A fused ring conjugated macromolecule based on benzodipyrrole and a preparation method and application thereof

Abstract

The application discloses a kind of based on benzodipyrrole fused ring conjugated macromolecule and its preparation method and application.The structure formula of the based on benzodipyrrole fused ring conjugated macromolecule is as shown in formula I, including fused ring benzodipyrrole center nucleus and electron-withdrawing end group, fused ring benzodipyrrole center nucleus is nitrogen bridge ladder structure, and electron-withdrawing end group is connected at the two ends of center nucleus;Its preparation process is to use 4,7-dibromobenzothiadiazole and its homologues as raw material, sequentially through Stille coupling and Vilsmeier-Haack reaction to obtain fused ring benzodipyrrole center nucleus, then end group structure is introduced by Knoevenagel reaction to obtain.The fused ring conjugated macromolecule is good as acceptor material Solubility, easy to process into film, and has good photoelectric conversion function, for preparing organic solar cell device, photoelectric conversion efficiency reaches nearly 16% single node cell conversion efficiency.At the same time, this kind of material is easy to form nanoparticles, and after absorbing photons, it is easy to form carriers on the surface to improve the photocatalytic hydrogen production rate.

Description

Technical Field

[0001] This invention relates to an organic photovoltaic acceptor material, and more particularly to a benzodipyrrole-based fused-ring conjugated macromolecule and its application in organic solar cells and photocatalytic hydrogen production, belonging to the field of organic semiconductor material preparation technology. Background Technology

[0002] With economic development and the increasing prominence of energy crises and environmental pollution, humanity must develop and utilize new renewable energy sources. Solar energy, as an inexhaustible and clean energy source, is the best alternative to fossil fuels. Solar energy is commonly used to produce solar cells and for photocatalytic hydrogen production. Solar cells are highly efficient solar energy utilization devices, utilizing the photovoltaic effect of organic semiconductors to achieve photoelectric conversion. Among the various types of solar cells developed by scientists, organic solar cells have significant advantages: low cost, high flexibility, environmental friendliness, simple manufacturing process, and the ability to be printed to fabricate flexible devices. Photocatalytic water splitting for hydrogen production has unique advantages. It converts solar energy into hydrogen energy, and both the raw materials and products are renewable energy sources. Therefore, theoretically, photocatalytic water splitting for hydrogen production can simultaneously solve the two major global problems of energy shortage and environmental pollution.

[0003] Currently, the core component of organic solar cells is the active layer, prepared by blending donor and acceptor materials. This layer is primarily responsible for converting photons into electrical charges and transporting these charges to the interface, enabling them to reach the electrodes and generate current. In early research, fullerene derivatives dominated; however, their drawbacks limited the development of solar cells, such as difficulty in energy level tuning and weak absorption in the visible light region. In recent years, more and more researchers have focused on developing non-fullerene acceptor materials. The successful development of non-fullerene acceptor materials benefits from their advantages, such as ease of energy level tuning, strong and wide absorption in the visible light region, and ease of synthesis and purification. In the past five years, organic solar cells have experienced rapid development due to the development of non-fullerene acceptors. Simultaneously, using non-fullerene acceptors to prepare nanoparticles for photocatalytic hydrogen production is a novel photocatalytic hydrogen production technology. Among organic photocatalysts, photovoltaic polymers / organic nanoparticles are the easiest to process in solution, possess the most diverse chemical structure / property optimization strategies, and have achieved the best hydrogen production rates.

[0004] Currently, the most efficient non-fullerene acceptors are mainly electron-withdrawing-electron-donating-electron-withdrawing (ADA) type non-fullerene acceptors. Recent research shows that introducing electron-withdrawing groups (such as benzothiadiazole) into the D-unit conjugated framework can modulate the energy levels of the acceptor material and enhance intermolecular forces, thereby improving photon utilization. However, for efficient light emission, tight interactions are considered detrimental to fluorescence, potentially leading to changes in the emission spectrum and a decrease in fluorescence quantum yield. This results in increased nonradiative recombination, thus reducing photoelectric conversion efficiency. To further improve the photoelectric conversion efficiency and photocatalytic hydrogen production rate of organic solar cells and meet market applications, there is an urgent need for new molecular synthesis designs to develop non-fullerene acceptor molecules. Summary of the Invention

[0005] The purpose of this invention is to provide a benzodipyrrole-based fused-ring conjugated macromolecule with good film-forming properties and high photoelectric conversion efficiency, so as to solve the problem of low photoelectric conversion efficiency of organic acceptor materials in existing organic solar cells.

[0006] Based on the complementary absorption of benzodipyrrole fused-ring conjugated macromolecules with donor materials, the presence of energy levels that match the donor materials, and high and balanced carrier mobility, it can be used to fabricate organic solar cells with high short-circuit current and energy conversion efficiency.

[0007] Benzodipyrrole-based fused-ring conjugated macromolecules possess near-infrared photon absorption, energy levels that match the donor material, and high and balanced carrier mobility, making them suitable for preparing single-component nanoparticles and heterojunction nanoparticles for photocatalytic hydrogen production.

[0008] The structural formula of the polycyclic fused-ring conjugated macromolecule of benzodipyrrole provided by this invention is shown in Formula I.

[0009]

[0010] In the formula, R1 is selected from C1-C30 alkyl, C1-C30 haloalkyl, C1-C30 alkoxy, C1-C30 alkylthio, and C4-C30 aryl; R2 is selected from H, halogen substituent, cyano, C1-C30 alkyl, C1-C30 haloalkyl, C1-C30 alkoxy, C1-C30 alkylthio, and C4-C30 aryl.

[0011] Preferably, R1 is selected from C1-C20 alkyl, C1-C20 haloalkyl, C1-C20 alkoxy, C1-C20 alkylthio, and C4-C20 aryl; R2 is selected from H, halogen substituent, cyano, C1-C20 alkyl, C1-C20 haloalkyl, C1-C20 alkoxy, C1-C20 alkylthio, and C4-C20 aryl.

[0012] More preferably, R1 is selected from C1-C12 alkyl, C1-C12 haloalkyl, C1-C12 alkoxy, C1-C12 alkylthio, and C4-C12 aryl; R2 is selected from H, halogen substituent, trifluoromethyl, cyano, C1-C12 alkyl, C1-C12 haloalkyl, C1-C12 alkoxy, C1-C12 alkylthio, and C4-C12 aryl;

[0013] Ar is selected from thiophene group, thiophene derivative group, bis(thiophene) group, bis(thiophene) derivative group, tri(thiophene) group, tri(thiophene) derivative group, benzo(thiophene) group, benzo(thiophene) derivative group, pyrrolo(thiophene) group, pyrrolo(thiophene) derivative group, pyrrolo(diphenyl) group, pyrrolo(diphenyl) derivative group, pentane(thiophene) group, pentane(diphenyl) group, and pentane(diphenyl) derivative group;

[0014] When Ar is selected from a thiophene derivative group, it means that the thiophene ring contains some common substituent groups, such as C1-C20 alkyl, C1-C20 alkoxy, carbonyl, ester (such as C1-C20 alkoxyacyl), phenyl, substituted phenyl (the benzene ring mainly contains C1-C20 alkyl or C1-C20 alkoxy), thiophene, or substituted thiophene (the thiophene ring mainly contains C1-C20 alkyl or C1-C20 alkoxy); similarly, when Ar is selected from a benzodithiophene derivative group, pyrrolodithiophene derivative group, pyrrolodibenzene derivative group, pentanodithiophene derivative group, or pentanodibenzene derivative group, it means that benzodithiophene, pyrrolodithiophene, pyrrolodibenzene, pentanodithiophene, or pentanodibenzene also contains some common substituent groups similar to those on the thiophene derivative group;

[0015] Preferably, Ar is selected from any one of the following groups (these groups share common characteristics, have similar chemical properties, and are all conjugated systems constructed from thiophene and / or benzene rings, and the conjugated systems may contain some common substituent groups): (the dashed lines indicate the connection positions)

[0016]

[0017] Wherein, R3 is a C1-C20 alkyl, C1-C20 alkoxy, carbonyl, C1-C20 ester (preferably a C1-C20 alkoxyacyl), phenyl, substituted phenyl (preferably a substituted phenyl contains at least one C1-C20 alkyl and / or C1-C20 alkoxy, most preferably contains one C1-C20 alkyl or C1-C20 alkoxy), thiophene, or substituted thiophene (preferably a substituted thiophene contains at least one C1-C20 alkyl and / or C1-C20 alkoxy, most preferably contains one C1-C20 alkyl or C1-C20 alkoxy).

[0018] Wherein, R3 is a C1-C20 alkyl, C1-C20 alkoxy, carbonyl, ester (preferably a C1-C20 alkoxyacyl), phenyl, substituted phenyl (preferably a substituted phenyl contains at least one C1-C20 alkyl and / or C1-C20 alkoxy, most preferably contains one C1-C20 alkyl or C1-C20 alkoxy), thiophene, or substituted thiophene (preferably a substituted thiophene contains at least one C1-C20 alkyl and / or C1-C20 alkoxy, most preferably contains one C1-C20 alkyl or C1-C20 alkoxy).

[0019] EG is selected from any of the following groups, with the dotted lines indicating the connection positions:

[0020]

[0021] Wherein, R4 is a hydrogen atom, a halogen substituent (the halogen substituent is fluorine, chlorine, bromine or iodine), a C1-C20 alkyl group, a C1-C20 alkoxy group, a C1-C20 carbonyl group, a C1-C20 ester group (such as a C1-C20 alkoxyacyl group), or a cyano group.

[0022] This invention further provides a method for preparing the aforementioned multi-fused-ring conjugated macromolecule, comprising the following steps:

[0023] 1) Compound X and compound A undergo a Stille coupling reaction to give compound B;

[0024]

[0025] In the formula, R2 is selected from H, halogen substituents, cyano, C1-C30 alkyl, C1-C30 haloalkyl, C1-C30 alkoxy, C1-C30 alkylthio, and C4-C30 aryl.

[0026] Ar is selected from thiophene group, thiophene derivative group, bis(thiophene) group, bis(thiophene) derivative group, tri(thiophene) group, tri(thiophene) derivative group, benzo(thiophene) group, benzo(thiophene) derivative group, pyrrolo(thiophene) group, pyrrolo(thiophene) derivative group, pyrrolo(diphenyl) group, pyrrolo(diphenyl) derivative group, pentane(thiophene) group, pentane(diphenyl) group, and pentane(diphenyl) derivative group;

[0027] 2) Compound B undergoes a reduction ring-opening reaction to yield compound C;

[0028]

[0029] 3) Compound C reacts with pyridine-2-formyl chloride hydrochloride via a nucleophilic substitution reaction to give compound D;

[0030]

[0031] In the formula, Py represents pyridinyl;

[0032] 4) Compound D undergoes a ring-closing reaction to give compound E;

[0033]

[0034] 5) Compound E reacts with a haloalkane via a nucleophilic substitution reaction to give compound F;

[0035]

[0036] The chemical formula of the haloalkane is R1X, where X is a halogen and R1 is selected from C1 to C30 alkyl, C1 to C30 haloalkyl, C1 to C30 alkoxy, C1 to C30 alkylthio, and C4 to C30 aryl.

[0037] 6) Compound F was reacted with Vilsmeier-Haack to give compound G;

[0038]

[0039] 7) Compound G reacts with EG via a Knoevenagel reaction to obtain the polyfused-ring conjugated macromolecule of benzodipyrrole as shown in any one of claims 1-3 of formula I;

[0040] EG can be any of the following structures, with the dashed lines indicating the connection points:

[0041]

[0042] Wherein, R4 is a hydrogen atom, a halogen substituent (the halogen substituent is fluorine, chlorine, bromine or iodine), a C1-C20 alkyl group, a C1-C20 alkoxy group, a carbonyl group, an ester group (such as a C1-C20 alkoxyacyl group) or a cyano group.

[0043] In the above preparation method, in step 1), the conditions for the Stille coupling reaction are as follows: the solvent is toluene, the catalyst is tetrakis(triphenylphosphine)palladium, the amount of catalyst added is 0.01% to 10% of the molar amount of compound A; the molar ratio of compound X to compound A is 1:2.2 to 3.5; and the reaction is carried out under reflux at 80 to 110°C for 24 to 48 hours.

[0044] In step 2), the conditions for the reduction ring-opening reaction are as follows: the solvent is glacial acetic acid, the reducing agent is zinc powder; the molar ratio of the reducing agent to compound B is 20:1; and the reaction is carried out under reflux at 120–140°C for 1 hour.

[0045] In step 3), the nucleophilic substitution reaction conditions are as follows: the solvent is dichloromethane, the catalyst is 4-dimethylaminopyridine, the base is triethylamine, the molar ratio of the catalyst to compound C is 1-2:1, the molar ratio of pyridine-2-formyl chloride hydrochloride to compound C is 1-3:1, the molar ratio of the base to compound C is 1-2:1, and the reaction is carried out under reflux at 25-30°C for 24 hours.

[0046] In step 4), the conditions for the ring-closing reaction are as follows: the solvent is N,N-dimethylformamide, the catalyst is manganese dioxide, copper acetate and acetic acid, the molar amounts of manganese dioxide, copper acetate, acetic acid and compound D are 3-6:1-2:2-4:1, and the reaction is carried out under reflux at 200°C for 1 hour.

[0047] In step 5), the conditions for the nucleophilic substitution reaction are as follows: the solvent is N,N-dimethylformamide, the base is potassium hydroxide, the molar ratio of the haloalkane to compound E is 3-6:1, and the reaction is carried out under reflux at 80-100°C for 15-24 hours.

[0048] In step 6), the conditions for the Vilsmeier-Haack reaction are as follows: the solvent is N,N-dimethylformamide, the formylation reagent is phosphorus oxychloride, the molar ratio of compound F to the formylation reagent is 1:15-25, and the reaction is carried out under reflux at 80-105°C for 8-12 hours.

[0049] In step 7), the conditions for the Knoevenagel reaction are as follows: chloroform is used as the solvent, pyridine is used as the acid binder, the molar ratio of compound G to EG is 1:5-12, and the reaction is carried out under reflux at 60-70°C for 12-16 hours.

[0050] The benzodipyrrole polycyclic fused-ring conjugated macromolecule provided by this invention can be used as an electron acceptor material for the preparation of organic solar cells;

[0051] The active layer for light trapping in the organic solar cell is prepared by combining the polycyclic fused ring conjugated macromolecule of benzodipyrrole with an electron donor material.

[0052] The electron donor material may be at least one of PM6, D18, PBDB-T, PTB7-Th and other organic electron donor materials;

[0053] The structural formula of PM6 is shown in formula a:

[0054]

[0055] The mass ratio of the electron donor material to the polycyclic fused ring conjugated macromolecule of benzodipyrrole is 1:1 to 2, 1:1 to 1.5, 1:1, or 1:1.5.

[0056] The present invention also provides an organic solar cell in which the active layer for light harvesting is composed of an electron donor material and an electron acceptor material, wherein the electron acceptor material is a polyfused cyclic conjugated macromolecule of benzodipyrrole.

[0057] The benzodipyrrole polycyclic fused-ring conjugated macromolecules described in this invention can also be used as or prepared as single-component photocatalysts for photocatalytic hydrogen production.

[0058] The single-component photocatalyst can be prepared according to the following method:

[0059] The solution of the polycyclic fused ring conjugated macromolecules of benzodipyrrole is heated to 40-50°C and then added to an aqueous solution of a surfactant. The microemulsion is obtained by sonication. The solvent is removed and the microemulsion is filtered to obtain nanoparticles (after removing the solvent, the nanoparticles are dispersed in water and then filtered again). Platinum is loaded onto the nanoparticles to obtain the single-component photocatalyst.

[0060] Solutions of the polycyclic fused-ring conjugated macromolecules of benzo[a]pyrrole can be prepared using chloroform, dichloromethane, ethyl acetate, etc.

[0061] The mass ratio of the benzodipyrrole-based fused-ring conjugated macromolecule, the surfactant, and the platinum is 1:0.001-0.02:0.2-0.5.

[0062] The surfactant is at least one of sodium 2-(3-thienyl)ethoxybutylsulfonate (TEBS), sodium dodecyl sulfate (SDS), sodium dodecylbenzenesulfonate (SDBS), sodium cholate (SC), and other commonly used surfactants.

[0063] The single-component photocatalysts prepared by the above method are also within the scope of protection of this invention.

[0064] The benzodipyrrole polycyclic fused-ring conjugated macromolecules described in this invention can also be used as or prepared as heterojunction photocatalysts for photocatalytic hydrogen production;

[0065] The heterojunction photocatalyst is formed by the polycyclic fused-ring conjugated macromolecules of benzodipyrrole and the electron donor material.

[0066] The heterojunction photocatalyst can be prepared according to the following method:

[0067] The solution of the polycyclic fused ring conjugated macromolecules of benzodipyrrole and the electron donor material is heated and then added to an aqueous solution of a surfactant to obtain a microemulsion; the solvent is removed and the microemulsion is filtered to obtain nanoparticles; platinum is loaded onto the nanoparticles to obtain the heterojunction photocatalyst.

[0068] Solutions of the benzo[a]pyrrole polycyclic fused-ring conjugated macromolecule and electron donor material can be prepared using chloroform, dichloromethane, ethyl acetate, etc.

[0069] The mass ratio of the benzodipyrrole-based fused-ring conjugated macromolecule, the surfactant, and the platinum is 1:0.001-0.02:0.2-0.5.

[0070] The mass ratio of the benzodipyrrole-based fused-ring conjugated macromolecule to the electron donor material is 1:1-2, 1:1-1.5, 1:1, or 1:1.5.

[0071] The surfactant is at least one of sodium 2-(3-thienyl)ethoxybutylsulfonate (TEBS), sodium dodecyl sulfate (SDS), sodium dodecylbenzenesulfonate (SDBS), sodium cholate (SC), and other commonly used surfactants.

[0072] The electron donor material is at least one of PM6, D18, PBDB-T, PTB7-Th and other organic electron donor materials.

[0073] The heterojunction photocatalyst prepared by the above method also falls within the scope of protection of this invention.

[0074] Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

[0075] The benzo[a]dipyrrole-based fused-ring conjugated macromolecule of this invention possesses a unique molecular structure. Its main body comprises a fused-ring benzo[a]dipyrrole central core and electron-withdrawing end groups. The fused-ring benzo[a]dipyrrole central core is a nitrogen-bridged ladder-shaped fused-ring structure, with electron-withdrawing end groups connecting both ends of the central core. It is also modified with alkyl or alkoxy chains. The fused-ring benzo[a]dipyrrole central core unit connects the benzo[a]thiadiazole to the conjugated group through a nitrogen atom. The lone pair of electrons from the nitrogen atom participates in conjugation, increasing the electron cloud density of the conjugated system and enhancing the electron-donating ability of the central core. Simultaneously, introducing alkyl chains onto the nitrogen atom not only increases the regional flatness of the central core, potentially improving charge mobility, but also further enhances the material's solubility. Introducing electron-withdrawing groups at both ends of the fused-ring benzo[a]dipyrrole central core unit effectively broadens the absorption range and increases the absorption coefficient.

[0076] This invention is based on the fact that benzodipyrrole, a fused-ring conjugated macromolecule, has good solubility, is easy to process into films, and exhibits strong visible and near-infrared light absorption properties and high charge mobility (≥10). -4 cm 2 ·V -1 ·s -1 These materials can be used to prepare solar cell materials with high short-circuit current and energy conversion efficiency, and are a class of promising acceptor materials.

[0077] This invention is based on benzodipyrrole, a fused-ring conjugated macromolecule. Compared with previous fullerene and its derivative materials, it can control energy levels, has good film-forming properties, and has high photoelectric conversion efficiency. Its finished product can be made into flexible solar panels.

[0078] This invention is based on the fact that benzodipyrrole, a fused-ring conjugated macromolecule, has a large surface tension and can form nanoparticles with small particle size, which can be used as a single-component or heterojunction photocatalyst with a high hydrogen production rate.

[0079] This invention is based on the mild and inexpensive synthesis conditions of benzodipyrrole fused-ring conjugated macromolecules, which is conducive to large-scale production. Attached Figure Description

[0080] Figure 1 This is a synthetic route diagram of the receptor material F1 prepared in Example 1.

[0081] Figure 2 The receptor material F1 prepared in Example 1 1 H NMR.

[0082] Figure 3 The receptor material F1 prepared in Example 1 13 C NMR.

[0083] Figure 4The absorption spectra of the receptor material F1 prepared in Example 1 in chloroform solution and in thin film state are shown.

[0084] Figure 5 The image shows the cyclic voltammetry curve of the receptor material F1 prepared in Example 1.

[0085] Figure 6 The current-voltage (JV) curve of the organic solar cell prepared in Example 5 is shown.

[0086] Figure 7 This is a synthetic route diagram of the receptor material F2 prepared in Example 2.

[0087] Figure 8 The receptor material F2 prepared in Example 2 1 H NMR.

[0088] Figure 9 The receptor material F2 prepared in Example 2 13 C NMR.

[0089] Figure 10 The absorption spectra of the receptor material F2 prepared in Example 2 are shown in chloroform solution and in thin film state.

[0090] Figure 11 The image shows the cyclic voltammetry curve of the receptor material F2 prepared in Example 2.

[0091] Figure 12 The current-voltage (JV) curve of the organic solar cell prepared in Example 6 is shown.

[0092] Figure 13 This is a synthetic route diagram of the receptor material F3 prepared in Example 3.

[0093] Figure 14 The receptor material F3 prepared in Example 3 1 HNMR.

[0094] Figure 15 The receptor material F3 prepared in Example 3 13 CNMR.

[0095] Figure 16 The absorption spectra of the receptor material F3 prepared in Example 3 are shown in chloroform solution and in thin film state.

[0096] Figure 17 The image shows the cyclic voltammetry curve of the receptor material F3 prepared in Example 3.

[0097] Figure 18 The current-voltage (JV) curve of the organic solar cell prepared in Example 7 is shown.

[0098] Figure 19 This is a synthetic route diagram of the receptor material F4 prepared in Example 4.

[0099] Figure 20 The receptor material F4 prepared in Example 4 1 H NMR.

[0100] Figure 21 The absorption spectra of the receptor material F4 prepared in Example 4 are shown in chloroform solution and in thin film state.

[0101] Figure 22 The image shows the cyclic voltammetry curve of the receptor material F4 prepared in Example 4.

[0102] Figure 23 The graph shows the photocatalytic hydrogen production rate of the F1 nanoparticles prepared in Example 8.

[0103] Figure 24 The graph shows the photocatalytic hydrogen production rate of the F2 nanoparticles prepared in Example 9.

[0104] Figure 25 The graph shows the photocatalytic hydrogen production rate of PM6 / F1 nanoparticles prepared in Example 10.

[0105] Figure 26 The graph shows the photocatalytic hydrogen production rate of PM6 / F2 nanoparticles prepared in Example 11. Detailed Implementation

[0106] Unless otherwise specified, the experimental methods used in the following examples are conventional methods.

[0107] Unless otherwise specified, all materials and reagents used in the following examples are commercially available.

[0108] The technical solution of the present invention will be further illustrated below through specific experimental methods.

[0109] The dichloromethane, ethyl acetate, petroleum ether, acetic acid, 1,2-dichloroethane, and trichloromethane used in the following examples were purchased from Tianjin Concord Chemical Reagent Factory; 4,7-dibromobenzothiadiazole, 4,7-dibromo-5,6-difluorobenzothiadiazole, 4,7-dibromo-5-difluorobenzothiadiazole, 4,7-dibromo-5,6-dimethoxybenzothiadiazole, bis(triphenylphosphine)palladium dichloride, zinc powder, copper acetate, manganese dioxide, anhydrous N,N-dimethylformamide, phosphorus oxychloride, and anhydrous tetrahydrofuran were purchased from Beijing Innocare Technology Co., Ltd.; 3-(dicyanomethylene)indophenone was purchased from Jiaxing Hepu Optoelectronic Technology Co., Ltd. All the purchased reagents were used directly without further processing.

[0110] Example 1: Preparation of fused-ring conjugated macromolecules of benzodipyrrole as shown in Formula I

[0111] In Formula I, the substituents are as follows:

[0112] R1 is Ar for R3 is

[0113] EG is When R2 is H-----.

[0114] Synthesis route diagram as follows Figure 1 As shown:

[0115] (1) Compound 2 and compound 1 are coupled via a Stille coupling reaction to give compound 3:

[0116]

[0117] Compound 1 (14.89 g, 25 mmol), compound 2 (3 g, 10 mmol), and Pd(PPh3)Cl2 (1.12 g, 1 mmol) and toluene (100 mL) were added to a round-bottom flask and stirred overnight at 110 °C. The reaction mixture was cooled to room temperature, and then the solvent was removed under reduced pressure. Chromatographic purification was performed on a silica gel column using dichloromethane / petroleum ether (1 / 3, v / v) as eluent to give compound 3 as a red solid (5.45 g, 74% yield).

[0118] (2) Compound 3 reacts with zinc powder and glacial acetic acid under nitrogen protection in a redox reaction to obtain compound 4:

[0119]

[0120] Compound 3 (5.45 g, 7.56 mmol), zinc powder (4.84 g, 75.6 mmol), and acetic acid (30 mL) were added to a round-bottom flask, and nitrogen gas was bubbled through the flask for 10 min. The mixture was stirred at 120 °C for 3 h. After cooling to room temperature, the mixture was filtered, and the resulting liquid phase was extracted twice with dichloromethane. The organic phase was dried over MgSO4. The solvent was removed under reduced pressure to give a red liquid. No further purification was required; proceed directly to the next step.

[0121] (3) Compound 4 undergoes a nucleophilic substitution reaction with 4-dimethylaminopyridine,pyridine-2-formyl chloride hydrochloride to give compound 5:

[0122]

[0123] Compound 4 (0.85 g, 1.2 mmol), N,N-dimethyl-4-aminopyridine hydrochloride (0.28 g, 2.31 mmol), triethylamine (0.3 mL), and dichloromethane (30 mL) were added to a three-necked round-bottom flask. The mixture was stirred at room temperature for 24 h, and then quenched with water. The mixture was extracted with dichloromethane, and the organic phase was dried over MgSO4. Purification was achieved by silica gel column chromatography using ethyl acetate / petroleum ether (1 / 3, v / v) as eluent, yielding compound 5 as a yellow solid (0.54 g, 51% yield).

[0124] (4) Compound 5, anhydrous copper acetate, manganese dioxide, and acetic acid undergo a condensation-ring-closure reaction under nitrogen protection to give compound 6:

[0125]

[0126] Compound 5 (0.65 g, 0.72 mmol), Cu(OAc)₂ (0.16 g, 0.86 mmol), MnO₂ (0.25 g, 2.88 mmol), AcOH (0.1 mL), and DMF (8 mL) were added to a round-bottom flask, and nitrogen gas was purged for 10 min. The mixture was stirred at 200 °C for 3 h. After cooling to room temperature, the mixture was filtered through diatomaceous earth, extracted with dichloromethane, and the organic phase was dried over MgSO₄. After removing the solvent under reduced pressure, a black solid was obtained, which could be directly proceeded to the next step without further purification.

[0127] (5) Compound 6 reacts with a haloalkane via a nucleophilic substitution reaction to give compound 7:

[0128]

[0129] Compound 6 (0.37 g, 0.542 mmol), 1-Bromo-2-ethylhexane (1.04 g, 5.42 mmol), KI (0.07 g, 0.43 mmol), cesium carbonate (1.75 g, 5.42 mmol), and DMF (10 mL) were added to a round-bottom flask, purged with argon for 15 min, and stirred at 80 °C for 15 h. After cooling to room temperature, the solvent was removed under reduced pressure, and the mixture was extracted with ethyl acetate. The organic phase was dried over MgSO4 and purified by silica gel column chromatography using dichloromethane / petroleum ether (1 / 10, v / v) as eluent, yielding a yellow solid (0.15 g, 23% yield).

[0130] (6) Compound 7 was given to compound 8 via the Vilsmeier-Haack reaction;

[0131]

[0132] POCl3 (0.3 mL) and DMF (3 mL) were added to a three-necked round-bottom flask, nitrogen gas was purged for 10 min, and the mixture was stirred at 0 °C for 2 h. Then, compound 7 (0.15 g, 0.16 mmol) was dissolved in 1,2-dichloroethane solution (5 mL) and added to the reaction flask. The mixture was stirred at 80 °C for 12 h, cooled to room temperature, extracted with saturated CH3COONa (aq), and then extracted with dichloromethane (2 x 10 mL). The organic phase was dried over anhydrous MgSO4 and filtered. After removing the solvent from the filtrate, the mixture was purified by column chromatography on silica gel using petroleum ether / dichloromethane (3 / 1, v / v) as the eluent to give an orange solid (0.13 g, 84% yield).

[0133] (7) Compounds 8 and 5,6-difluoro-3-(dicyanomethylene)indone were reacted via the Knoevenagel reaction to yield the F1 acceptor material (Formula I-1):

[0134]

[0135] Compound 8 (0.13 g, 0.15 mmol), 5,6-difluoro-3-(dicyanomethylene)indophenone (184 mg, 0.8 mmol, purchased from Hepu Optoelectronics Co., Ltd.), pyridine (0.5 mL), and chloroform (15 mL) were added to a three-necked round-bottom flask. Nitrogen gas was purged for 15 min, then the mixture was refluxed and stirred for 12 h. After cooling to room temperature, methanol (50 mL) was added, and the mixture was filtered. Silica gel column chromatography was performed using petroleum ether / dichloromethane (2 / 1, v / v) as eluent to give a blue solid (0.12 g, 76% yield).

[0136] Nuclear magnetic resonance spectrum as follows Figure 2 , Figure 3 As shown: 1 H NMR (400MHz, CD2Cl2): δ9.11 (s, 2H), 8.53 (t, J=8.0Hz, 2H), 7.72-7.69 (m, 2H), 7.63 (s, 2H), 4.73 (d, J=8.0Hz, 4H), 3.20 (t, J=8.0Hz, 4H), 2.06-2.02 (m, 2H), 1.86 (t, J=8.0Hz, 4H), 1.37-0.85 (m, 48H), 0.85-0.73 (m, 12H), 0.66-0.59 (m, 6H). 13C NMR (101MHz, CD2Cl2): δ186.39, 159.38, 156.04, 154.18, 153.30, 1544.37, 13 9.15, 137.05, 135.61, 135.10, 133.54, 131.08, 123.57, 120.08, 115.49, 115. 27, 115.22, 112.78, 112.61, 68.71, 55.62, 55.37, 53.83, 53.56, 40.63, 32.34 , 31.57, 30.04, 29.91, 29.75, 28.03, 23.83, 23.11, 14.28, 13.90, 10.59, 0.00. MS(MALDI-TOF) m / z calcd. for(C 82 H 88 F4N6O2S4): 1392.58. Found: 1393.83.

[0137] The UV-Vis absorption spectrum of F1 is as follows: Figure 4 As shown, the solution exhibits a strong absorption peak in the wavelength range of 600–800 nm, with a maximum molar extinction coefficient of 2.3 × 10⁻⁶. 5 M –1 ·cm –1 The film absorbs most strongly at around 804 nm; the maximum absorption peak of the film is redshifted by 68 nm compared to that in the solution.

[0138] Cyclic voltammetry curves as shown Figure 4 As shown, its HOMO energy level is -5.64 eV, its LUMO energy level is -3.81 eV, and its band gap is 1.83 eV, indicating that the multi-fused ring conjugated macromolecule shown in Formula I-1 has good electron acceptance ability and can match the energy levels of most common electron donor materials.

[0139] Example 2: Preparation of fused-ring conjugated macromolecules of benzodipyrrole

[0140] The substituents in Formula I are as follows:

[0141] R1 is Ar for R3 is

[0142] EG is When R2 is F-----.

[0143] Synthetic routes such as Figure 7 As shown.

[0144] (1) Compound 2 and compound 1 are coupled via a Stille coupling reaction to give compound 3:

[0145]

[0146] Compound 1 (14.89 g, 25 mmol), compound 2 (3 g, 10 mmol), and Pd(PPh3)Cl2 (1.12 g, 1 mmol) and toluene (100 mL) were added to a round-bottom flask and stirred overnight at 110 °C. The reaction mixture was cooled to room temperature, and then the solvent was removed under reduced pressure. Chromatographic purification was performed on a silica gel column using dichloromethane / petroleum ether (1 / 3, v / v) as eluent to give compound 3 as a red solid (5.45 g, 74% yield).

[0147] (2) Compound 3 reacts with zinc powder and glacial acetic acid under nitrogen protection in a redox reaction to obtain compound 4:

[0148]

[0149] Compound 3 (5.54 g, 7.56 mmol), zinc powder (4.84 g, 75.6 mmol), and acetic acid (30 mL) were added to a round-bottom flask, and nitrogen gas was bubbled through for 10 min. The mixture was stirred at 120 °C for 3 h. After cooling to room temperature, the mixture was filtered, and the resulting liquid phase was extracted twice with dichloromethane. The organic phase was dried over MgSO4. The solvent was removed under reduced pressure to give a red liquid. No further purification was required; proceed directly to the next step.

[0150] (3) Compound 4 undergoes a nucleophilic substitution reaction with 4-dimethylaminopyridine,pyridine-2-formyl chloride hydrochloride to give compound 5:

[0151]

[0152] Compound 4 (1.07 g, 1.4 mmol), N,N-dimethyl-4-aminopyridine hydrochloride (0.28 g, 2.31 mmol), triethylamine (0.4 mL), and dichloromethane (30 mL) were added to a three-necked round-bottom flask and stirred at room temperature for 24 h. The mixture was then quenched with water. The mixture was extracted with dichloromethane, and the organic layer was dried over MgSO4 and filtered. After removing the solvent under reduced pressure, the mixture was purified by silica gel column chromatography using ethyl acetate / petroleum ether (1 / 3, v / v) as eluent to give compound 5 as a yellow solid (0.71 g, 51% yield).

[0153] (4): Compound 5, anhydrous copper acetate, manganese dioxide and acetic acid undergo a condensation and cyclization reaction under nitrogen protection to give compound 6:

[0154]

[0155] Compound 5 (0.65 g, 0.72 mmol), Cu(OAc)₂ (0.16 g, 0.86 mmol), MnO₂ (0.25 g, 2.88 mmol), AcOH (0.1 mL), and DMF (8 mL) were added to a round-bottom flask, and nitrogen gas was purged for 10 min. The mixture was stirred at 200 °C for 3 h. After cooling to room temperature, the mixture was filtered through diatomaceous earth, extracted with dichloromethane, and the organic layer was dried with MgSO₄. After removing the solvent under reduced pressure, a black solid was obtained, which could be directly proceeded to the next step without further purification.

[0156] (5) Compound 6 reacts with a haloalkane via a nucleophilic substitution reaction to give compound 7:

[0157]

[0158] Compound 6 (0.4 g, 0.54 mmol), 1-Bromo-2-ethylhexane (1.04 g, 5.42 mmol), KI (0.07 g, 0.43 mmol), cesium carbonate (1.75 g, 5.42 mmol), and DMF (10 mL) were added to a round-bottom flask, purged with argon for 15 min, and stirred at 80 °C for 15 h. After removing the solvent from the filtrate, the organic phase was extracted with ethyl acetate and water. The organic phase was dried over MgSO4 and filtered. After removing the solvent under reduced pressure, the phase was purified by silica gel column chromatography using dichloromethane / petroleum ether (1 / 10, v / v) as the eluent, yielding a yellow solid. This solid was added to the next step as soon as possible to prevent spoilage.

[0159] (6) Compound 7 was given to compound 8 via the Vilsmeier-Haack reaction;

[0160]

[0161] POCl3 (0.3 mL) and DMF (3 mL) were added to a three-necked round-bottom flask, nitrogen gas was purged for 10 min, and the mixture was stirred at 0 °C for 2 h. Then, compound 7 (0.15 g, 0.16 mmol) was dissolved in 1,2-dichloroethane solution (5 mL) and added to the reaction flask. After stirring at 80 °C for 12 h, the mixture was cooled to room temperature, quenched with saturated CH3COONa(aq), and extracted with dichloromethane (2 x 10 mL). The organic phase was dried over anhydrous MgSO4 and filtered. After removing the solvent from the filtrate, the mixture was purified by column chromatography on silica gel using petroleum ether / dichloromethane (3 / 1, v / v) as the eluent to give an orange solid (0.13 g, 84% yield).

[0162] (7) Compounds 8 and 5,6-difluoro-3-(dicyanomethylene)indoline ketone were used to obtain F2 acceptor materials via the Knoevenagel reaction:

[0163]

[0164] Compound 8 (0.13 g, 0.15 mmol), 5,6-difluoro-3-(dicyanomethylene)indophenone (184 mg, 0.8 mmol, purchased from Hepu Optoelectronics Co., Ltd.), pyridine (0.5 mL), and chloroform (CHCl3) (15 mL) were added to a three-necked round-bottom flask. Nitrogen gas was purged for 15 min, followed by reflux and stirring for 12 h. After cooling to room temperature, the reaction mixture was poured into methanol (50 mL) and filtered. The resulting solid was purified by silica gel column chromatography using petroleum ether / dichloromethane (2 / 1, v / v) as eluent, finally yielding a blue solid (0.12 g, 76% yield).

[0165] Nuclear magnetic resonance spectrum as follows Figure 8 , Figure 9 As shown: 1 H NMR (400MHz, CDCl3): δ9.16 (s, 2H), 8.58 (m, 2H), 7.74-7.65 (m, 2H), 4.68 (d, J=8.0Hz, 4H), 3.21 (t, J=8 .0Hz, 4H), 2.04(s, 2H), 1.87-1.84(m, 4H), 1.54-1.26(m, 48H), 0.90-0.85(m, 12H), 0.75-0.68(m, 6H). 13 C NMR (101MHz, CDCl3): δ158.72, 155.75, 153.76, 153.20, 152.99, 145.12, 139.15, 136. 70, 135.50, 134.54, 133.26, 128.67, 126.03, 120.08, 115.49, 115.27, 114.83, 114.44 , 112.41, 77.32, 77.00, 76.69, 69.00, 55.35, 53.40, 40.10, 38.81, 38.64, 36.58, 34.3 1, 31.49, 30.01, 29.63, 29.35, 27.86, 27.19, 23.23, 22.83, 19.09, 14.09, 11.39, 0.00. MS(MALDI-TOF)m / zcalcd. for(C 82 H 86 F6N6O2S4): 1428.86. Found: 1429.7.

[0166] The UV-Vis absorption spectrum of F2 is as follows: Figure 10 As shown, the solution exhibits a strong absorption peak in the wavelength range of 600–800 nm, with a maximum molar extinction coefficient of 2.0 × 10⁻⁶. 5 M –1·cm –1 The film exhibits the strongest absorption at 769 nm; the maximum absorption peak of the film is redshifted by 63 nm compared to that in the solution.

[0167] Cyclic voltammetry curves as shown Figure 11 As shown, its HOMO energy level is -5.74 eV, its LUMO energy level is -3.96 eV, and its band gap is 1.78 eV, indicating that the multi-fused ring conjugated macromolecule shown in Formula I-2 has good electron acceptance ability and can match the energy levels of most common electron donor materials.

[0168] Example 3: Preparation of fused-ring conjugated macromolecules of benzodipyrrole

[0169] The substituents in Formula I are as follows:

[0170] R1 is Ar for R3 is

[0171] EG is When R2 is F-----, H-----.

[0172] Synthetic routes such as Figure 13 As shown.

[0173] (1) Compound 2 and compound 1 are coupled via a Stille coupling reaction to give compound 3:

[0174]

[0175] Compound 1 (14.00 g, 24 mmol), compound 2 (3.1 g, 9.5 mmol), and Pd(PPh3)Cl2 (1.12 g, 1 mmol) and toluene (100 mL) were added to a round-bottom flask and stirred overnight at 110 °C. The reaction mixture was cooled to room temperature, and the solvent was removed under reduced pressure. Chromatographic purification was performed on a silica gel column using dichloromethane / petroleum ether (1 / 3, v / v) as eluent to give compound 3 as a red solid (5.45 g, 74% yield).

[0176] (2) Compound 3 reacts with zinc powder and glacial acetic acid under nitrogen protection in a redox reaction to obtain compound 4:

[0177]

[0178] Compound 3 (5.50 g, 7.56 mmol), zinc powder (4.84 g, 75.6 mmol), and acetic acid (30 mL) were dissolved in a round-bottom flask, and nitrogen gas was bubbled through the flask for 10 min. The mixture was stirred at 120 °C for 3 h. After cooling to room temperature, the mixture was filtered, and the resulting liquid phase was extracted twice with dichloromethane. The organic phase was dried over MgSO4. The solvent was removed under reduced pressure to give a red liquid. No further purification was required; proceed directly to the next step.

[0179] (3) Compound 4 undergoes a nucleophilic substitution reaction with 4-dimethylaminopyridine,pyridine-2-formyl chloride hydrochloride to give compound 5:

[0180]

[0181] Compound 4 (1.00 g, 1.4 mmol), N,N-dimethyl-4-aminopyridine hydrochloride (0.28 g, 2.31 mmol), triethylamine (0.4 mL), and dichloromethane (30 mL) were added to a three-necked round-bottom flask and stirred at room temperature for 24 h. The mixture was then quenched with water. The mixture was extracted with dichloromethane, and the organic layer was dried over MgSO4 and filtered. After removing the solvent under reduced pressure, the mixture was purified by silica gel column chromatography using ethyl acetate / petroleum ether (1 / 3, v / v) as eluent to give compound 5 as a yellow solid (0.65 g, 51% yield).

[0182] (4) Compound 5, anhydrous copper acetate, manganese dioxide and acetic acid undergo a condensation-ring-closure reaction under nitrogen protection to give compound 6:

[0183]

[0184] Compound 5 (0.65 g, 0.71 mmol), copper acetate (0.16 g, 0.86 mmol), manganese dioxide (0.25 g, 2.88 mmol), acetic acid (0.1 mL), and N,N-dimethylformamide (8 mL) were added to a round-bottom flask, and nitrogen gas was purged for 10 min. The mixture was stirred at 200 °C for 3 h. After cooling to room temperature, the mixture was filtered through diatomaceous earth, extracted with dichloromethane, and the organic layer was dried with anhydrous magnesium sulfate. After removing the solvent under reduced pressure, a black solid was obtained, which could be directly proceeded to the next step without further purification.

[0185] (5) Compound 6 reacts with a haloalkane via a nucleophilic substitution reaction to give compound 7:

[0186]

[0187] Compound 6 (0.38 g, 0.54 mmol), 1-Bromo-2-ethylhexane (1.04 g, 5.42 mmol), KI (0.07 g, 0.43 mmol), cesium carbonate (1.75 g, 5.42 mmol), and DMF (10 mL) were added to a round-bottom flask, purged with argon for 15 min, and stirred at 80 °C for 15 h. After removing the solvent from the filtrate, the organic phase was extracted with ethyl acetate and water. The organic phase was dried over MgSO4 and filtered. After removing the solvent under reduced pressure, the phase was purified by silica gel column chromatography using dichloromethane / petroleum ether (1 / 10, v / v) as the eluent, yielding a yellow solid. This solid was added to the next step as soon as possible to prevent spoilage.

[0188] (6) Compound 7 was given to compound 8 via the Vilsmeier-Haack reaction;

[0189]

[0190] POCl3 (0.3 mL) and DMF (3 mL) were added to a three-necked round-bottom flask, nitrogen gas was purged for 15 min, and the mixture was stirred at 0 °C for 2 h. Then, compound 7 (0.16 g, 0.16 mmol) was dissolved in 1,2-dichloroethane solution (5 mL) and added to the reaction flask. After stirring at 80 °C for 12 h, the mixture was cooled to room temperature, quenched with saturated CH3COONa(aq), and extracted with dichloromethane (2 x 10 mL). The organic phase was dried over anhydrous MgSO4 and filtered. After removing the solvent from the filtrate, the mixture was purified by column chromatography on silica gel using petroleum ether / dichloromethane (3 / 1, v / v) as the eluent to give an orange solid (0.13 g, 84% yield).

[0191] (7) Compounds 8 and 5,6-difluoro-3-((dicyanomethylene)indoline ketone were used to obtain F3 acceptor materials via the Knoevenagel reaction:

[0192]

[0193] Synthesis of F3: Compound 8 (0.1 g, 0.10 mmol), 5,6-difluoro-3-(dicyanomethylene)indophenone (184 mg, 0.8 mmol), pyridine (0.5 mL), and chloroform (15 mL) were added to a three-necked round-bottom flask. Nitrogen gas was purged for 15 min, then the mixture was refluxed and stirred for 12 h. After cooling to room temperature, methanol (50 mL) was added and the mixture was filtered. Silica gel column chromatography was performed using petroleum ether / dichloromethane (2 / 1, v / v) as eluent to give a blue solid (0.11 g, 76% yield).

[0194] Nuclear magnetic resonance spectrum as follows Figure 14 , Figure 15 As shown: 1H NMR (300MHz, CDCl3): δ9.13 (s, 2H), 8.55 (m, 2H), 7.73 (m, 2H), 7.26 (s, 1H) 4.68 (d, J=6.0Hz, 4H), 3.1 9(t, J=6.0Hz, 4H), 2.34-1.83(m, 6H), 1.85-1.1.82(m, 25H), 1.38-1.22(m, 33H), 1.05-0.66(m, 11H). 13 C NMR (101MHz, CDCl3): δ186.16, 158.85, 153.92, 145.04, 143.96, 139.54, 138.44, 136.39, 135.81, 135.34, 134.50, 133.21, 129.37, 126.6 4, 119.79, 115.04, 114.83, 114.56, 112.39, 77.34, 77.02, 76.70, 56.06, 40.08, 29.71, 29.35, 27.57, 22.23, 19.11, 14.13, 13.73, 10.32. (MALDI-TOF)m / zcalcd. for(C 58 H 87 F5N6O2S4):968.50. Found:1410.57.

[0195] The UV-Vis absorption spectrum of F3 is as follows: Figure 16 As shown, the solution exhibits a strong absorption peak in the wavelength range of 600–800 nm, with a maximum molar extinction coefficient of 1.5 × 10⁻⁶. 5 M –1 ·cm –1 The film exhibits the strongest absorption at 788 nm; the maximum absorption peak of the film is redshifted by 68 nm compared to that in the solution.

[0196] Cyclic voltammetry curves as shown Figure 17 As shown, its HOMO energy level is -5.64 eV, its LUMO energy level is -3.97 eV, and its band gap is 1.67 eV, indicating that the multi-fused ring conjugated macromolecule shown in Formula I-3 has good electron acceptance ability and can match the energy levels of most common electron donor materials.

[0197] Example 4: Preparation of fused-ring conjugated macromolecules of benzodipyrrole

[0198] The substituents in Formula I are as follows:

[0199] R1 is Ar for R3 is

[0200] EG is At that time, R2 is H3CO-----.

[0201] Synthetic routes such as Figure 19 As shown.

[0202] (1) Compound 2 and compound 1 are coupled via a Stille coupling reaction to give compound 3:

[0203]

[0204] Compound 1 (14.00 g, 24 mmol), compound 2 (3.3 g, 8.5 mmol), and Pd(PPh3)Cl2 (1.12 g, 1 mmol) and toluene (100 mL) were added to a round-bottom flask and stirred overnight at 110 °C. The reaction mixture was cooled to room temperature, and then the solvent was removed under reduced pressure. Chromatographic purification was performed on a silica gel column using dichloromethane / petroleum ether (1 / 3, v / v) as eluent to give compound 3 as a red solid (5.5 g, 82% yield).

[0205] (2) Compound 3 reacts with zinc powder and glacial acetic acid under nitrogen protection in a redox reaction to obtain compound 4:

[0206]

[0207] Compound 3 (5.90 g, 7.56 mmol), zinc powder (4.84 g, 75.6 mmol), and acetic acid (30 mL) were dissolved in a round-bottom flask, and nitrogen gas was bubbled through the flask for 10 min. The mixture was stirred at 120 °C for 3 h. After cooling to room temperature, the mixture was filtered, and the resulting liquid phase was extracted twice with dichloromethane. The organic phase was dried over MgSO4. The solvent was removed under reduced pressure to give a red liquid. No further purification was required; proceed directly to the next step.

[0208] (3) Compound 4 undergoes a nucleophilic substitution reaction with 4-dimethylaminopyridine,pyridine-2-formyl chloride hydrochloride to give compound 5:

[0209]

[0210] Compound 4 (1.01 g, 1.4 mmol), N,N-dimethyl-4-aminopyridine hydrochloride (0.28 g, 2.31 mmol), triethylamine (0.4 mL), and dichloromethane (30 mL) were added to a three-necked round-bottom flask and stirred at room temperature for 24 h. The mixture was then quenched with water. The mixture was extracted with dichloromethane, and the organic layer was dried over MgSO4 and filtered. After removing the solvent under reduced pressure, the mixture was purified by silica gel column chromatography using ethyl acetate / petroleum ether (1 / 3, v / v) as eluent to give compound 5 as a yellow solid (0.67 g, 51% yield).

[0211] (4): Compound 5, anhydrous copper acetate, manganese dioxide and acetic acid undergo a condensation and cyclization reaction under nitrogen protection to give compound 6:

[0212]

[0213] Compound 5 (0.67 g, 0.70 mmol), copper acetate (0.16 g, 0.86 mmol), manganese dioxide (0.25 g, 2.88 mmol), acetic acid (0.1 mL), and N,N-dimethylformamide (8 mL) were added to a round-bottom flask, and nitrogen gas was purged for 10 min. The mixture was stirred at 200 °C for 3 h. After cooling to room temperature, the mixture was filtered through diatomaceous earth, extracted with dichloromethane, and the organic layer was dried with anhydrous magnesium sulfate. After removing the solvent under reduced pressure, a black solid was obtained, which could be directly proceeded to the next step without further purification.

[0214] (5) Compound 6 reacts with a haloalkane via a nucleophilic substitution reaction to give compound 7:

[0215]

[0216] Compound 6 (0.40 g, 0.54 mmol), 1-Bromo-2-ethylhexane (1.04 g, 5.42 mmol), KI (0.07 g, 0.43 mmol), cesium carbonate (1.75 g, 5.42 mmol), and DMF (10 mL) were added to a round-bottom flask, purged with argon for 15 min, and stirred at 80 °C for 15 h. After removing the solvent from the filtrate, the organic phase was extracted with ethyl acetate and water. The organic phase was dried over MgSO4 and filtered. After removing the solvent under reduced pressure, the phase was purified by silica gel column chromatography using dichloromethane / petroleum ether (1 / 10, v / v) as the eluent, yielding a yellow solid. This solid was added to the next step as soon as possible to prevent spoilage.

[0217] (6) Compound 7 was given to compound 8 via the Vilsmeier-Haack reaction;

[0218]

[0219] POCl3 (0.3 mL) and DMF (3 mL) were added to a three-necked round-bottom flask, nitrogen gas was purged for 15 min, and the mixture was stirred at 0 °C for 2 h. Then, compound 7 (0.16 g, 0.16 mmol) was dissolved in 1,2-dichloroethane solution (5 mL) and added to the reaction flask. After stirring at 80 °C for 12 h, the mixture was cooled to room temperature, quenched with saturated CH3COONa(aq), and extracted with dichloromethane (2 x 10 mL). The organic phase was dried over anhydrous MgSO4 and filtered. After removing the solvent from the filtrate, the mixture was purified by column chromatography on silica gel using petroleum ether / dichloromethane (3 / 1, v / v) as the eluent to give an orange solid (0.14 g, 84% yield).

[0220] (7) Compounds 8 and 5,6-difluoro-3-(dicyanomethylene)indoline ketone were used to obtain F4 acceptor materials via the Knoevenagel reaction:

[0221]

[0222] Synthesis of F4: Compound 8 (0.1 g, 0.10 mmol), 5,6-difluoro-3-(dicyanomethylene)indophenone (184 mg, 0.8 mmol), pyridine (0.5 mL), and chloroform (15 mL) were added to a three-necked round-bottom flask. Nitrogen gas was purged for 15 min, then the mixture was refluxed and stirred for 12 h. After cooling to room temperature, methanol (50 mL) was added and the mixture was filtered. Silica gel column chromatography was performed using petroleum ether / dichloromethane (2 / 1, v / v) as eluent to give a blue solid (0.12 g, 76% yield).

[0223] Nuclear magnetic resonance spectrum as follows Figure 20 As shown: 1 H NMR (300MHz, CDCl3): δ9.15 (s, 2H), 8.57 (t, J=9.0Hz, 2H), 7.70 (t, J=9.0Hz, 2H), 4.62 (d, J=9.0Hz, 4H), 4 .19(m, 6H), 3.22(m, 4H), 2.07-1.99(m, 6H), 1.85-1.55(m, 25H), 1.51-1.14(m, 33H), 1.09-0.69(m, 12H). (MALDI-TOF)m / zcalcd. for(C 58 H 92 N6F4O4S4):1452.08. Found:1453.97.

[0224] The UV-Vis absorption spectrum of F4 is as follows: Figure 21 As shown, the solution exhibits a strong absorption peak in the wavelength range of 600–800 nm, with a maximum molar extinction coefficient of 1.3 × 10⁻⁶. 5 M –1 ·cm –1 The film exhibits the strongest absorption at 818 nm; the maximum absorption peak of the film is redshifted by 74 nm compared to that in the solution.

[0225] Cyclic voltammetry curves as shown Figure 22 As shown, its HOMO energy level is -5.60 eV, LUMO energy level is -3.87 eV, and band gap is 1.75 eV, indicating that the multi-fused ring conjugated macromolecule shown in I-4 has good electron acceptance ability and can match the energy levels of most common electron donor materials.

[0226] Example 5: Fabrication of Organic Solar Cells

[0227] The indium tin oxide (ITO) glass used as the cathode (purchased from Shenzhen Nanbo Float Glass Co., Ltd.) was first cleaned with detergent, then ultrasonically cleaned with deionized water, acetone, and isopropanol in sequence. After drying, a 30nm thick PEDOT:PSS anode modification layer was spin-coated and dried at 150℃ for 15 minutes for later use.

[0228] Commercially available PM6 was used as the donor material and F1 as the acceptor material, and a solution of 16 mg / mL was prepared at a mass ratio of 1:1 or 1:1.5. This solution was then spin-coated onto the aforementioned PEDOT:PSS layer, and after drying, a light-harvesting active layer (with an effective area of ​​4 mm²) was obtained. 2 A 5 nm thick PDINN cathode modification layer was spin-coated onto the active layer under vacuum (absolute pressure 2 × 10⁻⁶). - 5 A metallic Ag of approximately 80 nm is deposited by vapor deposition (Pa) as the cathode of a solar cell.

[0229] A simulated solar light source was used with an AM1.5 filter (SAN-EI ELECTRIC Co., Ltd. model XES-70S1), at 100mW / cm². 2 Photocurrent density was measured under varying light intensity, calibrated using a standard monocrystalline silicon solar cell (purchased from VLSI Standards Inc.). Dark current density was also measured in the dark state. The resulting IV curves were measured using a Keithley 2450 Source-Measure Unit, controlled by a computer via LabVIEW software. The resulting IV curves are shown below. Figure 6 As shown.

[0230] The performance of a solar cell made using commercially available PM6 as the donor material and F1 as the acceptor material, according to the ITO / PEDOT:PSS / PM6:F1 / PDINN / Ag ratio.

[0231] Table 1 lists the performance parameters of the solar cells with different ratios of PM6 and F1 materials in the active layer.

[0232] Table 1. Parameters of solar cell devices based on acceptor materials

[0233]

[0234] Example 6: Fabrication of Organic Solar Cells

[0235] Organic solar cells were prepared using Formula I-2 (F2) as the acceptor material, following the method described in Example 5.

[0236] The photocurrent density test method is the same as in Example 5, and the obtained IV curve is shown below. Figure 12 As shown.

[0237] Commercially available PM6 was used as the donor material and F2 as the acceptor material, prepared into a 16 mg / mL solution at a mass ratio of 1:1 or 1:1.5. The performance of solar cells fabricated using ITO / PEDOT:PSS / PM6:F2 / PDINN / Ag was analyzed. The highest photoelectric conversion efficiency (15.6%) was observed when the PM6:F2 mass ratio was 1:1.5, with an open-circuit voltage of 0.902 V and a short-circuit current of 22.5 mA / cm². 2 The fill factor is 77.5%.

[0238] Example 7: Fabrication of Organic Solar Cells

[0239] Organic solar cells were prepared using Formula I-3 (F3) as the acceptor material, following the method in Example 5.

[0240] The photocurrent density test method is the same as in Example 5, and the obtained IV curve is shown below. Figure 18 As shown.

[0241] Commercially available PM6 was used as the donor material and F3 as the acceptor material, prepared into a 16 mg / mL solution at a mass ratio of 1:1 or 1:1.5. The performance of solar cells fabricated using ITO / PEDOT:PSS / PM6:F3 / PDINN / Ag was analyzed. The highest photoelectric conversion efficiency (15.2%) was observed when the PM6:F3 mass ratio was 1:1.5, with an open-circuit voltage of 0.914 V and a short-circuit current of 22.3 mA / cm². 2 The fill factor is 75.6%.

[0242] Example 8: Preparation and Application of Photocatalytic Single-Component Nanoparticles

[0243] Dissolve F1 (1 mg) in 2 mL of chloroform to prepare a 0.5 mg / mL solution. -1The solution was heated at 50°C for 2 hours. The nanoparticle precursor solution (1 mL) was added to 4 mL of 2-(3-thienyl)ethoxybutylsulfonate (TEBS) aqueous solution at different mass ratios. The solution was then sonicated for 5 minutes using a sonic SCIENTZ-IID processor to obtain a microemulsion. The microemulsion was evaporated to remove chloroform, yielding nanoparticles with a stable surfactant dispersed in water. Finally, the dispersion was filtered (0.45 μm mixed cellulose) to remove any large aggregates. The final composition was determined as follows: 2 mL of methanol was added to 1 mL of the sample for deemulsification. Then, a certain amount of chloroform was added to extract the semiconductor material from the mixture. Finally, the final mass of the nanoparticles in the solution was determined by UV-Vis measurement.

[0244] Nanoparticles (50 μg) formed by F1 were added to 7.5 mL of 0.2 M ascorbic acid aqueous solution and placed in a circulating batch reactor (5.786 cm²) at 5 °C. 2 In. By adding a certain amount of potassium hexachloroplatinate aqueous solution (0.4 mg / mL) -1 The desired platinum loading was obtained by purging the reactor with nitrogen multiple times to remove oxygen, and the pressure was set to 1.4 kPa. Unless otherwise specified, all suspensions containing nanoparticles of formula (1) above were stirred and illuminated with a 300 W Xe lamp equipped with a mirror module (330–1100 nm) and an AM 1.5 G filter. The nanoparticles in the suspension were then irradiated under light of 400–800 nm. Hydrogen evolution was evaluated using an all-glass fully automated online trace gas analysis system (lab solar-6a, PerfectLight) and an online gas chromatograph (thermal conductivity detector, nitrogen carrier). The photocatalytic performance of F1 nanoparticles with different TEBS weight ratios and platinum loading ratios was determined under AM 1.5 G illumination. Unless otherwise specified, all illumination intensities were 100 mW / cm². -2 The resulting hydrogen production rate curve is as follows: Figure 23 As shown, F1NPs achieved 81.75 mmol / h in 4 hours under a loading of 0.4 wt.% TEBS and 33 wt.% Pt. -1 ·g -1 The average hydrogen production rate.

[0245] Example 9: Preparation and Application of Photocatalytic Single-Component Nanoparticles

[0246] Following the method in Example 8, the F2 acceptor material was fabricated into photocatalytic single-component nanoparticles, and photocatalytic hydrogen production was performed. The resulting hydrogen production rate curve is shown below. Figure 24As shown, F2NPs achieved 121.6 mmol / h in 4 hours with a loading of 0.4 wt.% TEBS and 33 wt.% Pt. -1 ·g -1 Optimized average HER.

[0247] Example 10: Preparation and Application of Photocatalytic Heterojunction Nanoparticles

[0248] PM6 and F1 were dissolved separately in chloroform to prepare a solution with a concentration of 0.5 mg / mL. -1 The solution was heated at 50℃ for 2 hours. PM6 and F1 solutions were mixed at a volume ratio of 3:7, and 1 mL of each mixture was added to 4 mL of TEBS aqueous solutions with different mass ratios. The mixture was then sonicated for 5 minutes using a sonic SCIENTZ-IID ultrasonic mill to obtain a microemulsion. The microemulsion was removed by rotary evaporation, yielding nanoparticles with a stable surfactant dispersed in water. Finally, the dispersion was filtered (0.4 μm mixed cellulose) to remove any large aggregates. The final composition was determined as follows: 2 mL of methanol was added to 1 mL of the sample for deemulsification. A certain amount of chloroform was then added to extract the material dissolved in the chloroform. Finally, the final mass of the nanoparticles in the solution was determined by UV-Vis measurement.

[0249] 50 μg of the nanoparticles formed by the above formula were added to 7.5 mL of 0.2 M ascorbic acid aqueous solution and placed in a circulating batch reactor (cross-sectional area 5.786 cm²) at 5 °C. 2 In. By adding a certain amount of potassium hexachloroplatinate aqueous solution (0.4 mg / mL) - 1 The desired platinum loading was obtained by plucking the reactor with nitrogen multiple times to remove oxygen, and the pressure was set at 1.4 kPa. The reactor was illuminated with a 300W Xe lamp equipped with a 330–1100 nm reflector and an AM1.5G filter. Hydrogen production was analyzed using a fully automated online trace gas analysis system (Labsolar-6A, PerfectLight) and an online gas chromatograph (thermal conductivity detector, nitrogen carrier gas). The resulting hydrogen production rate curve is shown below. Figure 25 As shown, PM6:F1NPs achieved 143.9 mmol / h under a specific loading of 0.4 wt.% TEBS and 33 wt.% Pt over 10 hours. -1 ·g -1 Optimized average HER.

[0250] Example 11: Preparation and Application of Photocatalytic Heterojunction Nanoparticles

[0251] Following the method in Example 10, F2 acceptor material was fabricated into photocatalytic heterojunction nanoparticles, and photocatalytic hydrogen production was performed. The resulting hydrogen production rate curve is shown below. Figure 26 As shown, PM6:F2NPs achieved 230.6 mmol / h under a specific loading of 0.4 wt.% TEBS and 33 wt.% Pt over 10 hours. -1 ·g -1 Optimized average HER.

Claims

1. The polycyclic fused-ring conjugated macromolecule of benzodipyrrole shown in Formula I, Formula I In the formula, R1 is selected from C1~C20 alkyl, C1~C20 haloalkyl, and C1~C20 alkoxy groups; R2 is selected from H, halogen substituents, C1~C20 alkyl groups, C1~C20 haloalkyl groups, and C1~C20 alkoxy groups; Ar represents the following groups, with the dashed lines indicating the connection positions: in, R3 is a C1-C20 alkyl group or a C1-C20 alkoxy group; EG is selected from any of the following groups, with the dotted lines indicating the connection positions: Wherein, R4 is a hydrogen atom, a halogen substituent, a C1-C20 alkyl group, a C1-C20 alkoxy group, a C1-C20 carbonyl group, a C1-C20 ester group, or a cyano group.

2. The method for preparing the multi-fused-ring conjugated macromolecule according to claim 1, comprising the following steps: 1) Compound X reacts with compound A via a Stille coupling reaction to give compound B; In the formula, Ar and R2 are defined as in claim 1; 2) Compound B undergoes a reduction ring-opening reaction to yield compound C; 3) Compound C reacts with pyridine-2-formyl chloride hydrochloride via a nucleophilic substitution reaction to give compound D; In the formula, Py represents pyridinyl; 4) Compound D undergoes a ring-closing reaction to give compound E; 5) Compound E reacts with a haloalkane via a nucleophilic substitution reaction to give compound F; The chemical formula of the haloalkane is R1X, where X is a halogen, and R1 is defined as in claim 1. 6) Compound F was reacted with Vilsmeier-Haack to give compound G; 7) Compound G reacts with EG via a Knoevenagel reaction to obtain the benzodipyrrole polycyclic fused ring conjugated macromolecule shown in Formula I of claim 1; EG can be any of the following structures, with the dashed lines indicating the connection points: in, R4 is a hydrogen atom, a halogen substituent, a C1-C20 alkyl group, a C1-C20 alkoxy group, a C1-C20 carbonyl group, a C1-C20 ester group, or a cyano group.

3. The preparation method according to claim 2, characterized in that: In step 1), the conditions for the Stille coupling reaction are as follows: the catalyst is tetrakis(triphenylphosphine)palladium, and the amount of the catalyst added is 0.01% to 10% of the molar amount of compound A; the molar ratio of compound X to compound A is 1:2.2 to 3.5; and the reaction is carried out under reflux at 80 to 110°C for 24 to 48 hours. In step 2), the conditions for the reduction ring-opening reaction are as follows: the reducing agent is zinc powder; the molar ratio of the reducing agent to compound B is 20:1; and the reaction is carried out under reflux at 120–140°C for 1 hour. In step 3), the nucleophilic substitution reaction conditions are as follows: the catalyst is 4-dimethylaminopyridine, the base is triethylamine, the molar ratio of the catalyst to compound C is 1~3:1, the molar ratio of pyridine-2-formyl chloride hydrochloride to compound C is 1~3:1, the molar ratio of the base to compound C is 1~2:1, and the reaction is carried out under reflux at 25~30℃ for 24 hours. In step 4), the conditions for the ring-closing reaction are: the catalyst is manganese dioxide, copper acetate and acetic acid, the molar amounts of manganese dioxide, copper acetate, acetic acid and compound D are 3~6:1~2:2~4:1, and the reaction is carried out under reflux at 200°C for 1 hour. In step 5), the conditions for the nucleophilic substitution reaction are: the base is potassium hydroxide, the molar ratio of the haloalkane to compound E is 3-6:1, and the reaction is carried out under reflux at 80-100°C for 15-24 hours. In step 6), the conditions for the Vilsmeier-Haack reaction are as follows: the formylation reagent is phosphorus oxychloride, the molar ratio of compound F to the formylation reagent is 1:15-25, and the reaction is carried out under reflux at 80-105°C for 8-12 hours. In step 7), the conditions for the Knoevenagel reaction are as follows: the acid-binding agent is pyridine, the molar ratio of compound G to EG is 1:5 to 12, and the reaction is carried out under reflux at 60 to 70°C for 12 to 16 hours.

4. The application of the benzodipyrrole polycyclic fused-ring conjugated macromolecule of claim 1 in the preparation of a single-component photocatalyst for photocatalytic hydrogen production.

5. A method for preparing a single-component photocatalyst, comprising the following steps: A solution of the polycyclic fused ring conjugated macromolecule of benzodipyrrole as described in claim 1 is heated and then added to an aqueous solution of a surfactant to obtain a microemulsion; the solvent is removed and the microemulsion is filtered to obtain nanoparticles; platinum is loaded onto the nanoparticles to obtain the single-component photocatalyst. The mass ratio of the benzodipyrrole-based fused-ring conjugated macromolecule, the surfactant, and the platinum is 1:0.001-0.02:0.2-0.

5. The surfactant is at least one of sodium 2-(3-thienyl)ethoxybutylsulfonate, sodium dodecyl sulfate, sodium dodecylbenzenesulfonate, and sodium cholate.

6. The single-component photocatalyst prepared according to claim 5.

7. The application of the polycyclic fused-ring conjugated macromolecule of benzodipyrrole as described in claim 1 in the preparation of heterojunction photocatalysts for photocatalytic hydrogen production; The heterojunction photocatalyst comprises the multi-fused-ring conjugated macromolecule of benzodipyrrole and the electron donor material.

8. A method for preparing a heterojunction photocatalyst, comprising the following steps: The solution of the benzo[1] dipyrrole polycyclic fused ring conjugated macromolecule and the electron donor material as described in claim 1 is heated and then added to an aqueous solution of a surfactant to obtain a microemulsion; the solvent is removed and the microemulsion is filtered to obtain nanoparticles; platinum is loaded onto the nanoparticles to obtain the heterojunction photocatalyst. The mass ratio of the benzodipyrrole-based fused-ring conjugated macromolecule, the surfactant, and the platinum is 1:0.001-0.02:0.2-0.

5. The mass ratio of the benzodipyrrole-based fused-ring conjugated macromolecule to the electron donor material is 1:1~2; The surfactant is at least one of sodium 2-(3-thienyl)ethoxybutylsulfonate, sodium dodecyl sulfate, sodium dodecylbenzenesulfonate, and sodium cholate. The electron donor material is at least one of PM6, D18, PBDB-T and PTB7-Th.

9. The heterojunction photocatalyst prepared according to claim 8.

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