Organic electroluminescent material based on polyaryl spirobifluorene and application

Abstract

The invention relates to the field of organic electroluminescent materials, in particular to a material containing 4-aryl substituted fluorenone derivatives and 1, 4-diaryl spirobifluorene, which comprises 4-aryl fluorenone, 1, 4-diaryl fluorenone, 2, 4-diaryl fluorenone, 3, 5-diaryl fluorenone, 1, 4, 6-triaryl fluorenone, 2, 4, 6-triaryl fluorenone, 1, 4, 5, 7-tetraaryl fluorenone and 1, 4-diaryl spirobifluorene. The structural formula of the 4-aryl substituted fluorenone derivative and the structural formula of the 1, 4-diaryl spirobifluorene derivative are shown in the formula I. The invention provides the preparation method of the novel 1, 4-diaryl spirobifluorene material and the application of the novel 1, 4-diaryl spirobifluorene material as a pure hydrocarbon main material to manufacture a phosphorescent organic electroluminescent device.

Description

Technical Field

[0001] The present invention uses a transition metal-catalyzed hydrocarbon arylation reaction to rapidly construct a series of fluorenone derivatives and spirobifluorene derivatives, specifically 4-arylfluorenone, 1,4-diarylfluorenone, 1,4-diarylfluorenone, 3,5-diarylfluorenone, 1,4,6-triarylfluorenone, 2,4,6-triarylfluorenone, 1,4,5,7-tetraarylfluorenone and 1,4-diarylspirobifluorene, and studies the photophysical properties of 1,4-diarylspirobifluorene and its application as a host material in organic electroluminescent devices. Background Art

[0002] Organic light-emitting diodes (OLEDs) have attracted much attention due to their low starting voltage, high brightness, low power consumption, fast response, high clarity, good flexibility, and high luminous efficiency. Under the action of heavy metal atoms, phosphorescent molecules can easily capture and utilize singlet and triplet excitons, so that phosphorescent organic electroluminescent devices (PhOLEDs) can achieve 100% exciton utilization. In most cases, PhOLEDs must rely on the device configuration of the host-guest doped light-emitting layer to achieve efficiency improvement: uniformly dispersing the phosphorescent molecules in the host molecule array can simultaneously improve the photoluminescence efficiency of the light-emitting layer and reduce exciton quenching (such as triplet-triplet exciton quenching). In the light-emitting layer, the content of phosphorescent guest molecules is generally low (about 10wt%), so the dominant host molecules largely determine the physical properties of the light-emitting layer and directly affect the performance of the light-emitting device, especially the driving voltage and power efficiency of the device. Polyaryl spirobifluorene is an important pure carbon-hydrogen host material with the characteristics of high triplet energy level, good thermal stability and high glass transition temperature.

[0003] The synthesis of polyarylspirobifluorenes typically involves electrophilic bromination of fluorene, fluorenones, and spirobifluorenes, followed by Suzuki coupling with arylboronic acids. The C2 position exhibits the highest electrophilic activity, and therefore, most studies have focused on C2-substituted spirobifluorenes. Polyarylspirobifluorenes without C2 substitution are less studied, primarily due to synthetic challenges that limit the exploration of new polyarylspirobifluorene materials. Typically, the synthesis of asymmetric polyarylspirobifluorenes, particularly those with C1 or C4 aryl substitutions, requires the introduction of multiple halogen atoms with varying reactivities on the aromatic ring to enable selective Suzuki coupling.

[0004] In recent years, transition-metal-catalyzed hydrocarbon arylation has emerged as a highly effective strategy for achieving aromatic couplings and constructing fluorene structures. The selective intercyclic ortho-arylation of biphenyl-2-carboxylic acid or biphenyl-2-carboxaldehyde allows for the rapid synthesis of 4-arylspirobifluorenes. While selective intercyclic ortho-aryl olefination and alkynylation of biphenyl-2-carboxaldehyde have been successfully achieved using transient-directed strategies, its arylation remains a challenging task. Summary of the Invention

[0005] The purpose of the present invention is to provide a series of 4-aryl-substituted fluorenone derivatives and 1,4-diarylspirobifluorene materials, including 4-arylfluorenone, 1,4-diarylfluorenone, 2,4-diarylfluorenone, 3,5-diarylfluorenone, 1,4,6-triarylfluorenone, 2,4,6-triarylfluorenone, 1,4,5,7-tetraarylfluorenone, and 1,4-diarylspirobifluorene, and to apply the novel 1,4-diarylspirobifluorene materials as pure hydrocarbon host materials in PhOLEDs.

[0006] The 4-arylfluorenone, 1,4-diarylfluorenone, 2,4-diarylfluorenone, 3,5-diarylfluorenone, 1,4,6-triarylfluorenone, 2,4,6-triarylfluorenone, 1,4,5,7-tetraarylfluorenone and 1,4-diarylspirobifluorene compounds of the present invention have the structure shown in Formula I:

[0007]

[0008] wherein Ar is selected from a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaryl group having 6 to 30 carbon atoms, the heteroatom of the heteroaryl group is preferably selected from an oxygen atom, a nitrogen atom, a sulfur atom, and a selenium atom, and the substituents include but are not limited to a hydrogen atom, a deuterium atom, a halogen atom, a trifluoromethyl group, a C1-50 alkane, an alkoxy group, an alkylsilyl group, a nitro group, a cyano group, an ether group, a substituted amino group, an ester group, an aryl group, a heteroaryl group, and an aldehyde group;

[0009] R is selected from a hydrogen atom, a deuterium atom, a halogen atom, a trifluoromethyl group, a C1-50 alkane, an alkoxy group, an alkylsilyl group, a nitro group, a cyano group, an ether group, a substituted amino group, an ester group, and an aldehyde group;

[0010] Examples of the C1-50 substituted or unsubstituted alkyl group represented by R include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl, neopentyl, cyclopentyl, n-hexyl, cyclohexyl, and n-octyl;

[0011] Examples of the substituted or unsubstituted aryl or heteroaryl group having 6 to 30 carbon atoms represented by Ar include:

[0012]

[0013] Preferably, the synthesized fluorenone derivative containing 4 aromatic substitutions includes but is not limited to the following structural formula:

[0014]

[0015]

[0016]

[0017]

[0018] Preferably, the organic electroluminescent host material includes but is not limited to the following structural formula:

[0019]

[0020]

[0021]

[0022]

[0023] The second object of the present invention is to provide a method for preparing the above-mentioned organic electroluminescent host material. The reaction formula is as follows:

[0024]

[0025] The third object of the present invention is to provide a novel 1,4-diarylspirobifluorene-based pure hydrocarbon organic host material as a host material for a light-emitting layer, and its application in the field of manufacturing phosphorescent organic electroluminescent devices (PhOLEDs).

[0026] The fabricated organic electroluminescent device includes a stacked ITO conductive glass substrate (anode), a hole injection layer (HAT-CN), a hole transport layer (TAPC), an electron blocking layer (TCTA, mCP), a light-emitting layer (FIrPic / Ir(mphmp)2tmd / Ir(ppy)2acac doped with the organic electroluminescent host material of the present invention), an electron transport layer (TmPyPB), an electron injector (LiF), and a cathode layer (Al). The organic electroluminescent device was fabricated using vacuum evaporation. The molecular structures of some of the organic compounds used in the device are shown below.

[0027]

[0028] The beneficial effects of the present invention are:

[0029] 1. The polyaryl spirobifluorene compounds provided by the present invention have good photoelectric properties and thermal stability, and the HOMO and LUMO energy levels are easy to adjust, thereby adapting to a variety of luminescent materials, improving exciton utilization, reducing efficiency roll-off, and having good photoelectric properties.

[0030] 2. The 1,4-diarylspirobifluorene derivative material provided by the present invention can be used as the host material of blue, green and red phosphorescent OLEDs.

[0031] 3. The polyaryl spirobifluorene prepared by the present invention has great application potential in all-carbon skeleton main materials and provides a new synthesis strategy for this type of all-carbon skeleton main materials. This also demonstrates the superiority of C–H activation as a synthetic strategy in the development of optoelectronic materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 is the H NMR spectrum of compound 1;

[0033] Figure 2 is the carbon NMR spectrum of compound 1;

[0034] Figure 3 is the H NMR spectrum of compound B27;

[0035] Figure 4 is the carbon NMR spectrum of compound B27;

[0036] Figure 5 is the H NMR spectrum of compound T23;

[0037] Figure 6 is the carbon NMR spectrum of compound T23;

[0038] Figure 7 is the H NMR spectrum of compound 2;

[0039] Figure 8 is the carbon NMR spectrum of compound 2;

[0040] Figure 9 is the H NMR spectrum of compound B30;

[0041] Figure 10 is the carbon NMR spectrum of compound B30;

[0042] Figure 11 is the H NMR spectrum of compound T28;

[0043] Figure 12 is the carbon NMR spectrum of compound T28;

[0044] Figure 13 is the single crystal structure of compound T23;

[0045] Figure 14 This is the single crystal structure of compound T28;

[0046] Figure 15 Schematic diagram of the structure of the organic electroluminescent device of the present invention. DETAILED DESCRIPTION

[0047] In order to better understand the content of the present invention, the present invention is explained below with reference to specific examples, which are not intended to limit the scope of the present invention.

[0048] Preparation of Example Compound T23

[0049]

[0050] Synthesis of Compound 1: Under air atmosphere, 66.8 mg of bis(hetero)aryl aldehyde (0.2 mmol, 1.0 equiv.), 61.2 mg of iodobenzene (0.3 mmol, 1.5 equiv.), 4.5 mg of Pd(OAc)2 (0.02 mmol, 10 mol%), 7.9 mg of L-tert-leucine (0.06 mmol, 30 mol%), 66.3 mg of AgTFA (0.3 mmol, 1.5 equiv.), and 25.1 mg of ZnCO3 (0.2 mmol, 1.0 equiv.) were added to a Schlenk tube equipped with a magnetic stirrer. The reaction mixture was then heated and stirred at 100°C for 24 hours. After the reaction, the reaction mixture was cooled to room temperature, diluted with 5 mL of CH2Cl2, and filtered through celite. The celite was washed with 20-30 mL of CH2Cl2. The filtrate was concentrated under vacuum to obtain a crude product, which was purified by silica gel column chromatography (petroleum ether / ethyl acetate = 40 / 1, v / v) to obtain the target compound Compound 1 as a light yellow solid with a mass of 52.5 mg and a yield of 64%. 1 H NMR (400MHz, CDCl3): δ = 9.85 (s, 1H), 7.85-7.80 (m, 2H), 7.77-7.65 (m, 7H), 7.60-7.55 ( m,2H),7.48(t,J=7.2,2H),7.43-7.38(m,3H),7.20-7.18(m,3H),7.10-7.08(m,2H)ppm. 13C NMR (100 MHz, CDCl3): δ = 191.72, 145.35, 141.03, 140.69, 140.63, 139.93, 139.89, 138.96, 136.95, 133.66, 133.63, 131.90, 130.84, 130.00, 129.95, 128.99, 128.31, 127.91, 127.78, 127.61, 127.27, 127.19, 127.14 ppm. High-resolution mass spectrometry, ESI source, positive ion mode, molecular formula C 31 H 22 O, theoretical value 433.1563, tested value 433.1563.

[0051]

[0052] Synthesis of B27: TEAB (42 mg, 10 mol%) and K2S2O8 (1.08 g, 2.0 equiv.) were added to a 100 mL Schlenk tube and purged with N2 three times. Compound 1 (820 mg, 2.0 mmol) and DCE (10 mL) were then added. The resulting mixture was stirred at 120°C under N2 for 36 hours. The solution was then cooled to room temperature and the DCE was removed directly under vacuum. The crude product was purified by silica gel column chromatography (petroleum ether / CH2Cl2 = 3 / 1, v / v) to afford the title compound as a yellow solid. The mass was 522.4 mg, with a yield of 64%. 1 H NMR (400MHz, CDCl3): δ = 7.70 (t, J = 8.0, 4H), 7.56 (d, J = 8.4, 2H), 7.60 (d, J = 8.0, 1H), 7.53-7. 46(m,7H),7.40-7.36(m,2H),7.28(d,J=8.0,1H),7.22-7.16(m,2H),6.71(d,J=6.4,1H)ppm. 13 C NMR (100 MHz, CDCl3): δ = 193.20, 143.69, 142.26, 141.12, 141.01, 140.96, 139.64, 137.40, 136.59, 136.40, 134.68, 134.30, 131.41, 130.23, 129.81, 129.01, 128.96, 128.91, 128.33 ppm. High-resolution mass spectrometry, ESI source, positive ion mode, molecular formula C 31 H 20 O, theoretical value 431.1406, tested value 431.1404.

[0053]

[0054] Synthesis of T23: 2-Bromobiphenyl (769.2 mg, 3.3 mmol, 1.1 equiv.) was dissolved in dry THF (40 mL) and cooled to -78°C. A 2.5 M solution of n-BuLi (1.0 equiv.) in pentane was then added dropwise to the solution at -78°C. The resulting mixture was stirred at the same temperature for 1 hour, and B27 (1.22 g, 3 mmol, 1.0 equiv.) dissolved in dry THF (20 mL) was added dropwise. The reaction mixture was then heated to 75°C and stirred for 24 hours. After cooling to room temperature, a saturated ammonium chloride solution was added. The organic layer was extracted with ethyl acetate. The combined organic extracts were dried over sodium sulfate and concentrated under reduced pressure. The concentrated compound was dissolved in DCE (50-100 mL), and trifluoroborane etherate (5.0 equiv.) was slowly added, and the solution was stirred at room temperature for 3 hours. The reaction was then quenched with methanol and evaporated under reduced pressure. Finally, the crude product was purified by column chromatography (petroleum ether / CH 2 Cl 2 =6 / 1, v / v) to obtain the target compound as a white solid with a mass of 1.32 g and a yield of 81%. 1 H NMR (400MHz, CDCl3): δ=7.70-7.68(m,2H),7.62-7.54(m,3H),7.64(d,J=4.4,4H),7.39-7.29(m,4H),7.22(t,J= 7.6,2H),7.10(t,J=7.2,2H),7.05-6.95(m,4H),6.86(t,J=8.4,4H),6.56(d,J=7.2,1H),6.21(d,J=8.0,2H)ppm. 13 C NMR (100 MHz, CDCl3): δ = 149.64, 148.61, 146.43, 142.31, 141.67, 141.20, 141.12, 139.40, 139.35, 138.54, 137.78, 137.06, 129.89, 129.48, 128.93, 128.80, 128.76, 128.71, 127.82, 127.67, 127.41, 127.37, 127.16, 127.10, 125.32, 123.97, 123.77, 123.14, 119.93, 65.62 ppm. High-resolution mass spectrometry, ESI source, positive ion mode, molecular formula C 43 H 28 , theoretical value 567.2083, test value 567.2080.

[0055] Preparation of Example Compound T28

[0056]

[0057] Synthesis of Compound 2: Under air atmosphere, 82.0 mg of bis(hetero)aryl aldehyde (0.2 mmol, 1.0 equiv.), 61.2 mg of iodobenzene (0.3 mmol, 1.5 equiv.), 4.5 mg of Pd(OAc)2 (0.02 mmol, 10 mol%), 7.9 mg of L-tert-leucine (0.06 mmol, 30 mol%), 66.3 mg of AgTFA (0.3 mmol, 1.5 equiv.), and 25.1 mg of ZnCO3 (0.2 mmol, 1.0 equiv.) were added to a Schlenk tube equipped with a magnetic stirrer. The reaction mixture was then heated and stirred at 100°C for 24 hours. After the reaction, the reaction mixture was cooled to room temperature, diluted with 5 mL of CH2Cl2, and filtered through celite. The celite was washed with 20-30 mL of CH2Cl2. The filtrate was concentrated under vacuum to obtain a crude product, which was purified by silica gel column chromatography (petroleum ether / ethyl acetate = 40 / 1, v / v) to obtain the title compound as a light yellow solid. The mass was 58.3 mg, and the yield was 60%. 1H NMR (400MHz, CDCl3): δ=9.86(s,1H),7.89-7.83(m,5H),7.76-7.72(m,5H),7.62(d,J=8.0,1H),7.57(dd ,J1=7.6,J2=1.2,1H),7.50(t,J=7.2,4H),7.44-7.39(m,4H),7.21-7.19(m,3H),7.12-7.10(m,2H)ppm. 13 C NMR (100 MHz, CDCl3): δ = 191.53, 145.15, 142.60, 141.17, 141.15, 140.98, 140.24, 139.79, 136.95, 133.56, 133.52, 131.79, 130.73, 130.11, 129.86, 128.91, 128.22, 127.85, 127.68, 127.50, 127.40, 127.19, 127.07, 125.66, 125.11 ppm. High-resolution mass spectrometry, ESI source, positive ion mode, molecular formula C 37 H 26 O, theoretical value 509.1876, tested value 509.1874.

[0058]

[0059] Synthesis of B30: TEAB (42 mg, 10 mol%) and K2S2O8 (1.08 g, 2.0 equiv.) were added to a 100 mL Schlenk tube and purged with N2 three times. Compound 2 (972 mg, 2.0 mmol) and DCE (10 mL) were then added. The resulting mixture was stirred at 120°C under N2 for 36 hours. The solution was then cooled to room temperature and the DCE was removed directly under vacuum. The crude product was purified by silica gel column chromatography (petroleum ether / CH2Cl2 = 3 / 1, v / v) to afford the title compound as a yellow solid with a mass of 581.0 mg and a yield of 60%. 1 H NMR (400MHz, CDCl3): δ=7.89-7.88(m,1H),7.80-7.74(m,6H),7.63(d,J=6.0,1H) ,7.53-7.47(m,9H),7.40-7.35(m,4H),7.23-7.16(m,2H),6.71(d,J=7.6,1H)ppm. 13 C NMR (100 MHz, CDCl3): δ = 193.08, 143.67, 142.33, 141.50, 141.33, 141.07, 139.66, 138.39, 137.57, 136.41, 134.72, 134.28, 131.50, 130.36, 129.02, 128.97, 128.92, 128.36, 127.60, 127.53, 127.39, 126.14, 124.17, 123.25 ppm. High-resolution mass spectrometry, ESI source, positive ion mode, molecular formula C 37 H 24 O, theoretical value 485.1900, tested value 485.1901.

[0060]

[0061] Synthesis of T28: 2-Bromobiphenyl (769.2 mg, 3.3 mmol, 1.1 equiv.) was dissolved in dry THF (40 mL) and cooled to -78°C. A 2.5 M solution of n-BuLi (1.0 equiv.) in pentane was then added dropwise to the solution at -78°C. The resulting mixture was stirred at the same temperature for 1 hour, and B30 (1.45 g, 3 mmol, 1.0 equiv.) dissolved in dry THF (20 mL) was added dropwise. The reaction mixture was then heated to 75°C and stirred for 24 hours. After cooling to room temperature, a saturated ammonium chloride solution was added. The organic layer was extracted with ethyl acetate. The combined organic extracts were dried over sodium sulfate and concentrated under reduced pressure. The concentrated compound was dissolved in DCE (50-100 mL), and trifluoroborane etherate (5.0 equiv.) was then slowly added, and the solution was stirred at room temperature for 3 hours. The reaction was then quenched with methanol and evaporated under reduced pressure. Finally, the crude product was purified by column chromatography (petroleum ether / CH 2 Cl 2 =5 / 1, v / v) to obtain the target compound as a white solid with a mass of 1.45 g and a yield of 78%. 1 H NMR (400MHz, CDCl3): δ=7.70(d,J=6.8,2H),7.61-7.55(m,3H),7.42-7.28(m,12H),7.22-7.20(m,2H),7.09(d,J =7.6,1H),7.04-7.00(m,4H),6.97-6.93(m,1H),6.91-6.87(m,4H),6.52(d,J=7.2,1H),6.44(d,J=2.0,2H)ppm. 13 C NMR (100 MHz, CDCl3): δ = 149.77, 148.23, 145.92, 141.95, 140.98, 140.96, 140.06, 139.49, 139.35, 139.32, 137.07, 129.85, 129.36, 128.76, 128.66, 128.38, 127.74, 127.57, 127.45, 127.26, 127.16, 127.01, 126.97, 126.81, 123.70, 123.58, 123.57, 123.04, 119.71, 65.60 ppm. High-resolution mass spectrometry, ESI source, positive ion mode, molecular formula C 49 H 34 , theoretical value 621.2577, test value 621.2579.

[0062] Application examples of phosphorescent organic electroluminescent devices:

[0063] The present invention uses compounds T22, T23, T26, and T28 as main materials to prepare phosphorescent organic electroluminescent devices. Figure 15 As shown, the organic electroluminescent device comprises, from bottom to top, an ITO conductive glass substrate (1), a hole injection layer (2), a hole transport layer (3), a light-emitting layer (4), an electron transport layer (5), an electron injection layer (6), and a cathode layer (7). It should be understood that the device implementation process and results are only for better explanation of the present invention and are not intended to limit the present invention.

[0064]

[0065] Application Example 1

[0066] The phosphorescent organic electroluminescent device was prepared as follows:

[0067] 1. Cleaning ITO (indium tin oxide) glass: wash with alkali and deionized water in sequence, dry in a vacuum drying oven, and then treat in a plasma cleaner for 10 minutes;

[0068] 2. On the anode ITO glass, vacuum evaporate the hole injection layer HAT-CN (10 nm), the hole transport layer TAPC (30 nm), the electron blocking layer TCTA (10 nm), and the exciton blocking layer mCP (10 nm) in sequence at a rate of 0.1 nm / s.

[0069] 3. Vacuum-deposit a light-emitting layer (3%) Ir(mphmp)2tmd:T22 on the electron-blocking layer at a rate of 0.1 nm / s to a thickness of 20 nm.

[0070] 4. Vacuum evaporate the electron transport layer TmPyPb (40 nm) on the light-emitting layer at a rate of 0.1 nm / s; 5. Vacuum evaporate the electron injection layer LiF (0.8 nm) on the electron transport layer at a rate of 0.08 nm / s; 6. Vacuum evaporate the cathode Al (100 nm) on the electron injection layer at a rate of 0.1 nm / s.

[0071] The device structures used include:

[0072] Blue light: ITO / HAT-CN(10nm) / TAPC(30nm) / TCTA(10nm) / mCP(10nm) / T22:

[0073] 15wt%Flrpic,(20nm) / TmPyPB(50nm) / LiF(0.8nm) / Al(100nm);

[0074] ITO / HAT-CN(10nm) / TAPC(30nm) / TCTA(10nm) / mCP(10nm) / T23: 15 wt% Flrpic, (20nm) / TmPyPB(40nm) / LiF(0.8nm) / Al(100nm);

[0075] ITO / HAT-CN(10nm) / TAPC(30nm) / TCTA(10nm) / mCP(10nm) / T26: 15 wt% Flrpic, (20nm) / TmPyPB(40nm) / LiF(0.8nm) / Al(100nm);

[0076] ITO / HAT-CN(10nm) / TAPC(30nm) / TCTA(10nm) / mCP(10nm) / T28: 15 wt% Flrpic, (20nm) / TmPyPB(40nm) / LiF(0.8nm) / Al(100nm).

[0077] Green light: ITO / HAT-CN(10nm) / TAPC(30nm) / TCTA(10nm) / T22: 15 wt% Ir(ppy)2acac, (20nm) / TmPyPB(60nm) / LiF(0.8nm) / Al(100nm);

[0078] ITO / HAT-CN(10nm) / TAPC(30nm) / TCTA(10nm) / T23: 15 wt% Ir(ppy)2acac, (20nm) / TmPyPB(60nm) / LiF(0.8nm) / Al(100nm);

[0079] ITO / HAT-CN(10nm) / TAPC(30nm) / TCTA(10nm) / T26: 15 wt% Ir(ppy)2acac, (20nm) / TmPyPB(60nm) / LiF(0.8nm) / Al(100nm);

[0080] ITO / HAT-CN(10nm) / TAPC(30nm) / TCTA(10nm) / T28: 15 wt% Ir(ppy)2acac, (20nm) / TmPyPB(60nm) / LiF(0.8nm) / Al(100nm).

[0081] Red light: ITO / HAT-CN (10 nm) / TAPC (30 nm) / TCTA (10 nm) / mCP (10 nm) / T22:3 wt% Ir(mphmp)2tmd, (20 nm) / TmPyPB (40 nm) / LiF (0.8 nm) / Al (100 nm);

[0082] ITO / HAT-CN(10nm) / TAPC(30nm) / TCTA(10nm) / mCP(10nm) / T23:3wt%Ir(mphmp)2tmd,(20nm) / TmPyPB(40nm) / LiF(0.8nm) / Al(100nm);

[0083] ITO / HAT-CN(10nm) / TAPC(30nm) / TCTA(10nm) / mCP(10nm) / T26:3wt%Ir(mphmp)2tmd,(20nm) / TmPyPB(40nm) / LiF(0.8nm) / Al(100nm);

[0084] ITO / HAT-CN(10nm) / TAPC(30nm) / TCTA(10nm) / mCP(10nm) / T28:3wt%Ir(mphmp)2tmd,(20nm) / TmPyPB(40nm) / LiF(0.8nm) / Al(100nm).

[0085] The performance test results of devices 1 to 12 prepared in Application Examples 1-12 are shown in Table I.

[0086] Table I

[0087]

[0088]

[0089] As can be seen from Table I, the organic electroluminescent device prepared based on the material of the present invention exhibits good device performance, with a maximum current efficiency of 94.8 lm / W and a maximum EQE of 26.1%. The device exhibits excellent characteristics in terms of current efficiency and device efficiency.

[0090] The above descriptions are only some implementation cases of the present invention and are not intended to limit the present invention. Any modifications, replacements, etc. made within the spirit and principles of the present invention are included in the scope of protection of the present invention.

Claims

1. A series of novel 4-aryl-substituted fluorenone derivatives and 1,4-diarylspirobifluorene materials, including 4-arylfluorenone, 1,4-diarylfluorenone, 2,4-diarylfluorenone, 3,5-diarylfluorenone, 1,4,6-triarylfluorenone, 2,4,6-triarylfluorenone, 1,4,5,7-tetraarylfluorenone, and 1,4-diarylspirobifluorene, and the novel 1,4-diarylspirobifluorene materials are used as pure carbon-hydrogen host materials in phosphorescent organic electroluminescent devices, characterized in that: Its structural features are shown in Formula I: Wherein, Ar is selected from substituted or unsubstituted aryl groups having 6 to 30 carbon atoms, substituted or unsubstituted heteroaryl groups having 6 to 30 carbon atoms, the heteroatom of the heteroaryl group is preferably selected from oxygen atoms, nitrogen atoms, sulfur atoms, and selenium atoms, and the substituents include but are not limited to hydrogen atoms, deuterium atoms, halogen atoms, trifluoromethyl groups, C1-50 alkanes, alkoxy groups, alkylsilyl groups, nitro groups, cyano groups, ether groups, substituted amino groups, ester groups, aryl groups, heteroaryl groups, and aldehyde groups; R is selected from hydrogen atoms, deuterium atoms, halogen atoms, trifluoromethyl groups, C1-50 alkanes, alkoxy groups, alkylsilyl groups, nitro groups, cyano groups, ether groups, substituted amino groups, ester groups, and aldehyde groups.

2. The electroluminescent material molecule T23 according to claim 1, characterized in that: The 1-position is substituted by a biphenyl group, and the 4-position is substituted by a phenyl group. The specific structure is as shown in Formula II:

3. A method for preparing a polyaryl spirobifluorene electroluminescent material molecule T23 having a biphenyl group as a substituent at position 1 and a phenyl group as a substituent at position 4 as claimed in claim 1 or 2, characterized in that: The following steps are involved: 1) Under air atmosphere, 66.8 mg of bis(hetero)aryl aldehyde (0.2 mmol, 1.0 equiv.), 61.2 mg of iodobenzene (0.3 mmol, 1.5 equiv.), 4.5 mg of Pd(OAc)2 (0.02 mmol, 10 mol%), 7.9 mg of L-tert-leucine (0.06 mmol, 30 mol%), 66.3 mg of AgTFA (0.3 mmol, 1.5 equiv.), and 25.1 mg of ZnCO3 (0.2 mmol, 1.0 equiv.) were added to a Schlenk tube equipped with a magnetic stirrer; the reaction mixture was then heated and stirred at 100°C for 24 hours. The reaction formula is as follows: After the reaction, the reaction mixture was cooled to room temperature, diluted with 5 mL of CH2Cl2, and filtered through celite. The celite was washed with 20-30 mL of CH2Cl2. The filtrate was concentrated under vacuum to obtain a crude product, which was then purified by silica gel column chromatography (petroleum ether / ethyl acetate = 40 / 1, v / v) to obtain the title compound as a light yellow solid. 2) TEAB (42 mg, 10 mol%) and K2S2O8 (1.08 g, 2.0 equiv.) were added to a 100 mL Schlenk tube, and the tube was purged with N2 three times, followed by the addition of Compound 1 (820 mg, 2.0 mmol) and DCE (10 mL); the resulting mixture was stirred at 120° C. under N2 for 36 hours. The reaction formula is as follows: The solution was then cooled to room temperature, and DCE was directly removed under vacuum; the crude product was purified by silica gel column chromatography (petroleum ether / CH2Cl2=3 / 1, v / v) to obtain the title compound as a yellow solid; 3) 2-Bromobiphenyl (769.2 mg, 3.3 mmol, 1.1 equiv.) was dissolved in dry THF (40 mL) and cooled to -78°C; a pentane solution of 2.5 M n-BuLi (1.0 equiv.) was then added dropwise to the above solution at -78°C; the resulting mixture was stirred at the same temperature for 1 hour, and B27 (1.22 g, 3 mmol, 1.0 equiv.) dissolved in dry THF (20 mL) was added dropwise; the reaction mixture was then heated to 75°C and stirred for 24 hours. The reaction formula is as follows: After cooling to room temperature, a saturated ammonium chloride solution was added; the organic layer was extracted with ethyl acetate; the combined organic extracts were dried over sodium sulfate and concentrated under reduced pressure; the concentrated compound was dissolved in DCE (50-100 mL), and trifluoroboron etherate (5.0 equiv.) was then slowly added, and the solution was stirred at room temperature for 3 hours; the reaction was subsequently quenched with methanol and evaporated under reduced pressure; finally, the crude product was purified by column chromatography (petroleum ether / CH2Cl2=6 / 1, v / v) to give the title compound as a white solid.

4. As described in claims 1-3, polyaryl spirobifluorene is selected as the main material to prepare an organic electroluminescent device, characterized in that: The organic electroluminescent device uses phosphorescent material as the luminescent material, and comprises, from bottom to top, an ITO conductive glass substrate (1), a hole injection layer (2), a hole transport layer (3), a luminescent layer (4), an electron transport layer (5), an electron injection layer (6), and a cathode layer (7).

5. The method of claim 1 or 4, wherein the organic electroluminescent device is prepared The invention relates to an organic electroluminescent device with ITO glass as the anode, HAT-CN as the hole injection layer, TAPC as the hole transport layer, TCTA as the electron blocking layer, Ir(ppy)2acac doped in the organic electroluminescent host material T23 of the present invention as the light-emitting layer, TmPyPb as the electron transport layer, LiF as the electron injection layer, and Al as the cathode.

6. As claimed in claim 5, the performance test of the organic electroluminescent device prepared with polyaryl spirobifluorene as the main material is characterized in that the maximum power efficiency is 98.4 lm / W and the maximum external quantum efficiency (EQE) is 26.1%.

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