Synthetic method and photocatalytic application of azulene-based organic metal ring

Abstract

The invention discloses a synthesis method of an azulene-based organic metal ring, which belongs to the technical field of catalyst synthesis and is characterized in that a binuclear compound 1 and an azulene-based organic ligand 2 are used as raw materials to synthesize an azulene-based organic metal ring 3 through a one-pot method. The cyclic metal compound with photocatalytic activity is synthesized by taking an azulene organic ligand as an initial raw material through coordination site regulation and control. Compared with reported azulene-based organic metal rings, the azulene-based organic metal rings synthesized by the method have the obvious advantages of mild reaction conditions, short reaction time, high yield, simplicity in operation, high photocatalytic efficiency and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of catalyst synthesis, and in particular to a synthesis method and photocatalytic application of an azulene-based organometallic ring. Background Art

[0002] In 1987, Nobel Prize winner in Chemistry Lehn first proposed the concept of supramolecular chemistry. Since then, the field of supramolecular chemistry has developed rapidly, with structures ranging from simple to complex, organized, specific and functional. Since metals and ligands can spontaneously form coordination bonds with a bond energy of about 15-25 kcal / mol, and the coordination structure is predictable, coordination-induced self-assembly is an effective way to construct supramolecular coordination compounds. The complexes with a half-sandwich structure have certain novelty in structure, which is mainly due to the introduction of cyclopentadiene groups, which give them many advantages: directional bonding, improved solubility, and increased coordination sites. Therefore, rational design strategies and coordination site regulation are very important for constructing azulenyl organometallic rings.

[0003] Photocatalysis has the advantages of clean, mild, efficient reaction conditions and sustainable use of solar energy, so it has attracted widespread attention in the field of synthetic chemistry. Based on the light absorption ability of photocatalysts and the influence of electron transfer on catalytic efficiency, researchers have designed a variety of photocatalytic materials, including: organometallic complexes, organic dyes and inorganic semiconductors. However, so far, there are few reports on efficient photocatalytic reactions through organometallic rings, so it is of great significance to realize photocatalytic reactions through azulenyl organometallic rings. Summary of the invention

[0004] The object of the present invention is to provide a method for synthesizing an azulenyl organic metal ring with photocatalytic activity by regulating coordination sites.

[0005] The purpose of the present invention can be achieved through the following technical solutions: A method for synthesizing an azulenyl organometallic ring, using a binuclear compound 1 and an azulenyl organic ligand 2 as raw materials, and synthesizing an azulenyl organometallic ring 3 by a "one-pot method", the reaction equation is as follows: The specific steps are as follows: Under anhydrous and oxygen-free conditions, dichloro(pentamethylcyclopentadienyl)rhodium(III) dimer was added to a methanol solution, followed by the addition of AgOTf (silver trifluoromethanesulfonate), and the mixture was stirred at room temperature for 12 h in the dark. After the reaction, the mixture was centrifuged, and the supernatant solution (binuclear compound 1 was obtained in this process) was taken. Benzoquinone and 80 mmol / L methanol solution containing NaOH were added, and the mixture was stirred at room temperature for 12 h in the dark. The azulene organic ligand 2 was dissolved in DMA (dimethylacetamide) and added to the above reaction solution. The mixture was stirred at room temperature for 24 h in the dark. After the reaction, the mixture was centrifuged, and the supernatant solution was taken. The product, i.e., single crystal of azulene organic metal ring 3, was obtained by diffusion method.

[0006] Furthermore, the azulenyl organic ligand 2 is any one of the following structural formulas: .

[0007] Furthermore, the molar ratio of the dichloro(pentamethylcyclopentadienyl)rhodium(III) dimer to AgOTf is 1:2-1:10, preferably 1:6.

[0008] Furthermore, the molar ratio of the binuclear compound 1 to the azulene organic ligand 2 is 1:1 to 1:2, preferably 1:1.

[0009] Another object of the present invention is to provide an application of the azulenyl organometallic ring synthesized by the above method in a photocatalytic reaction, specifically, an application as a catalyst in a photocatalytic anisole reaction.

[0010] Beneficial effects of the present invention: Compared with those reported previously, the organic metal ring synthesized by the present invention has obvious advantages: mild reaction conditions, short reaction time, high yield, simple operation, high photocatalytic efficiency and the like. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The present invention will be further described below in conjunction with the accompanying drawings.

[0012] Figure 1 Figure 3 is the single crystal structure of the azulenyl organometallic ring 3a.

[0013] Figure 2 Figure 3 is the single crystal structure of the azulenyl organometallic ring 3b.

[0014] Figure 3 Figure 3 is the single crystal structure of the azulenyl organometallic ring 3c.

[0015] Figure 4 This is the H NMR spectrum of the azulenyl organometallic ring 3a.

[0016] Figure 5The ultraviolet absorption spectra of the azulenyl organic ligand 2a and the azulenyl organometallic ring 3a. DETAILED DESCRIPTION

[0017] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0018] Example 1: Preparation of azulenyl organometallic ring 3a Under anhydrous and oxygen-free conditions, dichloro(pentamethylcyclopentadienyl)rhodium(III) dimer (0.01 mmol) was added to 1 mL of methanol solution, followed by 0.04 mmol of AgOTf, and stirred at room temperature for 12 h in the dark. After the reaction was completed, centrifuged, the supernatant solution was taken, and 0.01 mmol of benzoquinone and 80 mmol / L methanol solution containing NaOH were added, and stirring was continued at room temperature in the dark for 12 h. 0.01 mmol of azulenyl organic ligand 2a was dissolved in 0.5 mL of DMA solution and added to the above mixed solution, and stirred at room temperature for 24 h in the dark. After the reaction was completed, centrifuged, the supernatant solution was taken, and the single crystal of azulenyl organic metal ring 3a was obtained by diffusion method with a yield of 60%, and the structural formula was: 1 H NMR (400 MHz, CD3OD): δ = 8.31-8.25 (m, 12H), 8.16 (m, 4H), 7.73(s, 2H), 7.65 (m, 2H), 7.53 (m, 4H), 7.32 (m, 4H), 5.73 (s, 4H), 1.74 (s,60H) ppm. 13 C{ 1 H} NMR (100 MHz, CD3CN): δ = 184.4, 152.9, 150.6, 143.4, 142.0,128.8, 127.4, 124.8, 123.7, 120.5, 109.3, 102.5, 96.9, 96.8, 94.5, 89.5, 9.0ppm. like Figure 1 As shown, it is a single crystal structure diagram of the azulene-based organometallic ring 3a. Figure 4 is the H NMR spectrum of the azulene organometallic ring 3a, Figure 5The ultraviolet absorption spectra of the azulenyl organic ligand 2a and the azulenyl organometallic ring 3a.

[0019] Example 2: Preparation of azulenyl organometallic ring 3b Under anhydrous and oxygen-free conditions, dichloro(pentamethylcyclopentadienyl)rhodium(III) dimer (0.01 mmol) was added to 1 mL of methanol solution, followed by 0.04 mmol of AgOTf, and stirred at room temperature for 12 h in the dark. After the reaction was completed, centrifuged, the supernatant solution was taken, and 0.01 mmol of benzoquinone and 80 mmol / L methanol solution containing NaOH were added, and stirring was continued at room temperature in the dark for 12 h. 0.01 mmol of azulenyl organic ligand 2b was dissolved in 0.5 mL of DMA solution and added to the above mixed solution, and stirred at room temperature for 24 h in the dark. After the reaction was completed, centrifuged, the supernatant solution was taken, and the single crystal of azulenyl organic metal ring 3b was obtained by diffusion method with a yield of 45%, and the structural formula was: like Figure 2 , which is a single crystal structure diagram of the azulene-based organometallic ring 3b.

[0020] Example 3: Preparation of azulenyl organometallic ring 3c Under anhydrous and oxygen-free conditions, dichloro(pentamethylcyclopentadienyl)rhodium(III) dimer (0.01 mmol) was added to 1 mL of methanol solution, followed by 0.04 mmol of AgOTf, and stirred at room temperature for 12 h in the dark. After the reaction was completed, centrifuged, the supernatant solution was taken, and 0.01 mmol of benzoquinone and 80 mmol / L methanol solution containing NaOH were added, and stirring was continued at room temperature in the dark for 12 h. 0.01 mmol of azulenyl organic ligand 2c was dissolved in 0.5 mL of DMA solution and added to the above mixed solution, and stirred at room temperature for 24 h in the dark. After the reaction was completed, centrifuged, the supernatant solution was taken, and the single crystal of the organometallic ring 3c was obtained by diffusion method with a yield of 41%, and the structural formula was: like Figure 3 , which is a single crystal structure diagram of the azulene-based organometallic ring 3c.

[0021] Example 4: Photocatalytic test The organic metal ring 3 synthesized by the above method was added into methanol as a photocatalyst together with anisole, and the mixed solution was placed into a reaction tube and reacted for 4 hours under O2 atmosphere and visible light, wherein the amounts of each reactant were 0.1 mmol of anisole, 1 mL of methanol, and 2.5 mg of catalyst.

[0022] After the reaction is completed, the solvent is removed, ether is added, the supernatant is taken, and it is spin-dried, and the product is analyzed by NMR. The homogeneous catalyst after the reaction is washed with ether three times, dried naturally, and recycled for the next time; The reaction formula is: In the above-mentioned thioanisole oxidation reaction, the yield of the product was 92%.

[0023] 1 H NMR (400 MHz, CDCl3): δ 7.63-7.60 (m, 2H), 7.50-7.48 (m, 3H), 2.69 (s, 3H).

[0024] Table 1 shows the yields of the oxidation reactions of different sulfide derivatives under homogeneous catalyst 3. It can be seen that the catalyst has universal applicability; in addition, it can be seen that the oxidation yield of sulfide derivatives can reach up to 96%.

[0025] Table 1 Different reaction substrates and product yields The above specific implementation method part specifically introduces the analytical method involved in the present invention. It should be noted that the above introduction is only to help those skilled in the art better understand the method and ideas of the present invention, rather than limiting the relevant content. Without departing from the principle of the present invention, those skilled in the art may also make appropriate adjustments or modifications to the present invention, and the above adjustments and modifications shall also fall within the scope of protection of the present invention.

Claims

1. A method for synthesizing an azulenyl organometallic ring, characterized in that: Using binuclear compound 1 and azulenyl organic ligand 2 as raw materials, azulenyl organometallic ring 3 was synthesized by a one-pot method. The reaction equation is shown below: 。 2. The method for synthesizing an azulenyl organometallic ring according to claim 1, characterized in that: The specific steps are as follows: Under anhydrous and oxygen-free conditions, dichloro(pentamethylcyclopentadienyl)rhodium(III) dimer was added to a methanol solution, followed by the addition of AgOTf, and the mixture was stirred at room temperature for 12 h in the dark. After the reaction, the mixture was centrifuged and the supernatant solution was collected. In this process, binuclear compound 1 was obtained. Benzoquinone and 80 mmol / L methanol solution containing NaOH were added, and the mixture was stirred at room temperature in the dark for 12 h. Azulenyl organic ligand 2 was dissolved in DMA and added to the above reaction solution. The mixture was stirred at room temperature for 24 h in the dark. After the reaction, the mixture was centrifuged and the supernatant solution was collected. The product, i.e., single crystal of azulenyl organic metal ring 3, was obtained by diffusion method.

3. The method for synthesizing an azulenyl organometallic ring according to claim 2, characterized in that: The azulenyl organic ligand 2 is any one of the following structural formulas: 。 4. The method for synthesizing an azulenyl organometallic ring according to claim 2, characterized in that: The molar ratio of the dichloro(pentamethylcyclopentadienyl)rhodium(III) dimer to AgOTf is 1:2-1:

10.

5. The method for synthesizing an azulenyl organometallic ring according to claim 4, characterized in that: The molar ratio of the dichloro(pentamethylcyclopentadienyl)rhodium(III) dimer to AgOTf is 1:

6.

6. The method for synthesizing an azulenyl organometallic ring according to claim 2, characterized in that: The molar ratio of the binuclear compound 1 to the azulene organic ligand 2 is 1:1 to 1:

2.

7. The method for synthesizing an azulenyl organometallic ring according to claim 6, characterized in that: The molar ratio of the binuclear compound 1 and the azulene organic ligand 2 is 1:

1.

8. Use of the azulenyl organometallic ring obtained by the synthesis method according to claim 1 or 2 in photocatalytic reactions.

9. The use according to claim 8, characterized in that: Application as a catalyst in the photocatalytic anisole reaction.

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