Nitrogen-containing heterocyclic compound and light-emitting device

Abstract

The invention discloses a nitrogen-containing heterocyclic compound and a luminescent device, and belongs to the field of organic electroluminescent materials. The nitrogen-containing heterocyclic compound takes an azabenzophenanthrene macroring as a core, is connected with an R group containing a benzene ring or a hybrid benzene ring, has high conjugacy, and can effectively disperse electrons, so that the molecular stability is improved, and matching with the energy level of an adjacent luminescent layer or transport layer is facilitated. The phenanthroline or dipyridyl structure can provide coordination complexing sites, improve coordination complexing ability, facilitate injection and transmission of electrons, introduce more N atoms and O atoms, facilitate formation of hydrogen bonds with hydrogen atoms, improve intermolecular stacking conditions of the material, improve electron injection and transmission ability of the material and reduce driving voltage, so that the material can be applied to the field of organic light emitting devices. And the luminous efficiency and the service life of the device can be effectively improved by applying the material to a charge generation layer of the luminescent device.

Description

Technical Field

[0001] This application relates to the field of organic electroluminescent materials, and in particular to nitrogen-containing heterocyclic compounds and light-emitting devices. Background Technology

[0002] Organic light-emitting diodes (OLEDs), as a new generation of display technology, have advantages such as ultra-thinness, self-illumination, wide viewing angle, fast response, high luminous efficiency, good temperature adaptability, simple production process, low driving voltage, and low energy consumption. They have been widely used in industries such as flat panel displays, flexible displays, solid-state lighting, and automotive displays.

[0003] Organic light-emitting devices (OLEDs) have various structural designs, with tandem OLEDs being a particularly promising form. In tandem OLEDs, multiple light-emitting units, each containing a light-emitting layer, are stacked between the anode and cathode. These units are interconnected by charge-generating layers (CGLs). Under the influence of an electric field, the CGLs generate electron-hole pairs and inject charge carriers into adjacent light-emitting layers or other functional layers, achieving synergistic luminescence from the multi-layered light-emitting units. Therefore, the CGL material is crucial to the performance of tandem OLEDs.

[0004] However, the number of CGL materials that can meet the application requirements is very limited, and traditional CGL materials do not match the energy levels of adjacent light-emitting or transport layers, resulting in problems such as high driving voltage and low efficiency, which greatly limits the luminous efficiency and lifespan of light-emitting devices. Summary of the Invention

[0005] Based on this, the main objective of this application is to provide a nitrogen-containing heterocyclic compound that can match the energy level of an adjacent light-emitting layer or transport layer, has a low driving voltage and high efficiency, and can effectively improve the luminous efficiency and lifetime of the device when used as a charge generation layer.

[0006] The first aspect of this application provides a nitrogen-containing heterocyclic compound with the structure shown in Formula I:

[0007]

[0008] The structure of R is shown in Equation II:

[0009]

[0010] X1, X2, X3, X4, X5, and X6 are each independently selected from C or N;

[0011] R1 and R2 are each independently selected from H, C1-C6 alkyl, substituted or unsubstituted aryl with 6-30 ring atoms, or substituted or unsubstituted heteroaryl with 6-30 ring atoms;

[0012] R3, R4, R5 and R6 are each independently selected from H, -CN, C1-C6 alkyl, substituted or unsubstituted aryl group with 6-30 ring atoms, unsubstituted heteroaryl group with 6-30 ring atoms, or are not present;

[0013] Alternatively, R3 and R4, R4 and R5, and R5 and R6 can each independently form a cyclization group to constitute a phenyl, pyridinyl, pyrimidinyl, or quinolinyl group, and when R4 and R5 form a cyclization group, R3 and R4, and R5 and R6 do not form a cyclization group.

[0014] Each substituent is independently selected from H, -CN, C1-C6 alkyl, aryl with 6-12 ring atoms, heterocyclic with 5-18 ring atoms, or...

[0015] The nitrogen-containing heterocyclic compound contains at least one selected from... or Substructures; X1', X2', X3', and X4' are each independently selected from C or N.

[0016] The nitrogen-containing heterocyclic compound of this application has a benzo[a]phenanthrene macrocycle as its core and is connected to an R group containing a benzene ring or a hybrid benzene ring. It exhibits high conjugation, effectively dispersing electrons and thus improving molecular stability. This also facilitates energy level matching with adjacent light-emitting or transport layers. The phenanthrene-roline or bipyridine structure provides coordination and complexation sites, improving coordination and complexation capabilities, which is beneficial for electron injection and transport. The introduction of more N and O atoms facilitates hydrogen bonding with hydrogen atoms, improving intermolecular stacking and enhancing electron injection and transport capabilities, while reducing the driving voltage. Therefore, using this compound as a charge generation layer in light-emitting devices can effectively improve device luminous efficiency and lifetime.

[0017] A second aspect of this application provides a method for preparing the nitrogen-containing heterocyclic compound described in the first aspect, comprising the following steps:

[0018] The nitrogen-containing heterocyclic compound was prepared by reacting compound A with R1-B(OH)2, R2-B(OH)2 and RB(OH)2.

[0019]

[0020] A third aspect of this application provides a charge-generating layer comprising one or more of the nitrogen-containing heterocyclic compounds described in the first aspect.

[0021] A fourth aspect of this application provides a light-emitting device comprising one or more of the nitrogen-containing heterocyclic compounds described in the first aspect or the charge-generating layer described in the third aspect;

[0022] Optionally, the light-emitting device includes an electroluminescent device;

[0023] Optionally, the electroluminescent device includes a stacked organic light-emitting device.

[0024] The beneficial effects of this application are:

[0025] The nitrogen-containing heterocyclic compounds of this application have good charge generation ability, fast electron transport ability, high glass transition temperature and thermal stability, and can easily form good amorphous thin films. They can reduce driving voltage and improve the luminous efficiency and lifetime of devices, and can be well applied in the field of electroluminescence technology. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of this application clearer and to provide a more thorough and comprehensive understanding of the disclosure of this application, the technical solutions of this application will be clearly and completely described below in conjunction with specific embodiments. The described embodiments are only a part of the embodiments of this application, and not all of them.

[0027] The implementation of this application is described in detail below. This embodiment is implemented based on the technical solution of this application, and provides detailed implementation methods and specific operation processes, but the protection scope of this application is not limited to the following embodiment.

[0028] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0029] Unless otherwise stated or in case of contradiction, the terms or phrases used herein shall have the following meanings:

[0030] In this application, the terms "multiple" or "various" are used unless otherwise specified, referring to a quantity greater than or equal to 2. For example, "one or more" or "at least one" means one or more of two.

[0031] In this application, terms such as "further" and "especially" are used to describe purposes and indicate differences in content, but should not be construed as limiting the scope of protection of this application.

[0032] In this application, the technical features described in an open-ended manner include both closed technical solutions consisting of the listed features and open technical solutions that include the listed features.

[0033] In this application, when numerical intervals (i.e., numerical ranges) are involved, unless otherwise specified, the distribution of selectable numerical values ​​within the numerical interval is considered continuous, and includes the two endpoints of the numerical interval (i.e., the minimum and maximum values), as well as every numerical value between these two endpoints. Unless otherwise specified, when a numerical interval refers only to integers within that numerical interval, it includes the two endpoint integers of the numerical range, as well as every integer between the two endpoints, which is equivalent to directly listing every integer. When multiple numerical ranges are provided to describe features or characteristics, these numerical ranges can be merged. In other words, unless otherwise specified, the numerical ranges disclosed herein should be understood to include any and all subranges included therein. The "numerical value" in the numerical interval can be any quantitative value, such as a number, percentage, ratio, etc. The term "numerical interval" can be broadly included to include numerical interval types such as percentage intervals, ratio intervals, and proportion intervals.

[0034] In this application, unless otherwise specified, the temperature parameters are permitted to be either constant-temperature treatment or variations within a certain temperature range. It should be understood that the constant-temperature treatment allows temperature fluctuations within the precision range of the instrument control. Fluctuations are permitted within ranges such as ±5℃, ±4℃, ±3℃, ±2℃, and ±1℃.

[0035] In this application, when any variable (e.g., R1, R2, etc.) appears more than once in any component of a compound, the definition of each occurrence is independent of the definitions of other occurrences. Similarly, combinations of substituents and variables are permitted, provided that such combinations stabilize the compound. It should be understood that those skilled in the art can select the substituents and substitution forms of the compounds of this application to provide chemically stable compounds that can be easily synthesized from readily available starting materials using techniques in the art and methods presented herein. If a substituent is itself substituted by more than one group, it should be understood that these groups can be on the same carbon atom or on different carbon atoms, as long as structural stability is achieved.

[0036] In this application, in the description of the number of carbon atoms, i.e., the number following the capital letter "C", such as "C6-C30", "C1-C6", etc., the number after "C", such as "1", "6", or "30", indicates the number of carbon atoms in a specific functional group. That is, "C6-C30" or "6-30 carbon atoms in the ring" means that the functional group can include any integer or range of carbon atoms between 6 and 30, such as 6, 10, 15, 20, 25, 30, etc. Similarly, "C1-C6 alkyl" refers to an alkyl group having 1, 2, 3, 4, 5, or 6 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, cyclopropyl, n-butyl, isobutyl, sec-butyl. tert-butyl, cyclobutyl, n-pentyl, isopentyl, neopentyl, cyclopentyl, methylcyclopentyl, ethylcyclopentyl, n-hexyl, isohexyl, cyclohexyl; "aryl with 6-12 ring atoms" refers to aryl groups with 6, 7, 8, 9, 10, 11, or 12 ring atoms, and "heterocyclic group with 5-18 ring atoms" refers to heterocyclic groups with 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, or 18 ring atoms.

[0037] In this application, "aryl" can be a single ring (monocyclic) or multiple rings fused together or covalently linked (bicyclic or more), such as phenyl, biphenyl, naphthyl, etc. "Heteroaryl" is an aryl group containing one or more heteroatoms, such as phenylcarbazolyl, benzothiophene, dibenzothiophene, triphenylamino, etc., whose heteroatoms can be N, O or S.

[0038] In this application, the "substituent" can be substituted at any position, and can be one or more substitutions, such as substitution of the benzene ring or aromatic heterocycle, and can be substituted at the para, meta or ortho position, or multiple positions simultaneously.

[0039] In this application, each structural formula contains The term refers to the linking site, which may contain substituents, but does not restrict the specific structure of the substituents to be linked.

[0040] In this application, the term "substructure" refers to a subset of structural units within a compound molecule. These units possess specific chemical and physical properties within the overall molecular structure. They are fundamental components of the molecular structure, determining the chemical reactivity of the compound and influencing its physical properties. Substructures may contain substituents or be fused with other ring structures; the presence of such substructures is sufficient for the compound to be considered valid. For example, compound H44 contains a substructure. (X1', X2', X3', X4' are C), and this substructure is substituted with methyl and phenyl groups; for example, compound 41 contains the substructure Its aromatic ring further fuses with the benzene ring. Furthermore, nitrogen-containing heterocyclic compounds may contain one or more defined substructures; the more of these substructures present, the better the device performance.

[0041] Organic light-emitting devices (OLEDs) have various structural designs, with tandem OLEDs being a particularly promising form. In tandem OLEDs, multiple light-emitting units, each containing a light-emitting layer, are stacked between the anode and cathode. These units are interconnected by charge-generating layers (CGLs). Under the influence of an electric field, the CGLs generate electron-hole pairs and inject charge carriers into adjacent light-emitting layers or other functional layers, achieving synergistic luminescence from the multi-layered light-emitting units. Therefore, the CGL material is crucial to the performance of tandem OLEDs.

[0042] However, the number of CGL materials that can meet the application requirements is very limited, and traditional CGL materials do not match the energy levels of adjacent light-emitting or transport layers, resulting in problems such as high driving voltage and low efficiency, which greatly limits the luminous efficiency and lifespan of light-emitting devices.

[0043] Based on this, this application provides a nitrogen-containing heterocyclic compound that can match the energy level of an adjacent light-emitting layer or transport layer, has a low driving voltage and high efficiency, and its use as a charge generation layer in a light-emitting device can effectively improve the device's luminous efficiency and lifetime.

[0044] The first aspect of this application provides a nitrogen-containing heterocyclic compound with the structure shown in Formula I:

[0045]

[0046] The structure of R is shown in Equation II:

[0047]

[0048] X1, X2, X3, X4, X5, and X6 are each independently selected from C or N;

[0049] R1 and R2 are each independently selected from H, C1-C6 alkyl, substituted or unsubstituted aryl with 6-30 ring atoms, or substituted or unsubstituted heteroaryl with 6-30 ring atoms;

[0050] R3, R4, R5 and R6 are each independently selected from H, -CN, C1-C6 alkyl, substituted or unsubstituted aryl group with 6-30 ring atoms, unsubstituted heteroaryl group with 6-30 ring atoms, or are not present;

[0051] Alternatively, R3 and R4, R4 and R5, and R5 and R6 can each independently form a cyclization group to constitute a phenyl, pyridinyl, pyrimidinyl, or quinolinyl group, and when R4 and R5 form a cyclization group, R3 and R4, and R5 and R6 do not form a cyclization group.

[0052] Each substituent is independently selected from H, -CN, C1-C6 alkyl, aryl with 6-12 ring atoms, heterocyclic with 5-18 ring atoms, or...

[0053] The nitrogen-containing heterocyclic compound contains at least one selected from... or Substructures; X1', X2', X3', and X4' are each independently selected from C or N.

[0054] The nitrogen-containing heterocyclic compound of this application has a benzo[a]phenanthrene macrocycle as its core and is connected to an R group containing a benzene ring or a hybrid benzene ring. It exhibits high conjugation, effectively dispersing electrons and thus improving molecular stability. This also facilitates energy level matching with adjacent light-emitting or transport layers. The phenanthrene-roline or bipyridine structure provides coordination and complexation sites, improving coordination and complexation capabilities, which is beneficial for electron injection and transport. The introduction of more N and O atoms facilitates hydrogen bonding with hydrogen atoms, improving intermolecular stacking and enhancing electron injection and transport capabilities, while reducing the driving voltage. Therefore, using this compound as a charge generation layer in light-emitting devices can effectively improve device luminous efficiency and lifetime.

[0055] In some embodiments, R1 and R2 are each independently selected from H, C1-C6 alkyl, phenyl, naphthyl, biphenyl, m-tolyl, p-tolyl, ... One of them.

[0056] In some embodiments, R3, R4, R5, and R6 are each independently selected from H, -CN, C1-C6 alkyl, phenyl, and non-existent. Alternatively, R3 and R4 can form a ring to constitute phenyl, pyridyl, pyrimidyl, or quinolinyl, while R5 and R6 cannot form a ring; or R4 and R5 can form a ring to constitute phenyl, pyridyl, pyrimidyl, or quinolinyl, while R3 and R6 cannot form a ring; or R5 and R6 can form a ring to constitute phenyl, pyridyl, pyrimidyl, or quinolinyl, while R3 and R4 cannot form a ring; or R3 and R4 can form a ring to constitute phenyl or pyridyl, while R5 and R6 can form a ring to constitute phenyl or pyridyl.

[0057] In some embodiments, X1 and X2 are C, and the structure of the nitrogen-containing heterocyclic compound is shown in Formula I-1:

[0058] At least one of R1, R2, and R contains a substructure or

[0059]

[0060] Alternatively, X1 is C and X2 is N, and the structure of the nitrogen-containing heterocyclic compound is shown in Formula I-2:

[0061]

[0062] Alternatively, X1 is N and X2 is C, and the structure of the nitrogen-containing heterocyclic compound is shown in Formula I-3:

[0063] At least one of R1 and R2 contains a substructure or Alternatively, the structure formed by the rings containing R1, R2, and X1 may contain substructures.

[0064] or

[0065] In some embodiments, R is selected from one of formulas II-1 to II-7:

[0066]

[0067]

[0068] In some embodiments, R is selected from one of formulas III-1 to III-11:

[0069]

[0070] In some embodiments, R is selected from phenyl, naphthyl, m-tolyl, p-tolyl, and o-tolyl.

[0071]

[0072] One of them.

[0073] In some embodiments, the nitrogen-containing heterocyclic compound includes at least one of the following compounds:

[0074]

[0075]

[0076]

[0077]

[0078]

[0079]

[0080]

[0081]

[0082] A second aspect of this application provides a method for preparing the nitrogen-containing heterocyclic compound described in the first aspect, comprising the following steps:

[0083] The nitrogen-containing heterocyclic compound was prepared by reacting compound A with R1-B(OH)2, R2-B(OH)2 and RB(OH)2.

[0084]

[0085] In some embodiments, reacting compound A with R1-B(OH)2, R2-B(OH)2 and RB(OH)2 to prepare the nitrogen-containing heterocyclic compound specifically includes:

[0086] Compound A was reacted with R1-B(OH)2 and R2-B(OH)2 to prepare compound C;

[0087]

[0088] The nitrogen-containing heterocyclic compound was prepared by reacting compound C with RB(OH)2.

[0089] In some embodiments, the molar ratio of R1-B(OH)2 to compound A is (1.5-0.9):1; the molar ratio of R2-B(OH)2 to compound A is (1.5-0.9):1.

[0090] In some embodiments, compound A reacts with R1-B(OH)2 and R2-B(OH)2 in the presence of K2CO3 and Pd(PPh3)4.

[0091] In some embodiments, the molar ratio of K2CO3 to compound A is (1.5-2.5):1.

[0092] In some embodiments, the molar ratio of Pd(PPh3)4 to compound A is (0.01-0.1):1.

[0093] In some embodiments, the reaction conditions of compound A with R1-B(OH)2 and R2-B(OH)2 include: a reaction temperature of 70°C-90°C and a reaction time of 6h-20h.

[0094] In some embodiments, compound C reacts with RB(OH)2 in the presence of K2CO3 and Pd(PPh3)4.

[0095] In some embodiments, the reaction conditions of compound C with RB(OH)2 include: a reaction temperature of 80°C-120°C and a reaction time of 6h-20h.

[0096] In some embodiments, the molar ratio of K2CO3 to compound C is (1.5-2.5):1.

[0097] In some embodiments, the molar ratio of Pd(PPh3)4 to compound C is (0.01-0.1):1.

[0098] A third aspect of this application provides a charge-generating layer comprising one or more of the nitrogen-containing heterocyclic compounds described in the first aspect.

[0099] A fourth aspect of this application provides a light-emitting device comprising one or more of the nitrogen-containing heterocyclic compounds described in the first aspect or the charge-generating layer described in the third aspect;

[0100] Optionally, the light-emitting device includes an electroluminescent device;

[0101] Optionally, the electroluminescent device includes a stacked organic light-emitting device.

[0102] Unless otherwise specified, the raw materials used in the following experiments can be purchased from the market.

[0103] The following are specific examples.

[0104] The preparation route for intermediate compound A is as follows:

[0105]

[0106] 1) Synthesis of HB: At low temperature, reactants HA (100 mmol) and 200 mL THF were added to a reaction flask. At -65°C or below, 50 mL of n-BuLi (1.5 mmol / L) was slowly added, and the mixture was stirred for 12 hours. The reaction was terminated with 100 mL of HCl (1 mol / L). The mixture was extracted with diethyl ether, and the collected organic phase was dried over anhydrous magnesium sulfate, then extracted again with diethyl ether. Recrystallization from ethanol yielded the intermediate product HB (71% yield).

[0107] 2) Synthesis of HC: At low temperature, reactants HB (25 mmol) and 250 mL THF were placed in a round flask. 30 mL of n-BuLi (1.5 mol / L) was added at -78 °C, and the mixture was stirred continuously at -78 °C for 120 min. Then, 50 mmol of Trimethyltin chloride was slowly added, and the mixture was stirred for 24 hours. After the reaction was complete, an appropriate amount of water was added, followed by extraction with diethyl ether. The mixture was then recrystallized from dichloromethane / hexane to obtain the intermediate product HC (68% yield).

[0108] 3) Synthesis of HE: Under a nitrogen atmosphere, reactants HC (30 mmol), HD (30 mmol), and Pd(PtBu3)2 (0.8 g, 5 mol%) were added to 300 mL of THF, and the mixture was stirred continuously at 60 °C for 12 hours. The temperature was then lowered to room temperature, the reactants were filtered, and column chromatography with hexane / dichloromethane was performed to obtain the intermediate product HE (yield 67%).

[0109] 4) Synthesis of HF: Under a nitrogen atmosphere, reactants HE (20 mmol) and NBS (40 mmol) were added to 100 mL of dichloromethane. The mixture was stirred continuously at 60 °C for 12 hours. After the reaction was completed, the water in the organic layer was extracted with MC and dried with magnesium sulfate. After removing the solvent, the reactants were subjected to column chromatography (eluent ratio of hexane / dichloromethane 15:1) to obtain the intermediate product HF (yield 84%).

[0110] 5) Synthesis of compound A: At low temperature, HF (20 mmol) was added to a mixed solvent of dichloromethane (DCM) and dimethyl sulfoxide (DMSO) (2:1, 250 mL), and Cl2 was introduced. The reaction was carried out for 4 hours. After the reaction was completed, the mixture was dried with magnesium sulfate to remove the solvent. The reactants were then subjected to column chromatography (eluent ratio of hexane / dichloromethane 20:1) to obtain compound A (yield 65%).

[0111] Preparation Example 1

[0112] Preparation of compound H2:

[0113]

[0114] 1) Synthesis of C2: Under a nitrogen atmosphere, the reaction solvent was added to a reaction flask in a ratio of toluene:ethanol:water = 7:2:1. Then, K2CO3 (20 mmol), compound A2 (10 mmol), compound B2 (20 mmol), and Pd(PPh3)4 (0.5 mmol) were added sequentially. The mixture was heated to 80 °C and reacted overnight. After the reaction was complete, the mixture was cooled to room temperature and extracted with dichloromethane / H2O. The collected organic phase was dried over anhydrous Na2SO4, filtered, and the filtrate was collected. The solvent was removed by rotary evaporation and purified by column chromatography to obtain intermediate C2 (yield 81%).

[0115] 2) Synthesis of H2: Under a nitrogen atmosphere, 1,4-dioxane was added to a reaction flask, followed by K2CO3 (16 mmol), intermediate C2 (8 mmol), compound D2 (16 mmol), and Pd(PPh3)4 (0.45 mmol). The mixture was heated to 100 °C and reacted overnight. After the reaction was complete, the mixture was cooled to room temperature and extracted with dichloromethane / H2O. The collected organic phase was dried over anhydrous Na2SO4, filtered, and the filtrate was collected. The solvent was removed by rotary evaporation, and the filtrate was purified by column chromatography to obtain compound H2 (75% yield).

[0116] MALDI-TOF (m / z): C 44 H 26 N6: Calculated value: 638.22, measured value: 638.71.

[0117] Elemental analysis (%): Calculated values: C, 82.74; H, 4.10; N, 13.16; Test values: C, 82.74; H, 4.11; N, 13.16.

[0118] 1H NMR: δ7.75(2H,td,J=5.1,1.5Hz),7.91(2H,ddd,J=7.4,1.5,0.5Hz),8.34-8.84(16H,8.40(dddd,J=5.6 ,1.7,1.4,0.5Hz),8.42(ddd,J=7.4,5.1,1.3Hz),8.44(dt,J=1.8,0.5Hz),8.52(td,J=5.8,0.5Hz),8.63 (dtd,J=5.9,1.4,0.5Hz),8.64(ddd,J=5.6,5.0,0.5Hz),8.69(dd,J=5.8,1.4Hz),8.78(dd,J=6.4,1.8Hz )),8.94(2H,dd,J=6.4,0.5Hz),9.12-9.25(4H,9.18(dd,J=5.0,1.7Hz),9.19(ddd,J=5.1,1.3,0.5Hz)).

[0119] Preparation Example 2

[0120] Preparation of compound H19:

[0121]

[0122] The synthesis method of compound H19 is similar to that of H2, except that A2 and B2 in reaction 1) are replaced with equimolar amounts of A19 and B19, respectively; and C2 and D2 in reaction 2) are replaced with equimolar amounts of C19 and D19, respectively.

[0123] MALDI-TOF (m / z): C 48 H 30 N6: Calculated value: 690.25, measured value: 690.59.

[0124] Elemental analysis (%): Calculated values: C, 83.46; H, 4.38; N, 12.17; Test values: C, 83.46; H, 4.37; N, 12.18.

[0125] 1H NMR: δ7.85(2H,ddd,J=5.9,5.1,2.0Hz),8.00-8.29(8H,8.06(dd,J=7.0,1.7Hz),8.11(td,J=5.8,1.8Hz), 8.23(ddd,J=5.6,2.0,0.5Hz)),8.35-8.64(8H,8.41(ddd,J=5.8,2.0,0.5Hz),8.49(dd,J=7.0,6.0Hz),8. 56(t,J=0.5Hz),8.58(dd,J=6.0,1.7Hz)),8.70-8.93(6H,8.76(dt,J=6.5,0.5Hz),8.86(dd,J=6.5,1.7Hz ),8.88(dt,J=1.7,0.5Hz)),9.00-9.23(6H,9.06(ddd,J=5.1,1.8,0.5Hz),9.17(ddd,J=5.6,1.8,0.5Hz)).

[0126] Preparation Example 3

[0127] Preparation of compound H23:

[0128]

[0129] The synthesis method of compound H23 is similar to that of H2, except that A2 and B2 in reaction 1) are replaced with equimolar amounts of A23 and B23, respectively; and C2 and D2 in reaction 2) are replaced with equimolar amounts of C23 and D23, respectively.

[0130] MALDI-TOF (m / z): C 62 H 42 O2N4P2: Calculated value: 936.28, measured value: 936.45.

[0131] Elemental analysis (%): Calculated values: C, 79.48; H, 4.52; O, 3.41; N, 5.98; P, 6.61; Test values: C, 79.48; H, 4.51; O, 3.41; N, 5.97; P, 6.62.

[0132] 1H NMR: δ7.24-7.51(20H,7.31(dddd,J=7.7,7.6,1.5,0.5Hz),7.33(dddd,J=7.7,1.7,1.5,0.5Hz),7.45(tt,J= 7.6,1.7Hz)),7.73(2H,ddd,J=6.0,5.1,1.5Hz),7.92(2H,ddd,J=7.7,1.5,0.5Hz),8.04-8.20(6H,8.10(ddd ,J=7.1,1.9,0.5Hz),8.13(ddd,J=7.7,6.0,1.5Hz)),8.41(2H,dt,J=1.7,0.5Hz),8.59-8.71(6H,8.65(ddd, J=7.1,1.4,0.5Hz),8.65(dd,J=7.2,1.7Hz)),8.91(2H,dd,J=7.2,0.5Hz),9.18(2H,ddd,J=5.1,1.5,0.5Hz).

[0133] Preparation Example 4

[0134] Synthesis of compound H35:

[0135]

[0136] The synthesis method of compound H35 is similar to that of H2, except that A2 and B2 in reaction 1) are replaced with equimolar amounts of A35 and B35, respectively; and C2 and D2 in reaction 2) are replaced with equimolar amounts of C35 and D35, respectively.

[0137] MALDI-TOF (m / z): C 54 H 32 N4: Calculated value: 736.26, measured value: 736.64.

[0138] Elemental analysis (%): Calculated values: C, 88.02; H, 4.38; N, 7.60; Test values: C, 88.01; H, 4.37; N, 7.61.

[0139] 1H NMR: δ7.74(2H,tdd,J=6.9,1.7,1.4Hz),8.06(4H,dddd,J=6.8,2.0,1.6,0.5Hz),8.20(4H,dddd,J=6.9,6.8,1.7,0.5 Hz),8.44-8.59(4H,8.50(dddd,J=5.5,1.7,1.6,0.5Hz),8.53(dd,J=6.7,0.5Hz)),8.65-9.05(14H,8.71(ddt,J=6.1 ,1.6,0.5Hz),8.80(dd,J=6.4,1.7Hz),8.83(dt,J=6.4,0.5Hz),8.84(dt,J=1.7,0.5Hz),8.88(ddd,J=6.7,1.6,0.5H z), 8.89 (ddt, J = 6.1, 1.6, 0.5Hz), 8.99 (ddd, J = 5.5, 5.0, 0.5Hz)), 9.15 (2H, dd, J = 5.0, 1.7Hz), 9.28 (2H, t, J = 0.5Hz).

[0140] Preparation Example 5

[0141] Preparation of compound H56:

[0142]

[0143] The synthesis method of compound H56 is similar to that of H2, except that A2 and B2 in reaction 1) are replaced with equimolar amounts of A56 and B56, respectively; and C2 and D2 in reaction 2) are replaced with equimolar amounts of C56 and D56, respectively.

[0144] MALDI-TOF (m / z): C 64 H 40 N8: Calculated value: 921.08, measured value: 921.37.

[0145] Elemental analysis (%): Calculated values: C, 83.46; H, 4.38; N, 12.17; Test values: C, 83.46; H, 4.37; N, 12.18.

[0146] 1H NMR: δ7.80(2H,tdd,J=6.2,1.7,1.3Hz),8.00(2H,ddd,J=6.0,1.9,0.5Hz),8.07-8.20(6H,8.13(tdd,J=6.2,1.9,0.5Hz),8.14(td,J =5.0,1.4Hz)),8.30(4H,dddd,J=6.1,1.7,1.5,0.5Hz),8.49(4H,dddd,J=6.3,2.0,0.5Hz),8.64-8.95(6H,8.70(td,J=5.0,1.9Hz),8 .79(ddd,J=6.0,5.1,1.5Hz),8.89(td,J=5.1,1.7Hz)),8.98-9.24(14H,9.04(ddd,J=6.3,1.8,0.5Hz),9.11(ddd,J=5.0,1.5,0.5Hz ),9.14(ddd,J=5.1,1.4,0.5Hz),9.17(dd,J=5.1,0.5Hz),9.19(ddd,J=5.0,1.7,0.5Hz),9.19(t,J=0.5Hz)),9.45(2H,d,J=5.1Hz).

[0147] Preparation Example 6

[0148] Preparation of compound H59:

[0149]

[0150] The synthesis method of compound H59 is similar to that of H2, except that A2 and B2 in reaction 1) are replaced with equimolar amounts of A59 and B59, respectively; and C2 and D2 in reaction 2) are replaced with equimolar amounts of C59 and D59, respectively.

[0151] MALDI-TOF (m / z): C 54 H 32 N8: Calculated value: 792.27, measured value: 792.44.

[0152] Elemental analysis (%): Calculated values: C, 81.80; H, 4.07; N, 14.13; Test values: C, 81.81; H, 4.08; N, 13.10.

[0153] 1H NMR: δ7.90-8.07(6H,7.97(dddd,J=7.0,6.9,1.8,0.5Hz),8.01(tt,J=7.0,1.5Hz)),8.09-8.28(6H,8.1 5(td,J=6.1,2.0Hz),8.22(dddd,J=6.9,1.9,1.5,0.5Hz)),8.36(4H,ddd,J=6.0,2.0,0.5Hz),8.45-8.6 6(8H,8.50(t,J=0.5Hz),8.52(d,J=7.3Hz),8.55(td,J=6.1,1.5Hz),8.60(ddd,J=6.1,2.0,0.5Hz)),8. 87-9.08(4H,8.93(dd,J=7.3,0.5Hz),9.02(ddd,J=6.1,1.5,0.5Hz)),9.19(4H,ddd,J=6.0,1.9,0.5Hz).

[0154] Preparation Example 7

[0155] Preparation of compound H72:

[0156]

[0157] The synthesis method of compound H72 is similar to that of H2, except that A2 and B2 in reaction 1) are replaced with equimolar amounts of A72 and B72, respectively; and C2 and D2 in reaction 2) are replaced with equimolar amounts of C72 and D72, respectively.

[0158] MALDI-TOF (m / z): C 62 H 36 N8: Calculated value: 892.31, measured value: 892.65.

[0159] Elemental analysis (%): Calculated values: C, 83.39; H, 4.06; N, 12.55; Test values: C, 83.40; H, 4.05; N, 12.56.

[0160] 1H NMR: δ7.73(2H,ddd,J=5.5,5.2,2.0Hz),8.42(2H,ddd,J=5.1,2.0,0.6Hz),8.58-8.89(10H,8.64(dtd,J=5.5,1.7,0.5Hz),8.68(dd,J=5.3, 0.5Hz),8.76(dd,J=5.7,2.0Hz),8.80(ddt,J=5.1,1.7,0.5Hz),8.83(dd,J=6.0,1.7Hz)),8.91-9.25(14H,8.96(dt,J=1.7,0.5Hz),9.00(t ,J=0.5Hz),9.04(ddd,J=5.5,5.0,0.5Hz),9.09(dt,J=6.0,0.5Hz),9.13(ddd,J=5.5,1.3,0.6Hz),9.17(dd,J=5.0,1.7Hz),9.19(td,J=5.2 ,1.3Hz)),9.25-9.41(8H,9.31(ddd,J=5.3,1.5,0.5Hz),9.32(ddt,J=5.1,1.5,0.5Hz),9.32(dd,J=5.7,0.5Hz),9.36(dd,J=2.0,0.5Hz)).

[0161] Preparation Example 8

[0162] Preparation of compound H78:

[0163]

[0164] The synthesis method of compound H78 is similar to that of H2, except that A2 and B2 in reaction 1) are replaced with equimolar amounts of A78 and B78, respectively; and C2 and D2 in reaction 2) are replaced with equimolar amounts of C78 and D78, respectively.

[0165] MALDI-TOF (m / z): C 54 H 28 N8: Calculated value: 788.24, measured value: 788.68.

[0166] Elemental analysis (%): Calculated values: C, 82.22; H, 3.58; N, 14.20; Test values: C, 83.22; H, 3.57; N, 12.21.

[0167] 1H NMR: δ8.26(4H,ddd,J=7.1,1.9,0.5Hz),8.47-8.87(14H,8.53(d,J=7.1Hz),8.55(t,J=0.5Hz) ,8.59(dtd,J=5.5,1.7,0.5Hz),8.68(dd,J=5.7,0.5Hz),8.79(ddd,J=7.1,1.3,0.5Hz),8.81( ddt,J=6.0,1.7,0.5Hz)),8.93-9.25(8H,8.99(dd,J=7.1,0.5Hz),9.05(ddd,J=5.5,5.0,0.5H z),9.14(ddd,J=5.7,1.8,0.5Hz),9.19(dd,J=5.0,1.8Hz)),9.32(2H,ddt,J=6.0,1.8,0.5Hz).

[0168] Example 1

[0169] This embodiment provides a multilayer electroluminescent organic light-emitting device, the specific fabrication steps of which include:

[0170] (1) Cut the glass substrate into 50mm×50mm×0.7mm pieces, sonicate them in isopropanol and deionized water for 30min respectively, and then clean them under ozone for 10min; mount the glass substrate with ITO anode obtained by magnetron sputtering onto the vacuum deposition equipment.

[0171] (2) Preparation of hole injection layer: under a vacuum of 2×10 -6 At Pa, compounds HT-1 and PD-1 were vacuum-deposited on the ITO anode layer, with HT-1 as the host material and PD-1 as the dopant material. The mass ratio of HT-1 to PD-1 was 95:5, and the thickness was 8 nm, serving as a hole injection layer.

[0172] (3) Preparation of the first hole transport layer: Compound HT-1 was vacuum-deposited on the hole injection layer as the first hole transport layer with a thickness of 22 nm;

[0173] (4) Vacuum evaporation of the first light-emitting layer on the first hole transport layer: using organic compound BH-1 as the host material and BD-1 as the dopant material, with a mass ratio of BH-1 to BD-1 of 99:1, and a thickness of 20nm for the first light-emitting layer.

[0174] (5) Preparation of the first hole blocking layer: Compound HB-1 is vacuum-deposited on the first light-emitting layer as the first hole blocking layer with a thickness of 5 nm;

[0175] (6) Preparation of the first electron transport layer: Vacuum evaporation of compounds ET-1 and Alq3 on the first hole blocking layer as the first electron transport layer, with a mass ratio of ET-1 to Alq3 of 1:1 and a thickness of 10 nm;

[0176] (7) Preparation of N-type charge generation layer (NCGL): Compounds H2 and Yb are vacuum evaporated on the first electron transport layer as NCGL, with H2 as the host material and Yb as the dopant material. The mass ratio of H2 to Yb is 97:3 and the thickness is 20nm.

[0177] (8) Preparation of P-type charge generation layer (PCGL): Compounds HT-1 and PD-1 were vacuum evaporated on NCGL as PCGL, with HT-1 as the host material and PD-1 as the dopant material. The mass ratio of HT-1 to PD-1 was 90:10 and the thickness was 12 nm.

[0178] (9) Preparation of the second hole transport layer: Compound HT-1 was vacuum-deposited on PCGL as the second hole transport layer with a thickness of 50 nm;

[0179] (10) Preparation of the second light-emitting layer: Vacuum evaporation of the second light-emitting layer on the second hole transport layer, using compound BH-1 as the host material and BD-1 as the dopant material, with a mass ratio of BH-1 to BD-1 of 99:1 and a thickness of 20nm.

[0180] (11) Preparation of the second hole blocking layer: Compound HB-1 is vacuum-deposited on the second light-emitting layer as the second hole blocking layer with a thickness of 5 nm;

[0181] (12) Preparation of the second electron transport layer: Vacuum evaporation of compounds ET-1 and Alq3 on the second hole blocking layer as the second electron transport layer, with a mass ratio of ET-1 to Alq3 of 1:1 and a thickness of 30 nm;

[0182] (13) Preparation of electron injection layer: Yb is vacuum-deposited on the second electron transport layer as an electron injection layer with a thickness of 1 nm;

[0183] (14) Preparation of cathode: A magnesium-silver electrode is vacuum-deposited on the electron injection layer as the cathode, with a Mg to Ag mass ratio of 1:9 and a thickness of 13 nm.

[0184] (15) Preparation of capping layer: Compound CPL-1 with a thickness of 600 nm is vacuum evaporated on the cathode as a capping layer to obtain the Tandem OLED device.

[0185] Example 2

[0186] Except for replacing the NCGL main material H2 in step (7) with H19, the rest is the same as in Example 1.

[0187] Example 3

[0188] Except for replacing the NCGL main material H2 in step (7) with H23, the rest is the same as in Example 1.

[0189] Example 4

[0190] Except for replacing the NCGL main material H2 in step (7) with H35, the rest is the same as in Example 1.

[0191] Example 5

[0192] Except for replacing the NCGL main material H2 in step (7) with H56, the rest is the same as in Example 1.

[0193] Example 6

[0194] Except for replacing the NCGL main material H2 in step (7) with H59, the rest is the same as in Example 1.

[0195] Example 7

[0196] Except for replacing the NCGL main material H2 in step (7) with H72, the rest is the same as in Example 1.

[0197] Example 8

[0198] Except for replacing the NCGL main material H2 in step (7) with H78, the rest is the same as in Example 1.

[0199] Comparative Example 1

[0200] Except for replacing the NCGL main material H2 in step (7) with NCGL-1, the rest is the same as in Example 1.

[0201] Comparative Example 2

[0202] Except for replacing the NCGL main material H2 in step (7) with NCGL-2, the rest is the same as in Example 1.

[0203] The compound structures used in the Tandem OLED devices of the above embodiments or comparative examples are as follows:

[0204]

[0205] Test case

[0206] Device operating voltage and current efficiency testing:

[0207] The current of the Tandem OLED devices in the examples and comparative examples was measured at different voltages using a Keithley 2365A digital nanovoltmeter. The current density at different voltages was then obtained by dividing the current by the emitting area. The luminance and radiant energy flux density of the devices at different voltages were measured using a Konicaminolta CS-2000 spectroradiometer. Based on the current density and luminance of the devices at different voltages, the current density at the same current density (10 mA / cm²) was obtained. 2 The operating voltage V and current efficiency BI (Cd / A / CIEy) are used to determine the operating voltage V and current efficiency BI (Cd / A / CIEy).

[0208] The working voltage (V) of the test in Comparative Example 1 REF The value of the operating voltage (Von) of the embodiment or comparative example relative to Comparative Example 1 (Von / V) is denoted as 100%. REF = Operating voltage of the embodiment / Operating voltage of comparative example 1 × 100%.

[0209] The current efficiency (BI) of the test in Comparative Example 1 REF The current efficiency (BI) of the embodiment or comparative example is denoted as 100%. The value of BI / BI for Comparative Example 1 is also shown. REF = Current efficiency of the embodiment or comparative example / Current efficiency of comparative example 1 × 100%.

[0210] The device lifetime in the embodiments and comparative examples is defined as the time (LT95) for the initial brightness to decrease from 100% to 95% of its initial brightness. Comparative Example 1 serves as a reference, with a device lifetime of LT95. REF Defined as 100%, LT95 / LT95 REF = Device lifetime of other embodiments and comparative examples / Device lifetime of comparative example 1, that is, the device lifetime of other embodiments and comparative examples relative to comparative example 1.

[0211] A lower operating voltage means that the device requires less electrical energy to operate under the same conditions, thus reducing power consumption, improving energy efficiency, and extending battery life. Current efficiency refers to the amount of light or other effective output a device can produce given a current input; high current efficiency means that the device can output more light or achieve higher performance with the same input current. Power consumption typically refers to the energy consumed or output by a device per unit time. For tandem OLED devices, a relatively lower operating voltage and relatively higher current efficiency can reduce power consumption, resulting in higher brightness or higher luminous efficiency. The time it takes for the initial brightness (100%) to decrease to 95% can be used to measure the lifetime of a tandem OLED device; a higher value indicates a better lifetime.

[0212] The specific data is shown in Table 1.

[0213] Table 1 OLED Device Performance Test Results

[0214] OLED devices NCGL main material Von / VREF (%) BI / BlREF (%) LT95 / LT95REF (%) Example 1 H2 95.9 104.6 106.3 Example 2 H19 96.4 103.7 104.0 Example 3 H23 95.1 104.2 105.7 Example 4 H35 97.7 103.6 104.9 Example 5 H56 96.3 105.1 107.2 Example 6 H59 95.4 104.3 102.7 Example 7 H72 96.0 103.7 105.6 Example 8 H78 94.7 104.8 106.3 Comparative Example 1 NCGL-1 100 100 100 Comparative Example 2 NCGL-2 98.4 101.8 94.0

[0215] As can be seen from Table 1, the Tandem OLED devices provided in Examples 1-8 of this application have lower operating voltage, higher current efficiency, and longer lifespan.

[0216] Compared to Comparative Examples 1 and 2, the Tandem OLED using the nitrogen-containing heterocyclic compound defined in this application exhibits a significantly lower operating voltage, improved current efficiency, and extended lifetime. This may be attributed to the high conjugation of the nitrogen-containing heterocyclic compound, which effectively disperses electrons, thereby enhancing molecular stability and facilitating energy level matching with adjacent layers. Simultaneously, it provides more coordination and complexation sites, improving coordination and complexation capabilities. The introduction of more N and O atoms facilitates hydrogen bond formation with hydrogen atoms, improving intermolecular stacking and enhancing electron injection transport capabilities, thus reducing the driving voltage. Furthermore, the nitrogen-containing heterocyclic compound provided in this application possesses excellent thermal stability and film-forming properties, contributing to device stability and extending device lifetime.

[0217] Furthermore, as can be seen from the examples and Comparative Example 2, whether or not a nitrogen-containing heterocyclic compound contains a phenanthroline or bipyridine structure has a significant impact on its performance.

[0218] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as the combination of these technical features is not contradictory, it should be considered to be within the scope of this specification.

[0219] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A nitrogen-containing heterocyclic compound, characterized in that, The structure is shown in Equation I: The structure of R is shown in Equation II: X1, X2, X3, X4, X5, and X6 are each independently selected from C or N; R1 and R2 are each independently selected from H, C1-C6 alkyl, substituted or unsubstituted aryl with 6-30 ring atoms, or substituted or unsubstituted heteroaryl with 6-30 ring atoms; R3, R4, R5 and R6 are each independently selected from H, -CN, C1-C6 alkyl, substituted or unsubstituted aryl group with 6-30 ring atoms, unsubstituted heteroaryl group with 6-30 ring atoms, or are not present; Alternatively, R3 and R4, R4 and R5, and R5 and R6 can each independently form a cyclization group to constitute a phenyl, pyridinyl, pyrimidinyl, or quinolinyl group, and when R4 and R5 form a cyclization group, R3 and R4, and R5 and R6 do not form a cyclization group. Each substituent is independently selected from H, -CN, C1-C6 alkyl, aryl with 6-12 ring atoms, heterocyclic with 5-18 ring atoms, or... The nitrogen-containing heterocyclic compound contains at least one selected from... or Substructures; X1', X2', X3', and X4' are each independently selected from C or N.

2. The nitrogen-containing heterocyclic compound according to claim 1, characterized in that, R1 and R2 are each independently selected from H, C1-C6 alkyl, phenyl, naphthyl, biphenyl, m-tolyl, p-tolyl, One of them.

3. The nitrogen-containing heterocyclic compound according to claim 1, characterized in that, R3, R4, R5, and R6 are each independently selected from H, -CN, C1-C6 alkyl, phenyl, or non-existent. Alternatively, R3 and R4 can form a ring to constitute phenyl, pyridyl, pyrimidyl, or quinolinyl, while R5 and R6 cannot form a ring; or R4 and R5 can form a ring to constitute phenyl, pyridyl, pyrimidyl, or quinolinyl, while R3 and R6 cannot form a ring; or R5 and R6 can form a ring to constitute phenyl, pyridyl, pyrimidyl, or quinolinyl, while R3 and R4 cannot form a ring; or R3 and R4 can form a ring to constitute phenyl or pyridyl, while R5 and R6 can form a ring to constitute phenyl or pyridyl.

4. The nitrogen-containing heterocyclic compound according to any one of claims 1-3, characterized in that, X1 and X2 are C, and the structure of the nitrogen-containing heterocyclic compound is shown in Formula I-1: At least one of R1, R2, and R contains a substructure or Alternatively, X1 is C and X2 is N, and the structure of the nitrogen-containing heterocyclic compound is shown in Formula I-2: Alternatively, X1 is N and X2 is C, and the structure of the nitrogen-containing heterocyclic compound is shown in Formula I-3: At least one of R1 and R2 contains a substructure or Alternatively, the structure formed by the rings containing R1, R2, and X1 may contain substructures. or 5. The nitrogen-containing heterocyclic compound according to any one of claims 1-3, characterized in that, R is selected from one of formulas II-1 to II-7:

6. The nitrogen-containing heterocyclic compound as described in claim 5, characterized in that, R is selected from one of Equations III-1 to III-12:

7. The nitrogen-containing heterocyclic compound according to claim 6, characterized in that, R is selected from phenyl, naphthyl, m-tolyl, p-tolyl, and o-tolyl. One of them.

8. The nitrogen-containing heterocyclic compound according to any one of claims 1-3, characterized in that, The nitrogen-containing heterocyclic compound includes at least one of the following compounds:

9. The method for preparing the nitrogen-containing heterocyclic compound according to any one of claims 1-8, characterized in that, Includes the following steps: The nitrogen-containing heterocyclic compound was prepared by reacting compound A with R1-B(OH)2, R2-B(OH)2 and RB(OH)2.

10. A charge generation layer, characterized in that, Includes one or more of the nitrogen-containing heterocyclic compounds according to any one of claims 1-8.

11. A light-emitting device, characterized in that, Includes one or more of the nitrogen-containing heterocyclic compounds according to any one of claims 1-8 or the charge-generating layer according to claim 10; Optionally, the light-emitting device includes an electroluminescent device; Optionally, the electroluminescent device includes a stacked organic light-emitting device.

Images