A dynamic organic room-temperature phosphorescent supercooled liquid and its preparation method and application

Abstract

The present invention belongs to the field of preparation and application of organic room-temperature phosphorescent supercooled liquid materials, and specifically discloses a dynamic organic room-temperature phosphorescent supercooled liquid and its preparation method and application. The present invention realizes the formation of supercooled liquid by introducing terminal hydroxyl groups, and realizes the generation of organic room-temperature phosphorescence by introducing amide bonds, and finally realizes the application of such materials in the fields of security encryption and flexible optoelectronic devices. The materials of the present invention have the following characteristics: (1) The raw materials for organic reactions are cheap, the synthesis steps are few, and the biological toxicity is low; (2) The materials have a high quantum yield; (3) The materials have the flexible characteristics of organic materials; (4) Based on the extremely high processability of supercooled liquids, applications in information encryption, biological imaging, and flexible optoelectronic devices can be realized. Therefore, the liquid-based organic room-temperature phosphorescent materials of the present invention have great commercial potential.

Description

Technical Field

[0001] The present invention belongs to the technical field of new materials, and particularly relates to a dynamic organic room temperature phosphorescent supercooled liquid and a preparation method and application thereof. Background Art

[0002] Organic room temperature phosphorescence (RTP) materials have received extensive attention in recent years due to their diverse excited state properties, such as large Stokes shift, high quantum efficiency, long lifetime, etc. Most RTP materials are insensitive to external stimuli and exhibit static phosphorescence behavior. That is to say, under ambient conditions, the phosphorescence properties do not change before and after excitation. In contrast, dynamic RTP materials exhibit tunable phosphorescence characteristics under external stimuli and have great potential in sensing, light-emitting switches, security papers, data storage, etc. Currently, the reported dynamic RTP materials are all organic crystals or polymers, and these materials have poor processability, flexibility or stretchability, which limits their applications, especially in the field of flexible electronics.

[0003] Liquid molecules have superior processability and flexibility, but due to strong molecular motion, triplet excitons return to the ground state in a non-radiative transition manner. Developing RTP molecular luminescent liquids under ambient conditions is a formidable challenge. Supercooled liquids (SCLs) are a special type of molecular liquid that exhibits high viscosity and high stretchability below the melting point, having both the condensation characteristics of solids and the flexibility of liquids, and are an excellent choice for developing organic RTP liquids.

[0004] Currently, there are some supercooled liquids with RTP, but these supercooled liquids only exhibit static luminescence behavior and cannot be applied in the field of intelligent response. Summary of the Invention

[0005] The purpose of the present invention is to overcome the above deficiencies and provide an RTP supercooled liquid with dynamic response characteristics, involving important photophysical properties such as the dynamic luminescence and lifetime of the material. Under supercooled liquid state, the material is excited by ultraviolet light, and the emission color is tunable (red, green, blue), and the emission lifetime distribution is wide (from nanoseconds to several hours). The main purpose of the present invention is to construct a class of single-component supercooled liquids with dynamic RTP luminescence properties.

[0006] Another purpose of the present invention is to provide a preparation method for this type of dynamic response material. This method realizes the formation of supercooled liquid by introducing terminal hydroxyl groups, and realizes the generation of organic room temperature phosphorescence by introducing amide bonds, and finally realizes the application of this type of material in the fields of information encryption and flexible optoelectronic devices.

[0007] Another purpose of the present invention is to provide the application of this material in the fields of information encryption, flexible optoelectronic devices, etc.

[0008] In order to promote the wide application of dynamic organic phosphorescent liquid materials in life, the inventors designed and prepared a series of highly efficient dynamic organic phosphorescent supercooled liquids, and the object of the present invention is achieved in the following manner:

[0009] An organic room temperature phosphorescent material based on supercooled liquid state, and this material is a compound with the following structure:

[0010]

[0011] Wherein, R1 is

[0012]

[0013] R2 is

[0014]

[0015] Preferably, R1 is:

[0016] Preferably, R2 is:

[0017] The preparation process of the above compound is as follows:

[0018]

[0019] The above preparation process uses dichloromethane as a solvent, and the carbonyl chloride containing the R1 group and the amine containing the R2 group react at a molar ratio of 1:1.5 - 2 under room temperature conditions, and the stirring reaction time is 5 - 6 h. Preferably, the carbonyl chloride containing the R1 group and the amine containing the R2 group react at a molar ratio of 1:2 under room temperature conditions, and the stirring reaction time is 6 h.

[0020] The above RTP supercooled liquid exhibits a dynamic phosphorescent phenomenon under the irradiation of ultraviolet light and is effectively applied in fields such as information encryption and flexible optoelectronic devices. The specific implementation methods of information encryption and flexible optoelectronic devices are as follows: The above molecules are melted at high temperature and evenly coated on filter paper, and a mask template is placed above the filter paper and ultraviolet light irradiation is continuously carried out to achieve the input of information. The melted molecules can also be printed on a PDMS film through inkjet printing technology to achieve the application in flexible optoelectronic devices.

[0021] Strong hydrogen bond interactions can be formed between the hydroxyl groups of monohydric alcohols, and a highly viscous supercooled liquid can be formed after thermal annealing. It is assumed that a flexible side chain with a terminal hydroxyl group is introduced onto the π-conjugated phosphorescent chromophore to construct an RTP supercooled liquid. At the same time, 3 O2 will be encapsulated in this type of supercooled liquid, thus quenching the phosphorescence. After ultraviolet light irradiation, 3 O2 will be converted into 1 O2, thus gradually restoring the phosphorescence.

[0022] The organic room-temperature phosphorescent material of the present invention has dynamic response characteristics. The material is melted and annealed to room temperature to form a stable supercooled liquid. Under the irradiation of an ultraviolet lamp, the phosphorescent emission gradually increases. After activation, the supercooled liquid can be restored to the initial state after being placed under environmental conditions for a period of time.

[0023] The present invention characterized the structure of the organic RTP supercooled liquid by nuclear magnetic resonance (NMR), single crystal X-ray diffraction, etc.; through the measurement of the emission spectrum excited by ultraviolet light and the luminescence lifetime, the photophysical properties and dynamic response characteristics of this series of RTP materials were studied in detail; by introducing chromophores with different conjugation lengths, the photophysical properties of the RTP materials were regulated.

[0024] The beneficial effects of the present invention compared with the prior art:

[0025] (1) The raw materials for the organic reaction of the invented material are cheap, the synthesis steps are few, and the biological toxicity is low;

[0026] (2) The material has a high quantum yield;

[0027] (3) The material has the flexible characteristics of organic materials;

[0028] (4) Based on the extremely high processability of the supercooled liquid, applications in information encryption, bioimaging, and flexible optoelectronic devices can be realized.

[0029] Therefore, the present invention not only has a simple preparation method and low raw material prices, but also these pure organic room-temperature phosphorescent materials can not only form stable supercooled liquids, but also achieve dynamic response RTP characteristics under the alternating stimulation of ultraviolet and heating, and can be effectively applied in the fields of information encryption and flexible optoelectronic devices. The liquid-based organic room-temperature phosphorescent materials of the present invention have great commercial potential. Brief Description of the Drawings

[0030] Figure 1 . Photoluminescence spectra of Compound 1, Compound 2, and Compound 3 under different ultraviolet excitation times;

[0031] In the figure, a is the photoluminescence spectrum of Compound 1 under different ultraviolet excitation times; b is the photoluminescence spectrum of Compound 2 under different ultraviolet excitation times; c is the photoluminescence spectrum of Compound 3 under different ultraviolet excitation times.

[0032] Figure 2 . Preliminary application photos of Compound 2 in information encryption and flexible optoelectronic devices.

[0033] In the figure, a is a schematic diagram of the preparation process of the novel flexible encryption test paper; b is a photo of the 5-time encryption test paper for information writing and information erasure; c is a photo of the PDMS patterned film prepared with compound 2 under bright field (top), before ultraviolet activation in dark field (middle), and after ultraviolet activation (bottom); d is a photo of the patterned PDMS film before (top) and after (bottom) stretching under ultraviolet light irradiation; e is the length change of the PDMS film after 20 repeated stretches; f is a photo of the nitrile rubber glove patterned with compound 2 under bright field (top) and dark field (bottom).

[0034] Figure 3 is the 1 HNMR spectrum of compound 2;

[0035] Figure 4 is the 13 C NMR spectrum of compound 2;

[0036] Figure 5 is the X-ray single crystal diffraction structure of compound 2;

[0037] Figure 6 is the (a) phosphorescence spectrum and (b) corresponding lifetime decay spectrum of the supercooled liquid of compound 2 at different photoactivation times from 0 to 120 s under environmental conditions. Specific Embodiments

[0038] The present invention will be further described below through specific embodiments, and the above-mentioned and other objects, features, and advantages of the present invention will become more obvious.

[0039] Example 1:

[0040] Specific synthesis process of a dynamic organic room temperature phosphorescent supercooled liquid (compound 1):

[0041] Weigh phenothiazine-10-carbonyl chloride (1.0 g, 3.81 mmol) with an electronic balance and add it to a two-necked round-bottom flask. Then add 25 ml of dichloromethane (DCM) as the solvent and stir at room temperature. Then add ethanolamine (0.458 ml, 7.62 mmol) and react at room temperature for 6 h. After the reaction is completed, remove the solvent through a vacuum rotary evaporator and make sand. The crude product is purified 2 times by column chromatography (petroleum ether: ethyl acetate = 1:4) to obtain a white solid (0.67 g, 64.8%). 11H NMR(CDCl3): δ 7.59–7.52 (m, 2H), 7.39 (dd, J = 7.7, 0.8 Hz, 2H), 7.31 (dd, J = 11.1, 4.3 Hz, 2H), 7.19 (td, J = 7.6, 0.8 Hz, 2H), 5.45 (s, 1H), 3.74–3.60 (m, 2H), 3.42–3.30 (m, 2H), 2.54 (s, 1H). 13 13C NMR(CDCl3): δ 155.96, 138.55, 133.60, 128.26, 127.41, 127.09, 126.83, 63.06, 43.87.

[0042] Example 2:

[0043] Synthesis process of a dynamic organic room temperature phosphorescent supercooled liquid (Compound 2):

[0044] Weigh phenothiazine-10-carbonyl chloride (1.0 g, 3.81 mmol) with an electronic balance and add it to a two-necked round-bottom flask. Then add 25 ml of dichloromethane (DCM) as the solvent and stir at room temperature. Next, add 4-amino-1-butanol (0.704 ml, 7.62 mmol) and react at room temperature for 6 h. After the reaction is completed, remove the solvent by a rotary evaporator under vacuum and make sand. Purify the crude product by column chromatography (petroleum ether: ethyl acetate = 1:4) twice to obtain an oily substance. Place it in the refrigerator overnight to obtain a white solid (0.69 g, 53.7%). 1 1H NMR(CDCl3): δ 7.55 (d, J = 7.9 Hz, 2H), 7.38 (d, J = 7.8 Hz, 2H), 7.30 (t, J = 7.0 Hz, 2H), 7.18 (t, J = 7.6 Hz, 2H), 5.15 (s, 1H), 3.80–3.43 (m, 2H), 3.27 (s, 2H), 1.63–1.47 (m, 4H). 13C NMR(CDCl3): δ 154.92, 138.79, 133.58, 128.17, 127.30, 127.24, 126.65, 62.48, 40.76, 29.77, 26.61.

[0045] Example 3:

[0046] Synthesis process of a dynamic organic room temperature phosphorescent supercooled liquid (Compound 3):

[0047] Weigh phenothiazine-10-carbonyl chloride (1.0 g, 3.81 mmol) using an electronic balance and add it to a two-necked round-bottom flask. Then add 25 ml of dichloromethane (DCM) as the solvent, stir at room temperature, and then add 6-amino-1-butanol (0.892 g, 7.62 mmol). React at room temperature for 6 h. After the reaction is completed, remove the solvent using a rotary evaporator under vacuum and make it into a sand-like state. Purify the crude product by column chromatography (petroleum ether: ethyl acetate = 1:4) twice to obtain an oily substance, and place it in the refrigerator overnight to obtain a white solid (0.75 g, 59.9%). 1 H NMR (CDCl3): δ 7.55 (dd, J = 8.0, 1.0 Hz, 2H), 7.38 (dd, J = 7.8, 1.3 Hz, 2H), 7.30 (td, J = 7.8, 1.4 Hz, 2H), 7.18 (td, J = 7.6, 1.2 Hz, 2H), 4.99 (t, J = 4.8 Hz, 1H), 3.59 (t, J = 6.5 Hz, 2H), 3.23 (dd, J = 13.1, 6.9 Hz, 2H), 1.50 (ddd, J = 21.5, 14.3, 7.1 Hz, 4H), 1.41–1.20 (m, 4H)., 13C NMR (CDCl3): δ 154.79, 138.83, 133.55, 128.17, 127.29, 127.19, 126.63, 62.78, 40.83, 32.62, 29.93, 26.52, 25.30.

[0048] Example 4:

[0049] Information encryption and flexible light-emitting devices:

[0050] Melt compound 2, evenly coat it on filter paper, then cool it. Cover the filter paper with a mask and then irradiate it with ultraviolet light, and the information is written; remove the mask and irradiate the filter paper again, and the information is erased. Melt compound 2 and use an inkjet printer to print it on a flexible PDMS film to realize the preparation of a flexible light-emitting device.

[0051] Comparative Example 1:

[0052] Synthesis process of a crystalline organic room-temperature phosphorescent molecule (compound 4):

[0053] Weigh 1.0 g (3.81 mmol) of phenothiazine-10-carbonyl chloride using an electronic balance and add it to a two-necked round-bottom flask. Then add 25 ml of dichloromethane (DCM) as the solvent and stir at room temperature. Next, add hexan-1-amine (0.38 g, 3.82 mmol) and react at room temperature for 6 h. After the reaction is completed, remove the solvent using a rotary evaporator under vacuum and triturate. Purify the crude product by column chromatography (petroleum ether:ethyl acetate = 1:4) twice to obtain a white solid (0.91 g, 72.9%). 1 H NMR (DMSO-d6): δ 7.49 (dd, J = 8.0, 1.2 Hz, 2H), 7.41 (dd, J = 7.7, 1.4 Hz, 2H), 7.30 (td, J = 7.7, 1.5 Hz, 2H), 7.19 (td, J = 7.6, 1.3 Hz, 2H), 6.45 (t, J = 5.6 Hz, 1H), 3.00 (dd, J = 13.7, 6.3 Hz, 2H), 1.44–1.27 (m, 2H), 1.19 (t, J = 5.6 Hz, 6H), 0.80 (t, J = 6.9 Hz, 3H). 13 C NMR (DMSO-d6): δ 154.55, 139.62, 132.45, 128.27, 127.92, 127.48, 126.70, 31.51, 29.80, 26.54, 22.58, 14.43. After melting the compound 4 and cooling it to room temperature, the compound 4 underwent a recrystallization process. Thus, it can be seen that the terminal hydroxyl group is an important reason for achieving the dynamic RTP behavior of the supercooled liquid.

[0054] The embodiments of the present invention have been described above. The above description is exemplary and not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations are obvious to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments.

Claims

1. An organic room-temperature phosphorescent material based on supercooled liquid, characterized in that The material is a compound with the following structure: or or 。 2. A method for preparing the organic room temperature phosphorescent material according to claim 1, characterized in that Using dichloromethane as a solvent, phenothiazine-10-carbonyl chloride and ethanolamine react at a molar ratio of 1:1.5 - 2 at room temperature, with a stirring reaction time of 5 - 6 h; Or using dichloromethane as a solvent, phenothiazine-10-carbonyl chloride and 4-amino-1-butanol react at a molar ratio of 1:1.5 - 2 at room temperature, with a stirring reaction time of 5 - 6 h; Or using dichloromethane as a solvent, phenothiazine-10-carbonyl chloride and 6-amino-1-butanol react at a molar ratio of 1:1.5 - 2 at room temperature, with a stirring reaction time of 5 - 6 h.

3. Application of the organic room temperature phosphorescent material described in claim 1 in information encryption and flexible optoelectronic devices.

4. The application according to claim 3, wherein The organic room temperature phosphorescent material is melted at high temperature and evenly coated on filter paper. A mask template is placed above the filter paper and ultraviolet light irradiation is continuously carried out to achieve information entry and application in information encryption.

5. The application according to claim 3, wherein After the organic room temperature phosphorescent material is melted at high temperature, the molten molecules are inkjet printed on a PDMS film to achieve application in flexible optoelectronic devices.

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