Near-infrared luminescent material based on aryl indole donor and preparation method and application thereof

Abstract

The invention discloses a near-infrared luminescent material based on an aryl indole donor and a preparation method and application thereof, and belongs to the technical field of organic photoelectric semiconductors, the near-infrared luminescent material has a D-A-D structure, the aggregation-induced emission characteristic of the near-infrared luminescent material is ensured by an electron donor and an acceptor core unit in the molecular structure of the near-infrared luminescent material, and the near-infrared luminescent material has a good application prospect. The selection of a strong electron acceptor promotes the molecular absorption / emission wavelength to a near-infrared region. The near-infrared luminescent material disclosed by the invention is simple in synthetic route, low in cost, controllable in energy level and excellent in luminescent behavior, has good fluorescence quantum yield and good photodynamic / photothermal effect, and can be widely applied to the fields of organic semiconductor devices, biosensing and the like.

Description

Technical Field

[0001] The invention belongs to the technical field of organic photoelectric semiconductors, and in particular relates to a near-infrared luminescent material based on an aryl indole donor, and a preparation method and application thereof. Background Art

[0002] Organic optoelectronic semiconductor materials have the properties of strong structural designability, adjustable energy levels, adjustable spectra, wide-spectrum absorption and strong fluorescence emission. They have become the main body of the new generation of electronic information materials and have received extensive attention and application in the fields of organic light-emitting diodes, organic field-effect transistors, organic solar cells, perovskite solar cells, photodetectors, and biosensing and diagnosis. The research and development of new and efficient organic conjugated semiconductor materials will surely have broad market prospects in the electronics industry. Organic semiconductor materials with near-infrared absorption and emission properties are widely used in organic electronic devices, nanobiology, and flexible electronics. At present, the emission wavelengths of the most widely studied fluorescent materials are mostly in the visible light region (400-700nm) and the near-infrared region I (700-900nm). However, in this band, the light energy intensity is high, the light scattering degree is high, the penetration depth of biological tissue is shallow, and it is difficult to reach deep tissues. In contrast, the development of optical diagnostic materials emitting in the near-infrared region II (NIR-II, 1000-1700nm) can effectively make up for the above shortcomings and maximize the advantages of optical diagnostic materials.

[0003] Compared with inorganic and polymer materials, organic small molecule materials have become excellent choices for constructing photodiagnostic materials because of their easy modification, precise structure / purity and good biocompatibility. However, in physiological environments, hydrophobic fused aromatic ring compounds will inevitably form clusters, accompanied by strong intermolecular π-π interactions, which promote aggregation and lead to the occurrence of fluorescence quenching (ACQ) phenomenon. Compared with traditional dye molecules, AIE (aggregation-induced emission) molecules with propeller-shaped conformation emit bright fluorescence because the excited state energy is mainly dissipated through the radiative transition pathway due to the limited intramolecular motion in the aggregated state; at the same time, the twisted AIE molecules can still dissipate the excited state energy through the non-radiative transition pathway through the local motion of the multi-rotor unit in the aggregated state, and then be used for PAI (photoacoustic imaging), PTI (photothermal imaging) and PTT (photothermal therapy). Therefore, through reasonable molecular design, the controllable regulation between radiative transition and non-radiative transition in the excited state energy of NIR-II AIE molecules can be achieved. Summary of the invention

[0004] The present invention provides a near-infrared luminescent material and a preparation method and application thereof, so as to obtain a near-infrared organic semiconductor with more beneficial performance, richer structure, easier functionalization and large-scale production.

[0005] Technical solution: A near-infrared luminescent material based on an aryl indole donor, the chemical structure of the near-infrared luminescent material is as follows:

[0006] Wherein, the A is or , X is O, S, Se, Te or NR, and R is selected from: substituted or unsubstituted C1~C24 alkyl (C1~C24 straight chain or branched alkyl), alkoxy chain containing C3~C24, aryl with 1~2 C1~C24 straight chain alkyl or branched alkyl.

[0007] The R1 and R2 are independently selected from: C1-C24 straight chain or branched chain alkyl.

[0008] The Ar1 and Ar2 are independently selected from: substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C4-C30 heteroaryl.

[0009] Preferably, in the near-infrared luminescent material, A is any of the following structures:

[0010]

[0011] Preferably, in the near-infrared luminescent material, Ar1 and Ar2 are each independently any of the following structures:

[0012] Wherein, R3~R5 are each independently selected from: deuterium, F, Cl, Br, I, CN; C1~C24 alkyl; C1~C24 alkoxy; substituted or unsubstituted aryl, aryl includes phenyl, biphenyl, naphthyl, triphenylene, anthracenyl, pyrene, phenanthrenyl, chrysene and peryl, and the substituent is deuterium, F, Cl, CN, C1~C24 alkyl, C1~C24 alkoxy.

[0013] Furthermore, the near-infrared luminescent material includes the following compounds:

[0014]

[0015]

[0016]

[0017]

[0018]

[0019]

[0020]

[0021]

[0022]

[0023]

[0024]

[0025]

[0026]

[0027]

[0028]

[0029]

[0030]

[0031] The present invention provides a method for preparing the near-infrared luminescent material, which specifically comprises: adding a bromine-containing or chlorine-containing compound of an acceptor unit, a donor unit compound, and a catalyst into a solvent to obtain a reaction solution; purifying the reaction solution through a silica gel column, and then recrystallizing to obtain a powdered near-infrared luminescent material. The donor unit and the acceptor unit undergo a Stille coupling reaction to obtain a near-infrared luminescent fluorescent molecular compound.

[0032] In the structure of the near-infrared luminescent material, when the left and right sides of A are symmetrical structural formulas, the synthesis reaction formula is as follows: .

[0033] In the structure of the near-infrared luminescent material, when the left and right sides of A are asymmetric structural formulas, the synthesis reaction formula is as follows: .

[0034] Preferably, in the reaction solution, the molar concentration of the acceptor unit is 0.1~2.0mmol / mL, the molar ratio of the acceptor unit to the donor unit is 1:(2.1~2.6), the molar ratio of the catalyst to the reaction substrate is (0.02~4.00):100, the reaction substrate refers to the acceptor unit and the donor unit; the catalyst is tetrakistriphenylphosphine palladium; the solvent is one of toluene, chlorobenzene, and xylene, preferably ultra-dry deoxygenated toluene.

[0035] Preferably, in the preparation method, the reaction temperature is 100-120° C. and the reaction time is 8 h.

[0036] Preferably, in the preparation method, the step of purifying the reaction solution to obtain the near-infrared luminescent material comprises: purifying the reaction solution through a silica gel column whose detergent is dichloromethane:petroleum ether (volume ratio is 3:10), and then recrystallizing with dichloromethane and methanol to obtain a powdered near-infrared luminescent material.

[0037] The near-infrared luminescent material prepared by the present invention can be used in organic optoelectronic devices or biosensors and imaging equipment. Specifically, it can be applied to the functional layer of an organic light-emitting diode device, such as a light-emitting layer; it can be used in a perovskite solar cell composition in a perovskite solar cell device as a hole transport layer; in the field of biosensing and imaging, the near-infrared luminescent material can be used as a light absorption and light emission unit of a nanoprobe or a photosensitizer.

[0038] Compared with the prior art, the present invention has the following beneficial effects: 1) The fluorescence emission peak of the compound of the present invention appears in the range of 700 to 1600 nm.

[0039] 2) The compound of the present invention has a multiple DA structure with strong donor properties and strong acceptor properties, and is a near-infrared fluorescent luminescent molecule with a high triplet energy level, a small ΔEST, a high PLQY, near-infrared luminescence, high stability and a high glass transition temperature.

[0040] The arrangement of the donor units in the molecule can, on the one hand, effectively regulate the overlap of the electron clouds between the donor and the acceptor, significantly affect the energy level, band gap and triplet excited state energy level, and improve the singlet and triplet energy level difference (△Est); on the other hand, the close-packed connection mode between the donor and the acceptor is affected by the dihedral angle of the bridging structure, which will obtain a better photoluminescence efficiency (PLQY). At the same time, the three-dimensional molecular structure of the donor part and the rigid planar large conjugated structure of the acceptor unit have an impact on its molecular crystallinity, and the stacking mode of the molecule in the aggregated state can be effectively regulated, so that the compound of the present invention has better morphological stability and excellent film stability in the electroluminescent device, which is beneficial to the corresponding device life and the performance and luminous efficiency of the OLED device. Multiple electron-rich donor units are conducive to obtaining high HOMO energy levels and balanced electron and hole transport properties, which is conducive to its application in perovskite solar cell devices.

[0041] The molecule of the present invention has multiple donor monomers, which results in a densely packed shielding effect between the donor and acceptor units, and is beneficial to maintaining a high fluorescence quantum efficiency in a solid or condensed state, and is beneficial to its application in fluorescence imaging; its near-infrared second-zone absorption and emission characteristics are beneficial to its application in second-zone imaging and photoacoustic imaging; its near-infrared absorption characteristics are beneficial to its application in photothermal therapy; its relatively low singlet-triplet energy level difference is beneficial to intramolecular interseat crossing, thereby obtaining a long-life triplet state, and is beneficial to its application in photodynamic therapy.

[0042] 3) The starting materials for the preparation of the compounds of the present invention are easily available, the synthetic route is simple, the reaction conditions are mild, the operation steps are simple, the cost is low, and it is conducive to large-scale production. The energy level of the compounds of the present invention is controllable, the luminescence behavior is excellent, and they have good fluorescence quantum yield and good photodynamic / photothermal effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 The ultraviolet absorption spectra of the near-infrared fluorescent molecules A-7 and C-7 in Examples 1 and 2 of the present invention are shown.

[0044] Figure 2 Graphs showing the fluorescence emission spectra of the near-infrared fluorescent molecules A-7 and C-7 in Examples 1 and 2 of the present invention.

[0045] Figure 3 This is a near-infrared photothermal heating curve of the nanoparticles prepared from the near-infrared fluorescent molecule A-7 in Example 1 of the present invention relative to water.

[0046] Figure 4 This is a near-infrared photothermal heating curve of the nanoparticles prepared from the near-infrared fluorescent molecule C-7 in Example 2 of the present invention relative to water. DETAILED DESCRIPTION

[0047] The technical solution of the present invention is described in detail below through embodiments, but the protection scope of the present invention is not limited to the embodiments.

[0048] The present invention discloses a near-infrared luminescent material based on an aryl indole donor, and a preparation method and application thereof, wherein the near-infrared luminescent material has the advantages of high luminescence efficiency, tunable luminescence wavelength, low synthesis cost, good stability, etc. The present invention introduces a conjugated receptor central structure at a specific site with an electron-rich conjugated group with hole transport properties to construct a new near-infrared luminescent fluorescent molecule, which can obtain a near-infrared organic semiconductor with more beneficial performance, richer structure, easier functionalization and large-scale production.

[0049] In the present specification, when no definition is otherwise provided, "substituted" means that at least one hydrogen of the substituent or compound is replaced with deuterium, halogen, cyano, substituted or unsubstituted C1 to C24 alkyl, C3 to C24 cycloalkyl, C6 to C24 aryl, C2 to C24 heteroaryl or a combination thereof.

[0050] In this specification, when no definition is provided otherwise, "alkyl" refers to an aliphatic hydrocarbon group. The alkyl group may be a C1 to C24 alkyl group. More specifically, the alkyl group may be a C1 to C20 alkyl group or a C1 to C10 alkyl group. For example, a C1 to C4 alkyl group may have 1 to 4 carbon atoms in the alkyl chain and may be selected from methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl and tert-butyl.

[0051] Specific examples of the alkyl group may be methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, hexyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl and the like.

[0052] In this specification, "aryl" refers to a group including at least one hydrocarbon aromatic part, and all elements of the hydrocarbon aromatic part have p-orbitals forming conjugation, such as phenyl, naphthyl, etc., two or more hydrocarbon aromatic parts can be connected by a σ bond and can be, for example, biphenyl, terphenyl, quaterphenyl, etc., or two or more hydrocarbon aromatic parts are directly or indirectly fused to provide a non-aromatic fused ring. For example, it can be fluorenyl. The aryl group can include a monocyclic, polycyclic or fused polycyclic (i.e., rings that share adjacent carbon atom pairs) functional group.

[0053] Example 1 This embodiment provides a structure as shown in Formula A-7:

[0054] The preparation method of compound A-7 specifically comprises the following steps:

[0055] Step 1): Synthesis of Compound Ⅰ In a 500mL two-necked bottle, 2,5-dibromonitrobenzene (10g, 35.6mmol), 2-thiopheneboric acid (5.47g, 42.7mmol), anhydrous potassium carbonate (9.83g, 71.2mmol), tetrahydrofuran (100ml), water (25mL) were added, and nitrogen was blown for 15min. Then, under nitrogen flow, tetrakis(triphenylphosphine)palladium (110mg) was added; the reaction was carried out under nitrogen protection, heated at 80°C for 4 hours, and after the reaction was completed, the reaction was cooled to room temperature, extracted with dichloromethane and water, and passed through anhydrous sodium sulfate to remove the solvent. The bright yellow oily substance (7.3g, 76% yield) was purified by silica gel column, HR-MS (ACPI-M +, m / z): 284.13.

[0056] Step 2): Synthesis of Compound II In a 250 mL two-necked bottle, compound I (5 g, 17.6 mmol), triphenylphosphine (13.8 g, 52.6 mmol), and ultra-dry chlorobenzene (30 mL) were added, and nitrogen was blown for 15 min, and then refluxed at 140 ° C overnight. After the reaction was completed, the reaction was cooled to room temperature, and chlorobenzene was removed by vacuum distillation. After purification by silica gel column, the yellow-white powder product (4.2 g, yield 80%) was obtained by recrystallization. HR-MS (ACPI-M + , m / z): 252.13.

[0057] Step 3): Synthesis of Compound III In a 250 mL two-necked bottle, compound II (5 g, 19.8 mmol), 1-bromohexane (4.26 g, 19.8 mmol), potassium hydroxide (3.34 g, 59.5 mol), potassium iodide (0.33 g, 0.2 mol), and ultra-dry tetrahydrofuran (30 mL) were added, and nitrogen was blown for 15 min, and then heated at 70 ° C for 4 hours. After the reaction was completed, the reaction was cooled to room temperature, extracted with dichloromethane and water, and passed through anhydrous sodium sulfate to remove the solvent. The light yellow oily substance (4.5 g, yield 95%) was purified by silica gel column. HR-MS (ACPI-M + , m / z): 336.29.

[0058] Step 4): Synthesis of Compound IV In a 100mL two-necked bottle, add compound III (2g, 5.9mmol) and ultra-dry tetrahydrofuran (15mL). After blowing nitrogen for 15min, cool to -78℃ and add n-butyl lithium (3.8mL) dropwise. After the addition is complete, the system turns light yellow. The temperature is naturally raised to -50℃ without temperature control and maintained for 10min. The temperature is slowly lowered to -78℃ again and tributyltin chloride (2.13g, 6.5mmol) is quickly added. Then the temperature is naturally raised to room temperature. The system is yellow. After stirring for 4 hours, petroleum ether is added first and then water is added dropwise. The system gradually becomes transparent. The mixture is extracted with water and petroleum ether, and anhydrous sodium sulfate is passed. After removing the solvent, the crude compound (1.6g, yield 82%) is obtained. HR-MS (ACPI-M + , m / z): 546.45.

[0059] Step 5): Synthesis of Compound V In a 100 mL two-necked bottle, compound IV (2 g, 3.7 mmol), 4,8-dibromo-1H,5H-benzo[1,2-c:4,5-c']bis([1,2,5]thiadiazole) (0.61 g, 1.7 mmol), tetrakis(triphenylphosphine)palladium (10 mg), deoxygenated toluene (15 mL) were added, nitrogen was blown for 15 min, and then heated at 100 ° C for 4 hours. After the reaction was completed, the reaction was cooled to room temperature, the solvent was removed, and the dark green product (0.5 g, product 62%) was purified by silica gel column. HR-MS (ACPI-M + , m / z): 704.99.

[0060] Example 2 This embodiment provides a structure as shown in formula C-7:

[0061] The preparation method of compound C-7 specifically comprises the following steps:

[0062] Step 1): Synthesis of Compound Ⅰ In a 250 mL two-necked bottle, 3-bromocarbazole (5 g, 20.3 mmol), 1-bromohexane (4.36 g, 26.4 mmol), potassium hydroxide (3.42 g, 70.0 mmol), potassium iodide (0.34 g, 2.0 mmol), and ultra-dry tetrahydrofuran (30 mL) were added, and nitrogen was blown for 15 min, and then heated at 70 ° C for 4 hours. After the reaction was completed, the reaction was cooled to room temperature, extracted with dichloromethane and water, and passed through anhydrous sodium sulfate to remove the solvent. The transparent oily substance (4.8 g, 96% yield) was purified by silica gel column. HR-MS (ACPI-M + , m / z): 330.27.

[0063] Step 2): Synthesis of Compound II In a 100mL two-necked bottle, add compound I (2g, 6.1mmol), ultra-dry tetrahydrofuran (15mL), blow nitrogen for 15min, cool to -78℃, add n-butyl lithium (3.8mL) dropwise, after the addition is complete, the system turns light yellow, and the temperature is naturally raised to -50℃ without temperature control, maintained for 10min, and then slowly cooled to -78℃ and tributyltin chloride (2.17g, 6.7mmol) is quickly added, and then naturally heated to room temperature, the system is yellow. After stirring for 4 hours, petroleum ether is added first and then water is added dropwise, and the system gradually becomes transparent. The mixture is extracted with water and petroleum ether, and anhydrous sodium sulfate is passed. After removing the solvent, the crude compound (1.72g, yield 85%) is obtained, HR-MS (ACPI-M + , m / z): 540.42.

[0064] Step 3): Synthesis of Compound III In a 100 mL two-necked bottle, compound II (2 g, 3.7 mmol), 4,8-dibromo-1H,5H-benzo[1,2-c:4,5-c']bis([1,2,5]thiadiazole) (0.62 g, 1.8 mmol), tetrakis(triphenylphosphine)palladium (10 mg), deoxygenated toluene (15 mL) were added, nitrogen was blown for 15 min, and then heated at 100 ° C for 4 hours. After the reaction was completed, the reaction was cooled to room temperature, the solvent was removed, and the dark green product (0.53 g, product 69%) was purified by silica gel column. HR-MS (ACPI-M + , m / z): 692.94.

[0065] Example 3 This embodiment provides a structure as shown in Formula B-7:

[0066] The preparation method of compound B-7 specifically comprises the following steps:

[0067] Step 1): Synthesis of Compound Ⅰ In a 500mL two-necked bottle, 2,5-dibromonitrobenzene (10g, 35.6mmol) and thieno[3,2-b]thiophenetin reagent (16.8g, 39.1mmol) were added. After bubbling nitrogen for 15min, tetrakis(triphenylphosphine)palladium (560mg) was added under nitrogen flow. The reaction was carried out under nitrogen protection and heated at 120°C for 24 hours. After the reaction was completed, the reaction was cooled to room temperature, extracted with dichloromethane and water, and passed through anhydrous sodium sulfate to remove the solvent. The solid was purified by silica gel column to obtain a brown-red solid (6.2g, 60% yield). HR-MS (ACPI-M + , m / z): 340.21.

[0068] Step 2): Synthesis of Compound II In a 250 mL two-necked bottle, compound I (5 g, 14.7 mmol), triphenylphosphine (11.6 g, 44.2 mmol), and ultra-dry chlorobenzene (30 mL) were added, and nitrogen was blown for 15 min, and then refluxed at 140 ° C overnight. After the reaction was completed, the reaction was cooled to room temperature, and chlorobenzene was removed by vacuum distillation. After purification by silica gel column, the yellow-white powder product (3.2 g, yield 56%) was obtained by recrystallization. HR-MS (ACPI-M + , m / z): 308.21.

[0069] Step 3): Synthesis of Compound III In a 250 mL two-necked bottle, compound II (5 g, 16.2 mmol), 1-bromohexane (2.7 g, 16.4 mmol), potassium hydroxide (2.7 g, 48.1 mmol), potassium iodide (0.27 g, 1.6 mmol), and ultra-dry tetrahydrofuran (30 mL) were added, and nitrogen was blown for 15 min, and then heated at 70 ° C for 4 hours. After the reaction was completed, the reaction was cooled to room temperature, extracted with dichloromethane and water, and passed through anhydrous sodium sulfate to remove the solvent. The light yellow oily substance (4.5 g, yield 95%) was purified by silica gel column. HR-MS (ACPI-M + , m / z): 392.37.

[0070] Step 4): Synthesis of Compound IV In a 100mL two-necked bottle, compound III (2g, 5.1mmol) and ultra-dry tetrahydrofuran (15mL) were added. After blowing nitrogen for 15min, the temperature was lowered to -78℃ and n-butyl lithium (3.2mL) was added dropwise. After the addition was completed, the system turned light yellow. The temperature was naturally raised to -50℃ without temperature control and maintained for 10min. The temperature was slowly lowered to -78℃ again and tributyltin chloride (1.69g, 5.2mmol) was quickly added. Then the temperature was naturally raised to room temperature. The system was yellow. After stirring for 4 hours, petroleum ether was added first and then water was added dropwise. The system gradually became transparent. The mixture was extracted with water and petroleum ether, passed through anhydrous sodium sulfate, and the solvent was removed to obtain a crude compound (1.5g, yield 72%). HR-MS (ACPI-M + , m / z): 602.53.

[0071] Step 5): Synthesis of Compound V In a 100 mL two-necked bottle, compound IV (2 g, 3.3 mmol), 4,8-dibromo-1H,5H-benzo[1,2-c:4,5-c']bis([1,2,5]thiadiazole) (0.55 g, 1.56 mmol), tetrakis(triphenylphosphine)palladium (10 mg), deoxygenated toluene (15 mL) were added, nitrogen was blown for 15 min, and then heated at 100 ° C for 4 hours. After the reaction was completed, the reaction was cooled to room temperature, the solvent was removed, and the dark green product (0.5 g, product 65%) was purified by silica gel column. HR-MS (ACPI-M + , m / z): 817.15.

[0072] Example 4 This embodiment provides a structure as shown in Formula E-1:

[0073] The preparation method of compound E-1 specifically comprises the following steps:

[0074] Step 1): Synthesis of Compound Ⅰ In a 500mL two-necked bottle, 2-naphthaleneboric acid (10g, 58.1mmol), 4-bromo-1-iodo-2-nitrobenzene (19.1g, 58.1mmol), potassium carbonate (9.6g, 69.5mmol), water (20mL), dioxane (120mL) were added, and nitrogen was blown for 15min. Then, under nitrogen flow, tetrakis(triphenylphosphine)palladium (600mg) was added; the reaction was carried out under nitrogen protection, heated at 60°C for 8 hours, and after the reaction was completed, the reaction was cooled to room temperature, extracted with dichloromethane and water, and passed through anhydrous sodium sulfate to remove the solvent. The light yellow solid (7.8g, 76% yield) was purified by silica gel column. HR-MS (ACPI-M + , m / z): 328.17.

[0075] Step 2): Synthesis of Compound II In a 250 mL two-necked bottle, compound I (5 g, 15.2 mmol), triphenylphosphine (12.0 g, 45.8 mmol), and ultra-dry chlorobenzene (30 mL) were added, and nitrogen was blown for 15 min, and then heated under reflux at 140 ° C overnight. After the reaction was completed, the reaction was cooled to room temperature, and chlorobenzene was removed by vacuum distillation. After purification by silica gel column, the yellow-white powder product (3.2 g, yield 60%) was obtained by recrystallization. HR-MS (ACPI-M + , m / z): 296.17.

[0076] Step 3): Synthesis of Compound III In a 250 mL two-necked bottle, compound II (5 g, 16.9 mmol), 1-bromohexane (2.8 g, 16.9 mmol), potassium hydroxide (2.8 g, 50.7 mmol), potassium iodide (0.28 g, 1.6 mmol), and ultra-dry tetrahydrofuran (30 mL) were added, and nitrogen was blown for 15 min, and then heated at 70 ° C for 4 hours. After the reaction was completed, the reaction was cooled to room temperature, extracted with dichloromethane and water, and passed through anhydrous sodium sulfate to remove the solvent. The light yellow oily substance (4.1 g, yield 91%) was purified by silica gel column. HR-MS (ACPI-M + , m / z): 380.33.

[0077] Step 4): Synthesis of Compound IV In a 100mL two-necked bottle, add compound III (2g, 5.3mmol), ultra-dry tetrahydrofuran (15mL), blow nitrogen for 15min, cool to -78℃, add n-butyl lithium (3.2mL) dropwise, after the addition is complete, the system turns light yellow, and the temperature is naturally raised to -50℃ without temperature control, maintained for 10min, and then slowly cooled to -78℃ and tributyltin chloride (1.75g, 5.4mmol) is quickly added, and then naturally raised to room temperature, the system is yellow. After stirring for 4 hours, petroleum ether is added first and then water is added dropwise, and the system gradually becomes transparent. The mixture is extracted with water and petroleum ether, and anhydrous sodium sulfate is passed. After removing the solvent, the crude compound (1.1g, yield 69%) is obtained, HR-MS (ACPI-M + , m / z): 590.48.

[0078] Step 5): Synthesis of Compound V In a 100 mL two-necked bottle, compound IV (2 g, 3.4 mmol), 4,8-dibromo-1H,5H-benzo[1,2-c:4,5-c']bis([1,2,5]thiadiazole) (0.57 g, 1.6 mmol), tetrakis(triphenylphosphine)palladium (10 mg), deoxygenated toluene (15 mL) were added, nitrogen was blown for 15 min, and then heated at 100 ° C for 4 hours. After the reaction was completed, the reaction was cooled to room temperature, the solvent was removed, and the dark green product (0.6 g, product 68%) was purified by silica gel column. HR-MS (ACPI-M + , m / z): 793.06.

[0079] The performance tests of A-7 and C-7 prepared in Example 1 and Example 2 were performed. The results are as follows: Figure 1 and Figure 2 As shown, Figure 1 and Figure 2 They are the UV absorption and fluorescence emission spectra of A-7 and C-7, respectively. Figure 1 and Figure 2 This indicates that the compound prepared by the present invention has a long-wavelength emission effect in the second near-infrared region.

[0080] A-7 and C-7 prepared in Example 1 and Example 2 were coated with F127 (also known as poloxamer 407, a commonly used non-ionic triblock copolymer) to form A-7 and C-7 nanoparticles. The coating method was the existing method. Figure 3 and Figure 4 They are the near-infrared photothermal heating curves of A-7 and C-7 nanoparticles relative to water. Figure 3 and Figure 4 In the table, 50-200ug / ml refers to the concentration of the sample (the concentration of nanoparticles in ultrapure water). Figure 3 and Figure 4This indicates that the prepared nanoparticles have potential application value in fluorescence imaging and photothermal therapy.

[0081] As described above, although the present invention has been shown and described with reference to specific preferred embodiments, it should not be construed as limiting the present invention itself. Various changes may be made to the form and details without departing from the spirit and scope of the present invention.

Claims

1. A near-infrared luminescent material based on an aryl indole donor, characterized in that: The chemical structure formula of the near-infrared luminescent material is as follows: ； Among them, A is or , X is O, S, Se, Te or NR, and R is selected from: Substituted or unsubstituted C1~C24 alkyl, alkoxy chain containing C3~C24, aryl with 1~2 C1~C24 straight chain alkyl or branched chain alkyl; R1 and R2 are independently selected from: C1-C24 straight or branched chain alkyl; Ar1 and Ar2 are each independently selected from: substituted or unsubstituted C6~C30 aryl, substituted or unsubstituted C4~C30 heteroaryl.

2. The near-infrared luminescent material according to claim 1, characterized in that: A is any of the following structures: ； 。 3. The near-infrared luminescent material according to claim 1, characterized in that: Ar1 and Ar2 are each independently any of the following structures: ； Wherein, R3 to R5 are each independently selected from: Deuterium, F, Cl, Br, I, CN; C1-C24 alkyl; C1-C24 alkoxy; Substituted or unsubstituted aryl, wherein the aryl includes phenyl, biphenyl, naphthyl, triphenylene, anthracenyl, pyrenyl, phenanthrenyl, chrysene and perylenyl, and the substituent is deuterium, F, Cl, CN, C1-C24 alkyl, C1-C24 alkoxy.

4. The near-infrared luminescent material according to claim 1, characterized in that: The near-infrared luminescent material includes the following compounds: ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； 。 5. The method for preparing the near-infrared luminescent material according to claim 1, characterized in that: The preparation method comprises the following steps: adding a bromine-containing or chlorine-containing acceptor unit compound, a donor unit compound and a catalyst into a solvent to obtain a reaction solution; purifying the reaction solution through a silica gel column and then recrystallizing the solution to obtain a powdered near-infrared luminescent material.

6. The method for preparing the near-infrared luminescent material according to claim 5, characterized in that: In the structure of the near-infrared luminescent material, when the left and right sides of A are symmetrical structural formulas, the synthesis reaction formula is as follows: ； In the structure of the near-infrared luminescent material, when the left and right sides of A are asymmetric structural formulas, the synthesis reaction formula is as follows: 。 7. The method for preparing the near-infrared luminescent material according to claim 5, characterized in that: In the reaction solution: the molar concentration of the acceptor unit is 0.1-2.0 mmol / mL, the molar ratio of the acceptor unit to the donor unit is 1:(2.01-2.6), the molar ratio of the catalyst to the reaction substrate is (0.02-4.00):100, the reaction substrate refers to the acceptor unit and the donor unit; the catalyst is tetrakistriphenylphosphine palladium; the solvent is one of toluene, chlorobenzene and xylene.

8. The method for preparing the near-infrared luminescent material according to claim 5, characterized in that: The reaction temperature is 100-120° C., and the reaction time is 4-8 h.

9. The use of the near-infrared luminescent material according to claim 1, characterized in that: The near-infrared luminescent material is used in organic optoelectronic devices or biosensors and imaging equipment.

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