Anthracene-based complex and its preparation method and application

Abstract

The present invention relates to the technical field of organic photoelectric materials, and in particular to an anthracene-based complex [Au(anbdtim)2][Au(CN)2], a preparation method and application thereof. The molecular structure of the complex is shown below: #imgabs0# wherein [Au(CN)2] ‑ Anion and [Au(anbdtim)2] + The cations have the interaction between Au(I) and can form a specific supramolecular structure. They have molecular recognition effect on aromatic organic solvents and show conversion behavior of fluorescence emission. Therefore, they can be used to identify and detect aromatic organic solvents such as benzene, toluene, etc., or made into anti-counterfeiting materials.

Description

[0001] The present invention relates to the technical field of organic photoelectric materials, and in particular to an anthracene-based complex [Au(anbdtim)2][Au(CN)2], a preparation method and application thereof. The complex can form a specific supramolecular structure, and thus has a molecular recognition effect on aromatic organic solvents and exhibits a conversion behavior of fluorescence emission, and can be used to identify and detect aromatic organic solvents such as benzene, toluene, etc., or be made into anti-counterfeiting materials. Background Art

[0002] Benzene, toluene, ethylbenzene and xylene are representative benzene series (BTEX), which are colorless and transparent solutions with toxic and pungent odors. As important chemical solvents and raw materials, they have broad application prospects in medicine, pesticides, synthetic materials, etc.

[0003] It is worth noting that these benzene series have neurotoxicity and genotoxicity. Long-term exposure can cause anemia and leukemia in the human body, and with the increase of contact concentration, the risk of leukemia in the human body increases significantly. Since chemical wastewater is difficult to treat, benzene, toluene, xylene and other benzene series discharged into wastewater are great potential hazards to humans. At present, the impact of these benzene series on water resources and human health has attracted widespread attention from the society. Therefore, it is of great significance to detect the wastewater discharged by chemical enterprises producing or using benzene series. At present, the existing detection methods include gas chromatography, gas chromatography-mass spectrometry, and headspace solid phase microextraction. However, this type of method requires expensive equipment and maintenance costs, and the operation is cumbersome and requires special personnel to operate, which limits its application to a certain extent. Therefore, it is of great significance to develop a low-cost and easy-to-operate detection method to detect benzene series.

[0004] In addition, the field of anti-counterfeiting materials also requires a variety of simple and practical materials and detection methods to quickly identify whether the product is genuine and original.

[0005] There are patents related to the detection of aromatic organic compounds in the prior art, such as patent CN 108445155 A, which reports a test paper made of a polymer biphasic self-assembly material. After the polyamide in the test paper is complexed with benzene, the test paper is twisted and deformed, thereby realizing the detection of benzene and its derivatives. However, the distortion of this test paper is easily affected by external factors (such as wind, light, etc.). Patent CN 107915655 A reports an organic compound, which will only transform the system from a solution to an organic gel when it encounters a benzene series, realizing the detection of compounds such as benzene and toluene. However, the disclosed method also has certain disadvantages. Concentration and temperature are important factors affecting the formation of colloids, so the detection method has certain limitations.

[0006] Patent CN 111205856 discloses a fluorescent material for detecting benzene compounds. Two molecules are assembled through π···π interaction to obtain a fluorescent material, which interacts with volatile organic benzene compounds and exhibits a significant fluorescence enhancement phenomenon.

[0007] In addition, anthracene-based monovalent gold complexes have been reported in the literature (Q.-S. Li, C.-Q. Wan, R.-Y. Zou, F.-B. Xu, H.-B. Song, X.-J. Wan, Z.-Z. Zhang, Inorg. Chem. 2006, 45, 1888-1890; H. Zhuo, X. Chi, M. Jiang, H. Xu, M. Zeng, Chem. Asian J. 2021, 16, 1165-1170; PLAng, VH Nguyen, JHK Yip, Dalton Trans. 2021, 50, 11422-11428.), showing tunable luminescence behavior. However, both the structure and the luminescence behavior are very different from the present invention.

[0008] The present invention synthesizes a gold complex [Au(anbdtim)2][Au(CN)2] for the first time, which has not been reported in the literature. Studies have shown that the interaction between the cations and cations in the compound of the present invention and Au(I) can form a specific supramolecular structure, which has a molecular recognition effect on aromatic organic solvents and exhibits a conversion behavior of fluorescence emission, so it can be used to identify and detect aromatic organic solvents such as benzene, toluene, etc., or made into anti-counterfeiting materials.

[0009] Compared with the prior art of using fluorescent materials to detect benzene compounds, the present invention utilizes the dual changes in the wavelength and intensity of the fluorescent material, and the detection results are easier to observe and more accurate. Summary of the invention

[0010] One of the purposes of the present invention is to provide an anthracene-based complex [Au(anbdtim)2][Au(CN)2], which has a molecular recognition effect on aromatic organic solvents and exhibits fluorescence emission conversion behavior.

[0011] Another object of the present invention is to provide a method for preparing the anthracene-based complex [Au(anbdtim)2][Au(CN)2].

[0012] Another object of the present invention is to provide an application of the anthracene-based complex in identifying and detecting aromatic organic solvents.

[0013] To achieve the above purpose, the present invention synthesized an anthracene-based complex [Au(anbdtim)2][Au(CN)2] for the first time, and the molecular structure is shown below:

[0014]

[0015] The coordination compound comprises two anthracene-imidazole dithiophene vinyl ligands anbdtim; the central metal ion of the complex is a monovalent gold ion; the two ligands anbdtim coordinate with the gold ion through the imidazole nitrogen atom, and the gold ion exhibits a linear coordination configuration; and [Au(CN)2]- is used as a counter anion in the complex.

[0016] The [Au(CN)2]- anion and the [Au(anbdtim)2]+ cation have an Au(I) interaction to form a specific supramolecular structure. Aromatic solvent molecules, such as benzene molecules, can be embedded in the structure through aromatic stacking. Under heating conditions, the aromatic solvent molecules can be separated from the structure. Under the conditions of alternate embedding and losing aromatic solvent molecules, the complex [Au(anbdtim)2][Au(CN)2] exhibits a reversible change in fluorescence between blue-green and steel blue (see the figure in the specification). Figure 4 ).

[0017] That is, when the aromatic organic solvent molecules are embedded in or separated from the supramolecular structure, the anthracene-based complex exhibits a conversion of fluorescence emission, which means that the compound has a molecular recognition effect on the aromatic organic solvent.

[0018] The preparation method of the anthracene-based complex [Au(anbdtim)2][Au(CN)2] mainly includes the following steps: (1) preparing [Au(SMe2)Cl] and anthracene-imidazole dithiophene vinyl ligand anbdtim respectively; (2) reacting [Au(SMe2)Cl] and ligand anbdtim to obtain the complex [Au(anbdtim)2]PF6; (3) converting [Au(anbdtim)2]PF6 into [Au(anbdtim)2][Au(CN)2] by ion exchange reaction. Specifically, it includes the following processes:

[0019] Preparation of [Au(SMe2)Cl] and anthracene-imidazole dithiophene vinyl ligand anbdtim:

[0020] The gold compound [Au(SMe2)Cl] can be synthesized according to the literature [Z.Tian, ​​X.Yang, B.Liu, J.Zhao, D.Zhong, Y.Wu, G.Zhou W.-Y.Wong, J.Mater.Chem.C 2018, 6, 6023-6032.].

[0021] The ligand anbdtim is prepared from anbdtiH, that is, according to the following steps:

[0022]

[0023] AnbdtiH, a potassium or sodium base or carbonate (such as K2CO3, Na2CO3, KOH or NaOH) and DMF are mixed, a DMF solution of CH3I is added thereto to react for a period of time, an excess of water is added to obtain a precipitate, the precipitate is washed with water and ether, and dried in air to obtain anthracene-imidazole dithiophene vinyl ligand anbdtim. The molar ratio of anbdtiH to the potassium or sodium base or carbonate is 1:3-5; the molar ratio of anbdtiH to CH3I is 1:1-2, and the amount of DMF is not particularly limited, and a sufficient amount is sufficient. The reaction temperature is controlled at 30-50oC, the reaction time is 15-24 hours, and the reaction process is monitored by thin layer chromatography.

[0024] The raw material anbdtiH can be synthesized according to the literature [J.-F.Chen, D.-P.Gong, J.Wen, H.Ma, D.-K.Cao, Chem.Sci.2016,7,451-456].

[0025] (2) Preparation of the complex [Au(anbdtim)2]PF6: [Au(SMe2)Cl], AgPF6 and anthracene ligand anbdtim were mixed in a molar ratio of 1:1-2:2-3, and an appropriate amount of CH3CN was added as a reaction solvent. The mixture was reacted at 70-90oC for 20-30 hours. After the reaction was completed, the precipitate was removed, the solution was evaporated to dryness under reduced pressure, and the residue was washed with ethyl acetate to obtain the [Au(anbdtim)2]PF6 complex.

[0026] (3) Preparation of the complex [Au(anbdtim)2][Au(CN)2]: [Au(anbdtim)2]PF6 is reacted with KAu(CN)2 or NaAu(CN)2 in a mixture of dichloromethane and water (volume ratio of 1:0.5-1.5) for 3-6 hours. The organic layer is separated and the solution is evaporated to dryness under reduced pressure to separate dichloromethane, and the resulting residue is [Au(anbdtim)2][Au(CN)2].

[0027] By utilizing the molecular recognition effect and reversible fluorescence conversion behavior of the supramolecular structure formed by the anthracene-based complex of the present invention on aromatic organic solvents, aromatic organic solvents can be identified and detected, and anti-counterfeiting materials can also be developed.

[0028] Specifically, when an aromatic organic solvent encounters the anthracene complex of the present invention, it will be embedded in the supramolecular structure formed by the anthracene complex through aromatic stacking, and the anthracene complex will change from the original steel blue to blue-green; and under heating conditions, the aromatic organic solvent will evaporate again, so that the anthracene complex [Au(anbdtim)2][Au(CN)2] will restore the original steel blue fluorescence. Therefore, the reversible luminescence conversion behavior of the complex of the present invention can be used to identify and detect aromatic organic solvents, such as benzene, toluene, etc. This reversible fluorescence conversion behavior can also be used bidirectionally to develop anti-counterfeiting materials.

[0029] The anthracene-based complex of the present invention is a solid powder, which has the above-mentioned molecular recognition effect on aromatic organic solvents and exhibits reversible fluorescence conversion behavior on aromatic organic solvents. Therefore, it can be used directly or after being formed in the application scenarios of related identification and detection of aromatic organic solvents or anti-counterfeiting materials.

[0030] Since the anthracene-based complex is easy to form a film, for ease of operation, in specific implementation, a film of the compound can be prepared on various carriers used, such as a glass slide: the benzene solution of [Au(anbdtim)2][Au(CN)2] is evaporated to dryness on a glass slide (the benzene in the free state has evaporated at this time, but the benzene embedded in the supramolecular structure still exists), and a film emitting blue-green fluorescence is obtained. The film is heated at 100°C for 5 minutes, and the benzene in the supramolecular structure also evaporates away, and a film emitting steel blue fluorescence is obtained. The film can restore the original blue-green fluorescence when it contacts the benzene solvent again. This reversible luminescence conversion property can be used to identify or detect aromatic organic solvents. The complex can also be made into anti-counterfeiting materials or other materials or scenes that can utilize this reversible luminescence conversion property.

[0031] Beneficial effects of the present invention:

[0032] The gold complex [Au(anbdtim)2][Au(CN)2] of the present invention is simple to synthesize and has a relatively high yield. The compound changes color obviously, and the change of luminescent color can be judged by naked eyes. Compared with the method of detecting benzene compounds using fluorescent materials in the prior art, the present invention utilizes the dual changes of luminescent wavelength and intensity of fluorescent materials, so that the detection result is easier to observe and the result is more accurate. In addition, the compound is easy to form a film, and is convenient to be made into a device for practical use. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The present invention is further described with reference to the accompanying drawings, but the embodiments in the accompanying drawings do not constitute any limitation to the present invention.

[0034] Figure 1H NMR spectrum (400 MHz, CDCl3) of compound [Au(anbdtim)2][Au(CN)2], δ(ppm): 2.10, 2.43, 2.46 (4 singlets, 24H from eight methyl groups on four thiophene rings), 3.16 (singlet, 6H from methyl groups on two imidazole rings), 6.65, 6.94 (2 singlets, 4H from four thiophenes), 7.39 (broad peak, 4H), 7.62 (multiplet, 8H), 8.15 (doublet, 4H, J=8.0Hz), 8.75 (s, 2H) [7.39-8.75, a total of 18 H groups are from two anthracene groups];

[0035] Figure 2 High-resolution electrospray of compound [Au(anbdtim)2][Au(CN)2] in CH2Cl2-CH3OH solution, upper figure: [Au(anbdtim)]+, lower figure: [Au(CN)2]-;

[0036] Figure 3 Molecular structure of the compound [Au(anbdtim)2]PF6 (crystal structure determination). Since the compound [Au(anbdtim)2]PF6 has the same coordinated cation as [Au(anbdtim)2][Au(CN)2], the cation in the compound [Au(anbdtim)2][Au(CN)2] has a clear structure.

[0037] Figure 4 Under the conditions of alternately inserting and losing aromatic solvent molecules, the complex [Au(anbdtim)2][Au(CN)2] exhibits a reversible fluorescence transition between blue-green and steel-blue. DETAILED DESCRIPTION

[0038] The present invention is further described in conjunction with the following examples.

[0039] Example:

[0040] Preparation of anthracene-imidazole dithiophene vinyl ligand anbdtim: First, prepare [Au(SMe2)Cl] and anbdtiH according to the literature method to obtain the raw materials for the following reaction.

[0041] AnbdtiH (0.5mmol, 0.2323g), K2CO3 (2mmol, 0.2760g), DMF (10mL) and CH3I (0.5mmol, 32μL) were added to the single-necked flask, and the mixture was reacted at room temperature for 20 hours. After the reaction, 100mL of deionized water was added to the reaction system to generate a yellow precipitate, which was filtered, washed with water, and vacuum dried to obtain 214mg of a yellow product with a yield of 89% (based on anbdtiH).

[0042] Preparation of the complex [Au(anbdtim)2]PF6: Under argon protection, a mixture of [Au(SMe2)Cl] (0.1mmol, 0.0294g), CH3CN (20mL), AgPF6 (0.12mmol, 0.0304g) and anbdtim (0.2mmol, 0.0956g) was reacted at 80°C for 24 hours. After the reaction, the AgCl precipitate was first filtered out, and the filtrate was decompressed and dried to obtain a white crude product, which was then washed three times with ethyl acetate (10mL×3) to obtain 95.0mg of a white product with a yield of 73.1% (based on [Au(SMe2)Cl]).

[0043] Preparation of the complex [Au(anbdtim)2][Au(CN)2]: The obtained compound [Au(anbdtim)2]PF6 (0.015mmol, 0.0200g) was dissolved in dichloromethane (4mL), and then an aqueous solution (4mL) of KAu(CN)2 (0.046mmol, 0.0133g) was added, and the mixture was stirred at about 5oC for 4 hours. After the reaction was completed, the organic layer was separated and the solvent was dried under reduced pressure to obtain 20mg of a green product with a yield of 97% (based on the compound [Au(anbdtim)2]PF6).

[0044] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. An anthracene complex [Au(anbdtim)2][Au(CN)2], the molecular structure of which is shown below: The coordination compound comprises two anthracene-imidazole dithiophene vinyl ligands anbdtim; the central metal ion of the complex is a monovalent gold ion; the two ligands anbdtim coordinate with the gold ion through the imidazole nitrogen atom, and the gold ion exhibits a linear coordination configuration; the complex contains [Au(CN)2] - as a counter anion.

2. The method for preparing anthracene gold complex according to claim 1 comprises the following steps: (1) synthesizing a gold compound [Au(SMe2)Cl] and anthracene-imidazole dithiophene vinyl ligand anbdtim respectively; (2) reacting [Au(SMe2)Cl] and the ligand anbdtim to obtain a complex [Au(anbdtim)2]PF6; (3) converting [Au(anbdtim)2]PF6 into [Au(anbdtim)2][Au(CN)2] by an ion exchange reaction.

3. The preparation method according to claim 2, wherein in step (1), the anthracene-imidazole dithiophene vinyl ligand anbdtim is prepared by reacting anbdtiH, a base of potassium or sodium with CH3I.

4. The preparation method according to claim 2, wherein in step (1), the anthracene-imidazole dithiophene vinyl ligand anbdtim is prepared by reacting anbdtiH, potassium or sodium carbonate with CH3I.

5. The preparation method according to claim 2, wherein in step (2), the [Au(anbdtim)2]PF6 complex is prepared by reacting [Au(SMe2)Cl], AgPF6 and anthracene ligand anbdtim.

6. The preparation method according to claim 2, wherein the complex [Au(anbdtim)2][Au(CN)2] in (3) is prepared by an ion exchange reaction between [Au(anbdtim)2]PF6 and KAu(CN)2 or NaAu(CN)2.

7. Use of the anthracene-based complex according to claim 1 in identifying and detecting aromatic organic solvents such as benzene or toluene and in anti-counterfeiting materials.

8. The use of the anthracene-based complex according to claim 7, characterized in that When the aromatic organic solvents benzene or toluene encounter the anthracene complex, they will be embedded in the supramolecular structure formed by the anthracene complex through aromatic stacking, and the anthracene complex will change from its original steel blue to blue-green; and under heating conditions, the aromatic organic solvents benzene or toluene will evaporate again and leave the supramolecular structure, so that the anthracene complex [Au(anbdtim)2][Au(CN)2] will restore its original steel blue fluorescence.

9. The use of the anthracene-based complex according to claim 7, wherein an aromatic solution of [Au(anbdtim)2][Au(CN)2] is first coated on a carrier and evaporated to dryness to obtain a film emitting blue-green fluorescence. The film is heated, and the aromatic solvent molecules leave the supramolecular structure of the anthracene-based complex to obtain a film emitting steel blue fluorescence. The film can recover its original blue-green fluorescence when it contacts the aromatic solvent again.

10. The use of the anthracene-based complex according to claim 9, characterized in that The aromatic base solution is a benzene solution.

Images