Electroluminescent material and applications

Abstract

The application belongs to the technical field of organic electronic devices, and particularly discloses an electroluminescent material, and also relates to application of the electroluminescent material in an electroluminescent device. The electroluminescent material provided by the application uses a first compound with a H-L-Ar structure and a second compound with a structure shown in a general formula (II), and the first compound and the second compound are used in combination, and are used in a light-emitting layer of an electroluminescent device, so that the electroluminescent device has lower voltage, higher efficiency and longer service life, and the performance of the device is improved.

Description

Technical Field

[0001] This invention relates to the field of organic electronic device technology, specifically disclosing an electroluminescent material and its application in electroluminescent devices. Background Technology

[0002] Organic electronic devices include, but are not limited to, the following: organic light-emitting diodes (OLEDs), organic field-effect transistors (O-FETs), organic light-emitting transistors (OLETs), organic photovoltaic devices (COPVs), dye-sensitized solar cells (DSSCs), organic optical detectors, organic photoreceptors, organic field-effect devices (OFQDs), light-emitting electrochemical cells (LEGS), organic laser diodes, and organic plasma light-emitting devices. In 1987, Tang et al. of Eastman Kodak first reported a green electroluminescent device made of a double-layer organic thin film. The device used indium tin oxide (ITO) as the anode, and deposited a 75 nm thick amorphous, pinhole-free aromatic diamine film on the anode for hole transport. Then, a 60 nm thick 8-hydroxyquinoline aluminum film was deposited on the aromatic diamine film as both an electron transport layer and a light-emitting layer. A magnesium-silver alloy was used as the cathode. This double-layer film structure successfully reduced the turn-on voltage to 5.5 V and achieved high emissivity (>1000 cd·m³). -2 With a wavelength of 550 nm and an external quantum efficiency of 1.0%, it has great practical significance. In 1994, Kido et al. in Japan first fabricated an organic electroluminescent device that emits white light. They doped three fluorescent dyes of blue, green, and orange into a poly(N-vinylcarbazole) (PVK) film as a hole transport layer and emission layer, used a 1,2,4-triazole derivative (TAZ) as a hole blocking layer, and 8-hydroxyquinoline aluminum (Alq3) as an electron transport layer. The device was composed of a multilayer structure of glass substrate / ITO / PVK / TAZ / Alq3 / Mg:Ag. Under a driving voltage of 14V, they achieved a wide coverage of the visible light region and a brightness of up to 3400 cd·m. -2 The high-brightness white light emission is achieved by doping a polymer film with fluorescent compounds of various colors to form a single light-emitting layer. This discovery by Kido et al. adds a significant chapter to the application of organic electroluminescence, opens the door to the field of lighting for organic light-emitting devices, and promotes the further development of organic light-emitting devices.

[0003] Organic light-emitting devices emit light in two forms: fluorescence and phosphorescence. Fluorescence is emitted using the energy of singlet excitons, while phosphorescence is emitted using the energy of both singlet and triplet excitons. Because the ratio of singlet to triplet excitons is fixed at 1:3, theoretically, the internal quantum efficiency of fluorescent devices using only singlet excitons is at most 25%, while the internal quantum efficiency of phosphorescent devices can reach 100%.

[0004] Currently, organometallic complexes and organic electroluminescent devices with phosphorescence emission have been reported, but in many applications such as TVs and lighting equipment, the lifetime of OLEDs is insufficient, and higher efficiency OLEDs are still needed. Typically, the higher the brightness of an OLED, the shorter its lifetime. Therefore, for long-term use and high-resolution displays, OLEDs with high luminous efficiency and long lifetimes are required.

[0005] For the development of phosphorescent OLEDs, selecting suitable host materials and phosphorescent emitting materials for combined use is an important and widespread research direction. However, the performance of devices using combinations of host materials and phosphorescent emitting materials reported so far still has room for improvement. To meet the industry's ever-increasing demands, selecting suitable host materials and phosphorescent emitting materials for combined use is a relatively efficient R&D approach, and new material combinations still require further research and development. Summary of the Invention

[0006] The purpose of this invention is to develop an electroluminescent material that uses a first compound having an HL-Ar structure and a second compound having the structure shown in general formula (II). By using the combination of the first and second compounds in the light-emitting layer of an electroluminescent device, the electroluminescent device can achieve lower voltage, higher efficiency and longer lifespan, thereby improving the device's performance.

[0007] Specifically, in a first aspect, the present invention provides an electroluminescent material, comprising:

[0008] (i) First compound: has an HL-Ar structure;

[0009] (ii) Second compound: having the structure shown in general formula (II);

[0010]

[0011] Wherein, H represents the structure shown in general formula (I):

[0012]

[0013] Ring 1 and ring 2 are independently selected from carbon rings having 6-18 carbon atoms and heterocyclic rings having 3-18 carbon atoms; ring 1 and ring 2 may have substituents or be unsubstituents, and when substituents are present, the number of substituents is 1-4; the substituents are selected from deuterium, halogens, substituted or unsubstituted alkyl groups having 1-20 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3-20 carbon atoms, substituted or unsubstituted heteroalkyl groups having 1-20 carbon atoms, substituted or unsubstituted heterocyclic alkyl groups having 3-20 carbon atoms, substituted or unsubstituted aralkyl groups having 7-30 carbon atoms, substituted or unsubstituted alkoxy groups having 1-20 carbon atoms, and substituted or unsubstituted... The following groups are included: substituted aryloxy groups having 6-30 carbon atoms; substituted or unsubstituted alkenyl groups having 2-20 carbon atoms; substituted or unsubstituted alkynyl groups having 2-20 carbon atoms; substituted or unsubstituted aryl groups having 6-30 carbon atoms; substituted or unsubstituted heteroaryl groups having 3-30 carbon atoms; substituted or unsubstituted alkylsilyl groups having 3-20 carbon atoms; substituted or unsubstituted arylsilyl groups having 6-20 carbon atoms; and substituted or unsubstituted groups having 0-20 carbon atoms and containing one or more of the following groups: amino, acyl, carbonyl, carboxylic acid, ester, cyano, isocyano, hydroxyl, mercapto, sulfinyl, sulfonyl, or phosphine.

[0014] A 1 A 2 A 3 A 4 Each is independently selected from N and CR;

[0015] A 5 A 6 A 7 Each is independently selected from N, CR, and Y, with one of them being Y; Y is selected from O, S, Se, and NR. N CR a R b and SiR a R b ;

[0016] L is selected from single-bonded, substituted or unsubstituted aryl groups with 6-30 carbon atoms, and substituted or unsubstituted heteroaryl groups with 3-30 carbon atoms;

[0017] Ar, R, R N R a R bEach is independently selected from H, deuterium, halogen, substituted or unsubstituted alkyl groups having 1-20 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3-20 carbon atoms, substituted or unsubstituted heteroalkyl groups having 1-20 carbon atoms, substituted or unsubstituted heterocycloalkyl groups having 3-20 carbon atoms, substituted or unsubstituted aralkyl groups having 7-30 carbon atoms, substituted or unsubstituted alkoxy groups having 1-20 carbon atoms, substituted or unsubstituted aryloxy groups having 6-30 carbon atoms, and substituted or unsubstituted groups having 2-20 carbon atoms. Alkenyl, substituted or unsubstituted alkynyl with 2-20 carbon atoms, substituted or unsubstituted aryl with 6-30 carbon atoms, substituted or unsubstituted heteroaryl with 3-30 carbon atoms, substituted or unsubstituted alksilyl with 3-20 carbon atoms, substituted or unsubstituted arylsilyl with 6-20 carbon atoms, and substituted or unsubstituted groups containing one or more of amino, acyl, carbonyl, carboxylic acid, ester, cyano, isocyano, hydroxyl, mercapto, sulfinyl, sulfonyl or phosphine with 0-20 carbon atoms.

[0018] Or, A 1 A 2 A 3 A 4 Adjacent substituents can be bridged to form a fused ring structure; and / or, A 5 A 6 A 7 Adjacent substituents on ring 1 and ring 2 can be bridged to form a fused ring structure; and / or, adjacent substituents on ring 1 and ring 2 can be bridged to form a fused ring structure; the fused ring structure may have substituents or no substituents;

[0019] In general formula (II), M is selected from metals with a relative atomic mass greater than 40;

[0020] L' is selected from the group shown in formula L'1 or formula L'2:

[0021]

[0022] in:

[0023] R 100 ~R 103 Each of these can independently represent H, deuterium, halogen, cyano, substituted or unsubstituted alkyl or alkoxy groups having 1-30 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3-30 carbon atoms, substituted or unsubstituted aryl groups having 6-30 carbon atoms, or substituted or unsubstituted heteroaryl groups having 3-30 carbon atoms; or, R 100 ~R 103The adjacent groups can be linked to form a ring and a fused ring structure with the pyridine ring. The fused ring structure is selected from substituted or unsubstituted quinolinyl, substituted or unsubstituted benzofuranopyridyl, substituted or unsubstituted benzothiophenopyridyl, substituted or unsubstituted indenepyridyl, substituted or unsubstituted benzofuranoquinolinyl, substituted or unsubstituted benzothiophenoquinolinyl, and substituted or unsubstituted indenequinolinyl.

[0024] R 104 ~R 107 Each of these can independently represent H, deuterium, halogen, cyano, substituted or unsubstituted alkyl or alkoxy groups having 1-30 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3-30 carbon atoms, substituted or unsubstituted aryl groups having 6-30 carbon atoms, or substituted or unsubstituted heteroaryl groups having 3-30 carbon atoms; or, R 104 ~R 107 The adjacent groups can be linked to form a ring and form a fused structure with the benzene ring. The fused ring structure is selected from substituted or unsubstituted naphthyl, substituted or unsubstituted fluorenyl, substituted or unsubstituted dibenzothiophene, substituted or unsubstituted dibenzofuran, substituted or unsubstituted indopyridyl, substituted or unsubstituted benzofuranopyridyl, and substituted or unsubstituted benzothiophenopyridyl.

[0025] R 201 ~R 211 Each of these can independently represent H, deuterium, halogen, substituted or unsubstituted alkyl group having 1-30 carbon atoms, substituted or unsubstituted cycloalkyl group having 3-30 carbon atoms, or substituted or unsubstituted aryl group having 6-30 carbon atoms; or, R 201 ~R 211 Adjacent groups can be linked to form a ring, which is a five-membered or six-membered ring containing or without heteroatoms;

[0026] n' represents the integer 1, 2, or 3.

[0027] In a preferred embodiment of the present invention, H has the structure shown in general formula (I-1):

[0028]

[0029] Among them, A 1 A 2 A 3 A 4 A 8 A 9 A 10 A 11 A 12 Each is independently selected from N and CR;

[0030] A 5 A6 A 7 Each is independently selected from N, CR, and Y, with one of them being Y; Y is selected from O, S, Se, and NR. N CR a R b and SiR a R b ; Specifically, when A 5 When A is Y, it is as shown in Equation 3-2. 6 When A is Y, it is as shown in Equation 3-1. 7 When the value is Y, it is as shown in Equation 3-3:

[0031]

[0032] Among them, R, R N R a R b Each is independently selected from H, deuterium, halogen, substituted or unsubstituted alkyl groups having 1-20 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3-20 carbon atoms, substituted or unsubstituted heteroalkyl groups having 1-20 carbon atoms, substituted or unsubstituted heterocycloalkyl groups having 3-20 carbon atoms, substituted or unsubstituted aralkyl groups having 7-30 carbon atoms, substituted or unsubstituted alkoxy groups having 1-20 carbon atoms, substituted or unsubstituted aryloxy groups having 6-30 carbon atoms, and substituted or unsubstituted groups having 2-20 carbon atoms. Alkenyl, substituted or unsubstituted alkynyl with 2-20 carbon atoms, substituted or unsubstituted aryl with 6-30 carbon atoms, substituted or unsubstituted heteroaryl with 3-30 carbon atoms, substituted or unsubstituted alksilyl with 3-20 carbon atoms, substituted or unsubstituted arylsilyl with 6-20 carbon atoms, and substituted or unsubstituted groups containing one or more of amino, acyl, carbonyl, carboxylic acid, ester, cyano, isocyano, hydroxyl, mercapto, sulfinyl, sulfonyl or phosphine with 0-20 carbon atoms.

[0033] Or, A 1 A 2 A 3 A 4 Adjacent substituents can be bridged to form a fused ring structure; and / or, A 5 A 6 A 7 Adjacent substituents can be bridged to form a fused ring structure; and / or, A 8 A 9 A 10 Adjacent substituents can be bridged to form a fused ring structure; and / or, A 11 A 12 They can be bridged together to form a ring structure.

[0034] In a more preferred embodiment of the present invention, H is selected from any of the structures shown below H-1 to H-215:

[0035]

[0036]

[0037]

[0038]

[0039]

[0040]

[0041]

[0042]

[0043]

[0044]

[0045] In this context, "*" indicates the bond position between the group and L.

[0046] In a preferred embodiment of the present invention, L is selected from single bonds, substituted or unsubstituted phenylene, substituted or unsubstituted naphthylene, substituted or unsubstituted biphenylene, substituted or unsubstituted terphenylene, substituted or unsubstituted pyridylene, substituted or unsubstituted pyrimidinylene, substituted or unsubstituted pyrazinylene, substituted or unsubstituted furanylene, substituted or unsubstituted thiopheneylene, substituted or unsubstituted dibenzofuranylene, and substituted or unsubstituted dibenzothiopheneylene.

[0047] More preferably, the L is selected from single bond, phenylene, naphthylene, biphenylene, pyridylene, quinolinylene, pyrimidinylene, phenyl-substituted pyrimidinylene, quinazolinylene, pyrazinylene, quinoxalinylene, dibenzofuranylene, dibenzothiopheneylene, furanylene, thiopheneylene, triphenylene, and terphenylene.

[0048] More preferably, the L is selected from any of the structures shown in L-0 to L-50, wherein the H in the structures shown in L-0 to L-50 can be partially or completely replaced by deuterium atoms:

[0049]

[0050]

[0051] In this context, "*" indicates the bond position between the group and H. This indicates the bonding position between the group and Ar.

[0052] In a preferred embodiment of the present invention, the Ar is selected from H, deuterium, halogens, substituted or unsubstituted alkyl groups having 1-10 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3-10 carbon atoms, substituted or unsubstituted heteroalkyl groups having 1-10 carbon atoms, substituted or unsubstituted heterocycloalkyl groups having 3-10 carbon atoms, substituted or unsubstituted aralkyl groups having 7-20 carbon atoms, substituted or unsubstituted alkoxy groups having 1-10 carbon atoms, and substituted or unsubstituted... Aryloxy groups having 6-20 carbon atoms, substituted or unsubstituted alkenyl groups having 2-10 carbon atoms, substituted or unsubstituted alkynyl groups having 2-10 carbon atoms, substituted or unsubstituted aryl groups having 6-20 carbon atoms, substituted or unsubstituted heteroaryl groups having 3-20 carbon atoms, substituted or unsubstituted alkoxyl groups having 3-10 carbon atoms, substituted or unsubstituted arylsilyl groups having 6-10 carbon atoms, and substituted or unsubstituted amino groups having 0-10 carbon atoms.

[0053] Preferably, the Ar is selected from H, deuterium, substituted or unsubstituted phenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted biphenyl, substituted or unsubstituted triphenyl, substituted or unsubstituted triazine, substituted or unsubstituted pyrimidinyl, substituted or unsubstituted quinazolinyl, substituted or unsubstituted benzoquinazolinyl, substituted or unsubstituted quinoxalinyl, substituted or unsubstituted benzoquinoxalinyl, substituted or unsubstituted quinolinyl, substituted or unsubstituted benzoquinoxalinyl, substituted or unsubstituted isoquinoline. , substituted or unsubstituted benzoisoquinoline, substituted or unsubstituted triazolyl, substituted or unsubstituted pyrazolyl, substituted or unsubstituted benzopyrazolyl, substituted or unsubstituted imidazolyl, substituted or unsubstituted benzoimidazolyl, substituted or unsubstituted oxazolyl, substituted or unsubstituted benzooxazolyl, substituted or unsubstituted thiazolyl, substituted or unsubstituted benzothiazolyl, substituted or unsubstituted dibenzothiophene, substituted or unsubstituted benzothiophene, substituted or unsubstituted dibenzofuranyl, substituted or unsubstituted benzofuranyl.

[0054] More preferably, the Ar is selected from any of the structures shown in Ar-1 to Ar-106, wherein the H in the structures shown in Ar-1 to Ar-106 can be partially or completely replaced by deuterium atoms:

[0055]

[0056]

[0057]

[0058]

[0059]

[0060] in, This indicates the bonding position between the group and L.

[0061] In a preferred embodiment of the present invention, in the first compound HL-Ar, H is selected from the group consisting of structures numbered H-1 to H-215, L is selected from the group consisting of structures numbered L-0 to L-50, and Ar is selected from the group consisting of structures numbered Ar-1 to Ar-106.

[0062] Alternatively, H can be selected from the group consisting of structures numbered H-1 to H-215, L can be selected from the group consisting of structures numbered L-0 to L-50, and Ar can be selected from the group consisting of structures numbered Ar-1 to Ar-106, and the hydrogen in the HL-Ar structure can be partially or completely replaced by deuterium.

[0063] As a more preferred embodiment of the present invention, the first compound HL-Ar is selected from any of the compounds listed in the table below, or compounds formed by replacing all or part of the H in the compounds listed below with deuterium:

[0064]

[0065]

[0066]

[0067]

[0068]

[0069]

[0070]

[0071]

[0072]

[0073]

[0074]

[0075]

[0076] The first compound shown above, numbered C1 to C963, has an HL-Ar structure, wherein H, L, and Ar are as follows:

[0077] For compounds C1 to C215, L is L-0, Ar is Ar-1, and H corresponds to H-1 to H-215 respectively;

[0078] For compounds C216 to C225, L is L-0, Ar is Ar-24, and H corresponds to H-1 to H-10 respectively;

[0079] The compound is C226, where H is H-10, L is L-3, and Ar is Ar-24;

[0080] The compound is C227, where H is H-11, L is L-3, and Ar is Ar-24;

[0081] In compounds C228 to C432, L is L-0, Ar is Ar-24, and H corresponds to H-11 to H-215 respectively;

[0082] For compounds C433 to C647, L is L-1, Ar is Ar-97, and H corresponds to H-1 to H-215 respectively;

[0083] In compounds C648 to C658, L is L-0, H is H-2, and Ar corresponds to Ar-2 to Ar-12, respectively.

[0084] Compound C659, H is H-2, L is L-3, Ar is Ar-12;

[0085] Compound C660, H is H-2, L is L-0, Ar is Ar-13;

[0086] Compound C661, where H is H-2, L is L-3, and Ar is Ar-13;

[0087] In compounds C662 to C753, L is L-0, H is H-2, and Ar corresponds to Ar-14 to Ar-106 (excluding Ar-24), respectively.

[0088] In compounds C754 to C858, L is L-1, H is H-82, and Ar corresponds to Ar-1 to Ar-106 (excluding Ar-97), respectively.

[0089] In compounds C859 to C963, L is L-1, H is H-160, and Ar corresponds to Ar-1 to Ar-106 (excluding Ar-97).

[0090] In a preferred embodiment of the present invention, in the general formula (II), M is selected from Ir, Rh, Re, Os, Pt, Au, Cu; preferably, M is selected from Ir, Os, Pt; more preferably, M is Ir.

[0091] More preferably, the second compound is selected from compounds with the following structures:

[0092]

[0093]

[0094]

[0095]

[0096] Secondly, the present invention provides the application of the electroluminescent material in electroluminescent devices.

[0097] Preferably, the electroluminescent material is used in the organic layer of the electroluminescent device.

[0098] More preferably, the electroluminescent material is used in the light-emitting layer of the electroluminescent device.

[0099] Thirdly, in the application described in this invention, the first compound is the host material of the light-emitting layer, and the second compound is a light-emitting material.

[0100] Preferably, the mass ratio of the first compound to the second compound is (80-99):(1-20), more preferably (90-99):(1-10), even more preferably (95-99):(1-5), and more preferably (97-99):(1-3), for example 97:3, 98:2, or 99:1.

[0101] Fourthly, the present invention provides an electroluminescent device comprising the electroluminescent material described above.

[0102] The electroluminescent device includes an anode, a cathode, and an organic layer disposed between the anode and the cathode. Preferably, the organic layer is a light-emitting layer, and the light-emitting layer includes the electroluminescent material, namely the first compound and the second compound.

[0103] Preferably, the electroluminescent device emits red or white light.

[0104] Fifthly, the present invention provides a display component including the electroluminescent device described above.

[0105] The novel electroluminescent material provided by this invention, using a first compound having an HL-Ar structure and a second compound having the general formula (II), can be used in the light-emitting layer of an electroluminescent device. This novel material combination enables the electroluminescent device to achieve lower voltage, higher efficiency, and longer lifetime, significantly improving device performance. Detailed Implementation

[0106] The technical solution of the present invention will be described in detail below.

[0107] It should be understood that when a molecular segment is described as a substituent or otherwise attached to another part, its name may be written according to whether it is a segment (e.g., phenyl, phenylene, naphthyl, dibenzofuranyl) or according to whether it is a whole molecule (e.g., benzene, naphthalene, dibenzofuran). As used herein, these different ways of specifying substituents or attaching segments are considered equivalent.

[0108] In the compounds mentioned in this disclosure, hydrogen atoms can be partially or completely replaced by deuterium. Other atoms such as carbon and nitrogen can also be replaced by their other stable isotopes. Substitution with other stable isotopes in the compounds is likely preferred due to their ability to enhance device efficiency and stability.

[0109] In the compounds mentioned in this disclosure, multiple substitution refers to the range including disubstitution, up to the maximum number of available substitutions. When a substituent in a compound mentioned in this disclosure represents multiple substitution (including disubstitution, trisubstitution, tetrasubstitution, etc.), it means that the substituent can be present at multiple available substitution positions on its linkage structure. The substituent present at multiple available substitution positions can be the same structure or different structures.

[0110] In the compounds mentioned in this disclosure, unless explicitly specified, for example, that adjacent substituents can optionally connect to form a ring, adjacent substituents in the compounds cannot connect to form a ring. In the compounds mentioned in this disclosure, the optional connection of adjacent substituents to form a ring includes both cases where adjacent substituents can connect to form a ring and cases where adjacent substituents do not connect to form a ring. When adjacent substituents can optionally connect to form a ring, the resulting ring can be a monocyclic or polycyclic ring, and can be an alicyclic, heterocyclic, aromatic, or heteroaromatic ring. In this context, adjacent substituents can refer to substituents bonded to the same atom, substituents bonded to carbon atoms directly bonded to each other, or substituents bonded to carbon atoms further away. Preferably, adjacent substituents refer to substituents bonded to the same carbon atom and substituents bonded to carbon atoms directly bonded to each other.

[0111] The statement that adjacent substituents can optionally connect to form a ring is also intended to be understood as referring to two substituents bonded to the same carbon atom connecting to each other via chemical bonds to form a ring, as exemplified by the following formula:

[0112]

[0113] The statement that adjacent substituents can optionally link to form a ring is also intended to be understood as referring to two substituents bonded to carbon atoms directly bonded to each other forming a ring through chemical bonds, as exemplified by the following formula:

[0114]

[0115] Furthermore, the statement that adjacent substituents can optionally connect to form a ring is also intended to mean that, in the case where one of the two substituents bonded to the carbon atom directly bonded to each other represents hydrogen, the second substituent bonds at the position where the hydrogen atom is bonded, thereby forming a ring. This is illustrated by the following example:

[0116]

[0117] The technical solution of the present invention will be further described below through specific embodiments. These embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Any equivalent changes or modifications made without departing from the spirit of the invention should be included within the scope of the claims.

[0118] The preparation methods of the first and second compounds selected in this invention are not limited. Typical but not limited examples are the following compounds, whose synthetic routes and preparation methods are as follows.

[0119] Example 1: Synthesis of Compound C434

[0120]

[0121] The synthesis steps are as follows:

[0122] (1) Synthesis of C434-IM-1

[0123]

[0124] In a 1 L dry round-bottom flask, SM1 (16.7 g, 1.0 eq, 100 mmol), SM2 (26.4 g, 1.1 eq, 110 mmol), potassium carbonate (15.2 g, 1.1 eq, 110 mmol), and copper sulfate pentahydrate (1.25 g, 0.05 eq, 5 mmol) were added sequentially. The mixture was stirred, purged with nitrogen three times, and then heated to 250 °C for 2.5 hours. After the reaction was complete, the mixture was cooled to room temperature. The solid was dissolved in a mixture of dichloromethane and water. The mixture was separated, extracted with dichloromethane, and the organic phases were combined. The mixture was washed once with sodium chloride aqueous solution, dried over anhydrous magnesium sulfate, concentrated, and separated by column chromatography to obtain a grayish-white solid C434-IM-1 (15.0 g).

[0125] (2) Synthesis of C434-IM-2

[0126]

[0127] In a 1L dry round-bottom flask under nitrogen protection, C434-IM-1 (32.7g, 1.0eq, 100mmol) and 400mL of ultra-dry tetrahydrofuran were added sequentially. The mixture was cooled to -78℃, and then n-butyllithium (2.5M, 44mL, 1.1eq, 110mmol) was added dropwise. The reaction was continued at this temperature for 1 hour. Then, triisopropyl borate (28.3g, 1.5eq, 150mmol) was added, and the mixture was slowly heated to room temperature and reacted overnight. Then, a suitable amount of dilute hydrochloric acid was added, and the mixture was stirred for another hour. Then, a suitable amount of water was added, and the mixture was extracted with ethyl acetate to separate the organic phase. The organic phase was dried with anhydrous magnesium sulfate, concentrated, and then slurried with a suitable amount of n-heptane. The mixture was filtered to obtain a creamy white solid intermediate C434-IM-2 (21.4g).

[0128] (3) Synthesis of C434-IM-3

[0129]

[0130] In a 1 L dry round-bottom flask, C434-IM-2 (14.65 g, 1.0 eq, 50 mmol), SM3 (11.7 g, 1.0 eq, 50 mmol), potassium carbonate (17.25 g, 2.5 eq, 125 mmol), and tetraphenylphosphine palladium (1.7 g, 0.03 eq, 1.5 mmol) were added sequentially. Nitrogen gas was purged three times. Under nitrogen protection, 400 mL of toluene, 40 mL of ethanol, and 40 mL of water were added, and the mixture was heated to 95 °C and reacted for 24 hours. After the reaction was complete, the mixture was cooled to room temperature, extracted with ethyl acetate, and the organic phase was separated. The organic phase was dried over anhydrous magnesium sulfate, concentrated, and separated by column chromatography to obtain a yellow solid intermediate, C434-IM-3 (13.1 g).

[0131] (4) Synthesis of C434-IM-4

[0132]

[0133] In a 1 L dry round-bottom flask under nitrogen protection, C434-IM-3 (20.2 g, 1.0 eq, 50 mmol), cesium carbonate (48.9 g, 3.0 eq, 150 mmol), palladium acetate (561 mg, 0.05 eq, 2.5 mmol), tricyclohexylphosphine tetrafluoroborate (1.84 g, 0.1 eq, 2.858 mmol), and 400 mL of xylene were added sequentially. The mixture was heated to 150 °C and reacted for 24 hours. After the reaction was complete, the mixture was cooled to room temperature, filtered through diatomaceous earth, and the diatomaceous earth was washed with an appropriate amount of dichloromethane. The filtrate was concentrated and separated by column chromatography to obtain a yellow solid intermediate, C434-IM-4 (15.1 g).

[0134] (5) Synthesis of C434-IM-5

[0135]

[0136] In a dry 1L round-bottom flask under nitrogen protection, C434-IM-4 (18.4 g, 1.0 eq, 50 mmol), triphenylphosphine (39.4 g, 3.0 eq, 150 mmol), and 400 mL of o-dichlorobenzene were added sequentially. The mixture was heated to 150 °C and reacted for 12 hours. After the reaction was complete, the solvent was removed by concentration under reduced pressure, and the solution was separated by column chromatography to obtain a yellow solid intermediate, C434-IM-5 (11.9 g).

[0137] (6) Synthesis of C434

[0138]

[0139] In a 1L dry round-bottom flask under nitrogen protection, C434-IM-5 (16.8g, 1.0eq, 50mmol), SM4 (19.6g, 1.2eq, 60mmol), cesium carbonate (32.6g, 2.0eq, 100mmol), and 400mL of N,N-dimethylacetamide were added sequentially. The mixture was heated to 150℃ and reacted for 12 hours. After the reaction was complete, the mixture was cooled to room temperature, and a suitable amount of water was added dropwise. A large amount of yellow solid precipitated. The crude product was filtered off and separated by column chromatography to obtain yellow solid C434 (21.9g).

[0140] Product MS (m / e): 643.66; Elemental analysis (C) 43 H 25 N5S): Theoretical values: C: 80.23%, H: 3.91%, N: 10.88%; Measured values: C: 80.31%, H: 3.95%, N: 10.76%.

[0141] Example 2: Synthesis of Compound C535

[0142]

[0143] Following the synthesis method of Example 1, SM2 (3,4-dibromothiophene) was replaced with 3-bromo-2-iodothiophene, and a suitable material ratio was selected. All other raw materials and steps were the same as in Example 1, and yellow solid C535 was prepared.

[0144] Product MS (m / e): 643.51; Elemental analysis (C) 43 H 25 N5S): Theoretical values: C: 80.23%, H: 3.91%, N: 10.88%; Measured values: C: 80.45%, H: 3.72%, N: 10.81%.

[0145] Example 3: Synthesis of Compound C589

[0146]

[0147] Following the synthesis method of Example 1, SM2 (3,4-dibromothiophene) was replaced with 2-bromo-3-iodothiophene, and a suitable material ratio was selected. All other raw materials and steps were the same as in Example 1, and yellow solid C589 was prepared.

[0148] Product MS (m / e): 643.34; Elemental analysis (C) 43 H 25 N5S): Theoretical values: C: 80.23%, H: 3.91%, N: 10.88%; Measured values: C: 80.35%, H: 3.83%, N: 10.68%.

[0149] Example 4: Synthesis of Compound P-23

[0150]

[0151] The synthesis route is as follows:

[0152]

[0153] The synthesis steps include:

[0154] (1) Synthesis of N-(3,5-dichlorobenzyl)-2,2-diethoxyethylamine: 49.4 g (284 mmol) of 3,5-dichlorobenzaldehyde, 37.8 g (284 mmol) of 2,2-diethoxyethylamine, and 270 mL of toluene were placed in a 500 mL three-necked flask. The mixture was heated to reflux under N2 protection for 24 hours, and the aqueous byproducts were collected using a Dean-Stark apparatus. After evaporation of the solvent, 82 g of a pale yellow liquid was obtained.

[0155] (2) Synthesis of 5,7-dichloroisoquinoline: Trifluoromethanesulfonic acid (15.4 g, 103 mmol) was loaded into a 100 mL three-necked flask equipped with a Dean-Stark apparatus and a feeding funnel. The trifluoromethanesulfonic acid was first heated to 120 °C, and N-(3,5-dichlorobenzylmethyl)-2,2-diethoxyethylamine (4 g, 13.78 mmol) dissolved in 4 mL of DCM was added dropwise to the acid. After the addition, the mixture was heated at 120 °C for 2 hours, then cooled to room temperature, and the reaction was quenched by adding 8 mL of MeOH. The reaction mixture was poured into an aqueous solution of ammonium hydroxide (120 mmol), prepared to be alkaline with another aqueous solution of ammonium hydroxide, and stirred and filtered. Distillation yielded a white solid (2.1 g).

[0156] (3) Synthesis of 5,7-diisobutylisoquinoline: 5,7-dichloroisoquinoline (5.8 g, 29.3 mmol), isobutylboronic acid (8.96 g, 88 mmol), dicyclohexyl(2,6-dimethoxy-[11-biphenyl]-2-yl)phosphine (0.962 g, 2.34 mmol), Pd2(dba)3 (0.536 g, 0.586 mmol), K3PO4 (21.8 g, 103 mmol), 150 mL toluene, and 15 mL water were placed in a flask. The reaction mixture was purified by bubbling with N2 for 30 minutes, followed by heating to reflux overnight. Upon completion of the reaction, 6.7 g of product was obtained by silica gel chromatography using 15% ethyl acetate (v / v) in hexane as the eluent.

[0157] (4) Synthesis of 1-(3,5-dimethylphenyl)-5,7-diisobutylisoquinoline: 5,7-diisobutylisoquinoline (7.4 g, 30.7 mmol) in 50 mL of anhydrous THF was added dropwise to (3,5-dimethylphenyl)magnesium bromide (100 mL, 50.0 mmol) at room temperature and stirred for 16 hours. The reaction mixture was then heated to reflux for 5 hours. GC and HPLC analysis indicated that the reaction was complete, but contained a small amount of reduction byproducts. These byproducts were converted to the desired product by treatment with DDQ in THF. 6.5 g of product was obtained after water treatment.

[0158] (5) Synthesis of 1-(3,5-dimethylphenyl)-5,7-diisobutylisoquinoline iridium dimer: 1-(3,5-dimethylphenyl)-5,7-diisobutylisoquinoline (6.0 g, 17.37 mmol), IrCl3·H2O (2.57 g, 6.95 mmol), 90 mL of 2-ethoxyethanol, and 30 mL of water were placed in a 250 mL flask. The reaction mixture was heated to reflux for 19 hours under nitrogen protection. After filtration and washing with methanol, 4.6 g of 1-(3,5-dimethylphenyl)-5,7-diisobutylisoquinoline iridium dimer was obtained, which could be used in the next step without further purification.

[0159] (6) Synthesis of compound P-23: 1-(3,5-dimethylphenyl)-5,7-diisobutylisoquinoline iridium dimer (1.5 g, 0.82 mmol), 2,4-pentanedione (1.63 g, 16.36 mmol), Na₂CO₃ (1.73 g, 16.36 mmol), and 2-ethoxyethanol (60 mL) synthesized in step (5) were placed in a 250 °C flask and stirred at room temperature for 72 hours. The resulting precipitate was filtered and washed with methanol. Further purification was achieved by passing the solid through a silica gel stopper (pretreated with 15% triethylamine in hexane). 0.68 g of the product was obtained after this treatment.

[0160] Product MS (m / e): 980.23; Elemental analysis (C) 55 H 67 IrN2O2): Theoretical values: C: 67.38%, H: 6.89%, N: 2.86%; Measured values: C: 67.42%, H: 6.72%, N: 2.63%.

[0161] Example 5: Synthesis of the second compound P-54

[0162]

[0163] The synthesis route is as follows:

[0164]

[0165] The synthesis steps include:

[0166] (1) Synthesis of 4-chloro-2-methylbenzoyl chloride: Oxaloyl chloride (26.8 g, 258 mmol) was added dropwise to a mixture of 4-chloro-2-methylbenzoic acid (24.0 g, 141 mmol) in dichloromethane (20 mL) and dimethylformamide (4 mL) at room temperature. The reaction was stirred at room temperature for 2 hours. Hexane was added and the reaction mixture was concentrated to give 4-chloro-2-methylbenzoyl chloride (26.6 g), which was used directly in the next step without purification.

[0167] (2) Synthesis of 4-chloro-2-methylbenzamide: 30% ammonium hydroxide (300 mL, 4.76 mol) was cooled in a salt ice bath. 4-chloro-2-methylbenzoyl chloride (26.4 g, 140 mmol) in tetrahydrofuran (150 mL) was added and stirred for 1 hour. Water was added. The crystals were filtered off and washed with water, then dried under vacuum to obtain 4-chloro-2-methylbenzamide (20.0 g).

[0168] (3) Synthesis of 4-chloro-N-((dimethylamino)methylene)-2-methylbenzamide: A mixture of 4-chloro-2-methylbenzamide (20.8 g, 123 mmol) and 1,1-dimethylmethylamine (17.5 g, 147 mmol) in tetrahydrofuran (250 mL) was refluxed for 2.5 h and then concentrated. The resulting crystals were ground in hexane and filtered to give 4-chloro-N-((dimethylamino)methylene)-2-methylbenzamide (25.7 g).

[0169] (4) Synthesis of 6-chloroisoquinoline-1-ol: A mixture of 4-chloro-N-((dimethylamino)methylene)-2-methylbenzamide (25.7 g, 114 mmol), sodium tert-butoxide (25.7 g, 267 mmol), and tetrahydrofuran (450 mL) was refluxed under N2 for 3 hours and then poured into water (1 L). The pH was adjusted to 4 with an aqueous HCl solution. The solid was filtered off, washed with water, and dried under vacuum to give 6-chloroisoquinoline-1-ol (14.7 g).

[0170] (5) Synthesis of 4,6-dichloroisoquinoline-1-ol: A mixture of 6-chloroisoquinoline-1-ol (13.5 g, 75 mmol) and acetonitrile (400 mL) was heated to reflux. N-chlorosuccinimide (10.57 g, 79 mmol) was added dropwise to acetonitrile (110 mL). The mixture was refluxed overnight. Crystals were filtered off. The filtrate was concentrated, and the resulting crystals were washed with water, combined with the above crystals, and dried under vacuum to give 4,6-dichloroisoquinoline-1-ol (14.2 g). It was used directly in the next step.

[0171] (6) Synthesis of 4,6-dichloroisoquinoline-1-yl trifluoromethanesulfonic acid ester: A mixture of 14.2 g (66.5 mmol) of 4,6-dichloroisoquinoline-1-ol, 10.8 mL (133 mmol) of pyridine, and 200 mL of dichloromethane was cooled in an ice bath. Trifluoromethanesulfonic anhydride (22.4 mL, 133 mmol) was added dropwise. The mixture was stirred overnight at room temperature. Water was added and NaHCO3 (20 g) was added slowly. The organic layer was separated, dried over Na2SO4, concentrated, and rapidly separated by silica gel chromatography (hexane:dichloromethane 4:1, v / v) to obtain 4,6-dichloroisoquinoline-1-yl trifluoromethanesulfonic acid ester (37 g).

[0172] (7) Synthesis of 4,6-dichloro-1-(3,5-dimethylphenyl)isoquinoline: A mixture of 4,6-dichloroisoquinoline-1-yl trifluoromethanesulfonate (4.0 g, 11.6 mmol), 3,5-dimethylphenylboronic acid (1.6 g, 10.8 g), Pd(PPh3)4 (0.67 g, 0.58 mmol), potassium carbonate (4.79 g, 34.7 mmol), toluene (100 mL), and water (10 mL) was purified under nitrogen and refluxed overnight. The concentrated toluene layer was separated by silica gel chromatography (hexane:dichloromethane 2:1, v / v) to give 4,6-dichloro-1-(3,5-dimethylphenyl)isoquinoline (3.0 g).

[0173] (8) Synthesis of 1-(3,5-dimethylphenyl)-4,6-diisobutylisoquinoline: A mixture of 4,6-dichloro-1-(3,5-dimethylphenyl)isoquinoline (3.2 g, 10.59 mmol), isobutylboronic acid (4.32 g, 42.4 mmol), Pd2(dba)3 (0.388 g, 0.424 mmol), dicyclohexyl(2,6-dimethoxy-[1,1'-biphenyl-1-2-yl)phosphine (0.696 g, 1.694 mmol), K3PO4·H2O (24.38 g, 106 mmol), toluene (133 mL) and water (11 mL) was purified with nitrogen for 30 minutes and refluxed overnight. The toluene layer was separated by silica gel chromatography (100% dichloromethane to 4:1 dichloromethane: ethyl acetate, v / v) to give 1-(3,5-dimethylphenyl)-4,6-diisobutylisoquinoline (2.6 g).

[0174] (9) Synthesis of 1-(3,5-dimethylphenyl)-4,6-diisobutylisoquinoline iridium dimer: A mixture of 1-(3,5-dimethylphenyl)-4,6-diisobutylisoquinoline (3.3 g, 9.55 mmol), IrC13·3H2O (1.475 g, 3.98 mmol), 2-ethoxyethanol (45 mL) and water (15 mL) was refluxed overnight and then filtered and washed with methanol to give 1-(3,5-dimethylphenyl)-4,6-diisobutylisoquinoline iridium dimer (6.1 g).

[0175] (10) Synthesis of compound P-54: A mixture of 1-(3,5-dimethylphenyl)-4,6-diisobutylisoquinoline iridium dimer (0.8 g, 0.436 mmol), 3,7-diethylnonane-4,6-dione (0.925 g, 4.36 mmol), potassium carbonate (0.603 g, 4.36 mmol), and 2-ethoxyethanol (60 mL) was stirred overnight at room temperature, filtered, washed with methanol, and separated by chromatography on silica gel (hexane:chloromethane 4:1, v / v, silica gel pretreated with triethylamine). The residue was dissolved in dichloromethane and 2-propanol. Dichloromethane was removed on a rotary evaporator, and 0.42 g of product was obtained after filtration.

[0176] Product MS (m / e): 1092.45; Elemental analysis (C) 63 H 83 IrN2O2): Theoretical values: C: 69.26%, H: 7.66%, N: 2.56%; Measured values: C: 69.33%, H: 7.58%, N: 2.53%.

[0177] Example 6: Synthesis of the second compound P-58

[0178]

[0179] The synthesis route is as follows:

[0180]

[0181] The synthesis steps include:

[0182] (1) Synthesis of (Z)-1-(4-chlorophenyl)-N-(2,2-diethoxyethyl)methylimine: 39.8 g (284 mmol) of 4-chlorobenzaldehyde, 37.8 g (284 mmol) of 2,2-diethoxyethylamine, and 270 mL of toluene were placed in a 500 mL three-necked flask. The mixture was heated to reflux under N2 protection for 24 hours, and the aqueous byproducts were collected using a Dean-Stark apparatus. After evaporation of the solvent, 72.4 g of a pale yellow liquid was obtained.

[0183] (2) Synthesis of 6-chloroisoquinoline: Trifluoromethanesulfonic acid (15.4 g, 103 mmol) was loaded into a 100 mL three-necked flask equipped with a Dean-Stark apparatus and a feeding funnel. The trifluoromethanesulfonic acid was first heated to 120 °C, and (Z)-1-(4-chlorophenyl)-N-(2,2-diethoxyethyl)methylimine (3.5 g, 13.78 mmol) dissolved in 4 mL of LDCM was added dropwise to the acid. After the addition, the mixture was heated at 120 °C for 2 hours, then cooled to room temperature, and the reaction was quenched by adding 8 mL of MeOH. The reaction mixture was poured into an aqueous solution of ammonium hydroxide (120 mmol), prepared to be alkaline with another aqueous solution of ammonium hydroxide, and stirred and filtered. Distillation yielded a white solid (1.6 g).

[0184] (3) Synthesis of 6-isopropylisoquinoline: 6-chloroisoquinoline (4.8 g, 29.3 mmol), isopropylboronic acid (7.7 g, 88 mmol), dicyclohexyl(2,6-dimethoxy-[11-biphenyl]-2-yl)phosphine (0.962 g, 2.34 mmol), Pd2(dba)3 (0.536 g, 0.586 mmol), K3PO4 (21.8 g, 103 mmol), 150 mL toluene, and 15 mL water were placed in a flask. The reaction mixture was purified by bubbling with N2 for 30 minutes, followed by heating to reflux overnight. GC-MS analysis indicated that the reaction was complete. 4.7 g of product was obtained by silica gel chromatography using 15% ethyl acetate (v / v) in hexane as the eluent.

[0185] (4) Synthesis of 1-(3,5-dimethylphenyl)-6-isopropylisoquinoline: 5.3 g (30.7 mmol) of 6-isopropylisoquinoline in 50 mL of anhydrous THF was added dropwise to 100 mL (50.0 mmol) of magnesium bromide (3,5-dimethylphenyl) at room temperature, and the mixture was stirred for 16 hours. The reaction mixture was then heated to reflux for 5 hours. GC and HPLC analysis indicated that the reaction was complete. The small amount of reduction byproducts present were converted to the desired product by treatment with DDQ in THF. After water treatment, 5.1 g of the product was obtained.

[0186] (5) Synthesis of 1-(3,5-dimethylphenyl)-6-isopropylisoquinoline iridium dimer: 1-(3,5-dimethylphenyl)-6-isopropylisoquinoline (4.8 g, 17.37 mmol), IrCl3·H2O (2.57 g, 6.95 mmol), 90 mL of 2-ethoxyethanol, and 30 mL of water were placed in a 250 mL flask. The reaction mixture was heated to reflux for 19 hours under nitrogen protection. After filtration and washing with methanol, 3.8 g of 1-(3,5-dimethylphenyl)-6-isopropylisoquinoline iridium dimer was obtained, which could be used in the next step without further purification.

[0187] (6) Synthesis of compound P-58: 1-(3,5-dimethylphenyl)-6-isopropylisoquinoline iridium dimer synthesized in step (5) (1.3 g, 0.82 mmol), 3,7-diethyl-5-methylnonane-4,6-dione (3.7 g, 16.36 mmol), Na₂CO₃ (1.73 g, 16.36 mmol), and 2-ethoxyethanol (60 mL) were placed in a 250 mL flask and stirred at room temperature for 72 hours. The resulting precipitate was filtered and washed with methanol. Further purification was achieved by passing the solid through a silica gel stopper (pretreated with 15% triethylamine in hexane). 0.7 g of the product was obtained after this treatment.

[0188] Product MS (m / e): 966.55; Elemental analysis (C) 54 H 65 IrN2O2): Theoretical values: C: 67.12%, H: 6.78%, N: 2.90%; Measured values: C: 67.22%, H: 6.63%, N: 2.95%.

[0189] Those skilled in the art should understand that the above preparation method is merely an exemplary example, and those skilled in the art can obtain other compounds of the present invention by improving it.

[0190] Electroluminescent devices were fabricated using the electroluminescent materials provided by this invention. This invention does not specifically limit the fabrication method of the electroluminescent devices; the preparation methods in the following embodiments are merely examples and should not be construed as limitations. Those skilled in the art can reasonably improve the preparation methods of the following embodiments based on existing technology. For example, the proportions of various materials in the light-emitting layer are not specifically limited, and those skilled in the art can reasonably select them within a certain range based on existing technology. For instance, based on the total weight of the light-emitting layer materials, the first compound accounts for 80%–99%, and the second compound accounts for 1%–20%, preferably 1%–10%. The first compound and the second compound are mixed to form the light-emitting layer, wherein the mass ratio of the first compound to the second compound is (80–99):(1–20), more preferably (90–99):(1–10), even more preferably (95–99):(1–5), more preferably (97–99):(1–3), for example, 97:3, 98:2, or 99:1.

[0191] Device Example 1

[0192] Device fabrication steps: First, the glass substrate with a 120 nm thick indium tin oxide (ITO) anode is cleaned and then treated with UV ozone and oxygen plasma. After treatment, the substrate is dried in a nitrogen-filled glove box to remove moisture, then mounted on a substrate holder and placed in a vacuum chamber. The organic layer fabrication begins at a vacuum degree of approximately 10... -8 Under Torr, The deposition rate is achieved sequentially on the ITO anode via thermal vacuum. Simultaneously, the deposited compounds HT and NDP-9 are used as a hole injection layer (HIL), with a thickness of [missing information]. Compound HT is used as a hole transport layer (HTL) with a thickness of [missing information]. Compound EB is used as an electron blocking layer (EBL) with a thickness of [missing information]. Then, the first compound C434, as the host material, and the second compound P-23, as the dopant (i.e., the luminescent material), are co-deposited as the luminescent layer (EML) with a thickness of [missing information]. Compound HB was used as the hole blocking layer (HBL), with a thickness of [missing information]. On the hole-blocking layer, compound ET and 8-hydroxyquinoline-lithium (Liq) are co-deposited as an electron transport layer (ETL) with a thickness of [missing information]. Finally, vapor deposition Thick 8-hydroxyquinoline-lithium (Liq) was used as the electron injection layer (EIL) and deposited by evaporation. Aluminum was used as the cathode. The device was then transferred back to the glove box and sealed with a glass cover to complete the device.

[0193] Referring to Device Example 1, Device Examples 2 through 5 were prepared. Specifically: Device Example 2 was obtained by replacing the host material in the emissive layer (EML) of Device Example 1 with the first compound C535; Device Example 3 was obtained by replacing the host material in the emissive layer (EML) of Device Example 1 with the first compound C589; Device Example 4 was obtained by replacing the dopant (i.e., the luminescent material) in the emissive layer (EML) of Device Example 1 with the second compound P-54; and Device Example 5 was obtained by replacing the dopant (i.e., the luminescent material) in the emissive layer (EML) of Device Example 1 with the second compound P-58.

[0194] Referring to the above device examples, Comparative Examples 1 to 5 were prepared. Specifically, in Device Example 1, the dopant (i.e., the luminescent material) in the light-emitting layer (EML) was replaced with compound RD to obtain Comparative Example 1; in Device Example 2, the dopant (i.e., the luminescent material) in the light-emitting layer (EML) was replaced with compound RD to obtain Comparative Example 2; in Device Example 3, the dopant (i.e., the luminescent material) in the light-emitting layer (EML) was replaced with compound RD to obtain Comparative Example 3; in Device Example 4, the host material in the light-emitting layer (EML) was replaced with compound CBP to obtain Comparative Example 4; and in Device Example 5, the host material in the light-emitting layer (EML) was replaced with compound CBP to obtain Comparative Example 5.

[0195] The detailed device layer structures and thicknesses of each embodiment and comparative example are shown in Table 1 below. The layers used are made of more than one material and are obtained by doping different compounds in the described weight ratios.

[0196] Table 1. Device structures of the device embodiments and comparative examples.

[0197]

[0198] The chemical structures of the materials used in the above devices are shown below:

[0199]

[0200]

[0201] The device performance of the above embodiments and comparative examples was tested, and Table 2 lists the performance at 15 mA / cm². 2 Under the specified conditions, the voltage (V), power efficiency (PE), and device lifetime (LT) of devices in Examples 1-5 and Comparative Examples 1-5 were measured. 97 ).

[0202] Table 2 Device Performance Test Data

[0203]

[0204] As shown in Table 2, the device comparative examples of the present invention were set up with reference to the device experiments disclosed in the prior art (e.g., patent KR1020150077220A), and the host material (e.g., compound CBP) commonly used in the prior art (e.g., patent KR1020150077220A) and the phosphorescent material (e.g., compound RD) commonly used in the prior art (e.g., patent KR1020150077220A) were used as comparative example compounds.

[0205] The test data of the above devices show that: Examples 1-3 use the combination of the present invention (first compounds C434, C535, and C589 and second compound P-23 as the light-emitting layer, respectively) and Comparative Examples 1-3 use first compounds C434, C535, and C589 and RD as the light-emitting layer, respectively. Comparing these sets of data, whether it is voltage, power efficiency, or lifetime, the combination of the present invention, that is, when compound P-23 is used as the dopant, is significantly improved compared with compound RD. In particular, in terms of power efficiency and lifetime, it brings unexpected and significant effects to the device performance.

[0206] Examples 4-5 used the combination of the present invention (first compound C434 and second compounds P-54 and P-58 as the light-emitting layers) and Comparative Examples 4-5 (compound CBP and second compounds P-54 and P-58 as the light-emitting layers), and through the change of the main material, the present invention unexpectedly brought about excellent device performance. It was found that in terms of driving voltage, using the first compound C434 significantly reduced the voltage, and both power efficiency and lifetime were significantly improved, especially the lifetime, which showed an astonishing improvement of over a hundredfold.

[0207] In summary, the electroluminescent material disclosed in this invention, by combining the first compound and the second compound, exhibits excellent overall device performance in the device due to the good energy matching between the two types of compounds, such as lower driving voltage, higher efficiency, and ultra-long device life.

[0208] It should be understood that although the present invention has been described in detail above with general descriptions, specific embodiments, and experiments, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of the present invention fall within the scope of protection claimed by the present invention.

Claims

1. An electroluminescent material, characterized in that, include: (i) First compound: has an HL-Ar structure; (ii) Second compound: The H is selected from any of the following structures: ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ； " "Indicates the keyway position with L; The L is selected from any of the structures shown below, from L-0 to L-50: ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ； " "Indicates the keyway position with H," "Indicates the bond position with Ar; The Ar is selected from any of the following structures: ， ， ， ， ， ， ， ， ， ， ， ， ； " "Indicates the keyway position with L; The second compound is selected from compounds with the following structures: ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， 。 2. The electroluminescent material according to claim 1, characterized in that, The first compound HL-Ar is selected from any of the following compounds: 。 3. The application of the electroluminescent material according to any one of claims 1 to 2 in the light-emitting layer of an electroluminescent device.

4. The application according to claim 3, characterized in that, The first compound is the main material of the light-emitting layer, and the second compound is the light-emitting material.

5. The application according to claim 3, characterized in that, The mass ratio of the first compound to the second compound is (80-99):(1-20).

6. The application according to claim 3, characterized in that, The mass ratio of the first compound to the second compound is (90-99):(1-10).

7. The application according to claim 3, characterized in that, The mass ratio of the first compound to the second compound is (95-99):(1-5).

8. An electroluminescent device comprising the electroluminescent material according to any one of claims 1 to 2.

9. The electroluminescent device according to claim 8, characterized in that, The electroluminescent device emits red or white light.

10. A display component, characterized in that, Includes the electroluminescent device as described in claim 8 or 9.

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