Eu-TCPP-SO4 crystal, and preparation method and application thereof

Abstract

The present application relates to the field of MOF crystal material synthesis and sonodynamic antibacterial technology combined application, in particular to a kind of Eu-TCPP-SO4 Crystal and its preparation method and application.The present application is self-assembled by Eu (III) nitrate pentahydrate, meso-tetra (4-carboxyphenyl) porphyrin (TCPP) and sulfate ion coordination, and a kind of rare earth-porphyrin complex with specific crystal structure-Eu-TCPP-SO4 Crystal is constructed.The Eu-TCPP-SO4 Crystal disclosed in the present application has high sonodynamic activity and good stability as a sonosensitizer, overcomes the limitations of low efficiency and poor stability of the sonosensitizer in the prior art, and can provide a safer and more effective solution for practical antibacterial applications.

Description

Technical Field

[0001] This invention relates to the field of combined application of MOF crystal material synthesis and acoustic-dynamic antibacterial technology, and more specifically, to an Eu-TCPP-SO4 crystal, its preparation method, and its application. Background Technology

[0002] Due to antibiotic resistance, invading bacteria can survive, exacerbating inflammatory responses and preventing normal wound healing, ultimately leading to chronic diseases, sepsis, and even death. Therefore, there is an urgent need to develop effective non-antibiotic strategies to achieve antibacterial and anti-infective goals.

[0003] Similar to photodynamic therapy, sonodynamic antibacterial therapy is an emerging reactive oxygen species (ROS)-mediated antibacterial mechanism that has been extensively studied. Sonodynamic therapy (SDT) utilizes low-intensity ultrasound (US) to stimulate a sonosensitive agent, generating highly cytotoxic ROS, along with the heat and mechanical stress generated during the ultrasound process, to destroy bacteria or cells, thereby achieving a therapeutic effect. Compared to photodynamic therapy, the most significant advantages of US are its high tissue penetration depth, low tissue attenuation coefficient, and minimal energy loss, making it a promising candidate for antibacterial treatment.

[0004] In sonodynamic therapy (SDT), sonosensitizers are considered a key factor directly affecting the efficacy of SDT. Generally, sonosensitizers are classified into organic and inorganic sonosensitizers. Inorganic sonosensitizers have advantages such as high stability, but disadvantages include low bioavailability, low reactive oxygen species (ROS) generation efficiency, and high therapeutic doses. Organic sonosensitizers, on the other hand, have advantages such as high ROS yield, well-defined structures, and design flexibility. For example, porphyrin-based sonosensitizers, due to their high biocompatibility, have been approved for clinical research. However, porphyrins have drawbacks such as poor water solubility, low ROS quantum yield, and poor physiological stability (porphyrin ligands are prone to aggregation and self-quenching in physiological environments), which limit their application in sonodynamic antibacterial applications. Therefore, developing an ideal, highly safe, and highly efficient ROS-generating sonosensitizer is crucial. Summary of the Invention

[0005] To address the technical problem of low reactive oxygen quantum yield in existing porphyrin-based sound-sensing agents, this invention provides an Eu-TCPP-SO4 crystal, its preparation method, and its application.

[0006] This invention constructs a rare-earth-porphyrin complex—Eu-TCPP-SO4 crystal—with a specific crystal structure through coordination self-assembly of Eu(NO3)3•5H2O, mes-tetra(4-carboxyphenyl)porphyrin (TCPP), and sulfate ions. The Eu-TCPP-SO4 crystal significantly enhances its reactive oxygen species generation efficiency and physiological stability as a sound-sensing agent.

[0007] One of the objectives of this invention is to provide an Eu-TCPP-SO4 crystal.

[0008] The chemical formula of the Eu-TCPP-SO4 crystal is C 144 H 87 Eu9N 12 O 43 S2.

[0009] The chemical formula C 144 H 87 Eu9N 12 O 43 S2 refers to the ratio of the net number of atoms in the unit cell of Eu-TCPP-SO4 crystal.

[0010] The smallest asymmetric unit of the Eu-TCPP-SO4 crystal comprises: three crystallographically independent metallic Eu units. 3 + The unit consists of ions, four completely deprotonated tetrakis(4-carboxyphenyl)porphyrin molecules, two water molecules, and two-thirds of a sulfate ion. The two-thirds sulfate ion refers to the fact that the sulfate ion is located exactly on the three-dimensional axis of symmetry, thus dividing it into three equal parts. Therefore, the smallest asymmetric unit contains two-thirds of an independent sulfate ion.

[0011] The Eu-TCPP-SO4 crystal belongs to the hexagonal crystal system. P -3 space group.

[0012] The unit cell parameters of the Eu-TCPP-SO4 crystal include: a=22.8981 Å, b=22.8981 Å, c=18.0750 Å, α=90°, β=90°, γ=120°.

[0013] The unit cell parameters of the Eu-TCPP-SO4 crystal are shown in Table 1.

[0014] Table 1. Unit cell parameters of Eu-TCPP-SO4 crystals

[0015]

[0016] The Eu-TCPP-SO4 crystal is a metal-organic framework material.

[0017] The Eu-TCPP-SO4 crystal contains a metallic Eu cluster, bridging oxygen atoms, organic ligands, water molecules, and sulfate ions;

[0018] The metal Eu cluster consists of 9 metal Eu atoms 3+ Ionic composition;

[0019] The organic ligand is a fully deprotonated medium-tetra(4-carboxyphenyl)porphyrin with the chemical formula C. 48 H 26 N4O8;

[0020] Nine Eu atoms in a metal Eu cluster 3+ Ions are linked to each other via O atoms, to organic ligands, to water molecules, and to sulfate ions; and to Eu... 3+ The ion-linked O atoms come from bridging oxygen atoms, oxygen atoms of organic ligands, oxygen atoms of water molecules, and oxygen atoms of sulfate ions.

[0021] Each metal Eu cluster is linked to twelve organic ligands, six water molecules, and two sulfate groups, and each organic ligand is linked to four metal Eu clusters.

[0022] Nine Eu atoms in a metal Eu cluster 3+ The ion coordinates with 24 O atoms of twelve organic ligands, 6 O atoms of six water molecules, and 6 O atoms of two sulfate groups.

[0023] The Eu-TCPP-SO4 crystal has a smooth hexagonal prism appearance and is a purplish-black crystal.

[0024] The Eu-TCPP-SO4 crystals are produced by reacting Eu(NO3)3•5H2O, 4,4'-dipyridyl disulfide, and meso-tetra(4-carboxyphenyl)porphyrin.

[0025] Eu(NO3)3•5H2O cannot be replaced by other Eu salts. If other metal europium salts are used instead of Eu(NO3)3•5H2O, the Eu-TCPP-SO4 crystals cannot be synthesized.

[0026] 4,4'-dipyridyl disulfide cannot be replaced by other ligands containing disulfide bonds. If other ligands containing disulfide bonds are used to replace 4,4'-dipyridyl disulfide, the Eu-TCPP-SO4 crystal cannot be synthesized.

[0027] The Eu-TCPP-SO4 crystals can be prepared by a hot solvent method from raw materials including Eu(NO3)3•5H2O, 4,4'-dipyridyl disulfide, meso-tetra(4-carboxyphenyl)porphyrin, and 4-fluorobenzoic acid.

[0028] A second objective of this invention is to provide a method for preparing the Eu-TCPP-SO4 crystal described in one of the objectives of this invention.

[0029] The preparation method of the Eu-TCPP-SO4 crystal includes:

[0030] (1) Dissolve Eu(NO3)3•5H2O, 4,4'-dipyridinyl disulfide, meso-tetra(4-carboxyphenyl)porphyrin and 4-fluorobenzoic acid in a solvent to obtain a raw material solution;

[0031] (2) The raw material solution is reacted at 5.5-28 kPa and 80-120℃;

[0032] (3) After the reaction is completed, the mixture is cooled, separated, washed and dried in sequence to obtain the Eu-TCPP-SO4 crystal.

[0033] In step (1), the solvent is selected from at least one of N,N-dimethylformamide, deionized water and ethanol.

[0034] In step (1), the change in the molar ratio of Eu(NO3)3•5H2O, 4,4'-dipyridyl disulfide, and meso-tetra(4-carboxyphenyl)porphyrin affects the product structure. Specifically, when the molar ratio of Eu(NO3)3•5H2O, 4,4'-dipyridyl disulfide, and meso-tetra(4-carboxyphenyl)porphyrin exceeds the range of 1:(1.5-2.5):(0.05-0.15), it is impossible to prepare a material with a crystalline structure, let alone obtain the Eu-TCPP-SO4 crystals described in this invention. Therefore, as a preferred embodiment, the molar ratio of Eu(NO3)3•5H2O, 4,4'-dipyridyl disulfide, and methyl-tetra(4-carboxyphenyl)porphyrin is 1:(1.5-2.5):(0.05-0.15), for example 1:1.8:(0.05-0.15), 1:2.0:(0.05-0.15), 1:2.3:(0.05-0.15), 1:(1.5-2.5):0.08, 1:(1.5-2.5):0.1, and 1:(1.5-2.5):0.12. When the molar ratio of Eu(NO3)3•6H2O, 4,4'-dipyridyl disulfide, and meso-tetra(4-carboxyphenyl)porphyrin is 1:2:0.1, the prepared Eu-TCPP-SO4 crystal has a hexagonal prism structure, good crystallinity, a smooth crystal surface, and is free of cracks. Therefore, as a more preferred embodiment, the molar ratio of Eu(NO3)3•6H2O, 4,4'-dipyridyl disulfide, and meso-tetra(4-carboxyphenyl)porphyrin is 1:2:0.1.

[0035] In step (1), the role of 4-fluorobenzoic acid is to provide a weakly acidic environment. During the synthesis process, 4-fluorobenzoic acid can slowly release protons (H+). + This creates a mild acidic environment, under which the formation rate and morphology of the metal Eu clusters can be controlled, which is more conducive to obtaining highly coordinated metal Eu clusters. 1,4-Fluorobenzoic acid cannot be replaced by other acids; if other acids are used to replace 4-fluorobenzoic acid, highly coordinated metal Eu clusters cannot be obtained, and the Eu-TCPP-SO4 crystals described in this invention cannot be obtained.

[0036] In step (1), the concentration of 4-fluorobenzoic acid in the raw material solution affects the formation of Eu-TCPP-SO4 crystals. If the molar concentration of 4-fluorobenzoic acid is too high, it accelerates proton release, increases the acidity of the raw material solution, and causes the nucleation rate of the metal Eu clusters to be too fast, which is detrimental to the stable formation of crystals. If the molar concentration of 4-fluorobenzoic acid is too low, it reduces proton release, weakens the acidity of the raw material solution, and causes the nucleation rate of the metal Eu clusters to be too slow, greatly prolonging the crystal cultivation time and resulting in higher time costs. When the molar concentration of 4-fluorobenzoic acid in the raw material solution is limited to 1.5-2.5 mmol, the synthesized Eu-TCPP-SO4 crystals have high crystallinity, are free of impurities, have a smooth surface without cracks, and exhibit a regular hexagonal prism morphology. Therefore, as a preferred option, the molar concentration of 4-fluorobenzoic acid in the feed solution is 1.5-2.5 mmol, for example 1.7 mmol, 1.9 mmol, 2.1 mmol, 2.3 mmol, 2.5 mmol, preferably 1.9 mmol.

[0037] The reaction temperature in step (2) is 80-120℃, for example 80℃, 90℃, 100℃, 110℃, 120℃, preferably 90-110℃.

[0038] The reaction pressure in step (2) is 5.5-28 kPa, for example 8 kPa, 10.5 kPa, 13 kPa, 15.5 kPa, 18 kPa, 20.5 kPa, 23 kPa, 25.5 kPa, 28 kPa, preferably 13 kPa.

[0039] In step (2), the reaction time can be the conventional reaction time for preparing MOFs using the hot solvent method. As a preferred option, the reaction time in step (2) is 24 h or more, for example, 36 h, 48 h, 54 h, 72 h, 96 h, and more preferably 72 h.

[0040] In step (2), if the cooling rate is too fast, a large number of crystal nuclei will be generated instantly during cooling, which will drastically consume the metal ions and organic ligands in the solution. This will result in each crystal nucleus not having enough material and time to grow in an orderly manner, usually yielding a large number of small, uneven microcrystals or powders. If the cooling rate is too slow, the cooling process will prolong the reaction time, increasing the time cost of material synthesis and resulting in low synthesis efficiency. As a preferred option, the cooling rate is 1-8℃ h. -1 For example, 2℃ h -1 3℃ h -1 4℃ h -1 5℃ h -1 6℃ h -1 7℃ h -1 Preferably 5℃ h -1 The cooling rate is 1-8℃ / h. -1 By inhibiting nucleation and promoting growth, a limited number of reactants can be concentrated on the growth of a few crystals, thereby enabling these crystals to grow larger and improving the crystallinity and stability of the crystalline material.

[0041] One specific method for preparing Eu-TCPP-SO4 includes the following steps:

[0042] 1) Weigh out Eu(NO3)3•5H2O, 4,4'-dipyridyl disulfide, meso-tetra(4-carboxyphenyl)porphyrin, and 4-fluorobenzoic acid and add them to a beaker; the molar ratio of Eu(NO3)3•5H2O, 4,4'-dipyridyl disulfide, and meso-tetra(4-carboxyphenyl)porphyrin is 1:(1.5-2.5):(0.05-0.15).

[0043] 2) Add 15 mL of N,N-dimethylformamide to the above beaker and sonicate the beaker in an ultrasonic bath for 5-30 min, preferably 20 min, to fully dissolve it and form a raw material solution without precipitate; the molar concentration of 4-fluorobenzoic acid in the raw material solution is 1.5-2.5 mmol.

[0044] 3) Transfer the raw material liquid to a 25 mL polytetrafluoroethylene inner liner, and place the inner liner into a 25 mL stainless steel reactor. The pressure inside the high-pressure reactor is 5.5-28 kPa. Place the reactor in an oven at 80-120 ℃, preferably 100 ℃, and maintain the temperature for 24-96 h, preferably 72 h.

[0045] 4) After the constant temperature period ends, slowly cool down to room temperature (approximately 25℃) at a rate of 1-8℃ / h. -1 Preferably 5℃ h -1 Then, the crystals are separated, washed, and dried to obtain the Eu-TCPP-SO4 crystals.

[0046] The "separation, washing, and drying" process includes: adding N,N-dimethylformamide and centrifuging to collect the lower layer; adding ethanol to the collected lower layer and centrifuging and washing until the supernatant is colorless; collecting the lower layer and drying it under vacuum at 50-60°C to obtain purplish-black crystals.

[0047] The Eu-TCPP-SO4 crystal provided by this invention is formed by reacting the organic ligand -tetra(4-carboxyphenyl)porphyrin with the metal Eu. 3+ The ion-bonded metal-organic framework (MOF) material has a porous framework structure that can effectively prevent the aggregation of 1,000-tetra(4-carboxyphenyl)porphyrin and improve the generation efficiency of reactive oxygen species.

[0048] Eu in the Eu-TCPP-SO4 crystal provided by this invention 3+ Ions can serve as adsorption sites for small substrate molecules H2O or O2. Adsorbed H2O is more easily oxidized to generate hydroxyl radicals (•OH), while adsorbed O2 has a greater ability to absorb and generate singlet oxygen. 1 O2), and •OH and 1 O2 is one of the key active components for achieving antibacterial effects, which helps to improve the antibacterial effect of materials.

[0049] Eu in the Eu-TCPP-SO4 crystal provided by this invention 3+ Ions formed metal Eu cluster nodes ， The metal Eu cluster consists of 9 metal Eu atoms 3+ Ionic composition, metal Eu 3+ Ions are the active sites for the reaction, and the metal Eu cluster has a large number of active sites, which is beneficial to improving the antibacterial properties of the material.

[0050] The Eu-TCPP-SO4 crystal provided by this invention has good stability, that is, better crystal quality, more stable crystal structure, and is less prone to decomposition.

[0051] In summary, the Eu-TCPP-SO4 crystal provided by this invention can be used as a sound-sensitive agent that combines high acoustic activity and good stability.

[0052] A third objective of this invention is to provide a sound-sensitive agent comprising Eu-TCPP-SO4 crystals as described in one objective of the invention or Eu-TCPP-SO4 crystals prepared by the preparation method described in another objective of the invention.

[0053] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0054] The Eu-TCPP-SO4 disclosed in this invention exhibits a high hydroxyl radical (•OH) generation rate. The •OH generation of Eu-TCPP-SO4 was evaluated using a methylene blue degradation experiment. The results showed that its degradation rate of methylene blue under ultrasonic irradiation was 5.73 μM min. -1 .

[0055] The Eu-TCPP-SO4 disclosed in this invention has a high singlet oxygen content ( 1 The amount of O2 generated was evaluated by the degradation experiment of 9,10-diphenylanthracene to determine the O2 content of Eu-TCPP-SO4. 1 The results showed that the degradation rate of 9,10-diphenylanthracene under ultrasonic treatment was 40.78 μM min. -1 .

[0056] The Eu-TCPP-SO4 disclosed in this invention, as a sound-sensing agent, has high crystallinity, good structural stability, and a high reactive oxygen generation rate, overcoming the limitations of low efficiency and poor stability of existing sound-sensing agents, and can provide a safer and more effective solution for practical antibacterial applications. Attached Figure Description

[0057] Figure 1 Single-crystal XRD of Eu-TCPP-SO4 crystal provided by the present invention;

[0058] Figure 2 This is a crystal structure diagram obtained from single-crystal XRD data;

[0059] Figure 3 for Figure 2 A schematic diagram of the structure of the purple polyhedron;

[0060] Figure 4 Figure 1 shows the experimental results of •OH radical generation. Among them, (A), (B), and (C) are the ultraviolet absorption spectra of MB under ultrasound (US), under Eu-TCPP-SO4 crystal treatment, and under Eu-TCPP-SO4 crystal + ultrasound (US) treatment, respectively; (D) is the characteristic absorbance variation curve of MB in different systems.

[0061] Figure 5 for 1 Figure 1 shows the experimental results of O2 free radical generation. (A), (B), and (C) are the ultraviolet absorption spectra of DPA under ultrasound (US), under Eu-TCPP-SO4 crystal treatment, and under Eu-TCPP-SO4 crystal + ultrasound (US) treatment, respectively. (D) is the characteristic absorbance variation curve of PDA in different systems.

[0062] Figure 6The morphology diagram of the Eu-TCPP-SO4 crystal provided by this invention. Detailed Implementation

[0063] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. It should be noted that the following embodiments are only used to further illustrate the present invention and should not be construed as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the content of the present invention are still within the scope of protection of the present invention.

[0064] All reagents used in the following examples and experimental cases are commercially available products.

[0065] Eu(NO3)3•5H2O has a purity of 99.99% and is manufactured by Beijing Huawirui Chemical Technology Co., Ltd.

[0066] 4,4'-Dipyridyl disulfide has a purity of 98% and is manufactured by Shanghai Haohong Biomedical Technology Co., Ltd.

[0067] The purity of the tetra(4-carboxyphenyl)porphyrin is 98%. Manufacturer: Beijing Huawirui Chemical Technology Co., Ltd.

[0068] 4-Fluorobenzoic acid has a purity of 98% and is manufactured by Shanghai Maclean Biochemical Technology Co., Ltd.

[0069] N,N-dimethylformamide has a purity of 99.5% and is manufactured by Tianjin Xinbote Chemical Co., Ltd.

[0070] The anhydrous ethanol has a purity of 99.7%. Manufacturer: Tianjin Xinbote Chemical Co., Ltd.

[0071] Example 1

[0072] Weigh 0.05 mmol of Eu(NO3)3•5H2O, 0.1 mmol of 4,4'-dipyridyl disulfide, 0.005 mmol of meso-tetra(4-carboxyphenyl)porphyrin, and 1.9 mmol of 4-fluorobenzoic acid and add them to a 25 mL beaker. Then add 15 mL of N,N-dimethylformamide to the beaker and sonicate it for 25 min to dissolve it completely, thus obtaining a mixed solution.

[0073] The mixed solution was transferred to a 25 mL polytetrafluoroethylene liner, which was then transferred to a high-pressure reactor with a pressure of 13 kPa. The reactor was then placed in an oven at 100°C and reacted for 72 h.

[0074] After the reaction is complete, it is carried out at 5℃ for h -1The mixture was slowly cooled to room temperature, and 7 mL of N,N-dimethylformamide was added. The mixture was centrifuged at 8000 r / min for 3 min, and the lower layer was collected. 7 mL of ethanol was added to the collected lower layer, and the mixture was centrifuged at 8000 r / min and washed until the supernatant was colorless. The lower layer was collected and dried under vacuum at 55 °C for 24 h to obtain purplish-black crystals.

[0075] Example 2

[0076] Weigh 0.05 mmol of Eu(NO3)3•5H2O, 0.15 mmol of 4,4'-dipyridyl disulfide, 0.005 mmol of meso-tetra(4-carboxyphenyl)porphyrin, and 1.9 mmol of 4-fluorobenzoic acid and add them to a 25 mL beaker. Then add 7.5 mL of N,N-dimethylformamide to the beaker and sonicate it for 25 min to dissolve it completely, thus obtaining a mixed solution.

[0077] The mixed solution was transferred to a 25 mL polytetrafluoroethylene liner, which was then transferred to a high-pressure reactor with a pressure of 13 kPa. The reactor was then placed in an oven at 100°C and reacted for 72 h.

[0078] After the reaction is complete, it is carried out at 5℃ for h -1 The mixture was slowly cooled to room temperature, and 7 mL of N,N-dimethylformamide was added. The mixture was centrifuged at 8000 r / min for 3 min, and the lower layer was collected. 7 mL of ethanol was added to the collected lower layer, and the mixture was centrifuged at 8000 r / min and washed until the supernatant was colorless. The lower layer was collected and dried under vacuum at 55 °C for 24 h to obtain purplish-black crystals.

[0079] Example 3

[0080] Weigh 0.05 mmol of Eu(NO3)3•5H2O, 0.1 mmol of 4,4'-dipyridyl disulfide, 0.0075 mmol of meso-tetra(4-carboxyphenyl)porphyrin, and 1.9 mmol of 4-fluorobenzoic acid and add them to a 25 mL beaker. Then add 15 mL of N,N-dimethylformamide to the beaker and sonicate it for 25 min to dissolve it completely, thus obtaining a mixed solution.

[0081] The mixed solution was transferred to a 25 mL polytetrafluoroethylene liner, which was then transferred to a high-pressure reactor with a pressure of 13 kPa. The reactor was then placed in an oven at 90°C and reacted for 96 h.

[0082] After the reaction is complete, it is carried out at 5℃ for h -1The mixture was slowly cooled to room temperature, and 7 mL of N,N-dimethylformamide was added. The mixture was centrifuged at 8000 r / min for 3 min, and the lower layer was collected. 7 mL of ethanol was added to the collected lower layer, and the mixture was centrifuged at 8000 r / min and washed until the supernatant was colorless. The lower layer was collected and dried under vacuum at 55 °C for 24 h to obtain purplish-black crystals.

[0083] Example 4

[0084] Weigh 0.05 mmol of Eu(NO3)3•5H2O, 0.1 mmol of 4,4'-dipyridyl disulfide, 0.005 mmol of meso-tetra(4-carboxyphenyl)porphyrin, and 1.5 mmol of 4-fluorobenzoic acid and add them to a 25 mL beaker. Then add 15 mL of N,N-dimethylformamide to the beaker and sonicate it for 25 min to dissolve it completely, thus obtaining a mixed solution.

[0085] The mixed solution was transferred to a 25 mL polytetrafluoroethylene liner, which was then transferred to a high-pressure reactor with a pressure of 13 kPa. The reactor was then placed in an oven at 90°C and reacted for 96 h.

[0086] After the reaction is complete, it is carried out at 5℃ for h -1 The mixture was slowly cooled to room temperature, and 7 mL of N,N-dimethylformamide was added. The mixture was centrifuged at 8000 r / min for 3 min, and the lower layer was collected. 7 mL of ethanol was added to the collected lower layer, and the mixture was centrifuged at 8000 r / min and washed until the supernatant was colorless. The lower layer was collected and dried under vacuum at 55 °C for 24 h to obtain purplish-black crystals.

[0087] Example 5

[0088] Weigh 0.05 mmol of Eu(NO3)3•5H2O, 0.1 mmol of 4,4'-dipyridyl disulfide, 0.005 mmol of meso-tetra(4-carboxyphenyl)porphyrin, and 2.5 mmol of 4-fluorobenzoic acid and add them to a 25 mL beaker. Then add 15 mL of N,N-dimethylformamide to the beaker and sonicate it for 25 min to dissolve it completely, thus obtaining a mixed solution.

[0089] The mixed solution was transferred to a 25 mL polytetrafluoroethylene liner, which was then transferred to a high-pressure reactor with a pressure of 13 kPa. The reactor was then placed in an oven at 90°C and reacted for 96 h.

[0090] After the reaction is complete, it is carried out at 5℃ for h -1The mixture was slowly cooled to room temperature, and 7 mL of N,N-dimethylformamide was added. The mixture was centrifuged at 8000 r / min for 3 min, and the lower layer was collected. 7 mL of ethanol was added to the collected lower layer, and the mixture was centrifuged at 8000 r / min and washed until the supernatant was colorless. The lower layer was collected and dried under vacuum at 55 °C for 24 h to obtain purplish-black crystals.

[0091] Product characterization

[0092] The purplish-black crystals prepared in Examples 1-5 were designated as Eu-TCPP-SO4 crystals and characterized by single-crystal XRD. The single-crystal XRD patterns of the Eu-TCPP-SO4 crystals prepared in Examples 1-5 were identical, as shown in... Figure 1 As shown. The crystal structure diagram obtained from single-crystal XRD data is as follows. Figure 2 As shown.

[0093] Figure 2 The results show that the smallest asymmetric structural unit of the Eu-TCPP-SO4 crystal consists of three crystallographically independent metallic Eu atoms. 3+ The ion consists of 4 completely deprotonated TCPP molecules, 2 water molecules, and 2 / 3 sulfate ions. (2 / 3 sulfate ions means that the sulfate ion is located exactly on the three-dimensional symmetry axis, so it is not divided into three parts, and the smallest asymmetric unit contains 2 / 3 independent sulfate ions).

[0094] Figure 2 The purple polyhedron in the middle is a cluster of metallic Eu and its surrounding area.

[0095] Figure 2 A schematic diagram of the structure of the purple polyhedron (metal Eu cluster and its surroundings) is shown below. Figure 3 As shown. Figure 3 Display: The metallic Eu cluster consists of 9 metallic Eu atoms 3+ Ionic composition, with 9 metal Eu atoms in the Eu cluster. 3+ The O atoms surrounding the ion come from bridging oxygen atoms, 12 completely deprotonated methyl-tetra(4-carboxyphenyl)porphyrins, 6 water molecules, and two sulfate ions.

[0096] The unit cell parameters of Eu-TCPP-SO4 crystal are shown in Table 1.

[0097] Example 1: Morphology of Eu-TCPP-SO4 crystals prepared as shown in the figure. Figure 6 As shown. Figure 6 The Eu-TCPP-SO4 crystals are shown to be smooth hexagonal prisms.

[0098] Performance testing

[0099] (a) Utilizing the principle that •OH can cause methylene blue molecules to open their rings and thus fade their color, an experiment to generate •OH free radicals was conducted by degrading methylene blue.

[0100] First, prepare a phosphate buffer solution (PBS) with a pH of 7.4. Then, use the PBS solution to prepare a 25 μg mL solution. -1 The Eu-TCPP-SO4 crystals (MOF material) prepared in Example 1 were prepared with methylene blue solution (MB) and PBS solution to a concentration of 1 mg / mL. -1 MOF material solution.

[0101] Using a blank group as a control group, the degradation effects of ultrasound alone and MOF material alone on MB were tested, and the degradation effect of MOF material on MB under ultrasound was also tested:

[0102] 1) Blank control: Take a 5 mL centrifuge tube, add 2 mL of the prepared methylene blue solution and 1 mL of PBS solution to the centrifuge tube, react for 1, 2, 3, 4 and 5 min respectively, and measure the change of absorbance of the system at 660 nm.

[0103] 2) Ultrasound group: Take a 5 mL centrifuge tube, add 2 mL of the prepared methylene blue solution and 1 mL of PBS solution to the centrifuge tube, and sonicate (1.5 W cm⁻¹). -2 The system was subjected to a 1 MHz, 50% duty cycle reaction for 1, 2, 3, 4, and 5 min, and the absorbance change at 664 nm was measured.

[0104] 3) MOF material group: Take a 5 mL centrifuge tube, add 2 mL of the prepared methylene blue solution and 1 mL of MOF material solution to the centrifuge tube, react for 1, 2, 3, 4 and 5 min respectively, and measure the change of absorbance of the system at 664 nm.

[0105] 4) Material plus sonication group: Take a 5 mL centrifuge tube, add 2 mL of the prepared methylene blue solution and 1 mL of MOF material solution to the centrifuge tube, and sonicate (1.5 W cm⁻¹). -2 The system was subjected to a 1 MHz, 50% duty cycle reaction for 1, 2, 3, 4 and 5 min respectively, and the absorbance change of the system at 660 nm was measured.

[0106] Test results are as follows Figure 4 As shown. Figure 4In the diagram, (A) is the UV absorption spectrum of MB under ultrasound (US) alone; (B) is the UV absorption spectrum of MB under Eu-TCPP-SO4 crystal treatment alone; (C) is the UV absorption spectrum of MB under Eu-TCPP-SO4 crystal + ultrasound (US) treatment; and (D) is the characteristic absorbance curve of MB in different systems as a function of ultrasound time. Figure 4 In the diagram, the horizontal axis of (A), (B), and (C) represents wavelength, and the vertical axis represents absorbance; the horizontal axis of (D) represents time, and the vertical axis represents the ratio of absorbance to initial absorbance.

[0107] Figure 4 The results showed that, compared with the blank control group, the absorbance of the Eu-TCPP-SO4 crystal and the ultrasonic-only group decreased slightly with increasing reaction time. However, when the Eu-TCPP-SO4 crystal and ultrasonication were used together, the absorbance of the system at 664 nm decreased significantly with increasing ultrasonication time. At 5 min, the degradation rate of MB by the Eu-TCPP-SO4 crystal was 1.21 μM min. -1 The degradation rate of MB by ultrasound is 0.28 μM min. -1 Eu-TCPP-SO4 crystals exhibit a degradation rate of up to 5.73 μM min under ultrasonic irradiation for MB. -1 This indicates that the Eu-TCPP-SO4 crystal of the present invention can generate a large number of •OH free radicals under the action of ultrasound.

[0108] (ii) Utilization 1 The principle that O2 can oxidize 9,10-diphenylanthracene molecules, causing them to fade, is achieved through the degradation of 9,10-diphenylanthracene. 1 O2 free radical generation experiment.

[0109] First, prepare a phosphate buffered saline (PBS) solution with a pH of 7.4. Then, use the PBS solution to prepare a 1 mg / mL solution. -1 A 9,10-diphenylanthracene (DPA) solution was used to prepare Eu-TCPP-SO4 crystals (MOF material) prepared in Example 1 using PBS solution to a concentration of 1 mg / mL. -1 MOF material solution.

[0110] Using a blank group as a control group, the degradation effects of single ultrasound and single MOF material on DPA were tested, and the degradation effect of MOF material on DPA under ultrasound was also tested:

[0111] 1) Blank control: Take a 5 mL centrifuge tube, add 2 mL of the prepared 9,10-diphenylanthracene solution and 1 mL of PBS solution to the centrifuge tube, react for 1, 2, 3, 4 and 5 min respectively, and measure the change of absorbance of the system at 380 nm.

[0112] 2) Ultrasonic group: Take a 5 mL centrifuge tube, add 2 mL of the prepared 9,10-diphenylanthracene solution and 1 mL of PBS solution to the centrifuge tube, and sonicate (1.5 W cm⁻¹). -2 The system was subjected to a 1 MHz, 50% duty cycle reaction for 1, 2, 3, 4, and 5 min, and the absorbance of the system at 380 nm was measured.

[0113] 3) MOF material group: Take a 5 mL centrifuge tube, add 2 mL of the prepared 9,10-diphenylanthracene solution and 1 mL of MOF material solution to the centrifuge tube, react for 1, 2, 3, 4 and 5 min respectively, and measure the change of absorbance of the system at 380 nm.

[0114] 4) Material plus sonication group: Take a 5 mL centrifuge tube, add 2 mL of the prepared 9,10-diphenylanthracene solution and 1 mL of MOF material solution to the centrifuge tube, and sonicate (1.5 W cm⁻¹). -2 The system was subjected to a 1 MHz, 50% duty cycle reaction for 1, 2, 3, 4 and 5 min respectively, and the absorbance change of the system at 380 nm was measured.

[0115] Test results are as follows Figure 5 As shown. Figure 5 In the diagram, (A) is the ultraviolet absorption spectrum of DPA under ultrasound (US) alone; (B) is the ultraviolet absorption spectrum of DPA under Eu-TCPP-SO4 crystal treatment alone; (C) is the ultraviolet absorption spectrum of DPA under Eu-TCPP-SO4 crystal + ultrasound (US) treatment; and (D) is the characteristic absorbance curve of PDA in different systems as a function of ultrasound time. Figure 5 In the diagram, the horizontal axis of (A), (B), and (C) represents wavelength, and the vertical axis represents absorbance; the horizontal axis of (D) represents time, and the vertical axis represents the ratio of absorbance to initial absorbance.

[0116] Figure 5The results showed that, compared with the blank control group, the absorbance of the Eu-TCPP-SO4 crystal and the ultrasonic-only group decreased slightly with increasing reaction time; however, when the Eu-TCPP-SO4 crystal and ultrasonication were used together, the absorbance of the system at 380 nm decreased significantly with increasing ultrasonication time. At 5 min, the degradation rate of DPA by the Eu-TCPP-SO4 crystal was 8.38 μM min. -1 The degradation rate of DPA by ultrasound was 3.78 μM min. -1 Eu-TCPP-SO4 crystals exhibited a degradation rate of up to 40.78 μM min under ultrasonic irradiation for DPA. -1 This demonstrates that the Eu-TCPP-SO4 crystal of the present invention can produce more [unclear - possibly "products" or "products"] under the action of ultrasound. 1 O2 free radicals.

Claims

1. An Eu-TCPP-SO4 crystal with the chemical formula C 144 H 87 Eu9N 12 O 43 S2; Its smallest asymmetric unit includes: Three crystallographically independent metals Eu 3+ The ions consist of 4 completely deprotonated medium-tetra(4-carboxyphenyl)porphyrin molecules, 2 water molecules, and 2 / 3 sulfate ions. Belongs to the hexagonal crystal system. P -3 space group; The unit cell parameters are: a=22.8981 Å, b=22.8981 Å, c=18.0750 Å, α=90°, β=90°, γ=120°.

2. The Eu-TCPP-SO4 crystal as described in claim 1, characterized in that, It is produced by the reaction of Eu(NO3)3•5H2O, 4,4'-dipyridyl disulfide, and meso-tetra(4-carboxyphenyl)porphyrin.

3. A method for preparing Eu-TCPP-SO4 crystal as described in any one of claims 1-2, comprising: (1) Dissolve Eu(NO3)3•5H2O, 4,4'-dipyridinyl disulfide, meso-tetra(4-carboxyphenyl)porphyrin and 4-fluorobenzoic acid in a solvent to obtain a raw material solution; (2) The raw material solution is reacted at 5.5-28 kPa and 80-120℃; (3) After the reaction is completed, the mixture is cooled, separated, washed and dried in sequence to obtain the Eu-TCPP-SO4 crystal.

4. The preparation method according to claim 3, characterized in that, The solvent is selected from at least one of N,N-dimethylformamide, deionized water, and ethanol; or / and, The molar ratio of Eu(NO3)3•5H2O, 4,4'-dipyridyl disulfide, and methyl-tetra(4-carboxyphenyl)porphyrin is 1:(1.5-2.5):(0.05-0.15); or / and, The molar concentration of 4-fluorobenzoic acid in the feed solution is 1.5-2.5 mmol.

5. The preparation method according to claim 3, characterized in that, The reaction temperature is 90-110℃; or / and, The reaction pressure is 5.5-28 kPa; or / and, The reaction time is more than 24 hours; or / and, The cooling rate is 1-8 ℃ h -1 .

6. The preparation method according to claim 3, characterized in that, The reaction time is 24-72 h; or / and, The cooling rate is 5 ± 1 ℃ h -1 .

7. A sound-sensitive agent comprising Eu-TCPP-SO4 crystals as described in any one of claims 1-2 or Eu-TCPP-SO4 crystals prepared by any one of claims 3-6.

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