BODIPY fluorescent compound with fixed donor structure as well as preparation method and application of BODIPY fluorescent compound

Abstract

According to the BODIPY fluorescent compound with the fixed donor structure, two molecules with fixed donor-acceptor conformation are prepared by connecting pyrene and carbazole of a donor part to an alpha-position of a BODIPY core by using a vinyl bridge, so that the fluorescence quantum yield is increased, and a narrow spectrum with very narrow half-peak width can be generated; and high-color-purity fluorescence emission is realized. Meanwhile, the BODIPY fluorescent compound with the fixed donor structure in the patent application has ultra-efficient near-infrared light emission in an organic solvent. The BODIPY fluorescent compound with the fixed donor structure can efficiently improve pi electron delocalization by means of a vinyl bridge, can enable carrier injection and transmission to be more balanced, and improves device performance, so that the BODIPY fluorescent compound with the fixed donor structure has remarkable economic value in the application aspects of light-emitting devices, light-emitting materials, display materials, intelligent materials and the like.

Description

Technical Field

[0001] The present application relates to the technical field of organic light-emitting materials, and more specifically, to a fluoroboryl pyrrole fluorescent compound with a fixed donor structure, and a preparation method and application thereof. Background Art

[0002] Organic light-emitting diodes (OLEDs) have great application potential in the fields of smart phones, flat-panel TVs, and solid-state lighting due to their advantages such as light weight, good flexibility, wide operating temperature range, high brightness and contrast, wide viewing angle, and short response time. OLED devices are of decisive significance to display technologies such as full-color display and solid-state lighting.

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

[0004] However, there are structural delays between the ground state and the twisted excited state, insufficient color purity, and relatively wide half-width. Commercial organic light-emitting diode technology requires high device efficiency, good color purity, and also requires a long device life. Therefore, how to discover and prepare a small molecule organic electroluminescent device with high color purity and narrow half-width is a technical problem that technicians in this field need to solve.

[0005] Application Contents

[0006] In order to overcome at least one problem of the above-mentioned prior art, the present application provides a fluoroboryl pyrrole fluorescent compound with a fixed donor structure. The fluoroboryl pyrrole fluorescent compound with a fixed donor structure has the advantages of high color purity and narrow half-peak width, and has great application potential in the fields of smart phones, flat-panel TVs, and solid-state luminescence. Among them, OLED devices are of decisive significance to display technologies such as full-color display and solid-state luminescence.

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

[0008] Another object of the present application is to provide the use of the above-mentioned fluoroboryl pyrrole fluorescent compound with a fixed donor structure in the preparation of luminescent materials, organic electroluminescent devices, smart materials, and polymer resins.

[0009] In order to solve the above technical problems, the technical solution adopted in this application is:

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

[0011]

[0012] Wherein 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 fluoroboryl pyrrole fluorescent compound has one of the following molecular structures:

[0019]

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

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

[0022] S2. The intermediate prepared in S1 is reacted with triethylamine and boron trifluoride ether by oxidation reaction 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]diazaboropyrimidine;

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

[0024]

[0025] S4. Replace the 3-formaldehyde-9-phenylcarbazole in step S1 with 1-pyrenecarboxaldehyde, and the subsequent steps are similar to obtain the target product:

[0026]

[0027] Preferably, the molar ratio of p-tert-butylbenzaldehyde to 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 etherate 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 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 for the reaction in step S3 is a toluene solution, the reaction temperature is 120-140° C., and the reaction time is 2-4 hours.

[0033] The present application also provides the use of the above-mentioned fluoroboryl pyrrole fluorescent compound with a fixed donor structure 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 fluoroboryl pyrrole fluorescent compound with a fixed donor structure provided by the present application is prepared by connecting the donor moieties pyrene and carbazole to the α-position of the BODIPY core using a vinyl bridge to prepare two molecules with a fixed donor-acceptor conformation. The compound has a weaker CT characteristic, improves the degree of rigidity, limits the loss of stretching or torsional vibration through an intramolecular conformational interlocking strategy, improves the fluorescence quantum yield, achieves efficient near-infrared luminescence without sacrificing FWHM, and can produce a narrow spectrum with a very narrow half-width and high color purity fluorescence emission. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 is the Ph-BDP prepared in step S2 1 HMNR diagram.

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

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

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

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

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

[0042] Figure 7 It is the emission spectra of the compounds Ph-BDP-Cz and Ph-BDP-PY prepared in step S4 in toluene solution. DETAILED DESCRIPTION

[0043] The embodiments of the present application will be described in detail below in conjunction with the examples, but it will be appreciated by those skilled in the art that the following examples are only used to illustrate the present application and should not be considered as limiting the scope of the present application. In the examples, if specific conditions are not specified, they are carried out according to normal conditions or the conditions recommended by the manufacturer. If the manufacturer is not specified for the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0044] It should be noted that:

[0045] In this application, unless otherwise specified, all the embodiments and preferred implementation methods mentioned herein can be combined with each other to form a new technical solution.

[0046] In the present application, unless otherwise specified, each reaction or operation step can be carried out sequentially or in a sequential manner. Preferably, the reaction method herein is carried out sequentially.

[0047] Unless otherwise specified, the professional and scientific terms used herein are the same as those familiar to those skilled in the art. In addition, any method or material similar or equivalent to the described content may also be applied to the present application.

[0048] The present application discloses a fluoroboryl pyrrole fluorescent compound with a fixed donor structure, which has a narrow-band emission. The fluoroboryl pyrrole fluorescent compound with a fixed donor structure has the following molecular structure:

[0049]

[0050] Wherein 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 fluoroboryl pyrrole fluorescent compound with a fixed donor structure in the present application is prepared by connecting the donor moieties pyrene and carbazole to the α-position of the BODIPY core using a vinyl bridge to prepare two molecules with a fixed donor-acceptor conformation, having a weak CT characteristic, improving the degree of rigidity, and limiting the loss of stretching or torsional vibration through an intramolecular conformational interlocking strategy, thereby improving the fluorescence quantum yield, achieving efficient near-infrared luminescence without sacrificing FWHM, improving the fluorescence quantum yield, and being able to produce a narrow spectrum with a very narrow half-width and high color purity fluorescence emission.

[0057] At the same time, the fluoroboryl pyrrole fluorescent compound with a fixed donor structure in the present application has ultra-efficient near-infrared light emission in an organic solvent. The fluoroboryl pyrrole fluorescent compound with a fixed donor structure relies on a vinyl bridge to efficiently improve π electron delocalization, making carrier injection and transmission more balanced and improving device performance, so 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 fluoroborane pyrrole derivative compound provided herein has one of the following molecular structures:

[0059]

[0060] The fluoroboryl pyrrole fluorescent compound with a fixed donor structure in the present application is prepared by connecting the donor moieties pyrene and carbazole to the α-position of the BODIPY core using a vinyl bridge to prepare two molecules with a fixed donor-acceptor conformation, having a weaker CT characteristic, improving the degree of rigidity, and limiting the loss of stretching or torsional vibration through an intramolecular conformational interlocking strategy, thereby improving the fluorescence quantum yield, achieving efficient NIR luminescence without sacrificing FWHM, and being able to produce a narrow spectrum with a very narrow half-width and high color purity fluorescence emission.

[0061] At the same time, it has ultra-efficient near-infrared light emission in organic solvents. This narrow-band emission fluoroboryl 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] The present application also provides a method for synthesizing the above-mentioned fluoroborylpyrrole fluorescent compound with a fixed donor structure. The method comprises the following steps:

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

[0064] S2. The intermediate prepared in S1 is reacted with triethylamine and boron trifluoride ether by oxidation reaction and complexation to generate 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]diazaboropyrimidine;

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

[0066]

[0067] S4. Replace the 3-formaldehyde-9-phenylcarbazole in step S1 with 1-pyrenecarboxaldehyde, and the subsequent steps are similar to obtain the target product Ph-BDP-PY;

[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, the molar ratio of the intermediate to triethylamine and boron trifluoride ether in step S2 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] The present application also provides the use of the above-mentioned fluoroboryl pyrrole fluorescent compound with a fixed donor structure in the preparation of luminescent materials, organic electroluminescent devices, and the synthesis of smart materials.

[0073] In step S1 of some preferred embodiments of the present application, the molar ratio of p-tert-butylbenzaldehyde and 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 the present application, the molar ratio of tert-butylbenzaldehyde to 2,4-dimethylbenzaldehyde in step S1 is (1-2):(1-4); more preferably, the molar ratio of tert-butylbenzaldehyde to 2,4-dimethylbenzaldehyde in step S1 is 1:4.

[0075] In some preferred embodiments of the present application, the solvent used in step S1 for oxidizing dipyrromethene by using the oxidant 2,3-dichloro-5,6-dicyanobenzoquinone is dichloromethane;

[0076] In some preferred embodiments of the present 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 the present application, the post-treatment described in step S1 is extraction and drying.

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

[0079] Preparation of intermediates

[0080] Add 120 ml of ultra-dry DCM to a double-necked flask. Add 2,4,6-trimethylbenzaldehyde (1.8 ml, 12 mmol) and 2,4-dimethylpyrrole (5 ml, 48 mmol) under nitrogen. Stir for 10 minutes. Then add 0.1 ml of TFA. After 4 hours of reaction, add 1 g of DDQ. The reaction mixture was extracted with DCM / H2O, and the organic layer was dried over anhydrous Na2SO4. Purify on a silica gel column to obtain an orange solid compound 1. Yield 1.89 g, 49.5%.

[0081] The chemical reaction equation is as follows:

[0082]

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

[0084] In some preferred embodiments of the present application, the solvent used in step S2 is dichloromethane. In some preferred embodiments of the present 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 the present application, the post-treatment in step S2 is concentration and separation. After the reaction is complete, the organic phase is concentrated under reduced pressure to obtain a crude product Ph-BDP.

[0086] In a more preferred embodiment of the present 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 into a 100 mL two-necked flask, and triethylamine (5 ml, 36 mmol) and boron trifluoride etherate (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 obtain 0.47 g of an orange solid (yield 82%).

[0089] The reaction equation is as follows:

[0090]

[0091] The NMR spectrum of the compound Ph-BDP prepared in step S2 is as follows: Figure 1 As shown. Figure 1 It can be seen that its characteristic wave number (ppm) is 1 H NMR (400MHz, Chloroform-d) δ6.94 (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 of the fluoroborane pyrrole plane, aromatic ring and styrene correspond to each other and the number is reasonable, indicating that the Ph-BDP compound has a single structure and high purity.

[0092] In some preferred embodiments of the present 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 the present application, the reaction solvent in step S3 is toluene.

[0095] In some preferred embodiments of the present application, the reaction condition is heating under reflux under the protection of an inert gas. 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 the present application, the temperature of the step S3 reaction is 120 to 140°C, and the reaction time is 2 to 4 hours. More preferably, the temperature of the step S3 reaction is 140°C, and the reaction time is 3 hours.

[0096] In some preferred embodiments of the present application, the treatment in step S3 is filtering, drying, concentrating, and separating. After the reaction is completed, the reaction solution is filtered, and after filtering, it is concentrated under reduced pressure to obtain a crude product; finally, petroleum ether and dichloromethane are used as eluents to perform silica gel column chromatography to separate Ph-BDP-Cz.

[0097] In a more preferred embodiment of the present 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), piperidine (0.005 mmol) were added to a 50 ml two-necked flask in sequence, the flask was evacuated under vacuum and replaced with dry argon three times, then toluene (10 ml) was added, and the mixture was stirred at 140°C for 3 hours, cooled and filtered, and the filtrate was distilled under reduced pressure to obtain a dark green solid. Silica gel powder was used as the stationary phase and petroleum ether / dichloromethane was used as the eluent to obtain 29.6 mg of a dark green solid 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. Figure 2 It can be seen that its characteristic wave number (ppm) is 1H NMR (500MHz, Chloroform-d) δ8.38 (s, 2H), 8.25 (d, J = 7.7 Hz, 2H), 7.84 (d, J = 15.9 Hz, 2H), 7.75 (d, J = 8.7 Hz, 2H), 7.66-7.55 (m, 8H), 7.52-7.46 (m, 4H), 7.41 (t, J = 7.7 Hz, 6H), 7.33 (t, J = 7.0 Hz, 2H), 6.97 (s, 2H), 6.69 (s, 2H), 2.36 (s, 3H), 2.15 (s, 6H), 1.48 (s, 6H)., the hydrogen atoms of the fluoroborane pyrrole plane, the aromatic ring and the styrene correspond to each other and the number is reasonable. This shows that the Ph-BDP-Cz compound has a single structure and high purity.

[0103] Figure 2 This is the hydrogen spectrum of the molecule Ph-BDP-Cz measured by Bruker 500MHz superconducting NMR instrument, the solvent is deuterated chloroform. Figure 4 Mass spectrum of Ph-BDP-Cz measured by Thermo Fisher HPLC-TQMS / TSQ Endura. MALDI-HRMS: calcd([C 60 H 47 BF2N4] + ),m / z 872.39,found,m / z872.27.

[0104] In some preferred embodiments of the present application, in step S4, the molar ratio of the BODIPY intermediate to 1-pyrenecarboxaldehyde, 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-pyrenecarboxaldehyde, glacial acetic acid and piperidine is 1:6:0.05:0.05.

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

[0107] In some preferred embodiments of the present application, the reaction condition is heating under reflux under the protection of an inert gas. 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 the present application, the temperature of the reaction in step S4 is 120 to 140°C, and the reaction time is 2 to 4 hours. More preferably, the temperature of the reaction in step S4 is 140°C, and the reaction time is 3 hours.

[0108] In some preferred embodiments of the present application, the treatment in step S4 is filtering, drying, concentrating, and separating. After the reaction is completed, the reaction solution is filtered, and after filtering, it is concentrated under reduced pressure to obtain a crude product; finally, petroleum ether and dichloromethane are used as eluents to perform silica gel column chromatography to separate Ph-BDP-PY.

[0109] In a more preferred embodiment of the present 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-pyrene carboxaldehyde (0.138 g, 0.6 mmol), glacial acetic acid (0.005 mmol), piperidine (0.005 mmol) were added to a 50 ml two-necked flask in sequence, the flask was evacuated under vacuum and replaced with dry argon three times, then toluene (10 ml) was added, and the mixture was stirred at 140°C for 3 hours, cooled and filtered, and the filtrate was distilled under reduced pressure to obtain a dark green solid, and silica gel powder was used as the stationary phase and petroleum ether / dichloromethane was used as the eluent to obtain 23.7 mg of a dark green solid 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. Figure 3 It can be seen that its characteristic wave number (ppm) is 1 H NMR (500MHz, Chloroform-d) δ8.38 (s, 2H), 8.25 (d, J = 7.7 Hz, 2H), 7.84 (d, J = 15.9 Hz, 2H), 7.75 (d, J = 8.7 Hz, 2H), 7.66-7.55 (m, 8H), 7.52-7.46 (m, 4H), 7.41 (t, J = 7.7 Hz, 6H), 7.33 (t, J = 7.0 Hz, 2H), 6.97 (s, 2H), 6.69 (s, 2H), 2.36 (s, 3H), 2.15 (s, 6H), 1.48 (s, 6H)., the hydrogen atoms of the fluoroborane pyrrole plane, the aromatic ring and the styrene correspond to each other and the number is reasonable. This shows that the Ph-BDP-PY compound has a single structure and high purity.

[0115] Figure 3 This is the hydrogen spectrum of the molecule Ph-BDP-PY measured by Bruker's 500MHz superconducting nuclear magnetic resonance instrument, and the solvent is deuterated chloroform. Figure 5Mass spectrum of the molecule Ph-BDP-PY tested by Thermo Fisher ultra-high performance liquid chromatography tandem triple quadrupole mass spectrometry* / TSQ Endura. MALDI-HRMS: calcd([C 60 H 47 BF2N4] + ),m / z 790.33,found,m / z790.45.

[0116] In this application, except for Ph-BDP-Cz and Ph-BDP-PY, other fluoroborylpyrrole derivatives are similar to the above two compounds in structure and belong to fluoroborylpyrrole derivatives. The fluoroborylpyrrole ring (as an electron acceptor) is used as a bridge, and with the help of the vinyl bridge structure, the electron-pulling effect of the donor R when it is 1 to 33 electron-pulling structures (such as ortho, meta, para-fluorophenyl, styrene, 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 a narrow spectrum with a very narrow half-peak width and high color purity fluorescence emission. Therefore, the preparation and characterization methods of other fluoroborylpyrrole derivatives are similar to the above two compounds and will not be repeated here.

[0117] At the same time, the preparation process of the compound described in the present application is simple, convenient, can be prepared in large quantities, and is economical and practical, which is conducive to factory-based production and preparation, and generates certain economic value, which is conducive to the promotion of its application.

[0118] Characterization and performance testing

[0119] The compounds Ph-BDP-Cz and Ph-BDP-PY prepared in step S3 and step S4 were used as test objects to test the photophysical properties of the compounds Ph-BDP-Cz and Ph-BDP-PY. The test results are as follows: Figure 6 , Figure 7 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 Shimadzu UV-2700 UV-visible spectrophotometer and Edinburgh FLS980.

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

[0122] The absorption wavelength of Ph-BDP-PY is 693nm and the emission wavelength is 723nm.

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

[0124] Both Ph-BDP-Cz and Ph-BDP-PY can exhibit high-purity bright near-infrared light emission, making this narrow-band emitting fluoroboryl pyrrole fluorescent compound with a fixed donor structure have significant application value and economic value in applications such as luminescent materials, smart materials, display materials, and luminescent devices.

[0125] In the present application, except for Ph-BDP-Cz and Ph-BDP-PY, the other fluoroboryl pyrrole fluorescent compounds with fixed donor structures are similar to the above two compounds in structure, and all belong to the fluoroboryl pyrrole ring as the main ring structure. The fluoroboryl pyrrole ring (as an electron acceptor) is used as a bridge, and with the help of the vinyl bridge structure, the donor (such as o-, m-, p-fluorophenyl, styrene, 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 fluoroboryl pyrrole fluorescent compounds with fixed donor structures can produce narrow spectrum with very narrow half-peak width and high color purity fluorescence emission.

[0126] The present application discloses a fluoroborylpyrrole fluorescent compound with a fixed donor structure. The two molecules with a fixed donor-acceptor conformation are prepared by connecting the donor moiety pyrene and carbazole to the α-position of the BODIPY core using a vinyl bridge. The compound has a weak CT characteristic, improves the rigidity, limits the loss of stretching or torsional vibration through the intramolecular conformation interlocking strategy, improves the fluorescence quantum yield, achieves efficient NIR luminescence without sacrificing FWHM, improves the fluorescence quantum yield, and can produce a narrow spectrum with a very narrow half-peak width and high color purity fluorescence emission. At the same time, the fluoroborylpyrrole fluorescent compound with a fixed donor structure in the present application can make carrier injection and transmission more balanced when preparing OLED light-emitting devices, thereby improving device performance. Therefore, the fluoroborylpyrrole fluorescent compound with a fixed donor structure having a narrow band emission has significant application value and economic value in applications such as luminescent materials, smart materials, display materials, and light-emitting devices. In particular, some compounds provide new ideas for the synthesis of photoluminescent polymer resins used in engineering.

[0127] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiments or examples are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

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

Claims

1. A fluoroboryl pyrrole fluorescent compound with a fixed donor structure, having narrow-band emission, characterized in that: The fluoroboryl pyrrole fluorescent compound with a fixed donor structure has the following molecular structural formula: Wherein DD is selected from one of the following structural formulas a to i: R1 and R2 are each selected from one of the following structural formulas 1 to 33:

2. The fluoroborylpyrrole fluorescent compound with a fixed donor structure according to claim 1, characterized in that: The fluoroboryl pyrrole fluorescent compound has one of the following molecular structures:

3. The method for preparing the fluoroboryl pyrrole fluorescent compound having a fixed donor structure according to claim 2, characterized in that: The steps include: S1. 2,4,6-trimethylbenzaldehyde, 2,4-dimethylpyrrole, 2,3-dichloro-5,6-dicyano-1,4-benzoquinone are condensed with pyrrole and aromatic aldehyde to obtain an intermediate; S2. The intermediate prepared in S1 is reacted with triethylamine and boron trifluoride ether by oxidation reaction 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]diazaboropyrimidine; S3. The BODIPY intermediate is reacted with 3-formaldehyde-9-phenylcarbazole, glacial acetic acid, and piperidine, using toluene solution as solvent, to obtain the target product by coupling reaction: S4. Replace the 3-formaldehyde-9-phenylcarbazole in step S1 with 1-pyrenecarboxaldehyde, and the subsequent steps are similar to obtain the target product:

4. The method for preparing the fluoroboryl pyrrole fluorescent compound with a fixed donor structure according to claim 3, characterized in that: The molar ratio of p-tert-butylbenzaldehyde to 2,4-dimethylpyrrole in step S1 is (1-2): (1-4).

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

6. The method for preparing the fluoroboryl pyrrole fluorescent compound with a fixed donor structure according to claim 3, characterized in that: In the step S2, the molar ratio of the intermediate to triethylamine and boron trifluoride etherate is (1-2): (10-30): (10-30).

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

8. The method for preparing the fluoroboryl pyrrole fluorescent compound with a fixed donor structure according to claim 3, characterized in that: In the 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).

9. The method for preparing a fluoroboryl pyrrole fluorescent compound having a fixed donor structure according to claim 8, characterized in that: 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.

10. Use of the fluoroboryl pyrrole fluorescent compound with a fixed donor structure as claimed in claim 1 in the preparation of luminescent materials, organic electroluminescent devices, smart materials, and the synthesis of polymer resins.

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