentrated by rotary evaporation, and column chromatography was performed (petroleum ether: dichloromethane: 1: 2, volume ratio) to obtain a pale green solid (3.43g, yield: 70%). The product is further extracted by sublimation. Mass Spectrometry MALDI-TOF (M/z) [ M⁺]: the test value was 981.24, and the theoretical value was 980.39. Elemental analysis (%) C48H29N3 theoretical values C89.36, H4.93, N5.71; test values C89.37, H4.93, N5.70

Example 6

This example P₆The preparation method comprises the following preparation steps:

M₁₂the synthesis of (2): m₁₂Is prepared by a one-pot method. In a 250mL round-bottom flask, 9, 10-phenanthrenequinone (20mmol, 4.16g), m-bromobenzaldehyde (20mmol, 3.68g), aniline (100mmol, 9.5mL), ammonium acetate (80mmol, 6.16g) were dissolved in 150mL glacial acetic acid and stirred at 120 ℃ under nitrogen for 4 hours under reflux. After the reaction, the reaction system was poured into 100mL of ice water, and a large amount of precipitate was instantaneously precipitated. The solid was filtered with suction and purified by column chromatography (petroleum ether: dichloromethane: 1, volume ratio) to give a white brown solid (8.05g, yield: 90%). Mass Spectrometry MALDI-TOF (M/z) [ M⁺]: the test value was 449.39, and the theoretical value was 448.06.

M₁₃Prepared by Suzuki coupling. In a 100mL round-bottom flask, M is added₁₂(5mmol, 2.24g), pinacol diboron (10mmol, 2.54g), potassium acetate (15mmol, 1.47g), [1,1' -bis (diphenylphosphino) ferrocene]Palladium dichloride (0.1mmol, 73mg) was dissolved in 60mL dioxane and stirred under reflux at 90 ℃ for 24 hours under nitrogen. After completion of the reaction, the reaction mixture was extracted with dichloromethane, the extract was concentrated by rotary evaporation, and column chromatography was performed (petroleum ether: dichloromethane: 1: 2, volume ratio) to obtain a white brown solid (1.48g, yield: 60%). Mass Spectrometry MALDI-TOF (M/z) [ M⁺]: the test value was 497.37, and the theoretical value was 496.23.

P₆The synthesis of (2): p₆Prepared by Suzuki coupling. In a 100mL round-bottom flask, M is added₁₃(5mmol，1.78g)，M₁(5mmol, 2.48g), Tetratriphenylphosphine palladium (0.1mmol, 115mg) was dissolved in 40mL of toluene and 20mL of aqueous potassium carbonate solution (2.0mol L)^-1) And stirring and refluxing at 90 ℃ for 24 hours under the protection of nitrogen. Reaction junctionAfter completion, the mixture was extracted with dichloromethane, the extract was concentrated by rotary evaporation, and column chromatography was performed (petroleum ether: dichloromethane: 1: 2, volume ratio) to obtain a pale green solid (2.26g, yield: 70%). The product is further extracted by sublimation. Mass Spectrometry MALDI-TOF (M/z) [ M⁺]: the test values were 647, 91 and the theoretical value was 647.24. Elemental analysis (%) C48H29N3 theoretical values C89.00, H4.51, N6.49; test values C89.03, H4.50, N6.47

Example 7

This example P₇The preparation method comprises the following preparation steps:

M₁₄the synthesis of (2): m₁₄Is prepared by a one-pot method. In a 250mL round-bottom flask, 9, 10-phenanthrenequinone (20mmol, 4.16g), p-tert-butylbenzaldehyde (20mmol, 3.34mL), m-bromoaniline (100mmol, 17.20g), ammonium acetate (80mmol, 6.16g) were dissolved in 150mL glacial acetic acid, and stirred at 120 ℃ under nitrogen for 4 hours under reflux. After the reaction, the reaction system was poured into 100mL of ice water, and a large amount of precipitate was instantaneously precipitated. The solid was filtered with suction and purified by column chromatography (petroleum ether: dichloromethane: 1, volume ratio) to give a white brown solid (9.05g, yield: 90%). Mass Spectrometry MALDI-TOF (M/z) [ M⁺]: the test value was 505.29, and the theoretical value was 504.12.

M₁₅The synthesis of (2): m₁₅Prepared by Suzuki coupling. In a 100mL round-bottom flask, M is added₁₄(5mmol, 2.52g), pinacol diboron (10mmol, 2.54g), potassium acetate (15mmol, 1.47g), [1,1' -bis (diphenylphosphino) ferrocene]Palladium dichloride (0.1mmol, 73mg) was dissolved in 60mL dioxane and stirred under reflux at 90 ℃ for 24 hours under nitrogen. After the reaction is finished, dichloromethane is used for extraction, rotary evaporation is carried out to concentrate an extract, and column chromatography separation (petroleum ether: dichloromethane is 1: 2, volume ratio) is carried out to obtain whiteBrown solid (1.65g, yield: 60%). Mass Spectrometry MALDI-TOF (M/z) [ M⁺]: the test value was 553.06, and the theoretical value was 552.29.

P₇The synthesis of (2): p₇Prepared by Suzuki coupling. In a 100mL round-bottom flask, M is added₁(5mmol，1.78g)，M₁₅(5mmol, 2.76g), Tetratriphenylphosphine palladium (0.1mmol, 115mg) was dissolved in 40mL of toluene and 20mL of aqueous potassium carbonate solution (2.0mol L)^-1) And stirring and refluxing at 90 ℃ for 24 hours under the protection of nitrogen. After completion of the reaction, the reaction mixture was extracted with dichloromethane, the extract was concentrated by rotary evaporation, and column chromatography was performed (petroleum ether: dichloromethane: 1: 2, volume ratio) to obtain a pale green solid (2.46g, yield: 70%). The product is further extracted by sublimation. Mass Spectrometry MALDI-TOF (M/z) [ M⁺]: the test value was 704.63, and the theoretical value was 703.30. Elemental analysis (%) C48H29N3 theoretical values C88.73, H5.30, N5.97; test values C88.71, H5.31, N5.98

Example 8

This example P₈The preparation method comprises the following preparation steps:

M₁₆the synthesis of (2): m₁₆Is prepared by a one-pot method. In a 250mL round-bottom flask, 9, 10-phenanthrenequinone (20mmol, 4.16g), m-bromobenzaldehyde (20mmol, 3.68g), m-bromoaniline (100mmol, 17.20g), ammonium acetate (80mmol, 6.16g) were dissolved in 150mL glacial acetic acid and stirred at 120 ℃ under nitrogen for 4 hours under reflux. After the reaction, the reaction system was poured into 100mL of ice water, and a large amount of precipitate was instantaneously precipitated. The solid was filtered with suction and purified by column chromatography (petroleum ether: dichloromethane: 1, volume ratio) to give a white brown solid (9.47g, yield: 90%). Mass Spectrometry MALDI-TOF (M/z) [ M⁺]: the test value was 526.73, and the theoretical value was 525.97.

M₁₇The synthesis of (2): m₁₇Prepared by Suzuki coupling. In a 100mL round-bottom flask, M is added₁₆(5mmol, 2.63g), pinacol diboron (10mmol, 2.54g), potassium acetate (15mmol, 1.47g), [1,1' -bis (diphenylphosphino) ferrocene]Palladium dichloride (0.1mmol, 73mg) was dissolved in 60mL dioxane and stirred under reflux at 90 ℃ for 24 hours under nitrogen. After completion of the reaction, the reaction mixture was extracted with dichloromethane, the extract was concentrated by rotary evaporation, and column chromatography was performed (petroleum ether: dichloromethane: 1: 2, volume ratio) to obtain a white brown solid (1.25g, yield: 40%). Mass Spectrometry MALDI-TOF (M/z) [ M⁺]: the test value was 623.55, and the theoretical value was 622.32.

P₈The synthesis of (2): p₈Prepared by Suzuki coupling. In a 100mL round-bottom flask, M is added₁(5mmol，1.78g)，M₁₇(5mmol, 3.11g), Tetratriphenylphosphine palladium (0.1mmol, 115mg) was dissolved in 40mL of toluene and 20mL of aqueous potassium carbonate solution (2.0mol L)^-1) And stirring and refluxing at 90 ℃ for 24 hours under the protection of nitrogen. After completion of the reaction, the reaction mixture was extracted with dichloromethane, the extract was concentrated by rotary evaporation, and column chromatography was performed (petroleum ether: dichloromethane: 1: 2, volume ratio) to obtain a pale green solid (3.23g, yield: 70%). The product is further extracted by sublimation. Mass Spectrometry MALDI-TOF (M/z) [ M⁺]: the test value was 925.36, and the theoretical value was 924.33. Elemental analysis (%) C48H29N3 theoretical values C89.59, H4.36, N6.06; test values C89.57, H4.35, N6.08

Example 9

A non-doped organic electroluminescent device takes organic blue light micromolecules with a molecular structure of P1 as a luminescent layer material, and the structure of the organic electroluminescent device is as follows:

ITO/HATCN (6nm)/TAPC (25nm)/TCTA (15nm)/EML (20nm)/TPBI (40nm)/LiF (1nm)/Al (120 nm). Wherein EML is a non-doped light-emitting layer with P1 as light-emitting material

The device preparation process is as follows: placing ITO transparent conductive glass in deionized water: soaking the mixture in ethanol for two hours, wiping the mixture clean by using dust-free paper, ultrasonically cleaning the mixture once by using deionized water, and finally repeatedly ultrasonically cleaning the mixture for three times by sequentially using isopropanol, acetone, methylbenzene, acetone and isopropanol. Before preparing the device, blow-drying the ITO glass substrate with nitrogen, irradiating for half an hour under ultraviolet ozone, then placing the ITO glass substrate in an evaporation chamber, vacuumizing to 5 multiplied by 10^-4And Pa, sequentially evaporating materials required by the device on the ITO glass substrate to obtain the organic electroluminescent device. The specific description is as follows: wherein HATCN is hole injection layer with thickness of 6nm and evaporation rate of 0.1A s^-1(ii) a TAPC is hole transport layer with thickness of 25nm and evaporation rate of 0.3A s^-1(ii) a TCTA as buffer layer with thickness of 15nm and evaporation rate of 0.3A s^-1(ii) a The thickness of the luminescent layer is 20nm, the evaporation speed is 0.3A s^-1(ii) a TPBI is an electron transport layer with a thickness of 40nm and an evaporation rate of 0.4A s^-1(ii) a LiF is an electron injection layer with a thickness of 1nm and an evaporation rate of 0.1A s^-1(ii) a Al as a cathode, a thickness of 120nm, a slightly slower deposition rate at the beginning of 0.7A s^-1As the thickness of the Al layer increases, the evaporation speed of the Al layer can be gradually increased to 2A s when the thickness of the Al layer reaches 20nm^-1。

This example uses P₁The current density-voltage-luminance curve, the current efficiency-luminance curve and the electroluminescence spectrum under different voltages of the undoped organic electroluminescent device of the luminescent layer material are respectively shown in fig. 5, fig. 6 and fig. 7. The photoelectric properties of the resulting device are shown in table 1.

Table 1: example 9 Performance results for undoped blue OLEDs devices

The structural formula of the material used in the organic electroluminescent device of this example is as follows:

the above embodiments are preferred embodiments of the present invention, but the present invention is not limited to the above embodiments, and any other changes, modifications, substitutions, combinations, and simplifications which do not depart from the spirit and principle of the present invention should be construed as equivalents thereof, and all such changes, modifications, substitutions, combinations, and simplifications are intended to be included in the scope of the present invention.

Claims

1. An organic blue light small molecule based on triplet-triplet annihilation mechanism, its structural formula is shown as P₁Shown in the figure:

2. the use of the organic blue light small molecule based on triplet-triplet annihilation mechanism as claimed in claim 1 in the preparation of non-doped blue light OLEDs.

3. The use of the organic blue-light small molecule based on triplet-triplet annihilation mechanism as claimed in claim 2 in the preparation of non-doped blue-light OLEDs (organic light emitting diodes) device, which comprises glass substrate, ITO anode, hole transport layer, light emitting layer, electron transport layer and cathode; the method is characterized in that: the light-emitting layer contains organic blue light small molecules based on triplet-triplet annihilation mechanism as claimed in claim 1.