A compound used as a host material in an organic electroluminescent device

Abstract

The present invention belongs to the technical field of organic light-emitting materials, and relates to a compound used as a main material in an organic electroluminescent device. The present invention provides a class of compounds with naphtho-polycyclic heterocyclic imidazole as a parent nucleus, which are modified with a specific type of group and are suitable for use as electroluminescent materials, especially when used as a main material of a light-emitting layer in an organic electroluminescent device, the driving voltage of the device can be reduced, and the brightness efficiency and life of the device can be improved.

Description

Technical Field

[0001] The invention belongs to the technical field of organic light-emitting materials and relates to a compound used as a main material in an organic electroluminescent device. Background Art

[0002] The luminescence mechanism of organic electroluminescent (OLED) display devices and lighting elements is a new optoelectronic information technology that directly converts electrical energy into light energy with the help of organic semiconductor functional materials under the action of a DC electric field. Its luminescent colors can be single red, green, blue, yellow light or combined white light.

[0003] Excitons are formed by combining holes and electrons injected from the positive and negative electrodes on the organic film. When the excitons return from the excited state to the stable ground state, they release energy in the form of light to emit light. Due to the limitations of the spin quantum statistics, traditional fluorescent materials can only utilize singlet excitons, which account for 25% of the total number of excitons, during the electroluminescence process. The remaining 75% of triplet excitons are inactivated through non-radiative transitions, resulting in a maximum internal quantum efficiency (IQE) of 25%. However, due to the heavy atom effect, phosphorescent metal complexes can utilize both singlet excitons and triplet excitons at the same time, so that the internal quantum efficiency of the device can reach 100%. In view of the current industrial application requirements of OLED devices, as well as the requirements of different functional film layers and optoelectronic properties of OLED devices, it is necessary to select more suitable and higher-performance OLED functional materials or a combination of multiple materials to achieve the comprehensive characteristics of high efficiency, long life and low voltage of the device.

[0004] Therefore, in order to maximize the performance of phosphorescent materials, it is necessary to dope phosphorescent materials into host materials to reduce the quenching effect of the luminescent material itself, thereby obtaining higher device performance. The triplet energy of phosphorescent materials themselves is relatively high. As the host of phosphorescent materials, its energy must be greater than that of the luminescent material, otherwise energy backflow is likely to occur, thereby reducing the luminous efficiency. In recent years, phosphorescent host materials have made great progress, but host materials with high triplet states and good stability are rare. The development of more high-performance phosphorescent host materials has always been a hot topic in the industry. As far as the actual needs of the current OLED display lighting industry are concerned, the current development of OLED materials is far from enough and lags behind the requirements of panel manufacturers. As a material company, it is particularly important to develop higher-performance organic functional materials. Summary of the invention

[0005] In view of this, the object of the present invention is to provide a compound with a naphtho-polycyclic heterocyclic imidazole as a parent core, and application thereof in an OLED device.

[0006] In one aspect, the present invention relates to a compound having a structure as shown in formula (I):

[0007] ;

[0008] Wherein, Ar1 is independently selected from the structure shown in formula (II),

[0009] ;

[0010] Y is selected from a single bond, C(R3R4), O, S, NAr3, Si(R3R4);

[0011] Z is selected from one of C and N;

[0012] X1 is selected from one of C (R5R6), O, S, and NAr4;

[0013] L1 is a single bond or a bridging group;

[0014] Ar2, Ar3, Ar4 are independently selected from a substituted or unsubstituted C6-C30 aryl group, or a substituted or unsubstituted C2-C30 heteroaryl group containing a N, O, or S heteroatom;

[0015] R1-R6 are independently selected from any one of hydrogen, deuterium, halogen, substituted or unsubstituted C1-C10 alkyl, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C2-C30 heteroaryl containing N, O, S heteroatom;

[0016] n is selected from 1, 2, 3;

[0017] p is selected from one of 0, 1, 2, 3, and 4;

[0018] m is selected from one of 0, 1, 2, and 3.

[0019] Preferably, in the compounds provided by the present invention, Ar1 is selected from any one of the following groups,

[0020] .

[0021] Furthermore, in the compounds provided by the present invention, the n>1, and the multiple Ar1s are the same as or different from each other.

[0022] Furthermore, in the compounds provided by the present invention, the p>1, the multiple R1s are the same as or different from each other, and / or the multiple adjacent R1s are connected to form a ring.

[0023] Furthermore, in the compounds provided by the present invention, m>1, multiple R2s are the same as or different from each other, and / or multiple adjacent R2s are connected to form a ring.

[0024] Furthermore, in the compound provided by the present invention, the bridging group is selected from one of a benzene ring, a naphthalene ring, a biphenyl, a pyridine, a pyrazine, a triazine, a quinoline, and an isoquinoline.

[0025] .

[0026] Furthermore, in the compounds provided by the present invention, any of the substitutions or unsubstitutions independently represent one of no substitution, a monosubstituent, a disubstituent, a trisubstituent, and a tetrasubstituent, and the multiple substituents are the same or different from each other.

[0027] Furthermore, in the compounds provided by the present invention, any of the substitutions or unsubstitutions independently represent one of a disubstituent, a trisubstituent, and a tetrasubstituent, and adjacent substituents are connected to form a ring.

[0028] Furthermore, in the compound provided by the present invention, it has the structure shown below,

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[0104] .

[0105] In another aspect, the present invention relates to use of the compound in an organic electroluminescent device or an organic electroluminescent apparatus.

[0106] On the other hand, the present invention relates to an organic electroluminescent device, comprising an anode layer, a cathode layer and an organic thin film layer located between the anode layer and the cathode layer, wherein the organic thin film layer comprises a hole injection layer, a first hole transport layer, a second hole transport layer, a light-emitting layer, a hole blocking layer, an electron transport layer and an electron injection layer, and the light-emitting layer contains the compound.

[0107] Compared with the prior art, the technical solution provided by the present invention has at least the following beneficial effects or advantages:

[0108] The compound provided by the present invention has a naphthopolycyclic heterocyclic imidazole as a parent core, and the parent core structure has a bipolar characteristic. In the parent core structure of the naphthopolycyclic heterocyclic (six-membered heterocyclic ring and five-membered ring containing N, O, Si, C, S) imidazole, the electron-richness of the parent core is adjusted by different N numbers on the naphthopolycyclic heterocyclic ring and pyridine or pyrazine, and a polybenzo five-membered ring group with electron-donating ability is connected to the electron-donating N atom of the imidazole, so that the compound with a specific structure has a suitable HOMO / LUMO energy level and triplet energy. When used as a phosphorescent light-emitting main material, the energy transfer between the host and the guest is guaranteed, the driving voltage is reduced, and the brightness efficiency and life of the device are significantly improved. The compound is a novel organic OLED functional material with relatively promising development prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0109] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0110] Figure 1 Schematic diagram of the structure of an organic electroluminescent element.

[0111] Among them, 1 is the substrate, 2 is the anode layer, 3 is the hole injection layer, 4 is the first hole transport layer, 5 is the second hole transport layer, 6 is the light emitting layer, 7 is the hole blocking layer, 8 is the electron transport layer, 9 is the electron injection layer, and 10 is the cathode layer. DETAILED DESCRIPTION

[0112] The technical scheme of the present invention is described below in conjunction with the examples, but the present invention is not limited to the following examples. The experimental methods and detection methods described in each example are conventional methods unless otherwise specified; the reagents and materials are available on the market unless otherwise specified, and the % in the following examples are all mass percentages unless otherwise specified.

[0113] Preparation Example

[0114] The synthesis methods of some intermediates and compounds are provided below. The synthesis methods of the remaining intermediates and compounds are similar and can be easily synthesized. The specific synthesis routes are shown below.

[0115] Synthesis of compound 1-1:

[0116]

[0117]

[0118] Synthesis of intermediate 1-1: Under nitrogen protection, raw material 1 (250.9 g, 1 mol), raw material 2 (157.0 g, 1 mol), Pd(PPh3)4 (tetrakis(triphenylphosphine)palladium, 46.2 g, 0.04 mol), K2CO3 (potassium carbonate, 276.0 g, 2 mol), TBAB (tetrabutylammonium bromide, 25.8 g, 0.08 mol), toluene (2000 mL), ethanol (1000 mL), water (500 mL) were added to a three-necked flask, stirred and heated to 78 °C for 6 h, then cooled to room temperature, washed with water until neutral, the organic phase was dried with 250 g of anhydrous magnesium sulfate and filtered, the filtrate was passed through a silica gel column, and then purified by recrystallization with toluene to obtain 227.2 g of intermediate 1-1, the content of which was 98.5264% by HPLC, and the yield was 80%.

[0119] Synthesis of intermediate 1-2: Under nitrogen protection, add intermediate 1-1 (199.4 g, 702 mmol), PPh3 (triphenylphosphine, 366.8 g, 1.4 mol), 600 mL o-dichlorobenzene to a three-necked flask, and heat and stir at 160°C for 20 h. After the reaction solution was cooled to room temperature 24°C, n-heptane was added to precipitate white crystals, which were filtered and then purified by recrystallization with toluene to obtain 132.7 g of intermediate 1-2. The content of HPLC was 99.8011%, and the yield was 75%.

[0120] Synthesis of intermediate 1-3: Under nitrogen protection, add intermediate 1-2 (99.5 g, 395 mmol), iodobenzene (80.5 g, 395 mmol), Pd2(dba)3 (tri(dibenzylideneacetone)dipalladium, 3.7 g, 4 mmol), P(t-Bu)3 (tri-tert-butylphosphine, 0.8 g, 4 mmol), sodium tert-butoxide (75.8 g, 790 mmol), 1000 mL toluene to a three-necked flask, stir and reflux at 110 °C for 2 h. After the reaction is complete, cool to room temperature, wash with water until neutral, dry the organic phase with 160 g of anhydrous magnesium sulfate and filter, pass the filtrate through a silica gel column, and recrystallize and purify with a toluene / ethanol mixed solvent to obtain 106.2 g of intermediate 1-3, with a content of 98.4290% and a yield of 82% according to HPLC.

[0121] Synthesis of intermediate 1-4: Under nitrogen protection, add intermediate 1-3 (79.7 g, 243 mmol) and 400 mL tetrahydrofuran to a three-necked flask. After the system is stirred evenly, the liquid nitrogen is cooled to -78°C, butyl lithium (175 mL, 280 mmol, 1.6 M) is added dropwise, and the reaction is kept warm for 1 h. Then trimethyl borate (41.6 g, 400 mmol) is added dropwise. After the reaction is completed, the temperature is naturally raised to room temperature and the reaction is continued for 2 h. After the reaction is completed, the reaction is quenched with an aqueous solution of ammonium chloride, diluted hydrochloric acid is added to adjust the pH to 3, 300 ml of toluene is added for extraction, and the organic phase is repeatedly washed with water. The organic phase is dried and filtered with 150 g of anhydrous magnesium sulfate, concentrated, squeezed out with ethanol, and purified to obtain 60.8 g of intermediate 1-4. The content detected by HPLC is 99.3491%, and the yield is 74%.

[0122] Synthesis of intermediate 1: Under nitrogen protection, intermediate 1-4 (50.0 g, 148 mmol), benzamidine hydrochloride (31.2 g, 200 mmol), Cu(OAc)2 (copper acetate, 54.2 g, 296 mmol), NaOPiv (sodium pivalate, 36.4 g, 296 mmol), and 300 ml of DMF solvent were added to a three-necked flask, heated to 50°C and stirred for reaction for 30 h, then O2 was continuously introduced, heated to 120°C and continued to react for 20 h, then naturally cooled to room temperature, and an aqueous ammonium hydroxide solution was added to quench the reaction. After adding 300 ml of dichloroethane, it was stirred and washed with water several times. The organic phase was dried with 100 g of anhydrous magnesium sulfate, filtered, passed through a silica gel column, and recrystallized twice with a toluene / petroleum ether mixed solvent to purify 34.0 g of intermediate 1. The content detected by HPLC was 98.1739%, and the yield was 56%.

[0123] The synthesis method of compound 1-1 refers to the synthesis of intermediate 1-3, and intermediate 1-2 and iodobenzene are replaced by intermediate 1 and intermediate 3-bromo-N-phenylcarbazole. The content detected by HPLC is 99.9162%, and the yield is 60%. The result of mass spectrometry detection of the obtained sample is: HR-MS (APCI): m / z 651.2423 [M+H] + ; C 46 H 29 N5 (%) calculated value: C, 84.7697; H, 4.4850; N, 10.7453; measured value: C, 84.7581; H, 4.4917; N, 10.7502.

[0124] Synthesis of compound 1-5:

[0125]

[0126] The synthesis method of intermediate 1-5 refers to the synthesis of intermediate 1-3, replacing intermediate 1-2 and iodobenzene with intermediate 1 and intermediate m-dibromobenzene, with a yield of 75%.

[0127] The synthesis method of compound 1-5 refers to the synthesis of intermediate 1-1, and raw materials 1 and 2 are replaced by intermediates 1-5 and intermediates 1-6. The content of HPLC detection is 99.9357%, and the yield is 57%. The result of mass spectrometry detection of the obtained sample is: HR-MS (APCI): m / z 817.2842 [M+H] + ; C 58 H 35 Calculated value of N5O (%): C, 85.1686; H, 4.3132; N, 8.5622; O, 1.9560; Found: C, 85.1623; H, 4.3199; N, 8.5691; O, 1.9487.

[0128] By referring to the synthesis methods of intermediate 1, compound 1-1 and compound 1-5, the compound in which Y is N in the general formula (I) can be synthesized. The only difference is that, depending on the product, an intermediate with corresponding groups Ar1 and Ar2 and a bridging group L1 needs to be used as a replacement, and the mass amount of the intermediate is changed according to the molar amount.

[0129] Synthesis of compound 2-1:

[0130]

[0131]

[0132] The synthesis method of intermediate 2-1 refers to the synthesis of intermediate 1-1, and raw materials 1 and 2 are replaced by raw materials 3 and 4, with a yield of 70%. Synthesis of intermediate 2-2: Under nitrogen protection, add intermediate 2-1 (100.0g, 335.6mmol) and 200mL tetrahydrofuran to a three-necked flask, slowly add phenylmagnesium bromide 1.0M tetrahydrofuran solution (1.0M-THF, 675mL) under stirring at room temperature 24°C, and heat to 50°C to continue the reaction for 6 hours after the addition is complete. After the reaction solution is cooled to room temperature 24°C, an ammonium chloride aqueous solution is added to quench the reaction, dilute hydrochloric acid is used to adjust the pH to 3, and then 300ml of dichloroethane is added. After stirring evenly, water is added to wash until neutral, the organic phase is dried with 100g anhydrous magnesium sulfate, filtered and concentrated, and the solid is squeezed out with ethanol. Purification gives 99.1g of intermediate 2-2, and the content detected by HPLC is 98.6027%, with a yield of 78%. Synthesis of intermediate 2-3: Under nitrogen protection, add intermediate 2-2 (50.0 g, 118.5 mmol), methanesulfonic acid (22.7 g, 237 mmol), and 300 mL toluene to a three-necked flask, and heat to 108°C for 3 h. After the reaction solution is cooled to room temperature, it is washed with water until neutral. The organic phase is dried with 100 g of anhydrous magnesium sulfate, filtered and concentrated, and recrystallized and purified with a mixed solvent of toluene and ethanol to obtain 39.2 g of intermediate 2-3. The HPLC detection content is 98.3254%, and the yield is 82%. The synthesis method of intermediate 2-4 refers to the synthesis of intermediate 1-4, replacing intermediate 1-3 with intermediate 2-3, and the yield is 74%. The synthesis of intermediate 2 refers to the synthesis of intermediate 1, replacing intermediate 1-4 with intermediate 2-4, and the yield is 56%.

[0133] The synthesis of compound 2-1 refers to the synthesis of intermediate 1-3, and intermediate 1-2 and iodobenzene are replaced by intermediate 2 and intermediate 3-bromo-9,9-dimethylfluorene. The content of HPLC detection is 99.9241%, and the yield is 50%. The result of mass spectrometry detection of the obtained sample is: HR-MS (APCI): m / z 678.2783[M+H] + ; C 49 H 34 N4 (%) calculated value: C, 86.6979; H, 5.0486; N, 8.2535; measured value: C, 86.6869; H, 5.0585; N, 8.2546.

[0134] Synthesis of compound 2-5:

[0135]

[0136] The synthesis method of intermediate 2-5 refers to the synthesis of intermediate 1-3, replacing intermediate 1-2 and iodobenzene with intermediate 2 and intermediate m-dibromobenzene, with a yield of 73%.

[0137] The synthesis method of compound 2-5 refers to the synthesis of intermediate 1-1, and raw materials 1 and 2 are replaced by intermediates 2-5 and intermediates 2-6. The content of HPLC detection is 99.9357%, and the yield is 52%. The result of mass spectrometry detection of the obtained sample is: HR-MS (APCI): m / z 778.2733 [M+H] + ; C 56 H 34 Calculated value of N4O (%): C, 86.3529; H, 4.4000; N, 7.1931; O, 2.0540; Found: C, 86.3483; H, 4.4048; N, 7.1952; O, 2.0517.

[0138] Synthesis of compound 2-36:

[0139]

[0140]

[0141] The synthesis method of intermediate 2-6 refers to the synthesis of intermediate 2-2, except that the intermediate phenylmagnesium bromide is replaced by the intermediate methylmagnesium bromide, with a yield of 80%.

[0142] The synthesis method of intermediate 2-7 refers to the synthesis of intermediate 2-3, replacing intermediate 2-2 with intermediate 2-6, with a yield of 84%.

[0143] The synthesis method of intermediate 2-8 refers to the synthesis of intermediate 1-4, replacing intermediate 1-3 with intermediate 2-7, with a yield of 72%.

[0144] The synthesis of intermediate 2-9 refers to the synthesis of intermediate 1, except that intermediate 1-4 is replaced by intermediate 2-8, with a yield of 59%.

[0145] The synthesis method of compound 2-36 refers to the synthesis of intermediate 1-3, and intermediate 1-2 and iodobenzene are replaced by intermediate 2-9 and intermediate 3-bromo-9,9-dimethylfluorene. The content detected by HPLC is 99.9126%, and the yield is 56%. The result of mass spectrometry detection of the obtained sample is: HR-MS (APCI): m / z 554.2470 [M+H] + ; C 39 H 30 N4 (%) calculated value: C, 84.4477; H, 5.4516; N, 10.1006; measured value: C, 84.4512; H, 5.4496; N, 10.0992.

[0146] By referring to the synthesis methods of intermediate 2, compound 2-1 and compound 2-36, the compound in which Y is C in the general formula (I) can be synthesized. The only difference is that, depending on the product, an intermediate with the corresponding group Ar1 and bridging group L1 needs to be used as a replacement, and the mass amount of the intermediate is changed according to the molar amount.

[0147] Synthesis of compound 3-1:

[0148]

[0149]

[0150] The synthesis method of intermediate 3-1 refers to the synthesis of intermediate 1-1, replacing raw materials 1 and 2 with raw materials 5 and 6, with a yield of 65%.

[0151] Synthesis of intermediate 3-2: Under nitrogen protection, add intermediate 3-1 (100.0 g, 320.5 mmol), HBr (800 mL), acetic acid (400 ml) into a three-necked flask, stir and heat to 100 °C for reaction, detect the raw materials by TLC, cool to room temperature 24 °C after the reaction is complete, add 200 ml of toluene, stir well and wash repeatedly with water until neutral, dry the organic phase with 150 g of anhydrous magnesium sulfate, and purify by silica gel column to obtain 60.0 g of intermediate 3-2, the content of which is 98.1941% by HPLC, and the yield is 74%.

[0152] The synthesis method of intermediate 3-3 refers to the synthesis of intermediate 1-4, replacing intermediate 1-3 with intermediate 3-2, with a yield of 70%.

[0153] The synthesis of intermediate 3 refers to the synthesis of intermediate 1, except that intermediate 1-4 is replaced by intermediate 3-3, with a yield of 53%.

[0154] The synthesis of compound 3-1 refers to the synthesis of intermediate 1-3, and intermediate 1-2 and iodobenzene are replaced by intermediate 3 and intermediate 2-bromo-dibenzofuran. The content of HPLC detection is 99.9804%, and the yield is 55%. The result of mass spectrometry detection of the obtained sample is: HR-MS (APCI): m / z 501.1477 [M+H] + ; C 34 H 19 Calculated value for N3O2 (%): C, 81.4232; H, 3.8186; N, 8.3783; O, 6.3799; Found: C, 81.4193; H, 3.8206; N, 8.3769; O, 6.3832.

[0155] Synthesis of compound 3-5:

[0156]

[0157] The synthesis method of intermediate 3-4 refers to the synthesis of intermediate 1-3, replacing intermediate 1-2 and iodobenzene with intermediate 3 and intermediate m-dibromobenzene, with a yield of 74%.

[0158] The synthesis method of compound 3-5 refers to the synthesis of intermediate 1-1, and raw materials 1 and 2 are replaced by intermediates 3-4 and intermediates 2-6. The content of HPLC detection is 99.9732%, and the yield is 51%. The result of mass spectrometry detection of the obtained sample is: HR-MS (APCI): m / z 627.1947 [M+H] + ; C 44 H 25 Calculated value of N3O2 (%): C, 84.1933; H, 4.0146; N, 6.6944; O, 5.0976; Found: C, 84.1992; H, 4.0107; N, 6.6913; O, 5.0988.

[0159] By referring to the synthesis methods of intermediate 3, compound 3-1 and compound 3-5, the compound in which Y is O in the general formula (I) can be synthesized. The only difference is that, depending on the product, an intermediate with the corresponding group Ar1 and bridging group L1 needs to be used as a replacement, and the mass amount of the intermediate is changed according to the molar amount.

[0160] Synthesis of compound 4-1:

[0161]

[0162]

[0163] Synthesis of intermediate 4-1: Under nitrogen protection, raw material 7 (200.0 g, 905 mmol), acetic anhydride (92.3 g, 905 mmol), and pyridine (1000 ml) were added to a three-necked flask, stirred and heated to 100 ° C for 2 h, and the raw materials were detected by TLC. After the reaction was complete, the mixture was cooled to room temperature 24 ° C, concentrated under reduced pressure to remove the solvent, and purified by recrystallization with ethanol to obtain 190.4 g of intermediate 4-1. The content detected by HPLC was 98.1302%, and the yield was 80%. The synthesis method of intermediate 4-2 refers to the synthesis of intermediate 1-1, and raw materials 1 and raw materials 2 are replaced by raw materials 8 and intermediate 4-1, with a yield of 65%. The synthesis method of intermediate 4-3 refers to the synthesis of intermediate 3-2, and intermediate 3-1 is replaced by intermediate 4-2, with a yield of 78%. The synthesis method of intermediate 4-4 refers to the synthesis of intermediate 1-4, and intermediate 1-3 is replaced by intermediate 4-3, with a yield of 72%. The synthesis of intermediate 4 was based on the synthesis of intermediate 1, except that intermediate 1-4 was replaced by intermediate 4-4, with a yield of 57%.

[0164] The synthesis of compound 4-1 refers to the synthesis of intermediate 1-3, and intermediate 1-2 and iodobenzene are replaced by intermediate 4 and intermediate 4-bromo-dibenzothiophene. The content of HPLC detection is 99.9264%, and the yield is 54%. The result of mass spectrometry detection of the obtained sample is: HR-MS (APCI): m / z 533.1020 [M+H] + ; C 34 H 19 N3S2 (%) calculated value: C, 76.5223; H, 3.5888; N, 7.8740; S, 12.0150; measured value: C, 76.5153; H, 3.5594; N, 7.8832; S, 12.0421.

[0165] Synthesis of compound 4-5:

[0166]

[0167] The synthesis method of intermediate 4-5 refers to the synthesis of intermediate 1-3, replacing intermediate 1-2 and iodobenzene with intermediate 4 and 2,2'-dibromobiphenyl, with a yield of 68%. The synthesis of compound 4-5 refers to the synthesis of intermediate 1-1, replacing raw materials 1 and 2 with intermediate 4-5 and intermediate 2-6, and the content detected by HPLC is 99.9371%, with a yield of 50%. The results of mass spectrometry detection of the obtained sample are: HR-MS (APCI): m / z 719.2031[M+H] + ; C 50 H 29 N3OS (%) calculated value: C, 83.4257; H, 4.0608; N, 5.8374; O, 2.2225; S, 4.4536; measured value: C, 83.4169; H, 4.0486; N, 5.8353; O, 2.2324; S, 4.4668. Referring to the synthesis methods of intermediate 4, compound 4-1 and compound 4-5, the compound in which Y is S in general formula (I) can be synthesized. The only difference is that according to different products, it is necessary to use an intermediate with the corresponding group Ar1 and the bridging group L1 to replace it, and the mass amount of the intermediate is changed according to the different molar amounts.

[0168] Synthesis of compound 5-1:

[0169]

[0170]

[0171] The synthesis method of intermediate 5-1 refers to the synthesis of intermediate 1-1, replacing raw materials 1 and 2 with raw materials 9 and 10, with a yield of 80%.

[0172] Synthesis of intermediate 5-2: Under nitrogen protection, add intermediate 5-1 (100.0 g, 253.2 mmol) and 500 mL tetrahydrofuran to a three-necked flask. Stir the system evenly and cool it to -10°C. Slowly add butyl lithium (317 mL, 506.4 mmol, 1.6 M) and keep the temperature for 1 h. Then add diphenyldichlorosilane tetrahydrofuran solution (63.8 g, 253.2 mmol, 200 ml tetrahydrofuran) and keep the temperature for 1 h. Then naturally warm to room temperature and continue to react for 2 h. After the reaction is completed, quench the reaction with an aqueous solution of ammonium chloride, add 500 ml toluene for extraction, wash repeatedly with water, dry and filter the organic phase with 150 g anhydrous magnesium sulfate, squeeze out with ethanol after concentration, and recrystallize and purify with a toluene / n-heptane mixed solvent to obtain 74.2 g of intermediate 5-2. The content detected by HPLC is 98.2903%, and the yield is 70%. The synthesis method of intermediate 5-3 refers to the synthesis of intermediate 1-4, replacing intermediate 1-3 with intermediate 5-2, with a yield of 74%. The synthesis of intermediate 5 refers to the synthesis of intermediate 1, replacing intermediate 1-4 with intermediate 5-3, with a yield of 50%.

[0173] The synthesis of compound 5-1 refers to the synthesis of intermediate 1-3, and intermediate 1-2 and iodobenzene are replaced by intermediate 5 and intermediate 5-4. The content of HPLC detection is 99.9731%, and the yield is 48%. The result of mass spectrometry detection of the obtained sample is: HR-MS (APCI): m / z 793.2662 [M+H] + ; C 55 H 35 Calculated value of N5Si (%): C, 83.1991; H, 4.4433; N, 8.8205; Si, 3.5371; Found: C, 83.1883; H, 4.4517; N, 8.8261; Si, 3.5339.

[0174] Synthesis of compound 5-5:

[0175]

[0176] The synthesis method of intermediate 5-4 refers to the synthesis of intermediate 1-3, and intermediate 1-2 and iodobenzene are replaced by intermediate 5 and intermediate p-dibromobenzene, with a yield of 71%. The synthesis method of compound 5-5 refers to the synthesis of intermediate 1-1, and raw materials 1 and 2 are replaced by intermediate 5-4 and intermediate N-phenylcarbazole-3-boronic acid. The content detected by HPLC is 99.9285%, and the yield is 58%. The results of mass spectrometry detection of the obtained sample are: HR-MS (APCI): m / z 819.2818 [M+H] + ; C 57 H 37 N5Si (%) calculated value: C, 83.4867; H, 4.5481; N, 8.5404; Si, 3.4248; measured value: C, 83.4921; H, 4.5421; N, 8.5473; Si, 3.4185. Referring to the synthesis methods of intermediate 5, compound 5-1 and compound 5-5, the compound in which Y is Si in general formula (I) can be synthesized. The only difference is that according to different products, it is necessary to use an intermediate with the corresponding group Ar1 and the bridging group L1 to replace it, and the mass amount of the intermediate is changed according to the different molar amounts.

[0177] Synthesis of compound 6-1:

[0178]

[0179] The synthesis of intermediate 6 was based on the synthesis of intermediate 1, except that intermediate 1-4 was replaced by intermediate 6-1, with a yield of 53%.

[0180] The synthesis of compound 6-1 refers to the synthesis of intermediate 1-3, and intermediate 1-2 and iodobenzene are replaced by intermediate 6 and raw material 11. The content detected by HPLC is 99.9783%, and the yield is 50%. The result of mass spectrometry detection of the obtained sample is: HR-MS (APCI): m / z 559.1797 [M+H] + ; C 39 H 21 N5 (%) calculated value: C, 83.7030; H, 3.7825; N, 12.5145; measured value: C, 83.7132; H, 3.7757; N, 12.5111.

[0181] Synthesis of compound 6-5:

[0182]

[0183] The synthesis method of intermediate 6-2 refers to the synthesis of intermediate 1-3, except that intermediate 1-2 and iodobenzene are replaced by intermediate 6 and intermediate 2,2'-dibromobiphenyl, with a yield of 68%.

[0184] The synthesis method of compound 6-5 refers to the synthesis of intermediate 1-1, and raw materials 1 and 2 are replaced by intermediate 6-2 and intermediate 9,9-dimethylfluorene-3-boronic acid. The content of HPLC detection is 99.9852%, and the yield is 55%. The result of mass spectrometry detection of the obtained sample is: HR-MS (APCI): m / z 664.2627 [M+H] + ; C 48 H 32 N4 (%) calculated value: C, 86.7205; H, 4.8519; N, 8.4276; measured value: C, 86.7138; H, 4.8538; N, 8.4324.

[0185] By referring to the synthesis methods of intermediate 6, compound 6-1 and compound 6-5, the compound in which Y in the general formula (I) is a single bond can be synthesized. The only difference is that, depending on the product, an intermediate with the corresponding group Ar1 and bridging group L1 needs to be used as a replacement, and the mass amount of the intermediate is changed according to the different molar amounts.

[0186] First, the performance parameters (including HOMO energy level and LUMO energy level, triplet energy T1) of device embodiments 1-30 and existing OLED materials H1 (Comparative Example 1) and H2 (Comparative Example 2) are measured. The results are shown in Table 1:

[0187] Table 1: Performance parameter measurement results of the compounds of the present invention and existing materials

[0188]

[0189] Note: The highest occupied molecular orbital (HOMO), the lowest unoccupied molecular orbital (LUMO), and the triplet energy T1 are the data obtained by simulation calculation in Gaussian 09 software. The calculation method adopts B3LYP hybrid functional, basis set 6-31g (d), Eg = absolute value of HOMO-LUMO;

[0190] As can be seen from Table 1, the compounds provided by the present invention have suitable HOMO / LUMO energy levels and triplet energy, which are beneficial to carrier transmission and energy transfer in OLED devices. The compounds of the present invention are suitable for use as phosphorescent host materials.

[0191] Taking some compounds provided by the present invention as examples, the compounds are applied as main materials of the light-emitting layer in organic electroluminescent devices to verify the excellent effects achieved.

[0192] Example 1

[0193] This embodiment provides an organic electroluminescent device, the structure of which is as follows: Figure 1As shown, it includes a substrate 1, an anode layer 2, a hole injection layer 3, a first hole transport layer 4, a second hole transport layer 5, a light emitting layer 6, a hole blocking layer 7, an electron transport layer 8, an electron injection layer 9 and a cathode layer 10 which are stacked in sequence.

[0194] Among them, the substrate 1 is a glass substrate with a thickness of 0.7 mm, the material of the anode layer 2 is indium tin oxide (ITO) with a high work function, the material of the hole injection layer 3 is HAT-CN with a thickness of 5 nm; the material of the first hole transport layer 4 is HT1 with a thickness of 60 nm; the material of the second hole transport layer 5 is HT2 with a thickness of 10 nm; the light-emitting layer 6 uses RD01 as the light-emitting material and compound 1 as the main material, with a doping mass ratio of 6% and a thickness of 30 nm; the material of the hole blocking layer 7 is HB1 with a thickness of 10 nm; the material of the electron transport layer 8 is ET1 with a thickness of 35 nm; the material of the electron injection layer 9 is Liq with a thickness of 2 nm; the material of the cathode layer is Al with a thickness of 100 nm.

[0195] The basic material structure used in each functional layer of the device is as follows:

[0196]

[0197]

[0198]

[0199] The specific preparation steps of the above organic electroluminescent device are as follows:

[0200] 1) Clean the ITO anode on the transparent glass or plastic substrate, and ultrasonically clean it with deionized water, acetone, and ethanol for 20 minutes respectively, and then perform plasma treatment in an oxygen atmosphere for 5 minutes; 2) Vacuum evaporation is used to deposit the hole injection layer material HAT-CN on the ITO anode layer with a thickness of 5nm, and this layer is used as the hole injection layer; 3) Vacuum evaporation is used to deposit the hole transport material HT1 on the hole injection layer with a thickness of 60nm, and this layer is used as the first hole transport layer; 4) Vacuum evaporation is used to deposit the hole transport material HT2 on the first hole transport layer HT1 with a thickness of 15nm, and this layer is used as the second hole transport layer; 5) Vacuum evaporation is used to deposit the hole transport material HT2 on the second hole transport layer. The light-emitting layer is deposited by evaporation, using compound 1-1 as the main material and RD01 as the red light doping material, with a doping mass ratio of 6% and a thickness of 30nm; 6) On the light-emitting layer, the hole blocking material HB1 is deposited by vacuum evaporation with a thickness of 10nm, and this layer is used as the hole blocking layer; 7) On the hole blocking layer, the electron transport material ET1 is deposited by vacuum evaporation with a thickness of 35nm, and this layer is used as the electron transport layer; 8) On the electron transport layer, the electron injection material Liq is deposited by vacuum evaporation with a thickness of 2nm, and this layer is used as the electron injection layer; 9) On the electron injection layer, the cathode Al is deposited by vacuum evaporation with a thickness of 100nm, and this layer is used as the cathode conductive electrode.

[0201] Embodiment 2 to Embodiment 15

[0202] The implementation process is the same as that of Example 1, except that the main material of the light-emitting layer is replaced by other developed compounds instead of Compound 1.

[0203] Comparative Example 1

[0204] The implementation process is the same as that of Example 1, except that H1 is used as the red light host material.

[0205] Example 16 to Example 30

[0206] The implementation process is the same as that of Example 1, except that the main material of the light-emitting layer is replaced by other developed compounds instead of compound 1-1, and GD01 is replaced by RD01 to produce a green light device.

[0207] Comparative Example 2

[0208] The implementation process is the same as that of Example 16, except that H2 is used as the green light host material.

[0209] The cathode and anode of each group of organic electroluminescent devices were connected by a known driving circuit, and the voltage-efficiency-current density relationship of the OLED device was tested by a standard method using a Keithley 2400 power supply combined with a PR670 photometer; the life of the device was tested by a constant current method under the test condition of a constant current density of 10 mA / cm 2 , the initial brightness of the device is 3000cd / m 2 The time it takes for the test brightness to decay to 95% of the initial brightness is the device LT95 life. The results are shown in Table 2.

[0210] Table 2: Comparison of performance results of organic electroluminescent devices in each group

[0211]

[0212] As can be seen from Table 2, the compounds provided by the present invention are applied as the main material of the light-emitting layer to OLED red light devices or green light devices, and the performance is improved. For example, the compound 3-34 in device embodiment 13 is used as the main material of red light, compared with H1 in the comparative example, the brightness efficiency and life are significantly improved, the brightness efficiency is increased by 28%, and the service life is increased by 67%; the compound 2-20 in device embodiment 20 is used as the main material of green light, compared with H2 in the comparative example, the brightness efficiency and life are also significantly improved. It can be seen that the efficiency and life of the device are well performed by selecting the compounds of the present invention, and the synthesis process of the material is simple, which has great application value in the application of OLED devices and has good industrialization prospects.

[0213] As described above, the basic principle, main features and advantages of the present invention are well described. The above embodiments and descriptions are only descriptions of the preferred implementation modes of the present invention, and the present invention is not limited by the above embodiments. Without departing from the spirit and scope of the present invention, various changes and improvements made by ordinary technicians in this field to the technical solution of the present invention should fall within the protection scope determined by the present invention.

Claims

1. A compound, characterized in that Having a structure as shown in formula (I), ； Wherein, Ar1 is independently selected from the structure shown in formula (II), ； Y is selected from a single bond, C(R3R4), O, S, NAr3, Si(R3R4); Z is selected from one of C and N; X1 is selected from one of C (R5R6), O, S, and NAr4; Ar2, Ar3, Ar4 are independently selected from C6~C30 aryl groups, and C2~C30 heteroaryl groups containing N, O, and S heteroatoms; R1-R6 are independently selected from any one of deuterium, halogen, C1-C10 alkyl, C6-C30 aryl, and C2-C30 heteroaryl containing N, O, and S heteroatoms; L1 is a bridging group, and n is selected from 1, 2, and 3; or L1 is a single bond and n is 1; p is selected from one of 0, 1, 2, 3, and 4; m is selected from one of 0, 1, 2, and 3; The bridging group is selected from a benzene ring, a naphthalene ring, a biphenyl, a pyridine, a pyrazine, a triazine, a quinoline, and an isoquinoline.

2. The compound according to claim 1, characterized in that The n>1, and the plurality of Ar1s are the same as or different from each other.

3. The compound according to claim 1, characterized in that The p>1, the multiple R1s are the same or different from each other, and / or the multiple adjacent R1s are connected to form a ring.

4. The compound according to claim 1, characterized in that The m>1, the multiple R2s are the same or different from each other, and / or the adjacent multiple R2s are connected to form a ring.

5. A compound, characterized in that Has the structure shown below, 。 6. Use of the compound according to any one of claims 1 to 5 in an organic electroluminescent device.

7. An organic electroluminescent device, comprising an anode layer, a cathode layer and an organic thin film layer located between the anode layer and the cathode layer, wherein the organic thin film layer comprises a hole injection layer, a first hole transport layer, a second hole transport layer, a light emitting layer, a hole blocking layer, an electron transport layer and an electron injection layer, characterized in that: The light-emitting layer contains the compound according to any one of claims 1 to 5.

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