Use of 2,3,5,6-pyrazinetetracarbonitrile as acceptor for preparing a photo-thermal conversion material for acceptor supramolecular complexes

Abstract

The application belongs to the technical field of photothermal conversion materials, and discloses the use of 2,3,5,6-pyrazine tetranitrile as an acceptor in the preparation of a donor-acceptor supramolecular complex photothermal conversion material. The donor-acceptor supramolecular complex photothermal conversion material prepared by using 2,3,5,6-pyrazine tetranitrile as an acceptor not only has long-wavelength absorption in the near infrared, a wide absorption range, and good absorption intensity, but also has excellent photothermal conversion capacity and good photothermal stability, and has great application potential in the fields of seawater desalination, sterilization, biological photodiagnosis and treatment, and the like.

Description

Technical Field

[0001] This invention belongs to the field of photothermal conversion materials technology, and specifically relates to the use of 2,3,5,6-pyrazinetetranitrile as an acceptor in the preparation of acceptor supramolecular complex photothermal conversion materials. Background Technology

[0002] Photothermal conversion materials refer to a class of materials that can convert light energy into heat energy through their own photothermal conversion mechanism under illumination. The wavelength range in which solar radiation energy is most concentrated is 0.2–4 μm. Due to the absorption effects of ozone, water vapor, and other substances in the Earth's atmosphere, solar radiation with wavelengths below 200 nm and above 2500 nm basically cannot reach the Earth's surface. The solar radiation bands that can reach the Earth's surface mainly include: ultraviolet light (250–400 nm, energy share 7%), visible light (400–760 nm, energy share 50%), and near-infrared light (760–2500 nm, energy share 43%). Developing photothermal conversion materials with high light-harvesting capacity and photothermal conversion efficiency can better convert light energy into heat energy, thus enabling applications in various fields such as seawater desalination, steam power generation, water purification, catalytic conversion, and phototherapy systems.

[0003] Currently, photothermal materials can be categorized into inorganic materials, organic materials, and their composites. Commonly used inorganic photothermal materials include nanostructured metals, carbon nanomaterials, and transition metal sulfides, which have been applied in catalysts, regenerative pharmaceuticals, and solar cells. Although inorganic materials offer advantages such as convenient preparation, strong near-infrared absorption, and photostability, their poor biodegradability and potential biotoxicity hinder their clinical application. Compared to inorganic materials, organic materials exhibit superior biocompatibility and biodegradability, and their ease of structural modification and tunable properties have led to rapid development. Typical organic photothermal materials include indocyanine green, porphyrins, and thiadiazole derivatives. To obtain high-performance organic photothermal agents, several methods have been extensively explored, including extending molecular conjugation length, covalently linking electron donor and acceptor fragments, suppressing radiative transitions by enhancing quenching effects, and increasing free radical concentration. However, complex design and cumbersome synthesis processes hinder the development of novel organic photothermal agents.

[0004] Therefore, organic supramolecular complexes, materials formed by the self-assembly of donors and acceptors in a specific molar ratio through supramolecular interactions, are considered an effective approach for preparing organic photothermal materials with enhanced stability and photothermal conversion efficiency. The photothermal conversion of these materials is controlled by simple and flexible non-covalent intermolecular interactions, and due to efficient charge transfer between the donor and acceptor, supramolecular complexes with narrower band gaps than the original components can be generated, thereby achieving long-wavelength absorption and better utilization of light energy. Therefore, organic supramolecular complexes are ideal photothermal materials. Summary of the Invention

[0005] To overcome the shortcomings and deficiencies of the existing technology, the primary objective of this invention is to provide the use of 2,3,5,6-pyrazinetetranitrile as an acceptor in the preparation of donor-acceptor supramolecular complex photothermal conversion materials. In the process of constructing donor-acceptor supramolecular materials, there are few electron acceptors to choose from. 2,3,5,6-pyrazinetetranitrile is an acceptor with strong electron absorption capacity. It can not only form supramolecular complexes with various donors, but also has good near-infrared absorption capacity, and can be used as a near-infrared photothermal conversion material.

[0006] Another object of the present invention is to provide a donor-acceptor supramolecular complex photothermal conversion material prepared by using 2,3,5,6-pyrazinetetranitrile as an acceptor.

[0007] Another object of the present invention is to provide a method for preparing the above-mentioned donor-acceptor supramolecular complex photothermal conversion material.

[0008] Another object of the present invention is to provide an application of the above-mentioned donor-acceptor supramolecular complex photothermal conversion material.

[0009] The objective of this invention is achieved through the following technical solution:

[0010] The use of 2,3,5,6-pyrazinetetranitrile as an acceptor in the preparation of donor-acceptor supramolecular complex photothermal conversion materials, wherein the donor-acceptor supramolecular complex photothermal conversion material is formed by supramolecular self-assembly of 2,3,5,6-pyrazinetetranitrile and donor molecules; wherein the donor molecules are perylene, pyrene, anthracene, naphthalene, 1H-finaene, phenanthrene, triphenylene, phenylene, trans-1,2-stilbene, dibenzotetrathiofulvalene, tetrathiofulvalene, or naphthalene. [1,2-b:5,6-b′]dithiophene, 9H-thioxanth-9-one, 9H-xanthanth-9-one, 10H-phenoxazine, 9,9-dimethyl-9,10-dihydroacridine, 9H-fluorene, carbazole, 9-methyl-9H-carbazole, dibenzofuran, dibenzothiophene, 3,3′,5,5′-tetramethylbenzidine, p-diaminobiphenyl, N1,N1,N4,N4-tetramethylphenyl-1,4-diamine, Triphenylamine, 4,4′-bis(9H-carbazole)-1,1′-biphenyl, 4,4′-bis(10H-phenoxazin-10-yl)-1,1′-biphenyl, 4,4′-bis(10H-phenthiazin-10-yl)-1,1′-biphenyl, 4,4′-bis(9,9-dimethylacridin-10(9H)-yl)-1,1′-biphenyl, N4,N4,N4′,N4′-tetraphenyl-[1,1′-biphenyl] The following is a list of the following: 1,4-di(9H-carbazole-9-yl)benzene, 1,4-di(10H-phenoxazine-10-yl)benzene, 1,4-di(10H-phenthiazine-10-yl)benzene, 1,4-bis(9,9-dimethylacridin-10(9H)-yl)benzene, N1,N1,N4,N4-tetraphenylbenzene-1,4-diamine, 10H-phenthiazine, and 10H-phenoxazine.

[0011] The donor molecule is 4,4'-bis(9H-carbazole)-1,1'-biphenyl, dibenzotetrathiofulvalene, or 3,3′,5,5′-tetramethylbenzidine.

[0012] It should be noted that the specific structural formula of the donor molecule used in this invention is as follows:

[0013]

[0014] Specifically, the structural formula of the receptor molecule 2,3,5,6-pyrazinetetranitrile is as follows:

[0015]

[0016] A donor-acceptor supramolecular complex photothermal conversion material, wherein the donor-acceptor supramolecular complex photothermal conversion material is formed by supramolecular self-assembly of the acceptor molecule 2,3,5,6-pyrazinetetranitrile and the donor molecule; wherein the donor molecule is perylene, pyrene, anthracene, naphthalene, 1H-finaene, phenanthrene, triphenylene, phenylene, trans-1,2-stilbene, dibenzotetrathiofulvalene, tetrathiofulvalene, or naphtho[1,2-b:5,6- [b′] Dithiophene, 9H-thioxanth-9-one, 9H-xanthanth-9-one, 10H-phenoxazine, 9,9-dimethyl-9,10-dihydroacridine, 9H-fluorene, carbazole, 9-methyl-9H-carbazole, dibenzofuran, dibenzothiophene, 3,3′,5,5′-tetramethylbenzidine, p-diaminobiphenyl, N1,N1,N4,N4-tetramethylphenyl-1,4-diamine, triphenylamine, 4,4′ -Di(9H-carbazole)-1,1'-biphenyl, 4,4'-Di(10H-phenoxazin-10-yl)-1,1'-biphenyl, 4,4'-Di(10H-phenothiazin-10-yl)-1,1'-biphenyl, 4,4'-bis(9,9-dimethylacridin-10(9H)-yl)-1,1'-biphenyl, N4,N4,N4',N4'-tetraphenyl-[1,1'-biphenyl]-4 Any one of 4'-diamine, 1,4-di(9H-carbazole-9-yl)benzene, 1,4-di(10H-phenoxazine-10-yl)benzene, 1,4-di(10H-phenthiazine-10-yl)benzene, 1,4-bis(9,9-dimethylacridin-10(9H)-yl)benzene, N1,N1,N4,N4-tetraphenylbenzene-1,4-diamine, 10H-phenthiazine, and 10H-phenoxazine.

[0017] The aforementioned donor-acceptor supramolecular complex photothermal conversion material is a dark green or black crystal.

[0018] The above-mentioned method for preparing the donor-acceptor supramolecular complex photothermal conversion material is carried out according to the following steps: the donor molecule and the acceptor molecule are added to a solvent, and the mixture is sonicated to completely dissolve them to obtain a mixed solution. The solvent is allowed to evaporate at room temperature to obtain the donor-acceptor supramolecular complex photothermal conversion material.

[0019] The molar ratio of the donor molecule to the acceptor molecule is 1:1 or 1:2.

[0020] The concentration of the mixture solution is 0.1 mg / mL to 0.5 mg / mL.

[0021] The solvent is tetrahydrofuran, dichloromethane, acetone, acetonitrile, chloroform, or 1,2-dichloroethane.

[0022] The above-mentioned donor-acceptor supramolecular complex photothermal conversion materials are used in the fields of seawater desalination, sterilization, and biophototherapy.

[0023] The present invention has the following advantages and beneficial effects compared with the prior art:

[0024] (1) This invention uses 2,3,5,6-pyrazinetetranitrile as an electron acceptor, which has a strong electron absorption capacity. Furthermore, the acceptor molecule has multiple cyano groups, which facilitates the formation of intermolecular forces. Therefore, it can form a stable donor-acceptor supramolecular complex photothermal conversion material through supramolecular self-assembly with various donor molecules in a specific ratio. The resulting supramolecular material can achieve absorption in the near-infrared II region. This material not only exhibits near-infrared absorption with maximum absorption peaks of 700 nm, 1100 nm, and 1000 nm, but also possesses stable photothermal conversion capabilities at 0.8 W / cm². 2 Under the irradiation of the corresponding laser, the temperature can be raised from 27.8℃ to 71.8℃, from 30.1℃ to 65.3℃, and from 30.2℃ to 83.4℃ respectively, and the heating effect can be adjusted by the laser power, showing good photothermal stability.

[0025] (2) The material mentioned in the paper "Cocrystals Strategy towards Materials for Near-Infrared Photothermal Conversion and Imaging" published in Angewandte Chemie International Edition in 2018 is similar to that of the present invention. The donor molecule is dibenzotetrathiofulvalene, and the acceptor molecule is different. However, the photothermal performance of the material in the paper is worse than that of the material of the present invention. The temperature reached after heating for 1 minute is lower. In addition, the laser used in the paper is 808nm, while the present invention uses a redder 1064nm laser. The 1064nm laser has a deeper penetration depth, which can avoid excessive energy concentration in the epidermal layer during treatment, thereby reducing the risk of overheating and unnecessary side effects. It has greater advantages in biophotothermal diagnosis and treatment. Attached Figure Description

[0026] Figure 1 This is a packing diagram of the crystal structure of the donor-acceptor supramolecular complex prepared in Example 1;

[0027] Figure 2 The X-ray diffraction patterns of the donor molecule (4,4'-bis(9H-carbazole)-1,1'-biphenyl), the acceptor molecule (2,3,5,6-pyrazinetetranitrile), and the prepared donor-acceptor supramolecular complex in Example 1 are shown.

[0028] Figure 3The infrared spectra of the donor molecule (4,4'-bis(9H-carbazole)-1,1'-biphenyl), the acceptor molecule (2,3,5,6-pyrazinetetranitrile), and the prepared donor-acceptor supramolecular complex in Example 1 are shown.

[0029] Figure 4 The UV-Vis-NIR solid-state diffuse reflectance absorption spectra of the donor molecule (4,4'-bis(9H-carbazole)-1,1'-biphenyl), the acceptor molecule (2,3,5,6-pyrazinetetranitrile), and the prepared donor-acceptor supramolecular complex in Example 1 are shown.

[0030] Figure 5 The donor molecule (4,4'-bis(9H-carbazole)-1,1'-biphenyl), the acceptor molecule (2,3,5,6-pyrazinetetranitrile), and the prepared donor-acceptor supramolecular complex in Example 1 were compared at a power density of 0.8 W / cm². 2 Time-temperature variation graph of 660nm laser irradiation over 1 minute;

[0031] Figure 6 The time-temperature variation of the donor-acceptor supramolecular complex prepared in Example 1 is shown in the graph of 1 min under 660 nm laser irradiation at different power densities.

[0032] Figure 7 The donor-acceptor supramolecular complex prepared in Example 1 was at 0.8 W / cm 2 Photothermal stability diagram under 660nm laser irradiation;

[0033] Figure 8 This is a packing diagram of the crystal structure of the donor-acceptor supramolecular complex prepared in Example 2;

[0034] Figure 9 The X-ray diffraction patterns of the donor molecule (dibenzotetrathiofulvalene), the acceptor molecule (2,3,5,6-pyrazinetetranitrile), and the prepared donor-acceptor supramolecular complex in Example 2 are shown.

[0035] Figure 10 The infrared spectra of the donor molecule (dibenzotetrathiofulvalene), the acceptor molecule (2,3,5,6-pyrazinetetranitrile), and the prepared donor-acceptor supramolecular complex in Example 2 are shown.

[0036] Figure 11 The UV-Vis-NIR solid-state diffuse reflectance absorption spectra of the donor molecule (dibenzotetrathiofulvalene), the acceptor molecule (2,3,5,6-pyrazinetetranitrile), and the prepared donor-acceptor supramolecular complex in Example 2 are shown.

[0037] Figure 12The donor molecule (dibenzotetrathiofulvalene), acceptor molecule (2,3,5,6-pyrazinetetranitrile), and the prepared donor-acceptor supramolecular complex in Example 2 were compared at a power density of 0.8 W / cm². 2 Time-temperature variation graph of 1064nm laser irradiation over 1 minute;

[0038] Figure 13 The time-temperature variation of the donor-acceptor supramolecular complex prepared in Example 2 is shown in the graph of 1 min under 1064 nm laser irradiation at different power densities.

[0039] Figure 14 The donor-acceptor supramolecular complex prepared in Example 2 was at 0.8 W / cm². 2 Photothermal stability diagram under 1064nm laser irradiation;

[0040] Figure 15 This is a packing diagram of the crystal structure of the donor-acceptor supramolecular complex prepared in Example 3;

[0041] Figure 16 The X-ray diffraction patterns of the donor molecule (3,3′,5,5′-tetramethylbenzidine), the acceptor molecule (2,3,5,6-pyrazinetetranitrile), and the prepared donor-acceptor supramolecular complex in Example 3 are shown.

[0042] Figure 17 The infrared spectra of the donor molecule (3,3′,5,5′-tetramethylbenzidine), the acceptor molecule (2,3,5,6-pyrazinetetranitrile), and the prepared donor-acceptor supramolecular complex in Example 3 are shown.

[0043] Figure 18 The UV-Vis-NIR solid-state diffuse reflectance absorption spectra of the donor molecule (3,3′,5,5′-tetramethylbenzidine), the acceptor molecule (2,3,5,6-pyrazinetetranitrile), and the prepared donor-acceptor supramolecular complex in Example 3 are shown.

[0044] Figure 19 The donor molecule (3,3′,5,5′-tetramethylbenzidine), the acceptor molecule (2,3,5,6-pyrazinetetranitrile), and the prepared donor-acceptor supramolecular complex in Example 3 were compared at a power density of 0.8 W / cm². 2 Time-temperature variation graph of 1064nm laser irradiation over 1 minute;

[0045] Figure 20 The time-temperature variation of the donor-acceptor supramolecular complex prepared in Example 3 is shown in the graph of 1 min under 1064 nm laser irradiation at different power densities.

[0046] Figure 21The donor-acceptor supramolecular complex prepared in Example 3 was at 0.8 W / cm 2 Photothermal stability diagram under 1064nm laser irradiation. Detailed Implementation

[0047] The present invention will be further described in detail below with reference to the embodiments and accompanying drawings, but the embodiments of the present invention are not limited thereto.

[0048] Unless otherwise specified, the experimental methods used in the following examples are conventional methods; the materials and reagents used are commercially available unless otherwise specified.

[0049] Example 1

[0050] A method for preparing a donor-acceptor supramolecular complex (i.e., the donor-acceptor supramolecular complex photothermal conversion material of the present invention) includes the following steps:

[0051] Weigh 2.4 mg of donor molecule 4,4'-bis(9H-carbazole)-1,1'-biphenyl and 1.8 mg of acceptor molecule 2,3,5,6-pyrazinetetranitrile (the molar ratio of donor molecule to acceptor molecule is 1:2), add 10 mL of chloroform as solvent, and sonicate until the donor molecule and acceptor molecule are completely dissolved to obtain a mixture solution (0.42 mg / mL). Then, allow it to stand at room temperature to evaporate to obtain a donor-acceptor supramolecular complex.

[0052] Example 2

[0053] A method for preparing a donor-acceptor supramolecular complex (i.e., the donor-acceptor supramolecular complex photothermal conversion material of the present invention) includes the following steps:

[0054] Weigh 3.0 mg of the donor molecule dibenzotetrathiofulvalene and 1.8 mg of the acceptor molecule 2,3,5,6-pyrazinetetranitrile (the molar ratio of donor to acceptor molecule is 1:1), add 10 mL of dichloromethane as solvent, and sonicate until the donor and acceptor molecules are completely dissolved to obtain a mixed solution (0.48 mg / mL). Then, allow it to stand at room temperature to evaporate and obtain the donor-acceptor supramolecular complex.

[0055] Example 3

[0056] A method for preparing a donor-acceptor supramolecular complex (i.e., the donor-acceptor supramolecular complex photothermal conversion material of the present invention) includes the following steps:

[0057] Weigh 2.4 mg of the donor molecule 3,3′,5,5′-tetramethylbenzidine and 1.8 mg of the acceptor molecule 2,3,5,6-pyrazinetetranitrile (the molar ratio of the donor molecule to the acceptor molecule is 1:1), add 10 mL of chloroform as a solvent, and sonicate until the donor molecule and the acceptor molecule are completely dissolved to obtain a mixed solution (0.42 mg / mL). Then, allow it to stand at room temperature to evaporate to obtain the donor-acceptor supramolecular complex.

[0058] Example 4: Structural testing of the acceptor supramolecular complex

[0059] The donor-acceptor supramolecular complexes prepared in Examples 1, 2, and 3 were analyzed using single-crystal X-ray diffraction to determine their structure and packing configuration. The results are as follows: Figure 1 , 8 As shown in Figures 1 and 15. X-ray powder diffraction was used to determine the donor molecules, acceptor molecules, and the prepared donor-acceptor supramolecular complexes in Examples 1, 2, and 3. The results are shown in Figure 15. Figure 2 , 9 As shown in Figures 1 and 16. The infrared spectra of the donor molecules, acceptor molecules, and the prepared donor-acceptor supramolecular complexes from Examples 1, 2, and 3 were measured, and the results are as follows. Figure 3 , 10 As shown in Figure 17.

[0060] from Figure 1 , 8 As can be seen from 15, the three donor-acceptor supramolecular complexes prepared are all co-crystals, and the donor and acceptor molecules in the three complexes are all mixed and stacked. The unit cell parameters of the donor-acceptor supramolecular complex in Example 1 are: a = 6.9978 (3), b = 8.9303 (6), c = 17.5240 (8), α = 96.814 (5)°, β = 95.504 (4)°, γ = 111.099 (5)°. The unit cell parameters of the donor-acceptor supramolecular complex in Example 2 are: a = 5.9074(7), b=7.6635(10), c=11.7785(16), α=83.493(11)°, β=76.827(11)°, γ=84.286(10)°, the cell parameters of the acceptor supramolecular complex described in Example 3 are: a=8.3665(11), b=8.7694(14), c=9.0460(13), α=61.713(16)°, β=70.044(13)°, γ=66.779(14)°.

[0061] from Figure 2 , 9As can be seen in Figure 16, compared to single donor and acceptor molecules, the formed donor-acceptor complex clearly produces new diffraction peaks, further proving the formation of the complex. The sharp diffraction peaks also indicate that the donor-acceptor complex has strong crystallinity and a stable structure. Figure 3 , 10 In the infrared spectrum of 17, a distinct infrared resonance peak can also be observed that is not simply the sum of the curves of the donor and acceptor molecules, which is consistent with the results of the X-ray spectrum.

[0062] Example 5: Optical property testing of donor molecules, acceptor molecules, and donor-acceptor supramolecular complexes

[0063] The donor molecules, acceptor molecules, and prepared donor-acceptor supramolecular complexes from Examples 1, 2, and 3 were subjected to UV-Vis-NIR solid-state diffuse reflectance absorption spectroscopy. The results are as follows: Figure 4 , 11 As shown in Figure 18.

[0064] from Figure 4 As can be seen, donor and acceptor molecules only have short-wavelength absorption, while the donor-acceptor supramolecular complex prepared in Example 1 not only has a wider absorption range, but also has a maximum absorption peak of about 700 nm and good absorption intensity, showing potential as a photothermal material.

[0065] from Figure 11 As can be seen, the supramolecular complex obtained in Example 2 also has absorption peaks different from those of the monomer, with the maximum absorption peak at 1100 nm and extending to 1300 nm, and is able to absorb photons in the near-infrared II region.

[0066] exist Figure 18 In Example 3, the donor-acceptor supramolecular complex obtained has a maximum absorption peak at 1000 nm and a large absorption intensity, and can also achieve near-infrared photothermal conversion.

[0067] Example 6: Photothermal Performance Testing of Donor Molecules, Acceptor Molecules, and Donor-Acceptor Supramolecular Complexes

[0068] The photothermal conversion performance of the donor molecule, acceptor molecule, and the prepared donor-acceptor supramolecular complex in Example 1 was tested using a power density of 0.8 W / cm². 2 Irradiation with a 660nm laser for 1 minute, followed by temperature monitoring using an infrared thermal imager, yielded the following results: Figure 5 As shown. Using different power densities (0.4 W / cm²) 2 0.6W / cm 2 0.8W / cm 2 1.0W / cm 21.2W / cm 2 The acceptor supramolecular complex prepared in Example 1 was irradiated with a 660nm laser for 1 min, and the temperature was monitored using an infrared thermal imager. The results are as follows: Figure 6 As shown. A power density of 0.8 W / cm² is used. 2 The acceptor supramolecular complex prepared in Example 1 was irradiated with an 808 nm laser for 1 min, then the laser was turned off for 3 min, and this cycle was repeated 5 times. The results were monitored using an infrared thermal imager. Figure 7 As shown.

[0069] from Figure 5 As can be seen, both single donor and acceptor molecules showed a slight temperature increase within 1 minute, while the prepared donor-acceptor complex increased from 27.8℃ to 71.8℃ within 1 minute, demonstrating a significant temperature increase. This indicates that the photothermal conversion capability was greatly enhanced after the donor-acceptor self-assembly. Figure 6 As can be seen, the heating effect on the acceptor complex is basically linearly related to the laser power density, and this relationship is particularly pronounced at a power density of 1.2 W / cm². 2 Under these conditions, the highest temperature can reach 96.4℃, which also indicates that the photothermal conversion temperature can be controlled by adjusting the laser power. In addition, in the photothermal cycling test, the highest temperature reached in 5 heating cycles was basically consistent, fluctuating around 72℃, which shows that the composite has good photothermal conversion stability and that high temperature does not affect the internal structure of the material.

[0070] The photothermal conversion performance of the donor molecule, acceptor molecule, and the prepared donor-acceptor supramolecular complex in Example 2 was tested using a power density of 0.8 W / cm². 2 Irradiation with a 1064nm laser for 1 minute, followed by temperature monitoring using an infrared thermal imager, yielded the following results: Figure 12 As shown. Using different power densities (0.4 W / cm²) 2 0.6W / cm 2 0.8W / cm 2 1.0W / cm 2 1.2W / cm 2 The acceptor supramolecular complex prepared in Example 2 was irradiated with a 1064 nm laser for 1 min, and the temperature was monitored using an infrared thermal imager. The results are as follows: Figure 13 As shown. A power density of 0.8 W / cm² is used. 2 The acceptor supramolecular complex prepared in Example 1 was irradiated with a 1064 nm laser for 1 min, then the laser was turned off for 3 min, and this cycle was repeated 5 times. The results were monitored using an infrared thermal imager. Figure 14 As shown.

[0071] Similar to Example 1, the individual donor and acceptor molecules did not show significant temperature increases under laser irradiation, while the temperature of the donor-acceptor complex increased from 30.1°C to 65.3°C after 1 minute of irradiation. With increased laser power density, the maximum achievable temperature was 85°C, and the photothermal conversion temperature and laser power density also exhibited a good linear relationship. Figure 14 As can be seen, the donor-acceptor complex in Example 2 also exhibits good photothermal stability during five heating and cooling cycles, making it a structurally stable photothermal material.

[0072] The photothermal conversion performance of the donor molecule, acceptor molecule, and the prepared donor-acceptor supramolecular complex in Example 3 was tested using a power density of 0.8 W / cm². 2 Irradiation with a 1064nm laser for 1 minute, followed by temperature monitoring using an infrared thermal imager, yielded the following results: Figure 19 As shown. Using different power densities (0.4 W / cm²) 2 0.6W / cm 2 0.8W / cm 2 1.0W / cm 2 1.2W / cm 2 The acceptor supramolecular complex prepared in Example 3 was irradiated with a 1064 nm laser for 1 min, and the temperature was monitored using an infrared thermal imager. The results are as follows: Figure 20 As shown. A power density of 0.8 W / cm² is used. 2 The acceptor supramolecular complex prepared in Example 1 was irradiated with a 1064 nm laser for 1 min, then the laser was turned off for 3 min, and this cycle was repeated 5 times. The results were monitored using an infrared thermal imager. Figure 21 As shown.

[0073] Similarly, the donor-acceptor complex obtained in Example 3 exhibited photothermal conversion capabilities different from those of a single donor and acceptor, at 0.8 W / cm². 2 After 1 minute of 1064nm laser irradiation, the temperature of the composite increased from 30.2℃ to 83.4℃, and under irradiation with the maximum power laser, the temperature rise reached 110.5℃. Furthermore, the photothermal conversion of the donor-acceptor composite in Example 3 also exhibited tunability and good stability, making it a promising candidate for photothermal materials in photothermal diagnostics and other applications.

[0074] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A donor-acceptor complex photothermal conversion supramolecular material, characterized in that: The donor-acceptor complex photothermal conversion supramolecular material is formed by supramolecular self-assembly of the acceptor molecule 2,3,5,6-pyrazinetetranitrile and the donor molecule; the donor molecule is dibenzotetrathiofulvalene or 3,3′,5,5′-tetramethylbenzidine.

2. The method for preparing the photothermal conversion supramolecular material of the donor-acceptor complex according to claim 1, characterized in that... Follow these steps: Donor and acceptor molecules are added to a solvent and sonicated to completely dissolve them to obtain a mixed solution. The solvent is then allowed to evaporate at room temperature to obtain a donor-acceptor complex photothermal conversion supramolecular material.

3. The preparation method according to claim 2, characterized in that: The molar ratio of the donor molecule to the acceptor molecule is 1:1 or 1:

2.

4. The preparation method according to claim 2, characterized in that: The concentration of the mixed solution is 0.1 mg / mL to 0.5 mg / mL.

5. The preparation method according to claim 2, characterized in that: The solvent is tetrahydrofuran, dichloromethane, acetone, acetonitrile, chloroform, or 1,2-dichloroethane.

6. The application of the donor-receptor complex photothermal conversion supramolecular material according to claim 1 in the preparation of seawater desalination materials, bactericidal materials or biophototherapy materials.

Images