A class of organometallic cages based on polythiol ligands, their preparation methods and applications

Abstract

This invention belongs to the field of supramolecular chemistry and materials technology, and discloses a class of organometallic cages based on polythiol ligands, their preparation methods, and applications; the general chemical formula of the organometallic cages based on polythiol ligands is: [(R n M) x L y (IL) z In this invention, M is a metal center; R is an organic group attached to the metal center M; n is the number of R groups attached to each metal center M; L is an aromatic polythiol ligand; IL is an ionic liquid; x, y, and z are all integers ≥1. This invention uses an ionic liquid as a reaction medium and combines it with a competitive coordination control strategy of organic amines to achieve controllable self-assembly of organometallic cages. These organometallic cages have unique melting and glass transition characteristics, can be used to prepare high-quality thin films through hot pressing film deposition technology, and can also be used as photoresist film deposition materials in various photolithography processes. They have broad application prospects in flexible electronics, packaging materials, micro-nano fabrication, and other fields.

Description

Technical Field

[0001] This invention belongs to the field of supramolecular chemistry and materials technology, specifically relating to a class of organometallic cages based on polythiol ligands, their preparation methods, and applications. Background Technology

[0002] Organometallic cages (OMCs) are discrete supramolecular structures formed by the self-assembly of metal nodes and organic ligands through coordination bonds. Due to their unique structure and properties, they exhibit great application potential in catalysis, gas adsorption, and molecular recognition. However, most existing OMCs are insoluble and infusible crystalline powders. Their processing, especially the preparation of high-quality thin films, mainly relies on solution methods such as spin coating and drop coating. These methods require the use of large amounts of toxic organic solvents, which is inconsistent with the concept of green development. Furthermore, the resulting films suffer from high surface roughness, susceptibility to pinhole defects, and uneven thickness, severely limiting their application in high-end fields such as flexible electronics, high-precision packaging, and micro / nano fabrication. Therefore, developing a solvent-free, directly thermoplasticizable OMC material, along with corresponding green preparation and processing technologies, has become an urgent technical challenge in this field. Summary of the Invention

[0003] To address the aforementioned problems, this invention proposes a class of organometallic cages based on polythiol ligands, their preparation methods, and applications.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: A class of organometallic cages based on polythiol ligands, wherein the general chemical formula of the organometallic cage based on polythiol ligands is: [(R n M) x L y (IL) z ] Wherein, M is a metal center; R is an organic group attached to the metal center M; n is the number of R groups attached to each metal center M; IL is an ionic liquid; x, y, and z are all integers ≥1, and their values ​​are jointly determined by the charge balance state and spatial structure matching requirements of the organometallic cage.

[0005] Preferably, the metal center is one of bismuth, antimony, and tin; the metal center originates from the general formula R. n M is an organometallic precursor, where n is 1, 2, or 3, and each R is identical or different, with R independently selected from C. 1-10 Alkyl, C 2-6 alkenyl, C 6-10 At least one of aryl or benzyl; the organometallic precursor is selected from at least one of triphenylbismuth, triethylbismuth, trimethyltin, triphenylantimony, or diphenylzinc.

[0006] Preferably, the aromatic polythiol ligand is a compound represented by the general formula HS-Ar-SH or HS-Ar1-X-Ar2-SH; wherein, in HS-Ar-SH, Ar is a benzene ring, pyridine ring, pyrimidine ring, thiophene ring or their substituted derivatives; in HS-Ar1-X-Ar2-SH, Ar1 and Ar2 may be the same or different, Ar1 and Ar2 are benzene rings or nitrogen-containing heteroaromatic rings, and X is a chemical bond, -S-, -SS-, -O-, -CH2-, -NH- or -SO2-.

[0007] Preferably, the aromatic polythiol ligand is at least one selected from 1,3-benzenedithiol, 1,4-benzenedithiol, 4,4'-thiobis(benzenediol), 4,4'-dithiobis(benzenediol), 4,4'-oxobis(benzenediol), 4,6-dimercaptopyrimidine, or 2,2'-thiodipyridine-5,5'-dithiol; the aromatic polythiol ligand is selected from any of the following structural types:

[0008] The aromatic polythiol ligand is selected from monocyclic aromatic or aromatic heterocyclic polythiols, wherein the aromatic ring is selected from benzene ring, pyridine ring, pyrimidine ring, pyridazine ring, or 1,3,5-triazine ring, and the ring has two or more thiol groups substituted on it.

[0009] Preferably, the ionic liquid is at least one of imidazolium salt, pyridinium salt, quaternary ammonium salt, or quaternary phosphonium salt.

[0010] Preferably, the ionic liquid is a 1-alkyl-3-methylimidazolium salt, wherein the alkyl chain length is C1-C2. 20 The anion of the 1-alkyl-3-methylimidazolium salt is selected from chloride ions, bromide ions, tetrafluoroborate ions, hexafluorophosphate ions, or bis(trifluoromethanesulfonyl)imide ions; the ionic liquid serves as a template agent and reaction medium in the crystallization process of organometallic cages based on polythiol ligands, and exists in the cavities or channels of the final structure of organometallic cages based on polythiol ligands.

[0011] A method for preparing an organometallic cage based on polythiol ligands includes the following steps: S1. Mix the organometallic precursor, aromatic polythiol ligand and ionic liquid in a uniform ratio to form a homogeneous mixed solution. S2. Add an organic amine to the mixed solution and heat to 60-150℃ to carry out the reaction for 1-7 days; the amount of organic amine added is 1.0 to 5.0 equivalents of the metal molar weight. S3. After the reaction is completed, the organometallic cage based on polythiol ligands is obtained by separation. The viscous effect of ionic liquids and the competitive coordination of organic amines work together to slow down the nucleation rate and control crystal growth.

[0012] Preferably, in step S2, the organic amine is at least one of aliphatic amines, alkanolamines, cyclic amines, or aromatic amines; the aliphatic amine is at least one of methylamine, ethylamine, n-propylamine, isopropylamine, ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, or tetramethylethylenediamine; the alkanolamine is at least one of 2-aminoethanol, 1-amino-2-propanol, 3-amino-1-propanol, diethanolamine, or diamino-1-butanol; the cyclic amine is at least one of piperidine, piperazine, or morpholine; and the aromatic amine is at least one of pyridine, pyrazine, or quinoline.

[0013] An application of an organometallic cage based on polythiol ligands is disclosed, wherein the organometallic cage based on polythiol ligands is used to prepare a heat-processable glassy material, which is then processed into a thin film product by hot pressing. The hot pressing process parameters are as follows: the organometallic cage based on polythiol ligands is heated to the melting temperature and then hot-pressed at 80-250℃ and 0.5-20 MPa for 1-30 minutes. The thin film product is an optical thin film, a dielectric layer, a flexible electronic substrate, or an encapsulation coating.

[0014] An application of an organometallic cage based on a polythiol ligand is disclosed, wherein the organometallic cage based on the polythiol ligand is used as a film-forming material in a photoresist composition; the photoresist composition is applied to 248 nm lithography, 193 nm lithography, extreme ultraviolet lithography, nanoimprint lithography, or electron beam lithography processes; the photoresist composition is a negative photoresist or a positive photoresist, and further comprises at least one of a solvent, a photoacid generator, a dissolution promoter, or a surfactant, wherein the mass of the photoacid generator accounts for 0.1-5 wt% of the total mass of the composition; the nanoimprint lithography is a thermal nanoimprint lithography; the molten glassy material of the organometallic cage based on the polythiol ligand is used as an imprinting agent; in extreme ultraviolet lithography, at least one of butyl acetate, amyl acetate, methyl isobutyl ketone, or isopropanol is used as a developer for the negative photoresist, and a 0.1%-5% (w / w) tetramethylammonium hydroxide aqueous solution is used as a developer for the positive photoresist.

[0015] By adopting the above technical solution, the present invention has the following beneficial effects: 1. The organometallic cage based on polythiol ligands of the present invention introduces flexible aromatic polythiol ligands and, combined with embedded ionic liquids, endows the material with unique melting and glass transition properties, breaking through the limitations of traditional organometallic cages that are insoluble and infusible, realizing solvent-free thermoplastic processing, and solving the technical problem of poor processability of existing materials.

[0016] 2. The preparation method of the present invention uses ionic liquid as the reaction medium to replace traditional volatile organic solvents, which is green and environmentally friendly. At the same time, it utilizes the viscosity effect of ionic liquid and the competitive coordination regulation strategy of organic amine to achieve controllable self-assembly of organometallic cages. The resulting product has a regular structure, good monodispersity, and high controllability of the synthesis process.

[0017] 3. This invention develops a hot-pressing film-forming technology based on the melting and glass transition characteristics of organometallic cages of polythiol ligands. It does not require the use of organic solvents, and the prepared films are dense and uniform with significantly lower surface roughness than films prepared by traditional spin coating methods. This provides a high-quality film preparation solution for the fields of flexible electronics and packaging materials.

[0018] 4. The organometal cage of the present invention can be used as a film-forming material for photoresist compositions, and is suitable for various photolithography processes such as 248 nm, 193 nm, extreme ultraviolet, nanoimprinting, and electron beam. It can be configured as a positive or negative photoresist and has important application potential in the field of micro-nano processing technology, providing a new material platform for advanced photolithography technology. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the crystal structure of the organometallic cage based on polythiol ligands prepared in Examples 1-6 of the present invention; Figure 2 Thermogravimetric analysis curve of the organometallic cage based on polythiol ligand prepared in Example 4 of this invention; Figure 3 The infrared spectra of the crystalline and hot-pressed thin film states of the organometallic cage based on polythiol ligands prepared in Example 4 of this invention are shown in comparison. Figure 4 This is a comparison of the surface roughness of the hot-pressed film and the spin-coated film based on the organometallic cage of polythiol ligands prepared in Example 4 of the present invention. Figure 5 This is a DUV lithographic pattern of the organometallic cage based on polythiol ligands prepared in Example 4 of the present invention. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to examples. It should be understood that the specific examples described herein are merely illustrative and not intended to limit the invention.

[0021] Unless otherwise stated, the raw materials and reagents used in the following examples are commercially available products or can be prepared by known methods. See Figures 1 to 5 . Example 1:

[0022] Synthesis of organometallic cages based on 1,4-benzenedithiol (BDT) Triphenylbismuth (220 mg, 0.5 mmol) and 1,4-benzenedithiol (BDT, 142 mg, 1 mmol) were dissolved in 1-decyl-3-methylimidazolium chloride ([DMIM]Cl, 1.0 g), and N-aminoethylpiperazine (4 mL) was added as an organic amine additive. The reaction was carried out in an oven at 80 °C for 7 days, followed by slow cooling to room temperature. Yellow polyhedral crystals precipitated, filtered, washed with ethanol, and dried to obtain the target organometallic cage. Single-crystal X-ray diffraction confirmed its zero-dimensional cage structure (structural schematic diagram corresponds to...). Figure 1 Example 1). Example 2:

[0023] Synthesis of organometallic cages based on 1,4-benzenedithiol (BDT) Triphenylbismuth (220 mg, 0.5 mmol) and 1,4-benzenedithiol (BDT, 106 mg, 0.75 mmol) were dissolved in 1-hexyl-3-methylimidazolium chloride ([HMIM]Cl, 1.0 g), and ethylene glycol (4 mL) and 3-amino-1,2-propanediol (0.5 mmol) were added as organic amine competitive ligands. The reaction was carried out in an oven at 80 °C for 7 days, followed by slow cooling to room temperature. Yellow rhombic crystals precipitated, filtered, washed with ethanol, and dried to obtain the target organometallic cage. Single-crystal X-ray diffraction confirmed its zero-dimensional cage structure (structural schematic diagram corresponds to...). Figure 1 Example 2). Example 3:

[0024] Synthesis of organometallic cages based on 1,4-benzenedithiol (BDT) Triphenylbismuth (220 mg, 0.5 mmol) and 1,4-benzenedithiol (BDT, 95 mg, 0.67 mmol) were dissolved in 1-hexyl-3-methylimidazolium chloride ([HMIM]Cl, 1.0 g), and methanol (4 mL) and 3-amino-1,2-propanediol (0.5 mmol) were added as organic amine competitive ligands. The reaction was carried out in an oven at 80 °C for 7 days, followed by slow cooling to room temperature. Yellow polyhedral crystals precipitated, filtered, washed with ethanol, and dried to obtain the target organometallic cage. Single-crystal X-ray diffraction confirmed its zero-dimensional cage structure (structural schematic diagram corresponds to...). Figure 1 Example 3). Example 4:

[0025] (1) Synthesis of organometallic cages based on 4,4'-thiobis(thiophenol) (TBT) Triphenylbismuth (220 mg, 0.5 mmol) and 4,4-thiobis(thiophene) (TBT, 188 mg, 0.75 mmol) were dissolved in 1-hexyl-3-methylimidazolium chloride ([HMIM]Cl, 1.0 g), and methanol (4 mL) and triethylenetetramine (0.5 mmol) were added as organic amine competitive ligands. The reaction was carried out in an oven at 80 °C for 1 day, followed by slow cooling to room temperature. Yellow rod-shaped crystals precipitated, filtered, washed with ethanol, and dried to obtain the target organometallic cage. Single-crystal X-ray diffraction confirmed its zero-dimensional cage structure (structural schematic diagram corresponds to...). Figure 1 Example 4).

[0026] (2) Characterization analysis of cluster properties like Figure 2 As shown, thermogravimetric analysis indicates that this organometallic cage exhibits good thermal stability below 180 °C and undergoes a molten glass transition at approximately 160-180 °C. Figure 3 As shown, Fourier transform infrared spectroscopy (FTIR) results indicate that the spectra of the material remain highly consistent before and after hot pressing, suggesting that the main structure remains stable during the hot processing.

[0027] (3) Hot pressing film application The organometallic cage crystals obtained in Example 4 were ground into a fine powder, placed in a mold, and hot-pressed at 180 °C and 5 MPa for 5 minutes. After cooling and demolding, a transparent and uniform film was obtained. Atomic force microscopy (AFM) characterization showed that the surface roughness (Ra) of this film was 0.839 nm. In comparison, a film formed by spin-coating the same amount of material (dissolved in DMF) had a roughness (Rq) of 4.46 nm. The results indicate that hot-pressing film formation technology can significantly reduce the surface roughness of the film. Figure 4 As shown.

[0028] (4) DUV lithography performance To verify the potential of the organometal cage material of this invention in photolithography applications, we explored the direct patterning of its hot-pressed thin film. A mask (such as a copper mesh or photolithography mask) with micron-level feature patterns was tightly bonded to the surface of the hot-pressed thin film. Subsequently, it was placed under a 200W high-pressure mercury lamp for direct exposure. After exposure, it was clearly observed that the pattern on the mask was successfully transferred to the thin film surface. After exposure, a clear pattern corresponding to the mask was formed on the thin film. This experiment demonstrates that the organometal cage material prepared by this invention has significant photoresponse characteristics, and its hot-pressed thin film can achieve direct formation of micron-level patterns through a simple mask exposure process. Example 5:

[0029] Synthesis of organometallic cages based on 4,4'-thiobis(benzyl)thiophenol (TBT) Triphenylbismuth (220 mg, 0.5 mmol) and 4,4-thiobis(thiophene)phenol (TBT, 188 mg, 0.75 mmol) were dissolved in 1-hexyl-3-methylimidazolium chloride ([HMIM]Cl, 1.0 g). N,N-dimethylformamide (DMF, 4 mL) and pentaethylenehexamine (0.5 mmol) were used as competing ligands for the organic amine. The reaction was carried out in an oven at 80 °C for 3 days, followed by slow cooling to room temperature. After standing for 30 minutes, octahedral crystals precipitated. The crystals were filtered, washed with ethanol, and dried to obtain the target organometallic cage. Single-crystal X-ray diffraction confirmed that it was a zero-dimensional cage structure (the structural diagram corresponds to...). Figure 1 Example 5). Example 6:

[0030] Synthesis of organometallic cages based on 4,4'-thiobis(benzyl)thiophenol (TBT) Triphenylbismuth (220 mg, 0.5 mmol) and 4,4-thiobis(thiophene)phenol (TBT, 188 mg, 0.75 mmol) were dissolved in 1-hexyl-3-methylimidazolium chloride ([HMIM]Cl, 1.0 g). N-methylformamide (NMF, 4 mL) and 3,5-dimethylpiperidine (0.5 mmol) were used as competing ligands for the organic amine. The reaction was carried out in an oven at 80 °C for 15 days, followed by slow cooling to room temperature. After standing for 30 minutes, octahedral crystals precipitated. The crystals were filtered, washed with ethanol, and dried to obtain the target organometallic cage. Single-crystal X-ray diffraction confirmed that it was a zero-dimensional cage structure (the structural diagram corresponds to...). Figure 1 Example 6).

[0031] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A class of organometallic cages based on polythiol ligands, characterized in that: The general chemical formula of the organometallic cage based on polythiol ligands is: [(R n M) x L y (HE) z ] Wherein, M is a metal center; R is an organic group attached to the metal center M; n is the number of R groups attached to each metal center M; IL is an ionic liquid; x, y, and z are all integers ≥1, and their values ​​are jointly determined by the charge balance state and spatial structure matching requirements of the organometallic cage.

2. The organometallic cage based on polythiol ligands as described in claim 1, characterized in that, The metal center is one of bismuth, antimony, and tin; the metal center originates from the general formula R. n M is an organometallic precursor, where n is 1, 2, or 3, and each R is identical or different, with R independently selected from C. 1-10 Alkyl, C 2-6 alkenyl, C 6-10 At least one of aryl or benzyl; the organometallic precursor is selected from at least one of triphenylbismuth, triethylbismuth, trimethyltin, triphenylantimony, or diphenylzinc.

3. The organometallic cage based on polythiol ligands as described in claim 1, characterized in that, The aromatic polythiol ligand is a compound represented by the general formula HS-Ar-SH or HS-Ar1-X-Ar2-SH; wherein, in HS-Ar-SH, Ar is a benzene ring, pyridine ring, pyrimidine ring, thiophene ring or their substituted derivatives; in HS-Ar1-X-Ar2-SH, Ar1 and Ar2 may be the same or different, Ar1 and Ar2 are benzene rings or nitrogen-containing heteroaromatic rings, and X is a chemical bond, -S-, -SS-, -O-, -CH2-, -NH- or -SO2-.

4. The organometallic cage based on polythiol ligands as described in claim 3, characterized in that: The aromatic polythiol ligand is at least one selected from 1,3-benzyl dithiol, 1,4-benzyl dithiol, 4,4'-thiobis(benzyl)thiophenol, 4,4'-dithiobis(benzyl)thiophenol, 4,4'-oxobis(benzyl)thiophenol, 4,6-dimercaptopyrimidine, or 2,2'-thiodipyridine-5,5'-dithiol; the aromatic polythiol ligand is selected from any of the following structural types: The aromatic polythiol ligand is selected from monocyclic aromatic or aromatic heterocyclic polythiols, wherein the aromatic ring is selected from benzene ring, pyridine ring, pyrimidine ring, pyridazine ring, or 1,3,5-triazine ring, and the ring has two or more thiol groups substituted on it.

5. The organometallic cage based on polythiol ligands as described in claim 1, characterized in that, The ionic liquid is at least one of imidazolium salt, pyridinium salt, quaternary ammonium salt, or quaternary phosphonium salt.

6. The organometallic cage based on polythiol ligands as described in claim 5, characterized in that, The ionic liquid is a 1-alkyl-3-methylimidazolium salt, wherein the alkyl chain length is C1-C2. 20 The anion of the 1-alkyl-3-methylimidazolium salt is selected from chloride ions, bromide ions, tetrafluoroborate ions, hexafluorophosphate ions, or bis(trifluoromethanesulfonyl)imide ions; the ionic liquid serves as a template agent and reaction medium in the crystallization process of organometallic cages based on polythiol ligands, and exists in the cavities or channels of the final structure of organometallic cages based on polythiol ligands.

7. A method for preparing an organometallic cage based on a polythiol ligand as described in any one of claims 1-6, characterized in that, Includes the following steps: S1. Mix the organometallic precursor, aromatic polythiol ligand and ionic liquid in a uniform ratio to form a homogeneous mixed solution. S2. Add an organic amine to the mixed solution and heat to 60-150℃ to carry out the reaction for 1-7 days; the amount of organic amine added is 1.0 to 5.0 equivalents of the metal molar weight. S3. After the reaction is completed, the organometallic cage based on polythiol ligands is obtained by separation. The viscous effect of ionic liquids and the competitive coordination of organic amines work together to slow down the nucleation rate and control crystal growth.

8. The method for preparing organometallic cages based on polythiol ligands as described in claim 7, characterized in that: In step S2, the organic amine is at least one of aliphatic amines, alkanolamines, cyclic amines, or aromatic amines; the aliphatic amine is at least one of methylamine, ethylamine, n-propylamine, isopropylamine, ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, or tetramethylethylenediamine; the alkanolamine is at least one of 2-aminoethanol, 1-amino-2-propanol, 3-amino-1-propanol, diethanolamine, or diamino-1-butanol; the cyclic amine is at least one of piperidine, piperazine, or morpholine; and the aromatic amine is at least one of pyridine, pyrazine, or quinoline.

9. An application of an organometallic cage based on a polythiol ligand as described in any one of claims 1-6, characterized in that: The organometal cage based on polythiol ligands is used to prepare a heat-processable glassy material, which is then processed into thin film products by hot pressing. The hot pressing process parameters are as follows: the organometal cage based on polythiol ligands is heated to the melting temperature and then hot-pressed for 1-30 minutes at 80-250℃ and 0.5-20 MPa. The thin film products are optical thin films, dielectric layers, flexible electronic substrates, or encapsulation coatings.

10. An application of an organometallic cage based on a polythiol ligand as described in any one of claims 1-6, characterized in that: The organometallic cage based on polythiol ligands is used as the film-forming material in the photoresist composition; the photoresist composition is applied to 248 nm lithography, 193 nm lithography, extreme ultraviolet lithography, nanoimprint lithography, or electron beam lithography processes; the photoresist composition is a negative photoresist or a positive photoresist, and also contains at least one of a solvent, a photoacid generator, a dissolution promoter, or a surfactant, wherein the mass of the photoacid generator accounts for 0.1-5 wt% of the total mass of the composition; the nanoimprint lithography is thermal nanoimprint lithography; the molten glassy material of the organometallic cage based on polythiol ligands is used as the imprinting agent; in extreme ultraviolet lithography, at least one of butyl acetate, amyl acetate, methyl isobutyl ketone, or isopropanol is used as the developer for the negative photoresist, and a 0.1%-5% (w / w) tetramethylammonium hydroxide aqueous solution is used as the developer for the positive photoresist.

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