CN112375088A

CN112375088A - Spiro nitrogen-containing organic luminescent compound, and preparation method and application thereof

Info

Publication number: CN112375088A
Application number: CN202011382116.8A
Authority: CN
Inventors: 王进政; 汪康; 赵贺; 孙峰; 于丹阳; 张思铭; 马晓宇
Original assignee: Jilin Optical and Electronic Materials Co Ltd
Current assignee: Jilin Optical and Electronic Materials Co Ltd
Priority date: 2020-11-30
Filing date: 2020-11-30
Publication date: 2021-02-19
Anticipated expiration: 2040-11-30
Also published as: CN112375088B

Abstract

The invention relates to the technical field of organic photoelectric materials, in particular to a spiro nitrogenous organic luminescent compound, and a preparation method and application thereof. The spiro nitrogen-containing organic luminescent compound provided by the invention has a structure shown in a formula I, a spiro derivative containing oxygen and nitrogen heteroatoms is used as a parent nucleus, and the existence of the heteroatoms not only destroys the molecular symmetry and avoids intermolecular aggregation, but also ensures that the molecules are not easy to crystallize and aggregate and have the characteristics of good film-forming property, and the finally obtained spiro nitrogen-containing organic luminescent compound has good electronic transmission property, so that an organic electroluminescent device prepared from the spiro nitrogen-containing organic luminescent compound has high luminous efficiency and long service life.

Description

Spiro nitrogen-containing organic luminescent compound, and preparation method and application thereof

Technical Field

The invention relates to the technical field of organic photoelectric materials, in particular to a spiro nitrogenous organic luminescent compound, and a preparation method and application thereof.

Background

With the advent of the information age, the living standard of people changes day by day, and the requirements for display technology are continuously improved. As a next generation star display technology, the OLED technology has the advantages of high contrast, flexibility, wide visual angle, quick response and the like, so that the OLED technology has the potential of well replacing the traditional display technology. At present, the OLED display screen with medium and small size is applied to high-end smart phones produced by companies such as Huashi, millet and Samsung on the market in a large scale, and the market feedback effect is good.

The OLED light-emitting device is like a sandwich structure and comprises a hole injection layer, a hole transport layer, a light-emitting layer, an electron transport layer and an electron injection layer. The Hole Transport Layer (HTL) is responsible for adjusting the injection rate and injection amount of holes, and the Electron Transport Layer (ETL) is responsible for adjusting the injection rate and injection amount of electrons. The electron transport material plays an extremely important role in the OLED, and the transport material with high electron mobility can enable electrons and holes of the device to be injected approximately in balance, so that the probability of exciton formation is increased, the leakage current formed by the fact that holes are transported to a cathode through the inside of the device due to the fact that the number of the holes is excessive in the device is reduced, and the light emitting brightness and the efficiency of the device are improved.

The electron transport material should have good electron transport properties; higher electron affinity; relatively high ionization energy; the ability to form an exciplex with the light-emitting layer; good film forming property and thermal stability, and difficult crystallization. Tris (8-hydroxyquinoline) aluminum (Alq3) has been used as an electron transport material for nearly 30 years since the invention, and there is much data to prove that it is superior to conventional materials.

In addition, for the collocation of OLED devices with different structures, the used photoelectric functional materials have stronger selectivity, and the performance of the same materials in the devices with different structures can also be completely different. Therefore, aiming at the industrial application requirements of the current OLED device, different functional film layers of the OLED device and the photoelectric characteristic requirements of the device, a more suitable OLED functional material or material combination with high performance needs to be selected to realize the comprehensive characteristics of high efficiency, long service life and low voltage of the device.

Disclosure of Invention

In view of the above, the technical problem to be solved by the present invention is to provide a spiro nitrogen-containing organic light-emitting compound, a preparation method and an application thereof, wherein an organic electroluminescent device prepared from the spiro nitrogen-containing organic light-emitting compound has high light-emitting efficiency and long service life.

The invention provides a spiro nitrogen-containing organic luminescent compound, which has a structure shown in a formula I:

wherein X is selected from N or C-R₅；

q is a natural number of 0-4;

X₁、X₂and X₃Independently selected from N or C, and X₁、X₂And X₃At least one of N;

R₁、R₂、R₃、R₄and R₅Independently selected from hydrogen, deuterium, halogen, cyano, carboxyl, nitro, hydroxyl, substituted or unsubstituted C1-C30 alkyl, C2-C30 alkenyl, substituted or unsubstituted C2-C30 alkynyl, substituted or unsubstituted C1-C30 alkoxy, C3-C30 cycloalkyl, substituted or unsubstituted C3-C30 cycloalkenyl, substituted or unsubstituted 3-to 7-membered heterocycloalkyl, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted 3-to 30-membered heteroaryl, substituted or unsubstituted C10-C30 fused ring group or substituted or unsubstituted C10-C60 spiro ring group;

or R₁、R₂、R₃、R₄And R₅Independently connected with adjacent substituent groups to form a monocyclic C3-C30 aliphatic seriesA monocyclic ring or an aromatic ring having at least one of C6 to C30, wherein carbon atoms in the monocyclic ring, the aliphatic ring having at least one of C3 to C30, and the aromatic ring having at least one of C6 to C30 are replaced with at least one of nitrogen, oxygen, and sulfur;

L₁and L₂Independently selected from a linkage, a substituted or unsubstituted C6-C30 aryl, a substituted or unsubstituted 3-to 30-membered heteroaryl, or a substituted or unsubstituted C10-C60 fused ring group.

In certain embodiments of the present invention, the spiro nitrogen-containing organic light-emitting compound has a structure represented by formula ii or formula iii:

in certain embodiments of the invention, R₁、R₂、R₃、R₄And R₅Independently selected from hydrogen, deuterium, halogen, cyano, carboxyl, nitro, hydroxyl, substituted or unsubstituted C1-C18 alkyl, C2-C10 alkenyl, substituted or unsubstituted C2-C10 alkynyl, substituted or unsubstituted C1-C10 alkoxy, C3-C6 cycloalkyl, substituted or unsubstituted C3-C18 cycloalkenyl, substituted or unsubstituted 3-to 7-membered heterocycloalkyl, substituted or unsubstituted C6-C24 aryl, substituted or unsubstituted 3-to 24-membered heteroaryl, substituted or unsubstituted C10-C18 condensed ring group or substituted or unsubstituted C10-C30 spiro ring group.

In certain embodiments of the invention, R₁、R₂、R₃、R₄And R₅Independently selected from hydrogen, deuterium, halogen, cyano, carboxyl, nitro, hydroxyl, substituted or unsubstituted C1-C6 alkyl, C2-C6 alkenyl, substituted or unsubstituted C2-C6 alkynyl, substituted or unsubstituted C1-C6 alkoxy, C3-C6 cycloalkyl, substituted or unsubstituted C3-C6 cycloalkenyl, substituted or unsubstituted 3-to 7-membered heterocycloalkyl, substituted or unsubstituted C6-C24 aryl, substituted or unsubstituted 3-to 18-membered heteroaryl, substituted or unsubstituted C10-C18 condensed ring group or substituted or unsubstituted C3583-C18 condensed ring groupSubstituted or unsubstituted spiro ring group of C10-C24.

In certain embodiments of the invention, R₁、R₂、R₃、R₄And R₅Independently linked to an adjacent substituent to form a monocyclic ring, an aliphatic ring having C3-C18, or an aromatic ring having C6-C24, wherein a carbon atom in the monocyclic ring, the aliphatic ring having C3-C18, or the aromatic ring having C6-C24 may be replaced by at least one of nitrogen, oxygen, and sulfur.

In certain embodiments of the invention, R₁Selected from hydrogen or methyl.

In certain embodiments of the invention, R₂Selected from hydrogen, methyl, methoxy or tert-butyl.

In certain embodiments of the invention, R₃Selected from hydrogen, methyl, phenyl or methoxy.

In certain embodiments of the invention, R₄One selected from the group consisting of formulae (4-1) to (4-18);

(4-1)；

(4-2)；

(4-3)；

(4-4)；

(4-5)；

(4-6)；

(4-7)；

(4-8)；

(4-9)；

(4-10)；

(4-11)；

(4-12)；

(4-13)；

(4-14)；

(4-15)；

(4-16)；

(4-17)；

(4-18)；-CN(4-19)。

in certain embodiments of the invention, R₅Selected from hydrogen, methyl, ethyl, tert-butyl, phenyl, pyridyl or biphenyl.

In certain embodiments of the present invention, L₁And L₂Independently selected from a linkage, a substituted or unsubstituted C6-C15 aryl, a substituted or unsubstituted 3-to 15-membered heteroaryl, or a substituted or unsubstitutedThe condensed ring group of C10-C30.

In certain embodiments of the present invention, L₁And L₂Independently selected from one or more of phenyl, benzyl, biphenyl, naphthyl, pyridyl, benzopyridyl, phenyl substituted pyridyl and furyl.

In the present invention, the term "substituted or unsubstituted" means substituted with one, two or more substituents selected from: deuterium; a halogen group; a nitrile group; a hydroxyl group; a carbonyl group; an ester group; a silyl group; a boron group; substituted or unsubstituted alkyl; substituted or unsubstituted cycloalkyl; substituted or unsubstituted alkoxy; substituted or unsubstituted alkenyl; substituted or unsubstituted alkylamino; substituted or unsubstituted heterocyclylamino; substituted or unsubstituted arylamine; substituted or unsubstituted aryl; and a substituted or unsubstituted heterocyclic group, or a substituent in which two or more substituents among the above-shown substituents are connected, or no substituent. For example, "a substituent in which two or more substituents are linked" may include a biphenyl group. In other words, biphenyl can be an aryl group, or can be interpreted as a substituent with two phenyl groups attached.

In some embodiments of the present invention, the spiro nitrogen-containing organic light-emitting compound has a structure represented by formula (1) to formula (104):

the invention also provides a preparation method of the spiro nitrogen-containing organic luminescent compound with the structure shown in the formula II, which comprises the following steps:

a1) carrying out heating reaction on a compound shown in a formula A-II, a compound shown in a formula B-II and phosphorus trichloride to obtain an intermediate C-II;

a2) intermediate C-II, Cu₂O, DMEDA and K₂CO₃Heating for reaction to obtain an intermediate D-II;

a3) reacting the organic solution of the intermediate D-II with an organic solution containing a compound shown as a formula E-II and n-butyllithium, and obtaining an intermediate F-II after terminating the reaction;

a4) reacting the intermediate F-II, glacial acetic acid and concentrated sulfuric acid, and obtaining an intermediate G-II after terminating the reaction;

a5) reacting the intermediate G-II, a reactant H-II, tetrakis (triphenylphosphine) palladium and potassium carbonate to obtain a spiro nitrogenous organic luminescent compound with a structure shown in a formula II;

wherein X is selected from N or C-R₅；

q is a natural number of 0-4;

R₁、R₂、R₃、R₄and R₅Independently selected from hydrogen, deuterium, halogen, cyano, carboxyl, nitro, hydroxyl, substituted or unsubstituted C1-C30 alkyl, C2-C30 alkenyl, substituted or unsubstituted C2-C30 alkynyl, substituted or unsubstituted C1-C30 alkoxy, hydroxyl,C3-C30 cycloalkyl, substituted or unsubstituted C3-C30 cycloalkenyl, substituted or unsubstituted 3-to 7-membered heterocycloalkyl, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted 3-to 30-membered heteroaryl, substituted or unsubstituted C10-C30 fused ring group, or substituted or unsubstituted C10-C60 spiro ring group;

or R₁、R₂、R₃、R₄And R₅Independently and adjacent substituents are connected to form a monocyclic ring, an aliphatic ring of C3-C30 or an aromatic ring of C6-C30, wherein carbon atoms in the monocyclic ring, the aliphatic ring of C3-C30 or the aromatic ring of C6-C30 can be replaced by at least one of nitrogen, oxygen and sulfur;

Step a 1):

in certain embodiments of the invention, the reaction is carried out under nitrogen.

In certain embodiments of the present invention, the solvent used for the reaction is anhydrous toluene and the reaction is a stirred reaction.

In certain embodiments of the invention, the reaction is carried out at a temperature of 80 ℃ for a period of 10 hours.

In some embodiments of the present invention, after the reaction is finished, the method further comprises:

and (3) extracting the reaction solution by using dichloromethane, drying the extracted organic layer, removing the solvent, adding ethyl acetate and ethanol, heating to 80 ℃, refluxing, stirring for 3 hours, performing suction filtration, and leaching the filtered solid by using petroleum ether to obtain an intermediate C-II.

Step a 2):

In certain embodiments of the invention, the solvent employed for the reaction is toluene.

In certain embodiments of the invention, the reaction is carried out at a temperature of 70 ℃ for a period of 8 hours.

and cooling to room temperature, extracting the reaction solution by using dichloromethane, removing the solvent, recrystallizing, leaching the filter cake obtained after filtering by using petroleum ether, and obtaining an intermediate D-II.

In certain embodiments of the invention, the recrystallization is performed in toluene.

Step a 3):

in some embodiments of the present invention, step a3) specifically includes:

and (3) dropwise adding the organic solution of the intermediate D-II into the organic solution containing the compound shown in the formula E-II and n-butyllithium, stirring at room temperature for reaction, and stopping the reaction to obtain an intermediate F-II.

In certain embodiments of the present invention, the dropping and the reacting are performed under a nitrogen protection.

In certain embodiments of the invention, the temperature of the dropwise addition is-78 ℃.

In certain embodiments of the invention, the reaction time is 10 hours.

In certain embodiments of the invention, the reaction is terminated by the addition of distilled water.

separating the liquid and collecting an organic phase, adding anhydrous magnesium sulfate for drying, and removing the solvent through a rotary evaporator to obtain an intermediate F-II.

Step a 4):

in some embodiments of the present invention, step a4) specifically includes:

adding glacial acetic acid into the intermediate F-II, heating to 120 ℃, dropwise adding concentrated sulfuric acid, and stirring for reaction.

In certain embodiments of the invention, the reaction is terminated by the addition of sodium bicarbonate solution. In some embodiments of the invention, before terminating the reaction, further comprising: and cooling to room temperature.

In certain embodiments of the present invention, after the reacting, further comprising:

separating, extracting the obtained water phase with dichloromethane, collecting the organic phase, adding anhydrous magnesium sulfate, drying, and removing the solvent to obtain an intermediate G-II.

Step a 5):

in certain embodiments of the invention, the reaction is carried out under a blanket of nitrogen.

In certain embodiments of the present invention, the solvent used for the reaction is a mixed solvent comprising toluene, ethanol and water. In certain embodiments, the volume ratio of toluene, ethanol, and water is 3: 1: 1.

in certain embodiments of the invention, the reaction is carried out at a temperature of 110 ℃ for a period of 8 hours.

cooling to room temperature, adding water for washing, filtering, leaching the obtained filter cake with ethanol and petroleum ether in sequence, recrystallizing, filtering again, leaching the obtained filter cake with petroleum ether, and drying to obtain the spiro nitrogen-containing organic luminescent compound with the structure shown in the formula II.

In certain embodiments of the invention, the recrystallization is performed in 1, 4-dioxane.

The invention also provides a preparation method of the spiro nitrogen-containing organic luminescent compound, which comprises the following steps:

b1) heating and refluxing the reactants A-III, the reactants B-III, CuBr, TEMPO, p-xylene and pyridine for reaction, and obtaining an intermediate C-III after terminating the reaction;

b2) reacting the organic solution of the intermediate C-III with an organic solution containing a compound shown as a formula D-III and n-butyllithium, and obtaining an intermediate E-III after terminating the reaction;

b3) reacting the intermediate E-III, glacial acetic acid and concentrated sulfuric acid, and obtaining an intermediate F-III after terminating the reaction;

b4) reacting the intermediate F-III, a reactant G-III, tetrakis (triphenylphosphine) palladium and potassium carbonate to obtain a spiro nitrogenous organic luminescent compound with a structure shown in a formula III;

wherein X is selected from N or C-R₅；

q is a natural number of 0-4;

Step b 1):

In certain embodiments of the invention, the heating to 120 ℃ is carried out for a reaction time of 36 h.

In some embodiments of the invention, before terminating the reaction, further comprising: and cooling to room temperature.

In some embodiments of the present invention, after the termination reaction is finished, the method further comprises:

separating, collecting organic phase, adding anhydrous magnesium sulfate, drying, removing solvent by rotary evaporator, adding silica gel, spin drying, and purifying by chromatography to obtain intermediate C-III.

In certain embodiments of the invention, the developing solvent used for chromatographic purification comprises petroleum ether and ethyl acetate, and the volume ratio of the petroleum ether to the ethyl acetate is 6-16: 1. in certain embodiments, the developing solvent used for chromatographic purification comprises petroleum ether and ethyl acetate, wherein the volume ratio of petroleum ether to ethyl acetate is 8: 1.

step b 2):

in some embodiments of the present invention, step b2) specifically includes:

and dropwise adding the organic solution of the intermediate C-III into the organic solution containing the compound shown in the formula D-III and n-butyllithium, stirring at room temperature for reaction, and stopping the reaction to obtain an intermediate E-III.

In certain embodiments of the invention, the reaction time is 10 hours.

separating the liquid and collecting an organic phase, adding anhydrous magnesium sulfate for drying, and removing the solvent through a rotary evaporator to obtain an intermediate E-III.

Step b 3):

in some embodiments of the present invention, step b3) specifically includes:

adding glacial acetic acid into the intermediate E-III, heating to 120 ℃, dropwise adding concentrated sulfuric acid, and stirring for reaction.

separating, extracting the obtained water phase with dichloromethane, collecting the organic phase, adding anhydrous magnesium sulfate, drying, and removing the solvent to obtain an intermediate F-III.

Step b 4):

cooling to room temperature, adding water for washing, filtering, leaching the obtained filter cake with ethanol and petroleum ether in sequence, recrystallizing, filtering again, leaching the obtained filter cake with petroleum ether, and drying to obtain the spiro nitrogen-containing organic luminescent compound with the structure shown in the formula III.

The spiro nitrogen-containing organic luminescent compound provided by the invention can be used as an electron transport layer material of an organic electroluminescent device.

The invention also provides an organic electroluminescent device which comprises the spiro nitrogen-containing organic luminescent compound or the spiro nitrogen-containing organic luminescent compound prepared by the preparation method.

In some embodiments of the present invention, the organic electroluminescent device comprises a first electrode, a second electrode, and one or more organic compound layers interposed between the two electrodes, at least one organic compound layer comprising the spiro nitrogen-containing organic light-emitting compound prepared according to the present invention.

In some embodiments of the present invention, at least one or more layers including a hole injection layer, a hole transport layer, an electron blocking layer, a light emitting layer, a hole blocking layer, an electron transport layer, and an electron injection layer are disposed between the first electrode and the second electrode. In some embodiments, a hole injection layer, a hole transport layer, a light emitting layer, a hole blocking layer, an electron transport layer, and an electron injection layer are sequentially disposed between the first electrode and the second electrode.

In certain embodiments of the present invention, the first electrode serves as an anode, which preferably comprises a material having a high work function, such as Ag, Pt or Au. Preferred anode materials are conductive mixed metal oxides. Particularly preferred is Indium Tin Oxide (ITO) or Indium Zinc Oxide (IZO). Furthermore, preference is given to electrically conductive doped organic materials, in particular electrically conductive doped polymers. Since the lifetime of the device of the invention is shortened in the presence of water and/or air, the device is suitably (depending on the application) structured, provided with contacts and finally sealed. In some embodiments, the first electrode is an ITO anode layer. In some embodiments, the ITO anode layer is 150nm thick.

In certain embodiments of the present invention, the material of the hole injection layer is HAT-CN. In some embodiments, the hole injection layer has a thickness of 10 nm.

The material of the hole transport layer is a material capable of receiving holes from the anode or the hole injection layer and transporting the holes to the light emitting layer, and has high hole mobility. In some embodiments of the present invention, the material of the hole transport layer includes, but is not limited to, an arylamine-based organic material, a conductive polymer, or a block copolymer having both a conjugated portion and a non-conjugated portion. In certain embodiments of the present invention, the material of the hole transport layer is NPB. In some embodiments, the hole transport layer has a thickness of 60 nm.

In some embodiments of the present invention, an electron blocking layer may be disposed between the hole transport layer and the light emitting layer. As the electron blocking layer, a material known in the art, for example, an arylamine-based organic material, may be used.

In some embodiments of the present invention, the material of the light emitting layer is a material capable of emitting visible light by receiving holes and electrons from the hole transport layer and the electron transport layer, respectively, and combining the received holes and electrons. The material of the light emitting layer may include a host material and a dopant material; the mass ratio of the main material to the doping material is 90-99.5: 0.5 to 10; the doping material may include fluorescent doping or phosphorescent doping.

The light emitting layer may emit red, green or blue light, and may be formed of a phosphorescent material or a fluorescent material, preferably a material having favorable quantum efficiency for fluorescence or phosphorescence.

The phosphorescent dopant material is a phosphorescent material including a metal complex of iridium, platinum, or the like. For example, Ir (ppy)₃Isogreen phosphorescent materials, FIrpic, FIr₆Iso-blue phosphorescent material and Btp₂Red phosphorescent materials such as ir (acac). As the fluorescent dopant material, a compound having an electron transporting action known in the art can be used.

In some embodiments of the present invention, the material of the light emitting layer includes a host material CBP and a dopant material FIrpic, and the mass ratio of the host material to the dopant material is 99.5: 0.5. in some embodiments, the light emitting layer has a thickness of 40 nm.

In some embodiments of the present invention, a compound having a hole blocking effect, which is well known in the art, may be used as the hole blocking layer material, for example, a phenanthroline derivative such as Bathocuproine (BCP), an oxazole derivative, a triazole derivative, a triazine derivative, and the like, but is not limited thereto. In certain embodiments of the present invention, the material of the hole blocking layer is TPBi. In certain embodiments, the hole blocking layer has a thickness of 10 nm.

In an embodiment of the present invention, the electron transport layer includes a spiro nitrogen-containing organic light emitting compound having a structure represented by formula i. In certain embodiments, the electron transport layer has a thickness of 30 nm.

The electron injection layer may function to promote electron injection. Has the ability of transporting electrons and prevents excitons generated in the light emitting layer from migrating to the hole injection layer. In some embodiments of the present invention, the material of the electron injection layer includes fluorenone, anthraquinone dimethane, diphenoquinone, thiopyran dioxide, oxazole, oxadiazole, triazole, imidazole, perylenetetracarboxylic acid, fluorenylidene methane, anthrone, and the like, and derivatives thereof, metal complexes, nitrogen-containing five-membered ring derivatives, and the like, but is not limited thereto. In certain embodiments of the present invention, the material of the electron injection layer is lithium hydroxyquinoline (Liq). In some embodiments, the electron injection layer has a thickness of 1.0 nm.

In certain embodiments of the invention, the second electrode, which acts as a cathode, preferably comprises a metal alloy or multilayer structure of a metal having a low work function, such as an alkaline earth metal, an alkali metal, a main group metal, or a lanthanide (e.g., Ca, Ba, Mg, Al, In, Mg, Yb, Sm, etc.). In some embodiments, the second electrode is an Al electrode having an electrode layer thickness of 100 nm.

The device of the invention can be used for an organic light-emitting device, an organic solar cell, electronic paper, an organic photoreceptor or an organic thin film transistor.

The source of the above-mentioned raw materials is not particularly limited in the present invention, and may be generally commercially available.

The spiro nitrogen-containing organic luminescent compound provided by the invention has a structure shown in a formula I, a spiro derivative containing oxygen and nitrogen heteroatoms is used as a parent nucleus, and the existence of the heteroatoms not only destroys the molecular symmetry and avoids intermolecular aggregation, but also ensures that the molecules are not easy to crystallize and aggregate and have the characteristics of good film-forming property, and the finally obtained spiro nitrogen-containing organic luminescent compound has good electronic transmission property, so that an organic electroluminescent device prepared from the spiro nitrogen-containing organic luminescent compound has high luminous efficiency and long service life.

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to the following embodiments of the present invention, and it should be understood that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1

Synthesis of a compound represented by formula (2):

(1) under the protection of nitrogen, a reactant A-II-2(100mmol), a reactant B-II-2(110mmol) and anhydrous toluene (500mL) are added into a flask, heated to 80 ℃ and stirred. Phosphorus trichloride (4mL) was added to react for 10h, then distilled water was added to the filtrate and the reaction solution was extracted with 300mL of dichloromethane, followed by drying the extracted organic layer using anhydrous magnesium sulfate. The solvent was then removed using a rotary evaporator to give a solid organic. After the concentration was completed, 100mL of ethyl acetate and 500mL of ethanol were added thereto, heated to 80 ℃ under reflux, stirred for 3 hours, and suction-filtered to obtain a solid, which was then rinsed with 100mL of petroleum ether to obtain intermediate C-II-2(35.8g, yield 76%, Ms: 470.95).

(2) Under the protection of nitrogen, intermediate C-II-2(70mmol), Cu₂O(3.55mmol,5mol％),DMEDA(3.55mmol,10mol％)，K₂CO₃(210mmol) was added to toluene (350mL) and heated to 70 ℃ for 8 h. After the reaction was completed, it was cooled to room temperature, and then distilled water was added to the filtrate and the reaction solution was extracted with 300mL of dichloromethane. The organic solvent was then spun off using a rotary evaporator, recrystallized from 100mL of toluene, and the filter cake obtained after filtration was rinsed with 100mL of petroleum ether to give intermediate D-II-2(17.4g, 80% yield, Ms: 311.09).

(3) Adding the reactant E-II-2(50mmol) into a three-neck flask, adding anhydrous tetrahydrofuran, replacing with nitrogen for three times, then cooling the reaction system to-78 ℃, dropwise adding (2.5M) n-BuLi (50mmol), and stirring at-78 ℃ for 2 h. And dissolving the intermediate D-II-2(50mmol) in tetrahydrofuran, dropwise adding into the reaction system, and heating to room temperature after dropwise adding and stirring for 10 h. Distilled water was added to terminate the reaction, and the organic phase was collected by liquid separation, dried over anhydrous magnesium sulfate. The solvent was removed by rotary evaporator to give intermediate F-II-2(18.0g, 72% yield, Ms: 499.13).

(4) Adding the intermediate F-II-2(35mmol) into a three-neck flask, adding 180mL of glacial acetic acid, heating to 120 ℃, dropwise adding 4mL of concentrated sulfuric acid, and stirring for 5 min. After cooling to room temperature, 80mL of sodium bicarbonate solution was added to quench the reaction, the layers were separated, the aqueous phase was extracted three times with 200mL of dichloromethane, the organic phase was collected, dried over anhydrous magnesium sulfate and the solvent was removed by rotary evaporator to give intermediate G-II-2(15.2G, 90%, Ms: 481.12).

(5) Under the protection of nitrogen, intermediate G-II-2(30mmol), reactant H-II-2(33mmol) and tetrakis (triphenylphosphine) palladium (Pd (PPh)₃)₄) (0.30mmol) and potassium carbonate (K)₂CO₃) (60mmol) was added to a mixed solvent of 120mL of toluene, 40mL of ethanol and 40mL of water, and the mixture was heated to 110 ℃ and reacted for 8 hours with stirring. After the reaction is finished, cooling to room temperature, adding 100mL of water, washing, filtering, sequentially washing a filter cake with 30mL of ethanol and 90mL of petroleum ether, placing the filter cake into 100mL of 1, 4-dioxane for recrystallization, filtering, washing the filter cake with 100mL of petroleum ether, and placing the filter cake into a 65 ℃ oven for drying to obtain the compound 2(19.1g, 79% of yield and Ms: 804.52).

The detection analysis of the obtained compound 2 showed the following results:

HPLC purity: is more than 99.65 percent.

Mass spectrometry test: a theoretical value of 804.29; the test value was 804.52.

Elemental analysis:

the theoretical values are: c, 86.54; h, 4.51; n, 6.96; o,1.99

The test values are: c, 86.52; h, 4.50; n, 6.97; and O, 2.01.

Example 2

Synthesis of a Compound represented by the formula (29):

(1) a flask was charged with reactant A-II-29(100mmol), reactant B-II-29(110mmol) and dry toluene (500mL) under nitrogen, heated to 80 deg.C, and stirred. Phosphorus trichloride (4mL) was added to react for 10h, then distilled water was added to the filtrate and the reaction solution was extracted with 300mL of dichloromethane, followed by drying the extracted organic layer using anhydrous magnesium sulfate. The solvent was then removed using a rotary evaporator to give a solid organic. After the end of the concentration, 100mL of ethyl acetate and 500mL of ethanol were added thereto, heated to 80 ℃ under reflux, stirred for 3h, and suction filtered to give a solid, which was then rinsed with 100mL of petroleum ether to give intermediate C-II-29(35.4g, yield 75%, Ms: 471.94).

(2) Under the protection of nitrogen, intermediate C-II-29(70mmol), Cu₂O(3.55mmol,5mol％),DMEDA(3.55mmol,10mol％)，K₂CO₃(210mmol) was added to toluene (350mL) and heated to 70 ℃ for 8 h. After the reaction was completed, it was cooled to room temperature, and then distilled water was added to the filtrate and the reaction solution was extracted with 300mL of dichloromethane. The organic solvent was then spun off using a rotary evaporator, recrystallized from 100mL of toluene, and the filter cake obtained after filtration was rinsed with 100mL of petroleum ether to give intermediate D-II-29(17.0g, 78% yield, Ms: 312.09).

(3) The reactant E-II-29(50mmol) was added to a three-necked flask, anhydrous tetrahydrofuran was added, nitrogen was substituted three times, then the reaction system was cooled to-78 ℃ and (2.5M) n-BuLi (50mmol) was added dropwise, and stirred at-78 ℃ for 2 h. And dissolving the intermediate D-II-29(50mmol) in tetrahydrofuran, dropwise adding into the reaction system, and heating to room temperature after dropwise adding and stirring for 10 h. Distilled water was added to terminate the reaction, and the organic phase was collected by liquid separation, dried over anhydrous magnesium sulfate. The solvent was removed by rotary evaporator to give intermediate F-II-29(18.2g, 73% yield, Ms: 500.13).

(4) Adding the intermediate F-II-29(35mmol) into a three-neck flask, adding 180mL of glacial acetic acid, heating to 120 ℃, dropwise adding 4mL of concentrated sulfuric acid, and stirring for 5 min. After cooling to room temperature, 80mL of sodium bicarbonate solution was added to terminate the reaction, the layers were separated, the aqueous phase was extracted three times with 200mL of dichloromethane, the organic phase was collected, dried over anhydrous magnesium sulfate and the solvent was removed by rotary evaporator to give intermediate G-II-29(15.0G, 89%, Ms: 482.12).

(5) Under the protection of nitrogen, intermediate G-II-29(30mmol), reactant H-II-29(33mmol) and tetrakis (triphenylphosphine) palladium (Pd (PPh)₃)₄) (0.30mmol) and potassium carbonate (K)₂CO₃) (60mmol) was added to a mixed solvent of 120mL of toluene, 40mL of ethanol and 40mL of water, and the mixture was heated to 110 ℃ and reacted for 8 hours with stirring. After the reaction is finished, the reaction product is cooled to room temperature, 100mL of water is added for washing, the filtration is carried out, the filter cake is washed by 30mL of ethanol and 90mL of petroleum ether in sequence, the obtained product is placed in 100mL of 1, 4-dioxane for recrystallization, the filtration is carried out, the filter cake is washed by 100mL of petroleum ether and is placed in a 65 ℃ oven for drying, and then the compound 29(17.0g, 82% yield) is obtained.

The compound 29 thus obtained was subjected to assay, and the results were as follows:

HPLC purity: is more than 99.52 percent.

Mass spectrometry test: a theoretical value of 691.24; the test value was 691.48.

Elemental analysis:

the theoretical values are: c, 83.34; h, 4.23; n, 10.12; o,2.31

The test values are: c, 83.31; h, 4.22; n, 10.15; o, 2.32.

Example 3

Synthesis of a compound represented by formula (58):

(1) under nitrogen protection, a 500mL flask was charged with CuBr (10mmol), (2,2,6, 6-tetramethylpiperidine) TEMPO (7.5mmol), reactant A-III-58(100mmol), reactant B-III-58(120mmol), p-xylene (250mL), and then pyridine (C)₅H₅N) (100mmol), heating to 120 ℃, condensing, refluxing, stirring, reacting for 36 hours, cooling to room temperature, adding distilled water to terminate the reaction, separating, collecting an organic phase, adding anhydrous magnesium sulfate, and drying. Spin-drying the solvent on a rotary evaporator, adding a proper amount of silica gel, spin-drying, and purifying by using a column chromatography, wherein a developing agent is petroleum ether: ethyl acetate 8:1 (volume ratio), namely the intermediate productIntermediate C-III-58(13.7g, 58%, Ms: 236.06).

(2) Adding the reactant C-III-58(50mmol) into a three-neck flask, adding anhydrous tetrahydrofuran, replacing with nitrogen for three times, then cooling the reaction system to-78 ℃, dropwise adding (2.5M) n-BuLi (50mmol), and stirring at-78 ℃ for 2 h. And dissolving the intermediate D-III-58(50mmol) in tetrahydrofuran, dropwise adding into the reaction system, and heating to room temperature after dropwise adding and stirring for 10 h. Distilled water was added to terminate the reaction, and the organic phase was collected by liquid separation, dried over anhydrous magnesium sulfate. The solvent was removed by rotary evaporator to give intermediate E-III-58(15.9g, 75% yield, Ms: 424.10).

(3) Adding the intermediate E-III-58(35mmol) into a three-neck flask, adding 180mL of glacial acetic acid, heating to 120 ℃, dropwise adding 4mL of concentrated sulfuric acid, and stirring for 5 min. After cooling to room temperature, 80mL of sodium bicarbonate solution was added to quench the reaction, the layers were separated, the aqueous phase was extracted three times with 200mL of dichloromethane, the organic phase was collected, dried over anhydrous magnesium sulfate and the solvent was removed by rotary evaporator to give intermediate F-III-58(12.5g, 88%, Ms: 406.09).

(4) Under the protection of nitrogen, intermediate F-III-58(30mmol), reactant G-III-58(33mmol) and tetrakis (triphenylphosphine) palladium (Pd (PPh)₃)₄) (0.30mmol) and potassium carbonate (K)₂CO₃) (60mmol) was added to a mixed solvent of 120mL of toluene, 40mL of ethanol and 40mL of water, and the mixture was heated to 110 ℃ and reacted for 8 hours with stirring. After the reaction is finished, the reaction product is cooled to room temperature, 100mL of water is added for washing, the filtration is carried out, the filter cake is sequentially washed by 30mL of ethanol and 90mL of petroleum ether, the obtained product is placed in 100mL of 1, 4-dioxane for recrystallization, the filtration is carried out, the filter cake is washed by 100mL of petroleum ether, and the obtained product is placed in a 65 ℃ oven for drying, so that the compound 58(14.1g, the yield is 81%, and Ms: 581.61) is obtained.

The compound 58 thus obtained was subjected to assay, and the results were as follows:

HPLC purity: is more than 99.73 percent.

Mass spectrometry test: a theoretical value of 581.26; the test value was 581.61.

Elemental analysis:

the theoretical values are: c, 80.53; h, 3.99; n, 7.22; o, 2.75; s,5.51

The test values are: c, 80.50; h, 3.99; n, 7.25; o, 2.75; s, 5.51.

Example 4

Synthesis of a compound represented by formula (95):

(1) under nitrogen protection, a 500mL flask was charged with CuBr (10mmol), (2,2,6, 6-tetramethylpiperidine) TEMPO (7.5mmol), reactant A-III-95(100mmol), reactant B-III-95(120mmol), p-xylene (250mL), and then pyridine (C)₅H₅N) (100mmol), heating to 120 ℃, condensing, refluxing, stirring, reacting for 36 hours, cooling to room temperature, adding distilled water to terminate the reaction, separating, collecting an organic phase, adding anhydrous magnesium sulfate, and drying. Spin-drying the solvent on a rotary evaporator, adding a proper amount of silica gel, spin-drying, and purifying by using a column chromatography, wherein a developing agent is petroleum ether: ethyl acetate 8:1 (vol/vol) gave intermediate C-III-95(12.7g, 54%, Ms: 236.06).

(2) Adding the reactant E-III-95(50mmol) into a three-neck flask, adding anhydrous tetrahydrofuran, replacing with nitrogen for three times, then cooling the reaction system to-78 ℃, dropwise adding (2.5M) n-BuLi (50mmol), and stirring at-78 ℃ for 2 h. And dissolving the intermediate D-III-58(50mmol) in tetrahydrofuran, dropwise adding into the reaction system, and heating to room temperature after dropwise adding and stirring for 10 h. Distilled water was added to terminate the reaction, and the organic phase was collected by liquid separation, dried over anhydrous magnesium sulfate. The solvent was removed by rotary evaporator to give intermediate F-III-95(15.5g, 73% yield, Ms: 424.10).

(3) Adding the intermediate F-III-95(35mmol) into a three-neck flask, adding 180mL of glacial acetic acid, heating to 120 ℃, dropwise adding 4mL of concentrated sulfuric acid, and stirring for 5 min. After cooling to room temperature, 80mL of sodium bicarbonate solution was added to terminate the reaction, the layers were separated, the aqueous phase was extracted three times with 200mL of dichloromethane, the organic phase was collected, dried over anhydrous magnesium sulfate and the solvent was removed by rotary evaporator to give intermediate G-III-95(12.2G, 86%, Ms: 406.09).

(4) Under the protection of nitrogen, reacting the intermediate G-III-95(30mmol), the reactant H-III-95(33mmol),Tetrakis (triphenylphosphine) palladium (Pd (PPh)₃)₄) (0.30mmol) and potassium carbonate (K)₂CO₃) (60mmol) was added to a mixed solvent of 120mL of toluene, 40mL of ethanol and 40mL of water, and the mixture was heated to 110 ℃ and reacted for 8 hours with stirring. After the reaction is finished, the reaction product is cooled to room temperature, 100mL of water is added for washing, the filtration is carried out, the filter cake is sequentially washed by 30mL of ethanol and 90mL of petroleum ether, the obtained product is placed in 100mL of 1, 4-dioxane for recrystallization, the filtration is carried out, the filter cake is washed by 100mL of petroleum ether, and the obtained product is placed in a 65 ℃ oven for drying to obtain the compound 95(16.7g, the yield is 82%).

The compound 95 thus obtained was subjected to detection analysis, and the results were as follows:

HPLC purity: is more than 99.70 percent.

Mass spectrometry test: a theoretical value of 680.23; the test value was 680.82.

Elemental analysis:

the theoretical values are: c, 81.16; h, 4.15; n, 12.35; o,2.35

The test values are: c, 81.20; h, 4.18; n, 12.32; o, 2.31.

Examples 5 to 21

The synthesis of compounds 5, 10, 15, 20, 25, 32, 38, 46, 54, 63, 69, 76, 81, 85, 90, 99, 102, mass spectra and molecular formulae are shown in table 1 below, with reference to the synthetic procedures of examples 1 to 4.

TABLE 1 molecular formula, mass spectra and yield statistics for the compounds prepared in examples 5-21

Examples	Compound (I)	Molecular formula	Mass spectrometryTheoretical value	Mass spectrometric test values	Yield%
						Example 5	5	C₆₆H₄₉N₃O	899.39	899.32	80
Example 6	10	C₅₈H₃₆N₄O	804.29	804.65	82
						Example 7	15	C₅₃H₃₃N₅O	755.27	755.41	83
Example 8	20	C₅₃H₃₃N₅O	755.88	755.52	86
						Example 9	25	C₄₉H₃₀N₄O₂	706.24	706.26	84
Example 10	32	C₅₂H₃₉N₅O	749.32	749.47	83
						Example 11	38	C₆₃H₄₂N₄O	870.34	870.95	85
Example 12	46	C₅₈H₄₀N₄O	808.32	808.51	86
						Example 13	54	C₄₇H₃₀N₄O	666.24	666.70	81
Example 14	63	C₄₄H₂₆N₄O₂	642.21	642.33	80
						Example 15	69	C₆₂H₄₁N₅O	871.33	871.45	83
Example 16	76	C₄₈H₂₉N₅O	691.24	691.95	85
						Example 17	81	C₄₇H₂₉N₅O	679.24	679.51	86
Example 18	85	C₆₄H₄₆N₄O	886.37	866.70	82
						Example 19	90	C₅₁H₃₁N₅O	729.25	729.33	84
Example 20	99	C₅₈H₃₄N₈O	858.29	858.45	83
						Example 21	102	C₅₁H₃₁N₅O	729.25	729.43	82

In addition, other compounds of the present application can be obtained by the synthetic methods according to the above-mentioned examples, and therefore, they are not illustrated herein.

Example 22

Preparation of organic electroluminescent device:

the transparent substrate layer is a transparent PI film, an ITO anode layer (the thickness of the ITO anode layer is 150nm) is compounded on the PI film to wash the ITO anode layer, and alkali washing, pure water washing and drying are sequentially carried out, and then ultraviolet-ozone washing is carried out to remove organic residues on the surface of the transparent ITO. HAT-CN having a thickness of 10nm was deposited on the ITO anode layer after the above washing by a vacuum deposition apparatus to be used as a hole injection layer. Subsequently, NPB was evaporated to a thickness of 60nm as a hole transport layer. And after the evaporation of the hole transport material is finished, manufacturing a light-emitting layer of the OLED light-emitting device, wherein the structure of the light-emitting layer comprises that CBP used by the OLED light-emitting layer is used as a main material, FIrpic is used as a doping material, the doping proportion of the doping material is 5 wt%, and the thickness of the light-emitting layer is 40 nm.

Vacuum evaporating TPBi with the thickness of 10nm as a hole blocking layer and a compound 2 as an electron transport layer (the thickness of the electron transport layer is 30nm) on the luminescent layer; lithium hydroxyquinoline (Liq) was vacuum-deposited on the electron transport layer to a thickness of 1.0nm as an electron injection layer. On the electron injection layer, an Al electrode layer (thickness 100nm) was formed, and this layer was used as a cathode layer.

The device structure is as follows: ITO/HAT-CN/NPB/CBP FIrpic/TPBi/Compound 2/Liq/Al.

After the OLED light emitting device was completed as described above, the anode and cathode were connected by a known driving circuit, and the current efficiency of the device and the lifetime of the device were measured. After the electroluminescent device is manufactured according to the steps, the driving voltage, the luminous efficiency and the service life of the device are measured.

The molecular structural formula of the related material is shown as follows:

examples 23 to 42

By substituting compound 2 used in example 22 with compounds 5, 10, 15, 20, 25, 29, 32, 38, 46, 54, 58, 63, 69, 76, 81, 85, 90, 95, 99, 102, respectively, as electron transport layers in the method of example 22, corresponding organic electroluminescent devices were prepared.

Comparative example 1

An organic electroluminescent device was produced in the same production method as in example 22, wherein the compound of the electron transport layer was replaced with a compound (Alq3) having a structure represented by formula (iv);

the organic electroluminescent devices prepared in examples 22 to 42 and comparative example 1 were each subjected to a forward DC bias voltage, and the organic electroluminescent characteristics were measured by a PR-650 photometric measuring instrument of Photo Research, and had a luminance of 1000cd/m²The life of T95 was measured using a life measuring device available from McScience. The results are shown in Table 2.

TABLE 2 test results of light emitting characteristics (luminance value 1000 cd/m) of the organic electroluminescent devices prepared in examples 22 to 42 and comparative example 1²)

As can be seen from Table 2, compared with comparative example 1, the driving voltage of the organic electroluminescent device prepared from the spiro nitrogen-containing organic luminescent compound is reduced by about 1.2-1.8V, the luminous efficiency is improved by 1.2-2.6 times, and the service life of the device is improved by 31-49 h. From the results of the above table 2, it can be confirmed that the organic electroluminescent device prepared using the compound provided by the present invention as an electron transport material can exhibit high luminous efficiency and long life and reduce driving voltage.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A spiro nitrogen-containing organic light-emitting compound has a structure shown in formula I:

wherein X is selected from N or C-R₅；

q is a natural number of 0-4;

2. The spiro nitrogen-containing organic luminescent compound according to claim 1, wherein R is R₁、R₂、R₃、R₄And R₅Independently selected from hydrogen, deuterium, halogen, cyano, carboxyl, nitro, hydroxyl, substituted or unsubstituted C1-C18 alkyl, C2-C10 alkenyl, substituted or unsubstituted C2-C10 alkynyl, substituted or unsubstituted C1-C10 alkoxy, C3-C6 cycloalkyl, substituted or unsubstituted C3-C18 cycloalkenyl, substituted or unsubstituted 3-to 7-membered heterocycloalkyl, substituted or unsubstituted C6-C24 aryl, substituted or unsubstituted 3-to 24-membered heteroaryl, substituted or unsubstituted C10-C18 fused ring group or substituted or unsubstituted C10-C30 spiro ring group;

R₁、R₂、R₃、R₄and R₅Independently linked to an adjacent substituent to form a monocyclic ring, an aliphatic ring having C3-C18, or an aromatic ring having C6-C24, wherein a carbon atom in the monocyclic ring, the aliphatic ring having C3-C18, or the aromatic ring having C6-C24 may be replaced by at least one of nitrogen, oxygen, and sulfur.

3. The spiro nitrogen-containing organic luminescent compound according to claim 1, wherein R is R₁、R₂、R₃、R₄And R₅Independently selected from hydrogen, deuterium, halogen, cyano, carboxyl, nitro, hydroxyl, substituted or unsubstituted C1-C6 alkyl, C2-C6 alkenyl, substituted or unsubstituted C2-C6 alkynyl, substituted or unsubstituted C1-C6 alkoxy, C3-C6 cycloalkyl, substituted or unsubstituted C3-C6 cycloalkenyl, substituted or unsubstituted 3-to 7-membered heterocycloalkyl, substituted or unsubstituted C6-C24 aryl, substituted or unsubstituted 3-to 18-membered heteroaryl, substituted or unsubstituted C10-C18 condensed ring group or substituted or unsubstituted C10-C24 spiro ring group.

4. The spiro nitrogen-containing organic luminescent compound according to claim 1, wherein R is R₁Selected from hydrogen or methyl;

R₂selected from hydrogen, methyl, methoxy or tert-butyl;

R₃selected from hydrogen, methyl, phenyl or methoxyA group;

R₄one selected from the group consisting of formulae (4-1) to (4-18);

R₅selected from hydrogen, methyl, ethyl, tert-butyl, phenyl, pyridyl or biphenyl.

5. The spiro nitrogen-containing organic light-emitting compound according to claim 1, wherein L is L₁And L₂Independently selected from a linkage, a substituted or unsubstituted C6-C15 aryl, a substituted or unsubstituted 3-to 15-membered heteroaryl, or a substituted or unsubstituted C10-C30 fused ring group.

6. The spiro nitrogen-containing organic light-emitting compound according to claim 1, wherein L is L₁And L₂Independently selected from one or more of phenyl, benzyl, biphenyl, naphthyl, pyridyl, benzopyridyl, phenyl substituted pyridyl and furyl.

7. The spiro nitrogen-containing organic light-emitting compound according to claim 1, wherein the spiro nitrogen-containing organic light-emitting compound has a structure represented by any one of formulae (1) to (104):

8. a preparation method of a spiro nitrogen-containing organic luminescent compound comprises the following steps:

wherein X is selected from N or C-R₅；

q is a natural number of 0-4;

R₁、R₂、R₃、R₄and R₅Independently selected from hydrogen, deuterium, halogen, cyano, carboxyl, nitro, hydroxy, substituted or unsubstitutedSubstituted C1-C30 alkyl, C2-C30 alkenyl, substituted or unsubstituted C2-C30 alkynyl, substituted or unsubstituted C1-C30 alkoxy, C3-C30 cycloalkyl, substituted or unsubstituted C3-C30 cycloalkenyl, substituted or unsubstituted 3-to 7-membered heterocycloalkyl, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted 3-to 30-membered heteroaryl, substituted or unsubstituted C10-C30 fused ring group, or substituted or unsubstituted C10-C60 spiro group;

9. A preparation method of a spiro nitrogen-containing organic luminescent compound comprises the following steps:

wherein X is selected from N or C-R₅；

q is a natural number of 0-4;

10. An organic electroluminescent device comprising the spiro nitrogen-containing organic luminescent compound according to any one of claims 1 to 7 or the spiro nitrogen-containing organic luminescent compound prepared by the preparation method according to any one of claims 8 to 9.