Near-infrared material suitable for solution processing as well as preparation method and application of near-infrared material

Abstract

The invention discloses a near-infrared material suitable for solution processing and a preparation method and application thereof, and relates to the field of organic light-emitting materials. The near-infrared material suitable for solution processing is composed of an electron acceptor fragment with strong rigidity and an electron donor fragment (N-(9, 9-bis (4-(tert-butylbenzene)-9H-fluorene-2-yl) amino) phenyl)-9, 9-bis (4-(tert-butylbenzene))-N-phenyl-9H-fluorene-2-amine) with a huge structure, the electron acceptor fragment is diphenyl [a, c] phenazine-11, 12-dione, and the electron donor fragment is an electron donor fragment (N-(9, 9-bis (4-(tert-butylbenzene)-9H-fluorene-2-yl) amino) phenyl)-9, 9-bis (4-(tert-butylbenzene)-N-phenyl-9H-fluorene-2-amine). And 2, 12-dinitrile. The material is a near-infrared material with thermal activation delayed fluorescence property, and the maximum external quantum efficiency of a prepared device is 8.33%.

Description

Technical Field

[0001] The present patent application relates to the technical field of organic electroluminescent materials, and more specifically, to a near-infrared material suitable for solution processing and a preparation method and application thereof. Background Art

[0002] To date, vacuum evaporation technology is still the main preparation process for most OLEDs. This preparation process gives OLEDs the advantages of low power consumption, high color gamut and flexible display. The efficiency of OLED devices manufactured using this process is currently developing rapidly. However, this process has complicated procedures, and its high manufacturing cost limits its industrial application. In contrast, OLED devices prepared by solution processing have advantages that cannot be ignored, such as low preparation cost and simple device structure. However, compared with the traditional evaporation method, the development of solution-based OLED devices is relatively slow, which is to some extent related to the film-making technology and storage environment during the preparation process.

[0003] Regarding the development of solution-processed devices, although there have been reports of good performance in recent years, they are basically concentrated on blue and green materials. In contrast, the performance of red light-emitting materials is poor, because the non-radiative transition rate of luminescent materials increases exponentially with the increase of emission wavelength. Especially for materials in the near-infrared region, they are more affected by the non-radiative transition rate, and there are very few examples with good performance. Therefore, it is urgent to develop solution-processable near-infrared materials.

[0004] Patent application content

[0005] In order to overcome one of the problems existing in the above-mentioned prior art, the primary purpose of this patent application is to provide a near-infrared material suitable for solution processing. The near-infrared material suitable for solution processing is a near-infrared material with thermally activated delayed fluorescence properties, and the maximum external quantum efficiency of the prepared device is 8.33%.

[0006] Another object of the present patent application is to provide a method for preparing the above-mentioned near-infrared material suitable for solution processing.

[0007] Another object of the present patent application is to provide the application of the above-mentioned near-infrared material suitable for solution processing in an organic light-emitting device.

[0008] The above-mentioned purpose of this patent application is achieved through the following technical solutions:

[0009] A near-infrared material suitable for solution processing, wherein the structural formula of the near-infrared material suitable for solution processing has the following molecular structure:

[0010]

[0011] This patent application also provides a method for preparing the above-mentioned near-infrared material suitable for solution processing, comprising the following steps:

[0012] S1. Preparation of intermediate D-0

[0013] Methyl o-bromobenzoate, p-chloroboric acid, tetrakistriphenylphosphine palladium, and potassium carbonate were placed in a two-necked flask, 1,4-dioxane and deionized water were injected under a nitrogen environment, and the mixture was reacted under an inert gas environment, and the reaction was refluxed. After the reaction, saturated brine and ethyl acetate were used for extraction in turn, and the upper organic phase was obtained, rotary evaporated, and finally purified by column chromatography to finally obtain the intermediate D-0, whose structure is shown below:

[0014]

[0015] S2. Preparation of intermediate D-1

[0016] 4-tert-butylphenylmagnesium bromide and D-0 were injected into a two-necked flask filled with an inert gas atmosphere in sequence, and the resulting mixture was refluxed and stirred at 50°C. After the reaction was completed, the mixture was cooled, and the cooled reaction mixture was quenched with a saturated ammonium chloride solution. The mixture was extracted with saturated brine and dichloromethane in sequence to obtain the lower organic phase, which was rotary evaporated. After the solvent was rotary dried, acetic acid and hydrochloric acid were added thereto, and the reaction refluxed for a period of time. After the reaction was completed, the mixture was cooled, and the cooled reaction mixture was quenched with water. The precipitate was filtered, washed with methanol and dried to finally obtain 9,9-bis(4-(tert-butyl)phenyl)-2-chloro-9H-fluorene D-1, the structure of which is shown below:

[0017]

[0018] S3. Preparation of Intermediate D-2

[0019] D-1, p-chloroaniline, palladium acetate, tri-tert-butylphosphine and potassium tert-butoxide were sequentially placed in a 50 ml two-necked flask, toluene was injected under a nitrogen environment, and the mixture was reacted under an inert gas environment at a temperature of 110°C. The reaction reflux time was 24 hours. After the reaction, the mixture was extracted with saturated brine and dichloromethane in turn, the lower organic phase was obtained, rotary evaporated, and finally purified by column chromatography to finally obtain D-2, the structure of which is shown below:

[0020]

[0021] S4. Preparation of intermediate D-3

[0022] D-2, bipyraclostrobin, dibenzylideneacetone dipalladium, potassium acetate, and 2-dicyclohexylphosphine-2',4',6'-triisopropylbiphenyl were placed in a 50 ml two-necked flask, 10 ml of 1,4-dioxane was injected under a nitrogen environment, and the mixture was reacted under a nitrogen environment, and then extracted with saturated brine and ethyl acetate to obtain the upper organic phase, which was rotary evaporated and finally purified by column chromatography to obtain the intermediate D-3, the structure of which is shown below:

[0023]

[0024] S5. Preparation of intermediate DCN-Br

[0025] 3-Bromo-9,10-phenanthrenequinone and 4,5-diaminophthalonitrile were placed in a single-necked flask, 20 ml of acetic acid was added thereto, and the mixture was heated at 120°C. After cooling to room temperature, the resulting mixture was poured into water and then filtered. The solid was washed with water and methanol to obtain a yellow solid intermediate DCN-Br, the structural formula of which is shown below:

[0026]

[0027] S6. Preparation of target product DCN-SPBu

[0028] D-3, DCN-Br, tetrakistriphenylphosphine palladium and potassium carbonate were put into a 50ml two-necked flask, 10ml of 1,4-dioxane and 2ml of deionized water were injected under nitrogen environment, and the mixture was reacted under nitrogen environment at 95°C. The reaction reflux time was 12h. After the reaction, the mixture was extracted with saturated brine and ethyl acetate in turn, the upper organic phase was obtained, rotary evaporated, and finally purified by column chromatography to finally obtain the target product DCN-SPBu, whose structural formula is shown as follows:

[0029]

[0030] Preferably, the reaction molar ratio of methyl o-bromobenzoate and p-chloroboric acid in step S1 is 1:1.2.

[0031] Preferably, the molar ratio of 4-tert-butylphenylmagnesium bromide to D-0 in step S2 is 4:1.

[0032] Preferably, in the step S3, the molar ratio of the intermediate D-1, p-chloroaniline, tri-tert-butylphosphine and potassium tert-butoxide is 1:0.45:0.09:4.5.

[0033] Preferably, in step S1, the temperature is heated to 100° C. for reaction, and the reaction time is 12 hours.

[0034] Preferably, in step S2, 15 ml of acetic acid and 2 ml of hydrochloric acid are added thereto, and the reaction is carried out at 125° C., and the reaction reflux time is 4 hours.

[0035] Preferably, the inert gas environment described in steps S1, S2 and S3 is achieved by first evacuating the reaction device and then filling it with high-purity nitrogen or argon.

[0036] Preferably, the step S4 is carried out under a nitrogen environment at a temperature of 100° C., and the reaction reflux time is 12 h.

[0037] This patent application also provides the application of the above-mentioned near-infrared material suitable for solution processing in an organic light-emitting device.

[0038] Compared with the prior art, the beneficial effects of this patent application are:

[0039] The near-infrared material suitable for solution processing of the present patent application is composed of a rigid electron acceptor fragment and an electron donor fragment with a bulky structure (N-(9,9-bis(4-(tert-butylbenzene)-9H-fluorene-2-yl)amino)phenyl)-9,9-bis(4-(tert-butylbenzene))-N-phenyl-9H-fluorene-2-amine), wherein the electron acceptor fragment is diphenyl[a,c]phenazine-11,12-dicarbonitrile. The material is a near-infrared material with thermally activated delayed fluorescence properties, and the maximum external quantum efficiency of the prepared device is 8.33%. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 The near-infrared material DCN-SPBu prepared for this patent application 1 HMNR diagram.

[0041] Figure 2 HRMS graph of the near-infrared material DCN-SPBu prepared for this patent application.

[0042] Figure 3 The normalized absorption spectrum and fluorescence emission spectrum of the ultraviolet absorption spectrum of the near-infrared material DCN-SPBu prepared in this patent application in toluene solution.

[0043] Figure 4 Temperature-dependent transient fluorescence spectrum of the near-infrared material DCN-SPBu prepared for this patent application from 100K to 300K under nitrogen conditions.

[0044] Figure 5 This is the fluorescence emission spectrum of the near-infrared material DCN-SPBu prepared in this patent application in n-hexane, toluene and dioxane solutions.

[0045] Figure 6The near-infrared material DCN-SPBu prepared for this patent application was heated at 10℃min in a nitrogen atmosphere. -1 TGA curve measured at a heating rate of .

[0046] Figure 7 Brightness-voltage-current density diagram of the near-infrared material DCN-SPBu prepared in this patent application with 15wt% doping in CBP film.

[0047] Figure 8 EQE-brightness diagram of the near-infrared material DCN-SPBu prepared in this patent application doped with 15wt% in CBP film.

[0048] Fig. 9 EL spectrum of the near-infrared material DCN-SPBu prepared for this patent application. DETAILED DESCRIPTION

[0049] The embodiments of the present patent application will be described in detail below in conjunction with the examples, but those skilled in the art will appreciate that the following examples are only used to illustrate the present patent application and should not be considered to limit the scope of the present patent application. If the specific conditions are not specified in the examples, they are carried out according to the normal conditions or the conditions recommended by the manufacturer. If the manufacturer is not specified for the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0050] It should be noted that:

[0051] In this patent application, unless otherwise specified, all the embodiments and preferred implementation methods mentioned herein can be combined with each other to form a new technical solution.

[0052] In the present patent application, unless otherwise specified, percentage (%) or part refers to the weight percentage or weight part relative to the composition.

[0053] In this patent application, unless otherwise specified, the components or preferred components involved can be combined with each other to form a new technical solution.

[0054] In this patent application, unless otherwise specified, the numerical range "a-b" represents an abbreviation of any real number combination between a and b, where a and b are real numbers. For example, the numerical range "1-5" means that all real numbers between "1-5" are listed in this document, and "1-5" is just an abbreviation of these numerical combinations.

[0055] The “range” disclosed in this patent application is in the form of a lower limit and an upper limit, which can be one or more lower limits, and one or more upper limits, respectively.

[0056] In this patent application, unless otherwise specified, each reaction or operation step can be carried out in sequence or in accordance with the sequence. Preferably, the reaction method herein is carried out in sequence.

[0057] Unless otherwise specified, the professional and scientific terms used herein are the same as those familiar to those skilled in the art. In addition, any method or material similar or equivalent to the described content may also be applied to this patent application.

[0058] This patent application provides a near-infrared material suitable for solution processing, and the structural formula of the near-infrared material suitable for solution processing has the following molecular structure:

[0059]

[0060] The present patent application provides a near-infrared material suitable for solution processing, which is composed of a rigid electron acceptor fragment and an electron donor fragment with a bulky structure (N-(9,9-bis(4-(tert-butylbenzene)-9H-fluorene-2-yl)amino)phenyl)-9,9-bis(4-(tert-butylbenzene))-N-phenyl-9H-fluorene-2-amine), wherein the electron acceptor fragment is diphenyl[a,c]phenazine-11,12-dicarbonitrile. The material is a near-infrared material with thermally activated delayed fluorescence properties, and the maximum external quantum efficiency of the prepared device is 8.33%.

[0061] This patent application also provides a method for preparing the above-mentioned near-infrared material suitable for solution processing. The method comprises the following steps:

[0062] S1. Preparation of intermediate D-0

[0063] Methyl o-bromobenzoate, p-chloroboric acid, tetrakistriphenylphosphine palladium, and potassium carbonate were placed in a two-necked flask, 1,4-dioxane and deionized water were injected under a nitrogen environment, and the mixture was reacted under an inert gas environment, and the reaction was refluxed. After the reaction, saturated brine and ethyl acetate were used for extraction in turn, and the upper organic phase was obtained, rotary evaporated, and finally purified by column chromatography to finally obtain the intermediate D-0, whose structure is shown below:

[0064]

[0065] S2. Preparation of intermediate D-1

[0066] 4-tert-butylphenylmagnesium bromide and D-0 were injected into a two-necked flask filled with an inert gas atmosphere in sequence, and the resulting mixture was refluxed and stirred at 50°C. After the reaction was completed, the mixture was cooled, and the cooled reaction mixture was quenched with a saturated ammonium chloride solution. The mixture was extracted with saturated brine and dichloromethane in sequence to obtain the lower organic phase, which was rotary evaporated. After the solvent was rotary dried, acetic acid and hydrochloric acid were added thereto, and the reaction refluxed for a period of time. After the reaction was completed, the mixture was cooled, and the cooled reaction mixture was quenched with water. The precipitate was filtered, washed with methanol and dried to finally obtain 9,9-bis(4-(tert-butyl)phenyl)-2-chloro-9H-fluorene D-1, the structure of which is shown below:

[0067]

[0068] S3. Preparation of Intermediate D-2

[0069] D-1, p-chloroaniline, palladium acetate, tri-tert-butylphosphine and potassium tert-butoxide were sequentially placed in a 50 ml two-necked flask, toluene was injected under a nitrogen environment, and the mixture was reacted under an inert gas environment at a temperature of 110°C. The reaction reflux time was 24 hours. After the reaction, the mixture was extracted with saturated brine and dichloromethane in turn, the lower organic phase was obtained, rotary evaporated, and finally purified by column chromatography to finally obtain D-2, the structure of which is shown below:

[0070]

[0071] S4. Preparation of intermediate D-3

[0072] D-2, bipyraclostrobin, dibenzylideneacetone dipalladium, potassium acetate, and 2-dicyclohexylphosphine-2',4',6'-triisopropylbiphenyl were placed in a 50 ml two-necked flask, 10 ml of 1,4-dioxane was injected under a nitrogen environment, and the mixture was reacted under a nitrogen environment, and then extracted with saturated brine and ethyl acetate to obtain the upper organic phase, which was rotary evaporated and finally purified by column chromatography to obtain the intermediate D-3, the structure of which is shown below:

[0073]

[0074] S5. Preparation of intermediate DCN-Br

[0075] 3-Bromo-9,10-phenanthrenequinone and 4,5-diaminophthalonitrile were placed in a single-necked flask, 20 ml of acetic acid was added thereto, and the mixture was heated at 120°C. After cooling to room temperature, the resulting mixture was poured into water and then filtered. The solid was washed with water and methanol to obtain a yellow solid intermediate DCN-Br, the structural formula of which is shown below:

[0076]

[0077] S6. Preparation of target product DCN-SPBu

[0078] D-3, DCN-Br, tetrakistriphenylphosphine palladium and potassium carbonate were put into a 50ml two-necked flask, 10ml of 1,4-dioxane and 2ml of deionized water were injected under nitrogen environment, and the mixture was reacted under nitrogen environment at 95°C. The reaction reflux time was 12h. After the reaction, the mixture was extracted with saturated brine and ethyl acetate in turn, the upper organic phase was obtained, rotary evaporated, and finally purified by column chromatography to finally obtain the target product DCN-SPBu, whose structural formula is shown as follows:

[0079]

[0080] In the preparation method described in the present patent application, the reaction molar ratio of methyl o-bromobenzoate and p-chloroboric acid in step S1 is 1:1.2.

[0081] In the preparation method described in the present patent application, the molar ratio of 4-tert-butylphenylmagnesium bromide and D-0 in step S2 is 4:1.

[0082] In the preparation method described in the present patent application, the molar ratio of the intermediate D-1, p-chloroaniline, tri-tert-butylphosphine and potassium tert-butoxide in step S3 is 1:0.45:0.09:4.5.

[0083] In the preparation method described in the present patent application, in step S1, the temperature is heated to 100° C. for reaction, and the reaction time is 12 hours.

[0084] In the preparation method described in the present patent application, in step S2, 15 ml of acetic acid and 2 ml of hydrochloric acid are added thereto, and the reaction is carried out at 125° C., and the reaction reflux time is 4 hours.

[0085] In the preparation method described in this patent application, the inert gas environment described in steps S1, S2 and S3 is achieved by first evacuating the reaction device and then filling it with high-purity nitrogen or argon.

[0086] In the preparation method described in the present application, the step S4 is carried out under a nitrogen environment at a temperature of 100° C., and the reaction reflux time is 12 hours.

[0087] This patent application also provides the application of the above-mentioned near-infrared material suitable for solution processing in an organic light-emitting device.

[0088] The preparation method of the near-infrared material DCN-SPBu suitable for solution processing will be described in detail below.

[0089] Example 1

[0090] S1. Preparation of intermediate D-0

[0091] Place methyl o-bromobenzoate (1065 mg, 5 mmol), p-chloroboric acid (936 mg, 6 mmol), tetrakistriphenylphosphine palladium (289 mg, 0.25 mmol), and potassium carbonate (2070 mg, 15 mmol) in a 100 ml two-necked flask, inject 25 ml of 1,4-dioxane and 5 ml of deionized water under a nitrogen environment, and react under a nitrogen environment at a temperature of 100 ° C. The reaction reflux time is 12 h. After the reaction, extract with saturated brine and ethyl acetate in turn, obtain the upper organic phase, and evaporate it. Use a developing solvent of dichloromethane: petroleum ether = 1:5 for column chromatography purification, and finally obtain 1058 mg D-0 (colorless liquid) (yield: 86%), and the structure of D-0 is shown below:

[0092]

[0093] The chemical reaction equation in this preparation method is as follows:

[0094]

[0095] Example 2

[0096] S2. Preparation of intermediate D-1

[0097] 4-tert-Butylphenylmagnesium bromide (34ml, 17mmol) and D-0 (1032mg, 4.2mmol) were injected into a 100ml two-necked flask filled with nitrogen atmosphere in the following order, and the obtained mixture was refluxed and stirred at 50°C for 5h. After the reaction was completed, it was cooled, and the cooled reaction mixture was quenched with a saturated ammonium chloride solution, extracted with saturated brine and dichloromethane in turn, and the lower organic phase was obtained. After rotary evaporation, the solvent was dried, and then 15ml of acetic acid and 2ml of hydrochloric acid were added thereto, and the reaction was carried out at 125°C. The reaction reflux time was 4h, and after the reaction was completed, it was cooled, and the cooled reaction mixture was quenched with water. The precipitate was filtered, washed with methanol and dried, and finally 1152mg D-1 (white solid) (yield: 59%) was obtained. The structure of intermediate D-1 is shown below:

[0098]

[0099] The chemical reaction equation in this preparation method is as follows:

[0100]

[0101] Example 3

[0102] S3. Preparation of Intermediate D-2

[0103] D-1 (464 mg, 1 mmol), p-chloroaniline (57 mg, 0.45 mmol), palladium acetate (810 mg, 0.045 mmol), tri-tert-butylphosphine (266 mg, 0.09 mmol), potassium tert-butoxide (504 mg, 4.5 mmol) were placed in a 50 ml two-necked flask, 15 ml of toluene was injected under a nitrogen environment, and the mixture was reacted under a nitrogen environment at a temperature of 110 ° C. The reaction reflux time was 24 h. After the reaction, saturated brine and dichloromethane were used for extraction in turn to obtain the lower organic phase, which was rotary evaporated. Column chromatography was performed with a developing solvent of dichloromethane: petroleum ether = 1:11 to purify, and finally 150 mg D-2 (white solid) (yield: 34%) was obtained (yield: 34.5%), wherein the structural formula of D-2 is as follows:

[0104]

[0105] The chemical reaction equation in this preparation method is as follows:

[0106]

[0107] Example 4

[0108] S4. Preparation of intermediate D-3

[0109] D-2 (150 mg, 0.153 mmol), biboric acid pinacol ester (79 mg, 0.31 mmol), dibenzylideneacetone dipalladium (7 mg, 0.00765 mmol), potassium acetate (45 mg, 0.46 mmol), 2-dicyclohexylphosphine-2',4',6'-triisopropylbiphenyl (7 mg, 0.0153 mmol) were put into a 50 ml two-necked flask, 1,4-dioxane 10 ml was injected under nitrogen environment, and the mixture was reacted under nitrogen environment at 100 ° C. The reaction reflux time was 12 h; after the reaction, saturated brine and ethyl acetate were used for extraction to obtain the upper organic phase, which was rotary evaporated and passed through a column with a developing solvent of dichloromethane: petroleum ether = 1:9 (volume ratio), and finally 99 mg D-3 (white solid) (yield: 60%) was obtained, wherein the structural formula of D-3 is as follows:

[0110]

[0111] The chemical reaction equation in this preparation method is as follows:

[0112]

[0113] Example 5

[0114] S5. Preparation of intermediate DCN-Br

[0115] 3-Bromo-9,10-phenanthrenequinone (858 mg, 3 mmol) and 4,5-diaminophthalonitrile (521.4 mg, 3.3 mmol) were placed in a 50 ml single-necked flask, 20 ml of acetic acid was added thereto, and heated at 120 °C. After cooling to room temperature, the resulting mixture was poured into water and then filtered. The solid was washed several times with water and methanol. 1040 mg of yellow solid was obtained with a yield of 85%. No further purification was required, and the next step of the reaction was carried out directly. Due to the extremely poor solubility of DCN-Br, its carbon spectrum and hydrogen spectrum could not be obtained, and the structural formula of DCN-Br is as follows:

[0116]

[0117] The chemical reaction equation in this preparation method is as follows:

[0118]

[0119] Example 6

[0120] S6. Target product DCN-SPBu

[0121] D-3 (201 mg, 0.187 mmol), DCN-Br (61 mg, 0.15 mmol), tetrakistriphenylphosphine palladium (12 mg, 0.01 mmol), potassium carbonate (77 mg, 0.56 mmol) were placed in a 50 ml two-necked flask, 1,4-dioxane 10 ml and deionized water 2 ml were injected under nitrogen environment, and the mixture was reacted under nitrogen environment and temperature of 95 ° C, and the reaction reflux time was 12 h. After the reaction, saturated brine and ethyl acetate were used for extraction in turn, and the upper organic phase was obtained and rotary evaporated. Column chromatography was used for purification with a developing solvent of dichloromethane: petroleum ether = 1:3, and finally 134 mg DCN-SPBu (purple solid) was obtained (yield: 55%), wherein the structural formula of DCN-SPBu is as follows:

[0122]

[0123] The chemical reaction equation in this preparation method is as follows:

[0124]

[0125] Characterization and performance testing

[0126] The compound prepared in Example 6 was characterized and tested for performance. The results are as follows: Figures 1 to 9 shown.

[0127] Figure 1The compound DCN-SPBu prepared in this patent application was tested for hydrogen spectrum using a Bruker 400MHz superconducting nuclear magnetic resonance instrument, with deuterated chloroform as the solvent. Figure 1 It can be seen that its characteristic wave number (ppm) is 1 H NMR (500MHz, CDCl3) δ9.29 (dd, J=13.0, 8.3Hz, 2H), 8.80–8.56 (m, 4H), 7.90 (d d,J=15.5,7.8Hz,2H),7.85–7.75(m,1H),7.67(d,J=7.4Hz,2H),7.59(d,J=8.2 Hz,2H),7.54(d,J=8.5Hz,1H),7.42–7.37(m,4H),7.36–7.32(m,2H),7.27–7. 20(m,12H),7.10(t,J=9.2Hz,10H),7.04(dd,J=8.1,2.2Hz,1H),1.28(s,36H). The integral value of the nuclear magnetic resonance hydrogen spectrum is basically consistent with the theoretical value of the target luminescent molecule, which can confirm that the near-infrared material DCN-SPBu suitable for solution processing is obtained. In addition, the peaks in the above hydrogen spectrum can correspond one-to-one with the hydrogen atoms of the DCN-SPBu molecule, and the number is reasonable, indicating that DCN-SPBu is synthesized, with a single structure and high purity.

[0128] Figure 2 This is the HRMS graph (i.e., high-resolution mass spectrum) of the compound DCN-SPBu prepared in Example 6. After calculation, the theoretical value of the near-infrared material DCN-SPBu suitable for solution processing is: 1277.63355, while the actual [M+H] + Value: 1278.64075, which further proves that the compound prepared in Example 6 is a near-infrared material compound DCN-SPBu suitable for solution processing.

[0129] Figure 3 The figure below shows the normalized absorption spectrum and fluorescence emission spectrum of the near-infrared material DCN-SPBu in toluene solution measured by Shimadzu UV-2700 UV-visible spectrophotometer. Figure 3 It can be seen that the intramolecular charge transfer absorption peak of the UV-visible absorption spectrum of DCN-SPBu, a near-infrared material suitable for solution processing, in toluene solution is mainly at 525nm, while the emission in toluene solution is around 670nm, which belongs to deep red light.

[0130] Figure 4 The figure shows the temperature-dependent transient fluorescence spectrum of the near-infrared material DCN-SPBu prepared in this patent application from 100K to 300K under nitrogen conditions. Figure 4It can be seen that as the ambient temperature rises, the delayed fluorescence component also increases, which shows that the molecule has thermally activated delayed fluorescence properties.

[0131] Figure 5 This is the fluorescence emission spectrum of the near-infrared material DCN-SPBu prepared in this patent application in n-hexane, toluene, and dioxane solutions. Figure 5 As shown, the fluorescence emission peaks of DCN-SPBu in n-hexane, toluene and dioxane solutions are 589 nm, 668 nm and 713 nm, respectively. As the polarity increases, a red shift occurs.

[0132] Figure 6 The near-infrared material DCN-SPBu prepared in this patent application is heated at 10℃min in a nitrogen atmosphere. -1 The TGA curve is obtained by measuring the heating rate. Figure 6 It can be seen that the molecule has good thermal stability and can be used for traditional device preparation.

[0133] Figure 7 This is a brightness-voltage-current density diagram of the near-infrared material DCN-SPBu prepared in this patent application doped with 15wt% in a CBP film.

[0134] Figure 8 EQE-brightness diagram of the near-infrared material DCN-SPBu doped with 15wt% CBP film prepared for this patent application. Figure 8 It can be seen that the maximum external quantum efficiency of the prepared device is 8.33%.

[0135] Fig. 9 EL spectrum of the near-infrared material DCN-SPBu prepared for this patent application. Fig. 9 It can be seen that the emission wavelength of the device is around 700nm, which is near-infrared red light emission.

[0136] The near-infrared material suitable for solution processing of the present patent application is composed of a rigid electron acceptor fragment and an electron donor fragment with a bulky structure (N-(9,9-bis(4-(tert-butylbenzene)-9H-fluorene-2-yl)amino)phenyl)-9,9-bis(4-(tert-butylbenzene))-N-phenyl-9H-fluorene-2-amine), wherein the electron acceptor fragment is diphenyl[a,c]phenazine-11,12-dicarbonitrile. The material is a near-infrared material with thermally activated delayed fluorescence properties, and the maximum external quantum efficiency of the prepared device is 8.33%.

[0137] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiments or examples are included in at least one embodiment or example of this patent application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0138] Although several embodiments of the present patent application have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present patent application, and the scope of the present patent application is defined by the claims and their equivalents.

Claims

1. A near-infrared material suitable for solution processing, characterized in that: The structural formula of the near-infrared material suitable for solution processing has the following molecular structure:

2. The method for preparing the near-infrared material suitable for solution processing according to claim 1, characterized in that: The following steps are involved: S1. Preparation of intermediate D-0 Methyl o-bromobenzoate, p-chloroboric acid, tetrakistriphenylphosphine palladium, and potassium carbonate were placed in a two-necked flask, 1,4-dioxane and deionized water were injected under a nitrogen environment, and the mixture was reacted under an inert gas environment, and the reaction was refluxed. After the reaction, saturated brine and ethyl acetate were used for extraction in turn, and the upper organic phase was obtained, rotary evaporated, and finally purified by column chromatography to finally obtain the intermediate D-0, whose structure is shown below: S2. Preparation of intermediate D-1 4-tert-butylphenylmagnesium bromide and D-0 were injected into a two-necked flask filled with an inert gas atmosphere in sequence, and the resulting mixture was refluxed and stirred at 50°C. After the reaction was completed, the mixture was cooled, and the cooled reaction mixture was quenched with a saturated ammonium chloride solution. The mixture was extracted with saturated brine and dichloromethane in sequence to obtain the lower organic phase, which was rotary evaporated. After the solvent was rotary dried, acetic acid and hydrochloric acid were added thereto, and the reaction refluxed for a period of time. After the reaction was completed, the mixture was cooled, and the cooled reaction mixture was quenched with water. The precipitate was filtered, washed with methanol and dried to finally obtain 9,9-bis(4-(tert-butyl)phenyl)-2-chloro-9H-fluorene D-1, the structure of which is shown below: S3. Preparation of Intermediate D-2 D-1, p-chloroaniline, palladium acetate, tri-tert-butylphosphine and potassium tert-butoxide were sequentially placed in a 50 ml two-necked flask, toluene was injected under a nitrogen environment, and the mixture was reacted under an inert gas environment at a temperature of 110°C. The reaction reflux time was 24 hours. After the reaction, the mixture was extracted with saturated brine and dichloromethane in turn, the lower organic phase was obtained, rotary evaporated, and finally purified by column chromatography to finally obtain D-2, the structure of which is shown below: S4. Preparation of Intermediate D-3 D-2, bipyraclostrobin, dibenzylideneacetone dipalladium, potassium acetate, and 2-dicyclohexylphosphine-2',4',6'-triisopropylbiphenyl were placed in a 50 ml two-necked flask, 10 ml of 1,4-dioxane was injected under a nitrogen environment, and the mixture was reacted under a nitrogen environment, and then extracted with saturated brine and ethyl acetate to obtain the upper organic phase, which was rotary evaporated and finally purified by column chromatography to obtain the intermediate D-3, the structure of which is shown below: S5. Preparation of intermediate DCN-Br 3-Bromo-9,10-phenanthrenequinone and 4,5-diaminophthalonitrile were placed in a single-necked flask, 20 ml of acetic acid was added thereto, and the mixture was heated at 120°C. After cooling to room temperature, the resulting mixture was poured into water and then filtered. The solid was washed with water and methanol to obtain a yellow solid intermediate DCN-Br, the structural formula of which is shown below: S6. Preparation of target product DCN-SPBu D-3, DCN-Br, tetrakistriphenylphosphine palladium and potassium carbonate were put into a 50ml two-necked flask, 10ml of 1,4-dioxane and 2ml of deionized water were injected under nitrogen environment, and the mixture was reacted under nitrogen environment at 95°C. The reaction reflux time was 12h. After the reaction, the mixture was extracted with saturated brine and ethyl acetate in turn, the upper organic phase was obtained, rotary evaporated, and finally purified by column chromatography to finally obtain the target product DCN-SPBu, whose structural formula is shown as follows:

3. The method for preparing a near-infrared material suitable for solution processing according to claim 2, characterized in that: The reaction molar ratio of methyl o-bromobenzoate and p-chloroboric acid in step S1 is 1:1.

2.

4. The method for preparing a near-infrared material suitable for solution processing according to claim 2, characterized in that: The molar ratio of 4-tert-butylphenylmagnesium bromide to D-0 in step S2 is 4:

1.

5. The method for preparing a near-infrared material suitable for solution processing according to claim 2, characterized in that: In the step S3, the molar ratio of the intermediate D-1, p-chloroaniline, tri-tert-butylphosphine and potassium tert-butoxide is 1:0.45:0.09:4.

5.

6. The method for preparing a near-infrared material suitable for solution processing according to claim 2, characterized in that: In the step S1, the temperature is heated to 100° C. for reaction, and the reaction time is 12 hours.

7. The method for preparing a near-infrared material suitable for solution processing according to claim 2, characterized in that: In the step S2, 15 ml of acetic acid and 2 ml of hydrochloric acid were added thereto, and the reaction was carried out at 125° C. and the reaction reflux time was 4 hours.

8. The method for preparing a near-infrared material suitable for solution processing according to claim 2, characterized in that: The inert gas environment described in steps S1, S2 and S3 is achieved by first evacuating the reaction device and then filling it with high-purity nitrogen or argon.

9. The method for preparing a near-infrared material suitable for solution processing according to claim 2, characterized in that: The step S4 is carried out under a nitrogen environment at a temperature of 100° C., and the reaction reflux time is 12 hours.

10. Use of the near-infrared material suitable for solution processing according to claim 1 in an organic light-emitting device.

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