Novel pure organic multiple illuminant based on aryl carbazole and preparation method thereof

Abstract

The invention relates to a novel pure organic multiple illuminant based on aryl carbazole and a preparation method thereof. The reaction structural formula is shown in the specification. The preparation method comprises the following steps: stirring a mixture of 4-bromo-4 '-iodobiphenyl or 2, 6-dibromonaphthalene, carbazole, K2CO3, copper powder and a solvent DMF (Dimethyl Formamide) under nitrogen to react; extracting, drying, filtering and performing rotary evaporation to obtain a crude product; mixing and reacting the obtained crude product, 4-hydroxybenzonitrile, Cs2CO3, CuBr, a ligand 1-(2-pyridyl)-2-acetone and a solvent DMSO (Dimethylsulfoxide); 4-[4 '-(9H-carbazole-9-yl)-4-biphenyloxy] benzonitrile or 4-[6-(9H-carbazole-9-yl)-2-naphthyloxy] benzonitrile with the instant fluorescence-delayed fluorescence-room temperature phosphorescence triple emission characteristic is obtained through drying, filtering, rotary evaporation, separation and purification. The method has good application potential in the fields of anti-counterfeiting, information encryption, organic light-emitting diodes, biosensing imaging and the like. # imgabs0 #

Description

Technical Field

[0001] The invention belongs to the field of luminescent materials and preparation thereof, and in particular relates to a novel pure organic multiple luminophore based on aryl carbazole and a preparation method thereof. Background Art

[0002] Light emission includes immediate fluorescence, phosphorescence and delayed fluorescence. Among them, immediate fluorescence is the most widely used luminescence phenomenon, which is the transition of molecules from S1 to S0. The formation probability of singlet and triplet excitons is 1:3. Only 25% of singlet excitons in immediate fluorescent materials can be used for luminescence, and 75% of triplet excitons are released in the form of non-radiative luminescence (converted into heat energy). The occurrence of delayed fluorescence involves complex processes such as internal conversion (IC), intersystem crossing (ISC) to triplet state and reverse intersystem crossing (RISC). Finally, the exciton returns to the S1 state to transition and emit light. Both immediate fluorescence and delayed fluorescence come from the radiative transition of the S1 state, so in the spectrum, the two emit at the same wavelength. The emission of room temperature phosphorescence comes from the transition of excitons from the triplet state T1 to the ground state S0. Therefore, the immediate fluorescence-delayed fluorescence-room temperature phosphorescence multiple luminophore can make more use of the energy converted into heat energy that is wasted by the immediate fluorescent material.

[0003] Traditional phosphorescent materials usually use heavy metals such as iridium and cadmium (Coordin Chem Rev., 2009, 253 (13-14): 1709-1758), which are not conducive to their large-scale application and promotion due to their toxicity and environmental problems. Pure organic room temperature phosphorescent materials, an organic compound that does not contain metal elements in its molecular structure, have become the mainstream of current research due to its advantages such as low cost, low toxicity, long triplet exciton lifetime and high exciton utilization rate. Li et al. first reported that non-aromatic pure organic small molecules prepared using cyanoacetic acid have long-lasting room temperature phosphorescence properties. The strong hydrogen bonds formed by the carboxyl group in cyanoacetic acid restrict the movement of the molecule and promote the ISC process of the exciton from the S1 state to the T1 state (Mater. Chem. Front., 2018, 2: 2124-2129.). Zhang et al. reported a series of amide-based pure organic compounds with efficient room temperature phosphorescence by introducing carbonyl and aromatic π units, and promoted the ISC process by introducing carbonyl groups (Adv. Mater., 2019, 31: 201807222).

[0004] When the energy difference between the triplet state and the singlet state is small, the triplet exciton can transition to the S1 state through RISC, and finally return to the ground state S0 to produce delayed fluorescence. Yu et al. synthesized a new donor-acceptor type organic light-emitting body, with quinoxaline as the electron acceptor and phenoxazine as the electron donor. The light-emitting body exhibits both thermally activated delayed fluorescence and room temperature phosphorescence (Adv. Opt. Mater, 2017, 5 (24): 1700588). Tang et al. reported a thermally activated delayed fluorescence molecule phenothiazine-di(trimethylphenyl) borane, which showed green electroluminescence with an emission peak of 540nm (Front. Chem., 2019, 7: 373).

[0005] Although room temperature phosphorescence and delayed fluorescence materials have made great progress in recent years, there are still few pure organic light emitters with multiple emission characteristics, especially those with triple emission characteristics of immediate fluorescence-delayed fluorescence-room temperature phosphorescence. Summary of the invention

[0006] The purpose of the present invention is to provide a new pure organic multiple luminophore based on aromatic carbazole and a preparation method thereof, which has triple emission characteristics of immediate fluorescence-delayed fluorescence-room temperature phosphorescence. Purely organic in the present invention means that the molecular structure of the luminophore is an organic compound without metal elements. Carbazole is selected as a fluorophore, biphenyl or naphthalene is used as a connecting bridge, and cyano is used as an ISC promoting factor. The structure of the pure organic multiple luminophore is expanded, and the problem of the small number of room temperature phosphorescence and delayed fluorescence materials is solved. The luminophore synthesis method of the present invention is simple, has few reaction steps, and is easy to industrialize.

[0007] The technical solution of the present invention is as follows:

[0008] A new pure organic multi-luminescent material based on aryl carbazole, the structural formula of which is as follows:

[0009]

[0010] Wherein R is one of the following groups:

[0011]

[0012] The preparation method of the novel pure organic multiple luminophore based on aryl carbazole of the present invention comprises the following steps:

[0013] 1) A mixture of 4-bromo-4'-iodobiphenyl or 2,6-dibromonaphthalene, carbazole, K2CO3, copper powder and solvent N,N-dimethylformamide (DMF) is stirred and reacted under nitrogen; after the reaction is completed, the mixture is filtered, poured into water, and extracted with ethyl acetate; the organic phase is dried, filtered, and rotary evaporated to obtain a crude product, which is then separated and purified by silica gel column chromatography using petroleum ether and dichloromethane as eluents to obtain 9-(4'-bromobiphenyl-4-yl)-9H-carbazole or 9-(6-bromo-2-naphthyl)-9H-carbazole;

[0014] 2) 9-(4'-bromobiphenyl-4-yl)-9H-carbazole or 9-(6-bromo-2-naphthyl)-9H-carbazole obtained in step 1), 4-hydroxybenzonitrile, Cs2CO3, CuBr, ligand 1-(2-pyridyl)-2-acetone and solvent dimethyl sulfoxide (DMSO) are mixed for reaction; after the reaction is completed, the reaction solution is filtered, then poured into water, extracted with ethyl acetate, the organic phase is dried, filtered, and the organic solvent in the filtrate is removed by rotary evaporation to obtain a crude product, and then the crude product is separated and purified by silica gel column chromatography using petroleum ether and dichloromethane as eluents to obtain 4-[4'-(9H-carbazole-9-yl)-4-biphenyloxy]benzonitrile or 4-[6-(9H-carbazole-9-yl)-2-naphthyloxy]benzonitrile.

[0015] In the step 1), the preferred reaction time is 30 to 42 hours, and the reaction temperature is 100 to 130°C.

[0016] In the step 2), the preferred reaction temperature is 100-130° C. and the reaction time is 14-20 hours.

[0017] In the step 1), the molar ratio of carbazole: 4-bromo-4'-iodobiphenyl or 2,6-dibromonaphthalene: catalyst copper powder: K2CO3 is preferably 1: (1-2): (1.5-2.5): (3-5); the weight volume ratio of carbazole: DMF is (5-7) g / 100 mL.

[0018] In the step 2), the molar ratio of 9-(4'-bromobiphenyl-4-yl)-9H-carbazole or 9-(6-bromo-2-naphthyl)-9H-carbazole:4-hydroxybenzonitrile:catalyst CuBr:ligand 1-(2-pyridyl)-2-acetone:Cs2CO3 is preferably 1:(1-2.5):(0.05-0.2):(0.1-0.4):(1-3); the weight volume ratio of 9-(4'-bromobiphenyl-4-yl)-9H-carbazole or 9-(6-bromo-2-naphthyl)-9H-carbazole:DMSO is (10-14) g / 100 mL.

[0019] The novel pure organic multiple luminophore based on aryl carbazole of the present invention is applied to the fields of anti-counterfeiting and encryption, information storage, organic electroluminescent diode and biosensor imaging.

[0020] The specific instructions are as follows:

[0021] A new pure organic multi-luminescent material based on aryl carbazole, the general structure of which is as follows:

[0022]

[0023] Wherein R is one of the following groups:

[0024]

[0025] When R is a biphenyl group, the luminophore is 4-[4'-(9H-carbazole-9-yl)-4-biphenyloxy]benzonitrile, and its structural formula is:

[0026]

[0027] When R is a naphthalene group, the luminophore is 4-[6-(9H-carbazole-9-yl)-2-naphthyloxy]benzonitrile, and its structural formula is:

[0028]

[0029] The present invention provides a method for preparing luminous bodies 4-[4'-(9H-carbazole-9-yl)-4-biphenyloxy]benzonitrile and 4-[6-(9H-carbazole-9-yl)-2-naphthyloxy]benzonitrile. The synthetic route is as follows: Fig. 9 shown.

[0030] Prepare according to the following steps:

[0031] Step 1) Synthesis of 9-(4'-bromobiphenyl-4-yl)-9H-carbazole or 9-(6-bromo-2-naphthyl)-9H-carbazole:

[0032] The reaction container is purged with nitrogen, and a mixture of 4-bromo-4'-iodobiphenyl or 2,6-dibromonaphthalene, carbazole, K2CO3, copper powder and solvent DMF is stirred and reacted for 30 to 42 hours under nitrogen, and the reaction temperature is 100 to 130°C; after the reaction is completed, it is filtered, then poured into water, and extracted with ethyl acetate; the organic phase is dried, filtered, and rotary evaporated to obtain a crude product, and then the crude product is separated and purified by silica gel column chromatography, with petroleum ether and dichloromethane as eluents, to obtain a white powder 9-(4'-bromobiphenyl-4-yl)-9H-carbazole or 9-(6-bromo-2-naphthyl)-9H-carbazole.

[0033] Step 2) Synthesis of 4-[4'-(9H-carbazole-9-yl)-4-biphenyloxy]benzonitrile or 4-[6-(9H-carbazole-9-yl)-2-naphthyloxy]benzonitrile:

[0034] The reaction container is purged with nitrogen, and 9-(4'-bromobiphenyl-4-yl)-9H-carbazole or 9-(6-bromo-2-naphthyl)-9H-carbazole, 4-hydroxybenzonitrile, Cs2CO3, CuBr, ligand 1-(2-pyridyl)-2-acetone and solvent DMSO are added; the reaction temperature is raised to 100-130°C, and the reaction is stirred for 14-20 hours under a nitrogen atmosphere; after the reaction is completed, the reaction solution is filtered, and then the reaction solution is poured into water, extracted with ethyl acetate, the organic phase is dried, filtered, and the organic solvent in the filtrate is removed by rotary evaporation to obtain a crude product, and then the crude product is separated and purified by silica gel column chromatography using petroleum ether and dichloromethane as eluents to obtain a light yellow target product 4-[4'-(9H-carbazole-9-yl)-4-biphenyloxy]benzonitrile or 4-[6-(9H-carbazole-9-yl)-2-naphthyloxy]benzonitrile.

[0035] Furthermore, in the preparation method of a new pure organic multiple luminophore based on aromatic carbazole described in the present invention, the molar mass ratio of carbazole: 4-bromo-4'-iodobiphenyl or 2,6-dibromonaphthalene in step 1) is 1: (1-2); the molar mass ratio of carbazole: catalyst copper powder is 1: (1.5-2.5); K2CO3 is used to create an alkaline environment for the reaction, and the molar mass ratio of carbazole to K2CO3 is 1: (3-5).

[0036] In the step 1), the weight volume ratio of carbazole to DMF is (5-7) g / 100 mL; the weight volume ratio of carbazole to water is (1-2) g / 100 mL; and the weight volume ratio of carbazole to the extractant ethyl acetate is (1-2) g / 100 mL.

[0037] The crude product obtained in step 1) is separated and purified by silica gel column chromatography, and the eluent is petroleum ether and dichloromethane (15-25:1, V / V).

[0038] In the step 2), the molar mass ratio of 9-(4'-bromobiphenyl-4-yl)-9H-carbazole or 9-(6-bromo-2-naphthyl)-9H-carbazole:4-hydroxybenzonitrile is 1:(1-2.5); the molar mass ratio of 9-(4'-bromobiphenyl-4-yl)-9H-carbazole or 9-(6-bromo-2-naphthyl)-9H-carbazole:catalyst CuBr is 1:(0.05-0.2); The molar mass ratio of 9-(4'-bromobiphenyl-4-yl)-9H-carbazole or 9-(6-bromo-2-naphthyl)-9H-carbazole: ligand 1-(2-pyridyl)-2-acetone is 1:(0.1-0.4); Cs2CO3 is used to create an alkaline environment, and the molar mass ratio of 9-(4'-bromobiphenyl-4-yl)-9H-carbazole or 9-(6-bromo-2-naphthyl)-9H-carbazole: Cs2CO3 is 1:(1-3).

[0039] In the step 2), the weight volume ratio of 9-(4'-bromobiphenyl-4-yl)-9H-carbazole or 9-(6-bromo-2-naphthyl)-9H-carbazole: DMSO is (10-14) g / 100 mL; the weight volume ratio of 9-(4'-bromobiphenyl-4-yl)-9H-carbazole or 9-(6-bromo-2-naphthyl)-9H-carbazole: water is (2-3) g / 100 mL; and the weight volume ratio of 9-(4'-bromobiphenyl-4-yl)-9H-carbazole or 9-(6-bromo-2-naphthyl)-9H-carbazole: the extractant ethyl acetate is (1.5-2.5) g / 100 mL.

[0040] The crude product obtained in step 2) is separated and purified by silica gel column chromatography, and the eluent is petroleum ether and dichloromethane (5-20:1, V / V).

[0041] The luminophore prepared by the present invention is characterized by a steady-state / transient fluorescence spectrometer. The steady-state fluorescence spectrum of the luminophore 4-[4'-(9H-carbazole-9-yl)-4-biphenyloxy]benzonitrile at room temperature and the delayed spectrum after 4 ms are shown in FIG. Figure 1 As shown. The fluorescence spectrum test results show that there are three immediate fluorescence peaks at wavelengths of 377nm, 413nm and 438nm, which are attributed to the radiation transition of excitons from the S1 excited state to the S0 ground state. In the delayed spectrum delayed by 4ms, there are also two emission peaks with lower intensity at 413nm and 438nm, which are delayed fluorescence peaks. Since both delayed fluorescence and immediate fluorescence are from the S1 state to the ground state S0 through radiation transition, the positions of the emission peaks of the two in the spectrum are the same. In addition, new emission peaks with higher intensity appear at 556nm and 606nm in the delayed spectrum. The emission peaks are room temperature phosphorescence peaks, which are attributed to the light emitted by the exciton transitioning from the triplet state T1 to the S0 ground state. Since the energy of the triplet state is lower than that of the singlet state, the wavelength of the phosphorescence emitted by the triplet transition is longer than the wavelength of the fluorescence emitted from the singlet transition. In summary, it can be seen from the steady-state fluorescence spectrum and the delayed spectrum that the luminophore 4-[4'-(9H-carbazole-9-yl)-4-biphenyloxy]benzonitrile has good prompt fluorescence-delayed fluorescence-room temperature phosphorescence triple emission characteristics.

[0042] The steady-state fluorescence spectrum of the luminophore 4-[6-(9H-carbazole-9-yl)-2-naphthyloxy]benzonitrile at room temperature and the delayed spectrum after 3 ms are shown in Figure 2. Figure 2As shown. Its fluorescence spectrum shows that there is an immediate fluorescence peak at a wavelength of 420nm, which is the transition from the S1 excited state to the S0 ground state. In the delayed spectrum delayed by 3ms, there is an emission peak with lower intensity at 420nm, which is the delayed fluorescence peak. Since it belongs to the transition of the exciton from the S1 excited state and the immediate fluorescence, it has the same position as the immediate fluorescence peak. In addition, in the delayed spectrum delayed by 3ms, a new emission peak with higher intensity appears at a wavelength of 575nm, which is the room temperature phosphorescence emission peak emitted from the transition of the exciton from the triplet state T1. The energy of the triplet state is lower than that of the singlet state, so the wavelength of the phosphorescence peak is longer than that of the fluorescence peak. In summary, it can be seen from the steady-state fluorescence spectrum and the delayed spectrum that the luminophore 4-[6-(9H-carbazole-9-yl)-2-naphthyloxy]benzonitrile exhibits good immediate fluorescence-delayed fluorescence-room temperature phosphorescence triple emission characteristics.

[0043] In the luminophore molecule of the present invention, the lone pair of electrons on the cyano nitrogen atom can participate in n→π* transition, can promote the occurrence of ISC, reduce the energy level difference between singlet and triplet, and then improve the output of triplet exciton, promote the emission of room temperature phosphorescence. And due to the reduction of the energy level difference between singlet and triplet, triplet exciton can also be transitioned back to S1 state by RISC, and finally return to ground state S0 to produce delayed fluorescence. In addition, the introduction of heteroatom N, O elements in the structure increases the interaction between molecules, can form a rigid environment, the introduction of biphenyl and naphthalene also contributes to the improvement of molecular rigidity, can limit the thermal motion of molecules, reduce energy loss and suppress the occurrence of non-radiative transition, so that energy is more emitted in the form of light.

[0044] By comprehensively utilizing these factors, the two molecular structures 4-[4'-(9H-carbazole-9-yl)-4-biphenyloxy]benzonitrile and 4-[6-(9H-carbazole-9-yl)-2-naphthyloxy]benzonitrile proposed in the present invention show good prompt fluorescence-delayed fluorescence-room temperature phosphorescence triple emission characteristics.

[0045] The novel pure organic multiple luminophore based on aryl carbazole of the present invention has good instant fluorescence-delayed fluorescence-room temperature phosphorescence triple emission performance, and has great application prospects in the fields of anti-counterfeiting and encryption, information storage, organic electroluminescent diodes and biosensor imaging.

[0046] The luminophore 4-[4'-(9H-carbazole-9-yl)-4-biphenyloxy]benzonitrile or 4-[6-(9H-carbazole-9-yl)-2-naphthyloxy]benzonitrile of the present invention is dissolved in an organic solvent, and then the letters "T" or "J" are written on a non-fluorescent white paper by dipping the solution respectively, and the solvent is evaporated. Figure 3 and Figure 4As shown, when observed under ordinary fluorescent light, no trace is left on the paper, but when irradiated with ultraviolet light, the written content can be clearly displayed, showing blue-purple fluorescent handwriting. Therefore, the luminous bodies 4-[4'-(9H-carbazole-9-yl)-4-biphenyloxy]benzonitrile and 4-[6-(9H-carbazole-9-yl)-2-naphthyloxy]benzonitrile of the present invention have application potential in the fields of information encryption and anti-counterfeiting.

[0047] Compared with the prior art, the present invention has the following beneficial effects:

[0048] The invention discloses a novel pure organic multiple luminophore based on aryl carbazole. Carbazole is selected as a fluorophore, biphenyl or naphthalene is used as a connecting bridge, and cyano is used as an ISC promoting factor to obtain two simple organic compounds with multiple emission characteristics and without metal elements. The lone pair of electrons on the cyano N atom can participate in the n→π* transition, thereby promoting the occurrence of ISC. The introduction of heteroatoms and biphenyl or naphthalene helps to construct a rigid environment, limit the thermal motion of molecules, inhibit non-radiative transitions, and further enhance the emission of room temperature phosphorescence and delayed fluorescence. The invention discloses a method for preparing a novel pure organic multiple luminophore based on aryl carbazole. Carbazole is used as a raw material and is obtained by two steps of CN coupling reaction and CO coupling reaction. The synthesis is simple, the reaction steps are few, and it is easy to industrialize. The luminophore prepared by the invention has good application potential in the fields of anti-counterfeiting, information encryption, organic electroluminescent diodes, biosensor imaging, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 It is a superposition diagram of the steady-state fluorescence spectrum of the luminophore 4-[4'-(9H-carbazole-9-yl)-4-biphenyloxy]benzonitrile at room temperature and the delayed spectrum after a delay of 4 ms;

[0050] Figure 2 It is a superposition diagram of the steady-state fluorescence spectrum of the luminophore 4-[6-(9H-carbazole-9-yl)-2-naphthyloxy]benzonitrile at room temperature and the delayed spectrum after a delay of 3 ms;

[0051] Figure 3 This is a real shot of the application of the luminescent material 4-[4'-(9H-carbazole-9-yl)-4-biphenyloxy]benzonitrile in the field of anti-counterfeiting encryption;

[0052] Figure 4 This is a real shot of the application of the luminescent material 4-[6-(9H-carbazole-9-yl)-2-naphthyloxy]benzonitrile in the field of anti-counterfeiting encryption;

[0053] Figure 5 9-(4'-bromobiphenyl-4-yl)-9H-carbazole 1 H NMR spectrum;

[0054] Figure 6 The luminescent substance 4-[4'-(9H-carbazole-9-yl)-4-biphenyloxy]benzonitrile 1 H NMR spectrum;

[0055] Figure 7 9-(6-bromo-2-naphthyl)-9H-carbazole 1 H NMR spectrum;

[0056] Figure 8 The luminophore 4-[6-(9H-carbazole-9-yl)-2-naphthyloxy]benzonitrile 1 H NMR spectrum;

[0057] Fig. 9 The invention provides a synthetic route for the luminophores 4-[4'-(9H-carbazole-9-yl)-4-biphenyloxy]benzonitrile and 4-[6-(9H-carbazole-9-yl)-2-naphthyloxy]benzonitrile. DETAILED DESCRIPTION

[0058] The present invention is further described below with reference to specific embodiments, but the present invention is not limited thereto.

[0059] Example 1: Synthesis of 4-[4'-(9H-carbazole-9-yl)-4-biphenyloxy]benzonitrile

[0060] 1) Purge the Schlenk tube equipped with a magnet with nitrogen, add carbazole (1.17 g, 7.0 mmol), K2CO3 (3.87 g, 28.0 mmol), 4-bromo-4'-iodobiphenyl (3.27 g, 9.1 mmol), copper powder (0.89 g, 14 mmol) and 20 mL DMF. The mixture is reacted under nitrogen for 36 h at a reaction temperature of 130 ° C. After the reaction is completed, filter, pour into 100 mL of water, and extract with 3×30 mL of ethyl acetate. The organic phase is dried, filtered, and rotary evaporated to obtain a crude product. The crude product is separated and purified by silica gel column chromatography using petroleum ether and dichloromethane (V / V, 20:1) as eluents to obtain 1.78 g of 9-(4'-bromobiphenyl-4-yl)-9H-carbazole with a yield of 64%, which is a white powder. The structure is characterized by nuclear magnetic resonance spectrometer, and the test results are: 1 H NMR (400MHz, DMSO-d6) δ8.25 (d, J = 7.6 Hz, 2H), 7.96 (d, J = 8.2 Hz, 2H), 7.81–7.66 (m, 6H), 7.44 (d, J = 4.0 Hz, 4H), 7.29 (dt, J = 8.0, 3.9 Hz, 2H). 1 H NMR Figure 5 shown.

[0061] 2) Purge the Schlenk tube equipped with a magnet with nitrogen, add 9-(4'-bromobiphenyl-4-yl)-9H-carbazole (1.19 g, 3.0 mmol), 4-hydroxybenzonitrile (0.71 g, 6.0 mmol), Cs2CO3 (1.95 g, 6.0 mmol), CuBr (43.0 mg, 0.3 mmol), ligand 1-(2-pyridyl)-2-propanone (81.1 mg, 0.6 mmol) and 10 mL DMSO. The reaction temperature is raised to 110°C and the reaction is sealed under nitrogen atmosphere for 20 h. After the reaction is completed, the reaction solution is filtered, and then poured into 50 mL of water, extracted with 3×20 mL of ethyl acetate, the organic phase is dried, filtered, and the organic solvent in the filtrate is removed by rotary evaporation to obtain a crude product, and then the crude product is separated and purified by silica gel column chromatography using petroleum ether and dichloromethane (V / V, 10:1) as eluents to obtain 0.68 g of light yellow powder 4-[4'-(9H-carbazole-9-yl)-4-biphenyloxy]benzonitrile, with a yield of 52%. The structure is characterized by nuclear magnetic resonance spectrometer, and the test results are: 1 H NMR (400 MHz, DMSO-d6) δ8.26 (dt, J=7.8, 1.0 Hz, 2H), 8.01–7.94 (m, 2H), 7.93–7.84 (m, 4H), 7.76–7.69 (m, 2H), 7.49–7.40 (m, 4H), 7.36–7.25 (m, 4H), 7.24–7.16 (m, 2H). 1 H NMR Figure 6 shown.

[0062] Example 2: Synthesis of 4-[4'-(9H-carbazole-9-yl)-4-biphenyloxy]benzonitrile

[0063] 1) Purge a Schlenk tube equipped with a magnetic electron with nitrogen, add carbazole (1.17 g, 7.0 mmol), K2CO3 (2.90 g, 21.0 mmol), 4-bromo-4'-iodobiphenyl (2.51 g, 7.0 mmol), copper powder (0.67 g, 10.5 mmol) and 16.7 mL DMF. The mixture is reacted under nitrogen for 30 h at a reaction temperature of 100°C. After the reaction is completed, filter, pour into 58.5 mL of water, and extract with 3×19.5 mL of ethyl acetate. The organic phase is dried, filtered, and rotary evaporated to obtain a crude product. The crude product is separated and purified by silica gel column chromatography using petroleum ether and dichloromethane (V / V, 15:1) as eluents to obtain 1.67 g of 9-(4'-bromobiphenyl-4-yl)-9H-carbazole, with a yield of 60%, as a white powder.

[0064] 2) Purge the Schlenk tube equipped with a magnet with nitrogen, add 9-(4'-bromobiphenyl-4-yl)-9H-carbazole (1.19 g, 3.0 mmol), 4-hydroxybenzonitrile (0.36 g, 3.0 mmol), Cs2CO3 (0.98 g, 3.0 mmol), CuBr (21.5 mg, 0.15 mmol), ligand 1-(2-pyridyl)-2-propanone (40.5 mg, 0.3 mmol) and 8.5 mL DMSO. The reaction temperature is raised to 100°C and the reaction is sealed under nitrogen atmosphere for 14 h. After the reaction, the reaction mixture was filtered and poured into 39.7 mL of water. The mixture was extracted with 3×15.9 mL of ethyl acetate. The organic phase was dried and filtered. The organic solvent in the filtrate was removed by rotary evaporation to obtain a crude product. The crude product was then separated and purified by silica gel column chromatography using petroleum ether and dichloromethane (V / V, 5:1) as eluents to obtain 0.54 g of light yellow powder 4-[4'-(9H-carbazole-9-yl)-4-biphenyloxy]benzonitrile with a yield of 41%.

[0065] Example 3: Synthesis of 4-[4'-(9H-carbazole-9-yl)-4-biphenyloxy]benzonitrile

[0066] 1) Purge a Schlenk tube equipped with a magnet with nitrogen, add carbazole (1.17 g, 7.0 mmol), K2CO3 (4.84 g, 35.0 mmol), 4-bromo-4'-iodobiphenyl (5.03 g, 14.0 mmol), copper powder (1.11 g, 17.5 mmol) and 23.4 mL DMF. The mixture is reacted under nitrogen for 42 h at a reaction temperature of 110°C. After the reaction is completed, filter, pour into 117 mL of water, and extract with 3×39 mL of ethyl acetate. The organic phase is dried, filtered, and rotary evaporated to obtain a crude product. The crude product is separated and purified by silica gel column chromatography using petroleum ether and dichloromethane (V / V, 25:1) as eluents to obtain 1.75 g of 9-(4'-bromobiphenyl-4-yl)-9H-carbazole, with a yield of 63%, as a white powder.

[0067] 2) Purge the Schlenk tube equipped with a magnet with nitrogen, add 9-(4'-bromobiphenyl-4-yl)-9H-carbazole (1.19 g, 3.0 mmol), 4-hydroxybenzonitrile (0.89 g, 7.5 mmol), Cs2CO3 (2.93 g, 9.0 mmol), CuBr (86.1 mg, 0.6 mmol), ligand 1-(2-pyridyl)-2-propanone (162.2 mg, 1.2 mmol) and 11.9 mL DMSO. The reaction temperature is raised to 130°C and the reaction is sealed under nitrogen atmosphere for 17 hours. After the reaction, the reaction mixture was filtered and poured into 59.5 mL of water. The mixture was extracted with 3×26.4 mL of ethyl acetate. The organic phase was dried and filtered. The organic solvent in the filtrate was removed by rotary evaporation to obtain a crude product. The crude product was then separated and purified by silica gel column chromatography using petroleum ether and dichloromethane (V / V, 20:1) as eluents to obtain 0.65 g of light yellow powder 4-[4'-(9H-carbazole-9-yl)-4-biphenyloxy]benzonitrile with a yield of 50%.

[0068] Example 4: Synthesis of 4-[6-(9H-carbazole-9-yl)-2-naphthyloxy]benzonitrile

[0069] 1) Purge the Schlenk tube equipped with a magnet with nitrogen, add carbazole (0.84g, 5.0mmol), K2CO3 (2.76g, 20.0mmol), 2,6-dibromonaphthalene (2.14g, 7.5mmol), copper powder (0.64g, 10.0mmol) and 15mL DMF. The mixture is reacted under nitrogen for 42h at a reaction temperature of 130℃. After the reaction is completed, filter it, pour it into 60mL water, and extract it with 3×20mL ethyl acetate. The organic phase is dried, filtered, and rotary evaporated to obtain a crude product. The crude product is separated and purified by silica gel column chromatography using petroleum ether and dichloromethane (V / V, 20:1) as eluents to obtain 1.11g of 9-(6-bromo-2-naphthyl)-9H-carbazole with a yield of 60%, which is a white powder. The structure is characterized by nuclear magnetic resonance spectrometer, and the test results are: 1 H NMR (400MHz, DMSO-d6) δ8.39 (d, J = 2.0 Hz, 1H), 8.28 (d, J = 7.5 Hz, 3H), 8.21 (d, J = 8.8 Hz, 1H), 8.05 (d, J = 8.9 Hz, 1H), 7.81 (dd, J = 8.7, 2.2 Hz, 1H), 7.76 (dd, J = 8.7, 2.0 Hz, 1H), 7.48–7.41 (m, 4H), 7.32 (ddd, J = 8.0, 5.4, 2.7 Hz, 2H). 1 H NMR Figure 7 shown.

[0070] 2) Purge the Schlenk tube equipped with a magnet with nitrogen, add 9-(6-bromo-2-naphthyl)-9H-carbazole (0.74 g, 2.0 mmol), 4-hydroxybenzonitrile (0.60 g, 5.0 mmol), Cs2CO3 (1.30 g, 4.0 mmol), CuBr (28.7 mg, 0.2 mmol), ligand 1-(2-pyridyl)-2-propanone (54.1 mg, 0.4 mmol) and 6 mL DMSO. The reaction temperature is raised to 120°C and the reaction is sealed under nitrogen atmosphere for 14 h. After the reaction is completed, the reaction solution is filtered, and then poured into 30 mL of water, extracted with 3×15 mL of ethyl acetate, the organic phase is dried, filtered, and the organic solvent in the filtrate is removed by rotary evaporation to obtain a crude product, and then the crude product is separated and purified by silica gel column chromatography using petroleum ether and dichloromethane (V / V, 10:1) as eluents to obtain 0.46 g of light yellow powder 4-[6-(9H-carbazole-9-yl)-2-naphthyloxy]benzonitrile, with a yield of 56%. The structure is characterized by nuclear magnetic resonance spectrometer, and the test results are: 1 HNMR (400MHz, DMSO-d6) δ8.28 (d, J = 7.5Hz, 3H), 8.19 (dd, J = 8.9, 2.0Hz, 2H), 7.90 (d, J = 8.8Hz, 2H), 7.81 (d, J = 2.5Hz, 1H), 7.76 (dd, J = 8.7, 2.2Hz, 1H), 7.46 (dd, J = 11.8, 3.2Hz, 5H), 7.35–7.28 (m, 2H), 7.24 (d, J = 8.8Hz, 2H). 1 H NMR Figure 8 shown.

[0071] Example 5: Synthesis of 4-[6-(9H-carbazole-9-yl)-2-naphthyloxy]benzonitrile

[0072] 1) Purge a Schlenk tube equipped with a magnet with nitrogen, add carbazole (0.84 g, 5.0 mmol), K2CO3 (2.07 g, 15.0 mmol), 2,6-dibromonaphthalene (1.43 g, 5.0 mmol), copper powder (0.48 g, 7.5 mmol) and 12 mL DMF. The mixture is reacted under nitrogen for 30 h at a reaction temperature of 100 ° C. After the reaction is completed, filter it, pour it into 42 mL of water, and extract it with 3×14 mL of ethyl acetate. The organic phase is dried, filtered, and rotary evaporated to obtain a crude product. The crude product is separated and purified by silica gel column chromatography using petroleum ether and dichloromethane (V / V, 15:1) as eluents to obtain 1.06 g of 9-(6-bromo-2-naphthyl)-9H-carbazole, with a yield of 57%, as a white powder.

[0073] 2) Purge the Schlenk tube equipped with a magnet with nitrogen, add 9-(6-bromo-2-naphthyl)-9H-carbazole (0.74 g, 2.0 mmol), 4-hydroxybenzonitrile (0.24 g, 2.0 mmol), Cs2CO3 (0.65 g, 2.0 mmol), CuBr (14.3 mg, 0.1 mmol), ligand 1-(2-pyridyl)-2-propanone (27.0 mg, 0.2 mmol) and 5.3 mL DMSO. The reaction temperature is raised to 100°C and the reaction is sealed under nitrogen atmosphere for 20 h. After the reaction, the reaction mixture was filtered and poured into 24.6 mL of water. The mixture was extracted with 3×9.9 mL of ethyl acetate. The organic phase was dried and filtered. The organic solvent in the filtrate was removed by rotary evaporation to obtain a crude product. The crude product was then separated and purified by silica gel column chromatography using petroleum ether and dichloromethane (V / V, 5:1) as eluents to obtain 0.42 g of light yellow powder 4-[6-(9H-carbazole-9-yl)-2-naphthyloxy]benzonitrile with a yield of 51%.

[0074] Example 6: Synthesis of 4-[6-(9H-carbazole-9-yl)-2-naphthyloxy]benzonitrile

[0075] 1) Purge a Schlenk tube equipped with a magnet with nitrogen, add carbazole (0.84 g, 5.0 mmol), K2CO3 (3.46 g, 25.0 mmol), 2,6-dibromonaphthalene (2.86 g, 10.0 mmol), copper powder (0.79 g, 12.5 mmol) and 16.8 mL DMF. The mixture is reacted under nitrogen for 36 h at a reaction temperature of 110 ° C. After the reaction is completed, filter it, pour it into 84 mL of water, and extract it with 3×28 mL of ethyl acetate. The organic phase is dried, filtered, and rotary evaporated to obtain a crude product. The crude product is separated and purified by silica gel column chromatography using petroleum ether and dichloromethane (V / V, 25:1) as eluents to obtain 1.08 g of 9-(6-bromo-2-naphthyl)-9H-carbazole, with a yield of 58%, as a white powder.

[0076] 2) Purge the Schlenk tube equipped with a magnet with nitrogen, add 9-(6-bromo-2-naphthyl)-9H-carbazole (0.74 g, 2.0 mmol), 4-hydroxybenzonitrile (0.36 g, 3.0 mmol), Cs2CO3 (1.95 g, 6.0 mmol), CuBr (57.4 mg, 0.4 mmol), ligand 1-(2-pyridyl)-2-propanone (108.1 mg, 0.8 mmol) and 7.4 mL DMSO. The reaction temperature is raised to 130°C and the reaction is sealed under nitrogen atmosphere for 16 h. After the reaction, the reaction mixture was filtered and poured into 37 mL of water. The mixture was extracted with 3×16.4 mL of ethyl acetate. The organic phase was dried and filtered. The organic solvent in the filtrate was removed by rotary evaporation to obtain a crude product. The crude product was then separated and purified by silica gel column chromatography using petroleum ether and dichloromethane (V / V, 20:1) as eluents to obtain 0.44 g of light yellow powder 4-[6-(9H-carbazole-9-yl)-2-naphthyloxy]benzonitrile with a yield of 54%.

[0077] Example 7: Multiple emission properties of luminophore 4-[4'-(9H-carbazole-9-yl)-4-biphenyloxy]benzonitrile

[0078] The luminescent material 4-[4'-(9H-carbazole-9-yl)-4-biphenyloxy]benzonitrile prepared by the present invention is tested for luminescent performance using a steady-state / transient fluorescence spectrometer. The steady-state fluorescence spectrum of the luminescent material 4-[4'-(9H-carbazole-9-yl)-4-biphenyloxy]benzonitrile at room temperature and the delayed spectrum after a delay of 4 ms are shown in FIG. Figure 1 As shown. There are three immediate fluorescence peaks at 377nm, 413nm and 438nm in the steady-state fluorescence spectrum. There are also two emission peaks with lower intensity at 413nm and 438nm in the delayed spectrum, which are delayed fluorescence peaks. In addition, new emission peaks with higher intensity appear at 556nm and 606nm in the delayed spectrum, which are room temperature phosphorescence peaks. The wavelength of the phosphorescence peak is longer than that of the fluorescence peak. The luminophore 4-[4'-(9H-carbazole-9-yl)-4-biphenyloxy]benzonitrile shows good immediate fluorescence-delayed fluorescence-room temperature phosphorescence triple emission characteristics.

[0079] Example 8: Multiple emission properties of luminophore 4-[6-(9H-carbazole-9-yl)-2-naphthyloxy]benzonitrile

[0080] The luminescent material 4-[6-(9H-carbazole-9-yl)-2-naphthyloxy]benzonitrile prepared by the present invention is tested for luminescent performance using a steady-state / transient fluorescence spectrometer. The steady-state fluorescence spectrum of the luminescent material 4-[6-(9H-carbazole-9-yl)-2-naphthyloxy]benzonitrile at room temperature and the delayed spectrum after 3 ms delay are shown in FIG. Figure 2As shown. There is an immediate fluorescence peak at 420nm in its steady-state fluorescence spectrum. There is also an emission peak with lower intensity at 420nm in its delayed spectrum, which is the delayed fluorescence peak. In addition, in the delayed spectrum, a new emission peak with higher intensity appears at a wavelength of 575nm, which is the room temperature phosphorescence emission peak, and its wavelength is longer than the wavelength of the fluorescence peak. In summary, the luminophore 4-[6-(9H-carbazole-9-yl)-2-naphthyloxy]benzonitrile exhibits good triple emission characteristics of immediate fluorescence-delayed fluorescence-room temperature phosphorescence.

[0081] Example 9: Application of 4-[4'-(9H-carbazole-9-yl)-4-biphenyloxy]benzonitrile in the field of anti-counterfeiting encryption

[0082] Weigh 3-8 mg of the luminophore 4-[4'-(9H-carbazole-9-yl)-4-biphenyloxy]benzonitrile into a centrifuge tube, add 1-2 mL of dichloromethane, and place in an ultrasonic cleaner for 2-5 minutes to allow the luminophore to fully dissolve in the solvent. Then dip the solution and write the letter "T" manually on a white paper without fluorescence, and wait for the solvent to evaporate. Figure 3 As shown, it can be seen that there is no trace of the written words on the white paper under ordinary fluorescent light. When irradiated with ultraviolet light, the letter "T" is clearly displayed, showing blue-purple fluorescence, which shows the application potential of the luminescent body 4-[4'-(9H-carbazole-9-yl)-4-biphenyloxy]benzonitrile in the field of information encryption and anti-counterfeiting.

[0083] Example 10: Application of 4-[6-(9H-carbazole-9-yl)-2-naphthyloxy]benzonitrile in the field of anti-counterfeiting encryption

[0084] Weigh 3-8 mg of the luminophore 4-[6-(9H-carbazole-9-yl)-2-naphthyloxy]benzonitrile into a centrifuge tube, add 1-2 mL of dichloromethane, and place in an ultrasonic cleaner for 2-5 minutes to allow the luminophore to fully dissolve in the solvent. Then dip the solution and write the letter "J" manually on a non-fluorescent white paper, and wait for the solvent to evaporate. Figure 4 As shown, there is no trace of the written words on the white paper under ordinary fluorescent light, but when irradiated with ultraviolet light, the letter "J" is clearly displayed, showing blue-purple fluorescence, demonstrating the application potential of the luminescent body 4-[6-(9H-carbazole-9-yl)-2-naphthyloxy]benzonitrile in the field of information encryption and anti-counterfeiting.

[0085] The technical solutions disclosed and proposed by the present invention can be realized by those skilled in the art by referring to the contents of this article and appropriately changing the conditions, routes and other links. Although the methods and preparation techniques of the present invention have been described through preferred embodiments, relevant technicians can obviously modify or re-combine the methods and technical routes described herein without departing from the content, spirit and scope of the present invention to realize the final preparation technology. It should be particularly noted that all similar substitutions and modifications are obvious to those skilled in the art, and they are all considered to be included in the spirit, scope and content of the present invention.

Claims

1. A new pure organic multi-luminescent body based on aryl carbazole, characterized in that: Its structural formula is as follows: Wherein R is one of the following groups:

2. The method for preparing the novel pure organic multiple luminophore based on aryl carbazole according to claim 1, characterized in that: The steps include: 1): Stirring a mixture of 4-bromo-4'-iodobiphenyl or 2,6-dibromonaphthalene, carbazole, K2CO3, copper powder and solvent DMF under nitrogen for reaction; filtering after the reaction, then pouring into water, and extracting with ethyl acetate; drying, filtering and rotary evaporating the organic phase to obtain a crude product, and then separating and purifying the crude product by silica gel column chromatography, using petroleum ether and dichloromethane as eluents, to obtain 9-(4'-bromobiphenyl-4-yl)-9H-carbazole or 9-(6-bromo-2-naphthyl)-9H-carbazole; 2): 9-(4'-bromobiphenyl-4-yl)-9H-carbazole or 9-(6-bromo-2-naphthyl)-9H-carbazole obtained in step 1), 4-hydroxybenzonitrile, Cs2CO3, CuBr, ligand 1-(2-pyridyl)-2-acetone and solvent DMSO are mixed for reaction; after the reaction is completed, the mixture is filtered, and then the reaction solution is poured into water, extracted with ethyl acetate, the organic phase is dried, filtered, and the organic solvent in the filtrate is removed by rotary evaporation to obtain a crude product, and then the crude product is separated and purified by silica gel column chromatography using petroleum ether and dichloromethane as eluents to obtain 4-[4'-(9H-carbazole-9-yl)-4-biphenyloxy]benzonitrile or 4-[6-(9H-carbazole-9-yl)-2-naphthyloxy]benzonitrile.

3. The preparation method according to claim 2, characterized in that: In step 1), the reaction time is 30 to 42 hours and the reaction temperature is 100 to 130°C.

4. The preparation method according to claim 2, characterized in that: Step 2) The reaction temperature is 100-130° C. and the reaction time is 14-20 h.

5. The preparation method according to claim 2, characterized in that: In step 1), the molar ratio of carbazole: 4-bromo-4'-iodobiphenyl or 2,6-dibromonaphthalene: catalyst copper powder: K2CO3 is 1: (1-2): (1.5-2.5): (3-5); the weight volume ratio of carbazole: DMF is (5-7) g / 100 mL.

6. The preparation method according to claim 2, characterized in that: The molar ratio of 9-(4'-bromobiphenyl-4-yl)-9H-carbazole or 9-(6-bromo-2-naphthyl)-9H-carbazole:4-hydroxybenzonitrile:catalyst CuBr:ligand 1-(2-pyridyl)-2-propanone:Cs2CO3 in step 2) is 1:(1-2.5):(0.05-0.2):(0.1-0.4):(1-3); the weight-to-volume ratio of 9-(4'-bromobiphenyl-4-yl)-9H-carbazole or 9-(6-bromo-2-naphthyl)-9H-carbazole:DMSO is (10-14) g / 100 mL.

7. The novel pure organic multi-luminescent body based on aryl carbazole of claim 1 is applied in the fields of anti-counterfeiting and encryption, information storage, organic electroluminescent diodes and biosensor imaging.

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