A ring-encapsulated organic semiconductor material, its preparation method and application

Abstract

This invention belongs to the field of optoelectronic materials technology, specifically relating to a ring-wrapped organic semiconductor material, its preparation method, and its applications. The ring-wrapped organic semiconductor material of this invention has the following general structural formula: by introducing different π-bridge conjugated connecting units, the energy levels of the material are adjusted and absorption is broadened; different alkyl chains on the π-bridges can improve the solubility and processability of the material; and it contains symmetrical, sterically hindered ring-wrapped side chains, which can improve the planarity and conformational stability of the molecular conjugated framework, thereby improving intramolecular charge transport and achieving the goal of improving the efficiency of photovoltaic devices. The ring-wrapped organic semiconductor material of this invention has good planarity and rigidity, strong visible light and near-infrared absorption characteristics, and high charge mobility, and can be used to prepare organic solar cells with high short-circuit current and energy conversion efficiency.

Description

Technical Field

[0001] This invention belongs to the field of optoelectronic materials technology, specifically relating to an organic semiconductor material with a ring-encapsulated structure, its preparation method, and its application. Background Technology

[0002] Organic solar cells use organic semiconductors as the active materials for photoelectric conversion. Compared with inorganic solar cells, they have advantages such as low cost, thinness, light weight, simple manufacturing process, and the ability to be made into large-area flexible devices, showing broad development and application prospects. In recent years, organic solar cells (OSCs) based on fused-ring electron acceptors have developed rapidly, with their power conversion efficiency (PCE) exceeding 19%. However, constructing the conjugated framework of fused-ring electron acceptors (FREAs) requires multiple chemical reactions, often resulting in high synthesis complexity and preparation costs. The commercialization of OSCs still faces a key challenge—how to achieve high efficiency, long lifespan, and low cost for photovoltaic materials and solar cell devices.

[0003] Compared to fused-ring electron acceptors, non-fused-ring electron acceptors (NFREAs) have gradually become a promising research branch in organic photovoltaic acceptor materials due to their advantages such as simple module coupling, easy synthesis, and rich regulatory choices for the parent nucleus, π unit, and side chains. However, the conformational uncertainty caused by the rotatable single bond of NFREAs limits further improvement in their efficiency.

[0004] To address conformational instability, existing technologies employ intramolecular non-covalent interactions (S…O, H…F, S…N) in non-fused-ring acceptors to create conformational locks, restricting single-bond rotations of adjacent building blocks and achieving rigidity and planarity similar to that of fused-ring electron acceptor molecules. Another design strategy for non-fused-ring electron acceptors involves introducing large side chains into the conjugated backbone to increase steric hindrance. However, neither of these approaches effectively addresses molecular packing issues. Therefore, there is an urgent need to design novel electron acceptor materials to resolve conformational instability and molecular packing problems, thereby further improving the energy conversion efficiency of electron acceptor materials. Summary of the Invention

[0005] One of the objectives of this invention is to provide an organic semiconductor material with a ring-wrap structure, which has good planarity and rigidity, strong visible light-near infrared absorption characteristics and high charge mobility.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] An organic semiconductor material with a ring-encapsulated structure has the following general structural formula:

[0008]

[0009] Among them, the π2 unit of Formula I is a pentagonal aromatic heterocyclic unit or a fused pentagonal aromatic heterocyclic unit;

[0010] The π1 unit is selected from,

[0011] One of them;

[0012] Y is selected from one of the following: —CH2—, oxygen atom, sulfur atom, selenium atom, and tellurium atom;

[0013] R1 is selected from one of the following: hydrogen atom, C1-C6 straight-chain or branched saturated alkyl group, alkoxy group, alkylthio group, dialkylamino group, trimethylsilyl group, trifluoromethyl group, cyano group, and sulfonic acid group;

[0014] R2 is selected from C5-C 10 Straight-chain saturated alkyl groups, 1,4-dimethylphenyl, 3,3'-dimethyl-1,1'-biphenyl, (ethoxy) n (Ethylthio) n One of them; n is an integer from 2 to 4;

[0015] Electron-withdrawing group A is selected from

[0016] One of them.

[0017] Furthermore, the π² unit is selected from...

[0018]

[0019] One of them; R in the π2 unit is selected from C1-C 16 One of the following: a straight-chain or branched saturated alkyl group, a fluorine atom, a chlorine atom, a bromine atom, or a trifluoromethyl group.

[0020] Furthermore, X in the π1 unit is selected from one of nitrogen atom, oxygen atom, sulfur atom, selenium atom, and tellurium atom; R3 in the electron-withdrawing group A is selected from one of C1-C6 straight-chain saturated alkyl groups; X1 is selected from one of fluorine atom, chlorine atom, bromine atom, and trifluoromethyl group; and Y1 is selected from one of fluorine atom, chlorine atom, bromine atom, and trifluoromethyl group.

[0021] Furthermore, π1, π2, R1, R2, and A are selected from the following group groups:

[0022]

[0023]

[0024]

[0025]

[0026] Organic semiconductor materials s-1 to s-28 that form ring-encapsulated structures.

[0027] The second objective of this invention is to provide a method for preparing an organic semiconductor material with a ring-encapsulated structure.

[0028] To achieve the above objectives, the present invention adopts the following technical solution:

[0029] A method for preparing a ring-encapsulated organic semiconductor material includes the following steps:

[0030]

[0031] 1) The dichloromethane solvent system of compound II was reacted with boron tribromide, and then a quencher was added to quench the reaction. The reaction solution was post-treated to obtain compound III.

[0032] 2) Compound III and compound VII, along with a basic reagent, are dissolved together in an aprotic polar solvent and reacted. The reaction solution is then post-treated to obtain compound IV.

[0033] 3) Dissolve compound IV in tetrahydrofuran solution, react with n-butyllithium reagent and trimethyltin chloride solution, and then post-treat the reaction solution to obtain compound V;

[0034] 4) The compound of formula V and the monobromo-monaldehyde derivative of the π2 unit are dissolved in an aromatic reagent and reacted by Stille coupling under the action of a palladium catalyst. The reaction solution is then post-treated to obtain the compound of formula VI.

[0035] 5) The compound of formula VI is mixed with one of the following: cyanotannin derivative, cyclotannin derivative, dicyanobenzothiophene dioxide derivative, chloroform, and basic reagent, and subjected to Knoevenagel condensation reaction. The reaction solution is then post-treated to obtain the compound of formula I.

[0036] Further, the reaction conditions for step 1) of boron tribromide are as follows: boron tribromide is added under an inert gas atmosphere at a temperature of -20℃ to 0℃, and the reaction is carried out overnight at room temperature; the quenching agent quenches the reaction at a temperature of -20℃ to 0℃, and the molar ratio of compound II to boron tribromide is 1:(4~5).

[0037] Further, the reaction in step 2) is carried out under an inert gas atmosphere at a temperature of 80℃~100℃ for 24 hours, and the molar ratio of compound III to compound VII and basic reagent is 1:2:(4~8); in compound VII, Z is one of bromine, benzyl bromide, or hydroxyl, and R4 is selected from C5-C6. 12The reagent is one of saturated alkyl, phenyl, thienyl, thienyl-2-, biphenyl, naphthioyl, thienyl-2-, -(CH2CH2)2-, -(CH2CH2)3-, or -(CH2CH2)4-; the alkaline reagent is one of sodium carbonate, potassium carbonate, cesium carbonate, sodium bicarbonate, ammonium bicarbonate, lithium hydroxide, sodium hydroxide, potassium hydroxide, sodium tert-butoxide, potassium tert-butoxide, pyridine, or piperidine; the aprotic polar solvent is one of dimethyl sulfoxide, N,N-dimethylformamide, acetone, or acetonitrile.

[0038] Further, in step 3), compound IV is dissolved in tetrahydrofuran solution, and under an inert gas atmosphere, n-butyllithium reagent is added dropwise at -80℃ to -60℃. After stirring continuously for 2 hours, trimethyltin chloride is added dropwise, and the mixture is brought back to room temperature and stirred for 12 hours. The molar ratio of compound IV to n-butyllithium reagent and trimethyltin chloride is 1:(2~2.4):(2~2.4).

[0039] Further, the reaction in step 4) is carried out under an inert gas atmosphere, at a temperature of 110℃~130℃, for a time of 24h, and the molar ratio of compound V, π2 unit monobromoaldehyde derivative, and palladium catalyst is 1:(2~2.4):(0.1~0.05); the palladium catalyst is one of tetratetraphenylphosphine palladium, tris(dibenzylacetone)dipalladium, and tri-tert-butylphosphine complex; the aromatic reagent is one of toluene, o-xylene, mesitylene, and chlorobenzene.

[0040] The third objective of this invention is to provide an application of an organic semiconductor material with a ring-encapsulated structure.

[0041] To achieve the above objectives, the present invention adopts the following technical solution:

[0042] Application of an organic semiconductor material with the above-mentioned ring-wrapped structure in organic solar cells.

[0043] Compared with the prior art, the beneficial effects of this invention are as follows:

[0044] (1) The organic semiconductor material with the ring-enclosed structure of the present invention has strong visible light-near infrared absorption characteristics, i.e., high charge mobility;

[0045] (2) The organic semiconductor material with ring-wrap structure of the present invention can adjust the energy level and broaden the absorption by introducing different π-bridge conjugated connection units, and different alkyl chains on the π-bridge can improve the solubility and processing performance of the material;

[0046] (3) The organic semiconductor material with ring-wrapped structure of the present invention contains symmetrical steric hindrance ring-wrapped side chains, which can improve the planarity and conformational stability of the molecular conjugated skeleton, thereby improving intramolecular charge transport and achieving the purpose of improving the efficiency of photovoltaic devices.

[0047] (4) The organic semiconductor material with ring-encapsulated structure of the present invention has mild synthesis conditions, simple purification, low price, and can be produced and used on a large scale. Attached Figure Description

[0048] Figure 1 The image shows the UV absorption spectra of the solution and the thin film of compound s-1 in Example 1.

[0049] Figure 2 The diagram shows the UV absorption spectra of the solution and thin film of compound s-2 in Example 2.

[0050] Figure 3 The graph shows the current density and voltage variation of a photovoltaic device made using compound s-1 from Example 1 as the acceptor material. Detailed Implementation

[0051] The technical solution of the present invention will be further explained and described below with reference to specific embodiments, test examples and accompanying drawings.

[0052] Unless otherwise specified, the raw materials and preparation methods used in the following examples and test cases are all conventional materials and techniques in the art.

[0053] I. Implementation Examples

[0054] Example 1

[0055] The structure of compound s-1 is as follows: .

[0056] The synthetic route for compound s-1 is as follows:

[0057]

[0058] 1) After dissolving compound II (1 g, 2.280 mmol) in dichloromethane, boron tribromide was added dropwise at 0 °C under nitrogen protection. The mixture was then stirred at room temperature for 12 h. The mixture was then purified by sedimentation to obtain compound III.

[0059] 2) Compound III (300 mg, 0.784 mmol), compound VII (1,5-dibromopentane, 361 mg, 1.569 mmol), and cesium carbonate (1.022 g, 3.138 mmol) were dissolved together in acetone solution, heated to 80 °C and stirred for 24 h, and then purified by column chromatography to obtain compound IV.

[0060] 3) Compound IV (120 mg, 0.522 mmol) was dissolved in a dry tetrahydrofuran solution. Under nitrogen protection, n-butyllithium solution (0.52 mL, 1.305 mmol) was added dropwise at -78 °C. After stirring continuously for 2 h, trimethyltin chloride solution (1.57 mL, 1.566 mmol) was added dropwise. The mixture was then allowed to return to room temperature and stirred for 12 h. Compound V was purified by sedimentation.

[0061] 4) Compound V (120 mg, 0.142 mmol), 5-bromo-3-(2-ethylhexyl)thiophene-2-carboxaldehyde (108 mg, 0.355 mmol), and tetra(triphenylphosphine)palladium (8 mg, 0.007 mmol) were dissolved in toluene (10 mL) and mixed thoroughly. The mixture was heated to 110 °C and reacted for 24 h under nitrogen protection. The mixture was purified by column chromatography to obtain compound VI.

[0062] 5) Compound VI (65 mg, 0.067 mmol) was mixed with 5,6-difluoro-3-(dicyanomethylene)indone (34 mg, 0.147 mmol), chloroform (5 mL), and pyridine (0.1 mL) and reacted at room temperature for 8 h. The mixture was purified by column chromatography to obtain compound s-1.

[0063] 1 H NMR (300MHz, CDCl3) δ (ppm): 8.71 (s, 2H), 8.54-8.49 (m, 2H), 7.64 (t, J=7.5, 2H), 7.59 (s, 2H), 7.40 (t, J=8.4, 2H), 7.35 (s, 2H), 6.70 (d, J=8.4, 4H), 4.04-3.89 (m, 8H), 2.54 (d, J=6.9, 4H), 1.68-1.64 (m, 8H), 1.56-1.49 (m, 22H), 1.09-0.81 (m, 12H).

[0064] Example 2

[0065] The structural formula of compound s-2 is .

[0066] The preparation method of compound s-2 is as follows:

[0067] 1) Same as Example 1;

[0068] 2) The compound of formula VII was 1,4-di(bromomethyl)benzene (414 mg, 1.569 mmol), and the other conditions were the same as in Example 1;

[0069] 3) Compound IV (150 mg, 0.131 mmol) was dissolved in a dry tetrahydrofuran solution. Under nitrogen protection, n-butyllithium solution (0.13 mL, 0.329 mmol) was added dropwise at -78 °C. After stirring continuously for 2 h, trimethyltin chloride solution (0.40 mL, 0.395 mmol) was added dropwise. The mixture was then allowed to return to room temperature and stirred for 12 h. Compound V was purified by sedimentation.

[0070] 4) Compound V (120 mg, 0.116 mmol), 5-bromo-3-(2-ethylhexyl)thiophene-2-carboxaldehyde (88 mg, 0.290 mmol), and tetra(triphenylphosphine)palladium (7 mg, 0.006 mmol) were dissolved in toluene (10 mL) and mixed thoroughly. The mixture was heated to 110 °C and reacted for 24 h under nitrogen protection. The mixture was purified by column chromatography to obtain compound VI.

[0071] 5) Compound VI (60 mg, 0.058 mmol) was mixed with 5,6-difluoro-3-(dicyanomethylene)indone (28 mg, 0.123 mmol), chloroform (5 mL), and pyridine (0.1 mL) and reacted at room temperature for 8 h. The mixture was purified by column chromatography to obtain compound s-2.

[0072] 1 H NMR (300MHz, CDCl3) δ (ppm): 8.71 (s, 2H), 8.54-8.49 (m, 2H), 7.64 (t, J=7.5, 2H), 7.59 (s, 2H), 7.40 (t, J=8.4, 2H), 7.35 (s, 2H), 6.82 ( d, J=8.4, 8H), 6.70 (d, J=8.4, 4H), 4.04-3.89 (m, 8H), 2.54 (d, J=6.9, 4H), 1.68-1.64 (m, 8H), 1.56-1.49 (m, 10H), 1.09-0.81 (m, 12H).

[0073] Example 3

[0074] The structural formula of compound s-3 is .

[0075] The preparation method of compound s-3 is as follows:

[0076] 1) After dissolving compound II (1 g, 2.280 mmol) in dichloromethane, boron tribromide was added dropwise at -20 °C under nitrogen protection. The mixture was then stirred at room temperature for 12 h. The mixture was then purified by sedimentation to obtain compound III.

[0077] 2) Compound III (300 mg, 0.784 mmol), compound VII (triethylene glycol, 236 mg, 1.569 mmol), and cesium carbonate (1.022 g, 3.138 mmol) were dissolved together in acetone solution, heated to 100 °C and stirred for 24 h, and then purified by column chromatography to obtain compound IV.

[0078] 3) Formula IV (150 mg, 0.246 mmol) was dissolved in a dry tetrahydrofuran solution. Under nitrogen protection, n-butyllithium solution (0.25 mL, 0.614 mmol) was added dropwise at -80 °C. After stirring continuously for 2 h, trimethyltin chloride solution (0.74 mL, 0.737 mmol) was added dropwise. The mixture was then allowed to return to room temperature and stirred for 12 h. The product was purified by sedimentation to obtain compound V.

[0079] 4) Compound V (100 mg, 0.107 mmol), 5-bromo-3-(2-ethylhexyl)thiophene-2-carboxaldehyde (81 mg, 0.267 mmol), and tetrakis(triphenylphosphine)palladium (6 mg, 0.005 mmol) were dissolved in toluene (10 mL) and mixed thoroughly. The mixture was heated to 130 °C and reacted for 24 h under nitrogen protection. The mixture was purified by column chromatography to obtain compound VI.

[0080] 5) Compound VI (60 mg, 0.057 mmol) was mixed with 5,6-difluoro-3-(dicyanomethylene)indone (30 mg, 0.130 mmol), chloroform (5 mL), and pyridine (0.1 mL) and reacted at room temperature for 8 h. The mixture was purified by column chromatography to obtain compound s-3.

[0081] 1 H NMR (300MHz, CDCl3) δ (ppm): 8.91 (s, 2H), 8.54-8.49 (m, 2H), 7.63 (t, J=7.5Hz, 2H), 7.46 (t, J=8.4Hz, 2H), 7.36 (s, 2H), 6.90 (s, 2 H), 6.69 (d, J=8.4Hz, 4H), 4.00-3.99 (m, 12H), 3.82-3.80 (m, 12H), 2.85 (d, J=6.9Hz, 4H), 1.39-1.16 (m, 18H), 0.92-0.87 (m, 12H).

[0082] Example 4

[0083] The structural formula of compound s-5 is .

[0084] The preparation method of compound s-5 is basically the same as that in Example 1, except that: in step 1), compound II is... The remaining conditions were the same as in Example 1, and compound s-5 was prepared.

[0085] 1 H NMR (300MHz, CDCl3) δ 8.11 (m, 4H), 8.04 (s, 2H), 7.36-7.29 (m, 4H), 6.97 (d, J=7.9Hz, 4H), 3.98 (t, J=7.7Hz, 8H), 2 .93-2.79 (m, 4H), 1.81-1.57 (m, 14H), 1.43-1.18 (m, 16H), 1.05 (s, 3H), 0.91-0.89 (m, 12H).

[0086] Example 5

[0087] The structural formula of compound s-6 is .

[0088] The preparation method of compound s-6 is basically the same as that in Example 1, except that: in step 2), the compound of formula VII is 1,6-dibromohexane, and the other conditions are the same as in Example 1, so that compound s-6 can be prepared.

[0089] 1 H NMR (400MHz, CDCl3) δ: 8.91 (s, 2H), 8.54-8.51 (m, 2H), 7.65 (t, 2H), 7.40 (s, 2H), 6.93 (s, 2H), 6.76 (d, J=8.0Hz, 4H), 4.17-4.14 (m, 4H), 3.78-3.73 (m, 4H), 2.86 (d, J=4.0 Hz, 4H), 1.67-1.58 (m, 4H), 1.43-1.23 (m, 22H), 1.01-0.96 (m, 4H), 0.94-0.90 (m, 12H).MS (ESI): Calcd.for C 82 H 75 F4N4O6S4[M+H] + :1415.4500, Found:1415.4457.

[0090] Example 6

[0091] The structural formula of compound s-8 is .

[0092] The preparation method of compound s-8 is basically the same as that in Example 2, except that: the compound of formula VII is 1,7-dibromoheptane, and the other conditions are the same as in Example 2, so that compound s-8 can be prepared.

[0093] 1 H NMR (300MHz, CDCl3) δ (ppm) 8.90 (s, 2H), 8.54-8.49 (m, 2H), 7.64 (t, J=7.5Hz, 2H), 7.48 (t, J=8.4Hz, 2H), 7.37 (s, 2H), 6.93 (s, 2 H), 6.73 (d, J=8.4Hz, 4H), 4.06-3.88 (m, 8H), 2.85 (d, J=6.9Hz, 4H), 1.65-1.40 (m, 12H), 1.35-1.09 (m, 26H), 0.93-0.88 (m, 12H).

[0094] Example 7

[0095] The structural formula of compound S-9 is .

[0096] The preparation method of compound s-9 is basically the same as that in Example 1, except that: in step 1), compound II is... In step 2), the compound of formula VII was 1,8-dibromooctane, and the remaining conditions were the same as in Example 1, to prepare compound s-9.

[0097] 1 H NMR (300MHz, CDCl3) δ 8.14-8.08 (m, 4H), 7.27-7.18 (m, 4H), 7.02 (d, J=7.9Hz, 4H), 3.98 (t, J=7.8Hz, 8H), 2.9 4-2.81 (m, 4H), 1.82-1.67 (m, 8H), 1.50-1.18 (m, 32H), 1.5 (s, 4H), 0.91-0.89 (m, 12H).

[0098] Example 8

[0099] The structural formula of compound S-10 is .

[0100] The preparation method of compound s-10 is basically the same as that in Example 1, except that: in step 2), the compound of formula VII is 1,8-dibromooctane, and the other conditions are the same as in Example 1, so that compound s-10 is prepared.

[0101] 1H NMR (300MHz, CDCl3) δ 8.14-8.08 (m, 4H), 7.27-7.18 (m, 4H), 7.02 (d, J=7.9Hz, 4H), 3.98 (t, J=7.9Hz, 8H), 2.94-2.81 (m, 4H), 1.8 2-1.67 (m, 12H), 1.51-1.40 (m, 8H), 1.43-1.31 (m, 10H), 1.34-1.24 (m, 4H), 1.5 (s, 4H), 0.91-0.89 (m, 12H).

[0102] Example 9

[0103] The structural formula of compound s-12 is .

[0104] The preparation method of compound s-12 is basically the same as that in Example 1, except that: in step 2), the compound of formula VII is 1,10-dibromodecane, and the other conditions are the same as in Example 1, so that compound s-12 is prepared.

[0105] 1 H NMR (300MHz, CDCl3) δ (ppm) 8.90 (s, 2H), 8.54-8.49 (m, 2H), 7.63 (t, J=7.5Hz, 2H), 7.47 (t, J=8.4Hz, 2H), 7.37 (s, 2H), 6.89 (s, 2 H), 6.69 (d, J=8.4Hz, 4H), 4.11-3.88 (m, 8H), 2.85 (d, J=6.9Hz, 4H), 1.62-1.55 (m, 12H), 1.34-1.23 (m, 34H), 0.98-0.86 (m, 12H).

[0106] Example 10

[0107] The structural formula of compound S-13 is .

[0108] The preparation method of compound s-13 is basically the same as that in Example 5, except that: in step 1), compound II is... The remaining conditions were the same as in Example 5, and compound s-13 was prepared.

[0109] 1H NMR (300MHz, CDCl3) δ 8.15-8.04 (m, 4H), 6.56 (t, J=1.0Hz, 4H), 4.01 (t, J=7.7Hz, 8H), 2.93-2.79 (m, 4H), 2.62 -2.57 (m, 4H), 1.81-1.52 (m, 20H), 1.43-1.18 (m, 28H), 1.05 (s, 4H), 0.93-0.86 (m, 20H).

[0110] Example 11

[0111] The structural formula of compound S-15 is .

[0112] The preparation method of compound s-15 is basically the same as that in Example 7, except that: in step 1), compound II is... Step 2) Formula VII is 1,6-dibromohexane, and the remaining conditions are the same as in Example 7, to prepare compound S-15.

[0113] 1 H NMR (300MHz, CDCl3) δ 8.14-8.08 (m, 4H), 7.31 (s, 4H), 7.25 (s, 4H), 4.01 (t, J=7.9Hz, 8H), 2.94-2.81 (m, 4 H), 1.82-1.67 (m, 12H), 1.43-1.19 (m, 24H), 1.09-1.02 (m, 4H), 0.91-0.89 (m, 12H).

[0114] Example 12

[0115] The structural formula of compound S-17 is .

[0116] The preparation method of compound s-17 is basically the same as that in Example 11, except that: in step 1), compound II is... The structural formula of the monobromo-monaldehyde derivative of the π2 unit in step (4) is as follows: The remaining conditions were the same as in Example 11, and compound s-17 was prepared.

[0117] Example 13

[0118] The structural formula of compound S-18 is .

[0119] The preparation method of compound s-18 is basically the same as that in Example 1, except that: in step 1), compound II is... Step 2) Formula VII is 1,6-dibromohexane, and the structural formula of the monobromomonal derivative of the π2 unit in step (4) is... The remaining conditions were the same as in Example 1, and compound s-18 was prepared.

[0120] Example 14

[0121] The structural formula of compound S-20 is .

[0122] The preparation method of compound s-20 is basically the same as that in Example 13, except that: in step 1), compound II is... The structural formula of the monobromo-monaldehyde derivative of the π2 unit in step (4) is as follows: The remaining conditions were the same as in Example 13, and compound s-20 was prepared.

[0123] Example 15

[0124] The structural formula of compound S-22 is .

[0125] The preparation method of compound s-22 is basically the same as that in Example 6, except that: the structural formula of the monobromo-monaldehyde derivative of the π2 unit in step (4) is as follows: In step 5), compound VI was mixed with 5,6-dichloro-3-(dicyanomethylene)indophenone, chloroform, and pyridine and subjected to a Knoevenagel condensation reaction under the same conditions as in Example 6 to prepare compound s-22.

[0126] Example 16

[0127] The structural formula of compound S-23 is .

[0128] The preparation method of compound s-23 is basically the same as that in Example 15, except that: the structural formula of the monobromo-monaldehyde derivative of the π2 unit in step (4) is as follows: In step 5), compound VI was mixed with 5,6-dichloro-3-(dicyanomethylene)indophenone, chloroform, and pyridine and subjected to a Knoevenagel condensation reaction under the same conditions as in Example 15 to prepare compound s-23.

[0129] Example 17

[0130] The structural formula of compound S-26 is .

[0131] The preparation method of compound s-26 is basically the same as that in Example 15, except that: the structural formula of the monobromo-monaldehyde derivative of the π2 unit in step (4) is as follows: In step 5), compound VI was mixed with 2-(3-ethyl-4-oxothiazolidine-2-ylidene)malonitrile, chloroform, and pyridine and subjected to Knoevenagel condensation reaction under the same conditions as in Example 15 to prepare compound s-26.

[0132] Example 18

[0133] The structural formula of compound S-28 is The substituents are as follows: R1 is H, R2 is... π1 is π2 is A is .

[0134] The preparation method of compound s-28 is basically the same as that in Example 15, except that: the structural formula of the monobromo-monaldehyde derivative of the π2 unit in step (4) is as follows: In step 5), compound VI was mixed with 2-(6-oxo-5,6-dihydro-4H-cyclopentano[c]thiophene-4-ylidene)malonitrile, chloroform, and pyridine and subjected to a Knoevenagel condensation reaction under the same conditions as in Example 15 to prepare compound s-28.

[0135] Example 19

[0136] The structural formula of compound s-4 is .

[0137] The synthesis route is as follows:

[0138]

[0139] 1) After dissolving compound II (1 g, 2.424 mmol) in dichloromethane, boron tribromide was added dropwise at -10 °C under nitrogen protection. The mixture was then stirred at room temperature for 12 h. The mixture was then purified by precipitation to obtain compound III.

[0140] 2) Compound III (300 mg, 0.842 mmol), compound VII (1,5-dibromopentane, 387 mg, 1.683 mmol), and cesium carbonate (1.097 g, 3.367 mmol) were dissolved together in acetone solution, heated to 90 °C and stirred for 24 h, and then purified by column chromatography to obtain compound IV.

[0141] 3) Compound IV (150 mg, 0.304 mmol) was dissolved in a dry tetrahydrofuran solution. Under nitrogen protection, n-butyllithium solution (0.30 mL, 0.761 mmol) was added dropwise at -60 °C. After stirring continuously for 2 h, trimethyltin chloride solution (0.91 mL, 0.913 mmol) was added dropwise. The mixture was then allowed to return to room temperature and stirred for 12 h. Compound V was purified by sedimentation.

[0142] 4) Compound V (120 mg, 0.147 mmol), 5-bromo-3-(2-ethylhexyl)thiophene-2-carboxaldehyde (102 mg, 0.337 mmol), and tetrakis(triphenylphosphine)palladium (8 mg, 0.007 mmol) were dissolved in toluene (10 mL) and mixed thoroughly. The mixture was heated to 120 °C and reacted for 24 h under nitrogen protection. The mixture was purified by column chromatography to obtain compound VI.

[0143] 5) Compound VI (80 mg, 0.085 mmol) was mixed with 5,6-difluoro-3-(dicyanomethylene)indone (45 mg, 0.196 mmol), chloroform (5 mL), and pyridine (0.1 mL) and reacted at room temperature for 8 h. The mixture was purified by column chromatography to prepare compound s-4.

[0144] 1 H NMR (300MHz, CDCl3) δ (ppm): 8.71 (s, 2H), 8.54-8.49 (m, 2H), 7.64 (t, J=7.5, 2H), 7.59 (s, 2H), 7.40 (t, J=8.4, 2H), 6. 70 (d, J=8.4, 4H), 4.04-3.89 (m, 8H), 2.54 (d, J=6.9, 4H), 1.68-1.64 (m, 8H), 1.56-1.49 (m, 22H), 1.09-0.81 (m, 12H).

[0145] Example 20

[0146] The structural formula of compound s-7 is .

[0147] The preparation method of compound s-7 is basically the same as that of Example 19, except that: in step 2), the compound of formula VII is 1,6-dibromohexane, and the other conditions are the same as those of Example 19, so that compound s-7 can be prepared.

[0148] 1H NMR (300MHz, CDCl3) δ 8.07 (m, 4H), 7.18 (t, J=7.4Hz, 2H), 6.73 (d, J=7.5Hz, 4H), 3.98 (t, J=7.1Hz, 8H) , 2.89-2.77 (m, 4H), 1.80-1.73 (m, 10H), 1.49-1.20 (m, 12H), 0.92-0.88 (m, 12H).

[0149] Example 21

[0150] The structural formula of compound s-11 is .

[0151] The preparation method of compound s-11 is basically the same as that in Example 19, except that: in step 1), compound II is... Step 2) Compound VII is 1,9-dibromononane, and under the same conditions as in Example 19, compound s-11 is prepared.

[0152] 1 H NMR (300MHz, CDCl3) δ 8.15-8.04 (m, 6H), 7.71 (s, 2H), 7.44-7.37 (m, 2H), 7.30 (s, 2H), 6.84 (d, J=8.2Hz, 4H), 4.01 (t, J=7.9Hz, 8H), 2 .87-2.85 (m, 2H), 2.83-2.75 (m, 2H), 1.83-1.71 (m, 12H), 1.51-1.18 (m, 25H), 1.05 (s, 2H), 0.91-0.89 (m, 12H).

[0153] Example 22

[0154] The structural formula of compound S-14 is .

[0155] The preparation method of compound s-14 is basically the same as that in Example 20, except that: in step 1), compound II is... Compound s-14 was prepared under the same conditions as in Example 20.

[0156] 1H NMR (300MHz, CDCl3) δ 8.10-8.04 (m, 4H), 6.43 (t, J=1.0Hz, 4H), 4.01 (t, J=7.1Hz, 8H), 2.89-2.77 (m, 4H), 2.69-2.51 (m, 4H), 1 .80-1.73 (m, 7.1Hz, 12H), 1.62-1.56 (m, 4H), 1.49-1.36 (m, 8H), 1.36-1.20 (m, 32H), 0.94-0.84 (m, 20H).

[0157] Example 23

[0158] The structural formula of compound S-16 is .

[0159] The preparation method of compound s-16 is basically the same as that in Example 20, except that: in step 1), compound II is... The remaining conditions were the same as in Example 20, and compound s-16 was prepared.

[0160] 1 H NMR (300MHz, CDCl3) δ 8.01-8.04 (m, 4H), 7.11 (d, J=5.1Hz, 4H), 4.01 (t, J=7.1Hz, 8H), 2.89-2.77 (m, 4H), 1.80-1.73 (m, 8H ), 1.49-1.36 (m, 4H), 1.39-1.33 (m, 4H), 1.36-1.28 (m, 4H), 1.31-1.21 (m, 12H), 0.92-0.88 (m, 12H).

[0161] Example 24

[0162] The structural formula of compound S-19 is .

[0163] The preparation method of compound s-19 is basically the same as that in Example 20, except that: in step 1), compound II is... The remaining conditions were the same as in Example 20, and compound s-19 was prepared.

[0164] Example 25

[0165] The structural formula of compound s-21 is .

[0166] The preparation method of compound s-21 is basically the same as that in Example 20, except that: in step 1), compound II is... The structural formula of the monobromo-monaldehyde derivative of the π2 unit in step (4) is as follows: The remaining conditions were the same as in Example 20, and compound s-21 was prepared.

[0167] Example 26

[0168] The structural formula of compound S-24 is .

[0169] The preparation method of compound s-24 is basically the same as that in Example 19, except that: in step 2), the compound of formula VII is 1,7-dibromoheptane; and in step (4), the structural formula of the monobromomonal derivative of the π2 unit is... In step 5), compound VI was mixed with 2-(6-oxo-5,6-dihydro-4H-cyclopentano[c]thiophene-4-ylidene)malonitrile, chloroform, and pyridine and subjected to a Knoevenagel condensation reaction under the same conditions as in Example 19 to prepare compound s-24.

[0170] Example 27

[0171] The structural formula of compound S-25 is .

[0172] The preparation method of compound s-25 is basically the same as that in Example 26, except that: the structural formula of the monobromo-monaldehyde derivative of the π2 unit in step (4) is as follows: In step 5), compound VI was mixed with 2-(3-ethyl-4-oxothiazolidin-2-yl)malonitrile, chloroform, and pyridine and subjected to a Knoevenagel condensation reaction. The remaining conditions were the same as in Example 26, and compound s-25 was prepared.

[0173] Example 28

[0174] The structural formula of compound S-27 is The substituents are as follows: R1 is H, R2 is... π1 is π2 is A is .

[0175] The preparation method of compound s-27 is basically the same as that in Example 26, except that: the structural formula of the monobromo-monaldehyde derivative of the π2 unit in step (4) is as follows: Step 5) Compound VI was mixed with 3-(dicyanomethylene)indophenone, chloroform, and pyridine and subjected to a Knoevenagel condensation reaction under the same conditions as in Example 26 to prepare compound s-27. II. Experimental Examples

[0176] Experimental Example 1

[0177] Experimental Example 1: The ultraviolet absorption spectra of the trichloromethane solution and thin film of the organic semiconductor materials in Examples 1 and 2 were measured, and the results are as follows: Figures 1-2 As shown.

[0178] Figure 1 The image shows the UV absorption spectra of the solution and film of compound s-1 from Example 1. Figure 2 This is a graph showing the UV absorption spectra of the solution and thin film of compound s-2 from Example 2. Figures 1-2 It can be seen that the receptor molecules of compound S have similar absorption behavior in solution, with an absorption range of 550~850nm. Compared with the absorption in solution, the thin film absorption spectra of the two receptor molecules show a significant red shift, accompanied by the appearance of a left shoulder peak. This is due to the enhanced molecular aggregation in the thin film state.

[0179] Experimental Example 2

[0180] Experimental Example 2 used compounds s-1 to s-28 obtained in Examples 1 to 28 to prepare an inverted device. The device preparation process is as follows:

[0181] A ZnO solution was spin-coated onto a clean conductive glass slide and heated at 200°C for 20 min in air to achieve a ZnO thickness of 30 nm. The acceptor materials prepared in Examples 1-21 were dissolved in 1,2-dichlorobenzene at a donor-acceptor mass ratio of 1:1.2. The donor-acceptor blend solution was spin-coated onto the ZnO as an active layer with a thickness of 100 nm. The prepared active layer was transferred to a vacuum coating chamber and evacuated to a vacuum level of 2 × 10⁻⁶. -4 Organic solar cell devices were fabricated by sequentially depositing 4 nm MoO3 as a hole transport layer and 100 nm Ag as an electrode. The device configuration was ITO / ZnO (30 nm) / active layer (100 nm) / MoO3 (4.0 nm) / Ag (100 nm), where the resistance of ITO was 20 Ω / sq and the donor material was polymer D18.

[0182] At AM 1.5G, 100 mW / cm 2 Under light intensity, the open-circuit voltage, short-circuit current, fill factor, and energy conversion efficiency of the fabricated photovoltaic device were measured and are shown in Table 1. The current density versus voltage curve of compound s-2 in Example 2 is shown in Table 1. Figure 3 .

[0183] Table 1

[0184]

[0185]

[0186] Table 1 shows that photovoltaic devices fabricated using organic semiconductor materials from compounds S-1 to S-28 exhibit excellent performance. Among them, compound S-1, when used as an electron acceptor in organic photovoltaic materials, has an open-circuit voltage of 0.78 V and a short-circuit voltage of 24.36 mA / cm². -2 The fill factor is 67.55%, and the energy conversion efficiency is 12.80%. When compound S-2 acts as an electron acceptor in organic photovoltaic materials, its open-circuit voltage is 0.80V, and its short-circuit voltage is 26.03mA / cm². -2 The fill factor is 74.77% and the energy conversion efficiency is 15.63%.

[0187] The ring-wrapped organic semiconductor material of this invention adjusts the energy levels and broadens absorption by introducing different π-bridge conjugated connecting units. Different alkyl chains on the π-bridges improve the material's solubility and processability. Furthermore, the inclusion of symmetrical, sterically hindered ring-wrapped side chains enhances the planarity and conformational stability of the molecular conjugated framework, thereby improving intramolecular charge transport and ultimately increasing the efficiency of photovoltaic devices. This invention also provides a method for preparing the ring-wrapped organic semiconductor material. The synthesis conditions are mild, the purification process is simple, and the cost is low. The resulting material exhibits good planarity and rigidity, strong visible and near-infrared absorption characteristics, and high charge mobility, making it suitable for fabricating organic solar cells with high short-circuit current and high energy conversion efficiency.

[0188] The above are merely preferred embodiments of the present invention and are not limited to the examples described above. Those skilled in the art will recognize that various modifications and variations can be made based on the principles of the present invention. Any modifications or improvements made should be considered within the scope of protection of the present invention.

Claims

1. An organic semiconductor material with a ring-encapsulated structure, characterized in that, It has the following general structural formula: In the general structural formula, π1, π2, R1, R2, and A are selected from the following group groups: Y is selected from one of the following: —CH2—, oxygen atom, sulfur atom, selenium atom, and tellurium atom.

2. A method for preparing the ring-encapsulated organic semiconductor material s-1 as described in claim 1, characterized in that, Includes the following steps: 1) After dissolving 2.280 mmol of compound II in dichloromethane, boron tribromide was added dropwise at 0 °C under nitrogen protection. The mixture was then stirred at room temperature for 12 h. The mixture was then purified by precipitation to obtain compound III. 2) 0.784 mmol of compound III, 1.569 mmol of compound VII 1,5-dibromopentane, and 3.138 mmol of cesium carbonate were dissolved together in acetone solution, heated to 80 °C and stirred for 24 h, and then purified by column chromatography to obtain compound IV. 3) Dissolve 0.522 mmol of compound IV in dry tetrahydrofuran solution, add 1.305 mmol of n-butyllithium solution dropwise under nitrogen protection at -78 °C, stir continuously for 2 h, add 1.566 mmol of trimethyltin chloride solution dropwise, restore to room temperature and stir for 12 h, and purify by sedimentation to obtain compound V. 4) 0.142 mmol of compound V, 0.355 mmol of 5-bromo-3-(2-ethylhexyl)thiophene-2-carboxaldehyde, and 0.007 mmol of tetra(triphenylphosphine)palladium were dissolved in 10 mL of toluene and mixed thoroughly. The mixture was heated to 110 °C and reacted for 24 h under nitrogen protection. The mixture was then purified by column chromatography to obtain compound VI. 5) 0.067 mmol of compound VI was mixed with 0.147 mmol of 5,6-difluoro-3-(dicyanomethylene)indophenone, 5 mL of chloroform and 0.1 mL of pyridine and reacted at room temperature for 8 h. The mixture was then purified by column chromatography to obtain compound s-1.

3. The application of the organic semiconductor material with the ring-enclosed structure as described in claim 1, characterized in that, Applications in organic solar cells.

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