A linear non-conjugated cluster luminescent molecule and its preparation and application

Abstract

The present invention discloses a linear non-conjugated cluster luminescent molecule and its preparation and application. The structure of the cluster luminescent molecule is shown in formula (1): wherein n is an integer from 0 to 6, R 1 and R 2 Each independently selected from -H or -Br. This cluster luminescent material emits fluorescence at an excitation wavelength of 240nm to 260nm. Its structure is relatively flexible and highly symmetrical, and its luminescent properties can be tuned by varying the chain length, resulting in a luminescent material with excellent luminescent properties. The preparation method for this material is simple, reliable, and low-cost.

Description

Technical Field

[0001] The present invention belongs to the field of organic cluster luminescent materials, and in particular relates to a linear non-conjugated cluster luminescent molecule, its preparation and its application in a light-emitting device. Background Art

[0002] Luminescent materials, as important functional materials for information display, are widely used in display devices, chemical sensing, and bioimaging. Depending on the material, they are divided into two types: inorganic and organic. Organic luminescent materials are gaining increasing attention due to their diverse variety, tunable colors, and ease of synthesis. Therefore, how to manipulate their luminescence properties by changing their molecular structure has been a key research focus in the field of organic luminescent materials.

[0003] Currently, the emission wavelength and efficiency of luminescent molecules can be effectively controlled based on the theory of molecular valence conjugation. However, anomalous visible light emission has been observed in non-conjugated molecules widely found in nature, such as proteins, cellulose, and amino acids. This provides a novel strategy for the design of long-wavelength luminescent materials. Furthermore, the structural flexibility of these non-conjugated systems greatly enhances the material's processability. Therefore, the study of these unique luminescence phenomena not only has important theoretical and applied value, but also provides new strategies for the design and performance control of fluorescent materials.

[0004] Patent publication number CN112521534A discloses a method for preparing a cluster-induced highly fluorescent non-conjugated polymer. First, a polyvinylpyrrolidone solution is prepared. Second, the polyvinylpyrrolidone solution and ascorbic acid solution are mixed and reacted at 0-100°C for 2-12 hours to obtain a product solution (PVP-APDs). Finally, the PVP-APDs solution is mixed with a 5-30 mM m-phenylenediamine solution and reacted at 0-80°C for 1-5 hours to obtain a product solution (PVP-APDs@MPD). The resulting non-conjugated polymer exhibits a fluorescence quantum yield of up to 46.9% and exhibits cluster-induced emission properties.

[0005] Linear non-conjugated oligomeric aromatic hydrocarbons are highly symmetrical and relatively flexible non-conjugated structures. They also offer advantages such as simple structural composition and strong controllability, making them ideal models for studying the relationship between non-conjugated molecular structure and luminescence properties. However, currently reported synthetic methods for linear non-conjugated oligomers suffer from drawbacks such as harsh reaction conditions, cumbersome steps, poor substrate compatibility, and low yields of target products (Die Makromolekulare Chemie, 1974, 175, 2423-2439; Tetrahedron Letters, 1985, 26, 6023-6026). Therefore, the search for a simple and efficient method for preparing linear non-conjugated oligomers has long been a focus of attention in the fields of organic synthesis and optical materials. Summary of the Invention

[0006] To address the current bottlenecks in this field, the present invention aims to provide a novel, reliable, and easily synthesized linear non-conjugated cluster luminescent molecule. The linear non-conjugated cluster luminescent molecule is a class of non-conjugated linear oligoaromatic molecules. The linear non-conjugated molecular structure of the present invention is relatively flexible and highly symmetrical, and its luminescent properties can be tuned by varying the chain length, resulting in a luminescent material with excellent luminescent properties.

[0007] The present invention is achieved through the following technical solutions:

[0008] A linear non-conjugated cluster luminescent molecule, the structure of which is shown in formula (1):

[0009]

[0010] In formula (1), n ​​is an integer from 0 to 6;

[0011] In formula (1), R 1 and R 2 are independently selected from the substituents shown in formula (2) or (3):

[0012]

[0013] The linear non-conjugated cluster luminescent molecules emit fluorescence at an excitation light wavelength of 240nm to 260nm.

[0014] The benzene rings of the linear non-conjugated cluster luminescent molecule are isolated from each other without traditional valence bond conjugation, and the luminescence principle is cluster luminescence.

[0015] In a monodisperse state, the material provided by the present invention produces only short-wavelength emission peaks attributed to n- or π-electron groups. However, after clustering, it produces clustered emission peaks at longer wavelengths, attributed to spatial conjugation. The material also exhibits the excitation-dependent luminescence behavior characteristic of clustered luminescent materials, meaning that within a certain range, the emission gradually redshifts with increasing excitation wavelength.

[0016] Preferably, the structure of the linear non-conjugated cluster luminescent molecule is as shown in formula (4) to formula (7):

[0017]

[0018] The present invention also provides a method for preparing the linear non-conjugated cluster luminescent molecule. The preparation method is simple to operate, reliable in route and low in cost.

[0019] A method for preparing the linear non-conjugated cluster luminescent molecule, comprising the following steps:

[0020] (1) adding n-butyl lithium dropwise to a degassed THF (tetrahydrofuran) solution of an aryl bromide at -80 to -70°C, stirring uniformly to obtain a reaction solution, adding a THF solution of an aryl formaldehyde dropwise to the reaction solution, stirring at room temperature, washing, extracting, separating the liquids after completion of the reaction, discarding the aqueous phase, drying the organic phase, filtering, and concentrating to obtain a crude product, which is separated by column chromatography to obtain a linear non-conjugated oligomeric aromatic hydrocarbon molecule containing a hydroxyl group;

[0021] The structure of the aryl bromide is shown in formula (8):

[0022]

[0023] In formula (8), n1=0 or 1, R 3 is -H or -Br;

[0024] The structure of the aromatic formaldehyde is shown in formula (9):

[0025]

[0026] In formula (9), R 4 is -H, -CHO or -CH2-Ph;

[0027] (2) dissolving the obtained linear non-conjugated oligomeric aromatic hydrocarbon molecules containing hydroxyl groups and sodium borohydride in trifluoroacetic acid and stirring at room temperature. After the reaction is completed, adjusting the pH to 9-11, washing, extraction, separation, discarding the aqueous phase, drying the organic phase, filtering, and concentrating to obtain a crude product, and separating by column chromatography to obtain the linear non-conjugated cluster luminescent molecules.

[0028] The linear non-conjugated cluster luminescent molecule of the present invention uses brominated aromatic hydrocarbon as raw material, undergoes nucleophilic addition with aromatic formaldehyde to generate linear non-conjugated molecules containing hydroxyl groups, and then reduces the linear non-conjugated cluster luminescent molecule.

[0029] Preferably, in step (1) of the preparation method, the molar ratio of the aryl bromide, n-butyl lithium and aryl formaldehyde is 1:(1.1-2.2):(1.1-2.2).

[0030] Preferably, in step (2) of the preparation method, the molar ratio of the linear non-conjugated oligomeric aromatic hydrocarbon molecules containing hydroxyl groups to sodium borohydride is 1:(10-15).

[0031] Preferably, in step (1) of the preparation method, the eluent for the column chromatography is a mixture of petroleum ether and ethyl acetate, and the volume ratio of petroleum ether to ethyl acetate in the mixture of petroleum ether and ethyl acetate is 5:1.

[0032] Preferably, in step (2) of the preparation method, the eluent for the column chromatography is a mixture of petroleum ether and ethyl acetate, and the volume ratio of petroleum ether to ethyl acetate in the mixture of petroleum ether and ethyl acetate is 50:1.

[0033] In order to obtain a linear non-conjugated aromatic hydrocarbon containing a pair of hydroxyl groups in step (1), the n-butyl group should be appropriately excessive and the bromine atoms on the bromoaromatic hydrocarbon should be completely replaced.

[0034] The present invention also provides a method for preparing a linear non-conjugated cluster luminescent molecule having a structure such as formula (4). The preparation method comprises the following steps: adding n-butyl lithium dropwise to a degassed THF solution of 4-bromodiphenylmethane at a low temperature of -80 to -70°C, stirring uniformly to obtain a reaction solution, adding a THF solution of benzaldehyde dropwise to the reaction solution, wherein the molar ratio of 4-bromodiphenylmethane to benzaldehyde is 1:0.8 to 1.2, stirring at room temperature, washing, extracting, separating the liquids, discarding the aqueous phase, drying the organic phase, filtering, and concentrating to obtain a crude product, which is then separated by column chromatography to obtain a linear non-conjugated oligomeric aromatic hydrocarbon molecule containing a hydroxyl group; and dissolving the obtained linear non-conjugated oligomeric aromatic hydrocarbon molecule containing a hydroxyl group and sodium borohydride in trifluoroacetic acid, stirring at room temperature, adjusting the pH to 9 to 11, washing, extracting, separating the liquids, discarding the aqueous phase, drying the organic phase, filtering, and concentrating to obtain a crude product, which is then separated by column chromatography to obtain a linear non-conjugated cluster luminescent molecule having a structure such as formula (4).

[0035] The present invention also provides a method for preparing a linear non-conjugated cluster luminescent molecule having a structure as shown in formula (5). The preparation method comprises the following steps: adding n-butyl lithium dropwise to a degassed THF solution of 1-bromo-4-[(4-bromophenyl)methyl]benzene at a low temperature of -80 to -70°C, stirring uniformly to obtain a reaction solution, adding a THF solution of benzaldehyde dropwise to the reaction solution, wherein the molar ratio of the 1-bromo-4-[(4-bromophenyl)methyl]benzene to the benzaldehyde is 1:1.6 to 2.4, stirring at room temperature, washing, extracting, separating, discarding the aqueous phase, drying the organic phase, filtering, and concentrating to obtain a crude product, and separating the crude product through column chromatography to obtain a linear non-conjugated oligomeric aromatic hydrocarbon molecule containing a hydroxyl group; and dissolving the obtained linear non-conjugated oligomeric aromatic hydrocarbon molecule containing a hydroxyl group and sodium borohydride in trifluoroacetic acid, stirring at room temperature, adjusting the pH to 9 to 11, washing, extracting, separating, discarding the aqueous phase, drying the organic phase, filtering, and concentrating to obtain a crude product, and separating the crude product through column chromatography to obtain a linear non-conjugated cluster luminescent molecule having a structure as shown in formula (5).

[0036] The present invention also provides a method for preparing a linear non-conjugated cluster luminescent molecule having a structure such as formula (6). The preparation method comprises the following steps: adding n-butyl lithium dropwise to a degassed THF solution of 4-bromodiphenylmethane at a low temperature of -80 to -70°C, stirring uniformly to obtain a reaction solution, adding a THF solution of p-diphenylmethane dropwise to the reaction solution, wherein the molar ratio of the 4-bromodiphenylmethane to the p-diphenylaldehyde is 1.6 to 2.4:1, stirring at room temperature, washing, extracting, separating, discarding the aqueous phase, drying the organic phase, filtering, and concentrating to obtain a crude product, and separating the crude product through column chromatography to obtain a linear non-conjugated oligomeric aromatic hydrocarbon molecule containing a hydroxyl group; and dissolving the obtained linear non-conjugated oligomeric aromatic hydrocarbon molecule containing a hydroxyl group and sodium borohydride in trifluoroacetic acid, stirring at room temperature, adjusting the pH to 9 to 11, washing, extracting, separating, discarding the aqueous phase, drying the organic phase, filtering, and concentrating to obtain a crude product, and separating the crude product through column chromatography to obtain a linear non-conjugated cluster luminescent molecule having a structure as shown in formula (6).

[0037] The present invention also provides a method for preparing a linear non-conjugated cluster luminescent molecule having a structure such as formula (7). The preparation method comprises the following steps: adding n-butyl lithium dropwise to a degassed THF solution of 1-bromo-4-[(4-bromophenyl)methyl]benzene at a low temperature of -80 to -70°C, stirring uniformly to obtain a reaction solution, adding a THF solution of 4-benzylbenzaldehyde dropwise to the reaction solution, wherein the molar ratio of 1-bromo-4-[(4-bromophenyl)methyl]benzene to 4-benzylbenzaldehyde is 1:1.6 to 2.4, stirring at room temperature, washing, extracting, separating the liquids, and discarding the water after the reaction is completed. The obtained linear non-conjugated oligomeric aromatic hydrocarbon molecules containing hydroxyl groups and sodium borohydride are dissolved in trifluoroacetic acid and stirred at room temperature. After the reaction is completed, the pH is adjusted to 9-11, washed, extracted, separated, the aqueous phase is discarded, the organic phase is dried, filtered, and concentrated to obtain a crude product, which is separated by column chromatography to obtain a linear non-conjugated cluster luminescent molecule with a structure such as formula (7).

[0038] The present invention also provides a method for controlling the fluorescence of the linear non-conjugated cluster luminescent molecules.

[0039] A method for controlling the fluorescence of the linear non-conjugated cluster luminescent molecules, comprising: increasing the concentration of the linear non-conjugated cluster luminescent molecules in a solution to form clusters and red-shift the wavelength of the emitted light; and reducing the concentration of the linear non-conjugated cluster luminescent molecules in a solution to blue-shift the wavelength of the emitted light.

[0040] The present invention also provides application of the linear non-conjugated cluster luminescent molecules in luminescent devices.

[0041] Compared with the prior art, the present invention has at least the following advantages:

[0042] 1. The present invention creatively synthesizes a class of linear non-conjugated cluster luminescent molecules with a novel structure, further enriching the types of linear non-conjugated oligomer molecules.

[0043] 2. The preparation method of a linear non-conjugated cluster luminescent molecule provided by the present invention is simple to operate, reliable in route and low in cost.

[0044] 3. The luminescent properties of a linear non-conjugated cluster luminescent molecule provided by the present invention can be regulated by changing the chain length.

[0045] 4. The linear non-conjugated oligomer provided by the present invention has a simple and regular molecular configuration, and its constituent units are single and all are aromatic hydrocarbons, which eliminates the interference of heteroatoms for the study of luminescence mechanism.

[0046] 5. The present invention provides new ideas and new options for the design and preparation of non-conjugated luminescent material molecules, and also provides a new building block for studying the optical physics theory of spatial interactions. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 is the fluorescence emission spectrum of OPM[3] in acetonitrile solution with 0% and 90% water content;

[0048] Figure 2 is the fluorescence emission spectrum of OPM[4] in acetonitrile solution with 0% and 90% water content;

[0049] Figure 3 is the fluorescence emission spectrum of OPM[5] in acetonitrile solution with 0% and 90% water content;

[0050] Figure 4 The fluorescence emission spectra of OPM[6] in 0% and 90% acetonitrile solutions containing water. DETAILED DESCRIPTION

[0051] The present invention will be further described below in conjunction with the accompanying drawings and specific examples. It should be understood that these examples are intended to illustrate the present invention and are not intended to limit the scope of the invention. The operating methods in the following examples where no specific conditions are specified are generally performed under conventional conditions or as recommended by the manufacturer.

[0052] Example 1

[0053] Synthesis of linear non-conjugated oligomer OPM-OH[3] containing a pair of hydroxyl groups:

[0054]

[0055] Under argon protection, 4-bromodiphenylmethane (1.0 mmol) dissolved in 5 mL of THF was added to a dry 50 mL Schlenk flask. At -78 ° C, n-butyl lithium (1.1 mmol, 1.6 M hexane solution) was added dropwise to the 4-bromodiphenylmethane solution. After stirring for 15-30 minutes, a benzaldehyde solution (1.0 mmol) dissolved in 5 mL of THF was added dropwise to the slurry. The reaction mixture was warmed to room temperature and stirred for 2 hours. After the reaction was completed, 20 mL of saturated brine was added and extracted with dichloromethane (3×30 mL). The organic phases were combined, dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure to obtain the crude product. After column chromatography separation, the eluent was petroleum ether: ethyl acetate = 5:1, and the target product OPM-OH was purified and concentrated to obtain a white solid [3].

[0056] Synthesis method of linear non-conjugated oligomer OPM[3]:

[0057]

[0058] Dissolve OPM-OH[3] in 10 mL of trifluoroacetic acid (TFA), then slowly add sodium borohydride (10 mmol). After stirring at room temperature for 1 hour, pour into 50 mL of ice water to quench the mixture. Then add sodium hydroxide aqueous solution to adjust the reaction mixture to pH = 10. Add 50 mL of saturated brine, extract with dichloromethane (3×30 mL), combine the organic phases, dry over anhydrous sodium sulfate, filter, and concentrate under reduced pressure to obtain a crude product. Separate by column chromatography using petroleum ether: ethyl acetate = 50:1 as eluent, and purify and concentrate to obtain the target product OPM[3] as a white solid.

[0059] The product characterization data prepared in this example are as follows:

[0060] Linear non-conjugated oligomer OPM[3]

[0061] 1 H NMR (600MHz, Chloroform-d) δ7.28 (dd, J=8.7, 6.7Hz, 4H), 7.19 (td, J=6.8, 1.5Hz, 6H), 7.11 (s, 4H), 3.95 (s, 4H).

[0062] Example 2

[0063] Synthesis of linear non-conjugated oligomer OPM-OH[4] containing a pair of hydroxyl groups:

[0064]

[0065] Under argon protection, 1-bromo-4-[(4-bromophenyl)methyl]benzene (2.0 mmol) dissolved in 5 mL of THF was added to a dry 50 mL Schlenk flask. At -78 ° C, n-butyl lithium (2.2 mmol, 1.6 M hexane solution) was added dropwise to the 1-bromo-4-[(4-bromophenyl)methyl]benzene solution. After stirring for 15-30 minutes, a benzaldehyde solution (4.0 mmol) dissolved in 5 mL of THF was added dropwise to the slurry. The reaction mixture was warmed to room temperature and stirred for 3 hours. After the reaction was completed, 50 mL of saturated brine was added and extracted with dichloromethane (3×30 mL). The organic phases were combined, dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure to obtain the crude product. After column chromatography separation, the eluent was petroleum ether: ethyl acetate = 5:1, and the target product OPM-OH [4] was purified and concentrated to obtain a white solid.

[0066] Synthesis method of linear non-conjugated oligomer OPM[4]:

[0067]

[0068] Dissolve OPM-OH[4] in 40 mL of trifluoroacetic acid (TFA), then add sodium borohydride (40 mmol) in batches. After stirring at room temperature for 1 hour, pour into 100 mL of ice water to quench the mixture. Then add sodium hydroxide aqueous solution to adjust the reaction mixture to pH = 10. Add 100 mL of saturated brine, extract with dichloromethane (3×30 mL), combine the organic phases, dry over anhydrous sodium sulfate, filter, and concentrate under reduced pressure to obtain a crude product. Separate by column chromatography using petroleum ether: ethyl acetate = 50:1 as eluent, and purify and concentrate to obtain the target product OPM[4] as a white solid.

[0069] The product characterization data prepared in this example are as follows:

[0070] Linear non-conjugated oligomer OPM[4]

[0071] 1 H NMR (600MHz, DMSO-d6) δ7.26(t,J=7.6Hz,1H),7.21–7.14(m,1H),7.11(s,2H),3.87(s,1H),3.83(s,1H).

[0072] Example 3

[0073] Synthesis of linear non-conjugated oligomer OPM-OH[5] containing a pair of hydroxyl groups:

[0074]

[0075] Under argon protection, 4-bromodiphenylmethane (2.0 mmol) dissolved in 5 mL of THF was added to a dry 50 mL Schlenk flask. At -78 ° C, n-butyl lithium (2.2 mmol, 1.6 M hexane solution) was added dropwise to the 4-bromodiphenylmethane solution. After stirring for 15-30 minutes, a solution of p-diphenylaldehyde (1.0 mmol) dissolved in 5 mL of THF was added dropwise to the slurry. The reaction mixture was warmed to room temperature and stirred for 3 hours. After the reaction was completed, 50 mL of saturated brine was added and extracted with dichloromethane (3×30 mL). The organic phases were combined, dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure to obtain the crude product. After column chromatography separation, the eluent was petroleum ether: ethyl acetate = 5:1, and the target product OPM-OH was purified and concentrated to obtain a white solid [5].

[0076] Synthesis method of linear non-conjugated oligomer OPM[5]:

[0077]

[0078] Dissolve OPM-OH[5] in 10 mL of trifluoroacetic acid (TFA), then add sodium borohydride (10 mmol) in batches. After stirring at room temperature for 1 hour, pour into 50 mL of ice water to quench the mixture. Then add aqueous sodium hydroxide solution to adjust the reaction mixture to pH = 10. Add 50 mL of saturated brine and extract with dichloromethane (3×30 mL). Combine the organic phases, dry over anhydrous sodium sulfate, filter, and concentrate under reduced pressure to obtain a crude product. Separate by column chromatography using petroleum ether: ethyl acetate = 50:1 as the eluent, and purify and concentrate to obtain the target product OPM[5] as a white solid.

[0079] The product characterization data prepared in this example are as follows:

[0080] Linear non-conjugated oligomer OPM[5]

[0081] 1 H NMR (600MHz, DMSO-d6) δ7.26 (t, J = 7.5Hz, 4H), 7.21–7.14 (m, 6H), 7.12–7.07 (m, 12H), 3.87 (s, 4H), 3.81 (s, 4H).

[0082] Example 4

[0083] Synthesis of linear non-conjugated oligomer OPM-OH[6] containing a pair of hydroxyl groups:

[0084]

[0085] Under argon protection, 1-bromo-4-[(4-bromophenyl)methyl]benzene (2.0 mmol) dissolved in 5 mL of THF was added to a dry 50 mL Schlenk flask. At -78 ° C, n-butyl lithium (2.2 mmol, 1.6 M hexane solution) was added dropwise to the 1-bromo-4-[(4-bromophenyl)methyl]benzene solution. After stirring for 15-30 minutes, a solution of 4-benzylbenzaldehyde (4.0 mmol) dissolved in 5 mL of THF was added dropwise to the slurry. The reaction mixture was warmed to room temperature and stirred for 4 hours. After the reaction was completed, 50 mL of saturated brine was added and extracted with dichloromethane (3×30 mL). The organic phases were combined, dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure to obtain the crude product. After column chromatography separation, the eluent was petroleum ether: ethyl acetate = 5:1, and the target product OPM-OH was purified and concentrated to obtain a white solid [6].

[0086] Synthesis method of linear non-conjugated oligomer OPM[6]:

[0087]

[0088] Dissolve OPM-OH[5] in 10 mL of trifluoroacetic acid (TFA), then add sodium borohydride (10 mmol) in batches. After stirring at room temperature for 1 hour, pour into 50 mL of ice water to quench the mixture. Then add aqueous sodium hydroxide solution to adjust the reaction mixture to pH = 10. Add 50 mL of saturated brine and extract with dichloromethane (3×30 mL). Combine the organic phases, dry over anhydrous sodium sulfate, filter, and concentrate under reduced pressure to obtain a crude product. Separate by column chromatography using petroleum ether: dichloromethane = 5:1 as eluent, and purify and concentrate to obtain the target product OPM[6] as a white solid.

[0089] The product characterization data prepared in this example are as follows:

[0090] Linear non-conjugated oligomer OPM[6]

[0091] 1 H NMR (600MHz, Chloroform-d) δ7.27(d,J=7.7Hz,4H),7.21–7.15(m,6H),7.08(d,J=6.4Hz,16H),3.93(s,4H),3.89(s,4H),3.88(s,2H).

[0092] Example 5

[0093] The cluster luminescence performance of the linear non-conjugated oligomers OPM[3], OPM[4], OPM[5] and OPM[6] synthesized in Examples 1 to 4 was tested.

[0094] The specific steps include:

[0095] (a) Prepare OPM[3], OPM[4], OPM[5] and OPM[6] samples at a concentration of 10 -3 10 mL of 1 mol / L acetonitrile mother solution.

[0096] (b) Take 300ul of the mother solution prepared in step (a) and place it in a cuvette. Prepare 10% and 90% water contents in the cuvette. -4 mol / L sample solution and measure its emission spectrum.

[0097] Figure 1-Figure 4 These are the fluorescence emission spectra of OPM[3], OPM[4], OPM[5] and OPM[6] molecules in acetonitrile solutions with water content of 0% and 90%, respectively, with the excitation light wavelength being 250nm.

[0098] The prepared OPM[3], OPM[4], OPM[5], and OPM[6] molecules exhibited a maximum emission peak wavelength of 285 nm in pure acetonitrile solution, while their maximum emission peak wavelength in 90% water-containing acetonitrile solution ranged from 320 nm to 425 nm. Compared to the emission in pure acetonitrile, the luminescence of the cluster molecules formed in the 90% water content exhibited a significant red shift.

[0099] In addition, it should be understood that after reading the above description of the present invention, those skilled in the art may make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the claims attached to this application.

Claims

1. A method for controlling the fluorescence of a linear non-conjugated cluster luminescent molecule, characterized in that: Increasing the concentration of the linear non-conjugated cluster luminescent molecules in the solution to form clusters, thereby red-shifting the emission wavelength; decreasing the concentration of the linear non-conjugated cluster luminescent molecules in the solution, thereby blue-shifting the emission wavelength; The structure of the linear non-conjugated cluster luminescent molecule is shown in formula (1): In formula (1), n ​​is an integer from 0 to 6; In formula (1), R 1 and R 2 is a substituent as shown in formula (3):

2. The method for controlling the fluorescence of a linear non-conjugated cluster luminescent molecule according to claim 1, wherein: The linear non-conjugated cluster luminescent molecules emit fluorescence at an excitation light wavelength of 240nm to 260nm.

3. The method for controlling the fluorescence of a linear non-conjugated cluster luminescent molecule according to claim 1, wherein: The structure of the linear non-conjugated cluster luminescent molecule is shown in formula (4) to formula (7):

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