Pure organic room-temperature phosphorescent material with ultra-long charge transfer triplet property, preparation method thereof and application of pure organic room-temperature phosphorescent material as organic photoinitiator

Abstract

The invention belongs to the technical field of organic compounds, and particularly relates to a pure organic room-temperature phosphorescent material with an ultra-long charge transfer triplet property, a preparation method of the pure organic room-temperature phosphorescent material and application of the pure organic room-temperature phosphorescent material as an organic photoinitiator. The pure organic room-temperature phosphorescent material with the ultra-long charge transfer triplet property has a structural general formula as shown in a formula I or II. The photoinitiator can be used as a single-component photoinitiator, a system added with the photoinitiator can be effectively photocured under an LED light source, a pure organic photocuring coating which emits light under ultraviolet irradiation and has the long afterglow property after illumination is formed, and the formed material, coating and pattern can emit fluorescence under the dark field ultraviolet irradiation condition, have long afterglow after an ultraviolet lamp is turned off, and have the long afterglow property after the ultraviolet lamp is turned off. And the fine pattern of the coating can be clearly, completely and quickly evaluated, so that optical monitoring can be synchronously realized when the method is applied to the curing fields of photoresist, three-dimensional printing and the like. The compound can also be directly added into a coating to form a long afterglow coating of a pure organic system. General formula I; formula II.

Description

Technical Field

[0001] This invention belongs to the field of organic compound technology, specifically relating to a class of pure organic room temperature phosphorescent materials with ultralong charge transfer triplet properties, their preparation method, and their application as organic photoinitiators. Background Technology

[0002] The photocuring process can generally be described as follows: under ultraviolet / visible light irradiation, the ground-state molecules of a photoinitiator absorb photons and enter an excited state, generating active initiating species that induce polymerization and cross-linking reactions of monomers or oligomers in the system to form a dense polymer. Photocuring systems typically include various functionalized polymeric monomers, oligomers, and photoinitiators. Although used in small quantities, photoinitiators are a key component of photocuring systems. Currently, photoinitiators can be classified into free radical and cationic types, with free radical photoinitiators being the most widely used. Based on their principle, free radical photoinitiators can be further divided into two categories: cleavage-type and hydrogen-abstraction-type. Cleavage-type photoinitiators undergo α-cleavage / β-cleavage of the excited-state molecular backbone under light irradiation to generate active initiating species, but the excited-state lifetime is short, and their induction of polymerization requires high energy, generally requiring the use of mercury lamps / UV LEDs as light sources, resulting in high energy consumption. In contrast, a single-component photoinitiator whose own backbone is not destroyed, together with an additional second component, constitutes the initiation system, generating active initiating species under light irradiation. However, during the curing process, as the viscosity of the system gradually increases, the excited-state photoinitiator and co-initiator need to collide to generate active initiating species, which usually makes the polymerization efficiency less than that of pyrolysis photoinitiators. This is usually because the excited-state lifetime of general compounds is very short.

[0003] In molecular excited states, the triplet lifetime (which can range from microseconds, milliseconds to seconds, or even longer) is much longer than that of the singlet state (typically on the nanosecond timescale). Therefore, current photoinitiators primarily focus on increasing the intersystem crossing rate from singlet to triplet states, thereby improving the triplet generation rate. A common method to increase the intersystem crossing rate is to incorporate "heavy" elements (high atomic numbers) into the molecule, such as platinum, iridium, iodine, and bromine. While this has successfully increased triplet yield, the incorporation of heavy atoms also has inherent drawbacks, including increased cost, synthetic complexity or toxicity, and reduced photostability, limiting its application in certain heavy metal-sensitive fields, such as in biology and semiconductors. Due to the spin-forbidden nature of phosphorescence, when the triplet lifetime reaches the millisecond or even second level, organic room temperature phosphorescence (ORTP) materials exhibit visible afterglow luminescence from a single organic compound. Therefore, organic room temperature phosphorescence materials can serve as single-component photoinitiators. Organic room-temperature phosphorescent materials can be divided into locally excited-state luminescence and charge-transfer-state luminescence. Furthermore, if the triplet state exhibits charge transfer (… 3Photocatalysis (CT) properties offer advantages in improving photocatalytic reaction efficiency, promoting artificial photosynthesis, and enhancing photovoltaic material performance. It has already been applied in fields such as anti-counterfeiting, information encryption and storage, electroluminescence, bioimaging, sensing, and photodynamic therapy. However, reports on its application in photocuring are limited, mainly due to the sharp increase in viscosity during the later stages of photocuring. 3 The long-lived species of CT-ORTP materials place higher demands on them, while existing literature reports... 3 The triplet lifetime of CT-ORTP materials is mostly less than 100ms. Summary of the Invention

[0004] The purpose of this invention is to provide a class of pure organic room-temperature phosphorescent materials with ultralong charge-transfer triplet properties, their preparation method, and their application as organic photoinitiators. The pure organic room-temperature phosphorescent materials provided by this invention have long charge-transfer triplet properties. 3 With a long CT lifespan, these materials emit room-temperature phosphorescence and can be used as organic photoinitiators to form photocurable coatings. The resulting materials, coatings, and patterns fluoresce under dark-field ultraviolet light irradiation and exhibit a long afterglow even after the ultraviolet light is turned off. This allows for clear, complete, and rapid evaluation of the coating's fine details, making them applicable to photoresist, 3D printing, and other curing fields. Simultaneous optical monitoring is also possible, significantly expanding the application areas of photocurable technology. Furthermore, these materials can also be used independently as afterglow materials in anti-counterfeiting and other applications.

[0005] To achieve the above objectives, the present invention provides the following technical solution: This invention provides a class of pure organic room-temperature phosphorescent materials with ultralong charge-transfer triplet properties, having the general structural formula shown in Formula I or II: General Formula I; General Formula II; The structure of the D group in general formula I or II is shown in formula a, b or c: Formula a Formula b Formula c; In formulas a, b, and c, R is selected from hydrogen atoms, C atoms, and C atoms. 1-20 Alkoxy, cyano, unsubstituted or substituted C 1-20 Straight-chain alkyl, unsubstituted or substituted C 3-20 Branched alkyl groups, substituted or unsubstituted C3-20 cycloalkyl groups, biphenyl groups, or C 4-20 Alkyl-substituted phenyl; the substituted C 1-20 Straight-chain alkyl or substituted C 1-20 The substituents of the branched alkyl group are selected from one or more of cycloalkyl, amide, hydroxy, alkoxy, or alkathioyl groups; the substituents of the substituted C3-20 cycloalkyl group are alkyl groups, and the C3-20 substituted C3-20 cycloalkyl group is an alkyl group.1-20 Straight-chain alkyl, cycloalkyl-substituted C 1-20 The total number of carbons in branched alkyl or alkyl-substituted C3-20 cycloalkyl groups is C 4-20 ; At least one of R1, R2 and R3 in formula c is fused with the benzene ring structure in formula c, and R1, R2 and R3 are each independently selected from pyrazinyl, pyridinyl, phenyl or benzene derivative groups, wherein the benzene derivative group is selected from naphthyl, halophenyl or alkylphenyl.

[0006] Preferably, in formula a, R is selected from hydrogen atoms, C 1-20 straight-chain alkyl, C 1-20 Branched alkyl or cyano groups; in formula b, R is selected from hydrogen atom, C 1-20 Branched alkyl or C 1-20 alkoxy group; in formula c, R is selected from hydrogen atom or C. 1-20 Alkoxy; at least one of R1, R2 and R3 in formula c is fused with pyrazinyl, pyridyl or phenyl.

[0007] Preferably, the D group has any one of the following structures: , , , , , , , , , , , , .

[0008] Preferably, it has any one of the following structures: , , , , , , , , , , , , , , .

[0009] This invention provides a method for preparing a pure organic room-temperature phosphorescent material with ultralong charge transfer triplet properties as described in the above technical solution. The method for preparing the pure organic room-temperature phosphorescent material with ultralong charge transfer triplet properties with the structure shown in Formula I includes the following steps: The compounds with the structure shown in Formula III, the compounds with the structure shown in Formula IV, an organopalladium catalyst, and an acid-binding agent were subjected to a nucleophilic substitution reaction in a polar solvent to obtain a pure organic room temperature phosphorescent material with ultralong charge transfer triplet properties as shown in Formula I. The preparation method of the pure organic room temperature phosphorescent material with ultralong charge transfer triplet property of the structure shown in Formula II includes the following steps: The compound with the structure shown in Formula III, the compound with the structure shown in Formula V, an organopalladium catalyst, and an acid-binding agent were subjected to a nucleophilic substitution reaction in a polar solvent to obtain a pure organic room temperature phosphorescent material with ultralong charge transfer triplet properties as shown in Formula II. Formula III Formula IV Formula V.

[0010] Preferably, the method for preparing the compound with the structure shown in Formula III includes the following steps: Nucleophilic substitution reaction was carried out in an organic solvent with 4-bromo-2,6-difluorobenzonitrile, pinacol diboronic acid ester, palladium catalyst, and acid-binding agent to give the compound with the structure shown in Formula III.

[0011] This invention provides the application of the pure organic room temperature phosphorescent material with ultralong charge transfer triplet properties as described in the above technical solution, or the pure organic room temperature phosphorescent material with ultralong charge transfer triplet properties prepared by the preparation method described in the above technical solution, as a single-component photoinitiator.

[0012] This invention provides the application of the pure organic room-temperature phosphorescent material with ultralong charge transfer triplet properties as described in the above technical solution, or the pure organic room-temperature phosphorescent material with ultralong charge transfer triplet properties prepared by the preparation method described in the above technical solution, as an afterglow material.

[0013] This invention provides a photocurable material, the raw materials of which include a prepolymerized photosensitive resin, an active monomer, and a photoinitiator. The photoinitiator is characterized in that it is either a pure organic room-temperature phosphorescent material with ultralong charge transfer triplet properties as described in the above-described technical solution, or a pure organic room-temperature phosphorescent material with ultralong charge transfer triplet properties prepared by the preparation method described in the above-described technical solution.

[0014] Preferably, the prepolymerized photosensitive resin is a resin containing vinyl groups; and the active monomer is a monomer containing vinyl groups.

[0015] This invention provides a class of pure organic room-temperature phosphorescent materials with ultralong charge-transfer triplet properties, possessing the general structural formula shown in Formula I or II. This invention uses 4-(3,5-difluorophenyl)benzylnitrile as the electron acceptor unit and diphenylamine, carbazole, and their derivatives as electron donor units. The compounds provided by this invention exhibit good molar extinction coefficients and long charge-transfer triplet properties. 3 The CT lifetime allows it to be used as a single-component photoinitiator added to ordinary photocuring systems. The added system can be effectively photocured under an LED light source, forming a pure organic photocurable coating that emits light under ultraviolet light and exhibits long afterglow. Furthermore, the formed material, coating, and pattern fluoresce under dark-field ultraviolet light irradiation and retains a long afterglow even after the ultraviolet light is turned off, allowing for clear, complete, and rapid evaluation of the coating's fine details. This enables applications in photoresist, 3D printing, and other curing fields, and allows for simultaneous optical monitoring, significantly expanding the application areas of photocuring technology. In addition, this type of compound can also be directly added to coatings to form long-afterglow coatings in pure organic systems. The pure organic room-temperature phosphorescent material with ultralong charge-transfer triplet properties provided by this invention has wide applications, including but not limited to photoresist, 3D printing, and anti-counterfeiting fields. Attached Figure Description

[0016] Figure 1 Vacuum steady-state and vacuum delayed spectra of Al2, a pure organic room-temperature phosphorescent material with ultralong charge-transfer triplet properties prepared for embodiments of the present invention. Figure 1 The left image in the figure; and the temperature-varying spectrum of Al2, a pure organic room-temperature phosphorescent material with ultralong charge-transfer triplet properties prepared according to the embodiments of the present invention, in air. Figure 1 (The right side of the image); Figure 2 Vacuum lifetime decay curves of pure organic room-temperature phosphorescent materials A1 and A12 with ultralong charge-transfer triplet properties prepared in an embodiment of the present invention; Figure 3 The pattern of the photocurable coating of Al2, a pure organic room-temperature phosphorescent material with ultralong charge transfer triplet properties prepared for an embodiment of the present invention, under ultraviolet light irradiation. Figure 3 (Left image) and magnified afterglow patterns at 0s, 3s, and 5s after the UV lamp irradiation was turned off. Figure 3 (The right side of the image). Detailed Implementation

[0017] This invention provides a class of pure organic room-temperature phosphorescent materials with ultralong charge-transfer triplet properties, having the general structural formula shown in Formula I or II: General Formula I; General Formula II; The structure of the D group in general formula I or II is shown in formula a, b or c: Formula a Formula b Formula c; In formulas a, b, and c, R is selected from hydrogen atoms, C atoms, and C atoms. 1-20 Alkoxy, cyano, unsubstituted or substituted C 1-20 Straight-chain alkyl, unsubstituted or substituted C 3-20 Branched alkyl groups, substituted or unsubstituted C3-20 cycloalkyl groups, biphenyl groups, or C 4-20 Alkyl-substituted phenyl; the substituted C 1-20 Straight-chain alkyl or substituted C 1-20 The substituents of the branched alkyl group are selected from one or more of cycloalkyl, amide, hydroxy, alkoxy, or alkathioyl groups; the substituents of the substituted C3-20 cycloalkyl group are alkyl groups, and the C3-20 substituted C3-20 cycloalkyl group is an alkyl group. 1-20 Straight-chain alkyl, cycloalkyl-substituted C 1-20 The total number of carbons in branched alkyl or alkyl-substituted C3-20 cycloalkyl groups is C 4-20 ; At least one of R1, R2 and R3 in formula c is fused with the benzene ring structure in formula c, and R1, R2 and R3 are each independently selected from pyrazinyl, pyridinyl, phenyl or benzene derivative groups, wherein the benzene derivative group is selected from naphthyl, halophenyl or alkylphenyl.

[0018] In this invention, R in formula a is preferably selected from hydrogen atoms, C 1-20 straight-chain alkyl, C 1-20 Branched alkyl or cyano groups, further preferably selected from hydrogen atoms, C 1-10 straight-chain alkyl, C 1-10 Branched alkyl or cyano groups, more preferably selected from hydrogen atoms, C 1-5 straight-chain alkyl, C 1-5 The branched alkyl or cyano group can be a hydrogen atom, methyl, isopropyl or cyano group in the examples.

[0019] In this invention, R in formula b is preferably selected from hydrogen atoms, C 1-20 Branched alkyl or C 1-20 Alkoxy groups, further preferably selected from hydrogen atoms, C 1-10 Branched alkyl or C 1-10 Alkoxy groups, more preferably selected from hydrogen atoms, C 1-5 Branched alkyl or C 1-5 Alkoxy groups, in the examples, can be hydrogen atoms, tert-butyl groups, or methoxy groups.

[0020] In this invention, R in formula c is preferably selected from hydrogen atoms or C atoms. 1-20 Alkoxy groups, further preferably selected from hydrogen atoms or C atoms. 1-10 Alkoxy groups, in the examples, can be hydrogen atoms or methoxy groups.

[0021] In this invention, at least one or two of R1, R2, and R3 in formula c are fused with the benzene ring structure in formula c. R1 is selected from pyrazinyl, pyridyl, or phenyl. R2 is selected from pyrazinyl, pyridyl, or phenyl. R3 is selected from pyrazinyl, pyridyl, or phenyl.

[0022] In this invention, the D group preferably has any one of the following structures: , , , , , , , , , , , , .

[0023] In this invention, the pure organic room-temperature phosphorescent material with ultralong charge-transfer triplet properties has any one of the following structures: , , , , , , , , , , , , , , .

[0024] This invention provides a method for preparing a pure organic room-temperature phosphorescent material with ultralong charge transfer triplet properties as described in the above technical solution.

[0025] In this invention, unless otherwise specified, all raw materials / components used in the preparation are commercially available products well known to those skilled in the art.

[0026] In this invention, the preparation method of the pure organic room temperature phosphorescent material with ultralong charge transfer triplet property of the structure shown in Formula I includes the following steps: The compounds with the structure shown in Formula III, the compounds with the structure shown in Formula IV, an organopalladium catalyst, and an acid-binding agent were subjected to a nucleophilic substitution reaction in a polar solvent to obtain a pure organic room-temperature phosphorescent material with ultralong charge-transfer triplet properties as shown in Formula I.

[0027] In this invention, the method for preparing the compound with the structure shown in Formula III preferably includes the following steps: a nucleophilic substitution reaction is carried out in an organic solvent with 4-bromo-2,6-difluorobenzonitrile, pinacol diboronate, a palladium catalyst, and an acid-binding agent to obtain the compound with the structure shown in Formula III. In this invention, the palladium catalyst is preferably tetrakis(triphenylphosphine)palladium or [1,1'-bis(diphenylphosphine)ferrocene]palladium dichloride. The acid-binding agent is preferably potassium carbonate or potassium acetate. The organic solvent is preferably one or more of benzene, toluene, xylene, chlorobenzene, dichlorobenzene, tetrahydrofuran, 1,4-dioxane, N-methylpyrrolidone, dimethylformamide, dimethylacetamide, dimethyl sulfoxide, hexamethylphosphoramide, sulfolane, acetonitrile, and benzonitrile, more preferably 1,4-dioxane. In this invention, the molar ratio of 4-bromo-2,6-difluorobenzonitrile to the pinacol diboronic acid ester is preferably 4.24~10:5.08~12, and in the examples it can be 10:12. The molar ratio of 4-bromo-2,6-difluorobenzonitrile to the palladium catalyst is preferably 4.24~10:0.2~0.5, and in the examples it can be 10:0.5. The molar ratio of 4-bromo-2,6-difluorobenzonitrile to the acid-binding agent is preferably 4.24~10:12.7~30, and in the examples it can be 10:30. This invention does not have special requirements for the amount of organic solvent used, as long as the nucleophilic substitution reaction proceeds smoothly. In this invention, the temperature of the nucleophilic substitution reaction is preferably 100℃, and the holding time of the nucleophilic substitution reaction is preferably 36 h. In this invention, the nucleophilic substitution reaction is preferably carried out in a protective gas atmosphere, preferably argon or nitrogen. The nucleophilic substitution reaction is preferably carried out under stirring conditions. In this invention, the nucleophilic substitution reaction yields a nucleophilic substitution reaction solution. Preferably, the nucleophilic substitution reaction solution is post-treated to obtain the compound with the structure shown in Formula III. The post-treatment preferably includes the following steps: cooling the nucleophilic substitution reaction solution to room temperature and performing solid-liquid separation; extracting the obtained liquid phase with dichloromethane (DCM) to obtain an extracted organic phase; drying the extracted organic phase and removing the solvent to obtain a crude product of the compound with the structure shown in Formula III; and purifying the crude product of the compound with the structure shown in Formula III by column chromatography to obtain a pure product of the compound with the structure shown in Formula III. In this invention, the solid-liquid separation is preferably carried out under pressure filtration; the extraction is preferably performed three times; and the drying reagent is preferably anhydrous sodium sulfate. The solvent removal is preferably carried out under reduced pressure rotary evaporation; the eluent used for column chromatography purification is preferably a mixed solvent of petroleum ether (PE) and dichloromethane (DCM), with a volume ratio of PE to DCM preferably of 4-5:1.

[0028] In this invention, the method for preparing the compound with the structure shown in Formula IV preferably includes the following steps: a nucleophilic substitution reaction is carried out on a DH compound, 1,4-dibromo-2,5-difluorobenzene, and an acid-binding agent in an organic solvent to obtain the compound with the structure shown in Formula IV. In this invention, the D group in the DH compound preferably has any one of the following structures: , , , , , , , , , , , , .

[0029] In this invention, when preparing the compound with the structure shown in Formula IV: the acid-binding agent is preferably potassium carbonate, potassium acetate, or sodium hydride. The organic solvent is preferably one or more of benzene, toluene, xylene, chlorobenzene, dichlorobenzene, tetrahydrofuran, 1,4-dioxane, N-methylpyrrolidone, dimethylformamide, dimethylacetamide, dimethyl sulfoxide, hexamethylphosphoramide, sulfolane, acetonitrile, and benzonitrile, more preferably dimethylformamide or... N 1,4-Methylpyrrolidone, preferably dimethylformamide. In this invention, the molar ratio of the DH compound to 1,4-dibromo-2,5-difluorobenzene is preferably 1.75~3.20:1, more preferably 2~3:1, and in the examples it can be 2.06:1 or 2.03:1. The molar ratio of the DH compound to the acid-binding agent is preferably 0.5~1:1, and in the examples it can be 0.67:1 or 1:1. This invention does not have special requirements for the amount of the organic solvent used, as long as the nucleophilic substitution reaction proceeds smoothly. In this invention, the temperature of the nucleophilic substitution reaction is preferably 25~50°C, and the holding time of the nucleophilic substitution reaction is preferably 12 h. The nucleophilic substitution reaction is preferably carried out in a protective gas atmosphere, preferably argon or nitrogen. The nucleophilic substitution reaction is preferably carried out under stirring. In this invention, after the nucleophilic substitution reaction, a nucleophilic substitution reaction solution is obtained. This invention preferably performs post-treatment on the nucleophilic substitution reaction solution to obtain the compound with the structure shown in Formula IV. In this invention, the post-processing preferably includes the following steps: mixing the nucleophilic substitution reaction solution with water, and then performing solid-liquid separation to obtain a compound with the structure shown in Formula IV. The solid-liquid separation is preferably performed by vacuum filtration.

[0030] In this invention, when preparing a pure organic room-temperature phosphorescent material with ultralong charge-transfer triplet properties of the structure shown in Formula I: the organic palladium catalyst is preferably tetrakis(triphenylphosphino)palladium. The acid-binding agent is preferably cesium carbonate or potassium carbonate. The polar solvent preferably includes an organic solvent and water, wherein the organic solvent preferably includes one or more of benzene, toluene, xylene, chlorobenzene, dichlorobenzene, tetrahydrofuran, 1,4-dioxane, N-methylpyrrolidone, dimethylformamide, dimethylacetamide, dimethyl sulfoxide, hexamethylphosphoramide, sulfolane, acetonitrile, and benzonitrile, more preferably toluene. The volume ratio of the organic solvent to water is preferably 5 to 10:1. In this invention, the molar ratio of the compound with the structure shown in Formula III to the compound with the structure shown in Formula IV is preferably 1 to 10:1, more preferably 2 to 5:1, and in the examples it can be 2.5:1, 2.4:1, or 4.9:1. The molar ratio of the compound with the structure shown in Formula III to the organopalladium catalyst is preferably 40-105:1, and in the examples it can be 50:1, 48:1 or 43:1. The molar ratio of the compound with the structure shown in Formula III to the acid-binding agent is preferably (2-5.25):(3.15-8.4), and in the examples it can be 2.5:6, 2.4:6 or 2.15:3.15. This invention does not have special requirements for the amount of the polar solvent used, as long as the nucleophilic substitution reaction proceeds smoothly. In this invention, the temperature of the nucleophilic substitution reaction is preferably 110-120 °C, and the holding time of the nucleophilic substitution reaction is preferably 12-24 h. The nucleophilic substitution reaction is preferably carried out in a protective gas atmosphere, preferably argon or nitrogen. The nucleophilic substitution reaction is preferably carried out under stirring conditions. In this invention, the nucleophilic substitution reaction yields a nucleophilic substitution reaction solution. Preferably, this invention involves post-processing the nucleophilic substitution reaction solution to obtain a pure organic room-temperature phosphorescent material with ultralong charge-transfer triplet properties of the structure shown in Formula I. In this invention, the post-processing preferably includes the following steps: cooling the nucleophilic substitution reaction solution to room temperature and mixing it with water; extracting the resulting liquid phase component with dichloromethane (DCM) to obtain an extracted organic phase; drying the extracted organic phase and removing the solvent to obtain a crude pure organic room-temperature phosphorescent material with ultralong charge-transfer triplet properties of the structure shown in Formula I; and purifying the crude pure organic room-temperature phosphorescent material with ultralong charge-transfer triplet properties of the structure shown in Formula I by column chromatography to obtain a pure pure organic room-temperature phosphorescent material with ultralong charge-transfer triplet properties of the structure shown in Formula I. In this invention, the number of extractions is preferably three, and the drying time is preferably anhydrous sodium sulfate. The preferred embodiment for solvent removal is rotary evaporation under reduced pressure; the eluent used in the column chromatography purification is preferably a mixed solvent of petroleum ether (PE) and ethyl acetate (EA), with the volume ratio of PE to EA preferably being 4:1, and the mesh size of the packing material used in the column chromatography purification being 100-200 mesh.

[0031] In this invention, the preparation method of the pure organic room temperature phosphorescent material with ultralong charge transfer triplet property of the structure shown in Formula II includes the following steps: A nucleophilic substitution reaction was carried out on the compound with the structure shown in Formula III, the compound with the structure shown in Formula V, an organopalladium catalyst, and an acid-binding agent in a polar solvent to obtain a pure organic room temperature phosphorescent material with ultralong charge transfer triplet properties as shown in Formula II.

[0032] In this invention, the preparation method of the compound with the structure shown in Formula III has been given in detail above and will not be repeated here.

[0033] In this invention, the preparation method of the compound with the structure shown in Formula V is basically the same as that of the compound with the structure shown in Formula IV above, except that the raw material 1,4-dibromo-2,5-difluorobenzene used to prepare the compound with the structure shown in Formula IV is replaced with 1,5-dibromo-2,4-difluorobenzene, while the other conditions remain unchanged.

[0034] In this invention, when preparing the compound with the structure shown in Formula V: the molar ratio of the DH compound to 1,5-dibromo-2,4-difluorobenzene is preferably 1.75~3.20:1, more preferably 2~3:1, and in the examples it can be 2.03:1. The molar ratio of the DH compound to the acid-binding agent is preferably 0.5~1:1, and in the examples it can be 1:1.

[0035] In this invention, the preparation method of the pure organic room-temperature phosphorescent material with ultralong charge-transfer triplet properties of Formula II is basically the same as that of the pure organic room-temperature phosphorescent material with ultralong charge-transfer triplet properties of Formula I described above. The difference is that the compound with the structure of Formula IV used to prepare the pure organic room-temperature phosphorescent material with ultralong charge-transfer triplet properties of Formula II is replaced with the compound with the structure of Formula V, while the other conditions remain unchanged. In this invention, the molar ratio of the compound with the structure of Formula III to the compound with the structure of Formula IV is preferably 1~10:1, more preferably 2~5:1, and can be 5:1 in the examples. The molar ratio of the compound with the structure of Formula III to the organic palladium catalyst is preferably 40~105:1, and can be 105:1 in the examples. The molar ratio of the compound with the structure of Formula III to the acid-binding agent is preferably (2~5.25):(3.15~8.4), and can be 5.25:8.4 in the examples.

[0036] This invention provides the application of the pure organic room temperature phosphorescent material with ultralong charge transfer triplet properties as described in the above technical solution, or the pure organic room temperature phosphorescent material with ultralong charge transfer triplet properties prepared by the preparation method described in the above technical solution, as a single-component photoinitiator.

[0037] This invention provides the application of the pure organic room-temperature phosphorescent material with ultralong charge transfer triplet properties as described in the above technical solution, or the pure organic room-temperature phosphorescent material with ultralong charge transfer triplet properties prepared by the preparation method described in the above technical solution, as an afterglow material.

[0038] This invention provides a photocurable material. The raw materials of the photocurable material include a prepolymerized photosensitive resin, an active monomer, and a photoinitiator. The photoinitiator is either the ultralong charge-transfer triplet property pure organic room-temperature phosphorescent material described in the above-described technical solution or the ultralong charge-transfer triplet property pure organic room-temperature phosphorescent material prepared by the preparation method described in the above-described technical solution. In this invention, the raw materials of the photocurable material also include a solvent.

[0039] In this invention, the prepolymerized photosensitive resin is preferably a resin having vinyl unsaturated groups. In this invention, the active monomer is preferably a monomer having vinyl unsaturated groups.

[0040] As one or more embodiments of the present invention, the photocurable material is specifically a photocurable coating.

[0041] In this invention, the mass percentage of the pure organic room temperature phosphorescent material with ultralong charge transfer triplet properties in the photocurable material is preferably 0.001~10%, more preferably 0.001~9.5%, and even more preferably 0.005~9%. In the embodiments, it can be 0.005%, 0.01%, 0.05%, 0.5%, 1.2%, 2%, 3%, 4%, 5%, 7%, 8% or 9%.

[0042] In this invention, the mass percentage of the prepolymerized photosensitive resin in the photocurable material is preferably 40.2% to 60%. The mass percentage of the active monomer is preferably 34.7% to 50%.

[0043] In this invention, the photoinitiator is preferably one or two of the pure organic room temperature phosphorescent materials with ultralong charge transfer triplet properties as shown in Formula I and Formula II. When there are two, the mass ratio of the two is preferably 1:1.

[0044] In this invention, the prepolymerized photosensitive resin (i.e., the base resin) is preferably a methacrylate / methacrylic acid / methyl methacrylate copolymer, wherein the molar ratio of methacrylate, methacrylic acid, and methyl methacrylate in the methacrylate / methacrylic acid / methyl methacrylate copolymer is preferably 50:15:30. The weight-average molecular weight (Mw) of the methacrylate / methacrylic acid / methyl methacrylate copolymer is preferably 70,000.

[0045] In this invention, the active monomer is preferably one or more of tripropylene glycol diacrylate (TPGDA), 1,6-hexanediol diacrylate (HDDA), and trimethylolpropane triacrylate (TMPTA).

[0046] In this invention, the preparation method of the photocurable material preferably includes the following steps: dissolving a prepolymerized photosensitive resin, an active monomer, and a photoinitiator in an organic solvent to obtain a mixture; coating the mixture onto a template surface to obtain a wet film; heating the wet film to remove the solvent to obtain a dry film; and exposing the dry film for photocuring to obtain the photocurable material. In this invention, the template is preferably a PET template. The thickness of the wet film is preferably 2 μm, and the solvent removal temperature is preferably 90 °C. During photocuring, this invention preferably attaches a mask to the dry film. The exposure light source is preferably a 410 nm LED surface light source.

[0047] To further illustrate the present invention, the technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0048] Example 1 The synthetic route for the pure organic room-temperature phosphorescent material A1 with ultralong charge-transfer triplet properties provided in this embodiment is as follows: ; (1) Synthesis of compound III Under an argon atmosphere, 4-bromo-2,6-difluorobenzonitrile (2.18 g, 10 mmol), pinacol diboronate (3.05 g, 12 mmol), tetrakis(triphenylphosphine)palladium (366 mg, 0.5 mmol), potassium acetate (2.94 g, 30 mmol), and 1,4-dioxane (30 mL) were added to a 250 mL pressure-resistant branch tube. o Stirring at C for 6 h. After the reaction returned to room temperature, filter under reduced pressure, extract with DCM (30 mL × 3), and collect the organic phase. Dry the organic phase with anhydrous Na₂SO₄, remove the organic solvent under reduced pressure, and purify the crude product by rapid column chromatography (eluent: / = 4:1) to obtain the product. 1 H NMR (400 MHz, CDCl3) δ7.42 (d, 2H), 1.34 (s, 12H). HRMS found: 265.1086.

[0049] (2) Synthesis of compounds with the structure shown in Formula 1 Under an argon atmosphere, potassium acetate (0.596 g, 6.08 mmol), diphenylamine (1.03 g, 4.08 mmol), and 10 mL of dimethylformamide (DMF) were added to a three-necked flask and stirred at room temperature for 30 min. Then, 1,4-dibromo-2,5-difluorobenzene (0.54 g, 1.98 mmol) was added, and the reaction was allowed to proceed for 12 h. After the reaction was complete, the reaction solution was poured into water, and the product was obtained by filtration. 1 H NMR (400 MHz, (CD3)2SO) δ 7.24 (t, 8H), 7.08 – 7.07 (m, 10H), 7.00 (t, 4H). HRMSfound: 568.0152.

[0050] (3) Synthesis of the compound with the structure shown in A1 Under an argon atmosphere, intermediate 1 (1.10 g, 1 mmol), compound III (513 mg, 2.5 mmol), tetrakis(triphenylphosphine)palladium (58 mg, 0.05 mmol), anhydrous potassium carbonate (828 mg, 6 mmol), and a toluene-water mixed solvent (12 mL) were mixed. / =5:1), 110 o Stir at C for 12 h. After the reaction has returned to room temperature, pour the reaction mixture into water and extract with DCM (100 mL × 3). Collect the organic phase and dry it with anhydrous Na₂SO₄. Remove the organic solvent under reduced pressure. Purify the crude product by rapid column chromatography using the following eluent: / = 4:1) to obtain the product. 1 H NMR (400 MHz, (CD3)2SO) δ 7.47 (d, 4H), 7.42 (s, 2H) 7.24 (t, 8H), 7.08 (d, 8H), 7.01 (t, 4H). HRMS found: 686.2097.

[0051] Example 2 The synthesis route of the pure organic room-temperature phosphorescent material A2 with ultralong charge transfer triplet properties in this embodiment is as follows: ; The synthesis method is as described in Example 1, using... replace Compound A2 was synthesized. 1H NMR(400 MHz, (CD3)2SO) δ 7.47 (d, 4H), 7.41 (s, 2H), 7.15 – 7.13 (m, 16H), 2.32(s, 12H). HRMS found: 742.2725.

[0052] Example 3 The synthesis route of the pure organic room-temperature phosphorescent material A3 with ultralong charge transfer triplet properties in this embodiment is as follows: ; The synthesis method is as described in Example 1, using... replace Compound A3 was synthesized. 1 H NMR (400 MHz, (CD3)2SO) δ 7.47 (d, 4H), 7.42 (s, 2H), 7.18 (d, 8H), 7.06 (d, 8H), 2.87 (q, 4H), 1.20 (d, 24H). HRMS found: 854.3971.

[0053] Example 4 The synthesis route of the pure organic room-temperature phosphorescent material A4 with ultralong charge transfer triplet properties in this embodiment is as follows: ; The synthesis method is as described in Example 1, using... replace Compound A4 was synthesized. 1 H NMR(400 MHz, (CD3)2SO) δ 7.48 – 7.47 (m, 12H), 7.42 (s, 2H), 7.36 (d, 8H). HRMSfound: 786.1901.

[0054] Example 5 The synthesis route of the pure organic room-temperature phosphorescent material A5 with ultralong charge-transfer triplet properties in this embodiment is as follows: ; (1) Synthesis of compound III The synthesis of intermediate III was the same as in Example 1.

[0055] (2) Synthesis of compounds with the structure shown in Formula 5 Under an argon atmosphere, potassium acetate (0.596 g, 6.08 mmol), carbazole (1.03 g, 6.08 mmol), and 10 mL of DMF were added to a three-necked flask and stirred at room temperature for 30 min. Then, 1,4-dibromo-2,5-difluorobenzene (0.82 g, 3.00 mmol) was added, and the reaction was allowed to proceed for 12 h. After the reaction was complete, the reaction solution was poured into water, and the product was obtained by filtration. 1 H NMR (400 MHz, (CD3)2SO) δ 7.58 – 7.56 (m, 10H), 7.41 – 7.20 (m, 8H). HRMS found: 563.9836.

[0056] (3) Synthesis of the compound with the structure shown in A5 Under an argon atmosphere, intermediate 5 (0.56 g, 1 mmol), compound III (492 mg, 2.4 mmol), tetrakis(triphenylphosphine)palladium (58 mg, 0.05 mmol), anhydrous potassium carbonate (828 mg, 6 mmol), and a toluene-water mixed solvent (12 mL) were mixed. / =5:1), 110 o Stir at C for 12 h. After the reaction has returned to room temperature, pour the reaction mixture into water, extract with DCM (100 mL × 3), collect the organic phase, and dry with anhydrous Na₂SO₄. Remove the organic solvent under reduced pressure, and purify the crude product by rapid column chromatography using the following eluent: / = 4:1) to obtain the product. 1 H NMR (400 MHz, (CD3)2SO) δ 8.60 – 8.52 (m, 6H), 7.94 – 7.88 (m, 4H), 7.50 – 7.35 (m, 8H), 7.20 – 7.16 (m, 4H). HRMS found: 682.1779.

[0057] Example 6 The synthesis route of the pure organic room-temperature phosphorescent material A6 with ultralong charge transfer triplet properties in this embodiment is as follows: ; The synthesis method is as described in Example 5, using... replace Compound A6 was synthesized. 1 H NMR (400MHz, (CD3)2SO) δ8.54 (s, 2H), 8.36 (s, 4H), 7.62 – 7.48 (m, 12H), 1.43 (s, 36H). HRMS found: 1320.6192.

[0058] Example 7 The synthesis route of the pure organic room-temperature phosphorescent material A7 with ultralong charge-transfer triplet properties in this embodiment is as follows: ; The synthesis method is as described in Example 5, using... replace Compound A7 was synthesized. 1 H NMR (400 MHz, (CD3)2SO) δ HRMS found: 802.2201.

[0059] Example 8 The synthesis route of the pure organic room-temperature phosphorescent material A8 with ultralong charge transfer triplet properties in this embodiment is as follows: ; (1) Synthesis of compound III The synthesis of intermediate III was the same as in Example 1.

[0060] (2) Synthesis of compounds with the structure shown in Formula 8 Under an argon atmosphere, potassium acetate (0.60 g, 6.08 mmol), 2,3-benzocarbazole (1.32 g, 6.08 mmol), and 10 mL of DMF were added to a three-necked flask and stirred at room temperature for 30 min. Then, 1,4-dibromo-2,5-difluorobenzene (0.82 g, 3.00 mmol) was added, and the reaction was allowed to proceed for 12 h. After the reaction was complete, the reaction solution was poured into water, and the product was obtained by filtration. 1 H NMR (400MHz, (CD3)2SO) δ 8.11 – 8.28 (m, 6H), 7.74 – 7.69 (m, 4H), 7.58 – 7.51 (m, 8H), 7.40 (s, 2H), 7.20 – 7.16 (m, 2H). HRMS found: 664.0150.

[0061] (3) Synthesis of the compound with the structure shown in A8 Under an argon atmosphere, intermediate 8 (0.70 g, 1.05 mmol), compound III (0.57 g, 2.15 mmol), tetrakis(triphenylphosphine)palladium (60 mg, 0.05 mmol), anhydrous potassium carbonate (435 mg, 3.15 mmol), and a toluene-water mixture (12 mL) were mixed. / =10:1), 110 o Stir at C for 24 h. After the reaction has returned to room temperature, pour the reaction mixture into water, extract with DCM (100 mL × 3), collect the organic phase, and dry with anhydrous Na₂SO₄. Remove the organic solvent under reduced pressure, and purify the crude product by rapid column chromatography using the following eluent: / = 4:1) to obtain the product. 1 H NMR (400 MHz, (CD3)2SO) δ 8.55-8.28 (m,6H), 8.11-7.94 (m, 4H), 7.75 - 7.47 (m, 10H), 7.40 (s, 2H), 7.20-7.16 (m,4H). HRMS found: 782.2095.

[0062] Example 9 The synthesis route of the pure organic room-temperature phosphorescent material A9 with ultralong charge transfer triplet properties in this embodiment is as follows: ; The synthesis method is as described in Example 8, using... replace Compound A9 was synthesized. 1 H NMR (400MHz, DMSO) δ 8.89 (d, 2 H), 8.70 (d, 2 H), 8.12-8.05 (m, 4 H), 7.97 (d, 2H), 7.79 (td, 1H), 7.60-7.50 (m, 6 H), 7.46 (dd, 2 H), 7.42-7.37 (m, 2 H). HRMSfound: 782.2095.

[0063] Example 10 The synthesis route of the pure organic room-temperature phosphorescent material A10 with ultralong charge-transfer triplet properties in this embodiment is as follows: ; The synthesis method is as described in Example 8, using... replace Compound A10 was synthesized.1 H NMR (400MHz, DMSO) δ 8.90 (d, 2H), 8.31 (s, 2H), 8.21 – 8.05 (m, 4H), 7.98 – 7.91 (m,3H), 7.82 (t, 3H), 7.76 – 7.65 (m, 2H), 7.62 – 7.53 (m, 4H), 7.15 (d, 4H), 4.02 (s, 6H). HRMS found: 842.2304.

[0064] Example 11 The synthesis route of the pure organic room-temperature phosphorescent material A11 with ultralong charge-transfer triplet properties in this embodiment is as follows: ; The synthesis method is as described in Example 8, using... replace Compound A11 was synthesized. 1 H NMR (400MHz, DMSO) δ 8.95 (d, 2H), 8.55 – 8.46 (m, 6H), 8.08 (d, 2H), 7.64 – 7.47 (m,10H), 7.35 – 7.16 (m, 4H). HRMS found: 784.1998.

[0065] Example 12 The synthesis route of the pure organic room-temperature phosphorescent material A12 with ultralong charge-transfer triplet properties in this embodiment is as follows: ; The synthesis method is as described in Example 8, using... replace Compound A12 was synthesized. 1 H NMR (400MHz, DMSO) δ 8.81 (d, 4H), 8.61 (d, 2H), 7.67 – 7.47 (m, 8H), 7.35 – 7.16 (m,6H). HRMS found: 786.1904.

[0066] Example 13 The synthesis route of the pure organic room-temperature phosphorescent material A13 with ultralong charge-transfer triplet properties in this embodiment is as follows: ; The synthesis method is as described in Example 8, using... replace Compound A13 was synthesized. 1 H NMR (400MHz, DMSO) δ HRMS found: 882.2407.

[0067] Example 14 The synthesis route of the pure organic room-temperature phosphorescent material A14 with ultralong charge-transfer triplet properties in this embodiment is as follows: ; (1) Synthesis of compound III The synthesis of intermediate III was the same as in Example 1.

[0068] (2) Synthesis of compounds with the structure shown in Formula 14 Under an argon atmosphere, potassium acetate (0.596 g, 6.08 mmol), carbazole (1.02 g, 6.08 mmol), and 10 mL of DMF were added to a three-necked flask and stirred at room temperature for 30 min. Then, 1,5-dibromo-2,4-difluorobenzene (0.82 g, 3.00 mmol) was added, and the reaction was allowed to proceed for 12 h. After the reaction was complete, the reaction solution was poured into water, and the product was obtained by filtration. 1 H NMR (400 MHz, (CD3)2SO) δ HRMS found: 563.9837.

[0069] (3) Synthesis of the compound with the structure shown in A14 Under an argon atmosphere, intermediate 14 (0.59 g, 1.05 mmol), compound III (1.396 g, 5.25 mmol), tetrakis(triphenylphosphine)palladium (60 mg, 0.05 mmol), anhydrous potassium carbonate (1.160 g, 8.40 mmol), and a toluene-water mixed solvent (12 mL) were mixed. / =10:1), 110 oStir at C for 14 h. After the reaction has returned to room temperature, pour the reaction mixture into water, extract with DCM (100 mL × 3), collect the organic phase, and dry with anhydrous Na₂SO₄. Remove the organic solvent under reduced pressure, and purify the crude product by rapid column chromatography using the following eluent: / = 5:1) to obtain the product. 1 H NMR (400 MHz, DMSO) δ 8.55 (d, 2H),8.19-8.15 (m, 3H), 7.97 – 7.88 (m, 7H), 7.47 (d, 4H), 7.35 – 7.16 (m, 6H).HRMS found: 682.1781.

[0070] Example 15 The synthesis route of the pure organic room-temperature phosphorescent material A15 with ultralong charge-transfer triplet properties in this embodiment is as follows: ; The synthesis method is as described in Example 14, using... replace Compound A15 was synthesized. 1 H NMR (400MHz, DMSO) δ 8.91 (d, 2H), 8.72 (d, 2H), 8.43 (s, 1H), 8.26 (s, 1H), 8.06 (d,2H), 7.96 (d, 2H), 7.75 (t, 2H), 7.64 (t, 2H), 7.59 – 7.34 (m, 8H), 7.25 (d,4H). HRMS found: 783.2168.

[0071] Test Example 1 The photophysical properties of photoinitiators A1, A2, A3, A4, A5, A6, A7, A8, A9, A10, A11, A12, A13, A14, and A15 obtained in Examples 1-15 were studied (acetonitrile was used as the solvent, and the test concentration was 1×10⁻⁶). -5 (mol / L), the data are shown in Table 1.

[0072] Table 1. Results of photophysical property studies of compounds A1-A15

[0073] As shown in Table 1, compounds A1, A2, A3, A4, A5, A6, A7, A8, A9, A10, A11, A12, A13, A14, and A15 all exhibit high molar extinction coefficients. Taking molecule A12 as an example, the steady-state and delayed-state spectra of this molecule show inconsistent positions and peak shapes; simultaneously, the transient photoluminescence decay curve indicates that the spectrum of the long-lived species A12 exhibits a red shift relative to the steady-state fluorescence spectrum, and the spectral intensity increases with increasing temperature. Figure 1 The above experimental results demonstrate that A12 is a pure organic room-temperature phosphorescent material with charge-transfer triplet properties, a long delayed lifetime, and can effectively initiate polymerization.

[0074] Test Example 2 Thin film sample preparation method: Compounds A1~A15 and polymethyl methacrylate (PMMA) were dissolved in 1,2-dichloroethane to prepare thin film samples with a concentration of 10 mg / mL. -1 The solution was prepared by first adding one of the compounds A1 to A15 (at a mass fraction of 1.0 wt%) to the PMMA solution to obtain a mixed solution. Using quartz as a substrate, the mixed solution was coated onto the substrate surface using a pipette, and then a spin coater was used to obtain the thin film sample to be tested.

[0075] Model of spin coater: KW-4A desktop spin coater from the Microelectronics Research Center of the Chinese Academy of Sciences.

[0076] Spin coating conditions: Spindle speed 500 rpm min -1 Run for 15 seconds, then increase the speed to 1500 rpm. -1 The test run lasted 45 seconds. Lifetime decay curve test method: The thin film sample to be tested was subjected to a vacuum test using a Horiba Fluorolog-3 fluorescent spectrophotometer. The results are as follows: Figure 2 And as shown in Table 2.

[0077] Figure 2 The left side of the figure shows the photoluminescence decay curve of compound A1 prepared in Example 1; Figure 2 The right side of the figure shows the photoluminescence decay curve of compound A12 prepared in Example 12.

[0078] Table 2. Luminescence lifetime data of compounds A1~A15

[0079] Taking compounds A1 and A12 as examples, under vacuum conditions, the fluorescence lifetime of their 1.0 wt% PMMA-doped films is only about 20 ns (23 ns for A1 and 24 ns for A12). The lifetimes of the long-lived excited species of A1 and A12 are 0.85 s and 1.16 s, respectively (PL decay curves are shown in the figure). Figure 2 (As shown). In the above experimental results, compounds A1, A3, A4, A6, A7, A8, A9, A10, A11, and A12 are all τ. 3 CT More than 500 ms 3 CT-ORTP material is characterized by its long lifespan. 3 CT phosphorescent materials.

[0080] Application Example 1 Preparation of UV-curable materials (mass fraction) Base resin 40.2-60%; Monomer content: 34.7-50%; Photoinitiator 0.005-9.0%.

[0081] The base resin is a copolymer of methacrylate / methacrylic acid / methyl methacrylate, wherein the molar ratio of methacrylate, methacrylic acid, and methyl methacrylate is 50:15:30, and the weight-average molecular weight (Mw) of the base resin is 70,000. The monomers are any one of tripropylene glycol diacrylate (TPGDA), 1,6-hexanediol diacrylate (HDDA), and trimethylolpropane triacrylate (TMPTA). An additional 5 mL of acetone is added for dissolution. The photoinitiator is one or more of the compounds prepared in Examples 1-15 above (when using multiple compounds as photoinitiators, the mass is the same).

[0082] Development and exposure The prepared photocurable component was coated onto a PET template using a wire rod, with a film thickness of approximately 2 μm. The film was then dried at 90 °C for 5 min to remove the solvent. The coated PET plate was then cooled to room temperature, a mask was attached, and exposure was performed using an LED surface light source (365 nm, 100 mW). Next, development was performed at 25 °C using a 1% (w / w) NaOH aqueous solution, followed by washing with ultrapure water and air drying. Finally, the plate was baked at 220 °C for 30 min, and the resulting pattern was evaluated.

[0083] Table 3. Polymerization results of compounds A1-A15 as photoinitiators

[0084] In Table 3, the mass fraction of the photoinitiator is the percentage of the photoinitiator relative to the total mass of the base resin, polymer monomer, and photoinitiator.

[0085] The polymerization results are shown in Table 3. All the pure organic room-temperature phosphorescent materials with ultralong charge-transfer triplet properties used could effectively initiate photocuring. Taking the coating obtained from compound A12 as an example, the cured coatings were colorless and transparent under natural light, with no visible abnormalities. Under dark-field ultraviolet light irradiation (… Figure 3 (A) in the image emits fluorescence, allowing for clear observation of the pattern. After irradiation with ultraviolet light for 5 seconds and then turned off, the coating emits delayed phosphorescence with an afterglow lasting up to 12 seconds. A magnified view is shown below. Figure 3 As shown in B, C, and D, the afterglow times are 0, 3, and 5 seconds, respectively. Taking the pattern with an afterglow time of 3 seconds as an example, there are a small number of unluminescent dark spots in the bottom cured strip, indicating that there is a defect in the polymer pattern here. The experimental results prove that the afterglow luminescence clearly shows much richer details than the fluorescent pattern, which can provide fine coating condition analysis for the required fields, and can also be used for anti-counterfeiting.

[0086] The results for compounds prepared in other examples were similar to those for compound A12.

[0087] As can be seen from the above embodiments, the pure organic room-temperature phosphorescent material with ultralong charge transfer triplet properties provided by the present invention has long... 3 With a long CT lifespan, these materials emit room-temperature phosphorescence, enabling them to act as organic photoinitiators to form photocurable coatings. The resulting materials, coatings, and patterns fluoresce under dark-field ultraviolet light irradiation, exhibiting a long afterglow even after the UV lamp is turned off. This allows for clear, complete, and rapid evaluation of the coating's fine details, making them applicable to curing fields such as photoresists and 3D printing. Simultaneous optical monitoring is also possible, significantly expanding the application areas of photocuring technology. Furthermore, these materials can also be used independently as afterglow materials in fields such as anti-counterfeiting.

[0088] Although the above embodiments have provided a detailed description of the present invention, they are only some embodiments of the present invention, and not all embodiments. Other embodiments can be obtained based on these embodiments without creative effort, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A class of pure organic room-temperature phosphorescent materials with ultralong charge-transfer triplet properties, characterized in that, Having the general formula shown in Equation I or II: General Formula I; General Formula II; The structure of the D group in general formula I or II is shown in formula a, b or c: Formula a Formula b Formula c; In formulas a, b, and c, R is selected from hydrogen atoms, C atoms, and C atoms. 1-20 Alkoxy, cyano, unsubstituted or substituted C 1-20 Straight-chain alkyl, unsubstituted or substituted C 3-20 Branched alkyl groups, substituted or unsubstituted C3-20 cycloalkyl groups, biphenyl groups, or C 4-20 Alkyl-substituted phenyl; the substituted C 1-20 Straight-chain alkyl or substituted C 1-20 The substituents of the branched alkyl group are selected from one or more of cycloalkyl, amide, hydroxy, alkoxy, or alkathioyl groups; the substituents of the substituted C3-20 cycloalkyl group are alkyl groups, and the C3-20 substituted C3-20 cycloalkyl group is an alkyl group. 1-20 Straight-chain alkyl, cycloalkyl-substituted C 1-20 The total number of carbons in branched alkyl or alkyl-substituted C3-20 cycloalkyl groups is C 4-20 ; At least one of R1, R2 and R3 in formula c is fused with the benzene ring structure in formula c, and R1, R2 and R3 are each independently selected from pyrazinyl, pyridinyl, phenyl or benzene derivative groups, wherein the benzene derivative group is selected from naphthyl, halophenyl or alkylphenyl.

2. The pure organic room-temperature phosphorescent material with ultralong charge-transfer triplet properties according to claim 1, characterized in that, In formula a, R is selected from hydrogen atoms, C 1-20 straight-chain alkyl, C 1-20 Branched alkyl or cyano groups; in formula b, R is selected from hydrogen atom, C 1-20 Branched alkyl or C 1-20 alkoxy group; in formula c, R is selected from hydrogen atom or C. 1-20 Alkoxy; at least one of R1, R2 and R3 in formula c is fused with pyrazinyl, pyridyl or phenyl.

3. The pure organic room-temperature phosphorescent material with ultralong charge-transfer triplet properties according to claim 2, characterized in that, The D group has any one of the following structures: 、 、 、 、 、 、 、 、 、 、 、 、 。 4. The pure organic room-temperature phosphorescent material with ultralong charge-transfer triplet properties according to any one of claims 1 to 3, characterized in that, It has any of the following structures: 、 、 、 、 、 、 、 、 、 、 、 、 、 、 。 5. A method for preparing a pure organic room-temperature phosphorescent material with ultralong charge-transfer triplet properties as described in any one of claims 1 to 4, characterized in that, The preparation method of the pure organic room temperature phosphorescent material with the ultralong charge transfer triplet property of the structure shown in Formula I includes the following steps: The compounds with the structure shown in Formula III, the compounds with the structure shown in Formula IV, an organopalladium catalyst, and an acid-binding agent were subjected to a nucleophilic substitution reaction in a polar solvent to obtain a pure organic room temperature phosphorescent material with ultralong charge transfer triplet properties as shown in Formula I. The preparation method of the pure organic room temperature phosphorescent material with ultralong charge transfer triplet property of the structure shown in Formula II includes the following steps: The compound with the structure shown in Formula III, the compound with the structure shown in Formula V, an organopalladium catalyst, and an acid-binding agent were subjected to a nucleophilic substitution reaction in a polar solvent to obtain a pure organic room temperature phosphorescent material with ultralong charge transfer triplet properties as shown in Formula II. Formula III Formula IV Formula V.

6. The preparation method according to claim 5, characterized in that, The preparation method of the compound with the structure shown in Formula III includes the following steps: Nucleophilic substitution reaction was carried out in an organic solvent with 4-bromo-2,6-difluorobenzonitrile, pinacol diboronic acid ester, palladium catalyst, and acid-binding agent to give the compound with the structure shown in Formula III.

7. The application of the pure organic room temperature phosphorescent material with ultralong charge transfer triplet properties as described in any one of claims 1 to 4, or the pure organic room temperature phosphorescent material with ultralong charge transfer triplet properties prepared by the preparation method described in claim 5 or 6, as a single-component photoinitiator.

8. The application of the pure organic room-temperature phosphorescent material with ultralong charge transfer triplet properties as described in any one of claims 1 to 4, or the pure organic room-temperature phosphorescent material with ultralong charge transfer triplet properties prepared by the preparation method described in claim 5 or 6, as an afterglow material.

9. A photocurable material, characterized in that, The raw materials of the photocurable material include prepolymerized photosensitive resin, active monomer and photoinitiator, characterized in that the photoinitiator is a pure organic room temperature phosphorescent material with ultralong charge transfer triplet property as described in any one of claims 1 to 4 or a pure organic room temperature phosphorescent material with ultralong charge transfer triplet property prepared by the preparation method described in claim 5 or 6.

10. The photocurable material according to claim 9, characterized in that, The prepolymerized photosensitive resin is a resin containing vinyl groups; the active monomer is a monomer containing vinyl groups.

Images