A nitrogen-containing heterocyclic biphenyl diamine compound and a preparation method and application thereof

Abstract

The application belongs to the field of new materials, and more particularly relates to a nitrogen-containing heterocyclic biphenyldiamine compound and a preparation method and application thereof. A structural general formula is shown in formula I or formula II: wherein R is Y is one of C, N, O, S, C=O and S=O. A PI film prepared by using the compound can realize low thermal expansion coefficient and good heat resistance while maintaining good mechanical properties and optical properties.

Description

Technical Field

[0001] This invention belongs to the field of new materials, and more specifically, relates to a nitrogen-containing heterocyclic biphenyl diamine compound, its preparation method and application. Background Technology

[0002] In recent years, organic light-emitting diode (OLED) displays have flourished due to their advantages such as high brightness, wide viewing angle, fast response, and ultra-thinness. Organic electroluminescent materials, with their flexible, foldable, and even stretchable properties, are suitable for fabricating organic light-emitting devices on flexible polymer substrates. Therefore, the use of polymer thin films as substrates for flexible OLED displays has attracted widespread interest from researchers. Currently, the main research focus on flexible substrates is on high-temperature resistant polymer thin films, including polyimide (PI), polyethylene naphthalate (PEN), polyethylene terephthalate (PET), and polycarbonate (PC). Among these, PI is considered a very promising polymer thin film material due to its excellent thermal, mechanical, and dielectric properties.

[0003] However, there are still some challenges in using polyimide substrates for flexible displays, especially in the field of foldable and rollable displays. An ideal PI substrate should have the following characteristics: (1) extremely high thermal stability during the fabrication of low-temperature polycrystalline silicon thin-film transistors (TFTs), capable of withstanding high process temperatures (>450℃), thus avoiding contamination of OLED devices by volatile substances generated from the thermal decomposition of the PI substrate; (2) low coefficient of thermal expansion (CTE: 0-5ppm K). -1(3) Sufficient flexibility to meet the bending requirements of flexible OLED displays. However, it is worth noting that improving high-temperature resistance or reducing CTE often sacrifices the flexibility of the PI substrate. In addition, it is very difficult to systematically adjust the thermal dimensional stability of the PI substrate to achieve better compatibility between the substrate and different inorganic or metal laminates used as buffer layers, barrier layers, TFTs or flexible electrodes. Studies have shown that introducing structural units with better linearity and rigidity into the PI backbone or forming hydrogen bonds between molecular chains are effective ways to improve the thermal dimensional stability of PI films. BPDA / PDA has high heat resistance and low in-plane CTE value (10-15ppm / K), but the CTE value still cannot meet the requirements of flexible OLEDs for polymer substrates. Due to the highly ordered arrangement of molecular chains, PMDA / PDA has a much lower CTE than BPDA / PDA. However, PMDA / PDA films are prone to brittleness due to poor entanglement between rod-shaped molecular chains, making it impossible to fabricate self-supporting films. Therefore, many researchers have focused on the construction of hydrogen bonds between PI molecular chains, such as introducing imidazole or amide groups into the main chain structure. This hydrogen bonding inhibits molecular mobility and reduces free volume, effectively lowering the CTE value, even leading to negative CTE values. These PI films maintain low CTE values ​​of 0-5 ppm / K, but due to the high strength of hydrogen bonds between PI molecular chains, the elongation at break is often less than 10%, and these films are yellow and opaque, with a transmittance at 400 nm often less than 1%. Therefore, these films do not meet the requirements for flexible OLED display substrate materials. Although various methods have been used to modify traditional PI to improve its transmittance, these methods focus on improving optical performance while neglecting the thermal properties of PI. These transparent PI films often have high CTE values ​​(>20 ppm / K), making them unsuitable for use as flexible substrate materials.

[0004] Therefore, finding an ideal flexible transparent substrate material with high thermal stability, low CTE value, and excellent mechanical properties has always been a hot topic in materials science. Given this background and market demand, there is an urgent need to develop a new type of flexible substrate material that not only meets optical performance standards but also possesses excellent thermal properties and dimensional stability to meet increasingly stringent application requirements. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the purpose of this invention is to provide a novel polyimide film. While retaining the advantages of traditional PI films, this film achieves a combination of low coefficient of thermal expansion (CTE) and high mechanical strength through unique molecular design. It aims to solve the technical problem that existing polyimide films cannot simultaneously achieve thermal stability, mechanical properties and optical properties.

[0006] To achieve the above objectives, the present invention provides a nitrogen-containing heterocyclic benzidine compound, the general structural formula of which is shown in Formula I or Formula II:

[0007]

[0008] Where R is Y is one of C, N, O, S, C=O, and S=O.

[0009] According to another aspect of the present invention, a method for preparing a nitrogen-containing heterocyclic benzidine compound of formula I is provided, characterized by comprising the following steps:

[0010] (1) Synthesis of nitrogen-containing heterocyclic diboronic ester compounds:

[0011]

[0012] Where X is a halogen element, Y is one of C, N, O, S, C=O, S=O; A is one of Pd(pph3)2Cl2, Pd(dppf)Cl2, Pd(OAc)2, Pd(PPh3)4; and B is one of K2CO3, KOAc, K3PO4.

[0013] (2) Synthesis of nitrogen-containing heterocyclic diamine compounds:

[0014]

[0015] Where X is a halogen element, C is one of Pd(pph3)2Cl2, Pd(dppf)Cl2, Pd(OAc)2, Pd(PPh3)4; and D is one of K2CO3, KOAc, K3PO4.

[0016] According to another aspect of the invention, an application of the aforementioned nitrogen-containing heterocyclic biphenyl diamine compound is provided for the preparation of polyimides.

[0017] According to another aspect of the invention, a polyimide film is provided containing the aforementioned nitrogen-containing heterocyclic biphenyl diamine compound.

[0018] In summary, compared with the prior art, the above-described technical solutions conceived by this invention mainly possess the following technical advantages:

[0019] (1) This invention provides a nitrogen-containing heterocyclic benzidine compound for preparing novel polyimide films. PI films prepared using this compound can achieve a low coefficient of thermal expansion and good heat resistance while maintaining good optical and mechanical properties. The core of this invention lies in designing and synthesizing a novel diamine monomer containing hydrogen bond donor groups, and this hydrogen bond donor is heat-resistant. The coefficient of thermal expansion of the polyimide film can be controlled by adjusting the hydrogen bond content.

[0020] (2) In this invention, a novel polyimide (PI) film was successfully developed by utilizing hydrogen bonding. This film exhibits a significantly improved elastic modulus (i.e., strength) due to its unique chemical structure design, which allows hydrogen bonding and the rigidity of the benzene ring to interact effectively. The polyimide film obtained through this method exhibits superior mechanical properties, making it suitable for applications requiring high strength and durability.

[0021] (3) This invention proposes a unique polymer structure design in which the nitrogen-containing heterocyclic ring and the attached benzene ring are coplanar, giving the polymer film good dimensional stability and heat resistance. The side benzene rings are connected to the central benzene ring and have a high degree of linear orientation, giving the polymer both flexibility and high dimensional stability. Due to its uniqueness, the polymer structure of this invention has potential application value for the development of high-performance materials and is suitable for various industrial fields, including but not limited to films, coatings, fibers, and composite materials.

[0022] (4) In this invention, hydrogen bonds are introduced to promote a more ordered stacking of molecular chains, which significantly enhances the interaction forces between polymer molecular chains. This enhanced interaction force leads to an increase in the molecular chain packing density and effectively restricts the degree of freedom of movement of polymer chains within the material. Therefore, the resulting modified polymer film exhibits superior dimensional stability compared to the original film, thereby achieving a low coefficient of thermal expansion (CTE) for the PI film and enhancing the dimensional stability of the material under temperature changes.

[0023] (5) The dimensional stability and flexibility of polyimide films can be further controlled by adjusting the amount of nitrogen-containing heterocyclic diamine monomers added.

[0024] (6) This invention provides a simple and effective method for preparing nitrogen-containing heterocyclic diamine compounds. The reaction steps are simple, the raw materials are readily available and the cost is low.

[0025] (7) This invention provides a new option for the manufacture of flexible OLED substrate materials.

[0026] (8) The nitrogen-containing heterocyclic diamine compounds of the present invention were used to prepare polyimide films. According to the test, the PI film prepared in the preferred embodiment had a glass transition temperature as high as 380°C, a coefficient of thermal expansion (CTE) value as low as 7.2 ppm / K, an elastic modulus as high as 6.7 GPa, and an elongation at break as high as 28%. Compared with the PI film without the addition of the compounds of the present invention, the CTE value of the PI film of the present invention was reduced by 41.46%, the elastic modulus was increased by 17.54%, and the elongation at break was increased by 418.51%.

[0027] (9) The PI film prepared using the nitrogen-containing heterocyclic diamine compound of the present invention also has excellent dimensional stability (CTE < 10 ppm / K) and thermal stability (T). d1 With its high temperature (>500℃) and flexibility (elongation at break >10%), it is adapted to specific application environments, such as high-temperature operation and flexible optoelectronic devices, thereby meeting the increasingly diverse application needs. Attached Figure Description

[0028] Figure 1 This is the 1H NMR spectrum of 2,7-bis[(2-trifluoromethyl-4-amino)phenyl]-9-hydro-carbazole, the product synthesized in the second step of Example 1.

[0029] Figure 2 This is the 1H NMR spectrum of 3,6-bis[(2-trifluoromethyl-4-amino)phenyl]-9-hydro-carbazole, the product synthesized in the second step of Example 2.

[0030] Figure 3 This is the 1H NMR spectrum of 2,8-bis[(2-trifluoromethyl-4-amino)phenyl]-5,10-dihydrophenazine, the product synthesized in the second step of Example 5.

[0031] Figure 4 This is the infrared spectrum of the PAA solution synthesized in Example 1.

[0032] Figure 5 This is the infrared spectrum of the PAA solution synthesized in Example 2.

[0033] Figure 6 This is the infrared spectrum of the polyimide film prepared using the PAA solution from Example 1.

[0034] Figure 7 This is the infrared spectrum of the polyimide film prepared using the PAA solution in Example 2.

[0035] Figure 8 This is the infrared spectrum of the polyimide film prepared using the PAA solution in Example 3.

[0036] Figure 9This is the infrared spectrum of the polyimide film prepared using the PAA solution in Example 4.

[0037] Figure 10 The mechanical test curves are those of the polyimide film prepared in Example 1.

[0038] Figure 11 The mechanical test curves are those of the polyimide film prepared in Example 2.

[0039] Figure 12 The mechanical test curves are those of the polyimide film prepared in Example 3.

[0040] Figure 13 The mechanical test curves are those of the polyimide film prepared in Example 4. Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions in the embodiments of this invention will be clearly and completely described below in conjunction with the embodiments of this invention. Those skilled in the art should understand that the embodiments described are merely illustrative of the invention and should not be considered as specific limitations thereof. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0042] The embodiments of the present invention are implemented under the premise of the technical solution of the present invention, and detailed implementation methods and processes are given. However, the protection scope of the present invention is not limited to the following embodiments. The process parameters in the following embodiments that do not specify specific conditions are generally in accordance with conventional conditions.

[0043] The endpoints and any values ​​of the ranges disclosed in this invention are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this invention.

[0044] This invention aims to provide a novel polyimide film that, while retaining the advantages of traditional PI films, achieves a combination of low coefficient of thermal expansion, high elastic modulus, and high elongation at break through unique molecular design and preparation processes. Furthermore, this invention also considers optimizing the optical and thermal properties of the film to adapt it to specific application environments, such as high-temperature and bending-resistant operations, thereby meeting increasingly diverse application demands.

[0045] Therefore, the present invention provides a nitrogen-containing heterocyclic diamine compound, the general structural formula of which is shown in Formula I or Formula II:

[0046]

[0047]

[0048] Where R is Y is one of C, N, O, S, C=O, and S=O.

[0049] In some embodiments, the R group insertion site is at positions 2,7, 3,6, 3,7, or 2,8; in preferred embodiments, R is... At that time, its access site is one of the 2nd, 7th, or 3rd, 6th position disubstituted; R is At that time, its access site is one of the 3, 7 or 2, 8 disubstituted sites.

[0050] Formulas (1-1) to (1-13) list the structural formulas of some of the nitrogen-containing heterocyclic diamine compounds described in this invention:

[0051]

[0052]

[0053] As an example, the present invention also provides a method for preparing nitrogen-containing heterocyclic diamine compounds of Formula I, comprising the following steps (the method for preparing nitrogen-containing heterocyclic diamine compounds of Formula II follows the same preparation approach):

[0054] (1) Synthesis of nitrogen-containing heterocyclic diboronic ester compounds:

[0055]

[0056] Where X is a halogen element (F, Cl, Br, or I), The disubstitution in the middle can be one of the 2nd or 7th position, or the 3rd or 6th position. The disubstitution in Y is one of the 2nd, 8th or 3rd, 7th position, and Y is one of C, N, O, S, C=O, S=O.

[0057] In some embodiments, A is one of Pd(pph3)2Cl2, Pd(dppf)Cl2, Pd(OAc)2, and Pd(PPh3)4; and B is one of K2CO3, KOAc, and K3PO4.

[0058] (2) Synthesis of nitrogen-containing heterocyclic diamine compounds:

[0059]

[0060] In some embodiments, X is a halogen element (F, Cl, Br or I), C is one of Pd(pph3)2Cl2, Pd(dppf)Cl2, Pd(OAc)2, Pd(PPh3)4; and D is one of K2CO3, KOAc, K3PO4.

[0061] In some embodiments, the reaction temperature in step (1) is 80-100℃, the reaction solvent is one of tetrahydrofuran, toluene, or 1,4-dioxane, and the reaction time is 3-6 h. In step (2), the reaction temperature is 90-120℃, the reaction solvent is one of toluene / water, tetrahydrofuran / water, or 1,4-dioxane / water, and the reaction time is 12-24 h.

[0062] The nitrogen-containing heterocyclic diamine compounds provided by this invention can be used to prepare polyimides. The specific preparation method can be the same as existing PI film preparation processes; in some embodiments, the specific steps include:

[0063] (S1) The diamine monomer and the nitrogen-containing heterocyclic biphenyl diamine compound are first dissolved in a solvent. After the diamine monomer is completely dissolved, the dianhydride monomer is added in multiple portions and reacted at room temperature for 12-24 hours to obtain a polyamic acid (PAA) solution.

[0064] (S2) The polyamic acid solution obtained in step (1) is uniformly dispersed on the substrate surface, heated to evaporate the solvent in the polyamic acid solution, and then heated to cause the polyamic acid to undergo a dehydration cyclization reaction to obtain a polyimide film.

[0065] In some embodiments, the diamine monomer in step (S1) is one or more of p-phenylenediamine (PDA), 4,4'-diaminodiphenyl ether (ODA), 1,3-phenylenediamine (MPD), and 2,2'-di(trifluoromethyl)diaminobiphenyl (TFMB); the solvent is one of N,N-dimethylacetamide (DMAC) and / or N-methylpyrrolidone (NMP); and the dianhydride monomer is one or more of 3,3',4,4'-biphenyltetracarboxylic acid dianhydride (BPDA), 4,4'-(hexafluoroisopropylidene)phthalic anhydride (6FDA), 1,2,4,5-pyromellitic dianhydride (PMDA), and 4,4'-oxobisphthalic anhydride (ODPA). The molar ratio of the diamine monomer to the nitrogen-containing heterocyclic diamine compound in step (S1) is 1-9:1. The molar ratio of the diamine monomer to the dianhydride monomer is 1-5:10.

[0066] In some embodiments, step (S2) involves heating the polyamic acid solution to evaporate the solvent at a temperature of 60-80°C, followed by further heating to induce a dehydration and cyclization reaction in the polyamic acid at a temperature of 100-400°C for 2-5 hours.

[0067] This invention addresses two main issues: firstly, by introducing a nitrogen-containing heterocyclic structure as a hydrogen bond donor; and secondly, by introducing trifluoromethyl and benzene ring substituents to increase molecular volume and linear orientation. In the nitrogen-containing heterocyclic benzene diamine derivatives of this invention, the hydrogen atom on the nitrogen (N) can act as a hydrogen bond donor, providing interchain hydrogen bonding and reducing the interchain spacing, thereby lowering the coefficient of thermal expansion of the polyimide. The biphenyl structure enhances the rigidity of the molecule, improving the heat resistance of the polyimide, while also increasing its elastic modulus and elongation at break.

[0068] The following is an example:

[0069] Example 1

[0070] The preparation method of nitrogen-containing heterocyclic benzidine compounds with the following structure includes the following steps:

[0071]

[0072] (1) 2,7-dibromocarbazole (10 g, 30.77 mmol), bis-pinacol borate (23 g, 90.57 mmol), and potassium acetate (18 g, 0.183 mol) were added to a 250 ml three-necked flask at room temperature. The mixture was purged with nitrogen three times. 200 ml of deoxygenated anhydrous 1,4-dioxane was injected using a syringe. Then, 1.123 g of bis(triphenylphosphine)palladium dichloride was added under a nitrogen atmosphere. The mixture was heated to 80 °C and reacted for 6 h. The mixture was then cooled to room temperature, and the solvent was evaporated by rotary evaporation. The crude product was purified by column chromatography to obtain a white crystalline powder with a yield of 94%. 1 ¹H NMR (600MHz, CDCl₃) δ: 8.24 (s, 1H), 8.12–8.11 (d, 2H), 7.95 (d, 2H), 7.70–7.69 (d, 2H), 1.39 (s, 24H). This confirms the synthesis of the target product.

[0073] (2) 3 g (7.15 mmol) of the above product and K2CO3 (4.94 g, 35.74 mmol) were added to a 100 ml three-necked flask. The mixture was then purged with nitrogen three times. 60 ml of deoxygenated 1,4-dioxane and 10 ml of distilled water were added. Then tetra(triphenylphosphine)palladium (0.41 g, 0.35 mmol) and 4-bromo-3-(trifluoromethyl)aniline (3.6 g, 150 mmol) were added. The mixture was then heated to 100 °C and reacted for 12 h. The reaction was monitored by TLC. After the reaction was completed, the mixture was cooled to room temperature, and the aqueous phase was separated. The remaining solution was rotary evaporated to obtain the crude product, which was purified by column chromatography to obtain a white pure product with a yield of 83%. 1¹H NMR (600MHz, DMSO) δ 11.26 (s, ¹H), 8.09–8.08 (d, ²H), 7.34 (s, ²H), 7.15–7.14 (d, ²H), 7.06–7.05 (d, ²H), 7.02 (s, ²H), 6.87–6.86 (d, ²H), 5.63 (s, ⁴H). This confirms the synthesis of the target product.

[0074] Example 2

[0075] The preparation method of nitrogen-containing heterocyclic benzidine compounds with the following structure includes the following steps:

[0076]

[0077] (1) 3,6-dibromocarbazole (10 g, 30.77 mmol), bis-pinacol borate (23 g, 90.57 mmol), and potassium acetate (18 g, 0.183 mol) were added to a 250 ml three-necked flask at room temperature. The mixture was purged with nitrogen three times. 200 ml of deoxygenated anhydrous 1,4-dioxane was injected using a syringe. Then, 1.123 g of bis(triphenylphosphine)palladium dichloride was added under a nitrogen atmosphere. The mixture was heated to 80 °C and reacted for 6 h. The mixture was then cooled to room temperature, and the solvent was evaporated by rotary evaporation. The crude product was purified by column chromatography to obtain a white crystalline powder with a yield of 92%. 1 ¹H NMR (600MHz, CDCl₃) δ: 8.23 ​​(s, 1H), 8.11–8.10 (d, 2H), 7.94 (d, 2H), 7.69–7.68 (d, 2H), 1.38 (s, 24H). This confirms the synthesis of the target product.

[0078] (2) 3 g (7.15 mmol) of the above product and K2CO3 (4.94 g, 35.74 mmol) were added to a 100 ml three-necked flask. The mixture was then purged with nitrogen three times. 60 ml of deoxygenated 1,4-dioxane and 10 ml of distilled water were added. Then tetra(triphenylphosphine)palladium (0.41 g, 0.35 mmol) and 4-bromo-3-(trifluoromethyl)aniline (3.6 g, 150 mmol) were added. The mixture was then heated to 100 °C and reacted for 12 h. The reaction was monitored by TLC. After the reaction was completed, the mixture was cooled to room temperature, and the aqueous phase was separated. The remaining solution was rotary evaporated to obtain the crude product, which was purified by column chromatography to obtain a white pure product with a yield of 82%. 1¹H NMR (600MHz, DMSO) δ: 11.25 (s, 1H), 8.08–8.07 (d, 2H), 7.33 (s, 2H), 7.14–7.13 (d, 2H), 7.05–7.04 (d, 2H), 7.01 (s, 2H), 6.86–6.85 (d, 2H), 5.62 (s, 4H). The synthesis of the target product was confirmed.

[0079] Example 3

[0080] The preparation method of nitrogen-containing heterocyclic benzidine compounds with the following structure includes the following steps:

[0081]

[0082] (1) At room temperature, 2,7-dibromo-9,10-dihydroacridine (15.37 g, 30.77 mmol), bis-pinacol boronic acid ester (23 g, 90.57 mmol), and potassium acetate (18 g, 0.183 mol) were added to a 250 ml three-necked flask. The mixture was purged with nitrogen three times. 200 ml of deoxygenated anhydrous 1,4-dioxane was injected using a syringe. Then, 1.123 g of bis(triphenylphosphine)palladium dichloride was added under a nitrogen atmosphere. The mixture was heated to 80 °C and reacted for 6 h. The mixture was then cooled to room temperature, and the solvent was evaporated by rotary evaporation. The crude product was purified by column chromatography to obtain a white crystalline powder with a yield of 96%. 1 ¹H NMR (600MHz, CDCl₃) δ: 8.24 (s, 1H), 8.12–8.11 (d, 2H), 7.95 (d, 2H), 7.70–7.69 (d, 2H), 3.45 (s, 2H), 1.39 (s, 24H). This confirms the synthesis of the target product.

[0083] (2) 3.1 g (7.15 mmol) of the above product and K2CO3 (4.94 g, 35.74 mmol) were added to a 100 ml three-necked flask. The mixture was then purged with nitrogen three times. 60 ml of deoxygenated 1,4-dioxane and 10 ml of distilled water were added. Then, tetra(triphenylphosphine)palladium (0.41 g, 0.35 mmol) and 4-bromo-3-(trifluoromethyl)aniline (3.6 g, 150 mmol) were added. The mixture was then heated to 100 °C and reacted for 12 h. The reaction was monitored by TLC. After the reaction was completed, the mixture was cooled to room temperature, and the aqueous phase was separated. The remaining solution was rotary evaporated to obtain the crude product, which was purified by column chromatography to obtain a white pure product with a yield of 85%. 1H NMR(600MHz,DMSO)δ:11.24(s,1H),8.12-8.11(d,2H),7.36(s,2H),7.17-7.16(d, 2H),7.08-7.06(d,2H),7.04(s,2H),6.89-6.88(d,2H),5.65(s,4H),4.23(s,2H).

[0084] Example 4

[0085] The preparation method of nitrogen-containing heterocyclic benzidine compounds with the following structure includes the following steps:

[0086]

[0087] (1) At room temperature, 3,6-dibromo-9,10-dihydroacridine (15.37 g, 30.77 mmol), bis-pinacol boronic acid ester (23 g, 90.57 mmol), and potassium acetate (18 g, 0.183 mol) were added to a 250 ml three-necked flask. The mixture was purged with nitrogen three times. 200 ml of deoxygenated anhydrous 1,4-dioxane was injected using a syringe. Then, 1.123 g of bis(triphenylphosphine)palladium dichloride was added under a nitrogen atmosphere. The mixture was heated to 80 °C and reacted for 6 h. The mixture was then cooled to room temperature, and the solvent was evaporated by rotary evaporation. The crude product was purified by column chromatography to obtain a white crystalline powder with a yield of 92%. 1 ¹H NMR (600MHz, CDCl₃) δ: 8.24 (s, 1H), 8.12–8.11 (d, 2H), 7.95 (d, 2H), 7.70–7.69 (d, 2H), 3.43 (s, 2H), 1.39 (s, 24H). This confirms the synthesis of the target product.

[0088] (2) 3.1 g (7.15 mmol) of the above product and K2CO3 (4.94 g, 35.74 mmol) were added to a 100 ml three-necked flask. The mixture was then purged with nitrogen three times. 60 ml of deoxygenated 1,4-dioxane and 10 ml of distilled water were added. Then, tetra(triphenylphosphine)palladium (0.41 g, 0.35 mmol) and 4-bromo-3-(trifluoromethyl)aniline (3.6 g, 150 mmol) were added. The mixture was then heated to 100 °C and reacted for 12 h. The reaction was monitored by TLC. After the reaction was completed, the mixture was cooled to room temperature, and the aqueous phase was separated. The remaining solution was rotary evaporated to obtain the crude product, which was purified by column chromatography to obtain a white pure product with a yield of 83%. 1H NMR(600MHz,DMSO)δ:11.24(s,1H),8.09-8.08(d,2H),7.34(s,2H),7.15-7.14(d, 2H),7.06-7.05(d,2H),7.02(s,2H),6.87-6.86(d,2H),5.63(s,4H),4.21(s,2H).

[0089] Example 5

[0090] The preparation method of nitrogen-containing heterocyclic benzidine compounds with the following structure includes the following steps:

[0091]

[0092] (1) At room temperature, 2,8-dibromo-5,10-dihydrophenazine (10.46 g, 30.77 mmol), bis-pinacol borate (23 g, 90.57 mmol), and potassium acetate (18 g, 0.183 mol) were added to a 250 ml three-necked flask. The mixture was purged with nitrogen three times. 200 ml of deoxygenated anhydrous 1,4-dioxane was injected using a syringe. Then, 1.123 g of bis(triphenylphosphine)palladium dichloride was added under a nitrogen atmosphere. The mixture was heated to 80 °C and reacted for 6 h. The mixture was then cooled to room temperature, and the solvent was evaporated by rotary evaporation. The crude product was purified by column chromatography to obtain a white crystalline powder with a yield of 92%. 1 ¹H NMR (600MHz, CDCl₃) δ: 8.56 (s, 2H), 8.23–8.22 (d, 2H), 7.85 (d, 2H), 7.73–7.71 (d, 2H), 1.36 (s, 24H). This confirms the synthesis of the target product.

[0093] (2) 3.1 g (7.15 mmol) of the above product and K2CO3 (4.94 g, 35.74 mmol) were added to a 100 ml three-necked flask. The mixture was then purged with nitrogen three times. 60 ml of deoxygenated 1,4-dioxane and 10 ml of distilled water were added. Then, tetra(triphenylphosphine)palladium (0.41 g, 0.35 mmol) and 4-bromo-3-(trifluoromethyl)aniline (3.6 g, 150 mmol) were added. The mixture was then heated to 100 °C and reacted for 12 h. The reaction was monitored by TLC. After the reaction was completed, the mixture was cooled to room temperature, and the aqueous phase was separated. The remaining solution was rotary evaporated to obtain the crude product, which was purified by column chromatography to obtain a white pure product with a yield of 84%. 1H NMR(600MHz,DMSO)δ:10.70(s,2H),8.28(s,2H),7.94-7.92(d,2H),7.47-7 .45(d,2H),7.35-7.33(d,2H),6.99(s,2H),6.85-6.83(d,2H),6.04(s,4H).

[0094] Example 6

[0095] The preparation method of nitrogen-containing heterocyclic benzidine compounds with the following structure includes the following steps:

[0096]

[0097] (1) At room temperature, 3,7-dibromo-10-hydrophenoxazine (10.49 g, 30.77 mmol), bis-pinacol borate (23 g, 90.57 mmol), and potassium acetate (18 g, 0.183 mol) were added to a 250 ml three-necked flask. The mixture was purged with nitrogen three times. 200 ml of deoxygenated anhydrous 1,4-dioxane was injected using a syringe. Then, 1.123 g of bis(triphenylphosphine)palladium dichloride was added under a nitrogen atmosphere. The mixture was heated to 80 °C and reacted for 6 h. After cooling to room temperature, the solvent was evaporated by rotary evaporation. The crude product was purified by column chromatography to obtain a white crystalline powder with a yield of 96%. 1 ¹H NMR (600MHz, CDCl₃) δ: 8.53 (s, 1H), 8.22–8.21 (d, 2H), 7.85 (d, 2H), 7.75–7.73 (d, 2H), 1.36 (s, 24H). This confirms the synthesis of the target product.

[0098] (2) 3.11 g (7.15 mmol) of the above product and K2CO3 (4.94 g, 35.74 mmol) were added to a 100 ml three-necked flask. The mixture was then purged with nitrogen three times. 60 ml of deoxygenated 1,4-dioxane and 10 ml of distilled water were added. Then, tetra(triphenylphosphine)palladium (0.41 g, 0.35 mmol) and 4-bromo-3-(trifluoromethyl)aniline (3.6 g, 150 mmol) were added. The mixture was then heated to 100 °C and reacted for 12 h. The reaction was monitored by TLC. After the reaction was completed, the mixture was cooled to room temperature, and the aqueous phase was separated. The remaining solution was rotary evaporated to obtain the crude product, which was purified by column chromatography to obtain a white pure product with a yield of 85%. 1¹H NMR (600MHz, DMSO) δ: 11.23 (s, ¹H), 8.13–8.12 (d, ²H), 7.36 (s, ²H), 7.18–7.17 (d, ²H), 7.09–7.08 (d, ²H), 7.05 (s, ²H), 6.89–6.88 (d, ²H), 5.65 (s, ⁴H). The synthesis of the target product was confirmed.

[0099] Example 7

[0100] The preparation method of nitrogen-containing heterocyclic benzidine compounds with the following structure includes the following steps:

[0101]

[0102] (1) At room temperature, 2,8-dibromo-10-hydrophenoxazine (10.49 g, 30.77 mmol), bis-pinacol borate (23 g, 90.57 mmol), and potassium acetate (18 g, 0.183 mol) were added to a 250 ml three-necked flask. The mixture was purged with nitrogen three times. 200 ml of deoxygenated anhydrous 1,4-dioxane was injected using a syringe. Then, 1.123 g of bis(triphenylphosphine)palladium dichloride was added under a nitrogen atmosphere. The mixture was heated to 80 °C and reacted for 6 h. After cooling to room temperature, the solvent was evaporated by rotary evaporation. The crude product was purified by column chromatography to obtain a white crystalline powder with a yield of 95%. 1 ¹H NMR (600MHz, CDCl₃) δ: 8.24 (s, 1H), 8.12–8.11 (d, 2H), 7.95 (d, 2H), 7.70–7.69 (d, 2H), 1.36 (s, 24H). This confirms the synthesis of the target product.

[0103] (2) 3.11 g (7.15 mmol) of the above product and K2CO3 (4.94 g, 35.74 mmol) were added to a 100 ml three-necked flask. The mixture was then purged with nitrogen three times. 60 ml of deoxygenated 1,4-dioxane and 10 ml of distilled water were added. Then tetra(triphenylphosphine)palladium (0.41 g, 0.35 mmol) and 4-bromo-3-(trifluoromethyl)aniline (3.6 g, 150 mmol) were added. The mixture was then heated to 100 °C and reacted for 12 h. The reaction was monitored by TLC. After the reaction was completed, the mixture was cooled to room temperature, and the aqueous phase was separated. The remaining solution was rotary evaporated to obtain the crude product, which was purified by column chromatography to obtain a white pure product with a yield of 86%. 1¹H NMR (600MHz, DMSO) δ: 11.23 (s, ¹H), 8.06–8.05 (d, ²H), 7.32 (s, ²H), 7.13–7.142 (d, ²H), 7.04–7.03 (d, ²H), 7.01 (s, ²H), 6.86–6.85 (d, ²H), 5.61 (s, ⁴H). The synthesis of the target product was confirmed.

[0104] Example 8

[0105] The preparation method of nitrogen-containing heterocyclic benzidine compounds with the following structure includes the following steps:

[0106]

[0107] (1) At room temperature, 3,7-dibromo-10-hydrophenthiazide (10.98 g, 30.77 mmol), bis-pinacol borate (23 g, 90.57 mmol), and potassium acetate (18 g, 0.183 mol) were added to a 250 ml three-necked flask. The mixture was purged with nitrogen three times. 200 ml of deoxygenated anhydrous 1,4-dioxane was injected using a syringe. Then, 1.123 g of bis(triphenylphosphine)palladium dichloride was added under a nitrogen atmosphere. The mixture was heated to 80 °C and reacted for 6 h. The mixture was then cooled to room temperature, and the solvent was evaporated by rotary evaporation. The crude product was purified by column chromatography to obtain a white crystalline powder with a yield of 93%. 1 ¹H NMR (600MHz, CDCl₃) δ: 8.24 (s, 1H), 8.12–8.11 (d, 2H), 7.95 (d, 2H), 7.70–7.69 (d, 2H), 1.39 (s, 24H). This confirms the synthesis of the target product.

[0108] (2) 3.22 g (7.15 mmol) of the above product and K2CO3 (4.94 g, 35.74 mmol) were added to a 100 ml three-necked flask. The mixture was then purged with nitrogen three times. 60 ml of deoxygenated 1,4-dioxane and 10 ml of distilled water were added. Then tetra(triphenylphosphine)palladium (0.41 g, 0.35 mmol) and 4-bromo-3-(trifluoromethyl)aniline (3.6 g, 150 mmol) were added. The mixture was then heated to 100 °C and reacted for 12 h. The reaction was monitored by TLC. After the reaction was completed, the mixture was cooled to room temperature, and the aqueous phase was separated. The remaining solution was rotary evaporated to obtain the crude product, which was purified by column chromatography to obtain a white pure product with a yield of 86%. 1¹H NMR (600MHz, DMSO) δ 11.26 (s, ¹H), 8.09–8.08 (d, ²H), 7.34 (s, ²H), 7.15–7.14 (d, ²H), 7.06–7.05 (d, ²H), 7.02 (s, ²H), 6.87–6.86 (d, ²H), 5.63 (s, ⁴H). This confirms the synthesis of the target product.

[0109] Example 9

[0110] The preparation method of nitrogen-containing heterocyclic benzidine compounds with the following structure includes the following steps:

[0111]

[0112] (1) At room temperature, 2,8-dibromo-10-hydrophenthiazide (10.98 g, 30.77 mmol), bis-pinacol borate (23 g, 90.57 mmol), and potassium acetate (18 g, 0.183 mol) were added to a 250 ml three-necked flask. The mixture was purged with nitrogen three times. 200 ml of deoxygenated anhydrous 1,4-dioxane was injected using a syringe. Then, 1.123 g of bis(triphenylphosphine)palladium dichloride was added under a nitrogen atmosphere. The mixture was heated to 80 °C and reacted for 6 h. The mixture was then cooled to room temperature, and the solvent was evaporated by rotary evaporation. The crude product was purified by column chromatography to obtain a white crystalline powder with a yield of 94%. 1 ¹H NMR (600MHz, CDCl₃) δ: 8.22 (s, 1H), 8.15–8.14 (d, 2H), 7.93 (d, 2H), 7.68–7.67 (d, 2H), 1.34 (s, 24H). This confirms the synthesis of the target product.

[0113] (2) 3.22 g (7.15 mmol) of the above product and K2CO3 (4.94 g, 35.74 mmol) were added to a 100 ml three-necked flask. The mixture was then purged with nitrogen three times. 60 ml of deoxygenated 1,4-dioxane and 10 ml of distilled water were added. Then, tetra(triphenylphosphine)palladium (0.41 g, 0.35 mmol) and 4-bromo-3-(trifluoromethyl)aniline (3.6 g, 150 mmol) were added. The mixture was then heated to 100 °C and reacted for 12 h. The reaction was monitored by TLC. After the reaction was completed, the mixture was cooled to room temperature, and the aqueous phase was separated. The remaining solution was rotary evaporated to obtain the crude product, which was purified by column chromatography to obtain a white pure product with a yield of 82%. 1¹H NMR (600MHz, DMSO) δ: 11.22 (s, ¹H), 8.13–8.12 (d, ²H), 7.37 (s, ²H), 7.19–7.18 (d, ²H), 7.09–7.07 (d, ²H), 7.04 (s, ²H), 6.89–6.87 (d, ²H), 5.66 (s, ⁴H). The synthesis of the target product was confirmed.

[0114] Example 10

[0115] The preparation method of nitrogen-containing heterocyclic benzidine compounds with the following structure includes the following steps:

[0116]

[0117] (1) At room temperature, 2,7-dibromo-9-hydroacridone (10.86 g, 30.77 mmol), bis-pinacol boronic acid ester (23 g, 90.57 mmol), and potassium acetate (18 g, 0.183 mol) were added to a 250 ml three-necked flask. The mixture was purged with nitrogen three times. 200 ml of deoxygenated anhydrous 1,4-dioxane was injected using a syringe. Then, 1.123 g of bis(triphenylphosphine)palladium dichloride was added under a nitrogen atmosphere. The mixture was heated to 80 °C and reacted for 6 h. After cooling to room temperature, the solvent was evaporated by rotary evaporation. The crude product was purified by column chromatography to obtain a white crystalline powder with a yield of 94%. 1 ¹H NMR (600MHz, CDCl₃) δ: 8.28 (s, 1H), 8.16–8.15 (d, 2H), 7.98 (d, 2H), 7.75–7.73 (d, 2H), 1.42 (s, 24H). This confirms the synthesis of the target product.

[0118] (2) 3.19 g (7.15 mmol) of the above product and 4.94 g (35.74 mmol) of K2CO3 were added to a 100 ml three-necked flask. The mixture was then purged with nitrogen three times. 60 ml of deoxygenated 1,4-dioxane and 10 ml of distilled water were added. Then, tetra(triphenylphosphine)palladium (0.41 g, 0.35 mmol) and 4-bromo-3-(trifluoromethyl)aniline (3.6 g, 150 mmol) were added. The mixture was then heated to 100 °C and reacted for 12 h. The reaction was monitored by TLC. After the reaction was completed, the mixture was cooled to room temperature, and the aqueous phase was separated. The remaining solution was rotary evaporated to obtain the crude product, which was purified by column chromatography to obtain a white pure product with a yield of 83%. 1¹H NMR (600MHz, DMSO) δ: 11.28 (s, ¹H), 8.13–8.12 (d, ²H), 7.36 (s, ²H), 7.18–7.16 (d, ²H), 7.08–7.07 (d, ²H), 7.05 (s, ²H), 6.88–6.87 (d, ²H), 5.64 (s, ⁴H). The synthesis of the target product was confirmed.

[0119] Example 11

[0120] The preparation method of nitrogen-containing heterocyclic benzidine compounds with the following structure includes the following steps:

[0121]

[0122] (1) At room temperature, 3,6-dibromo-9-hydroacridone (10.86 g, 30.77 mmol), bis-pinacol boronic acid ester (23 g, 90.57 mmol), and potassium acetate (18 g, 0.183 mol) were added to a 250 ml three-necked flask. The mixture was purged with nitrogen three times. 200 ml of deoxygenated anhydrous 1,4-dioxane was injected using a syringe. Then, 1.123 g of bis(triphenylphosphine)palladium dichloride was added under a nitrogen atmosphere. The mixture was heated to 80 °C and reacted for 6 h. After cooling to room temperature, the solvent was evaporated by rotary evaporation. The crude product was purified by column chromatography to obtain a white crystalline powder with a yield of 93%. 1 ¹H NMR (600MHz, CDCl₃) δ: 8.27 (s, 1H), 8.15–8.14 (d, 2H), 7.99 (d, 2H), 7.75–7.74 (d, 2H), 1.42 (s, 24H). This confirms the synthesis of the target product.

[0123] (2) 3.19 g (7.15 mmol) of the above product and 4.94 g (35.74 mmol) of K2CO3 were added to a 100 ml three-necked flask. The mixture was then purged with nitrogen three times. 60 ml of deoxygenated 1,4-dioxane and 10 ml of distilled water were added. Then, tetra(triphenylphosphine)palladium (0.41 g, 0.35 mmol) and 4-bromo-3-(trifluoromethyl)aniline (3.6 g, 150 mmol) were added. The mixture was then heated to 100 °C and reacted for 12 h. The reaction was monitored by TLC. After the reaction was completed, the mixture was cooled to room temperature, and the aqueous phase was separated. The remaining solution was rotary evaporated to obtain the crude product, which was purified by column chromatography to obtain a white pure product with a yield of 85%. 1¹H NMR (600MHz, DMSO) δ: 11.32 (s, ¹H), 8.13–8.12 (d, ²H), 7.36 (s, ²H), 7.19–7.17 (d, ²H), 7.08–7.07 (d, ²H), 7.04 (s, ²H), 6.88–6.87 (d, ²H), 5.66 (s, ⁴H). The synthesis of the target product was confirmed.

[0124] Example 12

[0125] The preparation method of nitrogen-containing heterocyclic benzidine compounds with the following structure includes the following steps:

[0126]

[0127] (11) At room temperature, 11.48 g (30.77 mmol) of 2,7-dibromo-10-hydro-phenthiazine-5-oxide, 23 g (90.57 mmol) of bis-pinacol boronic acid ester, and 18 g (0.183 mol) of potassium acetate were added to a 250 ml three-necked flask. The mixture was purged with nitrogen three times. 200 ml of deoxygenated anhydrous 1,4-dioxane was injected using a syringe. Then, 1.123 g of bis(triphenylphosphine)palladium dichloride was added under a nitrogen atmosphere. The mixture was heated to 80 °C and reacted for 6 h. The mixture was then cooled to room temperature, and the solvent was evaporated by rotary evaporation. The crude product was purified by column chromatography to obtain a white crystalline powder with a yield of 95%. 1 ¹H NMR (600MHz, CDCl₃) δ: 8.28 (s, 1H), 8.17–8.16 (d, 2H), 8.05 (d, 2H), 7.83–7.82 (d, 2H), 1.43 (s, 24H). This confirms the synthesis of the target product.

[0128] (2) 3.34 g (7.15 mmol) of the above product and 4.94 g (35.74 mmol) of K2CO3 were added to a 100 ml three-necked flask. The mixture was then purged with nitrogen three times. 60 ml of deoxygenated 1,4-dioxane and 10 ml of distilled water were added. Then, tetra(triphenylphosphine)palladium (0.41 g, 0.35 mmol) and 4-bromo-3-(trifluoromethyl)aniline (3.6 g, 150 mmol) were added. The mixture was then heated to 100 °C and reacted for 12 h. The reaction was monitored by TLC. After the reaction was completed, the mixture was cooled to room temperature, and the aqueous phase was separated. The remaining solution was rotary evaporated to obtain the crude product, which was purified by column chromatography to obtain a white pure product with a yield of 86%. 1¹H NMR (600MHz, DMSO) δ: 11.32 (s, ¹H), 8.15–8.13 (d, ²H), 7.44 (s, ²H), 7.25–7.24 (d, ²H), 7.16–7.15 (d, ²H), 7.12 (s, ²H), 6.97–6.96 (d, ²H), 5.73 (s, ⁴H). The synthesis of the target product was confirmed.

[0129] Example 13

[0130] The preparation method of nitrogen-containing heterocyclic benzidine compounds with the following structure includes the following steps:

[0131]

[0132] (1) At room temperature, 11.48 g (30.77 mmol) of 3,6-dibromo-10-hydro-phenthiazine-5-oxide, 23 g (90.57 mmol) of bis-pinacol boronic acid ester, and 18 g (0.183 mol) of potassium acetate were added to a 250 ml three-necked flask. The mixture was purged with nitrogen three times. 200 ml of deoxygenated anhydrous 1,4-dioxane was injected using a syringe. Then, 1.123 g of bis(triphenylphosphine)palladium dichloride was added under a nitrogen atmosphere. The mixture was heated to 80 °C and reacted for 6 h. The mixture was then cooled to room temperature, and the solvent was evaporated by rotary evaporation. The crude product was purified by column chromatography to obtain a white crystalline powder with a yield of 96%. 1 ¹H NMR (600MHz, CDCl₃) δ: 8.27 (s, 1H), 8.16–8.15 (d, 2H), 8.03 (d, 2H), 7.85–7.84 (d, 2H), 1.41 (s, 24H). This confirms the synthesis of the target product.

[0133] (2) 3.34 g (7.15 mmol) of the above product and K2CO3 (4.94 g, 35.74 mmol) were added to a 100 ml three-necked flask. The mixture was then purged with nitrogen three times. 60 ml of deoxygenated 1,4-dioxane and 10 ml of distilled water were added. Then, tetra(triphenylphosphine)palladium (0.41 g, 0.35 mmol) and 4-bromo-3-(trifluoromethyl)aniline (3.6 g, 150 mmol) were added. The mixture was then heated to 100 °C and reacted for 12 h. The reaction was monitored by TLC. After the reaction was completed, the mixture was cooled to room temperature, and the aqueous phase was separated. The remaining solution was rotary evaporated to obtain the crude product, which was purified by column chromatography to obtain a white pure product with a yield of 82%. 1¹H NMR (600MHz, DMSO) δ: 11.30 (s, 1H), 8.14–8.13 (d, 2H), 7.42 (s, 2H), 7.23–7.22 (d, 2H), 7.14–7.13 (d, 2H), 7.10 (s, 2H), 6.94–6.92 (d, 2H), 5.71 (s, 4H). The synthesis of the target product was confirmed.

[0134] The following are application examples:

[0135] Application Example 1

[0136] Preparation of polyimide films of 3,3',4,4'-biphenyltetracarboxylic acid dianhydride / 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl and 2,7-bis[(2-trifluoromethyl-4-amino)phenyl]-9-hydro-carbazole heterocyclic diamine series.

[0137] (S1) Under N2 atmosphere, 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl and 2,7-bis[(2-trifluoromethyl-4-amino)phenyl]-9-hydro-carbazole heterocyclic diamine prepared in Example 1 were added to 50 mL three-necked flasks at molar ratios of 10:0, 9:1, 8:2, 7:3, 6:4, and 5:5, respectively. Then, 6 mL of anhydrous DMAC was added. After the solid was completely dissolved, 3,3',4,4'-biphenyltetracarboxylic acid dianhydride (2 mmol, 0.5884 g) was added to the solution in three batches. The reaction was stirred at room temperature for 24 h to obtain a polyamic acid (PAA) solution.

[0138] (S2) The PAA solution obtained in step (S1) is uniformly dispersed on the surface of a glass plate and dried at 80°C for 1 hour. Subsequently, these glass plates are placed in an oven and imidized by heating at 100°C, 150°C, 200°C, 250°C, 300°C and 350°C for 0.5 hours each, to obtain polyimide films with different contents of nitrogen-containing heterocyclic biphenyl diamine compounds prepared in Example 1, which are designated as PI-0, PI-1, PI-2, PI-3, PI-4 and PI-5, respectively.

[0139] Application Example 2

[0140] Preparation of polyimide films of 3,3',4,4'-biphenyltetracarboxylic acid dianhydride / 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl and 3,6-bis[(2-trifluoromethyl-4-amino)phenyl]-9-hydro-carbazole heterocyclic diamine series.

[0141] (S1) Under N2 atmosphere, 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl and 3,6-bis[(2-trifluoromethyl-4-amino)phenyl]-9-hydro-carbazole heterocyclic diamine prepared in Example 2 were added to a 50 mL three-necked flask in molar ratios of 10:0, 9:1, 8:2, 7:3, 6:4, and 5:5. Then, 6 mL of anhydrous DMAC was added. After the solid was completely dissolved, 3,3',4,4'-biphenyltetracarboxylic acid dianhydride (2 mmol, 0.5884 g) was added to the solution in three batches. The reaction was stirred at room temperature for 24 h to obtain a polyamic acid (PAA) solution.

[0142] (S2) The PAA solution obtained in step (S1) is uniformly dispersed on the surface of a glass plate and dried at 80°C for 1 hour. Subsequently, these glass plates are placed in an oven and imidized by heating at 100°C, 150°C, 200°C, 250°C, 300°C and 350°C for 0.5 hours respectively, thereby obtaining polyimide films with different contents of nitrogen-containing heterocyclic biphenyl diamine compounds prepared in Example 2, which are designated as PI-0, PI-1, PI-2, PI-3, PI-4 and PI-5 respectively.

[0143] Application Example 3

[0144] Preparation of polyimide films of 3,3',4,4'-biphenyltetracarboxylic acid dianhydride / 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl and 2,7-bis[(2-trifluoromethyl-4-amino)phenyl]-9,10-dihydroacrylidine heterocyclic diamine series.

[0145] (S1) Under N2 atmosphere, 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl and 2,7-bis[(2-trifluoromethyl-4-amino)phenyl]-9,10-dihydroacrylidine heterocyclic diamine prepared in Example 3 were added to a 50 mL three-necked flask in molar ratios of 10:0, 9:1, 8:2, 7:3, 6:4, and 5:5. Then, 6 mL of anhydrous DMAC was added. After the solid was completely dissolved, 3,3',4,4'-biphenyltetracarboxylic acid dianhydride (2 mmol, 0.5884 g) was added to the solution in three batches. The reaction was stirred at room temperature for 24 h to obtain a polyamic acid (PAA) solution.

[0146] (S2) The PAA solution obtained in step (S1) is uniformly dispersed on the surface of a glass plate and dried at 80°C for 1 hour. Subsequently, these glass plates are placed in an oven and imidized by heating at 100°C, 150°C, 200°C, 250°C, 300°C and 350°C for 0.5 hours respectively, thereby obtaining polyimide films with different contents of nitrogen-containing heterocyclic biphenyl diamine compounds prepared in Example 3, which are designated as PI-0, PI-1, PI-2, PI-3, PI-4 and PI-5 respectively.

[0147] Application Example 4

[0148] Preparation of polyimide films of 3,3',4,4'-biphenyltetracarboxylic acid dianhydride / 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl and 3,6-bis[(2-trifluoromethyl-4-amino)phenyl]-9,10-dihydroacrylidine heterocyclic diamine series.

[0149] (S1) Under N2 atmosphere, 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl and 3,6-bis[(2-trifluoromethyl-4-amino)phenyl]-9,10-dihydroacrylidine heterocyclic diamine prepared in Example 4 were added to a 50 mL three-necked flask in molar ratios of 10:0, 9:1, 8:2, 7:3, 6:4, and 5:5. Then, 6 mL of anhydrous DMAC was added. After the solid was completely dissolved, 3,3',4,4'-biphenyltetracarboxylic acid dianhydride (2 mmol, 0.5884 g) was added to the solution in three batches. The reaction was stirred at room temperature for 24 h to obtain a polyamic acid (PAA) solution.

[0150] (S2) The PAA solution obtained in step (S1) is uniformly dispersed on the surface of a glass plate and dried at 80°C for 1 hour. Subsequently, these glass plates are placed in an oven and imidized by heating at 100°C, 150°C, 200°C, 250°C, 300°C and 350°C for 0.5 hours respectively, thereby obtaining polyimide films with different contents of nitrogen-containing heterocyclic biphenyl diamine compounds prepared in Example 4, which are designated as PI-0, PI-1, PI-2, PI-3, PI-4 and PI-5 respectively.

[0151] Application Example 5

[0152] Preparation of polyimide films of 3,3',4,4'-biphenyltetracarboxylic acid dianhydride / 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl and 2,8-bis[(2-trifluoromethyl-4-amino)phenyl]-5,10-dihydrophenazine heterocyclic diamine series.

[0153] (S1) Under N2 atmosphere, 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl and 2,8-bis[(2-trifluoromethyl-4-amino)phenyl]-5,10-dihydrophenazine heterocyclic diamine prepared in Example 5 were added to a 50 mL three-necked flask in molar ratios of 10:0, 9:1, 8:2, 7:3, 6:4, and 5:5. Then, 6 mL of anhydrous DMAC was added. After the solid was completely dissolved, 3,3',4,4'-biphenyltetracarboxylic acid dianhydride (2 mmol, 0.5884 g) was added to the solution in three batches. The reaction was stirred at room temperature for 24 h to obtain a polyamic acid (PAA) solution.

[0154] (S2) The PAA solution obtained in step (S1) is uniformly dispersed on the surface of a glass plate and dried at 80°C for 1 hour. Subsequently, these glass plates are placed in an oven and imidized by heating at 100°C, 150°C, 200°C, 250°C, 300°C and 350°C for 0.5 hours respectively, thereby obtaining polyimide films with different contents of nitrogen-containing heterocyclic biphenyl diamine compounds prepared in Example 5, which are designated as PI-0, PI-1, PI-2, PI-3, PI-4 and PI-5 respectively.

[0155] Application Example 6

[0156] Preparation of polyimide films of 3,3',4,4'-biphenyltetracarboxylic acid dianhydride / 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl and 3,7-bis[(2-trifluoromethyl-4-amino)phenyl]-10-hydrophenoxazine heterocyclic diamine series.

[0157] (S1) Under N2 atmosphere, 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl and 3,7-bis[(2-trifluoromethyl-4-amino)phenyl]-10-hydrophenoxazine heterocyclic diamine prepared in Example 6 were added to a 50 mL three-necked flask in molar ratios of 10:0, 9:1, 8:2, 7:3, 6:4, and 5:5. Then, 6 mL of anhydrous DMAC was added. After the solid was completely dissolved, 3,3',4,4'-biphenyltetracarboxylic acid dianhydride (2 mmol, 0.5884 g) was added to the solution in three batches. The reaction was stirred at room temperature for 24 h to obtain a polyamic acid (PAA) solution.

[0158] (S2) The PAA solution obtained in step (S1) is uniformly dispersed on the surface of a glass plate and dried at 80°C for 1 hour. Subsequently, these glass plates are placed in an oven and imidized by heating at 100°C, 150°C, 200°C, 250°C, 300°C and 350°C for 0.5 hours respectively, thereby obtaining polyimide films with different contents of nitrogen-containing heterocyclic biphenyl diamine compounds prepared in Example 6, which are designated as PI-0, PI-1, PI-2, PI-3, PI-4 and PI-5 respectively.

[0159] Application Example 7

[0160] (S1) Under N2 atmosphere, 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl and 2,8-bis[(2-trifluoromethyl-4-amino)phenyl]-10-hydrophenoxazine heterocyclic diamine prepared in Example 7 were added to a 50 mL three-necked flask in molar ratios of 10:0, 9:1, 8:2, 7:3, 6:4, and 5:5. Then, 6 mL of anhydrous DMAC was added. After the solid was completely dissolved, 3,3',4,4'-biphenyltetracarboxylic acid dianhydride (2 mmol, 0.5884 g) was added to the solution in three batches. The reaction was stirred at room temperature for 24 h to obtain a polyamic acid (PAA) solution.

[0161] (S2) The PAA solution obtained in step (S1) is uniformly dispersed on the surface of a glass plate and dried at 80°C for 1 hour. Subsequently, these glass plates are placed in an oven and imidized by heating at 100°C, 150°C, 200°C, 250°C, 300°C and 350°C for 0.5 hours respectively, thereby obtaining polyimide films with different contents of nitrogen-containing heterocyclic biphenyl diamine compounds prepared in Example 7, which are designated as PI-0, PI-1, PI-2, PI-3, PI-4 and PI-5 respectively.

[0162] Application Example 8

[0163] (S1) Under N2 atmosphere, 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl and 3,7-bis[(2-trifluoromethyl-4-amino)phenyl]-10-hydrophenthiazine heterocyclic diamine prepared in Example 8 were added to a 50 mL three-necked flask in molar ratios of 10:0, 9:1, 8:2, 7:3, 6:4, and 5:5. Then, 6 mL of anhydrous DMAC was added. After the solid was completely dissolved, 3,3',4,4'-biphenyltetracarboxylic acid dianhydride (2 mmol, 0.5884 g) was added to the solution in three batches. The reaction was stirred at room temperature for 24 h to obtain a polyamic acid (PAA) solution.

[0164] (S2) The PAA solution obtained in step (S1) is uniformly dispersed on the surface of a glass plate and dried at 80°C for 1 hour. Subsequently, these glass plates are placed in an oven and imidized by heating at 100°C, 150°C, 200°C, 250°C, 300°C and 350°C for 0.5 hours respectively, thereby obtaining polyimide films with different contents of nitrogen-containing heterocyclic biphenyl diamine compounds prepared in Example 8, which are designated as PI-0, PI-1, PI-2, PI-3, PI-4 and PI-5 respectively.

[0165] Application Example 9

[0166] (S1) Under N2 atmosphere, 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl and 2,8-bis[(2-trifluoromethyl-4-amino)phenyl]-10-hydrophenthiazide prepared in Example 9 were added to a 50 mL three-necked flask in molar ratios of 10:0, 9:1, 8:2, 7:3, 6:4, and 5:5. Then, 6 mL of anhydrous DMAC was added. After the solid was completely dissolved, 3,3',4,4'-biphenyltetracarboxylic acid dianhydride (2 mmol, 0.5884 g) was added to the solution in three batches. The reaction was stirred at room temperature for 24 h to obtain a polyamic acid (PAA) solution.

[0167] (S2) The PAA solution obtained in step (S1) is uniformly dispersed on the surface of a glass plate and dried at 80°C for 1 hour. Subsequently, these glass plates are placed in an oven and imidized by heating at 100°C, 150°C, 200°C, 250°C, 300°C and 350°C for 0.5 hours respectively, thereby obtaining polyimide films with different contents of nitrogen-containing heterocyclic biphenyl diamine compounds prepared in Example 9, which are designated as PI-0, PI-1, PI-2, PI-3, PI-4 and PI-5 respectively.

[0168] Application Example 10

[0169] (S1) Under N2 atmosphere, 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl and 2,7-bis[(2-trifluoromethyl-4-amino)phenyl]-9-hydroacridone prepared in Example 10 were added to a 50 mL three-necked flask in molar ratios of 10:0, 9:1, 8:2, 7:3, 6:4, and 5:5. Then, 6 mL of anhydrous DMAC was added. After the solid was completely dissolved, 3,3',4,4'-biphenyltetracarboxylic acid dianhydride (2 mmol, 0.5884 g) was added to the solution in three batches. The reaction was stirred at room temperature for 24 h to obtain a polyamic acid (PAA) solution.

[0170] (S2) The PAA solution obtained in step (S1) is uniformly dispersed on the surface of a glass plate and dried at 80°C for 1 hour. Subsequently, these glass plates are placed in an oven and imidized by heating at 100°C, 150°C, 200°C, 250°C, 300°C and 350°C for 0.5 hours respectively, thereby obtaining polyimide films with different contents of nitrogen-containing heterocyclic biphenyl diamine compounds prepared in Example 10, which are designated as PI-0, PI-1, PI-2, PI-3, PI-4 and PI-5 respectively.

[0171] Application Example 11

[0172] (S1) Under N2 atmosphere, 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl and 3,6-bis[(2-trifluoromethyl-4-amino)phenyl]-9-hydroacridone prepared in Example 11 were added to a 50 mL three-necked flask in molar ratios of 10:0, 9:1, 8:2, 7:3, 6:4, and 5:5. Then, 6 mL of anhydrous DMAC was added. After the solid was completely dissolved, 3,3',4,4'-biphenyltetracarboxylic acid dianhydride (2 mmol, 0.5884 g) was added to the solution in three batches. The reaction was stirred at room temperature for 24 h to obtain a polyamic acid (PAA) solution.

[0173] (S2) The PAA solution obtained in step (S1) is uniformly dispersed on the surface of a glass plate and dried at 80°C for 1 hour. Subsequently, these glass plates are placed in an oven and imidized by heating at 100°C, 150°C, 200°C, 250°C, 300°C and 350°C for 0.5 hours respectively, thereby obtaining polyimide films with different contents of nitrogen-containing heterocyclic biphenyl diamine compounds prepared in Example 11, which are designated as PI-0, PI-1, PI-2, PI-3, PI-4 and PI-5 respectively.

[0174] Application Example 12

[0175] (S1) Under N2 atmosphere, 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl and 2,7-dibromo-10-hydro-phenthiazine-5-oxide prepared in Example 12 were added to a 50 mL three-necked flask in molar ratios of 10:0, 9:1, 8:2, 7:3, 6:4, and 5:5. Then, 6 mL of anhydrous DMAC was added. After the solid was completely dissolved, 3,3',4,4'-biphenyltetracarboxylic acid dianhydride (2 mmol, 0.5884 g) was added to the solution in three batches. The reaction was stirred at room temperature for 24 h to obtain a polyamic acid (PAA) solution.

[0176] (S2) The PAA solution obtained in step (S1) is uniformly dispersed on the surface of a glass plate and dried at 80°C for 1 hour. Subsequently, these glass plates are placed in an oven and imidized by heating at 100°C, 150°C, 200°C, 250°C, 300°C and 350°C for 0.5 hours respectively, thereby obtaining polyimide films with different contents of nitrogen-containing heterocyclic biphenyl diamine compounds prepared in Example 12, which are designated as PI-0, PI-1, PI-2, PI-3, PI-4 and PI-5 respectively.

[0177] Application Example 13

[0178] (S1) Under N2 atmosphere, 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl and 3,6-dibromo-10-hydro-phenthiazine-5-oxide prepared in Example 13 were added to a 50 mL three-necked flask in molar ratios of 10:0, 9:1, 8:2, 7:3, 6:4, and 5:5. Then, 6 mL of anhydrous DMAC was added. After the solid was completely dissolved, 3,3',4,4'-biphenyltetracarboxylic acid dianhydride (2 mmol, 0.5884 g) was added to the solution in three batches. The reaction was stirred at room temperature for 24 h to obtain a polyamic acid (PAA) solution.

[0179] (S2) The PAA solution obtained in step (S1) is uniformly dispersed on the surface of a glass plate and dried at 80°C for 1 hour. Subsequently, these glass plates are placed in an oven and imidized by heating at 100°C, 150°C, 200°C, 250°C, 300°C and 350°C for 0.5 hours respectively, thereby obtaining polyimide films with different contents of nitrogen-containing heterocyclic biphenyl diamine compounds prepared in Example 13, which are designated as PI-0, PI-1, PI-2, PI-3, PI-4 and PI-5 respectively.

[0180] Application Examples

[0181] Results and Discussion:

[0182] Figure 1 This is the 1H NMR spectrum of 2,7-bis[(2-trifluoromethyl-4-amino)phenyl]-9-hydrocarbazole, the product synthesized in the second step of Example 1. (From...) Figure 1 It can be seen that, 1 ¹H NMR (600MHz, DMSO) δ 11.26 (s, 1H), 8.09–8.08 (d, 2H), 7.34 (s, 2H), 7.15–7.14 (d, 2H), 7.06–7.05 (d, 2H), 7.02 (s, 2H), 6.87–6.86 (d, 2H), 5.63 (s, 4H), confirming the synthesis of the target product.

[0183] Figure 2This is the 1H NMR spectrum of 3,6-bis[(2-trifluoromethyl-4-amino)phenyl]-9-hydro-carbazole, the product synthesized in the second step of Example 2. (From...) Figure 2 It can be seen that, 1 ¹H NMR (600MHz, DMSO) δ: 11.25 (s, ¹H), 8.08–8.07 (d, ²H), 7.33 (s, ²H), 7.14–7.13 (d, ²H), 7.05–7.04 (d, ²H), 7.01 (s, ²H), 6.86–6.85 (d, ²H), 5.62 (s, ⁴H). The target product was successfully synthesized.

[0184] Figure 3 This is the 1H NMR spectrum of the product synthesized in step 2 of Example 6, 3,7-bis[(2-trifluoromethyl-4-amino)phenyl]-10-hydrophenoxazine. (From...) Figure 3 It can be seen that, 1 ¹H NMR (600MHz, DMSO) δ: 11.23 (s, ¹H), 8.13–8.12 (d, ²H), 7.36 (s, ²H), 7.18–7.17 (d, ²H), 7.09–7.08 (d, ²H), 7.05 (s, ²H), 6.89–6.88 (d, ²H), 5.65 (s, ⁴H). The synthesis of the target product was confirmed.

[0185] Figure 4 , Figure 5 The images show the infrared spectra of the PAA solutions synthesized in Examples 1 and 2. Figure 4 , Figure 5 It can be seen that the characteristic absorption peaks of polyamic acid (PAA) are at 1629 and 1626 cm⁻¹. -1 (The C=O peak in the carboxyl group) indicates that PAA was successfully synthesized.

[0186] Figure 6 This is the infrared spectrum of the polyimide film prepared using the PAA solution from Example 1. Figure 6 It can be seen that the amide bond characteristic peak of PAA disappears, and the carbonyl characteristic peak of the imine ring is at 1727 cm⁻¹. -1 The presence of this indicates that PAA has been completely imidized to form polyimide.

[0187] Figure 7 This is the infrared spectrum of the polyimide film prepared using the PAA solution from Example 2. Figure 7 It can be seen that the amide bond characteristic peak of PAA disappears, and the carbonyl characteristic peak of the imine ring is at 1724 cm⁻¹. -1 The presence of this indicates that PAA has been completely imidized to form polyimide.

[0188] Figure 8This is the infrared spectrum of the polyimide film prepared using the PAA solution from Example 3. Figure 8 It can be seen that the amide bond characteristic peak of PAA disappears, and the carbonyl characteristic peak of the imine ring is at 1725 cm⁻¹. -1 The presence of this indicates that PAA has been completely imidized to form polyimide.

[0189] Figure 9 This is the infrared spectrum of the polyimide film prepared using the PAA solution from Example 4. Figure 9 It can be seen that the amide bond characteristic peak of PAA disappears, and the carbonyl characteristic peak of the imine ring is at 1723 cm⁻¹. -1 The presence of this indicates that PAA has been completely imidized to form polyimide.

[0190] Figure 10 These are the mechanical test curves of the polyimide film prepared in Example 1. Figure 10 Calculations show that the elastic moduli of polyimide films PI-0 and PI-1 are 5.7 GPa and 5.9 GPa, respectively, and the elongation at break is 5.4% and 10.7%, respectively.

[0191] Figure 11 These are the mechanical test curves of the polyimide film prepared in Example 2. Figure 11 Calculations show that the elastic moduli of polyimide films PI-0 and PI-1 are 5.7 GPa and 6.2 GPa, respectively, and the elongation at break is 5.4% and 15.6%, respectively.

[0192] Figure 12 These are the mechanical test curves of the polyimide film prepared in Example 3. Figure 12 Calculations show that the elastic moduli of polyimide films PI-0 and PI-1 are 5.7 GPa and 6.6 GPa, respectively, and the elongation at break is 5.4% and 21.8%, respectively.

[0193] Figure 13 These are the mechanical test curves of the polyimide film prepared in Example 4. Figure 13 Calculations show that the elastic moduli of polyimide films PI-0 and PI-1 are 5.7 GPa and 6.7 GPa, respectively, and the elongation at break is 5.4% and 24.8%, respectively.

[0194] Table 1. Glass transition temperature, thermogravimetric loss, coefficient of thermal expansion, and optical properties of PI films in Application Examples 1-4

[0195]

[0196] It is easy to see that, in the various application examples, PI-1, obtained by introducing nitrogen-containing heterocyclic benzidine compounds during the preparation of PI films, has a significantly lower CTE compared to PI-0 without the introduction of this compound, and a lower glass transition temperature (T0). g The PI film prepared using nitrogen-containing heterocyclic benzidine compounds exhibits significantly improved elastic modulus and elongation at break, indicating that it possesses excellent mechanical properties, dimensional stability, and thermal properties. Furthermore, the transmittance at 550 nm remains above 87%, meeting the requirements of the flexible AMOLED display industry. Although a 1% weight loss corresponds to a temperature (T...) d1 ) and the temperature corresponding to 5% (T) d5 The temperature has decreased slightly, but it is still above 500℃, which meets the application requirements.

[0197] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. The application of nitrogen-containing heterocyclic benzidine compounds, characterized in that, Used for the preparation of polyimides; the nitrogen-containing heterocyclic biphenyl diamine compound has the general structural formula shown in Formula I: Formula I Where R is or Y is one of CH2, NH, O, S, C=O, and S=O.

2. The application as described in claim 1, characterized in that, The preparation method of the nitrogen-containing heterocyclic benzidine compound shown in Formula I includes the following steps: (1) Synthesis of nitrogen-containing heterocyclic diboronic ester compounds: Wherein, X is a halogen element, Y is one of CH2, NH, O, S, C=O, S=O; A is one of Pd(PPh3)2Cl2, Pd(dppf)Cl2, Pd(OAc)2, Pd(PPh3)4; and B is one of K2CO3, KOAc, K3PO4. (2) Synthesis of nitrogen-containing heterocyclic diamine compounds: Where X is a halogen element, C is one of Pd(PPh3)2Cl2, Pd(dppf)Cl2, Pd(OAc)2, and Pd(PPh3)4, and D is one of K2CO3, KOAc, and K3PO4.

3. The application as described in claim 2, characterized in that, In step (1), the reaction temperature is 80-100℃, the reaction solvent is one of tetrahydrofuran, toluene, or 1,4-dioxane, and the reaction time is 3-6 h.

4. The application as described in claim 2, characterized in that, In step (2), the reaction temperature is 90-120℃, the reaction solvent is one of the following: a mixed solvent of toluene / water, a mixed solvent of tetrahydrofuran / water, or a mixed solvent of 1,4-dioxane / water, and the reaction time is 12-24 h.

5. The application as described in claim 1, characterized in that, Includes the following steps: (S1) The diamine monomer and the nitrogen-containing heterocyclic biphenyl diamine compound monomer are first dissolved in a solvent. After the diamine monomer is completely dissolved, the dianhydride monomer is added in multiple portions to react and obtain a polyamic acid solution. (S2) The polyamic acid solution obtained in step (S1) is uniformly dispersed on the substrate surface, heated to evaporate the solvent in the polyamic acid solution, and then heated to cause the polyamic acid to undergo a dehydration cyclization reaction to obtain a polyimide film.

6. The application as described in claim 5, characterized in that, The diamine monomer in step (S1) is one or more of p-phenylenediamine, 4,4'-diaminodiphenyl ether, 1,3-phenylenediamine, and 2,2'-bis(trifluoromethyl)diaminobiphenyl; and / or, The solvent is one or more of N,N-dimethylacetamide or N-methylpyrrolidone; and / or The dianhydride monomer is one or more of 3,3',4,4'-biphenyltetracarboxylic acid dianhydride, 4,4'-(hexafluoroisopropylidene)diphthalic anhydride, 1,2,4,5-pyromellitic dianhydride, and 4,4'-oxobisphthalic anhydride.

7. A polyimide film, characterized in that, Contains nitrogen-containing heterocyclic benzidine compounds as shown in Formula I. Formula I Where R is or Y is one of CH2, NH, O, S, C=O, and S=O.

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