A series of five-coordinate copper complex crystal materials, their preparation methods and applications
By using five-coordinate Cu(II) complex crystal materials as catalysts, the problems of long reaction time and non-recyclability of existing catalysts have been solved, realizing a highly efficient and simple Knoevenagel condensation reaction, which has good prospects for industrialization.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- TIANJIN UNIVERSITY OF TECHNOLOGY
- Filing Date
- 2022-01-30
- Publication Date
- 2026-07-17
AI Technical Summary
Existing Knoevenagel reaction catalysts suffer from problems such as long reaction times, complex catalyst manufacturing, and non-recyclability, which affect the development of tertiary oil recovery technology and energy utilization efficiency.
Using five-coordinate Cu(II) complex crystal materials as catalysts, the Knoevenagel condensation reaction is catalyzed at room temperature through a simple preparation method. The central Cu(II) ion is an unsaturated five-coordinate structure, forming a flexible hydrophilic layer, which improves catalytic activity and achieves efficient heterogeneous catalysis.
It achieves high efficiency, easy separation and recovery of catalysts, shortens reaction time, improves yield, and has good substrate universality, making it suitable for large-scale industrial applications.
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Figure CN116554209B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to complex crystal materials containing five-coordinate Cu(II) and their preparation methods and applications, belonging to the field of novel multifunctional materials technology. Background Technology
[0002] Functional coordination crystal materials have attracted much attention from researchers due to their excellent properties in optics, electricity, magnetism, catalysis, and other fields, and have gradually become a focus of research in chemistry, materials science, and other fields. In recent years, due to their diverse types, rich structures, tunable specific surface area, and controllable chemical composition, coordination materials have played a very important role in organic synthesis as a promising new type of catalyst.
[0003] Over the past two decades, countries worldwide have increasingly emphasized global climate change, and my country's related carbon emission plans have been gradually implemented. However, as a crucial task in achieving current goals, improving oil recovery, especially the development of tertiary oil recovery technology, will be a major technological breakthrough in addressing the current energy shortage and excessive carbon emissions. Knoevenagel condensation, as a key reaction for synthesizing novel oil displacement intermediates α,β-unsaturated carbonyl compounds (a core material in the "chemical flooding" technology of tertiary oil recovery), has always been a hot topic in chemist research. Furthermore, the Knoevenagel condensation reaction has mild conditions, simple post-processing, and high yields, and has become a major method for synthesizing α,β-unsaturated carbonyl compounds. However, current catalysts used in the Knoevenagel reaction still face many problems, such as long reaction times, complex catalyst fabrication, or lack of recyclability. Addressing these issues by leveraging the inherent advantages of complexes to develop inexpensive and readily available high-efficiency catalysts, achieving faster, simpler, and higher-yield reactions, will be of great significance for the development of novel high-efficiency catalysts, the research of functional complex crystal materials, and even for current carbon emission and energy utilization. Summary of the Invention
[0004] In order to overcome the shortcomings of the prior art, the purpose of this invention is to provide a series of five-coordinate Cu(II) complex crystal materials, their preparation methods and applications.
[0005] This invention utilizes a five-coordinate copper complex crystal material as a catalyst for the Knoevenagel reaction, providing a new research approach for the design of catalysts that introduce different metal reactive sites to catalyze different reaction types.
[0006] Another objective of this invention is that this series of five-coordinate (coordinate-unsaturated) Cu(II) complex crystal materials exhibit high catalytic performance in Knoevenagel condensation reactions, excellent substrate versatility, solvent-free green synthesis conditions at room temperature, and easy separability, all of which make practical production and use of catalysts possible. More importantly, the series of five-coordinate copper complex crystal materials involved in this invention also have the advantages of simple preparation and inexpensive raw materials.
[0007] The objective of this invention is achieved through the following technical solution.
[0008] A series of methods for preparing five-coordinate copper complex crystal materials includes the following steps:
[0009] The method for preparing crystalline materials is characterized by including the following steps:
[0010] Step 1: Mix X mol of copper acetate monohydrate with water to obtain solution A. The ratio of acetate to water by mass fraction is 1:(30-50).
[0011] Step 2: Dissolve X mol of 3-thiophene malonic acid (H2TMA) and X mol of auxiliary ligand A (crystal material 1: A = 2,2′-bipyridine (bpy); crystal material 2: A = 1,10-o-phenanthroline (phen); crystal material 3: A = 3-cyanopyridine (3-CNPy) in ethanol to obtain solutions B. The ratio of the organic ligand H2TMA to ethanol is 1:(30-50) by mass fraction.
[0012] Step 3: Add solution B from step 2 to solution A from step 1, stir at room temperature for 30 minutes, and filter to obtain clear solution C;
[0013] Step 4: Place the clear solution C obtained in Step 3 in a fume hood for 12-24 hours, filter to obtain a solid, and wash the solid to obtain the complex crystal material. Specifically: 1 is blue needle-like crystals [Cu(TMA)(bpy)(H2O)]·2H2O; 2 is light green flaky crystals [Cu(TMA)(phen)]·3H2O; 3 is blue blocky crystals [Cu(TMA)(3-CNPy)].
[0014] In step 4, the method for cleaning the solid is to wash the solid alternately with distilled water and ethanol, and the number of times the solid is washed with distilled water and ethanol is 6.
[0015] The three five-coordinate Cu(II) complex crystal materials obtained according to the above steps are: 1 is a zero-dimensional (OD) complex, 2 is a one-dimensional (1D) complex, and 3 is a two-dimensional (2D) complex. The characteristic feature is that the central Cu(II) active site has an adjustable five-coordinate mode. Of the three five-coordinate Cu(II) complex crystal materials, 1 belongs to an orthorhombic crystal system with space group Pbca and cell parameters as follows: α=β=γ=90.00°; 2 belongs to the monoclinic crystal system, space group P21 / n, and cell parameters are: α=γ=90.00°, β=95.27°; 3 belongs to the monoclinic crystal system, space group P21 / n, and cell parameters are: α=γ=90.00°, β=93.73°.
[0016] In the above technical solution, in the three five-coordinate Cu(II) complex crystal materials, the central Cu(II) ion is five-coordinate and contains empty coordination sites. Among them, the five-coordinate copper complex crystal material 1 is characterized in that each metal Cu(II) ion is coordinated with a water molecule (O5), two oxygen atoms (O1, O3) from different carboxylic acid groups in a TMA ion, and two nitrogen atoms (N1, N2) from a bpy molecule, forming a twisted tetrahedral geometry; the five-coordinate copper complex crystal material 2 is characterized in that each Cu(II) ion is coordinated with three oxygen atoms (O1, O2A, O3) from different carboxylic acid groups in two TMA ions and two nitrogen atoms (N1, N3) from a phen molecule, and adjacent metal copper ions form a chain structure through carboxylic acid oxygen; the five-coordinate copper complex crystal material 3 is characterized in that each Cu(II) ion is coordinated with four oxygen atoms (O1, O2B, O3, O4A) from different carboxylic acid groups in three TMA ions and a nitrogen atom (N1) from a 3-CNPy molecule, and adjacent copper ions are connected through carboxylic acid oxygen to form a layered structure. Compared to 1 and 2, 3 does not contain lattice water molecules, but similar to 2, the central Cu(II) ions can also be linked into a 2D planar structure by the carboxylic acid oxygen of TMA ions.
[0017] In the above technical solution, the central metal Cu(II) ion is an unsaturated five-coordinated structure with empty coordination sites, while the coordinated water in 1 is easy to leave, forming a more stable four-coordinated structure; the structures of such crystal materials 1 and 2 also contain lattice water, which is easy to form intermolecular hydrogen bonds and then self-assemble into a flexible hydrophilic layer, which can improve the catalytic reaction activity.
[0018] The above three five-coordinate Cu(II) complex crystal materials were used as highly efficient Lewis acid-base catalysts in the Knoevenagel condensation reaction.
[0019] In the above technical solution, when complexes 1, 2 and 3 are used as catalysts, the Knoevenagel condensation reaction can be efficiently catalyzed at room temperature, and the expansion of reaction substrates has a certain degree of universality, laying the foundation for practical industrial application.
[0020] (1) The optimal reaction conditions for 0D complex 1 as a catalyst for Knoevenagel condensation reaction are: 1.3 mmol malononitrile, 1.0 mmol benzaldehyde, 0.005 mmol catalyst, and solvent-free reaction at room temperature for 1 hour with a yield of up to 100% and selectivity of 100%.
[0021] (2) The optimal reaction conditions for 1D complex 2 as a catalyst for Knoevenagel condensation reaction are: 1.3 mmol malononitrile, 1.0 mmol benzaldehyde, 0.005 mmol catalyst, solvent-free reaction at room temperature for 1 hour, yield 94.25%, selectivity 100%.
[0022] (3) The optimal reaction conditions for 2D complex 3 as a catalyst for Knoevenagel condensation reaction are: 1.3 mmol malononitrile, 1.0 mmol benzaldehyde, 0.005 mmol catalyst, solvent-free reaction at room temperature for 1 hour, yield 32.16%, selectivity 100%.
[0023] Compared with the prior art, the beneficial technical effects of the present invention are as follows:
[0024] The reactants and catalysts involved in this invention are inexpensive, and the catalyst synthesis method is simple, easy to operate, yields high amounts, is easy to scale up, and the resulting crystalline materials have stable chemical properties, making them easy to widely apply. Malononitrile with an active methylene group forms a flexible hydrophilic layer through hydrogen bonds in a five-coordinate (0D, 1D) complex, which is introduced onto a site with tunable Lewis acidity to achieve highly efficient heterogeneous catalysis. The catalyst maintains high activity while shortening the reaction time, enabling a one-pot catalytic reaction to produce α,β-unsaturated carbonyl compounds with high economic value. Furthermore, the universality of the substrate indicates that this type of catalyst meets the needs of large-scale production and has excellent industrialization prospects.
[0025] The strategy of using five-coordinate (coordinate-unsaturated) copper complex crystal materials as Knoevenagel reaction catalysts in this invention also provides a new research idea for the design of catalysts that introduce different metal reactive sites for catalyzing different reaction types. Attached Figure Description
[0026] Figure 1 This is the coordination unit of the five-coordinate Cu(II) complex crystal material 1 of the present invention;
[0027] Figure 2 This is the coordination unit of the five-coordinate Cu(II) complex crystal material 2 of the present invention;
[0028] Figure 3 This is a structural diagram of the five-coordinate Cu(II) complex crystal material 2 of the present invention;
[0029] Figure 4 This is the coordination unit of the five-coordinate Cu(II) complex crystal material 3 of the present invention;
[0030] Figure 5 This is a structural diagram of the five-coordinate Cu(II) complex crystal material 3 of the present invention;
[0031] Figure 6 The XRD pattern of the five-coordinate Cu(II) complex crystal material 1 of the present invention (1a, 1b and 1c in the figure are synthesized crystals);
[0032] Figure 7 The curve showing the yield of the Knoevenagel condensation reaction catalyzed by the five-coordinate Cu(II) complex crystal material 1 as a catalyst in this invention is as follows: Detailed Implementation
[0033] The technical solution of the present invention will be further described below with reference to specific embodiments.
[0034] The instruments involved in the following embodiments are as follows:
[0035] The single-crystal structure was determined using an XtaLAB PRO X-ray single-crystal diffractometer from Rigaku Corporation, Japan, at room temperature. The single-crystal structure determination procedure was as follows: A single crystal of suitable size (approximately 0.2 mm in diameter) was placed on the single-crystal diffractometer, and a Cu Kα crystal monochromated with a graphite monochromator was used. X-rays were used as the light source, and diffraction points were collected at room temperature. The complex was... Diffraction data were collected using a scanning method. All diffraction data underwent semi-empirical absorption correction using the SADABS program. Unit cell parameters were determined using the least squares method. The crystal structure of the complex was determined using the SHELXTL-97 program. The crystal structure was solved directly, first by determining the coordinates of all non-hydrogen atoms using the difference function method and the least squares method, then obtaining the positions of hydrogen atoms using the theoretical hydrogenation method, and finally refining the crystal structure using the least squares method.
[0036] Powder X-ray diffraction was performed using a Rigaku D / max-2500 X-ray diffractometer from Rigaku Corporation, Japan, at room temperature and tube voltage of 40 kV.
[0037] The catalytic effect of the Knoevenagel condensation reaction was qualitatively and quantitatively determined by gas chromatography-mass spectrometry (GC-MS). An Agilent 7890B / 5977B GC-MS instrument was used, and an HP-5 column was employed.
[0038] In the following examples, all pharmaceuticals are commercially available reagents that require no pretreatment before use. The sources of these reagents are as follows:
[0039] Copper acetate monohydrate: analytical grade, Shanghai Aladdin Biochemical Technology Co., Ltd.; 3-thiophene malonic acid: analytical grade, Bailingwei Technology Co., Ltd.; 2,2′-bipyridine: analytical grade, Bailingwei Technology Co., Ltd.; 1,10-o-phenanthroline: analytical grade, Bailingwei Technology Co., Ltd.; 3-cyanopyridine: analytical grade, Bailingwei Technology Co., Ltd.
[0040] Example 1
[0041] A method for preparing an OD Cu(II) complex crystal material includes the following steps:
[0042] Step 1: In a beaker, mix 1 mol of copper acetate monohydrate with distilled water to obtain solution A. The mass ratio of copper acetate monohydrate to water is 1:30.
[0043] Step 2: Add 1 mol of 3-thiophene malonic acid and 1 mol of 2,2′-bipyridine to an ethanol solution and mix thoroughly to obtain solution B. The mass ratio of 3-thiophene malonic acid to ethanol is 1:30.
[0044] Step 3: Transfer solution B from step 2 to solution A from step 1, stir vigorously for 30 minutes, and filter to obtain clear solution C;
[0045] Step 4: Place the clear solution C obtained in Step 3 in a fume hood for 12 hours, filter to obtain a solid, and wash the solid to obtain blue needle-like crystals [Cu(TMA)(bpy)(H2O)]·2H2O (1a). The method for washing the solid was to wash it alternately with distilled water and ethanol, a total of 6 times, with a yield of 62% (calculated as copper).
[0046] Complex 1 is characterized by an unsaturated five-coordinate configuration of the central Cu(II) ion. Each Cu(II) ion coordinates with a water molecule (O5), two oxygen atoms (O1, O3) from different carboxylic acid groups in a TMA ion, and two nitrogen atoms (N1, N2) from a bpy molecule, forming a distorted tetrahedral geometry. Specific crystal parameters are shown in Tables 1 and 4 above. The coordination units of complex 1 are as follows: Figure 1 As shown.
[0047] like Figure 6 X-ray powder diffraction showed that the diffraction peak position (1a) of the OD Cu(II) complex crystal material prepared in Example 1 was consistent with the diffraction peak position of the theoretical simulation diagram based on the single crystal structure, indicating that the structure of the synthesized complex crystal sample was consistent with its single crystal and the phase purity was very high.
[0048] Example 2
[0049] A method for preparing an OD Cu(II) complex crystal material includes the following steps:
[0050] Step 1: In a beaker, mix 1 mol of copper acetate monohydrate with distilled water to obtain solution A. The ratio of copper acetate monohydrate to water by mass fraction is 1:40.
[0051] Step 2: Add 1 mol of 3-thiophene malonic acid and 1 mol of 2,2′-bipyridine to an ethanol solution and mix thoroughly to obtain solution B. The mass fraction ratio of 3-thiophene malonic acid to ethanol is 1:40.
[0052] Step 3: Transfer solution B from step 2 to solution A from step 1, stir vigorously for 30 minutes, and filter to obtain clear solution C;
[0053] Step 4: Place the clear solution C obtained in Step 3 in a fume hood for 12 hours, filter to obtain a solid, and wash the solid to obtain blue needle-like crystals as 1b. The solid was washed alternately with distilled water and ethanol, a total of 6 times. The yield was 58% (based on copper).
[0054] X-ray powder diffraction is shown in... Figure 6 Compared with its simulation, the powder diffraction pattern (1b) of the crystal prepared in Example 2 shows that, except for slight differences in the intensity of some peaks, the positions of the peaks match well, indicating that the material has high phase purity.
[0055] Example 3
[0056] A method for preparing an OD Cu(II) complex crystal material includes the following steps:
[0057] Step 1: In a beaker, mix 1 mol of copper acetate monohydrate with distilled water to obtain solution A. The mass ratio of copper acetate monohydrate to water is 1:50.
[0058] Step 2: Add 1 mol of 3-thiophene malonic acid and 1 mol of 2,2′-bipyridine to an ethanol solution and mix thoroughly to obtain solution B. The mass fraction ratio of 3-thiophene malonic acid to ethanol is 1:50.
[0059] Step 3: Transfer solution B from step 2 to solution A from step 1, stir vigorously for 30 minutes, and filter to obtain clear solution C;
[0060] Step 4: Place the clear solution C obtained in Step 3 in a fume hood for 12 hours, filter to obtain a solid, and wash the solid to obtain blue needle-like crystals as 1c. The solid was washed alternately with distilled water and ethanol, a total of 6 times. The yield was 52% (based on copper).
[0061] X-ray powder diffraction is shown in... Figure 6 The X-ray powder diffraction peak position (1c) of the OD Cu(II) complex crystal material prepared in Example 3 also matches the simulation diagram well, which also shows that the obtained complex crystal sample has a uniform phase.
[0062] Example 4
[0063] A method for preparing a 1D Cu(II) complex crystal material includes the following steps:
[0064] Step 1: In a beaker, mix 1 mol of copper acetate monohydrate with distilled water to obtain solution A. The mass ratio of copper acetate monohydrate to water is 1:30.
[0065] Step 2: Add 1 mol of 3-thiophene malonic acid and 1 mol of 1,10-phenanthroline to an ethanol solution and mix thoroughly to obtain solution B. The mass ratio of 3-thiophene malonic acid to ethanol is 1:30.
[0066] Step 3: Transfer solution B from step 2 to solution A from step 1, stir vigorously for 30 minutes, and filter to obtain clear solution C;
[0067] Step 4: Place the clear solution C obtained in Step 3 in a fume hood for 24 hours, filter to obtain a solid, and wash the solid to obtain light green flaky crystals [Cu(TMA)(phen)(H2O)]·H2O(2). The solid was washed alternately with distilled water and ethanol, a total of 6 times. The yield was 57% (based on copper).
[0068] The characteristic of 1D complex 2 is that each Cu(II) ion is coordinated with three oxygen atoms (O1, O2A, O3) from different carboxylic acid groups in two TMA ions and two nitrogen atoms (N1, N3) from a phen molecule, with adjacent copper ions forming a chain structure through carboxylic acid oxygen groups. In 2, Cu(II) ions are linked into a 1D chain structure through carboxylic acid oxygen groups in TMA ions. Specific crystal parameters of complex 2 are shown in Tables 2 and 5 above. The coordination units of complex 2 are as follows: Figure 2 As shown, the structural diagram is as follows Figure 3 As shown.
[0069] Example 5
[0070] A method for preparing a 2D Cu(II) complex crystal material includes the following steps:
[0071] Step 1: In a beaker, mix 1 mol of copper acetate monohydrate with distilled water to obtain solution A. The mass ratio of copper acetate monohydrate to water is 1:30.
[0072] Step 2: Add 1 mol of 3-thiophene malonic acid and 1 mol of 3-cyanopyridine to an ethanol solution and mix thoroughly to obtain solution B. The mass fraction ratio of 3-thiophene malonic acid to ethanol is 1:30.
[0073] Step 3: Transfer solution B from step 2 to solution A from step 1, stir vigorously for 30 minutes, and filter to obtain clear solution C;
[0074] Step 4: Place the clear solution C obtained in Step 3 in a fume hood for 16 hours, filter to obtain a solid, and wash the solid to obtain blue blocky crystals of [Cu(TMA)(3-CNPy)](3). The method for washing the solid is as follows: wash the solid alternately with distilled water and ethanol, and wash with distilled water and ethanol a total of 6 times. The yield is 53% (calculated as copper).
[0075] The characteristic of 2D complex 3 is that each Cu(II) ion is coordinated with four oxygen atoms (O1, O2B, O3, O4A) of different carboxylic acid groups in three TMA ions and a nitrogen atom (N1) of a 3-CNPy molecule. Compared with 1 and 2, 3 does not contain coordinated water molecules, but similar to 2, the central Cu(II) ions can also be linked to form a 2D planar structure through carboxylic acid oxygen atoms of TMA ions. The specific crystal parameters of complex 3 are shown in Tables 3 and 6 above. The coordination units of complex 3 are as follows: Figure 4 As shown, the structural diagram is as follows Figure 5 As shown.
[0076] Example 6
[0077] Three five-coordinate Cu(II) complexes were used in the Knoevenagel condensation reaction, including the following steps:
[0078] Benzaldehyde (1.0 mmol), malononitrile (1.3 mmol), and catalyst (0.5 mol%) were added to a Schlenk reaction tube. The mixture was stirred at room temperature for 1 hour, and the catalyst was recovered by centrifugation after the reaction was complete. The catalyst was washed with ethanol and water, dried, and then recycled without further purification or regeneration. The catalytic effect of the reaction was qualitatively and quantitatively determined using gas chromatography-mass spectrometry (GC-MS).
[0079]
[0080] Experiments were conducted on the above model reaction using catalyst 1 to measure the yield over time, as shown in Figure 7. The reaction reached 100% yield within 1 hour, indicating that complex 1 possesses advantages such as high catalytic activity, good selectivity, and high stability. Yield is defined as the ratio of the amount of product to the amount of benzaldehyde added.
[0081] Example 7
[0082] The above model reaction was expanded to include 22 substrates using catalyst 1, including aldehydes modified with different functional groups and compounds containing active methylene groups. As shown in Table 7, different substrates all showed certain yields, indicating that complex 1 has universality for different substrates in the Knoevenagel condensation reaction. Table 7 shows the substrate expansion for the Knoevenagel condensation reaction catalyzed by the five-coordinate Cu(II) complex crystal material 1 of this invention.
[0083] The present invention has been described above by way of example. It should be noted that any simple modifications, alterations or other equivalent substitutions that can be made by those skilled in the art without creative effort without departing from the core of the present invention fall within the protection scope of the present invention.
[0084] Table 1 shows the crystal data and structural refinement data for 0D Cu(II) complex crystal material 1 as follows:
[0085]
[0086] Table 2 shows the crystal data and structural refinement data of 1D Cu(II) complex crystal material 2 as follows:
[0087]
[0088] Table 3 shows the crystal data and structural refinement data of 2D Cu(II) complex crystal material 3 as follows:
[0089]
[0090] Table 4 shows some characteristic bond lengths and bond angles of 0D mononuclear complex crystal material 1:
[0091]
[0092] Table 5 shows some characteristic bond lengths and bond angles of 1D mononuclear complex crystal material 2:
[0093]
[0094] Symmetry transformation used to generate equivalent atoms: #2x+1, y, z.
[0095] Table 6 shows some characteristic bond lengths and bond angles of 2D mononuclear complex crystal material 3:
[0096]
[0097] Symmetry transformations used to produce equivalent atoms: #1x+1 / 2, -y+1 / 2, z+1 / 2; #2x+1 / 2, -y+1 / 2, z-1 / 2
[0098] Table 7. Substrate extension for 0D Cu(II) complex crystal material 1 as a catalyst for Knoevenagel condensation reaction:
[0099]
[0100]
[0101]
[0102] Reaction conditions: Nos. 1-18: 1.0 mmol aldehydes, 1.3 mmol malononitrile; Nos. 19-22: 1.0 mmol active methylene compound, 1.3 mmol benzaldehyde, room temperature, 60 min, 0.5 mol% OD Cu(II) complex functional material 1 as catalyst; all products and yields were determined by gas chromatography-mass spectrometry (GC-MS).
Claims
1. 3 kinds of five-coordinate copper complex crystal materials, characterized in that The chemical formulas of the three five-coordinate copper complex crystal materials are as follows: [Cu(TMA)(bpy)(H2O)]·2H2O, abbreviated as 1; [Cu(TMA)(phen)]·3H2O, abbreviated as 2; [Cu(TMA)(3-CNPy)], abbreviated as 3; wherein TMA is 3-thiophene malonate ion, bpy is 2,2'-bipyridine, phen is 1,10-o-phenanthroline, and 3-CNPy is 3-cyanopyridine; Of the three crystal materials, 1 belongs to the orthorhombic crystal system with space group Pbca; 2 belongs to the monoclinic crystal system with space group P21 / n; and 3 belongs to the monoclinic crystal system with space group P21 / n. In all three five-coordinate copper complex crystal materials, the central Cu(II) ion is five-coordinated and contains empty coordination sites. Specifically, in crystal material 1, each metallic Cu(II) ion is coordinated with the O5 of a water molecule, the two oxygen atoms O1 and O3 of different carboxylic acid groups in a TMA ion, and the two nitrogen atoms N1 and N2 of a bpy molecule, forming a twisted tetrahedral structure. The geometric shape of the crystal material 2 is as follows: Each Cu(II) ion is coordinated with three oxygen atoms O1, O2A and O3 from different carboxylic acid groups in two TMA ions and two nitrogen atoms N1 and N3 from a phen molecule. Adjacent copper ions form a chain structure through carboxylic acid oxygen. Each Cu(II) ion in crystal material 3 is coordinated with four oxygen atoms O1, O2B, O3 and O4A from different carboxylic acid groups in three TMA ions and a nitrogen N1 from a 3-CNPy molecule. Adjacent copper ions are connected by carboxylic acid oxygen to form a layered structure. The crystal data and structural refinement data of the five-coordinate copper complex crystal material 1 are as follows: The crystal data and structural refinement data of the five-coordinate copper complex crystal material 2 are as follows: The crystal data and structural refinement data of the five-coordinate copper complex crystal material 3 are as follows:
2. The method for preparing the three five-coordinate copper complex crystal materials according to claim 1, characterized in that, Includes the following steps: Step 1: Mix 1 mol of copper acetate monohydrate with water to obtain solution A; wherein, by mass fraction, the ratio of copper acetate monohydrate to water is 1:(30-50); Step 2: Dissolve 1 mol of H2TMA and 1 mol of auxiliary ligand A in ethanol, wherein in crystal material 1, A = bpy, in crystal material 2, A = phen, and in crystal material 3, A = 3-CNPy; after dissolution, solutions B are obtained respectively, wherein the ratio of H2TMA to ethanol by mass fraction is 1:(30-50). Step 3: Add solution B from step 2 to solution A from step 1, stir at room temperature for 30 minutes, and filter to obtain clear solution C; Step 4: Place the clear solution C obtained in Step 3 in a fume hood for 12-24 hours, filter to obtain a solid, and wash the solid to obtain the complex crystal material; specifically: 1 is blue needle-like crystals [Cu(TMA)(bpy)(H2O)]·2H2O; 2 is light green flaky crystals [Cu(TMA)(phen)]·3H2O; 3 is blue blocky crystals [Cu(TMA)(3-CNPy)].
3. The preparation method according to claim 2, characterized in that, In step 4, the method for cleaning the solid is to wash the solid alternately with distilled water and ethanol, and the number of times the solid is washed with distilled water and ethanol is 6.
4. The application of the three five-coordinate copper complex crystal materials as described in claim 1, characterized in that... The complex crystal material is used as a catalyst for the Knoevenagel reaction.
5. The application according to claim 4, characterized in that: (1) Reaction conditions when crystal material 1 is used as a catalyst for Knoevenagel condensation reaction: 1.3 mmol malononitrile, 1.0 mmol benzaldehyde, 0.005 mmol catalyst, solvent-free reaction at room temperature for 1 hour, yield 100%, selectivity 100%; (2) Reaction conditions when crystal material 2 is used as a catalyst for Knoevenagel condensation reaction: 1.3 mmol malononitrile, 1.0 mmol benzaldehyde, 0.005 mmol catalyst, solvent-free reaction at room temperature for 1 hour, yield 94.25%, selectivity 100%; (3) Reaction conditions when crystal material 3 is used as a catalyst for Knoevenagel condensation reaction: 1.3 mmol malononitrile, 1.0 mmol benzaldehyde, 0.005 mmol catalyst, solvent-free reaction at room temperature for 1 hour, yield 32.16%, selectivity 100%.