TWI755589B - Carbazole compounds, the manufacturing method and the use of the same as light emitting materials, and organic light emitting diodes - Google Patents

Abstract

A carbazole compound, the manufacturing method and the use of the same as light emitting materials, and organic light emitting diodes are provided. Two bipolar compounds based on carbazole or tricarbazole substituted benzimidazo＜1,2-f＞phenanthridine have been synthesized in which the carbazole as well as tricarbazole are C10-linked to the benzimidazo＜1,2-f＞phenanthridine unit.

Description

Carbazole compound, method for producing the same, use as light-emitting material, and organic light-emitting diode element

The present invention relates to a carbazole compound, its production method, its use as a light-emitting material, and an organic light-emitting diode element.

In recent years, liquid crystal display devices (Liquid Crystal Display) have become the mainstream of various display devices. For example, household televisions, personal computers, laptop computers, monitors, mobile phones and digital cameras are all products that use a large number of liquid crystal display devices. The backlight module used in the liquid crystal display device is used for supplying a light source with sufficient brightness and uniform distribution of the liquid crystal, so that the liquid crystal display device can display images normally.

Based on the advantages of wide viewing angle, fast response time, high brightness, low power consumption, and wide operating temperature range, organic light-emitting diodes have gradually become common light-emitting elements for backlight modules. Nowadays, organic light-emitting diodes mostly use host-guest light-emitting two-body systems. The selection of appropriate phosphorescent guest light-emitting bodies can theoretically make the internal quantum efficiency reach 100%. Therefore, phosphorescent light-emitting materials have recently become a very important development of organic electroluminescent materials. direction.

In the development of blue host materials, the triplet energy level of the host material must be higher than or equal to the triplet energy level of the guest material, so as to avoid energy loss caused by energy back transfer, which in turn leads to luminous efficiency (also known as current efficiency; Therefore, it is a necessary condition to have a large triplet energy level. In addition, in addition to energy level matching, the material of the organic light-emitting layer needs to have a high glass transition temperature (Tg) to have better thermal stability.

The main purpose of the present invention is to provide a carbazole compound with the characteristics of blue light emission range, high glass transition temperature and good light emission efficiency.

Another object of the present invention is to provide the use of a carbazole compound as a light-emitting material.

Another object of the present invention is to provide a method for producing a carbazole compound.

Another object of the present invention is to provide an organic light emitting diode device with better efficiency and longer service life.

其中，R為咔唑基。 The carbazole compound of the present invention has the structure of the following formula (A):

wherein R is a carbazolyl group.

In an embodiment of the present invention, the carbazole compound has the structure of the following formula (1):

In an embodiment of the present invention, the carbazole compound having the structure of the preceding formula (A) is used as a light-emitting material.

In one embodiment of the present invention, the method for producing a carbazole compound produces the compound 1 shown below by the following reaction formula,

In an embodiment of the present invention, the method for producing a carbazole compound produces the compound 3 shown below by the following reaction formula.

In one embodiment of the present invention, a method for producing a carbazole compound produces a compound of the following formula (1), that is, a 4-cbzCBIZ compound, by the following reaction formula.

電子輸送層設置於發光層上。電子注入層設置於電子輸送層上。第二導電層設置於電子注入層上。 In an embodiment of the present invention, the organic light emitting diode device includes a first conductive layer, a hole transport layer, an electron blocking layer, a light emitting layer, an electron transport layer, an electron injection layer, and a second conductive layer. The hole transport layer is disposed on the first conductive layer. The electron blocking layer is provided on the hole transport layer. The light-emitting layer is disposed on the electron blocking layer, and includes a carbazole compound having the structure of the following formula (1):

The electron transport layer is disposed on the light emitting layer. The electron injection layer is disposed on the electron transport layer. The second conductive layer is disposed on the electron injection layer.

In an embodiment of the present invention, the organic light emitting diode element further comprises a second light emitting layer, disposed between the light emitting layer and the electron blocking layer, comprising compound ID5, and having the following structure,

In an embodiment of the present invention, the carbazole compound has the structure of the following formula (2):

In an embodiment of the present invention, the carbazole compound having the structure of the preceding formula (2) is used as a light-emitting material.

In an embodiment of the present invention, the method for producing a carbazole compound produces the compound 8 shown below by the following reaction formula.

In an embodiment of the present invention, the method for producing a carbazole compound produces the compound 8 shown below by the following reaction formula.

In one embodiment of the present invention, the method for producing a carbazole compound prepares the compound 9 shown below by the following reaction formula.

In one embodiment of the present invention, the method for producing a carbazole compound produces a compound of the following formula (2), that is, a 4-tcbzCBIZ compound, through the following reaction formula.

電子輸送層設置於發光層上。電子注入層設置於電子輸送層上。第二導電層設置於電子注入層上。 In an embodiment of the present invention, the organic light emitting diode device includes a first conductive layer, a hole transport layer, an electron blocking layer, a light emitting layer, an electron transport layer, an electron injection layer, and a second conductive layer. The hole transport layer is disposed on the first conductive layer. The electron blocking layer is provided on the hole transport layer. The light-emitting layer is disposed on the electron blocking layer and includes a carbazole compound having the structure of the following formula (2):

The electron transport layer is disposed on the light emitting layer. The electron injection layer is disposed on the electron transport layer. The second conductive layer is disposed on the electron injection layer.

100: the first conductive layer

200: hole transport layer

300: electron blocking layer

400: light-emitting layer

500: electron transport layer

600: Electron injection layer

700: the second conductive layer

900: Organic Light Emitting Diode Components

Figure 1A is an X-Ray crystal structure diagram of the 4-cbzCBIZ compound.

Figure 1B is a UV-Vis absorption spectrum of the 4-cbzCBIZ compound.

2A and 2B are graphs showing the test results of the electrochemical properties of the 4-cbzCBIZ compound.

3A to 3D are graphs showing the results of thermal properties testing of the 4-cbzCBIZ compound.

Figures 4A to 4C are graphs showing the results of energy transfer testing of 4-cbzCBIZ compounds.

FIGS. 5A and 5B are graphs of the test results of thin-film state energy levels of the 4-cbzCBIZ compound.

FIG. 6A is a schematic diagram of an embodiment of the organic light emitting diode device of the present invention.

FIG. 6B is a schematic diagram of the device structure and energy level of the organic light emitting diode device embodiment of the present invention.

7A and 7B are graphs showing the current density-voltage test results of the organic light emitting diode device of the present invention.

FIG. 7C is a graph showing the luminance-voltage test result of the organic light emitting diode device of the present invention.

FIG. 7D is a CIE color coordinate result diagram of the organic light emitting diode element of the present invention.

8A to 8D are diagrams showing the efficiency test results of the organic light emitting diode device of the present invention.

9A and 9B are graphs showing the test results of emission spectrum of the organic light emitting diode element of the present invention with different concentrations of Firpic elements under operating voltages of 4.5V and 12V, respectively.

10A and 10B are schematic diagrams of device structures and energy levels of different embodiments of the organic light emitting diode device of the present invention.

11A and 11B are graphs of current density-voltage test results of different embodiments of the organic light emitting diode device of the present invention.

FIG. 11C is a graph showing luminance-voltage test results of different embodiments of the organic light emitting diode device of the present invention.

FIG. 11D is a CIE color coordinate result diagram of different embodiments of the organic light emitting diode device of the present invention.

12A to 12C are diagrams showing the efficiency test results of different embodiments of the organic light emitting diode device of the present invention.

13A and 13B are graphs of emission spectrum results of elements with different electron transport layers in different embodiments of the organic light emitting diode element of the present invention under operating voltages of 4.5V and 12V, respectively.

FIG. 14 is a schematic diagram of the device structure and energy level of the organic light emitting diode device according to different embodiments of the present invention.

15A and 15B are graphs of current density-voltage test results of different embodiments of the organic light emitting diode device of the present invention.

FIG. 15C is a graph showing luminance-voltage test results of different embodiments of the organic light emitting diode device of the present invention.

FIG. 15D is a CIE color coordinate result diagram of different embodiments of the organic light emitting diode device of the present invention.

16A to 16D are diagrams showing the efficiency test results of different embodiments of the organic light emitting diode device of the present invention.

17A and 17B are graphs of emission spectrum results of elements with different electron transport layers in different embodiments of the organic light emitting diode element of the present invention under operating voltages of 5V and 12V, respectively.

Figure 18 is an X-Ray crystal structure diagram of the 4-tcbzCBIZ compound.

Figures 19A to 19C are graphs of thermal properties test results of 4-tcbzCBIZ compounds.

20A and 20B are graphs showing the measurement results of the photophysical properties of the 4-tcbzCBIZ compound and the 4-3cbzBIZ compound.

21A and 21B are graphs showing the measurement results of electrochemical properties of the 4-tcbzCBIZ compound.

其中，R為咔唑基。 The carbazole compound of the present invention has the structure of the following formula (A):

wherein R is a carbazolyl group.

即4-cbzCBIZ化合物。 In one embodiment, the carbazole compound has the structure of the following formula (1):

Namely 4-cbzCBIZ compound.

In one embodiment of the present invention, the preparation process of the 4-cbzCBIZ compound is shown in the following reaction formula.

More specifically, compound 1 is prepared by the following reaction formula,

In one embodiment, take carbazole (Carbazole, 3.2g, 19.16mmol) and potassium carbonate (Potassium carbonate, K ₂ CO ₃ , 2.66g, 19.25mmol) in a 100-ml round-bottom flask, and then add dimethyl methylene Dimethyl sulfoxide (DMSO, 36 mL) was reacted at 120° C. for one hour, and then 3-Fluoro-2-nitroaniline (3-Fluoro-2-nitroaniline, 2 g, 12.82 mmol) was added to react for five hours. The reaction was tracked with TLC chips. After the reaction was completed, the solvent was distilled off under reduced pressure, and dichloromethane was used as the washing liquid and filtered with celite. After the filtrate was concentrated by cyclotron, the eluent was n-hexane to ethyl acetate 6: 1. Carry out tube chromatography to obtain 2.34 g of orange-red solid with a yield of 60% (yield=actual yield/theoretical yield*100%). Using nuclear magnetic resonance spectrometer and mass spectrometer as identification, the results are: 1H NMR (400MHz, (CD3)2SO): δ 8.19 (d, J=7.6Hz, 2H), 7.53 (t, J=8.0, 1H), 7.39(t,J=7.2Hz,2H),7.27(t,J=7.2Hz,2H),7.18(t,J=7Hz,3H),6.82(dd,J1=7.2Hz,J2=0.8Hz,1H ), 6.73(s, 2H); 13C NMR (100MHz, (CD3)2SO): δ 175.16, 145.05, 140.37, 133.71, 132.14, 130.97, 126.28, 122.78, 120.49, 120.09, 118.68, 116.63, 109.20.HRMS (MALDI ) m/z calcd for C18H13N3O2 303.1008, obsd.303.0988(M+).

Compound 2 is prepared by the following reaction formula,

In one example, 2-Bromobenzaldehyde (2-Bromobenzaldehyde, 2 g, 10.87 mmol), 2-Chlorobenzeneboronic acid (2.03 g, 13.01 mmol), Sodium carbonate (Na ₂ CO ₃ , 1.73g, 16.3mmol), tetrakis(triphenylphosphine)palla-dium(0), Pd( _PPh3 ) ₄ , 0.25g, 0.22mmol) in a 25ml double-necked flask, rack The condenser tube and the three-way valve were installed, and after the argon gas was pumped for three times, dimethylformamide (Dimethylformamide, DMF, 21.74 mL) which had been dehydrated and deoxygenated was added, and the reaction was carried out at 100° C. for two hours. The reaction was tracked with TLC sheet. After the reaction was completed, the solvent was distilled off under reduced pressure, and dichloromethane was used as the washing liquid and filtered with celite. After the filtrate was concentrated by cyclotron, the eluent was n-hexane to ethyl acetate 20: 1. Perform tube chromatography to obtain 1.88 g of compound 2 as a clear liquid with a yield of 78%. The structure identification of the compound is shown in the literature (Bioorg.Med.Chem . 2013 , 21 , 2568-2576).

Compound 3 is prepared by the following reaction formula,

In one embodiment, take compound 1 (1 g, 3.3 mmol), compound 2 (0.78 g, 3.61 mmol), sodium metabisulfite (Sodium metabisulfite, 0.57 g, 3.61 mmol), stannous chloride (Tin(II) chloride, SnCl ₂ , 2.19 g, 11.55 mmol) in a 100-mL round-bottomed flask, and then added dehydrated dimethylformamide (Dimethylformamide, DMF, 18.15 mL), ethanol (Ethanol, 18.15 mL), at 130 ° C React for three hours. The reaction was tracked with TLC sheet. After the reaction was completed, the solvent was distilled off under reduced pressure, and dichloromethane was used as the washing solution and filtered through celite. After the filtrate was concentrated by cyclotron, the eluent was n-hexane to dichloromethane 1: 1 Carry out tube chromatography to obtain 1.23 g of compound 3 as a brown oily product with a yield of 80%. Using nuclear magnetic resonance spectrometer and mass spectrometer as identification, the results are: ¹ H NMR (400MHz, (CD _{3) 2} SO): δ 12.61(s, 1H), 8.24(d, J=6.4Hz, 2H), 7.77 (d,J=6.0Hz,1H),7.62(d,J=7.6Hz,1H),7.56-7.48(m,2H),7.37-7.17(m,11H),7.09-7.03(m,2H); ¹³ C NMR (100MHz, (CD ₃ ) ₂ SO): δ 152.07, 140.73, 139.66, 138.73, 138.47, 136.64, 131.91, 131.61, 131.05, 131.96, 128.93, 127.94, 127.18, 126.63, 125.94 , 122.79, 120.05, 119.54, 111.33, 110.52. HRMS(ESI) m/z calcd for C ₃₁ H ₂₀ ClN ₃ 469.1436, obsd.470.1443(M+1 ⁺ ).

The 4-cbzCBIZ compound was prepared by the following reaction formula,

In one embodiment, take compound 3 (1.13g, 2.41mmol), palladium acetate (Palladium(II) acetate, Pd(OAc) ₂ , 0.11g, 0.49mmol), 4,5-bisdiphenylphosphine-9 ,9-dimethylxanthene (4,5-Bis(diphenylphosphino)-9,9-dimethylxanthene, Xantphos, 0.28g, 0.48mmol), cesium carbonate (Caesium carbonate, Cs ₂ CO ₃ , 2.35g, 7.21 mmol) ) in a 25 ml double-necked bottle, put on a condenser tube and a three-way valve, and after pumping and exchanging argon three times, add dimethylformamide (Dimethylformamide, DMF, 12 mL) that has been dehydrated and deoxygenated, and react at 160 ° C. Five Hour. The reaction was tracked with TLC sheet. After the reaction was completed, the solvent was distilled off under reduced pressure, and dichloromethane was used as the washing solution and filtered through celite. After the filtrate was concentrated by cyclotron, the eluent was n-hexane to dichloromethane 1: 1 Carry out tube chromatography to obtain 0.76 g of 4-cbzCBIZ compound as a white solid with a yield of 73%. Using nuclear magnetic resonance spectrometer, mass spectrometer and X-Ray single crystal diffractometer as identification, the results are: ¹ H NMR (400MHz, (CD ₃ ) ₂ SO): δ 8.71 (d, J=8.4Hz, 1H) ,8.59-8.54(m,3H),8.42(d,J=8.4Hz,1H),8.25-8.23(m,2H),7.82(t,J=8Hz,1H),7.75-7.67(m,3H) , 7.61 (t, J=8Hz, 1H), 7.55 (t, J=7.6Hz, 1H) 7.35-7.31 (m, 6H); ¹³ C NMR (100MHz, (CD ₃ ) ₂ SO): δ 145.54, 142.21 , 134.93,134.63,131.33,130.26,130.02,129.46,129.21,126.89,126.30,125.42,125.04,124.05,123.96,123.70,123.60,122.89,122.51,120.65,120.39,116.74,114.39,111.42.HRMS (MALDI) m /z calcd for C ₃₁ H ₁₉ N ₃ 433.1579, obsd.433.1592(M ⁺ ). The X-Ray crystal structure diagram is shown in Fig. 1A.

The 4-cbzCBIZ compound was further tested below.

In one example, Photophysical Properties measurements were performed on the 4-cbzCBIZ compound.

More specifically, UV-visible absorption spectra (UV-visible absorption spectra) were measured using equipment such as a UV-Vis absorption spectrometer (UV-1601PC, Shimadzu Corporation, Japan), a fluorescence spectrometer (F-4500, Hitachi Corporation, Japan). absorption spectrum (UV), normal temperature fluorescence emission spectrum (FL), low temperature fluorescence emission spectrum (LTFL) and low temperature phosphorescence emission spectrum (PH). The measurement conditions are as follows: using spectral grade tetrahydrofuran (THF) as a solvent, the compound is prepared into a solution to be tested with a concentration of 10 ^-5 M, and the ultraviolet-visible absorption spectrum and room temperature fluorescence emission spectrum are measured; use spectral grade 2 - Methyltetrahydrofuran (2-Methyltetrahydrofuran, 2-MeTHF) was used as a solvent, the compound was prepared into a solution to be tested with a concentration of 10 ^-5 M, and liquid nitrogen was used as a refrigerant. Measurement of low temperature phosphorescence emission spectra. The measured spectral data were normalized. The measurement results are shown in Figure 1B and Table 1 below.

其中，^a最大吸收波長 ^b吸光係數 ^c吸收波長起始值 ^dE_g=1240.8/λ_onset ^Abs；^e常溫螢光最大放射波長/低溫螢光最大放射波長/低溫磷光放射波長起始值 ^fE_T=1240.8/λ_oneset ^Ph； ^g以coumarin 1於THF之量子產率作為標準品(Q.Y.=0.85)，其餘化合物皆於THF下作測量。

Among them, ^a maximum absorption wavelength ^b absorption coefficient ^c absorption wavelength initial value ^d E _g =1240.8/λ _onset ^Abs ; ^e room temperature fluorescence maximum emission wavelength/low temperature fluorescence maximum emission wavelength/low temperature phosphorescence emission wavelength initial value ^f E _T =1240.8/λ _oneset ^Ph ; ^g takes the quantum yield of coumarin 1 in THF as a standard (QY=0.85), and all other compounds are measured under THF.

According to the ultraviolet-visible absorption spectrum (UV) of the 4-cbzCBIZ compound shown in Fig. 1, the absorption peak at wavelength 290-295 nm belongs to the absorption of π-π ^* of the carbazole group, which is the stronger spin-allowed absorption . The absorption peak at the wavelength of 300-350 nm belongs to the absorption of the carbazole group n-π ^* , which is a weaker absorption peak. The onset wavelength (λ _onset ^Abs ) of ultraviolet-visible absorption light is located at 382 nm, and the calculated energy level difference is 3.28 eV. According to the room temperature fluorescence emission spectrum (FL) of the 4-cbzCBIZ compound, with 291 nm as the excitation wavelength, the measured maximum room temperature fluorescence emission wavelength is located at 416 nm. In low temperature fluorescence emission spectroscopy (LTFL), because the measurement environment is reduced to 77K, the molecules cannot rotate freely, and the rigidity is strong, so it cannot release energy through non-radiative methods, and the emission is blue-shifted, and the maximum wavelength is located at 397nm . The onset wavelength (λ _onset ^PH ) of low-temperature phosphorescence is located at 443 nm, and the calculated triplet state energy ₍ ET ) is 2.8 eV, which is higher than that of the common blue light emitter bis(4,6-difluorobenzene) The triplet energy level (2.70eV) of Bis[2-(4,6-difluorophenyl)pyridinato-C2,N](picolinato)iridium(III), Firpic), Therefore, this series of compounds has the potential to be used as the host luminescent material of blue organic light-emitting diodes with FIrpic as the guest luminescent material.

In one example, Electrochemical Properties tests were performed on the 4-cbzCBIZ compound. More specifically, it is measured by using (CHI 1405, CH Instruments, USA), using cyclic voltammetry (CV) and differential-pulse voltammetry (DPV) to measure Oxidation potential (E ^ox ) and reduction potential (E ^re ) of the compound, and then the highest filled molecular energy level (E _HOMO ) and the lowest filled molecular energy level (E _LUMO ) of the compound are calculated. The measurement conditions are as follows: the measurement of oxidation potential and reduction potential is performed with silver/silver chloride (Ag/AgCl) as the reference electrode and platinum wire (Pt) as the auxiliary electrode.

For the measurement of oxidation potential, a glassy carbon electrode was used as the working electrode, and dichloromethane (Dichloromethane), which had been dewatered by phosphorus ^pentoxide (P ₂ O ₅ ), was used as a solvent. Tetrabutylammonium perchlorate (TBAP) was used as the electrolyte solution, and the compound was prepared into a solution with a concentration of 10 ^-3 M to be tested, and the oxidation potential (E ^ox ) was measured.

In the measurement of reduction potential, glassy carbon electrode was used as working electrode, dimethylformamide (DMF) which had been dewatered by calcium hydride was used as solvent, and 10 ^-1 M tetrabutylammonium perchlorate solution was used as electrolyte solution. The compound was prepared into a solution to be tested with a concentration of 10 ^-3 M. The solution to be tested was deoxygenated in a nitrogen environment, and then the reduction potential (E ^re ) was measured under nitrogen.

Ferrocene was used as calibration standard. The platinum electrode was used as the working electrode, the water-removed dichloromethane and the water-removed dimethylformamide were used as the solvent, respectively, and 10 ^-1 M tetrabutylammonium perchlorate was prepared. The solution was used as an electrolyte, and ferrocene was prepared into a solution with a concentration of 10 ^-3 M to be tested, and its oxidation potential (E ^ox ) was measured by cyclic voltammetry.

The data measured by cyclic voltammetry and differential pulse voltammetry is not the absolute energy level value of each material, so ferrocene is used as the calibration standard to measure the relative potential value, and then calculate the absolute potential of the compound value. The highest filled electron energy level (E _HOMO ) and the lowest filled electron energy level (E _LUMO ) of the compound are calculated according to the following formula: E _HOMO =△E+E _{HOMO(ferrocene)} =-1.2×(E _DPV ^ox -E ^Fc+/Fc )+(-4.8) eV

E _LUMO =△E+E _{HOMO(ferrocene)} =-0.92×(E _DPV ^re -E ^Fc+/Fc )+(-4.8)eV

E _DPV in the formula is the maximum value of the first peak of differential pulse wave voltammetry; E ^Fc+/Fc is the value of (Epa+Epo)/2 obtained by ferrocene by cyclic voltammetry. The test results are shown in Figures 2A, 2B and Table 2 below.

其中，^a以差式脈波伏安法測量且以二茂鐵校正所得第一個氧化峰之電位；^b以差式脈波伏安法測量且以二茂鐵校正所得第一個還原峰之電位；^c溶液態之最高填滿電子軌域(HOMO)與最低未填滿電子軌域(LUMO)之能階；^d以AC2測量薄膜態之能階，E_LUMO=E_HOMO+Eg。

Wherein, ^a is the potential of the first oxidation peak measured by differential pulse voltammetry and corrected by ferrocene; ^b is the potential of the first reduction peak obtained by differential pulse voltammetry and corrected by ferrocene; ^c The energy levels of the highest filled electron orbital (HOMO) and the lowest unfilled electron orbital (LUMO) in the solution state; ^d The energy level of the thin film state is measured by AC2, E _LUMO =E _HOMO +Eg.

From the measurement results, it can be known that the E _HOMO of compound 4-cbzCBIZ is higher and the E _LUMO is lower than that of common blue guest light-emitting materials (E _HOMO =5.7eV, E _LUMO =3.1eV). In addition, it has a matching energy level with common electron transfer and hole materials, which can reduce the energy barrier of electron and hole injection. Therefore, this series of compounds have potential as blue light host materials.

In one example, thermal property testing was performed on the 4-cbzCBIZ compound. More specifically, a differential scanning card meter (Differential Scanning Calorimeter, DSC) (Q20 type differential scanning card meter, TA Instruments, USA) was used to measure the melting point (T _m ) and glass transition temperature (T _g of the compound) of the compound. ), crystallization point (T _c ). The measurement conditions are as follows: under the nitrogen flow rate of 20mL/min, the heating rate is 10°C/min, the temperature is increased from 30°C to 350-400°C, and the maximum temperature is maintained for one minute, and then the temperature is lowered to 30°C at the same cooling rate of 10°C/min. The same process was repeated twice, and the second measurement was used as the glass transition temperature of the compound; the thermal decomposition temperature (T) of the compound was measured with a Thermogravimetric Analyzer (TGA) (PerkinElmer TGA 7, PerkinElmer, USA). _d ). The measurement conditions are as follows: under nitrogen flow, the heating rate is 10°C/min, and the temperature is raised from room temperature to 800°C. When the loss ratio of the tested compound reaches 5 wt%, the temperature at this time is the thermal cracking temperature of the compound. The test results are shown in Figures 3A to 3D and Table 3 below.

It can be seen from Table 3 that the glass transition temperature of the 4-cbzCBIZ compound is as high as 128°C. Since the main structure of benzimidazole (benzimidazole) was changed to benzimidazo cyclized phenanthridine compound (benzimidazo<1,2-f>phenanthridine), the rotation of the single bond was successfully reduced without increasing the molecular weight, so that the Increasing the rigidity of the structure increases the glass transition temperature and improves the thermal stability of the molecule. The 4-cbzCBIZ compound can be seen to have crystallization points (Tc) at 225°C and 260°C, and the temperature is quite high, indicating that the compound still has quite good stability in the amorphous state. Generally, the manufacturing temperature of the component is about 200℃. If the thermal cracking temperature (Td) of the material is too low, the material will be decomposed and destroyed during evaporation, thus affecting the efficiency of the component. The thermal cracking temperature of compound 4-cbzCBIZ is 341℃, which can be applied to components make.

In one example, energy transfer assays are performed on 4-cbzCBIZ compounds. The measurement conditions are as follows: first take 45 mg of compound 4-cbzCBIZ and 225 mg of polystyrene (PS), use sodium thiosulfate (Sodium thiosulfate, Na ₂ S ₂ O ₃ .5H ₂ O) to remove chlorine, Potassium carbonate (K ₂ CO ₃ ) to remove acid and chloroform (CHCl ₃ ) to remove water by molecular sieve was used as a solvent to prepare 4.5 ml of main luminophore mother solution, and then take 0.5 ml to nine samples respectively. bottle. Next, take 10 mg of guest phosphor FIrpic, prepare 20 ml of guest phosphor mother solution with chloroform, take 0, 0.1, 0.3, 0.5, 0.7, 0.9, 1.1, 1.3, 1.5 ml to the above nine sample bottles as 0wt %, 1wt%, 3wt%, 5wt%, 7wt%, 9wt%, 11wt%, 13wt%, 15wt%, and finally add chloroform respectively to prepare a total of 2 ml of the solution to be coated. After the coating solution is subjected to ultrasonic vibration to mix the solute and solvent evenly, use a 0.45 μm PTTE filter to filter dust and impurities, and then spin coating (Spin coating) at 3000 rpm for 60 seconds. On a quartz glass plate, and heated at 80°C for 10 minutes in a vacuum state, turn off the heating, continue to cool down in a vacuum state for 30 minutes, and then use a fluorescence spectrometer (F-4500, Hitachi, Japan) to measure the thin-film state light. physical properties. The measurement results are shown in Figs. 4A to 4C.

As shown in Figure 4A, the UV-Vis absorption spectrum of the guest luminophore FIrpic has a singlet metal-to-ligand charge-transfer (MLCT) absorption peak at a wavelength of 380 nm, while compound 4 The thin-film fluorescence emission spectrum of -cbzCBIZ falls at 360-550 nm, and the two partially overlap, indicating that there is energy transfer between this compound and the guest luminophore FIrpic. That is, when the compound 4-cbzCBIZ absorbs energy, it releases energy in the form of light. After absorbing its energy, the guest luminophore will transition to an excited state and release energy in the form of light emission. This process is consistent with the light emission mechanism of the host-guest light-emitting system.

As shown in Figure 4B, with the increase of the weight percentage of the blended guest luminophore FIrpic, the intensity of the thin film fluorescence emission peak of compound 4-cbzCBIZ decreases, while the fluorescence emission peak intensity of the guest luminophore FIrpic at 450-550 nm increases, Therefore, it can be inferred that there is an energy transfer phenomenon between the compound 4-cbzCBIZ and FIrpic.

In order to understand the relationship between the doping concentration of the host-guest luminophore and the energy transfer efficiency, the energy transfer formula E=1-(F _DA /F _D ) is used to calculate, where F _DA is the host luminophore with the doped guest luminophore. The integrated value of the light emission curve, and F _D is the integrated value of the fluorescence emission curve of the main luminophore without the guest luminophore, and the calculated E value is plotted against the mixing concentration of the guest luminophore. As shown in Figure 4C, the highest energy transfer efficiency of compound 4-cbzCBIZ with FIrpic is 87%.

In one example, thin film state energy level testing was performed on compound 4-cbzCBIZ. More specifically, it was measured with a spectroradiometer (cs1000, Konica minolta, Japan). The measurement results are shown in Figures 5A, 5B and Table 4 below.

其中，E_LUMO=E_HOMO+E_g。測量之薄膜態E_LUMO和E_HOMO與常見的傳電子、電洞材料具有相互匹配的能階，能夠減少電子、電洞注入能障。因此，此系列化合物皆有潛力作為藍光主發光體材料。

where E _LUMO =E _HOMO +E _g . The measured thin-film E _LUMO and E _HOMO have matching energy levels with common electron-conveying and hole materials, which can reduce the energy barrier of electron and hole injection. Therefore, this series of compounds have potential as blue light host materials.

電子輸送層500設置於發光層400上。電子注入層600設置於電子輸送層500上。第二導電層700設置於電子注入層600上。 As shown in the embodiment shown in FIG. 6 , the organic light emitting diode element 900 of the present invention includes a first conductive layer 100, a hole transport layer 200, an electron blocking layer 300, a light emitting layer 400, an electron transport layer 500, an electron injection layer 600, and the second conductive layer 700 . The hole transport layer 200 is disposed on the first conductive layer 100 . The electron blocking layer 300 is disposed on the hole transport layer 200 . The light-emitting layer 400 is disposed on the electron blocking layer 300, and includes a carbazole compound having the structure of the following formula (1):

The electron transport layer 500 is disposed on the light emitting layer 400 . The electron injection layer 600 is disposed on the electron transport layer 500 . The second conductive layer 700 is disposed on the electron injection layer 600 .

In one embodiment, the first conductive layer 100 is an anode, and preferably has a work function above 4.5 eV. The material of the first conductive layer 100 may be indium tin oxide (ITO), tin oxide, gold, silver, platinum or copper.

In one embodiment, the hole transport layer (HTL) 200 is 4,4'-cyclohexylbis[N,N-bis(4-methylphenyl)aniline](4,4'-Cyclohexylidenebis [N,N-bis(4- methylphenyl)benzenamine], TAPC), the thickness is preferably 50nm. However, in different embodiments, the hole transport layer may be 1,3,5-tris(diphenylamino)benzene (1,3,5-Tris(diphenylamino)benzene, TDAB), 2,2',7, 7'-Tetrakis(diphenylamino)-9,9'-spirobifluorene (2,2',7,7'-Tetrakis(diphenylamino)-9,9'-spirobifluorene, SPIRO-TAD), and the thickness is not The limit is 50nm.

In one embodiment, the electron block layer (EBL) 300 is 1,3-Bis(N-carbazolyl)benzene (1,3-Bis(N-carbazolyl)benzene, mCP), and the thickness is preferably is 10nm. However, in different embodiments, the electron blocking layer can be diphenylbis[4-(pyridin-3-yl)phenyl]silane (Diphenylbis(4-(pyridin-3-yl)phenyl)silane, DPPS), fluorine LiF (LiF), Tris(8-hydroxyquinolinato)aluminium (Alq ₃ ), Bis(10-hydroxybenzo[h]quinolinato) beryllium (Bis(10-hydroxybenzo[h]quinolinato) beryllium, Bebq ₂ ), 3-(Biphenyl-4-yl)-5-(4-tert-butylphenyl)-4-phenyl-4H-1,2,4-triazole (3-(Biphenyl- 4-yl)-5-(4-tert-butylphenyl)-4-phenyl-4H-1,2,4-triazole, TAZ) or 2,9-dimethyl-4,7-biphenyl-1,10 -2,9-Dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP), and the thickness is not limited to 10 nm.

In one embodiment, the electron transport layer (ETL) 500 is Diphenylbis(4-(pyridin-3-yl)phenyl) silane, DPPS), the thickness is preferably 55nm. However, in different embodiments, the electron transport layer 500 may be (2,4,6-Tris[3-(diphenylphosphinyl)phenyl]-1,3,5-triazine, PO-T2T), (2,4,6- tris[3-(1H-pyrazol-1-yl)phenyl]-1,3,5-triazine, 3P-T2T), and the thickness is not limited to 55 nm.

In one embodiment, the electron injection layer 600 is lithium fluoride. However, in other embodiments, the electron injection layer 600 may be lithium superoxide (Lithium superoxide, LiO ₂ ), lithium boron oxide (Lithium metaborate LiBO ₂ ), and the thickness is preferably 0.8 nm.

In one embodiment, the second conductive layer 700 is aluminum. However, in different embodiments, the second conductive layer 700 may be indium, magnesium-indium alloy, magnesium-aluminum alloy, aluminum-lithium alloy or magnesium-silver alloy, and the thickness is preferably 120 nm. The second conductive layer 700 is preferably a cathode.

More specifically, in one embodiment, the organic light emitting diode device is fabricated by sequentially depositing on ITO (Indium tin oxide) by vacuum evaporation. Its structure is: using transparent and conductive ITO as anode; TAPC as hole conduction layer; mCP as electron blocking layer; main luminescent material mixed with different concentrations of FIrpic as luminescent layer; DPPS as electron conduction layer; Electron injection layer; aluminum as cathode. Among them, the light-emitting layer uses 4-cbzCBIZ compound as the light-emitting body material or parent material mixed with different proportions of FIrpic as shown in Table 5 below. Viewed from different angles, the 4-cbzCBIZ compound can be used as a luminescent material.

The current density-voltage test was carried out on the organic light emitting diode element, and measured with a spectroradiometer (cs1000, Konica minolta, Japan). The results are shown in Figures 7A and 7B. As shown in Figures 7A and 7B, it can be observed that when the 4-cbzCBIZ compound is mixed with 12% Firpic compound, there is a higher current density. The driving voltage (Vt) is defined as the operating voltage when the current density is 20 mA/cm ² . As shown in Table 6 below, the element mixed with 12% FIrpic has the lowest driving voltage of 7.48 V.

The organic light emitting diode element was subjected to a luminance-voltage test, measured with a spectrocolorimeter (cs1000, Konica minolta, Japan), and the results are shown in Fig. 7C. As shown in FIG. 7C , the device mixed with 18% FIrpic achieves the highest luminance of 2205cd/m ² .

Measured with a spectrocolorimeter (cs1000, Konica minolta Co., Japan), the results are shown in the CIE diagram of FIG. 7D. The luminescence color of the compound 4-cbzCBIZ element shifted to blue and then to green with the increase of voltage, indicating that the recombination zone first shifted to the cathode and then moved to the anode, which also means that with the increase of voltage, electrons The speed increase is more obvious than the electric hole speed.

The organic light emitting diode element was tested for efficiency, measured with a spectrocolorimeter (cs1000, Konica minolta, Japan), and the results are shown in FIGS. 8A to 8D and Table 7 below.

According to the current density-luminous efficiency (ηc) and current density-luminous power (ηp) plots, it can be observed that the maximum luminous efficiency of the element mixed with 18% FIrpic is 16.84cd when the operating voltage of the element is 4.5V /A, the maximum luminous power is 11.78 lm/W. The life time (Lifetime) of the component is measured as the time required for the brightness of 1000cd/m ² to 500cd/m ² . When the 4-cbzCBIZ compound is mixed with 18% FIrpic, the longest life time is 10 minutes.

The spectrum was measured with a spectrocolorimeter (cs1000, Konica minolta, Japan), and the spectrum results are shown in FIGS. 9A to 9B. According to the spectrum results, it can be observed that with the increase of voltage, the peak intensity of the element of compound 4-cbzCBIZ at a wavelength of about 500 nm tends to increase, and there is a red-shift phenomenon.

Based on the above test, 4-cbzCBIZ compound can have better luminous efficiency and longest lifetime when blended with 18% FIrpic. According to this condition, the electron conduction layer is optimized. It is expected that by replacing different electron conduction layers, the The energy levels are more matched and the light emission efficiency is improved. In one embodiment, the structure of the organic light emitting diode device uses transparent and conductive ITO as the anode (first electrode); TAPC as the hole transport layer (HTL); mCP as the electron blocking layer (EBL); Mix different concentrations of FIrpic main luminescent material as emissive layer (EML); use three electron transport layers (ETL), namely DPPS, (2,4,6-Tris[3-(diphenylphosphinyl)phenyl]-1,3,5 -triazine, PO-T2T), (2,4,6-tris[3-(1H-pyrazol-1-yl)phenyl]-1,3,5-triazine, 3P-T2T); lithium fluoride (LiF) As electron injection layer (EIL); aluminum (Al) as cathode. 6B, 10A, and 10B are schematic diagrams of the device structure and energy levels of the organic light emitting diode device embodiments of the electron transport layer using DPPS, PO-T2T, and 3P-T2T, respectively. More specifically, the electron transport layer uses 3P-T2T and PO-T2T as shown in Table 8 below.

The current density-voltage test was carried out on the organic light-emitting diode elements whose front electron transport layers were DPPS, 3P-T2T and PO-T2T respectively, and measured with a spectrocolorimeter (cs1000, Konica minolta, Japan). The results are shown in Figure 11A, 11B. As shown in FIGS. 11A and 11B , it can be observed that the element with PO-T2T as the electron transport layer has a higher current density at a higher voltage. The driving voltage (Vt) is defined as the operating voltage when the current density is 20 mA/cm ² . As shown in Table 9 below, the driving voltage of the three different components is between 8.2-10.9V.

The brightness-voltage test was carried out on the organic light-emitting diode elements whose front electron transport layers were DPPS, 3P-T2T and PO-T2T respectively, and measured with a spectrocolorimeter (cs1000, Konica minolta, Japan). The results are shown in Figure 11C . As shown in FIG. 11C , the device with 18% FIrpic blending achieves the highest luminance of 2205 cd/m ² .

The CIE color coordinates are shown in Fig. 11D. As measured by a spectrocolorimeter (cs1000, Konica minolta, Japan), the luminescence color of the 4-cbzCBIZ compound element shifts to blue and then to green as the voltage increases, indicating that the binding The Recombination zone moves towards the cathode first and then moves towards the anode, which also means that with the increase of voltage, the speed of electrons increases more than that of holes.

Efficiency tests were carried out on organic light-emitting diode devices whose front electron transport layers were DPPS, 3P-T2T, and PO-T2T, respectively, and were measured with a spectrocolorimeter (cs1000, Konica minolta, Japan). The results are shown in Figures 12A to 12C and the following shown in Table 10.

Taking the current density-luminous efficiency (ηc) and current density-luminous power (ηp) as a plot, it can be observed that the element with DPPS as the electron conduction layer has a maximum luminous efficiency of 16.84 when the operating voltage of the element is 4.5V. cd/A, the maximum luminous power is 11.78 lm/W; with 3P-T2T as the element of the electron conduction layer, when the operating voltage of the element is 5V, the maximum luminous efficiency is 15.98cd/A, and when the operating voltage of the element is 4.5V, the The maximum luminous power is 10.43 lm/W; when PO-T2T is used as the element of the electron conduction layer, when the operating voltage of the element is 7V, the maximum luminous efficiency is 19.29cd/A, and when the operating voltage of the element is 5.5V, the maximum luminous power is 10.67lm/W.

According to the spectrum shown in Figures 13A and 13B , measured with a spectrocolorimeter (cs1000, Konica minolta, Japan), it can be observed that as the voltage increases, the element of the 4-cbzCBIZ compound is located at the peak intensity (Intensity) at a wavelength of about 500 nm. There is an upward trend, and there is a redshift phenomenon.

In one embodiment, in order to balance the electron conduction rate and the hole conduction rate in the device to improve the efficiency and life of the device, as shown in Figure 14, an additional layer of compound ID5 and 4-cbzCBIZ compound is added to form a double EML layer. ) element, the architecture is shown in Table 11 below. Among them, the structure of compound ID5 is as follows.

The current density-voltage test was performed on the organic light emitting diode element, and the measurement was performed with a spectroradiometer (cs1000, Konica minolta, Japan). The results are shown in Figures 15A and 15B. From Figures 15A and 15B, it can be observed that the device with the 20nm ID5 light-emitting layer has a higher current density. The driving voltage (Vt) is defined as the operating voltage when the current density is 20 mA/cm ² . As shown in Table 12 below, the device with 20nm ID5 light-emitting layer has the lowest driving voltage of 7.09V, which is lower than the driving voltage of the device with pure 4-cbzCBIZ mixed with Firpic.

The organic light emitting diode element was subjected to a luminance-voltage test, measured with a spectrocolorimeter (cs1000, Konica minolta, Japan), and the results are shown in Fig. 15C. As shown in FIG. 15C , the device with the 20nm ID5 light-emitting layer achieves the highest luminance of 18490cd/m ² .

Measured with a spectrocolorimeter (cs1000, Konica minolta Co., Japan), the results are shown in the CIE graph shown in FIG. 15D. The luminescence color of the compound 4-cbzCBIZ element shifted to blue and then to green with the increase of voltage, indicating that the recombination zone first shifted to the cathode and then moved to the anode, which also means that with the increase of voltage, electrons The speed increase is more obvious than the electric hole speed.

Efficiency tests were carried out on the organic light emitting diode elements of the front row, measured with a spectrocolorimeter (cs1000, Konica minolta, Japan), and the results are shown in FIGS. 16A to 16C and Tables 13 and 14 below.

Using the current density-luminous efficiency (η c) and current density-luminous power (η p) plots, it can be observed that, with a 10nm ID5 compound luminescent layer, the maximum luminous efficiency is 20.02 when the operating voltage of the device is 5.0V cd/A; and the device with 20nm ID5 compound light-emitting layer, when the operating voltage of the device is 3.5V, the maximum luminous power is 16.9 lm/W.

Table 14

The Lifetime of the component is shown in Figure 16D. The measurement method is the time required for the brightness from 1000cd/m ² to 500cd/m ² , with a 10nm ID5 light-emitting layer element, the longest lifetime is 221 minutes. Compared to pure 4-cbzCBIZ blended Firpic elements, the lifetime is longer.

According to the spectra shown in Figures 17A and 17B, measured with a spectrocolorimeter (cs1000, Konica minolta, Japan), it can be observed that the components doped with ID5 are all blue-shifted, and as the voltage increases, the compound 4-cbzCBIZ is more blue-shifted. The peak intensity (Intensity) of the component located at a wavelength of about 500nm has a tendency to increase, and there is a phenomenon of red shift.

即4-tcbzCBIZ化合物。 In one embodiment, the carbazole compound of the present invention has the structure of the following formula (2):

Namely 4-tcbzCBIZ compound.

In an embodiment of the present invention, the preparation process of 4-tcbzCBIZ compound is shown in the following reaction formula.

More specifically, in the above reaction formula, the structure of compound 5 is:

The preparation method comprises: taking 9-acetyl-3,6-diiodo carbazole (9-acetyl-3,6-diiodo carbazole, 5.66g, 12.3mmol), carbazole (Carbazole, 4.2g, 25.1mmol) , cuprous oxide (Copper(I)oxide, Cu ₂ O, 3.5g, 24.6mmol) in a 25ml double-necked flask, put on a condenser tube and a three-way valve, and after pumping argon for three times, add dewatered and deoxygenated The dimethylacetamide (Dimethylacetamide, DMAc, 12.3 mL) was reacted at 170° C. for sixteen hours. The reaction was tracked with a TLC sheet. After the reaction was completed, the solvent was distilled off under reduced pressure, and dichloromethane was used as the washing solution and filtered through celite. Potassium hydroxide (KOH, 6.8 g, 122.7 mmol) was added to the concentrated filtrate, and tetrahydrofuran (THF, 50 mL) was used as a solvent, and methanol (Methanol, 17 mL) and pure water (H ₂ O) were added. , 7 mL), and reacted at 80 °C for one hour. The reaction was tracked with TLC tablets. After the reaction was completed, the solvent was swirled and concentrated to dryness, and ethyl acetate was used as the washing liquid and filtered with celite. After the filtrate was swirled and concentrated, the eluent was n-hexane to ethyl acetate 4: 1 Carry out tube chromatography, and then wash the powder with dichloromethane to obtain a white solid, 3.92 g, with a yield of 65%. For the identification of compounds, please refer to Zheng Yujie's master's thesis: Zheng Yujie, Synthesis, properties and application in phosphorescent organic light-emitting diodes of tricarbazole and benzimidazole bipolar materials. National Taiwan University, 2018 .

The structure of compound 6 is:

The preparation method comprises: taking 2-fluoro-6-bromonitrobenzene (6-Bromo-2-fluoronitrobenzene, 3g, 13.6mmol), phthalimide (Phthalimide, 3g, 20.4mmol), sodium hydride ( Sodium hydride, NaH, 0.49 g, 20.4 mmol) was placed in a 100-mL round-bottom flask, and then dimethyl sulfoxide (DMSO, 27 mL) was added, and the reaction was carried out at 120° C. for six hours. The reaction was tracked with TLC sheet. After the reaction was completed, the solvent was distilled off under reduced pressure, and dichloromethane was used as the washing solution and filtered through celite. After the filtrate was concentrated by cyclotron, the eluent was n-hexane to dichloromethane 1: 1 Carry out tube chromatography to obtain a pale yellow solid, 2.09 g, with a yield of 44%. Using nuclear magnetic resonance spectrometer and mass spectrometer as identification, the result is ¹ H NMR (400MHz, (CDCl ₃ ): δ 7.95-7.93(m, 4H), 7.83-7.81(m, 3H), 7.53(t, J= 8.4Hz, 1H), 7.43 (dd, J ₁ =1.2Hz, J ₂ =8.0Hz, 1H); ¹³ C NMR (100MHz, (CDCl ₃ ): δ 165.99, 135.08, 135.04, 132.11, 131.54, 129.85, 126.39 ,124.46,115.23.HRMS(MALDI)m/z calcd for C ₁₄ H ₇ BrN ₂ O ₄ 345.9589,obsd.345.9213(M ⁺ ).

The structure of compound 7 is:

The preparation method comprises: taking compound 5 (1.2 g, 2.4 mmol), compound 6 (0.8 g, 2.31 mmol), cuprous oxide (Copper(I) oxide, Cu ₂ O, 0.66 g, 4.6 mmol) in 25 ml of bismuth A neck flask, a condenser tube and a three-way valve were installed, and after argon was pumped for three times, dimethylacetamide (DMAc, 2.3 mL), which had been dehydrated and deoxygenated, was added to react at 170° C. for 16 hours. The reaction was tracked with TLC sheet. After the reaction was completed, the solvent was distilled off under reduced pressure, and dichloromethane was used as the washing solution and filtered through celite. After the filtrate was concentrated by cyclotron, the eluent was n-hexane to dichloromethane 1: 1 Carry out tube chromatography to obtain 0.67 g of pale yellow solid with a yield of 38%. Using nuclear magnetic resonance spectrometer and mass spectrometer as identification, the result is ¹ H NMR (400MHz, ((CD ₃ ) ₂ SO): δ 8.31(d, J=1.6Hz, 2H), 8.16(d, J=8.0Hz ,4H),8.07(t,J=8.0Hz,1H),8.01(dd,J ₁ =3.2Hz,J ₂ =5.6Hz,2H),7.94(dd,J ₁ =0.8Hz,J ₂ =8.0Hz ,1H),7.89(dd,J ₁ =3.2Hz,J ₂ =5.2Hz,2H),7.85(dd,J ₁ =0.8Hz,J ₂ =8.0Hz,1H),7.66(dd,J ₁ =2.0 Hz, J ₂ =8.8Hz, 2H), 7.50(d, J=8.8Hz, 2H), 7.45-7.39(m, 8H), 7.30-7.26(m, 4H); ¹³ C NMR (100MHz, (CDCl _{3 )} ): δ 166.43,142.05,141.37,135.55,133.77,132.29,131.96,131.88,131.67,127.33,126.99,126.36,124.96,124.71,123.56,120.58,120.25,120.19,111.56,110.16..HRMS (ESI) m / z calcd for C ₅₀ H ₄₉ N ₅ O ₄ 763.2220, obsd.763.2197(M ⁺ ).

其製備方式包含： The structure of compound 8 is:

Its preparation method includes:

Method 1: Take compound 7 (0.43 g, 0.56 mmol), use Tetrahydrofuran (THF, 2.8 mL) as a solvent, stir at room temperature until the solid dissolves, and then add hydrazine monohydrate (N ₂ H ₄ , 0.17 mL) for three hours at room temperature. The reaction was tracked with TLC tablets. After the reaction was completed, the solvent was swirled and concentrated to dryness, and dichloromethane was used as the washing solution and filtered with celite. After the filtrate was swirled and concentrated, the eluent was n-hexane to dichloromethane 1: 1 Carry out tube chromatography to obtain 0.29 g of orange-red solid with a yield of 81%.

Method 2: Take 3-fluoro-2-nitrobenzene (compound 4) (3-Fluoro-2-nitroaniline, 0.2 g, 1.3 mmol) and cesium carbonate (Caesium carbonate, Cs ₂ CO ₃ , 0.63 g, 1.93 mmol) Dimethyl sulfoxide (DMSO, 5 mL) was added to a 100-mL round-bottom flask, and after reacting at 110° C. for one hour, compound 5 (0.96 g, 1.9 mmol) was added and reacted for five hours. The reaction was tracked with TLC sheet. After the reaction was over, the solvent was distilled off under reduced pressure, and dichloromethane was used as the washing solution and filtered through celite. After the filtrate was concentrated by cyclone, it was first washed with ethyl acetate, and most of the compound 5 was filtered out. , and then use the eluent as n-hexane and dichloromethane 1:1 to conduct tube chromatography to obtain 0.66 g of orange-red solid with a yield of 81%.

Using nuclear magnetic resonance spectrometer and mass spectrometer as identification, the results are: ¹ H NMR (400MHz, (CD ₃ ) ₂ SO): δ 8.67(d,J=2.0Hz,2H),8.25(d,J=7.6Hz ,4H),7.68-7.61(m,3H),7.50(d,J=8.8Hz,2H),7.44-7.37(m,8H),7.30-7.26(m,5H),7.03(dd,J ₁ = 1.2 Hz, J ₂ =7.6 Hz, 1H), 6.94 (s, 2H); ¹³ C NMR (100 MHz, (CD ₃ ) ₂ SO): δ 144.88, 142.12, 141.11, 134.51, 132.41, 131.05, 126.70, 126.33, 124.65, 123.52, 120.56, 120.12, 119.58, 119.44, 111.30, 110.20. HRMS(MALDI) m/z calcd for C ₄₂ H ₂₇ N ₅ O ₂ 633.2165, obsd.633.2142(M ⁺ ).

The structure of compound 9 is:

Its preparation method comprises: taking compound 8 (1g, 1.58mmol), compound 2 (0.38g, 1.76mmol), sodium metabisulfite (Sodium metabisulfite, 0.27g, 1.71mmol), stannous chloride (Tin(II) chloride, SnCl ₂ , 1.05g, 5.54mmol) in a 100ml round-bottom flask, and then add dehydrated dimethylformamide (Dimethylformamide, DMF, 8.7mL), ethanol (Ethanol, 8.7mL), and react at 130 °C three hours. The reaction was tracked with TLC sheet. After the reaction was completed, the solvent was distilled off under reduced pressure, and dichloromethane was used as the washing solution and filtered through celite. After the filtrate was concentrated by cyclotron, the eluent was n-hexane to dichloromethane 1: 2 Carry out tube chromatography to obtain 0.97 g of brown oily product with a yield of 77%. Using nuclear magnetic resonance spectrometer and mass spectrometer as identification, the results are: ¹ H NMR (400MHz, (CD ₃ ) ₂ SO): δ 12.88(s, 1H), 8.65(s, 2H), 8.26(d, J= 7.6Hz, 4H), 7.84(d, J=4.4Hz, 1H), 7.62-7.58(m, 3H), 7.54-7.48(m, 3H), 7.46-7.38(m, 10H), 7.28(tJ=7.2 Hz, 6H), 7.28(t, J=7.2Hz, 6H), 7.20(d, J=8.4Hz, 2H), 7.13(s, 1H), 7.04(s, 1H); ¹³ C NMR(100MHz,( _{CD 3) 2 SO): δ} 141.19,141.15,140.59,139.06,138.57,132.00,131.46,131.15,130.26,129.93,129.63,129.10,128.84,128.06,126.47,126.11,125.90,125.56,123.60,122.45,120.45, 119.95, 119.69, 112.00, 109.69. HRMS (ESI) m/z calcd for C ₅₅ H ₃₄ ClN ₅ 799.2503, obsd.800.2593 (M+1 ⁺ ).

其製備方式包含：取化合物9(3.24g，4.06mmol)、乙酸鈀(Palladium(II)acetate，Pd(OAc)₂，0.18g，0.8mmol)、4,5-雙二苯基膦-9,9-二甲基氧雜蒽(4,5-Bis(diphenylphosphino)-9,9-dimethylxanthene，Xantphos，0.47g，0.81mmol)、碳酸銫(Caesium carbonate，Cs₂CO₃，3.96g，12.15mmol)於50毫升雙頸瓶，架上冷凝管及三向閥，抽換氬氣三次後，加入已除水除氧之二甲基甲醯胺(Dimethylformamide，DMF，20.3mL)於160℃下反應四小時。以TLC片追蹤反應，反應結束後，減壓蒸餾除去溶劑，以二氯甲烷為洗液並以矽藻土過濾，濾液經過迴旋濃縮後，再以沖提液為正己烷比二氯甲烷1：1進行管住層析，可得白色固體2.17克，產率70%。以核磁共振光譜儀、質譜儀和X-Ray單晶繞射儀做為鑑定，其結果為：¹H NMR(400MHz,CD₂Cl₂)：δ 8.76-8.70(m,2H),8.65(d,J=8.0Hz,1H),8.60(dd,J₁=1.2Hz,J₂=8.0Hz,1H),8.46(d,J=8.4Hz,1H),8.39(d,J=1.2Hz,2H),8.17(d,J=7.6Hz,4H),7.91-7.75(m,4H),7.66-7.59(m,6H)7.49-7.40(m,8H),7.30-7.26(m,4H)；¹³C NMR(100MHz,CD₂Cl₂)：δ 148.72,146.40,142.26,141.95,141.79,134.72,134.62,131.35,130.65,130.22,129.94,129.18,128.63,126.78,126.33,126.31,125.41,124.95,124.59,123.75,123.69,123.49,123.37,122.83,122.40,120.55, 120.03,116.63,114.79,112.92,110.24.HRMS(ESI)m/z calcd for C₃₁H₁₉N₃ 763.2736,obsd.763.2825(M⁺)。X-Ray晶體結構圖如圖18所示。 The structure of 4-tcbzCBIZ compound is:

Its preparation method comprises: taking compound 9 (3.24g, 4.06mmol), palladium acetate (Palladium(II) acetate, Pd(OAc) ₂ , 0.18g, 0.8mmol), 4,5-bisdiphenylphosphine-9, 9-Dimethylxanthene (4,5-Bis(diphenylphosphino)-9,9-dimethylxanthene, Xantphos, 0.47 g, 0.81 mmol), cesium carbonate (Caesium carbonate, Cs ₂ CO ₃ , 3.96 g, 12.15 mmol) In a 50-ml double-necked flask, a condenser tube and a three-way valve were installed, and after argon was pumped for three times, dimethylformamide (DMF, 20.3 mL), which had been dehydrated and deoxygenated, was added to react at 160 °C for four times. Hour. The reaction was tracked with TLC sheet. After the reaction was completed, the solvent was distilled off under reduced pressure, and dichloromethane was used as the washing solution and filtered through celite. After the filtrate was concentrated by cyclotron, the eluent was n-hexane to dichloromethane 1: 1 Carry out tube chromatography to obtain 2.17 g of white solid with a yield of 70%. Using nuclear magnetic resonance spectrometer, mass spectrometer and X-Ray single crystal diffractometer as identification, the results are: ¹ H NMR (400MHz, CD ₂ Cl ₂ ): δ 8.76-8.70(m, 2H), 8.65(d, J=8.0Hz,1H),8.60(dd,J1 ₌ 1.2Hz,J2=8.0Hz,1H ₎ ,8.46(d,J=8.4Hz,1H),8.39(d,J=1.2Hz,2H) ,8.17(d,J=7.6Hz,4H), ^7.91-7.75 (m,4H),7.66-7.59(m,6H)7.49-7.40(m,8H),7.30-7.26(m,4H); _{NMR (100MHz, CD 2 Cl 2} ): δ 148.72,146.40,142.26,141.95,141.79,134.72,134.62,131.35,130.65,130.22,129.94,129.18,128.63,126.78,126.33,126.31,125.41,124.95,124.59,123.75 ,123.69,123.49,123.37,122.83,122.40,120.55, 120.03,116.63,114.79,112.92,110.24.HRMS(ESI)m/z calcd for C ₃₁ H ₁₉ N ₃ 763.2736, ^{obsd.763.2825} (M ). The X-Ray crystal structure diagram is shown in Figure 18.

The 4-tcbzCBIZ compound was further tested below.

In one example, thermal property testing was performed on the 4-tcbzCBIZ compound. More specifically, a differential scanning card meter (Differential Scanning Calorimeter, DSC) (Q20 type differential scanning card meter, TA Instruments, USA) was used to measure the melting point (T _m ) and glass transition temperature (T _g of the compound) of the compound. ), crystallization point (T _c ). The measurement conditions are as follows: under the nitrogen flow rate of 20mL/min, the heating rate is 10°C/min, the temperature is increased from 30°C to 350-400°C, and the maximum temperature is maintained for one minute, and then the temperature is lowered to 30°C at the same cooling rate of 10°C/min. The same process was repeated twice, and the second measurement was used as the glass transition temperature of the compound; the thermal decomposition temperature (T) of the compound was measured with a Thermogravimetric Analyzer (TGA) (PerkinElmer TGA 7, PerkinElmer, USA). _d ). The measurement conditions are as follows: under nitrogen flow, the heating rate is 10°C/min, and the temperature is raised from room temperature to 800°C. When the loss ratio of the tested compound reaches 5wt%, the temperature at this time is the thermal cracking temperature of the compound. The test results are shown in Figures 19A to 19C and Table 15 below.

It can be seen from Table 15 that the glass transition temperature of the 4-tcbzCBIZ compound is as high as 216.93°C. Since the main structure of benzimidazole (benzimidazole) was changed to benzimidazo cyclized phenanthridine compound (benzimidazo<1,2-f>phenanthridine), the rotation of the single bond was successfully reduced without increasing the molecular weight, so that the Increasing the rigidity of the structure increases the glass transition temperature and improves the thermal stability of the molecule. Generally, the manufacturing temperature of the component is about 200℃. If the thermal cracking temperature (Td) of the material is too low, the material will be decomposed and destroyed during evaporation, thus affecting the efficiency of the component. The thermal cracking temperature of compound 4-tcbzCBIZ is 473℃, which can be applied Component production. Due to the low melting point of the 4-tcbzCBIZ compound, it cannot be sublimated, so the device is fabricated by solution spin coating.

In one example, Photophysical Properties measurements were performed on the 4-tcbzCBIZ compound and the 4-3cbzBIZ compound. Among them, the structure of 4-3cbzBIZ compound is:

More specifically, UV-visible absorption spectra (UV-visible absorption spectra) were measured using equipment such as a UV-Vis absorption spectrometer (UV-1601PC, Shimadzu Corporation, Japan), a fluorescence spectrometer (F-4500, Hitachi Corporation, Japan). absorption spectrum (UV), normal temperature fluorescence emission spectrum (FL), low temperature fluorescence emission spectrum (LTFL) and low temperature phosphorescence emission spectrum (PH). The measurement conditions are as follows: using spectral grade tetrahydrofuran (THF) as a solvent, the compound is prepared into a solution to be tested with a concentration of 10 ^-5 M, and the ultraviolet-visible absorption spectrum and room temperature fluorescence emission spectrum are measured; use spectral grade 2 - Methyltetrahydrofuran (2-Methyltetrahydrofuran, 2-MeTHF) was used as a solvent, the compound was prepared into a solution to be tested with a concentration of 10 ^-5 M, and liquid nitrogen was used as a refrigerant. Measurement of low temperature phosphorescence emission spectra. The measured spectral data were normalized. The measurement results are shown in Figures 20A, 20B and Table 16 below.

其中，^a最大吸收波長 ^b吸光係數 ^c吸收波長起始值 ^dE_g=1240.8/λ_onset ^Abs；^e常溫螢光最大放射波長/低溫螢光最大放射波長/低溫磷光放射波長起始值 ^fE_T=1240.8/λ_oneset ^Ph；^g以coumarin 1於THF之量子產率作為標準品(Q.Y.=0.85)，其餘化合物皆於THF下作測量。 Table 16

Among them, ^a maximum absorption wavelength ^b absorption coefficient ^c absorption wavelength initial value ^d E _g =1240.8/λ _onset ^Abs ; ^e room temperature fluorescence maximum emission wavelength/low temperature fluorescence maximum emission wavelength/low temperature phosphorescence emission wavelength initial value ^f E _T =1240.8/λ _oneset ^Ph ; ^g takes the quantum yield of coumarin 1 in THF as a standard (QY=0.85), and all other compounds are measured under THF.

According to the ultraviolet-visible absorption spectrum (UV) of the 4-tcbzCBIZ compound shown in Figure 20A, the absorption peak at the wavelength of 290-295 nm belongs to the absorption of π-π ^* of the carbazole group, which is the stronger spin-allowed absorption . The absorption peak at the wavelength of 300-350 nm belongs to the absorption of the carbazole group n-π ^* , which is a weaker absorption peak. The onset wavelength (λ _onset ^Abs ) of ultraviolet-visible absorption light is located at 376 nm, and the calculated energy level difference is 3.30 eV. The room temperature fluorescence emission spectrum (FL) of 4-tcbzCBIZ compound, with 292nm as the excitation wavelength, the measured maximum room temperature fluorescence emission wavelength is located at 440nm. In low temperature fluorescence emission spectroscopy (LTFL), because the measurement environment is reduced to 77K, the molecules cannot rotate freely, and the rigidity is strong, so it cannot release energy through non-radiative methods, and the emission is blue-shifted, and the maximum wavelength is located at 400nm . The onset wavelength (λ _onset ^PH ) of low-temperature phosphorescence is located at 44 nm, and the calculated triplet state energy (E _T ) is 2.8 eV1, which is higher than the triplet energy level (2.70 eV) of the common blue light emitter FIrpic. ), therefore, this series of compounds have potential as host luminescent materials for blue organic light-emitting diodes with FIrpic as guest luminescent material.

In one example, Electrochemical Properties tests were performed on the 4-tcbzCBIZ compound. More specifically, it is measured by using (CHI 1405, CH Instruments, USA), using cyclic voltammetry (CV) and differential-pulse voltammetry (DPV) to measure Oxidation potential (E ^ox ) and reduction potential (E ^re ) of the compound, and then the highest filled molecular energy level (E _HOMO ) and the lowest filled molecular energy level (E _LUMO ) of the compound are calculated. The measurement conditions are as follows: the measurement of oxidation potential and reduction potential is performed with silver/silver chloride (Ag/AgCl) as the reference electrode and platinum wire (Pt) as the auxiliary electrode.

For the measurement of oxidation potential, a glassy carbon electrode is used as the working electrode, and dichloromethane (Dichloromethane), which has been dewatered by calcium hydride (Cacium hydride), is used as a solvent, and a ^10-1 M tetrabutylammonium perchlorate solution is prepared. (Tetrabutylammonium perchlorate, TBAP) was used as the electrolyte solution, and the compound was prepared into a solution with a concentration of 10 ^-3 M to be tested, and the oxidation potential (E ^ox ) was measured.

In the measurement of reduction potential, glassy carbon electrode was used as working electrode, dimethylformamide (DMF) which had been dewatered by calcium hydride was used as solvent, and 10 ^-1 M tetrabutylammonium perchlorate solution was used as electrolyte solution. The compound was prepared into a solution to be tested with a concentration of 10 ^-3 M. The solution to be tested was deoxygenated in a nitrogen environment, and then the reduction potential (E ^re ) was measured under nitrogen.

Ferrocene was used as calibration standard. Using platinum electrode (Platium electrode) as working electrode (Working electrode), using dewatered dichloromethane and dewatered dimethylformamide as solvent, configure 10 ^-1 M tetrabutylammonium perchlorate The solution was used as an electrolyte, and ferrocene was prepared into a solution with a concentration of 10 ^-3 M to be tested, and its oxidation potential (E ^ox ) was measured by cyclic voltammetry.

The data measured by cyclic voltammetry and differential pulse voltammetry is not the absolute energy level value of each material, so ferrocene is used as the calibration standard to measure the relative potential value, and then calculate the absolute potential of the compound value. The highest filled electron energy level (E _HOMO ) and the lowest filled electron energy level (E _LUMO ) of the compound are calculated according to the following formula: E _HOMO =△E+E _{HOMO(ferrocene)} =-1.2×(E _DPV ^ox -E ^Fc+/Fc )+(-4.8) eV

E _LUMO =△E+E _{HOMO(ferrocene)} =-0.92×(E _DPV ^re -E ^Fc+/Fc )+(-4.8)eV

E _DPV in the formula is the maximum value of the first peak of differential pulse wave voltammetry; E ^Fc+/Fc is the value of (Epa+Epc)/2 obtained by ferrocene by cyclic voltammetry. The test results are shown in Figures 21A, 21B and Table 17 below.

^a以差式脈波伏安法測量且以二茂鐵校正所得第一個氧化峰之電位；^b以差式脈波伏安法測量且以二茂鐵校正所得第一個還原峰之電位；^c溶液態之最高填滿電子軌域(HOMO)與最低未填滿電子軌域(LUMO)之能階；^d以AC2測量薄膜態之能階，E_LUMO=E_HOMO+Eg。

^a Potential of the first oxidation peak measured by differential pulse voltammetry and corrected by ferrocene; ^b Potential of the first reduction peak measured by differential pulse voltammetry and corrected by ferrocene; ^c Solution The energy level of the highest filled electron orbital (HOMO) and the lowest unfilled electron orbital (LUMO) of the state; ^d The energy level of the thin film state is measured by AC2, E _LUMO =E _HOMO +Eg.

It can be known from the measurement results that the E _HOMO of the 4-tcbzCBIZ compound is higher and the E _LUMO is lower than that of the commonly used blue guest light-emitting materials (E _HOMO = 5.7 eV, E _LUMO = 3.1 eV). In addition, it has a matching energy level with common electron transfer and hole materials, which can reduce the energy barrier of electron and hole injection. Therefore, this series of compounds have potential as blue light host materials.

Although the foregoing description and drawings have disclosed the preferred embodiment of the present invention, it must be understood that various additions, many modifications and substitutions may be made in the preferred embodiment of the present invention without departing from the The spirit and scope of the principles of the present invention as defined by the scope of the claims. Those of ordinary skill in the art to which this invention pertains will appreciate that the invention is capable of many modifications in form, structure, arrangement, proportions, materials, elements and assemblies. Therefore, the embodiments disclosed herein should be considered to illustrate the present invention, rather than to limit the present invention. The scope of the present invention shall be defined by the appended claims, including their legal equivalents, and not limited to the foregoing description.

100: the first conductive layer

200: hole transport layer

300: electron blocking layer

400: light-emitting layer

500: electron transport layer

600: Electron injection layer

700: the second conductive layer

900: Organic Light Emitting Diode Components

Claims (13)

A carbazole compound having the structure of the following formula (1):

A carbazole compound having the structure of the following formula (2):

A use of the carbazole compound as claimed in claim 1 or 2 as a light-emitting material. A method for producing a carbazole compound, the compound 1 shown below is prepared by the following reaction formula,

A method for producing a carbazole compound, the compound 3 shown below is prepared by the following reaction formula,

A method for producing a carbazole compound, wherein the compound of the formula (1) shown below is prepared by the following reaction formula,

An organic light-emitting diode element, comprising: a first conductive layer; a hole transport layer, disposed on the first conductive layer; an electron blocking layer, disposed on the hole transport layer; a light-emitting layer, disposed on On the electron blocking layer, a carbazole compound is included, which has the structure of the following formula (1):

An electron transport layer is arranged on the light emitting layer; an electron injection layer is arranged on the electron transport layer; a second conductive layer is arranged on the electron injection layer. The organic light-emitting diode element according to claim 7, further comprising a second light-emitting layer disposed between the light-emitting layer and the electron blocking layer, comprising compound ID5, and having the following structure:

A method for producing a carbazole compound, the compound 8 shown below is prepared by the following reaction formula,

A method for producing a carbazole compound, the compound 8 shown below is prepared by the following reaction formula,

A kind of manufacture method of carbazole compound, make compound 9 shown below by following reaction formula,

A method for producing a carbazole compound, wherein the compound of the formula (2) shown below is prepared by the following reaction formula,

An organic light-emitting diode element, comprising: a first conductive layer; a hole transport layer, arranged on the first conductive layer; an electron blocking layer, arranged on the hole transport layer; a light-emitting layer, arranged on On the electron blocking layer, a carbazole compound is included, which has the structure of the following formula (2):

An electron transport layer is arranged on the light emitting layer; an electron injection layer is arranged on the electron transport layer; a second conductive layer is arranged on the electron injection layer.

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