Connection and its application

Abstract

Connection with a structure of formula II: where n is a positive integer from 1 to 2; A CR0 is; Z is selected independently from the group of O or S; R0-R4 are independently selected from the group consisting of hydrogen, deuterium, substituted or unsubstituted C1-C8 alkyl, or substituted or unsubstituted C3-C20 cycloalkyl, wherein at least one of R1 and R2 is a substituted or unsubstituted C3-C20 cycloalkyl, wherein the substitution is substitution by deuterium, F, Cl, Br, C1-C4 alkyl, C3-C6 cycloalkyl, cyano or isonitrile, and wherein the substitution is monosubstitution up to the maximum possible substitution; and XY is an OO-type or CN-type ligand.

Description

Technical field

[0001] The present invention relates to the technical field of organic electroluminescence and an organic luminescence material suitable for organic electroluminescence devices, in particular a compound and its application in organic electroluminescence devices. State of the art

[0002] Currently, organic electroluminescent devices (OLEDs), as a new generation of display technologies, have attracted increasing attention in both the display and lighting sectors and offer broad application potential. However, compared to market requirements, the luminous efficacy, operating voltage, lifetime, and other characteristics of OLED devices still need to be enhanced and improved.

[0003] In general, the basic structure of OLED devices consists of various organic functional material films with different functions mixed between metal electrodes, like a sandwich structure. Driven by current, electron holes and electrons are injected from the cathode and anode respectively; after traveling a certain distance, the electron holes and electrons recombine in the light-emitting layer and are released in the form of light or heat, thus generating the luminescence of the OLED.

[0004] However, organic functional materials are the core components of organic electroluminescence devices, and thermal stability, photochemical stability, electrochemical stability, quantum yield, film formation stability, crystallinity, color saturation of the material, etc., represent a major factor in device performance.

[0005] In general, functional organic materials include fluorescent and phosphorescent materials. Fluorescent materials are typically small organic molecules; generally, only 25% of the singlet state can be used to emit light, resulting in a relatively low light yield. Phosphorescent materials, on the other hand, can utilize the energy of 75% of the triplet excitons in addition to 25% of the singlet state due to spin-orbit coupling caused by the heavy-atom effect, thus improving their light yield. However, compared to fluorescent materials, phosphorescent materials were developed later, and their thermal stability, lifetime, and color saturation remain challenging areas for improvement. Several compounds are currently being developed as phosphorescent materials.For example, patent document CN107973823 discloses a type of quinoline-iridium compound, but the color saturation and device performance, in particular the luminous efficacy and device lifetime of such compounds, need improvement; patent document CN106459114 discloses a type of β-diketone ligand-coordinated iridium compound, but the sublimation temperature of such compounds is high, the color saturation is not good, and in particular the device performance is not ideal and needs further improvement. Further generic compounds are disclosed in documents EP 3 007 244 A1 and EP 2 940 098 A1. Content of the invention

[0006] One of the objectives of the present invention is to provide a phosphorescent compound that exhibits the advantages of a low sublimation temperature, high optical and electrochemical stability, high color saturation, high luminous efficacy, long device lifetime, etc., and can be used in organic electroluminescent devices. In particular, the compound can be used as a dopant material emitting red light in the OLED industry.

[0007] Against this background, the invention relates to a compound with a structure of formula II: wherein n is a positive integer from 1 to 2, and wherein A is CR0, and wherein Z is independently selected from the group consisting of O or S, and wherein R0-R4 are independently selected from the group consisting of hydrogen, deuterium, substituted or unsubstituted C1-C8 alkyl, or substituted or unsubstituted C3-C20 cycloalkyl; and wherein at least one of R1 and R2 is a substituted or unsubstituted C3-C20 cycloalkyl, and wherein the substitution is substitution by deuterium, F, Cl, Br, C1-C4 alkyl, C3-C6 cycloalkyl, cyano, or isonitrile; and wherein the substitution is monosubstitution up to the maximum number of substitutions. XY is a ligand of the OO type or CN type.

[0008] R1 is a preferred substituted or unsubstituted C3-C20 cycloalkyl. R2 is a preferred substituted or unsubstituted C3-C20 cycloalkyl. R1 and R2 are both preferred substituted or unsubstituted C3-C20 cycloalkyl.

[0009] The preferred compound for substitution is D, in particular a C1-C4 alkyl partially or completely substituted by D.

[0010] The preferred compound for substitution is F, in particular a C1-C4 alkyl partially or completely substituted by F.

[0011] The preferred compound for substitution is a substituted or unsubstituted C3-C6 cycloalkyl.

[0012] The preferred compound is R4 not H, wherein it is particularly preferred that the position of the R4 substituent is the adjacent or opposite position of the metal-carbon bond (CM bond).

[0013] As the preferred compound, XY is not the same as the ligand on the left side.

[0014] The preferred compound XY is a 1,3-diketone compound.

[0015] A preferred connection is one of the following:

[0016] Preferably, ZO is selected, wherein R1-R4 are independently selected from the group consisting of hydrogen, deuterium, substituted or unsubstituted C1-C4 alkyl, or substituted or unsubstituted C3-C20 cycloalkyl; and wherein at least one of R1 and R2 is a substituted or unsubstituted C3-C20 cycloalkyl, and wherein the substitution is by deuterium, F, Cl, Br, C1-C4 alkyl, C3-C6 cycloalkyl, cyano, or isonitrile; and wherein the substitution is monosubstitution to the maximum number of substitutions. A preferred compound is one of the following: CPD 1 CPD 2 CPD 3 CPD 4 CPD 5 CPD 6 CPD 7 CPD 8 CPD 9 CPD 10 CPD 11 CPD 12 CPD 13 CPD 14 CPD 15 CPD 16 CPD 17 CPD 18 CPD 19 CPD 20 CPD 21 CPD 22 CPD 23 CPD 24 CPD 25 CPD 26 CPD 27 CPD 28 CPD 29 CPD 30 CPD 31 CPD 32 CPD 33 CPD 34 CPD 35 CPD 36 CPD 37 CPD 38 CPD 39 CPD 40 CPD 41 CPD 42 CPD 43 CPD 44 CPD 45 CPD 46 CPD 47 CPD 48 CPD 49 CPD 50 CPD 51 CPD 52 CPD 53 CPD 54 CPD 55 CPD 56 CPD 57 CPD 58 CPD 59 CPD 60 CPD 61 CPD 62 CPD 63 CPD 64 CPD 65 CPD 66 CPD 67 CPD 68 CPD 69 CPD 70 CPD 71 CPD 72 CPD 73 CPD 74 CPD 75 CPD 76 CPD 77 CPD 78 CPD 79 CPD 80 CPD 81 CPD 82 CPD 83 CPD 84 CPD 85 CPD 86 CPD 87 CPD 88 CPD 89 CPD 90 CPD 91 CPD 92 CPD 93 CPD 94 CPD 95 CPD 96 CPD 97 CPD 98 CPD 99 CPD 100 CPD 101 CPD 102 CPD 103 CPD 104 CPD 105 CPD 106 CPD 107 CPD 108 CPD 133 CPD 134 CPD 135 CPD 136 CPD 137 CPD 138 CPD 139 CPD 140 CPD 141 CPD 142 CPD 143 CPD 144

[0017] A further objective of the present invention is to provide a phosphorescent OLED material containing the above compound.

[0018] A further objective of the present invention is to provide an OLED device containing the above compound.

[0019] The material of the present invention exhibits the advantages of a low sublimation temperature, high photochemical and electrochemical stability, high color saturation, high luminous efficacy, long device lifetime, etc. As a phosphorescent material, the material of the present invention can convert the excited triplet state into light, thus improving the luminous efficacy of the organic electroluminescence device and reducing energy consumption. Detailed descriptions

[0020] The following embodiments serve only to provide a better understanding of the technical invention and should not be regarded as a specific limitation of the present invention.

[0021] The raw materials and solvents involved in the synthesis of the compounds in the present invention are all obtained from suppliers well known to those skilled in the art, such as Alfa and Acros. Example 1: Synthesizing CPD (7 / 9 / 12) Synthesize the common intermediate B:

[0022] Successive addition of compound A (98 g, 375.3 mmol, 1.0 eq.), bis(pinacolato)diboron (114.3 g, 450.3 mmol, 1.2 eq.), Pd(dppf)Cl₂ (5.49 g, 7.51 mmol, 0.02 eq.), KOAc (73.67 g, 750.6 mmol, 2.0 eq.), and dioxane (1 L) to a 3 L three-necked flask, vacuum sealing, nitrogen replacement three times, heating the oil bath to approximately 100°C, stirring for 16 hours, taking samples, and monitoring the complete reaction of crude material A by TLC. Cooling to room temperature, batch transfer to a 1 L one-necked flask to remove most of the dioxane by rotary evaporation, then adding toluene. (600 ml), heat to dissolve, add deionized water for three washes (200 ml each time), separate the liquid, filter the organic phase through silica gel (200-300 mesh, 50 g) and rinse with 100 ml toluene. The organic phase is concentrated to a residue of approximately 150 ml, 300 ml n-hexane is added, and the mixture is left to incubate for 4 hours.Stirred at room temperature and crystallized. Filtered, the filter cake was rinsed with 80 ml of n-hexane and dried to obtain 90.8 g of off-white solid compound B, with a yield of 78.5%. Mass spectrum: 309.2(M+H), 1H NMR (400 MHz, CDCl3) δ 7.93 (d, J = 7.7 Hz, 1H), 7.86 (s, 1H), 7.75 (s, 1H), 7.57 (d, J = 8.2 Hz, 1H), 7.46 (t, J = 7.7 Hz, 1H), 7.36 (t, J = 7.4 Hz, 1H), 2.31 (s, 3H), 1.14 (s, 12H). Synthesizing the common ligand compound 1: Synthesizing compound 1-3:

[0023] Successive addition of compound 1-1 (25 g, 103.09 mmol, 1.0 eq.), compound 1-2 (13.85 g, 123.71 mmol, 1.2 eq.), Pd-132 (1.46 g, 2.06 mmol, 0.02 eq.), K3PO4 (43.77 g, 206.19 mmol, 2.0 eq.), toluene (375 ml) into a 1 L three-necked flask, vacuum sealing, three times replacement with nitrogen, heating of the oil bath to about 60°C, stirring for 16 hours, removal of samples and TLC monitoring of the basically complete reaction of the raw material 1-1. Cool to room temperature, add ethyl acetate (300 ml) to the reaction flask, add deionized water for washing (150 ml / times) three times, separate the liquid, and concentrate the organic phase under reduced pressure to form the solid. The crude product is separated by column chromatography (EA:Hex = 1:10). After drying, 18.4 g of off-white solid compound 1-3 are obtained, with a yield of 77.7%. Mass spectrum: 230.1 (M+H) Synthesizing compounds 1-4:

[0024] Successive addition of compound 1-3 (18.02 g, 78.46 mmol, 1.24 eq-), compound B (19.5 g, 63.27 mmol, 1.0 eq.), Pd-132 (0.45 g, 0.632 mmol, 0.01 eq.), Na2CO3 (13.41 g, 126.5 mmol, 2.0 eq.), tetrahydrofuran (180 ml), deionized water (90 ml) into a 500 ml three-necked flask, vacuum sealing, three times replacement with nitrogen, heating of the oil bath to about 60°C, stirring for 2 hours, removal of samples and TLC monitoring of the basically complete reaction of the raw material 1-3. Cool to room temperature, add ethyl acetate (300 ml) to the reaction flask, add deionized water for washing (150 ml / time) three times, separate the liquid, and concentrate the organic phase under reduced pressure to form the solid. Recrystallize the crude product with toluene / methanol (crude product: toluene: methanol = 1:5:40), and after drying the product, 17.1 g of white solid compound 1-4 are obtained, with a yield of 72%.Mass spectrum: 376.2 (M+H). Synthesizing compound 1:

[0025] Successive addition of compound 1-4 (17 g, 45.28 mmol, 1.0 eq.), 10% palladium on carbon (7.23 g, 6.79 mmol, 0.15 eq.), and a mixed solvent of tetrahydrofuran (34 mL) and ethanol (51 mL) to a 250 mL one-necked flask. Introduction of H₂ into the reaction flask. Heating of the oil bath to approximately 60°C. Stirring for 24 hours. Taking samples and monitoring the complete reaction of crude material 1-4 by TLC. Cooling to room temperature. Direct filtration of the reaction liquid. Collection of the filtrate for concentration and drying. The crude product is separated by column chromatography (EA:Hex = 1:8). After drying, 14.63 g of off-white solid compound 1 are obtained, with a yield of 85.6%. Mass spectrum: 378.2(M+H), 1H NMR (400 MHz, CDCl3) δ 8.65 (d, J = 5.7 Hz, 1H), 7.94 (d, J = 7.4 Hz, 1H), 7.86 (s, 1H), 7.72 (d, J = 7.9 Hz, 2H), 7.69 - 7.56 (m, 2H), 7.52 (s, 1H), 7.44 - 7.25 (m, 3H), 2.96 (s, 1H), 2.31 (s, 3H), 1.96 (s, 2H), 1.72 (t, J = 25.0 Hz, 6H). Synthesizing the common intermediate compound 2:

[0026] Add compound 1 (22.6 g, 0.06 mol, 3.0 eq.) and IrCl3 3H2O (7.04 g, 0.02 mol, 1.0 eq.) to a flask, then add 2-ethoxyethanol (133.4 mL) and deionized water (66.7 mL), stir the mixture, and reflux it at 110°C for 16 hours under nitrogen protection. Filter after cooling to room temperature, and dry the filter residue successively with methanol (100 mL x 3) and n-hexane (100 mL x 3) to obtain compound 3 (25.26 g, 64.5%). The obtained compound is used directly in the next step without purification. Synthesizing CPD 7

[0027] Dissolve compound 2 (5.88 g, 3 mmol, 1.0 eq.) in ethylene glycol monoethyl ether (30 ml). Successively add anhydrous sodium carbonate (6.36 g, 60 mmol, 20.0 eq.) and acetylacetone (3 g, 30 mmol, 10.0 eq.). After the additions are complete, stir the mixture at 40°C for 16 hours under the protection of nitrogen and then cool to room temperature. Add 2 g of diatomaceous earth and 300 ml of dichloromethane to the reaction liquid. Then filter the mixture through diatomaceous earth and silica gel. Remove the dichloromethane from the resulting filtrate by centrifugation, and add 40 ml of isopropanol to the remaining liquid. Precipitate the red solid and filter. The solid is suspended in ethyl acetate to obtain the target compound CPD 7 (3.92 g, 62.6%). Sublimation and purification of 3.92 g of CPD 7 crude product yields sublimated pure CPD 7 (2.98 g, 76.2%). Mass spectrum: 1045.35 (M+H) Synthesizing CPD 9

[0028] Dissolve compound 3 (5.88 g, 3 mmol, 1.0 eq.) in ethylene glycol monoethyl ether (30 ml). Successively add anhydrous sodium carbonate (6.36 g, 60 mmol, 20.0 eq.) and 3,7-diethyl-4,6-nandione (6.36 g, 30 mmol, 10.0 eq.). After the additions are complete, stir the mixture at 40°C for 16 hours under the protection of nitrogen and then cool to room temperature. Add 2 g of diatomaceous earth and 300 ml of dichloromethane to the reaction liquid. Then filter the mixture through diatomaceous earth and silica gel. Remove the dichloromethane from the resulting filtrate by centrifugation, and add 40 ml of isopropanol to the remaining liquid. Precipitate the red solid and filter. The solid is suspended in ethyl acetate to obtain the target compound CPD 9 (4.09 g, 58.9%). Sublimation and purification of 4.09 g of crude CPD 9 yields sublimated pure CPD 9 (2.96 g, 72.3%). Mass spectrum: 1157.47 (M+H) Synthesis of CPD 12 Synthesizing compound 3:

[0029] Dissolve compound 2 (19.6 g, 0.01 mol, 1.0 eq.) in DCM (500 ml). Successively add silver trifluoromethanesulfonate (5.25 g, 0.02 mol, 2.0 eq.) and methanol (50 ml) to the reaction liquid. After the additions are complete, stir the mixture at 30°C for 16 hours under nitrogen. Pass the reaction liquid through silica gel and diatomaceous earth to remove insoluble solids, and dry the filtrate by centrifugal force to obtain compound 3 (22.6 g). The product obtained is used directly in the next reaction. Synthesizing CPD 12

[0030] Dissolve compound 3 (3.47 g, 3 mmol, 1.0 eq.) and 2-phenylpyridine (1.4 g, 9 mmol, 3.0 eq.) in absolute ethanol (100 ml). After the addition is complete, stir the mixture under reflux at 80°C for 16 hours under nitrogen protection and then cool to room temperature. Filter, and the filter residue is washed successively three times with methanol and n-hexane. After drying, the target compound CPD 12 (1.74 g, 52.8%) is obtained. Sublime and purify 1.74 g of CPD 12 crude to obtain sublimed pure CPD 12 (1.16 g, 66.4%). Mass spectrum: 1100.37 (M+H) Example 2 (Synthesizing CPD 31 / 33 / 36) Synthesizing the common intermediate compound 5: Synthesizing compound 4:

[0031] Successive addition of compound 1 (14.3 g, 37.88 mmol, 1.0 eq.), sodium tert-butoxide (10.92 g, 113.65 mmol, 3 eq.), and DMSO-d6 (172 ml) to a 250 ml one-necked flask, vacuum sealing, nitrogen replacement three times, heating the oil bath to 75°C, stirring for 24 hours. Cooling to room temperature, adding heavy water (35 ml) and stirring for 10 min. A yellow solid precipitates, then adding deionized water (350 ml) and stirring for 10 min. The yellow solid is collected by suction filtration. The solid is dissolved in ethyl acetate (450 ml), then deionized water is added three times for washing (200 ml / time), the liquid is separated, the aqueous phases are combined and extracted once with a small amount of ethyl acetate, the organic phases are combined, then concentration and drying take place.The crude product is separated by column chromatography (EA:Hex = 1:8). After drying, 12.8 g of white solid compound 4 are obtained, with a yield of 88.6%. Mass spectrum: 382.5 (M+H) 1H NMR (400 MHz, CDCl3) δ 8.65 (d, J = 5.7 Hz, 1H), 7.94 (d, J = 7.4 Hz, 1H), 7.86 (s, 1H), 7.72 (d, J = 7.9 Hz, 2H), 7.69 - 7.56 (m, 2H), 7.52 (s, 1H), 7.44 - 7.25 (m, 3H), 1.99 (m, 2H), 1.89 - 1.58 (m, 6H). Synthesizing Compound 5:

[0032] Referring to the synthesis and post-treatment conditions of compound 2, compound 5 (30.34 g, 77.3%) is obtained. The obtained compound is used directly in the next step without purification. Synthesis of CPD 31: Analogous to the synthesis and purification procedure of CPD 7, the target compound CPD 31 (2.82 g, 81.2%) is obtained. Sublimation and purification of 2.82 g of CPD 31 crude product yields sublimated pure CPD 31 (1.93 g, 68.4%). Mass spectrum: 1041.4 (M+H) Synthesis of CPD 33: Analogous to the synthesis and purification procedure of CPD 9, the target compound CPD 33 (3.37 g, 79.5%) is obtained. Sublimation and purification of 3.37 g of CPD 33 crude product yields sublimated pure CPD 33 (2.55 g, 75.6%). Mass spectrum: 1165.5 (M+H). Synthesis of CPD 36: Analogous to the synthesis and purification procedure of CPD 12, the target compound CPD 36 (4.37 g, 45.6%) is obtained. Sublimation and purification of 4.37 g of CPD 36 crude product yields sublimated pure CPD 36 (2.89 g, 66.1%). Mass spectrum: 1108.4 (M+H) Example 3 (CPD Synthesis of CPD 61 / 63 / 66) Synthesizing the common intermediate compound 7: Synthesizing compound 7-2:

[0033] With reference to the synthesis and treatment process of compounds 1-3, only the corresponding raw materials need to be changed. Synthesizing compound 7-3:

[0034] With regard to the synthesis and treatment process of compounds 1-4, only the corresponding raw materials need to be changed. Synthesizing compound 7-4:

[0035] Successive addition of compound 7-3 (25 g, 64.19 mmol, 1.0 eq.) and dichloromethane (150 ml) to a 500 ml one-necked flask, lowering the temperature of the reaction system to about 0°C and slowly adding bis(2-methoxyethyl)aminosulfur trifluoride (BAST, 35.51 ml, 192.58 mmol, 3.0 eq.) dropwise, stirring at room temperature for 16 hours after addition, taking samples and monitoring the basically complete reaction of the crude material 7-3 by TLC. The reaction liquid is added to saturated sodium carbonate solution (450 ml), the mixture is stirred for 0.5 hours, left to stand for separation, and the aqueous layer is then extracted once by adding dichloromethane (150 ml), the organic phases are combined and washed three times with deionized water (100 ml / time), the liquids are separated, and the organic phases are concentrated and dried.The crude product is separated by column chromatography (EA:Hex = 1:10). After drying, 19.28 g of white solid compound 7-4 are obtained, with a yield of 73%. Mass spectrum: 412.4 Synthesis of compound 7. Referring to the synthesis and treatment processes of compound 1, only the corresponding raw materials need to be changed. Mass spectrum: 414.2 (M+H), 1 H NMR (400 MHz, CDCl3) δ 8.65 (d, J = 5.7 Hz, 1H), 7.94 (d, J = 7.4 Hz, 1H), 7.86 (s, 1H), 7.72 (d, J = 7.9 Hz, 2H), 7.69 - 7.56 (m, 2H), 7.52 (s, 1H), 7.44 - 7.25 (m, 3H), 3.26 (d, 1H), 2.44 (m, 1H), 2.32 (s, 3H),2.03 (m, J = 28.1, 24.1 Hz, 4H), 1.76 (m, 1H). Synthesizing the common intermediate compound 8:

[0036] Referring to the synthesis and post-treatment conditions of compound 2, compound 8 (28.6 g, 68.6%) is obtained. The obtained compound is used directly in the next step without purification. Synthesizing CPD 61:

[0037] Analogous to the synthesis and purification procedure of CPD 7, the target compound CPD 61 (2.81 g, 79.1%) is obtained. Sublimation and purification of 2.81 g of crude CPD 61 yields sublimated pure CPD 61 (1.84 g, 65.4%). Mass spectrum: 1117.2 (M+H) Synthesizing CPD 63:

[0038] Analogous to the synthesis and purification procedure of CPD 9, the target compound CPD 63 (2.92 g, 76.7%) is obtained. Sublimation and purification of 2.92 g of crude CPD 63 yields sublimated pure CPD 63 (2.04 g, 69.8%). Mass spectrum: 1233.5 (M+H) Synthesizing CPD 66:

[0039] Analogous to the synthesis and purification procedure of CPD 12, the target compound CPD 66 (3.51 g, 42.1%) is obtained. Sublimation and purification of 3.51 g of crude CPD 66 yields sublimated pure CPD 66 (1.97 g, 56.1%). Mass spectrum: 1172.3 (M+H). Example 4 (Synthesis of CPD 67 / 69 / 72) Synthesizing the common intermediate compound 10: Synthesizing compound 10-2:

[0040] With reference to the synthesis and treatment process of compounds 1-3, only the corresponding raw materials need to be changed. Synthesizing compound 10-3:

[0041] With regard to the synthesis and treatment process of compounds 1-4, only the corresponding raw materials need to be changed. Synthesizing compound 10-4:

[0042] With regard to the synthesis and treatment process of compound 7-4, only the corresponding raw materials need to be changed.

[0043] Synthesizing Compound 10: Referring to the synthesis and treatment procedures of Compound 1, only the corresponding raw materials need to be changed. Mass spectrum: 396.2 (M+H) 1 H NMR (400 MHz, CDCl3) δ 8.65 (d, J = 5.7 Hz, 1H), 7.94 (d, J = 7.4 Hz, 1H), 7.86 (s, 1H), 7.72 (d, J = 7.9 Hz, 2H), 7.69 - 7.56 (m, 2H), 7.52 (s, 1H), 7.44 - 7.25 (m, 3H). 4.75 (m, 1H), 3.29 (m, 1H), 2.51 (m, 1H), 2.31 (s, 3H), 2.06 - 1.48 (m, 5H). Synthesizing the common intermediate compound 11: Synthesizing compound 11:

[0044] Referring to the synthesis and post-treatment conditions of compound 2, compound 11 (30.32 g, 69.2%) is obtained. The obtained compound is used directly in the next step without purification. Synthesizing CPD 67:

[0045] Analogous to the synthesis and purification procedure of CPD 7, the target compound CPD 67 (3.11 g, 81.2%) is obtained. Sublimation and purification of 3.11 g of crude CPD 67 yields sublimated pure CPD 67 (2.33 g, 74.9%). Mass spectrum: 1081.2 (M+H). Synthesis of CPD 69:

[0046] Analogous to the synthesis and purification procedure of CPD 9, the target compound CPD 69 (2.72 g, 73.2%) is obtained. Sublimation and purification of 2.72 g of crude CPD 69 yields sublimated pure CPD 69 (2.12 g, 77.9%). Mass spectrum: 1193.5 (M+H) Synthesizing CPD 72:

[0047] Analogous to the synthesis and purification procedure of CPD 12, the target compound CPD 72 (4.7 g, 57.6%) is obtained. Sublimation and purification of 4.7 g of crude CPD 72 yields sublimated pure CPD 72 (2.83 g, 60.2%). Mass spectrum: 1136.3 (M+H). Example 5 (Synthesis of CPD 133 / 135 / 138) Synthesizing the common intermediate compound 13: Synthesizing compound 13-2:

[0048] With reference to the synthesis and treatment process of compounds 1-3, only the corresponding raw materials need to be changed. Synthesizing compound 13-3:

[0049] With regard to the synthesis and treatment process of compounds 1-4, only the corresponding raw materials need to be changed. Synthesizing Compound 13:

[0050] Referring to the synthesis and treatment processes of compound 1, only the corresponding raw materials need to be changed. Mass spectrum: 406.2 (M+H), 1H NMR (400 MHz, CDCl3) δ 8.65 (d, J = 5.7 Hz, 1H), 7.94 (d, J = 7.4 Hz, 1H), 7.86 (s, 1H), 7.72 (d, J = 7.9 Hz, 2H), 7.69 - 7.56 (m, 2H), 7.52 (s, 1H), 7.44 - 7.25 (m, 3H), 3.04 (d, 1H), 2.31 (s, 3H), 1.99 (d, J= 1.6 Hz, 2H), 1.75 (m, 1H), 1.51 (m, 1H), 1.34 (m, 1H), 1.26 (m, 1H), 0.87 (s, 6H). Synthesizing the common intermediate compound 14:

[0051] Referring to the synthesis and post-treatment conditions of compound 2, compound 14 (28.75 g, 65.2%) is obtained. The obtained compound is used directly in the next step without purification. Synthesizing CPD 133:

[0052] Analogous to the synthesis and purification procedure of CPD 7, the target compound CPD 133 (2.45 g, 76.2%) is obtained. Sublimation and purification of 2.45 g of CPD 133 crude product yields sublimated pure CPD 133 (1.85 g, 75.5%). Mass spectrum: 1101.3 (M+H) Synthesizing CPD 135:

[0053] Analogous to the synthesis and purification procedure of CPD 9, the target compound CPD 135 (2.81 g, 73.3%) is obtained. Sublimation and purification of 2.81 g of crude CPD 135 yields sublimated pure CPD 135 (2.01 g, 71.5%). Mass spectrum: 1213.5 (M+H) Synthesizing CPD 138:

[0054] Analogous to the synthesis and purification procedure of CPD 12, the target compound CPD 138 (3.85 g, 46.7%) is obtained. Sublimation and purification From 3.85 g of crude CPD 138 to obtain sublimated pure CPD 138 (2.11 g, 54.8%). Mass spectrum: 1156.5 (M+H)

[0055] The appropriate materials are selected, and a similar process can be used for synthesis and sublimation to obtain other compounds. Application example: Fabrication of organic electroluminescent devices. A 50 mm × 50 mm × 1.0 mm glass substrate with transparent ITO electrodes (100 nm) is ultrasonically cleaned in ethanol for 10 min, dried at 150 °C, and then treated with N₂ plasma for 30 min.The washed glass substrate is installed on the substrate holder of the vacuum evaporation device. First, the compound HATCN is evaporated onto the surface of a side equipped with the transparent electrode lead using the transparent electrode masking process to form a thin film 5 nm thick. Next, a layer of HTM1 is evaporated to form a thin film 60 nm thick. Then, a layer of HTM2 is evaporated onto the HTM1 thin film to form a thin film 10 nm thick. Finally, a co-evaporation mode is used on the HTM2 film layer to evaporate the host material CBP and the dopant material (reference compound X, CPD X). The film thickness is 30 nm, and the ratio of host material to dopant material is 90%:10%.The AlQ3 film layer (25 nm) and the LiF film layer (1 nm) are then sequentially deposited onto the light-emitting layer, and finally a layer of metal Al (100 nm) is deposited as an electrode.

[0056] Evaluation: The devices mentioned above are tested for device performance. In each embodiment and comparison example, a constant current supply (Keithley 2400) is used, a fixed current density is applied to the light-emitting element, and the light spectrum is tested using a spectral radiation system (CS 2000). The voltage value and the time at which the test brightness reaches 90% of the initial brightness (LT90) are measured simultaneously. The results are as follows: Dotiermaterial Anlaufspan nung V Stromausb eute Cd / A Leistungsa usbeute lm / W Spitzenwe llenlänge nm LT90@ 3000nits Ausführun gsbeispiel 1 CPD 7 4.18 29.3 22.0 616 186 Ausführun gsbeispiel 2 CPD 9 4.15 32.5 24.6 617 225 Ausführun gsbeispiel 3 CPD 12 4.14 28.8 21.9 615 213 Ausführun gsbeispiel 4 CPD 31 4.16 29.6 22.4 616 203 Ausführun gsbeispiel 5 CPD 33 4.16 33.2 25.1 618 229 Example 6 CPD 36 4.17 29.2 22.0 616 220 Example 7 CPD 61 4.25 30.2 22.3 620 178 Example 8 CPD 63 4.21 31.3 23.4 621 186 Example 9 CPD 66 4.26 29.9 22.1 620 192 Example 10 CPD 67 4.22 29.1 21.7 618 183 Example 11 CPD 69 4.25 30.9 22.8 619 199 Example 12 CPD 72 4.19 28.6 21.4 619 189 Example 17 CPD 135 4.17 30.4 22.9 617 197 Comparison example 1 comparative verb connection 1 4.56 21 14.46 610 102 Comparison example 2 comparative verb connection 2 4.41 20 14.24 612 116 Comparison example 3 Comparative verb connection 3 4.64 21 14.21 611 94 Comparison example 4 Comparative verb connection 4 4.88 18 11.58 608 82

[0057] From the data comparison in the table above, it can be seen that the organic electroluminescence device using the compound of the present invention as a dopant exhibits superior performance in terms of operating voltage, luminous efficacy and lifetime of the device compared to the reference compound.

[0058] Comparison of sublimation temperature: the sublimation temperature is defined as the temperature at which the evaporation rate of 1 angstrom per second at a vacuum of 10 degrees. -7 Torr corresponds.

[0059] The results are as follows: Doping material Sublimation temperature CPD 9 269 CPD 63 252 CPD 69 251 CPD 135 262 Comparison connection 1 280 Comparison connection 2 288 Comparison connection 3 286 Comparison connection 4 276

[0060] The data comparison in the table above shows that the compound of the present invention has a lower sublimation temperature and is suitable for industrial application.

[0061] The present invention unexpectedly provides a higher luminous efficacy and an improved lifetime of the device through a specific arrangement of substituents, while the sublimation temperature is unexpectedly lower compared to the prior art. The foregoing results show that the compound of the present invention offers the advantages of a lower sublimation temperature, high optical and electrochemical stability, high color saturation, high luminous efficacy, a long lifetime of the device, and the like, and can be used in organic electroluminescent devices. In particular, as a dopant emitting red light, the compound has the potential to be used in the OLED industry.

Claims

[1] A compound having a structure of formula II:wherein n is a positive integer from 1 to 2; A CR0 is; Z is independently selected from the group of O or S; R0-R4 are independently selected from the group consisting of hydrogen, deuterium, substituted or unsubstituted C1-C8 alkyl, or substituted or unsubstituted C3-C20 cycloalkyl, wherein at least one of R1 and R2 is substituted or unsubstituted C3-C20 cycloalkyl, wherein the substitution is substitution by deuterium, F, Cl, Br, C1-C4 alkyl, C3-C6 cycloalkyl, cyano or isonitrile, and wherein the substitution is monosubstitution up to the maximum possible substitution; and XY is an OO-type or CN-type ligand. [2] A compound according to claim 1, wherein the substitution is substitution by D, F, C3-C6 cycloalkyl, or C1-C4 alkyl partially or fully substituted by D or F. [3] A compound according to claim 1, wherein R4 is not H. [4] A compound according to claim 3, wherein the position of the R4 substituent is the adjacent position of the metal-Ir-carbon bond or the opposite position of the metal-Ir-carbon bond. [5] A compound according to claim 1, wherein the XY ligand is not the same as the ligand on the left side. [6] A compound according to claim 5, wherein XY is a 1,3-diketone compound. [7] A compound according to claim 1, wherein the compound is one of the following compounds: [8] A compound according to claim 7, wherein Z is one of O or S, wherein R1-R4 are independently selected from the group consisting of hydrogen, deuterium, substituted or unsubstituted C1-C4 alkyl, or substituted or unsubstituted C3-C20 cycloalkyl; and wherein at least one of R1 and R2 is substituted or unsubstituted C3-C20 cycloalkyl, and wherein said substitution is substitution by deuterium, F, Cl, Br, C1-C4 alkyl, C3-C6 cycloalkyl, cyano or isonitrile; and wherein said substitution is monosubstitution up to the maximum possible substitution. [9] A compound according to claim 1, having one of the following structural formulas: CPD 1 CPD 2 CPD 3 CPD 4 CPD 5 CPD 6 CPD 7 CPD 8 CPD 9 CPD 10 CPD 11 CPD 12 CPD 13 CPD 14 CPD 15 CPD 16 CPD 17 CPD 18 CPD 19 CPD 20 CPD 21 CPD 22 CPD 23 CPD 24 CPD 25 CPD 26 CPD 27 CPD 28 CPD 29 CPD 30 CPD 31 CPD 32 CPD 33 CPD 34 CPD 35 CPD 36 CPD 37 CPD 38 CPD 39 CPD 40 CPD 41 CPD 42 CPD 43 CPD 44 CPD 45 CPD 46 CPD 47 CPD 48 CPD 49 CPD 50 CPD 51 CPD 52 CPD 53 CPD 54 CPD 55 CPD 56 CPD 57 CPD 58 CPD 59 CPD 60 CPD 61 CPD 62 CPD 63 CPD 64 CPD 65 CPD 66 CPD 67 CPD 68 CPD 69 CPD 70 CPD 71 CPD 72 CPD 73 CPD 74 CPD 75 CPD 76 CPD 77 CPD 78 CPD 79 CPD 80 CPD 81 CPD 82 CPD 83 CPD 84 CPD 85 CPD 86 CPD 87 CPD 88 CPD 89 CPD 90 CPD 91 CPD 92 CPD 93 CPD 94 CPD 95 CPD 96 CPD 97 CPD 98 CPD 99 CPD 100 CPD 101 CPD 102 CPD 103 CPD 104 CPD 105 CPD 106 CPD 107 CPD 108 CPD 133 CPD 134 CPD 135 CPD 136 CPD 137 CPD 138 CPD 139 CPD 140 CPD 141 CPD 142 CPD 143 CPD 144 o [10] Use of the compound according to any one of claims 1 to 9 in the organic electroluminescent device. [11] Use according to claim 10, wherein the compound according to any one of claims 1 to 9 is used as a dopant material for a phosphorescent host material in a light-emitting layer.

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