Linear Pt (NHC) 2 metal organic carboxylic acid ligand for constructing MOFs as well as preparation method and application of linear Pt (NHC) 2 metal organic carboxylic acid ligand
By preparing linear Pt(NHC)2 organometallic carboxylic acid ligands, double carbene Pt-organic metal complexes were synthesized for use in MOF materials. This solved the problems of stability and interaction regulation of platinum(II) carbene complexes in homogeneous catalytic systems, and improved the optical and catalytic performance of MOF materials.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- BENGBU MEDICAL COLLEGE
- Filing Date
- 2026-01-15
- Publication Date
- 2026-05-12
AI Technical Summary
Existing platinum(II) carbene organometallic complexes exhibit poor stability in homogeneous catalytic systems, making them difficult to separate and recover, which affects product purification. Furthermore, the platinum-platinum interaction is difficult to regulate, limiting their application.
Linear Pt(NHC)2 organometallic carboxylic acid ligands were prepared, and double carbene Pt-organic metal complexes were synthesized through coordination chemistry and organometallic chemistry methods. These complexes were used to construct MOF materials and to regulate the Pt-metal distance to achieve metalophilic interactions and MMLCT processes.
This improved the stability and catalytic performance of platinum metal organic complexes, enabling the regulation of the optical and catalytic properties of MOF materials.
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Figure CN122011038A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of preparation technology of organic ligands for MOF construction, specifically relating to a class of linear Pt(NHC)2 organometallic carboxylic acid ligands for MOF construction, their preparation methods and applications. Background Technology
[0002] Platinum(II) carbene organometallic complexes, especially those based on N-heterocyclic carbenes (NHC), are a research hotspot and frontier in modern organometallic chemistry and materials science. Combining the strong σ-electron-donating ability and excellent stability of NHC with the unique photophysical properties of platinum (such as phosphorescence and long-lived excited states) allows for the preparation of platinum organometallic complexes with even superior properties. Platinum(II) carbene organometallic complexes have wide applications, such as serving as excellent anticancer drugs in the biomedical field; as excellent yellow phosphor materials in the luminescence field, used in LEDs to combine with blue light to produce white light; and as catalysts exhibiting excellent catalytic performance in many chemical reactions. Meanwhile, platinum(II) possesses d... 8 With a closed-shell electronic structure, when the distance between two platinum(II) complex molecules is appropriate, there is metalophilicity and MMLCT (metal-to-ligand charge transfer) process, which can further enhance the properties of platinum complexes, such as promoting catalytic reactions, improving reaction efficiency, and increasing photon yield.
[0003] While homogeneous catalytic systems offer high reaction efficiency and no substrate diffusion limitations, they also present several challenges. These include poor catalyst stability and short lifespan; difficulty in separating and recovering catalysts from the reaction system, hindering recycling and resulting in high costs; difficulty in separating catalysts from products, impacting product purification and increasing energy consumption; and the challenge of controlling the distance between platinum-platinum complexes in homogeneous systems, making platinum-platinum interactions difficult and limiting the application of platinum organometallic complexes.
[0004] MOFs (Metal-Organic Facility Materials) are organic-inorganic hybrid crystalline materials developed over the past three decades. They are ideal for catalysis and drug delivery due to their controllable structure, simple synthesis methods, easy separation and recovery from the system, precise structure, well-defined atomic sites, strong designability, and tunable pore size. MOFs can be used to immobilize platinum (II) organometallic complexes, providing a unique microenvironment to enhance their stability. Furthermore, the designability of MOF structures allows for precise control of the platinum-platinum distance through MOF configuration adjustment, enabling metalophilic interactions and the MMLCT process. This improves the performance of Pt-organometallic complexes, allowing for the regulation of their optical and catalytic properties through distance control between Pt metals, thus providing a platform for structure-activity relationship research. If the designed Pt(NHC)₂-based organometallic ligands can be synthesized, various MOF configurations can be constructed, allowing for the regulation of Pt-organometallic complex performance. Summary of the Invention
[0005] The technical problem solved by this invention is to provide a class of linear Pt(NHC)2 organometallic carboxylic acid ligands for constructing MOFs, their preparation methods and applications. The method first prepares the required ligands, and then synthesizes linear Pt(NHC)2-based metal-organic complex ligands based on the target product bis-carbene (NHC) through coordination chemistry and organometallic chemistry. These ligands can be used to construct MOF materials, and the constructed MOF materials have good optical and catalytic properties.
[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: a class of linear Pt(NHC)2 organometallic carboxylic acid ligands for constructing MOFs, wherein the linear Pt(NHC)2 organometallic carboxylic acid ligands include H2PPyDC-Pt(NHC)2 and H2DPPyDC-Pt(NHC)2, with corresponding structural formulas as follows:
[0007] , .
[0008] The method for preparing linear Pt(NHC)2 organometallic carboxylic acid ligands according to the present invention, wherein the synthetic route for the linear Pt(NHC)2 organometallic carboxylic acid ligand H2PPyDC-Pt(NHC)2 is as follows:
[0009]
[0010]
[0011] .
[0012] Furthermore, the specific synthetic steps of the linear Pt(NHC)2 organometallic carboxylic acid ligand H2PPyDC-Pt(NHC)2 are as follows:
[0013] Step S1: 6-bromonicotinic acid methyl ester and 4-methoxycarbonylphenylboronic acid were dissolved in ethylene glycol dimethyl ether to prepare a mixed solution. Then, tetrakis(triphenylphosphine)palladium was added as a catalyst and potassium carbonate aqueous solution. After deoxygenation, the reaction was carried out under nitrogen at 90-110℃. After the reaction was completed, the product was directly evaporated to dryness and then extracted with dichloromethane and water. The organic layer was evaporated to dryness and washed with ethanol to obtain the yellow solid product Me2PPyDC.
[0014] Step S2: Me2PPyDC and potassium tetrachloroplatinate are dissolved in a mixed solution of 2-ethoxyethanol and water to prepare a mixed solution. After deoxygenation, the solution is reacted at 70~90℃ under nitrogen. After the reaction is completed and cooled, the product (Me2PPyDC-Pt)2 is obtained by direct filtration.
[0015] Step S3: Dissolve (Me2PPyDC-Pt)2 and 3,3'-methylenebis(1-methyl-3-imidazolium bromide) in dimethyl sulfoxide to prepare a mixed solution, then add triethylamine, remove oxygen, and react under nitrogen at 80~100℃. After the reaction is complete, cool to room temperature and extract with dichloromethane and saturated brine. Take the organic layer, evaporate to dryness, and then recrystallize with ethanol to obtain the yellow solid product Me2PPyDC-Pt(NHC)2.
[0016] Step S4: Prepare a mixed solution by dissolving Me2PPyDC-Pt(NHC)2 and sodium hydroxide in a mixture of water and ethanol, and then react at 80~100℃. After the reaction is complete and cooled to room temperature, evaporate the ethanol in the system, acidify with hydrochloric acid at 0℃, and obtain the yellow solid product H2PPyDC-Pt(NHC)2 by centrifugation and washing with water.
[0017] The method for preparing linear Pt(NHC)2 organometallic carboxylic acid ligands according to the present invention, wherein the synthetic route for the linear Pt(NHC)2 organometallic carboxylic acid ligand H2DPPyDC-Pt(NHC)2 is as follows:
[0018]
[0019]
[0020]
[0021] .
[0022] Furthermore, the specific synthetic steps of the linear Pt(NHC)2 organometallic carboxylic acid ligand H2DPPyDC-Pt(NHC)2 are as follows:
[0023] Step S1: Dissolve 2,5-dibromopyridine and 4-methoxycarbonylphenylboronic acid in N,N-dimethylformamide to prepare a mixed solution, then add palladium acetate and tricyclohexylphosphine as catalysts, then add potassium phosphate aqueous solution, remove oxygen, and react under nitrogen at 130~150℃. After the reaction is complete, filter while hot, then evaporate directly to dryness, then extract with dichloromethane and water, take the organic layer, evaporate to dryness, wash with ethanol to obtain yellow solid product Me2DPPyDC;
[0024] Step S2: Me2DPPyDC and potassium tetrachloroplatinate are dissolved in a mixed solution of 2-ethoxyethanol and water to prepare a mixed solution. After deoxygenation, the solution is reacted at 80~100℃ under nitrogen. After the reaction is completed and cooled, the product (Me2DPPyDC-Pt)2 is obtained by direct filtration.
[0025] Step S3: Dissolve (Me2DPPyDC-Pt)2 and 3,3'-methylenebis(1-methyl-3-imidazolium bromide) in dimethyl sulfoxide to prepare a mixed solution, then add triethylamine, remove oxygen, and react under nitrogen at 80~100℃. After the reaction is complete and cooled to room temperature, extract with dichloromethane and saturated brine, take the organic layer, evaporate to dryness, and then recrystallize with ethanol to obtain the brownish-yellow solid product Me2DPPyDC-Pt(NHC)2.
[0026] Step S4: Prepare a mixed solution by dissolving Me2DPPyDC-Pt(NHC)2 and sodium hydroxide in a mixture of water and ethanol, and then react at 90~100℃. After the reaction is completed and cooled to room temperature, evaporate the ethanol in the system, acidify with hydrochloric acid at 0℃, and obtain the brownish-yellow solid product H2DPPyDC-Pt(NHC)2 by centrifugation and washing with water.
[0027] The application of the linear Pt(NHC)2 organometallic carboxylic acid ligand described in this invention in the construction of metal-organic framework materials or metal-organic thin-layer materials.
[0028] Furthermore, the specific process for constructing metal-organic framework (MOFs)-Pt based on the linear Pt(NHC)2 organometallic carboxylic acid ligand H2PPyDC-Pt(NHC)2 is as follows: The ligand H2PPyDC-Pt(NHC)2, the metal compound HfCl4 / ZrCl4, the solvent DMF, and the modifier acetic acid are added to a serum bottle, ultrasonically mixed, and then reacted at 80-100℃. After the reaction is complete, the mixture is cooled to room temperature, centrifuged, and the resulting solid is washed multiple times with fresh DMF to obtain a yellow solid. The yellow solid is then dried to obtain the MOF material, denoted as MOFs-Pt. The corresponding synthetic route is as follows:
[0029] .
[0030] Furthermore, the specific process for constructing metal-organic framework materials MOFs-Pt-E based on the linear Pt(NHC)2 organometallic carboxylic acid ligand H2PPyDC-Pt(NHC)2 is as follows: The ligand H2PPyDC, the metal compound HfCl4 / ZrCl4, the solvent DMF, and the modifier acetic acid are added to a serum bottle, ultrasonically mixed, and then reacted at 100-120℃. After the reaction is complete, the mixture is cooled to room temperature and centrifuged to obtain solid MOFs. A solution of H2PPyDC-Pt(NHC)2 is prepared using the ligand H2PPyDC-Pt(NHC)2. The obtained solid MOFs are then dispersed in the H2PPyDC-Pt(NHC)2 solution to form a dispersion. The dispersion is then stirred and reacted at 100-120℃. After the reaction, the mixture is cooled to room temperature, centrifuged to separate the yellow solid, washed multiple times with fresh DMF, and then dried to obtain the MOF material, denoted as MOFs-Pt-E. The corresponding synthetic route is as follows:
[0031] .
[0032] Furthermore, the specific process for constructing metal-organic framework (MOF) materials MOFs-Pt-D based on the linear Pt(NHC)2 organometallic carboxylic acid ligand H2PPyDC-Pt(NHC)2 is as follows: Ligand H2PPyDC, ligand H2PPyDC-Pt(NHC)2, metal compound HfCl4 / ZrCl4, solvent DMF, and modifier acetic acid are added to a serum bottle, ultrasonically mixed, and reacted at 80-100℃. After the reaction is complete, the mixture is cooled to room temperature and centrifuged to obtain a solid. The solid is washed multiple times with fresh DMF to obtain a yellow solid, which is then dried to obtain the MOF material, denoted as MOFs-Pt-D. The corresponding synthetic route is as follows:
[0033] .
[0034] Compared with the prior art, the present invention has the following advantages and beneficial effects: The present invention uses a class of molecules containing phenylpyridine (PPy) as the parent ligand, and designs the structure of phenylpyridine. First, two carboxyl groups are introduced at the 4 position of the benzene ring and the 5 position of the pyridine ring, making it the shortest heterogeneous bimolecular ligand based on phenylpyridine containing carboxyl groups (denoted as H2PPyDC); second, a benzene ring is introduced at the 5 position of the pyridine ring, and then carboxyl groups are introduced at the 4 positions of the two benzene rings within the molecule, forming a ligand based on phenylpyridine containing carboxyl groups with an extended benzene ring (denoted as H2DPPyDC). In the synthesis of the complexes, the carboxylic acid esters corresponding to H2PPyDC and H2DPPyDC (denoted as Me2PPyDC and Me2DPPyDC, respectively) were reacted with potassium tetrachloroplatinate (K2PtCl4) in a solvent under heating to obtain two dimers of Pt-organic metal complexes (denoted as (Me2PPyDC-Pt)2 and (Me2DPPyDC-Pt)2, respectively). These dimers were then reacted with biscarbene ligands to obtain biscarbene-coordinated Pt-organic metal complexes (denoted as Me2PPyDC-Pt(NHC)2 and Me2DPPyDC-Pt(NHC)2, respectively). After hydrolysis with sodium hydroxide aqueous solution and acidification, carboxylic acid ligands for Pt-organic metal complexes (denoted as H2PPyDC-Pt(NHC)2 and H2DPPyDC-Pt(NHC)2, respectively, which can be used for MOF synthesis, were obtained. The prepared ligands can be used to construct metal-organic framework materials (MOFs). Frameworks and metal-organic layers (MOLs) are used to construct materials that also have good optical and catalytic properties. Attached Figure Description
[0035] Figure 1 The NMR spectrum of Me2PPyDC.
[0036] Figure 2 This is the mass spectrum of Me2PPyDC.
[0037] Figure 3 The NMR spectrum of (Me2PPyDC-Pt)2.
[0038] Figure 4 The NMR spectrum of Me2PPyDC-Pt(NHC)2.
[0039] Figure 5 This is the mass spectrum of Me2PPyDC-Pt(NHC)2.
[0040] Figure 6The NMR spectrum of H2PPyDC-Pt(NHC)2.
[0041] Figure 7 This is the mass spectrum of H2PPyDC-Pt(NHC)2.
[0042] Figure 8 The powder X-ray diffraction patterns of the synthesized MOFs are compared with the simulated patterns.
[0043] Figure 9 The fluorescence spectra of the synthesized MOFs-Pt, MOFs-Pt-D, and MOFs-Pt-E and their corresponding CIE coordinate distributions are shown.
[0044] Figure 10 The reaction kinetics curves for the reduction of acetophenone to pinacol by MOFs-Pt catalysis.
[0045] Figure 11 The NMR spectrum of Me2DPPyDC.
[0046] Figure 12 This is the mass spectrum of Me2DPPyDC.
[0047] Figure 13 The NMR spectrum of (Me2DPPyDC-Pt)2.
[0048] Figure 14 The NMR spectrum of Me2DPPyDC-Pt(NHC)2.
[0049] Figure 15 This is the mass spectrum of Me2DPPyDC-Pt(NHC)2.
[0050] Figure 16 The NMR spectrum of H2DPPyDC-Pt(NHC)2.
[0051] Figure 17 This is the mass spectrum of H2DPPyDC-Pt(NHC)2. Detailed Implementation
[0052] The following examples further illustrate the above-described content of the present invention, but it should not be construed as limiting the scope of the subject matter of the present invention to the following examples. All technologies implemented based on the above-described content of the present invention fall within the scope of the present invention.
[0053] Example 1
[0054] 1. Synthesis of Me2PPyDC:
[0055]
[0056] Methyl 6-bromonicotinic acid and 4-methoxycarbonylphenylboronic acid were prepared in a molar ratio of 1:1, and 50 mL of a mixed solution with a methyl 6-bromonicotinic acid concentration of 26 mg / mL was prepared by dissolving methyl 6-bromonicotinic acid in ethylene glycol dimethyl ether. 92 mg of tetrakis(triphenylphosphine)palladium was added as a catalyst, followed by 4 mL of 1M potassium carbonate aqueous solution. After deoxygenation, the mixture was reacted at 100 °C for three days under nitrogen atmosphere. After the reaction was complete, the mixture was directly evaporated to dryness, then extracted with dichloromethane and water. The organic layer was evaporated to dryness and washed with ethanol to obtain the yellow solid product Me2PPyDC. Its 1H NMR data are attached. Figure 1 As shown in the attached mass spectrometry data. Figure 2 As shown.
[0057] 2. Synthesis of (Me2PPyDC-Pt)2:
[0058]
[0059] Me₂PPyDC and potassium tetrachloroplatinate were dissolved in 20 mL of a mixture of 2-ethoxyethanol and water at a volume ratio of 9:1 to prepare a mixed solution with a Me₂PPyDC concentration of 5 mg / mL. After deoxygenation, the mixture was reacted at 80 °C for 20 h under nitrogen atmosphere. After cooling, the product was directly filtered to obtain an orange-yellow solid product (Me₂PPyDC-Pt)₂. Its 1H NMR spectrum data is attached. Figure 3 As shown, mass spectrometry data could not be tested due to its poor solubility.
[0060] 3. Synthesis of Me2PPyDC-Pt(NHC)2:
[0061]
[0062] The product (Me2PPyDC-Pt)2 and 3,3'-methylenebis(1-methyl-3-imidazolium bromide) were dissolved in 6 mL of dimethyl sulfoxide to prepare a mixed solution with a (Me2PPyDC-Pt)2 concentration of 20 mg / mL. Then, 0.8 mL of triethylamine was added, and after deoxygenation, the mixture was reacted at 90 °C for 15 h under nitrogen atmosphere. After the reaction was completed and cooled to room temperature, the mixture was extracted with dichloromethane and saturated brine. The organic layer was evaporated to dryness and then recrystallized from ethanol to obtain the yellow solid product Me2PPyDC-Pt(NHC)2. Its 1H NMR data are attached. Figure 4 As shown in the attached mass spectrometry data. Figure 5 As shown.
[0063] 4. Synthesis of H2PPyDC-Pt(NHC)2:
[0064]
[0065] The product Me2PPyDC-Pt(NHC)2 and sodium hydroxide were dissolved in a 1:1 mass ratio in a 10:1 volume ratio of water and ethanol to prepare a mixed solution with a concentration of 5 g / mL of Me2PPyDC-Pt(NHC)2. The mixed solution was then reacted at 90 °C for 20 h. After the reaction was completed and cooled to room temperature, the ethanol in the system was evaporated. The solution was then acidified with 3 M hydrochloric acid at 0 °C. The product was then separated by centrifugation and washed with water to obtain a yellow solid product H2PPyDC-Pt(NHC)2. Its 1H NMR data are attached. Figure 6 As shown in the attached mass spectrometry data. Figure 7 As shown.
[0066] 5. Synthesis of MOFs:
[0067] 5.1 Direct synthesis of MOFs-Pt from H2PPyDC-Pt(NHC)2
[0068]
[0069] MOFs-Pt was synthesized using a solvothermal method. The ligand H₂PPyDC-Pt(NHC)₂, the metal compound HfCl₄ / ZrCl₄, the solvent DMF, and the modifier acetic acid were added to a serum bottle in a molar ratio of 3:5:1000:5000. After ultrasonic mixing, the mixture was reacted at 90°C for 24 hours. After the reaction was complete and cooled to room temperature, the solid was obtained by centrifugation and washed three times with fresh DMF to obtain a yellow solid. The yellow solid was then dried to obtain the MOF material, denoted as MOFs-Pt. Its powder X-ray diffraction pattern is shown below. Figure 8 As shown.
[0070] 5.2 Synthesis of MOFs-Pt-E containing H2PPyDC-Pt(NHC)2 via ligand exchange
[0071]
[0072] Pt-free MOFs were prepared by a solvothermal method. Ligand H2PPyDC, metal compound HfCl4 / ZrCl4, solvent DMF, and modifier acetic acid were added to a serum bottle in a molar ratio of 3:5:1000:5000. After ultrasonic mixing, the mixture was reacted at 110℃ for 24 h. After the reaction was complete, the mixture was cooled to room temperature and centrifuged to obtain solid MOFs. A 5 mg / mL H2PPyDC-Pt(NHC)2 solution was prepared. 10 mL of HCl solution was added, and the MOF solid prepared above was dispersed in H2PPyDC-Pt(NHC)2 solution to form a dispersion with a total concentration of H2PPyDC-Pt(NHC)2 and MOF solid of 15 mg / mL. The dispersion was then stirred at 110 °C for 5 days. After the reaction was completed, the mixture was cooled to room temperature and centrifuged to separate the yellow solid. The solid was washed three times with fresh DMF and dried to obtain the MOF material, denoted as MOFs-Pt-E. Its powder X-ray diffraction pattern is shown below. Figure 8 As shown.
[0073] 5.3 Synthesis of MOFs-Pt-D by doping with H2PPyDC-Pt(NHC)2 ligand and other ligands
[0074]
[0075] The ligands H2PPyDC and H2PPyDC-Pt(NHC)2, the metal compound HfCl4 / ZrCl4, the solvent DMF, and the modifier acetic acid were added to a serum bottle in a molar ratio of 1.5:1.5:5:1000:5000. After ultrasonic mixing, the mixture was reacted at 90℃ for 24 hours. After the reaction was completed and cooled to room temperature, the solid was obtained by centrifugation and washed three times with fresh DMF to obtain a yellow solid. The yellow solid was dried to obtain the MOF material, denoted as MOFs-Pt-D. Its powder X-ray diffraction pattern is shown below. Figure 8 As shown.
[0076] 6. Fluorescence spectroscopy testing and CIE coordinate plotting:
[0077] Take 10 mL of each of the synthesized MOFs-Pt, MOFs-Pt-D, and MOFs-Pt-E and prepare an ethanol dispersion with a concentration of 0.1 mg / mL. Then, take 3 mL of each dispersion for fluorescence testing. Excite the sample at a wavelength of 410 nm and test the fluorescence emission spectrum. The test results are as follows: Figure 9 As shown in Table 1, the CIE coordinates corresponding to the fluorescence spectra of the three MOFs and the spectrum of a 450nm commercial LED lamp were calculated using the three primary color coordinates. Then, the LED spectrum at 450nm and the spectra of the three MOFs were plotted in CIE coordinates, as shown in Table 1. Figure 9As shown in D in the figure, it can be seen from the figure that the LED spectrum at 450nm is in the blue light region, and the fluorescence spectra of the three MOFs fall in the yellow light region. The two can be combined to produce white light.
[0078] Table 1. Fluorescence spectra of MOFs-Pt, MOFs-Pt-D, and MOFs-Pt-E and their corresponding CIE coordinates for a 450 nm commercial LED.
[0079] spectrum X coordinate Y coordinate 450nm LED spectrum 0.147 0.055 MOFs-Pt fluorescence spectroscopy 0.4029 0.5734 MOFs-Pt-D fluorescence spectroscopy 0.4106 0.5708 MOFs-Pt-E fluorescence spectroscopy 0.4106 0.5708
[0080] 7. Catalytic reaction:
[0081]
[0082]
[0083] The catalytic reductive coupling reaction of benzaldehyde and acetophenone using MOFs-Pt as a catalyst yielded the corresponding pinacol product in high yield. The catalytic reaction conditions were as follows: 0.3 mmol of the substrate benzyl alcohol or acetophenone was dissolved in 4 mL of methanol, then 2.6 μmol of MOFs-Pt catalyst was added, followed by 0.6 mmol of N,N-diisopropylethylamine as a reducing agent. A 24 W LED lamp with a wavelength of 395 nm was used as the light source for photocatalytic reaction, and the reaction time was 12 h. The reaction results are shown in Table 2 and [Table data would be inserted here]. Figure 10 As shown.
[0084] Table 2. Results of MOFs-Pt catalytic conversion of benzyl alcohol and its derivatives
[0085]
[0086] Example 2
[0087] 1. Synthesis of Me2DPPyDC:
[0088]
[0089] 2,5-Dibromopyridine and 4-methoxycarbonylphenylboronic acid were weighed in a mass ratio of 2:3 and dissolved in N,N-dimethylformamide to prepare a mixed solution of 20 mg / mL 2,5-dibromopyridine. 33 mg of palladium acetate and 84 mg of tricyclohexylphosphine were added as catalysts, followed by 4.5 mL of 1 M potassium phosphate aqueous solution. After deoxygenation, the mixture was reacted at 140 °C under nitrogen for two days. After the reaction was complete, the mixture was filtered while hot, then evaporated directly to dryness, and extracted with dichloromethane and water. The organic layer was evaporated to dryness and washed with ethanol to obtain the yellow solid product Me2DPPyDC. Its 1H NMR data are attached. Figure 10 As shown in the attached mass spectrometry data. Figure 11 As shown.
[0090] 2. Synthesis of (Me2DPPyDC-Pt)2:
[0091]
[0092] The product Me₂DPPyDC and potassium tetrachloroplatinate were dissolved in 30 mL of a mixed solution of 2-ethoxyethanol and water in a volume ratio of 10:1 at a mass ratio of 5:6 to prepare a mixed solution with a total concentration of 2.5 mg / mL of Me₂DPPyDC and potassium tetrachloroplatinate. After deoxygenation, the mixture was reacted at 90 °C for 24 h under nitrogen atmosphere. After the reaction was completed and cooled, the product was directly filtered to obtain a yellow solid product (Me₂DPPyDC-Pt)₂. Its 1H NMR spectrum data is attached. Figure 12 As shown, due to its poor solubility, mass spectrometry data could not be tested.
[0093] 3. Synthesis of Me2DPPyDC-Pt(NHC)2:
[0094]
[0095] Weigh out the product (Me2DPPyDC-Pt)2 and 3,3'-methylenebis(1-methyl-3-imidazolium bromide) at a mass ratio of 5:3, dissolve them in dimethyl sulfoxide to prepare a mixed solution of 5 mL with a total concentration of 13 mg / mL of (Me2DPPyDC-Pt)2 and 3,3'-methylenebis(1-methyl-3-imidazolium bromide). Then add 0.5 mL of triethylamine, remove oxygen, and react at 90 °C for 20 h under nitrogen. After the reaction is complete, cool to room temperature and extract with dichloromethane and saturated brine. Evaporate the organic layer to dryness, and then recrystallize with ethanol to obtain the brownish-yellow solid product Me2DPPyDC-Pt(NHC)2. Its 1H NMR data are attached. Figure 13 As shown in the attached mass spectrometry data. Figure 14 As shown.
[0096] 4. Synthesis of H2DPPyDC-Pt(NHC)2:
[0097]
[0098] The product Me₂DPPyDC-Pt(NHC)₂ and sodium hydroxide were weighed at a mass ratio of 1:1 and dissolved in 40 mL of a water-ethanol mixture with a volume ratio of 3:1 to form a mixed solution with a total concentration of 3.5 mg / mL for Me₂DPPyDC-Pt(NHC)₂ and sodium hydroxide. The mixed solution was then reacted at 95 °C for 24 h. After the reaction was completed and cooled to room temperature, the ethanol in the system was evaporated. The solution was then acidified with 3 M hydrochloric acid at 0 °C. The product was separated by centrifugation and washed with water to obtain a brownish-yellow solid product H₂DPPyDC-Pt(NHC)₂. Its 1H NMR data are attached. Figure 15As shown in the attached mass spectrometry data. Figure 16 As shown.
[0099] The above embodiments describe the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are only illustrative of the principles of the present invention. Various changes and modifications can be made to the present invention without departing from the scope of the principles of the present invention, and all such changes and modifications fall within the protection scope of the present invention.
Claims
1. A class of linear Pt(NHC)₂ organometallic carboxylic acid ligands for constructing MOFs, characterized in that: The linear Pt(NHC)2 organometallic carboxylic acid ligands include H2PPyDC-Pt(NHC)2 and H2DPPyDC-Pt(NHC)2, with the corresponding structural formulas as follows: 、 。 2. A method for preparing the linear Pt(NHC)₂ organometallic carboxylic acid ligand as described in claim 1, characterized in that... The synthetic route for the linear Pt(NHC)2 organometallic carboxylic acid ligand H2PPyDC-Pt(NHC)2 is as follows: 。 3. The method for preparing linear Pt(NHC)₂ organometallic carboxylic acid ligands according to claim 2, characterized in that... The specific synthetic steps for the linear Pt(NHC)2 organometallic carboxylic acid ligand H2PPyDC-Pt(NHC)2 are as follows: Step S1: 6-bromonicotinic acid methyl ester and 4-methoxycarbonylphenylboronic acid were dissolved in ethylene glycol dimethyl ether to prepare a mixed solution. Then, tetrakis(triphenylphosphine)palladium was added as a catalyst and potassium carbonate aqueous solution. After deoxygenation, the reaction was carried out under nitrogen at 90-110℃. After the reaction was completed, the product was directly evaporated to dryness and then extracted with dichloromethane and water. The organic layer was evaporated to dryness and washed with ethanol to obtain the yellow solid product Me2PPyDC. Step S2: Me2PPyDC and potassium tetrachloroplatinate are dissolved in a mixed solution of 2-ethoxyethanol and water to prepare a mixed solution. After deoxygenation, the solution is reacted at 70~90℃ under nitrogen. After the reaction is completed and cooled, the product (Me2PPyDC-Pt)2 is obtained by direct filtration. Step S3: Dissolve (Me2PPyDC-Pt)2 and 3,3'-methylenebis(1-methyl-3-imidazolium bromide) in dimethyl sulfoxide to prepare a mixed solution, then add triethylamine, remove oxygen, and react under nitrogen at 80~100℃. After the reaction is complete, cool to room temperature and extract with dichloromethane and saturated brine. Take the organic layer, evaporate to dryness, and then recrystallize with ethanol to obtain the yellow solid product Me2PPyDC-Pt(NHC)2. Step S4: Prepare a mixed solution by dissolving Me2PPyDC-Pt(NHC)2 and sodium hydroxide in a mixture of water and ethanol, and then react at 80~100℃. After the reaction is complete and cooled to room temperature, evaporate the ethanol in the system, acidify with hydrochloric acid at 0℃, and obtain the yellow solid product H2PPyDC-Pt(NHC)2 by centrifugation and washing with water.
4. A method for preparing the linear Pt(NHC)₂ organometallic carboxylic acid ligand as described in claim 1, characterized in that... The synthetic route for the linear Pt(NHC)2 organometallic carboxylic acid ligand H2DPPyDC-Pt(NHC)2 is as follows: 。 5. The method for preparing linear Pt(NHC)₂ organometallic carboxylic acid ligands according to claim 4, characterized in that... The specific synthetic steps for the linear Pt(NHC)2 organometallic carboxylic acid ligand H2DPPyDC-Pt(NHC)2 are as follows: Step S1: Dissolve 2,5-dibromopyridine and 4-methoxycarbonylphenylboronic acid in N,N-dimethylformamide to prepare a mixed solution, then add palladium acetate and tricyclohexylphosphine as catalysts, then add potassium phosphate aqueous solution, remove oxygen, and react under nitrogen at 130~150℃. After the reaction is complete, filter while hot, then evaporate directly to dryness, then extract with dichloromethane and water, take the organic layer, evaporate to dryness, wash with ethanol to obtain yellow solid product Me2DPPyDC; Step S2: Me2DPPyDC and potassium tetrachloroplatinate are dissolved in a mixed solution of 2-ethoxyethanol and water to prepare a mixed solution. After deoxygenation, the solution is reacted at 80~100℃ under nitrogen. After the reaction is completed and cooled, the product (Me2DPPyDC-Pt)2 is obtained by direct filtration. Step S3: Dissolve (Me2DPPyDC-Pt)2 and 3,3'-methylenebis(1-methyl-3-imidazolium bromide) in dimethyl sulfoxide to prepare a mixed solution, then add triethylamine, remove oxygen, and react under nitrogen at 80~100℃. After the reaction is complete and cooled to room temperature, extract with dichloromethane and saturated brine, take the organic layer, evaporate to dryness, and then recrystallize with ethanol to obtain the brownish-yellow solid product Me2DPPyDC-Pt(NHC)2. Step S4: Prepare a mixed solution by dissolving Me2DPPyDC-Pt(NHC)2 and sodium hydroxide in a mixture of water and ethanol, and then react at 90~100℃. After the reaction is completed and cooled to room temperature, evaporate the ethanol in the system, acidify with hydrochloric acid at 0℃, and obtain the brownish-yellow solid product H2DPPyDC-Pt(NHC)2 by centrifugation and washing with water.
6. The application of the linear Pt(NHC)2 organometallic carboxylic acid ligand as described in claim 1 in the construction of metal-organic framework materials or metal-organic thin-layer materials.
7. The application according to claim 6, characterized in that... The specific process for constructing metal-organic framework (MOFs)-Pt based on the linear Pt(NHC)2 organometallic carboxylic acid ligand H2PPyDC-Pt(NHC)2 is as follows: Ligand H2PPyDC-Pt(NHC)2, metal compound HfCl4 / ZrCl4, solvent DMF, and modifier acetic acid are added to a serum vial. After ultrasonic mixing, the mixture is reacted at 80-100℃. After the reaction is complete, the temperature is lowered to room temperature, centrifuged, and the obtained solid is washed multiple times with fresh DMF to obtain a yellow solid. The yellow solid is dried to obtain the MOF material, denoted as MOFs-Pt. The corresponding synthetic route is as follows: 。 8. The application according to claim 6, characterized in that... The specific process for constructing metal-organic framework materials (MOFs)-Pt-E based on the linear Pt(NHC)2 organometallic carboxylic acid ligand H2PPyDC-Pt(NHC)2 is as follows: Ligand H2PPyDC, metal compound HfCl4 / ZrCl4, solvent DMF, and modifier acetic acid are added to a serum bottle, ultrasonically mixed, and reacted at 100-120℃. After the reaction is complete, the mixture is cooled to room temperature and centrifuged to obtain solid MOFs. A solution of H2PPyDC-Pt(NHC)2 is prepared using ligand H2PPyDC-Pt(NHC)2. The obtained solid MOFs are then dispersed in the H2PPyDC-Pt(NHC)2 solution to form a dispersion. The dispersion is then stirred and reacted at 100-120℃. After the reaction, the mixture is cooled to room temperature, centrifuged to separate the yellow solid, washed multiple times with fresh DMF, and dried to obtain the MOF material, denoted as MOFs-Pt-E. The corresponding synthetic route is as follows: 。 9. The application according to claim 6, characterized in that... The specific process for constructing metal-organic framework (MOF) materials based on the linear Pt(NHC)2 organometallic carboxylic acid ligand H2PPyDC-Pt(NHC)2 is as follows: Ligand H2PPyDC, ligand H2PPyDC-Pt(NHC)2, metal compound HfCl4 / ZrCl4, solvent DMF, and modifier acetic acid are added to a serum vial. After ultrasonic mixing, the mixture is reacted at 80-100℃. After the reaction is complete, the temperature is lowered to room temperature, and the solid is obtained by centrifugation. The solid is washed multiple times with fresh DMF to obtain a yellow solid, which is then dried to obtain the MOF material, denoted as MOFs-Pt-D. The corresponding synthetic route is as follows: 。