CN113402718A

CN113402718A - Zinc complex constructed by terephthalic acid containing trifluoromethyl side chain and 4, 4' -bipyridyl and preparation method thereof

Info

Publication number: CN113402718A
Application number: CN202011174427.5A
Authority: CN
Inventors: 刘峥; 魏润芝; 王胜; 黄悦
Original assignee: Guilin University of Technology
Current assignee: Guilin University of Technology
Priority date: 2020-10-28
Filing date: 2020-10-28
Publication date: 2021-09-17

Abstract

The invention discloses a zinc complex constructed by terephthalic acid containing trifluoromethyl side chain and 4, 4' -bipyridyl and a preparation method thereof. The method takes 2, 5-bis (trifluoromethyl) terephthalic acid as a ligand and 4,4 '-bipyridine as an auxiliary ligand to react with zinc chloride in a mixed solvent of N, N-dimethylformamide and water to obtain [ ZnL (4, 4' -bipy) (H)₂O)]_nA zinc complex. The coordination of the complex adopts oxygen atom and nitrogen atom and Zn²⁺The coordination mode of ion chelation is that mononuclear zinc ions extend infinitely through the connection of ligands to form a three-dimensional network-shaped crystal structure. The zinc complex belongs to a monoclinic system, and the space group is P2₁N, unit cell parameter of

α＝90.00°，β＝91.635(2)°，γ＝90.00°，

And Z is 4. The preparation method disclosed by the invention has the advantages of simple process, good repeatability, environmental friendliness, higher yield and the like. The invention successfully prepares [ ZnL (4, 4' -bipy) (H)₂O₎]_nProvides a new way for preparing the polycarboxylic acid transition metal complex.

Description

Zinc complex constructed by terephthalic acid containing trifluoromethyl side chain and 4, 4' -bipyridyl and preparation method thereof

Technical Field

The invention belongs to the technical field of metal organic complex preparation, and particularly relates to a zinc complex constructed by terephthalic acid containing trifluoromethyl side chains and 4, 4' -bipyridyl and a preparation method thereof.

Background

The metal-organic framework compounds (MOFs) are coordination polymers constructed by inorganic metal and organic ligands, and MOFs materials with variable property structures can be prepared by changing metal ions, organic ligands or acting force between the metal ions and the organic ligands. Polycarboxylic acids are widely used for constructing one-dimensional, two-dimensional and three-dimensional supramolecular complexes with novel structures and unique properties due to various flexible bonding modes of the polycarboxylic acids. Due to the diversity of dihedral angles between the carboxyl planes and the benzene ring planes in the aromatic polycarboxylic acid ligand, it is possible to fix the metal center in different directions, thereby exhibiting unique advantages. Meanwhile, the aromatic polycarboxylic acid ligand and the metal central ion can be self-assembled through hydrogen bonds or pi-pi interaction to form various topological structures or supermolecular structures, so that the aromatic polycarboxylic acid ligand and the metal central ion can show excellent performance in the fields of catalysis, molecular conductors, molecular magnets, nonlinear optics and the like, and the rigid structural characteristics of the aromatic polycarboxylic acid ligand and the metal central ion can lay a foundation for constructing a pore structure and prevent a through structure from being generated.

The application provides a method for preparing 2, 5-bis (trifluoromethyl) terephthalic acid (H)₂L), 4 '-bipyridine (4, 4' -bipy) and transition metal zinc salt (ZnCl)₂) The raw material is subjected to a solvothermal method to obtain the compound with the chemical formula of [ ZnL (4, 4' -bipy) (H)₂O)]_nA zinc complex structure and a preparation method thereof.

Disclosure of Invention

The purpose of the invention is as follows: provides a zinc complex constructed by terephthalic acid containing trifluoromethyl side chain and 4, 4' -bipyridyl and a preparation method thereof.

The idea of the invention is as follows: based on the excellent properties of aromatic polycarboxylic acid ligand, 2, 5-bis (trifluoromethyl) terephthalic acid is adopted as a main ligand, 4, 4' -bipyridyl is adopted as an auxiliary ligand, and oxygen atom, bipyridyl nitrogen atom and Zn are reacted through²⁺Ion chelation coordination, and an infinitely extended three-dimensional network structure is formed.

Terephthalic acid containing trifluoromethyl side chain andthe zinc complex constructed by the 4, 4' -bipyridyl has the structural characteristics that: belonging to monoclinic system, space group is P2₁N, unit cell parameter of

α＝90.00°，β＝91.635(2)°，γ＝90.00°，

The crystallographic data are shown in table 1, and the part and bond angle are shown in table 2.[ ZnL (4, 4' -bipy) (H)₂O)]_nThe ellipsoid diagram of the molecular structure of the complex is shown in figure 1, the polyhedral diagram of the complex is shown in figure 2, and the three-dimensional stacking diagram of the complex is shown in figure 3.

TABLE 1 [ ZnL (4, 4' -bipy) (H)₂O)]_nCrystallographic data of

TABLE 2 [ ZnL (4, 4' -bipy) (H)₂O)]_nPartial bond length of

Angle of harmony key (°)

[ZnL(4,4′-bipy)(H₂O)]_nThe preparation method comprises the following steps:

(1) weigh 0.0273g ZnCl₂0.0604g of 2, 5-bis (trifluoromethyl) terephthalic acid, 0.0312g of 4, 4' -bipyridine in a beaker containing 6mL of N, N-dimethylformamide and 4mL of distilled water; and (3) stirring the mixed solution obtained in the step (1) for 30min by using a magnetic stirrer at room temperature to obtain a mixed solution.

(2) Transferring the mixed solution prepared in the step (2) into a 25mL reaction kettle with a polytetrafluoroethylene bottle, putting the reaction kettle into an oven, heating the reaction kettle to 90 ℃, reacting for 72 hours, and reacting at 10 ℃ for h^-1Cooling to 60 ℃, keeping the temperature for 2 hours, closing the oven, cooling to room temperature in a natural state, taking out the reaction kettle, and generating colorless transparent blocky crystals, namely the zinc complex constructed by the terephthalic acid containing the trifluoromethyl side chain and the 4, 4' -bipyridyl.

The preparation method provided by the invention has the advantages of easy operation, good reproducibility, environmental protection, no pollution and the like, and the obtained [ ZnL (4, 4' -bipy) (H)₂O)]_nThe purity is high, and the preparation method provides a new way for the polycarboxylic acid transition metal complex.

Drawings

FIG. 1 shows the chemical formula of [ ZnL (4, 4' -bipy) (H) according to the present invention₂O)]_nThe molecular structure of the zinc complex is an ellipsoid diagram.

FIG. 2 shows a chemical formula of [ ZnL (4, 4' -bipy) (H) according to the present invention₂O)]_nPolyhedral diagram of zinc complex.

FIG. 3 shows the chemical formula of [ ZnL (4, 4' -bipy) (H) according to the present invention₂O)]_nThree-dimensional stacking diagram (along direction b) of the zinc complex.

Detailed Description

Example 1:

(1) weigh 0.0273g ZnCl₂0.0604g of 2, 5-bis (trifluoromethyl) terephthalic acid, 0.0312g of 4, 4' -bipyridine in a beaker containing 6mL of N, N-dimethylformamide and 4mL of distilled water; stirring with magnetic stirrer for 30min to obtain mixed solution;

(2) transferring the mixed solution prepared in the step (1) into a 25mL reaction kettle with a polytetrafluoroethylene bottle, putting the reaction kettle into an oven, heating the reaction kettle to 90 ℃, reacting for 72 hours, and reacting at 10 ℃ for h^-1OfCooling to 60 ℃, keeping the temperature for 2h, closing the oven, cooling to room temperature in a natural state, taking out the reaction kettle, and generating colorless transparent blocky crystals, namely the zinc complex constructed by the terephthalic acid containing the trifluoromethyl side chain and the 4, 4' -bipyridyl. The yield was 53.36%.

(3) Structural analysis of zinc complex constructed by terephthalic acid containing trifluoromethyl side chain and 4, 4' -bipyridyl: theoretical value of elemental analysis as C₂₀H₁₂F₆N₂O₅Zn calculation (%): c, 44.47; n, 5.19; h, 2.22. Measured value (%): c, 44.15; n, 5.93; h, 2.08.

As can be seen from the crystallographic data in Table 1, the complex belongs to the monoclinic system and has a space group of P2₁N, unit cell parameter of

α＝90.00°，β＝91.635(2)°， γ＝90.00°，

Z＝4；

As can be seen from the attached figure 1, the basic unit of the complex comprises 1 Zn (II) central ion, 3 main ligands, 2, 5-bis (trifluoromethyl) terephthalic acid, 2 auxiliary ligands, 4' -bipyridine and 1 coordinated water molecule;

as shown in the attached figure 2, in the complex, a central metal ion Zn (II) is respectively coordinated with 2 carboxyl oxygen atoms of a ligand 2, 5-bis (trifluoromethyl) terephthalic acid, 2 nitrogen atoms of 4, 4' -bipyridyl and an oxygen atom of a coordinated water molecule to form a six-coordination structure (symmetric codes of (a) -x +1, -y +1, -z +1, (b) x +1/2, -y +3/2, z +1/2, (c) x-1/2, -y +3/2, z +1/2, (d) x-1/2, -y +3/2, z-1/2, (e) x +1/2, -y +3/2 and z-1/2). The sum of the bond angles formed by each of the coordinating atoms N1, N2, O1, O3 and the central atom Zn (II) ion is 359.74 degrees, which is close to the ideal 360 degrees, which indicates that the 4 coordinating atoms form an equatorial plane and have better planarity. The O2 and O5 on the ligand are located at axial positions, and the axial bond angle O2-Zn1-O5(178.43 degrees) shows that the complex is in a regular octahedral configuration.

As can be seen from Table 2, coordinationThe bond Zn-O is long at

In the middle, the Zn-N bond length is in

The bond angle O — Zn — X (X ═ O, N) is in the normal range from 80.93 ° (18) to 178.43 ° (19) °.

As can be seen from the b-direction stacking diagram of the complex (FIG. 3 in the figure), the complex is Zn²⁺Is a metal node, L^2-And 4, 4' -bipy is used as a connector to be connected with each other to form an infinitely extending two-dimensional network structure, and the layers are orderly stacked to form a three-dimensional structure under the action of O-H-O molecular hydrogen bonds.

Claims

1. Zinc complex [ ZnL (4,4 '-bipy) (H) constructed by terephthalic acid containing trifluoromethyl side chain and 4, 4' -bipyridine₂O)]_nCharacterized in that the molecular formula is C₂₀H₁₂F₆N₂O₅Zn with molecular weight of 539.69, oxygen atom and nitrogen atom and Zn²⁺The coordination mode of ion chelation is that mononuclear zinc ions are infinitely extended through the connection of ligands to form a three-dimensional network-shaped crystal structure, the zinc complex belongs to a monoclinic system, and the space group is P2₁N, unit cell parameter of

α＝90.00°，β＝91.635(2)°，γ＝90.00°，

Z is 4, the crystallographic data is shown in Table 1, the part and the bond angle are shown in Table 2,

TABLE 1 [ ZnL (4, 4' -bipy) (H)₂O)]_nCrystallographic data of

TABLE 2 [ ZnL (4, 4' -bipy) (H)₂O)]_nPartial bond length of

Angle of harmony key (°)

The zinc complex constructed by the terephthalic acid containing the trifluoromethyl side chain and the 4, 4' -bipyridyl is characterized by comprising the following specific steps:

(1) weigh 0.0273g ZnCl₂0.0604g of 2, 5-bis (trifluoromethyl) terephthalic acid and 0.0312g of 4, 4' -bipyridine are dissolved in a beaker containing 6mL of N, N-dimethylformamide and 4mL of distilled water, and stirred for 30min by a magnetic stirrer at room temperature to prepare a mixed solution;

(2) transferring the mixed solution prepared in the step (1) into a 25mL reaction kettle with a polytetrafluoroethylene bottle, putting the reaction kettle into an oven, heating the reaction kettle to 90 ℃, reacting for 72 hours, and reacting at 10 ℃ for h^-1Cooling to 60 ℃, keeping the temperature for 2 hours, closing the oven, cooling to room temperature in a natural state, taking out the reaction kettle, and generating colorless transparent blocky crystals, namely the zinc complex constructed by the terephthalic acid containing the trifluoromethyl side chain and the 4, 4' -bipyridyl.