An organic electrophosphorescent material and its application

Abstract

The present invention belongs to the technical field of organic electroluminescent display, and specifically discloses an organic electrophosphorescent material, and also relates to its application in organic electroluminescent devices. The organic electrophosphorescent material provided by the present invention has (H) n ‑Ir‑L (3‑n) The structure can be applied in the field of organic electroluminescence and used as a phosphorescent material. When applied to organic electroluminescent devices, the prepared electroluminescent devices show superior performance of high brightness, high efficiency and long life.

Description

Technical Field

[0001] The invention relates to the technical field of organic electroluminescent display, and specifically discloses an organic electrophosphorescent luminescent material, and also relates to the application of the organic electroluminescent device. Background Art

[0002] Electroluminescent display devices can be divided into inorganic electroluminescent display devices and organic electroluminescent display devices according to the different materials constituting the light-emitting layer. Compared with inorganic electroluminescent display devices, organic electroluminescent display devices have incomparable advantages, such as full-color luminescence in the visible spectrum, extremely high brightness, extremely low driving voltage, fast response time and simple manufacturing process.

[0003] The research on organic electroluminescence started in the 1860s. Pope first realized electroluminescence on anthracene single crystals, but the driving voltage was as high as 100V at that time and the quantum efficiency was very low. In 1987, Tang and VanSlyke used a double-layer film structure with 8-hydroxyquinoline aluminum complex (Alq3) as the light-emitting layer and electron transport layer, TAPC as the hole transport layer, and ITO electrode and Mg:Ag electrode as the anode and cathode respectively, to produce a high brightness (>1000cd / m 2 ), high-efficiency (1.5lm / W) green light organic electroluminescent thin film devices, and their driving voltage dropped below 10V. In 1990, Burroughes et al. used poly(p-phenylene phenylene) (PPV) to prepare polymer thin film electroluminescent devices to obtain a blue-green light output with a quantum efficiency of 0.05%, and its driving voltage was less than 14V. In 1991, Braun et al. used PPV derivatives to produce green and orange light output with a quantum efficiency of 1%, and its driving voltage was about 3V. These research advances immediately attracted widespread attention from scientists in various countries, and research on organic electroluminescence was widely carried out worldwide and gradually began to enter the market.

[0004] Generally speaking, the structure of an organic electroluminescent display device includes an anode formed on a substrate, and a hole transport layer, a light-emitting layer, an electron transport layer and a cathode formed on the anode in sequence. The hole transport layer, the light-emitting layer and the electron transport layer are organic thin films composed of organic compounds. The driving principle of an organic electroluminescent display device with the above structure is as follows: as long as a voltage is applied between the anode and the cathode, holes are injected from the anode through the hole transport layer into the light-emitting layer; at the same time, electrons are injected from the cathode through the electron transport layer into the light-emitting layer; in the light-emitting layer region, carriers are rearranged to form excitons, and the excited state excitons are converted to the ground state, causing the light-emitting layer molecules to emit light.

[0005] Organic electroluminescent materials are divided into fluorescent materials that utilize singlet excitons and phosphorescent materials that utilize triplet excitons according to their different luminescence mechanisms. Phosphorescent materials have higher luminescence efficiency than fluorescent materials because phosphorescent materials can utilize 75% of triplet excitons and 25% of singlet excitons, while fluorescent materials only utilize 25% of singlet excitons. Phosphorescent materials are usually organic metal compounds containing heavy metals, and the luminescent layer formed by them is composed of a main material and a dopant material, and the dopant material emits light by transferring energy from the main material.

[0006] At present, organic metal complexes and organic electroluminescent devices with phosphorescent emission have been reported, and patents have also disclosed a variety of organic metal complex phosphorescent materials. For example, US Pat. No. 6,687,266 discloses a class of iridium (Ir) complexes containing benzimidazole ligands. Since such compounds have low phosphorescent efficiency, poor stability and life span, their commercialization is impeded. Therefore, it is of great significance to improve the structure of such compounds to develop new phosphorescent materials with better performance and promote commercial applications. Summary of the invention

[0007] The purpose of the present invention is to develop an organic electrophosphorescent material, in particular to develop a new organic electrophosphorescent material containing a metal iridium complex, which is applied to an organic electroluminescent device. The prepared electroluminescent device exhibits superior performance of high purity, high efficiency and long life.

[0008] Specifically, in the first aspect, the present invention provides an organic electrophosphorescent material having (H) n -Ir-L (3-n) Structure, wherein H has a structure shown in general formula (I):

[0009]

[0010] In the general formula (I), Ring A, Ring B, Ring C and Ring D are each independently selected from a carbocyclic ring having 5 to 18 carbon atoms or a heterocarbocyclic ring having 3 to 18 carbon atoms;

[0011] Rx1, Rx2, Rx3, and Rx4 are each independently selected from H, a deuterium atom, an alkyl group, a deuterated alkyl group, a cyano group, an alkoxy group, an alkylamino group, an alkylthio group, a fluorine atom, a trifluoromethyl group, an aromatic group, and a heterocyclic aromatic group, and / or, adjacent substituents in Rx1, Rx2, Rx3, and Rx4 may be bridged to form a parallel ring structure;

[0012] m1, m2, m3, and m4 each independently represent an integer from 0 to 5;

[0013] L is a monovalent dicoordinate anion with the structural formula wherein the bonding atoms X and Y are independently selected from oxygen atoms, nitrogen atoms, and carbon atoms;

[0014] n represents 1, 2 or 3;

[0015] Where “﹡” represents the bonding position.

[0016] As an embodiment of the present invention, the L is selected from the group represented by formula La or formula Lb:

[0017]

[0018] Where: In the formula La, R 12 ~R 19 are independently selected from H, a deuterium atom, an alkyl group, a deuterated alkyl group, an alkoxy group, an alkylamino group, an alkylthio group, a fluorine atom, a trifluoromethyl group, an aromatic group and a heterocyclic aromatic group, and / or R 12 ~R 19 The adjacent substituents are bridged to form a ring structure;

[0019] And / or, in formula Lb, R 20 ~R 26 are independently selected from H, a deuterium atom, an alkyl group, a deuterated alkyl group, an alkoxy group, an alkylamino group, an alkylthio group, a fluorine atom, a trifluoromethyl group, an aromatic group and a heterocyclic aromatic group, and / or R 20 ~R 26 The adjacent substituents are bridged to form a ring structure;

[0020] Among them, “---” represents a bonding position.

[0021] As an embodiment of the present invention, the organic electrophosphorescent material (H) provided by the present invention is n -Ir-L (3-n) It can be represented by the structure shown in the following general formula VIII, general formula IX or general formula X:

[0022]

[0023] m is 1 or 2;

[0024]

[0025] Among them, ring A, ring B, ring C and ring D, Rx1, Rx2, Rx3, Rx4, m1, m2, m3, m4, and R 12 ~R 19 , R 20 ~R 26 As defined above.

[0026] As an embodiment of the present invention, H has a structure represented by general formula (I-1) or general formula (I-2):

[0027]

[0028] Wherein, Rx1, Rx2, Rx3, Rx4, m1, m2, m3, m4 are as defined above;

[0029] X1-X5 are each independently selected from O, S, N or CRy;

[0030] Ry is selected from H, a deuterium atom, an alkyl group, a deuterated alkyl group, a cyano group, an alkoxy group, an alkylamino group, an alkylthio group, a fluorine atom, a trifluoromethyl group, an aromatic group, and a heterocyclic aromatic group.

[0031] As a preferred embodiment of the present invention, H has a structure represented by any of the following general formulas:

[0032]

[0033]

[0034] In formula I-1-1, I-1-2, I-2-1, I-2-2, and I-2-3, Rx1, Rx2, Rx3, Rx4, and Ry are each independently selected from H, a deuterium atom, an alkyl group, a deuterated alkyl group, a cyano group, an alkoxy group, an alkylamino group, an alkylthio group, a fluorine atom, a trifluoromethyl group, an aromatic group, and a heterocyclic aromatic group;

[0035] m1, m2, m3, and m4 each independently represent an integer of 0 to 5; when m1, m2, m3, and m4 represent an integer of 2 or more, adjacent substituents in Rx1, Rx2, Rx3, and Rx4 may be bridged to form a parallel ring structure;

[0036] In formula I-2-4, Rx2, Rx3, and Rx4 are each independently selected from H, a deuterium atom, an alkyl group, a deuterated alkyl group, a cyano group, an alkoxy group, an alkylamino group, an alkylthio group, a fluorine atom, a trifluoromethyl group, an aromatic group, and a heterocyclic aromatic group;

[0037] m2, m3, and m4 each independently represent an integer of 0 to 5; when m2, m3, and m4 represent an integer of 2 or more, adjacent substituents in Rx2, Rx3, and Rx4 may be bridged to form a cyclic structure;

[0038] R1, R2, and R3 are each independently selected from H, a deuterium atom, an alkyl group, a deuterated alkyl group, a cyano group, an alkoxy group, an alkylamino group, an alkylthio group, a fluorine atom, a trifluoromethyl group, an aromatic group, and a heterocyclic aromatic group, and / or adjacent substituents in R1, R2, and R3 can be bridged to form a parallel ring structure.

[0039] As a further preferred embodiment of the present invention, Rx1, Rx2, Rx3, Rx4, and Ry are each independently selected from H, a deuterium atom, a C1-C5 alkyl group, a C1-C5 deuterated alkyl group, a cyano group, an alkoxy group containing 1 to 5 C atoms, an alkylamino group containing 1 to 5 C atoms, an alkylthio group containing 1 to 5 C atoms, a fluorine atom, a trifluoromethyl group, a phenyl group, a substituted phenyl group, and a heterocyclic aromatic group; or, adjacent substituents in Rx1, Rx2, Rx3, and Rx4 are bridged to form a parallel ring structure, and the parallel ring structure is any one of a substituted or unsubstituted five-membered ring, a substituted or unsubstituted six-membered ring, a substituted or unsubstituted five-membered heterocycle, and a substituted or unsubstituted six-membered heterocycle, and the substituent used for substitution is a C1-C5 alkyl group, a phenyl group, or a benzo group, and the five-membered heterocycle or the six-membered heterocycle contains at least one heteroatom, and the heteroatom is arbitrarily selected from an oxygen atom, a sulfur atom, and a nitrogen atom.

[0040] In the present application, the C1-C5 alkyl group may be a straight-chain alkyl group or a branched alkyl group, such as methyl, ethyl, n-propane, isopropyl, sec-butyl, n-butyl, isobutyl, tert-butyl, pentyl, neopentyl, and the like.

[0041] The C1-C5 deuterated alkyl group is a C1-C5 alkyl group in which some hydrogen atoms are replaced by deuterium. Similarly, the C1-C5 alkyl group may be a straight chain alkyl group or a branched alkyl group. The C1-C5 deuterated alkyl group may be, for example, a deuterated methyl group, a deuterated isopropyl group, a deuterated pentyl group, a deuterated neopentyl group, and the like.

[0042] Alkoxy groups containing 1 to 5 carbon atoms are C n H 2n+1 The group represented by O-, wherein n is 1 to 5. The alkoxy group containing 1 to 5 carbon atoms may be methoxy, ethoxy, or the like.

[0043] Adjacent substituents in Rx1, Rx2, Rx3, and Rx4 can also form a ring structure by bridging. When forming a ring structure, the ring structure can be any one of a substituted or unsubstituted five-membered ring, a substituted or unsubstituted six-membered ring, a substituted or unsubstituted five-membered heterocycle, and a substituted or unsubstituted six-membered heterocycle. The five-membered heterocycle or the six-membered heterocycle contains at least one heteroatom, and the heteroatom is arbitrarily selected from an oxygen atom, a sulfur atom, and a nitrogen atom. For example, the ring structure can be a benzo ring, a furan ring, a thien ring, a cyclopentene ring, etc. The ring structure can be further substituted by a substituent, such as substituted by a benzo group, substituted by an alkyl group, etc.

[0044] As a further preferred embodiment of the present invention, Rx1, Rx2, Rx3, Rx4, and Ry are each independently selected from H, a deuterium atom, a C1-C5 alkyl group, a C1-C5 deuterated alkyl group, a phenyl group, a fluorine atom, an alkoxy group containing 1 to 5 C atoms, and a trifluoromethyl group. Alternatively, adjacent substituents in Rx1, Rx2, Rx3, and Rx4 are bridged to form a parallel ring structure, and the parallel ring structure is any one of a substituted or unsubstituted five-membered ring, a substituted or unsubstituted benzene ring, and a substituted or unsubstituted five-membered heterocyclic ring, and the substituents used for substitution are C1-C5 alkyl groups, phenyl groups, and benzo groups, and the five-membered heterocyclic ring has at least one heteroatom, and the heteroatom is arbitrarily selected from oxygen atoms and sulfur atoms.

[0045] More preferably, Rx1, Rx2, Rx3, Rx4, and Ry are each independently selected from H, methyl, deuterated methyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, deuterated isopropyl, phenyl, pentyl, deuterated pentyl, fluorine atom, and methoxy group; or, adjacent substituents in Rx1, Rx2, Rx3, and Rx4 are bridged to form a parallel ring structure, and the parallel ring structure is any one of a substituted or unsubstituted benzene ring, a substituted or unsubstituted furan ring, a substituted or unsubstituted thiophene ring, and a substituted or unsubstituted cyclopentene ring, and the substituent used is benzo or methyl.

[0046] As a more preferred embodiment of the present invention:

[0047]

[0048] In formula I-1-1, m1 is 0 or not 0. When m1 is not 0, adjacent substituents in Rx1 are bridged to form a benzo ring structure;

[0049] m2 and m3 are 0; m4 is 2 or 3, and Rx4 is methyl or isopropyl.

[0050]

[0051] In formula I-1-2, m1 is 0 or not 0. When m1 is not 0, adjacent substituents in Rx1 are bridged to form a benzo ring or a substituted benzo ring structure; wherein the number of substituents is 1-2, and the substituents are selected from methoxy, trifluoromethyl, fluorine atom, and deuterium atom;

[0052] m2 and m3 are 0; m4 is 2 or 3, and Rx4 is methyl or isopropyl;

[0053] Ry is phenyl or methyl.

[0054]

[0055] In formula I-2-1, m1 is an integer of 1 to 4, Rx1 is selected from methyl, deuterated methyl, trifluoromethyl, deuterium atom, ethyl, fluorine atom, phenyl, substituted phenyl, the substituted phenyl may have 1 to 2 substituents selected from methyl, deuterated methyl, butyl, deuterated butyl, and adjacent substituents in Rx1 may be bridged to form a benzo ring structure;

[0056] m2 and m3 are 0; m4 is 2 or 3, and Rx4 is methyl or isopropyl.

[0057]

[0058] In formula I-2-2, m1, m2, and m3 are 0; m4 is 2 or 3, and Rx4 is methyl or isopropyl.

[0059]

[0060] In formula I-2-3, m1, m2, and m3 are 0; m4 is 2 or 3, and Rx4 is methyl or isopropyl.

[0061]

[0062] In formula I-2-4, at least two of R1, R2, and R3 are not H, and when they are not H, the groups represented are different, and the groups represented are selected from deuterated methyl and phenyl. Adjacent substituents in R1, R2, and R3 can be bridged to form a benzo ring structure;

[0063] m2 and m3 are 0; m4 is 2 or 3, and Rx4 is methyl or isopropyl.

[0064] In the organic electrophosphorescent material provided by the present invention, the H is selected from any of the following structures:

[0065]

[0066]

[0067]

[0068]

[0069]

[0070]

[0071]

[0072]

[0073] As a preferred embodiment of the present invention, in the formula La:

[0074]

[0075] The R 12 ~R 19 are independently selected from H, a deuterium atom, a C1-C5 alkyl group, a fluorine atom, a phenyl group, a substituted phenyl group, a C1-C5 deuterated alkyl group, a cyano group, an alkoxy group containing 1 to 5 C atoms, an alkylamino group containing 1 to 5 C atoms, an alkylthio group containing 1 to 5 C atoms, a trifluoromethyl group, and a heterocyclic aromatic group; or, R 12 ~R 19 The adjacent substituents are bridged to form a parallel ring structure, and the parallel ring structure is any one of a substituted or unsubstituted five-membered ring, a substituted or unsubstituted six-membered ring, a substituted or unsubstituted five-membered heterocycle and a substituted or unsubstituted six-membered heterocycle. The substituents used are C1-C5 alkyl, phenyl, benzo, pyrido, alkyl-substituted pyrido, deuterated alkyl-substituted pyrido, and the five-membered heterocycle or six-membered heterocycle contains at least one heteroatom, and the heteroatom is arbitrarily selected from oxygen atoms, sulfur atoms, and nitrogen atoms.

[0076] More preferably, the R 12 ~R 19 are independently selected from H, C1-C5 alkyl, fluorine atom, phenyl, C1-C5 deuterated alkyl; or, R 12 ~R 19 The adjacent substituents are bridged to form a parallel ring structure, the parallel ring structure is any one of a substituted or unsubstituted benzene ring, a substituted or unsubstituted five-membered heterocycle, the substituted substituents are C1-C5 alkyl, phenyl, benzo, pyrido, pyrido substituted by an alkyl containing 1 to 5 C atoms, and pyrido substituted by a deuterated alkyl containing 1 to 5 C atoms, the five-membered heterocycle has at least one heteroatom, and the heteroatom is arbitrarily selected from an oxygen atom and a sulfur atom.

[0077] Still more preferably, wherein R 12 ~R 19 are independently selected from H, methyl, fluorine, phenyl, deuterated methyl, isopropyl, deuterated isopropyl; or, R 12 ~R 19 The adjacent substituents are bridged to form a parallel ring structure, which is any one of a substituted or unsubstituted benzene ring, a substituted or unsubstituted furan ring, and a substituted or unsubstituted six-membered ring, and the substituent used is a deuterated methyl-substituted pyrido group, a methyl-substituted pyrido group or a benzo group.

[0078] More preferably, in the formula La, R 12 ~R 19Each is independently selected from H, a deuterium atom, a methyl group, a trifluoromethyl group, a phenyl group, an ethyl group, a deuterated methyl group, and a deuterated phenyl group.

[0079] As a preferred embodiment of the present invention, in the formula Lb:

[0080]

[0081] The R 20 ~R 26 are independently selected from H, a deuterium atom, a C1-C5 alkyl group, a fluorine atom, a C1-C5 deuterated alkyl group, an alkoxy group containing 1 to 5 C atoms, an alkylamino group containing 1 to 5 C atoms, an alkylthio group containing 1 to 5 C atoms, a trifluoromethyl group, or R 20 ~R 26 The adjacent substituents are bridged to form a ring structure, and the ring structure is a cycloalkyl or cycloalkenyl group containing 3 to 6 C atoms.

[0082] More preferably, the R 20 ~R 26 are independently selected from H, a deuterium atom, a fluorine atom, a C1-C5 alkyl group, or R 20 ~R 26 The adjacent substituents are bridged to form a ring structure, and the ring structure is a cycloalkyl group containing 3 to 6 C atoms.

[0083] More preferably, in the formula Lb, R 20 ~R 26 are independently selected from H, methyl, ethyl, fluorine atoms, or R 20 ~R 26 The adjacent substituents are bridged to form a ring structure, and the ring structure is a cyclopentyl group or a cyclohexyl group.

[0084] As a preferred embodiment of the present invention, L is selected from any of the following structures:

[0085]

[0086] As a preferred embodiment of the present invention, the organic electrophosphorescent material (H) n -Ir-L (3-n) Select any of the following compounds:

[0087]

[0088]

[0089]

[0090]

[0091]

[0092]

[0093]

[0094]

[0095]

[0096]

[0097]

[0098]

[0099]

[0100] In a second aspect, the present invention provides an application of an organic electrophosphorescent material in the preparation of an organic electroluminescent device.

[0101] Preferably, the organic electrophosphorescent material is used as a dye material of a host material in an organic electroluminescent device.

[0102] The material of the invention is used as a dye doped in an organic electroluminescent device to emit light. The electroluminescent device prepared by using the phosphorescent material of the invention exhibits superior performances of high purity, high brightness and high efficiency.

[0103] Further preferably, the doping concentration of the phosphorescent material provided by the present invention in the host material is 3-12%, further preferably 3-10%, further preferably 3-8%, and more preferably 3-5%. It was surprisingly found in the study that when the doping concentration of the phosphorescent material in the host material is about 5%, the performance of the device is the best. The doping concentration is the mass percentage concentration.

[0104] In a third aspect, the present invention provides an organic electroluminescent device, comprising a light-emitting layer, wherein the light-emitting layer comprises the organic electrophosphorescent material of the present invention.

[0105] Preferably, the light-emitting layer comprises a host material and a dye material, and the dye material comprises the organic electrophosphorescent light-emitting material described in the present invention.

[0106] More preferably, the doping concentration of the organic electrophosphorescent material in the host material is 3-12%, more preferably 3-10%, still more preferably 3-8%, and even more preferably 3-5%.

[0107] Specifically, the present invention provides an organic electroluminescent device, including a substrate, and an anode layer, a plurality of light-emitting unit layers and a cathode layer sequentially formed on the substrate; the light-emitting unit layer includes a hole injection layer, a hole transport layer, a light-emitting layer, and an electron transport layer, the hole injection layer is formed on the anode layer, the hole transport layer is formed on the hole injection layer, the cathode layer is formed on the electron transport layer, and there are multiple light-emitting layers between the hole transport layer and the electron transport layer. The light-emitting material of the light-emitting layer is the iridium-containing phosphorescent light-emitting material provided by the present invention.

[0108] In a fourth aspect, the present invention provides a display device, which includes the organic electroluminescent device described in the present invention.

[0109] In a fifth aspect, the present invention further provides a lighting device, which comprises the organic electroluminescent device described in the present invention.

[0110] The present invention provides a new organic electroluminescent phosphorescent material containing metal iridium, which can be used as a dye material of the main material of the luminescent layer. The organic electroluminescent device made of the phosphorescent material provided by the present invention has the superior performance of high purity, high brightness, high efficiency and long life. DETAILED DESCRIPTION

[0111] The technical scheme of the present invention is described in detail below through specific examples. The following examples are used to illustrate the present invention, but are not used to limit the scope of the present invention. Any other equivalent changes or modifications completed without departing from the spirit disclosed by the present invention should be included in the scope of the claims.

[0112] Example 1: Synthesis of ligand H13

[0113]

[0114] The synthetic route is as follows:

[0115]

[0116] The synthesis steps are:

[0117] (1) In a 3 L flask, 105 g (591.0 mmol) of N-bromosuccinimide was dissolved in 1.5 L of acetone, and then 25 g (148.0 mmol) of diphenylamine dissolved in 150 mL of acetone was slowly added dropwise. Thereafter, the mixture was stirred at room temperature for 5 hours. After adding 1.5 L of ice water and stirring for 1 hour, the obtained solid was filtered. The dried solid was refluxed in a small amount of toluene for 1 hour. After cooling to room temperature, the obtained solid was collected by filtration to obtain 29.0 g of white solid compound H13-1.

[0118] (2) In a 1L flask, 129.0 g (59.8 mmol) of intermediate H13-1, 1.9 g (5.9 mmol) of tetrabutylammonium bromide, 18.4 g (328 mmol) of potassium hydroxide and 397 mL of THF were added and stirred under reflux for 4 hours. After cooling to room temperature, 7.3 g (89.7 mmol) of chloromethyl ether was added dropwise and stirred at room temperature for 5 hours. After the reaction was completed, the mixture was extracted with distilled water and dichloromethane (DCM). The separated organic phase was dried over sodium sulfate and the solvent was removed under reduced pressure. The reaction product was crystallized and solidified with methanol to obtain 30.2 g of white solid compound H13-2.

[0119] (3) In a 2L flask, 34.1g (64.5mmol) of intermediate H13-2 was dissolved in 645mL of ether and cooled to -78°C. 57mL (142mmol) of n-butyl lithium (n-BuLi, 2.5M hexane solution) was slowly added dropwise. After the addition was complete, stirring was continued for 1 hour, and 13.6g (70.9mmol) of (2,4,6-trimethylphenyl) dimethyl borate was slowly added dropwise. The mixture was stirred while the temperature was slowly raised to room temperature. After terminating the reaction with distilled water, the separated organic layer was dried over anhydrous sodium sulfate, and the solvent was removed under reduced pressure. The reaction product was solidified using methanol to obtain 22.0g of beige solid compound H13-3.

[0120] (4) In a 2L flask, 22.0 g (44.1 mmol) of intermediate H13-3 was dissolved in 645 mL of THF and cooled to -78°C. 38.8 mL (96.9 mmol) of n-butyl lithium (n-BuLi, 2.5 M hexane solution) was slowly added dropwise. After the addition was completed, stirring was continued for 1 hour, and the reaction was terminated with a saturated aqueous solution of ammonium chloride. Extracted with distilled water and chloroform. The organic layer was dried over anhydrous sodium sulfate and the solvent was removed under reduced pressure. The reactant was dissolved in 220 mL of ether and then concentrated. 7.4 mL of HCl was slowly added dropwise and then stirred at room temperature. After the reaction was completed, it was neutralized with a saturated aqueous solution of sodium carbonate. Extracted with distilled water and chloroform. The organic layer was dried over anhydrous sodium sulfate and the solvent was removed under reduced pressure. The reactant was purified by silica gel column chromatography (Hex:DCM) to obtain 3.0 g of yellow solid compound H13-4.

[0121] (5) Under nitrogen protection, add H13-4 (29.7 g, 0.1 mol), 2-bromo-4-(methyl-d3)pyridine (17.4 g, 0.1 mol), copper powder (6.3 g, 0.1 mol), 18-crown-6 (26.4 g, 0.1 mol), potassium carbonate (20.7 g, 0.15 mol), and 800 ml of o-dichlorobenzene in a 2L three-necked flask equipped with a magnetic stirrer. After nitrogen replacement, add H13-4 (29.7 g, 0.1 mol), 2-bromo-4-(methyl-d3)pyridine (17.4 g, 0.1 mol), copper powder (6.3 g, 0.1 mol), 18-crown-6 (26.4 g, 0.1 mol), potassium carbonate (20.7 g, 0.15 mol), and o-dichlorobenzene 800 ml in sequence. Heat and reflux the mixture under nitrogen protection for 10 hours to complete the reaction. Cool the mixture, add water, and evaporate o-dichlorobenzene. Wash the solid product with water, filter and dry it, separate it by column chromatography, and spin dry it to obtain 15.6 g of light yellow solid H13.

[0122] Product MS (m / e): 391; Elemental analysis (C 27 H 22 D3BN2): Theoretical value C: 82.87%, H: 7.21%, N: 7.16%; Measured value C: 82.69%, H: 7.03%, N: 7.23%.

[0123] Example 2: Synthesis of ligand H36

[0124]

[0125] The synthetic route is as follows:

[0126]

[0127] The synthesis steps are as follows: referring to the synthesis steps of Example 1, H13-2 is first synthesized, (2,4,6-triisopropylphenyl)dimethyl borate is used instead of (2,4,6-trimethylphenyl)dimethyl borate in step (3), and 2-bromo-4-phenylpyridine is used instead of 2-bromo-4-(methyl-d3)pyridine in step (5). The other raw materials and steps are the same as those in Example 1 to obtain ligand H36.

[0128] Product MS (m / e): 534; Elemental analysis (C 38 H 39 BN2): Theoretical value C: 85.38%, H: 7.35%, N: 5.24%; Measured value C: 85.26%, H: 7.28%, N: 5.30%.

[0129] Example 3: Synthesis of ligand H93

[0130]

[0131] The synthetic route is as follows:

[0132]

[0133] The synthesis steps are as follows: refer to the synthesis step (5) of Example 1, replace H13-4 with H36-2, and replace 2-bromo-4-(methyl-d3)pyridine with 2-bromo-5-methoxy-1-phenyl-1H-benzo[d]imidazole to obtain ligand H93.

[0134] Product MS (m / e): 603; Elemental analysis (C 41 H 42 BN3O): Theoretical value C: 81.58%, H: 7.01%, N: 6.96%; Measured value C: 81.47%, H: 6.94%, N: 7.12%.

[0135] Example 4: Synthesis of Compound C13

[0136]

[0137] The reaction formula is as follows:

[0138]

[0139] The synthesis steps are as follows: Ir(acac)3 (4.9 g, 10 mmol), ligand H13 (15.6 g, 40 mmol), and 150 mL of glycerol are added to a 250 ml three-necked flask equipped with a magnetic stirrer and a reflux condenser. Vacuum and fill with N2 for 5 times to remove oxygen from the system. Heat and reflux in an oil bath at 190°C for 24 hours under N2 protection. Cool naturally to room temperature, filter, wash with water, n-hexane, and ether in turn, and dry to obtain a yellow crude product. Dissolve in CH2Cl2 and separate on a column, using CH2Cl2 as the eluent, and drain the solvent to obtain 5.4 g of a yellow powder.

[0140] Product MS (m / e): 1364; Elemental analysis (C 81 H 63 D9B3IrN6): Theoretical value C: 71.37%, H: 5.99%, N: 6.17%; Measured value C: 71.26%, H: 5.91%, N: 6.32%.

[0141] Example 5: Synthesis of Compound C559

[0142]

[0143] The reaction formula is as follows:

[0144]

[0145] The synthesis steps are:

[0146] (1) In a 500 mL three-necked flask equipped with a mechanical stirrer, a reflux condenser and a nitrogen protection device, add the following in sequence: ligand H93 (25 mmol, 15.1 g), hydrated iridium trichloride (10 mmol, 3.35 g), ethylene glycol monoethyl ether 90 mL, and distilled water 30 mL. Vacuum and fill with N2 for 5 times to remove oxygen from the system. Heat to 110°C and reflux for 24 hours. After natural cooling, add 10 mL of distilled water, shake, filter, wash with water, and wash with ethanol. Vacuum dry to obtain 11.2 g of crude dichlorobridged intermediate C559-1 as a yellow solid.

[0147] (2) In a 250 ml three-necked flask equipped with a magnetic stirrer and a reflux condenser, add the intermediate C559-1 (5 mmol, 8.0 g), acetylacetone (25 mmol, 2.5 g, 2.6 mL), anhydrous Na2CO3 (22 mmol, 2.35 g) and 100 mL of ethylene glycol monoethyl ether in sequence. Evacuate and fill with N2 for 5 times to remove oxygen from the system. Heat and reflux in an oil bath at 120°C under N2 protection for 24 hours. Cool naturally to room temperature, filter, wash with water, n-hexane, and ether in sequence, and dry to obtain a yellow crude product. Dissolve in CH2Cl2 and separate on a column, using CH2Cl2 as the eluent, and drain the solvent to obtain 4.6 g of a yellow powder.

[0148] Product MS (m / e): 1498; Elemental analysis (C 87 H 90 B2IrN6O4): Theoretical value C: 69.78%, H: 6.06%, N: 5.61%; Measured value C: 69.69%, H: 5.94%, N: 5.03%.

[0149] Example 6: Synthesis of Compound C769

[0150]

[0151] The reaction formula is as follows:

[0152]

[0153] The synthesis steps are:

[0154] (1) In a 100 mL three-necked flask equipped with a mechanical stirrer, a reflux condenser and a nitrogen protection device, add phenylpyridine (15 mmol, 2.5 mL), hydrated iridium trichloride (6 mmol, 2.01 g), 45 mL of ethylene glycol monoethyl ether and 15 mL of distilled water in sequence. Evacuate and fill with N2 for five times to remove oxygen from the system. Heat to 110°C and reflux for 24 hours. After natural cooling, add 10 mL of distilled water, shake, filter, wash with water and ethanol. Vacuum dry to obtain 2.6 g of crude dichlorobridged intermediate C769-1 as a yellow solid.

[0155] (2) In a 500 mL three-necked flask equipped with a nitrogen protection device, the dichloro bridged intermediate C769-1 (10.7 g, 10 mmol) and 150 ml of dichloromethane were added in sequence, and the mixture was stirred thoroughly. Then, a 200 ml methanol solution of silver trifluoromethanesulfonate (6.4 g, 25 mmol) was added, and the mixture was stirred for 24 hours under light-proof conditions. After cooling to room temperature, the generated AgCl was filtered out with diatomaceous earth, and the filtrate was dried to obtain a yellowish brown solid powder C769-2. The solid was used directly in the next step without treatment.

[0156] (3) In a 250 ml three-necked flask, add the khaki solid C769-2 (5.1 g, 6.9 mmol) obtained in step (2) above and ligand H36 (11.2 g, 21 mmol), then add 100 ml of ethanol, heat the mixture under reflux for 36 hours, cool the reactants to room temperature, filter the generated yellow solid, dissolve the solid in dichloromethane, and separate by column chromatography to obtain 3.2 g of a bright yellow solid.

[0157] Product MS (m / e): 1034; Elemental analysis (C 60 H 54 BIrN4): Theoretical value C: 69.69%, H: 5.26%, N: 5.42%; Measured value C: 69.60%, H: 5.18%, N: 5.59%.

[0158] Referring to the above synthesis method, other specific organic electrophosphorescent compounds listed in the present invention were synthesized.

[0159] Example 7: Stability Verification Experiment

[0160] 5 g of each of the commercial reference compound D01 and the compound C559 prepared in the present invention were placed in a high vacuum sublimation apparatus at 6.0*10 -4 The sublimation was carried out at a vacuum degree of 1.5 Pascal and a temperature of 280°C for 20 hours. The sublimation results are shown in Table 1.

[0161] Control Compound

[0162] Table 1

[0163]

[0164] From the data in the above table, it can be seen that the purity of the compound C559 provided by the present invention does not change after sublimation, while the purity of the control compound D01 decreases significantly after sublimation. It can be seen that the compound of the present invention can effectively improve the thermal stability of the prepared phosphorescent material.

[0165] Example 8: Preparation of OLED Device

[0166] The following is an application example of the OLED device of the compound of the present invention. This example provides a group of OLED devices, and the structure of the device is: ITO / HATCN (1nm) / HT01 (65nm) / TAPC (40nm) / DIC-TRZ: 3% of the phosphorescent material compound of the present invention (40nm) / TPBI (5nm) ET01: QLi (1:1) (40nm) / LiF (1nm) / Al.

[0167] The molecular structure of each functional layer material is as follows:

[0168]

[0169]

[0170] Preparation of OLED-1 device:

[0171] The compound C559 prepared in the present invention is selected as the phosphorescent luminescent material, and its doping concentration is 3% (mass percentage), and an OLED-1 device is prepared. The specific preparation method is as follows:

[0172] (1) a glass plate coated with an ITO transparent conductive layer was ultrasonically treated in a commercial cleaning agent, rinsed in deionized water, ultrasonically degreased in a mixed solvent of acetone:ethanol (volume ratio 1:1), baked in a clean environment until the water was completely removed, cleaned with ultraviolet light and ozone, and bombarded with a low-energy cation beam;

[0173] (2) Place the glass substrate with the anode in a vacuum chamber and evacuate the chamber to a vacuum of 1×10 -5 ~9×10 -3 Pa, vacuum evaporating HATCN as a hole injection layer on the above anode layer film, the evaporation rate is 0.1nm / s, and the total evaporation film thickness is 1nm; then evaporating the first hole layer HT01, the evaporation rate is 0.1nm / s, and the thickness is 65nm; then evaporating the second hole transport layer TAPC, the evaporation rate is 0.1nm / s, and the evaporation film thickness is 40nm;

[0174] (3) vacuum evaporating EML on the hole transport layer TAPC as the light-emitting layer of the device, the EML comprising the main material DIC-TRZ and the dye material C559 of the present invention, with a doping mass percentage concentration of 3%, forming the organic light-emitting layer of the device, the evaporation rate is 0.2nm / s, and the total evaporation film thickness is 40nm; then evaporating 5nm of TPBI to form a hole blocking layer, the evaporation rate is 0.1nm / s;

[0175] (4) ET01:QLi with a mass ratio of 1:1 was evaporated on the hole blocking layer as the electron transport material of the device electron transport layer, the evaporation rate was 0.1 nm / s, and the total evaporation film thickness was 40 nm;

[0176] (5) On the electron transport layer, a 1 nm thick LiF layer was vacuum evaporated in sequence as an electron injection layer, and a 150 nm thick Al layer was used as the cathode of the device. After packaging, an OLED-1 device was obtained.

[0177] Preparation of OLED-2 to OLED-3 devices:

[0178] According to the above-mentioned method for preparing the OLED-1 device, only the doping concentration of the dye material C559 of the present invention in the main material DIC-TRZ in step (3) was changed from 3% to 5% and 8%, respectively, to prepare OLED-2 and OLED-3 devices.

[0179] The performance of the devices OLED-1 to OLED-3 prepared above was tested. The performance test results of each device are shown in Table 2.

[0180] Table 2

[0181]

[0182]

[0183] Comparing the test results of the above three light-emitting devices, it can be seen that the light-emitting device OLED-2 has the best performance, that is, when the doping concentration is about 5%, the brightness is the highest and the efficiency is also the highest.

[0184] Preparation of OLED-4 to OLED-5 devices:

[0185] According to the preparation method of the OLED-1 device, the dye material C559 of the present invention in step (3) was replaced by compounds C13 and C769 respectively, and the doping concentration in the host material DIC-TRZ was 5%, and OLED-4 to OLED-5 devices were prepared.

[0186] Comparative device 1 is prepared by using compound D01 of known structure as dye material to replace dye material C559 in OLED-1 device, and the doping concentration in host material DIC-TRZ is 5%.

[0187] The performance of the device OLED-2, devices OLED-4 to OLED-5, and comparative device 1 prepared above was tested. The performance test results of each device are shown in Table 3.

[0188] Table 3

[0189]

[0190] From the above results, it can be seen that compared with D01, C559 has improved stability of the compound itself, and the luminous efficiency of the corresponding device is improved, while the life span is also significantly extended. Moreover, compounds with different coordination modes can adjust the color of the light on the one hand, and also have a significant impact on the photoelectric performance and device life of the corresponding device, showing the wide adjustability of the luminous performance and device data of the compound of the present invention, and can provide solutions for different customer needs. Therefore, the phosphorescent material provided by the present invention can effectively solve the problems of the currently commonly used phosphorescent materials in terms of color purity, luminous efficiency and life span, and the organic electroluminescent device prepared by the phosphorescent material of the present invention shows the superior performance of high purity, high brightness, high efficiency and long life.

[0191] Although the present invention has been described in detail above by means of general description, specific implementation methods and tests, it is obvious to those skilled in the art that some modifications or improvements may be made to the present invention. Therefore, these modifications or improvements made without departing from the spirit of the present invention all fall within the scope of protection claimed by the present invention.

Claims

1. An organic electrophosphorescent material, characterized in that: Has (H) n -Ir-L (3-n) Structure, wherein the H has a structure represented by any of the following general formulas: In formula I-1-2 and I-2-1, R x1 and R y R is selected from H, C1-C5 alkyl, C1-C5 deuterated alkyl, alkoxy containing 1-5 C atoms, phenyl; x4 Selected from H, C1-C5 alkyl, C1-C5 deuterated alkyl; m1 and m4 each independently represent an integer from 0 to 5; In formula I-1-2, when m1 represents an integer of 2 or more, adjacent substituents in Rx1 can be bridged to form a benzo ring or a substituted benzo ring structure, wherein the number of substituents on the substituted benzo ring structure is 1-2, and the substituents on the substituted benzo ring structure are selected from methoxy, trifluoromethyl, fluorine atom, and deuterium atom; L is a monovalent dicoordinate anion with the structural formula wherein the bonding atoms X and Y are independently selected from oxygen atoms, nitrogen atoms, and carbon atoms; n represents 1, 2, or 3.

2. The organic electrophosphorescent material according to claim 1, characterized in that: The H is selected from any of the following structures:

3. The organic electrophosphorescent material according to claim 1, characterized in that: The L is selected from the group represented by formula La or formula Lb: Where: In the formula La, R 12 ~R 19 are independently selected from H, a deuterium atom, an alkyl group, a deuterated alkyl group, an alkoxy group, an alkylamino group, an alkylthio group, a fluorine atom, a trifluoromethyl group, an aromatic group and a heterocyclic aromatic group, and / or R 12 ~R 19 The adjacent substituents are bridged to form a ring structure; and / or, In formula Lb, R 20 ~R 26 are independently selected from H, a deuterium atom, an alkyl group, a deuterated alkyl group, an alkoxy group, an alkylamino group, an alkylthio group, a fluorine atom, a trifluoromethyl group, an aromatic group and a heterocyclic aromatic group, and / or R 20 ~R 26 Adjacent substituents are bridged to form a ring structure.

4. The organic electrophosphorescent material according to claim 3, characterized in that: The L is selected from any of the following structures:

5. Use of the organic electrophosphorescent material according to any one of claims 1 to 4 in the preparation of an organic electroluminescent device.

6. The use according to claim 5, characterized in that: The organic electrophosphorescent material is used as a dye material of a host material in an organic electroluminescent device.

7. An organic electroluminescent device, characterized in that: The organic electroluminescent device comprises a light-emitting layer, and the light-emitting layer comprises the organic electrophosphorescent material according to any one of claims 1 to 4.

8. The light emitting device according to claim 7, characterized in that: The light-emitting layer comprises a host material and a dye material, and the dye material comprises the organic electrophosphorescent light-emitting material according to any one of claims 1 to 4.

9. The light emitting device according to claim 8, characterized in that: The doping concentration of the organic electrophosphorescent material in the host material is 3-12%.

10. The light emitting device according to claim 8, characterized in that: The doping concentration of the organic electrophosphorescent material in the host material is 3-5%.

11. A display device or lighting device, characterized in that: The organic electroluminescent device according to claim 7 is included.

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