Non-conjugated light emitting molecules, methods of making and using the same

Abstract

The application discloses a kind of non-conjugated light-emitting molecules and preparation method and application in fluorescent field, light-emitting device thereof.The non-conjugated light-emitting molecules of the application have structure as any one of formula I-III:Non-conjugated light-emitting molecules of the application can emit fluorescence under 200-400nm excitation wavelength, and fluorescence emission wavelength is 350-500nm, wherein the half-peak width of solid fluorescence emission peak of compound II is only 40nm, and the luminous efficiency can reach 100%.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of non-conjugated light-emitting small molecules, in particular to a kind of non-conjugated light-emitting molecules and preparation method and application thereof. BACKGROUND

[0002] Light-emitting materials play a crucial role in people's production and life, especially in the fields of display devices, chemical sensing and biological imaging, and organic fluorescent materials are a very important branch of light-emitting materials.

[0003] Organic light-emitting diodes (OLEDs) are an important development direction of organic light-emitting materials, which have the advantages of high efficiency, high resolution, high contrast color, light weight, wide viewing angle and superior mechanical flexibility. These advantages need to be based on organic light-emitting materials with high color purity and high luminous efficiency. Therefore, narrow-band emission of organic light-emitting materials is of great significance for the development of high-quality OLED displays with larger color gamut.

[0004] At present, the fluorescent light-emitting efficiency of most organic light-emitting materials is uneven, and its fluorescent emission peak is relatively wide, so the development of OLED devices needs to use color filters or microcavities to improve the color purity of electroluminescent spectrum, which inevitably causes certain energy loss.

[0005] Non-conjugated light-emitting materials have attracted the attention of researchers in the relevant field since their discovery, mainly including some non-conjugated fluorescent small molecules and polymers, for example, triphenylmethane and its derivatives reported by the inventors (J. Am. Chem. Soc. 2021, 143, 9565-9574), and the fluorescent triphenylmethane triisocyanate disclosed in the patent specification with publication number CN 115433150A. These materials are formed by flexible chains. Therefore, the light-emitting material has good structural flexibility, good processability, and is simple to synthesize and easy to produce.

[0006] However, most of the current non-conjugated light-emitting molecules have relatively wide emission peaks and relatively low light-emitting efficiency.

[0007] Therefore, how to regulate the light-emitting performance by changing the structure of the molecule is the research focus of developing efficient non-conjugated light-emitting materials in the future.

[0008] The development of non-conjugated light-emitting molecules with high light-emitting efficiency and narrow half-peak width of emission peak is expected to become a candidate material for high-quality OLED devices. SUMMARY

[0009] The application provides a kind of non-conjugated light-emitting molecule and its preparation method and application, the light-emitting property of the non-conjugated light-emitting molecule of the application can be regulated by the position of substituent group and the charge density on aromatic ring, and it is a kind of light-emitting material with excellent light-emitting performance.

[0010] In the first aspect, the application provides a non-conjugated light-emitting molecule having any one of the following structures of formula I-III:

[0011]

[0012] Compound I is a para-substituted non-conjugated light-emitting molecule, which can be denoted as p-TBPM. Compound II is a meta-substituted non-conjugated light-emitting molecule, which can be denoted as m-TBPM. Compound III is an ortho-substituted non-conjugated light-emitting molecule, which can be denoted as o-TBPM.

[0013] The para-substituted and meta-substituted non-conjugated light-emitting molecules described above can be prepared by the following process:

[0014] In the first step, a para- or meta-dibromo-substituted six-membered aromatic ring compound is subjected to nucleophilic addition reaction with diethyl carbonate to obtain a tri-bromo-substituted triaryl methanol molecule;

[0015] In the second step, the tri-bromo-substituted triaryl methanol is reduced to obtain a tri-bromo-substituted triaryl methane molecule;

[0016] In the third step, the tri-bromo-substituted triaryl methane is subjected to Suzuki-Miyaura reaction with aryl boronic acid to obtain a para- or meta-substituted non-conjugated light-emitting molecule.

[0017] The ortho-substituted non-conjugated light-emitting molecule described above can be prepared by the following process:

[0018] In the first step, an ortho-diiodo-substituted six-membered aromatic ring compound is subjected to nucleophilic addition reaction with ortho-bromo aryl formaldehyde to obtain an ortho-bromo-substituted ortho-iodo-substituted diaryl methanol molecule;

[0019] In the second step, the ortho-bromo-substituted ortho-iodo-substituted diaryl methanol is subjected to reaction with a six-membered aromatic ring compound to obtain an ortho-bromo-substituted ortho-iodo-substituted triaryl methane;

[0020] In the third step, the ortho-bromo-substituted ortho-iodo-substituted triaryl methane is subjected to oxidation reaction and ion exchange reaction with potassium iodide to obtain an ortho-bromo aryl-substituted cyclic diaryl iodonium iodide;

[0021] In the fourth step, the ortho-bromo aryl-substituted cyclic diaryl iodonium iodide is subjected to heating decomposition reaction to obtain an ortho-bromo-substituted di-ortho-iodo-substituted triaryl methane;

[0022] In the fifth step, the ortho-bromo-substituted di-ortho-iodo-substituted triaryl methane is subjected to Suzuki-Miyaura reaction with aryl boronic acid to obtain an ortho-substituted non-conjugated light-emitting molecule.

[0023] In a second aspect, the present application provides a preparation method of the non-conjugated light-emitting molecule, a synthetic route of which is as follows:

[0024]

[0025] The preparation method comprises the following steps:

[0026] S11, under -80 to -70℃, drop n-butyllithium into a tetrahydrofuran solution of p-dibromobenzene, stir to obtain a reaction solution, then drop a tetrahydrofuran solution of diethyl carbonate into the reaction solution, stir to react at room temperature, after the reaction is completed, terminate, extract, separate, discard the aqueous phase, dry the organic phase, filter, concentrate to obtain a crude product, and separate the crude product by column chromatography to obtain p-tribromotriphenylmethanol, i.e. compound 1;

[0027] S12, add p-tribromotriphenylmethanol into formic acid, stir to react under reflux, after the reaction is completed, terminate, extract, separate, discard the aqueous phase, dry the organic phase, filter, concentrate to obtain a crude product, and separate the crude product by column chromatography to obtain p-tribromotriphenylmethane, i.e. compound 2;

[0028] S13, add p-tribromotriphenylmethane, phenylboronic acid, tetrakis(triphenylphosphine)palladium and potassium carbonate into a mixed solution of tetrahydrofuran and water, stir to react under reflux under nitrogen protection, after the reaction is completed, terminate, extract, separate, discard the aqueous phase, dry the organic phase, filter, concentrate to obtain a crude product, and separate the crude product by column chromatography to obtain the non-conjugated light-emitting molecule having the structure shown in formula I.

[0029] In the preparation method of the second aspect, the molar ratio of p-dibromobenzene, n-butyllithium and diethyl carbonate in step S11 can be (3.3-3.6):(3.0-3.3):1.

[0030] In the preparation method of the second aspect, the molar ratio of p-tribromotriphenylmethane, phenylboronic acid and tetrakis(triphenylphosphine)palladium in step S13 can be 1:(6.0-9.0):(0.05-0.20).

[0031] In the preparation method of the second aspect, the eluent of the column chromatography can be pure petroleum ether or a mixture of petroleum ether and ethyl acetate. The volume ratio of petroleum ether to ethyl acetate in the mixture of petroleum ether and ethyl acetate can be 1-1000:1.

[0032] In a third aspect, the present application provides a preparation method of the non-conjugated light-emitting molecule, a synthetic route of which is as follows:

[0033]

[0034] The preparation method comprises the following steps:

[0035] S21, under -80 to -70℃, drop n-butyllithium into m-dibromobenzene's tetrahydrofuran solution, stir to get reaction solution, then drop diethyl carbonate's tetrahydrofuran solution into the reaction solution, stir to react at room temperature, after the reaction, terminate, extract, separate, discard the water phase, dry the organic phase, filter, concentrate to get the crude product, separate by column chromatography to get m-tribromotriphenylmethanol, i.e. compound 3;

[0036] S22, add m-tribromotriphenylmethanol into formic acid, stir to react under reflux, after the reaction, terminate, extract, separate, discard the water phase, dry the organic phase, filter, concentrate to get the crude product, separate by column chromatography to get m-tribromotriphenylmethane, i.e. compound 4;

[0037] S23, add m-tribromotriphenylmethane, phenylboronic acid, tetrakis(triphenylphosphine)palladium and potassium carbonate into the mixed solution of tetrahydrofuran and water, stir to react under reflux under nitrogen protection, after the reaction, terminate, extract, separate, discard the water phase, dry the organic phase, filter, concentrate to get the crude product, separate by column chromatography to get the non-conjugated light-emitting molecule with the structure shown in formula II.

[0038] In the preparation method of the third aspect, in step S21, the molar ratio of m-dibromobenzene, n-butyllithium and diethyl carbonate can be (3.3-3.6):(3.0-3.3):1.

[0039] In the preparation method of the third aspect, in step S23, the molar ratio of m-tribromotriphenylmethane, phenylboronic acid and tetrakis(triphenylphosphine)palladium can be 1:(6.0-9.0):(0.05-0.20).

[0040] In the preparation method of the third aspect, the eluent of the column chromatography can be pure petroleum ether or a mixture of petroleum ether and ethyl acetate. The volume ratio of petroleum ether to ethyl acetate in the mixture of petroleum ether and ethyl acetate can be 1-1000:1.

[0041] In a fourth aspect, the present application provides a preparation method of a non-conjugated light-emitting molecule, the synthesis route of which is as follows:

[0042]

[0043] The preparation method comprises the following steps:

[0044] S31, under -40 to -50℃, drop isopropylmagnesium chloride into o-dibromobenzene's tetrahydrofuran solution, stir to get reaction solution, then drop o-bromobenzaldehyde's tetrahydrofuran solution into the reaction solution, stir to react at room temperature, after the reaction, terminate, extract, separate, discard the water phase, dry the organic phase, filter, concentrate to get the crude product, separate by column chromatography to get o-bromine o-iodobenzene methanol, i.e. compound 5;

[0045] S32, o-bromine o-iodine benzyl alcohol, benzene and hexafluoroisopropanol (HFIP) are added into a sealed tube, trifluoromethanesulfonic acid (TfOH) is added, then it is heated to 90-100°C, after the reaction is completed, it is terminated, extracted, separated, the water phase is discarded, the organic phase is dried, filtered, concentrated to obtain the crude product, column chromatography is used to separate o-bromine o-iodine triphenylmethane, i.e. compound 6;

[0046] S33, m-chloroperoxybenzoic acid (mCPBA) is dissolved in dichloromethane (DCM), the solution is cooled to -10-0°C, o-bromine o-iodine triphenylmethane is added into the solution, trifluoromethanesulfonic acid is added into the reaction solution at -10-0°C, then it is reacted at room temperature, after the reaction is completed, the solvent is removed by rotary evaporation, the obtained crude product is added into a mixed solution of potassium iodide, diethyl ether and water, filtered, dried to obtain o-bromine phenyl diphenyl iodonium iodide, i.e. compound 7;

[0047] S34, o-bromine phenyl diphenyl iodonium iodide is added into a sealed tube, heated to 150-200°C, after the reaction is completed, it is terminated, extracted, separated, the water phase is discarded, the organic phase is dried, filtered, concentrated to obtain the crude product, column chromatography is used to separate o-bromine di-o-iodine triphenylmethane, i.e. compound 8;

[0048] S35, o-bromine di-o-iodine triphenylmethane, phenylboronic acid, tetrakis(triphenylphosphine)palladium and potassium carbonate are added into a mixed solution of tetrahydrofuran and water, stirred and reacted under reflux in nitrogen protection, after the reaction is completed, it is terminated, extracted, separated, the water phase is discarded, the organic phase is dried, filtered, concentrated to obtain the crude product, column chromatography is used to separate the non-conjugated light-emitting molecule with the structure shown in formula III.

[0049] In the preparation method of the fourth aspect, in step S31, the molar ratio of o-diiodobenzene, o-bromobenzaldehyde and isopropyl magnesium chloride can be 1: (1.1-1.3): (1.0-1.1).

[0050] In the preparation method of the fourth aspect, in step S32, the molar ratio of o-bromine o-iodine benzyl alcohol, benzene and trifluoromethanesulfonic acid can be 1: (5.0-6.0): (0.1-0.3).

[0051] In the preparation method of the fourth aspect, in step S33, the molar ratio of o-bromine o-iodine triphenylmethane, m-chloroperoxybenzoic acid, trifluoromethanesulfonic acid and potassium iodide can be 1: (1.1-1.3): (3.0-4.0): (5.0-6.0).

[0052] In the preparation method of the fourth aspect, in step S35, the molar ratio of o-bromine di-o-iodine triphenylmethane, phenylboronic acid and tetrakis(triphenylphosphine)palladium can be 1: (6.0-9.0): (0.05-0.20).

[0053] In the preparation method of the fourth aspect, the eluent of the column chromatography can be pure petroleum ether or a mixture of petroleum ether and ethyl acetate. The volume ratio of petroleum ether to ethyl acetate in the mixture of petroleum ether and ethyl acetate can be 1-1000:1.

[0054] In the fifth aspect, the application provides an application of the non-conjugated light-emitting molecule in the first aspect in the field of fluorescence.

[0055] In the sixth aspect, the application provides an application of the non-conjugated light-emitting molecule in the first aspect in a light-emitting device.

[0056] In the seventh aspect, the application provides a fluorescence regulation method of the non-conjugated light-emitting molecule in the first aspect. By adding a poor solvent, the non-conjugated light-emitting molecule forms aggregation in a solution, a new long-wave emission peak appears in the red shift of the emission wavelength, and the fluorescence intensity is enhanced.

[0057] In the fluorescence regulation method of the seventh aspect, the poor solvent can be water.

[0058] The non-conjugated light-emitting molecule of the application is constructed on the basis of a non-conjugated skeleton, and the light-emitting property thereof belongs to weak interaction base light-emitting.

[0059] The non-conjugated light-emitting molecule of the application can emit fluorescence under an excitation light wavelength of 200-400 nm, and the fluorescence emission wavelength is 350-500 nm. The half peak width of the solid fluorescence emission peak of m-TBPM is 40 nm, and the solid light-emitting efficiency reaches 100%.

[0060] The non-conjugated light-emitting molecule of the application mainly has a fluorescence emission peak in the short wavelength region under light excitation in a monodisperse state, and after aggregation, a dominant light-emitting peak belonging to space conjugation is generated in the long wavelength region. The material does not exhibit excitation-dependent light-emitting behavior in a solid state, that is, the emission peak does not change with the change of the excitation light wavelength.

[0061] Compared with the prior art, the application has the following beneficial effects:

[0062] 1. The application creatively synthesizes a novel non-conjugated light-emitting molecule, which further enriches the system of non-conjugated light-emitting molecules.

[0063] 2. The preparation method of the non-conjugated light-emitting molecule provided by the application is simple, reliable and widely applicable.

[0064] 3. The light-emitting property of the non-conjugated light-emitting molecule provided by the application can be regulated by changing the position of the substituent group and the charge density on the aromatic ring.

[0065] 4、The solid light-emitting efficiency of the non-conjugated light-emitting molecule m-TBPM provided by the application can reach 100%, and the emission peak half-peak width is narrow, only 40 nm.

[0066] 5、The application provides a new strategy for the design and preparation of non-conjugated light-emitting materials, and provides a new building block for the study of the photophysical theory of spatial interaction. BRIEF DESCRIPTION OF DRAWINGS

[0067] Figure 1 Figure 6 is a fluorescence spectrum diagram of p-TBPM in tetrahydrofuran solution with water content of 0% and 90 vol%.

[0068] Figure 2 Figure 7 is a fluorescence spectrum diagram of m-TBPM in tetrahydrofuran solution with water content of 0% and 90 vol%.

[0069] Figure 3 Figure 8 is a fluorescence spectrum diagram of o-TBPM in tetrahydrofuran solution with water content of 0% and 90 vol%.

[0070] Figure 4 Figure 9 is a fluorescence spectrum diagram of 10 -5 mol / L, 10 -4 mol / L and 10 -3 mol / L m-TBPM tetrahydrofuran solution.

[0071] Figure 5 Figure 10 is a fluorescence spectrum diagram of solid m-TBPM under 280 nm and 320 nm light excitation. DETAILED DESCRIPTION

[0072] The application will be further described below in combination with the drawings and specific embodiments. It should be understood that these embodiments are only used to illustrate the application and not to limit the scope of the application.

[0073] Embodiment 1

[0074] Synthesis method of non-conjugated light-emitting molecule p-TBPM:

[0075]

[0076] The first step, under the condition of nitrogen protection and low temperature-78℃, n-butyllithium (3.3mmol, 2.5M n-hexane solution) was added dropwise to the solution of p-dibromobenzene (3.0mmol) in tetrahydrofuran (150mL). After stirring for 2h, diethyl carbonate (1.0mmol) in tetrahydrofuran (20mL) was added dropwise to the reaction solution, and stirred for 0.5h. Then the reaction solution was restored to room temperature and stirred for 12h. After the reaction was completed, 50mL of saturated brine was added, and dichloromethane (3×50mL) was used for extraction. The combined organic phase was dried over anhydrous sodium sulfate, filtered, and concentrated by rotary evaporation to obtain the crude product. Column chromatography was used for separation, and petroleum ether: ethyl acetate (volume ratio) = 10:1 was used as the eluent. The purified and concentrated product was p-tribromotriphenylmethanol. The second step, p-tribromotriphenylmethanol (1.0mmol) was added to formic acid (50mL) and stirred under reflux for 12h. After the reaction was completed, it was neutralized to neutral with saturated sodium carbonate solution. Then dichloromethane (3×50mL) was used for extraction, and the combined organic phase was dried over anhydrous sodium sulfate, filtered, and concentrated by rotary evaporation to obtain the crude product. Column chromatography was used for separation, and pure petroleum ether was used as the eluent. The purified and concentrated product was p-tribromotriphenylmethane. The third step, p-tribromotriphenylmethane (1.0mmol), phenylboronic acid (5.0mmol), tetrakis(triphenylphosphine)palladium (0.05mmol) and potassium carbonate (2M aqueous solution) were added to a mixed solution of tetrahydrofuran (40mL) and water (8mL). The reaction solution was stirred under reflux for 36h under nitrogen protection. After the reaction was completed, dichloromethane (3×50mL) was used for extraction, and the combined organic phase was dried over anhydrous sodium sulfate, filtered, and concentrated by rotary evaporation to obtain the crude product. Column chromatography was used for separation, and petroleum ether: ethyl acetate (volume ratio) = 50:1 was used as the eluent. The purified and concentrated product was the target molecule p-TBPM. The characterization data of the product p-TBPM prepared in this example are as follows: 1 H NMR (600 MHz, CDCl3), δ (ppm): 7.59 (d, J = 7.2 Hz, 6H), 7.56 (d, J = 8.1 Hz, 6H), 7.43 (t, J = 7.6 Hz, 6H), 7.33 (t, J = 7.3 Hz, 3H), 7.27 (d, J = 8.0 Hz, 6H), 5.66 (s, 1H).

[0077] Example 2

[0078] Synthesis method of non-conjugated light-emitting molecule m-TBPM:

[0079]

[0080] The first step, under the condition of nitrogen protection and low temperature-78℃, n-butyllithium (3.3mmol, 2.5M n-hexane solution) was added dropwise to the solution of m-dibromobenzene (3.0mmol) in tetrahydrofuran (150mL). After stirring for 2h, diethyl carbonate (1.0mmol) in tetrahydrofuran (20mL) was added dropwise to the reaction solution, and stirred for 0.5h. Then the reaction solution was restored to room temperature and stirred for 12h. After the reaction was completed, 50mL of saturated brine was added, and dichloromethane (3×50mL) was used for extraction. The combined organic phase was dried over anhydrous sodium sulfate, filtered, and concentrated by rotary evaporation to obtain the crude product. Column chromatography was used for separation, and petroleum ether: ethyl acetate (volume ratio) = 10:1 was used as the eluent. The purified and concentrated product was m-tribromotriphenylmethanol. The second step, m-tribromotriphenylmethanol (1.0mmol) was added to formic acid (50mL) and stirred under reflux for 12h. After the reaction was completed, it was neutralized to neutral with saturated sodium carbonate solution. Then dichloromethane (3×50mL) was used for extraction, and the combined organic phase was dried over anhydrous sodium sulfate, filtered, and concentrated by rotary evaporation to obtain the crude product. Column chromatography was used for separation, and pure petroleum ether was used as the eluent. The purified and concentrated product was m-tribromotriphenylmethane. The third step, m-tribromotriphenylmethane (1.0mmol), phenylboronic acid (5.0mmol), tetrakis(triphenylphosphine)palladium (0.05mmol) and potassium carbonate (2M aqueous solution) were added to a mixed solution of tetrahydrofuran (40mL) and water (8mL). The reaction solution was stirred under reflux for 36h under nitrogen protection. After the reaction was completed, dichloromethane (3×50mL) was used for extraction, and the combined organic phase was dried over anhydrous sodium sulfate, filtered, and concentrated by rotary evaporation to obtain the crude product. Column chromatography was used for separation, and petroleum ether: ethyl acetate (volume ratio) = 50:1 was used as the eluent. The purified and concentrated product was the target molecule m-TBPM. The product prepared in this example, m-TBPM, had the following characterization data: 1 H NMR (600 MHz, CDCl3), δ (ppm): 7.53 (d, J = 7.3 Hz, 6H), 7.47 (d, J = 9.9 Hz, 6H), 7.38 (q, J = 7.8 Hz, 9H), 7.31 (t, J = 7.3 Hz, 3H), 7.17 (d, J = 7.5 Hz, 3H), 5.74 (s, 1H).

[0081] Example 3

[0082] Synthesis method of non-conjugated light-emitting molecule o-TBPM:

[0083]

[0084] The first step, under nitrogen protection, isopropanol magnesium chloride (1.1 mmol, 2M tetrahydrofuran solution) is added dropwise to a solution of o-diiodobenzene (1.0 mmol) in tetrahydrofuran (50 mL), after stirring for 2 h, a solution of o-bromobenzaldehyde (1.1 mmol) in tetrahydrofuran (20 mL) is added dropwise to the reaction solution, and the reaction solution is restored to room temperature, and stirred at room temperature for 12 h. After the reaction is completed, 50 mL of saturated brine is added, extracted with dichloromethane (3 x 50 mL), the combined organic phase is dried over anhydrous sodium sulfate, filtered, and concentrated by rotary evaporation to obtain the crude product. Column chromatography is used for separation, and the eluent is petroleum ether: ethyl acetate (volume ratio) = 10:1. After purification and concentration, o-bromine o-iodine benzyl alcohol is obtained. The second step, o-bromine o-iodine benzyl alcohol (1.0 mmol), benzene (5.0 mmol) and hexafluoroisopropanol (30 mL) are added to a sealed tube, trifluoromethanesulfonic acid (0.1 mmol) is added, and then sealed and heated to 95°C for 18 h. After the reaction is completed, 50 mL of saturated brine is added, extracted with dichloromethane (3 x 50 mL), the combined organic phase is dried over anhydrous sodium sulfate, filtered, and concentrated by rotary evaporation to obtain the crude product. Column chromatography is used for separation, and the eluent is pure petroleum ether. After purification and concentration, o-bromine o-iodine triphenylmethane is obtained. The third step, under nitrogen protection, m-chloroperoxybenzoic acid (1.1 mmol) is dissolved in dichloromethane (10 mL), and the solution is cooled to 0°C. o-Bromine o-iodine triphenylmethane (1.0 mmol) is added to the solution, trifluoromethanesulfonic acid (3.3 mmol) is added to the reaction solution at 0°C, and then the reaction solution is restored to room temperature and reacted at room temperature for 2 h. After the reaction is completed, the solvent is removed by rotary evaporation. The crude product is added to a mixture of potassium iodide (5 mmol) in ethyl ether and water (10 mL / 10 mL), filtered and dried to obtain o-bromine phenyl diphenyl iodonium iodide. The fourth step, o-bromine phenyl diphenyl iodonium iodide (1 mmol) is added to a sealed tube and heated to 200°C. After the reaction is completed, 50 mL of saturated brine is added, extracted with dichloromethane (3 x 50 mL), the combined organic phase is dried over anhydrous sodium sulfate, filtered, and concentrated by rotary evaporation to obtain the crude product. Column chromatography is used for separation, and the eluent is pure petroleum ether. After purification and concentration, o-bromine di-o-iodine triphenylmethane is obtained. The fifth step, o-bromine di-o-iodine triphenylmethane (1.0 mmol), phenylboronic acid (5.0 mmol), tetrakis(triphenylphosphine)palladium (0.05 mmol) and potassium carbonate (2M aqueous solution) are added to a mixture of tetrahydrofuran (40 mL) and water (8 mL). The reaction solution is stirred under reflux for 36 h. After the reaction is completed, extracted with dichloromethane (3 x 50 mL), the combined organic phase is dried over anhydrous sodium sulfate, filtered, and concentrated by rotary evaporation to obtain the crude product. Column chromatography is used for separation, and the eluent is pure petroleum ether. After purification and concentration, the target molecule o-TBPM is obtained. The product o-TBPM prepared in this example has the following characterization data: 1H NMR (600 MHz, CDC13), δ (ppm): 7.20 (dd, J = 20.6, 7.1 Hz, 9H), 7.01 (t, J = 7.6 Hz, 6H), 6.89 (dd, J = 16.4, 7.4 Hz, 6H), 6.04 (s, 6H), 5.28 (s, 1H).

[0085] Example 4

[0086] The luminescence performance of the non-conjugated luminescent molecules p-TBPM, m-TBPM and o-TBPM in Examples 1-3 was tested.

[0087] Specifically comprising the following steps:

[0088] (a) Prepare tetrahydrofuran stock solutions of p-TBPM, m-TBPM and o-TBPM respectively, with a sample concentration of 10 -3 mol / L.

[0089] (b) Take 300 μL of the stock solution prepared in step (a), and prepare sample solutions with a water content of 0% and 90 vol% respectively, with a concentration of 10 -4 mol / L, and measure their fluorescence spectra, with the results shown in Figures 1-3 .

[0090] (c) Take the m-TBPM stock solution prepared in step (a), and dilute it with tetrahydrofuran to concentrations of 10 -4 mol / L, 10 - 5 mol / L respectively, and test the fluorescence spectra of the m-TBPM solutions with different concentrations, with the results shown in Figure 4 .

[0091] (d) Test the fluorescence spectra of m-TBPM solid under excitation by light with wavelengths of 280 nm and 320 nm (the results are shown in Figure 5 ), and the fluorescence quantum yield of the solid.

[0092] The maximum emission wavelengths of the p-TBPM, m-TBPM and o-TBPM molecules prepared in pure tetrahydrofuran solution are at 315 nm, while in tetrahydrofuran solution with a water content of 90 vol%, the maximum emission wavelengths are between 320 nm and 360 nm. Compared with the emission wavelengths in pure tetrahydrofuran, the fluorescence in the solution with a water content of 90 vol% has a significant red shift and enhancement.

[0093] The fluorescence spectra of m-TBPM tetrahydrofuran solutions with different concentrations can be found that, with the solution concentration changing from 10 -5 mol / L to 10 -4 mol / L to 10 -3The fluorescence intensity of the long wavelength peak of m-TBPM at 360 nm was continuously enhanced.

[0094] The long wavelength emission peak of the solid fluorescence of m-TBPM dominated under excitation at 280 nm and 320 nm.

[0095] The half-peak width of the fluorescence peak of the prepared p-TBPM, m-TBPM and o-TBPM was measured by fluorescence spectroscopy, and the fluorescence quantum yield was determined by using a calibrated integrating sphere. The results are shown in Table 1, wherein the quantum yield was measured by an instrument of the following model: FLS5 Photoluminescence Spectrometer (Edinburgh Instrument).

[0096] Table 1

[0097] Molecule Full width at half maximum (nm) Solid-state fluorescence quantum efficiency (%) p-TBPM 53 54.6 m-TBPM 40 100.0 o-TBPM ＞70 4.4

[0098] It should also be understood that various changes and modifications to the preferred embodiments described herein will be apparent to those skilled in the art; such changes and modifications being included within the scope of the application as defined by the appended claims.

Claims

1. A method for fluorescence modulation of a non-conjugated light-emitting molecule, characterized by, By adding a poor solvent, the non-conjugated light-emitting molecules form aggregation in solution, new long-wave emission peaks appear in the red shift of emission wavelength, and the fluorescence intensity is enhanced; The non-conjugated light-emitting molecules have the following structure II:

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