4-dimethylamino isophthalic acid-tetracyano benzene co-crystal, and preparation method and application thereof

Abstract

The application provides 4-aminoisophthalic acid dimethyl ester-tetracyano benzene eutectic, a preparation method and application thereof, the 4-aminoisophthalic acid dimethyl ester-tetracyano benzene eutectic is triclinic system, the space group is, the cell parameter is, alpha = 116.628 (2) °, beta = 99.297 (2) °, gamma = 100.912 (2) °, the cell volume is the 4-aminoisophthalic acid dimethyl ester-tetracyano benzene eutectic provided by the application improves the solid melting point of 4-aminoisophthalic acid dimethyl ester organic compound without changing the covalent bond of the compound, enhances the thermal stability, and realizes the regulation of fluorescence emission performance.

Description

Technical Field

[0001] This invention belongs to the field of organic solid-state luminescent material preparation technology, specifically relating to a 4-aminoisophthalate dimethyl ester-tetracyanophenyl eutectic, 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 "cocrystal" 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 pseudopolymorphism, 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 4-aminoisophthalate is an organic light-emitting material with excellent luminescent properties and a molecular formula of C2. 10 H 11 NO4, with a molecular weight of 209.2 and the English name Dimethyl4-aminobenzene-1,3-dicarboxylate, has a maximum emission wavelength in the ultraviolet region. However, its low solid melting point (below 130℃) has limited its further application in solid-state luminescent materials. Summary of the Invention

[0005] This invention provides a 4-aminoisophthalate-tetracyanobenzene cocrystal with controlled fluorescence emission performance and improved thermal stability, along with its preparation method and applications. Without altering the covalent bonds of the compounds, this invention uses tetracyanobenzene as a ligand and solvent evaporation to prepare an organic cocrystal fluorescent material based on 4-aminoisophthalate. The process is simple, the conditions are mild, the reproducibility is good, and the crystal product has high crystallinity and complete crystal habit, making it suitable for large-scale production and providing guidance for the development of organic light-emitting crystal materials.

[0006] One objective of this invention is to provide a dimethyl 4-aminoisophthalate-tetracyanobenzene eutectic, wherein the molecular formula of the dimethyl 4-aminoisophthalate-tetracyanobenzene eutectic is C4. 15 H 12 N3O4.

[0007] The crystallographic characteristics of the 4-aminoisophthalate dimethyl ester-tetracyanobenzene eutectic provided by this invention include crystallization in a triclinic crystal system and a space group of The unit cell parameters are b = 9.7117(2), α = 116.628(2)°, β = 99.297(2)°, γ = 100.912(2)°, and the unit cell volume is

[0008] The X-ray powder diffraction pattern of the dimethyl 4-aminoisophthalate-tetracyanobenzene eutectic provided by this invention is attached. Figure 1The 2θ diffraction angles are 10.8±0.2°, 12.7±0.2°, 14.9±0.2°, 15.3±0.2°, 16.9±0.2°, 17.3±0.2°, 18.2±0.2°, 18.6±0.2°, 19.7±0.2°, 20.7±0.2°, 21.2±0.2°, 21.4±0.2°, 22.3±0.2°, 23.1±0.2°, and 23.6±0.2°. Characteristic peaks are observed at 24.1±0.2°, 25.6±0.2°, 26.0±0.2°, 26.3±0.2°, 26.5±0.2°, 27.5±0.2°, 28.1±0.2°, 28.6±0.2°, 29.0±0.2°, 29.3±0.2°, and 30.3±0.2°, with 10.8±0.2° being the initial peak and the relative intensity of the characteristic peak at 27.5±0.2° being 100%.

[0009] The differential scanning calorimetry (DSC) spectrum of the dimethyl 4-aminoisophthalate-tetracyanobenzene eutectic provided by this invention is attached. Figure 2 It has a characteristic melting peak at 174±2℃.

[0010] A second objective of this invention is to provide a method for preparing dimethyl 4-aminoisophthalate-tetracyanophenyl eutectic as described in one objective, comprising:

[0011] Under ultrasonic treatment, solid raw materials of 4-aminoisophthalate and tetracyanobenzene were dissolved in a mixed solution of the first solvent and the second solvent, and then evaporated and crystallized to obtain 4-aminoisophthalate-tetracyanobenzene eutectic.

[0012] Preferably, the molar ratio of the dimethyl 4-aminoisophthalate solid raw material to the tetracyanobenzene solid raw material is 1:1.

[0013] Preferably, the first solvent is any one or a combination of at least two of methanol, ethanol, n-propanol, isopropanol, benzyl alcohol, and ethylene glycol.

[0014] Preferably, the second solvent is any one or a combination of at least two of acetone, butanone, cyclohexanone, and acetonitrile.

[0015] Preferably, the volume ratio of the first solvent to the second solvent is 1:(3-8).

[0016] Preferably, with the amount of 4-aminoisophthalate dimethyl ester solid raw material added being 0.3 mmol, the amount of the first solvent added is 1-3 mL.

[0017] Preferably, the evaporation crystallization is carried out under dark conditions, and the evaporation crystallization time is 3-5 days.

[0018] As a preferred embodiment of the present invention, the preparation method includes the following steps:

[0019] (1) Under the action of ultrasound, dimethyl 4-aminoisophthalate solid raw material and tetracyanobenzene solid raw material are mixed in a molar ratio of 1:1 and added to a mixture of first solvent and second solvent with a certain volume ratio. The mixture is heated until fully dissolved to obtain solution A.

[0020] (2) Under natural evaporation conditions, solution A was placed in a dark environment. After 3-5 days, dimethyl 4-aminoisophthalate-tetracyanobenzene eutectic was obtained. The product was a yellow flaky crystal. Microscopic photographs are attached. Figure 3 The crystal products have high crystallinity and complete crystal structure.

[0021] The 4-aminoisophthalate dimethyl ester-tetracyanobenzene eutectic of the present invention exhibits bright yellow light emission under ultraviolet light irradiation, as shown in the attached figure. Figure 4 As shown, the emission wavelength of the dimethyl 4-aminoisophthalate-tetracyanobenzene eutectic is 575 nm, which shows a significant red shift compared to dimethyl 4-aminoisophthalate, as illustrated in the attached figure. Figure 5 As shown, the average fluorescence lifetime is 8.44 ns and the quantum yield is 4.84%.

[0022] This invention uses tetracyanobenzene as a ligand to form an organic eutectic with dimethyl 4-aminoisophthalate through weak hydrogen bonds and π-π interactions, thereby altering the spatial arrangement of dimethyl 4-aminoisophthalate and preparing a solid-state luminescent material with excellent properties. This eutectic material increases the solid melting point of dimethyl 4-aminoisophthalate, enhances its thermal stability, and strengthens and improves its optical stability. Simultaneously, its luminescent properties, such as emission color, emission wavelength, average fluorescence lifetime, and quantum yield, are also altered. Attached Figure Description

[0023] Figure 1 X-ray diffraction pattern of the dimethyl 4-aminoisophthalate-tetracyanophenyl eutectic of this invention.

[0024] Figure 2 Differential scanning calorimetry (DSC) curve of the 4-aminoisophthalate dimethyl ester-tetracyanobenzene eutectic of this invention.

[0025] Figure 3 Microscopic photograph of the 4-aminoisophthalate dimethyl ester-tetracyanobenzene eutectic of this invention.

[0026] Figure 4 The fluorescence spectrum of the 4-aminoisophthalate dimethyl ester-tetracyanobenzene eutectic of this invention.

[0027] Figure 5The fluorescence lifetime of the 4-aminoisophthalate dimethyl ester-tetracyanophenyl eutectic of this invention. Detailed Implementation

[0028] The following detailed description, through specific embodiments, further illustrates the above-described content of the present invention. However, it should not be construed as limiting the scope of the present invention to the following embodiments. All technologies implemented based on the above-described content of the present invention fall within the scope of the present invention.

[0029] (1) Instruments used for PXRD testing: X-ray powder diffractometer

[0030] Instrument model: Rigaku D / max-2500 (Japan);

[0031] 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.

[0032] (2) Instruments for SCXRD testing: Single-crystal X-ray diffractometer

[0033] Instrument model: Rigaku Saturn 70 single crystal diffractometer (Japan);

[0034] Test method: CCD detector (graphite monochromator), molybdenum target Mo-Kα rays The sampling temperature was 113K.

[0035] (3) DSC testing instrument: differential calorimeter

[0036] Instrument model: Mettler Toledo DSC1 / 500;

[0037] Test method: Sample amount 5-10mg, heating rate 10℃ / min, protective gas nitrogen flow rate 50mL / min.

[0038] (4) Instruments for fluorescence emission spectroscopy and fluorescence lifetime testing: FLS1000 equipment from Edinburgh, UK.

[0039] Example 1

[0040] Under ultrasonic treatment, 20.9 mg of dimethyl 4-aminoisophthalate solid raw material and 17.8 mg of tetracyanobenzene solid raw material were mixed and added to a mixed solvent of 1 mL methanol and 3 mL acetone. Under natural evaporation conditions, the solution was placed in a dark environment, and after 3 days, 4-aminoisophthalate-tetracyanobenzene eutectic was obtained.

[0041] The X-ray powder diffraction pattern of the product prepared in Example 1 is represented by 2θ. Characteristic peaks are observed at 10.8°, 12.7°, 14.9°, 15.3°, 16.9°, 17.3°, 18.2°, 18.6°, 19.7°, 20.7°, 21.2°, 21.4°, 22.3°, 23.1°, 23.6°, 24.1°, 25.6°, 26.0°, 26.3°, 26.5°, 27.5°, 28.1°, 28.6°, 29.0°, 29.3°, and 30.3°, with 10.8° being the initial peak and the relative intensity of the characteristic peak at 27.5° being 100%. The differential scanning calorimetry (DSC) spectrum of the product is shown in the attached diagram. Figure 2 Similarly, there is a characteristic endothermic peak at 174℃, which is the melting peak. The product is a yellow, flaky crystal; microscopic images are attached. Figure 3 Similarly, the crystalline products exhibit high crystallinity and complete crystal habit. The dimethyl 4-aminoisophthalate-tetracyanobenzene eutectic displays a bright yellow emission under ultraviolet light, similar to the attached... Figure 4 Similarly, the emission wavelength of the eutectic is 575 nm, which shows a significant red shift compared to dimethyl 4-aminoisophthalate, and is similar to that of the attached... Figure 5 Similarly, the average fluorescence lifetime is 8.44 ns and the quantum yield is 4.84%.

[0042] Example 2

[0043] Under ultrasonic treatment, 41.8 mg of dimethyl 4-aminoisophthalate solid raw material and 35.6 mg of tetracyanobenzene solid raw material were mixed and added to a mixed solvent of 1 mL n-propanol and 5 mL butanone. Under natural evaporation conditions, the solution was placed in a dark environment, and after 4 days, 4-aminoisophthalate-tetracyanobenzene eutectic was obtained.

[0044] The X-ray powder diffraction pattern of the product prepared in Example 2 is represented by 2θ. Characteristic peaks are observed at 10.9°, 12.8°, 15.0°, 15.4°, 17.0°, 17.4°, 18.3°, 18.7°, 19.8°, 20.8°, 21.3°, 21.5°, 22.4°, 23.2°, 23.7°, 24.2°, 25.7°, 26.1°, 26.4°, 26.6°, 27.6°, 28.2°, 28.7°, 29.1°, 29.4°, and 30.4°. The 10.9° peak is the initial peak, and the relative intensity of the characteristic peak at 27.6° is 100%. The differential scanning calorimetry (DSC) spectrum of the product is shown in the attached diagram. Figure 2 Similarly, there is a characteristic endothermic peak at 175℃, which is the melting peak. The product is a yellow, flaky crystal; microscopic images are attached. Figure 3Similarly, the crystalline products exhibit high crystallinity and complete crystal habit. The dimethyl 4-aminoisophthalate-tetracyanobenzene eutectic displays a bright yellow emission under ultraviolet light, similar to the attached... Figure 4 Similarly, the emission wavelength of the eutectic is 575 nm, which shows a significant red shift compared to dimethyl 4-aminoisophthalate, and is similar to that of the attached... Figure 5 Similarly, the average fluorescence lifetime is 8.44 ns and the quantum yield is 4.84%.

[0045] Example 3

[0046] Under ultrasonic treatment, 41.8 mg of dimethyl 4-aminoisophthalate solid raw material and 35.6 mg of tetracyanobenzene solid raw material were mixed and added to a mixed solvent of 1 mL ethanol and 5 mL cyclohexanone. Under natural evaporation conditions, the solution was placed in a dark environment, and after 5 days, 4-dimethyl 4-aminoisophthalate-tetracyanobenzene eutectic was obtained.

[0047] The X-ray powder diffraction pattern of the product prepared in Example 3 is represented by 2θ. Characteristic peaks are observed at 10.7°, 12.6°, 14.8°, 15.2°, 16.8°, 17.2°, 18.1°, 18.5°, 19.6°, 20.6°, 21.1°, 21.3°, 22.2°, 23.0°, 23.5°, 24.0°, 25.5°, 25.9°, 26.2°, 26.4°, 27.4°, 28.0°, 28.5°, 28.9°, 29.2°, and 30.2°. The 10.7° peak is the initial peak, and the relative intensity of the characteristic peak at 27.4° is 100%. The differential scanning calorimetry (DSC) spectrum of the product is shown in the attached diagram. Figure 2 Similarly, there is a characteristic endothermic peak at 176℃, which is the melting peak. The product is a yellow, flaky crystal; microscopic images are attached. Figure 3 Similarly, the crystalline products exhibit high crystallinity and complete crystal habit. The dimethyl 4-aminoisophthalate-tetracyanobenzene eutectic displays a bright yellow emission under ultraviolet light, similar to the attached... Figure 4 Similarly, the emission wavelength of the eutectic is 575 nm, which shows a significant red shift compared to dimethyl 4-aminoisophthalate, and is similar to that of the attached... Figure 5 Similarly, the average fluorescence lifetime is 8.44 ns and the quantum yield is 4.84%.

[0048] Example 4

[0049] Under ultrasonic treatment, 20.9 mg of dimethyl 4-aminoisophthalate solid raw material and 17.8 mg of tetracyanobenzene solid raw material were mixed and added to a mixed solvent of 1 mL benzyl alcohol and 3 mL acetonitrile. Under natural evaporation conditions, the solution was placed in a dark environment, and after 4 days, 4-aminoisophthalate-tetracyanobenzene eutectic was obtained.

[0050] The X-ray powder diffraction pattern of the product prepared in Example 4 is represented by 2θ. Characteristic peaks are observed at 10.8°, 12.7°, 14.9°, 15.3°, 16.9°, 17.3°, 18.2°, 18.6°, 19.7°, 20.7°, 21.2°, 21.4°, 22.3°, 23.1°, 23.6°, 24.1°, 25.6°, 26.0°, 26.3°, 26.5°, 27.5°, 28.1°, 28.6°, 29.0°, 29.3°, and 30.3°. The 10.8° peak is the initial peak, and the relative intensity of the characteristic peak at 27.5° is 100%. The differential scanning calorimetry (DSC) spectrum of the product is shown in the attached diagram. Figure 2 Similarly, there is a characteristic endothermic peak at 173℃, which is the melting peak. The product is a yellow, flaky crystal; microscopic images are attached. Figure 3 Similarly, the crystalline products exhibit high crystallinity and complete crystal habit. The dimethyl 4-aminoisophthalate-tetracyanobenzene eutectic displays a bright yellow emission under ultraviolet light, similar to the attached... Figure 4 Similarly, the emission wavelength of the eutectic is 575 nm, which shows a significant red shift compared to dimethyl 4-aminoisophthalate, and is similar to that of the attached... Figure 5 Similarly, the average fluorescence lifetime is 8.44 ns and the quantum yield is 4.84%.

[0051] Example 5

[0052] Under ultrasonic treatment, 20.9 mg of dimethyl 4-aminoisophthalate solid raw material and 17.8 mg of tetracyanobenzene solid raw material were mixed and added to a mixed solvent of 1 mL ethylene glycol and 4 mL acetonitrile. Under natural evaporation conditions, the solution was placed in a dark environment, and after 5 days, 4-dimethyl 4-aminoisophthalate-tetracyanobenzene eutectic was obtained.

[0053] The X-ray powder diffraction pattern of the product prepared in Example 5 is represented by 2θ. Characteristic peaks are observed at 11.0°, 12.9°, 15.1°, 15.5°, 17.1°, 17.5°, 18.4°, 18.8°, 19.9°, 20.9°, 21.4°, 21.6°, 22.5°, 23.3°, 23.8°, 24.3°, 25.8°, 26.2°, 26.5°, 26.7°, 27.7°, 28.3°, 28.8°, 29.2°, 29.5°, and 30.5°, with 11.0° being the initial peak and the relative intensity of the characteristic peak at 27.7° being 100%. The differential scanning calorimetry (DSC) spectrum of the product is shown in the attached diagram. Figure 2 Similarly, there is a characteristic endothermic peak at 172℃, which is the melting peak. The product is a yellow, flaky crystal; microscopic images are attached. Figure 3Similarly, the crystalline products exhibit high crystallinity and complete crystal habit. The dimethyl 4-aminoisophthalate-tetracyanobenzene eutectic displays a bright yellow emission under ultraviolet light, similar to the attached... Figure 4 Similarly, the emission wavelength of the eutectic is 575 nm, which shows a significant red shift compared to dimethyl 4-aminoisophthalate, and is similar to that of the attached... Figure 5 Similarly, the average fluorescence lifetime is 8.44 ns and the quantum yield is 4.84%.

[0054] Example 6

[0055] Under ultrasonic treatment, 41.8 mg of dimethyl 4-aminoisophthalate solid raw material and 35.6 mg of tetracyanobenzene solid raw material were mixed and added to a mixed solvent of 1 mL methanol and 5 mL cyclohexanone. Under natural evaporation conditions, the solution was placed in a dark environment, and after 4 days, 4-aminoisophthalate-tetracyanobenzene eutectic was obtained.

[0056] The X-ray powder diffraction pattern of the product prepared in Example 6 is represented by 2θ. Characteristic peaks are observed at 10.6°, 12.5°, 14.7°, 15.1°, 16.7°, 17.1°, 18.0°, 18.4°, 19.5°, 20.5°, 21.0°, 21.2°, 22.1°, 22.9°, 23.4°, 23.9°, 25.4°, 25.8°, 26.1°, 26.3°, 27.3°, 27.9°, 28.4°, 28.8°, 29.1°, and 30.1°, with 10.6° being the initial peak and the relative intensity of the characteristic peak at 27.3° being 100%. The differential scanning calorimetry (DSC) spectrum of the product is shown in the attached diagram. Figure 2 Similarly, there is a characteristic endothermic peak at 174℃, which is the melting peak. The product is a yellow, flaky crystal; microscopic images are attached. Figure 3 Similarly, the crystalline products exhibit high crystallinity and complete crystal habit. The dimethyl 4-aminoisophthalate-tetracyanobenzene eutectic displays a bright yellow emission under ultraviolet light, similar to the attached... Figure 4 Similarly, the emission wavelength of the eutectic is 575 nm, which shows a significant red shift compared to dimethyl 4-aminoisophthalate, and is similar to that of the attached... Figure 5 Similarly, the average fluorescence lifetime is 8.44 ns and the quantum yield is 4.84%.

[0057] Example 7

[0058] Under ultrasonic treatment, 41.8 mg of dimethyl 4-aminoisophthalate solid raw material and 35.6 mg of tetracyanobenzene solid raw material were mixed and added to a mixed solvent of 1 mL methanol and 6 mL acetonitrile. Under natural evaporation conditions, the solution was placed in a dark environment, and after 5 days, 4-dimethyl 4-aminoisophthalate-tetracyanobenzene eutectic was obtained.

[0059] The X-ray powder diffraction pattern of the product prepared in Example 7 is represented by 2θ. Characteristic peaks are observed at 10.8°, 12.7°, 14.9°, 15.3°, 16.9°, 17.3°, 18.2°, 18.6°, 19.7°, 20.7°, 21.2°, 21.4°, 22.3°, 23.1°, 23.6°, 24.1°, 25.6°, 26.0°, 26.3°, 26.5°, 27.5°, 28.1°, 28.6°, 29.0°, 29.3°, and 30.3°, with 10.8° being the initial peak and the relative intensity of the characteristic peak at 27.5° being 100%. The differential scanning calorimetry (DSC) spectrum of the product is shown in the attached diagram. Figure 2 Similarly, there is a characteristic endothermic peak at 174℃, which is the melting peak. The product is a yellow, flaky crystal; microscopic images are attached. Figure 3 Similarly, the crystalline products exhibit high crystallinity and complete crystal habit. The dimethyl 4-aminoisophthalate-tetracyanobenzene eutectic displays a bright yellow emission under ultraviolet light, similar to the attached... Figure 4 Similarly, the emission wavelength of the eutectic is 575 nm, which shows a significant red shift compared to dimethyl 4-aminoisophthalate, and is similar to that of the attached... Figure 5 Similarly, the average fluorescence lifetime is 8.44 ns and the quantum yield is 4.84%.

[0060] Example 8

[0061] Under ultrasonic treatment, 62.7 mg of dimethyl 4-aminoisophthalate solid raw material and 53.4 mg of tetracyanobenzene solid raw material were mixed and added to a mixed solvent of 1 mL isopropanol and 8 mL acetonitrile. Under natural evaporation conditions, the solution was placed in a dark environment, and after 5 days, 4-dimethyl 4-aminoisophthalate-tetracyanobenzene eutectic was obtained.

[0062] The X-ray powder diffraction pattern of the product prepared in Example 8 is represented by 2θ. Characteristic peaks are observed at 11.0°, 12.9°, 15.1°, 15.5°, 17.1°, 17.5°, 18.4°, 18.8°, 19.9°, 20.9°, 21.4°, 21.6°, 22.5°, 23.3°, 23.8°, 24.3°, 25.8°, 26.2°, 26.5°, 26.7°, 27.7°, 28.3°, 28.8°, 29.2°, 29.5°, and 30.5°, with 11.0° being the initial peak and the relative intensity of the characteristic peak at 27.7° being 100%. The differential scanning calorimetry (DSC) spectrum of the product is shown in the attached diagram. Figure 2 Similarly, there is a characteristic endothermic peak at 172℃, which is the melting peak. The product is a yellow, flaky crystal; microscopic images are attached. Figure 3 (Note: This appendix) Figure 3(The color image is yellow; it has been adjusted to grayscale according to submission requirements.) Similarly, the crystalline product exhibits high crystallinity and complete crystal habit. The dimethyl 4-aminoisophthalate-tetracyanobenzene eutectic displays a bright yellow emission under ultraviolet light, similar to the attached... Figure 4 Similarly, the emission wavelength of the eutectic is 575 nm, which shows a significant red shift compared to dimethyl 4-aminoisophthalate, and is similar to that of the attached... Figure 5 Similarly, the average fluorescence lifetime is 8.44 ns and the quantum yield is 4.84%.

[0063] Example 9

[0064] Under ultrasonic treatment, 41.8 mg of dimethyl 4-aminoisophthalate solid raw material and 35.6 mg of tetracyanobenzene solid raw material were mixed and added to a mixed solvent of 1 mL methanol, 1 mL ethanol and 8 mL acetone. Under natural evaporation conditions, the solution was placed in a dark environment, and after 5 days, 4-dimethyl 4-aminoisophthalate-tetracyanobenzene eutectic was obtained.

[0065] The X-ray powder diffraction pattern of the product prepared in Example 9 is represented by 2θ. Characteristic peaks are observed at 10.8°, 12.7°, 14.9°, 15.3°, 16.9°, 17.3°, 18.2°, 18.6°, 19.7°, 20.7°, 21.2°, 21.4°, 22.3°, 23.1°, 23.6°, 24.1°, 25.6°, 26.0°, 26.3°, 26.5°, 27.5°, 28.1°, 28.6°, 29.0°, 29.3°, and 30.3°, with 10.8° being the initial peak and the relative intensity of the characteristic peak at 27.5° being 100%. The differential scanning calorimetry (DSC) spectrum of the product is shown in the attached diagram. Figure 2 Similarly, there is a characteristic endothermic peak at 173℃, which is the melting peak. The product is a yellow, flaky crystal; microscopic images are attached. Figure 3 Similarly, the crystalline products exhibit high crystallinity and complete crystal habit. The dimethyl 4-aminoisophthalate-tetracyanobenzene eutectic displays a bright yellow emission under ultraviolet light, similar to the attached... Figure 4 Similarly, the emission wavelength of the eutectic is 575 nm, which shows a significant red shift compared to dimethyl 4-aminoisophthalate, and is similar to that of the attached... Figure 5 Similarly, the average fluorescence lifetime is 8.44 ns and the quantum yield is 4.84%.

[0066] Example 10

[0067] Under ultrasonic treatment, 20.9 mg of dimethyl 4-aminoisophthalate solid raw material and 17.8 mg of tetracyanobenzene solid raw material were mixed and added to a mixed solvent of 0.5 mL methanol, 0.5 mL isopropanol and 3 mL butanone. Under natural evaporation conditions, the solution was placed in a dark environment, and after 4 days, 4-aminoisophthalate-tetracyanobenzene eutectic was obtained.

[0068] The X-ray powder diffraction pattern of the product prepared in Example 10 is represented by 2θ. Characteristic peaks are observed at 10.7°, 12.6°, 14.8°, 15.2°, 16.8°, 17.2°, 18.1°, 18.5°, 19.6°, 20.6°, 21.1°, 21.3°, 22.2°, 23.0°, 23.5°, 24.0°, 25.5°, 25.9°, 26.2°, 26.4°, 27.4°, 28.0°, 28.5°, 28.9°, 29.2°, and 30.2°, with 10.7° being the initial peak and the relative intensity of the characteristic peak at 27.4° being 100%. The differential scanning calorimetry (DSC) spectrum of the product is shown in the attached diagram. Figure 2 Similarly, there is a characteristic endothermic peak at 176℃, which is the melting peak. The product is a yellow, flaky crystal; microscopic images are attached. Figure 3 Similarly, the crystalline products exhibit high crystallinity and complete crystal habit. The dimethyl 4-aminoisophthalate-tetracyanobenzene eutectic displays a bright yellow emission under ultraviolet light, similar to the attached... Figure 4 Similarly, the emission wavelength of the eutectic is 575 nm, which shows a significant red shift compared to dimethyl 4-aminoisophthalate, and is similar to that of the attached... Figure 5 Similarly, the average fluorescence lifetime is 8.44 ns and the quantum yield is 4.84%.

[0069] This invention discloses and proposes a method for preparing a 4-aminoisophthalate dimethyl ester cocrystal with controlled fluorescence emission properties and improved 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 requirements 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 dimethyl 4-aminoisophthalate-tetracyanobenzene eutectic, characterized in that, The molecular formula of the dimethyl 4-aminoisophthalate-tetracyanobenzene eutectic is C 15 H 12 N3O4; The crystallographic characteristics of the 4-aminoisophthalate dimethyl ester-tetracyanobenzene eutectic include crystallization in a triclinic crystal system with space group P. The unit cell parameters are a = 8.7312(2) Å, b = 9.7117(2) Å, c = 9.9811(2) Å, α = 116.628(2) °, β = 99.297(2) °, γ = 100.912(2) °, and the unit cell volume is 713.03(3) Å. 3 .

2. The 4-aminoisophthalate dimethyl ester-tetracyanobenzene eutectic according to claim 1, characterized in that, The X-ray powder diffraction pattern of the dimethyl isophthalate-tetracyanobenzene eutectic shows that at 2θ diffraction angles of 10.8±0.2°, 12.7±0.2°, 14.9±0.2°, 15.3±0.2°, 16.9±0.2°, 17.3±0.2°, 18.2±0.2°, 18.6±0.2°, 19.7±0.2°, 20.7±0.2°, 21.2±0.2°, 21.4±0.2°, 22.3±0.2°, and 23°, the diffraction angles are... Characteristic peaks are found at 0.1±0.2°, 23.6±0.2°, 24.1±0.2°, 25.6±0.2°, 26.0±0.2°, 26.3±0.2°, 26.5±0.2°, 27.5±0.2°, 28.1±0.2°, 28.6±0.2°, 29.0±0.2°, 29.3±0.2°, and 30.3±0.2°, with 10.8±0.2° being the initial peak and the relative intensity of the characteristic peak at 27.5±0.2° being 100%.

3. The 4-aminoisophthalate dimethyl ester-tetracyanobenzene eutectic according to claim 1, characterized in that, The differential scanning calorimetry (DSC) spectrum of the 4-aminoisophthalate-tetracyanobenzene eutectic showed a characteristic melting peak at 174±2℃.

4. The method for preparing dimethyl 4-aminoisophthalate-tetracyanobenzene eutectic according to any one of claims 1-3, characterized in that, The preparation method includes the following steps: Under ultrasonic treatment, solid raw materials of 4-aminoisophthalate and tetracyanobenzene were dissolved in a mixed solution of the first solvent and the second solvent, and then evaporated and crystallized to obtain 4-aminoisophthalate-tetracyanobenzene eutectic.

5. The preparation method according to claim 4, characterized in that, The molar ratio of the 4-aminoisophthalate solid raw material to the tetracyanobenzene solid raw material is 1:

1.

6. The preparation method according to claim 4, characterized in that, The first solvent is any one or a combination of at least two of methanol, ethanol, n-propanol, isopropanol, benzyl alcohol, and ethylene glycol; The second solvent is any one or a combination of at least two of acetone, butanone, cyclohexanone, and acetonitrile.

7. The preparation method according to claim 4, characterized in that, The volume ratio of the first solvent to the second solvent is 1:(3-8).

8. The preparation method according to claim 4, characterized in that, Based on an addition amount of 0.3 mmol of dimethyl 4-aminoisophthalate solid raw material, the addition amount of the first solvent is 1-3 mL.

9. The preparation method according to claim 4, characterized in that, The evaporation and crystallization are carried out under dark conditions, and the evaporation and crystallization time is 3-5 days.

10. The application of the 4-aminoisophthalate dimethyl ester-tetracyanobenzene eutectic according to any one of claims 1-3 in the regulation of fluorescence properties.

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