Thermally excited delayed fluorescence materials based on non-conjugated polymers of phenylacridine and phenyltriazine substituents

Abstract

The present invention provides a non-conjugated polymer thermally excited delayed fluorescent material based on phenyl acridine and phenyl triazine substituents, which is a polymer obtained by polymerizing styrene with acridine substituents and styrene with phenyl triazine substituents as monomers. The material can reduce the triplet energy difference (ΔE ST ), which improves the fluorescence quantum yield (PLQY), improves the luminescence quality, and greatly improves the overall performance of the prepared thermally excited delayed fluorescence light-emitting device.

Description

Technical Field

[0001] The invention belongs to the technical field of electroluminescence, and in particular relates to a non-conjugated polymer thermally excited delayed fluorescence material. Background Art

[0002] In recent years, organic light-emitting diode (OLED) displays have attracted widespread attention due to their advantages, including high power efficiency, excellent color reproduction, and the ability to achieve flexible displays. To improve the efficiency of OLEDs, thermally excited delayed fluorescence (TADF) materials have been the most widely studied. The design mechanism of this type of material is to use donors and acceptors to construct a charge transfer excited state system. When the donor and acceptor have a large torsion angle, the HOMO and LUMO orbitals are almost completely separated, resulting in a small singlet-triplet energy difference, thereby achieving efficient TADF properties. In addition, polymer materials have attracted much attention due to their low preparation cost, easy solution processing, excellent flexibility and ductility, and the ability to adjust electronic properties through structural design and appropriate synthesis strategies.

[0003] Most luminescent polymers with charge transfer (CT) characteristics are based on conjugated DA structures and emission through bond charge transfer (TBCT). Although their luminescent color and excited state energy levels can be adjusted, a large red shift will occur, which is not conducive to regulating the emission color, and ΔE ST There is a contradiction between PLQY.

[0004] Therefore, it is necessary to develop and design strong charge transfer and small ΔE ST Polymer space charge transfer (TSCT) TADF luminescent materials with high PLQY are an effective approach. Summary of the Invention

[0005] In order to solve the above problems, the present invention provides a non-conjugated polymer thermally excited delayed fluorescent material based on phenylacridine and phenyltriazine substituents, which is a non-conjugated polymer with phenylacridine groups as transfer charge donors and phenyltriazine groups as transfer charge acceptors, forming a space charge transfer to achieve a smaller triplet energy difference (ΔE ST ), improves the fluorescence quantum yield (PLQY), avoids red shift, and improves the luminescence quality and overall performance. The invention is obtained by polymerizing styrene with acridine substituents and phenyltriazine substituents. The preparation method is easy to carry out, thereby completing the present invention.

[0006] The first aspect of the present invention provides a non-conjugated polymer thermally excited delayed fluorescent material based on phenylacridine and phenyltriazine substituents, which is a polymer obtained by polymerizing styrene with acridine substituents and styrene with phenyltriazine substituents as monomers.

[0007] A second aspect of the present invention provides a method for preparing the non-conjugated polymer based on phenylacridine and phenyltriazine substituents, wherein the preparation is carried out by addition polymerization of monomers containing styrene with acridine substituents and styrene with phenyltriazine substituents. The method specifically comprises the following steps:

[0008] Step 1, preparing styrene with acridine substituents;

[0009] Step 2, preparing styrene with phenyltriazine substituents;

[0010] Step 3: adding styrene with acridine substituents and styrene with phenyltriazine substituents into a solvent, heating and reacting to obtain a non-conjugated polymer based on phenylacridine and phenyltriazine substituents.

[0011] The non-conjugated polymer thermally excited delayed fluorescent material based on phenylacridine and phenyltriazine substituents and the preparation method thereof provided by the present invention have the following beneficial effects:

[0012] (1) In the present invention, a non-conjugated polymer with phenylacridine groups as charge donors and phenyltriazine groups as charge acceptors was prepared through reasonable molecular design to form a spatial charge transfer to achieve a smaller triplet energy difference (ΔE ST ), which increases the fluorescence quantum yield (PLQY), avoids red shift, and improves the luminescence quality.

[0013] (2) The preparation method of the non-conjugated polymer based on phenylacridine and phenyltriazine substituents provided by the present invention is easy to carry out, the synthesis conditions are easy to control, and the molecular synthesis route is reasonably designed, thereby realizing the synthesis of monomers and the preparation of target products. The obtained polymer has a narrow molecular weight distribution and uniform performance. The performance quality of the light-emitting device prepared thereby is easy to control, which is beneficial to practical applications.

[0014] (3) The light-emitting device prepared by the present invention using the non-conjugated polymer with phenylacridine and phenyltriazine substituents as the light-emitting layer material has excellent luminescence performance and greatly reduces the occurrence of red shift. In addition, the polymer has good thermal stability, high power efficiency and external quantum efficiency, low turn-on voltage, and good overall performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 The ultraviolet fluorescence spectrum of PVP-0.97DMAC-0.03DPhTz synthesized in Example 1 of the present invention is shown, wherein the ■ curve represents the ultraviolet absorption spectrum of the PVP-0.97DMAC-0.03DPhTz film, and the ● curve represents the fluorescence emission spectrum of the PVP-0.97DMAC-0.03DPhTz film;

[0016] Figure 2 The thermogravimetric analysis spectrum of PVP-0.97DMAC-0.03DPhTz synthesized in Example 1 of the present invention is shown;

[0017] Figure 3 FIG2 shows the ultraviolet fluorescence spectrum of PVP-0.92DMAC-0.08DPhTz synthesized in Example 2 of the present invention, wherein the ■ curve represents the ultraviolet absorption spectrum of the PVP-0.92DMAC-0.08DPhTz film, and the ● curve represents the fluorescence emission spectrum of the PVP-0.92DMAC-0.08DPhTz film;

[0018] Figure 4 The thermogravimetric analysis spectrum of PVP-0.92DMAC-0.08DPhTz synthesized in Example 2 of the present invention is shown;

[0019] Figure 5 FIG2 shows the ultraviolet fluorescence spectrum of PVP-0.83DMAC-0.17DPhTz synthesized in Example 3 of the present invention, wherein the ■ curve represents the ultraviolet absorption spectrum of the PVP-0.83DMAC-0.17DPhTz film, and the ● curve represents the fluorescence emission spectrum of the PVP-0.83DMAC-0.17DPhTz film;

[0020] Figure 6 The thermogravimetric analysis spectrum of PVP-0.83DMAC-0.17DPhTz synthesized in Example 3 of the present invention is shown;

[0021] Figure 7 The transient photoluminescence decay curves of the PVP-0.97DMAC-0.03DPhTz film synthesized in Example 1 of the present invention are shown. The ■ curve represents the decay curve at a temperature of 77K, the ● curve represents the decay curve at a temperature of 100K, the ▲ curve represents the decay curve at a temperature of 200K, and the ▼ curve represents the decay curve at a temperature of 300K.

[0022] Figure 8 The transient photoluminescence decay curves of the PVP-0.92DMAC-0.08DPhTz film synthesized in Example 2 of the present invention are shown. The ■ curve represents the decay curve at a temperature of 77K, the ● curve represents the decay curve at a temperature of 100K, the ▲ curve represents the decay curve at a temperature of 200K, and the ▼ curve represents the decay curve at a temperature of 300K.

[0023] Figure 9The transient photoluminescence decay curves of the PVP-0.83DMAC-0.17DPhTz film synthesized in Example 3 of the present invention are shown. The ■ curve represents the decay curve at a temperature of 77K, the ● curve represents the decay curve at a temperature of 100K, the ▲ curve represents the decay curve at a temperature of 200K, and the ▼ curve represents the decay curve at a temperature of 300K.

[0024] Figure 10 The voltage-current density relationship curve of the blue-green light TADF device prepared in Example 4 of the present invention is shown in the figure, with the ◆ curve representing the device based on PVP-0.97DMAC-0.03DPhTz, and the The curve represents a device based on PVP-0.92DMAC-0.08DPhTz, using The curve represents the device based on PVP-0.83DMAC-0.17DPhTz;

[0025] Figure 11 The voltage-brightness relationship curve of the blue-green TADF device prepared in Example 4 of the present invention is shown in the figure, with the ◆ curve representing the device based on PVP-0.97DMAC-0.03DPhTz, and the The curve represents a device based on PVP-0.92DMAC-0.08DPhTz, using The curve represents the device based on PVP-0.83DMAC-0.17DPhTz;

[0026] Figure 12 The brightness-current efficiency relationship curve of the blue-green TADF device prepared in Example 4 of the present invention is shown in the figure, with the ◆ curve representing the device based on PVP-0.97DMAC-0.03DPhTz, and the The curve represents a device based on PVP-0.92DMAC-0.08DPhTz, using The curve represents the device based on PVP-0.83DMAC-0.17DPhTz;

[0027] Figure 13 The brightness-power efficiency relationship curve of the blue-green TADF device prepared in Example 4 of the present invention is shown in the figure, with the ◆ curve representing the device based on PVP-0.97DMAC-0.03DPhTz, and the The curve represents a device based on PVP-0.92DMAC-0.08DPhTz, using The curve represents the device based on PVP-0.83DMAC-0.17DPhTz;

[0028] Figure 14The relationship between the brightness and external quantum efficiency of the blue-green TADF device prepared in Example 4 of the present invention is shown in the figure, with the ◆ curve representing the device based on PVP-0.97DMAC-0.03DPhTz, and the The curve represents a device based on PVP-0.92DMAC-0.08DPhTz, using The curve represents the device based on PVP-0.83DMAC-0.17DPhTz;

[0029] Figure 15 The electroluminescence curve of the blue-green TADF device prepared in Example 4 of the present invention is shown in the figure, with the ◆ curve representing the device based on PVP-0.97DMAC-0.03DPhTz, and the The curve represents a device based on PVP-0.92DMAC-0.08DPhTz, using The curve represents the device based on PVP-0.83DMAC-0.17DPhTz;

[0030] Figure 16 The ultraviolet fluorescence spectrum of PVP-0.95DMAC-0.05PhTzTPPO synthesized in Example 5 of the present invention is shown, wherein the ■ curve represents the ultraviolet absorption spectrum of PVP-0.95DMAC-0.05PhTzTPPO, and the ● curve represents the fluorescence emission spectrum of PVP-0.95DMAC-0.05PhTzTPPO;

[0031] Figure 17 The thermogravimetric analysis spectrum of PVP-0.95DMAC-0.05PhTzTPPO synthesized in Example 5 of the present invention is shown;

[0032] Figure 18 The ultraviolet fluorescence spectrum of PVP-0.90DMAC-0.10PhTzTPPO synthesized in Example 6 of the present invention is shown, wherein the ■ curve represents the ultraviolet absorption spectrum of PVP-0.90DMAC-0.10PhTzTPPO, and the ● curve represents the fluorescence emission spectrum of PVP-0.90DMAC-0.10PhTzTPPO;

[0033] Figure 19 The thermogravimetric analysis spectrum of PVP-0.90DMAC-0.10PhTzTPPO synthesized in Example 6 of the present invention is shown;

[0034] Figure 20The ultraviolet fluorescence spectrum of PVP-0.83DMAC-0.17PhTzTPPO synthesized in Example 7 of the present invention is shown, wherein the ultraviolet absorption spectrum of PVP-0.83DMAC-0.17PhTzTPPO is represented by the ■ curve, and the fluorescence emission spectrum of PVP-0.83DMAC-0.17PhTzTPPO is represented by the ● curve;

[0035] Figure 21 The thermogravimetric analysis spectrum of PVP-0.83DMAC-0.17PhTzTPPO synthesized in Example 7 of the present invention is shown;

[0036] Figure 22 The transient photoluminescence decay curves of the PVP-0.95DMAC-0.05PhTzTPPO film synthesized in Example 5 of the present invention are shown, with the ■ curve representing the decay curve at a temperature of 77 K, the ● curve representing the decay curve at a temperature of 100 K, the ▲ curve representing the decay curve at a temperature of 200 K, and the ▼ curve representing the decay curve at a temperature of 300 K;

[0037] Figure 23 The transient photoluminescence decay curves of the PVP-0.90DMAC-0.10PhTzTPPO film synthesized in Example 6 of the present invention are shown, with the ■ curve representing the decay curve at a temperature of 77K, the ● curve representing the decay curve at a temperature of 100K, the ▲ curve representing the decay curve at a temperature of 200K, and the ▼ curve representing the decay curve at a temperature of 300K;

[0038] Figure 24 The transient photoluminescence decay curves of the PVP-0.83DMAC-0.17PhTzTPPO film synthesized in Example 7 of the present invention are shown, with the ■ curve representing the decay curve at 77K, the ● curve representing the decay curve at 100K, the ▲ curve representing the decay curve at 200K, and the ▼ curve representing the decay curve at 300K;

[0039] Figure 25 The voltage-current density relationship curve of the green light TADF device prepared in Example 8 of the present invention is shown in the figure, with the ◆ curve representing the device based on PVP-0.95DMAC-0.05PhTzTPPO and the The curve represents a device based on PVP-0.90DMAC-0.10PhTzTPPO, with The curve represents the device based on PVP-0.83DMAC-0.17PhTzTPPO;

[0040] Figure 26The voltage-brightness relationship curve of the green light TADF device prepared in Example 8 of the present invention is shown in the figure, with the ◆ curve representing the device based on PVP-0.95DMAC-0.05PhTzTPPO and the The curve represents a device based on PVP-0.90DMAC-0.10PhTzTPPO, with The curve represents the device based on PVP-0.83DMAC-0.17PhTzTPPO;

[0041] Figure 27 The brightness-current efficiency relationship curve of the green light TADF device prepared in Example 8 of the present invention is shown in the figure, with the ◆ curve representing the device based on PVP-0.95DMAC-0.05PhTzTPPO and the The curve represents a device based on PVP-0.90DMAC-0.10PhTzTPPO, with The curve represents the device based on PVP-0.83DMAC-0.17PhTzTPPO;

[0042] Figure 28 The brightness-power efficiency relationship curve of the green light TADF device prepared in Example 8 of the present invention is shown in the figure, with the ◆ curve representing the device based on PVP-0.95DMAC-0.05PhTzTPPO and the The curve represents a device based on PVP-0.90DMAC-0.10PhTzTPPO, with The curve represents the device based on PVP-0.83DMAC-0.17PhTzTPPO;

[0043] Figure 29 The relationship between the brightness and external quantum efficiency of the green light TADF device prepared in Example 8 of the present invention is shown in the figure, with the ◆ curve representing the device based on PVP-0.95DMAC-0.05PhTzTPPO and the The curve represents a device based on PVP-0.90DMAC-0.10PhTzTPPO, with The curve represents the device based on PVP-0.83DMAC-0.17PhTzTPPO;

[0044] Figure 30 The electroluminescence curve of the green TADF device prepared in Example 8 of the present invention is shown in the figure, with the ◆ curve representing the device based on PVP-0.95DMAC-0.05PhTzTPPO and the The curve represents a device based on PVP-0.90DMAC-0.10PhTzTPPO, with The curves represent devices based on PVP-0.83DMAC-0.17PhTzTPPO. DETAILED DESCRIPTION

[0045] The present invention will be described in detail below through specific embodiments, and the features and advantages of the present invention will become clearer and more distinct with these descriptions.

[0046] The non-conjugated polymer thermally excited delayed fluorescent material based on phenyl acridine and phenyl triazine substituents provided by the present invention is obtained by polymerizing styrene with acridine substituents and styrene with phenyl triazine substituents. The non-conjugated polymer with phenyl acridine groups as charge donors and phenyl triazine groups as charge acceptors further reduces the triplet energy difference (ΔE ST ), which increases the fluorescence quantum yield (PLQY), reduces the red shift, and improves the luminescence quality and overall performance.

[0047] The first aspect of the present invention provides a non-conjugated polymer thermally excited delayed fluorescent material based on phenylacridine and phenyltriazine substituents, which is a polymer obtained by polymerizing styrene with acridine substituents and styrene with phenyltriazine substituents as monomers.

[0048] The styrene with an acridinium substituent is selected from para-acridine-substituted styrene or meta-acridine-substituted styrene, preferably para-acridine-substituted styrene. The acridinium substituent is selected from N-9,9-dialkyl-acridinyl, with a specific structure as shown in formula (1-1), R1 and R2 are each independently selected from an alkyl group containing C1-C8 carbon atoms, preferably an alkyl group containing C1-C3 carbon atoms, such as methyl, ethyl, propyl or isopropyl, and more preferably methyl.

[0049]

[0050] The styrene with phenyltriazine substituents is a para-phenyltriazine substituent styrene or a meta-phenyltriazine substituent styrene, preferably a para-phenyltriazine substituent styrene. The phenyltriazine substituent is selected from a substituent having a structure of formula (1-2) or formula (1-3), namely 4-phenyl-6-(4-diphenylphosphinooxy-phenyl)-1,3,5-triazinyl, 4,6-diphenyl-1,3,5-triazinyl, 4-substituted phenyl-6-(4-diphenylphosphinooxy-phenyl)-1,3,5-triazinyl or 4-substituted phenyl-4-phenyl-1,3,5-triazinyl; wherein R3 and R4 are each independently selected from hydrogen or an alkyl group containing C1-C8 carbon atoms, preferably hydrogen or an alkyl group containing C1-C3 carbon atoms, and more preferably hydrogen. Preferably, the phenyltriazine substituent is selected from 4,6-diphenyl-1,3,5-triazinyl and 4-phenyl-6-(4-diphenylphosphinooxy-phenyl)-1,3,5-triazinyl.

[0051]

[0052] In a preferred embodiment of the present invention, the polymer comprises the following structural units:

[0053]

[0054] Wherein, R1, R2, R3, and R4 are as described above respectively; R5 is phenyl or 4-diphenylphosphinoyl-phenyl; the ratio of a and b is (70-110):(3-30), preferably (75-105):(3-25), and more preferably (80-100):(3-20).

[0055] Preferably, the polymer comprises the following structural units:

[0056]

[0057] Among them, the ratio of a to b is (70-110):(3-30), preferably (75-105):(3-25), and more preferably (80-100):(3-20), such as the ratio of a to b is 97:3, 92:8, 83:17, 81:19, 95:5 or 90:10.

[0058] A second aspect of the present invention provides a method for preparing the non-conjugated polymer based on phenylacridine and phenyltriazine substituents, wherein the preparation is performed by free radical polymerization of monomers containing styrene with acridine substituents and styrene with phenyltriazine substituents. The method specifically comprises the following steps:

[0059] Step 1: Prepare styrene with acridine substituents.

[0060] The styrene with acridine substituents is specifically as described in the first aspect.

[0061] Monohalogenated styrene and 9,9-dialkylacridine are added to a solvent, and heated to react in a protective atmosphere in the presence of a catalyst to prepare the styrene with acridine substituents.

[0062] The monohalogenated styrene is selected from p-halogenated styrene or m-halogenated styrene, preferably p-halogenated styrene, and the halogenated styrene is selected from iodinated, brominated or chloro, preferably brominated or chloro, more preferably brominated.

[0063] In the 9,9-dialkylacridine, the alkyl groups are each independently selected from an alkyl group containing C1-C8 carbon atoms, preferably an alkyl group containing C1-C3 carbon atoms, such as methyl, ethyl, propyl or isopropyl, more preferably methyl.

[0064] The molar ratio of the monohalogenated styrene to the 9,9-dialkylacridine is 1:(0.6-1.6), preferably 1:(0.8-1.4), and more preferably 1:(1-1.2).

[0065] The solvent is selected from one or more of aromatic hydrocarbon solvents, such as toluene and xylene, ether solvents, such as tetrahydrofuran and ethylene glycol monomethyl ether, and amide solvents, such as N,N-dimethylformamide and N,N-dimethylacetamide, preferably one or more of toluene, xylene, N,N-dimethylformamide and N,N-dimethylacetamide, more preferably toluene.

[0066] The molar volume ratio of the monohalogenated styrene to the solvent is 1 mmol:(1-5) mL, preferably 1 mmol:(1.5-4) mL, and more preferably 1 mmol:(2-3) mL.

[0067] The catalyst is selected from palladium catalysts, such as palladium salts, palladium carbon, and palladium complexes, preferably one or more of palladium salts and / or palladium complexes, such as palladium acetate, Pd(AsPh3)4, Pd(n-Bu3P)4, Pd((MeO)3P)4, tris-(dibenzylideneacetone)dipalladium, tetrakis(triphenylphosphine)palladium, more preferably palladium acetate or tetrakis(triphenylphosphine)palladium. Preferably, the ligand compound added to the catalyst is preferably a phosphorus ligand, more preferably tri-tert-butylphosphine; the molar ratio of the ligand compound to the palladium in the catalyst is (2.5-4):1, preferably (3-3.5):1.

[0068] The molar ratio of the monohalogenated styrene to the catalyst is 1:(0.01-0.04), preferably 1:(0.015-0.035), more preferably 1:(0.02-0.03), and the molar amount of the catalyst is calculated based on the molar amount of palladium therein.

[0069] Preferably, the reaction is carried out under alkaline conditions. An alkaline substance is added to the reaction solution, wherein the alkaline substance is selected from one or more of alkali metal hydroxides, potassium alkoxides, and sodium alkoxides, preferably one or more of potassium alkoxides and sodium alkoxides, and more preferably potassium tert-butoxide and / or sodium tert-butoxide.

[0070] The molar ratio of the monohalogenated styrene to the alkaline substance is 1:(0.6-1.8), preferably 1:(0.8-1.5), and more preferably 1:(1-1.2).

[0071] The protective atmosphere is nitrogen and / or argon, such as argon. The reaction temperature is 105-145°C, preferably 115-135°C; and the reaction time is 8-16 hours, preferably 11-13 hours.

[0072] After the reaction is completed, the reaction solution is poured into deionized water for post-treatment. The reaction solution is extracted, the organic phase is separated and dried, the solvent is removed, and the product is purified to obtain styrene with acridine substituents.

[0073] The extraction comprises adding an extraction solvent to the reaction solution, wherein the extraction solvent is selected from one or more halogenated alkane solvents, such as dichloromethane; combining the organic layers and drying them with a desiccant (such as anhydrous Na2SO4), and then spin-drying; and purifying the crude product by flash column chromatography using a mixed solvent of petroleum ether and dichloromethane.

[0074] Step 2: preparing styrene with phenyltriazine substituents.

[0075] The styrene with phenyltriazine substituents is specifically as described in the first aspect.

[0076] Vinylphenylboronic acid pinesol ester or vinylphenylboronic acid and phenyl halogenated triazine compounds are added into a solvent, and heated to react in the presence of a catalyst to prepare styrene with phenyltriazine substituents.

[0077] The vinylbenzene pinesol borate is selected from 4-vinylbenzene pinesol borate or 3-vinylbenzene pinesol borate, preferably 4-vinylbenzene pinesol borate.

[0078] The vinylbenzene boronic acid is selected from 4-vinylbenzene boronic acid or 3-vinylbenzene boronic acid, and is preferably 4-vinylbenzene boronic acid.

[0079] The phenyl halogenated triazine compound is selected from 2,4-dihalogenated-6-phenyl-1,3,5-triazine, 2,4-dihalogenated-6-substituted phenyl-1,3,5-triazine, 2-halogenated-4,6-diphenyl-1,3,5-triazine or 2-halogenated-4-substituted phenyl-6-phenyl-1,3,5-triazine, as shown in formula (2-2) or formula (2-3), respectively, wherein R6 and R7 are each independently selected from hydrogen or an alkyl group containing C1-C8 carbon atoms, preferably hydrogen or an alkyl group containing C1-C3 carbon atoms, more preferably hydrogen. Preferably, the phenyl halogenated triazine compound is selected from 2-halogenated-4,6-diphenyl-1,3,5-triazine or 2,4-dihalogenated-6-phenyl-1,3,5-triazine, wherein X is bromo or chloro, preferably chloro.

[0080]

[0081] The molar ratio of the phenyl halogenated triazine compound to vinylphenylboronic acid (or vinylphenylboronic acid pinesol ester) is 1:(0.6-1.6), preferably 1:(0.8-1.4), and more preferably 1:(1-1.2).

[0082] The solvent is selected from a mixed solvent of water and an organic solvent. The organic solvent is selected from an ether solvent, such as tetrahydrofuran, ethylene glycol monomethyl ether, or an amide solvent, such as one or more of N,N-dimethylformamide and N,N-dimethylacetamide, preferably one or more of tetrahydrofuran, ethylene glycol monomethyl ether, N,N-dimethylformamide and N,N-dimethylacetamide, more preferably tetrahydrofuran. During the reaction, the organic solvent can dissolve the raw materials, and water is used to dissolve the inorganic base, which is conducive to the smooth progress of the Suzuki reaction.

[0083] The molar volume ratio of the phenyl halogenated triazine compound to the solvent is 1 mmol: (2.2-6.5) mL, preferably 1 mmol: (2.7-5.5) mL, and more preferably 1 mmol: (3.2-4.5) mL.

[0084] The catalyst is selected from palladium catalysts, such as palladium salts, palladium carbon, and palladium complexes, preferably one or more of palladium complexes, such as Pd(AsPh3)4, Pd(n-Bu3P)4, Pd((MeO)3P)4, tris-(dibenzylideneacetone)dipalladium, tetrakis(triphenylphosphine)palladium, and more preferably tetrakis(triphenylphosphine)palladium.

[0085] The molar ratio of the phenyl halogenated triazine compound to the catalyst is 1:(0.02-0.08), preferably 1:(0.03-0.07), more preferably 1:(0.04-0.06), and the molar amount of the catalyst is calculated based on the molar amount of palladium therein.

[0086] Preferably, the reaction is carried out under alkaline conditions. An alkaline substance is added to the reaction solution, wherein the alkaline substance is selected from one or more of carbonates, phosphates, monohydrogen phosphates, and hydroxides, preferably one or more of alkali metal carbonates and alkali metal phosphates, and more preferably sodium carbonate and / or potassium carbonate.

[0087] The molar ratio of the phenyl halogenated triazine compound to the alkaline substance is 1:(1.0-4.5), preferably 1:(1.5-3.5), and more preferably 1:(2-2.5).

[0088] The protective atmosphere is nitrogen and / or argon, such as argon. The reaction temperature is 60-100° C., preferably 70-90° C.; and the reaction time is 8-16 hours, preferably 11-13 hours.

[0089] After the reaction is completed, the reaction solution is poured into deionized water for post-treatment. The reaction solution is extracted, the organic phase is separated and dried, the solvent is removed, and the product is purified to obtain styrene with phenyltriazine substituents.

[0090] The extraction comprises adding an extraction solvent to the reaction solution, wherein the extraction solvent is selected from one or more halogenated alkane solvents, such as dichloromethane; combining the organic layers and drying them with a desiccant (such as anhydrous Na2SO4), and then spin-drying; and purifying the crude product by flash column chromatography using a mixed solvent of petroleum ether and dichloromethane.

[0091] When the phenyl halogenated triazine compound is selected from 2,4-dihalogenated-6-phenyl-1,3,5-triazine or 2,4-dihalogenated-6-substituted phenyl-1,3,5-triazine, specifically as shown in formula (2-2), the prepared 2-halogenated-4-phenyl-6-(4-vinylphenyl)-1,3,5-triazine (or 2-halogenated-4-substituted phenyl-6-(4-vinylphenyl)-1,3,5-triazine), (4-halogenated phenyl) diphenylphosphine, magnesium and iodine are added to a solvent, heated to react, and after the reaction is completed, the organic layer is extracted and then hydrogen peroxide is added. After oxidation and post-treatment, 2-(4-diphenylphosphinooxy-phenyl)-4-phenyl-6-(4-vinylphenyl)-1,3,5-triazine or 2-(4-diphenylphosphinooxy-phenyl)-4-substituted phenyl-6-(4-vinylphenyl)-1,3,5-triazine is obtained, preferably 2-triphenylphosphinooxy-4-phenyl-6-(4-vinylphenyl)-1,3,5-triazine; its structure is as shown in formula (3-1), R6 and R7 are each independently selected from hydrogen or an alkyl group containing C1-C8 carbon atoms, preferably hydrogen or an alkyl group containing C1-C3 carbon atoms, and more preferably hydrogen.

[0092]

[0093] The (4-halogenated phenyl)diphenyl phosphine is (4-bromophenyl)diphenyl phosphine or (4-chlorophenyl)diphenyl phosphine.

[0094] The molar ratio of the 2-halogeno-4-phenyl-6-(4-vinylphenyl)-1,3,5-triazine (or 2-halogeno-4-substituted phenyl-6-(4-vinylphenyl)-1,3,5-triazine and (4-halogenophenyl)diphenylphosphine) is 1:(0.8-1.6), preferably 1:(1-1.2).

[0095] The molar ratio of the magnesium rod to (4-halogenated phenyl) diphenylphosphine is 1:(0.8-1.6), preferably 1:(1-1.2). The molar ratio of the magnesium rod to elemental iodine is 1:(0.01-0.1), preferably 1:(0.01-0.02).

[0096] The solvent is selected from an ether solvent, preferably one or more selected from tetrahydrofuran, ethylene glycol monomethyl ether and diethyl ether, more preferably tetrahydrofuran. The molar volume ratio of the (4-halogenated phenyl)diphenylphosphine to the solvent is 1 mmol:(2-9) mL, preferably 1 mmol:(4-5) mL.

[0097] Under protective gas, the reaction is carried out at 40-80°C for 8-16 hours, preferably at 50-70°C for 10-14 hours.

[0098] After the reaction stops, the reaction solution is poured into water and extracted with a halogenated hydrocarbon solvent, such as dichloromethane. The organic layer is then washed three times with water, dried with a solid desiccant, spin-dried, oxidized with hydrogen peroxide, and then purified by column chromatography using a mixed solution of petroleum ether and ethyl acetate as an eluent to obtain a styrene with a phenyl triazine substituent, which is 2-(4-diphenylphosphinooxy-phenyl)-4-phenyl-6-(4-vinylphenyl)-1,3,5-triazine or 2-(4-diphenylphosphinooxy-phenyl)-4-substituted phenyl-6-(4-vinylphenyl)-1,3,5-triazine.

[0099] Step 3: adding styrene with acridine substituents and styrene with phenyltriazine substituents into a solvent, heating and reacting to obtain a non-conjugated polymer based on phenylacridine and phenyltriazine substituents.

[0100] The molar ratio of the styrene with acridine substituents to the styrene with phenyltriazine substituents is (70-110):(3-30), preferably (75-105):(3-25), and more preferably (80-100):(3-20).

[0101] The reaction is carried out under the action of an initiator, which is an azo compound, preferably one or more of azobisisobutyronitrile (AIBN), azobisisovaleronitrile (AMBN), azobisisoheptanenitrile (ABVN), azoisobutylcyanamide (CABN), and azobiscyclohexylcarbonitrile (ACCN), more preferably azobisisobutyronitrile (AIBN).

[0102] The solvent is selected from one or more of alcohol solvents, ether solvents, and ketone solvents, preferably one or more of methanol, isopropanol, tetrahydrofuran, ethylene glycol dimethyl ether, ethyl ether, butanone, and methyl ethyl ketone, more preferably tetrahydrofuran.

[0103] The protective atmosphere is nitrogen and / or argon, such as argon. The reaction temperature is 60-100°C, preferably 70-90°C; and the reaction time is 40-55h, preferably 45-50h.

[0104] After the reaction is completed, cold acetone is added to the reaction solution to precipitate the product, and then Soxhlet extraction is performed to obtain the target product.

[0105] The third aspect of the present invention provides an electroluminescent device prepared from a non-conjugated polymer thermally excited delayed fluorescent material based on phenylacridine and phenyltriazine substituents. The light-emitting layer material includes one or more non-conjugated polymers based on phenylacridine and phenyltriazine substituents.

[0106] The electroluminescent device comprises a substrate layer, a conductive anode layer, a hole injection layer, a hole transport layer, a light emitting layer, an exciton blocking layer, an electron transport layer, an electron injection layer and a cathode conductive layer.

[0107] The method of the present invention for preparing a light-emitting device using the non-conjugated polymer thermally excited delayed fluorescent material based on phenylacridine and phenyltriazine substituents specifically comprises the following steps:

[0108] 1. preparing a conductive anode layer;

[0109] The conductive anode layer is formed on the substrate layer. The conductive anode layer is selected from tin oxide conductive glass (ITO), a transparent conductive polymer such as polyaniline, and a semi-transparent metal such as Au. ITO or a semi-transparent metal is preferred, and ITO is more preferred. Preferably, the conductive anode layer is deposited using a vacuum evaporation method.

[0110] Preferably, the vacuum degree of vacuum evaporation is 1×10 -5 ~5×10 -5 mbar, the evaporation rate is set to 0.1-0.3 nm / s, the evaporation material is indium tin oxide on the glass or plastic substrate, and the thickness of the anode conductive layer is 60-170 nm, preferably 80-160 nm, and more preferably 100-150 nm.

[0111] Preferably, the following hole injection layer, hole transport layer, light emitting layer, hole blocking layer, electron transport layer, electron injection layer and cathode conductive layer are prepared by vacuum evaporation method.

[0112] 2. preparing a hole injection layer;

[0113] The hole injection layer is evaporated on the anode conductive layer, and the thickness of the evaporated layer is 40 to 80 nm, preferably 45 to 75 nm, more preferably 50 to 70 nm, such as 60 nm.

[0114] The hole injection layer material is selected from molybdenum oxide or a mixture of poly (3,4-ethylenedioxythiophene) and polystyrene sulfonate (PEDOT:PSS), preferably a mixture of PEDOT and PSS.

[0115] 3. preparing a light-emitting layer;

[0116] The light-emitting layer is continuously evaporated on the hole injection layer, and the evaporation thickness is 15-60 nm, preferably 20-50 nm, more preferably 25-40 nm, such as 30 nm.

[0117] The light-emitting layer material includes one or more non-conjugated polymers based on phenylacridine and phenyltriazine substituents.

[0118] 4. preparing an exciton blocking layer;

[0119] The exciton blocking layer is evaporated on the light-emitting layer, and the thickness of the evaporated layer is 2-20 nm, preferably 5-10 nm, such as 5 nm.

[0120] The hole transport layer material is selected from 9,9'-(1,3-phenyl)di-9H-carbazole (mCP) or bis[2-((oxy)diphenylphosphino)phenyl]ether (DPEPO), preferably DPEPO.

[0121] 5. preparing an electron transport layer;

[0122] The electron transport layer is one or more of TPBi (1,3,5-tris(1-phenyl-1H-benzimidazol-2-yl)benzene), TmPyPb (3,3'-[5'-[3-(3-pyridyl)phenyl][1,1':3',1"-terphenyl]-3,3"-diyl]dipyridine), Bphen (4,7-diphenyl-1,10-phenanthroline) and DBFDPO (dibenzofuran-4,6-bis(diphenylphosphine oxide), preferably TPBi.

[0123] The electron transport layer is evaporated on the exciton blocking layer, and the thickness of the evaporated layer is 25-55 nm, preferably 30-50 nm, more preferably 35-45 nm, such as 40 nm.

[0124] 7. preparing an electron injection layer;

[0125] The electron injection layer is evaporated on the electron transport layer, and the thickness of the evaporated layer is 1-15 nm, preferably 1-10 nm, more preferably 1-5 nm, such as 1 nm.

[0126] The electron injection layer material is selected from lithium tetrakis(8-hydroxyquinoline)borate (LiBq4) or LiF, preferably LiF.

[0127] 8. Prepare a cathode conductive layer, encapsulate, and obtain a thermally excited delayed fluorescence electroluminescent device.

[0128] The cathode conductive layer is evaporated on the electron injection layer, and the evaporated thickness is 70-130 nm, preferably 80-120 nm, more preferably 90-110 nm, such as 100 nm.

[0129] The cathode conductive layer material is selected from a single metal cathode or an alloy cathode, such as metal Al.

[0130] The non-conjugated polymer provided by the present invention is used as a thermally excited delayed fluorescent material, and has an acridine substituent and a phenyltriazine substituent, which serve as a charge donor and a charge acceptor, respectively, to reduce red shift and narrow the triplet energy difference (ΔE ST ), increasing the fluorescence quantum yield (PLQY), improving luminescence quality and overall performance. Thermally excited delayed fluorescence devices fabricated with it as the luminescent layer material exhibit low turn-on voltage, high brightness, high power efficiency, and high external quantum efficiency, achieving excellent overall performance.

[0131] Example

[0132] Example 1

[0133] (1) 1 mmol of 4-vinylbenzeneboronic acid, 1 mmol of 2-chloro-4,6-diphenyl-1,3,5-triazine, 0.05 mmol of tetrakis(triphenylphosphine)palladium, 2 mmol of potassium carbonate, and 1.7 ml of water were added to 2 ml of tetrahydrofuran solution and stirred. The mixture was reacted at 80°C for 12 hours under argon protection and stirring.

[0134] After the reaction was completed, the reaction solution was poured into deionized water and extracted with dichloromethane. The organic layer was washed three times with water, dried over anhydrous Na2SO4, and spin-dried. The crude product was separated and purified by column chromatography using a mixture of petroleum ether and dichloromethane (volume ratio of 10:1) as eluent to obtain 2,4-diphenyl-6-(4-vinylphenyl)-1,3,5-triazine (VP-DPhTz), the structure of which is as follows:

[0135]

[0136] (2) 1 mmol of p-bromostyrene, 1 mmol of 9,9-dimethylacridine, 0.025 mmol of palladium acetate, 1.1 mmol of potassium tert-butoxide, and 0.075 mmol of tri-tert-butylphosphine were added to 2 mL of toluene solution and mixed. The mixture was reacted at 120-130°C for 12 hours under argon protection. After the reaction was completed, the reaction solution was poured into deionized water and extracted with dichloromethane. The organic layer was washed three times with deionized water, dried over anhydrous Na2SO4, and spin-dried. The crude product was separated and purified by column chromatography using a mixture of petroleum ether and dichloromethane (volume ratio of the two was 6:1) as the eluent to obtain 9,9-dimethyl-10-(4-vinylphenyl)-9,10-dihydroacridine (VP-DMAC), the structure of which is as follows:

[0137]

[0138] (3) 0.95 mmol of VP-DMAC, 0.05 mmol of VP-DPhTz, and 0.02 mmol of azobisisobutyronitrile (AIBN) were added to 2 ml of anhydrous tetrahydrofuran and reacted at 80°C for 48 hours under argon protection. Cold acetone was added to precipitate the product, and Soxhlet extraction was performed for 48 hours to obtain the target product, i.e., the addition copolymerization product I of VP-DPhTz and VP-DMAC.

[0139] The H NMR spectrum data of the obtained copolymerization product I are as follows: 1 H NMR (TMS, CDCl3, 400MHz): δ = 8.745-8.348 (m, 6H), 7.381-6.911 (m, 204H), 6.786-6.390 (m, 134H) ,6.266-5.894(m,65H),2.746-2.275(m,32H),2.127-1.705(m,60H),1.631-1.334ppm(m,201H).

[0140] The product was subjected to gel permeation chromatography (GPC) test, and the molecular weight of the polymer was 26384, and the molecular weight distribution index PDI was 1.7. It can be seen that the copolymerization product I (PVP-0.97DMAC-0.03DPhTz) has the following structural units: (by the monomer and polymer 1 Calculated using H NMR. Find the characteristic peak (6H) of the acceptor (phenyltriazine group) monomer. Then, subtract the characteristic peak (6H) and the number of monomer aromatic hydrogens (8H) from the total number of aromatic hydrogens in the polymer (6 + 204 + 134 + 65 = 409H). The remaining hydrogen number (395H) is then divided by the number of aromatic hydrogens (12H) in the donor (phenylacridine group). This gives a donor-to-acceptor ratio of approximately 0.97:0.03. The calculation method is the same for subsequent examples.

[0141]

[0142] The ultraviolet fluorescence spectrum of PVP-0.97DMAC-0.03DPhTz obtained in this example is as follows Figure 1 shown.

[0143] The thermogravimetric analysis spectrum of PVP-0.97DMAC-0.03DPhTz obtained in this example is as follows Figure 2 As shown in the figure, it can be seen that the cracking temperature of PVP-0.97DMAC-0.03DPhTz reaches 383°C.

[0144] The PVP-0.97DMAC-0.03DPhTz film according to Example 1 was prepared, and the transient photoluminescence decay curve of the polymer film was tested.

[0145] Figure 7 This is the transient photoluminescence decay curve of the PVP-0.97DMAC-0.03DPhTz film synthesized in Example 1. The ■ curve represents the decay curve at a temperature of 77K, the ● curve represents the decay curve at a temperature of 100K, the ▲ curve represents the decay curve at a temperature of 200K, and the ▼ curve represents the decay curve at a temperature of 300K. It can be seen from the figure that with the increase of temperature, the lifetime becomes shorter, which proves its TADF property.

[0146] Example 2

[0147] 0.90 mmol of VP-DMAC prepared in Example 1, 0.10 mmol of VP-DPhTz prepared in Example 1, and 0.02 mmol of azobisisobutyronitrile were added to 2 ml of anhydrous tetrahydrofuran, and reacted at 80° C. for 48 hours under argon protection. Cold acetone was added to precipitate the product, and Soxhlet extraction was performed for 48 hours to obtain the target product, i.e., addition copolymerization product II of VP-DPhTz and VP-DMAC.

[0148] The H NMR spectrum data of the obtained copolymer product II are as follows: 1 H NMR (TMS, CDCl3, 400MHz): δ = 8.809-8.247 (m, 6H), 7.699-6.877 (m, 79H), 6.877-6.402 (m, 52H) ,6.358-5.696(m,25H),2.900-2.237(m,12H),2.179-1.704(m,24H),1.660-1.113ppm(m,78H).

[0149] Gel chromatography (GPC) analysis of the product revealed a molecular weight of 25954 and a molecular weight distribution index (PDI) of 2.2. Thus, the copolymer II (PVP-0.92DMAC-0.08DPhTz) had the following structural units:

[0150]

[0151] The ultraviolet fluorescence spectrum of PVP-0.92DMAC-0.08DPhTz obtained in this example is as follows Figure 3 shown.

[0152] The thermogravimetric analysis spectrum of PVP-0.92DMAC-0.08DPhTz obtained in this example is as follows Figure 4 As shown in the figure, it can be seen that the cracking temperature of PVP-0.92DMAC-0.08DPhTz reaches 384℃.

[0153] The PVP-0.92DMAC-0.08DPhTz film according to Example 2 was prepared, and the transient photoluminescence decay curve of the polymer film was tested.

[0154] Figure 8 This is the transient photoluminescence decay curve of the PVP-0.92DMAC-0.08DPhTz film synthesized in Example 2. The ■ curve represents the decay curve at a temperature of 77K, the ● curve represents the decay curve at a temperature of 100K, the ▲ curve represents the decay curve at a temperature of 200K, and the ▼ curve represents the decay curve at a temperature of 300K. As the temperature increases, the lifetime becomes significantly shorter, proving that it has excellent TADF properties.

[0155] Example 3

[0156] 0.80 mmol of VP-DMAC prepared in Example 1, 0.20 mmol of VP-DPhTz prepared in Example 1, and 0.02 mmol of azobisisobutyronitrile were added to 2 ml of anhydrous tetrahydrofuran, and reacted at 80° C. for 48 hours under argon protection. Cold acetone was added to precipitate the product, and Soxhlet extraction was performed for 48 hours to obtain the target product, i.e., addition copolymerization product III of VP-DPhTz and VP-DMAC.

[0157] The H NMR spectrum data of the obtained copolymer product III are as follows: 1 H NMR (TMS, CDCl3, 400MHz): δ = 8.711-8.252 (m, 6H), 7.403-6.897 (m, 36H), 6.802-6.425 (m, 22H) ,6.284-5.871(m,10H),2.784-2.254(m,5H),2.148-1.711(m,11H),1.665-1.145ppm(m,36H).

[0158] Gel chromatography (GPC) analysis of the product revealed a molecular weight of 25,366 and a molecular weight distribution index (PDI) of 2.4. Therefore, the copolymer III (PVP-0.83DMAC-0.17DPhTz) has the following structural units:

[0159]

[0160] The ultraviolet fluorescence spectrum of PVP-0.83DMAC-0.17DPhTz obtained in this example is as follows Figure 5 shown.

[0161] The thermogravimetric analysis spectrum of PVP-0.83DMAC-0.17DPhTz obtained in this example is as follows Figure 6As shown in the figure, it can be seen that the cracking temperature of PVP-0.83DMAC-0.17DPhTz reaches 386℃.

[0162] The PVP-0.83DMAC-0.17DPhTz film according to Example 3 was prepared, and the transient photoluminescence decay curve of the polymer film was tested.

[0163] Figure 9 This is the transient photoluminescence decay curve of the PVP-0.83DMAC-0.17DPhTz film synthesized in Example 3. The ■ curve represents the decay curve at a temperature of 77K, the ● curve represents the decay curve at a temperature of 100K, the ▲ curve represents the decay curve at a temperature of 200K, and the ▼ curve represents the decay curve at a temperature of 300K. As the temperature increases, the lifetime becomes shorter, proving that it has TADF properties.

[0164] Example 4

[0165] PVP-0.97DMAC-0.03DPhTz, PVP-0.92DMAC-0.08DPhTz and PVP-0.83DMAC-0.17DPhTz prepared in Examples 1, 2 and 3 were used to prepare green light TADF devices, which were prepared according to the following steps:

[0166] 1. Place the glass or plastic substrate cleaned with deionized water into the vacuum evaporator with a vacuum degree of 5×10 - 5 mbar, and the evaporation rate was set to 0.1–0.3 nm s -1 , on a glass or plastic substrate, an anode conductive layer with a thickness of 150nm is deposited using indium tin oxide as the material;

[0167] 2. Spin-coat a 60nm thick hole injection layer made of a mixture of PEDOT and PSS (5% PEDOT by mass) on the anode conductive layer;

[0168] 3. Spin-coat a 30 nm thick light-emitting layer made of PVP-0.97DMAC-0.03DPhTz, PVP-0.92DMAC-0.08DPhTz or PVP-0.83DMAC-0.17DPhTz on the hole injection layer;

[0169] 4. Continue to evaporate an exciton blocking layer DPEPO with a thickness of 5 nm on the light-emitting layer;

[0170] 5. Evaporating an electron transport layer with a thickness of 40 nm and TPBi on the exciton blocking layer;

[0171] 6. Evaporate LiF on the electron transport layer to form an electron injection layer with a thickness of 1 nm;

[0172] 7. A cathode conductive layer with a thickness of 100 nm and a material of metallic Al was evaporated on the electron injection layer, and then encapsulated to obtain an organic electroluminescent device based on a non-conjugated polymer TADF material of triazine-phosphine oxide auxiliary receptor.

[0173] The voltage-current density relationship curve of the blue-green light TADF device prepared with PVP-0.97DMAC-0.03DPhTz, PVP-0.92DMAC-0.08DPhTz or PVP-0.83DMAC-0.17DPhTz in this embodiment is shown in FIG. Figure 10 As shown, the curve ◆ represents the device based on PVP-0.97DMAC-0.03DPhTz, and the curve The curve represents a device based on PVP-0.92DMAC-0.08DPhTz, using The curve represents a device based on PVP-0.83DMAC-0.17DPhTz. The figure shows that the turn-on voltage of the device based on PVP-0.97DMAC-0.03DPhTz is 4.3V; the turn-on voltage of the device based on PVP-0.92DMAC-0.08DPhTz is 3.2V; and the turn-on voltage of the device based on PVP-0.83DMAC-0.17DPhTz is 3.1V.

[0174] The voltage-luminance relationship curve of the blue-green light TADF device prepared with PVP-0.97DMAC-0.03DPhTz, PVP-0.92DMAC-0.08DPhTz or PVP-0.83DMAC-0.17DPhTz in this embodiment is shown in FIG. Figure 11 As shown, the curve ◆ represents the device based on PVP-0.97DMAC-0.03DPhTz, and the curve The curve represents a device based on PVP-0.92DMAC-0.08DPhTz, using The curve represents the device based on PVP-0.83DMAC-0.17DPhTz. From this figure, we can see that the brightness of the device based on PVP-0.97DMAC-0.03DPhTz reaches a maximum of 647cd·m -2 The device based on PVP-0.92DMAC-0.08DPhTz has a maximum brightness of 1781cd·m -2 The brightness of the device based on PVP-0.83DMAC-0.17DPhTz reaches a maximum of 2948cd·m -2 .

[0175] The brightness-current efficiency relationship curve of the blue-green light TADF device prepared with PVP-0.97DMAC-0.03DPhTz, PVP-0.92DMAC-0.08DPhTz or PVP-0.83DMAC-0.17DPhTz in this embodiment is shown in FIG. Figure 12 As shown, the curve ◆ represents the device based on PVP-0.97DMAC-0.03DPhTz, and the curve The curve represents a device based on PVP-0.92DMAC-0.08DPhTz, using The curve represents the device based on PVP-0.83DMAC-0.17DPhTz. From this figure, we can see that the current efficiency of the device based on PVP-0.97DMAC-0.03DPhTz reaches the maximum value of 31.7cd·A -1 The device current efficiency based on PVP-0.92DMAC-0.08DPhTz reached a maximum of 44.7cd·A -1 The current efficiency of the device based on PVP-0.83DMAC-0.17DPhTz reached a maximum of 34.6cd·A -1 .

[0176] The brightness-power efficiency relationship curve of the blue-green light TADF device prepared with PVP-0.97DMAC-0.03DPhTz, PVP-0.92DMAC-0.08DPhTz or PVP-0.83DMAC-0.17DPhTz in this embodiment is shown in FIG. Figure 13 As shown, the curve ◆ represents the device based on PVP-0.97DMAC-0.03DPhTz, and the curve The curve represents a device based on PVP-0.92DMAC-0.08DPhTz, using The curve represents the device based on PVP-0.83DMAC-0.17DPhTz. From this figure, we can see that the power efficiency of the device based on PVP-0.97DMAC-0.03DPhTz reaches the maximum value of 23.1lm·W. -1 The power efficiency of the device based on PVP-0.92DMAC-0.08DPhTz reaches a maximum of 42.5lm·W -1 The power efficiency of the device based on PVP-0.83DMAC-0.17DPhTz reaches a maximum of 33.0lm·W -1 .

[0177] The brightness-external quantum efficiency relationship curve of the blue-green light TADF device prepared by PVP-0.97DMAC-0.03DPhTz, PVP-0.92DMAC-0.08DPhTz or PVP-0.83DMAC-0.17DPhTz in this embodiment is shown in FIG. Figure 14 As shown, the curve ◆ represents the device based on PVP-0.97DMAC-0.03DPhTz, and the curve The curve represents a device based on PVP-0.92DMAC-0.08DPhTz, using The curve represents the device based on PVP-0.83DMAC-0.17DPhTz. The figure shows that the external quantum efficiency of the device based on PVP-0.97DMAC-0.03DPhTz reaches a maximum of 14.2%, the external quantum efficiency of the device based on PVP-0.92DMAC-0.08DPhTz reaches a maximum of 18.3%, and the external quantum efficiency of the device based on PVP-0.83DMAC-0.17DPhTz reaches a maximum of 13.2%.

[0178] The electroluminescence spectrum curve of the blue-green TADF device prepared by PVP-0.97DMAC-0.03DPhTz, PVP-0.92DMAC-0.08DPhTz or PVP-0.83DMAC-0.17DPhTz in this embodiment is as follows: Figure 15 As shown, the curve ◆ represents the device based on PVP-0.97DMAC-0.03DPhTz, and the curve The curve represents a device based on PVP-0.92DMAC-0.08DPhTz, using The curve represents a device based on PVP-0.83DMAC-0.17DPhTz. The graph shows that the electroluminescence peak of the device based on PVP-0.97DMAC-0.03DPhTz is 490nm; the electroluminescence peak of the device based on PVP-0.92DMAC-0.08DPhTz is 494nm; and the electroluminescence peak of the device based on PVP-0.83DMAC-0.17DPhTz is 495nm.

[0179] Example 5

[0180] (1) 1 mmol of 4-vinylbenzeneboronic acid, 1 mmol of 2,4-dichloro-6-phenyl-1,3,5-triazine, 0.05 mmol of tetrakis(triphenylphosphine)palladium, 2 mmol of potassium carbonate, and 1.7 ml of water were added to 2 ml of tetrahydrofuran solution and stirred. The mixture was reacted at 80°C for 12 hours under argon protection and stirring.

[0181] After the reaction was completed, the reaction solution was poured into deionized water and extracted with dichloromethane. The organic layer was washed three times with water, dried over anhydrous Na2SO4, and spin-dried. The crude product was separated and purified by column chromatography using a mixture of petroleum ether and dichloromethane (volume ratio of 10:1) as eluent to obtain the product 2-chloro-4-phenyl-6-(4-vinylphenyl)-1,3,5-triazine, the structure of which is as follows:

[0182]

[0183] (2) 1 mmol of 2-chloro-4-phenyl-6-(4-vinylphenyl)-1,3,5-triazine, 1 mmol of (4-bromophenyl)diphenylphosphine (purchased from Alpha, purity 95%), 24 mg (about 1 mmol) of magnesium, and 0.01 mmol of I2 (initiator) were added to 4 ml of anhydrous tetrahydrofuran and reacted at 60°C for 12 hours under argon protection. After the reaction stopped, the reaction solution was poured into water and extracted with dichloromethane. The organic layer was washed three times with water, dried over anhydrous Na2SO4, and spin-dried. It was then oxidized with 1 mL of H2O2 (added with 8.8 mmol / ml of hydrogen peroxide solution) and purified by column chromatography using a mixture of petroleum ether and ethyl acetate (volume ratio of 2:3) as the eluent to obtain intermediate compound I (VP-PhTzTPPO). The specific structure is shown below.

[0184]

[0185] (2) 0.95 mmol of VP-DMAC prepared in Example 1, 0.05 mmol of VP-PhTzTPPO, and 0.02 mmol of AIBN were added to 2 ml of anhydrous tetrahydrofuran and reacted at 80° C. for 48 hours under argon protection. Cold acetone was added to precipitate the product, and Soxhlet extraction was performed for 48 hours to obtain the target copolymer IV.

[0186] The H NMR spectrum data of copolymer IV are as follows: 1 H NMR (TMS, CDCl3, 400MHz): δ = 8.690-8.244 (m, 6H), 7.809-7.622 (s, 6H), 7.501-6.905 (m, 130H), 6.779-6.4 06(s,79H),6.294-5.848(m,41H),2.741-2.271(m,19H),2.122-1.725(m,35H),1.651-1.204ppm(m,128H).

[0187] From the GPC data, it was found that the molecular weight of the polymer was 27084 and the PDI was 1.7.

[0188] It can be seen that the copolymer product IV (PVP-0.95DMAC-0.05PhTzTPPO) has the following structural units: (through the monomer and polymer 1 H NMR calculations reveal the following: Find the characteristic peak (6H) of the acceptor (phenyltriazine group) monomer, then subtract the number of the characteristic peak (6H) and the number of aromatic hydrogens (17H) in the monomer from the total number of aromatic hydrogens in the polymer (6+6+130+79+41=262H). The remaining hydrogen number (239H) is then divided by the number of aromatic hydrogens (12H) in the donor (phenylacridine group), resulting in a donor-to-acceptor ratio of approximately 0.95:0.05. The calculation method is the same for subsequent examples.

[0189]

[0190] The ultraviolet fluorescence spectrum of the copolymerized product IV obtained in this example is as follows Figure 16 shown.

[0191] The thermogravimetric analysis spectrum of the copolymer product IV obtained in this example is as follows Figure 17 As shown in the figure, it can be seen that the cracking temperature of the copolymer product IV reaches 393℃.

[0192] PVP-0.95DMAC-0.05PhTzTPPO was made into a film, and the transient photoluminescence decay curve of the polymer film was tested.

[0193] Figure 22 This is the transient photoluminescence decay curve of the PVP-0.95DMAC-0.05PhTzTPPO film synthesized in this example. The ■ curve represents the decay curve at a temperature of 77K, the ● curve represents the decay curve at a temperature of 100K, the ▲ curve represents the decay curve at a temperature of 200K, and the ▼ curve represents the decay curve at a temperature of 300K. As the temperature increases, the lifetime becomes shorter, proving that it has TADF properties. The ratio of transient fluorescence to delayed fluorescence can be calculated.

[0194] Example 6

[0195] 0.90 mmol of VP-DMAC prepared in Example 1, 0.10 mmol of VP-PhTzTPPO prepared in Example 5, and 0.02 mmol of AIBN were added to 2 ml of anhydrous tetrahydrofuran and reacted at 80° C. for 48 hours under argon protection. Cold acetone was added to precipitate the product, and Soxhlet extraction was performed for 48 hours to obtain the target product, copolymer V.

[0196] The H NMR spectrum data of copolymerization product V are as follows: 1H NMR (TMS, CDCl3, 400MHz): δ = 8.788-8.168 (m, 6H), 7.797-7.574 (m, 6H), 7.561-6.811 (m, 68H), 6.799-6.3 87(m,37H),6.310-5.690(m,19H),2.688-2.253(m,8H),2.216-1.721(m,18H),1.684-1.092ppm(m,62H).

[0197] From the GPC data, it was found that the molecular weight of the polymer was 25239 and the PDI was 1.9.

[0198] It can be seen that the copolymer product V (PVP-0.90DMAC-0.10PhTzTPPO) has the following structural units:

[0199]

[0200] The ultraviolet fluorescence spectrum of the copolymerization product V obtained in this example is as follows Figure 18 shown.

[0201] The thermogravimetric analysis spectrum of the copolymerization product V obtained in this example is as follows Figure 19 As shown in the figure, it can be seen that the cracking temperature of the copolymer product V reaches 388℃.

[0202] PVP-0.90DMAC-0.10PhTzTPPO film was prepared and the transient photoluminescence decay curve of the polymer film was tested.

[0203] Figure 23 This is the transient photoluminescence decay curve of the PVP-0.90DMAC-0.10PhTzTPPO film synthesized in this example. The ■ curve represents the decay curve at a temperature of 77K, the ● curve represents the decay curve at a temperature of 100K, the ▲ curve represents the decay curve at a temperature of 200K, and the ▼ curve represents the decay curve at a temperature of 300K. As the temperature increases, the lifetime becomes significantly shorter, proving that it has excellent TADF properties. In addition, the ratio of transient fluorescence to delayed fluorescence can be calculated.

[0204] Example 7

[0205] 0.80 mmol of VP-DMAC prepared in Example 1, 0.20 mmol of VP-PhTzTPPO prepared in Example 5, and 0.02 mmol of AIBN were added to 2 ml of anhydrous tetrahydrofuran and reacted at 80° C. for 48 hours under argon protection. Cold acetone was added to precipitate the product, and Soxhlet extraction was performed for 48 hours to obtain the target product, copolymer VI.

[0206] The H NMR spectrum data of copolymer VI are as follows: 1 H NMR (TMS, CDCl3, 400MHz): δ = 8.794-8.105 (m, 6H), 7.748-7.543 (m, 6H), 7.556-6.848 (m, 35H), 6.820-6. 430(m,18H),6.293-5.680(m,9H),2.791-2.195(m,4H),2.153-1.695(m,10H),1.667-0.848ppm(m,29H).

[0207] From the GPC data, it was found that the molecular weight of the polymer was 22385 and the PDI was 1.6.

[0208] It can be seen that the copolymer product VI (PVP-0.81DMAC-0.19PhTzTPPO) has the following structural units:

[0209]

[0210] The ultraviolet fluorescence spectrum of the copolymerization product VI obtained in this example is as follows Figure 20 shown.

[0211] The thermogravimetric analysis spectrum of the copolymerization product VI obtained in this example is as follows Figure 21 As shown in the figure, it can be seen that its cracking temperature reaches 393℃.

[0212] PVP-0.83DMAC-0.17PhTzTPPO film was prepared and the transient photoluminescence decay curve of the polymer film was tested.

[0213] Figure 24 This is the transient photoluminescence decay curve of the PVP-0.83DMAC-0.17PhTzTPPO film synthesized in this example. The ■ curve represents the decay curve at a temperature of 77K, the ● curve represents the decay curve at a temperature of 100K, the ▲ curve represents the decay curve at a temperature of 200K, and the ▼ curve represents the decay curve at a temperature of 300K. As the temperature increases, the lifetime becomes shorter, proving that it has excellent TADF properties. The ratio of transient fluorescence to delayed fluorescence can be calculated.

[0214] Example 8

[0215] Green light TADF devices were prepared using PVP-0.95DMAC-0.05PhTzTPPO, PVP-0.90DMAC-0.10PhTzTPPO and PVP-0.83DMAC-0.17PhTzTPPO prepared in Examples 5, 6 and 7, respectively. The specific preparation steps are as follows:

[0216] 1. Place the glass or plastic substrate cleaned with deionized water into the vacuum evaporator with a vacuum degree of 5×10 - 5 mbar, and the evaporation rate was set to 0.1–0.3 nm s -1 , on a glass or plastic substrate, an anode conductive layer with a thickness of 150nm is deposited using indium tin oxide as the material;

[0217] 2. Spin-coating a hole injection layer with a thickness of 60 nm and a PEDOT:PSS material (wherein the mass fraction of PEDOT is 5%) on the anode conductive layer;

[0218] 3. Spin-coat the hole injection layer with PVP-0.95DMAC-0.05PhTzTPPO, PVP-0.90DMAC-0.10PhTzTPPO and PVP-0.83DMAC-0.17PhTzTPPO to form a 30nm thick light-emitting layer.

[0219] 4. Continue to evaporate an exciton blocking layer DPEPO with a thickness of 5 nm on the light-emitting layer;

[0220] 5. Evaporating an electron transport layer with a thickness of 40 nm and TPBi on the exciton blocking layer;

[0221] 6. Evaporate LiF on the electron transport layer to form an electron injection layer with a thickness of 1 nm;

[0222] 7. A cathode conductive layer with a thickness of 100 nm and a material of metallic Al was evaporated on the electron injection layer, and then encapsulated to obtain an organic electroluminescent device based on a non-conjugated polymer TADF material with a phosphine oxide auxiliary acceptor.

[0223] The voltage-current density relationship curves of the green light TADF devices prepared by using PVP-0.95DMAC-0.05PhTzTPPO, PVP-0.90DMAC-0.10PhTzTPPO and PVP-0.83DMAC-0.17PhTzTPPO in this embodiment are shown in FIG. Figure 25 As shown, the curve ◆ represents the device based on PVP-0.95DMAC-0.05PhTzTPPO, and the curve The curve represents a device based on PVP-0.90DMAC-0.10PhTzTPPO, with The curve represents a device based on PVP-0.83DMAC-0.17PhTzTPPO. It shows that the turn-on voltage of the device based on PVP-0.95DMAC-0.05PhTzTPPO is 4.0V; the turn-on voltage of the device based on PVP-0.90DMAC-0.10PhTzTPPO is 3.7V; and the turn-on voltage of the device based on PVP-0.83DMAC-0.17PhTzTPPO is 3.5V.

[0224] The voltage-luminance relationship curves of the green TADF devices prepared using PVP-0.95DMAC-0.05PhTzTPPO, PVP-0.90DMAC-0.10PhTzTPPO and PVP-0.83DMAC-0.17PhTzTPPO in this embodiment are shown in FIG. Figure 26 As shown, the curve ◆ represents the device based on PVP-0.95DMAC-0.05PhTzTPPO, and the curve The curve represents a device based on PVP-0.90DMAC-0.10PhTzTPPO, with The curve represents the device based on PVP-0.83DMAC-0.17PhTzTPPO. From this figure, we can see that the brightness of the device based on PVP-0.95DMAC-0.05PhTzTPPO reaches a maximum of 1668cd·m -2 The device based on PVP-0.90DMAC-0.10PhTzTPPO has a maximum brightness of 2166cd·m -2 The brightness of the device based on PVP-0.83DMAC-0.17PhTzTPPO reached a maximum of 2708cd·m -2 .

[0225] The brightness-current efficiency relationship curves of green light TADF devices prepared using PVP-0.95DMAC-0.05PhTzTPPO, PVP-0.90DMAC-0.10PhTzTPPO and PVP-0.83DMAC-0.17PhTzTPPO are shown in the figure. Figure 27 As shown, the curve ◆ represents the device based on PVP-0.95DMAC-0.05PhTzTPPO, and the curve The curve represents a device based on PVP-0.90DMAC-0.10PhTzTPPO, with The curve represents the device based on PVP-0.83DMAC-0.17PhTzTPPO. From this figure, we can see that the current efficiency of the device based on PVP-0.95DMAC-0.05PhTzTPPO reaches the maximum value of 81.5cd·A -1The device current efficiency based on PVP-0.90DMAC-0.10PhTzTPPO reached a maximum of 80.5cd·A -1 The current efficiency of the device based on PVP-0.83DMAC-0.17PhTzTPPO reached a maximum of 23.1cd·A -1 .

[0226] The brightness-power efficiency relationship curves of the green light TADF devices prepared by PVP-0.95DMAC-0.05PhTzTPPO, PVP-0.90DMAC-0.10PhTzTPPO and PVP-0.83DMAC-0.17PhTzTPPO in this embodiment are shown in FIG. Figure 28 As shown, the curve ◆ represents the device based on PVP-0.95DMAC-0.05PhTzTPPO, and the curve The curve represents a device based on PVP-0.90DMAC-0.10PhTzTPPO, with The curve represents the device based on PVP-0.83DMAC-0.17PhTzTPPO. From this figure, we can see that the power efficiency of the device based on PVP-0.95DMAC-0.05PhTzTPPO reaches the maximum value of 60.9lm·W -1 The device power efficiency based on PVP-0.90DMAC-0.10PhTzTPPO reaches a maximum of 66.4lm·W -1 The power efficiency of the device based on PVP-0.83DMAC-0.17PhTzTPPO reached a maximum of 19.1lm·W -1 .

[0227] The brightness-external quantum efficiency relationship curves of green light TADF devices prepared using PVP-0.95DMAC-0.05PhTzTPPO, PVP-0.90DMAC-0.10PhTzTPPO and PVP-0.83DMAC-0.17PhTzTPPO are shown in the figure. Figure 29 As shown, the curve ◆ represents the device based on PVP-0.95DMAC-0.05PhTzTPPO, and the curve The curve represents a device based on PVP-0.90DMAC-0.10PhTzTPPO, with The curve represents devices based on PVP-0.83DMAC-0.17PhTzTPPO. The figure shows that the external quantum efficiency of devices based on PVP-0.95DMAC-0.05PhTzTPPO reaches a maximum of 27.2%; that of devices based on PVP-0.90DMAC-0.10PhTzTPPO reaches a maximum of 25.2%; and that of devices based on PVP-0.83DMAC-0.17PhTzTPPO reaches a maximum of 7.3%. Among them, the external quantum efficiency of the PVP-0.95DMAC-0.05PhTzDPPO device is one of the highest values ​​reported to date, indicating that this polymer has a low efficiency roll-off.

[0228] The electroluminescence spectrum curves of green TADF devices prepared by using PVP-0.95DMAC-0.05PhTzTPPO, PVP-0.90DMAC-0.10PhTzTPPO and PVP-0.83DMAC-0.17PhTzTPPO are shown in the figure. Figure 30 As shown, the curve ◆ represents the device based on PVP-0.95DMAC-0.05PhTzTPPO, and the curve The curve represents a device based on PVP-0.90DMAC-0.10PhTzTPPO, with The curve represents a device based on PVP-0.83DMAC-0.17PhTzTPPO. The graph shows that the electroluminescence peak of the device based on PVP-0.95DMAC-0.05PhTzTPPO is 518nm; the electroluminescence peak of the device based on PVP-0.90DMAC-0.10PhTzTPPO is 524nm; and the electroluminescence peak of the device based on PVP-0.83DMAC-0.17PhTzTPPO is 526nm.

[0229] The present invention has been described in detail above with reference to specific embodiments and / or exemplary examples and the accompanying drawings. However, these descriptions should not be construed as limiting the present invention. Those skilled in the art will appreciate that various equivalent substitutions, modifications, or improvements may be made to the technical solutions and implementations of the present invention without departing from the spirit and scope of the present invention, all of which fall within the scope of the present invention. The scope of protection of the present invention shall be determined by the appended claims.

Claims

1. A non-conjugated polymer thermally excited delayed fluorescent material based on phenylacridine and phenyltriazine substituents, which is a polymer obtained by polymerizing styrene with acridine substituents and styrene with phenyltriazine substituents as monomers. The styrene with acridine substituents is a para-acridine substituent styrene; The acridinium substituent is selected from N-9,9-dialkyl-acridinyl, and the specific structure is shown in formula (1-1), R1 and R2 are each independently selected from an alkyl group containing carbon atoms of C1-C8, ， The styrene with phenyltriazine substituents is a para-phenyltriazine substituent styrene; The phenyl triazine substituent is selected from formula (1-2); wherein R 3. R4 is independently selected from hydrogen or an alkyl group containing C1-C8 carbon atoms, ， The polymer comprises the following structural units: Wherein, R5 is 4-diphenylphosphinoyl-phenyl; the ratio of a to b is (90-97):(3-10).

2. The thermally excited delayed fluorescent material according to claim 1, wherein The polymer comprises the following structural units: 。 3. The thermally excited delayed fluorescent material according to claim 2, wherein in, The ratio of a and b is (90-95):(5-10).

4. A method for preparing a non-conjugated polymer thermally excited delayed fluorescent material based on phenylacridine and phenyltriazine substituents according to any one of claims 1 to 3, characterized in that: The method specifically comprises the following steps: Step 1, preparing styrene with acridine substituents; Step 2, preparing styrene with phenyltriazine substituents; Step 3: adding styrene with acridine substituents and styrene with phenyltriazine substituents to a solvent, heating and reacting to obtain a non-conjugated polymer based on phenylacridine and phenyltriazine substituents. In step 1, a halogenated styrene and 9,9-dialkyl acridine are added to a solvent, and heated to react in a protective atmosphere in the presence of a catalyst to prepare the styrene with acridine substituents. In step 2, vinylphenylboronic acid pinesol ester or vinylphenylboronic acid and a phenyl halogenated triazine compound are added to a solvent, and heated to react in the presence of a catalyst to prepare styrene with a phenyltriazine substituent; Among them, in step 2, The vinylbenzene pinesol borate is selected from 4-vinylbenzene pinesol borate; The phenyl halogenated triazine compound is selected from 2,4-dihalogenated-6-phenyl-1,3,5-triazine or 2,4-dihalogenated-6-substituted phenyl-1,3,5-triazine; The phenyl halogenated triazine compound is shown in formula (2-2), wherein R6 and R7 are each independently selected from hydrogen or an alkyl group containing carbon atoms of C1-C8; ， Wherein, X is bromo or chloro; The prepared 2-halogeno-4-(4-vinylphenyl)-6-phenyl-1,3,5-triazine or 2-halogeno-4-(4-vinylphenyl)-6-substituted phenyl-1,3,5-triazine, (4-halogenophenyl)diphenylphosphine, magnesium strips and iodine element are added to a solvent and heated for reaction to obtain 2-(4-diphenylphosphinooxy-phenyl)-4-(4-vinylphenyl)-6-phenyl-1,3,5-triazine or 2-(4-diphenylphosphinooxy-phenyl)-4-(4-vinylphenyl)-6-substituted phenyl-1,3,5-triazine.

5. The method according to claim 4, characterized in that in, R6 and R7 are each independently hydrogen or an alkyl group containing C1-C3 carbon atoms, X is chloro.

6. The method according to claim 4, characterized in that The phenyl halogenated triazine compound is selected from 2,4-dihalogenated-6-phenyl-1,3,5-triazine, Wherein, X is bromo or chloro.

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