A method for synthesizing a crown ether nested pyrene-based molecule

Abstract

The application discloses a synthesis method of a crown ether nested pyrene-based molecule, and specifically comprises the following steps: adding 3,5-bistrifluoromethyl benzylamine and dibenzo-24-crown-8-ether into an organic solvent, stirring, then adding 4-nitrophenyl (1-methylpyrene) carbonate, and reacting at room temperature to obtain the crown ether nested pyrene-based molecule. The crown ether nesting can enhance the solid-state light emitting intensity of the pyrene-based molecule, can well overcome the problem of weak fluorescence intensity of the pyrene-based molecule in the solid state caused by pi-pi stacking, and does not change the excitation and emission behavior of the pyrene-based molecule, thereby improving the feasibility of the pyrene-based molecule in the application of solid-state fluorescent materials.

Description

Technical Field

[0001] This invention relates to a method for synthesizing crown ether nested pyrene molecules. Background Technology

[0002] Organic light-emitting materials typically possess advantages such as high photoelectric efficiency, fast response, and molecular flexibility. They have been widely used in organic electroluminescent devices, chemical sensing, and biological probes, and also have potential applications in organic lasers and light-emitting field-effect transistors.

[0003] However, most traditional organic light-emitting materials possess large π-conjugated systems, exhibiting high fluorescence quantum yields in dilute solutions. But in aggregated states (high-concentration solutions or solids), the tight π-π packing of molecules forms excitosynthesies, leading to nonradiative energy conversion, weakened fluorescence, or even complete loss of fluorescence. This phenomenon is known as aggregation-caused quenching (ACQ). In practical applications, organic light-emitting materials often need to be fabricated as aggregates or thin films; therefore, ACQ severely limits the application effectiveness of these materials.

[0004] Pyrene, as a typical electron-rich, highly conjugated luminescent group, possesses excellent fluorescence properties, fluorescence lifetime, and thermal stability, and is widely used in various fields, such as organic light-emitting diodes (OLEDs), bioluminescent probes, and chemical sensors. However, in its aggregated state, pyrene exhibits a redshift in its fluorescence emission curve due to intermolecular π-π stacking, accompanied by a decrease in fluorescence intensity and fluorescence quantum yield—the ACQ phenomenon. To address these drawbacks, a common technique is covalent modification of pyrene, but these methods are not only difficult to synthesize but also alter the fluorescence properties of pyrene itself. Summary of the Invention

[0005] Purpose of the invention: The purpose of this invention is to provide a method for synthesizing crown ether-nested pyrene molecules. The crown ether-nested pyrene molecules obtained by this method have excellent fluorescence intensity, quantum yield and fluorescence lifetime, thereby solving the problem that the existing pyrene molecules have weak luminescence intensity in the solid state due to π-π stacking, without changing the excitation and emission behavior of pyrene molecules.

[0006] Technical solution: The method for synthesizing crown ether nested pyrene molecules according to the present invention is as follows: 3,5-bis(trifluoromethyl)benzylamine and dibenzo-24-crown 8-ether are added to an organic solvent, stirred, and then 4-nitrophenyl (1-methylpyrene) carbonate is added. After reacting at room temperature, crown ether nested pyrene molecules are obtained.

[0007] The molar ratio of 3,5-bis(trifluoromethyl)benzylamine, dibenzo-24-crown-8-ether, and 4-nitrophenyl(1-methylpyrene) carbonate is 1:1:1.

[0008] The reaction time at room temperature shall not be less than 72 hours.

[0009] The organic solvent is toluene.

[0010] The structural formula of the crown ether nested pyrene molecule obtained by the above synthetic method is as follows:

[0011]

[0012] The pyrene molecule obtained by this invention is a pyrene molecule with pyrene and 3,5-bis(trifluoromethylbenzene) as end groups, carbamate as the backbone, and dibenzo-24-crown-8 as the macrocycle nested in a crown ether.

[0013] The reaction equation for the synthesis method of this invention is as follows:

[0014]

[0015] Invention principle: This invention uses the special structure of mechanically interlocked molecules to nest pyrene molecules with crown ethers. The crown ether nesting can prevent the formation of π-π stacking between pyrene molecules, thereby improving the problem of weak fluorescence intensity caused by aggregation fluorescence quenching (ACQ) when pyrene molecules are used as solid luminescent materials.

[0016] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages: The present invention can obtain high-yield crown ether nested pyrene molecules through a one-step chemical reaction; the present invention enhances the solid-state luminescence intensity of pyrene molecules through crown ether nesting, which can effectively overcome the problem of weak fluorescence intensity caused by π-π stacking of pyrene molecules in the solid state, thereby improving the feasibility of pyrene molecules in solid-state fluorescent materials; and the crown ether nested pyrene molecules of the present invention, through subsequent crystallographic research and testing analysis, have been shown to have high-efficiency fluorescence behavior due to the special arrangement structure of the molecules, without changing the excitation and emission behavior of the pyrene molecules themselves. Attached Figure Description

[0017] Figure 1 The 1H NMR spectrum of a crown ether nested pyrene molecule;

[0018] Figure 2 High-resolution mass spectrometry of pyrene molecules nested within crown ethers;

[0019] Figure 3 Single-crystal X-ray diffraction of pyrene molecules nested within crown ethers;

[0020] Figure 4A schematic diagram of the structure of a pyrene molecule without crown ether nesting;

[0021] Figure 5 The 1H NMR spectrum of a pyrene molecule without crown ether nesting;

[0022] Figure 6 High-resolution mass spectrometry of pyrene molecules without crown ether nesting;

[0023] Figure 7 The figures show the fluorescence spectra of pyrene molecules with and without crown ether nesting. In the figure, the green spectral lines represent pyrene molecules with crown ether nesting, and the orange spectral lines represent pyrene molecules without crown ether nesting.

[0024] Figure 8 A powder fluorescence image of a crown ether nested pyrene molecule. Detailed Implementation

[0025] Example 1

[0026] The method for synthesizing crown ether nested pyrene molecules of the present invention is as follows:

[0027] 3,5-bis(trifluoromethyl)benzylamine (243.2 mg, 1 mmol) and dibenzo-24-crown 8-ether (448.5 mg, 1 mmol) were first stirred in toluene (10 mL) for 15 minutes. Then, 4-nitrophenyl(1-methylpyrene) carbonate (397.4 mg, 1 mmol) was added, and the mixture was stirred at room temperature for 72 hours. After the reaction, silica gel column chromatography was performed with petroleum ether / ethyl acetate (6 / 4, v / v) as the eluent to give a white solid, which was a crown ether-nested pyrene molecule (522.4 mg, 0.55 mmol), with a yield of 55%.

[0028] The 1H NMR characterization data of the crown ether nested pyrene molecule prepared in Example 1 are as follows: Figure 1 As shown:

[0029] 1H NMR(600MHz, CDCl3)δ8.43–8.36(m,1H),8.27(d,J=7.8Hz,0.23H),8.25–8.14(m,4.77H),8.1 4–7.98(m,5H),6.98(s,1H),6.91(t,J=4.2Hz,0.77H),6.71(t,J=4.0Hz,0.23H),6.67–6.59(m ,4H),6.50–6.43(m,4H),5.81(s,0.46H),5.77(s,1.54H),4.92(d,J=3.8Hz,0.46H),4.88(d, J=4.1Hz,1.54H),3.99–3.91(m,4H),3.88–3.80(m,8H),3.55–3.44(m,7H),3.31–3.18(m,5H).

[0030] The high-resolution mass spectrometry characterization data of the crown ether nested pyrene molecule prepared in Example 1 are as follows: Figure 2 As shown:

[0031] HRMS(ESI) m / z = 950.2509 [M+H] + Calculated for C 51 H 50 F6NO 10 950.3333;

[0032] m / z = 972.2318 [M + Na] + Calculated for C 51 H 49 F6NO 10 Na 972.3158.

[0033] Single-crystal X-ray diffraction characterization data of the crown ether nested pyrene molecule obtained in Example 1 are as follows: Figure 3 As shown, through Figure 3 It is evident that the crown ether is nested on the pyrene molecule. The successful synthesis of the target product of this invention was verified by proton nuclear magnetic resonance spectroscopy, high-resolution mass spectrometry, and single-crystal X-ray diffraction.

[0034] Comparative Example 1

[0035] Crownless ether nested pyrene molecules ( Figure 4 The synthesis method of ) is as follows:

[0036] 3,5-bis(trifluoromethyl)benzylamine (486.3 mg, 2 mmol) and 4-nitrophenyl(1-methylpyrene) carbonate (794.8 mg, 2 mmol) were added to toluene (10 mL) and stirred at room temperature for 72 hours. After the reaction, silica gel column chromatography was performed with petroleum ether / ethyl acetate (9 / 1, v / v) as the eluent to give a crownless pyrene molecule (812.3 mg, 1.62 mmol), with a yield of 81%.

[0037] The 1H NMR characterization data of the crownless ether-nested pyrene molecule prepared in Comparative Example 1 are as follows: Figure 5 As shown:

[0038] 1 H NMR (600MHz, CDCl3) δ8.31 (d, J = 9.2Hz, 1H), 8.24–8.19 (m, 2H), 8.19–8.14 (m, 2H), 8.11–8. 01(m,4H),7.79(s,1H),7.75(s,1H),5.89(s,2H),5.28(app.s,1H),4.52(d,J=6.3Hz,2H).

[0039] The high-resolution mass spectrometry characterization data of the crownless ether-nested pyrene molecule prepared in Comparative Example 1 are as follows: Figure 6 As shown:

[0040] HRMS(ESI) m / z = 502.1187 [M+H] + Calculated for C 27 H 18 F6NO2 502.1191.

[0041] The fluorescence intensity of the crown ether-nested pyrene molecule prepared in Example 1 and the pyrene molecule without crown ether nesting in Comparative Example 1 are compared. Figure 7 As shown, the fluorescence intensity of pyrene molecules with crown ether nesting is much higher than that of pyrene molecules without crown ether nesting (referring to fluorescence intensity in the solid state), and emits an emission similar to... Figure 8 The image shows a pure blue fluorescence.

[0042] The fluorescence quantum yield and fluorescence lifetime of the crown ether-nested pyrene molecule prepared in Example 1 were also much greater than those of the non-crown ether-nested pyrene molecule in Comparative Example 1, as shown in Table 1.

[0043] Table 1

[0044]

[0045] Crown ether nesting can greatly enhance the luminescence intensity of solid pyrene molecules. The solid-state fluorescence curve, quantum yield, and fluorescence lifetime of crown ether nested pyrene molecules were tested by fluorescence spectroscopy. Compared with pyrene molecules without crown ether nesting, pyrene molecules with crown ether nesting have superior fluorescence intensity (crown ether nesting can increase fluorescence quantum yield by more than 7 times), quantum yield, and fluorescence lifetime, without changing the excitation and emission behavior of pyrene molecules. Therefore, the crown ether nested pyrene molecules synthesized in this invention can effectively solve the problem of weak fluorescence when pyrene molecules are applied to solid-state luminescent materials.

Claims

1. A method for synthesizing crown ether nested pyrene molecules, characterized in that, Specifically, 3,5-bis(trifluoromethyl)benzylamine and dibenzo-24-crown 8-ether are added to an organic solvent, stirred, and then 4-nitrophenyl (1-methylpyrene) carbonate is added. After reacting at room temperature, a crown ether-nested pyrene molecule is obtained. The structural formula of the crown ether-nested pyrene molecule is as follows: .

2. The method for synthesizing crown ether nested pyrene molecules according to claim 1, characterized in that: The molar ratio of 3,5-bis(trifluoromethyl)benzylamine, dibenzo-24-crown-8-ether, and 4-nitrophenyl(1-methylpyrene) carbonate is 1:1:

1.

3. The method for synthesizing crown ether nested pyrene molecules according to claim 1, characterized in that: The reaction time at room temperature shall not be less than 72 hours.

4. The method for synthesizing crown ether nested pyrene molecules according to claim 1, characterized in that: The organic solvent is toluene.

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