Penta-substituted pyrene blue organic fluorescent material as well as preparation method and application thereof

Abstract

The invention discloses a penta-substituted pyrene blue organic fluorescent material as well as a preparation method and application thereof, and belongs to the technical field of organic electroluminescence. The penta-substituted pyrene organic fluorescent material is prepared by introducing a substituent group to a site 2 of pyrene molecules by utilizing the difference of activity of different sites of the pyrene molecules through a step-by-step introduction method, then introducing two aryl substituent groups to sites 1 and 3 of the pyrene molecules, and finally introducing two aryl substituent groups to sites 5 and 9 of the pyrene molecules. Different substituent groups are introduced into 1, 2, 3, 5 and 9 sites of pyrene molecules, so that on one hand, pi conjugate forms, intramolecular charge transfer paths, molecular dipole horizontal orientation and the like of organic molecules can be regulated and controlled, and luminous color modulation of the organic molecules and balance of carrier injection in OLED device application are realized; on the other hand, pi-pi stacking interaction among molecules is effectively inhibited, spectrum red shift is inhibited, and the light-emitting quantum efficiency of organic material molecules is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of organic electroluminescence, and in particular relates to a pentasubstituted pyrene blue organic fluorescent material and a preparation method and application thereof. Background Art

[0002] Organic light-emitting diodes (OLEDs) have the advantages of flat light emission, fast response speed, large area, and good flexibility. They have been widely used in the fields of lighting and flat-panel displays in daily life. The current mainstream commercial red and green light-emitting materials are phosphorescent materials, which almost meet commercial needs in terms of efficiency and stability. However, blue phosphorescent materials cannot meet commercial standards due to high cost, poor color purity, complex device manufacturing process, and severe roll-off at high brightness. Therefore, the current commercial blue light materials use the first generation of traditional fluorescent materials, which have low efficiency and brightness, and usually require lamination processes to compensate. Therefore, a new generation of blue light OLED materials with high efficiency and high stability has recently become a concern in this field.

[0003] According to the spin statistics theory, in traditional organic fluorescent materials, only 25% of singlet excitons can be utilized, while the remaining 75% of triplet excitons are wasted through non-radiative transitions, resulting in poor electroluminescent performance. In order to break through the obstacles of spin statistics limitations and make full use of excitons as much as possible, a new generation of high-efficiency fluorescent materials such as triplet-triplet annihilation (TTA), thermally activated delayed fluorescence (TADF) and "hot exciton" materials have been widely studied. Among them, TTA materials have been widely used in business due to their good device stability, long service life, low efficiency roll-off and other advantages.

[0004] Common TTA-type blue fluorescent materials are mainly composed of rigid conjugated molecules such as anthracene and pyrene as the core. Such materials usually have high fluorescence quantum yield and stability. Among them, pyrene, as a ring-fused polycyclic aromatic hydrocarbon (PAH), has both electron-donating and electron-withdrawing functions. It shows strong blue fluorescence and good quantum yield in solution, thus having excellent optical properties, and exhibits characteristics such as solution processability, good thermal stability, high charge carrier mobility and high luminescence efficiency in organic electroluminescent devices. However, due to the large rigid planar conjugated structure of pyrene molecules, it is very easy to form π-π stacking in the solid state to form excimers, resulting in aggregate fluorescence quenching, causing red shift of the electroluminescence spectrum, and resulting in a decrease in device efficiency, which restricts its application in the OLED field. Summary of the invention

[0005] The purpose of the present invention is to overcome the shortcomings of the above-mentioned prior art and provide a pentasubstituted pyrene-based blue organic fluorescent material and a preparation method and application thereof, so as to solve the problems that the planar structured pyrene-based blue organic fluorescent materials in the prior art are prone to pile up in the light-emitting layer, further causing the red shift of the electroluminescence spectrum and the decrease of device efficiency.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A pentasubstituted pyrene blue organic fluorescent material, the structural formula is:

[0008]

[0009] Among them, R1 to R5 are selected from any one of hydroxyl, alcoholic hydroxyl, alkyl, deuterated alkyl, alkoxy, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted condensed ring aryl, substituted or unsubstituted heterocondensed ring aryl, substituted or unsubstituted arylamine, substituted or unsubstituted heteroarylamine, substituted or unsubstituted heterocondensed ring arylamine, and substituted or unsubstituted condensed ring arylamine having 1 to 60 carbon atoms, and R1 to R5 are not hydrogen.

[0010] A further improvement of the present invention is:

[0011] Preferably, R1 is selected from any one of hydroxyl, alcoholic hydroxyl, C1-C6 alkyl, C1-C6 deuterated alkyl, C1-C6 alkoxy, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C2-C30 heteroaryl, substituted or unsubstituted C2-C30 condensed ring aromatic group, substituted or unsubstituted C2-C30 heterocondensed ring aromatic group, and R1 is not hydrogen.

[0012] Preferably, R2 to R5 are selected from any one of a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, a substituted or unsubstituted condensed ring aryl group, a substituted or unsubstituted heterocondensed ring aryl group, a substituted or unsubstituted arylamine group, a substituted or unsubstituted heteroarylamine group, a substituted or unsubstituted condensed ring arylamine group, and a substituted or unsubstituted heterocondensed ring arylamine group having 2 to 60 carbon atoms, and R2 to R5 are not hydrogen.

[0013] Preferably, R1 to R5 are any one of the following formulae:

[0014]

[0015]

[0016]

[0017] Wherein, X is identical or different from BR, CRR, NR, O, S; CRR represents two R groups attached to a C atom; R is independently selected from one of H, D, F, and CN, or R represents any one of hydroxyl, trifluoromethyl, methoxy, aldehyde, C1-C6 alkyl, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C2-C30 heteroaryl, substituted or unsubstituted C2-C30 condensed ring aryl, and substituted or unsubstituted C2-C30 heterocondensed ring aryl;

[0018] The substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C2-C30 heteroaryl, substituted or unsubstituted C2-C30 condensed ring aryl, substituted or unsubstituted C2-C30 heterocondensed ring aryl is independently selected from one of the following: phenyl, naphthyl, anthracenyl, phenanthryl, biphenyl, terphenyl, fluorenyl, pyridyl, carbazolyl, furanyl, pyrimidinyl, pyrazinyl, pyridazinyl, thienyl, benzothienyl, benzofuranyl, dibenzothienyl, dibenzofuranyl, oxazolyl, carbazolyl;

[0019] n is 0, 1, 2, 3 or 4;

[0020] The heteroaryl group refers to a group containing at least one heteroatom selected from B, N, O, and S, and * indicates the position of connection with the adjacent atom.

[0021] Preferably, R1 to R5 are any one of the following formulae:

[0022]

[0023]

[0024]

[0025]

[0026]

[0027]

[0028]

[0029]

[0030]

[0031] *Indicates the position connected to the adjacent atom.

[0032] Preferably, R1 is

[0033] Any one of .

[0034] Preferably, R2 is

[0035]

[0036] R3 is

[0037]

[0038] Preferably, R4 is

[0039]

[0040] Any of the following:

[0041] R5 is

[0042]

[0043] Any one of .

[0044] A method for preparing the above-mentioned pentasubstituted pyrene-based blue organic fluorescent material, wherein pyrene is subjected to a borylation reaction of a tert-butyl group and a CH bond to obtain an intermediate 2, intermediate 2 is subjected to a CC bonding reaction or a CN bonding reaction to obtain an intermediate 3 having an R1 substituent, intermediate 3 is subjected to a halogenation reaction to obtain an intermediate 5, intermediate 5 is subjected to a CC bonding reaction or a CN bonding reaction to obtain an intermediate 6 having R2 and R3 substitutions, intermediate 6 is subjected to a halogenation reaction to obtain an intermediate 7, and intermediate 7 is subjected to a CC or CN bonding reaction to obtain a pentasubstituted pyrene-based blue organic fluorescent material;

[0045] The process of obtaining intermediate 5 from intermediate 2 can also be carried out by halogenating intermediate 2 to obtain intermediate 4, and intermediate 4 is further subjected to hydroxylation to obtain intermediate 5.

[0046] An application of the above-mentioned pentasubstituted pyrene-based blue organic fluorescent material, wherein the pentasubstituted pyrene-based blue organic fluorescent material is used to prepare an organic electroluminescent device;

[0047] The organic electroluminescent device comprises an anode and a cathode arranged on a substrate, and an organic functional layer arranged between the anode and the cathode, wherein the light-emitting layer in the organic functional layer comprises at least one pentasubstituted pyrene-based blue organic fluorescent material according to any one of claims 1 to 8.

[0048] Compared with the prior art, the present invention has the following beneficial effects:

[0049] The invention discloses a pentasubstituted pyrene blue organic fluorescent material, which has a non-planar rigid structure, is a type of organic light-emitting material with a blue luminescent peak and high quantum efficiency, and is used to prepare an organic electroluminescent device. The organic fluorescent material can regulate the π conjugated form, intramolecular charge transfer path, molecular dipole horizontal orientation, etc. of the organic molecule by introducing different substituent groups at positions 1, 2, 3, 5, and 9 of the pyrene molecule, on the one hand, so as to achieve the balance between the luminescent color modulation of the organic molecule and the carrier injection in the application of the OLED device; on the other hand, it effectively suppresses the π-π stacking interaction between molecules, suppresses the red shift of the spectrum, and improves the luminescent quantum efficiency of the organic material molecule. Therefore, the pyrene blue organic fluorescent material is used as a luminescent material in a doped blue OLED device, and the prepared device has a series of advantages such as high external quantum efficiency and good color purity.

[0050] The invention discloses a method for preparing a pentasubstituted pyrene blue organic fluorescent material. The method utilizes the difference in activity of different sites of the pyrene molecule and introduces a substituent group at the 2nd position, then introduces two aryl substituent groups at the 1st and 3rd positions, and finally introduces two aryl substituent groups at the 5th and 9th positions to prepare a pentasubstituted pyrene organic fluorescent material.

[0051] The invention also discloses the application of a pentasubstituted pyrene blue organic fluorescent material, which is used as a guest material in a doped OLED device. The prepared device has a series of advantages such as a blue electroluminescent peak, high external quantum efficiency, high color purity, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 It is a schematic diagram of the structure of two organic electroluminescent devices (A and B) used in the present invention.

[0053] Figure 2 The target compound TC-33 1 H NMR spectra.

[0054] Figure 3 The target compound TC-34 1 H NMR spectra.

[0055] Figure 4 It is the target compound TC-41 1 H NMR spectra.

[0056] Figure 5 It is the target compound TC-58 1 H NMR spectra.

[0057] Figure 6 It is the target compound TC-61 1H NMR spectra.

[0058] Figure 7 It is the target compound TC-169 1 H NMR spectra.

[0059] Figure 8 The target compound TC-180 1 H NMR spectra.

[0060] Fig. 9 The target compound TC-207 1 H NMR spectra.

[0061] Fig.10 It is the target compound TC-217 1 H NMR spectra.

[0062] Fig.11 The target compound TC-230 1 H NMR spectra.

[0063] Fig.12 It is the target compound TC-231 1 H NMR spectra.

[0064] Fig.13 It is the target compound TC-446 1 H NMR spectra. DETAILED DESCRIPTION

[0065] The present invention is further described in detail below in conjunction with the accompanying drawings:

[0066] In order to enable those skilled in the art to understand the characteristics and effects of the present invention, the following is a general description and definition of the terms and expressions mentioned in the specification and claims. Unless otherwise specified, all technical and scientific terms used in the text are the common meanings understood by those skilled in the art for the present invention. In the event of a conflict, the definition in this specification shall prevail.

[0067] In this document, unless otherwise specified, “includes,” “including,” “contains,” “has,” or similar terms cover the meanings of “consisting of” and “mainly consisting of,” for example, “A includes a” covers the meanings of “A includes a and other” and “A only includes a.”

[0068] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall within the scope limited by the appended claims of the application equally.

[0069] The following examples use conventional instruments and equipment in the art. The experimental methods in the following examples where specific conditions are not specified are usually carried out under conventional conditions or under conditions recommended by the manufacturer. The various raw materials used in the following examples are conventional commercial products unless otherwise specified, and their specifications are conventional specifications in the art. In the specification of the present invention and the following examples, unless otherwise specified, "%" means weight percentage, "part" means weight part, and ratio means weight ratio.

[0070] The first aspect of the present invention discloses a pentasubstituted pyrene-based blue organic fluorescent material, the structural formula of which is as follows:

[0071]

[0072] In the above structural formula, R1 to R5 are selected from hydroxyl, alcoholic hydroxyl, alkyl, deuterated alkyl, alkoxy, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted condensed ring aryl, substituted or unsubstituted heterocondensed ring aryl, substituted or unsubstituted arylamine, substituted or unsubstituted heteroarylamine, substituted or unsubstituted heterocondensed ring arylamine, substituted or unsubstituted condensed ring arylamine and combinations thereof having 1 to 60 carbon atoms, and R1 to R5 are not hydrogen.

[0073] In the structural formula of the organic compound described in the present invention, R1 is preferably selected from any one of hydroxyl, alcoholic hydroxyl, C1-C6 alkyl, C1-C6 deuterated alkyl, C1-C6 alkoxy, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C2-C30 heteroaryl, substituted or unsubstituted C2-C30 condensed ring aromatic group, substituted or unsubstituted C2-C30 heterocondensed ring aromatic group, and R1 is not hydrogen.

[0074] R2 to R5 are preferably any one of a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, a substituted or unsubstituted condensed ring aryl group, a substituted or unsubstituted heterocondensed ring aryl group, a substituted or unsubstituted arylamine group, a substituted or unsubstituted heteroarylamine group, a substituted or unsubstituted condensed ring arylamine group, and a substituted or unsubstituted heterocondensed ring arylamine group having 2 to 60 carbon atoms, and R2 to R5 are not hydrogen.

[0075] In the present invention, the term "substituted or unsubstituted" means that the functional group described after the term may or may not have a substituent R. For example, "substituted or unsubstituted aryl" refers to an aryl having a substituent R or an unsubstituted aryl. The substituent R may be, for example, a hydroxyl group, an alcoholic hydroxyl group, an alkyl group, a deuterated alkyl group, an alkoxy group, an aryl group, a heteroaryl group, a condensed aryl group, an arylamine group, a heteroarylamine group, a condensed arylamine group or a condensed arylamine group; the number of substitutions may be one or more.

[0076] In the present invention, "plurality" means two or more, for example, 2, 3, 4, 5, 6, etc.

[0077] In some embodiments of the present invention, the following representative structures are used to represent the structural formula in which R1 to R5 are represented:

[0078]

[0079]

[0080]

[0081] Wherein, X is identical or different from BR, CRR, NR, O, S; CRR represents two R groups attached to a C atom; R is independently selected from one of H, D, F, and CN, or R represents any one of hydroxyl, trifluoromethyl, methoxy, aldehyde, C1-C6 alkyl, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C2-C30 heteroaryl, substituted or unsubstituted C2-C30 condensed ring aromatic group, or substituted or unsubstituted C2-C30 hetero condensed ring aromatic group;

[0082] The substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C2-C30 heteroaryl, substituted or unsubstituted C2-C30 condensed ring aryl, and substituted or unsubstituted C2-C30 heterocondensed ring aryl are independently selected from one of the following: phenyl, naphthyl, anthracenyl, phenanthryl, biphenyl, terphenyl, fluorenyl, pyridyl, carbazolyl, furyl, pyrimidinyl, pyrazinyl, pyridazinyl, thienyl, benzothienyl, benzofuranyl, dibenzothienyl, dibenzofuranyl, oxazolyl, and carbazolyl; n is 0, 1, 2, 3, or 4; the above-mentioned heteroaryl refers to a group containing at least one heteroatom selected from B, N, O, and S, and * indicates the position connected to the adjacent atom.

[0083] In some embodiments of the present invention, one or more of the following representative structures are used to independently represent R1 to R5 in the structural formula of claim 1:

[0084]

[0085]

[0086]

[0087]

[0088]

[0089]

[0090]

[0091]

[0092]

[0093] *Indicates the position connected to the adjacent atom.

[0094] Further, based on the above structural formula, the structural formula of the pentasubstituted pyrene-based blue organic fluorescent material is represented by any one of the structural formulas in the following table.

[0095] Table 1 Structural formula of pentasubstituted pyrene blue organic fluorescent materials

[0096]

[0097]

[0098]

[0099]

[0100]

[0101] In some embodiments of the present invention, R1 is

[0102] In some embodiments of the present invention, R2 is

[0103]

[0104] R3 is

[0105]

[0106] In some embodiments of the present invention, R4 is

[0107]

[0108] Any of the following:

[0109] R5 is

[0110]

[0111] Any one of .

[0112] The second aspect of the present invention discloses a method for preparing a pentasubstituted pyrene-based blue organic fluorescent material. The compound of the present invention can be synthesized through the following reaction path: using pyrene as the starting material, an intermediate 2 can be obtained through a simple tert-butyl substitution reaction and a CH bond borylation reaction, and intermediate 2 can be subjected to a CC or CN bonding reaction under appropriate conditions to obtain an intermediate 3 having R1 substitution, and then through a halogenation reaction such as bromination to obtain an intermediate 5; or intermediate 2 is subjected to a halogenation reaction such as bromination to obtain intermediate 4, and then through a hydroxylation reaction under appropriate conditions to obtain intermediate 5 (this process is mainly used to synthesize intermediate 5 with hydroxyl, alkylhydroxyl and alkyl at position 2); then intermediate 5 is subjected to a CC or CN bonding reaction with a suitable raw material under certain conditions to obtain an intermediate 6 having R2 and R3 substitutions, and then through a halogenation reaction such as bromination to obtain intermediate 7, and finally through a CC or CN bonding reaction under appropriate conditions to obtain the target compound molecule of the present invention.

[0113]

[0114] The specific preparation method comprises the following steps:

[0115] (1) According to the method reported in the literature (RSC Adv., 2015, 5, 8835–8848; Chem. Commun., 2005, 2172-2174), the raw material pyrene was tert-butyl substituted and boronic acid esterified to obtain intermediate 2.

[0116] (2) Under nitrogen protection, 3.8 g of intermediate 2 and 2.6 g of iodobenzene were completely dissolved in 75 mL of toluene in a round-bottom flask, and then 25 mL of potassium carbonate aqueous solution (2M), 25 mL of ethanol and 350 mg of tetrakis(triphenylphosphine)palladium were added, and the mixture was heated to 110° C. and stirred for 3 hours. After the reaction was completed, the mixture was cooled to room temperature, and the organic solvent was removed by vacuum distillation. The mixture was extracted with dichloromethane and saturated brine, and the organic phase was dried over anhydrous sodium sulfate. The dichloromethane was removed by vacuum distillation. The crude product was chromatographed on a silica gel column using petroleum ether as an eluent to obtain intermediate 3-1 (2.9 g) with a yield of 86%.

[0117]

[0118] By using the method of step (2), the iodobenzene is replaced with boronic acid or boronic acid ester of other groups to obtain the following intermediates 3-2 (3.2 g) and 3-3 (3.1 g), respectively, with yields of 83% and 55%.

[0119]

[0120] (3) Under nitrogen protection, 5 g of intermediate 3-1 and 5 g of N-bromosuccinimide were dissolved in 100 mL of tetrahydrofuran in a round-bottom flask, and the mixed solution was stirred at room temperature for 12 hours; after the reaction was completed, 10% sodium thiosulfate solution was added for neutralization, and the organic solvent was removed by vacuum distillation. The product was extracted with dichloromethane and saturated brine, and the organic phase was dried over anhydrous sodium sulfate. The dichloromethane was removed by vacuum distillation. The crude product was obtained by silica gel column chromatography using petroleum ether: dichloromethane (10:1) as the eluent to obtain intermediate 5-1 (4.2 g) with a yield of 60%.

[0121]

[0122] By using the method of step (3), intermediate 3-1 is replaced by intermediate 3-2 to obtain the following intermediate 5-2 (3.3 g) with a yield of 73%.

[0123]

[0124] (4) Under nitrogen protection, 2.1 g of intermediate 3-3, 2.3 g of N-bromosuccinimide, 890 mg of cuprous bromide and 0.2 mL of acetic acid were dissolved in 40 mL of dichloroethane in a round-bottom flask, and the mixture was heated to 100° C. and stirred for reaction for 24 hours. After the reaction was completed, the mixture was cooled to room temperature and the organic solvent was removed by vacuum distillation. The mixture was extracted with dichloromethane and saturated brine, and the organic phase was dried over anhydrous sodium sulfate. The crude product was obtained by vacuum distillation. Dichloromethane was used as the eluent and the mixture was chromatographed on a silica gel column to obtain intermediate 5-3 (2.0 g) with a yield of 65%.

[0125]

[0126] (5) Under nitrogen protection, 4.8 g of intermediate 2 and 4.7 g of N-bromosuccinimide were dissolved in 100 mL of tetrahydrofuran in a round-bottom flask, and the mixed solution was stirred at room temperature for 12 hours. After the reaction was completed, 10% sodium thiosulfate solution was added for neutralization, and the organic solvent was removed by vacuum distillation. The product was extracted with dichloromethane and saturated brine, and the organic phase was dried over anhydrous sodium sulfate. The crude product was obtained by vacuum distillation. The product was eluted with petroleum ether: dichloromethane (5:1) and subjected to silica gel column chromatography to obtain intermediate 4 (5.0 g) with a yield of 74%.

[0127]

[0128] (6) Under nitrogen protection, 3.9 g of intermediate 4 and 0.7 g of sodium hydroxide were added to 280 mL of tetrahydrofuran and stirred for 10 minutes. Then, 2 mL of hydrogen peroxide solution (30%) and 4 mL of water were added to the mixed solution, stirred at room temperature for 4 hours, and then the pH value of the mixed solution was adjusted to 1-2 using 1 M hydrochloric acid solution, and then filtered and washed with water, methanol and n-hexane under reduced pressure for multiple times to obtain intermediate 5-4 (2.8 g) with a yield of 90%.

[0129]

[0130] (7) Under nitrogen protection, 2.1 g of intermediate 5-1 and 3.1 g of 4-tert-butylphenylboronic acid were completely dissolved in 80 mL of toluene in a round-bottom flask, and then 20 mL of potassium carbonate aqueous solution (2M), 20 mL of ethanol and 250 mg of tetrakis(triphenylphosphine)palladium were added, and the mixture was heated to 110° C. and stirred for 12 hours. After the reaction was completed, the mixture was cooled to room temperature, and the organic solvent was removed by vacuum distillation. The mixture was extracted with dichloromethane and saturated brine, and the organic phase was dried over anhydrous sodium sulfate. The dichloromethane was removed by vacuum distillation. The crude product was chromatographed on a silica gel column using petroleum ether as an eluent to obtain intermediate 6-1 (1.3 g) with a yield of 50%.

[0131]

[0132] By using the method of step (7), intermediate 5-1 is replaced by intermediate 5-2 to intermediate 5-4, or 4-tert-butylphenylboronic acid is replaced by boronic acid or boric acid ester of other groups, the following intermediates 6-2 to intermediate 6-6 can be obtained with a yield of 45% to 73%.

[0133]

[0134] (8) Under nitrogen protection, 1.2 g of intermediate 6-1 was dissolved in 40 mL of dichloromethane in a round-bottom flask, and then a mixed solution of 0.2 mL of liquid bromine and 5 mL of dichloromethane was added dropwise at -75°C. After stirring for 30 minutes at this low temperature, the reaction device was moved to room temperature for reaction for 12 hours. After the reaction was completed, 10% sodium thiosulfate solution was added for neutralization, and the organic solvent was removed by vacuum distillation. The organic phase was extracted with dichloromethane and saturated brine, and the organic phase was dried over anhydrous sodium sulfate. The dichloromethane was removed by vacuum distillation. The crude product was chromatographed on a silica gel column using petroleum ether: dichloromethane (10:1) as the eluent to obtain intermediate 7-1 (1.22 g) with a yield of 78%.

[0135]

[0136] By using the method of step (8), intermediate 6-1 is replaced by intermediate 6-2 to intermediate 6-6, and the amount of liquid bromine is controlled to obtain the following intermediates 7-2 to intermediate 7-6 with a yield of 45% to 73%.

[0137]

[0138] The third aspect of the present invention discloses an application of a pentasubstituted pyrene-based blue organic fluorescent material, wherein the pentasubstituted pyrene-based blue organic fluorescent material is used to prepare two organic electroluminescent devices. The two organic electroluminescent devices include an anode and a cathode arranged on a substrate, and an organic functional layer arranged between the anode and the cathode, wherein at least one of the organic functional layers contains any one of the above-mentioned pentasubstituted pyrene-based blue organic fluorescent materials.

[0139] Furthermore, the substrates are all glass, the anodes are all conductive glass substrate layers, and the cathodes are all aluminum electrodes; the organic functional layers include a hole injection layer, a hole transport layer, an electron blocking layer, a light-emitting layer, a hole blocking layer, an electron transport layer and an electron injection layer or a combination thereof.

[0140] The light-emitting layer uses any one of the above-mentioned pentasubstituted pyrene blue organic fluorescent materials as a guest material or a host material.

[0141] Preferably, the light-emitting layer comprises a composition formed by any one of the above-mentioned pentasubstituted pyrene-based blue organic fluorescent materials as a guest material and one or more host materials.

[0142] The following is a further description of the specific embodiments.

[0143] [Synthesis of Example]

[0144] (1) Using intermediate 7-2 as raw material, 1.5 g of intermediate 7-2 and 1.1 g of phenylboronic acid were completely dissolved in 80 mL of toluene in a round-bottom flask under nitrogen protection, and then 20 mL of potassium carbonate aqueous solution (2M), 20 mL of ethanol and 250 mg of tetrakis(triphenylphosphine)palladium were added, and the mixture was heated to 110° C. and stirred for 12 hours. After the reaction was completed, the mixture was cooled to room temperature, and the organic solvent was removed by vacuum distillation. The mixture was extracted with dichloromethane and saturated brine, and the organic phase was dried over anhydrous sodium sulfate. The dichloromethane was removed by vacuum distillation. The crude product was chromatographed on a silica gel column using petroleum ether as an eluent, and then recrystallized to obtain the target compound TC-6 (880 mg) with a yield of 60%.

[0145]

[0146] (2) Using other intermediates 7-3 to 7-6 as raw materials, respectively, selecting a suitable boronic acid group, the synthesis steps are the same as (1) to obtain the target compounds TC-33, TC-34, TC-58, TC-217 and TC-446 with a yield of 53% to 86%.

[0147]

[0148] (3) Using intermediate 7-1 as raw material, 1.2 g of intermediate 7-1, 1.1 g of diphenylamine and 780 mg of sodium tert-butoxide were completely dissolved in 80 mL of toluene in a round-bottom flask under nitrogen protection, and then 180 mg of palladium acetate and 2.1 mL of tri-tert-butylphosphine were added in sequence, and the mixture was heated to 110° C. and stirred for 12 hours. After the reaction was completed, the mixture was cooled to room temperature, and the organic solvent was removed by vacuum distillation. The mixture was extracted with dichloromethane and saturated brine, and the organic phase was dried over anhydrous sodium sulfate. The dichloromethane was removed by vacuum distillation. The crude product was chromatographed on a silica gel column using petroleum ether: dichloromethane (10:1) as the eluent, and then recrystallized to obtain the target compound TC-207 (960 mg) with a yield of 64%.

[0149]

[0150] (4) Using other intermediates 7-2 to 7-6 as raw materials, respectively, selecting appropriate aromatic amine groups, the synthesis steps are the same as (1) to obtain the target compounds TC-41, TC-61, TC180, TC-230 and TC-231 with a yield of 30% to 67%.

[0151]

[0152] The structural characterization of the target compound obtained in the above preparation example is shown in the following table:

[0153] Table 2 Characterization results of target compounds

[0154]

[0155]

[0156]

[0157] In order to make the purpose, technical scheme and advantages of the present invention clearer, the application effect of the pyrene-based blue organic fluorescent material of the present invention in the device is described in detail below through device embodiments 1-12 and device comparative examples 1-4. The present invention adopts two device structures, wherein the manufacturing process of the device in device embodiments 2-6, device comparative examples 1 and comparative example 2 is exactly the same as that in device embodiment 1, and the manufacturing process of the device in device embodiments 8-12, device comparative examples 3 and comparative example 4 is exactly the same as that in device embodiment 7, and the same substrate material and electrode material are used, and the film thickness of the electrode material is also consistent, except that the light-emitting layer material in the device is replaced. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0158] As attached Figure 1 As shown in Figure (a), the first blue organic electroluminescent device A provided by the present invention is composed of a substrate 1, an anode layer 2, a hole injection layer 3, a hole transport layer 4, an electron blocking layer 5, a light-emitting layer 6, an electron transport layer 7, an electron injection layer 8 and a metal cathode 9, which are connected in sequence; wherein the substrate 1 is a glass substrate; the anode layer 2 is made of: ITO (indium tin oxide), and the surface resistance of the indium tin oxide layer is 15-20Ω / sq; the hole injection layer 3 is made of: 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene, referred to as (HAT-CN); the hole transport layer 4 is made of 4,4'-cyclohexyldi[N,N-di(4-methyl) The electron blocking layer 5 uses 4,4',4"-tri(carbazole-9-yl)triphenylamine, referred to as (TCTA); the light-emitting layer 6 uses 1,3-dicarbazolylphenyl, referred to as (mCP), which is used as the main material and is doped with TC-33, TC-34, TC-58, TC-169, TC-217, and TC-446, six blue fluorescent materials, in a mass fraction of 94:6; the electron transport layer 7 uses: 1,3,5-tri(3-pyridyl-3-phenyl), referred to as (TmPyPB); the electron injection layer uses LiF8; the metal cathode 9 uses high-purity metal Al.

[0159] As attached Figure 1As shown in FIG. 1( b), the second blue organic electroluminescent device B provided by the present invention is composed of a substrate 1, an anode layer 2, a hole injection layer 3, a hole transport layer 4, a light-emitting layer 6, an electron transport layer 7, an electron injection layer 8 and a metal cathode 9, which are connected in sequence; wherein the substrate 1 is a glass substrate; the anode layer 2 is made of: ITO (indium tin oxide), and the surface resistance of the indium tin oxide layer is 15-20Ω / sq; the hole injection layer 3 is made of 4,4',4'-tri[2-naphthylphenylamino]triphenylamine, referred to as (2T-NATA); the hole transport layer 4 is made of N,N'-di(1-naphthyl)-N,N '-Diphenyl-4,4'-diphenylenediamine, referred to as (NPB); the light-emitting layer 6 uses 9-(1-naphthyl)-10-(2-naphthyl)anthracene, referred to as (α,β-ADN) as the main material and TC-41, TC-61, TC180, TC-207, TC-230, five blue fluorescent materials are doped with a mass fraction of 96:4; the electron transport layer 7 uses 1,3,5-tri(1-phenyl-1H-benzimidazol-2-yl)benzene, referred to as (TPBi); the electron injection layer 8 uses LiF; the metal cathode 9 uses high-purity metal Al.

[0160] The technical effects of the compounds of the present invention are described in more detail below through device examples.

[0161] [Preparation of Device Example 1]

[0162] Use attached Figure 1 In the structure of device A, the ITO layer on the ITO glass substrate is first chemically etched into thin strip electrodes with a width of 10 mm and a length of 30 mm, and then ultrasonically cleaned with detergent and deionized water for 30 minutes, followed by ultrasonic cleaning with acetone and isopropanol for 30 minutes respectively, and then dried at 75°C and then cleaned with ultraviolet-ozone to remove organic residues on the transparent ITO surface.

[0163] The glass substrate with the anode is placed in a vacuum chamber and vacuum deposition is performed by vacuum evaporation device until the vacuum degree reaches 4×10 -4Pa, 5nm thick HAT-CN was sequentially deposited on the ITO anode layer 2 as a hole injection layer 3, and the deposition rate was controlled at 0.05nm / s; 30nm thick TAPC was used as a hole transport layer 4, and the deposition rate was controlled at 0.1nm / s; 5nm thick TCTA was used as an electron blocking layer 5, and the deposition rate was controlled at 0.05nm / s; 20nm thick mCP and TC-33 with a mass ratio of 94:6 light-emitting layer 6, and the deposition rate of the main material mCP was controlled at 0.0 94nm / s, the evaporation rate of the guest material TC-33 is set to 0.006nm / s according to the ratio of 4%; 30nm thick TmPyPB is used as the electron transport layer 7, and the evaporation rate is controlled at 0.1nm / s; then it is transferred to the metal evaporation chamber, and 1nm thick LiF is first evaporated as the electron injection layer 8, followed by evaporation of 100nm metal aluminum electrode layer, which is used as the cathode layer 9, and the evaporation rates of LiF and Al are controlled at 0.05nm / s and 0.3nm / s respectively. Finally, an organic electroluminescent device with a structure of ITO / HAT-CN (5nm) / TAPC (30nm) / TCTA (5nm) / mCP:TC-33=94:6 (20nm) / TmPyPB (30nm) / LiF (1nm) / Al (100nm) is prepared.

[0164] [Preparation of Device Example 7]

[0165] Use attached Figure 1 The structure of device B is as follows: first, the cleaning of the ITO glass substrate is the same as that in the device embodiment 1. The cleaned glass substrate with the anode is placed in a vacuum chamber and vacuum deposition is performed by a vacuum evaporation device until the vacuum degree is 4×10 -4Pa, 30nm thick 2T-NATA is sequentially deposited on the ITO anode layer 2 as a hole injection layer 3, and the deposition rate is controlled at 0.1nm / s; 30nm thick NPB is used as a hole transport layer 4, and the deposition rate is controlled at 0.1nm / s; 25nm thick α, β-ADN and TC-41 have a mass ratio of 96:4. The evaporation rate of the main material α, β-ADN is controlled to be 0.096nm / s, and the evaporation rate of the guest material TC-41 is set to 0.004nm / s according to the ratio of 4%; 30nm thick TPBi is used as an electron transport layer 7, and the evaporation rate is controlled at 0.1nm / s; then it is transferred to a metal evaporation chamber, and 1nm thick LiF is first evaporated as an electron injection layer 8, followed by 100nm metal aluminum electrode layer, which is used as metal 9, and the evaporation rates of LiF and Al are controlled at 0.05nm / s and 0.3nm / s respectively. Finally, an organic electroluminescent device with a structure of ITO / 2T-NATA (30nm) / NPB (30nm) / α,β-ADN:TC-41=96:4 (25nm) / TPBi (30nm) / LiF (1nm) / Al (100nm) was prepared.

[0166] The preparation steps of the remaining embodiments are the same as those of the above two embodiments, except that the guest materials in the light-emitting layer are replaced by the other compounds in the embodiments instead of TC-33 and TC-41. The results are shown in the following table.

[0167] The molecular structure formula of the relevant light-emitting layer material is shown below:

[0168]

[0169]

[0170] [Comparative Example 1 and Comparative Example 2]

[0171] The preparation steps are the same as those in the above embodiment, the device structure is the same or similar, and the guest material in the light-emitting layer adopts the reported (J. Mater. Chem. C, 2022, 10, 10866–10875; Adv. Optical Mater. 2023, 11, 2202490;) materials Py-BBz, Py-B2An, Py(5,9)BDPA and Py(5,9)BMTBA, and its specific structure is as follows:

[0172]

[0173] The device structures of the prepared device examples and comparative examples are shown in the following table:

[0174] Table 3 Device structure

[0175]

[0176]

[0177] The prepared devices were tested using a Keithley system. The device performance comparison results of Comparative Example 1, Comparative Example 2, Comparative Example 3, Comparative Example 4 and Examples 1 to 12 are shown in the following table:

[0178] Table 4 Device performance corresponding to the devices in the comparative examples and embodiments

[0179]

[0180]

[0181] The above results show that the pentasubstituted pyrene blue organic fluorescent material of the present invention is applied to an electroluminescent device. Compared with Comparative Examples 1 and 2, Examples 1-6 have a bluer emission peak and have the same or even higher emission brightness than Comparative Example 1, wherein the color coordinate y values ​​of Examples 4 and 6 are significantly reduced; compared with Comparative Examples 3 and 4, Examples 7-12 have a bluer emission peak and a higher maximum external quantum efficiency (EQE max ), and also has a narrower half-peak width and a smaller color coordinate y value, so that the device has better color purity; this technology reflects the difference in the activity of different sites of the pyrene molecule. Through the step-by-step introduction method, a substituent group is first introduced at its No. 2 position, then two aromatic substituent groups are introduced at its No. 1 and No. 3 positions, and finally two aromatic substituent groups are introduced at its No. 5 and No. 9 positions to prepare a five-substituted pyrene blue organic fluorescent material. By introducing different substituent groups at the No. 1, 2, 3, 5, and 9 positions of the pyrene molecule, on the one hand, the π conjugated form, intramolecular charge transfer path, molecular dipole horizontal orientation, etc. of the organic molecule can be regulated, and the luminescent color modulation of the organic molecule and the balance of carrier injection in the application of OLED devices can be achieved; on the other hand, the π-π stacking interaction between molecules is effectively suppressed, and the spectral red shift is suppressed. This type of luminescent material is used as a guest material in a doped blue OLED device, which causes the electroluminescence spectrum of the prepared device to blue shift, and improves the external quantum efficiency and color purity of the device.

[0182] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A pentasubstituted pyrene blue organic fluorescent material, characterized in that: The structural formula is: Among them, R1 to R5 are selected from any one of hydroxyl, alcoholic hydroxyl, alkyl, deuterated alkyl, alkoxy, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted condensed ring aryl, substituted or unsubstituted heterocondensed ring aryl, substituted or unsubstituted arylamine, substituted or unsubstituted heteroarylamine, substituted or unsubstituted heterocondensed ring arylamine, and substituted or unsubstituted condensed ring arylamine having 1 to 60 carbon atoms, and R1 to R5 are not hydrogen.

2. The pentasubstituted pyrene blue organic fluorescent material according to claim 1, characterized in that: R1 is selected from any one of hydroxyl, alcoholic hydroxyl, C1-C6 alkyl, C1-C6 deuterated alkyl, C1-C6 alkoxy, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C2-C30 heteroaryl, substituted or unsubstituted C2-C30 condensed ring aromatic group, substituted or unsubstituted C2-C30 heterocondensed ring aromatic group, and R1 is not hydrogen.

3. The pentasubstituted pyrene blue organic fluorescent material according to claim 1, characterized in that: R2 to R5 are selected from any one of substituted or unsubstituted aryl groups, substituted or unsubstituted heteroaryl groups, substituted or unsubstituted condensed ring aryl groups, substituted or unsubstituted heterocondensed ring aryl groups, substituted or unsubstituted arylamine groups, substituted or unsubstituted heteroarylamine groups, substituted or unsubstituted condensed ring arylamine groups, and substituted or unsubstituted heterocondensed ring arylamine groups having 2 to 60 carbon atoms, and R2 to R5 are not hydrogen.

4. The pentasubstituted pyrene blue organic fluorescent material according to claim 1, characterized in that: R1 to R5 are any one of the following formulae: Wherein, X is identical or different from BR, CRR, NR, O, S; R is independently selected from one of H, D, F, and CN, or R represents any one of hydroxyl, trifluoromethyl, methoxy, aldehyde, C1-C6 alkyl, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C2-C30 heteroaryl, substituted or unsubstituted C2-C30 condensed ring aryl, and substituted or unsubstituted C2-C30 heterocondensed ring aryl; The substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C2-C30 heteroaryl, substituted or unsubstituted C2-C30 condensed ring aryl, substituted or unsubstituted C2-C30 heterocondensed ring aryl is independently selected from one of the following: phenyl, naphthyl, anthracenyl, phenanthryl, biphenyl, terphenyl, fluorenyl, pyridyl, carbazolyl, furanyl, pyrimidinyl, pyrazinyl, pyridazinyl, thienyl, benzothienyl, benzofuranyl, dibenzothienyl, dibenzofuranyl, oxazolyl, carbazolyl; n is 0, 1, 2, 3 or 4; The heteroaryl group refers to a group containing at least one heteroatom selected from B, N, O, and S, and * indicates the position of connection with the adjacent atom.

5. The pentasubstituted pyrene blue organic fluorescent material according to claim 1, characterized in that: R1 to R5 are any one of the following formulae: *Indicates the position connected to the adjacent atom.

6. The pentasubstituted pyrene blue organic fluorescent material according to claim 1, characterized in that: R1 is Any one of .

7. The pentasubstituted pyrene blue organic fluorescent material according to claim 1, characterized in that: R2 is R3 is 8. The pentasubstituted pyrene blue organic fluorescent material according to claim 1, characterized in that: R4 is Any of the following: R5 is Any one of .

9. A method for preparing the pentasubstituted pyrene blue organic fluorescent material according to claim 1, characterized in that: Pyrene undergoes a borylation reaction between a tert-butyl group and a CH bond to obtain an intermediate 2, intermediate 2 undergoes a CC bonding reaction or a CN bonding reaction to obtain an intermediate 3 having an R1 substituent, intermediate 3 undergoes a halogenation reaction to obtain an intermediate 5, intermediate 5 undergoes a CC bonding reaction or a CN bonding reaction to obtain an intermediate 6 having R2 and R3 substitutions, intermediate 6 undergoes a halogenation reaction to obtain an intermediate 7, and intermediate 7 undergoes a CC or CN bonding reaction to obtain a pentasubstituted pyrene-based blue organic fluorescent material; The process of obtaining intermediate 5 from intermediate 2 can also be carried out by halogenating intermediate 2 to obtain intermediate 4, and intermediate 4 is further subjected to hydroxylation to obtain intermediate 5.

10. Use of the pentasubstituted pyrene blue organic fluorescent material according to claim 1, characterized in that: The pentasubstituted pyrene-based blue organic fluorescent material is used to prepare an organic electroluminescent device; The organic electroluminescent device comprises an anode and a cathode arranged on a substrate, and an organic functional layer arranged between the anode and the cathode, wherein the light-emitting layer in the organic functional layer comprises at least one pentasubstituted pyrene-based blue organic fluorescent material according to any one of claims 1 to 8.

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