2-amino terephthalic acid dimethyl ester co-crystal and a method for preparing the same

Abstract

The application provides a 2-amino terephthalic acid dimethyl ester eutectic crystal as well as a preparation method and application thereof, the eutectic crystal is of a triclinic system, a space group is, a cell parameter is, alpha = 100.928 (2) °, beta = 98.038 (2) °, gamma = 106.164 (2) °, and a cell volume is 0. 734 0 (3) nm3. The 2-amino terephthalic acid dimethyl ester-tetracyano benzene eutectic crystal provided by the application increases the solid melting point of the organic compound from 133.39 DEG C to 161.80 DEG C without changing the covalent bond of the compound, enhances the thermal stability, and meanwhile, the fluorescence emission color, the fluorescence lifetime and the quantum yield are all changed.

Description

Technical Field

[0001] This invention belongs to the field of organic solid-state luminescent material preparation technology, specifically relating to a eutectic based on 2-aminoterephthalate dimethyl ester, its preparation method, and its application. Background Technology

[0002] The earliest report on eutectics can be traced back to 1844 when the renowned chemist F. Wohler synthesized a eutectic of p-benzoquinone and hydroquinone in an experiment. After a period of silence, the term eutectic was first proposed by J. Schmidt and W. Snippes in 1967, and subsequently popularized by M.C. Etter. According to the literature, between 1980 and 2000, several terms and concepts were proposed, including mixed crystals, molecular recognition, supramolecular chemistry, and supramolecular synthons. In the following decade, there was considerable debate regarding the definition of eutectics. With the deepening of related research, researchers finally reached a consensus on the definition of eutectics in 2012. Forty-six scientists jointly published an article pointing out that eutectics are single-phase crystalline solid materials formed by two or more different molecular or ionic compounds in a fixed stoichiometric ratio, which are different from solvates and simple salts.

[0003] Organic light-emitting materials not only have potential applications in fields such as light-emitting diodes, field-effect transistors, photovoltaic devices, sensors, solid-state lasers, optical waveguides, and information storage, but are also extremely important in research fields such as biology, chemistry, materials science, and translational research. For example, in 2020, Professor Yan Dongpeng's research group at Beijing Normal University successfully prepared two organic cocrystals using 4-(1-naphthylene)pyridine as a model compound and selecting structurally similar fluorobenzoic acid analogs as ligands. The cocrystal formed by 4-(1-naphthylene)pyridine and 2,3,5,6-tetrafluoro-4-hydroxybenzoic acid exhibited significant optical waveguide properties, two-photon photoelectric emission, and high-performance polarized fluorescence under ultraviolet light irradiation. After irradiation, the crystal maintained its original morphology without breaking, and the emission wavelength and intensity of the crystal did not change. In contrast, the cocrystal formed by 4-(1-naphthylene)pyridine and 2,3,5,6-tetrafluorobenzoic acid rapidly underwent macroscopic splitting and jumping behavior after ultraviolet light irradiation. With the development of supramolecular chemistry and organic solid-state chemistry, researchers have gradually discovered that the emission performance of organic solids can be modulated by changing the spatial arrangement of organic fluorescent molecules. However, due to the complexity of the spatial structure of molecules when they form solids, the emission color of materials is often unpredictable. Therefore, how to rationally design the interaction modes and stacking methods of organic molecules inside molecular solids, and thus modulate their optical properties, is one of the important problems facing the field of organic light-emitting materials.

[0004] Dimethyl 2-aminoterephthalate is an organic luminescent material with excellent luminescent properties. It can also be used as an intermediate in pharmaceuticals, dyes, and color film pigments. Its molecular formula is C2. 10 H 11 NO4, with a molecular weight of 209.2, is named Dimethyl aminoterephthalate (DMAT). According to literature reports, 2-aminoterephthalate (DMAT) currently exists in two crystalline forms, named DMAT-B and DMAT-G. DMAT-B is prepared under environmental conditions by dissolving a solid raw material in dichloromethane and petroleum ether, sealing the test tube with a sealing film, and then using a slow solvent diffusion method to produce colorless, uniform, and clean-surfaced, strip-shaped crystals. Under ultraviolet light irradiation, DMAT-B exhibits strong deep blue luminescence, with a maximum absorption wavelength at 420 nm, a maximum emission wavelength at 449 nm, an absolute fluorescence quantum yield of 0.50, and a fluorescence lifetime of 14.22 ns. DMAT-G is prepared under environmental conditions by dissolving a solid raw material in dichloromethane and ethanol, and then using a slow solvent diffusion method to produce light green, plate-like crystals. Under ultraviolet light irradiation, DMAT-G exhibits green fluorescence, with a maximum emission wavelength at 499 nm, an absolute fluorescence quantum yield of 0.22, and a fluorescence lifetime of 20.55 ns. Summary of the Invention

[0005] This invention provides a co-crystal fluorescent material based on dimethyl 2-aminoterephthalate (DMT) with modulated luminescence properties and improved thermal stability, and its preparation method. Without altering the covalent bonds of the compound, this invention uses tetracyanobenzene as a ligand and employs liquid-assisted grinding and solvent evaporation to prepare an organic co-crystal fluorescent material based on DMT. The process is simple, the conditions are mild, the crystal structure is intact, and the crystal product has high crystallinity, providing guidance for the development of organic light-emitting crystal materials.

[0006] One objective of this invention is to provide a 2-aminodimethyl terephthalate eutectic (abbreviated as 2-aminodimethyl terephthalate-tetracyanobenzene eutectic), wherein the molecular formula of the 2-aminodimethyl terephthalate-tetracyanobenzene eutectic is C2. 30 H 24 N6O8.

[0007] The crystallographic characteristics of the 2-aminoterephthalate dimethyl terephthalate-tetracyanobenzene eutectic include that it is in a triclinic crystal.

[0008] Crystallized in the system, space group is The unit cell parameters are α = 100.928(2)°, β = 98.038(2)°, γ = 106.164(2)°, and the unit cell volume is

[0009] The X-ray powder diffraction pattern of the 2-aminoterephthalate-tetracyanobenzene eutectic exhibits diffraction angles of 7.8±0.2°, 9.8±0.2°, 11.0±0.2°, 14.0±0.2°, 14.4±0.2°, 14.6±0.2°, 15.6±0.2°, 16.1±0.2°, 16.6±0.2°, 18.8±0.2°, 19.0±0.2°, 19.4±0.2°, 20.4±0.2°, 20.9±0.2°, and 21.1±0.2°. Characteristic peaks are observed at 21.5±0.2°, 22.0±0.2°, 23.0±0.2°, 23.1±0.2°, 23.5±0.2°, 24.5±0.2°, 26.6±0.2°, 26.9±0.2°, 27.7±0.2°, 28.1±0.2°, 28.6±0.2°, 29.5±0.2°, 29.7±0.2°, and 30.7±0.2°, with 7.8±0.2° being the initial peak and the relative intensity of the characteristic peak at 27.7±0.2° being 100%.

[0010] Differential scanning calorimetry (DSC) spectra of the 2-aminoterephthalate-tetracyanobenzene eutectic showed a characteristic melting peak at 161.8 ± 1.0 °C.

[0011] The second objective of this invention is to provide a method for preparing the aforementioned 2-aminoterephthalate dimethyl ester-tetracyanophenyl eutectic.

[0012] One preparation method of the present invention includes the following:

[0013] Dimethyl 2-aminoterephthalate solid raw material and tetracyanobenzene solid raw material were mixed at a molar ratio of 1:(0.8-1.2) and ground under the action of an auxiliary solvent to obtain 2-aminoterephthalate eutectic.

[0014] Preferably, the grinding is carried out in a ball mill or an agate mortar;

[0015] Preferably, the grinding frequency is 10-30Hz and the grinding time is 5-20min.

[0016] Preferably, the auxiliary solvent includes any one or a combination of at least two of methanol, n-propanol, isopropanol, acetone, butanone, cyclohexanone, or acetonitrile;

[0017] Preferably, based on 1g of 2-aminoterephthalate solid raw material, the amount of auxiliary solvent added is 500-1000μL;

[0018] Preferably, the preparation method further includes drying the grinding product obtained by liquid-assisted grinding at a temperature of 20-30°C.

[0019] Another preparation method of the present invention includes the following:

[0020] A mixed solution containing solid 2-aminoterephthalate and solid tetracyanobenzene was evaporated and crystallized at 10-20℃ to obtain a eutectic of 2-aminoterephthalate.

[0021] Preferably, the method for preparing the mixed solution includes: mixing 2-aminoterephthalate solid raw material and tetracyanobenzene solid raw material in an organic solvent under ultrasonic action to obtain a mixed solution;

[0022] Preferably, the molar ratio of the dimethyl 2-aminoterephthalate solid raw material to the tetracyanobenzene solid raw material is 1:(0.8-1.2);

[0023] Preferably, the organic solvent includes any one or a combination of at least two of methanol, ethanol, n-propanol, isopropanol, butanone, cyclohexanone, or acetonitrile;

[0024] Preferably, the volume of the organic solvent is 2-5 mL, based on an addition amount of 0.1 mmol of 2-aminoterephthalate solid.

[0025] Preferably, the evaporation and crystallization time is 5-10 days;

[0026] Preferably, the preparation method further includes solid-liquid separation of the mixture obtained after evaporation and crystallization.

[0027] The third objective of this invention is to provide the application of the aforementioned 2-aminoterephthalate dimethyl ester-tetracyanophenyl eutectic in improving thermal stability and regulating fluorescence performance.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] This invention is the first to synthesize a 2-aminoterephthalate-tetracyanobenzene eutectic. Without changing the covalent bonds, the solid melting point of the eutectic is increased from 133.39℃ for the original 2-aminoterephthalate to 161.80℃ for the 2-aminoterephthalate-tetracyanobenzene eutectic, thus improving the thermal stability of the solid luminescent material.

[0030] The 2-aminoterephthalate-tetracyanobenzene eutectic synthesized in this invention exhibits a bright rose-red color under ultraviolet light irradiation. The maximum emission wavelength of the 2-aminoterephthalate-tetracyanobenzene eutectic shows a significant red shift compared to that of 2-aminoterephthalate. The average fluorescence lifetime and quantum yield of the 2-aminoterephthalate-tetracyanobenzene eutectic are significantly different from those of the original 2-aminoterephthalate compound.

[0031] This invention uses liquid-assisted grinding and solvent evaporation to prepare 2-aminoterephthalate dimethyl ester-tetracyanobenzene eutectic, which is simple, mild, and produces crystal products with high crystallinity. Attached Figure Description

[0032] Figure 1 The asymmetric unit of the 2-aminoterephthalate dimethyl ester-tetracyanophenyl eutectic synthesized in this invention.

[0033] Figure 2 The packing structure diagram of the 2-aminoterephthalate dimethyl ester-tetracyanobenzene eutectic synthesized in this invention in the bc plane.

[0034] Figure 3 X-ray diffraction pattern of the 2-aminoterephthalate dimethyl ester-tetracyanophenyl eutectic of this invention.

[0035] Figure 4 Differential scanning calorimetry (DSC) chromatogram of 2-aminoterephthalate dimethyl terephthalate-tetracyanophenyl eutectic.

[0036] Figure 5 Microscopic photograph of the 2-aminoterephthalate dimethyl ester-tetracyanobenzene eutectic of this invention.

[0037] Figure 6 The fluorescence spectrum of the 2-aminoterephthalate dimethyl ester-tetracyanophenyl eutectic of this invention.

[0038] Figure 7 The fluorescence lifetime of the 2-aminoterephthalate dimethyl ester-tetracyanobenzene eutectic of the present invention. Detailed Implementation

[0039] It should be noted that the following detailed descriptions are exemplary and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The technical solutions of the present invention are further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as specific limitations thereof.

[0040] Example 1

[0041] Weigh 20.9 mg of 2-aminoterephthalate solid and 14.3 mg of tetracyanobenzene solid and place them in a ball mill jar. Add 10 μL of methanol and ball mill at a frequency of 10 Hz for 20 min. Place the milled product at 20 °C to dry, and obtain 2-aminoterephthalate-tetracyanobenzene eutectic.

[0042] Example 2

[0043] Weigh 20.9 mg of 2-aminoterephthalate solid and 21.4 mg of tetracyanobenzene solid and place them in a ball mill jar. Add 21 μL of n-propanol and ball mill at a frequency of 20 Hz for 10 min. Place the milled product at 30 °C to dry, and obtain 2-aminoterephthalate-tetracyanobenzene eutectic.

[0044] Example 3

[0045] Weigh 20.9 mg of 2-aminoterephthalate solid and 17.8 mg of tetracyanobenzene solid and place them in a ball mill jar. Add 10 μL of isopropanol and ball mill at a frequency of 30 Hz for 10 min. Place the milled product at 20 °C to dry, and obtain 2-aminoterephthalate-tetracyanobenzene eutectic.

[0046] Example 4

[0047] Weigh 20.9 mg of 2-aminoterephthalate solid and 21.4 mg of tetracyanobenzene solid and place them in a ball mill jar. Add 15 μL of acetone and ball mill at a frequency of 30 Hz for 5 min. Place the milled product at 20 °C to dry, and obtain 2-aminoterephthalate-tetracyanobenzene eutectic.

[0048] Example 5

[0049] Weigh 20.9 mg of 2-aminoterephthalate solid and 17.8 mg of tetracyanobenzene solid and place them in a ball mill jar. Add 10 μL of butanone and ball mill at a frequency of 20 Hz for 10 min. Place the milled product at 20 °C to dry, and obtain 2-aminoterephthalate-tetracyanobenzene eutectic.

[0050] Example 6

[0051] Weigh 20.9 mg of 2-aminoterephthalate solid and 20 mg of tetracyanobenzene solid and place them in a ball mill jar. Add 10 μL of cyclohexanone and ball mill at a frequency of 30 Hz for 20 min. Place the milled product at 30 °C to dry, and obtain 2-aminoterephthalate-tetracyanobenzene eutectic.

[0052] Example 7

[0053] Weigh 20.9 mg of 2-aminoterephthalate solid and 18 mg of tetracyanobenzene solid into a ball mill jar, add 20 μL of acetonitrile, and ball mill at a frequency of 30 Hz for 10 min. Place the milled product at 30 °C to dry, and obtain 2-aminoterephthalate-tetracyanobenzene eutectic.

[0054] Example 8

[0055] Weigh 20.9 mg of 2-aminoterephthalate solid and 21.4 mg of tetracyanobenzene solid and place them in a ball mill jar. Add 10 μL of acetone and 10 μL of acetonitrile and ball mill at a frequency of 30 Hz for 10 min. Place the milled product at 30 °C to dry, and obtain 2-aminoterephthalate-tetracyanobenzene eutectic.

[0056] Example 9

[0057] Weigh 20.9 mg of dimethyl 2-aminoterephthalate solid and 21.4 mg of tetracyanobenzene solid and place them in a ball mill jar. Add 10 μL of methanol and 10 μL of acetone and ball mill at a frequency of 20 Hz for 30 min. Place the milled product at 30 °C to dry, and obtain 2-dimethyl 2-aminoterephthalate-tetracyanobenzene eutectic.

[0058] Example 10

[0059] Weigh 20.9 mg of 2-aminoterephthalate solid and 21.4 mg of tetracyanobenzene solid and place them in a ball mill jar. Add 10 μL of methanol and 10 μL of acetonitrile and ball mill at a frequency of 10 Hz for 20 min. Place the milled product at 30 °C to dry, and obtain 2-aminoterephthalate-tetracyanobenzene eutectic.

[0060] Example 11

[0061] Weigh 20.9 mg of 2-aminoterephthalate solid and 21.4 mg of tetracyanobenzene solid and place them in a ball mill jar. Add 10 μL of acetone and 10 μL of acetonitrile and ball mill at a frequency of 10 Hz for 20 min. Place the milled product at 30 °C to dry, and obtain 2-aminoterephthalate-tetracyanobenzene eutectic.

[0062] Example 12

[0063] Under ultrasonic treatment, 20.9 mg of solid 2-aminoterephthalate and 14.3 mg of solid tetracyanobenzene were mixed and added to 2 mL of methanol. The mixture was heated until the solid raw materials were completely dissolved. The resulting solution was placed at 10 °C for slow evaporation. After 7 days, 2-aminoterephthalate-tetracyanobenzene eutectic was obtained.

[0064] Example 13

[0065] Under ultrasonic treatment, 20.9 mg of solid 2-aminoterephthalate and 14.3 mg of solid tetracyanobenzene were mixed and added to 3 mL of ethanol. The mixture was heated until the solid raw materials were completely dissolved. The resulting solution was placed at 10 °C for slow evaporation. After 8 days, 2-aminoterephthalate-tetracyanobenzene eutectic was obtained.

[0066] Example 14

[0067] Under ultrasonic treatment, 20.9 mg of solid 2-aminoterephthalate and 17.8 mg of solid tetracyanobenzene were mixed and added to 5 mL of n-propanol. The mixture was heated until the solid raw materials were completely dissolved. The resulting solution was placed at 20 °C and allowed to evaporate slowly. After 5 days, 2-aminoterephthalate-tetracyanobenzene eutectic was obtained.

[0068] Example 15

[0069] Under ultrasonic treatment, 20.9 mg of solid 2-aminoterephthalate and 21.4 mg of solid tetracyanobenzene were mixed and added to 5 mL of isopropanol. The mixture was heated until the solid raw materials were completely dissolved. The resulting solution was placed at 15 °C for slow evaporation. After 10 days, 2-aminoterephthalate-tetracyanobenzene eutectic was obtained.

[0070] Example 16

[0071] Under ultrasonic treatment, 20.9 mg of solid 2-aminoterephthalate and 21.4 mg of solid tetracyanobenzene were mixed, and 2 mL of ethanol and 3 mL of acetone were added. The mixture was heated until the solid raw materials were completely dissolved. The resulting solution was placed at 20 °C for slow evaporation. After 5 days, 2-aminoterephthalate-tetracyanobenzene eutectic was obtained.

[0072] Example 17

[0073] Under ultrasonic treatment, 20.9 mg of solid 2-aminoterephthalate and 21.4 mg of solid tetracyanobenzene were mixed, and 2 mL of isopropanol and 3 mL of acetonitrile were added. The mixture was heated until the solid raw materials were completely dissolved. The resulting solution was placed at 10 °C for slow evaporation. After 10 days, 2-aminoterephthalate-tetracyanobenzene eutectic was obtained.

[0074] Example 18

[0075] Under ultrasonic treatment, 20.9 mg of solid 2-aminoterephthalate and 21.4 mg of solid tetracyanobenzene were mixed, and 2 mL of methanol and 3 mL of acetone were added. The mixture was heated until the solid raw materials were completely dissolved. The resulting solution was placed at 10 °C for slow evaporation. After 10 days, 2-aminoterephthalate-tetracyanobenzene eutectic was obtained.

[0076] Example 19

[0077] Under ultrasonic treatment, 20.9 mg of solid 2-aminoterephthalate and 21.4 mg of solid tetracyanobenzene were mixed and added to 3 mL of acetone and 2 mL of acetonitrile. The mixture was heated until the solid raw materials were completely dissolved. The resulting solution was placed at 15 °C for slow evaporation. After 10 days, 2-aminoterephthalate-tetracyanobenzene eutectic was obtained.

[0078] Example 20

[0079] Under ultrasonic treatment, 20.9 mg of solid 2-aminoterephthalate and 21.4 mg of solid tetracyanobenzene were mixed and added to 3 mL of methanol and 2 mL of acetonitrile. The mixture was heated until the solid raw materials were completely dissolved. The resulting solution was placed at 10 °C for slow evaporation. After 10 days, 2-aminoterephthalate-tetracyanobenzene eutectic was obtained.

[0080] The 2-aminoterephthalate dimethyl terephthalate-tetracyanophenyl eutectic prepared in the embodiments of the present invention was characterized and its properties were determined. The specific methods are as follows:

[0081] 1. Instruments used for SCXRD testing: Single-crystal X-ray diffractometer

[0082] Instrument model: Rigaku Saturn 70 single crystal diffractometer (Japan);

[0083] Test method: CCD detector (graphite monochromator), molybdenum target Mo-Kα rays The sampling temperature was 113.15K.

[0084] The 2-aminoterephthalate dimethyl terephthalate-tetracyanobenzene eutectic prepared in the embodiments of the present invention belongs to the triclinic crystal system, space group [missing information]. The unit cell parameters are α = 100.928(2)°, β = 98.038(2)°, γ = 106.164(2)°, and the unit cell volume is As attached Figure 1 As shown, the asymmetric unit contains one 2-aminoterephthalate (2-dimethyl terephthalate) molecule and one tetracyanobenzene molecule. The packing structure of the 2-aminoterephthalate-tetracyanobenzene eutectic in the bc plane is shown in the attached figure. Figure 2 As shown in Table 1, the crystallographic parameters of the 2-aminoterephthalate dimethyl ester-tetracyanobenzene eutectic are shown in Table 1.

[0085] Table 1

[0086]

[0087]

[0088] 2. Instruments used for PXRD testing: X-ray powder diffractometer

[0089] Instrument model: Rigaku D / max-2500 (Japan);

[0090] Test method: Copper target Cu-Kα rays Voltage 40kV, current 100mA, test angle 2-40°, step size 8° / min, exposure time 0.2s, test temperature room temperature (25℃), light tube slit width 1mm, detector slit width 2.7mm.

[0091] The powder X-ray diffraction pattern of the 2-aminoterephthalate dimethyl ester-tetracyanobenzene eutectic obtained in Example 4 of this invention is attached. Figure 3 As shown. X-ray powder diffraction of the 2-aminoterephthalate-tetracyanobenzene eutectic showed diffraction angles of 7.8±0.2°, 9.8±0.2°, 11.0±0.2°, 14.0±0.2°, 14.4±0.2°, 14.6±0.2°, 15.6±0.2°, 16.1±0.2°, 16.6±0.2°, 18.8±0.2°, 19.0±0.2°, 19.4±0.2°, 20.4±0.2°, 20.9±0.2°, 21.1±0.2°, and 2... Characteristic peaks are observed at 1.5±0.2°, 22.0±0.2°, 23.0±0.2°, 23.1±0.2°, 23.5±0.2°, 24.5±0.2°, 26.6±0.2°, 26.9±0.2°, 27.7±0.2°, 28.1±0.2°, 28.6±0.2°, 29.5±0.2°, 29.7±0.2°, and 30.7±0.2°, with 7.8±0.2° being the initial peak and the relative intensity of the characteristic peak at 27.7±0.2° being 100%.

[0092] 3. DSC testing instrument: Differential calorimeter scanner

[0093] Instrument model: Mettler Toledo DSC1 / 500;

[0094] Test method: Sample amount 5-10mg, heating rate 10℃ / min, protective gas nitrogen flow rate 50mL / min.

[0095] Differential scanning calorimetry analysis was performed on the 2-aminoterephthalate dimethyl terephthalate-tetracyanobenzene eutectic prepared in the embodiments of the present invention, as shown in the attached figure. Figure 4 As shown, the 2-aminoterephthalate dimethyl ester-tetracyanobenzene eutectic exhibits a sharp endothermic peak at 161.8℃, indicating that its melting point is approximately 161.8℃, further demonstrating that this substance is a single crystalline phase.

[0096] 4. Instruments for crystal morphology testing: Optical microscope

[0097] The crystal morphology of the 2-aminoterephthalate dimethyl ester-tetracyanobenzene eutectic product obtained in Example 12 of this invention was observed, as shown in the attached figure. Figure 5 As shown (Note: This appendix) Figure 5 The color image was originally orange, but was changed to grayscale as required for submission. The product is an orange blocky crystal.

[0098] 5. Instruments for fluorescence emission spectroscopy and fluorescence lifetime testing: FLS1000, Edinburgh, UK

[0099] The 2-aminoterephthalate dimethyl terephthalate-tetracyanobenzene eutectic prepared in the embodiments of the present invention exhibits a bright rose-red color under ultraviolet light irradiation, with a maximum emission wavelength of 606 nm (see attached image). Figure 6 Compared to dimethyl 2-aminoterephthalate, the emission wavelength shows a significant red shift, and the average fluorescence lifetime of the dimethyl 2-aminoterephthalate-tetracyanobenzene eutectic is 3.33 ns (see appendix). Figure 7 The quantum yield is 0.16%.

[0100] This invention discloses and proposes a 2-aminoterephthalate dimethyl terephthalate-tetracyanophenyl eutectic and its preparation method, which regulate fluorescence emission performance and improve thermal stability. The products and methods of this invention have been described through preferred embodiments. Those skilled in the art will readily be able to modify or appropriately alter and combine the methods and products described herein without departing from the content, spirit, and scope of this invention to achieve the technical aspects of this invention. It is particularly important to note that all similar substitutions and modifications are obvious to those skilled in the art and are considered to be included within the spirit, scope, and content of this invention.

Claims

1. A 2-aminoterephthalate dimethyl ester-tetracyanobenzene eutectic, characterized in that, The molecular formula of the 2-aminoterephthalate dimethyl ester-tetracyanophenyl eutectic is C 30 H 24 N6O8; The crystallographic characteristics of the 2-aminoterephthalate dimethyl terephthalate-tetracyanobenzene eutectic include crystallization in a triclinic crystal system with space group P. The unit cell parameters are a = 6.7011(2) Å, b = 9.6663(2) Å, c = 11.8016(3) Å, α = 100.928(2) °, β = 98.038(2) °, γ = 106.164(2) °, and the unit cell volume is 705.72(3) Å. 3 .

2. The 2-aminoterephthalate dimethyl ester-tetracyanobenzene eutectic according to claim 1, characterized in that, The X-ray powder diffraction pattern of the 2-aminoterephthalate-tetracyanobenzene eutectic shows diffraction angles of 7.8±0.2°, 9.8±0.2°, 11.0±0.2°, 14.0±0.2°, 14.4±0.2°, 14.6±0.2°, 15.6±0.2°, 16.1±0.2°, 16.6±0.2°, 18.8±0.2°, 19.0±0.2°, 19.4±0.2°, 20.4±0.2°, 20.9±0.2°, and 21.1±0.2°. Characteristic peaks are observed at 21.5±0.2°, 22.0±0.2°, 23.0±0.2°, 23.1±0.2°, 23.5±0.2°, 24.5±0.2°, 26.6±0.2°, 26.9±0.2°, 27.7±0.2°, 28.1±0.2°, 28.6±0.2°, 29.5±0.2°, 29.7±0.2°, and 30.7±0.2°, with 7.8±0.2° being the initial peak and the relative intensity of the characteristic peak at 27.7±0.2° being 100%.

3. The 2-aminoterephthalate dimethyl ester-tetracyanobenzene eutectic according to claim 1, characterized in that, The differential scanning calorimetry (DSC) spectrum of the 2-aminoterephthalate-tetracyanobenzene eutectic showed a characteristic melting peak at 161.8 ± 1.0 °C.

4. The method for preparing the 2-aminoterephthalate dimethyl terephthalate-tetracyanobenzene eutectic according to any one of claims 1-3, characterized in that, The preparation method includes the following steps: Dimethyl 2-aminoterephthalate solid raw material and tetracyanobenzene solid raw material were mixed at a molar ratio of 1:(0.8-1.2) and ground under the action of an auxiliary solvent to obtain 2-aminoterephthalate-tetracyanobenzene eutectic.

5. The preparation method according to claim 4, characterized in that, The grinding is carried out in a ball mill or an agate mortar.

6. The preparation method according to claim 4, characterized in that, The grinding frequency is 10-30 Hz, and the grinding time is 5-20 min.

7. The preparation method according to claim 4, characterized in that, The auxiliary solvent includes any one or a combination of at least two of methanol, n-propanol, isopropanol, acetone, butanone, cyclohexanone, or acetonitrile.

8. The preparation method according to claim 4, characterized in that, Based on an addition amount of 1 g of 2-aminoterephthalate solid raw material, the addition amount of the auxiliary solvent is 500-1000 μL.

9. The preparation method according to claim 4, characterized in that, The preparation method further includes drying the grinding product obtained by liquid-assisted grinding at a temperature of 20-30 ℃.

10. The method for preparing the 2-aminoterephthalate dimethyl terephthalate-tetracyanobenzene eutectic according to any one of claims 1-3, characterized in that, The preparation method includes the following steps: A mixed solution containing solid 2-aminoterephthalate and solid tetracyanobenzene was evaporated and crystallized at 10-20℃ to obtain a 2-aminoterephthalate-tetracyanobenzene eutectic.

11. The preparation method according to claim 10, characterized in that, The method for preparing the mixed solution includes: mixing 2-aminoterephthalate solid raw material and tetracyanobenzene solid raw material in an organic solvent under ultrasonic action to obtain a mixed solution.

12. The preparation method according to claim 11, characterized in that, The molar ratio of the 2-aminoterephthalate solid raw material to the tetracyanobenzene solid raw material is 1:(0.8-1.2).

13. The preparation method according to claim 11, characterized in that, The organic solvent includes any one or a combination of at least two of methanol, ethanol, n-propanol, isopropanol, butanone, cyclohexanone, or acetonitrile.

14. The preparation method according to claim 11, characterized in that, The volume of the organic solvent is 2-5 mL, based on an addition of 0.1 mmol of 2-aminoterephthalate solid.

15. The preparation method according to claim 10, characterized in that, The evaporation and crystallization process takes 5-10 days.

16. The preparation method according to claim 10, characterized in that, The preparation method further includes solid-liquid separation of the mixture obtained after evaporation and crystallization.

17. The application of the 2-aminoterephthalate dimethyl ester-tetracyanophenyl eutectic according to any one of claims 1-3 in improving the thermal stability and fluorescence performance regulation of solid-state luminescent materials.

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