A trianthryl compound, a preparation method thereof and application thereof as an energy storage material

Abstract

The application provides a trianthryl compound, a preparation method thereof and application thereof as an energy storage material, and belongs to the technical field of energy chemical industry. The trianthryl compound can be converted into a dimer by using 365nm ultraviolet light excitation, and simultaneously stores light energy as chemical energy. The stored energy can be depolymerized under 254nm light irradiation and simultaneously release heat. The trianthryl compound based on the light dimerization / depolymerization reaction to store / release light and heat energy has the advantages of simple synthesis method, high yield, and cyclic stability of energy storage and release process. The energy storage density of the trianthryl compound is up to 96kJ / mol, and the energy storage half-life is up to 100 days. The trianthryl compound provides a new strategy for light and heat energy storage and conversion technology.

Description

Technical Field

[0001] This invention relates to the field of energy and chemical technology, and in particular to a triflene anthracene compound, its preparation method, and its application as an energy storage material. Background Technology

[0002] Anthracene, a polycyclic aromatic hydrocarbon, possesses advantages such as controllable luminescence, easy energy and charge transfer, and unique photo- and thermo-reversible dimerization, leading to its long history of application in numerous fields of materials synthesis. Industrially, anthracene is typically oxidized first, followed by nitration and sulfonation processes to provide intermediates for dyes, pharmaceuticals, and optoelectronic materials. Anthracene is abundant in high-temperature coal tar. Patent CN115141077B provides a simple, mild, and low-cost method for separating anthracene from coal tar. However, this patent does not address the use of the separated anthracene for downstream product preparation, resulting in a relatively low level of product value and application depth for anthracene compounds. Patent CN119118837A provides an alkyl-functionalized anthracene compound and studies its application potential as a solar thermal fuel, but the performance of the anthracene-based solar thermal fuel prepared by this patent needs further improvement. Solar thermal fuels are molecular energy storage materials that achieve light energy storage and heat energy release based on reversible changes in molecular spatial configuration. Compared to traditional fossil fuels, this molecular energy storage material features a closed-loop utilization process, with advantages such as wide availability, abundant reserves, environmental friendliness, and controlled release. Therefore, developing novel polycyclic aromatic hydrocarbons (PAHs) such as anthracene as energy storage materials is of great significance. Summary of the Invention

[0003] The purpose of this invention is to provide a tribranched anthracene compound, its preparation method, and its application as an energy storage material. This tribranched anthracene compound can significantly improve its energy storage density and storage half-life as an energy storage material through intramolecular or intermolecular π-π interactions.

[0004] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0005] This invention provides a tribranched anthracene compound having the structure shown in Formula I:

[0006]

[0007] This invention provides a method for preparing the triclade anthracene compound described above, comprising the following steps:

[0008] Anthracene, N-methylformaniline, an oxidant and a first solvent were mixed and subjected to a formylation-condensation reaction to obtain 9-anthracene formaldehyde;

[0009] The 9-anthracene formaldehyde, reducing agent, and second solvent are mixed to carry out a reduction reaction to obtain 9-anthracene methanol;

[0010] The 9-anthracene methanol, the catalyst, and the third solvent were mixed to carry out a substitution reaction to obtain 4-(anthracene-9-ylmethoxy)-4-oxobutyric acid.

[0011] The 4-(anthracene-9-ylmethoxy)-4-oxobutyric acid, dehydrating agent, catalyst, triethanolamine, and a fourth solvent are mixed and subjected to esterification to obtain tri-anthracene compounds.

[0012] Preferably, the anthracene is obtained by separating coal tar.

[0013] Preferably, the oxidant includes phosphorus oxychloride; the molar ratio of anthracene, N-methylformamide and the oxidant is 1:2:2 to 1:4:4; and the volume ratio of N-methylformamide to the first solvent is 10:1 to 5:1.

[0014] Preferably, the formylation-condensation reaction is carried out at a temperature of 90–100°C for a time of 2–8 hours.

[0015] Preferably, the reducing agent includes sodium borohydride; the molar ratio of 9-anthracene formaldehyde to the reducing agent is 1:2 to 1:3; the reduction reaction is carried out at a temperature of 25°C for 4 to 8 hours.

[0016] Preferably, the third solvent comprises dichloromethane and pyridine; the volume ratio of dichloromethane to pyridine is 1:1 to 3:1.

[0017] Preferably, in the substitution reaction step, the catalyst comprises succinic anhydride and 4-dimethylaminopyridine; the molar ratio of 9-anthracene methanol, 4-dimethylaminopyridine and succinic anhydride is 1:1:4 to 1:2:6; the temperature of the substitution reaction is 25°C and the time is 24 to 48 hours.

[0018] Preferably, in the esterification reaction step, the dehydrating agent comprises 1-ethyl(3-dimethylaminopropyl)-3-carbodiimide hydrochloride; the catalyst comprises p-dimethylaminopyridine; the molar ratio of 4-(anthracite-9-ylmethoxy)-4-oxobutyric acid, dehydrating agent, catalyst and triethanolamine is 3:12:6:1 to 9:18:15:3; the temperature of the esterification reaction is 50 to 70°C and the time is 24 to 48 hours.

[0019] This invention provides the application of the tridented anthracene compounds described in the above technical solutions or the tridented anthracene compounds prepared by the above technical solutions as energy storage materials.

[0020] This invention provides a tripenlated anthracene compound. Under ultraviolet light irradiation, the anthracene compound absorbs light energy, thereby being excited to a higher energy state. At this point, the two anthracene rings react and form a dimer through π-π interactions. Under another beam of ultraviolet light irradiation, the dimer absorbs light energy, and the molecules transition to an excited state, breaking the intramolecular chemical bonds and reverting to two independent anthracene monomers. Specifically, the tripenlated anthracene compound can be excited into a dimer using 365nm ultraviolet light, simultaneously storing light energy as chemical energy. The stored energy can undergo depolymerization under 254nm light irradiation, releasing heat simultaneously. This method for synthesizing tripenlated anthracene compounds based on photodimerization / depolymerization reactions to store / release photothermal energy is simple, has high yield, and the energy storage and release process is cyclically stable. The energy storage density of this tripenlated anthracene compound is as high as 96kJ / mol, and the energy storage half-life is as long as 100 days.

[0021] Anthracene undergoes photodimerization and photodepolymerization due to its unique molecular structure and the changes in electronic energy levels under light irradiation. This invention utilizes the reversible photodimerization / depolymerization of anthracene to prepare tridentated anthracene compounds via formylation-condensation, substitution, and esterification reactions. The prepared tridentated anthracene compounds can undergo photodimerization under 365 nm light irradiation, storing photon energy, and then depolymerize under 254 nm light irradiation, releasing the stored energy as heat.

[0022] The anthracene used in this invention is derived from commercially available products or coal tar separation products. The application of this tri-branched anthracene compound as an energy storage material can not only broaden its diversified utilization path, but also further enrich the molecular photothermal storage system.

[0023] The anthracene compounds of this invention have a simple synthesis process, high yield, are easy to mass-produce, are stable in circulation, and are environmentally friendly in utilization, which can improve the level of clean utilization of coal tar. Attached Figure Description

[0024] Figure 1 This is a synthetic route diagram of the triclade anthracene compounds in this invention;

[0025] Figure 2 The images show the 1H NMR spectrum (deuterated chloroform) of the triclade anthracene compound in Example 1 (a) and the high-resolution mass spectrum of the anthracene compound (b).

[0026] Figure 3 The UV-Vis absorption spectra of the tridented anthracene compound in Example 2 after irradiation with 365nm and 254nm UV light for different times are shown in (a), and the photodimerization / depolymerization diagram of the tridented anthracene compound under alternating irradiation with 365nm and 254nm UV light is shown in (b).

[0027] Figure 4The storage energy density test curve (a) and recovery half-life curve (b) of the tri-anthracene compound in Example 3 are shown. Detailed Implementation

[0028] In this invention, unless otherwise specified, the raw materials or reagents required for preparation are all commercially available products well known to those skilled in the art.

[0029] This invention provides a tribranched anthracene compound having the structure shown in Formula I:

[0030]

[0031] like Figure 1 As shown, the present invention provides a method for preparing the triclade anthracene compound described in the above technical solution, comprising the following steps:

[0032] Anthracene, N-methylformaniline, an oxidant and a first solvent were mixed and subjected to a formylation-condensation reaction to obtain 9-anthracene formaldehyde;

[0033] The 9-anthracene formaldehyde, reducing agent, and second solvent are mixed to carry out a reduction reaction to obtain 9-anthracene methanol;

[0034] The 9-anthracene methanol, the catalyst, and the third solvent were mixed to carry out a substitution reaction to obtain 4-(anthracene-9-ylmethoxy)-4-oxobutyric acid.

[0035] The 4-(anthracene-9-ylmethoxy)-4-oxobutyric acid, dehydrating agent, catalyst, triethanolamine, and a fourth solvent are mixed and subjected to esterification to obtain tri-anthracene compounds.

[0036] In this invention, anthracene, N-methylformamide (MFA), an oxidant and a first solvent are mixed and subjected to a formylation-condensation reaction to obtain 9-anthracene formaldehyde.

[0037] In this invention, the anthracene is preferably a commercially available product or obtained by separating anthracene from coal tar; the present invention preferably uses the method for separating anthracene from coal tar disclosed in patent CN115141077B to extract anthracene.

[0038] In this invention, the oxidant preferably includes phosphorus oxychloride; the molar ratio of anthracene, N-methylformamide and the oxidant is preferably 1:2:2 to 1:4:4, more preferably 1:3:3.

[0039] In this invention, the first solvent is preferably o-dichlorobenzene; the volume ratio of N-methylformamide to the first solvent is preferably 10:1 to 5:1, more preferably 7 to 9:1.

[0040] In this invention, anthracene, N-methylformamide (MFA) and an oxidant are mixed, a first solvent is added, and the resulting mixture is heated and stirred in an oil bath to the reaction temperature and maintained for 30 to 60 minutes, more preferably 50 minutes. The anthracene dissolves to form a dark red solution, hydrochloric acid precipitates, and a formylation-condensation reaction is carried out.

[0041] In this invention, the temperature of the formylation-condensation reaction is preferably 90-100°C, more preferably 95-98°C, and the time is preferably 2-8 hours, more preferably 3-6 hours.

[0042] After the formylation-condensation reaction is completed, the present invention preferably adds dichloromethane to the obtained product and washes it several times with a saturated sodium chloride solution; the organic phase is dried on magnesium sulfate, filtered, and the solvent is evaporated to obtain 9-anthracene carboxaldehyde. The present invention does not have any particular limitations on the washing, drying, filtering, and solvent evaporation processes, which can be carried out according to procedures well known in the art.

[0043] In this invention, 9-anthracene formaldehyde, a reducing agent, and a second solvent are mixed to carry out a reduction reaction to obtain 9-anthracene methanol.

[0044] In this invention, the reducing agent preferably includes sodium borohydride; the molar ratio of 9-anthracene formaldehyde to the reducing agent is preferably 1:2 to 1:3, more preferably 1:2; the second solvent is preferably ethanol; this invention does not have a special limitation on the amount of the second solvent, as long as the reaction proceeds smoothly.

[0045] In this invention, the reducing agent is preferably added to a solvent containing 9-anthracene formaldehyde at 0°C, and the resulting mixture is subjected to a reduction reaction under stirring conditions; the temperature of the reduction reaction is preferably 25°C, and the time is preferably 4 to 8 hours, more preferably 4 hours.

[0046] After the reduction reaction is completed, the present invention preferably adds concentrated hydrochloric acid to the obtained product to decompose the unreacted reducing agent, then adds water to neutralize; then adds dichloromethane to separate the organic layer, washes several times with saturated sodium chloride solution, dries with anhydrous magnesium sulfate, filters, distills under reduced pressure, and recrystallizes the obtained crude product with ethanol to obtain 9-anthracene methanol.

[0047] In this invention, the mass concentration of the concentrated hydrochloric acid is preferably 12M; the volume ratio of the concentrated hydrochloric acid to the second solvent is preferably 1:15 to 1:10, more preferably 1:12.5; the volume ratio of the dichloromethane to the saturated sodium chloride solution is preferably 1:2 to 1:6, more preferably 1:3 to 4.8; the number of times the saturated sodium chloride solution is washed is preferably 2 to 6, more preferably 3 to 4; the reagent used for recrystallization is preferably ethanol; the recrystallization temperature is preferably 4°C; the recrystallization time is preferably 12 hours; the number of recrystallizations is preferably 2 to 5, more preferably 3. This invention does not have any special limitations on the drying, filtration, and vacuum distillation of the anhydrous magnesium sulfate; any process well known in the art can be followed. In the embodiments of this invention, the vacuum distillation conditions are specifically (0.02 MPa, 30°C, 1 hour).

[0048] In this invention, the 9-anthracene methanol, the catalyst, and the third solvent are mixed to carry out a substitution reaction to obtain 4-(anthracene-9-ylmethoxy)-4-oxobutyric acid (anthracene intermediate).

[0049] In this invention, in the substitution reaction step, the catalyst preferably includes succinic anhydride and 4-dimethylaminopyridine; the molar ratio of 9-anthracene methanol, 4-dimethylaminopyridine (DMAP) and succinic anhydride is preferably 1:1:4 to 1:2:6, more preferably 1:1:5 to 1:2:6.

[0050] In this invention, the third solvent preferably includes dichloromethane and pyridine; the volume ratio of dichloromethane to pyridine is preferably 1:1 to 3:1, more preferably 2 to 3:1; this invention does not have a special limitation on the amount of the third solvent, as long as the reaction proceeds smoothly.

[0051] In this invention, 9-anthracene methanol, 4-dimethylaminopyridine and succinic anhydride are mixed, and a third solvent is added to dissolve the mixture; the substitution reaction is carried out under stirring conditions.

[0052] In this invention, the temperature of the substitution reaction is preferably 25°C, and the time is preferably 24 to 48 hours, more preferably 36 to 48 hours.

[0053] After the substitution reaction is completed, the present invention preferably pours the resulting mixture into an ice / water mixture and heats it to room temperature; dichloromethane is added to separate the organic layer, and then the organic layer is extracted several times with a saturated sodium chloride solution. The collected organic layer is dried in anhydrous magnesium sulfate, filtered, and concentrated under vacuum to obtain 4-(anthracite-9-ylmethoxy)-4-oxobutyric acid. In the present invention, the volume ratio of dichloromethane to saturated sodium chloride solution is preferably 1:2 to 1:6, more preferably 1:2.5; the number of extractions with the saturated sodium chloride solution is preferably 2 to 5 times, more preferably 4 to 5 times; the vacuum concentration conditions preferably include 0.02 MPa, 30°C, and 1 h. The present invention does not have any special limitations on the drying process, and it can be carried out according to a process well known in the art.

[0054] In this invention, 4-(anthracene-9-ylmethoxy)-4-oxobutyric acid, a dehydrating agent, a catalyst, triethanolamine, and a fourth solvent are mixed and subjected to an esterification reaction to obtain a tri-branched anthracene compound.

[0055] In this invention, in the esterification reaction step, the dehydrating agent preferably includes 1-ethyl(3-dimethylaminopropyl)-3-carbodiimide hydrochloride (EDAC); the catalyst preferably includes p-dimethylaminopyridine (DMAP); the molar ratio of 4-(anthracite-9-ylmethoxy)-4-oxobutyric acid, dehydrating agent, catalyst and triethanolamine is preferably 3:12:6:1 to 3:18:15:3, more preferably 3:12:6:1.

[0056] In this invention, the fourth solvent is preferably chloroform; the amount of the fourth solvent is not particularly limited, as long as the reaction proceeds smoothly.

[0057] In this invention, 4-(anthracene-9-ylmethoxy)-4-oxobutyric acid, a dehydrating agent (EDAC), and a catalyst (DMAP) are mixed and then added to a fourth solvent. The mixture is magnetically stirred to dissolve the solid, and then triethanolamine is added. The resulting mixture is then subjected to an esterification reaction under continuous stirring.

[0058] In this invention, the temperature of the esterification reaction is preferably 50-70°C, more preferably 65°C, and the time is preferably 24-48h, more preferably 36h.

[0059] After the esterification reaction is completed, the present invention preferably adds 5 wt% dilute hydrochloric acid aqueous solution to the obtained product system and extracts the combined organic layer with saturated sodium bicarbonate aqueous solution. The obtained organic layer is dried with magnesium sulfate, filtered under reduced pressure, concentrated by rotary evaporation, and purified by column chromatography to obtain tri-anthracene compounds.

[0060] In this invention, the volume ratio of the dilute hydrochloric acid aqueous solution to the fourth solvent is preferably 1:3 to 1:6, more preferably 1:3.75 to 5; the extraction with the saturated sodium bicarbonate aqueous solution is preferably performed 3 to 5 times; the developing solvent used for column chromatography purification is preferably ethyl acetate and n-hexane, and the volume ratio of ethyl acetate to n-hexane is preferably 1:1 to 1:3, more preferably 1:2. This invention does not impose any special limitations on the drying, vacuum filtration, and rotary evaporation concentration of the magnesium sulfate; any process well known in the art can be followed. In the embodiments of this invention, specifically, vacuum filtration is performed at 0.02 MPa, followed by rotary evaporation concentration at 45°C for 1 to 2 hours.

[0061] This invention provides the application of the tridented anthracene compounds described in the above technical solutions or the tridented anthracene compounds prepared by the above technical solutions as energy storage materials.

[0062] This invention does not impose any special limitations on the application method; the tri-branched anthracene compound can be used directly as an energy storage material.

[0063] The technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0064] Example 1

[0065] 1) Anthracene (5.00 g, 28.00 mmol), N-methylformaniline (6.3 mL, 7.58 g, 56.00 mmol), and phosphorus oxychloride (8.56 g, 56.00 mmol) were placed in a 100 mL round-bottom flask containing 0.7 mL of o-dichlorobenzene. The mixture was then heated and stirred in an oil bath at 1500 rpm to 95 °C for 30 min. During this period, the anthracene dissolved to form a deep red solution, and hydrochloric acid precipitated. Heating continued for 3 h. After the reaction was completed, 25 mL of dichloromethane was added, followed by washing three times with 50 mL of saturated sodium chloride solution. The organic phase was dried on magnesium sulfate at room temperature for 12 h, filtered, and the solvent was evaporated at 30 °C for 1 h to obtain 9-anthracene carboxaldehyde.

[0066] Sodium borohydride (0.34 g, 9.60 mmol) was added to an ethanol solution (50 mL) containing 9-anthracene carboxaldehyde (1.00 g, 4.80 mmol) at 0 °C. The reaction mixture was stirred at 1500 r / min at 25 °C for 4 h. 5 mL of concentrated hydrochloric acid (12 M) was added dropwise, followed by water to neutrality. 25 mL of dichloromethane was added to separate the organic layer, which was washed three times with 50 mL of saturated sodium chloride solution. 150 g of anhydrous magnesium sulfate was dried at 45 °C for 12 h. After filtration and vacuum distillation (0.02 MPa, 30 °C, 1 h), the crude product was recrystallized from 50 mL of ethanol at 4 °C for 12 h. After recrystallization twice, a light yellow 9-anthracene methanol was obtained.

[0067] 2) A mixture of 9-anthracene methanol (2.08 g, 10.00 mmol), 4-dimethylaminopyridine (1.23 g, 10.0 mmol), and succinic anhydride (4.00 g, 40.0 mmol) was placed in a 250 mL round-bottom flask. Then, a mixed solution of 50 mL anhydrous dichloromethane and 50 mL anhydrous pyridine was added. The resulting mixture was stirred at 1500 r / min at 25 °C for 24 h. After the reaction was completed, the mixture was poured into 200 mL of ice / water mixture and heated to room temperature. 50 mL of dichloromethane was added to separate the organic layer. The organic layer was then washed three times with 100 mL of saturated sodium chloride solution. The collected organic layer was dried in 150 g of anhydrous magnesium sulfate at room temperature for 12 h, filtered, and concentrated under vacuum at 0.02 MPa and 30 °C for 1 h to obtain the intermediate product 4-(anthracene-9-ylmethoxy)-4-oxobutyric acid.

[0068] 3) 4-(anthracite-9-ylmethoxy)-4-oxobutyric acid (1.48 g, 4.80 mmol), 1-ethyl(3-dimethylaminopropyl)-3-carbodiimide hydrochloride (3.67 g, 19.20 mmol), and p-dimethylaminopyridine (1.17 g, 9.60 mmol) were sequentially placed in a 250 mL single-necked round-bottom flask, and 150 mL of chloroform was added. The mixture was magnetically stirred at 1500 rpm to dissolve the substances. Then, triethanolamine ( 2.38 g (1.60 mmol) was added to a round-bottom flask, and the mixture was stirred continuously at 65 °C for 24 h. After the reaction was completed, 50 mL of 5 wt% dilute hydrochloric acid aqueous solution was added, and the mixture was washed three times with 50 mL of saturated sodium bicarbonate aqueous solution. The resulting organic layer was dried over 200 g of magnesium sulfate, filtered under reduced pressure at 0.02 MPa, concentrated by rotary evaporation at 45 °C for 1 h, and purified by column chromatography (ethyl acetate and n-hexane, volume ratio = 1:2) to obtain tri-anthracene compounds.

[0069] Example 2

[0070] 1) Anthracene (5.00 g, 28.00 mmol), N-methylformaniline (9.45 mL, 11.34 g, 84.00 mmol), and phosphorus oxychloride (12.85 g, 84.00 mmol) were placed in a 100 mL round-bottom flask containing 1.35 mL of o-dichlorobenzene. The mixture was then heated and stirred in an oil bath at 1500 rpm to 98 °C for 50 min. During this period, the anthracene dissolved to form a deep red solution, and hydrochloric acid precipitated. Heating continued for 6 h. After the reaction was completed, 25 mL of dichloromethane was added, followed by washing four times with 75 mL of saturated sodium chloride solution. The organic phase was dried on magnesium sulfate at room temperature for 12 h, filtered, and the solvent was evaporated at 30 °C for 1 h to obtain 9-anthracene carboxaldehyde.

[0071] Sodium borohydride (0.34 g, 9.60 mmol) was added to an ethanol solution (50 mL) containing 9-anthracene carboxaldehyde (1.00 g, 4.80 mmol) at 0 °C. The reaction mixture was stirred at 1500 r / min at 25 °C for 4 h. 4 mL of concentrated hydrochloric acid (12 M) was added dropwise, followed by water until neutral. After the reaction was complete, 25 mL of dichloromethane was added to separate the organic layer. The layer was washed four times with 75 mL of saturated sodium chloride solution. 150 g of anhydrous magnesium sulfate was dried at 45 °C for 12 h. After filtration and vacuum distillation (0.02 MPa, 30 °C, 1 h), the crude product was recrystallized from 50 mL of ethanol at 4 °C for 12 h. After recrystallization three times, a light yellow 9-anthracene methanol was obtained.

[0072] 2) A mixture of 9-anthracene methanol (2.08 g, 10.00 mmol), 4-dimethylaminopyridine (2.44 g, 20.0 mmol), and succinic anhydride (5.00 g, 50.0 mmol) was placed in a 250 mL round-bottom flask. Then, a mixed solution of 100 mL anhydrous dichloromethane and 50 mL anhydrous pyridine was added. The resulting mixture was stirred at 1500 r / min at 25 °C for 36 h. After the reaction was completed, the mixture was poured into 200 mL of ice / water mixture and heated to room temperature. 100 mL of dichloromethane was added to separate the organic layer. The organic layer was then washed four times with 250 mL of saturated sodium chloride solution. The collected organic layer was dried in 150 g of anhydrous magnesium sulfate at room temperature for 12 h, filtered, and concentrated under vacuum at 0.02 MPa and 30 °C for 1 h to obtain the intermediate product 4-(anthracene-9-ylmethoxy)-4-oxobutyric acid.

[0073] 3) 4-(anthracite-9-ylmethoxy)-4-oxobutyric acid (1.48 g, 4.80 mmol), 1-ethyl(3-dimethylaminopropyl)-3-carbodiimide hydrochloride (3.67 g, 19.20 mmol), and p-dimethylaminopyridine (1.17 g, 9.60 mmol) were sequentially placed in a 250 mL single-necked round-bottom flask, and 150 mL of chloroform was added. The mixture was magnetically stirred at 1500 rpm to dissolve the compounds. Then, triethanolamine (2... 0.38 g (1.60 mmol) was added to a round-bottom flask, and the mixture was stirred continuously at 65 °C for 36 h. After the reaction was completed, 50 mL of 5 wt% dilute hydrochloric acid aqueous solution was added, and the mixture was washed three times with 150 mL of saturated sodium bicarbonate aqueous solution. The resulting organic layer was dried over 250 g of magnesium sulfate, filtered under reduced pressure at 0.02 MPa, concentrated by rotary evaporation at 45 °C for 2 h, and purified by column chromatography (ethyl acetate and n-hexane, volume ratio = 1:2) to obtain tri-anthracene compounds.

[0074] Example 3

[0075] 1) Anthracene (2.50 g, 14.00 mmol), N-methylformaniline (6.3 mL, 7.56 g, 56.00 mmol), and phosphorus oxychloride (8.57 g, 56.00 mmol) were placed in a 100 mL round-bottom flask containing 1.20 mL of o-dichlorobenzene. The mixture was then heated and stirred in an oil bath at 1500 rpm to 100 °C for 60 min. During this period, the anthracene dissolved to form a deep red solution, and hydrochloric acid precipitated. Heating continued for 8 h. After the reaction was completed, 25 mL of dichloromethane was added, followed by washing five times with 150 mL of saturated sodium chloride solution. The organic phase was dried on magnesium sulfate at room temperature for 12 h, filtered, and the solvent was evaporated at 30 °C for 1 h to obtain 9-anthracene carboxaldehyde.

[0076] Sodium borohydride (0.51 g, 14.40 mmol) was added to an ethanol solution (50 mL) containing 9-anthracene carboxaldehyde (1.00 g, 4.80 mmol) at 0 °C. The reaction mixture was stirred at 1500 r / min at 25 °C for 8 h. 5 mL of concentrated hydrochloric acid (12 M) was added dropwise, followed by water until neutral. After the reaction was complete, 25 mL of dichloromethane was added to separate the organic layer. The layer was washed 5 times with saturated sodium chloride solution (120 mL). 150 g of anhydrous magnesium sulfate was dried at 45 °C for 12 h. After filtration and vacuum distillation (0.02 MPa, 30 °C, 1 h), the crude product was recrystallized from 50 mL of ethanol at 4 °C for 12 h. After recrystallization 3 times, a light yellow 9-anthracene methanol was obtained.

[0077] 2) A mixture of 9-anthracene methanol (2.08 g, 10.00 mmol), 4-dimethylaminopyridine (2.44 g, 20.0 mmol), and succinic anhydride (6.00 g, 60.0 mmol) was placed in a 250 mL round-bottom flask. Then, a mixed solution of 150 mL anhydrous dichloromethane and 50 mL anhydrous pyridine was added. The resulting mixture was stirred at 1500 r / min at 25 °C for 48 h. After the reaction was completed, the mixture was poured into 200 mL of ice / water mixture and heated to room temperature. 150 mL of dichloromethane was added to separate the organic layer. The organic layer was then washed 5 times with 300 mL of saturated sodium chloride solution. The collected organic layer was dried in 150 g of anhydrous magnesium sulfate at room temperature for 12 h, filtered, and concentrated under vacuum at 0.02 MPa and 30 °C for 1 h to obtain the intermediate product 4-(anthracene-9-ylmethoxy)-4-oxobutyric acid.

[0078] 3) 4-(anthracite-9-ylmethoxy)-4-oxobutyric acid (1.48 g, 4.80 mmol), 1-ethyl(3-dimethylaminopropyl)-3-carbodiimide hydrochloride (3.67 g, 19.20 mmol), and p-dimethylaminopyridine (1.17 g, 9.60 mmol) were sequentially placed in a 250 mL single-necked round-bottom flask, and 150 mL of chloroform was added. The mixture was magnetically stirred at 1500 rpm to dissolve the compounds. Then, triethanolamine (2... 0.38 g (1.60 mmol) was added to a round-bottom flask, and the mixture was stirred continuously at 65 °C for 48 h. After the reaction was completed, 45 mL of 5 wt% dilute hydrochloric acid aqueous solution was added, and the mixture was washed 5 times with 100 mL of saturated sodium bicarbonate aqueous solution. The resulting organic layer was dried over 300 g of magnesium sulfate, filtered under reduced pressure at 0.02 MPa, concentrated by rotary evaporation at 45 °C for 2 h, and purified by column chromatography (ethyl acetate and n-hexane, volume ratio = 1:2) to obtain tri-anthracene compounds.

[0079] Characterization and performance testing

[0080] Figure 2 The images show the 1H NMR spectrum (deuterated chloroform) of the triclade anthracene compound in Example 1 (a) and the high-resolution mass spectrum (b) of the anthracene compound. Figure 2 As can be seen, tri-branched anthracene compounds have been successfully synthesized.

[0081] Figure 3 The tri-anthracene compound in Example 2 was irradiated with 365 nm and 254 nm ultraviolet light (methanol solution, 1 M, light power 15 mW / cm²). 2 (a) UV-Vis absorption spectra after different time intervals and (b) schematic diagram of photodimerization / depolymerization of triflene anthracene compounds under alternating irradiation with 365 nm and 254 nm UV light. Figure 3 It is known that triadenosine compounds can effectively complete reversible photodimerization / depolymerization reactions under ultraviolet light irradiation.

[0082] Figure 4 The storage energy density test curve of the tri-anthracene compound in Example 3 is shown in (a) (differential scanning calorimeter, heating at 10 °C / min, temperature range 0–220 °C) and (b) (UV-Vis spectrophotometer, the tri-anthracene compound was dissolved in dimethyl sulfoxide at a concentration of 1 M, and the resulting solution was subjected to 365 nm UV light at a concentration of 60 mW / cm²). 2 The absorbance of the dimer generated 2 hours after excitation was measured at a fixed wavelength after being placed in the dark at room temperature for different times. Figure 4 It can be calculated that the energy density of the tri-branched anthracene compound is 96 kJ / mol, and the energy storage time is as long as 90 days.

[0083] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A tribranched anthracene compound, characterized in that, It has the structure shown in Equation I:

2. The method for preparing the triclade anthracene compound according to claim 1, characterized in that, Includes the following steps: Anthracene, N-methylformaniline, an oxidant and a first solvent were mixed and subjected to a formylation-condensation reaction to obtain 9-anthracene formaldehyde; The 9-anthracene formaldehyde, reducing agent, and second solvent are mixed to carry out a reduction reaction to obtain 9-anthracene methanol; The 9-anthracene methanol, the catalyst, and the third solvent were mixed to carry out a substitution reaction to obtain 4-(anthracene-9-ylmethoxy)-4-oxobutyric acid. The 4-(anthracene-9-ylmethoxy)-4-oxobutyric acid, dehydrating agent, catalyst, triethanolamine, and a fourth solvent are mixed and subjected to esterification to obtain tri-anthracene compounds.

3. The preparation method according to claim 2, characterized in that, The anthracene is obtained by separating coal tar.

4. The preparation method according to claim 2, characterized in that, The oxidant includes phosphorus oxychloride; the molar ratio of anthracene, N-methylformamide and the oxidant is 1:2:2 to 1:4:4; the volume ratio of N-methylformamide to the first solvent is 10:1 to 5:

1.

5. The preparation method according to claim 2 or 4, characterized in that, The formylation-condensation reaction is carried out at a temperature of 90–100°C for 2–8 hours.

6. The preparation method according to claim 2, characterized in that, The reducing agent includes sodium borohydride; the molar ratio of 9-anthracene formaldehyde to the reducing agent is 1:2 to 1:3; the reduction reaction is carried out at a temperature of 25°C for 4 to 8 hours.

7. The preparation method according to claim 2, characterized in that, The third solvent comprises dichloromethane and pyridine; the volume ratio of dichloromethane to pyridine is 1:1 to 3:

1.

8. The preparation method according to claim 2 or 7, characterized in that, In the substitution reaction step, the catalyst includes succinic anhydride and 4-dimethylaminopyridine; the molar ratio of 9-anthracene methanol, 4-dimethylaminopyridine and succinic anhydride is 1:1:4 to 1:2:6; the temperature of the substitution reaction is 25°C and the time is 24 to 48 hours.

9. The preparation method according to claim 2, characterized in that, In the esterification reaction step, the dehydrating agent includes 1-ethyl(3-dimethylaminopropyl)-3-carbodiimide hydrochloride; the catalyst includes p-dimethylaminopyridine; the molar ratio of 4-(anthracite-9-ylmethoxy)-4-oxobutyric acid, dehydrating agent, catalyst and triethanolamine is 3:12:6:1 to 9:18:15:3; the temperature of the esterification reaction is 50 to 70°C and the time is 24 to 48 hours.

10. The application of the tri-branched anthracene compound of claim 1 or the tri-branched anthracene compound prepared by any one of claims 2 to 9 as an energy storage material.

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