An organic upconversion red light photosensitizer material and a preparation method and application thereof

Abstract

The application belongs to the field of organic photoelectric functional materials, and discloses an organic up-conversion red light photosensitizer material, a preparation method and application. The material has the structure shown in the following formula (I). The molecule has a D-pi-A-pi-D structure, wherein 4,7-dibromo benzo[1,2-c:4,5-c'] bis([1,2,5]thiadiazole), 4,7-dibromo benzo[c]-1,2,5-thiadiazole, 4,7-dibromo benzo[d]thiazole and 4,7-dibromo-2,1,3-benzoselenadiazole are used as strong electron acceptors, can reduce the energy gap of the molecule, and make the absorption peak / emission peak red shift; triphenylamine is used as a strong electron donor and a pi-bridge, a spiral structure is formed, steric hindrance is increased, and the aggregation-induced emission characteristics are ensured; the carboxyl group on the triphenylamine provides good amphiphilicity for the overall structure. The synthetic route of the application is simple, is a potential red light TADF material, and has good fluorescence quantum yield and up-conversion efficiency.

Description

Technical Field

[0001] This invention belongs to the field of organic optoelectronic functional materials, and specifically relates to an organic upconversion red light photosensitizer material, its preparation method, and its application. Background Technology

[0002] Upconversion luminescence refers to a process in which low-energy light molecules with longer wavelengths are absorbed and high-energy light molecules with shorter wavelengths are emitted. Because this process violates Stokes' law that the incident light energy is greater than the emitted light energy, it is also known as inverse Stokes shift luminescence. Triplet-triplet annihilation upconversion is a common upconversion luminescence system, typically composed of a photosensitizer, a masking agent, and a solvent. The structural design of the photosensitizer can significantly improve the fluorescence quantum yield and upconversion luminescence efficiency of the system.

[0003] Among various types of photosensitizers, thermally activated delayed fluorescence (TADF) molecules stand out due to their small band gap between the S1 and T1 states, which effectively reduces energy loss from intersystem crossing and thus enhances the anti-Stokes shift. However, to date, most red TADF materials generally exhibit weak electron-withdrawing ability and strong planarity, resulting in poor amphiphilicity. Therefore, through rational molecular design, it is possible to achieve red TADF materials with strong electron-withdrawing and electron-donating groups and good amphiphilicity.

[0004] By designing photosensitizer materials that can be directly dissolved in water and forming an upconversion system with an amphiphilic annihilation agent that matches the energy level of the material, red light can be effectively converted into blue light, greatly improving the utilization rate of solar energy and showing broad application prospects in photocatalysis and solar cells. Summary of the Invention

[0005] In order to overcome the shortcomings of existing photosensitizer materials, such as weak electron-withdrawing ability and poor amphiphilicity, the primary objective of this invention is to provide an organic upconversion red light photosensitizer material, which is an organic upconversion red light photosensitizer material with strong electron-withdrawing groups and strong electron-donating groups.

[0006] Another objective of this invention is to provide a method for preparing the above-mentioned organic upconversion red light photosensitizer material.

[0007] Another object of the present invention is to provide an application of the above-mentioned organic upconversion red light photosensitizer material.

[0008] The objective of this invention is achieved through the following technical solution:

[0009] An organic upconversion red light photosensitizer material having the structure shown in formula (Ⅰ):

[0010]

[0011] Where A is selected from One of them.

[0012] The preparation method of the above-mentioned organic upconversion red light photosensitizer material includes the following steps:

[0013] (1) Add substance ① and POCl3 (phosphorus oxychloride) to DMF (dimethylformamide) solvent, heat and stir under reflux to obtain intermediate product substance ②; then add intermediate product substance ②, potassium permanganate and potassium carbonate to acetone solvent, heat and stir under reflux to obtain reaction solution;

[0014] The structural formula of substance ① is:

[0015] The structural formula of the intermediate product ② is:

[0016] Where A is selected from One of them;

[0017] (2) Add water to the reaction solution obtained in step (1) to obtain the crude product;

[0018] (3) The crude product obtained in step (2) is purified to obtain an organic upconversion red light photosensitizer material.

[0019] The molar ratio of substance ① to DMF in step (1) is 1:4.5-5.

[0020] The reaction in step (1) is carried out at a temperature of 105°C for 48 hours.

[0021] The molar ratio of potassium permanganate, potassium carbonate and acetone in step (1) is 4-5:7-8:1.

[0022] The heating and reflux stirring in step (1) is carried out at a temperature of 60°C for 48 hours.

[0023] The specific steps for obtaining the crude product in step (2) include: adding water to the reaction solution obtained in step (1) to quench the reaction; extracting the quenched reaction solution with DCM (dichloromethane) solution and combining the organic phases in the extracted reaction solution; drying the reaction solution after combining the organic phases with anhydrous sodium sulfate and concentrating the dried reaction solution under reduced pressure to obtain the crude product.

[0024] Step (3) involves purifying the crude product obtained in step (2) according to the following steps:

[0025] The crude product was purified by silica gel column chromatography using a mixture of petroleum ether and dichloromethane as the eluent to obtain an organic upconversion red photosensitizer material.

[0026] The volume ratio of petroleum ether to dichloromethane in the eluent is 10:1 to 3:1.

[0027] The above-mentioned organic upconversion red light photosensitizer materials are used in upconversion systems that are also amphiphilic masking agents.

[0028] The present invention has the following advantages and effects compared with the prior art:

[0029] (1) The organic upconversion red light photosensitizer material provided by this invention has a D-π-A-π-D structure, wherein 4,7-dibromobenzo[1,2-c:4,5-c']bis([1,2,5]thiadiazole), 4,7-dibromobenzo[c]-1,2,5-thiadiazole, 4,7-dibromobenzo[d]thiaazole, and 4,7-dibromo-2,1,3-benzoselenide diazole act as strong electron acceptors, which can reduce the band gap of the molecule and redshift the absorption / emission peaks; triphenylamine acts as a strong electron donor and π-bridge, forming a helical structure, increasing steric hindrance, and ensuring its aggregation-induced luminescence characteristics; the carboxyl group on triphenylamine provides good amphiphilicity for the overall structure. The obtained amphiphilic photosensitizer material, together with an amphiphilic annihilator that matches its energy level, forms an upconversion system, which can effectively convert red light to blue light, greatly improving the utilization rate of solar energy, and has broad application prospects in photocatalysis and solar cells.

[0030] (2) The organic upconversion red light photosensitizer material designed in this invention has a simple synthesis route and is a potential red light TADF (thermally activated delayed fluorescence) material with good fluorescence quantum yield and upconversion efficiency, and has potential application prospects. Attached Figure Description

[0031] Figure 1 This is a synthetic route diagram of an organic upconversion red light photosensitizer material prepared in the embodiments of the present invention.

[0032] Figure 2 This is the UV-Vis absorption spectrum of BT2Z-2TPA-4COOH, an organic upconversion red photosensitizer material prepared in this embodiment of the invention, in toluene solvent. The chemical structural formula of BT2Z-2TPA-4COOH is as follows:

[0033]

[0034] Figure 3This is a steady-state fluorescence emission spectrum of BT2Z-2TPA-4COOH, an organic upconversion red photosensitizer material prepared in this embodiment of the invention, in toluene solvent. The chemical structural formula of BT2Z-2TPA-4COOH is as follows:

[0035]

[0036] Figure 4 This is an upconversion spectrum of BT2Z-2TPA-4COOH, an organic upconversion red photosensitizer material prepared in an embodiment of the present invention, in toluene solvent. The chemical structural formula of BT2Z-2TPA-4COOH is as follows:

[0037] Detailed Implementation

[0038] The following specific embodiments further illustrate the content of the present invention, but should not be construed as limiting the present invention.

[0039] Unless otherwise specified, all reagents used in the examples are commercially available.

[0040] This invention provides an organic upconversion red light photosensitizer material, the chemical structural formula of which is: in, It possesses a D-π-A-π-D structure, in which 4,7-dibromobenzo[1,2-c:4,5-c']bis([1,2,5]thiadiazole), 4,7-dibromobenzo[c]-1,2,5-thiadiazole, 4,7-dibromobenzo[d]thiazolazole, and 4,7-dibromo-2,1,3-benzoselenodiazole act as strong electron acceptors, which can reduce the band gap of the molecule and cause the absorption / emission peaks to redshift; triphenylamine acts as a strong electron donor and π-bridge, forming a helical structure, increasing steric hindrance, and ensuring its aggregation-induced luminescence properties; the carboxyl group on triphenylamine provides good amphiphilicity for the overall structure.

[0041] This invention provides a method for preparing the above-mentioned organic upconversion red light photosensitizer material, comprising the following steps:

[0042]

[0043] Step 1): Synthesis of compound substance ②:

[0044] Substance ① and phosphorus oxychloride were added to dimethylformamide solvent, and the mixture was heated and stirred under reflux at 105°C for 48 hours. The resulting mixture was cooled to room temperature, quenched with water, and extracted with dichloromethane solution. The organic phase was dried over anhydrous sodium sulfate, filtered, concentrated under reduced pressure, and purified by silica gel column chromatography to obtain intermediate substance ②.

[0045] Step 2): Synthesis of compound substance ③:

[0046] Intermediate product ②, potassium permanganate, and potassium carbonate were added to acetone solvent, and the mixture was heated under reflux with stirring at 60°C for 48 hours. The resulting mixture was cooled to room temperature, quenched with water, and extracted with dichloromethane solution. The organic phase was dried over anhydrous sodium sulfate, filtered, concentrated under reduced pressure, and purified by silica gel column chromatography to obtain final product ③, which is the organic upconversion red light photosensitizer material of this invention. The results of 1H NMR spectroscopy identification are as follows: 1 ¹H NMR (400MHz, Chloroform-d) δ 11.69 (s, 4H), 7.90 (d, J = 1.9Hz, 8H), 7.55 (d, J = 1.2Hz, 4H), 7.39 (d, J = 1.7Hz, 8H), 7.32 (d, J = 1.2Hz, 4H). High-resolution mass spectrometry identification results: HR-MS (ESI, m / z): [M] + Calcd.forC 46 H 28 N6O8S2 + :856.1410, found:856.1408. Its chemical structural formula is: in,

[0047] like Figure 1 As shown: Figure 1 This is a synthetic route diagram of an organic upconversion red light photosensitizer material prepared in the embodiments of the present invention.

[0048] like Figure 2 As shown: Figure 2 This is the UV-Vis absorption spectrum of BT2Z-2TPA-4COOH, an organic upconversion red photosensitizer material prepared in this embodiment of the invention, in toluene solvent. Figure 2 It can be seen that this material exhibits a strong absorption peak around 490 nm, and its distribution is relatively broad, indicating that the absorption peak of this material undergoes a red shift. The chemical structural formula of BT2Z-2TPA-4COOH is as follows:

[0049]

[0050] like Figure 3 As shown: Figure 3 This is the steady-state fluorescence emission spectrum of BT2Z-2TPA-4COOH, an organic upconversion red photosensitizer material prepared in this embodiment of the invention, in toluene solvent. Figure 3It can be seen that the material exhibits an emission peak at 630 nm under 532 nm excitation, indicating that the prepared compound possesses the long-wavelength emission effect of red light materials. The chemical structural formula of the above BT2Z-2TPA-4COOH is:

[0051] like Figure 4 As shown: Figure 4 This is an upconversion spectrum of BT2Z-2TPA-4COOH, an organic upconversion red light photosensitizer material prepared in an embodiment of the present invention, in toluene solvent. Figure 4 It can be seen that the steady-state emission spectrum of this material exhibits a blue upconversion emission peak at around 430 nm, which is significantly higher than the downconversion red emission peak, indicating that the prepared compound is suitable as an upconversion photosensitizer material. The chemical structural formula of the above BT2Z-2TPA-4COOH is:

[0052]

[0053] In summary, this invention provides an organic upconversion red light photosensitizer material with a D-π-A-π-D structure. 4,7-Dibromobenzo[1,2-c:4,5-c']bis([1,2,5]thiadiazole), 4,7-dibromobenzo[c]-1,2,5-thiadiazole, 4,7-dibromobenzo[d]thiaazole, and 4,7-dibromo-2,1,3-benzoselenide diazole act as strong electron acceptors, reducing the molecular band gap and causing a red shift in the absorption / emission peaks. Triphenylamine acts as a strong electron donor and π-bridge, forming a helical structure that increases steric hindrance and ensures its aggregation-induced luminescence properties. The carboxyl group on triphenylamine provides good amphiphilicity for the overall structure. Furthermore, this material, along with its energy-matching amphiphilic annihilation agent, forms an upconversion system that effectively converts red light to blue light, significantly improving the utilization rate of solar energy and showing broad application prospects in photocatalysis and solar cells.

[0054] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. An amphiphilic organic upconversion red light photosensitizer material, characterized in that: The material has the structure shown in formula (Ⅰ): Equation (Ⅰ).

2. The method for preparing an amphiphilic organic upconversion red light photosensitizer material according to claim 1, characterized in that... The following steps are included: (1) Add substance ① and phosphorus oxychloride to dimethylformamide solvent, heat and stir under reflux to obtain intermediate product substance ②; then add intermediate product substance ②, potassium permanganate and potassium carbonate to acetone solvent, heat and stir under reflux to obtain reaction solution; The structural formula of substance ① is: The structural formula of the intermediate product ② is: Where A is ; (2) Add water to the reaction solution obtained in step (1) to obtain the crude product; (3) The crude product obtained in step (2) is purified to obtain an amphiphilic organic upconversion red light photosensitizer material.

3. The preparation method according to claim 2, characterized in that: The molar ratio of substance ① to DMF in step (1) is 1:4.5-5.

4. The preparation method according to claim 2, characterized in that: The reaction temperature in step (1) is 105°C and the reaction time is 48 hours.

5. The preparation method according to claim 2, characterized in that: The molar ratio of potassium permanganate, potassium carbonate and acetone in step (1) is 4-5:7-8:

1.

6. The preparation method according to claim 2, characterized in that: The heating and reflux stirring in step (1) is carried out at a temperature of 60°C for 48 hours.

7. The preparation method according to claim 2, characterized in that: The specific steps for obtaining the crude product in step (2) include: adding water to the reaction solution obtained in step (1) to quench the reaction; extracting the quenched reaction solution with dichloromethane solution and combining the organic phases in the extracted reaction solution; drying the reaction solution after combining the organic phases with anhydrous sodium sulfate and concentrating the dried reaction solution under reduced pressure to obtain the crude product.

8. The preparation method according to claim 2, characterized in that: Step (3) involves purifying the crude product obtained in step (2) according to the following steps: The crude product was purified by silica gel column chromatography using a mixture of petroleum ether and dichloromethane as the eluent to obtain an amphiphilic organic upconversion red photosensitizer material.

9. The preparation method according to claim 8, characterized in that: The volume ratio of petroleum ether to dichloromethane in the eluent is 10:1 to 3:

1.

10. The application of the amphiphilic organic upconversion red light photosensitizer material according to claim 1 in an upconversion system that is also an amphiphilic masking agent.

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