CN110885677B

CN110885677B - Zinc complex synthesis and application of zinc complex as fluorescent probe and photodegradation catalyst

Info

Publication number: CN110885677B
Application number: CN201811104160.5A
Authority: CN
Inventors: 王俊; 陈宁宁; 贾立永
Original assignee: Yancheng Teachers University
Current assignee: Yancheng Teachers University
Priority date: 2018-09-07
Filing date: 2018-09-07
Publication date: 2023-03-03
Anticipated expiration: 2038-09-07
Also published as: CN110885677A

Abstract

The invention provides a zinc metal complex preparation and application thereof in a fluorescent probe and a photodegradation catalyst. The chemical formula of the complex is [ Zn (SDBA) (BMIOPE)] _n (ii) a Wherein H ₂ SDBA =4,4 '-sulfonyl dibenzoic acid, BMIOPE =4,4' -bis (2-methyl-1-imidazolyl) diphenyl ether. The zinc metal complex is formed by passing zinc ions through SDBA ^2‑ And a two-dimensional structure formed by self-assembly of BMIOPE ligands. The zinc complex shows obvious fluorescence quenching effect on ferric ions, can be used as a fluorescent probe of the zinc complex, and has potential application value in the fields of environmental monitoring and life science. In addition, the zinc complex has the properties of stable and efficient catalytic photodegradation dye: the methylene blue is basically completely degraded within 60 minutes, is easy to separate and can be recycled for multiple times.

Description

Zinc complex synthesis and application of zinc complex as fluorescent probe and photodegradation catalyst

Statement regarding funding research or development: the method is carried out under the subsidy of policy guidance type plan (obstetrical and research cooperation) -prospective combined research project (Grant No. BY2016066-08) in Jiangsu province.

Technical Field

The inventionBelongs to the technical field of organic synthesis and metal organic chemistry, and particularly relates to 4,4 '-di (2-methyl-1-imidazolyl) diphenyl ether (BMIOPE) and 4,4' -sulfonyl dibenzoic acid (H) ₂ SDBA) as ligand and preparation of zinc complex and application of zinc complex as ferric ion (Fe) ³⁺ ) Fluorescent probes and can effectively degrade Methylene Blue (MB) dyes.

Background

Ferric ion (Fe) ³⁺ ) Is a metal ion necessary for a living body, is an essential substance for producing heme and myoglobin and promoting vitamin B group metabolism, can participate in the constitution of various enzymes in the living body, and participates in a plurality of important biochemical reactions in biological cells. In the organism, many enzymes react with Fe ³⁺ As a catalyst for metabolism, fe in vivo ³⁺ Deficiencies can affect the activity of enzymes such as cytochrome C oxidase, heme enzyme, succinate dehydrogenase, etc. These enzymes are closely related to biological oxidation, tissue respiration, and the breakdown and synthesis of neurotransmitters. Lack of Fe ³⁺ Is an important reason for diseases such as anemia, hemochromatosis, intelligence deterioration, arthritis, diabetes and the like. Therefore, fe can be detected quickly, conveniently, accurately and quickly ³⁺ Has important significance.

The metal complex is used as a fluorescent probe, can detect various ions quickly and conveniently with high sensitivity and high selectivity, and the unique luminescence property of the metal complex can come from charge transfer between metal ions and ligands, transition inside the ligands and transition between the ligands. In addition, the metal complex has a novel and abundant porous structure, and luminescence can be realized by introducing a luminescent component into the hole. Therefore, the complex fluorescent probe with novel screening structure, high sensitivity and excellent selectivity realizes the detection and identification of specific metal ions, and has very important research significance and practical value.

The rapid development of the industry brings about a growing problem of ecological environment, and the living environment of human beings is continuously damaged, so that the problem of water pollution is growing. At present, the main source of water pollution in China is industrial wastewater, wherein the proportion of printing and dyeing wastewater in the industrial wastewater exceeds 35%. The printing and dyeing wastewater has the characteristics of large wastewater amount, high chroma, high toxicity, complex water quality and the like, and belongs to high-concentration refractory organic wastewater. Azo dyes such as Methylene Blue (MB) and Methyl Orange (MO) are extremely harmful in water, seriously harm the ecological balance of rivers and oceans, and enter human bodies through skin absorption, so that headache, vomiting and even irreversible damage to various organs and even carcinogenesis are caused. Therefore, the high efficiency treatment of azo dye pollutants in water is an important issue.

The traditional water treatment process is continuously reformed due to a series of defects of easy generation of secondary pollution, high energy consumption, low efficiency and the like, and the reformation of the simple traditional treatment process is gradually changed into the research and development of new materials for water treatment. The method for degrading dye wastewater by using the environmental purification material to catalyze light can degrade a plurality of complex macromolecules which are difficult to be biodegraded, and attracts more and more attention in the field of dye wastewater treatment.

A great number of reports about the application of the complex in the field of photodegradation dyes show that the complex with different molecular structures has better application in the field of photodegradation dyes. Compared with the traditional semiconductor materials for photodegradation, the complex has many advantages in the aspect of photodegradation of dyes: (1) The precision of the crystal structure is beneficial to researching the relation between the structure and the property of the ligand photodegradation dye; (2) The tunable active sites promote the efficient utilization of solar energy by the ligand photodegradation dye; (3) The porosity and the larger specific surface area of the complex can allow dye molecules to rapidly pass through a channel, which is very effective for improving the efficiency of photocatalytic degradation; (4) The interaction of the metal ions of the complex and the ligand can effectively separate photoelectrons and vacancies, thereby improving the photocatalytic activity. Therefore, the complex has high photocatalytic activity and chemical stability, and the synthesis method is simple, so that the complex is an ideal catalyst for photoreaction.

4,4' -bis (2-methyl-1-imidazolyl) biphenyl ether (BMIOPE) is a bridging ligand with strong coordination capacity. This ligand has two distinct features: firstly, the ligand is a V-type imidazole ligand with semi-flexibility, and two 2-methylimidazolyl groups are arranged at two ends of the V-type imidazole ligand, so that the synthesis of a complex is facilitated; secondly, the C-C bond between the rigid benzene ring and the 2-methylimidazole and the C-O-C bond between the two benzene rings can rotate to a certain degree to adapt to various coordination environments, metal complexes with different dimensions are easy to synthesize, and the synthesis of structures with different dimensions is a crucial step for completing device formation.

The invention belongs to the technical field of organic synthesis and metal organic chemistry, and relates to synthesis of a two-dimensional zinc metal fluorescent complex, in particular to 4,4 '-di (2-methyl-1-imidazolyl) diphenyl ether (BMIOPE) and 4,4' -sulfonyl dibenzoic acid (H) ₂ SDBA) as ligand and application thereof as fluorescent probe and photodegradation catalyst. According to the invention, divalent zinc ions are used as a main body, 4 '-di (2-methyl-1-imidazolyl) diphenyl ether and 4,4' -sulfonyl dibenzoic acid are used as ligand structures to construct a complex, the influence of different metal ions on the fluorescence performance of the metal complex is explored, meanwhile, the zinc fluorescent complex with a two-dimensional structure shows an obvious fluorescence quenching effect on ferric ions, and the zinc fluorescent complex serving as a fluorescent probe material has a wide application prospect in metal ion analysis and research. Furthermore, in the present invention, the complex we synthesized has a distinct photodegradability property for methylene blue dye: the methylene blue dye is basically completely degraded within 60 minutes, is easy to separate and recycle for multiple times, and the catalytic efficiency is basically kept unchanged.

Disclosure of Invention

The invention aims to provide a two-dimensional zinc complex which is used as a ferric ion fluorescent probe and can effectively catalyze and degrade methylene blue containing azo organic dye and a preparation method thereof. The invention adopts 4,4 '-di (2-methyl-1-imidazolyl) diphenyl ether, 4' -sulfonyl dibenzoic acid ligand and zinc nitrate hexahydrate to construct a zinc complex. The complex has a fluorescent recognition function on ferric ions, can detect the existence of trace ferric ions in an aqueous solution, can efficiently degrade methylene blue organic dye, and can ensure excellent catalytic activity and repeatability. The complex has the advantages of simple synthesis process, low cost, high efficiency, good reproducibility, sensitive detection, easy separation and high yield, can be applied to industrial production, and has potential application prospects in the fields of environmental monitoring, life science and pollutant degradation.

The chemical formula of the zinc complex used as the ferric ion fluorescent probe and the methylene blue light degradation catalyst is as follows: [ Zn (SDBA) (BMIOPE)] _n Wherein H is ₂ SDBA =4,4 '-sulfonyl dibenzoic acid, BMIOPE =4,4' -bis (2-methyl-1-imidazolyl) diphenyl ether. BMIOPE, H ₂ The structural formula of SDBA is as follows:

the structure of the two-dimensional zinc complex used as a ferric ion fluorescent probe and an azo organic dye methylene blue light degradation catalyst is shown in figure 1 (a), and the basic structural parameters are as follows:

the crystal of the zinc complex belongs to a monoclinic system, and the space group is P2 ₁ N, unit cell parameter of

α =90 °, β =101.716 (19) °, γ =90 °; each zinc atom in the complex is coordinated with two nitrogen atoms from two 4,4 '-bis (2-methyl-1-imidazolyl) diphenyl ether ligands and four oxygen atoms from two 4,4' -sulfonyl dibenzoic acid ligands to form an infinite two-dimensional network structure, as shown in fig. 1 (b).

The preparation method of the zinc complex comprises the following steps:

(1) The preparation method comprises the following steps: 4,4 '-bis (2-methyl-1-imidazolyl) diphenyl ether 4,4' -sulfonyldibenzoic acid zinc nitrate hexahydrate = 1: 1, H was added ₂ O (8 mL), mixing, putting into a polytetrafluoroethylene liner of a hydrothermal 25mL reaction kettle, mixing, and ultrasonically oscillating for 5 minutes to obtain a mixed solution;

(2) Drying the mixed solution at 100 ℃ for 72 hours, taking out the product, and separating the solid;

(3) The solid was washed three times with waterObtaining colorless transparent bulk crystals based on Zn (NO) ₃ ) ₂ ·6H ₂ The yield calculated by O is up to 61.2 percent.

Furthermore, the invention provides an application of the zinc complex as a ferric ion fluorescent probe, which can be used for monitoring ferric ions in environments and organisms. In addition, the invention also provides application of the zinc complex in removing methylene blue dye in water by catalytic photodegradation, and the zinc complex is used for treating methylene blue dye wastewater in natural water.

The invention has the advantages that: the preparation method has the advantages of simple process, high yield, easy separation, good reproducibility, high sensitivity, good catalytic efficiency and high yield, can obtain a single crystal form and a high-purity crystal material, and is easy for industrial production; the product has a fluorescent recognition function on ferric ions, can be used for detecting trace ferric ions in an aqueous solution, and has the advantages of qualitative, rapid, sensitive, high efficiency, simple and convenient operation and the like compared with the traditional detection method; the product can effectively catalyze and degrade methylene blue, and can be recycled for many times while the catalytic efficiency is basically kept unchanged.

Brief description of the drawings

FIG. 1 (a) is a crystal structure diagram of a zinc complex of the present invention; FIG. 1 (b) is a two-dimensional structural view of the zinc complex of the present invention.

FIG. 2 (a) is a graph of the fluorescence intensity of the zinc complex of the present invention for different metal solutions; FIG. 2 (b) is a graph showing the fluorescence intensity of the zinc complex of the present invention for iron ion solutions of different concentrations.

FIG. 3 is a graph showing the fluorescence intensity of the zinc complex of the present invention in the presence and absence of an aqueous solution of iron ions.

FIG. 4 is a graph showing the relationship between the time and the fluorescence intensity after adding iron ions to an aqueous solution of a zinc complex of the present invention.

FIG. 5 is a diagram showing the photocatalytic degradation of methylene blue by the zinc complex of the present invention.

Detailed Description

In order to better understand the invention, the following description is further provided in connection with the examples, but the invention is not limited to the following examples.

Example 1: synthesis of ligand 4,4' -bis (2-methyl-1-imidazolyl) diphenyl ether (BMIOPE)

Preparing 4,4 '-bis (2-methyl-1-imidazolyl) diphenyl ether (BMIOPE) from 4,4' -dibromodiphenyl ether, 2-methylimidazole, potassium carbonate and cuprous oxide by a one-pot method in a polar solvent under the heating condition;

wherein the mol ratio of 4,4' -dibromodiphenyl ether, 2-methylimidazole, potassium carbonate and cuprous oxide is 2: 8: 1; the reaction temperature is 180 ℃, and the reaction time is 3 days. 4,4 '-bis (2-methyl-1-imidazolyl) diphenyl ether (BMIOPE) is prepared from 4,4' -dibromodiphenyl ether, 2-methylimidazole, potassium carbonate and cuprous oxide in a polar solvent by a one-pot method under the heating condition.

Example 2: synthesis of the Complex

11.9mg of Zn (NO) ₃ ) ₂ ·6H ₂ O, 10.5mg of H ₂ SDBA and 16.5mg BMIOPE are dissolved in 8mL water, ultrasonic oscillation is carried out for 5min, the mixture is transferred into a polytetrafluoroethylene inner container of a 25mL hydrothermal reaction kettle and reacts for 72 hours under the temperature condition of 100 ℃, and the obtained product is washed twice (2 mL/time) by water to obtain colorless transparent blocky crystals. Based on Zn (NO) ₃ ) ₂ ·6H ₂ The yield calculated by O is as high as 61.2%.

Example 3: structural characterization of the Complex

Single crystals of appropriate size were selected with a microscope and analyzed at room temperature using a Siemens (Bruker) SMART CCD diffractometer (graphite monochromator, mo-Ka,

) Diffraction data was collected. The diffraction data were corrected for absorption using the SADABS program. Data reduction and structure resolution were done using SAINT and SHELXTL programs, respectively. And determining all non-hydrogen atom coordinates by a least square method, and obtaining the hydrogen atom position by a theoretical hydrogenation method. And (5) refining the crystal structure by adopting a least square method. As shown in FIGS. 1 (a) and 1 (b)Is [ Zn (SDBA) (BMIOPE)] _n Basic coordination and stacking mode. Some of the parameters for crystallographic diffraction point data collection and structure refinement are shown in the table below.

TABLE 1 crystallographic data of the complexes

R ₁ ＝∑||F _o |-|F _c ||/∑|F _o |.ωR ₂ ＝∑[w(F _o ² -F _c ² ) ² ]/∑[w(F _o ² ) ² ] ^1/2

Example 4: fluorescent properties of the complexes

And (3) testing the fluorescence property of the complex at room temperature by using an LS-55 type fluorescence spectrometer. As shown in FIG. 2 (a), at the selected metal ion [ M (NO) ₃ ) _x 。M＝Na ⁺ ，Li ⁺ ，Mg ²⁺ ，Ca ²⁺ ，Co ²⁺ ，Ni ²⁺ ，Zn ²⁺ ，Ag ⁺ ，Cd ²⁺ ，Mn ²⁺ ，Al ³⁺ ，Cu ²⁺ ，Fe ³⁺ ]In aqueous solution, the fluorescence intensity of the zinc complex prepared in example 2 shows dependence on metal ions and on Fe ³⁺ Shows complete fluorescence quenching effect and is expected to become Fe ³⁺ The fluorescent probe of (1).

To investigate the recognition of Fe in the aqueous solution by the Zinc Complex prepared in example 2 ³⁺ Sensitivity of (2) Fe ³⁺ Adding the fluorescent powder into an aqueous suspension of the material to prepare suspensions with different concentrations, and recording the change of the fluorescence intensity of the suspensions. As shown in FIG. 2 (b), the fluorescence intensity varied with Fe ³⁺ The concentration of the zinc complex still shows a descending trend, and the zinc complex can be calculated to obtain Fe in water ³ ⁺ The detection limit of (A) was 0.090mmol/L.

By comparison [ M (NO) as shown in FIG. 3 ₃ ) _x ，M ⁿ⁺ ＝Na ⁺ ，Li ⁺ ，Mg ²⁺ ，Ca ²⁺ ，Co ²⁺ ，Ni ²⁺ ，Zn ²⁺ ，Ag ⁺ ，Cd ²⁺ ，Mn ²⁺ ，Al ³⁺ ，Cu ²⁺ Free of Fe ³⁺ ]With addition of Fe ³⁺ The fluorescence intensity of the zinc complex prepared in example 2 can be seen from the graph, and the complex is Fe ³⁺ Has good selectivity.

As shown in FIG. 4, it can be seen that Fe in water of the zinc complex prepared in example 2 ³⁺ The detection time is short.

Example 5: photodegradation of complexes

30mg of the synthesized zinc complex of the present invention was weighed into 50mL of methylene blue aqueous solution (10 mg/L), and 5uL of H was added ₂ O ₂ Stirring in the dark for 30min to make the surface of the complex reach adsorption-desorption balance, then irradiating with a visible light while stirring, taking 1mL methylene blue aqueous solution every 10min, and immediately testing the change of absorbance. The photodegradation result shows that the degradation rate of the complex to methylene blue within 60min is respectively as high as 91.5%, and the complex can be recycled for multiple times (as shown in figure 5).

Claims

1. A zinc complex capable of effectively degrading methylene blue dye is characterized in that the chemical formula is [ Zn (SDBA) (BMIOPE)]n is, wherein H ₂ SDBA =4,4 '-sulfonyl dibenzoic acid, BMIOPE =4,4' -bis (2-methyl-1-imidazolyl) biphenyl ether; the crystal of the zinc complex belongs to a monoclinic system, the space group is P2 l/n, and the unit cell parameter is

α = γ =90 °, β =101.716 (19) °; the central zinc atom coordinates two nitrogen atoms from two 4,4 '-bis (2-methyl-1-imidazolyl) biphenyl ether ligands and four oxygen atoms from two 4,4' -sulfonyl dibenzoic acid ligands to form an infinite two-dimensional network.

2. A process for preparing a zinc complex according to claim 1, comprising the steps of: under a sealed condition, organic ligands of 4,4 '-bis (2-methyl-1-imidazolyl) diphenyl ether, 4' -sulfonyl dibenzoic acid and zinc nitrate hexahydrate are subjected to hydrothermal reaction in an aqueous solution to obtain the zinc complex with a crystal structure.

3. The method for producing a zinc complex according to claim 2, wherein: zinc nitrate hexahydrate, 4 '-bis (2-methyl-1-imidazolyl) diphenyl ether, 4' -sulfonyl dibenzoic acid was 1: 1, 8mL of deionized water was added per 0.05mmol of zinc nitrate hexahydrate, and hydrothermal reaction was carried out at 100 ℃ for three days.