Four-component metal organic cage based on perylene diimide and terphenyl and preparation method and application thereof

Abstract

The invention discloses a four-component metal organic cage as well as a preparation method and application thereof, and belongs to the technical field of supramolecular chemistry. The metal organic cage is based on self-assembly driven by transition metal coordination, a shape complementation strategy between ligands and a molecular docking method, and discloses a series of metal organic cages based on perylene diimide and p-terphenyl pyridine ligands, which are asymmetric in space structure and have four components. The function integration of the pyridine ligand in the metal cage can realize charge transfer in the multi-component metal organic cage, so that the metal cage can be applied to photocatalytic oxidation reaction.

Description

Technical Field

[0001] The present invention belongs to the technical field of supramolecular chemistry, and particularly relates to a four-component metal-organic cage based on perylene diimide and terphenyl, a preparation method thereof, and an application thereof. Background Art

[0002] In photocatalytic oxidation reactions, one of the challenging and important issues is to efficiently and selectively oxidize sulfides to sulfoxides under mild reaction conditions, so that no toxic sulfones and other by-products are produced. This is very important because sulfoxides play a crucial role in organic synthesis, pharmaceuticals, and polymers. Some sulfoxides, such as those found in drugs like omeprazole and sulindac, exhibit significant pharmacological properties. Current methods for synthesizing sulfoxides typically involve the use of multiple oxidants, resulting in excessive waste, facing challenges in selectivity, and the potential formation of unwanted sulfones. In addition, many existing protocols require high temperatures. In this regard, the development of a self-assembled cage with a unique geometry that uses functional ligands to selectively photo-oxidize sulfides to sulfoxides in high yields under aerobic and organic conditions is attractive.

[0003] Due to the moderate bond strength and the specific directionality of coordination bonds, metal coordination-driven self-assembly can effectively construct multi-component supramolecular coordination complexes. As a subset of multi-component supramolecular coordination complexes, metal cages are characterized by their well-defined three-dimensional structures and great functionalization potential, and have attracted increasing attention in a series of applications. However, most metal cages have a limited range of organic ligands, usually involving single metals and ligands, which leads to reduced structural diversity and functional integration compared to the highly complex self-assembled systems observed in biological processes. In recent years, Fujita, Stang, Clever, Nitschke, and other authors have conducted pioneering research on multi-component metal cages. Strategies such as template effects, charge separation, shape complementarity, and sub-component self-assembly have been effectively used to construct multi-component metal cages. However, further increasing the number of components significantly exacerbates the challenge of constructing multi-component metal cages. This difficulty is mainly due to the increasing complexity of the interactions between different ligands, which may lead to the formation of multiple structures during the self-assembly process, thereby reducing the possibility of achieving a single target structure. In addition, in multi-component metal cage systems, the thermodynamic stability and kinetic pathways may not be consistent, resulting in competing products driven by thermodynamic and kinetic factors. Therefore, multi-component metal cages with more than three organic ligands are still rare. In addition, although the above research has clearly studied the self-assembly process of multi-component metal cages, the relationship between the structural changes caused by the increased components and the functions they produce has not been explored in depth. Summary of the Invention

[0004] The object of the present invention is to overcome the above-mentioned disadvantages of the prior art, and to provide a four-component metal-organic cage based on perylene diimide and terphenyl, and its preparation method and application, so as to solve the problems of size matching, functional integration, charge transfer, selective photocatalytic oxidation of methyl phenyl sulfide, etc. in multi-component metal cages in the prior art.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] A four-component metal-organic cage based on perylene diimide and terphenyl, the structural formula is:

[0007]

[0008] A preparation method of the above-mentioned four-component metal-organic cage based on perylene diimide and terphenyl, comprising the following steps: dissolving a tetrapyridyl perylene diimide ligand, a tetrapyridyl terphenyl ligand, a tetradentate carboxylate ligand and a cisplatin metal ligand in a mixed solvent, subjecting the mixed system to ultrasonic treatment and stirring, and then obtaining a reaction product through a self-assembly reaction, and purifying the reaction product to obtain a cavity-containing metal-organic cage based on perylene diimide and terphenyl.

[0009] Preferably, the tetrapyridyl perylene diimide ligand is 4,7,11,14-tetrakis(4-pyridyl)perylene diimide.

[0010] Preferably, the tetrapyridyl terphenyl ligand is any one of tetrapyridyl terphenyl-benzene, tetrapyridyl terphenyl-anthracene or tetrapyridyl terphenyl-methoxy.

[0011] Preferably, the cisplatin metal ligand is cis-bis(triethylphosphine)di(trifluoromethanesulfonate)platinum(II).

[0012] Preferably, the tetradentate carboxylate ligand is sodium 4'-(4,7-bis(3-carboxyphenyl)-1H-benzo[d]imidazol-2-yl)-[1,1'-biphenyl]-3,5-dicarboxylate.

[0013] Preferably, the preparation process of the sodium 4'-(4,7-bis(3-carboxyphenyl)-1H-benzo[d]imidazol-2-yl)-[1,1'-biphenyl]-3,5-dicarboxylate includes the following steps:

[0014] (1) React 4,7-dibromo-2,3-benzothiadiazole, 3-ethoxycarbonylphenylboronic acid, tetrakis(triphenylphosphine)palladium and Cs 2 CO 3 to generate compound 1;

[0015] (2) Dissolve compound 1 in a mixed solution of THF and EtOH, and add NaBH 4and CoCl 2 ·6H 2 O, and after reaction, extract through brine and DCM. Mix the extract with 4-bromobenzaldehyde and ZrCl 4 . After recrystallization, compound 2 is obtained;

[0016] (3) React by mixing compound 2, 4-bromobenzaldehyde and ZrCl 4 , tetrakis(triphenylphosphine)palladium and Cs 2 CO 3 . Compound 3 is generated;

[0017] (4) Mix compound 3, potassium hydroxide, THF and water and reflux. Dropwise add HCl to the reflux solution to obtain compound 4;

[0018] (5) Dissolve compound 4 and sodium hydroxide in water. Precipitate a solid through acetone to obtain sodium 4'-(4,7-bis(3-carboxyphenyl)-1H-benzo[d]imidazol-2-yl)-[1,1'-biphenyl]-3,5-dicarboxylate.

[0019] Preferably, the mixed molar ratio of the tetrapyridyl perylene diimide ligand, the tetrapyridyl terphenyl ligand, the tetradentate carboxylate ligand and the cisplatin metal ligand is 1:1:2:8.

[0020] Preferably, the stirring process is that the stirring temperature is 55 °C and the stirring time is 12 h.

[0021] An application of the above-mentioned four-component metal-organic cage based on perylene diimide and terphenyl, which is used as a photocatalyst for photocatalytic oxidation reaction;

[0022] The photocatalytic oxidation can generate singlet oxygen, and the singlet oxygen is used to oxidize methyl phenyl sulfide.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] The present invention discloses a four-component metal-organic cage based on perylene diimide and terpyridine ligand. This metal-organic cage is based on the methods of transition-metal coordination-driven self-assembly, ligand shape complementarity strategy and molecular docking, and discloses a series of four-component metal-organic cages with spatially asymmetric structures based on perylene diimide and terpyridine ligand. The functional integration of the pyridine ligand in this metal cage realizes charge transfer in the cavity of the multi-component metal-organic cage and enables the application of photocatalytic oxidation reaction. Therefore, the metal-organic cage formed by combining p-terphenyl as an electron donor modified with methoxy and anthracene and perylene diimide as an electron acceptor can promote charge separation and charge transfer under light irradiation. In addition, the metal-organic cage can generate singlet oxygen under light irradiation, thereby oxidizing methyl phenyl sulfide to methyl phenyl sulfoxide. The present invention provides a strategy for incorporating multifunctional pyridine ligands into metal-organic cages for photocatalytic oxidation, which will contribute to the development of functional integration of pyridine ligand molecules, preparation strategies for multi-component gold-organic cages, and the application of metal-organic cages in photocatalysis.

[0025] The present invention also discloses a preparation method of a four-component metal-organic cage based on perylene diimide and terphenyl. This organic cage is prepared from a tetrapyridyl perylene diimide ligand, a tetrapyridyl terphenyl ligand, a tetradentate carboxylate ligand and a cisplatin metal ligand. During this preparation process, the sodium ion in the tetradentate carboxylate ligand dissociates in the solution, and the cisplatin metal ligand Pt(PEt 3 ) 2 (OTf) 2 after removing two trifluoromethanesulfonate anions in the solution, coordinates and self-assembles with the N atom in the pyridine group on the tetrapyridyl perylene diimide and the O atom on the tetradentate carboxylic acid through metal-organic coordination to form the target four-component organometallic cage. The dissociated trifluoromethanesulfonate ions serve as counterions around the Pt metal site of the metal cage. The yield of the four-component metal-organic cage based on perylene diimide and terphenyl prepared by this method can reach 90%. The preparation steps are simple, the raw materials are cheap and easy to obtain, the product is easy to purify, and the yield is high.

[0026] The present invention also discloses an application of a four-component metal-organic cage based on perylene diimide and terphenyl. The four-component metal-organic cage based on perylene diimide and terphenyl is a luminescent metal-organic cage assembled from a tetrapyridyl perylene diimide ligand, a tetrapyridyl terphenyl ligand, a tetradentate carboxylate ligand, and cisplatin. After the metal-organic cage absorbs photons, the tetrapyridyl terphenyl ligand, as an electron donor, can transfer electrons to the tetrapyridyl perylene diimide ligand to undergo charge transfer, forming a perylene diimide anion radical. In addition, the four-component metal cage can generate singlet oxygen through energy transfer under light irradiation, and this singlet oxygen can carry out the oxidation reaction of sulfides. The prepared four-component organometallic cage has a cavity with a definite size and can convert oxygen into singlet oxygen through energy transfer under light irradiation, and can selectively oxidize methyl phenyl sulfide to methyl phenyl sulfoxide, thus artificially preparing a photocatalytic oxidation system. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a flow chart for preparing the four-component metal-organic cage based on perylene diimide and terphenyl of the present invention;

[0028] Figure 2 It is a synthetic route diagram of the four-component metal-organic cage 5a based on perylene diimide and terphenyl prepared in Example 1;

[0029] Figure 3 For the four-component metal-organic cage 5a based on perylene diimide and terphenyl prepared in Example 1 1 HNMR spectrum;

[0030] Figure 4 For the four-component metal-organic cage 5a based on perylene diimide and terphenyl prepared in Example 1 31 PNMR spectrum;

[0031] Figure 5 It is a synthetic route diagram of the four-component metal-organic cage 5b based on perylene diimide and terphenyl prepared in Example 2;

[0032] Figure 6 For the four-component metal-organic cage 5b based on perylene diimide and terphenyl prepared in Example 2 1 HNMR spectrum;

[0033] Figure 7 For the four-component metal-organic cage 5b based on perylene diimide and terphenyl prepared in Example 2 31 PNMR spectrum;

[0034] Figure 8 It is a synthetic route diagram of the four-component metal-organic cage 5c based on perylene diimide and terphenyl prepared in Example 3;

[0035] Figure 9 1H NMR spectrum of the four-component perylene diimide- and terphenyl-based metal-organic cage 5c prepared in Example 3 1 ;

[0036] Figure 10 1H NMR spectrum of the four-component perylene diimide- and terphenyl-based metal-organic cage 5c prepared in Example 3 31 31P NMR spectrum;

[0037] Figure 11 Crystal structure diagrams of the four-component perylene diimide- and terphenyl-based metal-organic cages prepared in Examples 1-3;

[0038] Figure 12 UV absorption spectra of the four-component perylene diimide- and terphenyl-based metal-organic cages prepared in Examples 1-3;

[0039] Figure 13 Fluorescence emission spectra of the four-component perylene diimide- and terphenyl-based metal-organic cages prepared in Examples 1-3;

[0040] Figure 14 Fluorescence lifetimes of the four-component perylene diimide- and terphenyl-based metal-organic cages prepared in Examples 1-3;

[0041] Figure 15 Electron paramagnetic resonance spectra (EPR) of the four-component perylene diimide- and terphenyl-based metal-organic cages prepared in Examples 1-3;

[0042] Figure 16 Electrochemical impedance spectra of the four-component perylene diimide- and terphenyl-based metal-organic cages prepared in Examples 1-3;

[0043] Figure 17 Photocurrent tests of the four-component perylene diimide- and terphenyl-based metal-organic cages prepared in Examples 1-3;

[0044] Figure 18 Transient absorption spectra of the four-component perylene diimide- and terphenyl-based metal-organic cages prepared in Examples 1-3;

[0045] Figure 19 Transient absorption spectra of the four-component perylene diimide- and terphenyl-based metal-organic cages prepared in Examples 1-3;

[0046] Figure 20 Decay fitting curves of perylene diimide anion radicals of the four-component perylene diimide- and terphenyl-based metal-organic cages prepared in Examples 1-3;

[0047] Figure 21Calculation of the HOMO-LUMO energy levels of the four-component perylene diimide and terphenyl-based metal-organic cages prepared in Examples 1-3;

[0048] Figure 22 Synthesis route of benzyl methyl sulfide in Examples 1-3;

[0049] Figure 23 Conversion rate of benzyl methyl sulfide in Examples 1-3;

[0050] Figure 24 Yield of benzyl methyl sulfide in Examples 1-3;

[0051] Figure 25 Change in absorbance at 372 nm of DPHA (c = 150 μM) under the action of TPP (c = 10 μM) and the four-component metal cage (c = 10 μM) in Examples 1-3;

[0052] Figure 26 1H NMR spectrum of the intermediate product during the preparation of the tetradentate carboxylate ligand in Examples 1-3;

[0053] Figure 27 1H NMR spectrum of the intermediate product during the preparation of the tetradentate carboxylate ligand in Examples 1-3;

[0054] Figure 28 1H NMR spectrum of the tetradentate carboxylate ligand in Examples 1-3. Detailed Description of the Invention

[0055] The present invention will be further described in detail below with reference to the accompanying drawings:

[0056] To enable those skilled in the art to understand the features and effects of the present invention, the following provides a general description and definition of the terms and expressions mentioned in the specification and claims. Unless otherwise specified, all technical and scientific terms used herein shall have the ordinary meaning understood by those skilled in the art with respect to the present invention. In case of conflict, the definition in this specification shall prevail.

[0057] In this article, unless otherwise specified, "comprising", "including", "containing", "having" or similar expressions cover the meanings of "consisting of" and "consisting essentially of". For example, "A comprises a" covers the meanings of "A comprises a and others" and "A consists only of a".

[0058] The present invention will be further illustrated with specific examples below. It should be understood that these examples are only for illustrating the present invention and not for limiting the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of this application.

[0059] In the following examples, conventional instruments and equipment in the art are used. For the experimental methods without specific conditions noted in the following examples, they are generally carried out under conventional conditions or according to the conditions recommended by the manufacturer. In the following examples, various raw materials are used. Unless otherwise specified, commercially available products are used, and their specifications are conventional specifications in the art. In the specification of the present invention and the following examples, unless otherwise specified, "%" represents weight percentage, "parts" represents weight parts, and the ratio represents weight ratio.

[0060] As Figure 1-10 shown, in the first aspect of the present invention, a four-component metal-organic cage based on perylene diimide and terphenyl is disclosed. This metal-organic cage is composed of a tetrapyridyl perylene diimide ligand, a tetrapyridyl terphenyl ligand, a tetradentate carboxylate ligand, and a cisplatin metal ligand. The structural formula of this metal-organic cage is:

[0061]

[0062] In the second aspect of the present invention, a preparation method of a four-component metal-organic cage based on perylene diimide and terphenyl is disclosed. This preparation method includes the following steps: Dissolve the tetrapyridyl perylene diimide ligand and the tetrapyridyl terphenyl ligand by mixing with the tetradentate carboxylate ligand and the cisplatin metal ligand in a mixed solvent of acetonitrile and water. Ultrasonically treat the mixture and transfer it to a constant-temperature metal bath for stirring. The product obtained by self-assembly is subjected to a purification treatment operation to obtain a four-component metal-organic cage based on perylene diimide and terphenyl with a cavity.

[0063] As a preferred scheme, the tetrapyridyl perylene diimide ligand is 4,7,11,14-tetrakis(4-pyridyl)perylene diimide, and its structural formula is:

[0064]

[0065] As a preferred scheme, the tetrapyridyl terphenyl ligand is any one of tetrapyridyl-p-terphenyl-benzene, tetrapyridyl-p-terphenyl-anthracene, and tetrapyridyl-p-terphenyl-methoxy, and their structural formulas are respectively:

[0066]

[0067] As a preferred scheme, the tetradentate carboxylate ligand is sodium 4'-(4,7-bis(3-carboxyphenyl)-1H-benzo[d]imidazol-2-yl)-[1,1'-biphenyl]-3,5-dicarboxylate, and its structural formula is:

[0068]

[0069] Because this molecule utilizes a shape-matching strategy, the sodium isophthalate moiety (at the top of the molecule) can coordinate with the tetrapyridyl perylene diimide ligand, while the sodium terphenylcarboxylate moiety (at the bottom of the molecule) can coordinate with the tetrapyridyl terphenyl ligand. This molecule serves as an excellent bridge to bind multiple pyridine ligands within a metal cage, achieving the binding of multiple functional pyridine ligands.

[0070] The specific preparation process of this substance is as follows:

[0071]

[0072] Specifically, it includes the following steps:

[0073] (1) Add 4,7-dibromo-2,3-benzothiadiazole (1.60 g, 5.45 mmol), 3-ethoxycarbonylphenylboronic acid (2.75 g, 14.18 mmol), tetrakis(triphenylphosphine)palladium (630.05 mg, 0.54 mmol), and Cs 2 CO 3 (5.33 g, 16.36 mmol) to a 250 mL Schlenk flask. Degas and flush with N 2 . Add DMF (60 mL) and toluene (60 mL), and reflux the solution (110 °C) for 24 hours. After cooling the solution to room temperature, purify the crude product by column chromatography on silica gel to obtain a pale yellow compound 1 (yield: 2.24 g, 95%). The data of the hydrogen NMR spectrum are as follows: 1 H NMR (600 MHz, CDCl 3 , 295 K): δ 8.62 (t, J = 1.8 Hz, 2H), 8.21 (dt, J = 7.8, 1.5 Hz, 2H), 8.15 (dt, J = 7.8, 1.4 Hz, 2H), 7.86 (s, 2H), 7.64 (t, J = 7.8 Hz, 2H), 4.44 (q, J = 7.1 Hz, 4H), 1.43 (t, J = 7.2 Hz, 6H).

[0074] (2) Dissolve compound 1 (2 g, 4.6 mmol) in THF / EtOH (1:3, 160 mL). Add NaBH 4 (690 mg, 18.4 mmol) in portions. Add CoCl 2 ·6H 2 O (50 mg, 0.21 mmol). Reflux the resulting black mixture for 4 hours. Cool to room temperature, then filter. Concentrate the filtrate, extract with brine and DCM. Add an excess of 4-bromobenzaldehyde and ZrCl 4 (30.12 mg, 129.26

[0075] (617 mg, yield 84%) was obtained as a white solid by recrystallization from DCM / PE after stirring (24 h) and evaporation of the solvent.

[0076] (617 mg, with a yield of 84%). The data of the hydrogen spectrum are as follows: 1 H NMR (600 MHz, CDCl 3 , 295 K): δ 9.78 (s, 1H), 8.83 (d, J = 1.8 Hz, 1H), 8.42–8.39 (m, 1H), 8.34 (t, J = 1.8 Hz, 1H), 8.11 (d, J = 7.5 Hz, 1H), 8.07 (d, J = 7.8 Hz, 1H), 7.98–7.95 (m, 2H), 7.86–7.84 (m, 1H), 7.66–7.57 (m, 5H), 7.41 (d, J = 7.7 Hz, 1H), 4.46–4.40 (m, 4H), 1.44 (dt, J = 9.9, 7.1 Hz, 6H).

[0077] (3) Compound 2 (174 mg, 305.56 μmol), 3,5-dimethoxycarbonylphenylboronic acid (121.94 mg, 458.33 μmol), tetrakis(triphenylphosphine)palladium(0) (35.31 mg, 30.56 μmol) and Cs 2 CO 3 (298.67 mg, 916.67 μmol) were added to a 250 mL Schlenk flask. After degassing and purging with N 2 . DMF (60 mL), toluene (60 mL) and water (15 mL) were added and the solution was refluxed (110 °C) for 24 h. After cooling the solution to room temperature, the crude product was purified by column chromatography on silica gel to give white compound 3 (177 mg, yield 81%). The data of the hydrogen spectrum are as follows: 1 H NMR (600 MHz, CDCl 3 , 295 K): δ 10.01 (s, 1H), 8.87 (s, 1H), 8.67 (t, J = 1.5 Hz, 1H), 8.49 (d, J = 1.6 Hz, 3H), 8.39 (s, 1H), 8.23 (d, J = 8.0 Hz, 2H), 8.11 (s, 2H), 8.00 (s, 1H), 7.90 (s, 1H), 7.78 (d, J = 8.0 Hz, 2H), 7.63 (s, 2H), 7.44 (s, 1H), 4.45 (p, J = 7.0 Hz, 8H), 1.45 (t, J = 7.0 Hz, 12H), as Figure 26 shown.

[0078] (4) Compound 3 (177 mg, 249.02 μmol) and potassium hydroxide (223.54 mg, 3.98 mmol) were added to a 100 mL Schlenk flask. THF (20 mL) and water (10 mL) were added and the solution was refluxed at 70 °C for 12 hours. After the solution was cooled to room temperature, HCl was added dropwise to the solution to obtain a dark brown product, Compound 4 (101 mg, yield 68%). The 1H NMR data were as follows: 1 1H NMR (600 MHz, DMSO, 295 K): δ 13.33 (s, 4H), 8.50 (dd, J = 9.0, 1.6 Hz, 4H), 8.46 (d, J = 8.2 Hz, 2H), 8.24 (s, 2H), 8.05 (d, J = 7.8 Hz, 2H), 7.99 (d, J = 8.1 Hz, 2H), 7.73 (t, J = 7.7 Hz, 2H), 7.54 (s, 2H), as Figure 27 shown.

[0079] (5) Compound 4 (101 mg, 168.74 μmol) and sodium hydroxide (28.35 mg, 708.69 μmol) were added to an aqueous solution. After complete dissolution at room temperature, acetone was added to precipitate a solid, obtaining white Product 5 (90 mg, yield 78%). The 1H NMR data were as follows: 1 1H NMR (600 MHz, D 2 2O, 295 K): δ 8.14 (t, J = 1.7 Hz, 0H), 8.07 (s, 1H), 7.98 (s, 1H), 7.79 (dd, J = 17.3, 7.8 Hz, 2H), 7.66–7.62 (m, 1H), 7.51 (d, J = 8.0 Hz, 1H), 7.47 (t, J = 7.7 Hz, 1H), 7.14 (s, 1H), as Figure 28 shown.

[0080] As a preferred embodiment, the cisplatin metal ligand is cis-bis(triethylphosphine)bis(trifluoromethanesulfonate)platinum(II), and the structural formula is:

[0081]

[0082] OTf:

[0083] PEt 3 :

[0084] As a preferred embodiment, the tetrapyridyl perylene diimide ligand, the tetrapyridyl terphenyl ligand, the tetradentate carboxylate ligand and the cisplatin metal ligand are weighed and mixed in a molar ratio of 1:1:2:8, and a mixed solution is obtained by adding a mixed solvent of acetonitrile and water. The mixed solvent of acetonitrile and water has a volume ratio of acetonitrile:water = 4:1.

[0085] As a preferred embodiment, the mixed solution is ultrasonically treated and then placed in a metal bath for constant-temperature stirring for multicomponent self-assembly to obtain a product solution. The constant-temperature stirring temperature of the reaction solution is 55 °C, and the reaction time is 12 h.

[0086] As a preferred embodiment, the reaction product is purified to obtain a four-component metal-organic cage based on perylene diimide and terphenyl. The purification process is to remove the solvent and then redissolve it, and then obtain the four-component metal-organic cage based on perylene diimide and terphenyl after filtration, recrystallization, centrifugation and drying.

[0087] The method for removing the solvent is: N 2 Blow dry and rotary evaporate under vacuum. Preferably, the solvent removal method is N 2 Blow dry.

[0088] As one of the preferred embodiments, the solvents for redissolving are acetonitrile and acetone. Preferably, the solvent for redissolving is acetonitrile.

[0089] As one of the preferred embodiments, recrystallization is carried out with ether and isopropyl ether solvents after filtration. Preferably, recrystallization is carried out with ether after filtration.

[0090] As one of the preferred embodiments, the obtained precipitate is centrifuged and dried in vacuo at 80 °C for 12 h.

[0091] The third aspect of the present invention discloses an application of the above-mentioned four-component metal-organic cage based on perylene diimide and terphenyl. The metal-organic cage can undergo energy transfer to generate reactive oxygen species, namely singlet oxygen, and realize an oxidation reaction of methyl phenyl sulfide through singlet oxygen.

[0092] An embodiment of the present invention discloses a preparation method of a four-component metal-organic cage based on perylene diimide and terphenyl. The tetrapyridyl perylene diimide ligand and the tetrapyridyl terphenyl ligand are dissolved in a mixed solvent of acetonitrile and water together with the tetradentate carboxylate ligand and the cisplatin metal ligand. The mixture is ultrasonically treated for 30 s and transferred to a constant-temperature metal bath for stirring. The product obtained by self-assembly is subjected to a purification treatment operation to obtain a four-component metal-organic cage based on perylene diimide and terphenyl with a cavity structure.

[0093] As Figure 22 shown, the four-component metal-organic cage based on perylene diimide and terphenyl synthesized in the present invention is used as a photocatalyst for an oxidation reaction. The specific process is as follows:

[0094] Take a 10 mL glass bottle, add the phenylmethyl sulfide substrate, the standard sample, the four-component metal cage (1% mol), deuterated acetonitrile and a magnetic stir bar into the bottle, fill it with oxygen, and calculate the conversion rate and yield of phenylmethyl sulfide at different time intervals under 520 nm light irradiation.

[0095] The following is further illustrated with specific examples.

[0096] Example 1

[0097] See Figure 2 , this example discloses a preparation method of a four-component metal-organic cage based on perylene diimide and terphenyl, including the following steps:

[0098] (1) Weigh and mix 4,7,11,14-tetrakis(4-pyridyl)perylene diimide (3.26 mg, 3.64 μmol), terphenyl-4,4'',4'''-tris(4-pyridyl)-benzene (1.96 mg, 3.64 μmol), sodium 4'-(4,7-bis(3-carboxyphenyl)-1H-benzo[d]imidazol-2-yl)-[1,1'-biphenyl]-3,5-dicarboxylate (5 mg, 7.28 μmol) and cis-bis(triethylphosphine)platinum(II) bis(trifluoromethanesulfonate) (21.25 mg, 29.13 μmol) in a molar ratio of 1:1:2:8, and add them to a mixed solvent of acetonitrile / water (7.5 ml, 4:1, v / v) and dissolve to obtain a mixed solution.

[0099] (2) Ultrasonic the mixed solution for 30 s, then place it in a metal bath at a constant temperature of 55 °C and stir for 12 h, and then cool to room temperature to obtain a product solution.

[0100] (3) Remove the solvent by drying with a nitrogen stream, redissolve the residue with acetonitrile (2.0 mL) and filter, add diethyl ether (8.0 mL) to precipitate, and collect the four-component metal-organic cage based on perylene diimide and terphenyl after centrifugation and vacuum drying at 60 °C for 12 h. The four-component metal-organic cage 5a can be prepared through this example.

[0101] The 1 1H NMR spectrum and 31 31P NMR spectrum of the product prepared in this example are shown in Figure 3 and Figure 4 respectively.

[0102] (4) Take a 10 mL glass bottle, add the phenylmethyl sulfide substrate, the standard sample, the four-component metal cage (1% mol), deuterated acetonitrile and a magnetic stir bar into the bottle, fill it with oxygen, and calculate the conversion rate and yield of phenylmethyl sulfide at different time intervals under 520 nm light irradiation.

[0103] Example 2

[0104] Referring to Fig. 5, this embodiment discloses a preparation method of a four-component metal-organic cage based on perylene diimide and terphenyl, comprising the following steps:

[0105] (1) Weigh and mix 4,7,11,14-tetrakis(4-pyridyl)perylene diimide (3.26 mg, 3.64 μmol), tetrapyridyl-p-terphenyl-anthracene (2.33 mg, 3.64 μmol), sodium 4'-(4,7-bis(3-carboxyphenyl)-1H-benzo[d]imidazol-2-yl)-[1,1'-biphenyl]-3,5-dicarboxylate (5 mg, 7.28 μmol) and cis-bis(triethylphosphine)platinum(II) bis(trifluoromethanesulfonate) (21.25 mg, 29.13 μmol) in a molar ratio of 1:1:2:8, and add them to a mixed solvent of acetonitrile / water (7.5 ml, 4:1, v / v) to dissolve and obtain a mixed solution.

[0106] (2) Ultrasonic the mixed solution for 30 s, then place it in a metal bath at a constant temperature of 55 °C and stir for 12 h, and then cool to room temperature to obtain a product solution.

[0107] (3) Remove the solvent by drying with a nitrogen stream, redissolve the residue in acetonitrile (2.0 mL), filter, add diethyl ether (8.0 mL) to precipitate, and collect the four-component metal-organic cage based on perylene diimide and terphenyl after centrifugation and vacuum drying at 60 °C for 12 h. Metal-organic cage 5b can be prepared through this embodiment.

[0108] The 1 1H NMR spectrum and 31 31P NMR spectrum are respectively as shown in Figure 6 and Figure 7 shown.

[0109] (4) Take a 10 mL glass bottle, add phenylmethyl sulfide substrate, standard sample, four-component metal cage (1% mol), deuterated acetonitrile and a magnetic stir bar into the bottle, fill it with oxygen, and calculate the conversion rate and yield of phenylmethyl sulfide at different time intervals under 520 nm light irradiation.

[0110] Example 3

[0111] Referring to Figure 8 , this embodiment discloses a preparation method of a four-component metal-organic cage based on perylene diimide and terphenyl, comprising the following steps:

[0112] (1) Weigh and mix 4,7,11,14 - tetrakis(4 - pyridyl)perylene diimide (3.26 mg, 3.64 μmol), tetrapyridyl - p - terphenyl - methoxy (2.18 mg, 3.64 μmol), sodium 4'-(4,7 - bis(3 - carboxyphenyl)-1H - benzo[d]imidazol - 2 - yl)-[1,1'-biphenyl]-3,5 - dicarboxylate (5 mg, 7.28 μmol), and cis - bis(triethylphosphine)platinum(II) bis(trifluoromethanesulfonate) (21.25 mg, 29.13 μmol) in a molar ratio of 1:1:2:8, and add them to a mixed solvent of acetonitrile / water (7.5 ml, 4:1, v / v) to dissolve and obtain a mixed solution.

[0113] (2) Ultrasonic the mixed solution for 30 s, then place it in a metal bath at a constant temperature of 55 °C and stir for 12 h, and then cool to room temperature to obtain a product solution.

[0114] (3) Remove the solvent by drying with a nitrogen stream, redissolve the residue in acetonitrile (2.0 mL) and filter, add diethyl ether (8.0 mL) to precipitate, and collect the four - component metal - organic cage based on perylene diimide and terphenyl by vacuum drying at 60 °C for 12 h. Through this example, a metal - organic cage can be prepared.

[0115] The 1 1H NMR spectrum and 31 31P NMR spectrum are shown in Figure 9 and Figure 10 respectively.

[0116] (4) Take a 10 - mL glass bottle, add phenylmethyl sulfide substrate, standard sample, four - component metal cage (1% mol), deuterated acetonitrile, and a magnetic stir bar into the bottle, fill it with oxygen, and calculate the conversion rate and yield of phenylmethyl sulfide at different time intervals under 520 - nm light irradiation.

[0117] As shown in Figure 11 , from left to right are 5a, 5b, and 5c respectively. In the crystal structure of the metal - organic cage, each Pt coordinates with one O atom and one N atom. The N atom is the N atom in the pyridine group of tetrakis(4 - pyridyl)perylene diimide or tetrapyridyl - p - terphenyl, and the O atom is one O atom on the tetradentate carboxylate. Tetrakis(4 - pyridyl)perylene diimide and tetrapyridyl - p - terphenyl are regarded as the upper and lower bases of the cage - like compound respectively, the tetradentate carboxylic acid ligand is regarded as the side of the cage - like compound, and the Pt metal is regarded as the eight vertices of the cage - like compound.

[0118] Figure 12As shown, the ultraviolet-visible absorption spectra of the examples were tested to obtain the photophysical properties of the four-component metal cages 5a - 5c in acetonitrile. The four-component metal cages 5a - 5c all showed three typical absorption bands with central wavelengths of 459 nm, 490 nm, and 526 nm respectively, which belong to the three typical absorption bands of the PDI pyridine ligand and showed no obvious changes. In addition, compared with the four-component metal cage 5a, the anthracene in the four-component metal cage 5b is present on the terpyridine ligand and also showed two additional absorption bands at 373 nm and 395 nm, which originated from its characteristic π-π* dominated electronic transitions.

[0119] As Figure 13 shown, the fluorescence emission spectra of the four-component metal cages 5a - 5c were tested and it was found that they had good fluorescence emission ability. All four-component metal-organic cages had two fluorescence emission peaks with their maximum emission wavelengths at 550 nm and 581 nm respectively. This is because they have similar luminescent groups and conjugated structures, sharing the same parent nuclear structure, resulting in similar electron transition energy levels and the maximum emission wavelengths being concentrated in a similar region. In addition, there were significant differences in the fluorescence intensities of the four-component metal cages 5a - 5c, mainly due to the differences in quantum yields. In acetonitrile, when excited at a wavelength of 520 nm, the fluorescence quantum yields of the four-component metal cages 5a - 5c were measured to be 34.95%, 25.05%, and 30.16% respectively, which indicates that the four-component metal cages 5b and 5c underwent intramolecular transitions after photon absorption upon photoexcitation to generate charge-separated states, showing better charge separation effects.

[0120] Figure 14 As shown, after testing the fluorescence emission spectra and quantum yields of the four-component metal cages 5a - 5c, the fluorescence lifetime experiment was continued. The four-component metal cage 5a with an unmodified parent nucleus had a relatively long fluorescence lifetime of 4.16 ns in acetonitrile, indicating that no additional groups were introduced to interfere with the excited state. Therefore, the excited state mainly underwent fluorescence decay through radiative transitions and there was less competition from non-radiative transitions. The fluorescence lifetimes of the modified four-component metal cages 5b and 5c were 3.76 ns and 3.75 ns respectively, which indicates that the anthracene in the four-component metal cage 5b participated in intramolecular charge transfer as a large conjugated system, forming a charge-separated state that led to the dissipation of the excited state energy through non-radiative pathways, shortening the lifetime. The methoxy group in the four-component metal cage 5c enhanced the electron density of the parent nucleus, resulting in intramolecular charge transfer after photoexcitation to also form a separated state, and the introduction of the methoxy group increased the molecular flexibility, promoting the dissipation of vibrational energy. Therefore, the lifetime was shorter than that of the four-component metal cage 5b.

[0121] As Figure 15As shown, electron paramagnetic resonance (EPR) tests were performed on the four-component metal cages 5a - 5c to study the nature of charge separation after photoexcitation. TEMPO (2,2,6,6-tetramethylpiperidine 1-oxyl) is a stable free radical that can be oxidized by photo-generated holes (h+) to TEMPO+, resulting in a decrease in the intensity of its EPR signal. The greater the decrease in the signal, the higher the concentration of photo-generated holes in the system. The signal peaks of TEMPO decreased successively for the four-component metal cages 5b, 5c, and 5a, indicating that the four-component metal cage 5b has a stronger hole generation ability or efficient charge separation. Anthracene is an electron-donating group that forms a donor-acceptor structure with the parent nucleus, promoting the transfer from the donor to the acceptor after photoexcitation, forming a charge-separated state, reducing the probability of electron-hole recombination, allowing holes to exist stably and participate in the oxidation reaction to capture TEMPO, resulting in a significant decrease in the signal. The methoxy group is also an electron-donating group. After photoexcitation, due to limited charge separation efficiency, the signal decrease of the four-component metal cage 5c is less than that of 5b. For the unmodified parent nucleus, the electron-hole pairs recombine rapidly after photoexcitation, and the hole utilization rate is low, resulting in the least decrease in the EPR signal.

[0122] As Figure 16 shown, electrochemical impedance tests were performed on the four-component metal cages 5a - 5c to obtain the nature of charge separation after photoexcitation. The impedance radius corresponds to the charge transfer resistance R ct , which reflects the ease of charge transfer at the electrode surface. The smaller R ct , the higher the charge separation and transfer efficiency at the surface material interface. The larger R ct indicates that charge transfer is hindered, due to a high carrier recombination rate. The impedance radii of the four-component metal cages 5b, 5c, and 5a increased successively, indicating that the four-component metal cage 5b has a stronger charge separation efficiency. Anthracene, as an electron-donating group, forms a donor-acceptor structure with the parent nucleus, promoting the separation of photo-generated electron-hole pairs. Charge separation reduces the recombination of carriers, resulting in more free holes and electrons participating in charge transfer, significantly reducing R ct . The methoxy group is also an electron-donating group. After photoexcitation, due to limited charge separation efficiency, the impedance radius of the four-component metal cage 5c is higher than that of 5b. For the unmodified parent nucleus, the electron-hole pairs recombine rapidly after photoexcitation, and the hole utilization rate is low, resulting in a larger R ct .

[0123] As Figure 17As shown, photocurrent tests were performed on the four-component metal cages 5a - 5c to obtain the property of charge separation after photoexcitation. The photocurrent intensity directly reflects the separation efficiency and transport ability of electron-hole pairs. The larger the photocurrent, the higher the charge separation efficiency, the lower the carrier recombination rate, and the faster the charge migrates to the electrode; the smaller the photocurrent, the more restricted the charge separation or the more serious the carrier recombination, resulting in a decrease in the number of electron-hole pairs effectively participating in conduction. The photocurrents of the four-component metal cages 5b, 5c, and 5a decrease in turn, indicating that the four-component metal cage 5b has a stronger charge separation efficiency. Anthracene, as an electron-donating group, forms a donor-acceptor structure with the parent nucleus, promoting the separation of photo-generated electron-hole pairs. The charge separation reduces the carrier recombination, leading to more free holes and electrons participating in charge transfer and significantly increasing the photocurrent. The methoxy group is also an electron-donating group. After photoexcitation, the photocurrent of the four-component metal cage 5c is lower than that of 5b due to the limited charge separation efficiency. The unmodified parent nucleus has a rapid recombination of electron-hole pairs after photoexcitation and a low hole utilization rate, resulting in a low photocurrent.

[0124] As Figure 18 shown, transient absorption spectroscopy tests were performed on the four-component metal cages 5a - 5c to obtain the property of charge separation after photoexcitation. They all showed a ground-state bleach peak at 530 nm, indicating that photoexcitation led to a decrease in the ground-state molecules of the parent nucleus, corresponding to the formation of the excited state S 1 state of the parent nucleus. The appearance of the ground-state bleach peak in all metal cages at 0.2 ps indicates that the formation rate of the excited state is extremely fast; remaining stable from 0.2 ps to 0.92 ps indicates a relatively long excited-state lifetime and no rapid decay through radiative or non-radiative transitions. They all showed a stimulated emission peak at 580 nm, resulting from the radiative transition of the excited state S 1 to the ground state S 0 remaining stable from 0.2 ps to 0.92 ps indicates that the excited-state molecules did not significantly deactivate through non-radiative pathways. They all showed an absorption peak of the PDI anion radical at around 733 nm, which results from the electron donor transferring an electron to the acceptor PDI after excitation, and this is direct evidence of the generation of the charge-separated state. The intensity of the PDI anion radical absorption peak continuously increased from 0.2 ps to 0.92 ps, indicating that the charge separation process continued and did not reach equilibrium. The peak intensities of the PDI anion radicals of the four-component metal cages 5b and 5c were significantly higher than those of the four-component metal cage 5a, indicating a higher rate or total amount of electron transfer to PDI, reflecting a better charge separation efficiency.

[0125] As Figure 19As shown, the peak intensity increases from 0.2 ps to 0.92 ps, but then the intensity of each peak gradually decreases with the prolongation of time. Therefore, ten time periods were selected for comparison from 0.54 ps to 5335.22 ps. The ground state bleach peak at 530 nm continuously decreases, indicating that the concentration of the excited state of the parent nucleus decreases with time, resulting from radiative and non-radiative transitions, including charge recombination. The stimulated emission peak at 580 nm continuously decreases, indicating a decrease in the number of S1 state molecules. The decrease in the absorption peak intensity of the PDI anion radical around 730 nm directly reflects the charge separation process, where electrons return from the PDI anion radical to the parent nucleus and recombine with the hole h+, resulting in a decrease in its concentration.

[0126] Figure 20 As shown, the decay trajectories of the PDI anion radical peaks on the transient absorption spectra were respectively fitted, with the fitting exponent n = 2, to obtain τ 1 and τ 2 two kinds of time. In previous reports on the transient absorption spectra of PDI derivatives, τ 1 and τ 2 were respectively attributed to molecular structure rearrangement and the S1 excited state lifetime of the PDI anion radical, which is related to charge recombination. The τ 2 related to the charge separation efficiency or charge recombination of the four-component metal cages 5a - 5c after photoexcitation are 1238 ps, 1852 ps, and 1804 ps respectively, indicating that the four-component metal cage 5b has a lower charge recombination rate and a higher charge separation efficiency; while the unmodified four-component metal cage 5a has the highest charge recombination rate and the lowest charge separation efficiency. The above results show that by constructing an electron donor-donor structure to achieve efficient charge separation and a low recombination rate, significantly prolonging the S 1 state lifetime of the PDI anion radical is the key mechanism for optimizing optoelectronic properties.

[0127] As Figure 21 shown, DFT calculations were performed on the four-component metal cages 5a - 5c to obtain the HOMO-LUMO energy levels to study the nature of charge separation after photoexcitation. The band gap HOMO-LUMO gap represents the minimum energy required for electrons in the molecule to jump from the HOMO to the LUMO. If the band gap is smaller, it indicates that electron transition is easier, absorbing photons with lower energy, and the optoelectronic response is usually stronger; if the band gap is larger, higher energy photons are required for electron transition. The band gaps of the four-component metal cages 5b, 5c, and 5a increase in turn, indicating that the narrower band gap of the four-component metal cage 5b is beneficial to light absorption and charge separation, which is consistent with the results of the previous electrochemical impedance, photocurrent test, EPR photogenerated hole experiment, and the S 1 state lifetime of the PDI anion radical in the transient absorption spectrum. While the four-component metal cage 5a has the largest band gap, indicating that higher energy is required for electron transition and the optoelectronic properties are limited.

[0128] Figure 23 As shown in the figure, in an embodiment of the present invention, in the case of 1 mol% metal cage, the reaction is carried out under irradiation of a 520 nm green light source at room temperature. Under the action of a four-component metal-organic cage based on perylene diimide and terphenyl, the conversion rate of sulfide methyl phenyl sulfide is as high as 99%, and the yields are as high as 99%, 89% and 99.2% respectively. As time prolongs, the conversion rates of benzyl mercaptan under the action of the three four-component metal cages are all increasing, and finally almost completely convert the substrate. And under the action of the unmodified four-component metal cage 5a, the conversion rate of benzyl mercaptan gradually exceeds that of the other four-component metal cages. Figure 24 As shown in the figure, starting from 80 min, the yield of benzyl mercaptan is the highest under the action of the unmodified four-component metal cage 5a, and the yields of benzyl mercaptan under the actions of 5c and 5b decrease in turn. To explain this phenomenon, the calculation of the singlet oxygen quantum yield was carried out. Figure 25 As shown in the figure, singlet oxygen can destroy the conjugated structure of 9,10-diphenylanthracene (DPHA) and reduce the ultraviolet absorption peak, so it can be used to calculate the singlet oxygen quantum yield. Using tetraphenylporphyrin (TPP) as a reference, the singlet oxygen quantum yields of the four-component metal cages 5a, 5b and 5c were calculated to be 0.52, 0.42 and 0.48 respectively. This result corresponds to the yield, indicating that singlet oxygen is the main active oxygen species in this reaction. The singlet oxygen quantum yield of the four-component metal cage 5a is the highest, and the reaction rate is the fastest corresponding to the leading yield of benzyl mercaptan at 80 min. The four-component metal cages 5b and 5c may inhibit the generation of singlet oxygen, and charge separation enables the excited state energy to be preferentially used for electron transfer to generate superoxide anion radicals or hydroxyl radicals, rather than energy transfer to generate singlet oxygen. Therefore, their reaction rates and yields are both low.

[0129] The present invention discloses a preparation method of a four-component metal-organic cage based on perylene diimide and terphenyl: the organic cage is prepared from a tetrapyridyl perylene diimide ligand, a tetrapyridyl p-terphenyl ligand, a tetradentate carboxylate ligand and a cisplatin metal ligand. During the preparation process, the sodium ion in the tetradentate carboxylate ligand dissociates in the solution, and the cisplatin metal ligand Pt(PEt 3 ) 2 (OTf) 2After two trifluoromethanesulfonate anions are removed in solution, they coordinate and self-assemble with the N atoms in the pyridine groups of the tetrapyridyl perylene diimide and the tetrapyridyl terphenyl ligand and the O atoms in the tetradentate carboxylic acid through metal-organic coordination to form the target four-component organometallic cage. The trifluoromethanesulfonate ions after detachment act as counterions around the Pt metal sites of the metal cage. The yield of the four-component organometallic cage based on perylene diimide and terphenyl prepared by this method can reach 90%. For the four-component organometallic cage based on perylene diimide and terphenyl, the luminescent organometallic cage assembled from the tetrapyridyl perylene diimide ligand, the tetrapyridyl terphenyl ligand, the tetradentate carboxylate sodium, and cisplatin, effective charge separation can occur when the electron donor of the four-component organometallic cage is photoexcited, and charge transfer occurs to form the perylene diimide anion radical. Moreover, for the four-component organometallic cage based on perylene diimide and terphenyl, the absolute fluorescence quantum yields of the luminescent organometallic cages 5a-5c assembled from the tetrapyridyl perylene diimide ligand, the tetrapyridyl terphenyl ligand, the tetradentate carboxylate sodium, and cisplatin in acetonitrile are 34.95%, 25.05%, and 30.16% respectively. The prepared four-component organometallic cage has a cavity with a definite size and can convert oxygen into singlet oxygen through energy transfer under light irradiation, and can selectively oxidize methyl phenyl sulfide to methyl phenyl sulfoxide, thus artificially preparing a photocatalytic oxidation system.

[0130] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A four-component metal organic cage based on perylene diimide and terphenyl, characterized in that: The structural formula is: 。 2. A method for preparing a four-component metal organic cage based on perylene diimide and terphenyl as claimed in claim 1, characterized in that: The method comprises the following steps: dissolving a tetrapyridyl perylene diimide ligand, a tetrapyridyl terphenyl ligand, a tetradentate sodium carboxylate ligand and a cisplatin metal ligand in a mixed solvent, subjecting the mixed system to ultrasonic treatment and stirring, obtaining a reaction product through a self-assembly reaction, and purifying the reaction product to obtain a metal organic cage based on perylene diimide and terphenyl and having a cavity.

3. The method for preparing a four-component metal organic cage based on perylene diimide and terphenyl according to claim 2, characterized in that: The tetrapyridylperylene diimide ligand is 4,7,11,14-tetrakis(4-pyridyl)perylene diimide.

4. The method for preparing a four-component metal organic cage based on perylene diimide and terphenyl according to claim 2, characterized in that: The tetrapyridyl terphenyl ligand is any one of tetrapyridyl terphenyl-benzene, tetrapyridyl terphenyl-anthracene or tetrapyridyl terphenyl-methoxy.

5. The method for preparing a four-component metal organic cage based on perylene diimide and terphenyl according to claim 2, characterized in that: The cisplatin metal ligand is cis-bis(triethylphosphine)bis(trifluoromethanesulfonic acid)platinum(II).

6. The method for preparing a four-component metal organic cage based on perylene diimide and terphenyl according to claim 2, characterized in that: The tetradentate sodium carboxylate ligand is sodium 4'-(4,7-bis(3-carboxyphenyl)-1H-benzo[d]imidazol-2-yl)-[1,1'-biphenyl]-3,5-dicarboxylate.

7. The method for preparing a four-component metal organic cage based on perylene diimide and terphenyl according to claim 6, characterized in that: The preparation process of sodium 4'-(4,7-bis(3-carboxyphenyl)-1H-benzo[d]imidazol-2-yl)-[1,1'-biphenyl]-3,5-dicarboxylate comprises the following steps: (1) Compound 1 is generated by reacting 4,7-dibromo-2,3-benzothiadiazole, 3-ethoxycarbonylphenylboronic acid, tetrakistriphenylphosphine palladium and Cs2CO3; (2) Compound 1 was dissolved in a mixed solution of THF and EtOH, and NaBH4 and CoCl2·6H2O were added to react, and then extracted with brine and DCM. The extract was mixed with 4-bromobenzaldehyde and ZrCl4, and then recrystallized to obtain compound 2; (3) Compound 2, 4-bromobenzaldehyde, ZrCl4, tetrakistriphenylphosphine palladium and Cs2CO3 are mixed and reacted to generate compound 3; (4) Compound 3, potassium hydroxide, THF and water are mixed and refluxed, and HCl is added dropwise to the reflux solution to obtain compound 4; (5) Compound 4 and sodium hydroxide are dissolved in water, and a solid is precipitated by adding acetone to obtain sodium 4'-(4,7-bis(3-carboxyphenyl)-1H-benzo[d]imidazol-2-yl)-[1,1'-biphenyl]-3,5-dicarboxylate.

8. The method for preparing a four-component metal organic cage based on perylene diimide and terphenyl according to claim 2, characterized in that: The mixing molar ratio of the tetrapyridyl perylene diimide ligand, the tetrapyridyl terphenyl ligand, the tetradentate sodium carboxylate ligand and the cisplatin metal ligand is 1:1:2:

8.

9. The method for preparing a four-component metal organic cage based on perylene diimide and terphenyl according to claim 2, characterized in that: The stirring process was as follows: the stirring temperature was 55°C and the stirring time was 12 h.

10. An application of the four-component metal organic cage based on perylene diimide and terphenyl as claimed in claim 1, characterized in that: Used as a photocatalyst for photocatalytic oxidation reactions; The photocatalytic oxidation can generate singlet oxygen, which is used to oxidize methyl phenyl sulfide.

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