A photocatalyst with space charge transfer properties and its preparation method and application

Abstract

This patent application discloses a photocatalyst with spatial charge transfer properties, its preparation method, and its application. This photocatalyst with spatial charge transfer properties utilizes a naphthaleneimide light-absorbing group as an electron acceptor, which is then reacted with an electron donor group to form a photocatalyst with spatial charge transfer properties. These compounds possess long excited-state lifetimes and strong excited-state reduction capabilities, making them ideal photocatalysts. Combining these catalysts with acrylic resins to form photoresists, used in practical photolithography, allows for the observation of high-resolution patterns.

Description

Technical Field

[0001] This patent application relates to the field of photoredox catalytic polymerization technology, and more specifically, to a photocatalyst with spatial charge transfer properties, a preparation method thereof, and an application thereof. Background Art

[0002] Photoredox catalytic polymerization technology has important application value in actual photolithography, and the properties of the photocatalyst are the key factors determining the efficiency and conditions of photopolymerization. An ideal photocatalyst should have properties such as high intersystem crossing efficiency and long excited state lifetime. At present, commonly used photocatalysts are mainly transition metal complexes or halogen-substituted compounds (J.Am.Chem.Soc., 2020, 142, 14733-14742). In this type of compound, the presence of heavy atoms can effectively prolong the excited state lifetime of the compound, improve the intersystem crossing efficiency of the compound, and thus facilitate energy transfer in the catalytic polymerization process. However, photocatalysts containing heavy atoms have the disadvantages of high synthesis cost, high biological toxicity, and poor photostability. Therefore, it is particularly important to develop photocatalysts without heavy atoms.

[0003] Recently, some studies have shown that by constructing electron donor-acceptor compounds, intersystem crossing can be promoted through spin-orbit electron transfer to produce triplet states with long excited state lifetimes, which may be promising as new and efficient organic photocatalysts. However, the molecular structures of the electron donor-acceptor photocatalysts reported so far all rely on orthorhombic conformations, which has significant limitations in molecular design (Chem., 2019, 5, 138-155.). In addition, the excited state reduction ability of the catalysts reported so far for photopolymerization is generally weak, and they cannot directly transfer electrons to the photoinitiator. When performing actual polymerization, it is inevitable to add an organic base or a co-initiator. However, the presence of an organic base increases biological toxicity, and the presence of a co-initiator will lead to increased costs.

[0004] Patent application content

[0005] In order to overcome one of the problems existing in the above-mentioned prior art, the primary purpose of this patent application is to provide a photocatalyst with spatial charge transfer properties. This type of photocatalyst can simultaneously have the characteristics of long excited state lifetime and strong excited state reduction ability by constructing a non-orthogonal conformation with spatial charge transfer; the development of this type of photocatalyst effectively solves the current problems of high synthesis cost and the need to add co-initiators.

[0006] Another object of this patent application is to provide a method for preparing the above-mentioned photocatalyst with space charge transfer properties.

[0007] Another object of the present patent application is to provide the application of the above-mentioned photocatalyst having space charge transfer properties.

[0008] The above-mentioned purpose of this patent application is achieved through the following technical solutions:

[0009] A photocatalyst having a space charge transfer property, wherein the photocatalyst having a space charge transfer property has one of the following molecular structures:

[0010]

[0011] Wherein, R represents a functional group such as carbazole, tert-butylcarbazole, dibenzothiophene, dibenzofuran, phenothiazine, phenoxazine, acridine, diphenylamine, triphenylamine, thioxanthone, xanthone, naphthalene, anthracene, perylene, pyrene, etc.

[0012] This patent application also provides a method for preparing the above-mentioned photocatalyst having space charge transfer properties, comprising the following steps:

[0013] S1.S1. After dissolving 4-bromo-1,8-naphthalene dicarboxylic anhydride in an organic solvent, n-butylamine was slowly added dropwise under nitrogen, and the mixture was heated under reflux for 12 h. After post-treatment and purification, 4-bromo-1,8-naphthalene diamide was obtained;

[0014] S2. Under nitrogen atmosphere, 4-bromo-1,8-naphthalene diamide was dissolved in an organic solvent, and a boric acid raw material containing an electron donor was added. The mixture was heated under reflux under alkaline conditions with palladium catalysis for 8 hours, and the final product was obtained after post-treatment and purification.

[0015] Preferably, in step S1, the organic solvent is ethanol and the heating temperature is 80 degrees Celsius.

[0016] Preferably, in step S2, the organic solvent is toluene, ethanol and water, the catalyst is tetrakis(triphenylphosphine)palladium, the base is potassium carbonate, and the heating temperature is 90 degrees Celsius.

[0017] Preferably, in step S1, the purification is silica gel chromatography purification, and the developing solvent is petroleum ether and dichloromethane, and the volume ratio of the two is 1:1.

[0018] Preferably, in step S2, the purification is silica gel chromatography purification, and the developing solvent is petroleum ether and dichloromethane, and the volume ratio of the two is 1:1.

[0019] This patent application also provides the application of the above-mentioned photocatalyst with spatial charge transfer properties in photopolymerization or photolithography, wherein the photocatalyst is combined with a photoinitiator and an acrylic resin monomer to form a polymer system.

[0020] Preferably, in the application of the above-mentioned photocatalyst having space charge transfer properties in photopolymerization, the photocatalyst is combined with a photoinitiator and an acrylic resin monomer to form a polymer system.

[0021] More preferably, the molar ratio of the photocatalyst:photoinitiator:acrylic resin in the polymer system is 0.01:10:100 to 0.001:1:1000.

[0022] Compared with the prior art, the beneficial effects of this patent application are:

[0023] The photocatalyst synthesized in this patent application exhibits spatial charge transfer properties. Compared to traditional chemical bond electron transfer compounds, it has a large steric hindrance, which helps suppress energy losses caused by the compound's excited state vibration / rotation. Furthermore, the spatial charge transfer property facilitates intersystem crossing of molecules, resulting in the formation of triplet states with long excited state lifetimes. This, in turn, facilitates energy and electron transfer processes in subsequent photopolymerization / photolithography processes, improving polymerization and photolithography efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is the hydrogen nuclear magnetic resonance spectrum of the photocatalyst 4NI-1 prepared in Example 1 of this patent application.

[0025] Figure 2 This is the carbon nuclear magnetic resonance spectrum of the photocatalyst 4NI-1 prepared in Example 1 of this patent application.

[0026] Figure 3 This is the mass spectrum of the photocatalyst 4NI-1 prepared in Example 1 of this patent application.

[0027] Figure 4 This is the hydrogen nuclear magnetic resonance spectrum of the photocatalyst 3NI-1 prepared in Example 2 of this patent application.

[0028] Figure 5 This is the carbon nuclear magnetic resonance spectrum of the photocatalyst 3NI-1 prepared in Example 2 of this patent application.

[0029] Figure 6 This is the mass spectrum of the photocatalyst 3NI-1 prepared in Example 2 of this patent application.

[0030] Figure 7 This is the UV-visible absorption spectrum of the photocatalyst 4NI-1 prepared in Example 1 of this patent application.

[0031] Figure 8 This is the fluorescence emission spectrum of the photocatalyst 4NI-1 prepared in Example 1 of this patent application.

[0032] Figure 9 This is the UV-visible absorption spectrum of the photocatalyst 3NI-1 prepared in Example 2 of this patent application.

[0033] Figure 10This is the fluorescence emission spectrum of the photocatalyst 3NI-1 prepared in Example 2 of this patent application.

[0034] Figure 11 This is the excited state lifetime spectrum of the photocatalyst 4NI-1 prepared in Example 1 of this patent application.

[0035] Figure 12 This is the excited state lifetime spectrum of the photocatalyst 3NI-1 prepared in Example 2 of this patent application.

[0036] Figure 13 This is a photolithography example diagram of the photocatalyst 4NI-1 prepared in Example 1 of this patent application. DETAILED DESCRIPTION

[0037] The embodiments of the present application will be described in detail below with reference to the examples, but it will be understood by those skilled in the art that the following examples are only used to illustrate the present application and should not be considered as limiting the scope of the present application. Where specific conditions are not specified in the examples, they are carried out according to conventional conditions or the conditions recommended by the manufacturer. Where the manufacturers of the reagents or instruments are not specified, they are all conventional products that can be purchased commercially.

[0038] It should be noted that:

[0039] In this patent application, unless otherwise specified, all the embodiments and preferred implementation methods mentioned herein can be combined with each other to form a new technical solution.

[0040] In this patent application, unless otherwise specified, percentages (%) or parts refer to percentages or parts by weight relative to the composition.

[0041] In this patent application, unless otherwise specified, the components involved or their preferred components can be combined with each other to form a new technical solution.

[0042] In this patent application, unless otherwise specified, the numerical range "a-b" is an abbreviation for any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "1-5" indicates that all real numbers between "1-5" are listed herein, and "1-5" is merely an abbreviation for these numerical combinations.

[0043] The "range" disclosed in this patent application is in the form of lower limit and upper limit, which can be one or more lower limits, and one or more upper limits, respectively.

[0044] In this patent application, unless otherwise stated, each reaction or operation step can be carried out sequentially or in accordance with the sequence. Preferably, the reaction method herein is carried out sequentially.

[0045] Unless otherwise indicated, the professional and scientific terms used herein are the same as those familiar to those skilled in the art. In addition, any method or material similar or equivalent to the described content may also be applied to this patent application.

[0046] This patent application provides a photocatalyst with space charge transfer properties, wherein the photocatalyst with space charge transfer properties has one of the following molecular structures:

[0047]

[0048] Among them, R represents a functional group such as carbazole, tert-butylcarbazole, dibenzothiophene, dibenzofuran, phenothiazine, phenoxazine, acridine, diphenylamine, triphenylamine, benzene, naphthalene, anthracene, perylene, pyrene, N,N-dimethylaniline, and N,N-diethylaniline.

[0049] In some preferred embodiments, the photocatalyst having space charge transfer properties preferably has one of the following molecular structures:

[0050]

[0051]

[0052] This patent application also provides a method for preparing the above-mentioned photocatalyst having space charge transfer properties, comprising the following steps:

[0053] S1. After dissolving 4-bromo-1,8-naphthalene dicarboxylic anhydride in an organic solvent, n-butylamine was slowly added dropwise under nitrogen conditions, heated under reflux for 12 h, and post-processed and purified to obtain 4-bromo-1,8-naphthalene diamide;

[0054] S2. Under nitrogen atmosphere, 4-bromo-1,8-naphthalene diamide was dissolved in an organic solvent, and a boric acid raw material containing an electron donor was added. The mixture was heated under reflux under alkaline conditions with palladium catalysis for 8 hours, and the final product was obtained after post-treatment and purification.

[0055] The photocatalysts disclosed in this patent application are characterized by the attachment of different electron donors, R, and naphthalene imide, respectively, to the ortho position of the benzene ring. The close distance between the donor and acceptor planes enables both photocatalysts to exhibit space charge transfer properties, thereby promoting intersystem crossing and obtaining a triplet state with a long excited-state lifetime. The development of this type of photocatalyst effectively addresses the problems of existing catalysts, such as high synthesis cost, poor photostability, and short excited-state lifetime.

[0056] The photocatalyst in this patent application has the property of spatial charge transfer. Compared with traditional chemical bond electron transfer compounds, it has the characteristic of large steric hindrance, which is beneficial for suppressing the energy loss caused by the vibration / rotation of the compound's excited state (Nat. Mater., 2020, 19, 1332-1338). In addition, the property of spatial charge transfer is conducive to the occurrence of intersystem crossing of molecules, obtaining a triplet state with a long excited state lifetime, which in turn facilitates the energy transfer and electron transfer process in the subsequent photopolymerization / photolithography process, improving the polymerization and photolithography efficiency.

[0057] In the method for preparing the photocatalyst with space charge transfer properties described in this patent application, in step S1, the organic solvent is ethanol and the heating temperature is 80 degrees Celsius.

[0058] In the preparation method of the photocatalyst with space charge transfer properties described in this patent application, in step S2, the organic solvent is toluene, ethanol and water, the catalyst is tetrakis(triphenylphosphine)palladium, the base is potassium carbonate, and the heating temperature is 90 degrees Celsius.

[0059] In the preparation method of the photocatalyst with space charge transfer properties described in this patent application, in step S1, the purification is silica gel chromatography purification, the developing solvent volume is petroleum ether and dichloromethane, and the volume ratio of the two is 1:1.

[0060] In the preparation method of the photocatalyst with space charge transfer properties described in this patent application, in step S2, the purification is silica gel chromatography purification, the developing solvent volume is petroleum ether and dichloromethane, and the volume ratio of the two is 1:1.

[0061] This patent application also provides the application of the above-mentioned photocatalyst with spatial charge transfer properties in photopolymerization or photolithography.

[0062] In some preferred embodiments, the photocatalyst having space charge transfer properties is used in photopolymerization or photolithography, and the photocatalyst is combined with a photoinitiator and an acrylic resin monomer to form a polymer system.

[0063] In some more preferred embodiments, the molar ratio of the photocatalyst: photoinitiator: acrylic resin in the polymer system is 0.01:10:100 to 0.001:1:1000.

[0064] The following is a detailed description of the preparation method of the photocatalyst with space charge transfer properties in this patent application using specific examples.

[0065] Example 1 Preparation of Photocatalyst 4NI-1 in Formula (I)

[0066] The chemical reaction equation involved in this embodiment is as follows:

[0067]

[0068] The specific implementation process of step a above, i.e. step S1, is as follows:

[0069] 4Br-NO (1.00 g, 3.61 mmol) was dissolved in a two-necked flask containing 50 ml of anhydrous ethanol. Then, under a nitrogen atmosphere, n-butylamine (0.63 mL, 5.41 mmol) was slowly added dropwise to the reaction solution. The mixture was stirred and heated to 80 degrees Celsius under reflux. After reacting for 12 hours, the reaction solution was cooled to room temperature and the solvent was rotary evaporated. Extraction was repeated three times with dichloromethane and water. After drying over anhydrous sodium sulfate, the crude product was purified on a silica gel column with a polarity ratio of dichloromethane:petroleum ether = 1:1 to obtain 611 mg of the product. The yield was 51%. The obtained product was subjected to H NMR spectroscopy, and the results are as follows: 1 H NMR (400 MHz, CDCl3) δ8.65 (d, J = 7.3 Hz, 1H), 8.55 (d, J = 8.5 Hz, 1H), 8.40 (d, J = 7.8 Hz, 1H), 8.03 (d, J = 7.8 Hz, 1H), 7.84 (t, J = 7.9 Hz, 1H), 4.24-4.11 (m, 2H), 1.82-1.65 (m, 2H), 1.52-1.39 (m, 1H), 0.98 (t, J = 7.3 Hz, 3H), indicating that the obtained product 4Br-NI has a structure as shown in the structure in the above reaction equation.

[0070] The specific implementation process of step b above, i.e. step S2, is as follows:

[0071] 4Br-NI (100 mg, 0.30 mmol), 2-(9H-carbazol-9-yl)phenylboronic acid (95 mg, 0.33 mmol), and potassium carbonate (165 mg, 1.2 mmol) were dissolved in a two-necked flask containing a mixed solvent of toluene (20 mL), ethanol (20 mL), and water (10 mL). Under a nitrogen atmosphere, the atmosphere was replaced three times under negative pressure. Tetrakis(triphenylphosphine)palladium (17 mg, 0.015 mmol) was quickly added. After repeated replacement of nitrogen three times, the reaction solution was heated to 90°C for 8 hours. The reaction solution was cooled to room temperature and rotary evaporated to remove the solvent. The solution was then extracted three times with dichloromethane and water, dried over anhydrous sodium sulfate, and filtered. The crude product obtained after rotary evaporation was further purified by silica gel chromatography with a developing solvent of petroleum ether:dichloromethane = 1:1. The resulting yellow product was dried in a vacuum oven at 60°C for 24 hours to obtain 90 mg of the product with a yield of 61%.

[0072] Example 2 Preparation of Photocatalyst 3NI-1 in Formula (II)

[0073] The chemical reaction equation involved in this embodiment is as follows:

[0074]

[0075] The specific implementation process of step (a) above is as follows:

[0076] The raw material NO (5.00 g, 25.2 mmol) was dissolved in 100 mL of concentrated nitric acid and heated to 50°C. Bromine (0.97 mL, 18.9 mmol) was then slowly added dropwise over 10 minutes. The brown reaction solution was then allowed to react at 50°C for 4 hours, then cooled to 20°C. Water was then added and filtered to obtain 1.5 g of a white product, 3Br-NO. The product was not further purified.

[0077] The specific implementation process of step (b) above is as follows:

[0078] 3Br-NO (1.00 g, 3.61 mmol) was dissolved in 50 ml of anhydrous ethanol in a two-necked flask. Then, under a nitrogen atmosphere, n-butylamine (0.63 mL, 5.41 mmol) was slowly added dropwise to the reaction mixture. The mixture was stirred and heated to 80°C under reflux. After 12 hours of reaction, the reaction mixture was cooled to room temperature and the solvent was rotary evaporated. Extraction was repeated three times with dichloromethane and water. After drying over anhydrous sodium sulfate, the crude product was purified on a silica gel column with a polarity ratio of dichloromethane:petroleum ether (1:1) to obtain 554 mg of 3Br-NI in a 42% yield.

[0079] The specific implementation process of step (c) above is as follows:

[0080] 3Br-NI (100 mg, 0.30 mmol), 2-(9H-carbazol-9-yl)phenylboronic acid (130 mg, 0.45 mmol), and potassium carbonate (165 mg, 1.2 mmol) were dissolved in a two-necked flask containing a mixed solvent of toluene (10 mL), ethanol (10 mL), and water (5 mL). Under a nitrogen atmosphere, the atmosphere was replaced three times under negative pressure. Tetrakis(triphenylphosphine)palladium (17 mg, 0.015 mmol) was quickly added. After repeated replacement of nitrogen three times, the reaction solution was heated to 90°C for 8 hours. The reaction solution was cooled to room temperature and rotary evaporated to remove the solvent. The solution was then extracted three times with dichloromethane and water, dried over anhydrous sodium sulfate, and filtered. The crude product obtained after rotary evaporation was further purified by silica gel chromatography with a developing solvent of petroleum ether:dichloromethane = 1:1. The yellow product was dried in a vacuum oven at 60°C for 24 hours to obtain 99 mg of the product with a yield of 67%.

[0081] Performance Testing

[0082] The photocatalysts 4NI-1 and 3NI-1 prepared in Example 1 and Example 2 were characterized and tested for performance. Figures 1 to 9 shown.

[0083] The test method is as follows:

[0084] Compound structure detection: A Bruker 400 MHz superconducting nuclear magnetic resonance spectrometer was used, and the solvent was deuterated chloroform;

[0085] Mass spectrometry detection: 4NI-1 and 3NI-1 prepared in Example 1-2 were dissolved in dichloromethane to prepare a solution with a concentration of 1 mg / mL, and mass spectrometry was performed using a liquid chromatography-mass spectrometer LCMS-2020.

[0086] UV absorption spectrum detection: Shimadzu UV-visible spectrophotometer UV-2700 was used with a scanning range of 300–500 nm.

[0087] Emission spectrum detection: using a steady-state / transient fluorescence spectrometer (FLS980), with an excitation wavelength of 310 nm,

[0088] The test temperature was 300K under nitrogen protection.

[0089] The test results are as follows:

[0090] The molecular hydrogen spectrum of the photocatalyst 4NI-1 prepared in Example 1 is as follows: Figure 1 As shown, it can be seen that:

[0091] 1 H NMR (400MHz, CDCl3) δ8.44(d,J=6.7,1H),8.21(d,J=8.1,1H),8.13(d,J=7.2,1H),7.93(d,J=7.3,1H),7.84(s,1H),7.70(m,4H),7.50(t,J=7. 6,1H),7.34(d,J=7.1,2H),7.19(m,,2H),6.97(d,J=15.0,3H),4.17–3 .95(m,2H),1.61(d,J=7.9,2H),1.48–1.35(m,2H),0.93(t,J=6.8,3H). The peaks of the hydrogen nuclear magnetic resonance spectrum correspond one-to-one to the target product, and the quantity is reasonable, indicating that the photocatalyst 4NI-1 is prepared in Example 1, and the compound has a simple structure and high purity.

[0092] The carbon NMR spectrum of the photocatalyst 4NI-1 prepared in Example 1 is as follows: Figure 2 As shown, it can be seen that:

[0093] 13C NMR (100MHz, CDCl3) δ164.12,163.86,142.72,141.47,140.58,138.01,136.33,132.88,131.79 ,130.92,130.51,130.28,130.10,129.63,129.06,128.62,128.24,128.15,127.49,126.40,125 .87,125.34,123.07,123.01,122.75,121.88,120.28,120.14,119.90,119.60,109.85,109.58,40.20,30.13,20.36,13.83. The molecular carbon spectrum peaks can correspond one to one with the target product, and the quantity is reasonable; this shows that the photocatalyst 4NI-1 is prepared in Example 1, and the compound has a single structure and high purity.

[0094] Figure 3 The HRMS graph (i.e., mass spectrum) of the photocatalyst 4NI-1 prepared in Example 1 is shown. After calculation, the theoretical value of the photocatalyst 4NI-1 with space charge transfer properties is C34H26N2O2[(M+H) + ]:495.20670. Mass spectrometry revealed an actual m / z value of 495.20692, consistent with the molecular weight of the synthesized photocatalyst 4NI-1. This further demonstrates that the compound prepared in Example 1 is photocatalyst 4NI-1, which exhibits space charge transfer properties and possesses a simple structure and high purity. Combined with the above NMR and mass spectrometry results, it is clear that the product prepared in Example 1 is photocatalyst 4NI-1.

[0095] like Figure 4 As shown in FIG, the H NMR spectrum of the photocatalyst 3NI-1 with space charge transfer properties prepared in Example 2. It can be seen that:

[0096] 1H NMR (400MHz, CDCl3) δ8.53(s,1H),8.37(d,J=8.0Hz,1H),7.97(d,J=8.0Hz,2H),7.80(d,J=8.0Hz,1H),7.7 -7.64(m,2H),7.6 -7.53(m,2H),7.51-7.43(m,2H),7.29(d,J=8.0Hz,2H),7.16-7.10(m,4H), 4.11-4.04(m,2H),1.68-1.61(m,2H),1.49-1.35(m,2H),1.05-0.89(m,3H). The peaks of the hydrogen nuclear magnetic resonance spectrum correspond one-to-one to the target product, and the number is reasonable, indicating that the photocatalyst 3NI-1 was prepared in Example 2, and the compound has a simple structure and high purity.

[0097] The carbon NMR spectrum of the photocatalyst 3NI-1 prepared in Example 2 is as follows: Figure 5 As shown, it can be seen that:

[0098] 13 C NMR (150 MHz, CDCl3) δ162.91, 162.74, 140.20, 138.36, 136.15, 134.04, 132.65, 131.18, 130.66, 130.28, 130.09, 129.8, 129.26, 128.87, 128.28, 125.92, 125.78, 124.94, 122.08, 121.79, 121.25, 119.16, 118.78, 108.67, 39.11, 29.11, 19.30, 12.81. The molecular carbon spectrum peaks correspond one-to-one to the target product, and the quantity is reasonable, indicating that the photocatalyst 3NI-1 prepared in Example 2 has a single structure and high purity.

[0099] Figure 6 This is the HRMS graph (i.e., mass spectrum) of the photocatalyst 3NI-1 prepared in Example 2. After calculation, the theoretical value of the photocatalyst 3NI-1 with space charge transfer properties is: C 34 H 26 N2O2[(M+H) + ]:495.20670, while the actual m / z value determined by mass spectrometry was 495.20692, consistent with the relative molecular mass of the synthesized photocatalyst 3NI-1. This further demonstrates that the compound prepared in Example 2 is photocatalyst 3NI-1 with space charge transfer properties, a simple structure, and high purity. Combined with the above NMR and mass spectrometry results, it is clear that the product prepared in Example 2 is photocatalyst 3NI-1.

[0100] Using Shimadzu UV-2700 UV-visible spectrophotometer, 4NI-1 and 3NI-1 prepared in Examples 1 and 2 were dissolved in dichloromethane solution to prepare 1×10 -3 mol / L stock solution, diluted to 1×10 -5 mol / L for testing.

[0101] Fluorescence emission spectrometry: FLS980 fluorescence instrument, 4NI-1 and 3NI-1 prepared in Example were dissolved in dichloromethane solution to prepare 1×10 -3 mol / L stock solution, when testing, dilute to 1×10 -5 mol / L.

[0102] Figure 7 Including the 4NI-1 prepared in Example 1 at 1×10 -5 mol / L in acetonitrile. Figure 7 It can be seen that 4NI-1 has a high molar extinction coefficient (ε>10 ^4 M -1 cm -1 ), and the absorption is located in the ultraviolet band.

[0103] Figure 8 Including the 4NI-1 prepared in Example 1 at 1×10 -5 mol / L fluorescence emission spectrum in acetonitrile. Figure 8 It can be seen that the emission spectrum of 4NI-1 is broad and the fluorescence emission is weak, showing the properties of space charge transfer.

[0104] Figure 9 Including 3NI-1 prepared in Example 2 at 1×10 -5 mol / L in acetonitrile. Figure 9 It can be seen that 3NI-1 has a high molar extinction coefficient (ε>10 ^4 M -1 cm -1 ), and the absorption is located in the ultraviolet band.

[0105] Figure 10 Including 3NI-1 prepared in Example 2 at 1×10 -5 mol / L fluorescence emission spectrum in acetonitrile. Figure 8 It can be seen that the emission spectrum of 4NI-1 is broad and the fluorescence emission is weak, showing the properties of space charge transfer.

[0106] Figure 11 Nanosecond transient absorption spectrum of photocatalyst 4NI-1 prepared in Example 1 of this patent application. Figure 9 It can be seen that 4NI-1 has the characteristic of long excited state lifetime.

[0107] Figure 12 The excited state lifetime spectrum of the photocatalyst 3NI-1 prepared in Example 2 of this patent application is shown in FIG. Figure 12 It can be seen that the 3NI-1 catalyst also has the characteristics of long excited state lifetime.

[0108] Photopolymerization Application Examples

[0109] The above-mentioned photocatalyst is combined with a photoinitiator and an acrylic resin monomer to form a polymer system.

[0110] The molar ratio of photocatalyst: photoinitiator: acrylic resin in the above polymer system is 0.01:10:100 to 0.001:1:1000

[0111] The characteristics of the above-mentioned photopolymerization system are that it can be -2) After irradiation for 30 seconds under the conditions of , the monomer conversion rate can exceed 80%, and polymerization can occur without the presence of additional electron donors, indicating that the photocatalyst has strong excited state reduction ability.

[0112] Lithography applications

[0113] The above-mentioned polymer system is formed into a photoresist, and after spin coating, pre-baking, exposure and development, a high-resolution and clear pattern can be obtained, such as Figure 13 As shown, it can be shown that this type of photopolymerization system has important application value in practical lithography.

[0114] The photocatalysts with spatial charge transfer properties proposed in this patent application are based on the construction of non-orthogonal naphthalimide-based photocatalysts with spatial charge transfer. They simultaneously possess high intersystem crossing efficiency, long excited-state lifetime, and strong excited-state reduction ability. The development of this type of photocatalyst effectively addresses the current issues of high synthesis costs and the need for the addition of coinitiators.

[0115] The photocatalyst disclosed in this patent application exhibits spatial charge transfer properties. Compared to conventional chemical bond electron transfer compounds, it possesses significant steric hindrance, which helps suppress energy losses caused by excited-state vibrations and rotations. Furthermore, this spatial charge transfer property facilitates intersystem crossing of molecules, resulting in the formation of triplet states with long excited-state lifetimes. This, in turn, facilitates energy and electron transfer in subsequent photopolymerization and photolithography processes, improving polymerization and photolithography efficiency.

[0116] In the description of this specification, reference to the terms "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of this patent application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any appropriate manner in any one or more embodiments or examples.

[0117] Although several embodiments of the present patent application have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the present patent application, and the scope of the present patent application is defined by the claims and their equivalents.

Claims

1. A photocatalyst having space charge transfer properties, characterized in that: The photocatalyst having space charge transfer properties has one of the following molecular structures: Wherein, R represents carbazole, tert-butylcarbazole, dibenzothiophene, or dibenzofuran.

2. The photocatalyst having space charge transfer properties according to claim 1, characterized in that: The photocatalyst having space charge transfer properties has one of the following molecular structures:

3. The method for preparing the photocatalyst having space charge transfer properties according to claim 2, characterized in that: The following steps are involved: S1. After dissolving 4-bromo-1,8-naphthalene dicarboxylic anhydride in an organic solvent, n-butylamine was slowly added dropwise under nitrogen, heated under reflux for 12 h, and post-processed and purified to obtain 4-bromo-1,8-naphthalene diamide; S2. Under nitrogen atmosphere, 4-bromo-1,8-naphthalene diamide was dissolved in an organic solvent, and a boric acid raw material containing an electron donor was added. The mixture was heated under reflux under alkaline conditions with palladium catalysis for 8 hours, and the final product was obtained after post-treatment and purification.

4. The method for preparing a photocatalyst having space charge transfer properties according to claim 3, characterized in that: In step S1, the organic solvent is ethanol, and the heating temperature is 80 degrees Celsius.

5. The method for preparing a photocatalyst having space charge transfer properties according to claim 3, characterized in that: In step S2, the organic solvent is toluene, ethanol and water, the catalyst is tetrakis(triphenylphosphine)palladium, the base is potassium carbonate, and the heating temperature is 90 degrees Celsius.

6. The method for preparing a photocatalyst having space charge transfer properties according to claim 4, characterized in that: In step S1, the purification is silica gel chromatography purification, and the developing solvent is petroleum ether and dichloromethane, and the volume ratio of the two is 1:

1.

7. The method for preparing a photocatalyst having space charge transfer properties according to claim 4, characterized in that: In step S2, the purification is silica gel chromatography purification, and the developing solvent is petroleum ether and dichloromethane, and the volume ratio of the two is 1:

1.

8. Use of the photocatalyst with space charge transfer properties according to any one of claims 1 or 2 in photopolymerization or photolithography.

9. Use of the photocatalyst having space charge transfer properties in photopolymerization according to claim 8, characterized in that: The photocatalyst, photoinitiator and acrylic resin monomer are combined to form a polymer system.

10. Use of the photocatalyst with space charge transfer properties in photopolymerization according to claim 9, characterized in that: The molar ratio of the photocatalyst: the photoinitiator: the acrylic resin in the polymer system is 0.01:10:100 to 0.001:1:1000.

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