Isotope deuterium substituted A-pi-D-pi-A type small molecule compound, composition and preparation method

Abstract

The invention provides an isotope deuterium substituted A-pi-D-pi-A type small molecule compound, a composition and a preparation method. The structural formula of the small molecule compound is as follows: the composition comprises at least one isotope deuterium substituted A-pi-D-pi-A type small molecule compound; in the composition, the substitution number of deuterium atoms accounts for 1%-100% of the total number of hydrogen atoms. And the substitution number of deuterium atoms at the Y2 site accounts for 10%-20% of the total number of hydrogen atoms at the site. Deuterium atoms are introduced into main chain frameworks or side chain key sites of A-pi-D-pi-A type organic near-infrared light-emitting molecules, the novel deuterated organic near-infrared light-emitting material with improved performance is obtained, and by means of the heavy atom effect of the deuterated atoms, the irradiation exitance of a near-infrared light-emitting device with the material as a light-emitting layer is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of optoelectronic functional materials and relates to an A-π-D-π-A type small molecule compound, and specifically relates to an isotope deuterium-substituted A-π-D-π-A type small molecule compound, a composition and a preparation method. Background Art

[0002] Near-infrared (NIR) light generally refers to electromagnetic waves with wavelengths between 700 and 2500 nm, lying between visible light and mid-infrared light. Due to their low photon energy, strong tissue penetration, and weak autofluorescence in biological tissues, NIR luminescent materials have shown significant application potential in night vision security, optical communications, organic optoelectronic devices, bioimaging, and photodynamic therapy. Traditional inorganic NIR luminescent materials suffer from high preparation costs, complex processes, and low biocompatibility, limiting their expanded application. Organic NIR luminescent materials, however, have become a research hotspot in recent years due to their structural tunability, low cost, good compatibility, and ease of solution processing. Early organic NIR luminescent materials were primarily based on fused-ring aromatic hydrocarbons (such as perylene imide) or metal complexes (such as platinum and ruthenium complexes), but their luminescence efficiency was generally low and their synthesis steps were complex. After 2000, the rise of donor-acceptor (DA) molecular design strategies enabled the realization of more efficient NIR emission by modulating the intramolecular charge transfer (ICT) effect. For example, polymers or small molecule materials based on conjugated fused rings with charge-rich units such as indacene and benzodithiophene, and highly charge-deficient units such as benzothiadiazole and boron nitrogen fused rings, can extend the emission wavelength to above 900nm. However, organic light-emitting materials are usually limited by the energy gap law, that is, as the band gap of the material narrows and non-radiative recombination is enhanced, the fluorescence quantum yield (PLQY) decreases sharply with the red shift of wavelength, especially in the near-infrared region above 1000nm, the irradiation emission is often less than 0.1mW / cm 2 (Adv. Mater. 2009, 21, 111), and are largely of no practical value. Furthermore, compared to inorganic near-infrared luminescent materials, organic near-infrared luminescent materials are susceptible to photooxidation or aggregation quenching under light or high temperatures, necessitating further improvement in the stability of organic materials. However, existing technologies struggle to achieve both long wavelengths, high irradiance, and good stability.

[0003] Heavy atom substitution, particularly replacing a light-weight element with its heavier isotope or a heavier element from the same group, has become an effective means of improving the quantum efficiency of organic light-emitting materials (J. Phys. Chem. C, 2007, 111, 3491; Small Sci., 2021, 1, 2000057). These studies have introduced deuterium atoms into organic complexes or DA-type light-emitting materials to achieve improvements in the fluorescence quantum efficiency of visible light-emitting devices, extend fluorescence lifetime, and improve luminescence stability at higher temperatures. In addition, there are reports of introducing deuterium atoms into A-DA'DA type organic photovoltaic electron acceptor materials. With the help of the heavy atom effect of deuterium atoms, the vibration frequency of the molecular skeleton is effectively reduced, the exciton vibration coupling is suppressed, and non-radiative recombination is reduced, ultimately achieving a simultaneous improvement in the photovoltaic performance and stability of the device (Angew. Chem. Int. Ed., 2024, 63, 8, e202316227). Since organic photovoltaics are the reverse process of organic electroluminescence, this also illustrates from another perspective the effectiveness of deuterium substitution in improving the performance of photoelectric conversion materials and devices. A-π-D-π-A type fused ring small molecules are a class of high-efficiency near-infrared luminescent materials developed in recent years, achieving 3.89mW / cm at 1050nm. 2 The irradiance of the luminescent material is 100 nm (CN115513393A, Nature Photonics, 2022, 16, 752). Its molecular skeleton has an adjustable electron push-pull effect and a large rigid conjugated plane, making it one of the most promising organic near-infrared luminescent materials.

[0004] However, existing technologies have not yet seen the introduction of deuterium atoms into A-π-D-π-A type organic small molecules to improve their near-infrared luminescence radiation output and stability, which limits the further optimization and promotion of the performance of this type of material. Summary of the Invention

[0005] In view of the shortcomings of the existing technology, the purpose of the present invention is to provide an isotope deuterium substituted A-π-D-π-A type small molecule compound, composition and preparation method to solve the technical problem in the existing technology that the near-infrared luminescence radiation emittance and stability of A-π-D-π-A type small molecule compounds need to be further improved.

[0006] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0007] A deuterium-substituted A-π-D-π-A type small molecule compound, the structural formula of the small molecule compound is:

[0008]

[0009] Where:

[0010] R1 is independently C1-C20 alkyl, C1-C20 deuterated alkyl, C1-C20 alkyl-substituted phenyl, C1-C20 alkoxy-substituted phenyl, deuterated C1-C20 alkyl-substituted phenyl, deuterated C1-C20 alkoxy-substituted phenyl, C1-C20 alkyl-substituted thienyl, C1-C20 alkoxy-substituted thienyl, deuterated C1-C20 alkyl-substituted thienyl or deuterated C1-C20 alkoxy-substituted thienyl.

[0011] R2 is independently a hydrogen atom, a deuterium atom, a C1-C20 alkyl group, a C1-C20 deuterated alkyl group, a C1-C20 alkoxy group, a C1-C20 deuterated alkoxy group, a C1-C20 alkyl ester group, or a C1-C20 deuterated alkyl ester group.

[0012] X is independently an oxygen atom, a sulfur atom, a selenium atom or a tellurium atom.

[0013] Y1 is independently a hydrogen atom or a deuterium atom.

[0014] Y2 is independently a hydrogen atom or a deuterium atom.

[0015] A1 and A2 are both pull-electronic units.

[0016] The present invention also has the following technical features:

[0017] Preferably, R1 is a C1-C20 alkyl-substituted phenyl group, R2 is a C1-C20 alkoxy group, X is a selenium atom, Y1 is a hydrogen atom, Y2 is a deuterium atom, or one site of Y2 is a deuterium atom and the other site is a hydrogen atom.

[0018] Preferably, R1 is a deuterated phenyl group substituted with a C1-C20 alkyl group, R2 is a C1-C20 alkoxy group, X is a selenium atom, Y1 is a hydrogen atom, and Y2 is a hydrogen atom.

[0019] Preferably, R1 is a deuterated phenyl substituted with a C1-C20 alkyl group, R2 is a C1-C20 alkoxy group, X is a selenium atom, Y1 is a hydrogen atom, Y2 is a deuterium atom, or one site of Y2 is a deuterium atom and the other site is a hydrogen atom.

[0020] Preferably, R1 is a C1-C20 deuterated alkyl group, R2 is a C1-C20 alkoxy group, X is a selenium atom, Y1 is a hydrogen atom, Y2 is a deuterium atom, or one site of Y2 is a deuterium atom and the other site is a hydrogen atom.

[0021] Specifically, A1 and A2 are independently selected from one of the following structural formulas of pull-down electronic units:

[0022]

[0023] Where:

[0024] R4 is a linear alkyl group having 1 to 12 carbon atoms, a branched alkyl group having 1 to 12 carbon atoms, a linear deuterated alkyl group having 1 to 12 carbon atoms, or a branched deuterated alkyl group having 1 to 12 carbon atoms.

[0025] The hydrogen elements contained in the aromatic rings in the structures A1 and A2 are independently hydrogen atoms or deuterium atoms.

[0026] Preferably, A1 and A2 are both dichlorodicyanindanone or difluorodicyanindanone.

[0027] The present invention also protects a method for preparing the above-mentioned isotope deuterium-substituted A-π-D-π-A type small molecule compound, which replaces the raw materials required for the preparation of the A-π-D-π-A type small molecule compound with raw materials substituted with isotope deuterium.

[0028] The present invention also protects an isotope deuterium-substituted A-π-D-π-A type composition, which comprises at least one isotope deuterium-substituted A-π-D-π-A type small molecule compound as described above.

[0029] In the composition, the ratio of the number of deuterium atoms substituted to the total number of hydrogen atoms is 1% to 100%.

[0030] Preferably, the ratio of the number of deuterium atoms substituted at the Y2 site to the total number of hydrogen atoms at the site is 10% to 20%.

[0031] Compared with the prior art, the present invention has the following technical effects:

[0032] (I) The present invention introduces deuterium atoms into the backbone or key sites of the side chains of A-π-D-π-A type organic near-infrared luminescent molecules to obtain novel deuterated organic near-infrared luminescent materials with enhanced performance. By leveraging the heavy atom effect of deuterium atoms, the radiant output of near-infrared luminescent devices using these materials as the luminescent layer is improved.

[0033] (II) The preferred isotope deuterium-substituted A-π-D-π-A type small molecule compound of the present invention has an irradiation output of 9.92 mW / cm in the near-infrared band above 1000 nm. 2 , significantly higher than its non-deuterated counterpart.

[0034] (III) The preferred isotope deuterium-substituted A-π-D-π-A type small molecule compound of the present invention, wherein the deuterium substitution causes the 5% thermal weight loss temperature (T d ) is 7°C higher than its undeuterated analogue, increasing the stability of the material. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1Thermogravimetric analysis curves of Example Compound A1 and Comparative Compound B1 of the present invention are shown.

[0036] Figure 2 1 and 2 are photoluminescence spectra of Example Compound A1, Comparative Compound B1 and Composition 1 of the present invention.

[0037] Figure 3 This is a schematic diagram of a near-infrared light-emitting device prepared using Example Compound A1 of the present invention as the light-emitting layer and its structure.

[0038] Figure 4 1 and 2 are the electroluminescence spectra of Example Compound A1, Comparative Compound B1 and Composition 1 of the present invention.

[0039] Figure 5 1 and 2 are the current density-radiance-voltage (JRV) characteristic curves of Example Compound A1, Comparative Compound B1 and Composition 1 of the present invention.

[0040] The specific contents of the present invention are further explained in detail below with reference to the embodiments. DETAILED DESCRIPTION

[0041] It should be noted that, unless otherwise specified, all materials and instruments in the present invention are those known in the art.

[0042] The present invention carries out deuterium atom substitution at the main chain skeleton and key sites of the side chain of the A-π-D-π-A type small molecule compound, and the deuterium-substituted molecular structure has not been reported.

[0043] The present invention uses the heavy atom effect of deuterium atoms to reduce molecular vibration frequency, inhibit exciton vibration coupling, reduce non-radiative recombination, and achieve enhanced near-infrared luminescence irradiance and improved stability to meet the needs of organic near-infrared luminescence technology for high-efficiency materials.

[0044] The present invention uses this type of deuterium-substituted A-π-D-π-A type small molecules to prepare organic near-infrared light-emitting devices, and utilizes the heavy atom effect, the push-pull electronic properties of the charge-rich units and the charge-deficient units, etc. to adjust the band gap and spectral range of the material, thereby improving the luminescence performance of the device.

[0045] In the structural formula of the present invention, D represents a deuterium atom.

[0046] Specific embodiments of the present invention are given below. It should be noted that the present invention is not limited to the following specific embodiments, and all equivalent modifications made on the basis of the technical solution of this application fall within the protection scope of the present invention.

[0047] Example 1:

[0048] This example provides a method for preparing a deuterium-substituted A-π-D-π-A type small molecule compound, which is compound A1 of this example. The structural formula of compound A1 is:

[0049]

[0050] The synthetic route of compound A1 is:

[0051]

[0052] The method comprises the following steps:

[0053] Step 1, synthesis of compound 2:

[0054] Under nitrogen protection, deuterated p-hexylbromobenzene (2.1 g, 8.7 mmol) and dry tetrahydrofuran (15 mL) were added to a 100 mL three-necked flask, cooled to -30 ° C, and n-butyllithium (2.0 M, 8.7 mmol) was slowly added dropwise. The reaction was kept warm for 1 h. A tetrahydrofuran solution of compound 1 (0.76 g, 1.57 mmol) was slowly added. After continuing the reaction for 2 h, water was added to terminate the reaction. The mixture was extracted with ethyl acetate, dried, filtered, and concentrated to obtain a yellow solid. Glacial acetic acid (15 mL) and n-hexane (15 mL) were added, and concentrated sulfuric acid (1.5 mL) was slowly added dropwise after stirring. The reaction was continued at 40 ° C for 12 h. The crude product was washed with water, extracted, and rotary evaporated to obtain a crude product. The mixture was purified by silica gel column chromatography using a 15:1 mixed solvent of n-hexane / dichloromethane as the eluent to obtain 1.34 g of a dark yellow powder solid, i.e., compound 2 (yield 83%).

[0055] Step 2, synthesis of compound 3:

[0056] Under nitrogen protection, compound 2 (1.00 g, 0.98 mmol) and dry tetrahydrofuran (15 mL) were added to a 50 mL three-necked flask, cooled to -30 ° C, and n-butyl lithium (2.0 M, 1.08 mmol) was slowly added dropwise. The reaction was kept warm for 1 h, and trimethyltin chloride (0.25 g, 1.28 mmol) was added all at once. The temperature was slowly raised to room temperature and reacted for 2 h. After washing, drying, and concentration, the mixture was recrystallized from ethanol / tetrahydrofuran system to obtain 0.99 g of yellow needle-like crystals, i.e., compound 3 (yield 75%).

[0057] Step 3, synthesis of compound 4:

[0058] Under nitrogen protection, compound 3 (0.95 g, 0.71 mmol), 2-bromo-3 (2-octyldodecyloxy) -5-deuterated formylthiophene (0.93 g, 1.91 mmol) and toluene (25 mL) were added to a 100 mL three-necked flask, heated to reflux, and then added with catalyst tetrakis(triphenylphosphine) palladium (0.05 g, 0.04 mmol) and continued to reflux for 20 h. The crude product was washed with water, dried, and concentrated to give a crude product, which was purified by silica gel column chromatography using n-hexane / ethyl acetate 30:1 as eluent to give 0.89 g of a red solid, i.e., compound 4 (yield 69%).

[0059] Step 4, synthesis of compound A1:

[0060] Compound 4 (0.31 g, 0.17 mmol), dichlorodicyanindanone (0.22 g, 0.83 mmol), and chloroform (30 mL) were added to a 100 mL round-bottom flask and stirred. 1 mL of pyridine was added dropwise and the mixture was refluxed for 4 h. The system was then precipitated with methanol and filtered to obtain a crude product. The crude product was purified by silica gel column chromatography using chloroform as the eluent to obtain 0.34 g of a black powdery solid, namely, A1 (yield 86%). The liquid chromatography purity was 99%.

[0061] The structural characterization results of Compound A1 in this example are:

[0062] 1 H NMR (500MHz, CDCl3), δ (ppm): 8.72 (s, 2H), 7.88 (s, 2H), 7.74 (s, 2H), 7.48 (s, 4H), 7.19 (d, 8H), 7.11 (d, 8H), 4.1 3(d,4H),2.61-2.55(m,9H),1.92(dt,2H),1.60(dd,17H),1.33-1.21(m,81H),0.87(d,14H),0.85-0.82(m,12H).

[0063] 13C NMR (125MHz, CDCl3), δ (ppm): 185.34, 158.74, 156.98, 153.79, 153.30, 150.82, 140.95, 139.94, 139.2 6,138.36,138.28,138.02,137.91,137.80,134.95,130.71,128.57,127.55,126.95,125.78,124.43, 123.80,119.54,117.35,113.72,113.57,74.03,67.32,63.02,37.21,34.60,30.90,30.86,30.71,30.36,30.33,28.92,28.69,28.63,28.57,28.33,28.27,28.16,25.79,25.77,21.66,21.63,21.58,13.10.

[0064] It can be seen from the above characterization results that the compound A1 of this example is an isotope deuterium-substituted A-π-D-π-A type small molecule compound A1.

[0065] The thermogravimetric analysis curve of Example Compound A1 of the present invention is as follows Figure 1 shown.

[0066] Photoluminescence test of compound A1:

[0067] A1 was dissolved in dry chloroform solvent (1.0 mg / mL), 3 mL was taken and added to a quartz cuvette, and background spectrum was subtracted using pure chloroform solution. A 635 nm semiconductor laser was used as the excitation light source, and the light beam was focused to the center of the sample through a collimating lens group. The emitted light signal was collected by a liquid nitrogen-cooled InGaAs array detector. The entire experiment was carried out in a darkroom environment to avoid interference from ambient stray light. Photoluminescence (PL) spectrum is as follows Figure 2 shown.

[0068] Electroluminescence test of compound A1:

[0069] The compound A1 of this embodiment is used as a light-emitting layer material in an organic near-infrared light-emitting device. Specifically, the method for preparing the organic near-infrared light-emitting device is as follows:

[0070] The device structure uses ITO / PEDOT:PSS / A1 / PNDIT-F3N / Ag (ITO is indium tin oxide, PEDOT:PSS is poly (3,4-ethylenedioxythiophene) / polystyrene sulfonate, PNDIT-F3N is poly ((9,9-bis(3′-(N,N-dimethylamino)propyl))-2,7-ffluorene-alt-5,5′-bis(2,2′-thiophene)-2,6-naphthalene-1,4,5,8-tetracarboxylic acid-N,N′-di(2-ethylhexyl)imide)), and Ag is silver). The device and structure diagram are shown in the figure below. Figure 3 shown.

[0071] The hole transport layer PEDOT:PSS was spin-coated on ITO glass, and the rotation speed was controlled to make the PEDOT:PSS thickness about 30nm. Then, it was annealed on a 150℃ hot plate for 15min. Compound A1 was dissolved in chloroform to a concentration of 20mg / mL and spin-coated at a rotation speed of 1800rpm to obtain a light-emitting layer with a thickness of about 80-100nm. Then, a methanol solvent was used to spin-coat an electron transport layer PNDIT-F3N with a thickness of about 10nm. Finally, the mask was covered and a silver electrode with a thickness of about 100nm was evaporated by vacuum evaporation to obtain a near-infrared light-emitting device with an effective area of ​​0.045cm. 2 . Measure device performance and obtain electroluminescence spectra (EL, such as Figure 4 as shown) and current density-radiance-voltage (JRV, as shown) Figure 5 (shown) characteristic curve.

[0072] Comparative Example 1:

[0073] This comparative example provides a method for preparing a small molecule compound of the A-π-D-π-A type composition, which is compound B1 of this comparative example. The structural formula of compound B1 is:

[0074]

[0075] Referring to the preparation method given in the literature (Nature Photonics, 2022, 16, 752), the synthetic route of compound B1 is:

[0076]

[0077] The method comprises the following steps:

[0078] Step 1, synthesis of compound 2:

[0079] Under nitrogen protection, compound 1 (0.80 g, 0.60 mmol), 2-bromo-3 (2-octyldodecyloxy) -5-formylthiophene (1.02 g, 2.10 mmol) and toluene (30 mL) were added to a 100 mL three-necked flask, heated to reflux, and then added with catalyst tetrakis(triphenylphosphine) palladium (0.04 g, 0.03 mmol) and continued to reflux for 7 h. The crude product was washed with water, dried, and concentrated to obtain a crude product, which was purified by silica gel column chromatography using n-hexane / ethyl acetate 60:1 as eluent to obtain 0.70 g of a red solid, i.e., compound 2 (yield 65%).

[0080] Step 2, synthesis of compound B1:

[0081] Compound 2 (0.20 g, 0.11 mmol), dichlorodicyanindanone (0.15 g, 0.55 mmol), and chloroform (15 mL) were added to a 100 mL round-bottom flask and stirred. 1 mL of pyridine was added dropwise and the mixture was refluxed for 3 h. The system was then precipitated with methanol and filtered to obtain a crude product. The crude product was purified by silica gel column chromatography using chloroform as the eluent to obtain 0.15 g of a black powdery solid, namely B1 (yield 59%). The liquid chromatography purity was 99%.

[0082] The structural characterization results of compound B1 of this comparative example are:

[0083] 1 H NMR (500MHz, CDCl3), δ (ppm): 8.70 (s, 2H), 7.87 (s, 1H), 7.75 (s, 1H), 7.47 (s, 1H), 7.19 (d, 4H), 7.11 ( d,4H),4.14(s,2H),2.58(t,4H),1.92(m,1H),1.64-1.48(br,8H),1.36-1.23(br,40H),0.85(m,12H).

[0084] 13C NMR (125MHz, CDCl3), δ (ppm): 186.32, 171.31, 154.43, 152.09, 142.11, 141.11, 139.47, 139.14, 139.0 3,138.92,138.53,136.04,135.51,128.71,128.12,126.87,126.18,124.92,118.51,114.86,114.70,7 7.41,77.36,77.16,76.91,75.41,75.22,38.39,35.77,32.06,32.03,31.87,31.53,31.49,30.09,30.08,29.85,29.80,29.73,29.56,29.49,29.44,29.32,26.96,26.94,22.83,22.80,22.74,14.26,14.24.

[0085] It can be seen from the above characterization results that the compound B1 of this comparative example is the target product A-π-D-π-A type composition small molecule compound B1.

[0086] The thermogravimetric analysis curves of Example Compound A1 and Comparative Compound B1 of the present invention are shown in FIG. Figure 1 As shown, from Figure 1 The comparison shows that compound A1 contains CD bonds, which increases the bond cleavage energy barrier. Therefore, the weight loss starting temperature of compound A1 is higher than that of undeuterated compound B1. Deuteration makes the 5% weight loss temperature (T d ) was 7°C higher than that of the undeuterated analog compound B1, which increased the stability of the material.

[0087] Example 2:

[0088] This example provides a method for preparing a deuterium-substituted A-π-D-π-A type small molecule compound, which is compound A2 of this example. The structural formula of compound A2 is:

[0089]

[0090] The synthetic route of compound A2 is:

[0091]

[0092]

[0093] The method comprises the following steps:

[0094] Step 1, synthesis of compound 2:

[0095] Under nitrogen protection, deuterated p-hexylbromobenzene (2.1 g, 8.7 mmol) and dry tetrahydrofuran (15 mL) were added to a 100 mL three-necked flask, cooled to -30 ° C, and n-butyllithium (2.0 M, 8.7 mmol) was slowly added dropwise. The reaction was kept warm for 1 h. A tetrahydrofuran solution of compound 1 (0.76 g, 1.57 mmol) was slowly added. After continuing the reaction for 2 h, water was added to terminate the reaction. The mixture was extracted with ethyl acetate, dried, filtered, and concentrated to obtain a yellow solid. Glacial acetic acid (15 mL) and n-hexane (15 mL) were added, and concentrated sulfuric acid (1.5 mL) was slowly added dropwise after stirring. The mixture was reacted at 40 ° C for 12 h, washed with water, extracted, and rotary evaporated to obtain a crude product. The crude product was purified by silica gel column chromatography using a 15:1 mixed solvent of n-hexane / dichloromethane as the eluent to obtain 1.36 g of a dark yellow powder solid, i.e., compound 2 (yield 84%).

[0096] Step 2, synthesis of compound 3:

[0097] Under nitrogen protection, compound 2 (1.00 g, 0.98 mmol) and dry tetrahydrofuran (15 mL) were added to a 50 mL three-necked flask, cooled to -30 ° C, and n-butyl lithium (2.0 M, 1.08 mmol) was slowly added dropwise. The reaction was kept warm for 1 h, and trimethyltin chloride (0.25 g, 1.28 mmol) was added all at once. The temperature was slowly raised to room temperature and reacted for 2 h. After washing, drying, and concentration, the mixture was recrystallized from ethanol / tetrahydrofuran system to obtain 0.98 g of yellow needle-like crystals, i.e., compound 3 (yield 74%).

[0098] Step 3, synthesis of compound 4:

[0099] Under nitrogen protection, compound 3 (0.95 g, 0.71 mmol), 2-bromo-3 (2-octyldodecyloxy) -5-deuterated formylthiophene (0.47 g, 0.96 mmol), 2-bromo-3 (2-octyldodecyloxy) -5-formylthiophene (0.47 g, 0.96 mmol), and toluene (25 mL) were added to a 100 mL three-necked flask, heated to reflux, and then added with catalyst tetrakis (triphenylphosphine) palladium (0.05 g, 0.04 mmol) and continued to reflux for 20 h. The crude product was washed with water, dried, and concentrated to give the crude product, which was purified by silica gel column chromatography with n-hexane / ethyl acetate 30:1 as eluent to give 0.58 g of a red solid, i.e., compound 4 (yield 45%).

[0100] Step 4, synthesis of compound A2:

[0101] Compound 4 (0.31 g, 0.17 mmol), dichlorodicyanindanone (0.22 g, 0.83 mmol), and chloroform (30 mL) were added to a 100 mL round-bottom flask and stirred. 1 mL of pyridine was added dropwise and the mixture was refluxed for 4 h. The system was then precipitated with methanol and filtered to obtain a crude product. The crude product was purified by silica gel column chromatography using chloroform as the eluent to obtain 0.32 g of a black powdery solid, A2 (yield 82%). The liquid chromatography purity was 99%.

[0102] The structural characterization results of compound A2 in this example are:

[0103] 1 H NMR (500MHz, CDCl3), δ (ppm): 8.73 (s, 3H), 7.88 (s, 2H), 7.75 (s, 2H), 7.47 (s, 4H), 7.12 (d, 8H), 7.10 (d, 8H) ,4.16(s,4H),2.57-2.59(m,8H),1.92(m,2H),1.58-1.62(m,10H),1.25-1.36(m,86H),0.82-0.88(m,24H).

[0104] 13 C NMR (125MHz, CDCl3), δ (ppm): 185.34, 158.74, 156.98, 153.79, 153.30, 142.01, 141.0 3,139.51,139.04,136.51,135.94,128.57,128.00,126.76,124.84,120.53,120.32,1 17.35,113.72,96.13,75.04,67.99,60.41,38.25,35.62,31.89,31.74,31.35,29.95,29.73,29.66,29.60,29.35,29.30,26.80,25.79,25.77,22.68,22.66,22.61,14.12.

[0105] It can be seen from the above characterization results that the compound A2 of this example is an isotope deuterium-substituted A-π-D-π-A type small molecule compound A2.

[0106] Example 3:

[0107] This example provides a method for preparing a deuterium-substituted A-π-D-π-A type small molecule compound, which is compound A3 of this example. The structural formula of compound A3 is:

[0108]

[0109] The synthetic route of compound A3 is:

[0110]

[0111]

[0112] The method comprises the following steps:

[0113] Step 1, synthesis of compound 2:

[0114] Under nitrogen protection, deuterated p-hexylbromobenzene (2.1 g, 8.7 mmol) and dry tetrahydrofuran (15 mL) were added to a 100 mL three-necked flask, cooled to -30 ° C, and n-butyllithium (2.0 M, 8.7 mmol) was slowly added dropwise. The reaction was kept warm for 1 h, and a tetrahydrofuran solution of compound 1 (0.76 g, 1.57 mmol) was slowly added. After the reaction was continued for 2 h, water was added to terminate the reaction. The mixture was extracted with ethyl acetate, dried, filtered, and concentrated to obtain a yellow solid. Glacial acetic acid (15 mL) and n-hexane (15 mL) were added, and concentrated sulfuric acid (1.5 mL) was slowly added dropwise after stirring. The reaction was continued at 40 ° C for 12 h, washed with water, extracted, and rotary evaporated to obtain a crude product. The crude product was purified by silica gel column chromatography using a 15:1 mixed solvent of n-hexane / dichloromethane as the eluent to obtain 1.31 g of a dark yellow powder solid, i.e., compound 2 (yield 82%).

[0115] Step 2, synthesis of compound 3:

[0116] Under nitrogen protection, compound 2 (1.00 g, 0.98 mmol) and dry tetrahydrofuran (15 mL) were added to a 50 mL three-necked flask, cooled to -30 ° C, and n-butyl lithium (2.0 M, 1.08 mmol) was slowly added dropwise. The reaction was kept warm for 1 h, and trimethyltin chloride (0.25 g, 1.28 mmol) was added all at once. The temperature was slowly raised to room temperature and reacted for 2 h. After washing, drying, and concentration, the mixture was recrystallized from ethanol / tetrahydrofuran system to obtain 1.04 g of yellow needle-like crystals, i.e., compound 3 (yield 79%).

[0117] Step 3, synthesis of compound 4:

[0118] Under nitrogen protection, compound 3 (1.00 g, 0.75 mmol), 2-bromo-3 (2-octyldodecyloxy) -5-formylthiophene (0.98 g, 2.01 mmol) and toluene (25 mL) were added to a 100 mL three-necked flask, heated to reflux, and then added with catalyst tetrakis(triphenylphosphine) palladium (0.05 g, 0.04 mmol) and continued to reflux for 20 h. The crude product was washed with water, dried, and concentrated to obtain a crude product, which was purified by silica gel column chromatography using n-hexane / ethyl acetate 30:1 as eluent to obtain 1.04 g of a red solid, i.e., compound 4 (yield 76%).

[0119] Step 4, synthesis of compound A3:

[0120] Compound 4 (0.31 g, 0.17 mmol), dichlorodicyanindanone (0.22 g, 0.83 mmol), and chloroform (30 mL) were added to a 100 mL round-bottom flask and stirred. 1 mL of pyridine was added dropwise and the mixture was refluxed for 6 h. The system was then precipitated with methanol and filtered to obtain a crude product. The crude product was purified by silica gel column chromatography using chloroform as the eluent to obtain 0.35 g of a black powdery solid, i.e., A3 (yield 89%). The liquid chromatography purity was 99%.

[0121] The structural characterization results of compound A3 in this example are:

[0122] 1 H NMR (500MHz, CDCl3), δ (ppm): 8.72 (s, 4H), 7.88 (s, 2H), 7.74 (s, 2H), 7.47 (s, 4H), 4.13 (d, 4H),2.57(t,8H),1.92(m,2H),1.58-1.62(m,16H),1.22-1.36(m,80H),0.83-0.88(m,24H).

[0123] 13 C NMR (125MHz, CDCl3), δ (ppm): 186.22,152.20,155.10,154.80,154.32,153.46,153 .36,141.92,141.02,139.29,138.92,136.73,134.36,131.72,129.01,127.99,125. 45,124.82,120.54,118.35,114.97,112.43,112.25,75.02,68.33,64.05,38.24,35.62,31.91,31.74,31.39,29.65,29.33,29.18,26.79,22.67,22.65,22.60,14.11.

[0124] It can be seen from the above characterization results that the compound A3 of this example is an isotope deuterium-substituted A-π-D-π-A type small molecule compound A3.

[0125] Example 4:

[0126] This example provides a method for preparing a deuterium-substituted A-π-D-π-A type small molecule compound, which is compound A4 of this example. The structural formula of compound A4 is:

[0127]

[0128] The synthetic route of compound A4 is:

[0129]

[0130] The method comprises the following steps:

[0131] Step 1, synthesis of compound 2:

[0132] Under nitrogen protection, deuterated p-hexylbromobenzene (2.1 g, 8.7 mmol) and dry tetrahydrofuran (15 mL) were added to a 100 mL three-necked flask, cooled to -30 ° C, and n-butyllithium (2.0 M, 8.7 mmol) was slowly added dropwise. The reaction was kept warm for 1 h. A tetrahydrofuran solution of compound 1 (0.76 g, 1.57 mmol) was slowly added. After continuing the reaction for 2 h, water was added to terminate the reaction. The mixture was extracted with ethyl acetate, dried, filtered, and concentrated to obtain a yellow solid. Glacial acetic acid (15 mL) and n-hexane (15 mL) were added, and concentrated sulfuric acid (1.5 mL) was slowly added dropwise after stirring. The mixture was reacted at 40 ° C for 12 h, washed with water, extracted, and rotary evaporated to obtain a crude product. The crude product was purified by silica gel column chromatography using a 15:1 mixed solvent of n-hexane / dichloromethane as the eluent to obtain 1.36 g of a dark yellow powder solid, i.e., compound 2 (yield 84%).

[0133] Step 2, synthesis of compound 3:

[0134] Under nitrogen protection, compound 2 (1.00 g, 0.98 mmol) and dry tetrahydrofuran (15 mL) were added to a 50 mL three-necked flask, cooled to -30 ° C, and n-butyl lithium (2.0 M, 1.08 mmol) was slowly added dropwise. The reaction was kept warm for 1 h, and trimethyltin chloride (0.25 g, 1.28 mmol) was added all at once. The temperature was slowly raised to room temperature and reacted for 2 h. After washing, drying, and concentration, the mixture was recrystallized from ethanol / tetrahydrofuran system to obtain 1.03 g of yellow needle-like crystals, i.e., compound 3 (yield 78%).

[0135] Step 3, synthesis of compound 4:

[0136] Under nitrogen protection, compound 3 (1.00 g, 0.75 mmol), 2-bromo-3 (2-octyldodecyloxy) -5-deuterated formylthiophene (0.98 g, 2.01 mmol) and toluene (25 mL) were added to a 100 mL three-necked flask, heated to reflux, and then added with catalyst tetrakis(triphenylphosphine) palladium (0.05 g, 0.04 mmol) and continued to reflux for 20 h. The crude product was washed with water, dried, and concentrated to give a crude product, which was purified by silica gel column chromatography using n-hexane / ethyl acetate 30:1 as eluent to give 0.98 g of a red solid, i.e., compound 4 (yield 72%).

[0137] Step 4, synthesis of compound A4:

[0138] Compound 4 (0.31 g, 0.17 mmol), dichlorodicyanindanone (0.22 g, 0.83 mmol), and chloroform (30 mL) were added to a 100 mL round-bottom flask and stirred. 1 mL of pyridine was added dropwise and the mixture was refluxed for 6 h. The system was then precipitated with methanol and filtered to obtain a crude product. The crude product was purified by silica gel column chromatography using chloroform as the eluent to obtain 0.33 g of a black powdery solid, A4 (yield 84%). The liquid chromatography purity was 99%.

[0139] The structural characterization results of compound A4 in this example are:

[0140] 1 H NMR (500MHz, CDCl3), δ (ppm): 8.66 (s, 2H), 7.82 (s, 2H), 7.67 (s, 2H), 7.40 (s, 4H) ,4.06(d,4H),2.51(t,8H),1.85(m,2H),1.41-1.10(m,96H),0.97-0.75(m,24H).

[0141] 13 C NMR (125MHz, CDCl3), δ (ppm): 186.23, 159.74, 157.98, 154.81, 154.32, 153.45, 151.82, 141.95,141.01,139.37,139.28,138.91,136.74,134.36,131.72,128.56,127.98,125. 44,124.81,120.54,118.35,114.97,114.82,112.41,112.26,75.01,68.33,64.03,38.24,35.62,31.92,31.74,31.39,29.66,29.35,29.18,26.79,22.68,22.65,22.60,14.10.

[0142] It can be seen from the above characterization results that compound A4 of this example is an isotope deuterium-substituted A-π-D-π-A type small molecule compound A4.

[0143] Example 5:

[0144] This example provides a method for preparing a deuterium-substituted A-π-D-π-A type small molecule compound, which is compound A5 of this example. The structural formula of compound A5 is:

[0145]

[0146] The synthetic route of compound A5 is:

[0147]

[0148] The method comprises the following steps:

[0149] Step 1, synthesis of compound 2:

[0150] Under nitrogen protection, deuterated p-hexylbromobenzene (4.2 g, 17.4 mmol) and dry tetrahydrofuran (30 mL) were added to a 250 mL three-necked flask, cooled to -30 ° C, and n-butyllithium (2.0 M, 17.4 mmol) was slowly added dropwise. The reaction was kept warm for 1 h. A tetrahydrofuran solution of compound 1 (1.51 g, 3.14 mmol) was slowly added. After continuing the reaction for 2 h, water was added to terminate the reaction. The product was extracted with ethyl acetate, dried, filtered, and concentrated to obtain a yellow solid. Glacial acetic acid (30 mL) and n-hexane (30 mL) were added, and concentrated sulfuric acid (3 mL) was slowly added dropwise after stirring. The reaction was continued at 40 ° C for 12 h, washed with water, extracted, and rotary evaporated to obtain a crude product. The product was purified by silica gel column chromatography using a 15:1 mixed solvent of n-hexane / dichloromethane as the eluent to obtain 2.65 g of a dark yellow powder solid, i.e., compound 2 (yield 83%).

[0151] Step 2, synthesis of compound 3:

[0152] Under nitrogen protection, compound 2 (2.65 g, 2.60 mmol) and dry tetrahydrofuran (25 mL) were added to a 100 mL three-necked flask, cooled to -30 ° C, and n-butyl lithium (2.0 M, 2.86 mmol) was slowly added dropwise. The reaction was kept warm for 1 h, and trimethyltin chloride (0.67 g, 3.38 mmol) was added all at once. The temperature was slowly raised to room temperature and reacted for 2 h. After washing, drying, and concentration, the mixture was recrystallized from ethanol / tetrahydrofuran system to obtain 2.83 g of yellow needle-like crystals, namely compound 3 (yield 81%).

[0153] Step 3, synthesis of compound 4:

[0154] Under nitrogen protection, compound 3 (2.83 g, 2.11 mmol), 2-bromo-3 (2-octyldodecyloxy) -5-deuterated formylthiophene (2.79 g, 5.70 mmol) and toluene (50 mL) were added to a 250 mL three-necked flask, heated to reflux, and then added with catalyst tetrakis(triphenylphosphine) palladium (0.13 g, 0.11 mmol) and continued to reflux for 20 h. The crude product was washed with water, dried, and concentrated to give a crude product, which was purified by silica gel column chromatography using n-hexane / ethyl acetate 30:1 as eluent to give 3.02 g of a red solid, i.e., compound 4 (yield 78%).

[0155] Step 4, synthesis of compound A5:

[0156] Compound 4 (0.32 g, 0.17 mmol), difluorodicyanindanone (0.91 g, 0.83 mmol), and chloroform (30 mL) were added to a 100 mL round-bottom flask and stirred. 1 mL of pyridine was added dropwise and the mixture was refluxed for 6 h. The system was then precipitated with methanol and filtered to obtain a crude product. The crude product was purified by silica gel column chromatography using chloroform as the eluent to obtain 0.35 g of a black powdery solid, namely A5 (yield 91%). The liquid chromatography purity was 99%.

[0157] The structural characterization results of compound A5 in this example are:

[0158] 1 H NMR (500MHz, CDCl3), δ (ppm): 8.50 (t, 2H), 7.78 (s, 2H), 7.63 (t, 2H), 7.47 (s, 4H), 4.13 (s, 4H),2.58(t,8H),1.92(m,2H),1.58-1.62(m,16H),1.22-1.36(m,80H),0.83-0.87(m,24H).

[0159] 13 C NMR (125MHz, CDCl3), δ (ppm): 186.36,159.75,157.99,154.80,154.31,151.83,141.96,140 .95,140.26,139.37,139.29,139.03,138.91,135.96,131.72,129.57,128.56,127.95,126 .78,125.44,124.81,120.54,118.36,114.73,114.58,75.04,68.33,64.03,38.22,35.61,31.72,31.37,31.33,29.93,29.64,29.57,29.33,29.28,29.17,26.80,22.67,22.59,14.10.

[0160] It can be seen from the above characterization results that compound A5 of this example is an isotope deuterium-substituted A-π-D-π-A type small molecule compound A5.

[0161] Example 6:

[0162] This example provides a method for preparing a deuterium-substituted A-π-D-π-A type small molecule compound, which is compound A6 of this example. The structural formula of compound A6 is:

[0163]

[0164] The synthetic route of compound A6 is:

[0165]

[0166] The method comprises the following steps:

[0167] Step 1, synthesis of compound 2:

[0168] Compound 1 (1.2 g, 3.33 mmol) was dissolved in dimethyl sulfoxide (30 mL), and potassium tert-butoxide (2.24 g, 19.98 mmol) was gradually added to the system. After reacting at 80 ° C for 1 h, deuterated bromohexane (3.58 g, 20.10 mmol) was added dropwise. After the addition was complete, the temperature was raised to 90 ° C and the reaction was continued for 5 h. The reaction was then poured into ice water to terminate the reaction. The crude product was extracted with chloroform, dried, filtered, and concentrated to obtain the crude product. The product was purified on a silica gel column using n-hexane / dichloromethane 4:1 as the eluent to obtain 2.13 g of a light yellow solid, namely compound 2 (yield 82%).

[0169] Step 2, synthesis of compound 3:

[0170] Under nitrogen protection, compound 2 (1.00 g, 1.28 mmol) and dry tetrahydrofuran (15 mL) were added to a 50 mL three-necked flask, cooled to -30 ° C, and n-butyl lithium (2.0 M, 1.41 mmol) was slowly added dropwise. The reaction was kept warm for 1 h, and trimethyltin chloride (0.32 g, 1.66 mmol) was added all at once. The temperature was slowly raised to room temperature and reacted for 2 h. After washing, drying, and concentration, the mixture was recrystallized from ethanol / tetrahydrofuran system to obtain 1.02 g of light yellow needle-like crystals, i.e., compound 3 (yield 72%).

[0171] Step 3, synthesis of compound 4:

[0172] Under nitrogen protection, compound 3 (1 g, 0.90 mmol), 2-bromo-3 (2-octyldodecyloxy) -5-deuterated formylthiophene (1.18 g, 2.42 mmol) and toluene (25 mL) were added to a 100 mL three-necked flask, heated to reflux, and then added with catalyst tetrakis(triphenylphosphine) palladium (0.06 g, 0.05 mmol) and continued to reflux for 20 h. The crude product was washed with water, dried, and concentrated to give a crude product, which was purified by silica gel column chromatography using n-hexane / ethyl acetate 20:1 as eluent to give 0.92 g of an orange-red solid, namely compound 4 (yield 64%).

[0173] Step 4, synthesis of compound A6:

[0174] Compound 4 (0.27 g, 0.17 mmol), dichlorodicyanindanone (0.22 g, 0.83 mmol), and chloroform (30 mL) were added to a 100 mL round-bottom flask and stirred. 1 mL of pyridine was added dropwise and the mixture was refluxed for 4 h. The system was then precipitated with methanol and filtered to obtain a crude product. The crude product was purified by silica gel column chromatography using chloroform as the eluent to obtain 0.30 g of a black powdery solid, A6 (yield 84%). The liquid chromatography purity was 99%.

[0175] The structural characterization results of Compound A6 in this example are:

[0176] 1 H NMR (500MHz, CDCl3), δ (ppm): 8.73 (s, 2H), 7.87 (s, 2H), 7.75 (s, 2H), 7.48 (s, 4H), 1.58-1.63 (m, 10H), 1.22-1.36 (m, 62H), 0.83-0.87 (m, 12H).

[0177] 13 C NMR (125MHz, CDCl3), δ (ppm): 186.23,173.8,164.6,152.19,155.10,154.81,153.51,15 3.45,153.36,141.95,141.01,139.28,138.89,136.74,134.36,131.72,124.77,120.54 ,118.35,114.97,114.82,112.41,112.26,75.01,68.33,64.03,38.24,35.62,31.92,31.74,31.39,29.66,29.35,29.18,26.79,22.68,22.65,22.60,19.21,14.11,10.04,9.88.

[0178] It can be seen from the above characterization results that the compound A6 of this example is an isotope deuterium-substituted A-π-D-π-A type small molecule compound A6.

[0179] Example 7:

[0180] This example provides a method for preparing an isotope-deuterium-substituted A-π-D-π-A type composition, which comprises compound A1, compound B1, and compound A2. This composition is recorded as composition 1.

[0181] The ratio of the number of deuterium atoms substituted at the Y2 site in composition 1 to the total number of hydrogen atoms at the site is 17%, which can be achieved by adjusting the feed ratio of the intermediate 2-bromo-3 (2-octyldodecyloxy) -5-deuterated formylthiophene and 2-bromo-3 (2-octyldodecyloxy) -5-formylthiophene, or by adjusting the mixing ratio of A1, B1, and A2. For example, a 17% deuterium substitution rate at the Y2 site can be achieved with a mixing molar ratio of A1, B1, and A2 of 0.05 mol: 0.38 mol: 0.07 mol.

[0182] Taking the adjustment of the intermediate feed ratio as an example, the route for preparing composition 1 is as follows:

[0183]

[0184] The method comprises the following steps:

[0185] Step 1, synthesis of compound 2:

[0186] Under nitrogen protection, compound 1 (0.95 g, 0.71 mmol), 2-bromo-3 (2-octyldodecyloxy) -5-deuterated formylthiophene (0.16 g, 0.33 mmol), 2-bromo-3 (2-octyldodecyloxy) -5-formylthiophene (0.78 g, 0.96 mmol), and toluene (25 mL) were added to a 100 mL three-necked flask, heated to reflux, and then added with catalyst tetrakis (triphenylphosphine) palladium (0.05 g, 0.04 mmol) and continued to reflux for 20 h. The crude product was washed with water, dried, and concentrated to give the crude product, which was purified by silica gel column chromatography with n-hexane / ethyl acetate 30:1 as eluent to give 0.89 g of a red solid, i.e., compound 2 (yield 69%).

[0187] Step 2, synthesis of composition 1:

[0188] Compound 2 (0.31 g, 0.17 mmol), dichlorodicyanindanone (0.22 g, 0.83 mmol), and chloroform (30 mL) were added to a 100 mL round-bottom flask and stirred. 1 mL of pyridine was added dropwise and the mixture was refluxed for 4 h. The system was then precipitated with methanol and filtered to obtain a crude product. The crude product was then purified by silica gel column chromatography using chloroform as the eluent to obtain 0.31 g of a black powdery solid, namely, Composition 1 (yield 79%). The liquid chromatography purity was 99%.

[0189] The structural characterization results of the composition 1 of this embodiment are as follows:

[0190] 1H NMR (500MHz, CDCl3), δ (ppm): 8.69 (s, 3.51H), 7.86 (s, 2H), 7.75 (s, 2H), 7.48 (s, 4H), 7.21 (d, 8H), 7.12 (d, 8 H),4.14(s,4H),2.57-2.60(t,8H),1.30(m,2H),1.58-1.61(m,16H),1.23-1.36(m,80H),0.82-0.88(m,24H).

[0191] 13 C NMR (125MHz, CDCl3), δ (ppm): 185.33, 158.75, 156.98, 153.77, 153.31, 142.01, 141.0 3,139.51,139.04,136.50,135.94,128.58,128.00,126.76,124.84,120.53,120.33,1 17.36,113.72,96.13,75.04,67.99,60.40,38.25,35.62,31.89,31.74,31.35,29.96,29.73,29.66,29.60,29.35,29.30,26.80,25.79,25.77,22.68,22.67,22.61,14.10.

[0192] It can be seen from the above characterization results that the composition 1 of this embodiment is an A-π-D-π-A type composition 1 substituted with deuterium isotope.

[0193] The photoluminescence spectra of the compound A1, the comparative compound B1 and the composition 1 of the present invention are shown in FIG. Figure 2 As shown, from Figure 2 From the comparison in , it can be seen that deuteration causes the luminescence peak of A1 to slightly blue-shift, and the luminescence peak of the partially deuterated composition 1 remains basically unchanged compared with B1, but the photoluminescence quantum efficiency of the deuterated A1 and composition 1 are both improved.

[0194] The electroluminescence spectra of Example Compound A1, Comparative Compound B1 and Composition 1 of the present invention are as follows: Figure 4 As shown, from Figure 4 The comparison in Figure 2 shows that the peak intensity of the electroluminescence spectra of the deuterated compound A1 and composition 1 is improved compared with the undeuterated compound B1, and the electroluminescence peak intensity of the partially deuterated composition 1 is more significantly improved. The deuterated compound A1 has an irradiation output of 9.92 mW / cm in the near-infrared band above 1000 nm. 2 , significantly higher than that of the undeuterated compound B1.

[0195] The current density-radiance-voltage (JRV) characteristic curves of Example Compound A1, Comparative Compound B1 and Composition 1 of the present invention are shown in FIG. Figure 5 As shown, from Figure 5 From the comparison in , it can be seen that the devices prepared from the three materials all show obvious exponential growth at a lower injection voltage, among which the deuterated compound A1 and composition 1 show higher brightness at a lower injection voltage than the non-deuterated compound B1.

Claims

1. A deuterium-substituted A-π-D-π-A type small molecule compound, characterized in that: The structural formula of the small molecule compound is: Where: R1 is independently C1-C20 alkyl, C1-C20 deuterated alkyl, C1-C20 alkyl-substituted phenyl, C1-C20 alkoxy-substituted phenyl, deuterated C1-C20 alkyl-substituted phenyl, deuterated C1-C20 alkoxy-substituted phenyl, C1-C20 alkyl-substituted thienyl, C1-C20 alkoxy-substituted thienyl, deuterated C1-C20 alkyl-substituted thienyl, or deuterated C1-C20 alkoxy-substituted thienyl; R2 is independently a hydrogen atom, a deuterium atom, a C1-C20 alkyl group, a C1-C20 deuterated alkyl group, a C1-C20 alkoxy group, a C1-C20 deuterated alkoxy group, a C1-C20 alkyl ester group, or a C1-C20 deuterated alkyl ester group; X is independently an oxygen atom, a sulfur atom, a selenium atom or a tellurium atom; Y1 is independently a hydrogen atom or a deuterium atom; Y2 is independently a hydrogen atom or a deuterium atom; A1 and A2 are both pull-electronic units.

2. The isotope deuterium-substituted A-π-D-π-A type small molecule compound according to claim 1, characterized in that: R1 is a C1-C20 alkyl-substituted phenyl group, R2 is a C1-C20 alkoxy group, X is a selenium atom, Y1 is a hydrogen atom, Y2 is a deuterium atom, or one site of Y2 is a deuterium atom and the other site is a hydrogen atom.

3. The isotope deuterium-substituted A-π-D-π-A type small molecule compound according to claim 1, characterized in that: R1 is a deuterated phenyl group substituted with a C1-C20 alkyl group, R2 is a C1-C20 alkoxy group, X is a selenium atom, Y1 is a hydrogen atom, and Y2 is a hydrogen atom.

4. The isotope deuterium-substituted A-π-D-π-A type small molecule compound according to claim 1, wherein: R1 is a deuterated phenyl group substituted with a C1-C20 alkyl group, R2 is a C1-C20 alkoxy group, X is a selenium atom, Y1 is a hydrogen atom, Y2 is a deuterium atom, or one site of Y2 is a deuterium atom and the other site is a hydrogen atom.

5. The isotope deuterium-substituted A-π-D-π-A type small molecule compound according to claim 1, wherein: R1 is a C1-C20 deuterated alkyl group, R2 is a C1-C20 alkoxy group, X is a selenium atom, Y1 is a hydrogen atom, Y2 is a deuterium atom, or one site of Y2 is a deuterium atom and the other site is a hydrogen atom.

6. The isotope-deuterium-substituted A-π-D-π-A type small molecule compound according to claim 1, wherein: A1 and A2 are independently selected from one of the following structural formulas of electronic units: Where: R4 is a straight-chain alkyl group having 1 to 12 carbon atoms, a branched-chain alkyl group having 1 to 12 carbon atoms, a straight-chain deuterated alkyl group having 1 to 12 carbon atoms, or a branched-chain deuterated alkyl group having 1 to 12 carbon atoms; The hydrogen elements contained in the aromatic rings in the structures A1 and A2 are independently hydrogen atoms or deuterium atoms.

7. The isotope-deuterium substituted A-π-D-π-A type small molecule compound according to claim 1, characterized in that: A1 and A2 are both dichlorodicyanindanone or difluorodicyanindanone.

8. A method for preparing the isotope deuterium-substituted A-π-D-π-A type small molecule compound according to any one of claims 1 to 7, characterized in that: The method changes the raw materials required for the preparation of A-π-D-π-A type small molecule compounds into raw materials substituted with isotope deuterium.

9. An isotope deuterium-substituted A-π-D-π-A type composition, characterized in that: The composition comprises at least one isotope deuterium-substituted A-π-D-π-A type small molecule compound according to any one of claims 1 to 7; In the composition, the ratio of the number of deuterium atoms substituted to the total number of hydrogen atoms is 1% to 100%.

10. The isotope deuterium-substituted A-π-D-π-A type composition according to claim 9, characterized in that: The ratio of the number of deuterium atoms substituted at the Y2 site to the total number of hydrogen atoms at the site is 10% to 20%.

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