Synthesis and fluorescence application of copper complex based on anthraquinone-2, 7-disulfonic acid

Abstract

The invention discloses a preparation method and application of a complex of anthraquinone-2, 7-disulfonic acid, a 1, 10-phenanthroline ligand and Cu < 2 + >, and belongs to the technical field of crystal material synthesis. Comprising the following steps: S1, dissolving a metal copper salt in a proper amount of water, and carrying out uniform ultrasonic dissolution, S2, dissolving anthraquinone-2, 7-disulfonic acid in a proper amount of water, carrying out uniform ultrasonic dissolution, adding sodium hydroxide, and continuously carrying out ultrasonic treatment until the sodium hydroxide is completely reacted; s3: 1, 10-phenanthroline is dissolved in a proper amount of methanol, and ultrasonic dissolution is uniform, S4: a water solution containing copper salt is poured into a water solution containing anthraquinone-2, 7-disulfonic acid, then a phenanthroline methanol solution is added, stirring is conducted for 5 min, uniform oscillation is conducted, heating is conducted for 48 h at the temperature of 120 DEG C, standing and cooling are conducted to the room temperature, blue blocky crystals are obtained and washed three times with diethyl ether, and the anthraquinone-2, 7-disulfonic acid and 1, 10-phenanthroline are obtained. The invention relates to a copper (II) complex C38H24Cu2N4O10S2 based on a 1, 10-phenanthroline ligand. The complex has relatively high sensitivity and relatively good selectivity when being used as a fluorescent probe for detecting zinc ions.

Description

Technical Field

[0001] This invention relates to the field of crystal material synthesis technology, specifically to anthraquinone-2,7-disulfonic acid and 1,10-o-phenanthroline ligand with Cu. 2+ Preparation methods and applications of the complexes. Background Technology

[0002] As is well known, zinc is the second most abundant transition metal ion in the human body, playing a crucial role in a vast array of physiological processes, including neurotransmission, gene expression, and enzyme regulation. Its concentration can vary from approximately 1 nM to 1 mM. Imbalances in zinc ion concentration can lead to various pathological diseases, including Alzheimer's disease, epilepsy, Parkinson's disease, ischemic stroke, and diarrhea in infants and young children. Furthermore, zinc wastewater generated by industries such as smelting and electroplating also causes some pollution to the ecological environment.

[0003] Therefore, Zn 2+ The detection of zinc ions has significant practical implications. Over the years, numerous methods for detecting zinc ions have been reported, such as ICP-AES, electrochemical techniques, and AAS. However, these methods require sample pretreatment, have cumbersome procedures, and expensive equipment. In contrast, chemical sensors are considered an effective analytical method for detecting metal ions due to their advantages of simple sample preparation, low cost, and ease of operation. Furthermore, fluorescent chemical sensors are gaining wider application due to their potential use in bioimaging.

[0004] This study developed a novel fluorescent probe based on anthraquinone and o-phenanthroline ligands, a copper(II) complex that can detect Zn. 2+ The transient response causes a significant enhancement in fluorescence. Due to its unique coordination structure, this probe exhibits higher sensitivity and stronger selectivity compared to existing zinc ion detection probes. Furthermore, the introduction of sulfonic acid groups into the probe significantly improves its water solubility, making it more suitable for detecting zinc ions in wastewater and thus possessing practical value. Summary of the Invention

[0005] The purpose of this invention is to provide a synthesis and fluorescence characterization of a copper(II) complex based on anthraquinone-2,7-disulfonic acid and 1,10-phenanthroline ligands. This invention uses anthraquinone-2,7-disulfonic acid and 1,10-phenanthroline as organic ligands to synthesize the complex with copper salt via a solvothermal method. This complex exhibits high sensitivity and strong selectivity when used as a fluorescent probe to detect zinc ions, thus solving the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] This invention provides a copper(II) complex fluorescent probe based on anthraquinone-2,7-disulfonic acid and 1,10-phenanthroline ligands, with the molecular formula C. 38 H 24 Cu2N4O 10 S2, structural formula as follows Figure 1 As shown.

[0008] Its single-crystal parameters and some bond length data are shown in the table below:

[0009]

[0010] Symmetric code: i -X, 1-Y, 2-Z

[0011] The complexes of this invention belong to the triclinic crystal system, space group P-1, and exhibit a tetranuclear structure. Both Cu1 and Cu2 are five-coordinated. Cu1 coordinates with O1 in S1 and O2 and O3 on the two hydroxyl groups. Simultaneously, Cu1 coordinates with N1 and N2 on the o-phenanthroline, while Cu2 coordinates with O on the three hydroxyl groups and N on another o-phenanthroline. The coordination is identical except for the source of one oxygen atom, and they exhibit a pyramidal configuration. There are π-π interactions between o-phenanthroline ligands and between o-phenanthroline and the anthraquinone-2,7-disulfonic acid ligand. Cu1 1 Cu2 1 It is obtained by symmetric operations on Cu1 and Cu2, and the symmetric code i is -X, 1-Y, 2-Z.

[0012] The present invention also provides a method for preparing the above-mentioned complex for detecting metal ions, comprising the following steps:

[0013] S01: Sodium anthraquinone-2,7-disulfonic acid salt was passed through an ion exchange column to obtain anthraquinone-2,7-disulfonic acid ligand;

[0014] S02: Weigh out a copper salt and dissolve it in an appropriate amount of water. Sonicate the solution until it is homogeneous to obtain solution A.

[0015] S03: Weigh 2,7-H2AQDS and dissolve it in an appropriate amount of water. Sonicate the solution until it is completely dissolved. Then weigh sodium hydroxide and add it to the solution. Continue sonicating until the sodium hydroxide is completely dissolved to obtain solution B.

[0016] S04: Weigh 1,10-o-phenanthroline and dissolve it in an appropriate amount of methanol. Dissolve it evenly by sonication to obtain solution C.

[0017] S05: Add solutions A and C to solution B in sequence, stir for 5 min, shake until homogeneous, transfer to an oven, heat at 120℃ for 48 h, after which let stand and cool to room temperature to obtain blue block crystals, wash three times with ether, and confirm the structure on an X-ray single crystal diffractometer.

[0018] Further, in step S02, the molar volume ratio of the copper salt to water is 1:1-2, and the copper salt is one or more of CuCl2, Cu(NO3)2, and Cu(ClO4)2.

[0019] Further, in step S03, the molar volume ratio of anthraquinone-2,7-disulfonic acid to water is 1:1-2, and the molar ratio of NaOH to anthraquinone-2,7-disulfonic acid in solution B is 0.5-1:1.

[0020] Further, in step S04, the molar volume ratio of 1,10-o-phenanthroline to methanol is 1:0.5-1.

[0021] Further, in step S05, the molar ratio of copper salt, NaOH, and anthraquinone-2,7-disulfonic acid in solutions A, B, and C is 1-2:0.5-1:1; the molar ratio of 1,10-o-phenanthroline to anthraquinone-2,7-disulfonic acid is 1-2:1.

[0022] The present invention also provides the application of a copper(II) complex fluorescent probe based on anthraquinone-2,7-disulfonic acid and 1,10-phenanthroline ligand as described above in the determination of the optical properties of zinc ions.

[0023] Further, the application includes the following steps: adding the copper(II) complex fluorescent probe based on anthraquinone-2,7-disulfonic acid and 1,10-o-phenanthroline ligand to water to prepare a fluorescent probe solution; then preparing a metal ion test solution; adding the fluorescent probe solution to a four-way cuvette, then adding the metal ion test solution and distilled water, and placing it in a fluorescence instrument for measurement.

[0024] Furthermore, in the four-way cuvette, the concentration ratio of the fluorescent probe solution to the metal ion test solution is 2:1.

[0025] Furthermore, in the four-way cuvette, the volume ratio of the fluorescent probe solution, the metal ion test solution, and the distilled water is 2:1:40.

[0026] Further, the preparation steps of the metal ion test solution include: adding one or more metal ions such as ZnCl2, Pb(NO3)2, AgNO3, Cd(NO3)2, Fe(NO3)3, FeCl3, Cr(NO3)2, Ba(oAC)2, Ni(oAC)2, CuCl2, CaCl2, MnCl2, NaHCO3, NaI, NaNO3, CH3COONa, Na2SO4, NaCl, K2HPO3, K3PO4, KBr, KF, K2C2O4, KCl, and K2Cr2O7 to distilled water to obtain the metal ion test solution.

[0027] Compared with the prior art, the beneficial effects of the present invention are:

[0028] A large number of target probes can be obtained through simple solvothermal methods. The preparation method is simple and convenient, and the raw materials are inexpensive. The introduction of sulfonic acid groups into the structure can enhance water solubility and has advantages in testing pollutants in water samples. In terms of performance, due to the unique coordination structure of the complex and the excellent fluorescence properties of the anthraquinone ligand and o-phenanthroline ligand, it can detect extremely low concentrations of zinc ions. Attached Figure Description

[0029] Figure 1 This is a crystal structure diagram of the coordination compound in this invention;

[0030] Figure 2 The XRD powder diffraction pattern of the complex in this invention;

[0031] Figure 3 The UV-Vis spectrum of the complex in this invention;

[0032] Figure 4 The complex in this invention (1×10 -5 Fluorescence intensity graphs of H2O solutions with different metal ions added (mol / L);

[0033] Figure 5 The complex in this invention (1×10 -5 A bar chart showing the fluorescence intensity at the emission peak of 360 nm when different metal ions are added to an H2O solution (mol / L).

[0034] Figure 6 The complex in this invention is a Zn 2+ Fluorescence selectivity specificity;

[0035] Figure 7 The complex in this invention is a Zn 2+ Linear variation fitting plot of fluorescence intensity (50–450 nM). Detailed Implementation

[0036] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0037] Example 1

[0038] The method for preparing the probe for detecting metal ions according to the present invention includes the following steps:

[0039] S01: The purchased sodium anthraquinone-2,7-disulfonic acid salt (Aladdin 50g) was passed through an ion exchange column to obtain anthraquinone-2,7-disulfonic acid ligands with a yield of 95%.

[0040] S02: Weigh 1 mmol of copper nitrate and dissolve it in 2 ml of water. Sonicate the solution until homogeneous to obtain solution A.

[0041] S03: Weigh 1 mmol of anthraquinone-2,7-disulfonic acid and dissolve it in 2 ml of water. Sonicate the solution until it is completely dissolved. Then weigh 0.5 mmol of sodium hydroxide and add it to the solution. Continue sonicating until the sodium hydroxide is completely dissolved to obtain solution B.

[0042] S04: Weigh 1 mmol of 1,10-o-phenanthroline and dissolve it in 1 ml of methanol. Sonicate the solution until homogeneous to obtain solution C.

[0043] S05: Add solutions A and C sequentially to solution B, stir for 5 minutes, shake until homogeneous, transfer to an oven, heat at 120℃ for 48 hours, and after completion, allow to cool to room temperature to obtain blue blocky crystals. Wash three times with diethyl ether, and confirm the structure using an X-ray single-crystal diffractometer. Yield: 57%. Figure 1 As shown.

[0044] The coordination mode of this complex is as follows: Figure 1 As shown, it belongs to the triclinic crystal system, space group P-1, and exhibits a tetranuclear structure. Both Cu1 and Cu2 are five-coordinated. Cu1 coordinates with O1 in S1 and O2 and O3 on the two hydroxyl groups. At the same time, Cu1 coordinates with N1 and N2 on the o-phenanthroline, while Cu2 coordinates with O on the three hydroxyl groups and N on the other o-phenanthroline. The coordination of the two is consistent except for the source of one oxygen, and they exhibit a pyramidal configuration. There are π-π interactions between o-phenanthroline and between o-phenanthroline and anthraquinone-2,7-disulfonic acid. Cu1 1 Cu2 1 It is obtained by symmetric operations on Cu1 and Cu2, and the symmetric code i is -X, 1-Y, 2-Z.

[0045] Its single-crystal parameters and some bond length data are shown in the table below:

[0046]

[0047] The symmetric code i is -X, 1-Y, 2-Z.

[0048] Example 2

[0049] S01: The purchased sodium anthraquinone-2,7-disulfonic acid salt (Aladdin 50g) was passed through an ion exchange column to obtain anthraquinone-2,7-disulfonic acid ligands with a yield of 95%.

[0050] S02: Weigh 1 mmol of copper chloride and dissolve it in 2 ml of water. Sonicate the solution until homogeneous to obtain solution A.

[0051] S03: Weigh 1 mmol of anthraquinone-2,7-disulfonic acid and dissolve it in 2 ml of water. Sonicate the solution until it is completely dissolved to obtain solution B. Weigh 1 mol of sodium hydroxide and add it to the solution. Continue sonicating until the sodium hydroxide is completely dissolved to obtain solution B.

[0052] S04: Weigh 1 mmol of 1,10-o-phenanthroline and dissolve it in 0.5 ml of methanol. Sonicate until homogeneous to obtain solution C.

[0053] S05: Add solutions A and C sequentially to solution B, stir for 5 minutes, shake until homogeneous, transfer to an oven, heat at 120℃ for 48 hours, and after completion, allow to cool to room temperature to obtain blue blocky crystals. Wash three times with diethyl ether, and confirm the structure using an X-ray single-crystal diffractometer. Yield: 87%. Figure 1 As shown; simultaneously, powder diffraction of the complex was tested, revealing high crystallinity and phase purity, such as... Figure 2 As shown.

[0054] The yield was significantly improved by increasing the amount of sodium hydroxide used. The preferred molar ratio of NaOH to anthraquinone-2,7-disulfonic acid was 1:1.

[0055] Example 3

[0056] Application of the complex prepared in Example 1 as a fluorescent probe in determining the optical properties of zinc ions.

[0057] The specific steps are as follows: Add 4.8 mg of the fluorescent probe to 10 mL of water to prepare a fluorescent probe solution with a molar concentration of 1 mmol / L. Then, transfer 15 μL of the previously prepared fluorescent probe solution and dilute to 100 mL to obtain the desired molar concentration of 1 × 10⁻⁶. -5 Prepare fluorescent probe solution D with a molar concentration of 1×10⁻⁶ mol / L; then prepare a further solution with a molar concentration of 1×10⁻⁶ mol / L. -5The following metal ion test solutions were prepared at mol / L: ZnCl2, Pb(NO3)2, AgNO3, Cd(NO3)2, Fe(NO3)3, FeCl3, Cr(NO3)2, Ba(oAC)2, Ni(oAC)2, CuCl2, CaCl2, MnCl2, NaHCO3, NaI, NaNO3, CH3COONa, Na2SO4, NaCl, K2HPO3, K3PO4, KBr, KF, K2C2O4, KCl, and K2Cr2O7. 100 μL of each solution was weighed and added to a four-way cuvette. Then, 50 μL of the metal ion test solution was added, followed by 2 mL of distilled water. The solution was then placed in a fluorescence spectrometer for measurement. In this embodiment, different metal ions were added to the fluorescent probe D solution: ZnCl2, Pb(NO3)2, AgNO3, Cd(NO3)2, Fe(NO3)3, FeCl3, Cr(NO3)2, Ba(oAC)2, Ni(oAC)2, CuCl2, CaCl2, MnCl2, NaHCO3, NaI, NaNO3, CH3COONa, Na2SO4, NaCl, K2HPO3, K3PO4, KBr, KF, K2C2O4, KCl, and K2Cr2O7. The fluorescence intensity diagram of the test solution is shown below. Figure 4 and Figure 5 As shown, instrumental measurements revealed that zinc ions have a strong fluorescence enhancement effect on this complex.

[0058] Under 250nm excitation light, the fluorescence intensity at 360nm of different metal analytes is as follows: Figure 4 As shown, under 250 nm excitation, the peak value of the obtained emission spectrum is around 360 nm. With the addition of zinc ion test solution, the fluorescence intensity increases sharply, while the addition of other metal ion test solutions does not show significant changes. Figure 5 yes Figure 4 A bar chart of fluorescence intensity at the 360nm emission peak is more conducive to the detection of zinc ions. To further investigate the selective response of this probe to zinc ions, different metal ions were added to the system, and their fluorescence changes were detected. After adding 50 μL of other interfering metal ions (the aforementioned metal ion test solutions): iron, sodium, potassium, nickel, silver, chromium, manganese, cadmium, copper, barium, lead, and calcium ions, followed by 50 μL of zinc ion solution, the fluorescence intensity change at 360nm was not affected by the other interfering substances, thus achieving specific recognition of zinc ions; the fluorescence selectivity specificity of this complex for zinc ions is as follows: Figure 6 As shown, even in the presence of common metal cation interference, the complex still exhibits specific recognition of zinc ions, enabling it to be applied to various interferences in real-world environments to achieve detection objectives.

[0059] Example 4

[0060] Add 4.8 mg of the fluorescent probe prepared in Example 1 to 10 mL of water to prepare a fluorescent probe solution with a molar concentration of 1 mmol / L. Then, transfer 15 μL of the previously prepared fluorescent probe solution and dilute to 100 mL to obtain the desired molar concentration of 1 × 10⁻⁶. -5 Prepare a fluorescent probe solution D with a molar concentration of 1×10⁻⁶ mol / L. -5 A mol / L ZnCl2 aqueous solution was prepared. 100 μL of the solution was weighed and added to a four-way cuvette, followed by 10–90 μL of ZnCl2 solution and 2 mL of distilled water. The solution was then placed in a fluorescence spectrometer for measurement. The linear change in fluorescence intensity from 50 to 450 nM zinc ion concentration is shown in the graph below. Figure 7 As shown, a linear relationship was found between the fluorescence enhancement effect of zinc ions on the complex. Therefore, by plotting a standard curve, the zinc ion content can be detected, and the detection limit can be calculated to be 0.18 nM.

[0061] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0062] It should be noted that the above content merely illustrates the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. For those skilled in the art, various improvements and modifications can be made without departing from the principle of the present invention, and all such improvements and modifications fall within the scope of protection of the claims of the present invention.

Claims

1. A copper(II) complex fluorescent probe based on anthraquinone-2,7-disulfonic acid and 1,10-phenanthroline ligand, characterized in that, Its single-crystal parameters and some bond length data are shown in the table below: ； Symmetric code: i -X, 1-Y, 2-Z.

2. The method for preparing a copper(II) complex fluorescent probe based on anthraquinone-2,7-disulfonic acid and 1,10-phenanthroline ligand as described in claim 1, characterized in that, Includes the following steps: S01: Sodium anthraquinone-2,7-disulfonic acid salt was passed through an ion exchange column to obtain anthraquinone-2,7-disulfonic acid ligand; SO2: Metallic copper salt is dissolved in water and ultrasonically dissolved to obtain solution A; S03: Anthraquinone-2,7-disulfonic acid ligand is dissolved in water and sonicated until it is uniformly dissolved. Sodium hydroxide is added to it and sonication is continued until the sodium hydroxide is completely dissolved to obtain solution B. SO4: 1,10-o-phenanthroline was dissolved in methanol and sonicated until homogeneous to obtain solution C; S05: Add solutions A and C sequentially to solution B, stir for 5 min, shake until homogeneous, transfer to an oven, heat at 120℃ for 48 h, allow to cool to room temperature, and obtain blue blocky crystals. Wash three times with diethyl ether to obtain copper(II) complex fluorescent probe C. 38 H 24 Cu2N4O 10 S2.

3. The method for preparing a copper(II) complex fluorescent probe based on anthraquinone-2,7-disulfonic acid and 1,10-phenanthroline ligand according to claim 1, characterized in that, In step S02, the molar volume ratio of the copper salt to water is 1:1-2, and the copper salt is one or more of CuCl2, Cu(NO3)2, and Cu(ClO4)2.

4. The method for preparing a copper(II) complex fluorescent probe based on anthraquinone-2,7-disulfonic acid and 1,10-phenanthroline ligand according to claim 1, characterized in that, In step S03, the molar volume ratio of the anthraquinone-2,7-disulfonic acid ligand to water is 1:1-2, and the molar ratio of NaOH to the anthraquinone-2,7-disulfonic acid ligand is 0.5-1:

1.

5. The method for preparing a copper(II) complex fluorescent probe based on anthraquinone-2,7-disulfonic acid and 1,10-phenanthroline ligand according to claim 1, characterized in that, In step S04, the molar volume ratio of 1,10-o-phenanthroline to methanol is 1:0.5-1.

6. The method for preparing a copper(II) complex fluorescent probe based on anthraquinone-2,7-disulfonic acid and 1,10-phenanthroline ligand according to claim 1, characterized in that, In step S05, in solutions A, B, and C, the molar ratio of 1,10-phenanthroline to anthraquinone-2,7-disulfonic acid ligand is 1-2:1, and the molar ratio of copper salt, NaOH, and anthraquinone-2,7-disulfonic acid ligand is 1-2:0.5-1:

1.

7. The application of the copper(II) complex fluorescent probe based on anthraquinone-2,7-disulfonic acid and 1,10-phenanthroline ligand as described in claim 1 in the determination of the optical properties of zinc ions.

8. The application according to claim 7, characterized in that, Includes the following steps: The copper(II) complex fluorescent probe was added to water to prepare a fluorescent probe solution; then a metal ion test solution was prepared. Add the fluorescent probe solution to a four-way cuvette, then add the metal ion test solution and distilled water, and place it in a fluorescence analyzer for measurement.

9. The application according to claim 8, characterized in that, The concentration ratio of the fluorescent probe solution to the metal ion test solution in the four-way cuvette is 2:1; the volume ratio of the fluorescent probe solution, the metal ion test solution, and distilled water is 2:1:

40.

10. The application according to claim 8, characterized in that, The preparation steps of the metal ion test solution include: adding one or more metal ions such as ZnCl2, Pb(NO3)2, AgNO3, Cd(NO3)2, Fe(NO3)3, FeCl3, Cr(NO3)2, Ba(oAC)2, Ni(oAC)2, CuCl2, CaCl2, MnCl2, NaHCO3, NaI, NaNO3, CH3COONa, Na2SO4, NaCl, K2HPO3, K3PO4, KBr, KF, K2C2O4, KCl, and K2Cr2O7 to distilled water to obtain the metal ion test solution.

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