Preparation and application of an indolocarbazole compound and a double-mode afterglow material

Abstract

The application discloses a kind of indole and carbazole compound and preparation and application of double mode afterglow material, belong to the technical field of organic compound synthesis.The structural formula of indole and carbazole compound provided by the present application is as shown in formula (I):The indole and carbazole compound provided by the present application is a kind of indole and [2,3-A] carbazole derivative, by introducing alkyl chain, can limit and isolate the non-radiation vibration of chromophore and promote reverse intersystem crossing, so it can effectively increase the lifetime and quantum yield of ultraviolet thermal activation delayed fluorescence and blue room temperature phosphorescence, and, the compound of the present application is simple, further chemical modification with low difficulty to adjust afterglow performance.The compound of the present application is doped in different polymer matrix, and the ultraviolet thermal activation delayed fluorescence and blue room temperature phosphorescence with long lifetime, high afterglow quantum yield can be realized, and the double mode afterglow material of ultraviolet thermal activation delayed fluorescence and blue room temperature phosphorescence can be obtained.

Description

Technical Field

[0001] This invention belongs to the field of organic compound synthesis technology, and particularly relates to the preparation and application of an indole-carbazole compound and a dual-mode afterglow material. Background Technology

[0002] Long afterglow is a fascinating luminescent phenomenon with advantages such as long luminescent lifetime and large Stokes shift, and is generally used in applications such as intelligent chemical sensing, data encryption and anti-counterfeiting, and optoelectronic devices. Compared to the high cost and high toxicity of inorganic long afterglow materials, organic long afterglow materials have attracted widespread attention in recent years due to their low cost, ease of modification or synthesis, ease of processing, low toxicity, and good biocompatibility. Currently, achieving long afterglow materials with excellent properties such as ultra-long lifetime, high quantum yield, high color purity, and stimulus response is the pursuit of most researchers.

[0003] Currently, long-afterglow materials are still limited by their monotonous emission colors, mostly green and yellow, with emission wavelengths between 490-595 nm. Balancing the lifetime and quantum yield of blue light is difficult, and bright, long-lasting blue room-temperature phosphorescence is relatively scarce. This is mainly because solids often exhibit triplet annihilation or π-π stacking, causing a redshift in phosphorescence, making blue light difficult to achieve. Furthermore, blue light is a short-wavelength, high-energy emission light, with intense vibrations in the high-energy triplet excitons, resulting in significant non-radiative inactivation, making it difficult to balance the lifetime and quantum yield of blue light.

[0004] While significant progress has been made in room-temperature phosphorescence, examples of simultaneously achieving thermally activated delayed fluorescence and phosphorescently modulated afterglow color remain rare. Two-mode afterglow materials exhibiting both long lifetime and high quantum yield with ultraviolet thermally activated delayed fluorescence and blue phosphorescence are even rarer. Two-mode afterglow can be tunable by simply controlling temperature, rather than through cumbersome chemical synthesis and material preparation. Most reported two-mode afterglow materials are organic crystals, with almost none being polymer-based. Polymer-based materials are easily processable, making the realization of polymer-based two-mode afterglow significant and holding great potential for practical applications.

[0005] To date, reports on achieving UV thermally activated delayed fluorescence and blue phosphorescence are still scarce, and research on afterglow based on simple derivatives of indo[2,3-A]carbazole is also lacking. It is essential to synthesize long-lifetime, high-quantum-yield UV thermally activated delayed fluorescence and blue room-temperature phosphorescence dual-mode afterglow materials using inexpensive raw materials and simple methods, which could provide new directions for exploring high-energy emission dual-mode afterglow materials. Summary of the Invention

[0006] In order to overcome the problems existing in the prior art, one of the objectives of the present invention is to provide an indole-carbazole compound that can be used to prepare a dual-mode afterglow material with long lifetime, high afterglow quantum yield, and ultraviolet thermally activated delayed fluorescence and blue room temperature phosphorescence.

[0007] A second objective of this invention is to provide a method for preparing the above-mentioned indolocarbazole compound.

[0008] The third objective of this invention is to provide a dual-mode afterglow material.

[0009] The fourth objective of this invention is to provide a method for preparing the above-mentioned dual-mode afterglow material.

[0010] The fifth objective of this invention is to provide an application of the above-mentioned indolocarbazole compound or bimodal afterglow material.

[0011] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0012] A first aspect of the present invention provides an indole-carbazole compound, the structural formula of which is shown in formula (I):

[0013]

[0014] In formula (I), R1 is H, halogen, C1-C10 alkane, C1-C10 alkoxy, C1-C10 alkylamino, C1-C10 alkyl ester, C1-C10 alkyl carbonyl, C1-C10 alkyl amide, C1-C10 alkyl carboxyl or C1-C10 alkyl aryl; R2 is H, halogen, C1-C10 alkane, C1-C10 alkoxy, C1-C10 alkylamino, C1-C10 alkyl ester, C1-C10 alkyl carbonyl, C1-C10 alkyl amide, C1-C10 alkyl carboxyl or C1-C10 alkyl aryl; R3 is C1-C10 alkane, C1-C10 olefin, C1-C10 alkyl ester, C1-C10 alkyl carbonyl, C1-C10 alkyl amide or C1-C10 alkoxy.

[0015] In a specific embodiment of the present invention, the halogen is F, Cl, Br or I.

[0016] Preferably, in formula (I), R1 is H, halogen, or C1-C10 alkane group; R2 is H, halogen, or C1-C10 alkane group; R3 is C1-C10 alkane group; more preferably, in formula (I), R1 is H or C1-C10 alkane group; R2 is H or C1-C10 alkane group; R3 is C1-C10 alkane group; even more preferably, in formula (I), R1 is H; R2 is H; R3 is C2-C5 alkane group.

[0017] In a specific embodiment of the present invention, the structural formula of the compound is shown in formulas (1) to (3):

[0018]

[0019] A second aspect of the present invention provides a method for preparing the indole-carbazole compound described in the first aspect of the present invention, characterized by comprising the following steps: subjecting compound A and compound B to a substitution reaction to obtain the indole-carbazole compound;

[0020] The compound A is:

[0021] The compound B is:

[0022] Preferably, in the method for preparing the indolocarbazole compound, the substitution reaction is carried out in the presence of a basic compound; more preferably, the basic compound includes at least one of a base, a carbonate, or a bicarbonate; even more preferably, the basic compound is selected from carbonates.

[0023] In a specific embodiment of the present invention, the alkaline compound includes at least one of sodium carbonate, potassium carbonate, or cesium carbonate.

[0024] Preferably, in the method for preparing the indolocarbazole compound, the molar ratio of compound A to compound B is 1:(1-3); more preferably 1:(2.1-2.8); and even more preferably 1:(2.2-2.6).

[0025] Preferably, in the method for preparing the indolocarbazole compound, the substitution reaction is carried out in an organic solvent; more preferably, the organic solvent includes at least one of alcoholic organic solvents, amine organic solvents, or ether organic solvents; even more preferably, the organic solvent includes at least one of methanol, ethanol, isopropanol, ethylenediamine, N,N-dimethylformamide (DMF), diethyl ether, or dipropyl ether.

[0026] In a specific embodiment of the present invention, the organic solvent is selected from DMF.

[0027] Preferably, in the method for preparing the indolocarbazole compound, the reaction temperature of the substitution reaction is 10–50°C; more preferably 15–40°C; and even more preferably 20–30°C.

[0028] Preferably, in the method for preparing the indolocarbazole compound, the reaction time of the substitution reaction is 5-24 h; more preferably 8-20 h; and even more preferably 10-15 h.

[0029] A third aspect of the present invention provides a dual-mode afterglow material comprising the indole-carbazole compound and an organic polymer as described in the first aspect of the present invention.

[0030] Preferably, in the dual-mode afterglow material, the mass ratio of the indole-carbazole compound to the organic polymer is (0.0001-0.1):1; more preferably (0.0005-0.01):1; and even more preferably (0.0008-0.005):1.

[0031] Preferably, in the dual-mode afterglow material, the organic polymer includes linear polymers, cross-linked polymers, or combinations thereof.

[0032] Preferably, the linear polymer in the organic polymer includes at least one of polyvinyl alcohol (PVA), polyacrylamide, polymethyl methacrylate, polylactic acid, polyacrylonitrile, polypropylene, polystyrene, or polycarbonate; in a specific embodiment of the present invention, the linear polymer is selected from polyvinyl alcohol.

[0033] Preferably, the crosslinking polymer in the organic polymer includes at least one of epoxy resin, unsaturated polyester, melamine resin, phenolic resin, polyurethane or urea-formaldehyde resin; in a specific embodiment of the present invention, the crosslinking polymer is selected from melamine resin or epoxy resin.

[0034] A fourth aspect of the present invention provides a method for preparing the dual-mode afterglow material described in the third aspect of the present invention, comprising the following steps: mixing the indole-carbazole compound with the organic polymer or its prepolymer, heating to evaporate the solvent or performing a curing reaction to obtain the dual-mode afterglow material.

[0035] Preferably, in the preparation method of the dual-mode afterglow material, the temperature of the heating to evaporate the solvent or the curing reaction is 50-200°C.

[0036] Preferably, in the preparation method of the dual-mode afterglow material, the heating time for solvent evaporation or curing reaction is 1 to 15 hours.

[0037] Preferably, in the preparation method of the dual-mode afterglow material, the mixing temperature is 40–120°C.

[0038] Preferably, in the preparation method of the dual-mode afterglow material, when the organic polymer is selected from linear polymers, the indole-carbazole compound is mixed with the organic polymer, and the solvent is evaporated by heating to obtain the dual-mode afterglow material; when the organic polymer is selected from crosslinked polymers, the indole-carbazole compound is mixed with the prepolymer of the organic polymer, and the dual-mode afterglow material is obtained after curing reaction.

[0039] Preferably, in the method for preparing the dual-mode afterglow material, when the organic polymer is selected from linear polymers, the temperature of heating and evaporating the solvent is 50–120°C; more preferably 60–100°C; and even more preferably 70–90°C.

[0040] Preferably, in the method for preparing the dual-mode afterglow material, when the organic polymer is selected from linear polymers, the heating time for evaporating the solvent is 3 to 15 hours; more preferably 4 to 12 hours; and even more preferably 5 to 8 hours.

[0041] Preferably, in the method for preparing the dual-mode afterglow material, when the organic polymer is selected from linear polymers, the mixing temperature is 40–80°C; more preferably, it is 50–70°C.

[0042] Preferably, in the preparation method of the dual-mode afterglow material, when the organic polymer is selected from cross-linked polymers, the curing reaction temperature is 60-200°C; more preferably 70-180°C; and even more preferably 80-160°C.

[0043] Preferably, in the preparation method of the dual-mode afterglow material, when the organic polymer is selected from cross-linked polymers, the curing reaction time is 1 to 12 hours; more preferably 1.5 to 10 hours; and even more preferably 2 to 7 hours.

[0044] Preferably, in the method for preparing the dual-mode afterglow material, when the organic polymer is selected from cross-linked polymers, the mixing temperature is 80–120°C; more preferably, it is 90–100°C.

[0045] Preferably, in the preparation method of the dual-mode afterglow material, the indolocarbazole compound is first dissolved in an organic solvent, and then mixed with the organic polymer solution or its prepolymer; more preferably, the organic solvent includes tetrahydrofuran, ethanol, or a combination thereof.

[0046] The fifth aspect of the present invention provides an application of the indole-carbazole compound described in the first aspect of the present invention, or the dual-mode afterglow material described in the third aspect of the present invention, in the fields of information encryption, anti-counterfeiting identification, lighting, or organic light-emitting semiconductors.

[0047] The beneficial effects of this invention are as follows: The indolocarbazole compound provided by this invention is an indolo[2,3-A]carbazole derivative. By introducing an alkyl chain, this invention can restrict and isolate the nonradiative vibrations of the chromophore and promote inter-antisystem crossing, thus effectively increasing the lifetime and quantum yield of ultraviolet thermally activated delayed fluorescence and blue room-temperature phosphorescence. Furthermore, the compounds of this invention are simple to synthesize, and further chemical modification to adjust afterglow performance is easy. Doping the compounds of this invention onto different polymer matrices can achieve long-lifetime, high-afterglow quantum-yield ultraviolet thermally activated delayed fluorescence and blue room-temperature phosphorescence, resulting in organic dual-mode afterglow materials with ultraviolet thermally activated delayed fluorescence and blue room-temperature phosphorescence, which can be widely used in fields such as information encryption, anti-counterfeiting identification, lighting, or organic light-emitting semiconductors. Attached Figure Description

[0048] Figure 1 For the compound ICzoO2 of formula (1) obtained in Example 1 1 H NMR spectrum.

[0049] Figure 2 The image shows the ESI-MS spectrum of compound ICzoO2 of formula (1) obtained in Example 1.

[0050] Figure 3 The steady-state and delayed emission spectra of the ICzoO2@PVA film are shown.

[0051] Figure 4 The time-resolved decay curve of the ICzoO2@PVA film.

[0052] Figure 5 The delayed emission spectra of ICzoO2@PVA films at different temperatures under vacuum conditions are shown.

[0053] Figure 6 The time-resolved decay curves of the thermally activated delayed fluorescence emission band of ICzoO2@PVA film at different temperatures under vacuum conditions are shown.

[0054] Figure 7 Time-resolved decay curves of the room-temperature phosphorescence emission band of ICzoO2@PVA film at different temperatures under vacuum conditions.

[0055] Figure 8 The steady-state and delayed emission spectra of the ICzoO2@MF film are shown.

[0056] Figure 9 The time-resolved decay curve of the ICzoO2@MF film.

[0057] Figure 10 For the compound ICzoO3 of formula (2) obtained in Example 2 1 H NMR spectrum.

[0058] Figure 11 The image shows the ESI-MS spectrum of compound ICzoO3 of formula (2) obtained in Example 2.

[0059] Figure 12 The steady-state and delayed emission spectra of the ICzoO3@PVA film are shown.

[0060] Figure 13 The time-resolved decay curve of the ICzoO3@PVA film.

[0061] Figure 14 The delayed emission spectra of ICzoO3@PVA films at different temperatures under vacuum conditions are shown.

[0062] Figure 15 The time-resolved decay curves of the thermally activated delayed fluorescence emission band of ICzoO3@PVA film at different temperatures under vacuum conditions are shown.

[0063] Figure 16 Time-resolved decay curves of the room-temperature phosphorescence emission band of ICzoO3@PVA film at different temperatures under vacuum conditions.

[0064] Figure 17 The steady-state and delayed emission spectra of the ICzoO3@MF film are shown.

[0065] Figure 18 The time-resolved decay curve of the ICzoO3@MF film.

[0066] Figure 19 The steady-state and delayed emission spectra of the ICzoO3@EP film are shown.

[0067] Figure 20 The time-resolved decay curve of the ICzoO3@EP film.

[0068] Figure 21 For the compound ICzoO5 of formula (3) obtained in Example 3 1 H NMR spectrum.

[0069] Figure 22 The image shows the ESI-MS spectrum of compound ICzoO5 of formula (3) obtained in Example 3.

[0070] Figure 23 The steady-state and delayed emission spectra of the ICzoO5@PVA film are shown.

[0071] Figure 24 The time-resolved decay curve of the ICzoO5@PVA film.

[0072] Figure 25 The delayed emission spectra of ICzoO5@PVA films at different temperatures under vacuum conditions are shown.

[0073] Figure 26 The time-resolved decay curves of the thermally activated delayed fluorescence emission band of ICzoO5@PVA film at different temperatures under vacuum conditions are shown.

[0074] Figure 27 Time-resolved decay curves of the room-temperature phosphorescence emission band of ICzoO5@PVA film at different temperatures under vacuum conditions.

[0075] Figure 28 The steady-state and delayed emission spectra of the ICzoO5@MF film are shown.

[0076] Figure 29 The time-resolved decay curve of the ICzoO5@MF film.

[0077] Figure 30 The steady-state and delayed emission spectra of the ICzoO5@EP film are shown.

[0078] Figure 31 The time-resolved decay curve of the ICzoO5@EP film. Detailed Implementation

[0079] The following specific embodiments further illustrate the content of the present invention in detail. It should also be understood that the following embodiments are only for further explanation of the present invention and should not be construed as limiting the scope of protection of the present invention. Non-essential improvements and adjustments made by those skilled in the art based on the principles described herein are all within the scope of protection of the present invention. The specific process parameters, etc., in the following examples are merely examples within a suitable range; that is, those skilled in the art can make selections within a suitable range based on the description herein, and are not intended to be limited to the specific data in the examples below. Unless otherwise specified, the raw materials, reagents, or apparatus used in the following embodiments and comparative examples can be obtained from conventional commercial sources or by existing known methods.

[0080] In a specific embodiment of the present invention, the structural formula of the indolocarbazole compound is shown in formula (I):

[0081]

[0082] In formula (I), R1 is H, halogen, C1-C10 alkane, C1-C10 alkoxy, C1-C10 alkylamino, C1-C10 alkyl ester, C1-C10 alkyl carbonyl, C1-C10 alkyl amide, C1-C10 alkyl carboxyl or C1-C10 alkyl aryl; R2 is H, halogen, C1-C10 alkane, C1-C10 alkoxy, C1-C10 alkylamino, C1-C10 alkyl ester, C1-C10 alkyl carbonyl, C1-C10 alkyl amide, C1-C10 alkyl carboxyl or C1-C10 alkyl aryl; R3 is C1-C10 alkane, C1-C10 olefin, C1-C10 alkyl ester, C1-C10 alkyl carbonyl, C1-C10 alkyl amide or C1-C10 alkoxy.

[0083] In a specific embodiment of the present invention, the indobenzocarbazole compound includes the following steps: subjecting compound A and compound B to a substitution reaction to obtain the indobenzocarbazole compound;

[0084] The compound A is:

[0085] The compound B is:

[0086] In some specific embodiments of the present invention, the synthetic route of the indolocarbazole compound is as follows:

[0087]

[0088] Example 1

[0089] This example provides an indole-carbazole compound (ICzoO2), the structural formula of which is shown in formula (1):

[0090]

[0091] The synthesis steps of the compound of formula (1) are as follows:

[0092] 11,12-dihydroindolo[2,3-A]carbazole (0.500 g, 1.95 mmol), 1,2-dibromoethane (0.806 g, 4.29 mmol), and potassium carbonate (0.593 g, 4.29 mmol) were added to a three-necked flask, along with 15 mL of DMF as the reaction solvent. The mixture was stirred at room temperature for 12 h. After the reaction was complete, the reaction solution was slowly poured into ice water while stirring, resulting in the precipitation of a large amount of pale yellow solid. This solid was filtered, washed with pure water, and dried. The solid was purified by chromatography using dichloromethane / petroleum ether (1:1) as the eluent to give a white solid ICzoO2 (0.111 g, yield 20.12%). Figure 1 For ICzoO21 H NMR spectrum, its NMR characterization data are as follows 1 H NMR(600MHz,Chloroform-d)δ8.14(dt,J=7.9,1.0Hz,2H),7.79(s,2H),7.53(dt,J=8.0,0. 9Hz, 2H), 7.45 (ddd, J=8.2, 7.1, 1.2Hz, 2H), 7.30 (ddd, J=8.0, 7.1, 1.0Hz, 2H), 4.67 (s, 4H). Figure 2 The image shows the ESI-MS spectrum of ICzoO2.

[0093] Application Example 1

[0094] This example provides a dual-mode afterglow material (ICzoO2@PVA), comprising ICzoO2 obtained in Example 1 and polyvinyl alcohol (PVA), and the specific preparation steps are as follows:

[0095] A 10% (w / w) polyvinyl alcohol aqueous solution with a degree of alcoholysis of 72% was prepared as the host solution, and an ICzoO2 / tetrahydrofuran solution with a concentration of 2 mg / mL was prepared as the guest solution. 50 μL of the guest solution was mixed with 1 g of the host solution, and the mixture was sonicated at 60 °C to obtain a transparent mixture. This mixture was then heated at 80 °C for 6 h to obtain an ICzoO2@PVA film with an ICzoO2 doping mass ratio of 0.10%, which is the aforementioned dual-mode afterglow material.

[0096] Figure 3 The steady-state and delayed emission spectra of the ICzoO2@PVA film are shown. Figure 4 The time-resolved decay curves of the ICzoO2@PVA film are shown. The steady-state spectrum and the delayed emission spectrum of the ICzoO2@PVA film almost overlap. The delayed emission spectrum exhibits emission peaks at 370 nm and 390 nm with a lifetime of 1.01 s; and emission peaks at 423 nm and 457 nm with a lifetime of 1.12 s. Quantum yield measurements show that the absolute photoinduced quantum yield of the film is 56.88%, and the afterglow quantum yield is 38.67%. Figure 5 , 6 Figures 7 and 8 show the delayed emission spectra and time-resolved decay curves at different temperatures under vacuum conditions. The intensity of the emission peaks at 370 nm and 390 nm increases with increasing temperature, while the intensity of the emission peaks at 423 nm and 457 nm decreases with increasing temperature. Furthermore, the lifetime of the 390 nm emission band is similar to that of the 423 nm emission band at the same temperature, which proves that the 370 nm and 390 nm emission peaks belong to the ultraviolet thermally activated delayed fluorescence emission peaks, while the 423 nm and 457 nm emission peaks belong to the blue room temperature phosphorescence emission peaks.

[0097] Application Example 2

[0098] This example provides a dual-mode afterglow material (ICzoO2@MF), comprising ICzoO2 obtained in Example 1 and melamine resin (MF), and the specific preparation steps are as follows:

[0099] 43g of formaldehyde aqueous solution (mass fraction 37%-40%) and 30.4g of melamine were weighed to prepare a melamine resin prepolymer as the host solution, and an ICzoO2 / tetrahydrofuran solution with a concentration of 2mg / mL was prepared as the guest solution. 500μL of the guest solution was mixed with 1g of the host solution, and the mixture was sonicated at 100℃ for 1h to ensure homogeneity. Then, it was heated at 150℃ for 3h for crosslinking and curing to obtain an ICzoO2@MF film with an ICzoO2 doping mass ratio of 0.10%, which is the dual-mode afterglow material.

[0100] Figure 8 The steady-state and delayed emission spectra of the ICzoO2@MF film are shown. Figure 9 The time-resolved decay curves of the ICzoO2@MF film are shown. The steady-state spectrum and the delayed emission spectrum of the ICzoO2@MF film almost overlap. The peaks at 379 nm and 401 nm in the delayed emission spectrum are thermally activated delayed fluorescence peaks, covering the ultraviolet and visible light regions, with a lifetime of up to 0.93 s. The peaks at 425 nm and 457 nm are blue phosphorescence peaks with a lifetime of up to 1.13 s.

[0101] Example 2

[0102] This example provides an indolocarbazole compound (ICzoO3), the structural formula of which is shown in formula (2):

[0103]

[0104] The synthesis steps of the compound of formula (2) are as follows:

[0105] 11,12-dihydroindolo[2,3-A]carbazole (0.500 g, 1.95 mmol), 1,3-dibromopropane (0.985 g, 4.88 mmol), and cesium carbonate (1.59 g, 4.88 mmol) were added to a three-necked flask, along with 15 mL of DMF as the reaction solvent. The mixture was stirred at room temperature for 12 h. After the reaction was complete, the reaction solution was slowly poured into ice water while stirring, resulting in the precipitation of a large amount of pale yellow solid. This solid was filtered, washed with pure water, and dried. The solid was purified by chromatography using dichloromethane / petroleum ether (1:1) as the eluent to give a white solid ICzoO3 (0.250 g, yield 43.2%). Figure 10 For ICzoO3 1 H NMR spectrum, its NMR characterization data are as follows 1H NMR (600MHz, DMSO-d6) δ = 8.21 (dt, J = 7.8, 0.9, 2H), 7.97 (s, 2H), 7.72–7.67 (m, 2H), 7.46 (ddd, J = 8.2 ,7.0,1.2,2H),7.25(ddd,J=7.8,7.0,0.9,2H),4.69–4.63(m,4H),2.70(ddt,J=10.4,6.5,3.5,2H). Figure 11 The image shows the ESI-MS spectrum of ICzoO3.

[0106] Application Example 3

[0107] This example provides a dual-mode afterglow material (ICzoO3@PVA), comprising ICzoO3 obtained in Example 2 and polyvinyl alcohol (PVA). The specific preparation steps are as follows:

[0108] A 10% (w / w) aqueous solution of polyvinyl alcohol with a degree of hydrolysis of 72% was prepared as the host solution, and an ICzoO3 / tetrahydrofuran solution with a concentration of 2 mg / mL was prepared as the guest solution. 50 μL of the guest solution was mixed with 1 g of the host solution, and the mixture was sonicated at 60 °C to obtain a transparent mixture. The mixture was then heated at 80 °C for 6 h to obtain an ICzoO3@PVA film with an ICzoO3 doping mass ratio of 0.10%, which is the aforementioned dual-mode afterglow material.

[0109] Figure 12 The steady-state and delayed emission spectra of the ICzoO3@PVA film are shown. Figure 13 The time-resolved decay curves of the ICzoO3@PVA film are shown. The delayed emission spectrum of the ICzoO3@PVA film exhibits emission peaks at 380 nm and 400 nm with a lifetime of 1.09 s; and emission peaks at 433 nm and 464 nm with a lifetime of 1.41 s. Quantum yield measurements show that the absolute photoinduced quantum yield of the film is 69.40%, and the afterglow quantum yield is 42.76%. Figure 14 , 15 Figure 16 shows the delayed emission spectra and time-resolved decay curves at different temperatures under vacuum conditions. The intensity of the emission peaks at 380 nm and 400 nm increases with increasing temperature, while the intensity of the emission peaks at 433 nm and 464 nm decreases with increasing temperature. Furthermore, the lifetime of the 400 nm emission band is similar to that of the 433 nm emission band at the same temperature, proving that the 380 nm and 400 nm emission peaks belong to ultraviolet thermally activated delayed fluorescence emission peaks, while the 433 nm and 464 nm emission peaks belong to blue room-temperature phosphorescence emission peaks.

[0110] Application Example 4

[0111] This example provides a dual-mode afterglow material (ICzoO3@MF), comprising ICzoO3 obtained in Example 2 and melamine resin (MF). The specific preparation steps are as follows:

[0112] 43g of formaldehyde aqueous solution (mass fraction 37%-40%) and 30.4g of melamine were weighed to prepare a melamine resin prepolymer as the host solution, and an ICzoO3 / tetrahydrofuran solution with a concentration of 2mg / mL was prepared as the guest solution. 500μL of the guest solution was mixed with 1g of the host solution, and the mixture was sonicated at 100℃ for 1h to ensure homogeneity. Then, it was heated at 150℃ for 3h for crosslinking and curing to obtain an ICzoO3@MF film with an ICzoO3 doping mass ratio of 0.10%, which is the dual-mode afterglow material.

[0113] Figure 17 The steady-state and delayed emission spectra of the ICzoO3@MF film are shown. Figure 18 The time-resolved decay curves of the ICzoO3@MF film are shown. The 409 nm peak in the delayed emission spectrum of the ICzoO3@MF film is a thermally activated delayed fluorescence peak, starting at 373 nm and covering the visible and ultraviolet light regions, with a lifetime of up to 0.86 s. The peaks at 439 nm and 470 nm are blue phosphorescence peaks with a lifetime of up to 1.15 s.

[0114] Application Example 5

[0115] This example provides a dual-mode afterglow material (ICzoO3@EP), comprising ICzoO3 obtained in Example 2 and epoxy resin (EP). The specific preparation steps are as follows:

[0116] Using bisphenol A as the host solution, an ICzoO3 / tetrahydrofuran solution with a concentration of 2 mg / mL was prepared as the guest solution. 150 μL of the guest solution was mixed with 0.3 g of the host solution, and the mixture was ultrasonicated at 90 °C to obtain a transparent mixture. Then, 72 μL of ethylenediamine curing agent was added, and the mixture was stirred until homogeneous. Finally, the mixture was heated at 90 °C for 6 h for cross-linking and curing to obtain an ICzoO3@EP film with an ICzoO3 doping mass ratio of 0.10%, which is the aforementioned dual-mode afterglow material.

[0117] Figure 19 Steady-state and delayed emission spectra of the ICzoO3@EP film. Figure 20 The time-resolved decay curves of the ICzoO3@EP film are shown. The peaks at 388 nm and 404 nm in the delayed emission spectrum of the ICzoO3@EP film are thermally activated delayed fluorescence peaks, starting at 369 nm and covering the visible and ultraviolet light regions, with a lifetime of up to 0.40 s. The peaks at 437 nm and 469 nm are blue phosphorescence peaks with a lifetime of up to 0.42 s.

[0118] Example 3

[0119] This example provides an indolocarbazole compound (ICzoO5), the structural formula of which is shown in formula (3):

[0120]

[0121] The synthesis steps of the compound of formula (3) are as follows:

[0122] 11,12-dihydroindolo[2,3-A]carbazole (0.300 g, 1.17 mmol), 1,5-dibromopentane (0.673 g, 2.93 mmol), and cesium carbonate (0.953 g, 2.93 mmol) were added to a three-necked flask, along with 15 mL of DMF as the reaction solvent. The mixture was stirred at room temperature for 12 h. After the reaction was complete, the reaction solution was slowly poured into ice water while stirring, resulting in the precipitation of a large amount of pale yellow solid. This solid was filtered, washed with pure water, and dried. The solid was purified by chromatography using dichloromethane / petroleum ether (1:1) as the eluent to give a white solid ICzoO5 (0.140 g, yield 36.9%). Figure 21 For ICzoO5 1 H NMR spectrum, its NMR characterization data are as follows 1 H NMR (600MHz, DMSO-d6) δ = 8.24 (dt, J = 7.5, 0.9, 2H), 8.08 (s, 2H), 7.72 (d, J = 8.3, 2H), 7.46 (ddd, J = 8.2, 7 .0,1.3,2H),7.25(ddd,J=7.7,6.9,0.8,2H),5.05(t,J=6.2,4H),2.10(p,J=6.0,4H),1.51–1.36(m,2H). Figure 22 The image shows the ESI-MS spectrum of ICzoO5.

[0123] Application Example 6

[0124] This example provides a dual-mode afterglow material (ICzoO5@PVA), comprising ICzoO5 obtained in Example 3 and polyvinyl alcohol (PVA). The specific preparation steps are as follows:

[0125] A 10% (w / w) aqueous solution of polyvinyl alcohol with a degree of hydrolysis of 72% was prepared as the host solution, and an ICzoO5 / tetrahydrofuran solution with a concentration of 2 mg / mL was prepared as the guest solution. 50 μL of the guest solution was mixed with 1 g of the host solution, and the mixture was sonicated at 60 °C to obtain a transparent mixture. The mixture was then heated at 80 °C for 6 h to obtain an ICzoO5@PVA film with an ICzoO5 doping mass ratio of 0.10%, which is the aforementioned dual-mode afterglow material.

[0126] Figure 23Steady-state and delayed emission spectra of ICzoO5@PVA films. Figure 24 The time-resolved decay curves of the ICzoO5@PVA film are shown. The delayed emission spectrum of the ICzoO5@PVA film exhibits emission peaks at 381 nm and 400 nm with a lifetime of 2.15 s; and emission peaks at 441 nm and 473 nm with a lifetime of 2.52 s. Quantum yield measurements show that the absolute photoinduced quantum yield of the film is 65.80%, and the afterglow quantum yield is 23.64%. Figure 25 , 26 Figure 27 shows the delayed emission spectra and time-resolved decay curves at different temperatures under vacuum conditions. The intensity of the emission peaks at 381 nm and 400 nm increases with increasing temperature, while the intensity of the emission peaks at 441 nm and 473 nm decreases with increasing temperature. Furthermore, the lifetime of the 400 nm emission band is similar to that of the 441 nm emission band at the same temperature, proving that the 381 nm and 400 nm emission peaks belong to ultraviolet thermally activated delayed fluorescence emission peaks, while the 441 nm and 473 nm emission peaks belong to blue room-temperature phosphorescence emission peaks.

[0127] Application Example 7

[0128] This example provides a dual-mode afterglow material (ICzoO5@MF), comprising ICzoO5 obtained in Example 3 and melamine resin (MF), and the specific preparation steps are as follows:

[0129] 43g of formaldehyde aqueous solution (mass fraction 37%-40%) and 30.4g of melamine were weighed to prepare a melamine resin prepolymer as the host solution, and an ICzoO5 / tetrahydrofuran solution with a concentration of 2mg / mL was prepared as the guest solution. 500μL of the guest solution was mixed with 1g of the host solution, and the mixture was sonicated at 100℃ for 1h to ensure homogeneity. Then, it was heated at 150℃ for 3h for crosslinking and curing to obtain an ICzoO5@MF film with an ICzoO5 doping mass ratio of 0.10%, which is the dual-mode afterglow material.

[0130] Figure 28 The steady-state and delayed emission spectra of the ICzoO5@MF film are shown. Figure 29 The time-resolved decay curves of the ICzoO5@MF film are shown. The 408 nm peak in the delayed emission spectrum of the ICzoO5@MF film is a thermally activated delayed fluorescence peak, starting at 373 nm and covering the ultraviolet and visible light regions, with a lifetime of up to 1.68 s. The peaks at 447 nm and 477 nm are blue phosphorescence peaks with a lifetime of up to 2.31 s.

[0131] Application Example 8

[0132] This example provides a dual-mode afterglow material (ICzoO5@EP), comprising ICzoO5 obtained in Example 3 and epoxy resin (EP). The specific preparation steps are as follows:

[0133] Using bisphenol A as the host solution, an ICzoO5 / tetrahydrofuran solution with a concentration of 2 mg / mL was prepared as the guest solution. 150 μL of the guest solution was mixed with 0.3 g of the host solution, and the mixture was ultrasonicated at 90 °C to obtain a transparent mixture. Then, 72 μL of ethylenediamine curing agent was added, and the mixture was stirred until homogeneous. Finally, the mixture was heated at 90 °C for 6 h for cross-linking and curing to obtain an ICzoO5@EP film with an ICzoO5 doping mass ratio of 0.10%, which is the aforementioned dual-mode afterglow material.

[0134] Figure 30 Steady-state and delayed emission spectra of the ICzoO5@EP film. Figure 31 The time-resolved decay curves of the ICzoO5@EP film are shown. The peaks at 386 nm and 404 nm in the delayed emission spectrum of the ICzoO5@EP film are thermally activated delayed fluorescence peaks, starting at 373 nm and covering the ultraviolet and visible light regions, with a lifetime of up to 1.17 s. The peaks at 446 nm and 477 nm are blue phosphorescence peaks with a lifetime of up to 1.29 s.

[0135] The indolocarbazole compound provided by this invention is an indolo[2,3-A]carbazole derivative. By introducing an alkyl chain, this invention can restrict and isolate the nonradiative vibrations of the chromophore and promote inter-antisystem crossing, thus effectively increasing the lifetime and quantum yield of UV thermally activated delayed fluorescence and blue room-temperature phosphorescence. Furthermore, the compound of this invention is simple to synthesize, and further chemical modification to adjust the afterglow performance is easy. Doping the compound of this invention onto different polymer matrices can achieve long-lifetime, high-afterglow quantum-yield UV thermally activated delayed fluorescence and blue room-temperature phosphorescence, resulting in organic dual-mode afterglow materials with UV thermally activated delayed fluorescence and blue room-temperature phosphorescence, which can be widely used in information encryption, anti-counterfeiting identification, lighting, or organic light-emitting semiconductors.

Claims

1. A dual-mode afterglow material, characterized in that, The compounds include indolocarbazole compounds and organic polymers, wherein the structural formula of the indolocarbazole compounds is shown in formula (I): （I）； In formula (I), R1 is H, halogen or C1-C10 alkane group; R2 is H, halogen or C1-C10 alkane group; R3 is C1-C10 alkane group.

2. The dual-mode afterglow material of claim 1, wherein, The structural formulas of the indolocarbazole compounds are shown in formulas (1) to (3): （1）、 （2）、 （3）。 3. The dual-mode afterglow material according to claim 1 or 2, characterized in that The indobenzocarbazole compound is prepared by a method comprising the following steps: subjecting compound A to a substitution reaction with compound B to obtain the indobenzocarbazole compound; The compound A is: ; The compound B is: .

4. The dual-mode afterglow material of claim 3, wherein, The substitution reaction is carried out in the presence of a basic compound; And / or, the molar ratio of compound A to compound B is 1:(1~3).

5. The dual-mode afterglow material of claim 1, wherein, The mass ratio of the indolocarbazole compound to the organic polymer is (0.0001~0.1):

1.

6. The dual-mode afterglow material according to claim 1, characterized in that, The organic polymers include linear polymers, cross-linked polymers, or combinations thereof.

7. The dual-mode afterglow material according to claim 6, characterized in that, The linear polymer includes at least one of polyvinyl alcohol, polyacrylamide, polymethyl methacrylate, polylactic acid, polyacrylonitrile, polypropylene, polystyrene, or polycarbonate. And / or, the crosslinked polymer includes at least one of epoxy resin, unsaturated polyester, melamine resin, phenolic resin, polyurethane or urea-formaldehyde resin.

8. The method for preparing the dual-mode afterglow material according to any one of claims 1 to 7, characterized in that, The process includes the following steps: mixing the indolocarbazole compound with the organic polymer or its prepolymer, heating to evaporate the solvent or performing a curing reaction to obtain the dual-mode afterglow material.

9. The application of the dual-mode afterglow material according to any one of claims 1 to 7 in the fields of information encryption, anti-counterfeiting identification, lighting, or organic light-emitting semiconductors.

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