Fluorophore compound with fixed donor structure and preparation method and application thereof

Abstract

The application discloses a kind of fluorine boron pyrrole fluorescent compound with fixed donor structure, by using vinyl bridge, donor moiety pyrene and carbazole are connected to the alpha position of BODIPY core, to prepare two molecules with fixed donor-acceptor conformation, improve fluorescence quantum yield, can produce narrow spectrum with very narrow half peak width, high color purity fluorescent emission.Simultaneously, the fluorine boron pyrrole fluorescent compound with fixed donor structure in the present application has super high near-infrared light emission in organic solvent.The fluorine boron pyrrole fluorescent compound with fixed donor structure can efficiently improve π electron delocalization by vinyl bridge, can make carrier injection and transmission more balanced, improve device performance, so it has significant economic value in the application of light-emitting device, light-emitting material and display material, intelligent material and the like.

Description

Technical Field

[0001] This application relates to the field of organic light-emitting materials technology, and more specifically, to a fluoroboron pyrrole fluorescent compound with a fixed donor structure, its preparation method, and its application. Background Technology

[0002] Organic light-emitting diodes (OLEDs) have enormous application potential in smartphones, flat-screen TVs, and solid-state display technologies due to their advantages such as light weight, flexibility, wide operating temperature range, high brightness and contrast, wide viewing angle, and short response time. OLED devices are particularly crucial for full-color displays and solid-state display technologies.

[0003] To date, there have been many reports on materials based on small molecule organic electroluminescent devices. As a traditional donor-π-acceptor molecular structure, it can form a distorted conformation upon excitation, leading to efficient charge transfer and separation of the donor and acceptor.

[0004] However, structural lag between the ground state and the twisted excited state leads to drawbacks such as insufficient color purity and a wide half-width at half-maximum (HWHM). Commercial organic light-emitting diode (OLED) technology requires high device efficiency, good color purity, and long device lifetime. Therefore, discovering and fabricating a small-molecule organic electroluminescent device with high color purity and a narrow HWHM is a technical problem that needs to be solved by those skilled in the art.

[0005] Application content

[0006] To overcome at least one of the problems existing in the prior art, this application provides a fluoroboron pyrrole fluorescent compound with a fixed donor structure. This fluoroboron pyrrole fluorescent compound with a fixed donor structure has the advantages of high color purity and narrow half-maximum width, and has great application potential in fields such as smartphones, flat-panel TVs, and solid-state light emission. Among these, OLED devices are of decisive significance for full-color displays, solid-state light emission, and other display technologies.

[0007] Another objective of this application is to provide a method for preparing the above-mentioned fluoroboron pyrrole fluorescent compound with a fixed donor structure.

[0008] Another objective of this application is to provide the application of the above-mentioned fluoroboron pyrrole fluorescent compounds with fixed donor structures in the preparation of luminescent materials, organic electroluminescent devices, smart materials, and polymer resins.

[0009] To solve the above-mentioned technical problems, the technical solution adopted in this application is:

[0010] A fluoroboron pyrrole fluorescent compound with a fixed donor structure exhibits narrow-band emission. The fluoroboron pyrrole fluorescent compound with a fixed donor structure has the following molecular structural formula:

[0011]

[0012] In the formula, DD is selected from one of the following structural formulas a to i:

[0013]

[0014] R1 and R2 are each selected from one of the following structural formulas 1 to 33:

[0015]

[0016]

[0017]

[0018] Preferably, the fluoroboron pyrrole fluorescent compound has one of the following molecular structures:

[0019]

[0020] This application also provides a method for preparing the above-mentioned fluoroboron pyrrole fluorescent compound with a fixed donor structure, the method comprising the following steps:

[0021] S1. 2,4,6-trimethylbenzaldehyde, 2,4-dimethylpyrrole, and 2,3-dichloro-5,6-dicyano-1,4-benzoquinone are reacted with an aromatic aldehyde to obtain an intermediate.

[0022] S2. The intermediate obtained in S1 is reacted with triethylamine and boron trifluoride ether through oxidation and complexation to generate BODIPY intermediate, 5-difluoro-10-m-diphenyl-1,3,7,9-tetramethyl-5H-4l4,5l4-dipyrrolo[1,2-c:2',1'-f][1,3,2]diazaborine;

[0023] S3. The target product is obtained by Knoevenagel coupling reaction of the BODIPY intermediate with 3-formaldehyde-9-phenylcarbazole, glacial acetic acid, and piperidine, using toluene solution as solvent:

[0024]

[0025] S4. Replace 3-formaldehyde-9-phenylcarbazole in step S1 with 1-pyrenecarbaldehyde. Subsequent steps are similar to obtain the target product.

[0026]

[0027] Preferably, the molar ratio of p-tert-butylbenzaldehyde and 2,4-dimethylpyrrole in step S1 is (1-2):(1-4).

[0028] More preferably, the reaction temperature in step S1 is room temperature, and the reaction time is 4 to 6 hours.

[0029] Preferably, in step S2, the molar ratio of the intermediate to triethylamine and boron trifluoride ether is (1-2):(10-30):(10-30).

[0030] More preferably, the solvent used in step S2 is dichloromethane, the reaction temperature is room temperature, and the reaction time is 4 to 6 hours.

[0031] Preferably, in step S3, the molar ratio of the BODIPY intermediate to 3-formaldehyde-9-phenylcarbazole, glacial acetic acid, and piperidine is (1-2):(6-12):(0.005-0.1):(0.005-0.1).

[0032] More preferably, the solvent used in step S3 is a toluene solution, the reaction temperature is 120–140°C, and the reaction time is 2–4 hours.

[0033] This application also provides the use of the above-mentioned fluoroboron pyrrole fluorescent compounds with fixed donor structures in the preparation of luminescent materials, organic electroluminescent devices, smart materials, and the synthesis of polymer resins.

[0034] Compared with the prior art, the beneficial effects of this application are:

[0035] The fluoroboron pyrrole fluorescent compound provided in this application is prepared by using a vinyl bridge to connect the donor pyrene and carbazole to the α-position of the BODIPY core to prepare two molecules with a fixed donor-acceptor conformation. It has weaker CT properties, improves rigidity, and restricts the loss of stretching or torsional vibrations through an intramolecular conformational interlocking strategy, thereby improving the fluorescence quantum yield. It achieves efficient near-infrared emission without sacrificing FWHM and can produce narrow spectrum with very narrow half-width and high color purity fluorescence emission. Attached Figure Description

[0036] Figure 1 Ph-BDP obtained in step S2 1 HMNR diagram.

[0037] Figure 2 For the Ph-BDP-Cz obtained in step S3 1 HMNR diagram.

[0038] Figure 3 Ph-BDP-PY obtained in step S4 1 HMNR diagram.

[0039] Figure 4The mass spectrum of Ph-BDP-Cz obtained in step S3 is shown.

[0040] Figure 5 The mass spectrum of Ph-BDP-PY obtained in step S4 is shown.

[0041] Figure 6 The UV-Vis absorption of the compounds Ph-BDP-Cz and Ph-BDP-PY prepared in step S3 in toluene solution.

[0042] Figure 7 Emission spectra of compounds Ph-BDP-Cz and Ph-BDP-PY prepared in step S4 in toluene solution. Detailed Implementation

[0043] The embodiments of this application will be described in detail below with reference to examples. However, those skilled in the art will understand that the following examples are for illustrative purposes only and should not be considered as limiting the scope of this application. Unless otherwise specified in the examples, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all commercially available conventional products.

[0044] It should be noted that:

[0045] Unless otherwise specified, all embodiments and preferred embodiments mentioned herein can be combined to form new technical solutions.

[0046] In this application, unless otherwise stated, the various reactions or operation steps may be performed sequentially or in a particular order. Preferably, the reaction methods described herein are performed sequentially.

[0047] Unless otherwise stated, the technical and scientific terms used herein have the same meanings as those familiar to a person skilled in the art. Furthermore, any methods or materials similar to or equivalent to those described herein may also be used in this application.

[0048] This application discloses a fluoroboron pyrrole fluorescent compound with a fixed donor structure, exhibiting narrow-band emission. The fluoroboron pyrrole fluorescent compound with a fixed donor structure has the following molecular structural formula:

[0049]

[0050] In the formula, D is selected from one of the following structural formulas a to i:

[0051]

[0052] R1 and R2 are each selected from one of the following structural formulas 1 to 33:

[0053]

[0054]

[0055]

[0056] The fluoroboron pyrrole fluorescent compound with a fixed donor structure in this application is prepared by connecting the donor pyrene and carbazole to the α-position of the BODIPY core using a vinyl bridge. This results in two molecules with a fixed donor-acceptor conformation, exhibiting weaker CT properties and increased rigidity. The loss of stretching or torsional vibrations is limited by an intramolecular conformational interlocking strategy, thereby increasing the fluorescence quantum yield. Highly efficient near-infrared emission is achieved without sacrificing the FWHM, improving the fluorescence quantum yield, and producing a narrow spectrum with a very narrow half-width and high color purity fluorescence emission.

[0057] Meanwhile, the fluoroboron pyrrole fluorescent compound with a fixed donor structure in this application exhibits ultra-efficient near-infrared light emission in organic solvents. This fluoroboron pyrrole fluorescent compound with a fixed donor structure, relying on vinyl bridging, can efficiently enhance π-electron delocalization, resulting in a more balanced carrier injection and transport, thus improving device performance. Therefore, it has significant economic value in applications such as light-emitting devices, light-emitting materials, display materials, and smart materials.

[0058] In some embodiments, the fluoroboron pyrrole derivative compounds provided in this application have one of the following molecular structures:

[0059]

[0060] The fluoroboron-pyrrole fluorescent compound with a fixed donor structure in this application is prepared by connecting the donor pyrene and carbazole to the α-position of the BODIPY core using a vinyl bridge. This results in two molecules with a fixed donor-acceptor conformation, exhibiting weaker CT properties and increased rigidity. By restricting the loss of stretching or torsional vibrations through an intramolecular conformational interlocking strategy, the fluorescence quantum yield is improved. Highly efficient NIR luminescence is achieved without sacrificing FWHM, producing narrow spectra with very narrow half-widths and high color purity fluorescence emission.

[0061] Simultaneously, it exhibits ultra-efficient near-infrared light emission in organic solvents. This narrow-band emission fluoroboron pyrrole fluorescent compound with a fixed donor structure has significant economic value in applications such as light-emitting devices, light-emitting materials, display materials, and smart materials.

[0062] This application also provides a method for synthesizing the above-mentioned fluoroboron pyrrole fluorescent compound with a fixed donor structure. The method includes the following steps:

[0063] S1. 2,4,6-trimethylbenzaldehyde, 2,4-dimethylpyrrole, and 2,3-dichloro-5,6-dicyano-1,4-benzoquinone are reacted with an aromatic aldehyde to obtain an intermediate.

[0064] S2. The intermediate obtained in S1 is reacted with triethylamine and boron trifluoride ether through oxidation and complexation to generate the BODIPY intermediate Ph-BDP,5-difluoro-10-m-diphenyl-1,3,7,9-tetramethyl-5H-4l4,5l4-dipyrrolo[1,2-c:2',1'-f][1,3,2]diazaborine;

[0065] S3. The target product Ph-BDP-Cz was obtained by Knoevenagel coupling reaction of BODIPY intermediate with 3-formaldehyde-9-phenylcarbazole, glacial acetic acid and piperidine, using toluene solution as solvent.

[0066]

[0067] S4. Replace 3-formaldehyde-9-phenylcarbazole in step S1 with 1-pyrenecarbaldehyde. Subsequent steps are similar, and the target product Ph-BDP-PY can be obtained.

[0068]

[0069] Preferably, in step S1, the molar ratio of p-tert-butylbenzaldehyde to 2,4-dimethylpyrrole is (1-2):(1-4); the reaction temperature is room temperature, and the reaction time is 4-6 hours.

[0070] Preferably, in step S2, the molar ratio of the intermediate to triethylamine and boron trifluoride diethyl ether is (1-2):(10-30):(10-30), and the solvent used in step S2 is dichloromethane, the reaction temperature is room temperature, and the reaction time is 4-6 hours.

[0071] Preferably, in step S3, the molar ratio of BODIPY intermediate to 3-formaldehyde-9-phenylcarbazole, glacial acetic acid, and piperidine is (1-2):(6-12):(0.005-0.1):(0.005-0.1), and the solvent for the reaction in step S3 is toluene solution, the reaction temperature is 120-140°C, and the reaction time is 2-4 hours.

[0072] This application also provides the application of the above-mentioned fluoroboron pyrrole fluorescent compounds with fixed donor structures in the preparation of luminescent materials, organic electroluminescent devices, and the synthesis of smart materials.

[0073] In step S1 of some preferred embodiments of this application, the molar ratio of p-tert-butylbenzaldehyde to 2,4-dimethylbenzaldehyde is (1-2):(1-4); the reaction temperature is room temperature and the reaction time is 4-6 hours.

[0074] In some preferred embodiments of this application, the molar ratio of tert-butylbenzaldehyde and 2,4-dimethylbenzaldehyde in step S1 is (1-2):(1-4); more preferably, the molar ratio of tert-butylbenzaldehyde and 2,4-dimethylbenzaldehyde in step S1 is 1:4.

[0075] In some preferred embodiments of this application, the solvent used in step S1 to oxidize dipyrrolemethane with the oxidant 2,3-dichloro-5,6-dicyanbenzoquinone is dichloromethane;

[0076] In some preferred embodiments of this application, the reaction temperature in step S1 is room temperature and the reaction time is 4 to 6 hours; more preferably, the reaction temperature is room temperature and the reaction time is 6 hours.

[0077] In some preferred embodiments of this application, the post-processing described in step S1 is extraction and drying.

[0078] In a more preferred embodiment of this application, the specific operation steps of step S1 are as follows:

[0079] Preparation of intermediates

[0080] 120 ml of ultradry DCM was added to a two-necked flask. 2,4,6-Trimethylbenzaldehyde (1.8 ml, 12 mmol) and 2,4-dimethylpyrrole (5 ml, 48 mmol) were added under nitrogen atmosphere. The mixture was stirred for 10 minutes. Then 0.1 ml of TFA was added. After reacting for 4 hours, 1 g of DDQ was added. The reaction mixture was extracted with DCM / H₂O, and the organic layer was dried over anhydrous Na₂SO₄. Purification by silica gel column chromatography gave compound 1 as an orange solid. Yield: 1.89 g, 49.5%.

[0081] The chemical reaction equation is as follows:

[0082]

[0083] In some preferred embodiments of this application, the molar ratio of the intermediate to triethylamine and boron trifluoride ethyl ether in step S2 is (1-2):(10-30):(10-30). More preferably, the ratio of the intermediate to triethylamine and boron trifluoride ethyl ether in step S2 is 1:23:41.

[0084] In some preferred embodiments of this application, the solvent used in step S2 is dichloromethane. In some preferred embodiments of this application, the reaction temperature in step S2 is room temperature, and the reaction time is 2 to 6 hours; more preferably, the reaction temperature in step S2 is 25°C, and the reaction time is 4 hours.

[0085] In some preferred embodiments of this application, the post-processing in step S2 involves concentration and separation. After the reaction is complete, the organic phase is concentrated under reduced pressure to obtain the crude product Ph-BDP.

[0086] In a more preferred embodiment of this application, the specific operation steps of step S2 are as follows:

[0087] Preparation of Ph-BDP (BODIPY intermediate):

[0088] Compound 1 (0.5 g, 1.57 mmol) and dichloromethane (120 mL) were added to a 100 mL two-necked flask. Triethylamine (5 mL, 36 mmol) and boron trifluoride diethyl ether (8 mL, 65 mmol) were added dropwise at low temperature. The mixture was stirred at 25 °C for 4 hours and concentrated under reduced pressure to give 0.47 g of orange solid (yield 82%).

[0089] The reaction equation is as follows:

[0090]

[0091] The NMR spectrum of the compound Ph-BDP obtained in step S2 is as follows: Figure 1 As shown. From Figure 1 It can be seen that its characteristic wavenumber (ppm) is 1 ¹H NMR (400MHz, Chloroform-d) δ 6.94 (s, 2H), 5.96 (s, 2H), 2.56 (s, 6H), 2.33 (s, 3H), 2.09 (s, 6H), 1.38 (s, 6H). The hydrogen atoms in the fluoroboron pyrrole plane, aromatic ring, and styrene correspond one-to-one and are reasonably numerous. This indicates that the Ph-BDP compound has a simple structure and high purity.

[0092] In some preferred embodiments of this application, in step S3, the molar ratio of the BODIPY intermediate to 3-formaldehyde-9-phenylcarbazole, glacial acetic acid, and piperidine is (1-2):(6-12):(0.005-0.1):(0.005-0.1).

[0093] More preferably, the molar ratio of 3-formaldehyde-9-phenylcarbazole, glacial acetic acid, and piperidine is 1:6:0.05:0.05.

[0094] In some preferred embodiments of this application, the reaction solvent in step S3 is toluene.

[0095] In some preferred embodiments of this application, the reaction is carried out under reflux protection with an inert gas atmosphere. The inert gas in step S3 is nitrogen, argon, or helium. More preferably, the inert gas in step S3 is argon. In some preferred embodiments of this application, the reaction temperature in step S3 is 120–140°C, and the reaction time is 2–4 hours. More preferably, the reaction temperature in step S3 is 140°C, and the reaction time is 3 hours.

[0096] In some preferred embodiments of this application, the processing in step S3 includes filtration, drying, concentration, and separation. After the reaction is complete, the reaction solution is filtered, and after filtration, it is concentrated under reduced pressure to obtain the crude product; finally, Ph-BDP-Cz is separated by silica gel column chromatography using petroleum ether and dichloromethane as eluents.

[0097] In a more preferred embodiment of this application, the specific operation steps of step S3 are as follows:

[0098] Preparation of Ph-BDP-Cz (compound 3):

[0099] Ph-BDP (BODIPY intermediate) (38 mg, 0.1 mmol), 3-formaldehyde-9-phenylcarbazole (0.163 g, 0.6 mmol), glacial acetic acid (0.005 mmol), and piperidine (0.005 mmol) were sequentially added to a 50 mL two-necked flask. The flask was evacuated under vacuum and purged three times with dry argon. Then, toluene (10 mL) was added, and the mixture was stirred at 140 °C for 3 hours. After cooling and filtration, the filtrate was distilled under reduced pressure to obtain a dark green solid. Using silica gel powder as the stationary phase and petroleum ether / dichloromethane as the eluent, 29.6 mg of a dark green solid was obtained by column chromatography (yield 30%).

[0100] The reaction equation is as follows:

[0101]

[0102] The NMR spectrum of compound Ph-BDP-Cz is as follows: Figure 2 As shown. From Figure 2 It can be seen that its characteristic wavenumber (ppm) is 1¹H NMR (500MHz, Chloroform-d) δ 8.38 (s, 2H), 8.25 (d, J = 7.7Hz, 2H), 7.84 (d, J = 15.9Hz, 2H), 7.75 (d, J = 8.7Hz, 2H), 7.66–7.55 (m, 8H), 7.52–7.46 (m, 4H), 7.41 (t, J = 7.7Hz, 6H), 7.33 (t, J = 7.0Hz, 2H), 6.97 (s, 2H), 6.69 (s, 2H), 2.36 (s, 3H), 2.15 (s, 6H), 1.48 (s, 6H). The hydrogen atoms in the fluoroboron pyrrole plane, aromatic ring, and styrene are all correctly matched and of reasonable quantity. This indicates that the Ph-BDP-Cz compound has a simple structure and high purity.

[0103] Figure 2 The molecular Ph-BDP-Cz proton spectrum was measured using a Bruker 500MHz superconducting nuclear magnetic resonance spectrometer with deuterated chloroform as the solvent. Figure 4 Mass spectra of the molecule Ph-BDP-Cz as measured using a Thermo Fisher ultra-high performance liquid chromatography-tandem triple quadrupole mass spectrometer* / TSQ Endura. MALDI-HRMS:calcd([C 60 H 47 BF2N4] + ),m / z 872.39,found,m / z872.27.

[0104] In some preferred embodiments of this application, in step S4, the molar ratio of the BODIPY intermediate to 1-pyrene carbaldehyde, glacial acetic acid, and piperidine is (1-2):(6-12):(0.005-0.1):(0.005-0.1).

[0105] More preferably, the molar ratio of 1-pyrene formaldehyde, glacial acetic acid, and piperidine is 1:6:0.05:0.05.

[0106] In some preferred embodiments of this application, the reaction solvent in step S4 is toluene.

[0107] In some preferred embodiments of this application, the reaction is carried out under reflux protection with an inert gas atmosphere. The inert gas in step S4 is nitrogen, argon, or helium. More preferably, the inert gas in step S4 is argon. In some preferred embodiments of this application, the reaction temperature in step S4 is 120–140°C, and the reaction time is 2–4 hours. More preferably, the reaction temperature in step S4 is 140°C, and the reaction time is 3 hours.

[0108] In some preferred embodiments of this application, the processing in step S4 includes filtration, drying, concentration, and separation. After the reaction is complete, the reaction solution is filtered, and after filtration, it is concentrated under reduced pressure to obtain the crude product; finally, Ph-BDP-PY is separated by silica gel column chromatography using petroleum ether and dichloromethane as eluents.

[0109] In a more preferred embodiment of this application, the specific operation steps of step S4 are as follows:

[0110] Preparation of Ph-BDP-PY (compound 4):

[0111] Ph-BDP (BODIPY intermediate) (38 mg, 0.1 mmol), 1-pyrenecarboxaldehyde (0.138 g, 0.6 mmol), glacial acetic acid (0.005 mmol), and piperidine (0.005 mmol) were sequentially added to a 50 mL two-necked flask. The flask was evacuated under vacuum and purged three times with dry argon. Then, toluene (10 mL) was added, and the mixture was stirred at 140 °C for 3 hours. After cooling and filtration, the filtrate was distilled under reduced pressure to obtain a dark green solid. Using silica gel powder as the stationary phase and petroleum ether / dichloromethane as the eluent, 23.7 mg of a dark green solid was obtained by column chromatography (yield 30%).

[0112] The reaction equation is as follows:

[0113]

[0114] The NMR spectrum of compound Ph-BDP-PY is as follows: Figure 3 As shown. From Figure 3 It can be seen that its characteristic wavenumber (ppm) is 1 ¹H NMR (500MHz, Chloroform-d) δ 8.38 (s, 2H), 8.25 (d, J = 7.7Hz, 2H), 7.84 (d, J = 15.9Hz, 2H), 7.75 (d, J = 8.7Hz, 2H), 7.66–7.55 (m, 8H), 7.52–7.46 (m, 4H), 7.41 (t, J = 7.7Hz, 6H), 7.33 (t, J = 7.0Hz, 2H), 6.97 (s, 2H), 6.69 (s, 2H), 2.36 (s, 3H), 2.15 (s, 6H), 1.48 (s, 6H). The hydrogen atoms in the fluoroboron pyrrole plane, aromatic ring, and styrene are all correctly matched and of reasonable quantity. This indicates that the Ph-BDP-PY compound has a simple structure and high purity.

[0115] Figure 3 The 1H NMR spectrum of the molecular Ph-BDP-PY was measured using a Bruker 500MHz superconducting NMR spectrometer with deuterated chloroform as the solvent. Figure 5Mass spectra of the molecule Ph-BDP-PY, measured using a Thermo Fisher ultra-high performance liquid chromatography-tandem triple quadrupole mass spectrometer* / TSQ Endura. MALDI-HRMS:calcd([C 60 H 47 BF2N4] + ),m / z 790.33,found,m / z790.45.

[0116] In this application, besides Ph-BDP-Cz and Ph-BDP-PY, several other fluoroboron pyrrole derivatives, due to their structural similarity to the aforementioned two compounds, all belong to the fluoroboron pyrrole derivative class. Utilizing the fluoroboron pyrrole ring (as an electron acceptor) as a bridge, and through a vinyl bridge structure, the electron-withdrawing interaction of the donor R with an electron-withdrawing structure of 1–33 (e.g., ortho, meta, p-fluorophenyl, styryl, acrylate, (R or S) 5,5',6,6',7,7',8,8'-octahydro-1,1'-bi-2-naphthol-p-cyanophenyl, (R or S) 1,1'-bi-2-naphthol-p-cyanophenyl, etc.) can produce narrow spectra with very narrow half-maximum widths and high color purity fluorescence emission. Therefore, the preparation and characterization methods of the other fluoroboron pyrrole derivatives are similar to those of the aforementioned two compounds and will not be elaborated further here.

[0117] Meanwhile, the preparation process of the compound described in this application is simple, convenient, and can be prepared in large-scale batches. It is also economical and practical, which is conducive to industrial production and preparation, generates certain economic value, and facilitates its application and promotion.

[0118] Characterization and performance testing

[0119] Using the compounds Ph-BDP-Cz and Ph-BDP-PY prepared in steps S3 and S4 as test objects, the photophysical properties of compounds Ph-BDP-Cz and Ph-BDP-PY were tested, and the test results are as follows: Figure 6 , Figure 7 As shown.

[0120] Figure 6 , Figure 7 Normalized absorption and emission spectra of molecules Ph-BDP-Cz and Ph-BDP-PY in toluene solution, measured by a Shimadzu UV-2700 UV-Vis spectrophotometer and an Edinburgh FLS980 spectrophotometer.

[0121] like Figure 6 , Figure 7 As shown, the absorption wavelength of Ph-BDP-Cz is 672nm and the emission wavelength is 692nm.

[0122] Ph-BDP-PY has an absorption wavelength of 693nm and an emission wavelength of 723nm.

[0123] from Figure 6 , Figure 7 In addition, the applicant can also calculate that the emission half-widths of Ph-BDP-Cz and Ph-BDP-PY are 29 nm and 34 nm, respectively, which are much narrower than the half-widths of about 60 nm of traditional fluoroboron pyrrole fluorescent molecules.

[0124] Both Ph-BDP-Cz and Ph-BDP-PY exhibit high-purity bright near-infrared light emission, making these narrow-band emission fluoroboron pyrrole fluorescent compounds with fixed donor structures highly valuable for applications such as luminescent materials, smart materials, display materials, and light-emitting devices.

[0125] In this application, besides Ph-BDP-Cz and Ph-BDP-PY, several other fluoroboron pyrrole fluorescent compounds with fixed donor structures are structurally similar to the aforementioned two compounds. They all belong to the fluoroboron pyrrole ring main ring structure, using the fluoroboron pyrrole ring (as an electron acceptor) as a bridge. With the help of the vinyl bridge structure, the donor (e.g., ortho, meta, p-fluorophenyl, styryl, acrylate, (R or S) 5,5',6,6',7,7',8,8'-octahydro-1,1'-bi-2-naphthol-p-cyanophenyl, (R or S) 1,1'-bi-2-naphthol-p-cyanophenyl, etc.) pulls electrons from it. Therefore, through the same characterization and testing methods, other fluoroboron pyrrole fluorescent compounds with fixed donor structures can all produce narrow spectra with very narrow half-widths and high color purity fluorescence emission.

[0126] This application discloses a fluoroboron pyrrole fluorescent compound with a fixed donor structure. By using a vinyl bridge to connect the donor pyrene and carbazole to the α-position of the BODIPY core, two molecules with a fixed donor-acceptor conformation are prepared. This results in weaker CT properties, increased rigidity, and a strategy of intramolecular conformational interlocking to limit the loss of stretching or torsional vibrations, thereby improving the fluorescence quantum yield. Highly efficient NIR luminescence is achieved without sacrificing the FWHM, resulting in a narrow spectrum with a very narrow half-width and high color purity fluorescence emission. Furthermore, using this narrow-band emission fluoroboron pyrrole fluorescent compound with a fixed donor structure in the fabrication of OLED light-emitting devices allows for a more balanced carrier injection and transport, improving device performance. Therefore, this narrow-band emission fluoroboron pyrrole fluorescent compound with a fixed donor structure has significant application and economic value in luminescent materials, smart materials, display materials, and light-emitting devices. In particular, some compounds provide new ideas for the synthesis of photoluminescent polymer resins in engineering applications.

[0127] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with an embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0128] Although several embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.

Claims

1. A fluoroboron pyrrole fluorescent compound with a fixed donor structure, exhibiting narrow-band emission, characterized in that: The fluoroboron pyrrole fluorescent compound with a fixed donor structure has one of the following molecular structures: 。 2. The method for preparing the fluoroboron pyrrole fluorescent compound with a fixed donor structure as described in claim 1, characterized in that, Includes the following steps: S1. 2,4,6-trimethylbenzaldehyde, 2,4-dimethylpyrrole, and 2,3-dichloro-5,6-dicyano-1,4-benzoquinone were reacted with an aromatic aldehyde to obtain an intermediate. S2. The intermediate obtained in S1 is reacted with triethylamine and boron trifluoride ether through oxidation and complexation to generate BODIPY intermediate, 5-difluoro-10-m-diphenyl-1,3,7,9-tetramethyl-5H-4l4,5l4-dipyrrolo[1,2-c:2',1'-f][1,3,2]diazaborine; S3. The target product is obtained by coupling reaction of the BODIPY intermediate with 3-formaldehyde-9-phenylcarbazole, glacial acetic acid, and piperidine, using toluene solution as a solvent: ； S4. Replace 3-formaldehyde-9-phenylcarbazole in step S3 with 1-pyrenecarbaldehyde. The BODIPY intermediate reacts with 1-pyrenecarbaldehyde, glacial acetic acid, and piperidine, using toluene solution as a solvent, via a coupling reaction to obtain the target product. 。 3. The method for preparing a fluoroboron pyrrole fluorescent compound with a fixed donor structure according to claim 2, characterized in that, In step S1, the molar ratio of p-tert-butylbenzaldehyde to 2,4-dimethylpyrrole is (1~2):(1~4).

4. The method for preparing a fluoroboron pyrrole fluorescent compound with a fixed donor structure according to claim 3, characterized in that, The reaction temperature in step S1 is room temperature, and the reaction time is 4 to 6 hours.

5. The method for preparing the fluoroboron pyrrole fluorescent compound with a fixed donor structure according to claim 2, characterized in that: In step S2, the molar ratio of the intermediate to triethylamine and boron trifluoride ethyl ether is (1~2):(10~30):(10~30).

6. The method for preparing the fluoroboron pyrrole fluorescent compound with a fixed donor structure according to claim 5, characterized in that: The solvent used in step S2 is dichloromethane, the reaction temperature is room temperature, and the reaction time is 4-6 hours.

7. The method for preparing a fluoroboron pyrrole fluorescent compound with a fixed donor structure according to claim 2, characterized in that, In step S3, the molar ratio of the BODIPY intermediate to 3-formaldehyde-9-phenylcarbazole, glacial acetic acid, and piperidine is (1~2):(6~12):(0.005~0.1):(0.005~0.1).

8. The method for preparing a fluoroboron pyrrole fluorescent compound with a fixed donor structure according to claim 7, characterized in that, The solvent used in step S3 is toluene solution, the reaction temperature is 120-140°C, and the reaction time is 2-4 hours.

9. The application of the fluoroboron pyrrole fluorescent compound with a fixed donor structure as described in claim 1 in the preparation of luminescent materials, organic electroluminescent devices, smart materials, and the synthesis of polymer resins.

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