A type of condensed ring macrocyclic aromatic hydrocarbons and a method for synthesizing the same

Abstract

The present invention is applicable to the technical field of organic chemical synthesis, and provides a new type of condensed ring macrocyclic aromatic hydrocarbons and a synthesis method thereof. The condensed ring macrocyclic aromatic hydrocarbons disclosed in the present invention have the advantages of simple synthesis, easy purification, and high synthesis yield, and the present invention hybridizes different condensed rings in the same macrocyclic aromatic hydrocarbon skeleton with high yield through classical Friedel-Crafts acylation and Friedel-Crafts alkylation reactions, and successfully obtains condensed ring macrocyclic aromatic hydrocarbons with structural diversity, good host-guest properties, and high quantum yield luminescence. In addition, the present invention co-crystallizes the new condensed ring macrocyclic aromatic hydrocarbons with electron-deficient guests in a solution or grinds them in a solid state to prepare corresponding luminescent charge transfer assemblies, which provides a new building block for the development of supramolecular charge transfer cocrystals and promotes the development of this field.

Description

Technical Field

[0001] The invention belongs to the technical field of organic chemical synthesis, and in particular relates to a novel type of condensed ring macrocyclic aromatic hydrocarbons and a synthesis method thereof. Background Art

[0002] Macrocyclic host molecules are important tools for theoretical and applied research in the field of supramolecular chemistry. The design and synthesis of macrocyclic aromatic hydrocarbons with novel structures, good photophysical properties and host-guest properties have always been a hot topic and challenge in the field of supramolecular chemistry. With the in-depth development of supramolecular chemistry, a series of classic macrocyclic aromatic hydrocarbons have emerged, making macrocyclic chemistry more diversified in research fields such as molecular recognition and self-assembly. In recent years, based on traditional macrocyclic aromatic hydrocarbons, supramolecular chemists have used organic synthesis to report a series of new macrocyclic aromatic hydrocarbons with different structures, electrical properties, host-guest properties, and have expanded their applications in recognition, adsorption separation, biomedicine and other fields.

[0003] Condensed rings are a class of compounds rich in π electrons and have good photophysical properties, making them ideal for building complex macrocyclic systems. Driven by this trend, a series of condensed ring macrocyclic aromatic hydrocarbons with different topological structures and properties have been reported one after another. For example, the naphthalene molecular tube ( Chem. Sci. 2015, 6 , 6731), disc[n]arene reported by Professor Chen Chuanfeng's research group ( Angew. Chem. Int. Ed. 2021, 60 ,21927), pagoda[n] aromatics ( J. Am. Chem. Soc. 2020, 142 , 8262), Prism[n]arene reported by Professor Gaeta's research group ( J. Am. Chem. Soc. 2020, 142 , 1752), etc., and their corresponding research results have also been applied in the fields of aqueous guest recognition, adsorption separation, charge transfer eutectics and chiral luminescent materials, greatly enriching the types of supramolecular chemistry toolbox.

[0004] However, despite the significant progress made in the research of fused-ring macrocyclic aromatics, the synthesis of this type of molecules still faces some challenges. For example, the synthesis steps are cumbersome, resulting in low synthesis yields. Most of the reported fused-ring macrocyclic aromatics have relatively simple photophysical properties, which are difficult to meet the needs of diversified applications. More importantly, the hybridization of different fused rings in the same macrocyclic aromatic skeleton has not been reported. For this reason, a new type of fused-ring macrocyclic aromatics and their synthesis methods are proposed. Summary of the invention

[0005] The purpose of the present invention is to provide a new type of condensed ring macrocyclic aromatic hydrocarbons and a synthesis method thereof, aiming to solve the problems raised in the above background technology.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A new type of condensed ring macrocyclic aromatic hydrocarbon and its synthesis method, the synthesis route is as follows:

[0008] ;

[0009] Selected from ;

[0010] Wherein R1 is one of C1~C18 alkyl chains, preferably C1; R2 is one of H and C1~C18 alkyl chains, preferably H; the Lewis acid is one of trifluoroacetic acid, boron trifluoride ethyl ether, p-toluenesulfonic acid, trifluoromethanesulfonic acid and ferric chloride, preferably boron trifluoride ethyl ether; the solvent is one of dichloromethane, 1,2-dichloroethane, chloroform, tetrahydrofuran, acetonitrile and tetrachloroethane, preferably dichloromethane.

[0011] Furthermore, its specific structure is as follows:

[0012] ;

[0013] .

[0014] A method for synthesizing a novel condensed ring macrocyclic aromatic hydrocarbon 1 comprises the following steps:

[0015] Step 1: Synthesize the ring-forming monomer NM of the novel condensed ring macrocyclic aromatic hydrocarbon 1. The synthesis route is as follows:

[0016] ;

[0017] The synthesis steps are as follows: 2,6-dimethoxynaphthalene is dissolved in dichloromethane, then anhydrous aluminum chloride and 2,6-naphthalene dichloride are added, and pure water is added after stirring at room temperature for 1 hour to quench the reaction, and then the reaction solution is separated and dried, and the reaction solution is concentrated to obtain a crude product, and a yellow solid NMO is obtained by column chromatography separation, and then NMO is dissolved in trifluoroacetic acid, triethylsilane is added, and the reaction is carried out at room temperature for 8 hours, and then the white solid NM is obtained by suction filtration and water washing;

[0018] Step 2: Synthesis of a novel condensed ring macrocyclic aromatic hydrocarbon 1, namely N[6]A, the synthesis route is as follows:

[0019] ;

[0020] The synthesis steps are as follows: NM and polyformaldehyde are fully dissolved in dichloromethane, stirred for activation for 10 min, then boron trifluoride ether is added, reacted at room temperature for 10 min, sodium hydroxide aqueous solution is added to quench the reaction, the liquids are separated, washed, and dried, the reaction solution is concentrated to obtain a crude product, and white solid N[6]A is obtained by column chromatography.

[0021] A N[6]A@TCNB cocrystal is a charge transfer cocrystal of N[6]A and TCNB synthesized by the above-described synthesis method, and the preparation steps are as follows: weigh 16.21 mg N[6]A and 2.67 mg TCNB into a 5 mL centrifuge tube, add 3 mL of dichloromethane, and after ultrasonic dissolution, filter into a 5 mL bottle using a 0.22 μm filter membrane, and evaporate at room temperature for 1 day to obtain purple-red rectangular block crystals.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] The condensed ring macrocyclic aromatic hydrocarbons involved in the present invention have the advantages of simple synthesis, easy purification and high synthesis yield. In addition, the present invention hybridizes different condensed rings in the same macrocyclic aromatic hydrocarbon skeleton with high yield through classic Friedel-Crafts acylation and Friedel-Crafts alkylation reactions, and successfully obtains condensed ring macrocyclic aromatic hydrocarbons with structural diversity, good host-guest properties and high quantum yield luminescence. In addition, the present invention can prepare the corresponding luminescent charge transfer assembly by co-crystallizing the novel condensed ring macrocyclic aromatic hydrocarbons with electron-deficient guests in solution or grinding them in the solid state, which provides a new building block for the development of supramolecular charge transfer cocrystals and promotes the development of this field. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is the hydrogen nuclear magnetic resonance spectrum of NMO (400 MHz, CDCl3, 298 K).

[0025] Figure 2 This is the hydrogen nuclear magnetic resonance spectrum of NM (400 MHz, CDCl3, 298 K).

[0026] Figure 3 This is the hydrogen NMR spectrum of N[6]A (400 MHz, CDCl3, 298 K).

[0027] Figure 4 Crystal images of N[6]A@6THF; (a) is the front view of N[6]A (hydrogen atoms and solvents are omitted for the sake of structural simplicity); (b) is the side view of N[6]A (hydrogen atoms and solvents are omitted for the sake of structural simplicity); (c) is the front view of N[6]A@6THF; (d) is the side view of N[6]A@6THF.

[0028] Figure 5 The UV-visible absorption spectra and fluorescence emission spectra of NM and N[6]A in dichloromethane are shown in Figure 2. (a) is the UV-visible absorption spectrum of NM and N[6]A in dichloromethane; (b) is the fluorescence emission spectrum of NM and N[6]A in dichloromethane; (c) is the quantum yield diagram of NM in dichloromethane, Blank is the blank control; (d) is the quantum yield diagram of N[6]A in dichloromethane, Blank is the blank control.

[0029] Figure 6 Figure 2 is a diagram of the N[6]A@TCNB and the DA structure it forms; (a) is the front view of N[6]A@TCNB; (b) is the side view of N[6]A@TCNB; (c) is the DA structure diagram formed by N[6]A@TCNB.

[0030] Figure 7 Solid-state UV images of N[6]A and N[6]A@TCNB.

[0031] Figure 8 Solid-state fluorescence images of N[6]A and N[6]A@TCNB. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0033] The specific implementation of the present invention is described in detail below in conjunction with specific embodiments.

[0034] Example 1, Preparation of monomer compound NM: 2,6-dimethoxynaphthalene (5 g, 16.56 mmol) was dissolved in 300 mL of dichloromethane, and then anhydrous aluminum chloride (2.65 g, 19.92 mmol) was added. After sufficient stirring and dissolution, 2,6-naphthalene dichloride (1.68 g, 6.64 mmol) was added in batches. The mixture was vigorously stirred for 1 h at room temperature, and 200 mL of pure water was added to quench the reaction, and then the mixture was separated and dried. The reaction solution was concentrated to obtain a crude product, and yellow solid NMO (3 g, 81%) was obtained by column chromatography. NMO (1.3 g, 2.3 mmol) was dissolved in 20 mL of trifluoroacetic acid, and then 2 mL of triethylsilane was added. The mixture was reacted at room temperature for 8 h, filtered, and the filter cake was washed three times with pure water. The filter cake was dried in a vacuum oven to obtain a white solid NM (1.2 g, 98%). Figure 1 and Figure 2 These are the hydrogen NMR spectra of NMO and NM, respectively.

[0035] Example 2. Preparation of macrocyclic compound N[6]A: NM (1.2 g, 2.26 mmol) and paraformaldehyde (204 mg, 6.8 mmol) were dissolved in 400 mL of dichloromethane and stirred for activation for 10 min. Boron trifluoride etherate (0.6 mL) was then added. After stirring at room temperature for 10 min, 200 mL of sodium hydroxide aqueous solution was added to quench the reaction. The liquids were separated and the filtrate was washed three times with saturated brine and dried. The reaction solution was concentrated to obtain a crude product. White solid N[6]A (600 mg, 50%) was obtained by column chromatography. Figure 3 This is the hydrogen nuclear magnetic resonance spectrum of N[6]A.

[0036] Example 3. Cultivation and structure of N[6]A single crystal (N[6]A@6THF) ( Figure 4 );

[0037] Cultivation of N[6]A@6THF: Weigh 5 mg of N[6]A into a 5 mL centrifuge tube, add 2 mL of tetrahydrofuran (THF), and after thorough sonication, filter into a 5 mL vial using a 0.22 μm filter membrane and evaporate slowly at room temperature. After 12 h, colorless rhombus-shaped single crystals suitable for X-ray single crystal diffraction experiments can be obtained.

[0038] The crystal image of N[6]A@6THF is shown in Figure 4 As shown, from the front view and side view of the N[6]A crystal structure, it can be seen that the structure of this new type of condensed ring macrocyclic aromatic hydrocarbon is box-shaped, and the cavity size is about 12.5 Å×12.8 Å, with a nanometer-sized cavity. The two naphthalene units connected at the 2,6-positions show a 22.29° inclination inside the cavity. It is worth noting that one macrocyclic molecule can bond with 6 THF molecules, four of which are bonded to the upper side of the macrocyclic opening through multiple CH···O interactions, and the other two are also bonded to the macrocyclic cavity through multiple CH···O interactions, proving that N[6]A has good host-guest properties.

[0039] Example 4: Study on the Photophysical Properties of NM and N[6]A ( Figure 5 );

[0040] like Figure 5As shown in the figure, the UV-visible absorption spectra and fluorescence emission spectra of NM and N[6]A in dichloromethane show that the absorption peak of NM is at 340 nm and the emission peak is at 378 nm, while the absorption peak of N[6]A is at 350 nm and the emission peak is at 381 nm. It is worth noting that the quantum yield of NM and N[6]A in dichloromethane shows that the fluorescence quantum yield of N[6]A in dichloromethane is 97.08%, which is much higher than 68.31% of NM. This proves that this new type of condensed ring macrocyclic aromatic hydrocarbon has good photophysical properties and great application potential.

[0041] Example 5. Cultivation and photophysical properties of N[6]A@TCNB cocrystals ( Figure 6-Figure 8 );

[0042] Weigh 16.21 mg N[6]A and 2.67 mg 1,2,4,5-tetracyanobenzene (TCNB) into a 5 mL centrifuge tube, add 3 mL of dichloromethane, and after thorough sonication, filter into a 5 mL vial using a 0.22 μm filter membrane and evaporate slowly at room temperature. One day later, purple-red rectangular block crystals suitable for X-ray single crystal diffraction experiments were observed.

[0043] like Figure 6 As shown in the figure, from the front view and side view of the N[6]A@TCNB crystal, it can be found that three dichloromethane molecules are bonded to the cavity of the macrocycle, and TCNB produces an outer wall charge transfer interaction with the 2,6-dimethoxynaphthalene of N[6]A. It is worth noting that TCNB is sandwiched between the outer walls of the two macrocycles, and a "macrocycle inserted into the macrocycle" structure is formed between the macrocycles, thereby infinitely extending to form a DA structure. Figure 7 As shown in the solid UV images of N[6]A and N[6]A@TCNB, it can be seen that after the macrocycle forms a cocrystal with TCNB, an obvious charge transfer band is generated at around 550 nm, and Figure 8 It can be seen that after the formation of eutectic, its fluorescence emission red-shifted from the 400 nm blue light emission of N[6]A to the deep red and near-infrared emission of 685 nm, which provides a new reference case for the design and synthesis of new solid-state luminescent materials.

[0044] The above are only preferred embodiments of the present invention. It should be pointed out that, for those skilled in the art, several modifications and improvements can be made without departing from the concept of the present invention. These should also be regarded as the protection scope of the present invention. These will not affect the effect of the implementation of the present invention and the practicality of the patent.

Claims

1. A type of fused ring macrocyclic aromatic hydrocarbon, characterized in that: Its synthetic route is as follows: ； Selected from ； Wherein R1 is one of C1~C18 alkyl chains; R2 is one of H and C1~C18 alkyl chains; Lewis acid is one of trifluoroacetic acid, boron trifluoride ethyl ether, p-toluenesulfonic acid, trifluoromethanesulfonic acid and ferric chloride; solvent is one of dichloromethane, 1,2-dichloroethane, chloroform, tetrahydrofuran, acetonitrile and tetrachloroethane.

2. The fused ring macrocyclic aromatic hydrocarbon according to claim 1, characterized in that: Its specific structure is as follows: ； 。 3. A method for synthesizing a condensed ring macrocyclic aromatic hydrocarbon 1, characterized in that: The following steps are involved: Step 1: Synthesize the ring-forming monomer NM of the condensed ring macrocyclic aromatic hydrocarbon 1. The synthesis route is as follows: ； The synthesis steps are as follows: 2,6-dimethoxynaphthalene is dissolved in dichloromethane, then anhydrous aluminum chloride and 2,6-naphthalene dichloride are added, and pure water is added after stirring at room temperature for 1 hour to quench the reaction, and then the reaction solution is separated and dried, and the reaction solution is concentrated to obtain a crude product, and a yellow solid NMO is obtained by column chromatography separation, and then NMO is dissolved in trifluoroacetic acid, triethylsilane is added, and the reaction is carried out at room temperature for 8 hours, and then the white solid NM is obtained by suction filtration and water washing; Step 2: Synthesis of condensed ring macrocyclic aromatic hydrocarbon 1, namely N[6]A, the synthesis route is as follows: ； The synthesis steps are as follows: NM and polyformaldehyde are fully dissolved in dichloromethane, stirred for activation for 10 min, then boron trifluoride ether is added, reacted at room temperature for 10 min, sodium hydroxide aqueous solution is added to quench the reaction, the liquids are separated, washed, and dried, the reaction solution is concentrated to obtain a crude product, and white solid N[6]A is obtained by column chromatography.

4. A N[6]A@TCNB eutectic, characterized in that: The charge transfer eutectic of N[6]A and TCNB synthesized by the synthesis method as claimed in claim 3 is prepared by the following steps: 16.21 mg N[6]A and 2.67 mg TCNB are weighed into a 5 mL centrifuge tube, 3 mL of dichloromethane is added, and after ultrasonic dissolution, the mixture is filtered into a 5 mL bottle using a 0.22 μm filter membrane, and evaporated at room temperature for 1 day to obtain purple-red rectangular block crystals.

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