阅读说明：本技术 一种基于噻吩茚酮和芴的A-π-D-π-A型小分子太阳能电池受体材料及其制备方法 (A-pi-D-pi-A type small molecule solar cell receptor material based on thiophene indanone and fluorene and preparation method thereof ) 是由 赵鸿斌 廖俊旭 沈松平 徐键 郑培锦 徐耿标 孔浩君 余贺宇 于 2019-11-21 设计创作，主要内容包括：本发明公开了一种基于噻吩茚酮和芴的A-π-D-π-A型小分子太阳能电池受体材料及其制备方法。该类受体材料是以芴为中心核结构,噻吩、呋喃、苯等基团作为π桥,两端的醛基在常温常压下和吸电子基团噻吩茚酮的活性位点进行缩合反应得到对称型的目标分子。该类基于噻吩茚酮和芴的A-π-D-π-A型小分子太阳能电池受体材料合成方法简单,反应条件易于控制,产率较高,具有普遍适用性,可以高效合成；并可被广泛应用于能源、生命、分析、材料科学等领域,尤其适合作为有机小分子太阳能电池受体材料等。<Image he="167" wi="700" file="DDA0002281915370000011.GIF" imgContent="drawing" imgFormat="GIF" orientation="portrait" inline="no"></Image>(The invention discloses an A-pi-D-pi-A type micromolecule solar cell receptor material based on thiophene indanone and fluorene and a preparation method thereof. The receptor material takes fluorene as a central core structure, groups such as thiophene, furan, benzene and the like as a pi bridge, and aldehyde groups at two ends are subjected to condensation reaction with active sites of thiophene indanone which is an electron-withdrawing group at normal temperature and normal pressure to obtain a symmetrical target molecule. The A-pi-D-pi-A type micromolecule solar cell receptor material based on the thiophene indanone and the fluorene has the advantages of simple synthesis method, easily controlled reaction conditions, higher yield, universal applicability and high-efficiency synthesis; and can be widely applied to energy, life, analysis and materialsThe material is especially suitable for being used as an organic micromolecule solar cell receptor material and the like.)

1. A thiophene indanone and fluorene-based A-pi-D-pi-A type small molecule solar cell receptor material is characterized by having a structure of a general formula I:

in the formula I, pi is a pi bridge, and the pi bridge is specifically any one of the following structural units:

wherein n is a natural number of 1 to 20.

2. The preparation method of the A-pi-D-pi-A type small molecule solar cell receptor material based on the thiophenindione and the fluorene as claimed in claim 1, characterized by comprising the following steps:

(1) under the alkaline environment, carrying out boron esterification reaction on 2, 7-dibromofluorene and bis (pinacolato) boron ester to prepare an intermediate 1, wherein the structure is as follows:

(2) the intermediate 1 and 5-bromothiophene-2-formaldehyde are subjected to a suzuki reaction under the catalysis of a catalyst to obtain an intermediate 2, and the structure of the intermediate is as follows:

(3) the intermediate 1 and 5-bromofuran-2-formaldehyde are subjected to a suzuki reaction under the catalysis of a catalyst to obtain an intermediate 3, and the structure of the intermediate is as follows:

(4) the intermediate 1 and p-bromobenzaldehyde are subjected to a suzuki reaction under the catalysis of a catalyst to obtain an intermediate 4, and the structure of the intermediate is as follows:

(5) and carrying out condensation reaction on the intermediate 2 and the thiophene indanone to obtain a target molecule FTC1, wherein the structure is as follows:

(6) and carrying out condensation reaction on the intermediate 3 and the thiophene indanone to obtain a target molecule FTC2, wherein the structure is as follows:

(7) and carrying out condensation reaction on the intermediate 4 and the thiophene indanone to obtain a target molecule FTC3, wherein the structure is as follows:

3. the method for preparing the thiophene indanone and fluorene based A-pi-D-pi-A type small molecule solar cell receptor material according to claim 2, wherein in the steps (2) to (4), the reaction solvent used in the suzuki reaction is a mixture of a toluene solvent and a 2M sodium carbonate solution.

4. The preparation method of the A-pi-D-pi-A type small molecule solar cell receptor material based on thiophene indanone and fluorene according to claim 3, wherein the volume ratio of the toluene solvent to the 2M sodium carbonate solution is 2: 1-4: 1.

5. The method for preparing the A-pi-D-pi-A type small molecule solar cell receptor material based on the thiophenindione and the fluorene according to claim 2, wherein in the steps (2) to (4), the molar ratio of the intermediate 1 to the 5-bromothiophene-2-formaldehyde, the molar ratio of the intermediate 1 to the 5-bromofuran-2-formaldehyde and the molar ratio of the intermediate 1 to the p-bromobenzaldehyde are all 1:2 to 1: 6.

6. The preparation method of the thiophene indanone and fluorene based A-pi-D-pi-A type small molecule solar cell receptor material according to claim 2, wherein in the steps (2) - (4), the reaction temperature of the suzuki reaction is 90-110 ℃; the reaction time of the suzuki reaction is 24-36 hours.

7. The method for preparing the A-pi-D-pi-A type small molecule solar cell receptor material based on the thiophenindione and the fluorene according to claim 2, wherein in the steps (2) to (4), the catalysts are all Pd (PPh)₃)₄。

8. The preparation method of the A-pi-D-pi-A type small molecule solar cell receptor material based on thiophenindione and fluorene according to claim 2, wherein in the steps (5) to (7), the molar ratio of the intermediate 2 to the thiophenindione, the molar ratio of the intermediate 3 to the thiophenindione, and the molar ratio of the intermediate 4 to the thiophenindione are all 1:2 to 1: 8.

9. The method for preparing the A-pi-D-pi-A type small molecule solar cell receptor material based on the thiophenindione and the fluorene according to claim 2, wherein in the steps (5) - (7), the reaction temperature of the condensation reaction is 0-70 ℃; the condensation reaction time is 12-24 h.

The technical field is as follows:

the invention relates to a solar cell receptor material, in particular to an A-pi-D-pi-A type micromolecule solar cell receptor material based on thiophene indanone and fluorene and a preparation method thereof.

Background art:

the thiophene indanone is a novel electron-withdrawing group which is developed in recent years and is widely concerned and paid attention to, and the thiophene indanone derivative is a good photosensitive material, has good stability, high molar extinction coefficient and narrower energy gap, and has the characteristics of good photophysical chemical properties, stability, high energy conversion efficiency and the like when being used as an end-blocking group of a symmetrical small-molecule receptor material. Therefore, the micromolecule solar cell receptor material taking the thiophene indanone as the end capping group has good application prospect in the field of organic micromolecule solar cells.

However, so far, there are few reports about the application of organic small molecule solar cells using thiophen indanone as a blocking group, and there are problems of lack of sufficient molecular design and necessary optimization of synthetic route, single structure and low photovoltaic efficiency. Therefore, the preparation of different types of thiophene indanone derivatives from simpler raw materials through a simple synthetic route is a difficult point which needs to be solved urgently.

The invention content is as follows:

one of the technical problems to be solved by the invention is to provide an A-pi-D-pi-A type micromolecule solar cell receptor material based on thiophene indanone and fluorene, aiming at the defects of the prior art, the receptor material has the advantages of relatively high ultraviolet absorption, relatively high molar extinction coefficient and relatively stable photochemical property, and provides a new idea for constructing an organic solar cell material.

The invention provides a preparation method of an A-pi-D-pi-A type micromolecule solar cell receptor material based on thiophene indanone and fluorene, aiming at the defects of the prior art, and the preparation method is simple and has high yield of target products.

In order to solve the first technical problem, the invention adopts the following technical scheme:

a thiophene indanone and fluorene-based A-pi-D-pi-A type small molecule solar cell receptor material is characterized by having a structure of a general formula I:

in the formula I, pi is a pi bridge, and the pi bridge is specifically any one of the following structural units:

wherein n is a natural number of 1 to 20.

In order to solve the second technical problem, the invention adopts the following technical scheme:

a preparation method of an A-pi-D-pi-A type small molecule solar cell receptor material based on thiophene indanone and fluorene comprises the following steps:

(1) under the alkaline environment, carrying out boron esterification reaction on 2, 7-dibromofluorene and bis (pinacolato) boron ester to prepare an intermediate 1, wherein the structure is as follows:

(2) the intermediate 1 and 5-bromothiophene-2-formaldehyde are subjected to a suzuki reaction under the catalysis of a catalyst to obtain an intermediate 2, and the structure of the intermediate is as follows:

(3) the intermediate 1 and 5-bromofuran-2-formaldehyde are subjected to a suzuki reaction under the catalysis of a catalyst to obtain an intermediate 3, and the structure of the intermediate is as follows:

(4) the intermediate 1 and p-bromobenzaldehyde are subjected to a suzuki reaction under the catalysis of a catalyst to obtain an intermediate 4, and the structure of the intermediate is as follows:

(5) and carrying out condensation reaction on the intermediate 2 and the thiophene indanone to obtain a target molecule FTC1, wherein the structure is as follows:

(6) and carrying out condensation reaction on the intermediate 3 and the thiophene indanone to obtain a target molecule FTC2, wherein the structure is as follows:

(7) and carrying out condensation reaction on the intermediate 4 and the thiophene indanone to obtain a target molecule FTC3, wherein the structure is as follows:

as a preferable technical solution, in the steps (2) to (4), the reaction solvent used in the suzuki reaction is a mixture of a toluene solvent and a 2M sodium carbonate solution.

As a preferable technical scheme, the volume ratio of the toluene solvent to the 2M sodium carbonate solution is 2: 1-4: 1.

In a preferable embodiment, in the steps (2) to (4), the molar ratio of the intermediate 1 to the 5-bromothiophene-2-carbaldehyde, the molar ratio of the intermediate 1 to the 5-bromofuran-2-carbaldehyde, and the molar ratio of the intermediate 1 to the p-bromobenzaldehyde are all 1:2 to 1: 6.

As a preferable technical scheme, in the steps (2) to (4), the reaction temperature of the suzuki reaction is 90-110 ℃; the reaction time of the suzuki reaction is 24-36 hours.

As a preferable technical scheme, in the steps (2) to (4), the catalysts are all Pd (PPh)₃)₄。

In a preferable technical scheme, in the steps (5) to (7), the molar ratio of the intermediate 2 to the thiophenindione, the molar ratio of the intermediate 3 to the thiophenindione, and the molar ratio of the intermediate 4 to the thiophenindione are all 1:2 to 1: 8.

As a preferable technical scheme, in the steps (5) to (7), the reaction temperature of the condensation reaction is 0-70 ℃; the condensation reaction time is 12-24 h.

Due to the adoption of the technical scheme, the invention has the following beneficial effects:

according to the A-pi-D-pi-A type micromolecule solar cell receptor material based on thiophene indanone and fluorene, the pi bridge group is added between the donor unit and the receptor unit, so that the flatness of a target molecule is better, charge transmission in the molecule is facilitated, and the receptor material has excellent photoelectric performance.

The invention discloses a preparation method of an A-pi-D-pi-A type micromolecule solar cell receptor material based on thiophene indanone and fluorene, which has the advantages of easily controlled conditions, simple product purification, higher comprehensive yield and universality.

Description of the drawings:

FIG. 1 is a nuclear magnetic hydrogen spectrum of FTC 1;

FIG. 2 is a nuclear magnetic carbon spectrum of FTC 1;

FIG. 3 is a nuclear magnetic hydrogen spectrum of FTC 2;

FIG. 4 is a nuclear magnetic carbon spectrum of FTC 2;

FIG. 5 is a nuclear magnetic hydrogen spectrum of FTC 3;

FIG. 6 is a nuclear magnetic carbon spectrum of FTC 3;

FIG. 7 is a mass spectrum of FTC 1;

FIG. 8 is a mass spectrum of FTC 2;

FIG. 9 is a mass spectrum of FTC 3;

FIG. 10 is a graph of the thermogravimetric weight loss of target molecules FTC1, FTC2, FTC 3;

FIG. 11 is a plot of hole mobility for target molecule FTC1, FTC2, FTC3 blend membranes;

FIG. 12 is an electron mobility curve for a target molecule FTC1, FTC2, FTC3 blended membrane;

FIG. 13 is a J-V characteristic graph of target molecules FTC1, FTC2, FTC 3;

FIG. 14 is an IPCE plot of target molecules FTC1, FTC2, FTC 3.

The specific implementation mode is as follows:

the present invention is further illustrated by the following examples, which are provided for the purpose of illustration only and are not intended to be limiting.

Synthesis of intermediate 1

Adding 2, 7-dibromo-9, 9-dioctyl-9-fluorene (2.79g,5.10mmol), bis (pinacolato) boronate (4g, 15.70mmol), potassium acetate (4g, 40mmol), 1,4 dioxane solvent (180mL) and magnetite into a dry and clean 250mL three-necked flask, stirring to dissolve the reactants, vacuumizing the system, replacing with argon, and adding a proper amount of Pd (dppf) Cl catalyst₂Vacuumizing the system, replacing with argon, reacting at 80 deg.C overnight, monitoring until the reaction is complete, stopping the reaction, cooling to room temperature, extracting with ethyl acetate for 3-5 times, washing with saturated NaCl solution for 3-5 times, retaining the organic phase, and adding anhydrous MgSO₄The powder was dried, the solvent was removed under reduced pressure, and the product was isolated and purified by silica gel chromatography (ethyl acetate: petroleum ether ═ 12:1) to give intermediate 1(2.98g, 91% yield) as a white solid.¹H NMR(400MHz,CDCl₃)δ:7.82(d,J＝7.5Hz,1H),7.76–7.71(m,2H),2.04–1.95(m,2H),1.38(s,12H),1.17–0.98(m,10H),0.82(t,J＝7.1Hz,3H),0.53(s,2H).¹³C NMR(101MHz,CDCl₃)δ:150.49,143.93,133.67,128.92,119.42,83.74,55.21,40.13,31.82,29.97,29.22,24.97,23.61,22.63,14.13.

Synthesis of intermediate 2

Adding intermediate 1(2.44g,3.80mmol), 5-bromothiophene-2-formaldehyde (1.6g, 8.4mmol), tetrabutylammonium bromide (200mg, 0.62mmol), toluene (50mL) and magnetons into a dry and clean 250mL three-neck flask, stirring to dissolve reactants, adding potassium carbonate (30mL, 2M), continuing stirring for 10min, vacuumizing the system, replacing with argon, adding a proper amount of catalyst Pd (PPh)₃)₄Vacuumizing the system, replacing with argon, reacting at 90 deg.C for 36 hr, monitoring by a point plate until the reaction is completed, stopping the reaction, cooling the system to room temperature, extracting with appropriate amount of dichloromethane for 3-5 times, washing with appropriate amount of saturated NaCl solution for 3-5 times, retaining the organic phase, adding appropriate amount of anhydrous MgSO₄The powder was dried, the solvent was removed under reduced pressure, and the product was purified by silica gel column chromatography (petroleum ether: dichloromethane: ethyl acetate: 10:2:1) to give intermediate 2(1.83g, 79%) as a yellow solid.¹HNMR(400MHz,CDCl₃)δ:8.76(s,1H),8.34(d,J＝2.2Hz,1H),7.91(d,J＝2.2Hz,1H),7.80(d,J＝4.2Hz,1H),7.76(s,1H),7.73(s,1H),7.70(s,1H),7.54(d,J＝4.2Hz,1H),2.02(t,J＝4.1Hz,2H),0.99(d,J＝4.0Hz,10H),0.69(s,2H),0.56(dd,J＝13.0,9.3Hz,3H).¹³C NMR(101MHz,CDCl₃)δ:182.80,154.81,152.25,142.21,141.65,137.56,132.41,125.74,124.09,120.75,77.40,77.08,76.76,55.56,40.24,31.77,29.89,29.17,23.78,22.61,14.09.

Synthesis of intermediate 3

The synthesis of intermediate 3 was similar to that of intermediate 2, using 5-bromofuran-2-carbaldehyde (1.49g, 8.4mmol) and intermediate 1(2.44g,3.80mmol) as reactants, and isolated and purified to give intermediate 3(1.71g, 78%) as a yellow solid.¹H NMR(400MHz,CDCl₃)δ:9.67(s,1H),7.83(s,1H),7.81(s,1H),7.77(d,J＝7.9Hz,1H),7.37(d,J＝3.7Hz,1H),6.93(d,J＝3.7Hz,1H),2.10–2.05(m,2H),1.15–1.00(m,10H),0.76(t,J＝7.0Hz,3H),0.56(dd,J＝13.1,9.5Hz,2H).¹³C NMR(101MHz,CDCl₃)δ:150.49,143.94,141.95,138.68,133.69,128.92,126.05,124.61,119.92,119.42,118.12,115.45,83.73,77.38,77.07,76.75,56.39,55.21,40.14,33.84,31.81,29.97,29.33,26.80,24.97,23.62,22.64,14.12.

Synthesis of intermediate 4

The synthesis of intermediate 4 was similar to that of intermediate 2, with p-bromobenzaldehyde (1.54g, 8.4mmol) and intermediate 1(2.44g,3.80mmol) as reactants, and isolated and purified to give intermediate 4(1.86g, 82%) as a yellow solid.¹H NMR(400MHz,CDCl₃)δ:10.09(s,1H),8.00(d,J＝8.1Hz,2H),7.85(d,J＝6.5Hz,2H),7.83(d,J＝2.4Hz,2H),7.66(d,J＝7.9Hz,1H),7.62(s,1H),2.10–2.04(m,2H),1.17–1.03(m,10H),0.78(t,J＝7.0Hz,3H),0.71(s,2H).¹³C NMR(101MHz,CDCl₃)δ:191.96,152.09,147.55,140.96,138.91,135.13,130.37,127.75,126.59,121.75,120.58,77.43,77.11,76.80,55.55,40.36,31.79,29.96,29.20,23.83,22.62,14.11.