Elastic organic crystal material with multi-level stimulus-responsive room-temperature phosphorescence, preparation method and application thereof

Abstract

The present invention provides an elastic organic crystal material with multi-level stimulus-responsive room temperature phosphorescence, a preparation method and its application. The elastic organic crystal material with multi-level stimulus-responsive room temperature phosphorescence is a single-component benzil derivative having a structure shown in general formula (I). After grinding or thermal annealing the organic single-component benzil derivative crystal, conversion between room temperature phosphorescences of different emission wavelengths can be achieved. After applying a certain external force to the upright organic small molecule crystal, it will undergo an elastic bending, and after the external force is removed, it will return to its original upright state. The single-component organic small molecule crystal optical material of the present invention has the properties of multi-level stimulus-responsive room temperature phosphorescence and elasticity, and can be used in optoelectronic devices, display materials, information storage materials or anti-counterfeiting materials.

Description

Technical Field

[0001] The present invention relates to the technical field of organic luminescent materials, and in particular to an elastic organic crystal with multi-level stimulus responsiveness, a preparation method thereof, and applications thereof. Background Art

[0002] Crystallization-induced phosphorescence has been proven to be an effective method to achieve room-temperature phosphorescence emission of materials. However, the fragility of the crystals greatly limits its application scenarios in real life. Therefore, it is very important to develop elastic organic room-temperature phosphorescent crystals. However, current elastic luminescent crystals are generally based on fluorescence, and elastic organic crystals with room-temperature phosphorescence emission are rarely paid attention to. In addition, room-temperature phosphorescent materials with stimulus responsiveness have attracted widespread attention due to their huge application potential in bioimaging, organic optoelectronic devices, sensing, etc. Since the phosphorescence emission of the material has extremely high requirements for the rigid microenvironment in which the molecules are located and is very sensitive to oxygen, the current stimulus responsive materials are generally based on fluorescence and are multi-component (such as host-guest systems, metal complex systems and doping systems), which limits their application scenarios.

[0003] Therefore, if single-component organic crystals can be endowed with unique mechanical and photophysical properties such as elasticity and multi-level stimulus-responsive room-temperature phosphorescence, this will help expand the practical applications of such materials. Summary of the Invention

[0004] The present invention aims to provide an elastic organic crystal material with multi-stage stimuli-responsive room temperature phosphorescence, as well as its preparation method and application. In the present invention, an elastic organic crystal with multi-stage stimuli-responsive room temperature phosphorescence is prepared by simply modifying benzil and then using a mixed solvent volatilization method to obtain a crystal.

[0005] The specific technical solutions of the present invention include:

[0006] The present invention provides an elastic organic crystal material with multi-level stimulus-responsive room temperature phosphorescence. First, benzil is subjected to simple chemical modification, and then a mixed solvent volatilization method is used to obtain an elastic organic crystal material with multi-level stimulus-responsiveness. The elastic organic crystal material with multi-level stimulus-responsive room temperature phosphorescence has a structure shown in (I)

[0007]

[0008] Wherein, the R group has the structure shown as (R-1), (R-2);

[0009]

[0010] Wherein, n is an integer between 0 and 20.

[0011] Optionally, in some embodiments of the present application, n of the multi-level stimulus-responsive elastic organic crystal is 0 to 7. Preferably, n of the chiral polymer guest material is 6.

[0012] Optionally, in some embodiments of the present application, depending on the number of methylene groups in the molecule, the multi-level stimulus-responsive room-temperature phosphorescent elastic organic crystal material prepared by the present invention has the property of long-life luminescence, and the phosphorescence lifetime of the multi-level stimulus-responsive room-temperature phosphorescent elastic organic crystal is ≥0.1ms.

[0013] Optionally, in some embodiments of the present application, the phosphorescence quantum yield of the multi-level stimulus-responsive room-temperature phosphorescent elastic organic crystal material prepared by the present invention is adjustable according to the number of methylene groups in the molecule, and the absolute phosphorescence quantum yield of the multi-level stimulus-responsive room-temperature phosphorescent elastic organic crystal is ≥0.1%.

[0014] Optionally, in some embodiments of the present application, the elastic organic crystal material with multi-level stimulus-responsive room-temperature phosphorescence prepared by the present invention has a mechanical force stimulus-responsive property.

[0015] Optionally, in some embodiments of the present application, the elastic organic crystal material having multi-stage stimuli-responsive room temperature phosphorescence prepared by the present invention has a thermal stimulus-responsive property. The thermal stimulus-responsive thermal annealing temperature is between 70 and 150 degrees Celsius. Preferably, the thermal annealing temperature is 80 degrees Celsius.

[0016] Optionally, in some embodiments of the present application, the elastic organic crystal material with multi-stage stimuli-responsive room temperature phosphorescence prepared by the present invention exhibits solvent stimuli-responsive properties. The fumigation solvent may be selected from one or a mixture of dichloromethane, chloroform, ethyl acetate, tetrahydrofuran, and diethyl ether. Preferably, the fumigation solvent is dichloromethane.

[0017] Optionally, in some embodiments of the present application, the elastic organic crystal material with multi-level stimulus-responsive room temperature phosphorescence prepared by the present invention has elastic bending ability.

[0018] Correspondingly, an embodiment of the present application also provides a method for preparing the elastic organic crystal with stimulus-responsive room temperature phosphorescence, comprising: performing simple chemical modification on benzil, and then obtaining an elastic organic crystal material with multi-level stimulus responsiveness through a mixed solvent volatilization method.

[0019] Optionally, in some embodiments of the present application, in the method for preparing elastic organic crystals with stimuli-responsive room temperature phosphorescence, the good solvent is one or more of dichloromethane, chloroform, ethyl acetate, tetrahydrofuran, diethyl ether, N,N-dimethylformamide, and dimethyl sulfoxide, and the poor solvent is one or more of petroleum ether, n-hexane, and cyclohexane. Preferably, the good solvent is dichloromethane and the poor solvent is n-hexane.

[0020] In addition, the present invention also provides an application of the elastic organic crystal material with multi-level stimulus-responsive room-temperature phosphorescence in the preparation of optoelectronic devices, display materials, information storage materials or anti-counterfeiting materials.

[0021] The embodiments of the present application use benzyl derivatives as the parent material to prepare an elastic organic crystal material with multi-level stimulus-responsive room-temperature phosphorescence. The raw materials used in the embodiments of the present application are all pure organic compounds, which are widely available, easy to obtain, inexpensive, simple to synthesize, and convenient to prepare. The organic room-temperature phosphorescent crystal material prepared by the present invention has multi-level stimulus responsiveness and elasticity; the material has stable luminescent properties and can be used in air without the need for inert gas protection or a vacuum environment. The pure organic room-temperature phosphorescent material prepared by the present invention has a high absolute phosphorescence quantum yield, can respond to external forces, heat, and solvents, and the crystal has elastic properties that most crystals do not have, and is suitable for optoelectronic devices, display materials, information storage, or anti-counterfeiting materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 The phosphorescence spectrum of the elastic organic crystal material with multi-level stimulus-responsive room-temperature phosphorescence obtained in Example 1 of the present invention;

[0023] Figure 2 This is a phosphorescence lifetime spectrum of the elastic organic crystal material with multi-level stimulus-responsive room-temperature phosphorescence obtained in Example 1 of the present invention;

[0024] Figure 3 This is a phosphorescence spectrum with force stimulation response (before and after grinding) obtained in Example 2 of the present invention;

[0025] Figure 4 1 is a phosphorescence spectrum with thermal stimulus response (before and after thermal annealing) obtained in Example 4 of the present invention;

[0026] Figure 5 This is a phosphorescence spectrum obtained in Example 4 of the present invention with solvent stimulation response (before and after dichloromethane fumigation);

[0027] Figure 6 The photographs are of the luminescence changes of the elastic organic crystal material with multi-level stimulus-responsive room-temperature phosphorescence obtained in Examples 1 to 8 of the present invention before and after grinding;

[0028] Figure 7 This is a photograph of the elastic organic crystal material with multi-level stimulus-responsive room-temperature phosphorescence obtained in Example 6 of the present invention undergoing elastic bending after external force is applied;

[0029] Figure 8 This is a photo of the luminescence of the phosphorescent coating made of an elastic organic crystal material with multi-level stimulus-responsive room-temperature phosphorescence under ultraviolet light in Example 8 of the present invention. DETAILED DESCRIPTION

[0030] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without making creative efforts are within the scope of protection of this application.

[0031] Example 1.

[0032] In this embodiment, the target molecule is an elastic organic crystal material 3 with multi-level stimulus responsiveness. 3 is purchased directly from a reagent company in powder form. The specific steps for preparing the elastic organic crystal material with multi-level stimulus responsiveness are as follows:

[0033]

[0034] (1) Preparation of 3 single crystals of elastic organic crystal materials with multi-level stimulus responsiveness:

[0035] Compound 3 (20 mg) was dissolved in 8 mL of CH2Cl2 solution and dispersed homogeneously by ultrasonication. The solution was filtered through an ultrafiltration filter and transferred to a 20 mL sample vial. 8 mL of n-hexane was added to the top layer and allowed to stand for 7 days to obtain yellow needle-shaped crystals. The phosphorescence emission peak was around 530 nm, the phosphorescence lifetime was 1.720 ms, and the phosphorescence quantum yield was 34.8%.

[0036] Example 2.

[0037] In this embodiment, the reaction precursors provided are compounds 1, 2, and 3. The specific method for preparing an elastic organic crystal material with multi-level stimulus responsiveness includes the following steps.

[0038] (1) Synthesis of reaction precursor 1:

[0039]

[0040] Compound 3 (3 g, 9.2 mmol) was dissolved in 250 mL of acetic acid, followed by the addition of a 4:1 volume ratio of concentrated sulfuric acid / water solution. The reaction was stirred under reflux for 10 hours. After completion of the reaction, 200 mL of deionized water was added in an ice bath. The filtered solid was washed three times with water and then dried in a vacuum oven at 70°C to yield 1 (2.52 g) as a pale yellow powder.

[0041] (2) Synthesis of elastic organic crystal material 4 with multi-level stimulus responsiveness:

[0042]

[0043] Compound 1 (500 mg, 1.68 mmol) was added to 30 mL of dichloromethane, followed by 11-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride (2.60 g, 13.44 mmol), 4-dimethylaminopyridine (1.65 g, 13.44 mmol), and anhydrous ethanol (232.19 mg, 5.04 mmol). The mixture was allowed to react at room temperature for 12 hours. The solvent was then removed by rotary evaporation. The spin-dried product was purified by column chromatography (developing solvent ratio: petroleum ether: dichloromethane = 2:3) to obtain 4 as a pale yellow solid powder.

[0044] (3) Preparation of 4 single crystals of elastic organic crystal materials with multi-level stimulus responsiveness:

[0045] Compound 4 (20 mg) was dissolved in 8 mL of CH2Cl2 solution and dispersed homogeneously by ultrasonication. The solution was filtered through an ultrafiltration filter and transferred to a 20 mL sample vial. 8 mL of n-hexane was added to the top layer and allowed to stand for 7 days to obtain pale yellow needle-shaped crystals. The phosphorescence emission peak was around 500 nm, the phosphorescence lifetime was 0.517 ms, and the phosphorescence quantum yield was 14.9%.

[0046] Example 3.

[0047] In this embodiment, the reaction precursors provided are compounds 1 and 5. The specific method for preparing the elastic organic crystal material with multi-level stimulus responsiveness includes the following steps.

[0048] (1) Synthesis of elastic organic crystal material 6 with multi-level stimulus responsiveness:

[0049]

[0050] Compound 1 (500 mg, 1.68 mmol) was added to 30 mL of dichloromethane, followed by 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride (2.60 g, 13.44 mmol), 4-dimethylaminopyridine (1.65 g, 13.44 mmol), and n-propanol (302.90 mg, 5.04 mmol). The mixture was allowed to react at room temperature for 12 hours. The solvent was then removed by rotary evaporation. The spin-dried product was purified by column chromatography (developing solvent ratio: petroleum ether: dichloromethane = 2:3) to obtain a light yellow solid powder 6.

[0051] (2) Preparation of 6 single crystals of elastic organic crystal materials with multi-level stimulus responsiveness:

[0052] Compound 6 (20 mg) was dissolved in 8 mL of CH2Cl2 solution and dispersed homogeneously by ultrasonication. The solution was filtered through an ultrafiltration filter and transferred to a 20 mL sample vial. 8 mL of n-hexane was added to the top layer and allowed to stand for 7 days to obtain pale yellow needle-shaped crystals. The phosphorescence emission peak was around 513 nm, the phosphorescence lifetime was 1.400 ms, and the phosphorescence quantum yield was 18.1%.

[0053] Example 4.

[0054] In this embodiment, the reaction precursors provided are compounds 1 and 7. The specific method for preparing the elastic organic crystal material with multi-level stimulus responsiveness includes the following steps.

[0055] (1) Synthesis of elastic organic crystal material 8 with multi-level stimulus responsiveness:

[0056]

[0057] Compound 1 (500 mg, 1.68 mmol) was added to 30 mL of dichloromethane, followed by the addition of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride (2.60 g, 13.44 mmol), 4-dimethylaminopyridine (1.65 g, 13.44 mmol), and n-butanol (373.56 mg, 5.04 mmol). The mixture was allowed to react at room temperature for 12 hours. The solvent was then removed by rotary evaporation. The spin-dried product was purified by column chromatography (PE:DCM = 1:1) to obtain 8 as a white solid powder.

[0058] (2) Preparation of 8 single crystals of elastic organic crystal materials with multi-level stimulus responsiveness:

[0059] Compound 8 (20 mg) was dissolved in 8 mL of CH2Cl2 solution and dispersed homogeneously by ultrasonication. The solution was filtered through an ultrafiltration filter and transferred to a 20 mL sample vial. 8 mL of n-hexane was added to the vial and allowed to stand for 7 days to yield white needle-shaped crystals. Its phosphorescence emission peak was around 493 nm, the phosphorescence lifetime was 0.321 ms, and the phosphorescence quantum yield was 12.9%.

[0060] Example 5.

[0061] In this embodiment, the reaction precursors provided are compounds 1 and 9. The specific method for preparing the elastic organic crystal material with multi-level stimulus responsiveness includes the following steps.

[0062] (1) Synthesis of elastic organic crystal material 10 with multi-level stimulus responsiveness:

[0063]

[0064] Compound 1 (500 mg, 1.68 mmol) was added to 30 mL of dichloromethane, followed by 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride (2.60 g, 13.44 mmol), 4-dimethylaminopyridine (1.65 g, 13.44 mmol), and n-pentanol (444.28 mg, 5.04 mmol). The mixture was allowed to react at room temperature for 12 hours. The solvent was then removed by rotary evaporation. The spin-dried product was purified by column chromatography (developing solvent ratio: petroleum ether: dichloromethane = 2:3) to obtain 10 as a white solid powder.

[0065] (2) Preparation of 10 single crystals of elastic organic crystal materials with multi-level stimulus responsiveness:

[0066] Compound 10 (20 mg) was dissolved in 8 mL of CH2Cl2 solution and dispersed homogeneously by ultrasonication. The solution was filtered through an ultrafiltration filter and transferred to a 20 mL sample vial. 8 mL of n-hexane was added to the top layer and allowed to stand for 7 days to produce white needle-shaped crystals. Its phosphorescence emission peak was around 493 nm, the phosphorescence lifetime was 0.654 ms, and the phosphorescence quantum yield was 21.4%.

[0067] Example 6.

[0068] In this embodiment, the reaction precursors provided are compounds 1 and 11. The specific method for preparing the elastic organic crystal material with multi-level stimulus responsiveness includes the following steps.

[0069] (1) Synthesis of elastic organic crystal material 12 with multi-level stimulus responsiveness:

[0070]

[0071] Compound 1 (500 mg, 1.68 mmol) was added to 30 mL of dichloromethane, followed by 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride (2.60 g, 13.44 mmol), 4-dimethylaminopyridine (1.65 g, 13.44 mmol), and n-hexanol (514.98 mg, 5.04 mmol). The mixture was allowed to react at room temperature for 12 hours. The solvent was then removed by rotary evaporation. The spin-dried product was purified by column chromatography (developing solvent ratio: petroleum ether: dichloromethane = 2:3) to obtain 12 as a white solid powder.

[0072] (2) Preparation of 12 single crystals of elastic organic crystal materials with multi-level stimulus responsiveness:

[0073] Compound 12 (20 mg) was dissolved in 8 mL of CH2Cl2 solution and dispersed homogeneously by ultrasonication. The solution was filtered through an ultrafiltration filter and transferred to a 20 mL sample vial. 8 mL of n-hexane was added to the top layer and allowed to stand for 7 days to produce white needle-shaped crystals. The phosphorescence emission peak was around 493 nm, the phosphorescence lifetime was 0.763 ms, and the phosphorescence quantum yield was 25.1%.

[0074] Example 7.

[0075] In this embodiment, the reaction precursors provided are compounds 1 and 13. The specific method for preparing the elastic organic crystal material with multi-level stimulus responsiveness includes the following steps.

[0076] (1) Synthesis of elastic organic crystal material 14 with multi-level stimulus responsiveness:

[0077]

[0078] Compound 1 (500 mg, 1.68 mmol) was added to 30 mL of dichloromethane, followed by 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride (2.60 g, 13.44 mmol), 4-dimethylaminopyridine (1.65 g, 13.44 mmol), and n-heptanol (585.65 mg, 5.04 mmol). The mixture was allowed to react at room temperature for 12 hours. The solvent was then removed by rotary evaporation. The spin-dried product was purified by column chromatography (developing solvent ratio: petroleum ether: dichloromethane = 2:3) to obtain 14 as a white solid powder.

[0079] (2) Preparation of 14 single crystals of elastic organic crystal materials with multi-level stimulus responsiveness:

[0080] Compound 14 (20 mg) was dissolved in 8 mL of CH2Cl2 solution and dispersed homogeneously by ultrasonication. The solution was filtered through an ultrafiltration filter and transferred to a 20 mL sample vial. 8 mL of n-hexane was added to the vial and allowed to stand for 7 days to yield white needle-shaped crystals. The phosphorescence emission peak was around 493 nm, the lifetime was 0.213 ms, and the phosphorescence quantum yield was 7.0%.

[0081] Example 8.

[0082] In this embodiment, the reaction precursors provided are compounds 1 and 15. The specific method for preparing the elastic organic crystal material with multi-level stimulus responsiveness includes the following steps.

[0083] (1) Synthesis of elastic organic crystal material 16 with multi-level stimulus responsiveness:

[0084]

[0085] Compound 1 (500 mg, 1.68 mmol) was added to 30 mL of dichloromethane, followed by 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride (2.60 g, 13.44 mmol), 4-dimethylaminopyridine (1.65 g, 13.44 mmol), and n-octanol (656.34 mg, 5.04 mmol). The mixture was allowed to react at room temperature for 12 hours. The solvent was then removed by rotary evaporation. The spin-dried product was purified by column chromatography (developing solvent ratio: petroleum ether: dichloromethane = 2:3) to obtain 16 as a white solid powder.

[0086] (2) Preparation of 16 single crystals of elastic organic crystal materials with multi-level stimulus responsiveness:

[0087] Compound 16 (20 mg) was dissolved in 8 mL of CH2Cl2 solution and dispersed homogeneously by ultrasonication. The solution was filtered through an ultrafiltration filter and transferred to a 20 mL sample vial. 8 mL of n-hexane was added to the top layer and allowed to stand for 7 days to produce white needle-shaped crystals. The phosphorescence emission peak was around 493 nm, the phosphorescence lifetime was 0.300 ms, and the phosphorescence quantum yield was 11.4%.

[0088] The present invention has been described with reference to the above embodiments. However, the above embodiments are merely exemplary embodiments of the present invention. It should be noted that the disclosed embodiments do not limit the scope of the present invention. On the contrary, modifications and equivalents within the spirit and scope of the claims are intended to be within the scope of the present invention.

Claims

1. Application of a multi-stage stimulus-responsive room-temperature phosphorescent elastic organic crystal material in the preparation of optoelectronic devices, display materials, information storage materials or anti-counterfeiting materials, characterized in that: The preparation method of the elastic organic crystal material with multi-stage stimulus-responsive room temperature phosphorescence comprises the following steps: dissolving a compound having a chemical structure represented by formula (I) in a good solvent, uniformly dispersing the compound with ultrasonication, filtering the compound with an ultrafiltration head, adding a poor solvent, and allowing the compound to stand for several days to obtain the elastic organic crystal material with multi-stage stimulus-responsive room temperature phosphorescence; the good solvent is one or more of dichloromethane, chloroform, ethyl acetate, tetrahydrofuran, ether, N,N-dimethylformamide, and dimethyl sulfoxide; the poor solvent is one or more of petroleum ether, n-hexane, and cyclohexane. The structure of the R group is as follows: Wherein, n represents the number of methylene groups (-CH2), and n is any integer between 0 and 7.

2. The use according to claim 1, characterized in that The phosphorescence lifetime of the elastic organic crystal material with multi-level stimulus-responsive room-temperature phosphorescence is ≥0.1 ms.

3. The use according to claim 1, characterized in that The absolute phosphorescence quantum yield of the elastic organic crystal material with multi-level stimulus-responsive room-temperature phosphorescence is greater than or equal to 0.1%.

4. The use according to claim 1, characterized in that The elastic organic crystal material with multi-level stimulus-responsive room temperature phosphorescence has mechanical force stimulus responsiveness; the mechanical force stimulus response is to achieve the regulation of material luminescence by grinding.

5. The use according to claim 1, characterized in that The elastic organic crystal material with multi-level stimulus-responsive room temperature phosphorescence has thermal stimulus responsiveness; the thermal stimulus response is to use thermal annealing to achieve the regulation of material luminescence, with the temperature between 70 and 150 degrees Celsius.

6. The use according to claim 1, characterized in that The elastic organic crystal material with multi-level stimulus-responsive room temperature phosphorescence has solvent stimulus responsiveness; the solvent stimulus response is to achieve the regulation of the material's luminescence by using solvent fumigation.

7. The use according to claim 1, characterized in that The elastic organic crystal material with multi-level stimulus-responsive room-temperature phosphorescence has the ability of elastic bending.

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