A pyrazolonephenoxazine nitrogen-containing heterocyclic compound, a light-emitting composition, and an organic electroluminescent element

Abstract

The application discloses a pyrazolone phenoxazine nitrogen-containing heterocyclic compound, a light-emitting composition and an organic electroluminescent element, relates to the technical field of organic optoelectronic materials and elements, and the pyrazolone phenoxazine nitrogen-containing heterocyclic compound is a compound with a molecular structure general formula (1): the compound is a pyrazolone phenoxazine skeleton nitrogen-containing heterocyclic compound, has the characteristics of high performance and narrow emission spectrum, and can be applied to preparation of an organic electroluminescent element or an illumination element.

Description

Technical Field

[0001] This invention relates to the field of organic optoelectronic materials and components, and particularly to a pyrazolone-phenazine nitrogen-containing heterocyclic compound, a luminescent composition, and an organic electroluminescent element. Background Technology

[0002] Organic light-emitting diode (OLED) technology is a technique that uses organic semiconductor thin films to emit light under an applied voltage. It boasts numerous advantages, including flexibility, self-illumination, thinness, and low power consumption, and has been widely applied in smartphones, wearable devices, and automotive displays. Organic light-emitting materials, as a crucial part of the OLED display technology industry chain, represent a significant technological barrier; therefore, exploring OLED light-emitting materials that meet the requirements of display panels is of paramount importance.

[0003] With the continuous development and iteration of OLED display technology, next-generation display technologies require OLED luminescent materials to possess properties such as high luminous efficiency, long lifespan, and high color purity. Based on the light-emitting mechanism, OLED luminescent materials can be classified into traditional fluorescent materials, phosphorescent materials, and thermally activated delayed fluorescence materials. While phosphorescent materials achieve high efficiency and long lifespan, their presence of precious metals increases material costs. Furthermore, phosphorescent materials utilize charge-transfer luminescence between metals and ligands, resulting in significant spectral broadening, which is detrimental to improving color purity. Thermally activated delayed fluorescence materials utilize the reverse intersystem crossing from triplet to singlet state to achieve triplet exciton utilization. These materials achieve a smaller singlet-triplet energy difference by utilizing the overlapping electron clouds of the donor and acceptor, and the resulting charge-transfer luminescence also leads to broad-spectrum emission properties.

[0004] In recent years, narrow-spectrum OLED luminescent materials constructed with boron nitrogen as the molecular backbone have attracted much attention. These materials have a multi-resonance electron cloud distribution, which suppresses molecular vibrations that lead to spectral broadening, giving them an advantage in achieving high-efficiency, narrow-spectrum luminescent materials. However, boron nitrogen luminescent materials still have the following shortcomings or limitations: 1) The boron nitrogen molecular backbone has a large π-conjugated molecular backbone, which easily leads to intermolecular stacking, causing luminescence quenching, resulting in decreased luminescence efficiency and significant spectral broadening; 2) Conventional methods introduce charge-donating or charge-withdrawing units, or five- or six-membered fused ring units, into the boron nitrogen molecular backbone to regulate the luminescence peak position of the material. However, these methods easily lead to electron cloud distribution on the donor (acceptor) units or fused ring units, causing new vibrational peaks that enhance spectral broadening, thereby reducing color purity and hindering the application of the material in wide color gamut displays.

[0005] It is evident that existing technologies still need improvement and enhancement. Summary of the Invention

[0006] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a pyrazolinone-phenazine nitrogen-containing heterocyclic compound, a luminescent composition and an organic electroluminescent element, which aims to improve the luminous efficiency and color purity of existing luminescent materials.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] The first aspect of this invention provides a pyrazolinone-phenazine nitrogen-containing heterocyclic compound having the general molecular formula (1):

[0009]

[0010] Wherein, substituents R1 and R2 are each independently selected from halogen atoms, cyano groups, phenyl or biphenyl and their derivatives, fused-ring phenyl groups with 2 to 6 benzene rings and their derivatives, phenanthroline and its derivatives, pyridine and its derivatives, pyrimidine and its derivatives, triazine and its derivatives, pyrazine and its derivatives, fluorenyl and its derivatives, thiophene and its derivatives, furan and its derivatives, imidazole and its derivatives, indole and its derivatives, carbazole and its derivatives, indole-carbazole and its derivatives, boron nitrogen and its derivatives, aniline and its derivatives, acridine and its derivatives, phenazine and its derivatives, phenothiazine and its derivatives, phenoteneselene and its derivatives, thiathracene and its derivatives, thioxanthracene and its derivatives, phenoteneselene and its derivatives, phenothiazine and its derivatives, selenium and its derivatives, and these substituents are either unbonded or bonded to form further ring structures; n is selected from integers from 0 to 4;

[0011] R3 to R4 are each independently a hydrogen atom, a deuterium atom, a tritium atom, a halogen atom, a cyano group, a substituted or unsubstituted alkyl group with 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group with 3 to 20 carbon atoms, a substituted or unsubstituted alkoxy group with 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group with 6 to 50 carbon atoms, a substituted or unsubstituted cycloalkyl group with 6 to 50 carbon atoms, a substituted or unsubstituted cycloalkyl group with 6 to 50 carbon atoms, or a substituted or unsubstituted heteroaryl group with 5 to 50 carbon atoms, aniline and its derivatives, carbazole and its derivatives, indolecarbazole and its derivatives, boron nitrogen and its derivatives, acridine and its derivatives, benzothiophene and its derivatives, benzofuran and its derivatives, fluorenyl and its derivatives, phenoxazine and its derivatives, phenothiazine and its derivatives, phenyl or biphenyl and its derivatives.

[0012] A second aspect of the present invention provides a luminescent composition comprising a third compound and a first compound doped in the third compound, wherein the first compound is a nitrogen-containing heterocyclic compound of pyrazolone and phenazine as described above, and the mass percentage of the first compound doped is 0.3 to 20.0%.

[0013] The third invention provides an organic electroluminescent element, comprising a substrate, an anode layer, an organic light-emitting functional layer, and a cathode layer disposed on the substrate. The organic light-emitting functional layer includes one or more of a hole injection layer, a hole transport layer, a light-emitting layer, an electron transport layer, and an electron injection layer. The light-emitting layer is located between the hole transport layer and the electron transport layer. The light-emitting layer includes at least one pyrazolone-phenazine nitrogen-containing heterocyclic compound as described above, or a light-emitting composition as described above.

[0014] Beneficial effects:

[0015] The first aspect of this invention provides a nitrogen-containing heterocyclic compound of pyrazolinone-phenazine, which has the following beneficial effects: 1) By further introducing nitrogen atoms into the five-membered ring of pyrrolopyrazine to form a pyrazolinone-phenazine skeleton, the pyrazolinone-phenazine skeleton can regulate the light color of the luminescent molecule, avoiding the problem of luminescence spectrum broadening caused by the introduction of charge-giving (charge-withdrawing) units; 2) The pyrazolinone-phenazine molecular skeleton itself has strong rigidity and a short π-conjugated structure, which can suppress molecular stretching vibrations and molecular conformational relaxation behavior caused by π-conjugation, thus improving the emission spectrum. The broadening problem is effectively solved, resulting in a smaller spectral half-width; 3) By introducing substituents to the molecular backbone to assist chromophores, the molecular emission color is regulated to the blue region. At the same time, the small emission band gap of pyrazolone-phenazine is utilized to avoid excessive distribution of frontier orbital electron clouds on the auxiliary chromophores, so that the nitrogen-containing heterocyclic compound still maintains narrow emission spectral characteristics; 4) By incorporating auxiliary chromophores of different planes into the molecular backbone of pyrazolone-phenazine, the stacking effect between pyrrolopyrazine molecules can be effectively avoided, and the aggregation luminescence quenching caused by the stacking effect can be suppressed. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of an organic electroluminescent element.

[0017] Figure 2 This is the photoluminescence spectrum of compound 4-12 in toluene solution.

[0018] In the attached diagram, the following labels are used: 10, anode layer; 11, hole injection layer; 12, hole transport layer; 13, light-emitting layer; 14, second electron transport layer; 15, first electron transport layer; 16, electron injection layer; 17, cathode layer. Detailed Implementation

[0019] This invention provides a pyrazolone-phenazine nitrogen-containing heterocyclic compound, a luminescent composition, and an organic electroluminescent element. To make the objectives, technical solutions, and effects of this invention clearer and more explicit, the following embodiments are provided for further detailed explanation. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of the invention.

[0020] This invention provides a nitrogen-containing heterocyclic compound of pyrazolinone-phenazine, wherein the nitrogen-containing compound has the general molecular formula (1):

[0021]

[0022] In general formula (1), substituents R1 and R2 are each independently selected from halogen atoms, cyano groups, phenyl or biphenyl and their derivatives, fused-ring phenyl groups with 2 to 6 rings and their derivatives, phenanthroline and its derivatives, pyridine and its derivatives, pyrimidine and its derivatives, triazine and its derivatives, pyrazine and its derivatives, fluorenyl and its derivatives, thiophene and its derivatives, furan and its derivatives, imidazole and its derivatives, indole and its derivatives, carbazole and its derivatives, indole-carbazole and its derivatives, boron nitrogen and its derivatives, aniline and its derivatives, acridine and its derivatives, phenazine and its derivatives, phenothiazine and its derivatives, phenoteneselenoxine and its derivatives, thiaanthracene and its derivatives, thioxanthracene and its derivatives, phenoteneselenoxine and its derivatives, phenothiazine and its derivatives, selenium and its derivatives, and these substituents are either unbonded or bonded to form further ring structures; n is selected from integers from 0 to 4;

[0023] R3 to R4 are each independently a hydrogen atom, a deuterium atom, a tritium atom, a halogen atom, a cyano group, a substituted or unsubstituted alkyl group with 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group with 3 to 20 carbon atoms, a substituted or unsubstituted alkoxy group with 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group with 6 to 50 carbon atoms, a substituted or unsubstituted cycloalkyl group with 6 to 50 carbon atoms, a substituted or unsubstituted cycloalkyl group with 6 to 50 carbon atoms, or a substituted or unsubstituted heteroaryl group with 5 to 50 carbon atoms, aniline and its derivatives, carbazole and its derivatives, indolecarbazole and its derivatives, boron nitrogen and its derivatives, acridine and its derivatives, benzothiophene and its derivatives, benzofuran and its derivatives, fluorenyl and its derivatives, phenoxazine and its derivatives, phenothiazine and its derivatives, phenyl or biphenyl and its derivatives.

[0024] The nitrogen-containing heterocyclic fused-ring compounds of pyrazolinone-phenazine with the general formula (1) have the following characteristics: 1) By further introducing nitrogen atoms into the five-membered ring of pyrrolopyrazine, a pyrazolinone-phenazine skeleton is formed. This pyrazolinone-phenazine skeleton can regulate the light color of the luminescent molecule and avoid the problem of luminescence spectrum broadening caused by the introduction of an electro-donating (electro-withdrawing) unit; 2) The pyrazolinone-phenazine molecular skeleton itself has strong rigidity and a short π-conjugated structure, which can suppress the stretching vibration of the molecule and the conformational relaxation of the molecule caused by π-conjugation. To effectively solve the problem of emission spectrum broadening and give it a smaller spectral half-width; 3) By introducing substituents to the molecular skeleton to assist chromophores to regulate the color of molecular emission, since pyrazolinone-phenazine has a small emission band gap, the frontier orbital electron cloud is not distributed too much on the auxiliary chromophore, and the electron cloud is still mainly localized on the pyrazolinone-phenazine skeleton, thereby obtaining a stronger S0-S1 and S1-S0 transition dipole intensity and suppressing the spectral broadening behavior caused by the auxiliary chromophore.

[0025] Since the substituents R1 and R2 have different effects on the full width at half maximum (FWHM) of the compound at different positions, in a preferred embodiment, the pyrazolinone-phenazine nitrogen-containing heterocyclic compound has the structural formula of any one of formula (2-1), formula (2-2), or formula (2-3):

[0026]

[0027] In the aforementioned nitrogen-containing heterocyclic compounds of pyrazolinone-phenazine with the structural formulas (2-1), (2-2), and (2-3), the positions of the substituents R1 and R2 allow the electron cloud to be better localized on the pyrazolinone-phenazine skeleton, thereby better suppressing the spectral broadening behavior of the auxiliary chromophore and resulting in a narrower spectral half-width.

[0028] In a preferred embodiment, the substituents R1 and R2 are each independently selected from any one of the following substituents, but not limited to:

[0029]

[0030] In equations (3-1) to (3-12), Y, Z, and Q are each independently selected from C(R). 41 (R) 42 ), NR 43 O, S, Se, Si(R) 44 (R) 45 One of them;

[0031] Q1 is independently selected from hydrogen, deuterium, halogen, cyano, substituted or unsubstituted alkyl with 1 to 20 carbon atoms, substituted or unsubstituted alkenyl with 1 to 20 carbon atoms, substituted or unsubstituted alkynyl with 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl with 3 to 20 carbon atoms, amino, substituted or unsubstituted alkoxy with 1 to 20 carbon atoms, substituted or unsubstituted fluoroalkyl with 1 to 20 carbon atoms, substituted or unsubstituted fluoroalkoxy with 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl with 6 to 50 carbon atoms, substituted or unsubstituted alkylthio with 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl with 6 to 50 carbon atoms, -N(R 101 (R) 102 ), any one of aryl groups with 6 to 50 cyclic carbon atoms (substituted or unsubstituted) and heteroaryl groups with 5 to 50 cyclic atoms (substituted or unsubstituted);

[0032] P1~P 20 Each of the following is independently any one of hydrogen atom, deuterium atom, substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl group having 3 to 20 cyclic carbon atoms, substituted or unsubstituted aryl group having 6 to 50 cyclic carbon atoms, and substituted or unsubstituted heteroaryl group having 5 to 50 cyclic atoms;

[0033] L is any one of the following: substituted or unsubstituted alkyl with 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl with 3 to 20 carbon atoms, substituted or unsubstituted aryl with 6 to 50 carbon atoms, and substituted or unsubstituted heteroaryl with 5 to 50 carbon atoms; n is an integer from 0 to 3.

[0034] The R1 and R2 substituents in the aforementioned structural formula can control the emission color of the compound. In actual use, the corresponding structural formula can be selected according to actual needs to obtain the target color.

[0035] In a preferred embodiment, the heterocyclic compound is selected from one of the following chemical structures:

[0036]

[0037]

[0038]

[0039]

[0040]

[0041]

[0042]

[0043]

[0044] The aforementioned pyrazolone-phenazine nitrogen-containing heterocyclic compounds have narrow spectral half-widths and high luminous purity and luminous efficiency, making them suitable for use as electroluminescent materials.

[0045] To confirm that the aforementioned pyrazolinone-phenazine nitrogen-containing heterocyclic compounds possess high fluorescence quantum yield and narrow emission characteristics, photophysical performance tests were conducted using compound 4-12 as an example. The tests revealed that at room temperature, this compound exhibits high fluorescence quantum yield and narrow emission characteristics in toluene solution (concentration 1×10⁻⁶). -5 The emission peak position in M) is 461nm, specifically as follows: Figure 2 As shown, the full width at half maximum (FWHM) of the spectrum is 17 nm, and the fluorescence quantum yield is 92%. Simultaneously, comparative compounds 1 and 2 were tested under the same conditions, revealing fluorescence quantum yields of 82% and 90%, respectively, emission peak positions of 432 nm and 458 nm, and FWHMs of 17 nm and 23 nm, respectively. The results indicate that the pyrazolone-phenazine nitrogen-containing heterocyclic compound exhibits a higher fluorescence quantum yield compared to other nitrogen-containing heterocyclic compounds and narrow-spectrum boron-nitrogen compounds. Furthermore, introducing nitrogen atoms into the five-membered ring of pyrrolopyrazine can redshift the emission peak to the deep blue region.

[0046] In summary, the pyrazolone-phenazine nitrogen-containing heterocyclic compounds described in this application possess high fluorescence quantum yield and narrow emission characteristics, and can be widely used in luminescent materials.

[0047] Comparative compound 1 and comparative compound 2 have the following structural formulas:

[0048]

[0049]

[0050] A second aspect of the present invention also provides a luminescent composition comprising a third compound and a first compound doped in the third compound. The first compound is a nitrogen-containing heterocyclic compound of pyrazolone-phenazine as described above. Since the nitrogen-containing heterocyclic compound of pyrazolone-phenazine has high luminescent efficiency and luminescent color purity, when it is doped as a guest material in the third compound, which is the host material, it can work together with the third compound to emit light with a narrow spectral half-width and a high initial color intensity, and has high luminescent efficiency.

[0051] In a preferred embodiment, the luminescent composition comprises 0.3–20.0% of the first compound and 80.0–99.7% of the third compound by weight, and the luminescent composition of this ratio has good luminous efficiency.

[0052] In a preferred embodiment, the third compound is selected from, but is not limited to, one of the following compounds:

[0053]

[0054]

[0055]

[0056]

[0057] The third compound of the aforementioned structural formula can interact well with pyrazolone and phenazine nitrogen-containing heterocyclic compounds, thereby enabling the luminescent composition to have high luminescent efficiency.

[0058] In another embodiment, the luminescent composition further includes a second compound, which is a compound with an auxiliary luminescent effect, such as a photosensitive compound that can assist the luminescence of pyrazolone and phenazine nitrogen-containing heterocyclic compounds, but is not limited to a photosensitive compound, and may also be other compounds with auxiliary luminescent effects.

[0059] In a preferred embodiment, the luminescent composition comprises, by mass percentage: 0.3-10.0% of a first compound, 5.0-60.0% of a second compound, and 30.0-94.7% of a third compound. The luminescent composition with this ratio has high luminous efficiency.

[0060] Specifically, in the aforementioned luminescent composition comprising the first compound, the second compound, and the third compound, the second compound and the third compound are each independently selected from one of the following compounds, and the second compound is different from the third compound:

[0061]

[0062]

[0063]

[0064]

[0065]

[0066]

[0067] The combination of the second and third compounds of the aforementioned structural formula can give the pyrazolone and phenazine nitrogen-containing heterocyclic compound higher luminescence efficiency.

[0068] A third aspect of the present invention also provides an organic electroluminescent element comprising a substrate, an anode layer disposed on the substrate, an organic light-emitting functional layer, and a cathode layer. The organic light-emitting functional layer includes one or more of a hole injection layer, a hole transport layer, a light-emitting layer, an electron transport layer, and an electron injection layer. The light-emitting layer is located between the hole transport layer and the electron transport layer. The raw material composition for preparing the light-emitting layer includes the pyrazolone-phenazine nitrogen-containing heterocyclic compound as described above, or a light-emitting combination containing a pyrazolone-phenazine nitrogen-containing heterocyclic compound. Therefore, the organic electroluminescent element can have a high fluorescence quantum yield and narrow emission characteristics.

[0069] Specifically, the anode layer is used to inject holes into the hole transport layer or the light-emitting layer. It is usually made of materials with a work function greater than 4.5 eV, such as indium tin oxide (ITO), tin oxide (NESA), indium gallium zinc oxide (IGZO), silver, etc. These materials can be used to form anode layer thin films by thermal evaporation, sputtering, etc.

[0070] Specifically, the cathode layer is used to inject electrons into the electron injection layer, electron transport layer, or light-emitting layer, and it is typically made of a material with a low work function, such as aluminum, magnesium, silver, magnesium-silver alloys, magnesium-aluminum alloys, or aluminum-lithium alloys. The cathode layer can also be formed into a thin film by thermal evaporation, sputtering, or other methods, and the film thickness of the cathode layer is preferably selected in the range of 10–200 nm.

[0071] The electron injection layer is used to promote the injection of electrons from the cathode layer to the electron transport layer or the light-emitting layer, thereby improving the luminous brightness and lifetime of the organic electroluminescent element. As a preferred option, the electron injection layer is prepared by thermal evaporation using a material with a work function less than 3.8 eV, such as Li, Cs, Ba, Yb, LiF, CsF, BaO, etc., and the preferred film thickness of the electron injection layer is 0.1–15 nm.

[0072] The electron transport layer is disposed between the light-emitting layer and the cathode layer (or electron injection layer), and is used to transport electrons from the cathode or electron injection layer to the light-emitting layer. The electron transport layer may consist of one organic layer or two organic layers. When it consists of two organic layers, the organic layer closer to the cathode layer is defined as the first electron transport layer, and the organic layer closer to the light-emitting layer is defined as the second electron transport layer. The electron transport layer, as an electron transport material, is preferably an aromatic heterocyclic compound containing one or more heteroatoms within its molecule, and more preferably a nitrogen-containing ring derivative. Furthermore, as a nitrogen-containing ring derivative, it is preferably an aromatic ring having a nitrogen-containing six-membered or five-membered ring skeleton, or a fused aromatic ring compound having a nitrogen-containing six-membered or five-membered ring skeleton.

[0073] The thickness of the electron transport layer is generally 10–100 nm. When the electron transport layer consists of a first electron transport layer and a second electron transport layer, the thickness of the first electron transport layer is preferably 9–70 nm, and the thickness of the second electron transport layer is preferably 1–30 nm.

[0074] The hole transport layer is an organic layer disposed between the light-emitting layer and the anode layer (or hole injection layer), and its main function is to transport holes from the anode to the light-emitting layer. The hole transport layer may consist of one organic layer or two organic layers. When it consists of two organic layers, the organic layer closer to the anode layer is defined as the first hole transport layer, and the organic layer closer to the light-emitting layer is defined as the second hole transport layer.

[0075] Preferably, the hole transport layer is prepared from an aromatic amine compound, such as an aromatic amine derivative with the structural formula (70).

[0076]

[0077] These aromatic amine derivatives have better hole transport efficiency.

[0078] The thickness of the hole transport layer is generally 20–200 nm. When the hole transport layer consists of a first hole transport layer and a second hole transport layer, the thickness of the first hole transport layer is preferably 19–150 nm, and the thickness of the second hole transport layer is preferably 1–50 nm.

[0079] Specifically, the hole injection layer is disposed between the anode layer and the hole transport layer (or light-emitting layer) to promote hole injection from the anode layer to the hole transport layer or light-emitting layer, thereby reducing the driving voltage of the organic electroluminescent element and improving its brightness and lifetime. The hole injection layer is typically prepared using acceptor-type organic materials containing deep LUMO energy levels, such as HATCN, F3TCNQ, and HI-3, and its thickness is generally 1–50 nm.

[0080] The structural formulas of HATCN, F3-TCNQ, and HI-3 are as follows:

[0081]

[0082] In a preferred embodiment, the organic electroluminescent element is further doped with an n-type dopant in the electron transport layer and a p-type dopant in the hole transport layer. The main functions of the n-type and p-type dopant are to improve the transport properties of the electron transport layer and the hole transport layer, respectively, and to reduce the driving voltage of the organic electroluminescent element. Here, the n-type dopant can be selected from Li, Cs, Ba, Yb, CsF, BaO, Liq, Naq, Libpp, Bepq2, Bepp2, LiF, CsCO3, and ZnO; the p-type dopant can be selected from HATCN, F4TCNQ, and HI-3, but is not limited to these substances. When the hole transport layer contains the p-type dopant and the hole transport material, the doping concentration of the p-type dopant is preferably 0.1% to 50.0% by mass; when the hole transport layer contains the n-type dopant and the electron transport material, the doping concentration of the n-type dopant is preferably 1.0% to 90.0% by mass.

[0083] The preferred n-type dopant materials Liq, Naq, Libpp, Bepq2, and Bepp2 for the organic electroluminescent element of this application have the following structural formulas:

[0084]

[0085]

[0086] In summary, the organic electroluminescent element of the present invention, by using a luminescent composition containing pyrazolone and phenazine nitrogen-containing heterocyclic compounds as the luminescent material, combined with a hole injection layer, hole transport layer, electron transport layer and electron injection layer of special materials, can enable the organic electroluminescent element to have high fluorescence quantum yield and narrow emission characteristics.

[0087] To further illustrate the pyrazolone-phenazine nitrogen-containing heterocyclic compound, luminescent composition, and organic electroluminescent element provided by the present invention, the following examples are provided.

[0088] Examples 1-8

[0089] Example 1:

[0090]

[0091] Add 1 (1.16 g, 5 mmol), CuI (0.309 g, 1 mmol, 20 mol%), Phen (0.180 g, 1.0 mmol, 20 mol%), and anhydrous Cs₂CO₃ (2.44 g, 7.5 mmol) to 10 mL of o-DCB and heat to 180 °C. Stir for 24 h under nitrogen protection. After cooling to room temperature, wash a silica gel column with a large amount of DCM to remove CuI and Cs₂CO₃ and collect the filtrate. Remove the solvent by vacuum distillation. Then, purify the product by silica gel column chromatography with dichloromethane / petroleum ether (volume 1:3) as the developing solvent. Concentrate by rotary evaporation to obtain 2 (0.21 g, 14%) as a yellow-green powder.

[0092] A mixture of compounds 3 (0.52 g, 2.2 mmol), 2 (0.30 g, 1 mmol), Pd(PPh3)4 (72 mg, 0.06 mmol), and K2CO3 (0.83 g, 6 mmol) was added to a 50 mL double-necked flask and heated under nitrogen. 20 mL of a mixed solvent system of Toluene / EtOH / H2O (2:1:1, v / v) was injected into the reaction flask, and the reaction mixture was refluxed for 12 h. After cooling to room temperature, the mixture was poured into water and extracted twice with dichloromethane, then dried over anhydrous magnesium sulfate. After filtration, the mixture was concentrated by rotary evaporation. The crude product was purified by silica gel column chromatography using dichloromethane / petroleum ether (1:1, v / v) as the eluent to give a yellow powder 4-11 (0.42 g, 84%).

[0093] Example 2:

[0094]

[0095] 4 (1.16 g, 5 mmol), CuI (0.309 g, 1 mmol, 20 mol%), Phen (0.180 g, 1.0 mmol, 20 mol%), and anhydrous Cs₂CO₃ (2.44 g, 7.5 mmol) were added to 10 mL of o-DCB and heated to 180 °C. The mixture was stirred for 24 h under nitrogen protection. After cooling to room temperature, the silica gel column was washed with a large amount of DCM to remove CuI and Cs₂CO₃, and the filtrate was collected. The solvent was then removed by vacuum distillation. The product was then purified by silica gel column chromatography with a dichloromethane / petroleum ether (volume ratio 1:3) as the developing solvent. The product was concentrated by rotary evaporation to obtain 5 (0.180 g, 12%) as a yellow-green powder.

[0096] A mixture of compounds 3 (0.52 g, 2.2 mmol), 5 (0.30 g, 1 mmol), Pd(PPh3)4 (72 mg, 0.06 mmol), and K2CO3 (0.83 g, 6 mmol) was added to a 50 mL double-necked flask and heated under nitrogen. 20 mL of a mixed solvent system of Toluene / EtOH / H2O (2:1:1, v / v) was injected into the reaction flask, and the reaction mixture was refluxed for 12 h. After cooling to room temperature, the mixture was poured into water and extracted twice with dichloromethane, then dried over anhydrous magnesium sulfate. After filtration, the mixture was concentrated by rotary evaporation. The crude product was purified by silica gel column chromatography using dichloromethane / petroleum ether (1:1, v / v) as the eluent to give a yellow powder 4-12 (0.37 g, 78%).

[0097] Example 3:

[0098]

[0099] A mixture of 2 (0.30 g, 1.0 mmol), 6 (0.51 g, 3.0 mmol), Pd2(dba)3 (0.046 g, 0.05 mmol, 5 mol%), S-phos (0.082 g, 0.2 mmol, 20 mol%), and NaOtBu (0.38 g, 4.0 mmol) was heated to 140 °C in 60 mL of Xylenen:DMF (2:1 v / v) co-solvent under a nitrogen atmosphere for 24 h. The reaction mixture was extracted with ethyl acetate upon cooling, dried over anhydrous sodium sulfate, and concentrated by rotary evaporation. The crude product was purified by silica gel column chromatography using ethyl acetate / petroleum ether (1:20 v / v) as the eluent to give a yellow solid 4-19 (0.41 g, 72%).

[0100] Example 4:

[0101]

[0102] A mixture of 5 (0.30 g, 1.0 mmol), 6 (0.51 g, 3.0 mmol), Pd2(dba)3 (0.046 g, 0.05 mmol, 5 mol%), S-phos (0.082 g, 0.2 mmol, 20 mol%), and NaOtBu (0.38 g, 4.0 mmol) was heated to 140 °C in 60 mL of Xylenen:DMF (2:1 v / v) co-solvent under a nitrogen stream for 24 h. The reaction mixture was extracted with ethyl acetate upon cooling, dried over anhydrous sodium sulfate, and concentrated by rotary evaporation. The crude product was purified by silica gel column chromatography using ethyl acetate / petroleum ether (1:20 v / v) as eluent to give a yellow solid 4-21 (0.45 g, 76%).

[0103] Example 5:

[0104]

[0105] A mixture of 5 (0.30 g, 1.0 mmol), 7 (0.52 g, 3.0 mmol), Pd2(dba)3 (0.046 g, 0.05 mmol, 5 mol%), S-phos (0.082 g, 0.2 mmol, 20 mol%), and NaOtBu (0.38 g, 4.0 mmol) was heated to 140 °C in 60 mL of Xylenen:DMF (2:1 v / v) co-solvent under a nitrogen stream for 24 h. The reaction mixture was extracted with ethyl acetate upon cooling, dried over anhydrous sodium sulfate, and concentrated by rotary evaporation. The crude product was purified by silica gel column chromatography using ethyl acetate / petroleum ether (1:20 v / v) as eluent to give a yellow solid 4-24 (0.47 g, 78%).

[0106] Example 6:

[0107]

[0108] 1 (1.15 g, 5 mmol), 4 (1.15 g, 5 mmol), CuI (0.618 g, 2 mmol, 20 mol%), Phen (0.360 g, 2.0 mmol, 20 mol%), and anhydrous Cs₂CO₃ (4.88 g, 15 mmol) were added to 10 mL of o-DCB and heated to 180 °C. The mixture was stirred for 24 h under nitrogen protection. After cooling to room temperature, the silica gel column was washed with a large amount of DCM to remove CuI and Cs₂CO₃, and the filtrate was collected. The solvent was then removed by vacuum distillation. The product was then purified by silica gel column chromatography with a developing solvent ratio of DCM:PE = 1:2 (v / v). The product was concentrated by rotary evaporation to obtain 8 (0.220 g, 15%) as a yellow-green powder.

[0109] A mixture of 8 (0.30 g, 1.0 mmol), 9 (0.51 g, 1.5 mmol), Pd2(dba)3 (0.046 g, 0.05 mmol, 5 mol%), S-phos (0.082 g, 0.2 mmol, 20 mol%), and NaOtBu (0.38 g, 4.0 mmol) was heated to 140 °C in 60 mL of Xylenen:DMF (2:1 v / v) co-solvent under a nitrogen atmosphere for 24 h. The reaction mixture was extracted with ethyl acetate upon cooling, dried over anhydrous sodium sulfate, and concentrated by rotary evaporation. The crude product was purified by silica gel column chromatography using ethyl acetate / petroleum ether (1:20 v / v) as the eluent to give a yellow solid 10 (0.44 g, 76%).

[0110] A mixture of 10 (0.56 g, 1.0 mmol), 11 (0.41 g, 1.5 mmol), Pd2(dba)3 (0.046 g, 0.05 mmol, 5 mol%), S-phos (0.082 g, 0.2 mmol, 20 mol%), and NaOtBu (0.38 g, 4.0 mmol) was heated to 140 °C in 60 mL of Xylenen:DMF (2:1 v / v) co-solvent under a nitrogen stream for 24 h. The reaction mixture was extracted with ethyl acetate upon cooling, dried over anhydrous sodium sulfate, and concentrated by rotary evaporation. The crude product was purified by silica gel column chromatography using ethyl acetate / petroleum ether (1:20 v / v) as eluent to give a yellow solid 4-41 (0.623 g, 79%).

[0111] Example 7:

[0112]

[0113] A mixture of 2 (0.30 g, 1 mmol), 11 (0.81 g, 2 mmol), Pd2(dba)3 (0.046 g, 0.05 mmol, 5 mol%), S-phos (0.082 g, 0.2 mmol, 20 mol%), and NaOtBu (0.38 g, 4.0 mmol) was heated to 140 °C in 60 mL of Xylenen:DMF (2:1 v / v) co-solvent under a nitrogen atmosphere for 24 h. The reaction mixture was extracted with ethyl acetate upon cooling, dried over anhydrous sodium sulfate, and concentrated by rotary evaporation. The crude product was purified by silica gel column chromatography using ethyl acetate / petroleum ether (1:20 v / v) as the eluent to give a yellow-green powder 4-69 (0.63 g, 81%).

[0114] Example 8:

[0115]

[0116] Add 12 (2.09 g, 10 mmol), 13 (2.81 g, 11 mmol), and Cs2CO3 (4.88 g, 15 mmol) 、 A mixture of Pd(OAc)₂ (0.22 g, 1.0 mmol) and S-Phos (0.53 g, 1.0 mmol) was heated at 100 °C for 24 hours in 15 mL of toluene solution. The reaction mixture was extracted with DCM under cooling. The organic phase was dried over anhydrous sodium sulfate, filtered, and the filtrate was concentrated by rotary evaporation. The product was then purified by silica gel column chromatography with dichloromethane / petroleum ether (volume 1:5) as the developing solvent. The product was concentrated by rotary evaporation to give 14 (2.73 g, 64.09%) as a white powder.

[0117] A mixture of 4 (0.30 g, 1 mmol), 14 (0.81 g, 2 mmol), Pd2(dba)3 (0.046 g, 0.05 mmol, 5 mol%), S-phos (0.082 g, 0.2 mmol, 20 mol%), and NaOtBu (0.38 g, 4.0 mmol) was heated to 140 °C in 60 mL of Xylenen:DMF (2:1 v / v) co-solvent under a nitrogen stream for 24 h. The reaction mixture was extracted with ethyl acetate upon cooling, dried over anhydrous sodium sulfate, and concentrated by rotary evaporation. The crude product was purified by silica gel column chromatography using ethyl acetate / petroleum ether (1:20 v / v) as the eluent to give a yellow-green powder 4-77 (0.87 g, 86%).

[0118] Examples 1-8 illustrate nitrogen-containing heterocyclic compounds of pyrazolone and phenazine, and their specific structural formulas, elemental analyses, and molecular weights are shown in Table 1.

[0119] Table 1

[0120] Example compound Elemental analysis (%) molecular weight 1 4-11 C, 82.00; H, 6.07; N, 11.93 468.39 2 4-12 C, 82.03; H, 6.01; N, 11.96 468.13 3 4-19 C, 80.48; H, 4.61; N, 14.91 566.10 4 4-21 C, 80.50; H, 4.66; N, 14.84 566.34 5 4-24 C, 81.13; H, 3.99; N, 14.88 562.29 6 4-41 C, 82.29; H, 7.00; N, 10.71 786.77 7 4-69 C, 82.34; H, 6.98; N, 10.68 786.60 8 4-77 C, 86.23; H, 5.60; N, 8.17 1030.58

[0121] Examples 10-19

[0122] Examples 10-19 illustrate electroluminescent elements, and the specific fabrication process and performance testing experiments of these elements are as follows:

[0123] A 30mm × 30mm × 0.7mm thick glass substrate with an ITO transparent electrode (anode layer 10, ITO film thickness set to 95nm) was sequentially ultrasonically cleaned in acetone, cleaning solution, ultrapure water (3 times), and isopropanol, with each ultrasonic cleaning step lasting 10 minutes. The cleaned ITO glass substrate was then placed in an oven at 80℃ and baked for 3 hours.

[0124] The baked ITO glass substrate was subjected to vacuum plasma cleaning for 10 minutes.

[0125] The plasma-treated glass substrate is mounted on the substrate holder of a vacuum evaporation apparatus. First, HATCN compound is deposited on the side where transparent electrode lines are formed in a manner that covers the transparent electrode, forming a hole injection layer 11 with a film thickness of 10 nm.

[0126] Compound HT-10 is deposited on the hole injection layer 11 to form a first hole transport layer with a thickness of 40 nm.

[0127] Subsequently, the compound TCTA is deposited on the first hole transport layer to form a second hole transport layer with a thickness of 15 nm. The first hole transport layer and the second hole transport layer constitute the hole transport layer 12.

[0128] Subsequently, a third compound (host material), a second compound (sensitizer), and a first compound (guest material) are co-deposited on the second hole transport layer to form a light-emitting layer 13 with a thickness of 30 nm. The concentration of the first compound in the light-emitting layer is set to 1% by mass.

[0129] In Examples 10-19, the first compound and the second compound are specifically shown in Table 2.

[0130] Table 2

[0131] Example First compound (1% by mass) Second compound Third compound 10 4-11 8-69 (30% by mass) 8-56 11 4-12 8-69 (30% by mass) 8-56 12 4-19 8-15 (30% by mass) 8-56 13 4-21 8-15 (30% by mass) 8-56 14 4-24 8-69 (30% by mass) 8-56 15 4-41 8-69 (30% by mass) 8-56 16 4-69 8-69 (30% by mass) 8-56 17 4-77 8-45 (15% by mass) 8-56 18 4-69 8-10 (30% by mass) 8-56 19 4-69 8-13 (30% by mass) 8-56

[0132] Subsequently, SF3-TRZ is deposited on the light-emitting layer 13 to form a second electron transport layer 14 with a thickness of 15 nm.

[0133] Subsequently, Liq and ET-18 are co-deposited on the second electron transport layer 14, with the concentration of Liq set to 30% by mass, to form a first electron transport layer 15 with a film thickness of 25 nm.

[0134] In addition, Liq is deposited on the first electron transport layer 15 to form an electron injection layer 16 with a thickness of 2 nm.

[0135] Then, metal Al is deposited on the electron injection layer to form a cathode layer 17 with a film thickness of 100 nm.

[0136] It should be noted that, in the above preparation method, the specific structural formulas of SF3-TRZ, HT-10, TCTA, HATCN, Liq, and ET-18 are as follows:

[0137]

[0138] Comparative Examples 20-22

[0139] Comparative Examples 20-22 are given by comparison compounds 2-4. The method for preparing Comparative Examples 20-22 is the same as that for Examples 10-19. The first and second compounds of the luminescent layer in Comparative Examples 20-22 are specifically shown in 3 below.

[0140] Table 3

[0141] Comparative example First compound (1% by mass) Second compound Third compound 20 Compare compound 2 8-69 (30% by mass) 8-56 21 Compare compound 3 8-69 (30% by mass) 8-56 22 Compare compound 4 8-45 (15% by mass) 8-56

[0142] Comparative compound 3 and comparative compound 4 have the following structural formulas:

[0143]

[0144] Performance testing

[0145] The organic electroluminescent elements prepared in Examples 10-19 and Comparative Examples 20-22 were subjected to performance tests, the specific tests of which are as follows:

[0146] Measurements were taken using a spectroradiometer CS-2000 (Konica Minolta) and a digital source meter 2400 (Keithley), at a value of 1000 cd / m². 2 The organic electroluminescent device under test was driven by brightness, and its CIE1931 chromaticity coordinates (x,y), external quantum efficiency, emission peak position, and full width at half maximum (FWHM) of the electroluminescence spectrum (unit: nm) were measured. The specific test results are shown in Table 4.

[0147] Table 4

[0148]

[0149]

[0150] Comparing the performance results of Examples 10-19 and Comparative Examples 20-22 in Table 4, it can be seen that, with other materials remaining the same in the organic electroluminescent element structure, the full width at half maximum (FWHM) of the spectral components of the compound described in this application is smaller than that of the comparative compounds under the same light color. This is because the molecular skeleton of the pyrazolone-phenazine nitrogen-containing heterocyclic compound suppresses molecular vibrations and conformational relaxation that lead to spectral broadening, thereby exhibiting narrow emission spectral characteristics. Furthermore, compared to Comparative Compound 1, the compound of this application further introduces nitrogen atoms into the five-membered ring of pyrrolopyrazine, resulting in a further redshift of the molecule's emission color. Therefore, by using an auxiliary chromophore, the light color can be further redshifted to the green light range. On the other hand, the external quantum efficiency of the compound described in this application is higher than that of the organic electroluminescent element described in the comparative compounds under the same element structure. This is because the pyrazolone-phenazine nitrogen-containing heterocyclic compound has strong rigidity, which suppresses nonradiative transition vibrations. On the other hand, introducing nitrogen atoms into the indole-carbazole molecular skeleton can further enhance the molecular transition dipole strength, thereby further improving the luminous efficiency of the device prepared by the compound, and ultimately enabling the compound to have high-efficiency and high-color-purity blue light performance.

[0151] The experimental data above show that the novel organic material of this application, as the light-emitting object of organic electroluminescent elements, is a high-performance organic light-emitting functional material and is expected to be promoted for commercial application.

[0152] In the description of the embodiments of the present invention, it should be noted that the terms "first," "second," etc., are used only for distinguishing descriptions and should not be construed as indicating or implying relative importance.

[0153] It is understood that those skilled in the art can make equivalent substitutions or modifications to the technical solution and inventive concept of the present invention, and all such substitutions or modifications should fall within the protection scope of the appended claims.

Claims

1. A pyrazolinone-phenazine nitrogen-containing heterocyclic compound, characterized in that, It is a compound with the general molecular formula (1): （1）； Wherein, substituents R1 and R2 are each independently selected from any one of the following substituent groups: In equations (3-1) to (3-8), (3-10), and (3-11), Y, Z, and Q are each independently selected from C(R). 41 (R) 42 ), NR 43 O, S, Se, Si(R) 44 (R) 45 One of them; Q1 is independently selected from hydrogen, deuterium, halogen, cyano, unsubstituted alkyl with 1 to 20 carbon atoms, unsubstituted alkenyl with 1 to 20 carbon atoms, unsubstituted alkynyl with 1 to 20 carbon atoms, unsubstituted cycloalkyl with 3 to 20 carbon atoms, amino, unsubstituted alkoxy with 1 to 20 carbon atoms, unsubstituted fluoroalkyl with 1 to 20 carbon atoms, unsubstituted fluoroalkoxy with 1 to 20 carbon atoms, unsubstituted aryloxy with 6 to 50 carbon atoms, unsubstituted alkylthio with 1 to 20 carbon atoms, unsubstituted arylthio with 6 to 50 carbon atoms, -N(R 101 (R) 102 Any one of the following: an unsubstituted aryl group having 6 to 50 carbon atoms in the cyclic structure and an unsubstituted heteroaryl group having 5 to 50 carbon atoms in the cyclic structure; P1~P6, P8~P 16 P 18 ~P 20 Each of the following is independently selected from hydrogen atom, deuterium atom, unsubstituted alkyl group having 1 to 20 carbon atoms, unsubstituted cycloalkyl group having 3 to 20 cyclic carbon atoms, unsubstituted aryl group having 6 to 50 cyclic carbon atoms, and unsubstituted heteroaryl group having 5 to 50 cyclic atoms; L is any one of the following: an unsubstituted alkyl group with 1 to 20 carbon atoms, an unsubstituted cycloalkyl group with 3 to 20 carbon atoms, an unsubstituted aryl group with 6 to 50 carbon atoms, and an unsubstituted heteroaryl group with 5 to 50 carbon atoms; n is an integer from 0 to 3. R3 to R4 are each independently a hydrogen atom, deuterium atom, tritium atom, halogen atom, cyano group, phenyl group, or biphenyl group.

2. The pyrazolone-phenazine nitrogen-containing heterocyclic compound according to claim 1, characterized in that, Its structural formula is any one of formula (2-1), formula (2-2), or formula (2-3): 。 3. A pyrazolinone-phenazine nitrogen-containing heterocyclic compound, characterized in that, The heterocyclic compound is selected from one of the following chemical structures: 。 4. A luminescent composition, characterized in that, It includes a third compound and a first compound doped in the third compound, wherein the first compound is a nitrogen-containing heterocyclic compound of pyrazolone phenazine as described in any one of claims 1 to 3, and the mass percentage of the first compound doped is 0.3 to 20.0%.

5. The luminescent composition according to claim 4, characterized in that, It also includes a second compound; by mass percentage, the luminescent composition comprises: 0.3–10.0% of the first compound, 5.0–60.0% of the second compound, and 30.0–94.7% of the third compound.

6. The luminescent composition according to claim 4, characterized in that, The third compound is selected from one of the following compounds: 。 7. The luminescent composition according to claim 5, characterized in that, The second compound and the third compound are each independently selected from one of the following compounds, and the second compound is different from the third compound: 。 8. An organic electroluminescent device, comprising a substrate, an anode layer, an organic light-emitting functional layer, and a cathode layer disposed on the substrate, wherein the organic light-emitting functional layer includes one or more of a hole injection layer, a hole transport layer, a light-emitting layer, an electron transport layer, and an electron injection layer, and the light-emitting layer is located between the hole transport layer and the electron transport layer, characterized in that, The luminescent layer includes at least one nitrogen-containing heterocyclic compound of pyrazolone and phenazine as described in any one of claims 1 to 3, or a luminescent composition as described in any one of claims 4 to 7.

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