An organic electroluminescent material, its preparation method and applications

Abstract

The present invention belongs to the field of organic light-emitting technology, and relates to an organic electroluminescent material, a preparation method thereof and an application. The organic electroluminescent material disclosed by the present invention has a structure shown in General Formula I as described in the specification. The present invention discloses a luminescent compound having an organic fused ring. After being used in optoelectronic devices such as organic electroluminescent devices, the driving voltage of the optoelectronic device can be reduced, the luminous efficiency of the optoelectronic device can be significantly improved, and the service life of the optoelectronic device can be extended; moreover, the preparation process provided by the present invention has the characteristics of simple synthesis steps, easy purification and high yield of the target product, and is suitable for popularization and application.

Description

Technical Field

[0001] The present invention belongs to the technical field of organic light-emitting materials, and relates to an organic electroluminescent material, a preparation method thereof, and an application thereof in the preparation of organic electroluminescent devices. Background Art

[0002] In 1987, Dr. Ching W. Tang published the technology of electroluminescent diodes based on organic light-emitting materials. This technology has received extensive attention from researchers around the world and effectively promoted the development of organic electroluminescent technology in practical applications.

[0003] With the continuous progress of organic electroluminescent diode technology, organic electroluminescent devices have the characteristics of self-luminescence, wide viewing angle, high contrast ratio, short response time, low driving voltage, etc., and can achieve full-color OLED displays through three organic electroluminescent materials (red, green, and blue). It is the most promising new display technology and can be used for flat panel displays and lighting sources. At present, flat panel displays have achieved large-scale industrialization, and products applied in various industries have been mass-produced and put on the market.

[0004] With the continuous market launch of OLED products, people's requirements for the performance and stability of such products are getting higher and higher. The currently applied OLED materials and device structures still cannot completely solve various problems such as the efficiency, lifespan, and cost of OLED products. In order to meet people's higher requirements for OLED devices and better meet the requirements of future life, developing and synthesizing a variety of phosphorescent materials with high luminous efficiency and low driving voltage, and reducing the synthesis cost are the key problems to be solved in this field. Summary of the Invention

[0005] In view of this, the present invention provides an organic electroluminescent material, a preparation method thereof, and an application thereof in organic electroluminescent devices.

[0006] In order to achieve the above object, the first object of the present invention is to provide an organic electroluminescent material.

[0007] The following technical scheme is adopted:

[0008] The structural general formula of the organic electroluminescent material is General Formula I:

[0009]

[0010] R is selected from -L-(A)n;

[0011] L is selected from a substituted or unsubstituted C6-C30 aryl group, a substituted or unsubstituted C6-C30 heteroaryl group, and its heteroatoms contain at least one of O, S, N, Si, and Se;

[0012] n is selected from the integers 1 or 2, and when n is selected as 2, each A can be the same or different;

[0013] A is selected from substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C6-C30 heteroaryl, the heteroatoms of which contain at least one of O, S, N, Si, Se; substituted or unsubstituted C6-C30 arylamino, substituted or unsubstituted C6-C30 heteroarylamino, the heteroatoms of which contain at least one of O, S, N, Si, Se; substituted or unsubstituted C8-C30 fused ring group.

[0014] Optionally, the C6-C30 aryl is a monocyclic group or a polycyclic group; wherein, the polycyclic group has multiple rings with two carbons shared by two adjacent rings, at least one ring is an aromatic ring, and the other rings are at least one of cycloalkyl, cycloalkenyl, aryl and aromatic heterocyclic group;

[0015] The C6-C30 heteroaryl is any one of furan, thiophene, pyridine, carbazole, pyrazine, pyrimidine, triazine, quinoline, isoquinoline, quinoxaline, quinazoline, imidazole, benzimidazole.

[0016] Optionally, L is preferably selected from at least one of benzene, biphenyl, naphthalene, phenanthrene, anthracene, fluorene, benzofluorene, dibenzofluorene, triphenylene, fluoranthene, pyrene, perylene, spirofluorene, dibenzofuran, dibenzothiophene, pyridine, pyrazine, pyrimidine, triazine, quinoline, isoquinoline, quinoxaline, quinazoline, imidazole, benzimidazole, indenoacenaphthene or hydrogenated benzanthracene.

[0017] It should be noted that the above "substituted" means that the hydrogen atom bonded to the carbon atom of the compound becomes another substituent, and there is no restriction on the substitution position, as long as the position is the position where the hydrogen atom is substituted, that is, the position where the substituent can be substituted, and when two or more substituents are substituted, the two or more substituents can be the same or different from each other. The substituent is deuterium, halogen, cyano, C1-C30 alkyl, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C6-C30 heteroaryl, substituted or unsubstituted C8-C30 fused ring group.

[0018] Preferably, the chemical structural formula of the compound is any one of Formula L001 to Formula L308:

[0019]

[0020]

[0021]

[0022]

[0023]

[0024]

[0025]

[0026]

[0027]

[0028]

[0029]

[0030]

[0031]

[0032] Another object of the present invention is to provide a method for preparing the above-mentioned organic electroluminescent material, which specifically includes the following steps:

[0033]

[0034] (1) Under nitrogen protection, raw material A (1.0 eq), raw material B (1.0 eq), copper(I) iodide (0.5 eq), 1,10-phenanthroline (1.0 eq), potassium hydroxide (3.0 eq), and xylene (1000 ml) are added to a reaction flask, heated to 70 °C for reaction. After the reaction is completed, it is cooled, and the intermediate compound L-1 is obtained through column chromatography purification;

[0035] (2) Under nitrogen protection, raw material C (1.0 eq), raw material D (4.0 eq), and potassium acetate (2.0 eq) are added to a reaction flask, and the solvent 1,4-dioxane (1000 ml), tris(dibenzylideneacetone)dipalladium(0) (0.01 eq), and X-phos (0.08 eq) are added. It is heated to 100 °C for reaction. After the reaction is completed, it is cooled to room temperature, and the intermediate compound L-2 is obtained through column chromatography purification;

[0036] (3) Under nitrogen protection, compound L-1 (1.0 eq), compound L-2 (1.0 eq), potassium carbonate (2.0 eq), tetrakis(triphenylphosphine)palladium(0) (0.01 eq), toluene (400 ml), ethanol (200 ml), and water (200 ml) are added to a reaction flask, heated to 90 °C for reaction. After the reaction is completed, it is cooled to room temperature, and the intermediate L is obtained through column chromatography purification;

[0037] (4) Under nitrogen protection, the intermediate L (1.0 eq), the raw material E (1.1 eq) and sodium tert-butoxide (1.5 eq) were mixed, added to a solvent of toluene (400 ml), and tri(dibenzylideneacetone) palladium (0.01 eq) and tri-tert-butylphosphine (0.02 eq) were added, and heated to 120° C. for reaction. After the reaction was completed, it was purified by column chromatography and concentrated by rotary evaporation to obtain the general formula I.

[0038] Another object of the present invention is to provide a use of the above organic electroluminescent material in the preparation of an organic electroluminescent device.

[0039] The organic electroluminescent device comprises a first electrode, a second electrode and at least one organic layer arranged between the first electrode and the second electrode, wherein the organic layer comprises the organic electroluminescent material mentioned above.

[0040] Preferably, the organic layer includes a light-emitting layer; the light-emitting layer includes a main material and a doping material; the main material partially or entirely contains the organic electroluminescent material.

[0041] In addition, the organic layer may further include other functional layers, which may be specifically selected from one or more of the following functional layers: hole injection layer (HIL), hole transport layer (HTL), hole injection-hole transport functional layer (i.e., having both hole injection and hole transport functions), electron blocking layer (EBL), hole blocking layer (HBL), electron transport layer (ETL), electron injection layer (EIL), electron transport-electron injection functional layer (i.e., having both electron transport and electron injection functions).

[0042] There is no particular limitation on the types of the above-mentioned functional layers, and they may be conventional functional layers well known to those skilled in the art.

[0043] The first electrode serves as an anode, which preferably comprises a material with a high work function. For example Ag, Pt or Au. Preferred anode materials are conductive mixed metal oxides. Particularly preferred are indium tin oxide (ITO) or indium zinc oxide (IZO). Furthermore, preferred are conductive doped organic materials, in particular conductive doped polymers. Since the lifetime of the device according to the invention is shortened in the presence of water and / or air, the device is appropriately (depending on the application) structured, provided with contacts and finally sealed.

[0044] 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 organic materials based on arylamine, conductive polymers, block copolymers having both conjugated and non-conjugated parts, etc., but are not limited thereto.

[0045] The material of the light-emitting layer is a material that can emit visible light by respectively receiving holes and electrons from the hole transport layer and the electron transport layer and combining the received holes and electrons.

[0046] Preferably, the mass ratio of the host material to the doping material is (90 - 99.5):(0.5 - 10).

[0047] The doping material can include a fluorescent doping material and a phosphorescent doping material. The phosphorescent doping material includes phosphorescent materials of metal complexes such as iridium and platinum. For example, green phosphorescent materials such as Ir(ppy)3, blue phosphorescent materials such as FIrpic and FIr6, and red phosphorescent materials such as Btp2Ir(acac) can be used.

[0048] Specifically, the doping material can use the compound in European Patent Application 07102949.0 as the dopant in the light-emitting layer.

[0049] The electron blocking layer can be disposed between the hole transport layer and the light-emitting layer. As the electron blocking layer, materials known in the art can be used, such as arylamine-based organic materials.

[0050] For the hole blocking layer material, compounds known in the prior art having a hole blocking effect can be used, such as phenanthroline derivatives such as bathocuproine (BCP), oxazole derivatives, triazole derivatives, triazine derivatives, etc., but not limited thereto.

[0051] The electron transport layer can play a role in promoting electron transport. The electron transport material is a material that advantageously receives electrons from the cathode and transports the electrons to the light-emitting layer, and a material with high electron mobility is suitable. As the electron transport layer material of the organic electroluminescent device of the present invention, compounds known in the prior art having an electron transport effect can be used, such as an Al complex of 8-hydroxyquinoline; a complex containing Alq3; an organic radical compound; a hydroxyflavone-metal complex, etc., but not limited thereto.

[0052] The electron injection layer can play a role in promoting electron injection. It has the ability to transport electrons and prevents excitons generated in the light-emitting layer from migrating to the hole injection layer. The electron injection materials used in the present invention include fluorenone, anthraquinone dimethane, biphenylquinone, thiopyran dioxide, oxazole, dioxazole, triazole, imidazole, perylene tetracarboxylic acid, fluoreneylidene methane, anthrone, etc. and their derivatives, metal complexes, nitrogen-containing five-membered ring derivatives, etc., but not limited thereto.

[0053] The second electrode serves as a cathode and typically preferably uses a material with a small work function to enable smooth injection of electrons into the organic material layer. It includes: metals such as magnesium, calcium, sodium, potassium, titanium, indium, yttrium, lithium, gadolinium, aluminum, silver, tin, and lead, or their alloys; multi-layer structure materials such as LiF / Al or LiO2 / Al, and the layer thickness of this layer is preferably between 0.5 and 5 nm.

[0054] In the embodiments of the present invention, the above various functional layers can be formed by solution coating methods and vacuum deposition methods. Solution coating methods refer to spin coating, dip coating, inkjet printing, screen printing, spraying methods, etc., but are not limited thereto.

[0055] In addition, the above-mentioned organic electroluminescent device can be an organic electroluminescent device, an organic solar cell, an electronic paper, an organic photoreceptor, or an organic thin film transistor, etc., but is not limited thereto.

[0056] Compared with the prior art, the beneficial effects of the present invention are:

[0057] 1) A luminescent compound with an organic condensed ring provided by the present invention, after being used in optoelectronic devices such as organic electroluminescent devices, can reduce the driving voltage of the optoelectronic device, significantly improve the luminous efficiency of the optoelectronic device, and extend the service life of the optoelectronic device.

[0058] 2) The preparation method of the luminescent compound provided by the present invention has the characteristics of simple synthesis steps, easy purification, and high yield of the target product, and is suitable for popularization and application. Specific Embodiments

[0059] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0060] In this specification, each embodiment is described in a progressive manner. The key point of each embodiment is to illustrate the differences from other embodiments. The same or similar parts among the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the description of the method part.

[0061] Compound Example 1

[0062] This compound example provides a compound, whose chemical structural formula is Formula L001 in the invention content. The reaction route of the preparation method of this luminescent compound is as follows:

[0063]

[0064] The specific preparation method includes the following steps:

[0065] Under a nitrogen protection system, weigh raw material A (406.32 mmol, 100 g) (CAS: 16807-11-7), raw material B (406.32 mmol, 114.95 g) (CAS: 583-55-1), cuprous iodide (203.16 mmol, 38.69 g), 1,10-phenanthroline (406.32 mmol, 73.22 g), potassium hydroxide (1218.97 mmol, 68.39 g), and put them into the reaction system. Then, add 1000 mL of toluene to the reaction system, and reflux the reaction system at 120 °C for 24 hours under nitrogen protection. After the reaction is completed, cool the system to room temperature, purify it by silica gel column chromatography, concentrate the filtrate, and precipitate a solid to obtain intermediate compound L-1 (90.58 g, yield: 55.58%).

[0066] 1 HNMR(500MHz,Chloroform-d)δ8.12–8.06(m,1H),8.01(dd,J=7.3,1.6Hz,1H),7.65–7.59(m,1H),7.57(dd,J=7.5,1.5Hz,1H),7.47(dd,J=7.5,1.7Hz,1H),7.42(t,J=7.4Hz,1H),7.38(dd,J=7.4,1.6Hz,1H),7.36–7.28(m,3H),7.16(td,J=7.5,1.6Hz,1H).

[0067] Under a nitrogen protection system, weigh raw material C (307.69 mmol, 100 g) (CAS: 905702-33-2), raw material D (615.39 mmol, 156.27 g) (CAS: 73183-34-3), potassium acetate (769.23 mmol, 75.49 g), tris(dibenzylideneacetone)dipalladium(0) (3.08 mmol, 2.82 g), X-phos (24.62 mmol, 11.73 g), and put them into the reaction system. Then, add 1000 mL of 1,4-dioxane to the reaction system, and reflux the reaction system at 100 °C for 24 hours under nitrogen protection. After the reaction is completed, cool the system to room temperature, purify it by silica gel column chromatography, concentrate the filtrate, and precipitate a solid to obtain intermediate compound L-2 (60.17 g, yield: 46.66%).

[0068] 1HNMR (500MHz, Chloroform-d) δ9.98 (s, 1H), δ7.45 (dd, J=7.4, 1.6Hz, 2H), 7.30 (dd, J=7.5, 1.6Hz, 2H), 7.21 (s, 2H), 1.24 (s, 24H).

[0069] Under nitrogen protection, compound L-1 (149.59 mmol, 60 g), L-2 (149.59 mmol, 62.70 g), potassium carbonate (299.18 mmol, 41.29 g) were weighed and put into the reaction system. Then, 500 mL of toluene, 250 mL of ethanol, 250 mL of purified water, and tetrakis(triphenylphosphine)palladium (1.20 mmol, 1.73 g) were added to the reaction system. The reaction system was refluxed at 90° C. for 24 hours under nitrogen protection. After the reaction, the system was cooled to room temperature and purified by silica gel column chromatography. The filtrate was concentrated and solid precipitated to obtain the intermediate compound L001-1 (32.73 g, yield 53.83%).

[0070] 1 HNMR(500MHz,Chloroform-d)δ9.78(s,1H),8.17–8.04(m,1H),7.99(ddd,J=9.2,7.4,1.6Hz,2H),7.71(ddd,J= 7.5,3.8,1.6Hz,2H),7.66–7.53(m,3H),7.48(t,J=7.5Hz,1H),7.41(td,J=7.5,1.6Hz,1H),7.37–7.21(m,7H).

[0071] Under nitrogen protection, compound L001-1 (49.20 mmol, 20 g), L001-2 (54.12 mmol, 16.90 g) (CAS: 80984-79-8), sodium tert-butoxide (73.80 mmol, 7.09 g) were weighed and put into the reaction system. Then, 200 mL of toluene, tri(dibenzylideneacetone) palladium (0.49 mmol, 0.45 g) and 50% tri-tert-butylphosphine (0.98 mmol, 0.40 g) were added to the reaction system, and the reaction system was refluxed at 120°C for 24 hours under nitrogen protection. After the reaction, the system was cooled to room temperature and purified by silica gel column chromatography. The filtrate was concentrated and the solid precipitated to obtain the final compound L001 (21.37 g, yield: 68.10%).

[0072] HPLC purity: greater than 99%;

[0073] Mass spectrum: test value is 638.17;

[0074] Elemental Analysis:

[0075] Calculated values: C: 84.75%; H: 4.27%; N: 10.98%;

[0076] Test values: C: 83.69%; H: 3.88%; N: 11.59%;

[0077] 1 HNMR(500 MHz, Chloroform-d) δ 8.59–8.52 (m, 4H), 8.15–8.07 (m, 1H), 8.02 (dd, J = 7.5, 1.6 Hz, 1H), 7.87–7.78 (m, 2H), 7.70–7.58 (m, 6H), 7.49–7.40 (m, 8H), 7.37–7.29 (m, 5H). Compound Example 2

[0078] This compound example provides a compound whose chemical structural formula is Formula L021 in the invention content. The reaction route of the preparation method of this compound is as follows:

[0079]

[0080] Its specific preparation method includes the following steps:

[0081] Under a nitrogen protection system, weigh compound L021-1 (49.20 mmol, 20 g), L021-2 (54.12 mmol, 19.36 g) (CAS: 1472729-25-1), and sodium tert-butoxide (73.80 mmol, 7.09 g) into the reaction system. Then, add 200 mL of toluene, tris(dibenzylideneacetone)dipalladium(0) (0.49 mmol, 0.45 g), and 50% tris(tert-butyl)phosphine (0.98 mmol, 0.40 g) to the reaction system. React the system under nitrogen protection at 120 °C for 24 hours. After the reaction is completed, cool the system to room temperature, purify it by silica gel column chromatography, concentrate the filtrate, and solid precipitate to obtain the final compound L021 (22.54 g, yield: 62.94%).

[0082] HPLC purity: greater than 99%;

[0083] Mass spectrometry: The test value is 728.24;

[0084] Elemental analysis:

[0085] Calculated values: C: 84.16%; H: 4.02%; N: 9.62%; O: 2.20%;

[0086] Test values: C: 83.09%; H: 4.10%; N: 9.98%; O: 2.76%;

[0087] 1 HNMR (500 MHz, Chloroform-d) δ 8.59–8.53 (m, 2H), 8.13–8.08 (m, 1H), 8.02 (ddd, J = 8.2, 6.6, 1.5 Hz, 3H), 7.89–7.79 (m, 3H), 7.70–7.53 (m, 8H), 7.50–7.36 (m, 8H), 7.36–7.28 (m, 4H).

[0088] Compound Example 3

[0089] This compound example provides a compound with the chemical structural formula of Formula L065 in the invention content. The reaction route of the preparation method of this compound is as follows:

[0090]

[0091] Its specific preparation method includes the following steps:

[0092] Under a nitrogen protection system, weigh Compound L065-1 (104.48 mmol, 30 g) (CAS: 854952-58-2), L065-2 (104.48 mmol, 32.91 g) (CAS: 1973-01-9), and potassium carbonate (208.97 mmol, 28.84 g) into the reaction system. Then, add 200 mL of toluene, 100 mL of ethanol, 100 mL of pure water, and tetrakis(triphenylphosphine)palladium (1.05 mmol, 1.21 g) to the reaction system. Make the reaction system reflux at 70 °C for 24 hours under nitrogen protection. After the reaction is completed, cool the system to room temperature, purify it by silica gel column chromatography, concentrate the filtrate, and solid precipitate to obtain intermediate compound L065-3 (23.5 g, yield 47.12%);

[0093] 1 HNMR (500 MHz, Chloroform-d) δ 9.34 (d, J = 1.4 Hz, 1H), 8.59–8.53 (m, 2H), 8.21 (d, J = 7.5 Hz, 1H), 8.18–8.14 (m, 1H), 8.08 (dd, J = 7.5, 1.5 Hz, 1H), 7.63–7.57 (m, 1H), 7.55–7.42 (m, 7H), 7.38–7.28 (m, 3H).

[0094] Under nitrogen protection, compound L065-4 (49.20 mmol, 20 g), L065-3 (54.12 mmol, 25.84 g), sodium tert-butoxide (73.80 mmol, 7.09 g) were weighed and put into the reaction system. Then, 200 mL of toluene, tri(dibenzylideneacetone) palladium (0.49 mmol, 0.45 g) and 50% tri-tert-butylphosphine (0.98 mmol, 0.40 g) were added to the reaction system, and the reaction system was refluxed at 120°C for 24 hours under nitrogen protection. After the reaction, the system was cooled to room temperature and purified by silica gel column chromatography. The filtrate was concentrated and the solid precipitated to obtain the final compound L065 (25.83 g, yield: 65.38%).

[0095] HPLC purity: greater than 99%;

[0096] Mass spectrum: test value is 803.15;

[0097] Elemental Analysis:

[0098] Calculated values: C: 85.26%; H: 4.27%; N: 10.47%;

[0099] Test value C: 84.20%; H: 4.73%; N: 11.01%;

[0100] 1 HNMR(500MHz,Chloroform-d)δ9.31(d,J=1.5Hz,1H),8.59–8.50(m,2H),8.23–8.14(m,2H),8.09(ddd,J=18.3,7.3,1.6Hz,2H),8.02(dd,J= 7.5,1.6Hz,1H),7.83(ddd,J=13.3,7.5,1.5Hz,2H),7.69–7.58(m,5H),7.56(dd,J=7.5,1.5Hz,2H),7.53–7.36(m,10H),7.36–7.24(m,7H).

[0101] Compound Example 4

[0102] The compound embodiment provides a compound, whose chemical structural formula is Formula L082 in the invention summary, and the reaction route of the preparation method of the compound is as follows:

[0103]

[0104] The specific preparation method comprises the following steps:

[0105] Under nitrogen protection, compound L082-1 (49.20 mmol, 20 g), L082-2 (54.12 mmol, 13.02 g) (CAS: 7065-92-1), sodium tert-butoxide (73.80 mmol, 7.09 g) were weighed and put into the reaction system. Then, 200 mL of toluene, tri(dibenzylideneacetone) palladium (0.49 mmol, 0.45 g) and 50% tri-tert-butylphosphine (0.98 mmol, 0.40 g) were added to the reaction system, and the reaction system was refluxed at 120°C for 24 hours under nitrogen protection. After the reaction, the system was cooled to room temperature and purified by silica gel column chromatography. The filtrate was concentrated and the solid precipitated to obtain the final compound L082 (15.97 g, yield: 53.15%).

[0106] HPLC purity: greater than 99%;

[0107] Mass spectrum: test value is 611.22;

[0108] Elemental Analysis:

[0109] Calculated values: C: 86.53%; H: 4.29%; N: 9.17%;

[0110] Test value C: 85.10%; H: 4.80%; N: 10.04%;

[0111] 1 HNMR(500MHz,Chloroform-d)δ8.12(dd,J=7.3,1.6Hz,1H),8.02(td,J=7.7,1.7Hz,2H),7.99–7.93(m ,1H),7.86–7.82(m,1H),7.81–7.74(m,3H),7.68–7.53(m,8H),7.46–7.38(m,5H),7.37–7.26(m,5H).

[0112] Compound Example 5

[0113] The compound embodiment provides a compound, whose chemical structural formula is Formula L085 in the invention content, and the reaction route of the preparation method of the compound is as follows:

[0114]

[0115] The specific preparation method comprises the following steps:

[0116] Under nitrogen protection, compound L085-1 (49.20 mmol, 20 g), L085-2 (54.12 mmol, 15.33 g) (CAS: 59951-65-4), sodium tert-butoxide (73.80 mmol, 7.09 g) were weighed and put into the reaction system. Then, 200 mL of toluene, tris(dibenzylideneacetone) palladium (0.49 mmol, 0.45 g) and 50% tri-tert-butylphosphine (0.98 mmol, 0.40 g) were added to the reaction system, and the reaction system was refluxed at 120°C for 24 hours under nitrogen protection. After the reaction, the system was cooled to room temperature and purified by silica gel column chromatography. The filtrate was concentrated and the solid precipitated to obtain the final compound L085 (21.12 g, yield: 70.52%).

[0117] HPLC purity: greater than 99%;

[0118] Mass spectrum: test value is 609.34;

[0119] Elemental Analysis:

[0120] Calculated values: C: 90.76%; H: 4.64%; N: 4.60%;

[0121] Test value C: 88.90%; H: 5.38%; N: 5.63%;

[0122] 1 HNMR(500MHz,Chloroform-d)δ8.12(dd,J=7.1,1.9Hz,1H),8.02(dt,J=7.5,1.5Hz,2H),7.89(dd,J=7.5,1.7Hz,1H),7.84(dd,J=6.9,2.2Hz,1H) ,7.75(dd,J=7.5,1.5Hz,1H),7.66–7.56(m,7H),7.53(ddd,J=7.9,6.5, 1.6Hz,2H),7.48–7.39(m,5H),7.39–7.27(m,7H),7.21(t,J=7.5Hz,1H).

[0123] Compound Example 6

[0124] The compound embodiment provides a compound, whose chemical structural formula is Formula L097 in the invention content, and the reaction route of the preparation method of the compound is as follows:

[0125]

[0126] The specific preparation method comprises the following steps:

[0127] Under nitrogen protection, compound L097-1 (159.90 mmol, 60 g) (CAS: 148231-12-3), L097-2 (159.90 mmol, 46.04 g) (CAS: 100124-06-9), potassium carbonate (319.80 mmol, 44.13 g) were weighed and put into the reaction system. Then, 200 mL of toluene, 100 mL of ethanol, 100 mL of purified water, and tetrakis(triphenylphosphine)palladium (1.60 mmol, 1.85 g) were added to the reaction system. The reaction system was refluxed at 70° C. for 24 hours under nitrogen protection. After the reaction was stopped, the system was cooled to room temperature, purified by silica gel column chromatography, and the filtrate was concentrated to precipitate solid to obtain the intermediate compound L097-3 (25.60 g, yield 42.67%).

[0128] 1 HNMR(500MHz,Chloroform-d)δ8.79–8.61(m,2H),8.11–7.94(m,3H),7.90–7.81(m ,2H),7.58(dd,J=7.5,1.6Hz,1H),7.54–7.42(m,2H),7.36(td,J=7.5,1.6Hz,1H).

[0129] Under nitrogen protection, compounds L097-4 (49.20 mmol, 20 g), L097-3 (54.12 mmol, 20.31 g), and sodium tert-butoxide (73.80 mmol, 7.09 g) were weighed and put into the reaction system. Then, 200 mL of toluene, tri(dibenzylideneacetone) palladium (0.49 mmol, 0.45 g) and 50% tri-tert-butylphosphine (0.98 mmol, 0.40 g) were added to the reaction system, and the reaction system was refluxed at 120°C for 24 hours under nitrogen protection. After the reaction, the system was cooled to room temperature and purified by silica gel column chromatography. The filtrate was concentrated and the solid precipitated to obtain the final compound L097 (22.54 g, yield: 65.44%).

[0130] HPLC purity: greater than 99%;

[0131] HPLC purity: greater than 99%;

[0132] Mass spectrum: Test value is 701.04;

[0133] Elemental Analysis:

[0134] Calculated values: C: 85.69%; H: 4.03%; N: 7.99%; O: 2.28%;

[0135] Test value C: 84.73%; H: 4.32%; N: 8.45%; O: 2.45%;

[0136] 1 HNMR(500 MHz, Chloroform-d) δ 8.61 (d, J = 7.5 Hz, 1H), 8.54 (d, J = 7.5 Hz, 1H), 8.18 (d, J = 7.5 Hz, 1H), 8.14–8.08 (m, 1H), 8.08–7.97 (m, 4H), 7.85 (ddd, J = 9.8, 7.4, 1.5 Hz, 2H), 7.74 (dd, J = 7.5, 1.6 Hz, 1H), 7.69–7.50 (m, 8H), 7.49–7.28 (m, 8H), 7.25 (t, J = 7.5 Hz, 1H).

[0137] Compound Example 7

[0138] This compound example provides a compound with the chemical structural formula of Formula L109 in the invention content. The reaction route of the preparation method of this compound is as follows:

[0139]

[0140] Its specific preparation method includes the following steps:

[0141] Under a nitrogen protection system, weigh compound L109-1 (49.20 mmol, 20 g), L109-2 (54.12 mmol, 17.55 g) (CAS: 36809-26-4), and sodium tert-butoxide (73.80 mmol, 7.09 g) and put them into the reaction system. Then, add 200 mL of toluene, tris(dibenzylideneacetone) dipalladium(0) (0.49 mmol, 0.45 g), and 50% tris(tert-butyl)phosphine (0.98 mmol, 0.40 g) to the reaction system, and reflux the reaction system at 120 °C for 24 hours under nitrogen protection. After the reaction is completed, cool the system to room temperature, purify it by silica gel column chromatography, concentrate the filtrate, and precipitate the solid to obtain the final compound L109 (26.74 g, yield: 83.64%).

[0142] HPLC purity: greater than 99%;

[0143] Mass spectrometry: The measured value is 649.48;

[0144] Elemental analysis:

[0145] Calculated value C: 88.72%; H: 4.81%; N: 6.47%;

[0146] Measured value C: 87.38%; H: 5.23%; N: 7.24%;

[0147] 1HNMR(500 MHz, Chloroform-d) δ 8.15–8.08 (m, 1H), 8.02 (dd, J=7.5, 1.6 Hz, 1H), 7.86–7.80 (m, 1H), 7.73 (dd, J=7.5, 1.5 Hz, 1H), 7.67–7.62 (m, 2H), 7.62–7.55 (m, 4H), 7.49–7.44 (m, 2H), 7.43 (d, J=7.5 Hz, 1H), 7.38–7.23 (m, 9H), 7.23–7.16 (m, 3H), 7.15–7.07 (m, 6H). Compound Example 8

[0148] This compound example provides a compound with the chemical structural formula of Formula L111 in the invention content. The reaction route of the preparation method of this compound is as follows:

[0149]

[0150] Its specific preparation method includes the following steps:

[0151] Under a nitrogen protection system, weigh compound L111-1 (49.20 mmol, 20 g), L111-2 (54.12 mmol, 21.67 g) (CAS: 503299-24-9), and sodium tert-butoxide (73.80 mmol, 7.09 g) into the reaction system. Then, add 200 mL of toluene, tris(dibenzylideneacetone) dipalladium(0) (0.49 mmol, 0.45 g), and 50% tris(tert-butyl)phosphine (0.98 mmol, 0.40 g) to the reaction system. React the system under nitrogen protection at 120 °C for 24 hours. After the reaction is completed, cool the system to room temperature. Purify it by silica gel column chromatography. Concentrate the filtrate and solid precipitate to obtain the final compound L111 (23.48 g, yield: 65.74%).

[0152] HPLC purity: greater than 99%;

[0153] Mass spectrometry: The measured value is 726.81;

[0154] Elemental analysis:

[0155] Calculated value C: 89.35%; H: 4.86%; N: 5.79%;

[0156] Measured value C: 88.50%; H: 5.12%; N: 6.35%;

[0157] 1HNMR(500MHz,Chloroform-d)δ8.14–8.06(m,1H),8.02(dd,J=7.6,1.5Hz,1H),7.84(dd,J=7.5,1.5Hz,1H),7.72(dd,J=7.5,1.5Hz,1H),7.66–7.50(m,10H),7.50–7.23(m,13H),7.19(ddt,J=7.8,6.9,1.5Hz,5H),7.13–7.03(m,3H).

[0158] Compound Example 9

[0159] This compound example provides a compound with the chemical structural formula of Formula L173 in the invention content. The reaction route of the preparation method of this compound is as follows:

[0160]

[0161] Under a nitrogen protection system, weigh Compound L173-1 (99.44 mmol, 40 g) (CAS: 2244026-60-4), L173-2 (99.44 mmol, 27.45 g) (CAS: 3900-89-8), and potassium carbonate (198.88 mmol, 27.44 g) into the reaction system. Then, add 200 mL of toluene, 100 mL of ethanol, 100 mL of pure water, and tetrakis(triphenylphosphine)palladium (1.60 mmol, 1.85 g) to the reaction system. The reaction system is refluxed at 70 °C for 24 hours under nitrogen protection. After the reaction stops, the system is cooled to room temperature. After purification by silica gel column chromatography, the filtrate is concentrated and a solid precipitates to obtain intermediate compound L173-3 (22.10 g, yield 51.22%, Mw: 433.90);

[0162] 1 HNMR(500MHz,Chloroform-d)δ8.59–8.53(m,2H),8.03(ddd,J=12.3,7.4,1.5Hz,2H),7.94(dd,J=7.5,1.5Hz,1H),7.82–7.76(m,1H),7.61–7.54(m,2H),7.54–7.40(m,7H),7.37(td,J=7.4,1.7Hz,1H).

[0163] Its specific preparation method includes the following steps:

[0164] Under a nitrogen protection system, weigh out compound L173-4 (49.20 mmol, 20 g), L173-3 (54.12 mmol, 23.48 g), and sodium tert-butoxide (73.80 mmol, 7.09 g) and place them into the reaction system. Then, add 200 mL of toluene, tris(dibenzylideneacetone)dipalladium(0) (0.49 mmol, 0.45 g), and 50% tri-tert-butylphosphine (0.98 mmol, 0.40 g) to the reaction system. The reaction system is refluxed at 120 °C for 24 hours under nitrogen protection. After the reaction is completed, the system is cooled to room temperature, purified by silica gel column chromatography, the filtrate is concentrated, and a solid precipitates to obtain the final compound L173 (19.56 g, yield: 49.45%).

[0165] HPLC purity: greater than 99%;

[0166] Mass spectrometry: The measured value is 804.71;

[0167] Elemental analysis:

[0168] Calculated values: C: 85.16%; H: 4.14%; N: 8.71%; O: 1.99%;

[0169] Measured values: C: 84.33%; H: 4.56%; N: 8.98%; O: 2.11%;

[0170] 1HNMR (500 MHz, Chloroform-d) δ 8.60–8.50 (m, 2H), 8.11 (dd, J = 7.1, 1.9 Hz, 1H), 8.05–7.98 (m, 3H), 7.94–7.87 (m, 2H), 7.84 (dd, J = 7.5, 1.5 Hz, 1H), 7.74 (dd, J = 7.5, 1.5 Hz, 1H), 7.68–7.52 (m, 9H), 7.52–7.36 (m, 9H), 7.37–7.25 (m, 4H), 7.21 (t, J = 7.4 Hz, 1H).

[0171] Compound Example 10

[0172] This compound example provides a compound whose chemical structural formula is Formula L212 in the invention content. The reaction route of the preparation method of this compound is as follows:

[0173]

[0174] Its specific preparation method includes the following steps:

[0175] Under nitrogen protection, compound L212-1 (49.20 mmol, 20 g), L212-2 (54.12 mmol, 13.92 g) (CAS: 1564-64-3), sodium tert-butoxide (73.80 mmol, 7.09 g) were weighed and put into the reaction system. Then, 200 mL of toluene, tri(dibenzylideneacetone) palladium (0.49 mmol, 0.45 g) and 50% tri-tert-butylphosphine (0.98 mmol, 0.40 g) were added to the reaction system, and the reaction system was refluxed at 120°C for 24 hours under nitrogen protection. After the reaction, the system was cooled to room temperature and purified by silica gel column chromatography. The filtrate was concentrated and the solid precipitated to obtain the final compound L212 (20.44 g, yield: 71.29%).

[0176] HPLC purity: greater than 99%;

[0177] Mass spectrum: test value is 583.61;

[0178] Elemental Analysis:

[0179] Calculated values: C: 90.69%; H: 4.50%; N: 4.81%;

[0180] Test value C: 89.88%; H: 4.74%; N: 5.29%;

[0181] 1 HNMR(500MHz,Chloroform-d)δ8.33(dd,J=7.4,1.6Hz,2H),8.25(t,J=1.7Hz,1H),8 .12(dd,J=7.1,1.8Hz,1H),8.02(dd,J=7.5,1.6Hz,1H),7.92(dt,J=7.5,1.7Hz,2H) ,7.84(dd,J=7.5,1.5Hz,1H),7.76(dd,J=7.5,1.5Hz,1H),7.70–7.55(m,6H),7.49( td,J=7.5,1.5Hz,2H),7.46–7.36(m,4H),7.37–7.28(m,4H),7.24(t,J=7.5Hz,1H).

[0182] According to the preparation methods of compound examples 1 to 10, compound L and compound D were replaced by the corresponding compounds in the target product, thereby obtaining the following series of compounds, see Table 1 below. The products were detected and analyzed according to the detection methods in compound examples 1 to 10, and their mass spectra and molecular formulas are shown in Table 1.

[0183] Table 1

[0184]

[0185] For compounds whose specific synthesis methods are not listed otherwise, reference may be made to the above embodiments, and the existing synthesis methods in the art can be used for synthesis.

[0186] An embodiment of the present invention also provides an organic electroluminescent device prepared by using the luminescent compound provided in the above embodiment. The organic electroluminescent device includes: a first electrode, a second electrode, and one or more organic layers disposed between the two electrodes. Among them, one or more layers of the organic layers contain the compound shown in Chemical Formula I of the present invention; the compound shown in Chemical Formula I of the present invention can exist in a single form or in a mixture with other substances in the organic layer;

[0187] The organic layer includes at least one or several of a hole injection layer, a hole transport layer, a layer having both hole injection and hole transport skills, an electron blocking layer, a light emitting layer, a hole blocking layer, an electron transport layer, an electron injection layer, and a layer having both electron transport and electron injection skills.

[0188] To further describe the present invention, the following more specific device embodiments are listed.

[0189] Device Embodiment 1

[0190] The structure of the organic electroluminescent device is: ITO / NPB(20nm) / Red light host material: Ir(piq)3[10%](35nm) / TPBI(10nm) / Alq3(15nm) / LiF(0.5nm) / Al(150nm). Among them, "Ir(piq)3[10%]" refers to the doping ratio of the red light doping material, that is, the weight ratio of the red light host material to Ir(piq)3 is 100:10.

[0191]

[0192] The preparation process of the organic electroluminescent device is as follows:

[0193] The glass plate coated with the ITO transparent conductive layer is ultrasonically treated in a commercial cleaning agent, rinsed in deionized water, ultrasonically degreased in a mixed solvent of acetone: ethanol, baked in a clean environment until all moisture is completely removed, cleaned with ultraviolet light and ozone, and bombarded with a low-energy cation beam on the surface.

[0194] Place the above-mentioned glass substrate with the anode in a vacuum chamber, evacuate to 1×10 -5 ~9×10 -3 Pa, and vacuum deposit the hole transport layer NPB on the above anode layer film at a deposition rate of 0.1nm / s and a deposited film thickness of 20nm.

[0195] On top of the hole transport layer, the red light host material L001 and the dopant material Ir(piq)3 are vacuum-evaporated as the light-emitting layer of the organic light-emitting device at an evaporation rate of 0.1 nm / s and a total evaporation film thickness of 35 nm;

[0196] On top of the light-emitting layer, the electron transport layers TPBI and Alq3 are successively vacuum-evaporated at an evaporation rate of 0.1 nm / s, and the evaporation film thicknesses are 10 nm and 15 nm, respectively.

[0197] On top of the electron transport layer, 0.5 nm of LiF and 150 nm of Al are vacuum-evaporated as the electron injection layer and the cathode.

[0198] All the organic light-emitting devices are prepared by the above method, and the only difference lies in the selection of the red light host material.

[0199] The brightness, driving voltage, current efficiency, and lifetime test T95 of the prepared organic light-emitting devices were measured. Among them, the lifetime test T95 refers to the time required for the brightness to decrease to 95% of the initial brightness while maintaining the current density at the initial brightness constant (here it is 1000 cd / m2) at room temperature (25 - 27 °C).

[0200] Device Examples 2 - Device Example 20

[0201] Referring to the preparation method provided in Device Example 1 above, the light-emitting compound L001 used in Device Example 1 was replaced with the light-emitting compounds represented by Formula L011, L021, L025, L037, L065, L074, L082, L085, L097, L101, L109, L111, L155, L167, L173, L188, L191, L203, L212 provided in the above examples as the host material and mixed with the dopant material for evaporation coating, and the corresponding organic light-emitting devices were prepared.

[0202] Device Comparative Example 1

[0203] This device comparative example fabricated an organic light-emitting device. Specifically, according to the preparation method of Device Example 1, the compound L001 used in Device Example 1 was replaced with D-1 and D-2 as the host material and mixed with the dopant material for evaporation coating, and the corresponding organic light-emitting devices were prepared. Among them, the structural formulas of D-1 and D-2 are:

[0204]

[0205] At a brightness of 1000 cd / m 2Under the conditions described above, the organic electroluminescent devices obtained from Device Examples 1 to 20 and Device Comparative Examples 1 and 2 were subjected to luminescence performance testing. A KEITHLEY 2400 measurement unit and a CS-2000 spectro-radiance meter were used to test the driving voltage, lifespan, and luminescence efficiency. The test results are shown in Table 2:

[0206] Table 2

[0207]

[0208]

[0209] As can be seen from Table 2, when the compound provided in the embodiments of the present invention is used as the host material of the light-emitting layer of the organic electroluminescent device, compared with the existing host materials used, the driving voltage of the organic electroluminescent device can be significantly reduced, and the luminescence efficiency and service life of the organic electroluminescent device can be improved.

[0210] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An organic electroluminescent material, characterized in that, It has the structure shown in general formula I: The general formula 1 is specifically selected from the following structures:

2. A preparation method of the organic electroluminescent material as described in claim 1, characterized in that, The method specifically comprises the following steps: (1) Under nitrogen protection, raw material A, raw material B, cuprous iodide, o-phenanthroline, potassium hydroxide, and xylene are added to a reaction flask, and the temperature is raised to 70° C. for reaction. After the reaction is completed, the temperature is cooled and purified by column chromatography to obtain an intermediate compound L-1; (2) Under nitrogen protection, raw material C, raw material D, and potassium acetate were added to a reaction flask, and solvent 1,4-dioxane, tris(dibenzylideneacetone)dipalladium and X-phos were added, and the temperature was raised to 100° C. for reaction. After the reaction was completed, the temperature was lowered to room temperature, and the intermediate compound L-2 was purified by column chromatography; (3) Under nitrogen protection, compound L-1, compound L-2, potassium carbonate, tetrakis(triphenylphosphine)palladium, toluene, ethanol, and water were added to a reaction flask, and the temperature was raised to 90° C. for reaction. After the reaction was completed, the mixture was cooled to room temperature, and the intermediate L was purified by column chromatography; (4) Under nitrogen protection, the intermediate L, the raw material E and sodium tert-butoxide are mixed, added to a solvent of toluene, tri(dibenzylideneacetone)bispalladium and tri-tert-butylphosphine are added, and the mixture is heated to 120° C. for reaction. After the reaction is completed, the mixture is purified by column chromatography and concentrated by rotary evaporation to obtain the general formula I; The specific synthetic route is as follows:

3. Use of the organic electroluminescent material according to claim 1 or the organic electroluminescent material prepared by the method according to claim 2 in an organic electroluminescent device.

4. The application according to claim 3, characterized in that The organic electroluminescent device comprises a first electrode, a second electrode and at least one organic layer disposed between the first electrode and the second electrode; wherein: The organic layer contains the organic electroluminescent material.

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