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CN-121974928-A - Benzothiadiazole-terminated small molecule receptor and preparation method and application thereof

CN121974928ACN 121974928 ACN121974928 ACN 121974928ACN-121974928-A

Abstract

The invention discloses a benzothiadiazole end-capped small molecule acceptor and a preparation method and application thereof. The compound takes seven-membered condensed ring benzotriazoles with alkyl chains as an intermediate core and benzothiadiazole-substituted cyano-indenone as a non-fullerene acceptor material with end groups. The preparation method of the condensed ring nucleus takes 4, 7-dibromo-5, 6-dinitrobenzotriazol as a raw material, thiophene with alkyl chain is introduced through stille coupling reaction, then ring closure is carried out, alkyl chain is introduced on N through nucleophilic substitution, and aldehyde group is introduced through Vilsmeier-Haack. The preparation method of the end group takes boric acid ester and monobromocyano indenone as raw materials, and B is obtained through Suzuki-Miyaura reaction. Finally, the S1 compound is obtained through Knoevenagel reaction, the small molecule forms a definite conformation and has better solubility, and the small molecule has universal electron acceptor units, thus the small molecule is a potential photovoltaic material.

Inventors

  • LUO MEI
  • JIA GUOKAI
  • JIANG MENGTING
  • YANG SHIBAO
  • Yu Zhengzhang

Assignees

  • 湖南科技学院

Dates

Publication Date
20260505
Application Date
20260224

Claims (10)

  1. 1. A benzothiadiazole-terminated small molecule receptor, characterized by the following formula I: A formula I; wherein R 1 、R 2 、R 3 is independently selected from at least one of alkyl chain, alkyl chain or two-dimensional side chain of C 1 ~C 12 substituted by halogen atom, X is hydrogen, fluorine or chlorine.
  2. 2. The benzothiadiazole-terminated small molecule acceptor of claim 1, wherein R 1 is selected from the group consisting of C 1 ~C 12 alkyl chains substituted with halogen atoms and R 2 、R 3 is independently selected from the group consisting of C 1 ~C 12 alkyl chains.
  3. 3. The benzothiadiazole-terminated small molecule receptor of claim 2, wherein the structural formula is represented by S1: 。
  4. 4. a method for preparing a benzothiadiazole-terminated small molecule receptor according to any one of claims 1 to 3, comprising the steps of: (1) Compound 1 and compound 2 were coupled via stille to afford compound 3: ; (2) The compound 3 is subjected to condensation ring closure, and further reacts with halogenated hydrocarbon through nucleophilic substitution reaction to obtain a compound 4, wherein the halogenated hydrocarbon is R 3 X: ; (3) Compound 4 was reacted by Vilsmeier-Haack to give compound a: ; (4) Compound 5 and compound 6 were reacted by Suzuki-Miyaura to give compound B: ; (5) The compound A and the compound B react through Knoevenagel to obtain the compound of the formula I; wherein, R 1 、R 2 、R 3 and X in the above steps are the same as those in claims 1-3.
  5. 5. The preparation method of the benzothiadiazole end-capped small molecule acceptor is characterized in that the stille coupling reaction in the step (1) is carried out under the conditions that a solvent is toluene and/or o-xylene, a catalyst is tetraphenylpalladium phosphate, the addition amount of the catalyst is 2% -6% of the molar amount of the compound 1, the molar ratio of the compound 1 to the compound 2 is 1:2-1:4, and the reflux reaction is carried out for 12-48 hours at 100-120 ℃.
  6. 6. The preparation method of the benzothiadiazole end-capped small molecule acceptor is characterized in that the condensation ring-closure reaction in the step (2) is carried out under the conditions that a solvent is N-methyl pyrrolidone, a catalyst is triphenylphosphine, the molar ratio of the catalyst to the compound 3 is 10:1-20:1, and the reflux reaction is carried out for 12-24 hours at the temperature of 170-190 ℃; The nucleophilic substitution reaction is carried out under the conditions that N, N-dimethylformamide is used as a solvent, potassium carbonate is used as a neutralizing agent, KI is used as an affinity reagent source, halogenated hydrocarbon is bromoisooctane, the molar ratio of the halogenated hydrocarbon to the compound 3 is 5:1-10:1, the molar ratio of the potassium carbonate to the KI to the bromoisooctane is 50:2:25, and reflux reaction is carried out for 8-24 hours at the temperature of 80-100 ℃.
  7. 7. The preparation method of the benzothiadiazole terminated small molecule acceptor is characterized in that the Vilsmeier-Haack reaction condition in the step (3) is that a solvent is N, N-dimethylformamide, a formylating reagent is phosphorus oxychloride, the molar ratio of the phosphorus oxychloride to the compound 4 is 1:1-20:1, and reflux reaction is carried out for 8-12 hours at 80-95 ℃; The Suzuki-Miyaura reaction conditions are that a solvent is o-xylene and/or toluene, a catalyst is tetra (triphenylphosphine) palladium, the addition amount of the catalyst is 2% -6% of the molar amount of a compound 5, cesium carbonate is an alkaline reagent, the molar amount of the cesium carbonate is 8% -14 times of the compound 5, the molar ratio of the compound 5 to the compound 6 is 1:2.5-1:5, and the mixture is subjected to reflux reaction for 24-48 hours at 80-120 ℃; The Knoevenagel reaction condition in the step (5) is that chloroform is used as a solvent, an acid binding agent is pyridine, the molar ratio of the compound A to the compound B is 1:6-1:10, and reflux reaction is carried out for 8-16 hours at the temperature of 60-70 ℃.
  8. 8. The application of the benzothiadiazole-terminated small molecule acceptor according to any one of claims 1 to 3, which is characterized in that the benzothiadiazole-terminated small molecule acceptor is applied as an organic solar cell acceptor material.
  9. 9. The method of claim 8, wherein the active layer portion of the organic solar cell device comprises blending a benzothiadiazole-terminated small molecule acceptor material with a donor material.
  10. 10. The use of a benzothiadiazole-terminated small molecule acceptor according to claim 9, wherein the molar ratio of acceptor material to donor material is 1-1.5:1; the donor material is at least one of PM6, PTQ10 or D18: 。

Description

Benzothiadiazole-terminated small molecule receptor and preparation method and application thereof Technical Field The invention belongs to the technical field of preparation of organic solar cell materials, relates to synthesis of an organic solar cell receptor material, and particularly relates to a benzothiadiazole-terminated small molecule receptor, and a preparation method and application thereof. Background Organic Solar Cells (OSCs) have great commercial application potential in building integrated photovoltaics, greenhouses, wearable devices, and the like due to their advantages of flexibility, light weight, and large area solution processing. In recent years, a process for producing a plastic film, Thanks to the continuous optimization of material design and device structure, the photoelectric conversion efficiency of single junction and stacked OSCs has broken through 19% and 20%, respectively, showing good development potential. However, OSCs still face a key challenge in further efficiency enhancement, mainly manifested by large energy losses, especially the open circuit voltage loss (Δv loss) caused by non-radiative recombination, significantly limiting the open circuit voltage (V oc) and overall performance of the device. This voltage loss is one of the core factors responsible for the energy conversion efficiency gap between the two compared to conventional silicon-based batteries. Therefore, it is a key scientific issue that has been well understood and effective in suppressing non-radiative energy loss (Δe 3) to drive OSCs to achieve high efficiency and commercial applications. From the quantitative relationship of non-radiative recombination energy loss, Δe 3 = -kT/qln (EQEEL), it is known that Δe 3 is mainly related to the external quantum efficiency of charge transfer state electroluminescence (EQE EL). Raising the EQE EL value helps reduce non-radiative recombination energy losses. Recent studies have shown that increasing PLQY of narrow bandgap components through efficient hybridization of singlet excitons to Charge Transfer (CT) states is an effective strategy to increase EQE EL and reduce non-radiative recombination energy loss of organic solar cells. Thus, increasing PLQY of narrow bandgap receptors when paired with wide bandgap polymer donors is of great importance to reduce non-radiative recombination energy losses in organic solar cells. Disclosure of Invention Aiming at the problems that the non-radiative recombination energy loss and the charge transmission efficiency in an organic solar cell are difficult to cooperatively optimize and the like, the first aim of the invention is to provide a small molecule acceptor material with good film forming property, high fluorescence quantum yield and high charge mobility. A second object of the invention is to provide a method for preparing a benzothiadiazole terminated small molecule receptor which is mild in condition and simple in operation. A third object of the present invention is to provide an application of a benzothiadiazole-terminated small molecule acceptor, which has a stronger absorption in the uv-visible region (550-900 nm), a suitable energy level, and can be matched with a high-efficiency donor material (PM 6, D18) for realizing a high-efficiency organic solar cell. In order to achieve the technical purpose, the invention adopts the following technical scheme: a benzothiadiazole-terminated small molecule receptor, characterized by the following formula I: A formula I; wherein R 1、R2、R3 is independently selected from at least one of alkyl chain, alkyl chain or two-dimensional side chain of C 1~C12 substituted by halogen atom, X is hydrogen, fluorine or chlorine. Preferably, R 1 is selected from the group consisting of C 1~C12 alkyl chains substituted with halogen atoms and R 2、R3 is independently selected from the group consisting of C 1~C12 alkyl chains. Preferably, the structural formula is as follows S1: 。 the invention relates to a preparation method of a benzothiadiazole end-capped small molecule acceptor, which is characterized by comprising the following steps: (1) Compound 1 and compound 2 were coupled via stille to afford compound 3: ; (2) The compound 3 is subjected to condensation ring closure, and further reacts with halogenated hydrocarbon through nucleophilic substitution reaction to obtain a compound 4, wherein the halogenated hydrocarbon is R 3 X: ; (3) Compound 4 was reacted by Vilsmeier-Haack to give compound a: ; (4) Compound 5 and compound 6 were reacted by Suzuki-Miyaura to give compound B: ; (5) The compound A and the compound B react through Knoevenagel to obtain the compound of the formula I; Wherein, R 1、R2、R3 and X in the above steps are the same as described above. Preferably, the stille coupling reaction in the step (1) is carried out under the conditions that the solvent is toluene and/or o-xylene, the catalyst is tetraphenylpalladium phosphate, the addition amount of the catalyst is 2% -6% of