CN113321617A - Red light thermal induction delay fluorescent material, preparation method thereof and organic electroluminescent device - Google Patents

Red light thermal induction delay fluorescent material, preparation method thereof and organic electroluminescent device Download PDF

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CN113321617A
CN113321617A CN202110672526.4A CN202110672526A CN113321617A CN 113321617 A CN113321617 A CN 113321617A CN 202110672526 A CN202110672526 A CN 202110672526A CN 113321617 A CN113321617 A CN 113321617A
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fluorescent material
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red light
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light thermal
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战宏梅
李怡潼
姚兵
李阔飞
邓浩
程延祥
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Changchun Institute of Applied Chemistry of CAS
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Abstract

The invention provides a red light thermal induction delay fluorescent material, a preparation method thereof and an organic electroluminescent device. The red light thermal-induced delayed fluorescent material is a red light thermal-induced delayed fluorescent material with a multi-arm star-shaped structure shown in a formula (I), the band gap is narrow, and the energy level difference between a first excited singlet state and a first excited triplet state is small, so that the compound has red thermal-induced delayed fluorescence emission property; moreover, the rigid indenone receptor unit contains three carbonyl groups, the reverse intersystem crossing rate of the electroluminescent material based on the indenone derivative is favorably improved by utilizing the high intersystem crossing rate of the carbonyl groups, and meanwhile, the rigid plane structure is favorable for inhibiting non-radiative transition and improving the luminescent performance of the material. Meanwhile, the indenone derivative shown in the formula (I) has a multi-arm star-shaped structure, so that the intermolecular interaction is weakened, the solubility of the material is improved, and a solution processing device is convenient to process.

Description

Red light thermal induction delay fluorescent material, preparation method thereof and organic electroluminescent device
Technical Field
The invention relates to the field of luminescent materials, in particular to a red light thermal induction delay fluorescent material, a preparation method thereof and an organic electroluminescent device.
Background
The Organic Light Emitting Diode (OLED) has the advantages of light weight, good flexibility, wide viewing angle, high contrast and brightness, low energy consumption, fast response, autonomous light emission and the like, and has great application potential in the fields of flat panel display, smart phones, solid-state lighting and the like. The light emitting material is a key factor affecting the light emitting performance of the OLED. Conventional fluorescent materials are limited to exciton utilizations of only 25%, and have low luminous efficiencies. Phosphorescent complexes (i.e., phosphorescent materials) containing iridium (III), platinum (II), osmium (II), or other metals enhance intramolecular cross-over by spin-orbit coupling, and realize 100% utilization of singlet excitons and triplet excitons; however, the use of noble metals results in high synthesis cost and is not suitable for large-scale production. Thermally induced delayed fluorescence (TADF) materials have small singlet-triplet energy level differences (Δ E)ST) Triplet excitons can be converted to singlet excitons by reverse intersystem crossing processes for radiative emission, thereby achieving 100% exciton utilization. Compared with phosphorescent complexes, most TADF materials are pure organic compounds, do not need noble metals, and are more beneficial to commercial application of devices.
Pure organic TADF compounds having an internal quantum efficiency of up to 96.5% have been reported since professor Adachi 2012Nature,2012,492,234-238]The direction of the field is drawing wide attention in the academic world and the industrial world at home and abroad. A large number of highly efficient TADF phosphors have been reported successively through rapid development in recent years. The External Quantum Efficiency (EQE) of the green light and blue light TADF material breaks through 37 percent and exceeds that of a phosphorescent OLED. However, the development of the red TADF material is relatively delayed, the luminous efficiency is low, and a material satisfying the saturated red emission (λ)em>600nm and CIEx>0.6，CIEy<0.4), although the red TADF molecules with the EQE close to 30% have been reported successively, the overall performance, especially the severe efficiency roll-off at high luminance, is still difficult to meet the practical application requirements.
At present, the red TADF material is mainly a micromolecular compound which forms a twisted structure for a (D)/receptor (A), has a linear D (donor) -A (receptor), D-Ph-A or V-type D-A-D, D-Ph-A-Ph-D molecular structure, has small molecular weight, strong intermolecular force, easy aggregation and poor film forming property, adopts a high vacuum evaporation technology in the process of manufacturing a device, and is not beneficial to the development of full-color display of a large-size OLED. Compared with the evaporation type small molecule TADF material, the development of the TADF material which can be processed by solution is significantly insufficient, and particularly, the variety of the TADF material which can be processed by solution is very small.
In recent years, the urgent need for large-size OLED displays has driven the development of low-cost solution processing techniques and TADF materials. Although small molecule compounds are also applicable to solution processing such as printing, high molecular weight compounds and polymers are no doubt more desirable solution processing materials. Therefore, the development of efficient, solution processable red TADF materials is crucial to achieving large-scale full-color displays.
Disclosure of Invention
In view of the above, the present invention provides a red light thermal-induced delayed fluorescence material, a method for preparing the same, and an organic electroluminescent device. The red light thermal-induced delayed fluorescent material provided by the invention can realize saturated red light emission, can effectively inhibit non-radiative transition rate and improve reverse intersystem crossing rate, and improves the luminous performance of the red light thermal-induced delayed fluorescent material; in addition, it can also be used for an organic electroluminescent device by solution processing.
The invention provides a red light thermal induction delayed fluorescent material, which has a structure shown in a formula (I):
Figure BDA0003119219430000021
wherein:
the D unit is a donor unit with electron supply capacity and is selected from: substituted or unsubstituted aryl of C18-C80, substituted or unsubstituted heteroaryl of C18-C75; the heteroatoms in the heteroaryl group are nitrogen and/or oxygen.
Preferably, the D unit is selected from: substituted aryl of C26-C45 and substituted heteroaryl of C26-C45.
Preferably, the D unit is selected from the following structures:
Figure BDA0003119219430000031
wherein:
R1、R2independently selected from: C4-C30 alkyl, C4-C30 alkoxy or C6-C35 substituted aryl.
Preferably, in formula (I), 3
Figure BDA0003119219430000032
The substitution positions of the units are respectively: 2-or 3-position, 7-or 8-position, 12-or 13-position.
Preferably, in formula (I), 3
Figure BDA0003119219430000033
The combination of the substitution positions of the units is in the 3,8, 13-position or in the 2,7, 12-position.
The invention also provides a preparation method of the red light thermal induction delayed fluorescence material in the technical scheme, which comprises the following steps:
a) carrying out Aldol condensation reaction on the bromoindanone X to form a tribromo truxene intermediate Y;
b) reacting the tribromo truxene intermediate Y with arylboronic acid ester Z to form a multi-arm star-shaped precursor L;
c) carrying out oxidation reaction on the multi-arm star-shaped precursor L to form a red light thermal induction delayed fluorescent material shown in a formula (I);
Figure BDA0003119219430000041
in said formula Z, aryl Ar-is as defined in said formula (I)
Figure BDA0003119219430000042
A unit;
in the formula L, the D unit is a donor unit with electron supplying capability and is selected from: substituted or unsubstituted aryl of C18-C80, substituted or unsubstituted heteroaryl of C18-C75; the heteroatoms in the heteroaryl group are nitrogen and/or oxygen.
Preferably, the bromoindanone X is 5-bromoindanone or 6-bromoindanone.
Preferably, in the step a), the reaction temperature is 120-135 ℃, and the reaction time is 48-72 hours;
in the step b), the reaction temperature is 90-120 ℃, and the reaction time is 16-48 h;
in the step c), the oxidation reaction is carried out in the presence of an oxidizing agent and a basic substance;
the alkaline substance is benzyltrimethoxyammonium hydroxide.
The invention also provides an organic electroluminescent device, wherein a luminescent layer in the organic electroluminescent device contains a fluorescent material;
the fluorescent material is the red light thermal induction delayed fluorescent material in the technical scheme or the red light thermal induction delayed fluorescent material prepared by the preparation method in the technical scheme.
Preferably, the light emitting layer includes a fluorescent material and a host material;
the mass of the fluorescent material accounts for 1-15% of the total mass of the fluorescent material and the main body material.
The red light thermal-induced delayed fluorescent material is a red light thermal-induced delayed fluorescent material with a multi-arm star-shaped structure shown in a formula (I), the band gap is narrow, and the energy level difference between a first excited singlet state and a first excited triplet state is small, so that the compound has red thermal-induced delayed fluorescence emission property; moreover, the rigid indenone receptor unit contains three carbonyl groups, the reverse intersystem crossing rate of the electroluminescent material based on the indenone derivative is favorably improved by utilizing the high intersystem crossing rate of the carbonyl groups, and meanwhile, the rigid plane structure is favorable for inhibiting non-radiative transition and improving the luminescent performance of the material. Meanwhile, the indenone derivative shown in the formula (I) has a multi-arm star-shaped structure, so that the intermolecular interaction is favorably weakened, the solubility of the material is improved, a solution processing device is convenient, and the organic electroluminescent device prepared by using the material can realize saturated red light emission. In addition, the preparation method of the compound provided by the invention is simple and high in yield, and when the obtained compound is used for manufacturing a device, simple solution processing modes such as spin coating, ink jet printing and the like can be used, so that the manufacturing process of the electroluminescent device is simplified.
Experimental results show that the red light thermal induction delayed fluorescence material with the multi-arm star-shaped structure shown in the formula (I) has a liquid PL emission peak above 588 nm; the photoluminescence quantum efficiency of the solution is more than 0.56, and high luminous efficiency is shown; the electroluminescent device can present instantaneous emission with nanoscale service life and delayed emission with microsecond service life, has the property of thermally induced delayed fluorescence, has the proportion of delayed fluorescence up to more than 59 percent, and can realize saturated red light emission through the electroluminescent device prepared by a solution method.
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In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.
FIG. 1 is a graph showing the UV/VIS absorption and room temperature fluorescence and low temperature phosphorescence spectra of the product I-M form-a 1 obtained in example 1 in toluene solution;
FIG. 2 is a graph showing the UV/VIS absorption and room temperature fluorescence and low temperature phosphorescence spectra of the product I-M form-a 3 obtained in example 3 in toluene solution;
FIG. 3 is a graph showing the UV/VIS absorption and room temperature fluorescence and low temperature phosphorescence spectra of the product I-M form-a 2 obtained in example 4 in toluene solution;
FIG. 4 is a graph showing the transient fluorescence spectrum decay of the product I-M form-a 1 obtained in example 1 in a toluene solution;
FIG. 5 is a graph showing the transient fluorescence spectrum decay of the product I-M form-a 3 obtained in example 3 in a toluene solution;
FIG. 6 is a thermogravimetric analysis of the product I-M form-a 1 obtained in example 1;
FIG. 7 is a graph showing an EL spectrum of an organic electroluminescent device based on the product of example 1;
FIG. 8 is a graph showing a current density-voltage-luminance relationship of an organic electroluminescent device based on the product of example 1;
FIG. 9 is a graph of current efficiency versus luminance for an organic electroluminescent device based on the product of example 1;
FIG. 10 is a graph of power efficiency versus luminance for an organic electroluminescent device based on the product of example 1;
fig. 11 is a CIE diagram of an organic electroluminescent device based on the product of example 1.
Detailed Description
The invention provides a red light thermal induction delayed fluorescent material, which has a structure shown in a formula (I):
Figure BDA0003119219430000061
wherein:
the D unit is a donor unit with electron supply capacity and is selected from: substituted or unsubstituted aryl of C18-C80, substituted or unsubstituted heteroaryl of C18-C75; the heteroatoms in the heteroaryl group are nitrogen and/or oxygen.
Preferably, the D unit is selected from: substituted aryl of C26-C45 and substituted heteroaryl of C26-C45.
More preferably, the D unit is selected from the following structures:
Figure BDA0003119219430000062
Figure BDA0003119219430000071
in the above structure, the dotted line on the N atom represents the junction.
In the above structure, R1、R2Independently selected from: C4-C30 alkyl, C4-C30 alkoxy or C6-C35 substituted aryl. Preferably, R1、R2Independently selected from: -C6H13Tert-butyl, -C8H17- (2-ethyl) hexyl or 1-octylnonyl.
In some embodiments of the invention, the D unit is selected from the following structures:
Figure BDA0003119219430000072
in the present invention, in the formula (I), the numbers 2,3,7,8,12 and 13 represent the numbers of substitution positions on the mother ring. In the present invention, it is preferable that 3 of the above formula (I)
Figure BDA0003119219430000073
The substitution positions of the units are respectively: 2-or 3-position, 7-or 8-position, 12-or 13-position; i.e. of the upper right in formula (I)
Figure BDA0003119219430000074
The substitution position of the unit being 2-or 3-position, lower side
Figure BDA0003119219430000075
The substitution position of the unit being 7-or 8-position, upper left
Figure BDA0003119219430000076
The substitution position of the unit is 12-position or 13-position.
In the present invention, more preferably, 3 of the above-mentioned formula (I)
Figure BDA0003119219430000077
The combination of the substitution positions of the units is as follows: 3,8, 13-position, or 2,7, 12-position. Hereinafter, for convenience, the compound of formula (I) corresponding to the 3,8, 13-position of the substitution is referred to as "M-type" compound, and the compound of formula (I) corresponding to the 2,7, 12-position of the substitution is referred to as "N-type" compound.
In the invention, the red light thermal-induced delayed fluorescence material shown in the formula (I) is preferably one or more of the following compounds:
Figure BDA0003119219430000081
Figure BDA0003119219430000091
the red light thermal-induced delayed fluorescent material is a red light thermal-induced delayed fluorescent material with a multi-arm star-shaped structure shown in a formula (I), the band gap is narrow, and the energy level difference between a first excited singlet state and a first excited triplet state is small, so that the compound has red thermal-induced delayed fluorescence emission property; moreover, the rigid indenone receptor unit contains three carbonyl groups, the reverse intersystem crossing rate of the electroluminescent material based on the indenone derivative is favorably improved by utilizing the high intersystem crossing rate of the carbonyl groups, and meanwhile, the rigid plane structure is favorable for inhibiting non-radiative transition and improving the luminescent performance of the material. Meanwhile, the indenone derivative shown in the formula (I) has a multi-arm star-shaped structure, so that the intermolecular interaction is favorably weakened, the solubility of the material is improved, a solution processing device is convenient, and the organic electroluminescent device prepared by using the material can realize saturated red light emission. In addition, the preparation method of the compound provided by the invention is simple and high in yield, and when the obtained compound is used for manufacturing a device, simple solution processing modes such as spin coating, ink jet printing and the like can be used, so that the manufacturing process of the electroluminescent device is simplified.
The invention also provides a preparation method of the red light thermal induction delayed fluorescence material in the technical scheme, which comprises the following steps:
a) carrying out Aldol condensation reaction on the bromoindanone X to form a tribromo truxene intermediate Y;
b) reacting the tribromo truxene intermediate Y with arylboronic acid ester Z to form a multi-arm star-shaped precursor L;
c) carrying out oxidation reaction on the multi-arm star-shaped precursor L to form a red light thermal induction delayed fluorescent material shown in a formula (I);
Figure BDA0003119219430000101
in the formula Z, the aryl Ar-is
Figure BDA0003119219430000102
And (4) units.
With respect to step a): bromo indanone X is subjected to Aldol condensation reaction to form tribromo truxene intermediate Y.
In the invention, the bromoindanone is shown as formula X:
Figure BDA0003119219430000103
preferably, the bromoindanone X is 5-bromoindanone or 6-bromoindanone. When 6-bromoindanone is taken as a raw material, the corresponding compound of the formula (I) is an M-type compound with 3,8 and 13-substituted positions; when 5-bromoindanone is used as a raw material, the corresponding compound of the formula (I) is an N-type compound with the substitution positions of 2,7 and 12-positions.
In the invention, the temperature of Aldol condensation reaction (namely Aldol condensation reaction, also called Aldol condensation reaction) is preferably 120-135 ℃; the reaction time is preferably 48-72 h.
In the present invention, the reaction is preferably carried out in the presence of p-toluenesulfonic acid monohydrate and propionic acid; the p-toluenesulfonic acid monohydrate is used as a catalyst, the propionic acid is used as an additive, the propionic acid can play a role in solvation of p-toluenesulfonic acid anions, and the yield of products can be improved after the propionic acid is added. The mol ratio of the p-toluenesulfonic acid monohydrate to the bromoindanone X is preferably 1 to (3.3-4.5). The preferable dosage ratio of the propionic acid to the bromoindanone X is (3.5-4.8) mL: 1 mmol.
In the present invention, the condensation reaction is preferably carried out in an organic solvent. The organic solvent is preferably ortho-dichlorobenzene. In the present invention, the organic solvent is preferably a dry organic solvent. In the invention, the dosage ratio of the bromoindanone X to the organic solvent is preferably 1mmol to (2.1-4.2) mL.
In the present invention, the specific operation process of the step a) is preferably as follows: dissolving bromo-indanone X in an organic solvent, adding p-toluenesulfonic acid monohydrate and propionic acid, and heating to a target temperature for condensation reaction. After the condensation reaction, the tribromo truxene intermediate Y is formed.
In the invention, after the condensation reaction, reaction liquid containing tribromo truxene intermediate Y is obtained. In the present invention, the reaction solution is preferably subjected to a post-treatment. The post-treatment is preferably: mixing the obtained reaction solution with an alcohol solvent, adjusting the pH value of the solution to be neutral, separating out a large amount of solids, filtering, and washing a filter cake to obtain a tribromo truxene intermediate Y;
Figure BDA0003119219430000111
with respect to step b): and reacting the tribromo truxene intermediate Y with arylborate Z to form a multi-arm star-shaped precursor L.
In the invention, the arylboronic acid ester Z has the following structure:
Figure BDA0003119219430000112
in the arylboronic acid esters of the formula Z, the aryl Ar-group corresponds to that of the compounds of the formula (I)
Figure BDA0003119219430000113
The structure and the type of the D unit are the same as those described in the foregoing technical solutions, and are not described herein again. The arylboronic acid ester of the formula Z is not particularly limited in its origin, and may be generally commercially available or prepared according to a conventional preparation method well known to those skilled in the art.
Preferably, the arylboronic acid ester Z is selected from the following compounds:
Figure BDA0003119219430000114
Figure BDA0003119219430000121
wherein:
R1、R2independently selected from: C4-C30 alkyl, C4-C30 alkoxy or C6-C35 substituted aryl. Preferably, R1、R2Independently selected from: -C6H13Tert-butyl, -C8H17- (2-ethyl) hexyl or 1-octylnonyl.
In some embodiments of the invention, the arylboronic acid ester Z is selected from the following compounds:
Figure BDA0003119219430000131
in the invention, the molar ratio of the tribromo truxene intermediate Y to the arylboronic acid ester Z is preferably 1: 3.3-4.2.
In the present invention, the tribromoterpolyindene intermediateIntroducing 3 donor segments to the tribromo truxene intermediate Y through Suzuki coupling reaction between the Y and arylborate Z
Figure BDA0003119219430000132
Thereby forming a multi-arm star precursor L.
In the present invention, the reaction is preferably carried out in the presence of a catalyst and an organophosphine ligand. Among them, the catalyst is preferably tris (dibenzylideneacetone) dipalladium. The organophosphorus ligand is preferably tri-tert-butylphosphine tetrafluoroborate and/or 2-dicyclohexylphosphine-2 ', 6 ' -dimethoxy-1, 1 ' -biphenyl (Sphos). Wherein the molar ratio of the catalyst to the tribromotrimer indene intermediate Y is preferably (0.05-0.1) to 1. The mol ratio of the organic phosphine ligand to the tribromo truxene intermediate Y is preferably (0.15-0.4) to 1.
In the present invention, the reaction is preferably carried out in an organic solvent medium. The organic solvent is preferably toluene. In the invention, the dosage ratio of the organic solvent to the tribromotriazine indene intermediate Y is preferably (12-18) mL: 1 mmol.
In the present invention, the reaction is preferably carried out under a protective atmosphere. The kind of gas providing the protective atmosphere is not particularly limited, and may be an inert gas conventional in the art, such as nitrogen or argon.
In the present invention, the reaction is preferably: reacting at room temperature for a period of time, adding an alkaline solution, and then heating for reaction. Wherein the room temperature is specifically 18-25 ℃; the reaction time at room temperature is preferably 0.5-1 h. The alkaline substance in the alkaline solution is preferably potassium carbonate and/or potassium phosphate. The alkaline solution is preferably an alkaline solution after oxygen removal. The concentration of the alkaline solution is preferably 2-4M. The dosage ratio of the alkaline solution to the tribromotriazine indene intermediate Y is preferably (2-6) mL: 1 mmol. In the invention, the temperature rise reaction is preferably raised to 90-120 ℃; after the temperature is raised to the target temperature, the reaction time is preferably 16-48 h. Through the reaction, the multi-arm star-shaped precursor L is formed in the system.
In the present invention, after the above reaction, the following post-treatment is preferably further performed: extracting by using dichloromethane, collecting an organic phase, concentrating, and purifying the obtained crude product by using a silica gel chromatographic column to obtain a multi-arm star-shaped precursor L;
Figure BDA0003119219430000141
the type of the D unit is the same as that described in the foregoing technical solution, and is not described herein again.
Figure BDA0003119219430000142
The substituted positions of the units in the above formula L are the same as those in the above formula (I), and are not described herein again.
With respect to step c): and (3) carrying out oxidation reaction on the multi-arm star-shaped precursor L to form the red light thermal induction delayed fluorescent material shown in the formula (I).
In the present invention, the oxidation reaction is preferably carried out under the action of an oxidizing agent and an alkaline substance. The oxidant is preferably oxygen. The basic substance is preferably benzyltrimethoxyammonium hydroxide. The alkaline substance is preferably introduced in the form of an alkaline solution. The solvent in the alkali solution is preferably methanol. The concentration of the alkali solution is preferably 40 wt%, and the methanol solution of benzyltrimethoxyammonium hydroxide having a concentration of 40 wt% is commercially available and can be directly purchased from reagent companies. The dosage ratio of the alkali solution to the multi-arm star-shaped precursor L is preferably (4-8) mL: 1 mmol.
In the present invention, the reaction is preferably carried out in an organic solvent medium. The organic solvent is preferably pyridine. The dosage ratio of the organic solvent to the multi-arm star-shaped precursor L is preferably (25-35) mL: 1 mmol.
In the present invention, the temperature of the oxidation reaction is not particularly limited, and the oxidation reaction may be carried out at room temperature. The room temperature is specifically 18-25 ℃; the time of the oxidation reaction is preferably 24-72 h. Through the reaction, the red light heat-induced delayed fluorescence compound shown in the formula (I) is formed in the system.
In the present invention, after the above-mentioned oxidation reaction, the following post-treatment is preferably further performed: adding dichloromethane into the system for dilution, adjusting the pH value to be neutral by using acid liquor, washing an organic phase, drying, and purifying an obtained crude product by using a silica gel chromatographic column to obtain the red light thermal-induced delayed fluorescent material shown in the formula (I);
Figure BDA0003119219430000151
the type of the D unit is the same as that described above, and is not described herein again.
Figure BDA0003119219430000152
The positions of the units in formula (I) are the same as those described above and will not be described in detail here.
The molecules of the multi-arm star-shaped structure have a plurality of modification sites, so that the molecular weight can be improved, the solubility and the film-forming property of the material are improved, meanwhile, the intermolecular acting force is weak, a plurality of transition channels exist, and the improvement of the luminescent property of the material and the solution processing are facilitated. Therefore, how to obtain a red TADF material with a star structure, which has a simple synthesis method, high photoluminescence efficiency and is solution processable, is also a problem to be solved. The preparation method provided by the invention is simple and feasible, and can efficiently synthesize the compound with the multi-arm star-shaped structure shown in the formula (I).
The invention also provides an organic electroluminescent device, wherein a luminescent layer in the organic electroluminescent device contains a fluorescent material; the fluorescent material is the red light thermal induction delayed fluorescent material shown in the formula (I) in the technical scheme or the red light thermal induction delayed fluorescent material shown in the formula (I) prepared by the preparation method in the technical scheme.
In the invention, the light-emitting layer comprises a fluorescent material and a host material; wherein the mass of the fluorescent material is preferably 1-15% of the total mass of the fluorescent material and the main body material. The type of the host material is not particularly limited, and the host material may be a host material of a light emitting layer in an organic electroluminescent device in the prior art.
In the present invention, the light emitting layer can be processed in the following manner: the fluorescent material and the host material are dissolved in an organic solvent, and a film is formed to form a light-emitting layer. Wherein, the organic solvent preferably comprises at least one of chlorobenzene, dichlorobenzene, xylene and chloroform. The film-forming manner is not particularly limited, and may be a conventional preparation means in a solution processing type manner, such as spin coating, ink jet printing, or printing film-forming.
The organic electroluminescent device comprises a substrate, an anode layer, a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, an electron injection layer and a cathode layer which are sequentially stacked. The types and thicknesses of the rest layers except the light-emitting layer are not particularly limited, and the layers are conventional materials and conventional specifications in organic electroluminescent devices in the field. In the invention, the organic electroluminescent device is a light-emitting diode device.
Compared with the prior art, the invention has the following beneficial effects: 1) the red thermal-induced delayed fluorescence material with the multi-arm star structure is synthesized for the first time, and the luminous performance of the material can be regulated and controlled by introducing different donor fragments. 2) The synthesized star-shaped structure molecule based on the indenone receptor has good solubility and can be dissolved in most organic solvents, such as dichloromethane, toluene, chloroform, dichlorobenzene and the like; 3) the synthesized star TADF material based on the indenone has good red heat-induced delayed fluorescence property, can be applied to a solution-processed organic electroluminescent device, and realizes saturated red light emission.
For a further understanding of the invention, reference will now be made to the preferred embodiments of the invention by way of example, and it is to be understood that the description is intended to further illustrate features and advantages of the invention, and not to limit the scope of the claims. In the following examples, room temperature means 23 ℃.
Intermediate preparation example 1: the synthetic route for preparing the 3,8, 13-tribromoterphthalene intermediate (i.e. 3,8, 13-substituted form, i.e. Y-M) is as follows:
Figure BDA0003119219430000161
the preparation process comprises the following steps:
6-bromoindanone (3.0g,14.2mmol) and p-toluenesulfonic acid monohydrate (9.5g, 49.9mmol) were dissolved in dry o-dichlorobenzene (45mL), propionic acid (3.7mL) was added with stirring at room temperature, and the system was heated to 135 ℃ for reflux reaction for 72 h. After the reaction is finished, the reaction solution is cooled to room temperature, the reaction solution is poured into 100mL of methanol, 1M of NaOH aqueous solution is used for adjusting the pH value of the system to be neutral, a large amount of precipitate is separated out at the time, the filtration is carried out, and a filter cake is washed by methanol and ethanol in sequence to obtain an intermediate Y-M, wherein the light yellow solid is 2.3g, and the yield is 84%.
Intermediate preparation example 2: preparation of 2,7, 12-tribromoterphthalene intermediate (i.e. 2,7, 12-substituted, noted Y-N)
The synthetic route is as follows:
Figure BDA0003119219430000171
the preparation process comprises the following steps:
the procedure is as for intermediate preparation 1 except that the starting material 6-bromoindanone is replaced with 5-bromoindanone. As a result, the obtained product, intermediate Y-N, was a pale yellow solid with a yield of 81%.
Example 1: preparation of a Compound of formula (I) -formula I-M form-a 1
The synthetic route is as follows:
Figure BDA0003119219430000172
the preparation process comprises the following steps:
the intermediate Y-M (600mg, 1.0mmol) and 9, 9-dihexyl-10- (4-pinacolboronate phenyl) -9, 10-dihydroacridine represented by the formula a1 (2.0g, 3.63mmol) were dissolved in dry toluene (40mL), tris (dibenzylideneacetone) dipalladium (95mg, 0.10mmol) and tri-tert-butylphosphine tetrafluoroborate (96mg, 0.33mmol) were added under argon protection, and the mixture was reacted at room temperature for 0.5h, then an oxygen-removed 2M aqueous potassium carbonate solution (3mL) was added, and after stirring at room temperature for 0.5h, the reaction system was heated to 110 ℃ and refluxed for 24 h. After the reaction, the reaction solution is cooled to room temperature, poured into water, extracted with dichloromethane for three times, organic phases are combined and washed with water for 2 times, saturated salt solution is washed with water for 1 time, dried by anhydrous sodium sulfate, filtered and the solvent is evaporated to dryness. The crude product was subjected to silica gel column chromatography (petroleum ether: dichloromethane ═ 4:1 to 2:1) to give 0.96g of the precursor compound L-M form-a 1 as a pale yellow solid in 58% yield.
Precursor compound L-M form-a 1(620mg, 0.38mmol) and pyridine (9mL) were added to a 50mL single-neck flask, stirred at room temperature to form a pale yellow suspension, benzyltrimethylammonium hydroxide solution (Triton B,40 wt% in MeOH,2.2mL) was added, the reaction turned dark red instantly, and reacted under oxygen at room temperature for 48 h. After completion of the reaction, the reaction mixture was poured into 100mL of methylene chloride, and the pH was adjusted to about 7 with 1M aqueous hydrochloric acid solution. The organic phase was washed with water 2 times, saturated brine 1 time, dried over anhydrous sodium sulfate, filtered, and the solvent was evaporated. The crude product was subjected to silica gel column chromatography (petroleum ether: dichloromethane ═ 2:1) to give the desired product i-M form-a 1(502mg) as a red solid in 79% yield.1H NMR(500MHz,CDCl3)δ9.74(s,1H),8.07(d,J＝8.3Hz,2H),7.98(d,J＝7.7Hz,1H),7.89(dd,J＝7.7,1.3Hz,1H),7.47(d,J＝8.4Hz,2H),7.34(dd,J＝7.8,1.3Hz,2H),7.01-6.94(m,2H),6.89(dd,J＝10.8,4.1Hz,2H),6.27(dd,J＝8.3,0.9Hz,2H),2.03-1.93(m,4H),1.25-1.07(m,16H),0.83(t,J＝6.9Hz,6H)。
Example 2: preparation of compound of formula (I) -formula I-N form-a 1
The synthetic route is as follows:
Figure BDA0003119219430000181
the preparation process comprises the following steps:
the intermediate Y-N (600mg, 1.0mmol) and 9, 9-dihexyl-10- (4-pinacolboronate phenyl) -9, 10-dihydroacridine represented by the formula a1 (2.0g, 3.63mmol) were dissolved in dry toluene (40mL), tris (dibenzylideneacetone) dipalladium (95mg, 0.10mmol) and tri-tert-butylphosphine tetrafluoroborate (96mg, 0.33mmol) were added under argon protection, and the mixture was reacted at room temperature for 0.5h, then an oxygen-removed 2M aqueous potassium carbonate solution (3mL) was added, and after stirring at room temperature for 0.5h, the reaction system was heated to 110 ℃ and refluxed for 24 h. After the reaction, the reaction solution is cooled to room temperature, poured into water, extracted with dichloromethane for three times, organic phases are combined and washed with water for 2 times, saturated salt solution is washed with water for 1 time, dried by anhydrous sodium sulfate, filtered and the solvent is evaporated to dryness. The crude product was subjected to silica gel column chromatography (petroleum ether: dichloromethane ═ 4:1 to 2:1) to give 1.01g of the precursor compound L-N form-a 1 as a pale yellow solid in a yield of 61%.
Precursor compound L-N form-a 1(800mg, 0.50mmol) and pyridine (12mL) were added to a 50mL single-neck flask, stirred at room temperature to form a pale yellow suspension, benzyltrimethylammonium hydroxide solution (Triton B,40 wt% in MeOH,2.9mL) was added, the reaction turned dark red instantly, and reacted under oxygen at room temperature for 48 h. After completion of the reaction, the reaction mixture was poured into 100mL of methylene chloride, and the pH was adjusted to about 7 with 1M aqueous hydrochloric acid solution. The organic phase was washed with water 2 times, saturated brine 1 time, dried over anhydrous sodium sulfate, filtered, and the solvent was evaporated. The crude product was subjected to silica gel column chromatography (petroleum ether: dichloromethane ═ 2:1) to give the desired product i-N form-a 1(588mg) as a red solid in 71% yield.1H NMR(500MHz,CDCl3)δ9.88(s,1H),8.09(d,J＝8.3Hz,2H),7.96(d,J＝7.7Hz,1H),7.87(dd,J＝7.7,1.3Hz,1H),7.17(d,J＝8.4Hz,2H),7.38(dd,J＝7.8,1.3Hz,2H),7.11-6.83(m,2H),6.91(dd,J＝10.8,4.1Hz,2H),6.30(dd,J＝8.3,0.9Hz,2H),2.05-1.92(m,4H),1.27-1.05(m,16H),0.84(t,J＝6.9Hz,6H)。
Example 3: preparation of a Compound of formula (I) -formula I-M form-a 3
The synthetic route is as follows:
Figure BDA0003119219430000191
the preparation process comprises the following steps:
the intermediate Y-M (600mg, 1.04mmol) and 4-tert-butyl-N- (4-tert-butylphenyl) -N- (4- (pinacolato boronato) phenyl) aniline represented by the formula a3 (1.76g, 3.63mmol) were dissolved in dry toluene (40mL), and under the protection of argon, tris (dibenzylideneacetone) dipalladium (95mg, 0.10mmol) and tri-tert-butylphosphine tetrafluoroborate (96mg, 0.33mmol) were added to react at room temperature for 0.5h, an oxygen-removed 2M aqueous potassium carbonate solution (3mL) was added thereto, and after stirring at room temperature for half an hour, the reaction system was heated to 110 ℃ and refluxed for 24 h. After the reaction, the reaction solution is cooled to room temperature, poured into water, extracted with dichloromethane for three times, organic phases are combined and washed with water for 2 times, saturated salt solution is washed with water for 1 time, dried by anhydrous sodium sulfate, filtered and the solvent is evaporated to dryness. The crude product was chromatographed on a silica gel column (gradient elution: petroleum ether: dichloromethane ═ 1:1 → 1:2) to give 0.89g of the precursor compound Y-M form-a 3 as a pale yellow solid in 61% yield.
Precursor compound Y-M form-a 3(700mg, 0.50mmol) and pyridine (12mL) were added to a 50mL single-neck flask, stirred at room temperature to form a pale yellow suspension, benzyltrimethylammonium hydroxide solution (Triton B,40 wt% in MeOH,3.0mL) was added, the reaction turned dark red instantly, and reacted under oxygen at room temperature for 48 h. After completion of the reaction, the reaction mixture was poured into 100mL of methylene chloride, and the pH was adjusted to about 7 with 1M aqueous hydrochloric acid solution. The organic phase was washed with water 2 times, saturated brine 1 time, dried over anhydrous sodium sulfate, filtered, and the solvent was evaporated. The crude product was separated by silica gel column chromatography (gradient elution: petroleum ether: dichloromethane: 1 → dichloromethane → methanol: 100:1) to give the desired product i-M form-a 3(530mg) as a red solid in 73% yield.1H NMR(500MHz,CDCl3)δ9.71(s,1H),8.10(d,J＝7.8Hz,1H),7.88(d,J＝7.8Hz,1H),7.79(d,J＝8.3Hz,2H),7.45(d,J＝8.4Hz,2H),7.32(d,J＝8.6Hz,4H),6.93(d,J＝8.7Hz,4H),1.28(s,18H)。
Example 4: preparation of a Compound of formula (I) -formula I-M form-a 2
The synthetic route is as follows:
Figure BDA0003119219430000201
the preparation process comprises the following steps:
dissolving the intermediate Y-M (600mg, 1.04mmol) and 3, 6-di-tert-butyl-N- (4- (pinacolato boronato) phenyl) -9H-carbazole shown in the formula a2 (1.75g, 3.63mmol) in dry toluene (40mL), adding tris (dibenzylideneacetone) dipalladium (95mg, 0.10mmol) and tri-tert-butylphosphine tetrafluoroborate (96mg, 0.33mmol) under the protection of argon, reacting at room temperature for 0.5H, adding an oxygen-removed 2M potassium carbonate aqueous solution (3mL), stirring at room temperature for half an hour, heating the reaction system to 110 ℃, and carrying out reflux reaction for 24H. After the reaction, the reaction solution is cooled to room temperature, poured into water, extracted with dichloromethane for three times, organic phases are combined and washed with water for 2 times, saturated salt solution is washed with water for 1 time, dried by anhydrous sodium sulfate, filtered and the solvent is evaporated to dryness. The crude product was subjected to silica gel column chromatography (petroleum ether: dichloromethane ═ 5:1) to give 0.79g of the precursor compound L-M form-a 2 as a white solid in 54% yield.
Precursor compound L-M form-a 2(650mg, 0.46mmol) and pyridine (12mL) were added to a 50mL single-neck flask, stirred at room temperature to form a pale yellow suspension, benzyltrimethylammonium hydroxide solution (Triton B,40 wt% in MeOH,3.0mL) was added, the reaction turned dark red instantly, and reacted under oxygen at room temperature for 48 h. After completion of the reaction, the reaction mixture was poured into 100mL of methylene chloride, and the pH was adjusted to about 7 with 1M aqueous hydrochloric acid solution. The organic phase was washed with water 2 times, saturated brine 1 time, dried over anhydrous sodium sulfate, filtered, and the solvent was evaporated. The crude product was chromatographed on a silica gel column (gradient elution: petroleum ether: dichloromethane ═ 5:1 → 4:1) to give the desired product i-M form-a 2(518mg) as an orange-red solid in 78% yield.1H NMR(500MHz,CDCl3)δ9.66(s,1H),8.17(d,J＝1.5Hz,2H),7.97(d,J＝7.9Hz,1H),7.76(dd,J＝8.0,1.4Hz,1H),7.66(d,J＝8.3Hz,2H),7.49(d,J＝8.4Hz,2H),7.41(d,J＝8.7Hz,2H),7.33(dd,J＝8.7,1.7Hz,2H),1.47(s,18H)。
Example 5: preparation of the compound of formula (I) -formula I-M form-b 3
The synthetic route is as follows:
Figure BDA0003119219430000211
the preparation process comprises the following steps:
dissolving the intermediate Y-M (420mg, 0.73mmol) and 1-phenyl-3, 6-di-tert-butyl-N- (4- (pinacolboronato) phenyl) -9H-carbazole shown as a formula b3 (1.75g, 2.54mmol) in dry toluene (30mL), adding tris (dibenzylideneacetone) dipalladium (67mg, 0.07mmol) and 2-dicyclohexylphosphine-2 ', 6 ' -dimethoxy-1, 1 ' -biphenyl (95mg, 0.23mmol) under the protection of argon, reacting at room temperature for 0.5H, adding an oxygen-removed 2M potassium carbonate aqueous solution (2.5mL), stirring at room temperature for half an hour, heating the reaction system to 110 ℃, and carrying out reflux reaction for 24H. After the reaction, the reaction solution is cooled to room temperature, poured into water, extracted with dichloromethane for three times, organic phases are combined and washed with water for 2 times, saturated salt solution is washed with water for 1 time, dried by anhydrous sodium sulfate, filtered and the solvent is evaporated to dryness. The crude product was subjected to silica gel column chromatography (petroleum ether: dichloromethane ═ 5:1) to give 0.57g of the precursor compound L-M form-b 3 as a white solid in 48% yield.
Precursor compound L-M form-B3 (550mg, 0.34mmol) and pyridine (10mL) were added to a 50mL single-neck flask, stirred at room temperature to form a pale yellow suspension, benzyltrimethylammonium hydroxide solution (Triton B,40 wt% in MeOH,2.5mL) was added, the reaction turned red instantly, and the reaction was allowed to react at room temperature for 36h under oxygen. After completion of the reaction, the reaction mixture was poured into 80mL of methylene chloride, and the pH was adjusted to about 7 with 1M aqueous hydrochloric acid solution. The organic phase was washed with water 2 times, saturated brine 1 time, dried over anhydrous sodium sulfate, filtered, and the solvent was evaporated. The crude product was chromatographed on a silica gel column (gradient elution: petroleum ether: dichloromethane ═ 5:1 → 4:1) to give the desired product i-M form-b 3(369mg) as an orange-red solid in 65% yield.1H NMR(500MHz,CDCl3)δ9.53(s,1H),8.35(d,J＝8.2Hz,1H),8.28-8.25(m,2H),8.00(d,J＝1.8Hz,2H),7.92(d,J＝8.0Hz,1H),7.86(dd,J＝8.1,2.1Hz,1H),7.81-7.73(m,2H),7.52(d,J＝1.8Hz,2H),7.40(d,J＝8.1Hz,1H)1.51(s,9H),1.48(s,9H).
Example 6: preparation of the compound of formula (I) -formula I-M form-c 3
The synthetic route is as follows:
Figure BDA0003119219430000221
the preparation process comprises the following steps:
dissolving the intermediate Y-M (500mg, 0.86mmol) and 2, 5-di-tert-butyl-5- (9-heptadecyl) -11- (4- (pinacolboronic acid ester) phenyl) -5, 11-indolino [3,2, b ] carbazole shown in the formula c3 (2.44g, 3.63mmol) in dry toluene (60mL), adding tris (dibenzylideneacetone) dipalladium (73mg, 0.08mmol) and 2-dicyclohexylphosphine-2 ', 6 ' -dimethoxy-1, 1 ' -biphenyl (99mg, 0.24mmol) under the protection of argon, reacting at room temperature for 0.5h, adding an oxygen-removed 2M potassium carbonate aqueous solution (3mL), stirring at room temperature for half an hour, heating the reaction system to 110 ℃, and carrying out reflux reaction for 24 h. After the reaction, the reaction solution is cooled to room temperature, poured into water, extracted with dichloromethane for three times, organic phases are combined and washed with water for 2 times, saturated salt solution is washed with water for 1 time, dried by anhydrous sodium sulfate, filtered and the solvent is evaporated to dryness. The crude product was subjected to silica gel column chromatography (petroleum ether: dichloromethane ═ 3:1) to give 0.88g of precursor compound L-M form-c 3 as a white solid in 43% yield.
Precursor compound L-M form-c 3(800mg, 0.34mmol) and pyridine (15mL) were added to a 50mL single-neck flask, stirred at room temperature to form a pale yellow suspension, benzyltrimethylammonium hydroxide solution (Triton B,40 wt% in MeOH,2.7mL) was added, the reaction turned instantly deep red, and reacted at room temperature under oxygen for 36 h. After completion of the reaction, the reaction mixture was poured into 90mL of methylene chloride, and the pH was adjusted to about 7 with 1M aqueous hydrochloric acid solution. The organic phase was washed with water 2 times, saturated brine 1 time, dried over anhydrous sodium sulfate, filtered, and the solvent was evaporated. The crude product was chromatographed on a silica gel column (gradient elution: petroleum ether: dichloromethane ═ 4:1 → 1:1) to give the desired product i-M form-c 3(437mg) as a red solid in 53% yield.1H NMR(500MHz,CDCl3)δ9.71(s,1H),8.65(dd,J＝1.7Hz,1H),8.36(dd,J＝1.5Hz,1H),8.12(d,J＝8.3Hz,2H),7.98(d,J＝7.9Hz,1H),7.81(d,J＝8.0Hz,2H),7.64(d,J＝8.1Hz,1H),7.58-7.52(m,3H),7.17(s,2H),6.98(d,J＝7.8Hz,1H),4.51-4.89(m,1H),1.45-1.02(m,46H),0.83(t,J＝7.1Hz,6H).
Example 7
The products obtained in the examples were each dissolved in a toluene solution (concentration: 10)-5mol/L), performance tests are carried out:
testing ultraviolet/visible light absorption, room temperature fluorescence and low temperature phosphorescence spectra, and respectively referring to the results in FIGS. 1-3; wherein, FIG. 1FIG. 2 is a chart showing the UV/visible absorption, room temperature fluorescence and low temperature phosphorescence spectra of the product I-M form-a 1 obtained in example 1 in a toluene solution, FIG. 2 is a chart showing the UV/visible absorption, room temperature fluorescence and low temperature phosphorescence spectra of the product I-M form-a 3 obtained in example 3 in a toluene solution, and FIG. 3 is a chart showing the UV/visible absorption, room temperature fluorescence and low temperature phosphorescence spectra of the product I-M form-a 2 obtained in example 4 in a toluene solution. It can be seen that the products I-M form-a 1, I-M form-a 3 and I-M form-a 2 obtained in examples 1,3 and 4 have PL maximum emission peaks at 614nm, 609nm and 588nm in toluene solution, and the S of the compound is calculated according to the room temperature fluorescence spectrum and the low temperature phosphorescence spectrum of the compound in toluene solution1And T1Energy level, and the difference in energy level between the two, Δ ESTThe band gap and solution photoluminescence quantum efficiency of the compounds were calculated, and the results are shown in table 1. As can be seen from Table 1, the products I-M form-a 1, I-M form-a 3 and I-M form-a 2 obtained in examples 1,3 and 4 all have a smaller Δ EST(specifically 0.14-0.22 eV) and moderate photoluminescence quantum efficiency (specifically 0.56-0.74).
Testing a transient fluorescence spectrum attenuation curve, and referring to the results in FIGS. 4-5; wherein, FIG. 4 is the transient fluorescence spectrum attenuation curve of the product I-M form-a 1 obtained in example 1 in toluene solution, and FIG. 5 is the transient fluorescence spectrum attenuation curve of the product I-M form-a 3 obtained in example 3 in toluene solution. It can be seen that the products I-M form-a 1 and I-M form-a 3 obtained in examples 1 and 3 both exhibit a nanoscale lifetime transient emission and a microsecond lifetime delayed emission, confirming the thermally induced delayed fluorescence properties of the above compounds. In addition, the proportion of delayed fluorescence moiety was as high as 59% to 74%, indicating that the triplet excitons were mostly utilized.
FIG. 6 is a thermogravimetric analysis of the product I-M form-a 1 obtained in example 1, showing that the compound mass loss of 5% corresponds to a temperature of 421 ℃ indicating that compound I-M form-a 1 has good thermal stability.
As can be seen from Table 1, by selecting different Ar units, the resulting compounds have different Δ ESTA retardation component lifetime, a retardation component ratio, and a light emitting efficiency. Therefore, can be regulated and controlledThe D unit finely adjusts the luminescence property of the indenone derivative, so that the compound has efficient red heat-induced delayed fluorescence emission property.
Table 1 luminescence properties of the compounds obtained in the examples
Figure BDA0003119219430000241
As can be seen from the accompanying drawings and the test results in Table 1, the compound of formula (I) provided by the invention has a solution state PL emission peak above 588nm and a difference delta E between singlet state and triplet state energy levelsSTThe solution state luminous efficiency is more than 0.56 below 0.22eV, and high luminous efficiency is shown; and can present instantaneous emission with nanometer-scale lifetime and delayed emission with microsecond-scale lifetime, has the property of thermally induced delayed fluorescence, and the proportion of the delayed fluorescence is up to more than 59%.
Example 8
1. Preparing an organic electroluminescent device:
on a prepared Indium Tin Oxide (ITO) glass, acetone and deionized water are sequentially used for ultrasonic cleaning, and plasma treatment is carried out for 10 minutes. The PEDOT film was spin coated on ITO and annealed at 120 ℃ for 45 minutes to a thickness of about 40 nm. A solution of mCP in chlorobenzene, product I-M form-a 1 from example 3 (10mg/mL, mCP: the compound from example 3 in a weight ratio of 99: 1) was then spin coated in a nitrogen glove box and annealed at 100 ℃ for 30 minutes to give a light-emitting layer of about 40nm thickness. Then, the subsequent TmPyPB (60nm)/LiF (1nm)/Al (100nm) was obtained by vapor deposition in this order.
2. And (3) performance testing:
the test results of the obtained organic electroluminescent device are shown in fig. 7-11, wherein fig. 7 is an EL spectrum of the organic electroluminescent device based on the product of example 1, fig. 8 is a current density-voltage-luminance relationship diagram of the organic electroluminescent device based on the product of example 1, fig. 9 is a current efficiency-luminance relationship diagram of the organic electroluminescent device based on the product of example 1, fig. 10 is a power efficiency-luminance relationship diagram of the organic electroluminescent device based on the product of example 1, and fig. 11 is a CIE diagram of the organic electroluminescent device based on the product of example 1.
As can be seen from the above test results, the organic electroluminescent device based on the product of example 1 had an EL emission peak of 651nm, a turn-on voltage of 4.3V, and a maximum luminance of 2012cd/m2The current efficiency is 1.82cd/A, the power efficiency is 0.92lm/W, the external quantum efficiency is 2.1%, the color coordinates are (0.64,0.36), and the color coordinates are close to the standard red color coordinates (0.65,0.35) specified by the International Commission on illumination (CIE), which shows that the solution processing type saturated red TADF-OLED device can be obtained by the design scheme.
The foregoing examples are provided to facilitate an understanding of the principles of the invention and their core concepts, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. It should be noted that, for those skilled in the art, it is possible to make various improvements and modifications to the present invention without departing from the principle of the present invention, and those improvements and modifications also fall within the scope of the claims of the present invention. The scope of the invention is defined by the claims and may include other embodiments that occur to those skilled in the art. Such other embodiments are intended to be within the scope of the claims if they have structural elements that approximate the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.

Claims (10)

1. A red light thermal-induced delayed fluorescent material has a structure shown in formula (I):
Figure FDA0003119219420000011
wherein:
the D unit is a donor unit with electron supply capacity and is selected from: substituted or unsubstituted aryl of C18-C80, substituted or unsubstituted heteroaryl of C18-C75; the heteroatoms in the heteroaryl group are nitrogen and/or oxygen.
2. A luminescent material as claimed in claim 1, wherein the D unit is selected from: substituted aryl of C26-C45 and substituted heteroaryl of C26-C45.
3. A luminescent material as claimed in claim 1, wherein the D unit is selected from the following structures:
Figure FDA0003119219420000012
Figure FDA0003119219420000021
wherein:
R1、R2independently selected from: C4-C30 alkyl, C4-C30 alkoxy or C6-C35 substituted aryl.
4. The phosphor according to claim 1, wherein 3 of the compounds of formula (I)
Figure FDA0003119219420000022
The substitution positions of the units are respectively: 2-or 3-position, 7-or 8-position, 12-or 13-position.
5. The fluorescent material according to claim 1 or 4, wherein 3 of the compounds of formula (I)
Figure FDA0003119219420000023
The combination of the substitution positions of the units is in the 3,8, 13-position or in the 2,7, 12-position.
6. The preparation method of the red light thermal-induced delayed fluorescent material as claimed in any one of claims 1 to 5, characterized by comprising the following steps:
a) carrying out Aldol condensation reaction on the bromoindanone X to form a tribromo truxene intermediate Y;
b) reacting the tribromo truxene intermediate Y with arylboronic acid ester Z to form a multi-arm star-shaped precursor L;
c) carrying out oxidation reaction on the multi-arm star-shaped precursor L to form a red light thermal induction delayed fluorescent material shown in a formula (I);
Figure FDA0003119219420000024
in said formula Z, aryl Ar-is as defined in said formula (I)
Figure FDA0003119219420000031
A unit;
in the formula L, the D unit is a donor unit with electron supplying capability and is selected from: substituted or unsubstituted aryl of C18-C80, substituted or unsubstituted heteroaryl of C18-C75; the heteroatoms in the heteroaryl group are nitrogen and/or oxygen.
7. The method of claim 6, wherein the bromoindanone X is 5-bromoindanone or 6-bromoindanone.
8. The preparation method according to claim 6, wherein in the step a), the reaction temperature is 120-135 ℃ and the reaction time is 48-72 hours;
in the step b), the reaction temperature is 90-120 ℃, and the reaction time is 16-48 h;
in the step c), the oxidation reaction is carried out in the presence of an oxidizing agent and a basic substance;
the alkaline substance is benzyltrimethoxyammonium hydroxide.
9. An organic electroluminescent device, wherein a light-emitting layer in the organic electroluminescent device contains a fluorescent material;
the fluorescent material is the red light thermal induction delayed fluorescent material as defined in any one of claims 1 to 5 or the red light thermal induction delayed fluorescent material prepared by the preparation method as defined in any one of claims 6 to 8.
10. The organic electroluminescent device according to claim 9, wherein the light-emitting layer comprises a fluorescent material and a host material;
the mass of the fluorescent material accounts for 1-15% of the total mass of the fluorescent material and the main body material.
CN202110672526.4A 2021-06-17 2021-06-17 Red light thermal induction delay fluorescent material, preparation method thereof and organic electroluminescent device Pending CN113321617A (en)

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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20030008174A1 (en) * 2001-04-27 2003-01-09 Koichi Suzuki Organic luminescence device
CN107602551A (en) * 2017-09-26 2018-01-19 四川大学 A kind of preparation method and applications of the star-like non-fullerene small molecule receptor of broad-band gap
CN110590642A (en) * 2019-09-23 2019-12-20 大连理工大学 Electroluminescent material with indenone as electron acceptor and its application

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20030008174A1 (en) * 2001-04-27 2003-01-09 Koichi Suzuki Organic luminescence device
CN107602551A (en) * 2017-09-26 2018-01-19 四川大学 A kind of preparation method and applications of the star-like non-fullerene small molecule receptor of broad-band gap
CN110590642A (en) * 2019-09-23 2019-12-20 大连理工大学 Electroluminescent material with indenone as electron acceptor and its application

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
GANG ZHANG，ET AL.: "Rigid Conjugated Twisted Truxene Dimers and Trimers as Electron Acceptors", 《ANGEW. CHEM. INT. ED.》 *

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