Anthryl compound, preparation method thereof and application of anthryl compound as solar thermal fuel

Abstract

The invention provides an anthryl compound, a preparation method thereof and application of the anthryl compound as solar thermal fuel, and belongs to the field of energy and chemical industry. The anthryl compound can be converted into a dimer under the irradiation of 365nm ultraviolet light and store light energy as chemical energy at the same time, and is subjected to a photodepolymerization reaction under the irradiation of 254nm ultraviolet light and releases heat at the same time, that is, the anthryl solar thermal fuel can store or release photo-thermal energy through a reversible photodimerization / depolymerization reaction. In addition, the anthryl compound also has the unique advantage of light-operated reversible solid-liquid phase change, and the simultaneous storage of photon energy and phase change energy can be realized. The storage energy density of the anthryl compound is about 65 kJ / mol, and the storage half-life period is as long as 60 days. The anthryl compound and the preparation method thereof provided by the invention provide a new strategy for light energy storage and utilization.

Description

Technical Field

[0001] The invention relates to the field of energy chemical industry, and in particular to an anthracene-based compound and a preparation method thereof and application thereof as solar thermal fuel. Background Art

[0002] Anthracene, as a polycyclic aromatic hydrocarbon containing three rings, is widely used in chemical production. In industry, anthracene is generally oxidized first, and then nitrated, sulfonated and other processes are used to provide intermediates for dyes, medicines and optoelectronic materials. Anthracene is present in high levels in coal tar. Patent CN115141077B provides a method for separating anthracene from coal tar that is simple to operate, warm and low-cost. In addition, anthracene has the advantages of controllable luminescence, easy transfer of energy and charge, and unique light and heat reversible dimerization. However, the current preparation method of anthracene-based compounds is relatively complicated, and there are few reports on the development of anthracene-based solar thermal fuels based on photodimerization / depolymerization reactions. Solar thermal fuels are a type of molecular light switch based on reversible molecular spatial configuration changes to achieve light energy storage and heat energy release. The utilization process is cyclically stable and does not emit any gas or pollutants. Anthracene-based compounds exhibit relatively low electronic energy gaps due to their extended aromatic π system, and are easy to generate dimers, and the dimers can be rapidly depolymerized under illumination conditions. Therefore, the preparation of new anthracene-based compounds and their exploration as solar thermal fuels have important application value in broadening the application pathways of polycyclic aromatic hydrocarbon anthracene. Summary of the invention

[0003] The object of the present invention is to provide an anthracene-based compound and a preparation method thereof and application thereof as a solar thermal fuel.

[0004] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0005] The present invention provides an anthracene-based compound having a structure shown in Formula 1:

[0006]

[0007] In formula 1, n=10~16.

[0008] Preferably, n=10, 13 or 16.

[0009] The present invention provides a method for preparing the anthracene-based compound described in the above technical solution, comprising the following steps:

[0010] Anthracene, N-methylformanilide, phosphorus oxychloride and a first solvent are mixed to carry out a formylation-condensation reaction to obtain 9-anthracene carboxaldehyde;

[0011] The 9-anthracene formaldehyde, sodium borohydride and a second solvent are mixed and subjected to a reduction reaction to obtain 9-anthracene methanol;

[0012] The 9-anthracene methanol, succinic anhydride, 4-dimethylaminopyridine and a third solvent are mixed and subjected to a substitution reaction to obtain 4-(anthracen-9-ylmethoxy)-4-oxobutanoic acid;

[0013] The 4-(anthracen-9-ylmethoxy)-4-oxobutanoic acid, 1-ethyl(3-dimethylaminopropyl)-3-carbodiimide hydrochloride, 4-dimethylaminopyridine, a long-chain fatty alcohol and a fourth solvent are mixed and subjected to an esterification reaction to obtain an anthracene compound;

[0014] The long-chain fatty alcohol has 12 to 18 carbon atoms.

[0015] Preferably, the anthracene is prepared from coal tar.

[0016] Preferably, the molar ratio of anthracene, N-methylformanilide and phosphorus oxychloride is 1:2:2 to 1:4:4; the volume ratio of N-methylformanilide to the first solvent is 10:1 to 5:1;

[0017] The temperature of the formylation-condensation reaction is 90-100° C. and the time is 2-8 hours.

[0018] Preferably, the molar ratio of 9-anthracenecarboxaldehyde to sodium borohydride is 1:2 to 1:3; the temperature of the reduction reaction is 25° C., and the time is 4 to 8 hours.

[0019] Preferably, the third solvent includes dichloromethane and pyridine; the volume ratio of dichloromethane to pyridine is 1:1 to 3:1.

[0020] Preferably, the molar ratio of 9-anthracenemethanol, 4-dimethylaminopyridine and succinic anhydride is 1:1:4 to 1:2:6;

[0021] The temperature of the substitution reaction is 25° C. and the time is 24 to 48 hours.

[0022] Preferably, the molar ratio of 4-(anthracen-9-ylmethoxy)-4-oxobutanoic acid, 1-ethyl(3-dimethylaminopropyl)-3-carbodiimide hydrochloride, 4-dimethylaminopyridine and long-chain fatty alcohol is 1:4:2:1 to 1:6:5:3;

[0023] The temperature of the esterification reaction is 25° C. and the time is 24 to 48 hours.

[0024] The present invention provides the use of the anthracene-based compound described in the above technical solution or the anthracene-based compound prepared by the preparation method described in the above technical solution as a solar thermal fuel.

[0025] The present invention provides an anthracene-based compound, which can undergo a photodimerization reaction under the irradiation of ultraviolet light of a specific wavelength to store photothermal energy, and undergo a photodepolymerization reaction under the irradiation of ultraviolet light of another wavelength to release heat, that is, the anthracene-based compound can effectively undergo a reversible photodimerization / depolymerization reaction to store or release photothermal energy, and also has the unique advantage of a light-controlled reversible solid-liquid phase change. In addition, the anthracene-based compound has a high storage energy density (65kJ / mol) and a long storage half-life (3 days), which can realize the simultaneous utilization of stored photon energy and phase change energy, effectively improve the storage performance of solar thermal fuel, and the utilization process is cyclically stable without any greenhouse gas release.

[0026] The present invention utilizes the reversible photodimerization / depolymerization reaction of anthracene to prepare anthracene-based compounds through formylation-condensation reaction, substitution reaction and esterification reaction. The prepared anthracene-based compounds can undergo photodimerization under 365nm light irradiation accompanied by solid-liquid phase change to simultaneously store photon energy and phase change energy, and can undergo depolymerization under 254nm light irradiation accompanied by liquid-solid phase change, while releasing the stored light energy and phase change energy in the form of heat energy.

[0027] The preparation raw material anthracene used in the present invention is commercially available or is a coal tar separation product. The application of the anthracene-based compound as a solar thermal fuel can not only broaden its diversified utilization path, but also further enrich the solar thermal fuel molecular system.

[0028] The anthracene-based compound of the present invention has a simple synthesis process, high yield, easy mass production, stable circulation and environmentally friendly utilization process, and can improve the clean utilization level of coal tar. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a synthetic route diagram of the anthracene-based compound of the present invention;

[0030] Figure 2 The NMR hydrogen spectra (deuterated chloroform) of 9-anthracenemethanol (a), the intermediate product 4-(anthracen-9-ylmethoxy)-4-oxobutanoic acid (b), and the anthracene compound (c) prepared in Example 1, and the mass spectrum of the anthracene compound (d);

[0031] Figure 3 The anthracene compound in Example 1 was irradiated with 365 nm ultraviolet light (a) and 254 nm ultraviolet light (b) (illumination power 10 mW / cm 2 ) UV-visible absorption spectra after different time periods and schematic diagram of photodimerization / depolymerization of anthracene compounds under alternating irradiation of 365nm and 254nm UV light (c);

[0032] Figure 4 The anthracene compound prepared in Example 2 was excited by ultraviolet light (illumination power 50 mW / cm 2) optical photograph of photoreversible solid-liquid phase transition under ;

[0033] Figure 5 (a) storage energy density test curve and (b) recovery half-life curve of the anthracene-based compound in Example 3. DETAILED DESCRIPTION

[0034] The present invention provides an anthracene-based compound having a structure shown in Formula 1:

[0035]

[0036] In formula 1, n=10~16.

[0037] In the present invention, n=10, 13 or 16.

[0038] like Figure 1 As shown, the present invention provides a method for preparing the anthracene-based compound described in the above technical scheme, comprising the following steps:

[0039] Anthracene, N-methylformanilide, phosphorus oxychloride and a first solvent are mixed to carry out a formylation-condensation reaction to obtain 9-anthracene carboxaldehyde;

[0040] The 9-anthracene formaldehyde, sodium borohydride and a second solvent are mixed and subjected to a reduction reaction to obtain 9-anthracene methanol;

[0041] The 9-anthracene methanol, succinic anhydride, 4-dimethylaminopyridine and a third solvent are mixed and subjected to a substitution reaction to obtain 4-(anthracen-9-ylmethoxy)-4-oxobutanoic acid;

[0042] The 4-(anthracen-9-ylmethoxy)-4-oxobutanoic acid, 1-ethyl(3-dimethylaminopropyl)-3-carbodiimide hydrochloride, 4-dimethylaminopyridine, a long-chain fatty alcohol and a fourth solvent are mixed and subjected to an esterification reaction to obtain an anthracene compound;

[0043] The long-chain fatty alcohol has 12 to 18 carbon atoms.

[0044] In the present invention, unless otherwise specified, the required raw materials or reagents are commercially available products well known to those skilled in the art.

[0045] The invention mixes anthracene, N-methylformanilide, phosphorus oxychloride and a first solvent, and performs formylation-condensation reaction to obtain 9-anthracene formaldehyde.

[0046] In the present invention, the anthracene is preferably a commercially available product or obtained by separation from coal tar; the present invention preferably adopts the method for separating anthracene from coal tar disclosed in patent CN115141077B to extract anthracene.

[0047] In the present invention, the molar ratio of anthracene, N-methylformanilide and phosphorus oxychloride is preferably 1:2:2 to 1:4:4, more preferably 1:3:3.

[0048] In the present invention, the first solvent is preferably o-dichlorobenzene; the volume ratio of the N-methylformanilide to the first solvent is preferably 10:1 to 5:1, more preferably 7 to 9:1.

[0049] The present invention preferably mixes anthracene, N-methylformanilide and phosphorus oxychloride, adds a first solvent, heats and stirs the mixed liquid in an oil bath to a reaction temperature, and maintains the mixture for 30 to 60 minutes, more preferably 50 minutes, until anthracene dissolves to form a deep red solution, hydrochloric acid precipitates, and a formylation-condensation reaction is performed.

[0050] In the present 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 h, more preferably 3-6 h.

[0051] After the formylation-condensation reaction is completed, dichloromethane is added to the obtained product and then washed several times with a saturated sodium chloride solution; the organic phase is dried over magnesium sulfate, filtered, and the solvent is evaporated to obtain 9-anthracenecarboxaldehyde. The present invention has no special limitation on the washing, drying, filtering and evaporating the solvent, and can be carried out according to the process well known in the art.

[0052] The present invention mixes the 9-anthracene formaldehyde, sodium borohydride and a second solvent, and performs a reduction reaction to obtain 9-anthracene methanol.

[0053] In the present invention, the molar ratio of 9-anthracenecarboxaldehyde to sodium borohydride is preferably 1:2 to 1:3; the second solvent is preferably ethanol; the present invention has no particular limitation on the amount of the second solvent, as long as the reaction proceeds smoothly.

[0054] In the present invention, sodium borohydride is preferably added to a solvent containing 9-anthracenecarboxaldehyde at 0°C, and the mixture is subjected to a reduction reaction under stirring; the temperature of the reduction reaction is preferably 25°C, and the time is preferably 4 to 8 hours.

[0055] After the reduction reaction is completed, the present invention preferably adds concentrated hydrochloric acid to the obtained product to decompose unreacted sodium borohydride, and then adds water to neutralize; then adds dichloromethane to separate the organic layer, washes it several times with a saturated sodium chloride solution, dries it with anhydrous magnesium sulfate, filters it, and distills it under reduced pressure. The obtained crude product is recrystallized with ethanol to obtain 9-anthracenemethanol.

[0056] In the present 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 washings with the saturated sodium chloride solution is preferably 2 to 6 times, more preferably 3 to 4 times; the number of recrystallizations is preferably 2 to 5 times, more preferably 3 times.

[0057] The present invention mixes the 9-anthracene methanol, succinic anhydride, 4-dimethylaminopyridine and a third solvent, and performs a substitution reaction to obtain 4-(anthracen-9-ylmethoxy)-4-oxobutanoic acid.

[0058] In the present invention, the molar ratio of 9-anthracenemethanol, 4-dimethylaminopyridine and succinic anhydride is preferably 1:1:4 to 1:2:6, and more preferably 1:1:5 to 1:2:6.

[0059] In the present 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 2:1; the present invention has no special limitation on the amount of the third solvent, as long as the reaction proceeds smoothly.

[0060] In the present invention, 9-anthracene methanol, 4-dimethylaminopyridine and succinic anhydride are preferably mixed, a third solvent is added to dissolve the mixture, and the substitution reaction is carried out under stirring conditions.

[0061] In the present invention, the temperature of the substitution reaction is preferably 25° C., and the time is preferably 24 to 48 hours, more preferably 36 hours.

[0062] After the substitution reaction is completed, the resulting mixture is poured into an ice / water mixture and heated 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, and the collected organic layer is dried in anhydrous magnesium sulfate, filtered, and concentrated in vacuo to obtain 4-(anthracen-9-ylmethoxy)-4-oxobutanoic 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 times.

[0063] The present invention mixes the 4-(anthracen-9-ylmethoxy)-4-oxobutanoic acid, 1-ethyl(3-dimethylaminopropyl)-3-carbodiimide hydrochloride, 4-dimethylaminopyridine, a long-chain fatty alcohol and a fourth solvent, and performs an esterification reaction to obtain an anthracene compound.

[0064] In the present invention, the molar ratio of 4-(anthracen-9-ylmethoxy)-4-oxobutanoic acid, 1-ethyl(3-dimethylaminopropyl)-3-carbodiimide hydrochloride, 4-dimethylaminopyridine and long-chain fatty alcohol is preferably 1:4:2:1 to 1:6:5:3, more preferably 1:5:3:3; the number of carbon atoms of the long-chain fatty alcohol is 12 to 18, preferably 12, 15 or 18.

[0065] In the present invention, the fourth solvent is preferably chloroform; the present invention has no special limitation on the amount of the fourth solvent, as long as the reaction proceeds smoothly.

[0066] The present invention preferably mixes 4-(anthracen-9-ylmethoxy)-4-oxobutanoic acid, 1-ethyl(3-dimethylaminopropyl)-3-carbodiimide hydrochloride (EDAC) and 4-dimethylaminopyridine (DMAP), adds a fourth solvent, stirs magnetically to dissolve the solid, then adds a long-chain fatty alcohol, and performs an esterification reaction on the resulting mixture under continuous stirring.

[0067] In the present invention, the temperature of the esterification reaction is preferably 25° C., and the time is preferably 24 to 48 hours, more preferably 36 hours.

[0068] After the esterification reaction is completed, the present invention preferably adds a 5 wt% dilute hydrochloric acid aqueous solution to the obtained product system and extracts the combined organic layer with a saturated sodium bicarbonate aqueous solution, and the obtained organic layer is dried over magnesium sulfate, filtered under reduced pressure, concentrated by rotary evaporation, and purified by column chromatography to obtain an anthracene compound.

[0069] In the present 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 number of extractions with the saturated sodium bicarbonate aqueous solution is preferably 3 to 5 times; the developing solvent used for the 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.

[0070] The present invention provides the use of the anthracene-based compound described in the above technical solution or the anthracene-based compound prepared by the preparation method described in the above technical solution as a solar thermal fuel.

[0071] The present invention has no special limitation on the application method, and the anthracene-based compound can be directly used as a solar thermal fuel.

[0072] The technical solutions provided by the present invention are described in detail below in conjunction with the embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0073] Example 1

[0074] 1) Anthracene (5.00 g, 28.00 mmol), N-methylformanilide (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, and then heated and stirred at 1500 r / min in an oil bath to 95°C for 30 min; during this period, anthracene dissolved to form a deep red solution, hydrochloric acid precipitated, and heating was continued for 3 h; after the reaction was completed, 25 mL of dichloromethane was first added and then washed three times with 50 mL of saturated sodium chloride solution; the organic phase was dried over magnesium sulfate at room temperature for 12 h, filtered, and the solvent was evaporated at 30°C for 1 h to obtain 9-anthracenecarboxaldehyde. ; Sodium borohydride (0.34 g, 9.60 mmol) was added to an ethanol solution (50 mL) containing 9-anthracenecarboxaldehyde (1.00 g, 4.80 mmol) at 0°C, and the reaction mixture was stirred at 1500 r / min at 25°C for 4 h; 5 mL of concentrated hydrochloric acid (concentration of 12 M) was added dropwise, and then water was added to neutralize; 25 mL of dichloromethane was added to separate the organic layer, and the organic layer was washed with 50 mL of saturated sodium chloride solution for 3 times, and 150 g of anhydrous magnesium sulfate was dried at 45°C for 12 h. After filtering and vacuum distillation (0.02 MPa, 30°C, 1 h), the obtained crude product was recrystallized from 50 mL of ethanol at 4°C for 12 h. After recrystallization twice, light yellow 9-anthracenemethanol was obtained;

[0075] 2) A mixture of 9-anthracenemethanol (2.08 g, 10.00 mmol), 4-dimethylaminopyridine (1.23 g, 10.01 mmol) and succinic anhydride (4.00 g, 40.02 mmol) was placed in a 250 mL round-bottom flask, followed by addition of a mixed solution of 50 mL of anhydrous dichloromethane and 50 mL of anhydrous pyridine, and the resulting mixed solution was stirred at 1500 r / min at 25° C. for 24 h; after the reaction was completed, the mixture solution was poured into 200 mL of an ice / water mixture and heated to room temperature, 50 mL of dichloromethane was added to separate the organic layer, and then the organic layer was washed 3 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 in vacuo at 0.02 MPa and 30° C. for 1 h to obtain the intermediate product 4-(anthracen-9-ylmethoxy)-4-oxobutanoic acid.

[0076] 3) 4-(Anthracene-9-ylmethoxy)-4-oxobutanoic 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 placed in a 250 mL single-necked round-bottom flask, 150 mL of chloroform was added, and the mixture was dissolved by magnetic stirring at 1500 r / min, and then n-dodecanol was added. (0.89 g, 4.80 mmol) was added to a round-bottom flask, and the mixture was stirred at 25°C for 24 h; after the reaction, 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 obtained organic layer was dried over 150 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 an anthracene compound.

[0077] Example 2

[0078] 1) Anthracene (5.00 g, 28.00 mmol), N-methylformanilide (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, and then heated and stirred at 1500 r / min in an oil bath to 98° C. for 50 min; during this period, anthracene dissolved to form a deep red solution, hydrochloric acid precipitated, and heating was continued for 6 h; after the reaction was completed, 25 mL of dichloromethane was first added and then washed 4 times with 75 mL of saturated sodium chloride solution; the organic phase was dried over magnesium sulfate at room temperature for 12 h, filtered, and the solvent was evaporated at 30° C. for 1 h to obtain 9-anthracenecarboxaldehyde. ; Sodium borohydride (0.34 g, 9.60 mmol) was added to an ethanol solution (50 mL) containing 9-anthracenecarboxaldehyde (1.00 g, 4.80 mmol) at 0°C, and the reaction mixture was stirred at 1500 r / min at 25°C for 4 h; 4 mL of concentrated hydrochloric acid (concentration of 12 M) was added dropwise, and then water was added to neutralize; After the reaction was completed, 25 mL of dichloromethane was added to separate the organic layer, and the organic layer was washed 4 times with 75 mL of saturated sodium chloride solution, and 150 g of anhydrous magnesium sulfate was dried at 45°C for 12 h, filtered and distilled under reduced pressure (0.02 MPa, 30°C, 1 h), and the resulting crude product was recrystallized from 50 mL of ethanol at 4°C for 12 h. After recrystallization 3 times, light yellow 9-anthracenemethanol was obtained;

[0079] 2) A mixture of 9-anthracenemethanol (2.08 g, 10.00 mmol), 4-dimethylaminopyridine (2.44 g, 20.01 mmol) and succinic anhydride (5.00 g, 50.02 mmol) was placed in a 250 mL round-bottom flask, followed by addition of a mixed solution of 100 mL of anhydrous dichloromethane and 50 mL of anhydrous pyridine, and the resulting mixed solution was stirred at 1500 r / min at 25° C. for 36 h; after the reaction was completed, the mixture solution was poured into 200 mL of an ice / water mixture and heated to room temperature, 100 mL of dichloromethane was added to separate the organic layer, and then the organic layer was washed 4 times with 250 mL of a saturated sodium chloride solution, and the collected organic layer was dried in 150 g of anhydrous magnesium sulfate at room temperature for 12 h, filtered, and concentrated in vacuo at 0.02 MPa and 30° C. for 1 h to obtain the intermediate product 4-(anthracen-9-ylmethoxy)-4-oxobutanoic acid;

[0080] 3) 4-(Anthracene-9-ylmethoxy)-4-oxobutanoic 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 placed in a 250 mL single-necked round-bottom flask in sequence and 150 mL of chloroform was added, and the mixture was dissolved by magnetic stirring at 1500 r / min, and then n-dodecanol (1.78 g, 9.60 mmol) was added to the round-bottom flask, and the mixture was stirred at 25° C. for 36 h; after the reaction was completed, 30 mL of 5 wt% dilute hydrochloric acid aqueous solution was added, and the mixture was washed 4 times with 50 mL of saturated sodium bicarbonate aqueous solution, and the obtained organic layer was dried over 150 g of magnesium sulfate, filtered under reduced pressure at 0.02 MPa, concentrated at 45° C. for 1 h, and purified by column chromatography (ethyl acetate and n-hexane, volume ratio = 1:3) to obtain an anthracene compound.

[0081] Example 3

[0082] 1) Anthracene (2.50 g, 14.00 mmol), N-methylformanilide (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, and then heated and stirred at 1500 r / min in an oil bath to 100° C. for 60 min; during this period, anthracene dissolved to form a deep red solution, hydrochloric acid precipitated, and heating was continued for 8 h; after the reaction was completed, 25 mL of dichloromethane was first added and then washed 5 times with 150 mL of saturated sodium chloride solution; the organic phase was dried over magnesium sulfate at room temperature for 12 h, filtered, and the solvent was evaporated at 30° C. for 1 h to obtain 9-anthracenecarboxaldehyde; at 0 Sodium borohydride (0.51 g, 14.40 mmol) was added to an ethanol solution (50 mL) containing 9-anthracenecarboxaldehyde (1.00 g, 4.80 mmol) at 25°C, and the reaction mixture was stirred at 1500 r / min at 25°C for 8 h; 5 mL of concentrated hydrochloric acid (concentration of 12 M) was added dropwise, and then water was added to neutralize; after the reaction was completed, 25 mL of dichloromethane was added to separate the organic layer, and the organic layer was washed with a saturated sodium chloride solution (120 mL) for 5 times, and 150 g of anhydrous magnesium sulfate was dried at 45°C for 12 h, filtered and distilled under reduced pressure (0.02 MPa, 30°C, 1 h), and the obtained crude product was recrystallized from 50 mL of ethanol at 4°C for 12 h. After recrystallization 3 times, light yellow 9-anthracenemethanol was obtained;

[0083] 2) A mixture of 9-anthracenemethanol (2.08 g, 10.00 mmol), 4-dimethylaminopyridine (2.44 g, 20.01 mmol) and succinic anhydride (6.00 g, 60.02 mmol) was placed in a 250 mL round-bottom flask, followed by addition of a mixed solution of 150 mL anhydrous dichloromethane and 50 mL anhydrous pyridine, and the resulting mixed solution was stirred at 1500 r / min at 25° C. for 48 h; after the reaction was completed, the mixture solution was poured into 200 mL of an ice / water mixture and heated to room temperature, 150 mL of dichloromethane was added to separate the organic layer, and then the organic layer was washed 5 times with 300 mL of saturated sodium chloride solution, and the collected organic layer was dried in 150 g of anhydrous magnesium sulfate at room temperature for 12 h, filtered, and concentrated in vacuo at 0.02 MPa and 30° C. for 1 h to obtain the intermediate product 4-(anthracen-9-ylmethoxy)-4-oxobutanoic acid;

[0084] 3) 4-(Anthracene-9-ylmethoxy)-4-oxobutanoic acid (1.48 g, 4.80 mmol), 1-ethyl(3-dimethylaminopropyl)-3-carbodiimide hydrochloride (4.58 g, 24.00 mmol) and 4-dimethylaminopyridine (1.75 g, 14.40 mmol) were placed in a 250 mL single-necked round-bottom flask, 150 mL of chloroform was added, and the mixture was dissolved by magnetic stirring at 1500 r / min. Diol (2.68 g, 14.40 mmol) was added to a round-bottom flask, and the mixture was stirred at 25°C for 48 h. After the reaction, 40 mL of a 5 wt% aqueous solution of dilute hydrochloric acid was added, and the mixture was washed 5 times with 50 mL of a saturated aqueous solution of sodium bicarbonate. The resulting organic layer was dried over 150 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 = 1:2) to obtain an anthracene compound.

[0085] Characterization and performance testing

[0086] Figure 2 The following are the H NMR spectra (deuterated chloroform) of 9-anthracenemethanol (a), the intermediate product 4-(anthracen-9-ylmethoxy)-4-oxobutanoic acid (b), and the anthracene compound (c) prepared in Example 1, and the mass spectrum of the anthracene compound (d). Figure 2 It can be seen that the product 9-anthracene methanol, the intermediate product 4-(anthracen-9-ylmethoxy)-4-oxobutanoic acid and the target anthracene compound have been successfully synthesized.

[0087] Figure 3 The anthracene compound in Example 1 was irradiated with 365 nm ultraviolet light (a) and 254 nm ultraviolet light (b) (methanol solution, 1 M, irradiation power 10 mW / cm 2 ) UV-visible absorption spectra after different time periods and a schematic diagram of the photodimerization / depolymerization of anthracene compounds under alternating irradiation of 365nm and 254nm UV light (c). Figure 3 It can be seen that anthracene compounds can effectively complete reversible photodimerization / depolymerization reactions under ultraviolet light irradiation.

[0088] Figure 4 The anthracene compound prepared in Example 2 was excited by ultraviolet light (illumination power 50 mW / cm 2 ) under the light-induced reversible solid-liquid phase transition optical photograph. Figure 4 It can be seen that the prepared anthracene-based compounds can achieve reversible solid-liquid phase transition under ultraviolet light irradiation.

[0089] Figure 5 : (a) storage energy density test curve and (b) recovery half-life curve of the anthracene compound in Example 3. Figure 5It can be calculated that the energy density of anthracene-based compounds is 65 kJ / mol, and the energy storage time is up to 60 days.

[0090] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. An anthracene-based compound, characterized in that It has the structure shown in formula 1: In formula 1, n=10~16.

2. The anthracene-based compound according to claim 1, characterized in that The n=10, 13 or 16.

3. The method for preparing the anthracene-based compound according to claim 1 or 2, characterized in that: The following steps are involved: Anthracene, N-methylformanilide, phosphorus oxychloride and a first solvent are mixed to carry out a formylation-condensation reaction to obtain 9-anthracene carboxaldehyde; The 9-anthracene formaldehyde, sodium borohydride and a second solvent are mixed and subjected to a reduction reaction to obtain 9-anthracene methanol; The 9-anthracene methanol, succinic anhydride, 4-dimethylaminopyridine and a third solvent are mixed and subjected to a substitution reaction to obtain 4-(anthracen-9-ylmethoxy)-4-oxobutanoic acid; The 4-(anthracen-9-ylmethoxy)-4-oxobutanoic acid, 1-ethyl(3-dimethylaminopropyl)-3-carbodiimide hydrochloride, 4-dimethylaminopyridine, a long-chain fatty alcohol and a fourth solvent are mixed and subjected to an esterification reaction to obtain an anthracene compound; The long-chain fatty alcohol has 12 to 18 carbon atoms.

4. The preparation method according to claim 3, characterized in that: The anthracene is separated and obtained from coal tar.

5. The preparation method according to claim 3, characterized in that: The molar ratio of anthracene, N-methylformanilide and phosphorus oxychloride is 1:2:2 to 1:4:4; the volume ratio of N-methylformanilide to the first solvent is 10:1 to 5:1; The temperature of the formylation-condensation reaction is 90-100° C. and the time is 2-8 hours.

6. The preparation method according to claim 3, characterized in that: The molar ratio of 9-anthracenecarboxaldehyde to sodium borohydride is 1:2 to 1:3; the temperature of the reduction reaction is 25° C., and the time is 4 to 8 hours.

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

1.

8. The preparation method according to claim 3 or 7, characterized in that: The molar ratio of 9-anthracenemethanol, 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 3, characterized in that: The molar ratio of 4-(anthracen-9-ylmethoxy)-4-oxobutanoic acid, 1-ethyl(3-dimethylaminopropyl)-3-carbodiimide hydrochloride, 4-dimethylaminopyridine and long-chain fatty alcohol is 1:4:2:1 to 1:6:5:3; The temperature of the esterification reaction is 25° C. and the time is 24 to 48 hours.

10. Use of the anthracene-based compound according to any one of claims 1 to 2 or the anthracene-based compound prepared by the preparation method according to any one of claims 3 to 9 as solar thermal fuel.

Images