A blue fluorescent doped compound, a preparation method thereof and application thereof

Abstract

The application provides a blue fluorescent doped compound which is used as a doped compound of a light-emitting layer in an organic layer, wherein a parent core indole and carbazole heterocycle has the advantages of high fluorescent quantum efficiency, easy modification of structure and wide energy gap; a double arylamine group is used as a substituent, a pi-pi conjugated system exists in the molecular structure, the substituent itself has a strong charge transfer effect, and meanwhile, has excellent hole transport capacity, thermal stability and morphological stability, which is beneficial to improving the glass transition temperature and the light-emitting efficiency; and the device prepared by the application has the performance advantages of high efficiency, long service life and low driving voltage.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of organic light-emitting materials, in particular to a blue fluorescent doped compound, a preparation method thereof and application thereof. BACKGROUND

[0002] The 21st century is an era of rapid development of information technology. Various news media and social platforms have become important means for people to obtain, share and disseminate information. As the terminal display of information visualization, whether it is a mobile phone, a computer or a television, people are increasingly pursuing display devices with excellent performance. With the development of technology, the emergence of various wearable electronic devices and portable electronic devices has put forward higher requirements and challenges to display technology. Therefore, it is urgent to develop display devices with excellent color rendering effect, lightness, energy saving and high efficiency.

[0003] As a new flat panel display device, OLED has many advantages such as full solid state, high brightness, wide viewing angle, self-luminescence, fast response speed, use of flexible substrate, low power consumption and wide working temperature range. In terms of processing, organic electroluminescent devices can prepare luminescent thin films by vacuum evaporation and spin coating. Due to the incomparable advantages and technical prospects of the above other display technologies, it is expected that in the near future, OLED will enter all aspects of people's life, and even play an important role in the national economy and national defense industry. The development history of OLED and the development of OLED materials and devices are inseparable.

[0004] OLED materials are represented by fluorescent materials such as tris-(8-hydroxyquinoline) aluminum (Alq3). With continuous research, some organic fluorescent small molecules can also be used as light-emitting materials, mainly aromatic hydrocarbon compounds and heterocyclic compounds, including oxadiazoles, triazoles, stilbenes, benzimidazoles, anthracenes, biphenyls and the like. Most of these compounds are developed from the perspective of blue light-emitting materials.

[0005] Organic light-emitting materials are the core component of OLED panels, and their importance to the entire OLED industry chain is self-evident. Fluorescent materials can only utilize 25% of singlet excitons for luminescence due to spin-forbidden restrictions, limiting the efficiency of the device. Compared to mature green and red light-emitting materials, blue light-emitting materials still have great development space in terms of lifetime, color purity, stability and device efficiency. Therefore, the development of new and efficient blue fluorescent materials is of great significance to the development of OLEDs. SUMMARY

[0006] The technical problem solved by the present application is to provide a blue fluorescent doped compound, which can be used as a doping material in the organic layer of an organic electroluminescent device, and can make the organic electroluminescent device have the characteristics of long service life, high efficiency, low driving voltage and good stability.

[0007] Therefore, the present application provides a blue fluorescent dopant compound as shown in formula (I),

[0008]

[0009] wherein x1-x3 are each independently selected from 0 or 1;

[0010] a, b, c are each independently selected from an integer from 0 to 4;

[0011] X is selected from -O-, -S-, -C(R5)(R6)- or -N(R7)-;

[0012] R1-R4 are each independently selected from hydrogen, deuterium, substituted or unsubstituted C1-C30 straight chain alkyl, substituted or unsubstituted C3-C10 cycloalkyl, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted 3- to 30-membered heteroaryl;

[0013] Ar1-Ar6 are each independently selected from substituted or unsubstituted C3-C10 cycloalkyl, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted 3- to 30-membered heteroaryl;

[0014] R5-R7 are each independently substituted or unsubstituted C1-C6 alkyl, substituted or unsubstituted C6-C18 aryl, substituted or unsubstituted 2- to 15-membered heteroaryl.

[0015] Preferably, R1-R4 are each independently selected from hydrogen, deuterium, substituted or unsubstituted C1-C6 alkyl, substituted or unsubstituted C6-C18 aryl, substituted or unsubstituted 3- to 18-membered heteroaryl; preferably, R1-R4 are each independently selected from hydrogen, deuterium, methyl, ethyl, propyl, isopropyl, tert-butyl, cyclopentyl, cyclohexyl, alkoxy, aryloxy, phenyl, methylphenyl, biphenyl, naphthyl or terphenyl.

[0016] Preferably, the blue fluorescent dopant compound is specifically as shown in formula (II) to formula (V):

[0017]

[0018] Preferably, the blue fluorescent dopant compound as shown in formula (II) is specifically as shown in formula II-1 to formula II-4:

[0019]

[0020] Ar1 and Ar5 are the same, and Ar2 and Ar6 are the same.

[0021] Preferably, Ar1-Ar6 are independently selected from the following structures:

[0022]

[0023]

[0024] Preferably, R5-R7 are each independently selected from methyl, ethyl, phenyl or methylphenyl.

[0025] Preferably, the blue fluorescent doped compound is:

[0026]

[0027]

[0028]

[0029]

[0030]

[0031]

[0032]

[0033] The present application also provides a preparation method of the blue fluorescent doped compound, comprising the following steps:

[0034] reacting a compound as shown in formula (I-1) and a compound as shown in formula (I-2) under the action of CuI2 and o-phenanthroline in a nitrogen atmosphere to obtain an intermediate as shown in formula (I-3);

[0035] reacting the intermediate as shown in formula (I-3) and SnCl2·2H2O in a solvent to obtain an intermediate as shown in formula (I-4);

[0036] mixing the intermediate as shown in formula (I-4), hydrochloric acid and sodium nitrite and reacting to obtain an intermediate as shown in formula (I-5);

[0037] reacting one or more of a compound as shown in formula (I-61), a compound as shown in formula (I-62) and a compound as shown in formula (I-63) with the intermediate as shown in formula (I-5) in a nitrogen atmosphere in Pd2(dba)3, P(t-Bu)3 and t-BuONa to obtain a blue fluorescent doped compound as shown in formula (I);

[0038] x1, x2, x3 in the compound as shown in formula (I-1), the compound as shown in formula (I-2), x1, x2, x3 in the compound as shown in formula (I-61), the compound as shown in formula (I-62) are respectively selected according to the following table:

[0039]

[0040] wherein, x1-x2 are each independently selected as 0 or 1;

[0041] a, b, c are each independently selected as an integer from 0 to 4;

[0042] X is each independently selected as -O-, -S-, -C(R5)(R6)- or -N(R7)-;

[0043] R1-R4 are each independently selected from hydrogen, deuterium, substituted or unsubstituted C1-C30 straight chain alkyl, substituted or unsubstituted C3-C10 cycloalkyl, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted 3- to 30-membered heteroaryl;

[0044] Ar1-Ar6 are each independently selected from substituted or unsubstituted C3-C10 cycloalkyl, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted 3- to 30-membered heteroaryl;

[0045] R5-R7 are each independently substituted or unsubstituted C1-C6 alkyl, substituted or unsubstituted C6-C18 aryl, substituted or unsubstituted 2- to 15-membered heteroaryl.

[0046] The application also provides an organic electroluminescence device, comprising an organic layer, wherein the light-emitting layer of the organic layer comprises a host material and a dopant material, and the dopant material is the blue fluorescent dopant compound.

[0047] Preferably, the mass ratio of the host material to the dopant material is (90-99.5):(0.5-10).

[0048] The application provides a blue fluorescent dopant compound as a dopant compound of a light-emitting layer in an organic layer, wherein the mother nucleus indole and carbazole heterocycle has the advantages of high fluorescent quantum efficiency, easy modification of structure and wide energy gap; the double arylamine group as a substituent group has a strong charge transfer effect, and the π-π conjugated system existing in the molecular structure has excellent hole transport capacity, thermal stability and morphological stability, which is conducive to improving the glass transition temperature and the luminous efficiency; the device prepared by the application has the performance advantages of high efficiency, long service life, low driving voltage and good stability. BRIEF DESCRIPTION OF DRAWINGS

[0049] Figure 1 The nuclear magnetic hydrogen spectrum of compound 1 prepared for the embodiment 1 of the present application;

[0050] Figure 2 The nuclear magnetic hydrogen spectrum of compound 72 prepared for the embodiment 2 of the present application;

[0051] Figure 3 The nuclear magnetic hydrogen spectrum of compound 119 prepared for the embodiment 3 of the present application. DETAILED DESCRIPTION

[0052] In order to further understand the present application, the preferred embodiments of the present application are described below in conjunction with the examples, but it should be understood that these descriptions are only for further illustrating the features and advantages of the present application, but not for limiting the claims of the present application.

[0053] The embodiment of the present application discloses a blue fluorescent doped compound, and an organic electroluminescent device with long service life, high efficiency and good stability is obtained by using the fluorescent compound as a blue fluorescent doped material, specifically, the blue fluorescent doped compound is shown as formula (I):

[0054]

[0055] wherein x1-x2 are each independently selected from 0 or 1;

[0056] a, b, c are each independently selected from an integer from 0 to 4;

[0057] X is each independently selected from -O-, -S-, -C(R5)(R6)- or -N(R7)-;

[0058] R1-R4 are each independently selected from hydrogen, deuterium, substituted or unsubstituted C1-C30 straight chain alkyl, substituted or unsubstituted C3-C10 cycloalkyl, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted 3- to 30-membered heteroaryl;

[0059] Ar1-Ar6 are each independently selected from substituted or unsubstituted C3-C10 cycloalkyl, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted 3- to 30-membered heteroaryl;

[0060] R5-R7 are each independently substituted or unsubstituted C1-C6 alkyl, substituted or unsubstituted C6-C18 aryl, substituted or unsubstituted heteroaryl with a ring carbon atom number of 2-15.

[0061] In the blue fluorescent doped compound provided in the present application, x1, x2 and x3 are not all 0, and two of them are selected as 1 or three of them are selected as 1, in which case, the blue fluorescent doped compound is specifically shown as formula (II) to formula (V):

[0062]

[0063]

[0064] More specifically, the blue fluorescent dopant compound of formula (II) is specifically shown in the following structures of formula II-1 to II-4:

[0065]

[0066] and preferably, Ar1 is the same as Ar5, and Ar2 is the same as Ar6.

[0067] In the present application, a, b, c can be independently selected from 0, 1, 2, 3, or 4.

[0068] R5 to R7 in X are each independently selected from methyl, ethyl, phenyl, or methylphenyl.

[0069] R1 to R4 are each independently selected from hydrogen, deuterium, substituted or unsubstituted C1-C6 alkyl, substituted or unsubstituted C6-C18 aryl, substituted or unsubstituted 3- to 18-membered heteroaryl; more specifically, R1 to R4 are each independently selected from hydrogen, deuterium, methyl, ethyl, propyl, isopropyl, tert-butyl, cyclopentyl, cyclohexyl, alkoxy, aryloxy, phenyl, methylphenyl, biphenyl, naphthyl, or terphenyl.

[0070] Ar1 to Ar6 are independently selected from the following structures:

[0071]

[0072]

[0073] More specifically, the blue fluorescent dopant compound of formula (II) is specifically shown in the following structures of formula II-1 to II-4:

[0074]

[0075]

[0076]

[0077]

[0078]

[0079]

[0080]

[0081] The application also provides a preparation method of the blue fluorescent doped compound, comprising the following steps:

[0082] reacting the compound shown as formula (I-1) and the compound shown as formula (I-2) under the action of CuI2 and o-phenanthroline to obtain an intermediate shown as formula (I-3);

[0083] reacting the intermediate shown as formula (I-3) and SnCl2·2H2O in a solvent to obtain an intermediate shown as formula (I-4);

[0084] mixing the intermediate shown as formula (I-4), hydrochloric acid and sodium nitrite and reacting to obtain an intermediate shown as formula (I-5);

[0085] reacting one or more of the compound shown as formula (I-61), the compound shown as formula (I-62) and the compound shown as formula (I-63) with the intermediate shown as formula (I-5) in Pd2(dba)3, P(t-Bu)3 and t-BuONa under a nitrogen atmosphere to obtain the blue fluorescent doped compound shown as formula (I);

[0086] and x1, x2, x3 in the compound shown as formula (I-1) and the compound shown as formula (I-2) and x1, x2, x3 in the compound shown as formula (I-61) and the compound shown as formula (I-62) are respectively selected correspondingly;

[0087]

[0088] wherein x1-x2 are each independently selected as 0 or 1;

[0089] a, b, c are each independently selected as an integer from 0 to 4;

[0090] X is each independently selected as -O-, -S-, -C(R5)(R6)- or -N(R7)-;

[0091] R1-R4 are each independently selected from hydrogen, deuterium, substituted or unsubstituted C1-C30 straight chain alkyl, substituted or unsubstituted C3-C10 cycloalkyl, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted 3- to 30-membered heteroaryl;

[0092] Ar1-Ar6 are each independently selected from substituted or unsubstituted C3-C10 cycloalkyl, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted 3- to 30-membered heteroaryl;

[0093] R5~R7 each independently is substituted or unsubstituted C1~C6 alkyl, substituted or unsubstituted C6~C18 aryl, substituted or unsubstituted heteroaryl with 2~15 ring carbon atoms.

[0094] In the process of preparing the blue fluorescent dopant compound, the process of preparing the intermediate I-3 is as follows:

[0095] In a reaction vessel, the reactant I-1 (1.0 eq) and the reactant I-2 (1.0-1.2 eq) are dissolved in DMF, CuI (0.05-0.07 eq) and o-phenanthroline (0.1-0.2 eq) are added under nitrogen atmosphere, the mixture is heated to 120℃ and stirred for 10 h; after the reaction is completed, the filtrate is cooled to room temperature, then distilled water is added to the filtrate for washing, suction filtration, oven drying, recrystallization with toluene, and the intermediate I-3 is obtained;

[0096] The process of preparing the intermediate I-4 is as follows:

[0097] The intermediate I-3 (1.0 eq) and SnCl2·2H2O (5.0-6.0 eq) are dissolved in ethyl acetate (4.0-6.0 eq) and ethanol (4.0-6.0 eq), heated to 90℃ and stirred for 10 h, after the reaction is completed, cooled to room temperature, poured into 2M aqueous potassium hydroxide solution, extracted with ethyl acetate, the organic layer is collected, dried with anhydrous magnesium sulfate, and the solvent is removed using a rotary evaporator, and the intermediate I-4 is obtained;

[0098] The process of preparing the intermediate I-5 is as follows:

[0099] The intermediate I-4 (1.0 eq) and 2M HCl are added at 0℃, sodium nitrite (3.0 eq) is slowly added, stirred for 1 h, then the temperature is raised to 70℃ and the mixture is stirred for 3 h; after the reaction is completed, the obtained solid is cooled and filtered, the filtered solid is dissolved in chloroform and transferred to a separatory funnel for extraction; the extract is dried with MgSO4, filtered and concentrated, and the sample is purified by column chromatography with the developing agent: PE: EA = 1: (1-5) to obtain the intermediate I-5; the reaction in the above process is as follows:

[0100] For the cases of X1, X2 and X3 in the blue fluorescent dopant compound, the following synthesis methods are provided:

[0101] Case 1: One of X1, X2 and X3 is 1, and the synthesis route is as follows:

[0102]

[0103] (4) After adding intermediate I-5 (1.0 eq) and reactant I-6 (0.8-1.4 eq) dissolved in toluene into a reaction vessel, Pd2(dba)3 (0.01-0.02 eq), P(t-Bu)3 (0.03-0.06 eq), t-BuONa (2.0-3.0 eq) were added under a nitrogen atmosphere. The mixture was heated to 110°C and stirred for 10 h. Hot filtration was performed using celite, and after the filtrate was cooled to room temperature, distilled water was added to the filtrate for washing. After the liquid was separated, the organic phase was retained, and the aqueous phase was extracted with ethyl acetate. The combined organic layers were then dried using magnesium sulfate, and the solvent was removed using a rotary evaporator. Purification was performed using a chromatography column with dichloromethane: petroleum ether (1:1-9) as an eluent to obtain general formula I.

[0104] Case two, two of x1, x2, and x3 are 1, and the same reaction as described above, the only difference is that one more step 4 is added based on the corresponding product obtained;

[0105] Case three, three of x1, x2, and x3 are 1, and the same reaction as described above, the only difference is that two more step 4 are added based on the corresponding product obtained.

[0106] In the process of preparing a blue fluorescent dopant compound, according to the values of x1, x2, and x3 in the final product, the same values are set in the corresponding intermediate I-1 and I-2.

[0107] In the present application, the substitution in “substituted or unsubstituted” refers to being substituted with at least one substituent selected from the group consisting of deuterium, a halogen group, a nitrile group, a hydroxyl group, a carbonyl group, an ester group, a silyl group, a boron group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted alkylamine group, a substituted or unsubstituted heterocyclic amine group, a substituted or unsubstituted arylamine group, a substituted or unsubstituted aryl group, and a substituted or unsubstituted heterocyclic group, or a substituent connected with two or more substituents shown above. The term “substituted or unsubstituted” refers to not having a substituent.

[0108] The present application also provides an organic electroluminescent device comprising an organic layer, more specifically, a light-emitting layer of the organic layer comprises a host material and a dopant material, and the dopant material comprises the blue fluorescent dopant compound described in the above scheme.

[0109] The organic electroluminescent device of the present application can have a structure including a hole injection layer, a hole transport layer, an electron blocking layer, a light-emitting auxiliary layer, a light-emitting layer, a hole blocking layer, an electron transport layer, an electron injection layer, and the like as organic layers. However, the structure of the organic light-emitting element is not limited thereto, and can include a smaller or larger number of organic layers.

[0110] According to one embodiment of the present specification, the above-mentioned organic layer includes a light-emitting layer, and the light-emitting layer includes the compound represented by Formula I produced by the present application.

[0111] The first electrode serves as an anode, and the anode preferably includes a material having a high work function. For example, indium tin oxide (ITO) or indium zinc oxide (IZO). Since the lifetime of the device of the present application can be shortened in the presence of water and / or air, the device is appropriately structured, provided with a contact, and finally sealed, depending on the application.

[0112] The hole injection layer is a layer that injects holes from the electrode, and as a hole injection substance, it is preferable to be a compound that has a capability of transporting holes, has a hole injection effect from the anode, has an excellent hole injection effect to the light-emitting layer or the light-emitting material, and prevents the excitons generated in the light-emitting layer from migrating to the electron injection layer or the electron injection material.

[0113] The hole transport material is a material that can receive holes from the anode or the hole injection layer and transport the holes to the light-emitting layer, and has a high hole mobility; specific examples thereof include an organic material based on arylamine, a conductive polymer, a block copolymer having both a conjugated portion and a non-conjugated portion, and the like, but are not limited thereto.

[0114] The electron blocking layer can be provided between the hole transport layer and the light-emitting layer. As the electron blocking layer, a material known in the art, such as an organic material based on arylamine, can be used.

[0115] The light-emitting layer is a substance that can receive holes and electrons from the hole transport layer and the electron transport layer, respectively, and cause them to combine to emit light in the visible region, and is preferably a substance having a high quantum efficiency for fluorescence or phosphorescence. The light-emitting layer includes a host material and a dopant material.

[0116] The above-mentioned light-emitting layer can include a host material and a dopant material. The host material is an aromatic condensed ring derivative or a heterocycle-containing compound, or the like. Specifically, as the aromatic condensed ring derivative, anthracene derivatives, pyrene derivatives, naphthalene derivatives, pentacene derivatives, phenanthrene compounds, fluoranthene compounds, and the like are included, and as the heterocycle-containing compound, carbazole derivatives, diphenyl furan derivatives, ladder-type furan compounds, pyrimidine derivatives, and the like are included, but are not limited thereto.

[0117] The above-mentioned dopant material includes aromatic amine derivatives, styryl amine compounds, boron complexes, fluoranthene compounds, metal complexes, and the like.

[0118] In the present application, the mass ratio of the host material and the dopant material is 90-99.5:0.5-10; the dopant material contains the compound as shown in formula I prepared by the present application.

[0119] The hole blocking layer material can use the compound with hole blocking effect known in the prior art, for example, bathocuproin (BCP) and other phenanthroline derivatives, oxazole derivatives, triazole derivatives, triazine derivatives, and the like, but is not limited thereto.

[0120] The electron transport layer can play a role in promoting electron transport, and can use the compound with electron transport effect known in the prior art, for example, Al complex of 8-hydroxyquinoline; complex containing Alq3; organic radical compound; hydroxyflavone-metal complex, and the like.

[0121] The electron injection layer can play a role in promoting electron injection; has the ability to transport electrons, and prevents the excitons generated in the light-emitting layer from migrating to the hole injection layer. The electron injection material used in the present application includes fluorenone, anthraquinone dimethane, diphenylquinone, thiopyran dioxide, oxazole, oxadiazole, triazole, imidazole, perylene tetracarboxylic acid, fluorenylmethane, anthrone, and the like, and derivatives thereof, metal complexes, nitrogen-containing five-membered ring derivatives, and the like, but is not limited thereto.

[0122] The second electrode as a cathode, is usually preferred to have a material with a small work function to allow the electron to be smoothly injected into the organic material layer; for example, magnesium, calcium, sodium, potassium, titanium, indium, yttrium, lithium, gadolinium, aluminum, silver, tin, and lead, or an alloy thereof.

[0123] The organic light-emitting element of the present application can be a top emission type, a bottom emission type, or a bidirectional emission type, depending on the material used.

[0124] The device described in the present application can be used in an organic light-emitting device, an organic solar cell, electronic paper, an organic photoreceptor, or an organic thin film transistor.

[0125] In order to further understand the present application, the blue fluorescent dopant compound provided by the present application is described in detail below in conjunction with examples, and the protection scope of the present application is not limited by the following examples.

[0126] Example 1: Synthesis of compound 1

[0127] (1) In a reaction vessel, reactant 1-1 (100 mmol) and reactant 1-2 (120 mmol) were dissolved in DMF, CuI (5 mmol), o-phenanthroline (10 mmol) were added under nitrogen atmosphere, the mixture was heated to 120°C, and the mixture was stirred for 10 hours; after the reaction was completed, the filtrate was cooled to room temperature, then distilled water was added to the filtrate for washing, suction filtration, oven drying, recrystallization with toluene to obtain intermediate 1-3 (37.3 g, 76%);

[0128] (2) Intermediate 1-3 (70 mmol), SnCl2·2H2O (350 mmol) were dissolved in ethyl acetate (700 mL), ethanol (700 mL), heated to 90°C and stirred for 10 hours, after the reaction was completed, cooled to room temperature, poured into 2M aqueous potassium hydroxide solution, extracted with ethyl acetate, the organic layer was collected, dried with anhydrous magnesium sulfate, and the solvent was removed using a rotary evaporator to obtain intermediate 1-4 (29.4 g, 91%);

[0129] (3) Intermediate 1-4 (60 mmol) and 2M HCl were added at 0°C, sodium nitrite (180 mmol) was slowly added, and stirred for 1 hour; thereafter, the temperature was raised to 70°C and the mixture was stirred for 3 hours, after the reaction was completed, the obtained solid was cooled and filtered, the filtered solid was dissolved in chloroform, transferred to a separatory funnel for extraction, the extract was dried over MgSO4, filtered and concentrated, and the sample was purified by column chromatography using the developing agent: PE:EA = 1:(1-5) to obtain intermediate I-5 (20.0 g, 75%);

[0130] (4) After intermediate 1-5 (45 mmol) and reactant 1-6 (40.5 mmol) were dissolved in toluene in a reaction vessel, Pd2(dba)3 (0.45 mmol), P(t-Bu)3 (2.25 mmol), t-BuONa (90 mmol) were added under nitrogen atmosphere, heated to 110°C, and the mixture was stirred for 10 hours; hot suction filtration was performed using diatomite, the filtrate was cooled to room temperature, then distilled water was added to the filtrate for washing, the organic phase was retained after separation, and the aqueous phase was extracted with ethyl acetate; then the combined organic layer was dried using magnesium sulfate, and the solvent was removed using a rotary evaporator; column chromatography was performed using dichloromethane: petroleum ether (volume ratio 1:1-9) as the eluent to obtain intermediate 1-7 (23.6 g, 82%);

[0131] (5) After adding intermediate 1-7 (33 mmol) and reactant 1-8 (36.3 mmol) dissolved in toluene into a reaction container, Pd2(dba)3(0.5 mmol), P(t-Bu)3(1.98 mmol), t-BuONa (99 mmol) were added under nitrogen atmosphere, the mixture was heated to 110°C, and stirred for 10 h; hot filtration was performed using diatomite, after the filtrate was cooled to room temperature, distilled water was added to the filtrate for washing, after the liquid-liquid separation, the organic phase was retained, the aqueous phase was extracted with ethyl acetate, then the combined organic layer was dried using magnesium sulfate, and the solvent was removed using a rotary evaporator; compound 1 (28.4 g, 83%) was obtained by purification using a chromatographic column with dichloromethane: petroleum ether (volume ratio 1:1-9) as eluent. The above reaction process is as follows:

[0132]

[0133] The obtained compound 1 was detected and analyzed, and the results were as follows: mass spectrometry test: the theoretical value was 1026.30; the test value was 1026.55; elemental analysis: the theoretical value was C, 88.94; H, 5.40; N, 4.09; O, 1.56; the test value was C, 88.66; H, 5.61; N, 4.21; O, 1.64. The nuclear magnetic hydrogen spectrum is as shown in Figure 1 .

[0134] Example 2: Synthesis of compound 72

[0135] (1) After adding reactant 72-1 (100 mmol) and reactant 72-2 (100 mmol) dissolved in DMF into a reaction container, CuI (5 mmol), o-phenanthroline (10 mmol) were added under nitrogen atmosphere, the mixture was heated to 120°C, and stirred for 10 h of reaction, after the reaction was completed, the filtrate was cooled to room temperature, then distilled water was added to the filtrate for washing, filtration was performed, and after drying, recrystallization was performed with toluene to obtain intermediate 72-3 (37.3 g, 72%);

[0136] (2) Intermediate 72-3 (70 mmol), SnCl2·2H2O (420 mmol) were dissolved in ethyl acetate (700 mL), ethanol (700 mL), heated to 90°C and stirred for 10 h of reflux, after the reaction was completed, cooled to room temperature, poured into 2M aqueous potassium hydroxide solution, extracted with ethyl acetate, the organic layer was collected, dried with anhydrous magnesium sulfate, and the solvent was removed using a rotary evaporator to obtain intermediate 72-4 (30.4 g, 89%);

[0137] (3) Into a reaction vessel was added intermediate 72-4 (60 mmol) and 2M HCl at 0°C, and sodium nitrite (180 mmol) was slowly added, and stirred for 1 hour. Thereafter, the temperature was raised to 70°C and the mixture was stirred for 3 hours, and after the reaction was completed, the resulting solid was cooled and filtered, and the filtered solid was dissolved in chloroform and transferred to a separatory funnel, and the extract was dried over MgSO4, filtered and concentrated, and the sample was purified by column chromatography using a developing solvent of PE:EA = 1: (1-5) to obtain intermediate 72-5 (34.2 g, 77%);

[0138] (4) Into a reaction vessel was added intermediate 72-5 (45 mmol) and a reactant 72-6 (40.5 mmol) dissolved in toluene, and Pd2(dba)3(0.45 mmol), P(t-Bu)3(2.25 mmol), t-BuONa (90 mmol) were added under a nitrogen atmosphere. It was heated to 110°C, and the mixture was stirred for 10 hours, and hot-filtrated using celite, and after the filtrate was cooled to room temperature, distilled water was added to the filtrate to wash, and after the separation, the organic phase was retained, and the aqueous phase was extracted with ethyl acetate. Then, the combined organic layer was dried over magnesium sulfate, and the solvent was removed using a rotary evaporator. Purification was performed by column chromatography using dichloromethane: petroleum ether (1: (1-9)) as an eluent to obtain intermediate 72-7 (23.9 g, 83%);

[0139] (5) Into a reaction vessel was added intermediate 72-7 (33 mmol) and a reactant 72-8 (36.3 mmol) dissolved in toluene, and Pd2(dba)3(0.5 mmol), P(t-Bu)3(1.98 mmol), t-BuONa (99 mmol) were added under a nitrogen atmosphere. It was heated to 110°C, and the mixture was stirred for 10 hours, and hot-filtrated using celite, and after the filtrate was cooled to room temperature, distilled water was added to the filtrate to wash, and after the separation, the organic phase was retained, and the aqueous phase was extracted with ethyl acetate. Then, the combined organic layer was dried over magnesium sulfate, and the solvent was removed using a rotary evaporator. Purification was performed by column chromatography using dichloromethane: petroleum ether (1: (1-9)) as an eluent to obtain compound 72 (27.6 g, 84%). The above reaction is shown in the following formula:

[0140]

[0141] The resulting compound 72 was analyzed, and the results were as follows: mass spectrometry test: the theoretical value was 996.27; the test value was 996.44; elemental analysis: the theoretical value: C, 90.42; H, 5.36; N, 4.22; the test value: C, 90.17; H, 5.61; N, 4.30. The nuclear magnetic hydrogen spectrum is shown in Figure 2 ​

[0142] Example 3: Synthesis of compound 116

[0143] (1) - (3) Intermediate 116-5 has the same structure as intermediate 1-5, and the reaction steps are the same, which will not be repeated here;

[0144] (4) After adding intermediate 116-5 (45 mmol) and reactant 116-6 (40.5 mmol) dissolved in toluene into a reaction container, Pd2(dba)3(0.45 mmol), P(t-Bu)3(2.25 mmol), t-BuONa (90 mmol) were added under a nitrogen atmosphere. Heat to 110°C, and stir the mixture for 10 h; hot filtration with diatomite, after the filtrate is cooled to room temperature, distilled water is then added to the filtrate for washing, after the liquid separation, the organic phase is retained, and the aqueous phase is extracted with ethyl acetate; then the combined organic layer is dried with magnesium sulfate, and the solvent is removed using a rotary evaporator; with dichloromethane: petroleum ether (volume ratio 1: (1-9)) as the eluent, purification with a chromatographic column to obtain intermediate 116-7 (24.7 g, 82%);

[0145] (5) After adding intermediate 116-7 (33 mmol) and reactant 116-8 (36.3 mmol) dissolved in toluene into a reaction container, Pd2(dba)3(0.5 mmol), P(t-Bu)3(1.98 mmol), t-BuONa (99 mmol) were added under a nitrogen atmosphere. Heat to 110°C, and stir the mixture for 10 h. Hot filtration with diatomite, after the filtrate is cooled to room temperature, distilled water is then added to the filtrate for washing, after the liquid separation, the organic phase is retained, and the aqueous phase is extracted with ethyl acetate; then the combined organic layer is dried with magnesium sulfate, and the solvent is removed using a rotary evaporator. With dichloromethane: petroleum ether (volume ratio 1: (1-9)) as the eluent, purification with a chromatographic column to obtain compound 116 (24.0 g, 80%). The above reaction process is as follows:

[0146]

[0147] The obtained compound 116 was detected and analyzed, and the results were as follows: mass spectrometry test: the theoretical value was 908.12; the test value was 908.36; elemental analysis: the theoretical value: C, 88.62; H, 4.99; N, 4.63; O, 1.76; the test value: C, 88.24; H, 5.31; N, 4.70; O, 1.85. The nuclear magnetic hydrogen spectrum is as shown in Figure 3 .

[0148] Example 4

[0149] The synthesis of compounds 4, 8, 12, 18, 25, 30, 36, 40, 42, 47, 53, 58, 63, 68, 72, 78, 83, 89, 94, 98, 104, 110, 121, 128, 134 was accomplished by referring to the preparation method of examples 1-3, and the mass spectrum, molecular formula and yield are shown in Table 1.

[0150] Table 1 Mass spectrum, molecular formula and yield data table of different compounds

[0151]

[0152]

[0153] Application Example 1 Preparation of an organic electroluminescent device:

[0154] An organic electroluminescent device was prepared using the compound 1 prepared in Example 1, and the specific process is as follows:

[0155] a. ITO anode: The ITO (indium tin oxide)-Ag-ITO (indium tin oxide) glass substrate with a coating thickness of 150 nm was cleaned in distilled water for 2 times, ultrasonic washing for 30 min, and then repeatedly cleaned with distilled water for 2 times, ultrasonic washing for 10 min. After washing, it was transferred to an equal-spinning dryer for spinning, and finally baked in a vacuum oven at 220°C for 2 hours. After baking, it was cooled and ready for use. The substrate was used as an anode, and a coater was used to perform device evaporation process, and other functional layers were sequentially evaporated thereon;

[0156] b. HIL (hole injection layer): The hole injection layer materials HT and P-dopant were vacuum evaporated at an evaporation rate of The evaporation rate ratio of HT and P-dopant was 97:3, and the thickness was 10 nm.

[0157] c. HTL (hole transport layer): The hole transport layer of 130 nm of HT was vacuum evaporated on the hole injection layer at an evaporation rate of

[0158] d. Light-emitting auxiliary layer: A light-emitting auxiliary layer of 10 nm was vacuum evaporated on the hole transport layer at an evaporation rate of

[0159] e. EML (emitting layer): The host material (Host) and compound 1 were vacuum evaporated as an emitting layer on the light-emitting auxiliary layer at an evaporation rate of The evaporation rate ratio of Host and Dopant was 98:2, and the thickness was 25 nm.

[0160] f. ETL (electron transport layer): The electron transport layer was vacuum evaporated on the emitting layer at an evaporation rate of ​​ET and Liq as the electron transport layer, wherein the evaporation rate of ET and Liq is 50:50;

[0161] g、EIL (electron injection layer): 1.0 nm of Yb film was evaporated at an evaporation rate of 0.1 nm / s to form the electron injection layer; g、EIL (electron injection layer): 1.0 nm of Yb film was evaporated at an evaporation rate of 0.1 nm / s to form the electron injection layer;

[0162] h、Cathode: 18 nm of magnesium and silver was evaporated at an evaporation rate ratio of 1:9 to obtain the OLED device; h、Cathode: 18 nm of magnesium and silver was evaporated at an evaporation rate ratio of 1:9 to obtain the OLED device;

[0163] i、Light extraction layer: 70 nm of CPL was vacuum evaporated on the cathode at an evaporation rate of 1.0 nm / s as the light extraction layer; i、Light extraction layer: 70 nm of CPL was vacuum evaporated on the cathode at an evaporation rate of 1.0 nm / s as the light extraction layer;

[0164] j、Packaging of the substrate after evaporation: first, the cleaned cover plate was coated with UV glue by using a coating device, then the coated cover plate was moved to the pressing section, the substrate after evaporation was placed on the upper end of the cover plate, finally the substrate and the cover plate were bonded under the action of the bonding device, and the UV glue was cured by light at the same time.

[0165] Device structure:

[0166] ITO / Ag / ITO / HT:P-dopant (10 nm, 3%) / HT (130 nm) / light-emitting auxiliary layer (10 nm) / Host: compound 1 (25 nm, 2%) / ET:Liq (35 nm, 50%) / Yb (1 nm) / Mg:Ag (18 nm, 1:9) / CPL (70 nm).

[0167] The chemical formula of the corresponding substance is as follows:

[0168]

[0169] Application Example 2-138

[0170] The organic electroluminescence device of application example 2-138 was prepared according to the above preparation method of the organic electroluminescence device, except that compound 1 in application example 1 was replaced by the corresponding compound 2-138.

[0171] Comparative Example 1

[0172] The organic electroluminescence device was prepared according to the above preparation method of the organic electroluminescence device, except that compound 1 in application example 1 was replaced by comparative compound 1, wherein the structural formula of comparative compound 1 is as follows:

[0173]

[0174] Comparative Example 2

[0175] An organic electroluminescent device was prepared according to the above preparation method of an organic electroluminescent device, except that the compound 1 in Application Example 1 was replaced by Comparative Compound 2, wherein the structural formula of Comparative Compound 2 is as follows:

[0176]

[0177] Comparative Example 3

[0178] An organic electroluminescent device was prepared according to the above preparation method of an organic electroluminescent device, except that the compound 1 in Application Example 1 was replaced by Comparative Compound 3, wherein the structural formula of Comparative Compound 3 is as follows:

[0179]

[0180] The organic electroluminescent devices of the above Application Examples 1-138 and Comparative Examples 1-3 were subjected to a forward direct current bias voltage, and the organic electroluminescent characteristics were measured using a PR-650 luminance measuring device of Photo Research Company, and the luminance was 1000 cd / m 2 The T95 lifetime was measured using a lifetime measuring device of McScience Company; the results are shown in Table 2.

[0181] Table 2 Data Table of Test Results of Luminescent Characteristics of Different Compounds (Luminance Value is 1000 cd / m 2 )

[0182]

[0183]

[0184]

[0185]

[0186] As can be seen from Table 2, the organic electroluminescent devices formed by the compounds provided in the embodiments of the present application and the comparative compounds have improved BI value, lifetime, and glass transition temperature in all aspects. Since the driving voltage is mainly affected by the host, the driving voltage is reduced by 0.1-0.3, which has been significantly improved in voltage.

[0187] The above examples are only used to help understand the method of the present application and its core idea. It should be noted that for those skilled in the art, without departing from the principles of the present application, the present application can be improved and modified in several ways, and these improvements and modifications also fall within the scope of protection of the claims of the present application.

[0188] The foregoing description of the disclosed embodiments enables a person skilled in the art to make or use the application. Modifications of these embodiments will occur to persons of skill in the art, and that the appended claims are intended to cover all such modifications that do not depart from the true spirit and scope of the application. Therefore, the application is not limited to the embodiments shown but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A blue fluorescent doped compound, specifically:

2. An organic electroluminescent device comprising an organic layer, characterized in that, The light-emitting layer of the organic layer includes a host material and a dopant material, wherein the dopant material is the blue fluorescent dopant compound as described in claim 1.

3. The organic light-emitting element according to claim 2, characterized in that, The mass ratio of the host material to the doped material is (90-99.5):(0.5-10).

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