A pyridine aromatic amide luminescent macrocyclic compound and its preparation method and application

Abstract

This application discloses a pyridine aromatic amide luminescent macrocyclic compound, its preparation method, and its application. The compound, built from aromatic amide pentamers, is synthesized through a simple Suzuki reaction and acylation reaction, providing a novel approach for constructing a new class of rigid aromatic amide macrocycles. Experiments have shown that this macrocycle possesses an electron-rich cavity, demonstrating potential for supramolecular applications. It also exhibits thermally activated delayed fluorescence (TADF), suggesting potential applications in organic photoluminescent materials.

Description

Technical Field

[0001] The present application relates to the technical field of organic light-emitting materials, and more specifically, to a pyridine aromatic amide light-emitting macrocyclic compound and a preparation method and application thereof. Background Art

[0002] In recent years, organic light-emitting materials, owing to their exceptional properties, have made significant progress in diverse fields such as sensing, anti-counterfeiting, bioimaging, and display lighting. In particular, thermally activated delayed fluorescence (TADF) materials, with their quantum efficiencies reaching up to 100%, have garnered significant attention in organic light-emitting diodes (OLEDs). However, since most light-emitting materials suffer from severe emission quenching during self-aggregation, known as aggregation-concentration quenching (ACQ), this severely limits their applications.

[0003] Host macrocyclic molecules play a key role in the field of supramolecular chemistry, with significant applications in host-guest chemistry, self-assembly, molecular machines, and drug delivery. These macrocyclic molecules interact specifically with other molecules or ions through non-covalent interactions, making them a hot topic for research and application in supramolecular chemistry and materials science.

[0004] However, existing host macrocycles are often difficult to synthesize, have low yields, and have little research on luminescence. Developing simple and efficient strategies for luminescent macrocycles is of great significance.

[0005] Application Contents

[0006] In order to overcome one of the problems existing in the above-mentioned prior art, the primary purpose of this application is to provide a pyridine aromatic amide luminescent macrocyclic compound, which overcomes the shortcomings of the existing macrocyclic compounds such as the difficulty in synthesis and weak luminescence.

[0007] Another object of the present application is to provide a method for preparing the above-mentioned pyridine aromatic amide luminescent macrocyclic compound.

[0008] Another object of the present application is to provide an application of the above-mentioned pyridine aromatic amide luminescent macrocyclic compound.

[0009] The above-mentioned purpose of this application is achieved through the following technical solutions:

[0010] A pyridine aromatic amide luminescent macrocyclic compound, wherein the pyridine aromatic amide luminescent macrocyclic compound has the molecular structure shown in the following (I):

[0011]

[0012] Wherein, R1 to R2 are independently selected from C1 to C16 hydrocarbon groups.

[0013] Preferably, R1 to R6 are independently selected from one of the following structures:

[0014]

[0015] The present application also provides a method for preparing the above-mentioned pyridine aromatic amide luminescent macrocyclic compound, comprising the following steps:

[0016] S1. Dissolve diethyl 4-bromopyridine-2,6-dicarboxylate and an arylboronic acid in an organic solvent, add a base and a catalyst to react completely, and then post-treat to obtain TPA-N. Then, dissolve TPA-N in an organic solvent, perform an ester hydrolysis reaction under alkaline conditions, react completely, and then post-treat to obtain TPA-COOH. The structural formulas of TPA-N and TPA-COOH are shown below:

[0017]

[0018] S2. The pentamer is dissolved in an organic solvent, a catalyst is added, and hydrogen is introduced to complete the reaction. After post-treatment, an amino pentamer is obtained. The structural formula of the pentamer is shown below:

[0019]

[0020] Wherein, the R1 to R2 are independently selected from C1 to C16 hydrocarbon groups;

[0021] S3. TPA-COOH and an acylating agent are dissolved in an organic solvent, and after the reaction is complete, the product is slowly added to an organic solvent containing the amino pentamer obtained in step S2 and an acid-binding agent at low temperature. The reaction is complete and the product is post-treated to obtain a pyridine aromatic amide macrocycle PY-TPA, i.e., a macrocyclic compound having a structure as shown in formula (I).

[0022] Preferably, in step S1, the organic solvent is N,N-dimethylformamide, the aryl boronic acid is 4,4'-dimethoxy-4"-triphenylamine borate, the base is potassium carbonate, and the catalyst is tetrakis(triphenylphosphine)palladium.

[0023] More preferably, in step S1, the molar ratio of diethyl 4-bromopyridine-2,6-dicarboxylate, arylboronic acid, base, and catalyst is 1:(1.2-1.4):3:0.1.

[0024] Preferably, in step S2, the organic solvent is 1,2-dichloroethane or methanol.

[0025] Preferably, in step S3, the organic solvent is dichloromethane, the acylating agent is oxalyl chloride, and the acid binding agent is triethylamine.

[0026] Preferably, in step S3, the molar ratio of the TPA-COOH, acylating agent, acid binding agent and amino pentamer is (1-2):(2-4):(2-4):(1-2).

[0027] The present application also provides applications of the above-mentioned pyridine aromatic amide luminescent macrocyclic compound in host-guest recognition and organic photoluminescent materials.

[0028] Preferably, the applications of the above-mentioned pyridine aromatic amide luminescent macrocyclic compounds in host-guest recognition and organic photoluminescent materials include applications in adsorption separation, fluorescence sensing, and light-emitting devices.

[0029] Compared with the prior art, the present invention has the following advantages:

[0030] The pyridine aromatic amide luminescent macrocyclic compound provided in this application uses aromatic amide pentamers as building blocks. By combining the Suzuki reaction and the acylation reaction, a new type of pyridine macrocyclic luminescent compound is obtained in a high yield, which provides a new idea for constructing a new type of pyridine aromatic amide macrocycle. Experiments have shown that stable intramolecular hydrogen bonds can not only limit the intramolecular motion in the aggregated state, but also force the carbonyl group toward the macrocyclic cavity, thereby giving the macrocyclic TADF properties and strong complexing ability for power-deficient guests. Therefore, it can be applied to the field of organic photoluminescent materials and shows application potential in host-guest recognition. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is the hydrogen nuclear magnetic resonance spectrum of the compound PY-TPA prepared in Example 4 of the present application.

[0032] Figure 2 This is the mass spectrum of the compound PY-TPA prepared in Example 4 of the present application.

[0033] Figure 3 These are photoluminescence spectra of the compound PY-TPA prepared in Example 4 of the present application in solvents of different polarities.

[0034] Figure 4 These are the steady-state and delayed spectra of the compound PY-TPA prepared in Example 4 of the present application in toluene solution. DETAILED DESCRIPTION

[0035] The embodiments of the present application will be described in detail below with reference to the examples, but it will be understood by those skilled in the art that the following examples are merely illustrative of the present application and should not be considered as limiting the scope of the present application. In the examples, if specific conditions are not specified, the conditions are carried out according to conventional conditions or manufacturer recommendations. The reagents or instruments used are not specified by the manufacturer and are conventional products that can be purchased commercially.

[0036] It should be noted that:

[0037] In this application, unless otherwise specified, all the embodiments and preferred implementation methods mentioned herein can be combined with each other to form a new technical solution.

[0038] In this application, unless otherwise specified, percentages (%) or parts refer to percentages or parts by weight relative to the composition.

[0039] In this application, unless otherwise specified, the components involved or their preferred components can be combined with each other to form a new technical solution.

[0040] In this application, unless otherwise specified, the numerical range "a-b" is an abbreviation for any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "1-5" indicates that all real numbers between "1-5" are listed herein, and "1-5" is merely an abbreviation for these numerical combinations.

[0041] The "ranges" disclosed in this application are in the form of lower limits and upper limits, which can be one or more lower limits, and one or more upper limits, respectively.

[0042] In this application, unless otherwise stated, each reaction or operation step can be carried out sequentially or in a sequential manner. Preferably, the reaction method herein is carried out sequentially.

[0043] Unless otherwise indicated, the professional and scientific terms used herein are the same as those familiar to those skilled in the art. In addition, any method or material similar or equivalent to the described content may also be applied to this application.

[0044] The present application provides a pyridine aromatic amide luminescent macrocyclic compound, wherein the pyridine aromatic amide luminescent macrocyclic compound has the molecular structure shown in (I) below:

[0045]

[0046] Wherein, R1 to R2 are independently selected from C1 to C16 hydrocarbon groups.

[0047] In some preferred embodiments, R1 to R6 are independently selected from one of the following structures:

[0048]

[0049] The present application also provides a method for preparing the above-mentioned pyridine aromatic amide luminescent macrocyclic compound, comprising the following steps:

[0050] S1. Dissolve diethyl 4-bromopyridine-2,6-dicarboxylate and an arylboronic acid in an organic solvent, add a base and a catalyst to react completely, and then post-treat to obtain TPA-N. Then, dissolve TPA-N in an organic solvent, perform an ester hydrolysis reaction under alkaline conditions, react completely, and then post-treat to obtain TPA-COOH. The structural formulas of TPA-N and TPA-COOH are shown below:

[0051]

[0052] S2. The pentamer is dissolved in an organic solvent, a catalyst is added, and hydrogen is introduced to complete the reaction, followed by post-treatment to obtain an amino pentamer. The structural formula of the pentamer is shown below:

[0053]

[0054] Wherein, the R1 to R2 are independently selected from C1 to C16 hydrocarbon groups;

[0055] S3. TPA-COOH and an acylating agent are dissolved in an organic solvent, and after the reaction is complete, the product is slowly added to an organic solvent containing the amino pentamer obtained in step S2 and an acid-binding agent at low temperature. The reaction is complete and the product is post-treated to obtain a pyridine aromatic amide macrocycle PY-TPA, i.e., a macrocyclic compound having a structure as shown in formula (I).

[0056] The pyridine aromatic amide luminescent macrocyclic compounds described in this application use aromatic amide pentamers as building blocks. Through a combination of Suzuki reaction and acylation reaction, a new class of pyridine macrocyclic luminescent compounds was obtained in high yields. Strong intramolecular hydrogen bonds give these pyridine aromatic amide macrocyclic compounds an electron-rich cavity.

[0057] Based on rational molecular design, the pyridine aromatic amide luminescent macrocyclic compound of this application is able to form a strong intramolecular hydrogen bond with the oxygen atom of the alkoxy group adjacent to the amide bond, and the nitrogen atom of the pyridine can also form a strong intramolecular hydrogen bond with the amide nitrogen atom, thereby restricting intramolecular motion in the aggregated state, reducing non-radiative relaxation, and endowing it with TADF properties. Furthermore, because the plane of the amide bond is effectively fixed, the carbonyl group is forced to face the macrocyclic cavity, thus endowing the macrocyclic with the ability to complex charge-deficient guests.

[0058] In the preparation method described in the present application, in step S1, the organic solvent is N,N-dimethylformamide, the aryl boronic acid is 4,4'-dimethoxy-4"-triphenylamine borate, the base is potassium carbonate, and the catalyst is tetrakis(triphenylphosphine)palladium.

[0059] In the preparation method described in the present application, in step S1, the molar ratio of diethyl 4-bromopyridine-2,6-dicarboxylate, arylboronic acid, base, and catalyst is 1:(1.2-1.4):3:0.1.

[0060] In the preparation method described in the present application, in step S2, the organic solvent is 1,2-dichloroethane or methanol.

[0061] In the preparation method described in the present application, in step S3, the organic solvent is dichloromethane, the acylating agent is oxalyl chloride, and the acid binding agent is triethylamine.

[0062] In the preparation method described in the present application, in step S3, the molar ratio of the TPA-COOH, acylating agent, acid binding agent, and amino pentamer is (1-2):(2-4):(2-4):(1-2).

[0063] The present application also provides applications of the above-mentioned pyridine aromatic amide luminescent macrocyclic compound in host-guest recognition and organic photoluminescent materials.

[0064] In some preferred embodiments, the above-mentioned pyridine aromatic amide luminescent macrocyclic compounds are used in host-guest recognition and organic photoluminescent materials, including applications in adsorption separation, fluorescence sensing, and light-emitting devices.

[0065] The following is a detailed description of the preparation method of the pyridine aromatic amide luminescent macrocyclic compound in the present application using specific examples.

[0066] Example 1

[0067] The synthesis of pyridine triphenylamine TPA-N, the structural formula and synthesis path of TPA-N are as follows:

[0068]

[0069] N-Br (200.0 mg, 0.73 mmol), TPA-B (305.7 mg, 0.88 mmol), and potassium carbonate (302.2 mg, 2.19 mmol) were dissolved in dry N,N-dimethylformamide (30 mL). The solution was degassed three times with N2, and tetrakis(triphenylphosphine)palladium (8.43 mg, 0.07 mmol) was added. The mixture was refluxed at 70°C for 20 h. After completion of the reaction, the solvent was removed by distillation under reduced pressure, and the product was purified by silica gel column chromatography (DCM:PE = 5:1 → DCM) to obtain compound TPA-N (400 mg) in an 80% yield.

[0070] Example 2

[0071] The hydrolysis reaction of TPA-N. This application provides a preparation method of TPA-N hydrolysis:

[0072]

[0073] TPA-N (350.0 mg, 0.73 mmol) was dissolved in a mixture of tetrahydrofuran and methanol, and aqueous sodium hydroxide solution was added. The mixture was stirred at room temperature for 2 h. The solvent was removed by distillation under reduced pressure, and the mixture was dissolved in dichloromethane. Hydrochloric acid (5 mL) was added to acidify the mixture to a pH of 1-2, and the mixture was washed three times with water (50 mL). The organic phase was collected, dried over anhydrous sodium sulfate, filtered, and distilled under reduced pressure to obtain TPA-COOH (305 mg) with a yield of 63%.

[0074] Example 3

[0075] Pentamer reduction. This application provides a preparation method for pentamer reduction:

[0076]

[0077] P-NO2 (330 mg, 0.25 mmol) and palladium on carbon (60 mg, wt%) were dissolved in a mixture of 1,2-dichloroethane and methanol (100 mL, C2H4Cl2 / CH3OH, 5:1, v / v). The mixture was reacted at 70°C under a hydrogen atmosphere for 20 h. After the reaction, the palladium on carbon was removed by filtration under reduced pressure, and the solvent was evaporated under reduced pressure to obtain P-NH2, which was used directly in the next step.

[0078] Example 4

[0079] Synthesis of the luminescent macrocyclic PY-TPA. The structural formula and synthetic route of the PY-TPA are shown below:

[0080]

[0081] TPA-COOH (47 mg, 0.1 mmol) prepared in Example 2 was dissolved in dichloromethane, and oxalyl chloride (34 μL) was added. The mixture was stirred at room temperature for 1 h. After the reaction was completed, the solvent and excess oxalyl chloride were removed by distillation under reduced pressure. The obtained acyl chloride intermediate was dried under vacuum to obtain TPA-COCl. P-NH2 prepared in Example 3 was dissolved in a mixed solution of dichloromethane and triethylamine, and TPA-COCl dissolved in dichloromethane was slowly added dropwise at low temperature. The mixture was stirred overnight under a nitrogen atmosphere, and the resulting mixture was washed three times with water, dried over anhydrous sodium sulfate, and filtered. The crude product was purified by silica gel column chromatography (DCM / CH3OH=100 / 20) to obtain solid PY-TPA (49.2 mg) with a yield of 30%.

[0082] Performance Testing

[0083] This application uses the compounds prepared in the examples as examples for performance testing. In the macrocyclic compounds prepared in other examples, since the amide protons can form stable intramolecular hydrogen bonds with the oxygen atoms of the alkoxy groups adjacent to the amide bond, on the one hand, the intramolecular motion in the aggregated state is effectively suppressed, which reduces non-radiative relaxation and exhibits TADF properties; on the other hand, the intramolecular hydrogen bonding simultaneously forces the carbonyl group toward the macrocyclic cavity, thereby giving the macrocyclic TADF and strong complexing ability for the electron-deficient guest. Therefore, the macrocyclic compounds prepared in other examples all have the same effect as the compound obtained in Example 4.

[0084] H NMR detection: A 400 MHz NMR instrument from Bruker, Switzerland, was used, and the solvent was deuterated chloroform. Figure 1 As shown, the peaks of the molecular hydrogen spectrum can correspond one-to-one with the target compounds, and the number is reasonable. 1 H NMR(400MHz,Chloroform-d)δ10.08(s,2H),9.94(s,2H),9.20(s,2H),9.10(s,1H),8.98(s,2H),8.68(s,2H), 8.34(s,2H),8.18(d,J=9.1,2.8Hz,2H),7.68(d,J=8.5Hz,2H),7.13(d,J=8.8Hz,4H),7.07(d,J=9.1Hz,2H),6. 98(d,J=8.5Hz,2H),6.88(d,J=8.9Hz,4H),6.52(s,2H),6.49(s,1H),4.09(d,J=6.2Hz,6H),3.89(s,12H),3.8 2(s,8H),1.97(dt,J=13.0,6.4Hz,6H),1.56(dt,J=20.6,6.9Hz,10H),1.40-1.28(m,20H),0.98-0.88(m,24H).

[0085] Mass spectrometry detection: PY-TPA prepared in Example 4 was dissolved in dichloromethane to prepare a solution with a concentration of 1 mg / mL, and mass spectrometry was performed using a TSQ Endura ultra-high performance liquid chromatography coupled to a triple quadrupole mass spectrometer from Thermo Fisher Scientific, USA. Figure 2 As shown in the figure, the m / z value is 1652.87582 (z = 1), corresponding to one PY-TPA molecule complexing one H + Combining the above H NMR and MS results, it can be seen that the compound prepared in Example 4 has the structure PY-TPA.

[0086] Fluorescence emission spectrum detection: using a multifunctional spectrometer HPX-200C-HP-DUV, with an excitation wavelength of 365 nm, the compound prepared in Example 4 was dissolved in DCM to prepare 1×10 -3 mol / L mother solution was further diluted to 1×10 -5 mol / L solution, and test it. Figure 3 As shown, in the presence of different polar solvents, the maximum emission peak of compound PY-TPA gradually red-shifts with increasing polarity, proving that charge transfer (CT) exists in the macrocycle.

[0087] Steady-state and delayed spectral detection: Using a multifunctional spectrometer HPX-200C-HP-DUV, with an excitation wavelength of 365 nm, the compound prepared in Example 4 was dissolved in DCM to prepare 1×10 -3 mol / L stock solution, further diluted with TOL to 1×10 -5 mol / L solution, and test it. Figure 4 As shown, the compound PY-TPA is in toluene solution, and the maximum value of the emission peak can be calculated to obtain △E ST =0.13 eV, which is less than 0.3 eV, proving that the macrocycle has TADF properties.

[0088] The pyridine aromatic amide luminescent macrocyclic compounds described in this application use aromatic amide pentamers as building blocks. Through a combination of Suzuki reaction and acylation reaction, a new class of pyridine macrocyclic luminescent compounds was obtained in high yields. Strong intramolecular hydrogen bonds give these pyridine aromatic amide macrocyclic compounds an electron-rich cavity.

[0089] Based on rational molecular design, the pyridine aromatic amide luminescent macrocyclic compound of this application is able to form a strong intramolecular hydrogen bond with the oxygen atom of the alkoxy group adjacent to the amide bond, and the nitrogen atom of the pyridine can also form a strong intramolecular hydrogen bond with the amide nitrogen atom, thereby restricting intramolecular motion in the aggregated state, reducing non-radiative relaxation, and endowing it with TADF properties. Furthermore, because the plane of the amide bond is effectively fixed, the carbonyl group is forced to face the macrocyclic cavity, thus endowing the macrocyclic with the ability to complex charge-deficient guests.

[0090] The pyridine aromatic amide luminescent macrocyclic compound of the present application, with its rigid planar structure stabilized by hydrogen bonds and electron-rich cavity, shows great potential in the fields of host-guest recognition, liquid crystal materials, efficient construction of rotaxanes, and catalysis.

[0091] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with an embodiment or example is included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0092] Although several embodiments of the present application have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and purpose of the present application, and that the scope of the present application is defined by the claims and their equivalents.

Claims

1. A pyridine aromatic amide luminescent macrocyclic compound, characterized in that The pyridine aromatic amide luminescent macrocyclic compound has a molecular structure shown in the following formula (I): ； Formula (I); Wherein, R1~R2 are independently selected from C1~C16 hydrocarbon groups.

2. The pyridine aromatic amide luminescent macrocyclic compound according to claim 1, characterized in that The R1 to R2 are independently selected from one of the following structures: 、 、 、 、 、 、 、 。 3. The method for preparing the pyridine aromatic amide luminescent macrocyclic compound according to any one of claims 1 to 2, characterized in that: The following steps are involved: S1. Dissolve dimethyl 4-bromopyridine-2,6-dicarboxylate and 4,4'-dimethoxy-4''-triphenylamine borate in an organic solvent, add a base and a catalyst, react completely, and post-treat to obtain TPA-N. Then, dissolve TPA-N in an organic solvent, hydrolyze the ester under alkaline conditions, react completely, and post-treat to obtain TPA-COOH. The structural formulas of TPA-N and TPA-COOH are shown below: ； S2. The pentamer is dissolved in an organic solvent, a catalyst is added, and hydrogen is introduced to complete the reaction. The post-treatment is performed to obtain an amino pentamer. The structural formula of the pentamer is shown below: ； Wherein, R1 to R2 are as described in claim 1 or 2; S3. Dissolve TPA-COOH and the acylating agent in an organic solvent, wait for the reaction to be complete and post-processed, and slowly add the resulting product at low temperature to an organic solvent containing the amino pentamer obtained in step S2 and an acid-binding agent, react completely and post-process to obtain the pyridine aromatic amide luminescent macrocyclic compound as claimed in claim 1 or 2.

4. The method for preparing the pyridine aromatic amide luminescent macrocyclic compound according to claim 3, wherein: In step S1, the organic solvent is N,N-dimethylformamide, the base is potassium carbonate, and the catalyst is tetrakis(triphenylphosphine)palladium.

5. The method for preparing the pyridine aromatic amide luminescent macrocyclic compound according to claim 4, characterized in that: In step S1, the molar ratio of the dimethyl 4-bromopyridine-2,6-dicarboxylate, 4,4'-dimethoxy-4''-triphenylamine borate, base, and catalyst is 1: (1.2-1.4): 3: 0.

1.

6. The method for preparing the pyridine aromatic amide luminescent macrocyclic compound according to claim 3, characterized in that: In step S2, the organic solvent is 1,2-dichloroethane or methanol.

7. The method for preparing the pyridine aromatic amide luminescent macrocyclic compound according to claim 3, characterized in that: In step S3, the organic solvent is dichloromethane, the acylating agent is oxalyl chloride, and the acid binding agent is triethylamine.

8. The method for preparing the pyridine aromatic amide luminescent macrocyclic compound according to claim 3, characterized in that: In step S3, the molar ratio of TPA-COOH, acylating agent, acid binding agent and amino pentamer is (1-2): (2-4): (2-4): (1-2).

9. Use of the pyridine aromatic amide luminescent macrocyclic compound according to any one of claims 1 to 2 in organic photoluminescent materials.

10. Use of the pyridine aromatic amide luminescent macrocyclic compound according to any one of claims 1 to 2 in fluorescence sensing and light-emitting devices.

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