Receptor units based on oxaboron-nitrogen coordination, n-type polymers and preparation and use thereof

Abstract

The present application relates to the technical field of organic polymer and organic optoelectronic material, in particular to acceptor unit based on oxygen boron nitrogen coordination, n-type polymer and its preparation and application. The present application prepares acceptor unit with strong electron-withdrawing property through Schiff base boron nitrogen coordination reaction, bromination reaction and coupling reaction, and prepares conjugated polymer with lower LUMO energy level through polymerization reaction. Further, by taking the polymer as an organic semiconductor layer, an organic field effect transistor and an organic thermoelectric material with higher electron mobility and power factor are prepared. The present application realizes efficient synthesis of electron-deficient acceptor and preparation of high electron mobility polymer, promotes the application of n-type polymer semiconductor material in the field of flexible, printing and wearable electronics, and has important significance for realizing industrialization of organic optoelectronic devices.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of organic polymer and organic optoelectronic material, and particularly relates to acceptor units based on oxygen-boron-nitrogen coordination, n-type polymers and preparation and application thereof. BACKGROUND

[0002] Conjugated polymers have the advantages of light weight, low cost, good flexibility and solution processing, and have been widely studied in the fields of organic light-emitting diodes, organic field effect transistors, organic photovoltaic cells and organic thermoelectric materials. Among them, the organic field effect transistors prepared by using conjugated polymers as organic semiconductor layers have important applications in logic circuits, flexible displays, sensor arrays and wearable devices, which have attracted great attention from the academic and industrial circles. The organic semiconductor layer is the core component of the organic field effect transistor, and can be divided into three categories according to the type of carrier transport: hole transport (p-type), bipolar transport (ambipolar) and electron transport (n-type). In recent years, p-type and bipolar polymer semiconductors have developed rapidly, for example, the hole mobility of p-type polymer semiconductors is as high as 30 cm 2 V -1 s -1 , bipolar polymers exhibit balanced transport characteristics, and the hole and electron mobilities are both more than 3 cm 2 V -1 s -1 , in contrast, the performance of n-type polymers is still lagging behind, and the electron mobility (μ e ) is usually less than 3 cm 2 V -1 s -1 . High-performance n-type polymers are of great significance for the development of p-n junction-based organic electronic devices (including all-polymer solar cells and polymer thermoelectric devices), logic complementary circuits, reducing device power consumption, improving signal-to-noise ratio and improving anti-interference ability, and therefore the development of high-performance n-type polymer semiconductors is of great importance to the development of the field of organic electronics.

[0003] Building high performance n-type polymers usually requires acceptor units with compact molecular structure and strong electron-withdrawing property to achieve the lowest unoccupied molecular orbital (LUMO) energy level of the conjugated polymer < -4.00 eV, thereby promoting electron injection and air stability. In order to obtain a deeper LUMO energy level, strong electron-withdrawing groups are usually introduced into the polymer backbone to form copolymers, which is a major way to obtain high performance n-type polymer semiconductor materials. Currently, four types of acceptors with prominent electron-withdrawing groups (EWG) are commonly used to modify the polymer backbone: imides (such as naphthalene diimide, dithiophene imide), amides (such as isoindigo, diketopyrrolopyrrole), boron-nitrogen coordination bond and cyano functionalized building blocks. However, a single type of electron-withdrawing group usually has a higher LUMO energy level, which is not conducive to the effective injection and output of electrons. Therefore, how to develop acceptor units with strong electron-withdrawing properties to effectively reduce the LUMO energy level of the polymer and improve the electron mobility of the conjugated polymer is an important problem that needs to be solved at present. SUMMARY

[0004] In order to solve the above problems, the purpose of the present application is to provide an acceptor unit based on oxygen boron nitrogen coordination, n-type polymer and its preparation and application. The present application develops a conjugated polymer with low LUMO energy level to solve the problem of low electron mobility of the current n-type polymer semiconductor material, and successfully applies the prepared n-type polymer semiconductor material to an organic semiconductor device.

[0005] The purpose of the present application can be realized by the following technical solutions:

[0006] The first purpose of the present application is to provide an acceptor unit based on oxygen boron nitrogen coordination, and the chemical structure of the acceptor unit is shown in the following formula (I):

[0007] ,

[0008] In formula (I), m1 and m2 are independently 0 or 1; x1, x2, y1 and y2 are independently any integer from 1 to 20; R is a fluorine atom or a cyano group; Ar is one of the following structures:

[0009]

[0010] Wherein, X1, X2, X3 and X4 are independently selected from one of methyl, ethyl, isopropyl, methoxy, fluorine or chlorine, and Y1 and Y2 are independently selected from one of nitrogen or hydrogen.

[0011] In an embodiment of the present application, the acceptor unit based on oxygen boron nitrogen coordination is selected from one of the following structural formulae:

[0012]

[0013] A second object of the present application is to provide a preparation method of an acceptor unit based on oxygen-boron-nitrogen coordination, comprising the following steps:

[0014] (S1) placing 2,5-dihydroxy-1,4-benzene dicarboxaldehyde and alkylamine in a first solvent, and carrying out imine condensation reaction to obtain a Schiff base intermediate;

[0015] (S2) placing the Schiff base intermediate prepared in step (S1), N-diisopropylethylamine and boron trifluoride ether complex in a second solvent, and carrying out Schiff base boron-nitrogen coordination reaction to obtain 3,8-bis(alkyl)-tetrafluoro-benzo bis([1,3,2]oxazoline);

[0016] (S3) placing 3,8-bis(alkyl)-tetrafluoro-benzo bis([1,3,2]oxazoline) prepared in step (S2) and liquid bromine in a third solvent, and carrying out bromination reaction under the catalysis of a first catalyst to obtain 3,8-bis(alkyl)-tetrafluoro-5,10-dibromo-benzo bis([1,3,2]oxazoline);

[0017] (S4) placing 3,8-bis(alkyl)-tetrafluoro-5,10-dibromo-benzo bis([1,3,2]oxazoline) prepared in step (S3) and aryl tin in a fourth solvent, and carrying out coupling reaction under the catalysis of a second catalyst to obtain a first acceptor unit;

[0018] Or, (S5) placing the first acceptor unit prepared in step (S4), tin tetrachloride and trimethylsilyl cyanide in a fifth solvent, and carrying out reaction to obtain a second acceptor unit;

[0019] The acceptor unit based on oxygen-boron-nitrogen coordination is the first acceptor unit or the second acceptor unit;

[0020] The chemical structural formula of the first acceptor unit is shown in formula (II), and the chemical structural formula of the second acceptor unit is shown in formula (III).

[0021]

[0022] In formula (I) and formula (III), m1 and m2 are independently 0 or 1; x1, x2, y1 and y2 are independently any integer from 1 to 20; and Ar is one of the following structures:

[0023]

[0024] In formula (I) and formula (III), X1, X2, X3 and X4 are independently selected from one of methyl, ethyl, isopropyl, methoxy, fluorine or chlorine, and Y1 and Y2 are independently selected from one of nitrogen or hydrogen.

[0025] In one embodiment of the present application, in step (S1), the molar ratio of 2,5-dihydroxy-1,4-benzene-dicarboxaldehyde to alkylamine is 1:2.1-3;

[0026] During the reaction, the temperature is 60-100℃, and the time is 2.5-12h;

[0027] In step (S2), the molar ratio of the Schiff base intermediate, super dry N,N-diisopropyl ethylamine and super dry boron trifluoride etherate is 1:5-10:5-10;

[0028] During the reaction, the temperature is 25-80℃, and the time is 6-24h;

[0029] In step (S3), the molar ratio of 3,8-bis(alkyl)-tetrafluoro-benzo-bis([1,3,2]oxazoline) to liquid bromine is 1:10-20;

[0030] During the reaction, the temperature is 25-60℃, and the time is 4-12h.

[0031] In one embodiment of the present application, the first solvent is selected from one of N,N-dimethylformamide, ethanol or chloroform;

[0032] The second solvent is selected from one of toluene, chloroform or dichloromethane;

[0033] The third solvent is selected from one of dichloromethane or chloroform;

[0034] The first catalyst is FeCl3.

[0035] In one embodiment of the present application, in step (S4), the molar ratio of 3,8-bis(alkyl)-tetrafluoro-5,10-dibromo-benzo-bis([1,3,2]oxazoline) to aryl tin is 1:2-4;

[0036] During the reaction, the temperature is 90-120℃, and the time is 12-24h.

[0037] In one embodiment of the present application, in step (S4), the fourth solvent is selected from one of toluene or chlorobenzene;

[0038] The second catalyst is tris(dibenzylideneacetone)dipalladium;

[0039] During the reaction, a ligand also needs to be added, wherein the ligand is tris(o-methylphenyl)phosphine.

[0040] In step (S5), the molar ratio of the first acceptor unit, tin tetrachloride and trimethylsilyl cyanide is 1:10-20:10-20;

[0041] The reaction is carried out at room temperature for 12-24 hours.

[0042] In one embodiment of the present application, the fifth solvent is dichloromethane.

[0043] A third object of the present application is to provide an application of an acceptor unit based on oxygen-boron-nitrogen coordination in the preparation of an n-type polymer.

[0044] A fourth object of the present application is to provide an n-type polymer prepared from the above-mentioned acceptor unit based on oxygen-boron-nitrogen coordination, and the chemical structural formula of the n-type polymer is shown in formula (V):

[0045]

[0046] In formula (V), m1, m2, m3 and m4 are independently 0 or 1; n is an integer greater than 0; x1, x2, x3, x4, y1, y2, y3 and y4 are independently any integer from 1 to 20; R is a fluorine atom or a cyano group; and Ar is one of the following structures:

[0047]

[0048] In formula (V), X1, X2, X3 and X4 are independently selected from one of methyl, ethyl, isopropyl, methoxy, fluorine or chlorine, and Y1 and Y2 are independently selected from one of nitrogen or hydrogen.

[0049] In one embodiment of the present application, the acceptor unit based on oxygen-boron-nitrogen coordination is selected from one of the following structural formulas:

[0050]

[0051] n is an integer greater than 0.

[0052] A fifth object of the present application is to provide a preparation method of an n-type polymer, comprising the following steps:

[0053] (A1) placing an acceptor unit based on oxygen-boron-nitrogen coordination and N-bromosuccinimide in a sixth solvent to obtain a bromine-substituted acceptor unit based on oxygen-boron-nitrogen coordination through reaction;

[0054] (A2) dissolving the bromine-substituted acceptor unit based on oxygen-boron-nitrogen coordination prepared in step (A1), an alkyl-substituted thienyl pyrrolopyrrolidinone tin, tris(dibenzylideneacetone)dipalladium and tris(o-methylphenyl)phosphine in a seventh solvent, and obtaining an n-type polymer after reaction and post-processing.

[0055] In one embodiment of the present application, in step (A1), the molar ratio of the acceptor unit based on oxygen-boron-nitrogen coordination and N-bromosuccinimide is 1:2-1:3.

[0056] During the reaction, the temperature is 25-50 DEG C, and the time is 2-8h;

[0057] In step (A2), the molar ratio of the bromine-substituted oxygen-boron-nitrogen ligand-based acceptor unit, the alkyl-substituted thienyl pyrrolopyrrole diketone tin, tris(dibenzylideneacetone)dipalladium, tris(o-methylphenyl)phosphine is 1:1:0.05-0.1:0.05-0.1;

[0058] During the reaction, the temperature is 90-110 DEG C, and the time is 12-48h.

[0059] The sixth object of the present application is to provide an application of the n-type polymer in preparing an organic field effect transistor or an organic thermoelectric material.

[0060] The seventh object of the present application is to provide an organic field effect transistor prepared by the n-type polymer.

[0061] In an embodiment of the present application, the organic field effect transistor is of a top-gate bottom-contact structure, comprising a substrate with a thickness of 200-300nm, a source-drain electrode with a thickness of 10-40nm, a charge transport layer with a thickness of 1-1000nm, a dielectric layer with a thickness of 400-500nm, and a gate electrode with a thickness of 50-90nm.

[0062] In an embodiment of the present application, the substrate is a Si / SiO2 substrate, the source-drain electrode is made of gold, the dielectric layer is made of PMMA, and the gate electrode is made of gold.

[0063] In an embodiment of the present application, the electron mobility of the charge transport layer material in the organic field effect transistor is 3.0cm 2 V -1 s -1 The above.

[0064] The eighth object of the present application is to provide an organic thermoelectric material prepared by the n-type polymer, wherein the organic thermoelectric material is a semiconductor thin film.

[0065] In an embodiment of the present application, the organic thermoelectric material is prepared by the n-type polymer and an n-type dopant, and the n-type dopant is 4-(2,3-dihydro-1,3-dimethyl-1H-benzimidazol-2-yl)-N,N-diphenyl aniline.

[0066] In the present application, after being doped by the n-type polymer, the conductivity of the polymer semiconductor material can reach 95.5S cm -1 , and the power factor reaches 147.8μW m -1K -2 .

[0067] Compared with the prior art, the present application has the following beneficial effects:

[0068] (1) The acceptor unit based on oxygen-boron-nitrogen coordination of the present application has the characteristics of good planarity, rigid conjugated skeleton, strong intermolecular π-π interaction and deep LUMO energy level, and can be used for the construction of n-type polymer semiconductor materials; through n-type doping, the n-type polymer semiconductor material can also be applied to organic thermoelectric materials.

[0069] (2) The acceptor unit based on oxygen-boron-nitrogen coordination provided by the present application has a short synthesis step, and the total yield from the raw material to the target acceptor unit is as high as 38%, which has the advantages of short reaction time and high synthesis efficiency.

[0070] (3) The acceptor unit based on oxygen-boron-nitrogen coordination provided by the present application generally has a low LUMO energy level (<-3.94 eV), and the lowest can be reduced to -4.34 eV. The n-type polymer obtained based on the above acceptor unit through Stille polymerization reaction also has a low LUMO energy level (≈-4.0 eV), which is beneficial to the injection and output of electrons, thereby improving the electron mobility, and the electron mobility of the above n-type polymer reaches 3.04 cm 2 V -1 s -1 .

[0071] (3) The n-type polymer provided by the present application exhibits high electrical conductivity and power factor in organic thermoelectric materials, and the highest electrical conductivity can reach 95.5 S cm -1 , and the power factor reaches 147.8 μW m -1 K -2 . BRIEF DESCRIPTION OF DRAWINGS

[0072] Figure 1 is the nuclear magnetic resonance hydrogen spectrum of 3,8-bis(2-ethylhexyl)-tetrafluoro- benzobis([1,3,2]oxazoline) in Example 1;

[0073] Figure 2 is the nuclear magnetic resonance hydrogen spectrum of 3,8-bis(2-ethylhexyl)-tetrafluoro- benzobis([1,3,2]oxazoline) in Example 1;

[0074] Figure 3 is the nuclear magnetic resonance hydrogen spectrum of the fluorinated acceptor unit based on oxygen-boron-nitrogen coordination in Example 1;

[0075] Figure 4 is the nuclear magnetic resonance hydrogen spectrum of 3,8-bis(2-ethylhexyl)-tetrafluoro- benzobis([1,3,2]oxazoline) in Example 1;

[0076] Figure 5 NMR of 3,8-bis-hexyl-tetrafluoro 5,10-dibromo-benzo bis([1,3,2]oxazoline) in Example 2;

[0077] Figure 6 NMR of oxygen-boron-nitrogen coordination based fluorinated acceptor unit in Example 2;

[0078] Figure 7 NMR of oxygen-boron-nitrogen coordination based cyanoated acceptor unit in Example 2;

[0079] Figure 8 NMR of oxygen-boron-nitrogen coordination based fluorinated acceptor unit substituted by bromine in Example 3;

[0080] Figure 9 Absorption spectrum of n-type polymer P1 in Example 3;

[0081] Figure 10 NMR of oxygen-boron-nitrogen coordination based cyanoated acceptor unit substituted by bromine in Example 4;

[0082] Figure 11 Absorption spectrum of n-type polymer P2 in Example 4. DETAILED DESCRIPTION

[0083] The present application will be described in detail below with reference to the accompanying drawings and specific examples.

[0084] In the following examples, if not otherwise specified, the reagents used are commercially available reagents, and the detection means and methods used are conventional detection means and methods in the art.

[0085] Example 1

[0086] This example provides a preparation method of an oxygen-boron-nitrogen coordination based acceptor unit, which specifically comprises the following steps:

[0087] (S1) 2,5-dihydroxy-1,4-benzene dicarboxaldehyde (1 g, 6 mmol) and 2-ethylhexylamine (2.33 g, 2.96 mL, 18 mmol) were used as the reaction raw materials (the molar ratio of 2,5-dihydroxy-1,4-benzene dicarboxaldehyde to 2-ethylhexylamine was 1:3), and an imine condensation reaction was carried out in 50 mL of ethanol (the reaction temperature was 100°C, and the reaction time was 6 h). After the reaction was completed, the mixture was diluted with dichloromethane, dried with anhydrous magnesium sulfate, filtered, and concentrated under vacuum to obtain a Schiff base intermediate;

[0088] (S2) The Schiff base intermediate prepared in step (S1) was used as the raw material for the reaction (the molar ratio of the Schiff base intermediate, dry N,N-diisopropyl ethylamine and dry boron trifluoride etherate was 1:5:5), and a Schiff base boron-nitrogen complex reaction was carried out in 100 mL of dichloromethane (the reaction temperature was 50°C, and the reaction time was 12 h). After the reaction was completed, the crude product was further purified by a silica gel column using dichloromethane and petroleum ether as the eluent (the volume ratio of dichloromethane to petroleum ether was 1:1) to obtain 1.72 g of 3,8-bis(2-ethylhexyl)-tetrafluoro-benzobis([1,3,2]oxazoline) (the nuclear magnetic resonance hydrogen spectrum is shown in Figure 1 The yield was 60% (the yield from the end of step (S1) to step (S2) was 60%).

[0089] The chemical structural formula of 3,8-bis(2-ethylhexyl)-tetrafluoro-benzobis([1,3,2]oxazoline) is as follows:

[0090]

[0091] (S3) 3,8-bis(2-ethylhexyl)-tetrafluoro-benzobis([1,3,2]oxazoline) (2.42 g, 5 mmol) prepared in step (S2) was used as the raw material for the reaction (the molar ratio of 3,8-bis(2-ethylhexyl)-tetrafluoro-benzobis([1,3,2]oxazoline) to liquid bromine was 1:20), and a bromination reaction was carried out in 50 mL of chloroform (10 mg of FeCl3 was used as the catalyst, the reaction temperature was 60°C, and the reaction time was 4 h). After the reaction was completed, the crude product was further purified by a silica gel column using dichloromethane and petroleum ether as the eluent (the volume ratio of dichloromethane to petroleum ether was 1:1) to obtain 2.89 g of 3,8-bis(2-ethylhexyl)-tetrafluoro-5,10-dibromo-benzobis([1,3,2]oxazoline) (the nuclear magnetic resonance hydrogen spectrum is shown in Figure 2 The yield was 90%.

[0092] The chemical structural formula of 3,8-bis(2-ethylhexyl)-tetrafluoro-5,10-dibromo-benzobis([1,3,2]oxazoline) is as follows:

[0093]

[0094] (S4) 3,8-bis(2-ethylhexyl)-tetrafluoro 5,10-dibromo-bis([1,3,2]oxazoline) (642 mg, 1 mmol) prepared in step (S3) and tributyl(2-thienyl)tin (9.33 mg, 2.5 mmol) (molar ratio of 3,8-bis(2-ethylhexyl)-tetrafluoro 5,10-dibromo-bis([1,3,2]oxazoline) to tributyl(2-thienyl)tin is 1:2.5) were used as the starting materials for the coupling reaction in toluene (dichlorobis(tri- o-tolylphosphine)palladium (91.5 mg, 1 mmol) was used as the catalyst and tri- o-tolylphosphine (60.8 mg, 2 mmol) was used as the ligand, the reaction temperature was 110 °C, and the reaction time was 12 h), after the reaction was completed, the crude product was further purified by silica gel column using ethyl acetate and petroleum ether as the eluent (volume ratio of ethyl acetate to petroleum ether is 1:4), and 583 mg of 3,8-bis(2-ethylhexyl)-tetrafluoro-5,10-di(thiophen-2-yl)-bis([1,3,2]oxazoline), i.e., the acceptor unit based on oxygen-boron-nitrogen coordination: fluorinated acceptor unit based on oxygen-boron-nitrogen coordination (1H NMR spectrum is shown in Figure 3

[0095] The chemical structural formula of the fluorinated acceptor unit based on oxygen-boron-nitrogen coordination is as follows:

[0096]

[0097] Example 2

[0098] The present embodiment provides a preparation method of the acceptor unit based on oxygen-boron-nitrogen coordination, which specifically comprises the following steps:

[0099] (S1) 2,5-dihydroxy-1,4-benzene dicarboxaldehyde (1 g, 6 mmol) and n-hexylamine (1.8 g, 2.34 mL, 18 mmol) (molar ratio of 2,5-dihydroxy-1,4-benzene dicarboxaldehyde to n-hexylamine is 1:3) were used as the starting materials for the imine condensation reaction in 50 mL of ethanol (reaction temperature is 100 °C, and the reaction time is 6 h), after the reaction was completed, the mixture was diluted with dichloromethane, then dried with anhydrous magnesium sulfate, filtered, and concentrated under vacuum to obtain a Schiff base intermediate;

[0100] ​(S2) The Schiff base intermediate prepared in step (S1) was used as the raw material for the reaction (the molar ratio of the Schiff base intermediate, ultra-dry N,N-diisopropyl ethylamine, and ultra-dry boron trifluoride etherate was 1:5:5), and a Schiff base boron-nitrogen complex reaction was carried out in 100 mL of dichloromethane (the reaction temperature was 50°C, and the reaction time was 12 h). After the reaction was completed, the crude product was further purified by a silica gel column using dichloromethane and petroleum ether as the eluent (the volume ratio of dichloromethane to petroleum ether was 1:1) to obtain 1.54 g of 3,8-bis(hexyl)-tetrafluoro-benzo bis([1,3,2]oxazoline) (the 1H nuclear magnetic resonance spectrum is shown in Figure 4 The yield was 60% (the yield from the end of step (S1) to step (S2) was 60%).

[0101] The chemical structural formula of 3,8-bis(hexyl)-tetrafluoro-benzo bis([1,3,2]oxazoline) is as follows:

[0102]

[0103] (S3) 3,8-bis(hexyl)-tetrafluoro-benzo bis([1,3,2]oxazoline) (2.14 g, 5 mmol) prepared in step (S2) was used as the raw material for the reaction (the molar ratio of 3,8-bis(hexyl)-tetrafluoro-benzo bis([1,3,2]oxazoline) to liquid bromine was 1:20), and a bromination reaction was carried out in 50 mL of chloroform (10 mg of FeCl3 was used as the catalyst, the reaction temperature was 60°C, and the reaction time was 4 h). After the reaction was completed, the crude product was further purified by a silica gel column using dichloromethane and petroleum ether as the eluent (the volume ratio of dichloromethane to petroleum ether was 1:1) to obtain 5.64 g of 3,8-bis(hexyl)-tetrafluoro-5,10-dibromo-benzo bis([1,3,2]oxazoline) (the 1H nuclear magnetic resonance spectrum is shown in Figure 5 The yield was 90%.

[0104] The chemical structural formula of 3,8-bis(hexyl)-tetrafluoro-5,10-dibromo-benzo bis([1,3,2]oxazoline) is as follows:

[0105]

[0106] (S4) 3,8-bis(hexyl)-tetrafluoro 5,10-dibromo-bis([1,3,2]oxazolidine) (586 mg, 1 mmol) prepared in step (S3) and tributyl(2-thienyl)tin (9.33 mg, 2.5 mmol) as the raw materials (the molar ratio of 3,8-bis(hexyl)-tetrafluoro 5,10-dibromo-bis([1,3,2]oxazolidine) to tributyl(2-thienyl)tin was 1:2.5), were subjected to a coupling reaction in toluene (with tris(dibenzylideneacetone)dipalladium (91.5 mg, 1 mmol) as the catalyst and tri(o-tolyl)phosphine (60.8 mg, 2 mmol) as the ligand, the reaction temperature was 110 °C, and the reaction time was 12 h), and after the reaction was completed, the crude product was further purified by a silica gel column using ethyl acetate and petroleum ether as the eluent (the volume ratio of ethyl acetate to petroleum ether was 1:4) to obtain 583 mg of 3,8-bis(hexyl)-tetrafluoro-5,10-di(thiophen-2-yl)-bis([1,3,2]oxazolidine), i.e., an oxygen-boron-nitrogen coordination-based fluorinated acceptor unit (1H NMR spectrum as shown in Figure 6

[0107] The chemical structural formula of the oxygen-boron-nitrogen coordination-based fluorinated acceptor unit is as shown in the following formula:

[0108]

[0109] (S5) The oxygen-boron-nitrogen coordination-based fluorinated acceptor unit (1.18 g, 2 mmol) obtained in step (S4), tin tetrachloride (521 mg, 0.23 mL, 2 mmol), and trimethylsilyl cyanide (3.97 g, 5 mL, 40 mmol) were used as the raw materials (the molar ratio of the oxygen-boron-nitrogen coordination-based fluorinated acceptor unit, tin tetrachloride, and trimethylsilyl cyanide was 1:1:20), and a substitution reaction was performed in 20 mL of ultra-dry dichloromethane (the reaction temperature was room temperature, and the reaction time was 12 h), and after the reaction was completed, the crude product was recrystallized using dichloromethane and n-hexane to obtain 496 mg of an oxygen-boron-nitrogen coordination-based cyano-acceptor unit (1H NMR spectrum as shown in Figure 7

[0110] The chemical structural formula of the oxygen-boron-nitrogen coordination-based cyano-acceptor unit is as shown in the following formula:

[0111]

[0112] Example 3

[0113] This example provides a preparation method of an n-type polymer P1, which comprises the following steps:

[0114] ​​(A1) The oxygen-boron-nitrogen coordination-based fluorinated acceptor unit prepared in Example 1 (2.00 g, 3.08 mmol) and N-bromosuccinimide (1.21 g, 6.79 mmol) were used as the reaction raw materials (the molar ratio of 3,8-bis(2-ethylhexyl)-tetrafluoro-5,10-di(thiophen-2-yl)-benzo bis([1,3,2]oxazoline) to N-bromosuccinimide was 1:2.2), and a bromination reaction was carried out in 20 mL of chloroform (the reaction temperature was 50°C, and the reaction time was 6 h). After the reaction was completed, the crude product was further purified by a silica gel column using ethyl acetate and petroleum ether as the eluent (the volume ratio of ethyl acetate to petroleum ether was 1:4) to obtain 1.38 g of the bromine-substituted oxygen-boron-nitrogen coordination-based fluorinated acceptor unit (1H NMR is shown in Figure 8 ).

[0115] The chemical structural formula of the bromine-substituted oxygen-boron-nitrogen coordination-based fluorinated acceptor unit is as follows:

[0116]

[0117] (A2) The bromine-substituted oxygen-boron-nitrogen coordination-based fluorinated acceptor unit prepared in step (A1) (80.6 mg, 0.1 mmol), 2,5-bis(2-octyldodecyl)-3,6-bis(5-(trimethylstannyl)thiophen-2-yl)-2,5-dihydropyrrolo[3,4-c]pyrrole-1,4-dione (118.7 mg, 0.1 mmol), tris(dibenzylideneacetone)dipalladium (4.58 mg, 0.05 mmol), and tri(o-tolyl)phosphine (3.04 mg, 0.1 mmol) were used as the reaction raw materials (the molar ratio of the bromine-substituted oxygen-boron-nitrogen coordination-based fluorinated acceptor unit, 2,5-bis(2-octyldodecyl)-3,6-bis(5-(trimethylstannyl)thiophen-2-yl)-2,5-dihydropyrrolo[3,4-c]pyrrole-1,4-dione, tris(dibenzylideneacetone)dipalladium, and tri(o-tolyl)phosphine was 1:1:0.05:0.1), and the mixture was dissolved in 3.3 mL of toluene, subjected to nitrogen replacement three times, and heated to reflux to carry out a Stille polymerization reaction (the reaction temperature was 110°C, and the reaction time was 12 h). After the polymerization was completed, a capping agent was added to cap. After the reaction was completed, the reaction solution was dropped into methanol, and the solid was collected by filtration. The solid was purified by a Soxhlet extractor, and methanol, acetone, n-hexane, and chloroform were used as the extraction liquids, respectively. Finally, the chloroform extraction liquid was concentrated and dropped into methanol to obtain 82 mg of a black solid, which was n-type polymer P1 (the yield was 55%), and the absorption spectrum thereof is shown in Figure 9 .

[0118] The chemical structural formula of n-type polymer P1 is as follows:

[0119] n is an integer greater than 0.

[0120] High temperature gel permeation chromatography analysis (1,2,4-trichlorobenzene solvent, polystyrene standard) was performed on the prepared n-type polymer P1: Mw: 56.0 kDa, PDI: 2.8. n : 56.0 kDa, PDI: 2.8.

[0121] Example 4

[0122] This example provides a method for preparing an n-type polymer P2, comprising the following steps:

[0123] (A1) Using the oxygen-boron-nitrogen-coordinated cyano-acceptor unit obtained in Example 2 (1 g, 1.24 mmol), tin tetrachloride (323 mg, 0.15 mL, 1.24 mmol) and trimethylsilyl cyanide (2.46 g, 3.10 mL, 24.81 mmol) as the reaction raw materials (the molar ratio of the oxygen-boron-nitrogen-coordinated fluorinated acceptor unit, tin tetrachloride and trimethylsilyl cyanide is 1:1:20), a substitution reaction was carried out in 20 mL of ultra-dry dichloromethane (the reaction temperature was room temperature, and the reaction time was 12 h). After the reaction was completed, the crude product was recrystallized with dichloromethane and n-hexane to obtain 500 mg of the oxygen-boron-nitrogen-coordinated cyano-acceptor unit (1H nuclear magnetic resonance spectrum as shown in Figure 10 , the yield was 50%;

[0124] wherein the chemical structure of the bromine-substituted oxygen-boron-nitrogen-coordinated cyano-acceptor unit is as shown in the following formula:

[0125]

[0126] (A2) The bromine-substituted cyano-accepting unit based on oxoboron-nitrogen coordination prepared in step (A1) (83.4 mg, 0.1 mmol), 2,5-bis(2-octyldodecyl)-3,6-bis(5-(trimethylstannyl)thiophen-2-yl)-2,5-dihydropyrrolo[3,4-c]pyrrole-1,4-dione (118.7 mg, 0.1 mmol), tris(dibenzylideneacetone)dipalladium (4.58 mg, 0.05 mmol), tri(o-tolyl)phosphine (3.04 mg, 0.1 mmol) as raw materials (the molar ratio of the bromine-substituted cyano-accepting unit based on oxoboron-nitrogen coordination, 2,5-bis(2-octyldodecyl)-3,6-bis(5-(trimethylstannyl)thiophen-2-yl)-2,5-dihydropyrrolo[3,4-c]pyrrole-1,4-dione, tris(dibenzylideneacetone)dipalladium, tri(o-tolyl)phosphine was 1:1:0.05:0.1), were dissolved in 2 mL of toluene, and the Stille polymerization reaction was carried out by heating to reflux under nitrogen for 48 h (the reaction temperature was 110°C). After the polymerization was completed, a capping agent was added for capping. After the reaction was completed, the reaction solution was dropped into methanol, and the solid was collected by filtration. The solid was purified with a Soxhlet extractor, and methanol, acetone, n-hexane, and chloroform were used as extraction liquids, respectively. Finally, the chloroform extraction liquid was concentrated and dropped into methanol to obtain 78 mg of black solid, which was n-type polymer P2 (yield 52%), and the absorption spectrum thereof is shown in FIG. 1. Figure 11

[0127] The chemical structural formula of the n-type polymer P2 is as follows:

[0128] n is an integer greater than 0.

[0129] The prepared polymer P2 was subjected to high-temperature gel chromatography analysis (1,2,4-trichlorobenzene solvent, polystyrene standard): M n : 11.0 kDa, PDI: 2.6.

[0130] Example 5

[0131] This example provides an organic field effect transistor. The structure of the organic field effect transistor is top gate bottom contact, and the specific preparation process is as follows:

[0132] ​Si / SiO2 wafer with thickness of 200 μm was used as substrate, and was cleaned by ultrasonic in deionized water, ethanol and acetone, and was dried at 80 °C under vacuum. The source and drain electrodes were placed on the upper surface of the substrate, wherein the source and drain electrodes were gold electrodes with thickness of 25 nm by mask thermal evaporation, the channel width of the device was 4500 μm, and the channel length was 50 μm. The polymer P1 was dissolved in o-dichlorobenzene to obtain a polymer solution with a concentration of 8 mg / mL. The polymer solution was formed into an active layer on the Si / SiO2 wafer substrate by the method of spin coating, and was annealed on a hot stage at 160 °C for 10 minutes. Subsequently, 60 mg / mL PMMA solution in n-butyl acetate was spin-coated on the surface of the polymer film to form an insulating layer with a thickness of 500 nm, and the solvent was removed at 90 °C for 60 minutes. Finally, 50 nm thick gold was used as a gate electrode by mask thermal evaporation on the insulating layer, and the preparation of the organic field effect transistor was completed.

[0133] The device performance of the prepared field effect transistor was tested by a Keithley 4200SCS semiconductor tester in a nitrogen-filled glove box.

[0134] The device prepared in the above manner was tested, and the results are shown in Table 1.

[0135] Table 1 Performance test results of the organic field effect transistor of the present embodiment

[0136] Polymer electron mobility (cm 2 V -1 s -1 )]]> Threshold voltage (V) On / Off ratio P1 3.04 0～10 10 5 ~10 6 ]]

[0137] Example 6

[0138] The present embodiment provides an organic field effect transistor. The structure of the organic field effect transistor is top gate bottom contact, and the specific preparation process is as follows:

[0139] Si / SiO2 wafer with thickness of 200 μm was used as substrate, and was cleaned by ultrasonic in deionized water, ethanol and acetone, and was dried at 80 °C under vacuum. The source and drain electrodes were placed on the upper surface of the substrate, wherein the source and drain electrodes were gold electrodes with thickness of 25 nm by mask thermal evaporation, the channel width of the device was 4500 μm, and the channel length was 50 μm. The polymer P1 was dissolved in o-dichlorobenzene to obtain a polymer solution with a concentration of 8 mg / mL. The polymer solution was formed into an active layer on the Si / SiO2 wafer substrate by the method of spin coating, and was annealed on a hot stage at 160 °C for 10 minutes. Subsequently, 60 mg / mL PMMA solution in n-butyl acetate was spin-coated on the surface of the polymer film to form an insulating layer with a thickness of 500 nm, and the solvent was removed at 90 °C for 60 minutes. Finally, 50 nm thick gold was used as a gate electrode by mask thermal evaporation on the insulating layer, and the preparation of the organic field effect transistor was completed.

[0140] The device performance of the prepared field effect transistor was tested by a Keithley 4200SCS semiconductor tester in a glove box filled with nitrogen.

[0141] The device prepared in the present example was tested, and the results are shown in Table 2.

[0142] Table 2 Performance test results of the organic field effect transistor of the present example

[0143] Polymer electron mobility (cm 2 V -1 s -1 )]]> Threshold voltage (V) On / Off ratio P2 1.28 0～10 10 5 ~10 6 ]]

[0144] Example 7

[0145] The present example provides a preparation of a semiconductor thin film, specifically comprising the following steps:

[0146] A Si / SiO2 sheet with a thickness of 200 μm was used as a substrate, and after ultrasonic cleaning in deionized water, ethanol and acetone, the substrate was vacuum dried at 80°C; the source and drain electrodes were placed on the upper surface of the substrate, wherein the source and drain electrodes were 25 nm thick gold electrodes evaporated by a mask, the device channel width was 4500 μm, and the channel length was 50 μm; the polymer P1 was dissolved in o-dichlorobenzene to a concentration of 8 mg / mL to obtain a polymer solution; the dopant was 4-(1,3-dimethyl-2,3-dihydro-1H-benzimidazol-2-yl)-N,N-dimethylaniline, which was dissolved in n-butyl acetate to a concentration of 1.2 mg / mL to obtain a dopant solution; the polymer solution and the dopant solution were mixed, and then an active layer was formed on the Si / SiO2 substrate by a spin coating method, and annealed on a hot stage at 160°C for 10 minutes. After the annealing, a semiconductor thin film was obtained.

[0147] The prepared semiconductor thin film was transferred to a probe station for testing of the conductivity and the Seebeck coefficient, and the power factor = conductivity x Seebeck coefficient. 2 The results are shown in Table 3.

[0148] Table 3 Organic hot spot performance test results of the present example

[0149] Polymer Conductivity (S cm -1 )]]> Seebeck coefficient (μV K -1 )]]> Power factor (μW m -1 K -2 )]]> P1 9.8 -285.2 63.9

[0150] Example 8

[0151] The present example provides a preparation of a semiconductor thin film, specifically comprising the following steps:

[0152] Si / SiO2 wafer with a thickness of 200 μm was used as a substrate, and was cleaned by ultrasonic in deionized water, ethanol and acetone, and then was dried at 80 °C under vacuum; source and drain electrodes were placed on the upper surface of the substrate, wherein the source and drain electrodes were 25 nm thick gold electrodes prepared by mask evaporation, the device channel width was 4500 μm, and the channel length was 50 μm; polymer P2 was dissolved in o-dichlorobenzene to a concentration of 8 mg / mL to obtain a polymer solution; a dopant, 4-(1,3-dimethyl-2,3-dihydro-1H-benzimidazol-2-yl)-N,N-dimethylaniline, was dissolved in n-butyl acetate to a concentration of 1.2 mg / mL to obtain a dopant solution; the polymer solution and the dopant solution were mixed, and then an active layer was formed on the Si / SiO2 substrate by a spin coating method, and was annealed on a hot stage at 160 °C for 10 minutes, and then a semiconductor thin film was obtained.

[0153] The prepared semiconductor thin film was transferred to a probe station, and was tested for conductivity and Seebeck coefficient, and power factor = conductivity x Seebeck coefficient 2 The results are shown in Table 4.

[0154] Table 4: Organic thermoelectric performance test results of the example

[0155] Polymer Conductivity (S cm -1 )]]> Seebeck coefficient (μV K -1 )]]> Power factor (μW m -1 K -2 )]]> P2 95.5 -148.6 147.8

[0156] The above description of the examples is for the purpose of facilitating the understanding and use of the invention by those skilled in the art. Those skilled in the art can obviously make various modifications to the examples, and apply the general principles described herein to other examples without inventive labor. Therefore, the present invention is not limited to the above examples, and improvements and modifications made by those skilled in the art according to the interpretation of the present invention should be within the scope of protection of the present invention.

Claims

1. Oxygen-boron-nitrogen coordination-based acceptor unit, characterized in that, The chemical structure of the acceptor unit is shown in the following formula (I): ， In formula (I), m1 and m2 are independently 0 or 1; x1, x2, y1 and y2 are independently any integer from 1 to 20; R is a fluorine atom or a cyano group; Ar is one of the following structures: Wherein, X1, X2, X3 and X4 are independently selected from one of methyl, ethyl, isopropyl, methoxy, fluorine or chlorine, Y1 and Y2 are independently selected from one of nitrogen or hydrogen.

2. A method for preparing an acceptor unit based on oxoboron-nitrogen coordination, characterized by, The method comprises the following steps: (S1) reacting 2,5-dihydroxy-1,4-benzene dicarboxaldehyde with alkylamine in a first solvent to obtain a Schiff base intermediate; (S2) reacting the Schiff base intermediate prepared in step (S1), N,N-diisopropylethylamine and boron trifluoride ether complex in a second solvent to obtain 3,8-bis(alkyl)-tetrafluoro-benzobis([1,3,2]oxazoline); (S3) reacting 3,8-bis(alkyl)-tetrafluoro-benzobis([1,3,2]oxazoline) prepared in step (S2) with liquid bromine in a third solvent, catalyzed by a first catalyst, to obtain 3,8-bis(alkyl)-tetrafluoro-5,10-dibromo-benzobis([1,3,2]oxazoline); (S4) reacting 3,8-bis(alkyl)-tetrafluoro-5,10-dibromo-benzobis([1,3,2]oxazoline) prepared in step (S3) with aryl tin in a fourth solvent, catalyzed by a second catalyst, to obtain a first acceptor unit; Or, (S5) reacting the first acceptor unit prepared in step (S4), tin tetrachloride and trimethylsilyl cyanide in a fifth solvent to obtain a second acceptor unit; The acceptor unit based on oxygen-boron-nitrogen coordination is the first acceptor unit or the second acceptor unit; Wherein, the chemical structure of the first acceptor unit is shown in formula (II), and the chemical structure of the second acceptor unit is shown in formula (III); In formula (II) and formula (III), m1 and m2 are independently 0 or 1; x1, x2, y1 and y2 are independently any integer from 1 to 20; Ar is one of the following structures: Wherein, X1, X2, X3 and X4 are independently selected from one of methyl, ethyl, isopropyl, methoxy, fluorine or chlorine, Y1 and Y2 are independently selected from one of nitrogen or hydrogen.

3. The method of claim 2, wherein the acceptor unit is prepared by the reaction of a boronate with a nitrogen-containing compound. In step (S1), the molar ratio of 2,5-dihydroxy-1,4-benzene dicarboxaldehyde to alkylamine is 1:2.1-3; During the reaction, the temperature is 60-100℃, and the time is 2.5-12h; In step (S2), the molar ratio of the Schiff base intermediate, super dry N,N-diisopropylethylamine and super dry boron trifluoride ether complex is 1:5-10:5-10; During the reaction, the temperature is 25-80℃, and the time is 6-24h; In step (S3), the molar ratio of 3,8-bis(alkyl)-tetrafluoro-benzobis([1,3,2]oxazoline) to liquid bromine is 1:10-20; During the reaction, the temperature is 25-60℃, and the time is 4-12h; In step (S4), the molar ratio of 3,8-bis(alkyl)-tetrafluoro5,10-dibromo-benzobis([1,3,2]oxazoline) to aryltin is 1:2 to 4; During the reaction, the temperature is 90–120℃ and the time is 12–24 hours; In step (S5), the molar ratio of the first acceptor unit, tin tetrachloride, and trimethylcyanosilane is 1:10-20:10-20; During the reaction, the temperature was room temperature and the time was 12–24 hours.

4. Application of an oxygen-boron-nitrogen coordination-based acceptor unit in the preparation of n-type polymers.

5. An n-type polymer characterized in that, The n-type polymer, prepared from the oxygen-boron-nitrogen coordination-based acceptor unit according to claim 1, has the chemical structural formula shown in formula (V): In formula (V), m1, m2, m3, and m4 are all independently 0 or 1; n is an integer greater than 0; x1, x2, x3, x4, y1, y2, y3, and y4 are all independently any integer from 1 to 20; R is a fluorine atom or a cyano group; Ar is one of the following structures: Among them, X1, X2, X3 and X4 are each independently selected from one of methyl, ethyl, isopropyl, methoxy, fluorine or chlorine, and Y1 and Y2 are each independently selected from one of nitrogen or hydrogen.

6. A method for producing an n-type polymer, characterized by, Includes the following steps: (A1) The oxygen-boron-nitrogen-coordinated acceptor unit and N-bromosuccinimide were placed in a sixth solvent to react and obtain a bromine-substituted oxygen-boron-nitrogen-coordinated acceptor unit. (A2) The bromine-substituted acceptor unit based on oxygen-boron-nitrogen coordination, the alkyl-substituted thienylpyrrolopyrrole diketone tin, tris(dibenzylideneacetone dipalladium) and tris(o-methylphenyl)phosphine prepared in step (A1) are dissolved in a seventh solvent, and the reaction is followed by post-treatment to obtain the n-type polymer as described in claim 5.

7. The method for preparing an n-type polymer according to claim 6, characterized in that, In step (A1), the molar ratio of the oxygen-boron-nitrogen coordinated acceptor unit to N-bromosuccinimide is 1:2 to 1:3; During the reaction, the temperature is 25–50℃ and the time is 2–8 hours; In step (A2), the molar ratio of the bromine-substituted oxygen-boron-nitrogen-coordinated acceptor unit, the alkyl-substituted thienylpyrrolopyrrolidinone tin, the tris(dibenzylideneacetone)palladium, and the tris(o-methylphenyl)phosphine is 1:1:0.05-0.1:0.05-0.1; During the reaction, the temperature is 90–110℃ and the time is 12–48 hours.

8. The use of the n-type polymer as described in claim 5 in the preparation of organic field-effect transistors or organic thermoelectric materials.

9. An organic field effect transistor, characterized by The organic field-effect transistor is prepared from the n-type polymer described in claim 5.

10. An organic thermoelectric material, characterized by, The organic thermoelectric material is prepared from the n-type polymer described in claim 5.

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