A fused ring organic diradical compound, and a preparation method and application thereof

Abstract

The application discloses a fused ring type organic double free radical compound and a preparation method and application thereof, and belongs to the field of organic free radical compounds. The problems of few stable organic double free radical compounds, complex synthesis and poor stability in the prior art are solved. The fused ring type organic double free radical compound prepared by the application has good chemical stability and has the nature of magnetic performance, and has wide application prospects in the field of organic spin electronic devices. The chemical structure of the fused ring type organic double free radical compound is shown as formula (I).

Description

Technical Field

[0001] This invention relates to the field of organic free radical compound technology, specifically to a fused-ring organic diradical compound, its preparation method, and its application. Background Technology

[0002] Organic free radicals are atoms, molecules, or ions containing unpaired electrons, and they have broad research value in fields such as organic chemistry, materials science, and medical research. Compounds containing two strongly interacting unpaired electrons are called diradicals. Research on organic diradicals helps to elucidate the relationship between structure and properties in organic reactions, and has significant theoretical implications. Furthermore, organic diradical compounds have also found applications in conductive and magnetic materials. Open-shell fused-ring organic diradicals are an important class of organic π-conjugated molecules; they possess unique optical, electrical, and magnetic properties, and have potential applications in organic electronics and spintronics.

[0003] Most biradicals possess high reactivity and exist only as intermediates. The increased biradical properties often lead to poor stability in open-shell fused-ring compounds, thus their synthesis typically requires stringent conditions. Furthermore, the synthesis of fused-ring biradicals often necessitates relatively long synthetic steps. Although some fused-ring biradicals have been stably isolated, these compounds are generally thermodynamically and kinetically unstable, making them difficult to isolate. Therefore, the preparation of fused-ring biradical compounds remains a highly challenging task.

[0004] Studies have shown that carbon radicals have a stronger tendency to σ-dimerize, thus their applications are far less widespread than those of heteroatom radicals. Increasing the kinetic and thermodynamic stability of radicals can prolong their lifetime. Kinetic stability typically refers to protecting the spin center using steric hindrance. This method interferes with orbital interactions between radicals, thereby inhibiting σ-bond formation, but it also adversely affects the conductivity and magnetism of the radical. Spin / charge delocalization can thermodynamically stabilize open-shell radicals, a method that facilitates the preparation of open-shell fused-ring compounds.

[0005] Based on this, we designed and synthesized a fused-ring organic diradical compound, which is a structural extension of the fused indonium fluorene conjugated framework. By increasing steric hindrance and extending the conjugated system, we stabilized the fused-ring diradical, giving it good chemical stability and magnetic properties. It has broad application prospects in the field of organic spintronic devices. Summary of the Invention

[0006] To address the problems of limited quantity, complex synthesis, and poor stability of stable organic diradical compounds in existing technologies, the present invention aims to provide a fused-ring organic diradical compound, its preparation method, and its applications.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] Firstly, this invention proposes a fused-ring organic diradical compound, the key feature of which is that the chemical structure of the compound is shown in formula (I):

[0009]

[0010] Among them, R 1 R 2 R 3 R 4 These are the same or different groups, independently chosen from one of the following: hydrogen, methyl, methoxy, ethyl, isopropyl, or tert-butyl.

[0011] Secondly, the present invention provides a method for preparing the above-mentioned fused-ring organic diradical compound, comprising the following steps:

[0012] Step 1: Prepare the precursor to be oxidized;

[0013] Step 2: Under inert gas protection, dissolve the precursor to be oxidized in an organic solvent;

[0014] Step 3: Add 2,3-dichloro-5,6-dicyano-1,4-benzoquinone and react under heating conditions;

[0015] Step 4: After the reaction is complete, wait for the reaction solution to cool, remove the organic solvent under reduced pressure, and obtain the crude product.

[0016] Step 5: The crude product was purified by column chromatography and recrystallization to obtain a fused-ring organic diradical compound as shown in formula (I).

[0017] Furthermore, the preparation process of the precursor to be oxidized is as follows:

[0018] Step 1.1: Add the matrix, 2,5-dibromo-terephthalaldehyde, tetrakis(triphenylphosphine)palladium and K2CO3 to a mixed solution of toluene, ethanol and water that has been bubbled to remove oxygen, and stir the mixture at 90°C for 15 h.

[0019] Step 1.2: After the reaction, wait for the temperature to drop to room temperature, then separate the organic phase to obtain the intermediate;

[0020] Step 1.3: Under inert gas protection, add the intermediate to a reaction vessel containing dry THF, and slowly add a freshly prepared THF solution of 2,4,6-trimethylphenyl magnesium bromide at room temperature.

[0021] Step 1.4: Stir the mixture obtained in Step 1.3 for 2 hours, then slowly add ammonium chloride aqueous solution to quench the reaction, extract with ethyl acetate, dry with anhydrous Na2SO4, remove the solvent under reduced pressure, and transfer the obtained solid to a dry Schlenk flask.

[0022] Step 1.5: Under inert gas protection, add dry CH2Cl2 to a Schlenk flask, and add BF3·Et2O solution dropwise at room temperature. Mix and stir for 30 min, then add methanol to quench, remove all volatiles by vacuum distillation, and purify by column chromatography to obtain the precursor to be oxidized.

[0023] Thirdly, this invention proposes the application of the aforementioned fused-ring organic diradical compounds in the preparation of organic electronic spin devices.

[0024] The significant effects of this invention are:

[0025] 1. This invention utilizes indene fluorene units to design fused-ring radical compounds, that is, to extend the structure by fused indene fluorene conjugated framework, and obtain a structure with obvious diradical properties.

[0026] 2. The method for synthesizing fused-ring organic diradical compounds of the present invention is simple to operate, easy to purify, has a high yield, and can be synthesized on a gram-scale basis.

[0027] 3. Fused-ring diradicals are stabilized by increasing steric hindrance and extending the conjugated system, thus achieving air stability. Tests have shown that the UV-Vis absorption spectra of this type of fused-ring diradical remain unchanged in air for one year, offering potential for practical applications.

[0028] 4. Experimental testing showed that the fused-ring organic diradical compounds synthesized in this invention exhibit significant paramagnetic properties and have the potential to prepare organic electronic spin devices. Attached Figure Description

[0029] Figure 1 The above is the proton NMR spectrum of product 3 in Example 1 of this invention;

[0030] Figure 2 The image shows the carbon NMR spectrum of product 3 in Example 1 of this invention.

[0031] Figure 3 The above is the 1H NMR spectrum of product 4 in Example 1 of this invention;

[0032] Figure 4 The image shows the carbon NMR spectrum of product 4 in Example 1 of this invention.

[0033] Figure 5 This is a crystal structure diagram of the fused-ring organic diradical compound (product 5) of Example 1 of the present invention;

[0034] Figure 6 The UV-Vis absorption spectrum of the fused-ring organic diradical compound (product 5) of Example 1 of this invention is shown.

[0035] Figure 7 The UV-Vis absorption spectrum of the fused-ring organic diradical compound (product 5) of Example 1 of the present invention (exposed to air for one year);

[0036] Figure 8 The temperature-dependent electron spin resonance spectrum of the fused-ring organic diradical compound (product 5) of Example 1 of this invention;

[0037] Figure 9 The above is the 1H NMR spectrum of product 8 in Example 2 of this invention;

[0038] Figure 10 The image shows the carbon NMR spectrum of product 8 in Example 2 of this invention.

[0039] Figure 11 The crystal structure diagram of the fused-ring organic diradical compound (product 9) of Example 2 of the present invention is shown.

[0040] Figure 12 The UV-Vis absorption spectrum of the fused-ring organic diradical compound (product 9) of Example 2 of this invention;

[0041] Figure 13 The UV-Vis absorption spectrum of the fused-ring organic diradical compound (product 9) of Example 2 of the present invention (exposed to air for one year);

[0042] Figure 14 The temperature-dependent electron spin resonance spectrum of the fused-ring organic diradical compound (product 9) of Example 2 of this invention is shown. Detailed Implementation

[0043] To further illustrate the present invention, preferred embodiments of the present invention are described below in conjunction with specific implementation methods. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention and not for limiting the claims of the present invention.

[0044] A fused-ring organic diradical compound, the chemical structure of which is shown in formula (I):

[0045]

[0046] Among them, R 1 R 2 R 3 R 4 These are the same or different groups, independently chosen from one of the following: hydrogen, methyl, methoxy, ethyl, isopropyl, or tert-butyl.

[0047] The preparation method of the above-mentioned fused-ring organic diradical compounds includes the following steps:

[0048] Step 1: Prepare the precursor to be oxidized. The specific preparation process is as follows:

[0049] Step 1.1: Add the matrix, 2,5-dibromo-terephthalaldehyde, tetrakis(triphenylphosphine)palladium and K2CO3 to a mixed solution of toluene, ethanol and water that has been bubbled to remove oxygen, and stir the mixture at 90°C for 15 h.

[0050] Step 1.2: After the reaction, wait for the temperature to drop to room temperature, then separate the organic phase to obtain the intermediate;

[0051] Step 1.3: Under inert gas protection, add the intermediate to a reaction vessel containing dry THF, and slowly add a freshly prepared THF solution of 2,4,6-trimethylphenyl magnesium bromide at room temperature.

[0052] Step 1.4: Stir the mixture obtained in Step 1.3 for 2 hours, then slowly add ammonium chloride aqueous solution to quench the reaction, extract with ethyl acetate, dry with anhydrous Na2SO4, remove the solvent under reduced pressure, and transfer the obtained solid to a dry Schlenk flask.

[0053] Step 1.5: Under inert gas protection, add dry CH2Cl2 to a Schlenk flask, and add BF3·Et2O solution dropwise at room temperature. Mix and stir for 30 min, then add methanol to quench, remove all volatiles by vacuum distillation, and purify by column chromatography to obtain the precursor to be oxidized.

[0054] Step 2: Under inert gas protection, dissolve the precursor to be oxidized in an organic solvent;

[0055] Step 3: Add 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) and react under heating conditions;

[0056] Step 4: After the reaction is complete, wait for the reaction solution to cool, remove the organic solvent under reduced pressure, and obtain the crude product.

[0057] Step 5: The crude product was purified by column chromatography and recrystallization to obtain a fused-ring organic diradical compound as shown in formula (I).

[0058] In the above technical solution, the inert gas is nitrogen or argon; the organic solvent is toluene or xylene; the molar ratio of the precursor to be oxidized to 2,3-dichloro-5,6-dicyano-1,4-benzoquinone is 1:(2-4); the reaction temperature is 50-100℃, and the reaction time is 0.5-1.5h; the chemical structural formula of the precursor to be oxidized is shown in formula (II) or formula (III).

[0059]

[0060] In this invention, to facilitate the synthesis of the compound, the R... 1 R 2 R 3 R 4 For the same group, preferably the R 1 R 2 R 3 R 4 If all radicals are hydrogen-based or methoxy-based, then the chemical structural formula of the compound is shown in formula (IV) or formula (V):

[0061]

[0062] The fused-ring organic diradicals of the present invention have significant paramagnetic properties and can be used to prepare organic spintronic devices.

[0063] The terminology used in this invention generally has the meanings commonly understood by those skilled in the art, unless otherwise stated. To enable those skilled in the art to better understand the technical solutions of this invention, the invention will be further described in detail below with reference to embodiments.

[0064] In the following embodiments, the various processes and methods not described in detail are conventional methods known in the art. Unless otherwise specified, the materials, reagents, equipment, instruments, devices, etc. used in the following embodiments are all commercially available.

[0065] Example 1:

[0066] This embodiment provides a fused-ring organic diradical compound with the following chemical structure:

[0067]

[0068] In this embodiment, the preparation method of the above-mentioned fused-ring organic diradical compound is as follows:

[0069] Step 1: Prepare the precursor to be oxidized. The specific preparation process is as follows:

[0070] Step 1.1: Add compound 1 (1.65 g, 4.4 mmol), 2,5-dibromo-terephthalaldehyde 2 (0.58 g, 2.0 mmol), tetrakis(triphenylphosphine)palladium (69 mg, 0.06 mmol) and K2CO3 (2.12 g, 10 mmol) to a Schlenk tube in sequence, and then add a mixed solution of toluene (24 mL), ethanol (12 mL) and water (12 mL) that has been bubbled to remove oxygen. Stir the reaction at 90 °C for 15 h.

[0071] Step 1.2: After the reaction, wait for the temperature to drop to room temperature, add water and chloroform, separate the organic phase, extract the aqueous layer with chloroform (2×30mL), combine the organic phases, dry and remove the solvent, purify the crude product by column chromatography to obtain a pale yellow solid, which is the intermediate mentioned above, denoted as compound 3, with a yield of 1.45g and a yield of 91%.

[0072] The general reaction formula for the reaction of compound 1 with 2,5-dibromo-terephthalaldehyde 2 to prepare compound 3 is:

[0073]

[0074] The obtained molecule 3 was subjected to 1 H NMR and 13 C NMR analysis, such as Figure 1 and Figure 2 As shown. 1 H NMR (400MHz, CDCl3) δ9.99(s,2H),8.04(s,2H),7.18–7.05(m,38H). 13 C NMR (100MHz, CDCl3) δ192.0,144.6,144.4,143.5,143.5,143.4,142.2,140.1,136.5,134 .4,131.8,131.5,131.5,131.4,130.1,129.5,128.0,127.9,127.8,127.0,126.8,126.8.

[0075] Step 1.3: Add compound 3 (0.79 g, 1.0 mmol) to a Schlenk tube containing dry THF (15 mL) under nitrogen atmosphere, and then slowly add a freshly prepared THF (25 mL) solution of 2,4,6-trimethylphenyl magnesium bromide (2.28 g, 10.2 mmol) at room temperature.

[0076] Step 1.4: Stir the mixture obtained in Step 1.3 for 2 hours, then slowly add ammonium chloride aqueous solution to quench the reaction, extract with ethyl acetate (3×20mL), combine the organic phases, dry with anhydrous Na2SO4, remove the solvent under reduced pressure, and transfer the obtained solid to a dry Schlenk flask.

[0077] Step 1.5: Under a nitrogen atmosphere, add 20 mL of dry CH2Cl2, and add BF3·Et2O solution (1.94 mL, 15.5 mmol) dropwise at room temperature. After stirring the mixture for 30 minutes, slowly add methanol to quench the mixture, remove all volatiles by vacuum distillation, and purify the product by column chromatography to obtain a yellow solid, which is the precursor to be oxidized as shown in formula (II), denoted as compound 4, with a yield of 0.73 g and a yield of 73%.

[0078] The obtained molecule 4 was subjected to 1 H NMR and 13 C NMR analysis, such as Figure 3 and Figure 4 As shown. 1 H NMR (400MHz, CDCl3) δ7.48–7.40(m,4H),7.09–7.04(m,12H),6.97(m,22H),6.84(d,J=3.8Hz ,2H),6.63(d,J=7.8Hz,2H),5.28(s,2H),2.51(s,6H),2.30(s,6H),1.06(d,J=31.6Hz,6H). 13 C NMR (101MHz, CDCl3) δ146.9,146.9,146.8,144.0,144.0,143.8,143.7,143.7,142.9,141.3 ,141.1,141.0,140.4,140.3,139.3,138.0,137.9,137.8,137.7,136.1,136.0,134.2,134.2 ,131.5,131.4,131.3,131.3,130.8,130.7,130.3,130.3,130.2,128.8,127.7,127.7,127.6,127.6,127.4,126.5,126.4,119.4,115.7,49.4,49.4,21.8,21.8,21.0,21.0,18.9,18.7.

[0079] The general reaction formula for the reaction of compound 3 with freshly prepared 2,4,6-trimethylphenyl magnesium bromide to prepare compound 4 is:

[0080]

[0081] Step 2: Dissolve compound 4 (0.20 g, 0.2 mmol) in a dry Schlenk flask containing toluene (16 mL) under a nitrogen atmosphere;

[0082] Step 3: Dissolve DDQ (108 mg, 0.4 mmol) in toluene (5 mL), then transfer it to a Schlenk flask, heat the mixture to 50 °C and continue stirring for 1.5 h to carry out the reaction;

[0083] Step 4: After the reaction temperature drops to room temperature, the reaction mixture is rapidly separated on a silica gel column. The eluent is toluene. All volatiles are removed under reduced pressure to obtain the crude product.

[0084] Step 5: The obtained crude solid product was purified by column chromatography and recrystallization in CH2Cl2 / CH3CN to obtain a purple-red compound with the chemical structure shown in formula (IV), denoted as compound 5, whose crystal structure is as follows. Figure 5 As shown, the yield was 79 mg, with a yield rate of 40%.

[0085] The general reaction formula for the reaction of compound 4 with DDQ to produce compound 5 is:

[0086]

[0087] The fused-ring organic diradical compound synthesized in Example 1 was subjected to UV-Vis absorption spectroscopy analysis, such as... Figure 6 As shown, the maximum absorption wavelength of fused-ring organic diradical compound 5 is 529 nm. Figure 7 As shown, dilute solutions of fused-ring organic diradical compounds did not show significant changes in their UV-Vis absorption spectra after being exposed to air for one year, demonstrating good stability and indicating the potential of fused-ring organic diradical compounds as novel materials.

[0088] Electron paramagnetic resonance analysis was performed on the fused-ring organic diradical compound synthesized in Example 1, such as... Figure 8 As shown, the fused-ring organic diradical compounds exhibit a significant EPR signal with a g value of 2.0032, indicating the presence of unpaired electrons. The significant paramagnetic properties suggest that these fused-ring organic diradical compounds have the potential to function as organic spintronic devices.

[0089] Example 2:

[0090] This embodiment provides a fused-ring organic diradical compound with the following chemical structure:

[0091]

[0092] In this embodiment, the preparation method of the above-mentioned fused-ring organic diradical compound is as follows:

[0093] Step 1: Prepare the precursor to be oxidized. The specific preparation process is as follows:

[0094] Step 1.1: Add compound 6 (1.92 g, 4.4 mmol), 2,5-dibromo-terephthalaldehyde 2 (0.58 g, 2.0 mmol), tetrakis(triphenylphosphine)palladium (69 mg, 0.06 mmol) and K2CO3 (2.12 g, 10 mmol) to a Schlenk tube, followed by a mixed solution of toluene (24 mL), ethanol (12 mL) and water (12 mL) that has been bubbled to remove oxygen. Stir the mixture at 90 °C for 15 h.

[0095] Step 1.2: After the reaction, wait for the temperature to drop to room temperature. Since the crude product obtained from the reaction is a yellow powder with extremely poor solubility, it is basically insoluble in organic solvents (dichloromethane, ethyl acetate, chloroform, toluene, DMF, etc.). Therefore, water and ethyl acetate are added for extraction. The yellow powder obtained from the reaction will be suspended in the organic phase (ethyl acetate and toluene). The organic phase is filtered off and the yellow solid obtained is washed with dichloromethane.

[0096] The yellow solid, after drying, requires no further purification and can be directly used as a reactant in the reaction. This yellow solid is designated as compound 7, the intermediate described above, with a yield of 1.21 g, representing a yield of 66%.

[0097] The general reaction formula for the reaction of compound 6 with 2,5-dibromo-terephthalaldehyde 2 to prepare compound 7 is:

[0098]

[0099] Step 1.4: Under an argon atmosphere, add compound 7 (0.92 g, 1.0 mmol) to a Schlenk tube containing dry THF (15 mL), and then slowly add a freshly prepared THF (25 mL) solution of 2,4,6-trimethylphenyl magnesium bromide (2.28 g, 10.2 mmol) at room temperature.

[0100] Step 1.5: Stir the mixture obtained in Step 1.3 for 2 hours, then slowly add ammonium chloride aqueous solution to quench the reaction, extract with ethyl acetate (3×20mL), combine the organic phases, dry with anhydrous Na2SO4, remove the solvent under reduced pressure, and transfer the obtained solid to a dry Schlenk flask.

[0101] Step 1.6: Under an argon atmosphere, add 20 mL of dry CH2Cl2, and add BF3·Et2O solution (1.94 mL, 15.5 mmol) dropwise at room temperature. After stirring the mixture for 30 minutes, slowly add methanol to quench the reaction. Remove all volatiles by vacuum distillation, and purify the product by column chromatography to obtain a yellow solid, which is the precursor to be oxidized as shown in formula (III), denoted as compound 8, with a yield of 0.83 g and a yield of 74%.

[0102] The general reaction formula for the reaction of compound 7 with freshly prepared 2,4,6-trimethylphenyl magnesium bromide to prepare compound 8 is:

[0103]

[0104] The obtained molecule 8 was subjected to 1 H NMR and 13 C NMR analysis, such as Figure 9 and Figure 10 As shown. 1 H NMR(400MHz, CDCl3)δ7.53–7.38(m,4H),7.08–6.84(m,22H),6.70–6.49(m,10H) ,5.32(s,2H),3.73(s,12H),2.55(s,6H),2.30(s,6H),1.13(s,3H),1.05(s,3H). 13 CNMR(101MHz, CDCl3)δ158.1,158.1,146.9,146.9,146.8,144.2,144.2,143.5,140.4,140.3,140. 2,140.2,139.7,139.7,139.1,139.0,138.0,137.9,137.8,137.7,136.7,136.7,136.4,136.0,136 .0,134.3,134.2,132.7,132.6,131.5,130.6,130.5,130.3,130.3,128.7,127.7,127.4,126.2,119.4,119.4,115.6,113.1,113.0,113.0,55.2,55.1,49.5,49.4,21.8,21.8,21.1,21.0,18.9,18.7.

[0105] Step 2: Dissolve compound 8 (200 mg, 0.2 mmol) in a dry Schlenk flask containing xylene (16 mL) under an argon atmosphere;

[0106] Step 3: Dissolve DDQ (216 mg, 0.8 mmol) in toluene (5 mL), then transfer it to a Schlenk flask, heat the mixture to 100 °C and continue stirring for 0.5 h.

[0107] Step 4: After the reaction temperature drops to room temperature, the reaction mixture is rapidly separated on a silica gel column. The eluent is toluene. All volatiles are removed under reduced pressure to obtain the crude product.

[0108] Step 5: The obtained crude solid product is recrystallized in ethyl acetate / isopropanol to obtain a purple-red compound 9 with the chemical structural formula shown in formula (V), and its crystal structure is as follows. Figure 11 As shown, the yield was 89 mg, with a yield rate of 45%.

[0109] The general reaction formula for the reaction of compound 8 with DDQ to produce compound 9 is:

[0110]

[0111] The fused-ring organic diradical compound synthesized in Example 2 was subjected to UV-Vis absorption spectroscopy analysis, such as... Figure 12 As shown, the maximum absorption wavelength of fused-ring organic diradical compound 9 is 531 nm. Figure 13 As shown, dilute solutions of fused-ring organic diradical compounds did not show significant changes in their UV-Vis absorption spectra after being exposed to air for one year, demonstrating good stability and indicating the potential of fused-ring organic diradical compounds as novel materials.

[0112] Electron paramagnetic resonance analysis was performed on the fused-ring organic diradical compound synthesized in Example 2, such as... Figure 14 As shown, the fused-ring organic diradical compounds exhibit a significant EPR signal with a g value of 2.0034, indicating the presence of unpaired electrons. The significant paramagnetic properties suggest that these fused-ring organic diradical compounds have the potential to function as organic spintronic devices.

[0113] In summary, this invention utilizes indonium fluorene units to design fused-ring radical compounds, obtaining structures with significant diradical properties. Furthermore, the fused-ring diradicals are stabilized by increasing steric hindrance and extending the conjugated system, giving the diradicals air stability. Testing showed that the UV-Vis absorption spectra of these fused-ring diradicals remained unchanged in air for one year, providing potential for practical applications. The synthesis method is simple, easy to purify, and yields high quantities, enabling gram-scale synthesis. It also exhibits significant paramagnetic properties, showing potential for the fabrication of organic electron spin devices.

[0114] The technical solution provided by this invention has been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the embodiments above are only for the purpose of helping to understand the method and core ideas of this invention. It should be noted that those skilled in the art can make several improvements and modifications to this invention without departing from the principles of this invention, and these improvements and modifications also fall within the protection scope of the claims of this invention.

Claims

1. A fused-ring organic diradical compound, characterized in that, The chemical structure of the compound is shown in formula (I): Among them, R 1 R 2 R 3 R 4 These are the same or different groups, independently chosen from one of the following: hydrogen, methyl, methoxy, ethyl, isopropyl, or tert-butyl.

2. The fused-ring organic diradical compound according to claim 1, characterized in that, The R 1 R 2 R 3 R 4 They are the same group.

3. The fused-ring organic diradical compound according to claim 2, characterized in that, The R 1 R 2 R 3 R 4 All are hydrogen-based or methoxy-based.

4. A method for preparing a fused-ring organic diradical compound as described in any one of claims 1-3, characterized in that, Includes the following steps: Step 1: Prepare the precursor to be oxidized; Step 2: Under inert gas protection, dissolve the precursor to be oxidized in an organic solvent; Step 3: Add 2,3-dichloro-5,6-dicyano-1,4-benzoquinone and react under heating conditions; Step 4: After the reaction is complete, wait for the reaction solution to cool, remove the organic solvent under reduced pressure, and obtain the crude product. Step 5: The crude product was purified by column chromatography and recrystallization to obtain a fused-ring organic diradical compound as shown in formula (I).

5. The method for preparing the fused-ring organic diradical compound according to claim 4, characterized in that, The preparation process of the precursor to be oxidized is as follows: Step 1.1: Add the matrix, 2,5-dibromo-terephthalaldehyde, tetrakis(triphenylphosphine)palladium and K2CO3 to a mixed solution of toluene, ethanol and water that has been bubbled to remove oxygen, and stir the mixture at 90°C for 15 h. Step 1.2: After the reaction, wait for the temperature to drop to room temperature, then separate the organic phase to obtain the intermediate; Step 1.3: Under inert gas protection, add the intermediate to a reaction vessel containing dry THF, and slowly add a freshly prepared THF solution of 2,4,6-trimethylphenyl magnesium bromide at room temperature. Step 1.4: Stir the mixture obtained in Step 1.3 for 2 hours, then slowly add ammonium chloride aqueous solution to quench the reaction, extract with ethyl acetate, dry with anhydrous Na2SO4, remove the solvent under reduced pressure, and transfer the obtained solid to a dry Schlenk flask. Step 1.5: Under inert gas protection, add dry CH2Cl2 to a Schlenk flask, and add BF3·Et2O solution dropwise at room temperature. Mix and stir for 30 min, then add methanol to quench, remove all volatiles by vacuum distillation, and purify by column chromatography to obtain the precursor to be oxidized.

6. The method for preparing the fused-ring organic diradical compound according to claim 4 or 5, characterized in that, The chemical structural formula of the precursor to be oxidized is shown in formula (II) or formula (III):

7. The method for preparing the fused-ring organic diradical compound according to claim 4, characterized in that, The inert gas mentioned in step 2 is nitrogen or argon.

8. The method for preparing the fused-ring organic diradical compound according to claim 4, characterized in that, The organic solvent mentioned in step 2 is toluene or xylene.

9. The method for preparing the fused-ring organic diradical compound according to claim 4, characterized in that, In step 3, the molar ratio of the precursor to be oxidized to 2,3-dichloro-5,6-dicyano-1,4-benzoquinone is 1:(2-4).

10. The method for preparing the fused-ring organic diradical compound according to claim 4, characterized in that, In step 3, the reaction temperature is 50–100℃ and the reaction time is 0.5–1.5 h.

11. The use of a fused-ring organic diradical compound as described in any one of claims 1-3 in the preparation of organic electron spin devices.

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