阅读说明：本技术 一种非富勒烯受体材料、其制备方法和应用 (Non-fullerene acceptor material, preparation method and application thereof ) 是由 李维实 薛中鑫 许子文 刘丽娜 张翟 于 2021-06-16 设计创作，主要内容包括：本发明公开了一种非富勒烯受体材料、其制备方法和应用。该非富勒烯受体材料具有式(I)所示的结构。本发明所提供的非富勒烯受体材料可具有非稠环结构,在保证溶解性能的同时还可以保持分子主体的平面性,由此可利用非稠环结构单元灵活地构筑有机光伏材料分子,材料溶解度好,光吸收范围可以拓展至近红外区域,电子迁移率高,有利于新型高效给受体材料的开发。(The invention discloses a non-fullerene acceptor material, a preparation method and application thereof. The non-fullerene acceptor material has a structure shown in formula (I). The non-fullerene acceptor material provided by the invention can have a non-condensed ring structure, and can keep the planarity of a molecular main body while ensuring the solubility, so that organic photovoltaic material molecules can be flexibly constructed by using non-condensed ring structure units, the material solubility is good, the light absorption range can be expanded to a near infrared region, the electron mobility is high, and the development of novel efficient acceptor materials is facilitated.)

1. A non-fullerene acceptor material, wherein the non-fullerene acceptor material has a structure according to formula (I):

wherein, ring Ar¹And ring Ar^1′Independently an aromatic ring or a heteroaromatic ring independently having 1, 2, 3, or 4 heteroatoms independently selected from N, O and S;

ring Ar²And ring Ar^2′Independently an aromatic ring, a heteroaromatic ring, substituted with one or more R^aSubstituted aromatic rings, or by one or more R^aA substituted heteroaromatic ring independently having 1, 2, 3, or 4 heteroatoms independently selected from S, O and Se;

R^aindependently alkyl, alkoxy or alkylthio;

R¹、R²、R^1′and R^2′Independently is-C (R)^b)(R^c)(R^d)；

R^b、R^cAnd R^dIndependently is H or alkyl;

R¹and R²Are each in ring Ar²Adjacent positions of (a);

R^1′and R^2′Are each in ring Ar^2′Adjacent positions of (a);

R³and R^3′Independently is H, alkyl or alkoxy;

m and m' are independently 0, 1, 2, 3 or 4;

the mark end in the structure shown in the formula (I) is connected with an extended conjugated structure, and the extended conjugated structure is used for adjusting the band gap and the energy level distribution of the acceptor material.

2. The non-fullerene acceptor material according to claim 1, wherein the extended conjugated structure has a structure of formula (II) or (II'), wherein the structure of formula (II) and the ring Ar in the structure of formula (I) are²The structure represented by the formula (II') and the ring Ar in the structure represented by the formula (I) are connected^2′The connection is carried out in a connecting way,

wherein ring A and ring A' are independently absent, aromatic, heteroaromatic, substituted with one or more R^eSubstituted aromatic rings, or by one or more R^eA substituted heteroaromatic ring independently having 1, 2, 3, or 4 heteroatoms or heteroatom groups independently selected from N, O, S and C (═ O);

R^eindependently alkyl, alkoxy or alkylthio;

b and B' are independently

X is independently H, halogen, C₁-C₄Alkyl or C₁-C₄An alkoxy group;

r is independently H or alkyl.

3. The non-fullerene acceptor material according to claim 1 or 2,

ring Ar¹And ring Ar^1′Wherein said aromatic ring is independently C₆-C₁₂Aromatic rings such as benzene rings or naphthalene;

and/or, ring Ar¹And ring Ar^1′Wherein the heteroaromatic ring is independently a 5-12 membered heteroaromatic ring, such as a 5-6 membered monocyclic heteroaromatic ring or an 8-12 fused heteroaromatic ring, and is, for example, pyridine;

and/or, ring Ar²And ring Ar^2′Wherein said aromatic ring is independently C₆-C₁₂Aromatic rings such as benzene rings or naphthalene;

and/or, ring Ar²And ring Ar^2′Wherein the heteroaromatic ring is independently a 5-to 12-membered heteroaromatic ring, such as a 5-to 6-membered monocyclic heteroaromatic ring or an 8-to 12-membered fused heteroaromatic ring, and such as a 5-to 6-membered monocyclic heteroaromatic ring;

and/or, ring Ar²And ring Ar^2′Wherein the heteroaryl ring independently has 1, 2 or 3 heteroatoms, for example 1;

and/or, ring Ar²And ring Ar^2′Wherein the heteroatom is independently selected from S and Se, e.g. S;

and/or, ring Ar²And ring Ar^2′In, R^aIndependently 1, 2 or 3;

and/or, R^aWherein said alkyl is independently C₁～C₂₅Alkyl radicals, e.g. C₁～C₁₂Alkyl radicals, also e.g. C₁～C₄An alkyl group;

and/or, R^aWherein said alkoxy is independently C₁～C₂₅Alkoxy radicals, e.g. C₁～C₁₂Alkoxy radicals, e.g. C₁～C₄Alkoxy radicalA group;

and/or, R^aWherein said alkylthio is independently C₁～C₂₅Alkylthio radicals, e.g. C₁～C₁₂Alkylthio radicals, e.g. C₁～C₄An alkylthio group;

and/or, R^b、R^cAnd R^dWherein said alkyl is independently C₁～C₂₅Alkyl radicals, e.g. C₁～C₁₂Alkyl radicals, also e.g. C₁～C₄Alkyl groups such as methyl;

and/or, R³And R^3′Wherein said alkyl is independently C₁～C₂₅Alkyl radicals, e.g. C₁～C₁₂Alkyl radicals, also e.g. C₁～C₄An alkyl group;

and/or, R³And R^3′Wherein said alkoxy is independently C₁～C₂₅Alkoxy radicals, e.g. C₁～C₁₂Alkoxy radicals, e.g. C₁～C₄An alkoxy group;

and/or, in ring A and ring A', the aromatic rings are independently C₆-C₁₂Aromatic rings such as benzene rings or naphthalene;

and/or, in ring A and ring A', the heteroaromatic rings are independently 5-12 membered heteroaromatic rings, such as 5-6 membered monocyclic heteroaromatic rings or 8-12 fused heteroaromatic rings;

and/or, in ring a and ring a', the heteroaromatic ring independently has 1, 2 or 3 heteroatoms, for example 3;

and/or, in ring a and ring a', the heteroatoms are independently selected from N and S;

and/or, in ring A and ring A', R^eIndependently 1, 2 or 3;

and/or, R^eWherein said alkyl is independently C₁～C₂₅Alkyl radicals, e.g. C₁～C₁₂Alkyl radicals, also e.g. C₁～C₄An alkyl group;

and/or, R^eWherein said alkoxy is independently C₁～C₂₅Alkoxy radicals, e.g. C₁～C₁₂Alkoxy radicals, e.g. C₁～C₄An alkoxy group;

and/or, R^eWherein said alkylthio is independently C₁～C₂₅Alkylthio radicals, e.g. C₁～C₁₂Alkylthio radicals, e.g. C₁～C₄An alkylthio group;

and/or, in X, the halogen is independently F, Cl, Br or I;

and/or, in X, the C₁-C₄Alkyl is independently methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, or tert-butyl, such as methyl;

and/or, in X, the C₁-C₄Alkoxy is independently methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, or tert-butoxy, for example methoxy;

and/or, in R, the alkyl is independently C₁～C₂₅Alkyl radicals, e.g. C₁～C₁₂Alkyl radicals, also e.g. C₁～C₄An alkyl group.

4. The non-fullerene acceptor material according to claim 1 or 2,

ring Ar¹And ring Ar^1′Wherein the aromatic rings are independently benzene rings;

and/or, ring Ar²And ring Ar^2′Wherein the 5-6 membered monocyclic heteroaromatic ring is independently thiophene or selenene, such as thiophene;

and/or, ring Ar²And ring Ar^2′Wherein the 8-12 fused heteroaromatic rings are independently a benzodithiophene, a trithiophene, or a dithienocyclopentadiene;

and/or, R¹、R²、R^1′And R^2′In (1), the-C (R)^b)(R^c)(R^d) Independently methyl, ethyl, isopropyl or tert-butyl, such as methyl or isopropyl;

and/or, R³And R^3′Wherein said alkyl is independently methyl or isopropyl;

and/or in ring A and ring A', the 5-6 membered single heteroaromatic ring is independently thiophene, furan, pyrrole, imidazole, pyrazole, oxazole, pyridine or pyrazine;

and/or in ring a and ring a', the 8-12 fused heteroaromatic rings are independently benzothiophene, benzodithiophene, benzothiadiazole, benzodithiadiazole, thienothiadiazole, or thienopyrazine, such as 2,1, 3-benzothiadiazole;

and/or, in X, the halogen is independently F or Cl.

5. The non-fullerene acceptor material according to claim 1 or 2,

in the case of B and B', the reaction mixture,independently is

And/or, structural unitsIs composed ofFor exampleAlso for example

And/or, structural unitsIs composed ofFor exampleAlso for example

And/or, structural unitsIs composed of

6. The non-fullerene acceptor material according to claim 1 or 2,

ring Ar¹And ring Ar^1′Independently an aromatic ring;

and/or, ring Ar²And ring Ar^2′Independently a heteroaromatic ring;

and/or, R³And R^3′Independently is an alkyl group;

and/or, m and m' are independently 1;

and/or, ring a and ring a' are independently a non-or heteroaromatic ring;

and/or, B and B' are independently

And/or, X is independently H or halogen.

7. The non-fullerene acceptor material according to claim 1 or 2, wherein the structure of formula (I) is a structure of formula (I-1)For example

And/or the structures shown in the formulas (II) and (II') are independently

8. The non-fullerene acceptor material according to claim 1 or 2, wherein the non-fullerene acceptor material has any one of the following structures:

9. a compound of formula (III),

wherein, ring Ar¹Ring Ar^1′Ring Ar²Ring Ar^2′、R¹、R²、R³、R^1′、R^2′、R^3′M, m ', ring a ', B and B ' are as defined in any one of claims 1 to 8.

10. A process for the preparation of a compound of formula (III) according to claim 9, comprising the steps of: in an organic solvent, the compound represented by the formula (IV) is reacted with a compound H-B and a compound H-B' in the presence of an organic base as shown below,

wherein, the ring Ar¹Ring Ar^1′Ring Ar²Ring Ar^2′、R¹、R²、R³、R^1′、R^2′、R^3′M, m ', ring a ', B and B ' are as defined in any one of claims 1 to 8.

11. A compound of formula (IV),

wherein, the ring Ar¹Ring Ar^1′Ring Ar²Ring Ar^2′、R¹、R²、R³、R^1′、R^2′、R^3′M, m ', ring a and ring a' are as defined in any one of claims 1 to 8;

preferably, the compound of formula (IV) has any one of the following structures:

12. use of a non-fullerene acceptor material according to any one of claims 1 to 8 or a compound of formula (III) according to claim 9 as a material for a solar cell.

13. An organic solar cell device, characterized in that the acceptor material of the organic solar cell device is a non-fullerene acceptor material according to any one of claims 1 to 8 or a compound of formula (III) according to claim 9;

preferably, the organic solar cell device comprises an anode, a hole transport layer, a layer of a blend of the above non-fullerene acceptor material or the above compound of formula (III) with a donor polymer PM6, an electron transport layer and a cathode;

more preferably, the material of the anode is indium tin oxide; the hole transport layer is PEDOT PSS; the electron transport layer is made of PFN-Br; the cathode is made of aluminum.

Technical Field

The invention relates to a non-fullerene acceptor material, a preparation method and application thereof.

Background

In order to solve the increasingly sharp problem of energy, scientific and efficient use of clean energy such as solar energy is an important subject of research, and organic solar cells have the advantages of light weight, flexibility and easy processing as one of effective ways of using solar energy, and have gradually received wide attention from the scientific and industrial fields in recent years.

At present, the high-efficiency organic solar cell in the field generally adopts a bulk heterojunction type structure, and an active layer of the organic solar cell is formed by mixing donor and acceptor materials. The donor material is a p-type organic/polymeric semiconductor material, and the system is rich in electrons and has the ability to donate electrons and transport holes. The acceptor material is an n-type organic semiconductor material having the ability to accept and transfer electrons. In recent years, the invention of a large amount of high photovoltaic polymer and small molecular donor materials and the improvement of the preparation technology of a battery device are benefited, the optimal efficiency of the organic solar battery breaks through 18 percent, and the bright application prospect is shown.

The receptor materials which are mainstream nowadays are mainly novel non-fullerene receptors, and compared with the traditional fullerene receptor materials, the fullerene receptor materials are generally simpler and more convenient to synthesize, have wider and stronger absorption in a visible light region, and can meet different energy level requirements through relatively free structural design.

The existing efficient non-fullerene acceptor materials are generally structurally composed of a conjugated main body part consisting of a fused ring structure and long flexible side chains. The conjugated main body of the condensed ring ensures the planarity and the conjugation of the molecular main body, and is beneficial to the absorption of light and the transmission of carriers, but the condensed ring structure is usually synthesized more complexly, and the subsequent structure adjustment is relatively difficult. The long flexible side chain improves the solubility of the material, ensures the processing performance of the material, and is widely used in various organic semiconductor materials, but the side chain does not directly participate in the photoelectric conversion process.

Disclosure of Invention

The invention aims to solve the technical problems that the synthesis of a non-fullerene receptor material is complex and the structure adjustment is difficult in the prior art, so that the invention provides the non-fullerene receptor material, and a preparation method and application thereof.

The invention solves the problems through the following technical scheme:

the invention provides a non-fullerene acceptor material, which has a structure shown in a formula (I):

wherein, ring Ar¹And ring Ar^1′Independently an aromatic ring or a heteroaromatic ring independently having 1, 2, 3, or 4 heteroatoms independently selected from N, O and S;

ring Ar²And ring Ar^2′Independently an aromatic ring, a heteroaromatic ring, substituted with one or more R^aSubstituted aromatic rings, or by one or more R^aA substituted heteroaromatic ring independently having 1, 2, 3, or 4 heteroatoms independently selected from S, O and Se;

R^aindependently alkyl, alkoxy or alkylthio;

R¹、R²、R^1′and R^2′Independently is-C (R)^b)(R^c)(R^d)，R^b、R^cAnd R^dIndependently is H or alkyl;

R¹and R²Are each in ring Ar²Adjacent positions of (a);

R^1′and R^2′Are each in ring Ar^2′Adjacent positions of (a);

R³and R^3′Independently is H, alkyl or alkoxy;

m and m^′Independently 0, 1, 2, 3 or 4;

the mark end in the structure shown in the formula (I) is connected with an extended conjugated structure, and the extended conjugated structure is used for adjusting the band gap and the energy level distribution of the acceptor material.

In bookIn one embodiment of the invention, the extended conjugated structure may have formula (II) or (II)^′) The structure represented by the formula (II) and the ring Ar in the structure represented by the formula (I)²Are connected to the formula (II)^′) The structure shown and the ring Ar in the structure shown in the formula (I)^2′The connection is carried out in a connecting way,

wherein ring A and ring A' are independently absent, aromatic, heteroaromatic, substituted with one or more R^eSubstituted aromatic rings, or by one or more R^eA substituted heteroaromatic ring independently having 1, 2, 3, or 4 heteroatoms or heteroatom groups independently selected from N, O, S and C (═ O);

R^eindependently alkyl, alkoxy or alkylthio;

b and B' are independently

X is independently H, halogen, C₁-C₄Alkyl or C₁-C₄An alkoxy group;

r is independently H or alkyl.

In one embodiment of the present invention, ring Ar¹And ring Ar^1′Wherein the aromatic ring may independently be C₆-C₁₂Aromatic rings, such as benzene rings or naphthalene, and benzene rings, for example.

In one embodiment of the present invention, ring Ar¹And ring Ar^1′The heteroaromatic ring may be independently a 5-to 12-membered heteroaromatic ring, such as a 5-to 6-membered monocyclic heteroaromatic ring or an 8-to 12-membered fused heteroaromatic ring, and may be pyridine.

In one embodiment of the present invention, ring Ar²And ring Ar^2′Wherein the aromatic ring may independently be C₆-C₁₂Aromatic rings, such as benzene rings or naphthalene, and benzene rings, for example.

In the present inventionIn a certain embodiment of the invention, ring Ar²And ring Ar^2′The heteroaromatic ring may be independently a 5-to 12-membered heteroaromatic ring, such as a 5-to 6-membered monocyclic heteroaromatic ring or an 8-to 12-membered fused heteroaromatic ring, and further such as a 5-to 6-membered monocyclic heteroaromatic ring. The heteroaryl ring may independently have 1, 2 or 3 heteroatoms, for example 1. The heteroatoms may independently be independently selected from S and Se, e.g. S.

In one embodiment of the present invention, ring Ar²And ring Ar^2′Wherein the 5-to 6-membered monocyclic heteroaromatic ring may be independently thiopheneOr seleneneSuch as thiophene. The 8-12 fused heteroaromatic rings can be independently a benzodithiopheneBenzodithiopheneAnd trithiopheneOr dithienocyclopentadienes

In one embodiment of the present invention, ring Ar²And ring Ar^2′In, R^aAnd may be independently 1, 2 or 3.

In one embodiment of the present invention, R^aWherein the alkyl group may be independently C₁～C₂₅Alkyl radicals, e.g. C₁～C₁₂Alkyl radicals, also e.g. C₁～C₄Alkyl (methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, or tert-butyl).

In one embodiment of the present invention, R^aWherein the alkoxy group may be independentGround is C₁～C₂₅Alkoxy radicals, e.g. C₁～C₁₂Alkoxy radicals, e.g. C₁～C₄Alkoxy (methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy or tert-butoxy).

In one embodiment of the present invention, R^aWherein said alkylthio may independently be C₁～C₂₅Alkylthio radicals, e.g. C₁～C₁₂Alkylthio radicals, e.g. C₁～C₄Alkylthio (methylthio, ethylthio, n-propylthio, isopropylthio, n-butylthio, isobutylthio or tert-butylthio).

In one embodiment of the present invention, R^b、R^cAnd R^dWherein the alkyl group may be independently C₁～C₂₅Alkyl radicals, e.g. C₁～C₁₂Alkyl radicals, also e.g. C₁～C₄Alkyl (methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl or tert-butyl), for example methyl.

In one embodiment of the present invention, R¹、R²、R^1′And R^2′In (1), the-C (R)^b)(R^c)(R^d) And may independently be methyl, ethyl, isopropyl or tert-butyl, such as methyl or isopropyl, and also for example isopropyl.

In one embodiment of the present invention, R³And R^3′Wherein the alkyl group may be independently C₁～C₂₅Alkyl radicals, e.g. C₁～C₁₂Alkyl radicals, also e.g. C₁～C₄Alkyl (methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl or tert-butyl), for example also methyl or isopropyl.

In one embodiment of the present invention, R³And R^3′Wherein said alkoxy group may be independently C₁～C₂₅Alkoxy radicals, e.g. C₁～C₁₂Alkoxy radicals, e.g. C₁～C₄Alkoxy (methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy or tert-butoxy).

In one embodiment of the present invention, in ring A and ring A', the aromatic rings may independently be C₆-C₁₂Aromatic rings, such as benzene rings or naphthalene, and benzene rings, for example.

In one embodiment of the present invention, in the ring A and the ring A', the heteroaromatic rings may be independently 5-to 12-membered heteroaromatic rings, for example, 5-to 6-membered monocyclic heteroaromatic rings or 8-to 12-membered fused heteroaromatic rings. The heteroaryl ring may independently have 1, 2 or 3 heteroatoms, for example 3. The heteroatoms may be independently selected from N and S.

In a certain embodiment of the present invention, in ring a and ring a', the 5-to 6-membered single heteroaromatic ring may be independently thiophene, furan, pyrrole, imidazole, pyrazole, oxazole, pyridine or pyrazine. The 8-12 fused heteroaromatic rings can be independently benzothiophene, benzodithiophene, benzothiadiazole, benzodithiadiazole, thienothiadiazole, or thienopyrazine, such as 2,1, 3-benzothiadiazole.

In one embodiment of the present invention, R in ring A and ring A', R^eAnd may be independently 1, 2 or 3.

In one embodiment of the present invention, R^eWherein the alkyl group may be independently C₁～C₂₅Alkyl radicals, e.g. C₁～C₁₂Alkyl radicals, also e.g. C₁～C₄Alkyl (methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, or tert-butyl).

In one embodiment of the present invention, R^eWherein said alkoxy group may be independently C₁～C₂₅Alkoxy radicals, e.g. C₁～C₁₂Alkoxy radicals, e.g. C₁～C₄Alkoxy (methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy or tert-butoxy).

In one embodiment of the present invention, R^eWherein said alkylthio may independently be C₁～C₂₅Alkylthio radicals, e.g. C₁～C₁₂Alkylthio radicals, e.g. C₁～C₄Alkylthio (methylthio, ethylthio, n-propylthio, isopropylthio, n-butylthio, isobutylthio orTert-butylthio).

In one embodiment of the present invention, in X, the halogen may be independently F, Cl, Br or I, such as F or Cl.

In one embodiment of the present invention, in X, C is₁-C₄Alkyl groups may independently be methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl or tert-butyl, for example methyl.

In one embodiment of the present invention, in X, C is₁-C₄Alkoxy groups may independently be methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy or tert-butoxy, for example methoxy.

In one embodiment of the present invention, the alkyl group in R may be independently C₁～C₂₅Alkyl radicals, e.g. C₁～C₁₂Alkyl radicals, also e.g. C₁～C₄Alkyl (methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, or tert-butyl).

In one aspect of the present invention, in B and B', theCan independently be

In one embodiment of the present invention, ring Ar¹And ring Ar^1′Independently an aromatic ring.

In one embodiment of the present invention, ring Ar²And ring Ar^2′Independently a heteroaromatic ring.

In one embodiment of the present invention, R³And R^3′Independently an alkyl group.

In one embodiment of the invention, m and m' are independently 1.

In one embodiment of the invention, ring a and ring a' are independently a non-or heteroaromatic ring.

In one embodiment of the invention, B and B' are independently

In one embodiment of the invention, X is independently H or halogen.

In one aspect of the present invention, the structural unitCan be thatAnd can beFor exampleAlso for example

In one aspect of the present invention, the structural unitCan be thatAnd can beFor exampleAlso for example

In one aspect of the present invention, the structural unitCan be that

In one aspect of the present invention, the structure represented by the formula (I) may be a structure represented by the formula (I-1)

In one aspect of the present invention,can be independently absent, E.g. none or

In some embodiments of the invention, the structure of formula (I) may be

In one aspect of the present invention, the structure represented by the formula (II) and the formula (II)^′) The structures shown may independently be

In some embodiments of the invention, the non-fullerene acceptor material may have any one of the following structures:

the invention provides a compound shown as a formula (III),

wherein each group is as defined in any of the embodiments of the present invention.

In some embodiments of the invention, the compound of formula (III) may have any one of the following structures:

the invention provides a preparation method of the compound shown in the formula (III), which comprises the following steps: the compound represented by the formula (IV) may be reacted with the compound H-B and the compound H-B' in the presence of an organic base (e.g., pyridine) in an organic solvent (e.g., chloroform) as shown below,

wherein each group is as defined in any of the embodiments of the present invention.

The invention provides a compound shown as a formula (IV):

wherein each group is as defined in any of the embodiments of the present invention.

In one aspect of the present invention, the compound represented by formula (IV) may have any one of the following structures:

the invention provides an application of the non-fullerene acceptor material or the compound shown in the formula (III) as a solar cell material.

The invention provides an organic solar cell device, wherein an acceptor material of the organic solar cell device is the non-fullerene acceptor material or the compound shown in the formula (III).

In one aspect of the invention, the organic solar cell device comprises an anode, a hole transport layer, a layer of a blend of the above non-fullerene acceptor material or the above compound of formula (III) with a donor polymer PM6, an electron transport layer and a cathode.

Preferably, the material of the anode is Indium Tin Oxide (ITO); the hole transport layer is PEDOT PSS; the electron transport layer is made of PFN-Br; the cathode is made of aluminum (Al).

Unless otherwise specified, the terms in the present invention have the following meanings:

in the present invention, "alkyl" means a straight-chain or branched alkyl group having the specified number of carbon atoms.

In the present invention, "alkoxy" means a group-O-R^XWherein R is^XIs an alkyl group as defined above.

In the present invention, "alkylthio" means the group-S-R^XWherein R is^XIs an alkyl group as defined above.

On the basis of the common knowledge in the field, the above preferred conditions can be combined randomly to obtain the preferred embodiments of the invention.

The reagents and starting materials used in the present invention are commercially available.

The positive progress effects of the invention are as follows: the non-fullerene acceptor material provided by the invention can have a non-condensed ring structure, and can keep the planarity of a molecular main body while ensuring the solubility, so that organic photovoltaic material molecules can be flexibly constructed by using non-condensed ring structure units, the material solubility is good, the light absorption range can be expanded to a near infrared region, the electron mobility is high, and the development of novel efficient acceptor materials is facilitated.

Drawings

FIG. 1 shows the UV-visible absorption spectra of chloroform solutions of compounds i-Pr-BT, i-Pr-BT-F, and i-Pr-IC.

FIG. 2 shows the UV-VIS absorption spectra of the thin film states of compounds i-Pr-BT, i-Pr-BT-F, and i-Pr-IC.

FIG. 3 is a graph of current density and voltage of organic solar cell devices of compounds i-Pr-BT, i-Pr-BT-F, i-Pr-IC and PM 6.

Detailed Description

The invention is further illustrated by the following examples, which are not intended to limit the scope of the invention. The experimental methods without specifying specific conditions in the following examples were selected according to the conventional methods and conditions, or according to the commercial instructions.

Example 1: synthesis of Compound Me-BT

Step 1: synthesis of Compound 2-1

Magnesium turnings (2.92g, 120mmol) were added to a 250mL three-necked flask, argon was purged three times, and one pellet of iodine was added to the flask under argon flow followed by 30mL of anhydrous tetrahydrofuran. Dissolving mesitylene (23.89g, 120mmol) in 60mL of anhydrous tetrahydrofuran, adding 20mL of solution into a reaction system, heating to initiate reaction until the reaction solution becomes colorless, continuing to dropwise add the rest solution while keeping a slightly boiling state, heating and refluxing after dropwise addition is finished to completely react magnesium, and cooling for later use. Another 250mL three-necked flask was added with palladium acetate (269.4mg, 1.2mmol) and 2-dicyclohexylphosphino-2' - (N, N-dimethylamine) -biphenyl (2.29g, 4.8mmol) and argon was purged three times, then 3-bromothiophene (12.95g, 80mmol) and 40mL tetrahydrofuran were added, and the prepared Grignard reagent was added dropwise and heated under reflux. The reaction was monitored by thin layer chromatography with petroleum ether as the developing agent. After the reaction was completed, the reaction was quenched with saturated ammonium chloride, extracted with dichloromethane, washed with saturated brine, dried over anhydrous sodium sulfate, and concentrated. Separating by column chromatography using petroleum ether as eluent to obtain compound 2-1 as white solid 15.02g with yield 92.7%.

¹H NMR(400MHz,CDCl₃)δ:7.38(dd,J₁＝2.9Hz,J₂＝4.9Hz,1H),7.01(dd,J₁＝1.2Hz,J₂＝2.9Hz,1H),6.93(s,2H),6.92(dd,J₁＝1.2Hz,J₂＝4.9Hz,1H),2.32(s,3H),2.05(s,6H).MS(EI)m/z:202(M⁺).

Step 2: synthesis of Compound 2-2

In a 250mL three-necked flask, compound 2-1(10.74g, 53.1mmol) was added, 36mL of chloroform and 36mL of acetic acid were added, and N-bromosuccinimide (9.92g, 55.7mmol) was added thereto in portions with stirring, and the reaction was continued at room temperature until the reaction solution turned into a pale yellow clear solution. The reaction solution was neutralized with NaOH to near neutral, extracted with dichloromethane, washed with saturated sodium chloride solution, dried over anhydrous sodium sulfate, concentrated, and the resulting crude product was recrystallized from ethanol to isolate compound 2-2 as a white solid 10.92g, in 73.1% yield.

¹H NMR(400MHz,CDCl₃)δ:7.33(d,J＝5.8Hz,1H),6.94(s,2H),6.76(d,J＝5.8Hz,1H),2.32(s,3H),2.02(s,6H).MS(EI)m/z:282(M⁺).

And step 3: synthesis of Compounds 2-3

Magnesium turnings (365mg, 15mmol) were added to a 50mL three-necked flask, argon was purged three times, and one iodine pellet was added to the flask under argon flow followed by 5mL of anhydrous tetrahydrofuran. Dissolving the compound 2-2(4.22g, 15mmol) in 10mL of anhydrous tetrahydrofuran, adding 3mL of the solution into a reaction bottle, heating to initiate reaction until the reaction solution becomes colorless, keeping a slightly boiling state, continuously dropwise adding the rest solution, heating to reflux after dropwise adding is finished until magnesium completely reacts, and cooling for later use. Another 100mL three-necked flask was taken, and the compound 2-2(2.81g, 10mmol), palladium acetate (34mg, 0.15mmol) and 2-dicyclohexylphosphino-2' - (N, N-dimethylamine) -biphenyl (236mg, 0.6mmol) were added thereto, argon was evacuated three times, 20mL of anhydrous tetrahydrofuran was added, the prepared grignard reagent was added dropwise, and heating and reflux reaction were performed. The reaction was monitored by thin layer chromatography with petroleum ether as the developing agent. Quenching the reaction by using a saturated ammonium chloride solution after the reaction is completed, extracting by using dichloromethane, washing by using a saturated sodium chloride solution, drying by using anhydrous sodium sulfate, concentrating, and separating by using column chromatography, wherein an eluent is petroleum ether: dichloromethane 10: 1, compound 2-3 was isolated as a white solid, 2.53g, 62.9% yield.

¹H NMR(400MHz,CDCl₃)δ:7.06(d,J＝5.1Hz,1H),6.97(s,2H),6.67(d,J＝5.1Hz,1H),2.38(s,3H),1.98(s,6H).MS(EI)m/z:402(M⁺).

And 4, step 4: synthesis of Compounds 2-4

Adding 2-3(2.53g, 6.28mmol) of a compound into a 250mL three-necked bottle, pumping argon for three times, adding 100mL of anhydrous tetrahydrofuran, dropwise adding 8.8mL of a 2.5mol/L n-butyllithium solution at room temperature, continuing to stir at room temperature for 1h after dropwise adding, adding 15.1mL of a 1mol/L trimethyltin chloride solution into the reaction bottle, and stirring at room temperature for reaction for 12 h. The reaction is quenched with water, extracted with dichloromethane, washed with saturated sodium chloride solution, dried over anhydrous sodium sulfate and concentrated to obtain a yellow solid. The crude product was recrystallized from ethyl acetate to give 2.93g of compound 2-4 as a pale yellow solid with a yield of 64.0%.

¹H NMR(400MHz,CDCl₃)δ:6.85(s,2H),6.67(s,1H),2.33(s,3H),1.84(s,6H),0.25(s,9H).MS(EI)m/z:728.1(M⁺).

And 5: synthesis of Compounds 2-5

A100 mL three-necked flask was charged with compound 2-4(2.93g, 4.02mmol), 4-bromo-7-carboxaldehyde-2, 1, 3-benzothiadiazole (2.45g, 10.1mmol) and palladium tetratriphenylphosphine (92.9mg, 0.08mmol), argon was purged three times, and 40mL of redistilled toluene was added. And performing liquid nitrogen freezing-air extraction-thawing circulation for three times, removing dissolved oxygen in the solvent, and performing heating reflux reaction. The reaction was monitored by TLC and the developing solvent was dichloromethane. After the reaction is completed, dichloromethane is used for extraction reaction, saturated sodium chloride solution is used for washing, anhydrous sodium sulfate is used for drying, concentration and column chromatography separation are carried out, dichloromethane is used as eluent, and the compound 2-5 deep red solid 1.95g is obtained through separation, and the yield is 66.7%.

¹H NMR(400MHz,CDCl₃)δ:10.59(s,1H),8.15(d,J＝7.2Hz,1H),8.14(s,1H),7.69(d,J＝7.2Hz,1H),7.15(s,2H),2.44(s,3H),2.10(s,6H).MS(EI)m/z:727.1(M+H⁺)

Step 6: synthesis of Compound Me-BT

In a 250mL three-necked flask, compound 2-5(1.09g, 1.5mmol), 120mL chloroform, and 5mL pyridine were added. The reaction flask was placed in a low temperature thermostat and the temperature was reduced to-40 ℃. 3- (dicyanomethylene) indolone (1.17g, 6mmol) was added in portions to the reaction flask, stirred for 10min, and then heated to-15 ℃ to continue the reaction. The reaction was monitored by TLC and the developing solvent was dichloromethane. After completion of the reaction, the reaction mixture was poured into 300mL of methanol, and the precipitate was collected by filtration. Excess compound 3- (dicyanomethylene) indolone and pyridine were removed by washing with methanol, followed by washing with 15mL of n-hexane, diethyl ether and acetone in sequence three times each, and the resulting solid was added to ethyl acetate at 100mL and heated under reflux for about 1h, filtered while hot, and the precipitate was collected as 842.6mg of Me-BT dark blue solid, 52.1% yield.

¹H NMR(400MHz,CDCl₃)δ:9.54(s,1H),9.16-9.13(m,1H),8.73(d,J＝8.0Hz,1H),8.20(s,1H),7.97-7.94(m,1H),7.86-7.77(m,2H),7.72(d,J＝8.0Hz,1H),7.13(s,2H),2.51(s,3H),2.13(s,6H).HRMS(MALDI)m/z:1078.2(M⁺).Element Anal.Calcd for C₆₄H₃₈N₈O₂S₄:C 71.2％H 3.55％N 10.38％Found C 69.9％,H 4.02％,N 9.85％.

Example 2: synthesis of compound i-Pr-BT

Step 1: synthesis of Compounds 2-6

Triisopropylbromobenzene (14.16g, 50mmol), 3-thiopheneboronic acid (12.80g, 100mmol), potassium phosphate (21.23g, 100mmol), tris (dibenzylideneacetone) dipalladium (458mg, 0.5mmol) and 2-dicyclohexylphosphine-2 ',6' -dimethoxybiphenyl (821mg, 2mmol) were charged into a 500mL three-necked flask, argon was evacuated three times, 100mL of anhydrous toluene and 100mL of anhydrous tetrahydrofuran were added as solvents, three liquid nitrogen freeze-pump-thaw cycles were performed, dissolved oxygen in the solvent was removed, and heating and refluxing were performed. The reaction was monitored by TLC and the developing solvent was petroleum ether. Extracting with dichloromethane, washing with saturated sodium chloride solution, drying with anhydrous sodium sulfate, concentrating, separating with column chromatography to obtain compound 2-6 as white solid 14.10g with 98.4% yield, and eluting with petroleum ether.

¹H NMR(400MHz,CDCl₃)δ:7.35(dd,J₁＝2.9Hz,J₂＝4.8Hz,1H),7.04(s,2H),7.01(dd,J₁＝1.2Hz,J₂＝2.9Hz,1H),6.94(dd,J₁＝1.2Hz,J₂＝4.8Hz,1H),2.92(m,J＝6.8Hz,1H),2.66(m,J＝6.8Hz,2H),1.29(d,J＝6.8Hz,6H),1.09(d,J＝6.8Hz,6H),1.08(d,J＝6.8Hz,6H).MS(EI)m/z:286(M⁺).

Step 2: synthesis of Compounds 2-7

In a 250mL three-necked flask, compound 2-6(13.28g, 46.4mmol) was added, 30mL of chloroform and 30mL of acetic acid were added, and N-bromosuccinimide (8.66g, 48.7mmol) was added thereto in portions with stirring, and the reaction was continued at room temperature until the reaction solution turned into a pale yellow clear solution. Neutralizing the reaction liquid with NaOH to be nearly neutral, extracting with dichloromethane, washing with saturated sodium chloride solution, drying with anhydrous sodium sulfate, concentrating, taking a small amount of the solution in batches, and separating by column chromatography, wherein the used eluent is petroleum ether to obtain 7.51g of a compound 2-7 white solid, and the yield is 44.3%.

¹H NMR(400MHz,CDCl₃)δ:7.30(d,J＝5.4Hz,1H),7.04(s,2H),6.78(d,J＝5.4Hz,1H),2.93(m,J＝6.9Hz,1H),2.56(m,J＝6.9Hz,2H),1.29(d,J＝6.9Hz,6H),1.16(d,J＝6.9Hz,6H),1.05(d,J＝6.9Hz,6H).MS(EI)m/z:364(M⁺).

And step 3: synthesis of Compounds 2 to 8

Magnesium turnings (237mg, 9.75mmol) were added to a 50mL three-necked flask, argon was purged three times, and one iodine pellet was added to the flask under argon flow followed by 4mL of anhydrous tetrahydrofuran. Dissolving the compound 2-7(3.56g, 9.75mmol) in 8mL of anhydrous tetrahydrofuran, adding 3mL of the solution into a reaction bottle, heating to initiate reaction until the reaction solution becomes colorless, keeping a slightly boiling state, continuously dropwise adding the rest solution, heating to reflux after dropwise adding is finished until magnesium completely reacts, and cooling for later use. Another 100mL three-necked flask was taken, added with compound 2-7(2.37g, 6.5mmol), tris-dibenzylideneacetone dipalladium (22.5mg, 0.10mmol) and 2-dicyclohexylphosphine-2 ',6' -dimethoxybiphenyl (160.1mg, 0.39mmol), argon was evacuated three times, added with 16mL of anhydrous tetrahydrofuran, added dropwise with the prepared Grignard reagent, and heated under reflux for reaction. The reaction was monitored by TLC and the developing solvent was petroleum ether. Quenching the reaction by using a saturated ammonium chloride solution after the reaction is completed, extracting by using dichloromethane, washing by using a saturated sodium chloride solution, drying by using anhydrous sodium sulfate, concentrating, and separating by using column chromatography, wherein an eluent is petroleum ether: dichloromethane 10: 1, compound 2-8 was isolated as a white solid, 3.49g, 94.0% yield.

¹H NMR(400MHz,CDCl₃)δ:7.08(s,2H),6.98(d,J＝5.0Hz,1H),6.67(d,J＝5.0Hz,1H),2.98(m,J＝6.9Hz,1H),2.62(m,J＝6.9Hz,2H),1.33(d,J＝6.9Hz,6H),1.06(d,J＝6.9Hz,6H),1.02(d,J＝6.9Hz,6H).MS(EI)m/z:571.3(M⁺).

And 4, step 4: synthesis of Compounds 2-9

Adding 2-8(3.40g, 5.96mmol) of a compound into a 250mL three-necked bottle, pumping argon for three times, adding 80mL of anhydrous tetrahydrofuran, dropwise adding 8.4mL of a 2.5mol/L n-butyllithium solution at room temperature, continuing to stir and react for 1h at room temperature after dropwise adding, adding 14.4mL of a 1mol/L trimethyltin chloride solution into the reaction bottle, and stirring and reacting for 12h at room temperature. The reaction is quenched with water, extracted with dichloromethane, washed with saturated sodium chloride solution, dried over anhydrous sodium sulfate and concentrated to obtain a yellow solid. The crude product was recrystallized from ethyl acetate to give 3.24g of compound 2-9 as a pale yellow solid with a yield of 60.7%.

¹H NMR(400MHz,CDCl₃)δ:7.06(s,2H),2.96(m,J＝7.0Hz,1H),2.56(m,J＝7.0Hz,2H),1.32(d,J＝7.0Hz,6H),1.01(d,J＝7.0Hz,6H),1.00(d,J＝7.0Hz,6H),1.84(s,6H),0.17(s,9H).MS(EI)m/z:897.3(M⁺).

And 5: synthesis of Compounds 2-10

Adding compounds 2-9(1.62g, 1.81mmol), 4-bromo-7-aldehyde-2, 1, 3-benzothiadiazole ((1.10g, 4.53mmol) and palladium (41.8mg, 0.04mmol) of tetratriphenylphosphine into a 100mL three-necked flask, pumping argon for three times, adding 20mL of anhydrous toluene, performing three cycles of liquid nitrogen freezing-pumping-thawing, removing dissolved oxygen in the solvent, heating and refluxing, monitoring the reaction by TLC, using dichloromethane as a developing agent, performing extraction reaction by dichloromethane after the reaction is completed, washing by a saturated sodium chloride solution, drying by anhydrous sodium sulfate, concentrating, separating by column chromatography, using dichloromethane as an eluent, and separating to obtain 859mg of a compound 2-10 dark red solid with the yield of 53.0%.

¹H NMR(400MHz,CDCl₃)δ:10.67(s,1H),8.24(s,1H),8.11(d,J＝7.5Hz,1H),7.61(d,J＝7.5Hz,1H),7.25(s,2H),3.10(m,J＝6.9Hz,1H),2.77(m,J＝6.9Hz,2H),1.44(d,J＝6.9Hz,6H),1.17(d,J＝6.9Hz,6H),1.15(d,J＝6.9Hz,6H).MS(EI)m/z:895.3(M+H⁺).

Step 6: synthesis of compound i-Pr-BT

In a 100mL three-necked flask, compound 2-10(357.7mg, 0.40mmol), 40mL of chloroform, and 2.4mL of pyridine were added. The reaction flask was placed in a low temperature thermostat and the temperature was reduced to-40 ℃. 3- (dicyanomethylene) indolone (310.7mg, 1.60mmol) was added in portions to the reaction flask, stirred for 10min, and then heated to-15 ℃ to continue the reaction. The reaction was monitored by TLC and the developing solvent was dichloromethane. After completion of the reaction, the reaction mixture was poured into 200mL of methanol, and the precipitate was collected by filtration. Washing with methanol to remove excessive compounds 2-5 and pyridine, sequentially washing with 10mL of n-hexane, diethyl ether and acetone for three times respectively, adding 40mL of the obtained solid into ethyl acetate, heating and refluxing for about 1h, filtering while hot, and collecting precipitate which is 302.5mg of i-Pr-BT dark blue solid with the yield of 60.7%.

¹H NMR(400MHz,CDCl₃)δ:9.51(s,1H),9.09-9.07(m,1H),8.73(d,J＝8.2Hz,1H),8.21(s,1H),7.96-7.94(m,1H),7.86-7.77(m,2H),7.67(d,J＝8.2Hz,1H),7.26(s,2H),3.11(m,J＝6.9Hz,1H),2.77(m,J＝6.9Hz,2H),1.44(d,J＝6.9Hz,6H),1.18(d,J＝6.9Hz,6H),1.14(d,J＝6.9Hz,6H).HRMS(MALDI)m/z:1246.4(M⁺).Element Anal.Calcd for C₇₆H₆₂N₈O₂S₄:C 73.2％H 5.10％N 8.98％Found C 72.6％,H 5.26％,N 8.77％.

Example 3: synthesis of Compounds i-Pr-IC and i-Pr-IC-F

Step 1: synthesis of Compounds 2-11

In a 100mL three-necked flask, compound 2-8(1.14g, 2mmol), 30mL of 1, 2-dichloroethane and 1.9mL of phosphorus oxychloride were added, 1.6mL of N, N-dimethylformamide was added dropwise, and the reaction was heated under reflux for 24 hours. After the reaction is completed, extracting by dichloromethane, washing by saturated sodium chloride solution, drying by anhydrous sodium sulfate, concentrating, and separating by column chromatography, wherein the used eluent is petroleum ether: 1-dichloromethane: 1, compound 2-11 was isolated as a yellow solid 970.0mg, 77.4% yield.

¹H NMR(400MHz,CDCl₃)δ:9.74(s,1H),7.39(s,1H),7.14(s,2H),3.00(p,J＝6.9Hz,1H),2.48(p,J＝6.9Hz,2H),1.35(d,J＝6.9Hz,6H),1.05(t,J＝6.8Hz,12H).MS(EI)m/z:627.3(M+H⁺).

Step 2: synthesis of Compounds i-Pr-IC and i-Pr-IC-F

In a 100mL three-necked flask, compound 2-11(200m g, 0.32mmol), 30mL chloroform, and 1.9mL pyridine were added. The reaction flask was cooled in an ice bath and 3- (dicyanomethylene) indolone (248.6mg, 1.28mmol) was added portionwise and the reaction monitored by TLC using dichloromethane as the developing solvent. After the reaction is completed, the solvent is removed under reduced pressure, and column chromatography separation is carried out, wherein dichloromethane is used as eluent, and the compound i-Pr-IC dark red solid 203.5mg is obtained through separation, and the yield is 64.9%.

¹H NMR(400MHz,CDCl₃)δ:8.68–8.63(m,1H),8.62(s,1H),7.80(dd,J＝7.0,1.9Hz,1H),7.77–7.67(m,3H),7.23(s,2H),3.04(p,J＝6.9Hz,1H),2.55(p,J＝6.9Hz,2H),1.39(d,J＝6.9Hz,6H),1.14(d,J＝6.8Hz,6H),1.10(d,J＝6.8Hz,6H).MS(MALDI)m/z:978.4(M⁺)

In a 100mL three-necked flask, compound 2-11(200mg, 0.32mmol), 30mL of chloroform, and 1.9mL of pyridine were added. The reaction flask was cooled in an ice bath and 5, 6-difluoro-3- (dicyanomethylene) indolone (294.6mg, 1.28mmol) was added in portions and the reaction monitored by TLC using dichloromethane as the developing solvent. After the reaction is completed, the solvent is removed under reduced pressure, and column chromatography separation is carried out, wherein dichloromethane is used as eluent, and the compound i-Pr-IC-F dark red solid 172.1mg is obtained through separation, and the yield is 51.2%.

¹H NMR(400MHz,CDCl₃)δ:8.62(s,1H),8.50(dd,J＝9.9,6.4Hz,1H),7.72(s,1H),7.56(t,J＝7.5Hz,1H),7.22(s,2H),3.04(p,J＝6.8Hz,1H),2.51(p,J＝6.8Hz,3H),1.39(d,J＝6.9Hz,6H),1.13(d,J＝6.8Hz,6H),1.09(d,J＝6.8Hz,6H).MS(MALDI)m/z:1050.4(M⁺).

Example 4: synthesis of Compounds i-Pr-BT-F and i-Pr-BT-Cl

In a 100mL three-necked flask, compound 2-10(500.0mg, 0.56mmol), 50mL of chloroform, and 3.3mL of pyridine were added. The reaction flask was placed in a low temperature thermostat and the temperature was reduced to-40 ℃.5, 6-difluoro-3- (dicyanomethylene) indolone (514.7mg, 2.24mmol) was added portionwise to the reaction flask, stirred for 10min, and then warmed to room temperature to continue the reaction. The reaction was monitored by TLC and the developing solvent was dichloromethane. After completion of the reaction, the reaction mixture was poured into 200mL of methanol, and the precipitate was collected by filtration. Excess compound 5, 6-difluoro-3- (dicyanomethylene) indone and pyridine are removed by washing with methanol, then washing with 10mL of n-hexane, ethyl ether and acetone respectively for three times, and separating by column chromatography, wherein the used eluent is acetone and chloroform in turn, and i-Pr-BT-F dark blue solid 372.2mg is collected, and the yield is 50.4%.

¹H NMR(400MHz,CDCl₃)δ:9.54(s,1H),9.08(d,J＝7.9Hz,1H),8.57(dd,J＝9.8,6.4Hz,1H),8.23(s,1H),7.72(t,J＝7.4Hz,1H),7.67(d,J＝8.0Hz,1H),7.26(s,2H),3.11(p,J＝6.8Hz,1H),2.75(p,J＝6.8Hz,2H),1.44(d,J＝6.9Hz,6H),1.17(d,J＝6.8Hz,6H),1.14(d,J＝6.8Hz,6H).MS(MALDI)m/z:1318.3(M⁺)

In a 100mL three-necked flask, compound 2-10(500.0mg, 0.56mmol), 50mL of chloroform, and 3.3mL of pyridine were added. The reaction flask was placed in a low temperature thermostat and the temperature was reduced to-40 ℃.5, 6-dichloro-3- (dicyanomethylene) indolone (514.7mg, 2.24mmol) was added portionwise to the reaction flask, stirred for 10min, and then warmed to room temperature to continue the reaction. The reaction was monitored by TLC and the developing solvent was dichloromethane. After completion of the reaction, the reaction mixture was poured into 200mL of methanol, and the precipitate was collected by filtration. Excess compound 5, 6-dichloro-3- (dicyanomethylene) indolone and pyridine are removed by washing with methanol, then washing with 10mL of n-hexane, ether and acetone respectively for three times, and separating by column chromatography, wherein the used eluent is acetone and chloroform in turn, and the i-Pr-BT-Cl dark blue solid 170.1mg is collected, and the yield is 21.9%.

¹H NMR(400MHz,CDCl₃)δ:9.57(s,1H),9.11(d,J＝8.0Hz,1H),8.81(s,1H),8.24(s,1H),7.99(s,1H),7.68(d,J＝8.0Hz,1H),7.26(s,2H),3.11(p,J＝6.8Hz,1H),2.76(p,J＝6.6Hz,2H),1.45(d,J＝6.9Hz,6H),1.17(d,J＝6.8Hz,6H),1.14(d,J＝6.8Hz,6H).MS(MALDI)m/z:1384.1(M⁺)

Example 5: characterization of absorption spectra of small molecule receptor materials

Dissolving small molecule receptor materials i-Pr-BT, i-Pr-BT-F and i-Pr-IC in trichloromethane to prepare 10^-5And testing the ultraviolet-visible spectrum of the solution state by using the mol/L solution, wherein the tested spectrum is shown in figure 1. Dissolving i-Pr-BT, i-Pr-BT-F and i-Pr-IC in chloroform to prepare 10mg/mL, spin-coating on a quartz glass plate to obtain a receptor material film, and measuring the ultraviolet-visible spectrum in the film state, wherein the measured spectrum is shown in figure 2.

Example 6:

the organic micromolecule acceptor material and the donor polymer PM6 are used as active layers of the organic solar cell device, and the bulk heterojunction organic solar cell device can be obtained. The device structure is as follows: ITO/PEDOT PSS/active layer/PFN-Br/Al. Wherein the ITO is an indium tin oxide conductive glass substrate layer; PSS is a hole transport layer; the active layer is a blending layer of a donor material PM6 and an acceptor material i-Pr-BT or i-Pr-IC or i-Pr-BT-F, the blending mass ratio is PM6: 1:1.6, PFN-Br is an electron transport layer, and Al is a cathode.

Preparing an organic solar cell: and ultrasonically cleaning the ITO glass twice in deionized water, acetone and isopropanol solution, drying the ITO glass, performing ultraviolet-ozone treatment on the ITO glass for 30min, then spin-coating PEDOT (PSS) on the ITO glass at the spin-coating speed of 4000rpm for 60s, and then performing annealing treatment at 150 ℃ for 10 min. Will be provided withAnd dripping the prepared precursor solution of the active layer onto PEDOT (PSS), spin-coating at the rotation speed of 4000rpm for 30s, thermally annealing at the temperature of 100 ℃ for 5min, and spin-coating an electron transport layer PFN-Br solution at 3500rpm for 30 s. Followed by evaporation of the aluminum electrode. The current density-voltage curve (J-V) of the device is AM 1.5G (100 mW/cm) in a sunlight simulation system²) Obtained by the following test.

The current density and voltage curve of the i-Pr-BT based organic solar cell device is shown in FIG. 3, and the short-circuit current density of the device is 16.32mA/cm²The open circuit voltage was 0.68V, and the energy conversion efficiency was 7.57%.

The current density and voltage curve of the i-Pr-IC-based organic solar cell device is shown in FIG. 3, and the short-circuit current density of the device is 13.48mA/cm²The open circuit voltage was 0.79V, and the energy conversion efficiency was 7.52%.

The current density and voltage curve of the i-Pr-BT-F-based organic solar cell device is shown in FIG. 3, and the short-circuit current density of the device is 15.76mA/cm²The open circuit voltage was 0.46V, and the energy conversion efficiency was 3.71%.