Novel pure organic multi-luminescent body based on aryl carbazole and preparation method thereof

Abstract

The present invention relates to a novel pure organic multiple luminescent body based on aryl carbazole and a preparation method thereof. The reaction structural formula is shown in the following formula. A mixture of 4-bromo-4'-iodobiphenyl or 2,6-dibromonaphthalene, carbazole, K2CO3, copper powder and solvent DMF is stirred and reacted under nitrogen; after extraction, drying, filtration and rotary evaporation, a crude product is obtained; the obtained crude product, 4-hydroxybenzonitrile, Cs2CO3, CuBr, ligand 1-(2-pyridyl)-2-propanone and solvent DMSO are mixed and reacted; after drying, filtration, rotary evaporation and separation and purification, 4-[4'-(9H-carbazol-9-yl)-4-biphenyloxy]benzonitrile or 4-[6-(9H-carbazol-9-yl)-2-naphthyloxy]benzonitrile with instant fluorescence-delayed fluorescence-room temperature phosphorescence triple emission characteristics is obtained; it has good application potential in the fields of anti-counterfeiting, information encryption, organic light-emitting diodes, biosensing imaging, etc. #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. 1 To S 0 The probability of forming singlet and triplet excitons is 1:3, that is, only 25% of the singlet excitons in the fluorescent material can be used to emit light, and 75% of the triplet excitons are released in the form of non-radiative luminescence (converted into heat energy). The occurrence of delayed fluorescence involves a complex process such as internal conversion (IC), intersystem crossing (ISC) to triplet state and reverse intersystem crossing (RISC). Finally, the exciton returns to S 1 Both immediate fluorescence and delayed fluorescence come from S 1 The emission of room temperature phosphorescence comes from the radiative transition of the exciton from the triplet state T 1 To the ground state S 0 Therefore, the instantaneous fluorescence-delayed fluorescence-room temperature phosphorescence multiple luminescent body can make more use of the energy that is wasted by the instantaneous fluorescent material and converted into heat energy.

[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 groups in cyanoacetic acid restrict the movement of molecules and promote the excitons from S 1 State to T 1 The ISC process of the state (Mater. Chem. Front., 2018, 2: 2124-2129.). Zhang et al. reported a series of amide pure organic compounds with efficient room temperature phosphorescence by introducing carbonyl and aromatic π units, and promoted the ISC process by introducing carbonyl (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 S through RISC. 1 state, and finally returns to the ground state S0 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 exhibits 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): 4-bromo-4'-iodobiphenyl or 2,6-dibromonaphthalene, carbazole, K 2 CO 3A mixture of copper powder and solvent N,N-dimethylformamide (DMF) is stirred under nitrogen for reaction; 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 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, 4-hydroxybenzonitrile, Cs 2 CO 3 , CuBr, ligand 1-(2-pyridyl)-2-propanone 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), carbazole: 4-bromo-4'-iodobiphenyl or 2,6-dibromonaphthalene: catalyst copper powder: K 2 CO 3 The molar ratio is 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), 9-(4'-bromobiphenyl-4-yl)-9H-carbazole or 9-(6-bromo-2-naphthyl)-9H-carbazole is preferred: 4-hydroxybenzonitrile: catalyst CuBr: ligand 1-(2-pyridyl)-2-acetone: Cs 2 CO 3 The molar ratio is 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 vessel was purged with nitrogen and 4-bromo-4'-iodobiphenyl or 2,6-dibromonaphthalene, carbazole, K 2 CO 3 A mixture of copper powder and solvent DMF is stirred under nitrogen for 30 to 42 hours at a reaction temperature of 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, which is then separated and purified by silica gel column chromatography using 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 vessel was purged with nitrogen and 9-(4'-bromobiphenyl-4-yl)-9H-carbazole or 9-(6-bromo-2-naphthyl)-9H-carbazole, 4-hydroxybenzonitrile, Cs 2 CO 3 , CuBr, ligand 1-(2-pyridyl)-2-propanone and solvent DMSO; 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 petroleum ether and dichloromethane are used as eluents to separate and purify the crude product by silica gel column chromatography 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] Further, in the preparation method of a novel pure organic multiple luminophore based on aromatic carbazole according to the present invention, the molar mass ratio of carbazole to 4-bromo-4'-iodobiphenyl or 2,6-dibromonaphthalene in step 1) is 1:(1-2); the molar mass ratio of carbazole to catalyst copper powder is 1:(1.5-2.5); K 2 CO 3 To create an alkaline environment, carbazole and K 2 CO 3 The molar mass ratio 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); using Cs 2 CO 3 Create an alkaline environment, 9-(4'-bromobiphenyl-4-yl)-9H-carbazole or 9-(6-bromo-2-naphthyl)-9H-carbazole: Cs 2 CO 3 The molar mass ratio 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 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 excitons from S 1 Excited state to S 0 The delayed spectrum after 4ms also has two emission peaks with lower intensity at 413nm and 438nm, which are delayed fluorescence peaks. 1 The state returns to the ground state S by radiative transition 0Therefore, the positions of the emission peaks of the two spectra are the same. In addition, new emission peaks with higher intensity appear at 556nm and 606nm in the delayed spectrum. This emission peak is the room temperature phosphorescence peak, which is attributed to the excitons from the triplet state T 1 Transition to S 0 The light emitted from the ground state has a wavelength longer than the wavelength of the fluorescence emitted from the singlet transition, because the triplet state has lower energy than the singlet state. In summary, from the steady-state fluorescence spectrum and the delayed spectrum, it can be seen that the luminophore 4-[4'-(9H-carbazole-9-yl)-4-biphenyloxy]benzonitrile has good triple emission characteristics of immediate fluorescence-delayed fluorescence-room temperature phosphorescence.

[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 2 Its fluorescence spectrum shows that there is an instant fluorescence peak at a wavelength of 420nm, which is S 1 Excited state to S 0 The delayed fluorescence spectrum with a delay of 3ms has a low-intensity emission peak at 420nm, which is the delayed fluorescence peak. 1 The transition of the excited state is at the same position as the immediate fluorescence peak. In addition, in the delayed spectrum of 3ms, a new emission peak with higher intensity appears at a wavelength of 575nm, which is the transition of the exciton from the triplet state T 1 The room temperature phosphorescence emission peak emitted by the transition has a triplet state with lower energy than the singlet state, so the wavelength of the phosphorescence peak is longer than the wavelength of the fluorescence peak. In summary, from the steady-state fluorescence spectrum and the delayed spectrum, it can be seen that the luminophor 4-[6-(9H-carbazole-9-yl)-2-naphthyloxy]benzonitrile exhibits good immediate fluorescence-delayed fluorescence-room temperature phosphorescence triple emission characteristics.

[0043] In the luminescent molecule of the present invention, the lone pair of electrons on the cyano nitrogen atom can participate in the n→π* transition, which can promote the occurrence of ISC, reduce the energy level difference between the singlet state and the triplet state, and thus increase the yield of triplet excitons, thereby promoting the emission of room temperature phosphorescence. In addition, due to the reduction of the energy level difference between the singlet state and the triplet state, the triplet excitons can also transition back to S through RISC. 1 state, and finally returns to the ground state S 0 Produce delayed fluorescence. In addition, the introduction of heteroatoms N and O elements in the structure increases the interaction between molecules and can form a rigid environment. The introduction of biphenyl and naphthalene also helps to improve the rigidity of the molecule, which can limit the thermal motion of the molecule, reduce energy loss, inhibit the occurrence of non-radiative transitions, and allow more energy to be 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 4 As 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 1It 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 and add carbazole (1.17 g, 7.0 mmol), K 2 CO3 (3.87g, 28.0mmol), 4-bromo-4'-iodobiphenyl (3.27g, 9.1mmol), copper powder (0.89g, 14mmol) and 20mL DMF. The mixture was reacted under nitrogen for 36h at a reaction temperature of 130°C. After the reaction was completed, it was filtered and then poured into 100mL of water and extracted with 3×30mL of ethyl acetate. The organic phase was dried, filtered, and rotary evaporated to obtain a crude product. The crude product was separated and purified by silica gel column chromatography using petroleum ether and dichloromethane (V / V, 20:1) as eluents to obtain 1.78g of 9-(4'-bromobiphenyl-4-yl)-9H-carbazole with a yield of 64%, which was a white powder. The structure was characterized by nuclear magnetic resonance spectrometer, and the test results were: 1 H NMR (400 MHz, DMSO-d 6 )δ8.25(d,J=7.6Hz,2H),7.96(d,J=8.2Hz,2H),7.81–7.66(m,6H),7.44(d,J=4.0Hz,4H),7.29(dt,J=8.0,3.9Hz,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), Cs 2 CO 3 (1.95g, 6.0mmol), CuBr (43.0mg, 0.3mmol), ligand 1-(2-pyridyl)-2-propanone (81.1mg, 0.6mmol) and 10mL DMSO. The reaction temperature was raised to 110°C and the reaction was closed under a nitrogen atmosphere for 20h. After the reaction was completed, the reaction solution was filtered, and then poured into 50mL of water, extracted with 3×20mL of ethyl acetate, the organic phase was dried, filtered, and the organic solvent in the filtrate was removed by rotary evaporation to obtain a crude product, and then petroleum ether and dichloromethane (V / V, 10:1) were used as eluents to separate and purify the crude product by silica gel column chromatography to obtain 0.68g of light yellow powder 4-[4'-(9H-carbazole-9-yl)-4-biphenyloxy]benzonitrile, with a yield of 52%. The structure was characterized by nuclear magnetic resonance spectrometer, and the test results were: 1 H NMR (400 MHz, DMSO-d 6)δ8.26(dt,J=7.8,1.0Hz,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 the Schlenk tube equipped with a magnet with nitrogen and add carbazole (1.17 g, 7.0 mmol), K 2 CO 3 (2.90g, 21.0mmol), 4-bromo-4'-iodobiphenyl (2.51g, 7.0mmol), copper powder (0.67g, 10.5mmol) and 16.7mL DMF. The mixture was reacted under nitrogen for 30h at a reaction temperature of 100°C. After the reaction was completed, it was filtered and then poured into 58.5mL of water and extracted with 3×19.5mL of ethyl acetate. The organic phase was dried, filtered and rotary evaporated to obtain a crude product. The crude product was separated and purified by silica gel column chromatography using petroleum ether and dichloromethane (V / V, 15:1) as eluents to obtain 1.67g 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), Cs 2 CO 3 (0.98g, 3.0mmol), CuBr (21.5mg, 0.15mmol), ligand 1-(2-pyridyl)-2-propanone (40.5mg, 0.3mmol) and 8.5mL DMSO. The reaction temperature was raised to 100℃ and the reaction was closed under nitrogen atmosphere for 14h. After the reaction was completed, the reaction solution was filtered, and then poured into 39.7mL water, extracted with 3×15.9mL ethyl acetate, the organic phase was dried, filtered, and the organic solvent in the filtrate was removed by rotary evaporation to obtain a crude product, and then petroleum ether and dichloromethane (V / V, 5:1) were used as eluents to separate and purify the crude product by silica gel column chromatography to obtain 0.54g 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 the Schlenk tube equipped with a magnet with nitrogen and add carbazole (1.17 g, 7.0 mmol), K 2 CO 3 (4.84g, 35.0mmol), 4-bromo-4'-iodobiphenyl (5.03g, 14.0mmol), copper powder (1.11g, 17.5mmol) and 23.4mL DMF. The mixture was reacted under nitrogen for 42h at a reaction temperature of 110°C. After the reaction was completed, it was filtered and then poured into 117mL of water and extracted with 3×39mL of ethyl acetate. The organic phase was dried, filtered and rotary evaporated to obtain a crude product. The crude product was separated and purified by silica gel column chromatography using petroleum ether and dichloromethane (V / V, 25:1) as eluents to obtain 1.75g ​​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), Cs 2 CO 3 (2.93g, 9.0mmol), CuBr (86.1mg, 0.6mmol), ligand 1-(2-pyridyl)-2-propanone (162.2mg, 1.2mmol) and 11.9mL DMSO. The reaction temperature was raised to 130°C and the reaction was closed under a nitrogen atmosphere for 17h. After the reaction was completed, the reaction solution was filtered, and then poured into 59.5mL water, extracted with 3×26.4mL ethyl acetate, the organic phase was dried, filtered, and the organic solvent in the filtrate was removed by rotary evaporation to obtain a crude product, and then petroleum ether and dichloromethane (V / V, 20:1) were used as eluents to separate and purify the crude product by silica gel column chromatography to obtain 0.65g 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 (0.84 g, 5.0 mmol), K 2 CO 3(2.76g, 20.0mmol), 2,6-dibromonaphthalene (2.14g, 7.5mmol), copper powder (0.64g, 10.0mmol) and 15mL DMF. The mixture was reacted under nitrogen for 42h at a reaction temperature of 130°C. After the reaction was completed, it was filtered and then poured into 60mL of water and extracted with 3×20mL of ethyl acetate. The organic phase was dried, filtered, and rotary evaporated to obtain a crude product. The crude product was separated and purified by silica gel column chromatography using petroleum ether and dichloromethane (V / V, 20:1) as eluents to obtain 9-(6-bromo-2-naphthyl)-9H-carbazole 1.11g with a yield of 60%, as a white powder. The structure was characterized by nuclear magnetic resonance spectrometer, and the test results were: 1 H NMR (400 MHz, DMSO-d 6 )δ8.39(d,J=2.0Hz,1H),8.28(d,J=7.5Hz,3H),8.21(d,J=8.8Hz,1H),8.05(d,J=8.9Hz,1H),7.81(dd,J=8.7,2.2Hz,1H),7.76(dd,J=8.7,2.0Hz,1H),7.48–7.41(m,4H),7.32(ddd,J=8.0,5.4,2.7Hz,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), Cs 2 CO 3 (1.30g, 4.0mmol), CuBr (28.7mg, 0.2mmol), ligand 1-(2-pyridyl)-2-propanone (54.1mg, 0.4mmol) and 6mL DMSO. The reaction temperature was raised to 120°C and the reaction was closed under a nitrogen atmosphere for 14h. After the reaction was completed, the reaction solution was filtered, and then poured into 30mL of water, extracted with 3×15mL of ethyl acetate, the organic phase was dried, filtered, and the organic solvent in the filtrate was removed by rotary evaporation to obtain a crude product, and then petroleum ether and dichloromethane (V / V, 10:1) were used as eluents to separate and purify the crude product by silica gel column chromatography to obtain 0.46g of light yellow powder 4-[6-(9H-carbazole-9-yl)-2-naphthyloxy]benzonitrile, with a yield of 56%. The structure was characterized by nuclear magnetic resonance spectrometer, and the test results were: 1 HNMR (400 MHz, DMSO-d 6)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 the Schlenk tube equipped with a magnet with nitrogen, add carbazole (0.84 g, 5.0 mmol), K 2 CO 3 (2.07g, 15.0mmol), 2,6-dibromonaphthalene (1.43g, 5.0mmol), copper powder (0.48g, 7.5mmol) and 12mL DMF. The mixture was reacted under nitrogen for 30h at a reaction temperature of 100℃. After the reaction was completed, it was filtered and then poured into 42mL of water and extracted with 3×14mL of ethyl acetate. The organic phase was dried, filtered and rotary evaporated to obtain a crude product. The crude product was separated and purified by silica gel column chromatography using petroleum ether and dichloromethane (V / V, 15:1) as eluents to obtain 1.06g 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), Cs 2 CO 3 (0.65g, 2.0mmol), CuBr (14.3mg, 0.1mmol), ligand 1-(2-pyridyl)-2-propanone (27.0mg, 0.2mmol) and 5.3mL DMSO. The reaction temperature was raised to 100℃ and the reaction was closed under nitrogen atmosphere for 20h. After the reaction was completed, the reaction solution was filtered, and then poured into 24.6mL water, extracted with 3×9.9mL ethyl acetate, the organic phase was dried, filtered, and the organic solvent in the filtrate was removed by rotary evaporation to obtain a crude product, and then petroleum ether and dichloromethane (V / V, 5:1) were used as eluents to separate and purify the crude product by silica gel column chromatography to obtain 0.42g 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 the Schlenk tube equipped with a magnet with nitrogen, add carbazole (0.84 g, 5.0 mmol), K 2 CO 3 (3.46g, 25.0mmol), 2,6-dibromonaphthalene (2.86g, 10.0mmol), copper powder (0.79g, 12.5mmol) and 16.8mL DMF. The mixture was reacted under nitrogen for 36h at a reaction temperature of 110°C. After the reaction was completed, it was filtered and then poured into 84mL of water and extracted with 3×28mL of ethyl acetate. The organic phase was dried, filtered and rotary evaporated to obtain a crude product. The crude product was separated and purified by silica gel column chromatography using petroleum ether and dichloromethane (V / V, 25:1) as eluents to obtain 1.08g 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), Cs 2 CO 3 (1.95g, 6.0mmol), CuBr (57.4mg, 0.4mmol), ligand 1-(2-pyridyl)-2-propanone (108.1mg, 0.8mmol) and 7.4mL DMSO. The reaction temperature was raised to 130℃ and the reaction was closed under nitrogen atmosphere for 16h. After the reaction was completed, the reaction solution was filtered, and then poured into 37mL water, extracted with 3×16.4mL ethyl acetate, the organic phase was dried, filtered, and the organic solvent in the filtrate was removed by rotary evaporation to obtain a crude product, and then petroleum ether and dichloromethane (V / V, 20:1) were used as eluents to separate and purify the crude product by silica gel column chromatography to obtain 0.44g 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 1As 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 2 As 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: ； When R is a biphenyl group, the luminophore is 4-[4'-(9H-carbazole-9-yl)-4-biphenyloxy]benzonitrile, and its structural formula is: ； When R is a naphthalene group, the luminophore is 4-[6-(9H-carbazole-9-yl)-2-naphthyloxy]benzonitrile, and its structural formula is: 。 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): A mixture of 4-bromo-4'-iodobiphenyl or 2,6-dibromonaphthalene, carbazole, K2CO3, copper powder and solvent DMF is stirred under nitrogen for reaction; 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; 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; In step 1), the reaction time is 30-42 h, and the reaction temperature is 100-130 °C; 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; Step 2) The reaction temperature is 100-130 °C, and the reaction time is 14-20 h. 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 is 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.

3. The novel pure organic multi-luminescent body based on aryl carbazole of claim 1 is used in the fields of anti-counterfeiting and encryption.

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