阅读说明：本技术 基于六核铽簇的三维多孔配合物的合成方法和应用 (Synthetic method and application of three-dimensional porous complex based on six-core terbium cluster ) 是由 贺鸿明 李程鹏 杜淼 于 2018-06-11 设计创作，主要内容包括：本发明公开了一种基于六核铽簇的三维多孔配合物的合成方法和应用,铽配合物的化学式为[Tb<Sub>6</Sub>L<Sub>2</Sub>·(2-FBA)<Sub>2</Sub>·(H<Sub>2</Sub>O)<Sub>6</Sub>·(μ<Sub>3</Sub>-OH)<Sub>8</Sub>]<Sub>n</Sub>,其中,2-FBA为2-氟苯甲酸,L为羧基去质子的3,3′,5,5′-四(4-羧基苯基)-4,4′-联苯二胺阴离子配体,合成方法为在3,3′,5,5′-四(4-羧基苯基)-4,4′-联苯二胺、2-氟苯甲酸和铽(III)金属盐中加入N,N-二甲基甲酰胺使其均匀分散,于100～120℃下保持3～6天后,自然降至室温20～25℃,过滤后得到棕色块状单晶为铽配合物,本发明的铽配合物拥有催化位点和丰富的孔道结构,是一种良好的催化剂。(The invention discloses a synthetic method and application of a three-dimensional porous complex based on a six-core terbium cluster, wherein the chemical formula of the terbium complex is [ Tb ] 6 L 2 ·(2‑FBA) 2 ·(H 2 O) 6 ·(μ 3 ‑OH) 8 ] n The synthesis method comprises the steps of adding N, N-dimethylformamide into 3,3 ', 5,5 ' -tetra (4-carboxyphenyl) -4,4 ' -biphenyldiamine, 2-fluorobenzoic acid and terbium (III) metal salt to uniformly disperse the N, N-dimethylformamide, keeping the temperature at 100-120 ℃ for 3-6 days, naturally cooling to the room temperature of 20-25 ℃, and filtering to obtain brown blocky single crystals which are terbium complexesThe structure is a good catalyst.)

1. A terbium complex with a three-dimensional porous structure, which is characterized in that the chemical formula is [ Tb₆L₂·(2-FBA)₂·(H₂O)₆·(μ₃-OH)₈]_nWherein, the (μ)₃OH) is OH which plays a bridging role^-The 2-FBA is 2-fluorobenzoic acid, the L is a carboxyl deprotonated 3,3 ', 5,5 ' -tetra (4-carboxyphenyl) -4,4 ' -biphenyldiamine anion ligand, and the structure of the L is simply shown as follows:

2. a terbium complex according to claim 1, wherein the basic structural unit of said terbium complex comprises: one quarter of crystallographically independent Tb1, one half of crystallographically independent Tb2, one quarter of crystallographically independent 2-fluorobenzoic acid, one half of crystallographically independent mu₃-O (4) H, one-half crystallographically independent mu₃-O (7) H, one half crystallographically independent H₂O (5) and one-fourth crystallographically independent H₂O (6) and quarter of a fully deprotonated L^4-。

3. Root of herbaceous plantthe terbium complex according to claim 2, wherein each L is^4-The 2 oxygens of the same carboxyl group are O1 and O2, O1 is connected with a Tb1, O2 is connected with a Tb2, and each Tb1 is connected with a group consisting of four L^4-Four oxygen O1 in the carboxyl group of (2), two μ₃O4 of-O (4) H, two μ₃O7 of-O (7) H and one from H₂O6 connection of O (6); each Tb2 and from one 2-FBA^-one oxygen O3 from two L^4-two oxygen O2 in the carboxyl group of (2), two are derived from mu₃O4 of-O (4) H, two from μ₃O7 of-O (7) H and one from H₂O5 connection of O (5);

The number of Tb2 connected per O4 is two, the number of Tb1 is one, the number of Tb2 connected per O7 is two, and the number of Tb1 is one.

4. The terbium complex according to claim 3, wherein the unit cell parameter of the terbium complex is α＝90.00°，β＝90.00°，γ＝120.00°，Z＝6。

5. The terbium complex according to claim 4, wherein the three-dimensional skeleton of the terbium complex starts to decompose when the temperature is raised to 450-500 ℃, and the remaining residue is the metal oxide Tb₂O₃。

6. The method for synthesizing a terbium complex according to any one of claims 1 to 5, comprising the steps of:

Adding N, N-dimethylformamide into 3,3 ', 5, 5' -tetra (4-carboxyphenyl) -4,4 '-biphenyldiamine, 2-fluorobenzoic acid and terbium (III) metal salt to uniformly disperse the N, N-dimethylformamide, keeping the mixture at 100-120 ℃ for 3-6 days, naturally cooling the mixture to the room temperature of 20-25 ℃, and filtering the mixture to obtain a brown blocky single crystal, namely the terbium complex, wherein the mass ratio of the terbium (III) metal salt to the 3, 3', 5,5 '-tetra (4-carboxyphenyl) -4, 4' -biphenyldiamine to the 2-fluorobenzoic acid is 1: (1.8-2): (64 to 67).

7. The synthesis method according to claim 6, wherein the ratio of parts by weight of terbium (III) metal salt to parts by volume of the N, N-dimethylformamide is 1: (140-155), wherein the unit of the quantity parts of the substances is mmol, and the unit of the volume parts is mL.

8. The synthesis method according to claim 7, wherein the temperature for 3-6 days is 100-115 ℃; washing and drying the brown blocky single crystal obtained after filtration, wherein the washing agent adopted by washing is N, N-dimethylformamide, and the drying temperature is 20-25 ℃ at room temperature; the method for uniformly dispersing 3,3 ', 5,5 ' -tetrakis (4-carboxyphenyl) -4,4 ' -biphenyldiamine, 2-fluorobenzoic acid and terbium (III) metal salt in N, N-dimethylformamide is as follows: stirring for at least 30 minutes at room temperature of 20-25 ℃.

9. The terbium complex according to any one of claims 1 to 5 in CO₂Use in chemical immobilization to form cyclic carbonates.

10. Use according to claim 9, characterized in that the ratio of the amounts of substances is 1: (0.15-0.20) dispersing epichlorohydrin and tetrabutylammonium bromide in acetonitrile, adding the terbium complex serving as a heterogeneous catalyst, reacting at 70-85 ℃ for 24-36 hours in a carbon dioxide environment with one atmosphere of pressure, converting the epichlorohydrin into cyclic carbonate with the conversion rate up to 100%, wherein the ratio of the mass parts of the terbium complex to the mass parts of the epichlorohydrin is 50: (0.5-1.5);

The unit of the mass part is mg, and the unit of the mass part of the substance is mmol;

The ratio of the mass parts of the epichlorohydrin to the volume parts of the acetonitrile is 1: (2-3);

The terbium complex serving as the heterogeneous catalyst still keeps the original framework structure after being recycled for 3-6 times.

Technical Field

The invention relates to the technical field of organic-inorganic coordination compounds and crystallography, and mainly relates toThe three-dimensional porous complex is obtained by self-assembling organic ligands of 3,3 ', 5,5 ' -tetra (4-carboxyphenyl) -4,4 ' -biphenyldiamine and terbium (III) ions, and can be used as a heterogeneous catalyst for chemically fixing CO (carbon monoxide) due to the fact that the three-dimensional porous complex has an open pore channel structure and rich catalytic sites₂And an epoxy compound to give a cyclic carbonate.

Background

At present, China and other countries face a great environmental pollution problem, especially because of greenhouse gas CO₂And the like, a series of environmental problems caused by global temperature rise. Therefore, a large number of scientists all over the world are working on designing different materials for synthesizing the greenhouse gas CO₂Capture and conversion into more useful industrial raw materials, which not only can solve the global warming problem it generates, but also can convert it into useful chemical raw materials, such as: cyclic carbonates, and the like. The materials used at present mainly include various metal oxides, polymers, high molecular materials, molecular sieves, composite materials and the like. However, these materials still have many problems to be solved urgently, such as: poor stability, low efficiency, high price, poor selectivity, harsh reaction conditions and the like. Thus, more efficient materials are produced for CO₂The cycloaddition reaction with epoxy compounds is one of the problems to be solved urgently.

Coordination polymers, also known as metal-organic framework compounds, are three-dimensional, periodically ordered crystalline materials formed by coordination bonds of inorganic metal moieties and organic ligand moieties. Such materials have many excellent properties, such as: controllable pore channel structure, high specific surface area, rich structure and the like, so that the porous material has potential application value in various fields of heterogeneous catalysis, fluorescence detection, adsorption separation and the like. For decades, coordination polymers have been the hottest materials in many fields of coordination chemistry, crystallography, and materials science. Recently, scientists have tried to design and synthesize metal-organic framework compound materials that simultaneously contain a number of advantages, such as: contains rich pore canal, great amount of Lewis base sites and open metal sites.The material is used as heterogeneous catalyst to catalyze CO₂And an epoxy compound. However, the research in this field is relatively rare and faces many problems, such as: the pore channel size of the material is small, which is not beneficial to the diffusion of the substrate; the stability of the material is poor; high temperature and high pressure are required. To date, there has been no report of the use of a rigid organic ligand 3,3 ', 5,5 ' -tetrakis (4-carboxyphenyl) -4,4 ' -biphenyldiamine (abbreviated as H) containing an amino group₄L) for the construction of a catalyst useful for the chemical fixation of CO₂The porous metal-organic framework compound material of (1).

Disclosure of Invention

Aiming at the defects of the prior art, the invention aims to provide a terbium complex with a three-dimensional porous structure, wherein the terbium complex has a rich pore channel structure and a large number of amino sites and catalytic sites.

The invention also aims to provide a synthesis method of the terbium complex, the synthesis method uses rigid tetracarboxylic acid organic ligand 3,3 ', 5, 5' -tetra (4-carboxyphenyl) -4,4 '-biphenyldiamine using amino as Lewis base site, and the material containing two pore channel structures is constructed by deprotonating all carboxylic acid functional groups of the 3, 3', 5,5 '-tetra (4-carboxyphenyl) -4, 4' -biphenyldiamine and terbium ions.

It is another object of the present invention to provide said terbium complex in CO₂Application of terbium complex in chemical fixation of cyclic carbonate, namely, terbium complex in CO₂The cyclic carbonate synthesized by the catalyst and the epoxy compound has remarkable catalytic effect and excellent recycling capability, and can be widely applied to the field of catalytic crystal materials.

The purpose of the invention is realized by the following technical scheme.

A terbium complex with a three-dimensional porous structure, and the chemical formula is [ Tb₆L₂·(2-FBA)₂·(H₂O)₆·(μ₃-OH)₈]_nWherein, the (μ)₃OH) is OH which plays a bridging role in an inorganic cluster^-The 2-FBA is 2-fluorobenzeneThe acid, the L is a carboxyl deprotonated 3,3 ', 5,5 ' -tetra (4-carboxyphenyl) -4,4 ' -biphenyldiamine anion ligand, and the structure of the L is simply shown as the following formula:

In the above technical solution, the basic structural unit of the terbium complex includes: one quarter of crystallographically independent Tb1, one half of crystallographically independent Tb2, one quarter of crystallographically independent 2-fluorobenzoic acid, one half of crystallographically independent mu₃-O (4) H, one-half crystallographically independent mu₃-O (7) H, one half crystallographically independent H₂O (5) and one-fourth crystallographically independent H₂O (6) and quarter of a fully deprotonated L^4-。

In the above technical scheme, each L^4-the 2 oxygens of the same carboxyl group are O1 and O2, O1 is connected with a Tb1, O2 is connected with a Tb2, and each Tb1 is connected with a group consisting of four L^4-Four oxygen O1 in the carboxyl group of (2), two μ₃O4 of-O (4) H, two μ₃o7 of-O (7) H and one from H₂O6 connection of O (6); each Tb2 and from one 2-FBA^-one oxygen O3 from two L^4-Two oxygen O2 in the carboxyl group of (2), two are derived from mu₃o4 of-O (4) H, two from μ₃o7 of-O (7) H and one from H₂O5 connection of O (5);

The number of Tb2 connected per O4 is two, the number of Tb1 is one, the number of Tb2 connected per O7 is two, and the number of Tb1 is one.

in the technical scheme, the unit cell parameter of the terbium complex is α＝90.00°，β＝90.00°，γ＝120.00°，Z＝6。

in the technical scheme, when the temperature is raised to 450-500 ℃, the three-dimensional framework of the terbium complex starts to decompose, and the residual residue is metal oxide Tb₂O₃。

the synthesis method of the terbium complex comprises the following steps:

Adding N, N-dimethylformamide into 3,3 ', 5, 5' -tetra (4-carboxyphenyl) -4,4 '-biphenyldiamine, 2-fluorobenzoic acid and terbium (III) metal salt to uniformly disperse the N, N-dimethylformamide, keeping the mixture at 100-120 ℃ for 3-6 days, naturally cooling the mixture to the room temperature of 20-25 ℃, and filtering the mixture to obtain a brown blocky single crystal, namely the terbium complex, wherein the mass ratio of the terbium (III) metal salt to the 3, 3', 5,5 '-tetra (4-carboxyphenyl) -4, 4' -biphenyldiamine to the 2-fluorobenzoic acid is 1: (1.8-2): (64 to 67).

In the above technical solution, the ratio of parts by weight of the terbium (III) metal salt to parts by volume of the N, N-dimethylformamide is 1: (140-155), wherein the unit of the quantity parts of the substances is mmol, and the unit of the volume parts is mL.

In the technical scheme, the temperature for 3-6 days is 100-115 ℃.

In the technical scheme, the brown blocky single crystal obtained after filtration is washed and dried, the washing agent adopted by washing is N, N-dimethylformamide, and the drying temperature is 20-25 ℃ at room temperature.

In the above technical solution, the method for uniformly dispersing 3,3 ', 5,5 ' -tetrakis (4-carboxyphenyl) -4,4 ' -biphenyldiamine, 2-fluorobenzoic acid and terbium (III) metal salt in N, N-dimethylformamide comprises: stirring for at least 30 minutes at room temperature of 20-25 ℃.

In another aspect of the present invention, the terbium complex is present in CO₂Use of chemical immobilization to form cyclic carbonates, the ratio of the amounts of substances being 1: (0.15-0.20) dispersing epoxy chloropropane and tetrabutylammonium bromide in acetonitrile, adding the terbium complex serving as a heterogeneous catalyst, and reacting at 70-85 ℃ for 24-36 hours in a carbon dioxide environment with one atmosphere of pressureConverting epichlorohydrin into cyclic carbonate, wherein the conversion rate of the cyclic carbonate is up to 100%, and the ratio of the mass parts of the terbium complex to the mass parts of epichlorohydrin is 50: (0.5-1.5).

In the technical scheme, the unit of the mass parts is mg, and the unit of the mass parts is mmol.

In the technical scheme, the ratio of the mass parts of the epichlorohydrin to the volume parts of the acetonitrile is 1: (2-3).

In the technical scheme, the terbium complex serving as the heterogeneous catalyst still keeps the original framework structure after being recycled for 3-6 times.

Compared with the prior art, the invention has the following beneficial effects:

1. The Tb (III) metal-organic coordination compound (terbium complex) provided by the invention has catalytic sites and rich pore channel structures, and is a good catalyst.

2. The Tb (III) porous complex (terbium complex) containing 3,3 ', 5,5 ' -tetra (4-carboxyphenyl) -4,4 ' -biphenyldiamine is synthesized by a solvothermal method, the reaction operation is simple and easy to implement, required equipment is simple, reproducibility is good, and the prepared complex has the advantages of high yield, good thermal stability and the like.

3. Can be widely applied in the field of catalytic crystal materials for catalyzing CO₂When the cyclic carbonate is chemically fixed, the conversion rate can reach 100 percent at most.

Drawings

FIG. 1 is a diagram showing coordination environments of Tb (III) porous complexes of 3,3 ', 5,5 ' -tetrakis (4-carboxyphenyl) -4,4 ' -biphenyldiamine obtained in example 1 of the present invention;

FIG. 2 is a three-dimensional structural diagram of Tb (III) of 3,3 ', 5,5 ' -tetrakis (4-carboxyphenyl) -4,4 ' -biphenyldiamine obtained in example 1 of the present invention;

FIG. 3 is a graph showing experimental and theoretical X-ray powder diffraction (PXRD) analysis of Tb (III) of 3,3 ', 5,5 ' -tetrakis (4-carboxyphenyl) -4,4 ' -biphenyldiamine obtained in example 1 of the present invention;

FIG. 4 is a thermogravimetric analysis graph of a Tb (III) porous complex of 3,3 ', 5,5 ' -tetrakis (4-carboxyphenyl) -4,4 ' -biphenyldiamine obtained in example 1 of the present invention;

FIG. 5 is a graph of the cyclic X-ray powder diffraction (PXRD) pattern of the Tb (III) porous complex of 3,3 ', 5,5 ' -tetrakis (4-carboxyphenyl) -4,4 ' -biphenyldiamine obtained in example 1 of the present invention on epichlorohydrin and carbon dioxide to form a cyclic carbonate product.

Detailed Description

Terbium nitrate hexahydrate (98%) used in the following examples was purchased from tianjin schinseng and N, N-dimethylformamide (analytically pure) was purchased from the shanghai meirell chemical technology co.

3,3 ', 5,5 ' -tetrakis (4-carboxyphenyl) -4,4 ' -biphenyldiamine was synthesized in the literature: wen, h. -m.; li, B.; wang, h.; krishna, r.; chen, B.high acetyl/ethylene separation in amino acids zinc (II) metal-organic frame with low binding power, chem.Commun, 2016,52, 1166-.

Ortho-fluorobenzoic acid was purchased from san chemical technology (shanghai) ltd-ann naiji chemical with a purity of 95%.

All drugs and reagents were used directly without further purification.

A terbium complex with a three-dimensional porous structure, and the chemical formula is [ Tb₆L₂·(2-FBA)₂·(H₂O)₆·(μ₃-OH)₈]_nWherein (μ)₃OH) is OH which plays a bridging role in an inorganic cluster^-2-FBA is 2-fluorobenzoic acid, L is a carboxyl deprotonated 3,3 ', 5,5 ' -tetra (4-carboxyphenyl) -4,4 ' -biphenyldiamine anion ligand, and the structure of L is simply as follows:

The basic structural unit of the terbium complex comprises: one quarter of crystallographically independent Tb1, one half of crystallographically independent Tb2, one quarter of crystallographically independent 2-fluorobenzoic acid, one half of crystallographically independent mu₃-O (4) H, one-half crystallography independentMu of₃-O (7) H, one half crystallographically independent H₂O (5) and one-fourth crystallographically independent H₂O (6) and quarter of a fully deprotonated L^4-。

each L^4-The 2 oxygens of the same carboxyl group are O1 and O2, O1 is connected with a Tb1, O2 is connected with a Tb2, and each Tb1 is connected with a group consisting of four L^4-Four oxygen O1 in the carboxyl group of (2), two μ₃O4 of-O (4) H, two μ₃O7 of-O (7) H and one from H₂O6 connection of O (6); each Tb2 and from one 2-FBA^-one oxygen from two L^4-Two oxygen O2 in the carboxyl group of (2), two are derived from mu₃O4 of-O (4) H, two from μ₃O7 of-O (7) H and one from H₂o5 connection of O (5); a 2-FBA^-Each of the two oxygen O3 of (a) is linked to a Tb 2.

The number of Tb2 connected per O4 is two, the number of Tb1 is one, the number of Tb2 connected per O7 is two, and the number of Tb1 is one.

And one O4 and O7 are respectively arranged between Tb1 and Tb2 connected with 2 oxygen O1 and O2 of one carboxyl.

The technical scheme of the invention is further explained by combining specific examples.