A quinoid resonance structure polymer based on benzodifuran dione or its derivative and a preparation method and applications thereof

Abstract

The application relates to a quinoid resonance structure polymer based on benzodifuran dione or a derivative thereof, and the structure is shown in the following general formula: wherein X is selected from O or S atoms; pi is a unit containing a conjugated group and forms a conjugated system with benzodifuran dione or the derivative thereof; or is not present; and n is a natural integer. The application modifies the existing electron-withdrawing unit benzene [1,2-b:4,5-b"] difuran-2,6(3H,7H)-dione unit, grafts a halogenated element, and modifies the unit into a corresponding quinoid unit. The quinoid unit can effectively improve the planarity of an n-type conjugated polymer and reduce the LUMO energy level, so that an n-type conjugated polymer with excellent performance is prepared. Meanwhile, the unit is compatible with the existing palladium-catalyzed coupling / polymerization reaction, so that the preparation of various high-performance n-type conjugated polymers is realized.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of photoelectric materials, and particularly relates to a quinoid resonance structure polymer based on benzodifuran dione or derivatives thereof, a preparation method and application thereof. BACKGROUND

[0002] Conjugated polymer is a kind of polymer material with semiconductor / conductor properties. Due to its unique photoelectric performance and excellent mechanical properties, it has been widely used in electronic, information, energy and other fields.

[0003] According to the difference of carrier type, the conjugated polymer can be divided into P-type (mainly conducting holes) polymer and N-type (mainly conducting electrons) polymer. At present, great progress has been made in P-type conjugated polymer, however, only a few N-type materials have reached relatively excellent performance. However, the construction of logic circuit usually requires high-performance P-type and N-type materials at the same time. Therefore, it is of great significance to prepare a high-performance N-type conjugated polymer for promoting the development of conductive polymer field.

[0004] The construction of N-type conjugated polymer usually faces the following difficulties: firstly, the difficulty in designing the main chain structure. The common electron-deficient co-unit cannot well delocalize the carrier on the whole plane, which is not conducive to the transmission of the carrier; secondly, the difficulty in designing the stability of the material. Because water and oxygen easily cause the quenching of free electrons in the material, thus leading to the difficulty of N-type material and corresponding device to be stable in air. In order to improve the stability of N-type polymer in air, it is necessary to further reduce the lowest unoccupied orbital (LUMO) energy level of the material.

[0005] At present, most of the N-type conjugated polymers mainly introduce electron-withdrawing units (such as naphthalene diimide, perylene diimide, etc.) to reduce the LUMO energy level, but it is still difficult to meet the requirement of the stability of the electron on the polymer in air. At the same time, the commonly used electron-withdrawing units at present cannot well improve the electron mobility and conductivity of the material. Therefore, it is of great significance to develop a new type of electron-deficient polymer unit for the development of N-type conjugated polymer and the improvement of the performance of semiconductor devices.

[0006] In the prior art, Huang Fei's research group recently published a series of n-type open-shell conjugated polymers, which used benzodifuran dione and strong electron-withdrawing monomer DPP derivatives to copolymerize for n-type conjugated polymers, and achieved an intrinsic conductivity as high as 1.04 S / cm. However, the synthesis steps of the strong electron-withdrawing monomer are relatively complicated, which leads to the increase of industrialization cost; and the conductivity still has room for further improvement. CN115960338A discloses an n-type conjugated polymer blend and a preparation method and application thereof, which includes a one-step synthesis process of benzodifuran dione homopolymer, but this method usually leads to the doping of the polymer, and it is difficult to obtain a polymer with high electron mobility and without doping, thereby it is difficult to meet the application requirements of some organic semiconductor devices.

[0007] Therefore, it is urgent to find a technical solution to solve the defects existing in the prior art. SUMMARY

[0008] Based on this, in order to overcome the deficiencies in the prior art and meet the requirements of deep LUMO energy level and high electron mobility of n-type conjugated polymers, the present application provides a preparation method of a quinoid resonance unit with strong electron-withdrawing ability and the preparation and application of the corresponding conjugated polymer. The present application modifies the existing electron-withdrawing unit benzene [1,2-b:4,5-b"] difuran-2,6(3H,7H)-dione unit, grafts halogen elements, and modifies it into the corresponding quinoid unit. The quinoid unit can effectively further improve the planarity and electron mobility of n-type materials, thereby preparing a conductive polymer with excellent performance. At the same time, this unit is compatible with existing palladium-catalyzed coupling / polymerization reactions through Stille reaction, thereby realizing the preparation of various high-performance n-type conjugated polymers. In addition, by blending the polymer with a small molecule dopant, the doping state of the polymer can be accurately controlled, thereby realizing the accurate regulation of the performance of organic electronic devices.

[0009] One object of the present application is to disclose a quinoid resonance structure polymer based on benzodifuran dione or its derivative, which structure is shown in the following general formula:

[0010]

[0011] Among them,

[0012] The X is selected from O or S atom;

[0013] The π is a unit containing a conjugated group, and forms a conjugated system with benzodifuran dione or its derivative; or is absent;

[0014] The n is a natural integer. Preferably, n is selected from 1-2000.

[0015] Obviously, when π is not present, the general formula is a homopolymer.

[0016] Further, π is selected from one or more of thienyl, alkenyl, alkynyl, or derivatives of any of the above.

[0017] Further, when π is a unit containing a conjugated group, it is selected from one or more of the following units:

[0018]

[0019] wherein,

[0020] Y is selected from one or more of Te, Se, S, O, N-R7, Si(R8)2;

[0021] R1-R8 are independently selected from one or more of hydrogen atom, halogen atom, nitro group, alkyl group, alkylene group, alkyl derivative, alkylene derivative, phenyl group.

[0022] One or more carbons in the alkyl derivative or alkylene derivative are substituted with one or more of oxygen atom, amino group, sulfone group, carbonyl group, aryl group, alkenyl group, alkynyl group, ester group, cyano group, nitro group.

[0023] and / or

[0024] One or more hydrogens in the alkyl derivative or alkylene derivative are substituted with one or more of halogen, hydroxyl group, amino group, carboxyl group, cyano group, nitro group, aryl group, alkenyl group, alkynyl group.

[0025] wherein, the dotted line in the figure represents a covalent bond with the adjacent group.

[0026] Another object of the present application is to provide a method for preparing the above-mentioned quinoid resonance structure polymer based on benzodifuran dione or its derivative.

[0027] The method for preparing the quinoid resonance structure polymer based on benzodifuran dione or its derivative comprises the following steps:

[0028] S1, halogen functionalization of benzodifuran dione or its derivative to obtain an intermediate product;

[0029] S2, under the protection of inert gas, subjecting the substrate comprising the intermediate product to Stille polymerization reaction to obtain a product.

[0030] Further, the method for preparing the intermediate product is to blend benzodifuran dione or its derivative with halogenation reagent in a solvent for reaction.

[0031] Further, the reaction time is 1-100h. Further, the reaction time is 1-100h.

[0032] Further, the halogenation reagent is selected from one or more of a blend of copper bromide, N-bromosuccinimide, liquid bromine, copper chloride, iron chloride, copper iodide, iodine.

[0033] Another object of the present application is to provide the application of the above-mentioned quinoid resonance structure polymer based on benzodifuran dione or its derivative in the field of organic optoelectronic devices. Including but not limited to, its application in organic field effect transistors and organic thermoelectric devices as a functional layer material.

[0034] Further, the application of the blend material of the quinoid resonance structure polymer including benzodifuran dione or its derivative and small molecule doping in the field of organic optoelectronic devices.

[0035] The present application has the following beneficial effects:

[0036] 1. The present application successfully prepares halogenated quinoid derivatives of electron-accepting benzodifuran dione / benzodithiophene dione units by structural modification. The corresponding precursors have catalytic activity, so that the conjugated polymers can be constructed by common palladium-catalyzed reactions. The introduction of quinoid structure can promote the formation of quinoid resonance structure of the whole main chain, promote the transport of carriers, and improve the electron mobility of the material. On the other hand, due to the strong electron-accepting property of the quinoid resonance unit, the LUMO energy level of the material can be significantly reduced, so as to prepare n-type conjugated polymers with high electron transport capacity to meet the needs of organic electronic devices.

[0037] 2. The introduction of electron-accepting structure reduces the LUMO energy level of the material, ensuring the electron transport performance of the material. In addition, the introduction of quinoid structure can further promote the benzoquinone transformation of the whole main chain, further improve the electron mobility, and further improve the device performance.

[0038] 3. The present application uses palladium-catalyzed polymerization reaction to realize the self-polymerization of benzodifuran dione or Stille polymerization with one or more of thiophene group, alkenyl group, alkynyl group, or derivatives of any of the above groups. The present application successfully avoids the possible doping phenomenon and the generation of conductive substances in the reaction, realizes the preparation of n-type conjugated polymers with intrinsic high electron mobility. At the same time, through further doping, the effective control of the doping degree of the material can also be realized. Since the copolymerization unit of the present application is simpler, the cost is lower, and the formed conjugated polymer is more linear, so the mobility is improved compared with the reported polymers. BRIEF DESCRIPTION OF DRAWINGS

[0039] Figure 1 To test the ultraviolet-visible absorption spectrum of the quinoid resonance structure polymer based on benzodifuran dione prepared in Example 1 and Example 2 in Example 1.

[0040] Figure 2 The ESR test results of the quinoid resonance structure based on benzodifuran dione polymer of Example 1 and Example 2 after doping are shown in the following figures.

[0041] Figure 3 The conductive property of the thermoelectric device tested in Test Example 4 at different doping ratios is shown in the following figure.

[0042] Figure 4 The Seebeck coefficient of the thermoelectric device tested in Test Example 4 at different doping ratios is shown in the following figure.

[0043] Figure 5 The power factor of the thermoelectric device tested in Test Example 4 at different doping ratios is shown in the following figure. DETAILED DESCRIPTION

[0044] In order to more clearly illustrate the technical solutions of the present application, the following examples are listed. The raw materials, reactions and post-treatment methods appearing in the examples are all common raw materials on the market and technical means well known to those skilled in the art, unless otherwise stated.

[0045] The experimental methods used in the following examples are conventional methods unless otherwise stated; the reagents, materials, etc. used in the following examples can be obtained by commercial means unless otherwise stated.

[0046] Example 1

[0047] A quinoid resonance structure based on benzodifuran dione polymer PBFDOTh-T was prepared, and the reaction process is shown as follows:

[0048]

[0049]

[0050] The preparation method of BFDO-Br is as follows:

[0051] Benzodifuran dione was purchased from Angene Co., Ltd.

[0052] The monomer benzodifuran dione (10.52 mmol) was taken into a 500 mL double-mouth flask with a stirrer, N-bromosuccinimide (NBS) (26.3 mmol) was added, and 100 mL of tetrahydrofuran was added to stir and dissolve. Then 5.88 g of copper bromide was dissolved in 100 mL of DMF, which was slowly added to the two-mouth flask through a constant-pressure dropping funnel, and stirred at room temperature for 48 h in the dark. The solution was concentrated using a rotary evaporator, and the crude product was precipitated with methanol, and collected by filtration. The sample was purified by Soxhlet extraction with tetrahydrofuran, and 2.78 g of brown-yellow pure product was obtained, with a yield of 78%.

[0053] 1 H NMR (500 MHz, Chloroform-d, ppm) δ 6.50 (s, 2H).

[0054] BFDO-Th was prepared as follows:

[0055] To a 100 mL two-necked flask with a stir bar was added compound intermediate BFDO-Br (1) (1.45 mmol), followed by (4-(2-hexyldecyl)thiophen-2-yl)tributylstannane (3.03 mmol) and tris(o-tolyl)phosphine 264 mg. The substrate was dissolved in 33.4 mL of toluene and degassed with a vacuum pump and filled with nitrogen, the above procedure was repeated three times to make the reaction system nitrogen-protected. Then under the protection of nitrogen flow, tris(dibenzylideneacetone)dipalladium 132.3 mg (10% mmol) was added and heated to 80°C overnight. After the reaction was completed, the reaction solution was concentrated, then purified by silica gel column chromatography with petroleum ether: dichloromethane (2:1, v / v) as eluent to obtain a purple solid 531 mg with a yield of 46%.

[0056] 1 H NMR (500 MHz, Chloroform-d, ppm) δ 7.87 (d, J = 1.4 Hz, 2H), 7.22 (d, 2H), 7.02 (s, 2H), 2.60 (d, 4H), 1.35-1.20 (m, 50H), 0.88 (m, 12H).

[0057] BFDO-Th-Br was prepared as follows:

[0058] To a 100 mL single-necked flask with a stir bar was added compound BFDO-Th (0.745 mmol), 40 mL of tetrahydrofuran was added and nitrogen was blown for 15 min. Then NBS (2.235 mmol) was added. The resulting mixed solution was reacted overnight at 0°C in the dark. After that, the reaction solution was concentrated and purified by silica gel column chromatography with petroleum ether: dichloromethane (2:1, v / v) as eluent to obtain a blue-purple solid 592 mg with a yield of 83%.

[0059] 1 H NMR (500 MHz, Chloroform-d, ppm) δ 7.69 (s, 2H), 6.92 (s, 2H), 2.55 (d, 4H), 1.35-1.22 (m, 50H), 0.87 (m, 12H).

[0060] PBFDOTh-T was prepared as follows:

[0061] 2,5-bis(trimethyltin)thiophene, purchased from Zhengzhou Alpha Chemical Co., Ltd.

[0062] Compound BFDO-Th-Br (0.208 mmol) and monomer 2,5-bis(trimethyltin)thiophene (0.208 mmol) were added to a reaction tube with a stirrer, after nitrogen was passed for 5 min, 4 mL of chromatographically pure toluene was added to the reaction bottle, and the monomer was completely dissolved by ultrasonic for 10 min; the oxygen in the system was removed by four times of ice bath suction and replacement; under the protection of nitrogen flow, tris(dibenzylideneacetone)dipalladium 6 mg and tri(o-tolyl)phosphine 10 mg were added. The reaction tube was closed, heated to 100°C with stirring, and reacted for 24 h; after the reaction was completed, the polymer was precipitated with acetone, filtered, and the obtained precipitate was washed with acetone (50 mL) and n-hexane (50 mL) in turn, and the solid was dried in a vacuum drying box. After 24 h, the black solid PBFDOTh-T was obtained with a yield of 85%.

[0063] Example 2

[0064] Preparation of a quinoid resonance structure polymer PBFDOTh-Se based on benzodifuran dione, the reaction process is as follows:

[0065]

[0066] 2,5-bis(trimethyltin) selenophene, purchased from Shenzhen Ruixin Optoelectronic Material Technology Co., Ltd.

[0067] BFDO-Th-Br prepared in Example 1 (0.104 mmol) and 2,5-bis(trimethyltin) selenophene (0.104 mmol) were added to a reaction tube with a stirrer, after nitrogen was passed for 5 min, 4 mL of chromatographically pure toluene was added to the reaction bottle, and the monomer was completely dissolved by ultrasonic for 10 min; the oxygen in the system was removed by four times of ice bath suction and replacement; under the protection of nitrogen flow, tris(dibenzylideneacetone)dipalladium 3 mg and tri(o-tolyl)phosphine 5 mg were added. The reaction tube was closed, heated to 100°C with stirring, and reacted for 24 h; after the reaction was completed, the polymer was precipitated with acetone, filtered, and the obtained precipitate was washed with acetone (50 mL) and n-hexane (50 mL) in turn, and the solid was dried in a vacuum drying box. After 24 h, the black solid PBFDOTh-T was obtained with a yield of 78%.

[0068] Example 3

[0069] Preparation of a quinoid resonance structure polymer PBFDO-E based on benzodifuran dione or its derivative, the reaction process is as follows:

[0070]

[0071] Trans-1,2-bis(tri-n-butyltin)ethylene, purchased from Aldrich.

[0072] The compound BFDO-Br (0.1 mmol) prepared in Example 1 and hexa-n-butyltin (0.1 mmol) were added to a reaction tube with stirring, after nitrogen was passed for 5 min, super dry N,N-dimethylformamide (DMF) 10 mL was added to the reaction bottle; under ice bath, four times of air exchange; under the protection of nitrogen flow, 10 mg of tetrakis(triphenylphosphine)palladium was added. The reaction tube was closed, heated to 100°C with stirring, and reacted for 24 h; after the reaction was completed, the polymer was precipitated with acetone, filtered, and the obtained precipitate was washed with acetone (50 mL) and methanol (50 mL) in turn, and the solid was dried in a vacuum drying box. After 24 h, it was taken out to obtain black solid PBFDO-SP, with a yield of 75%.

[0073] Example 4

[0074] A preparation of a quinoid resonance structure polymer PBFDO-SP based on benzodifuran dione or its derivative, the reaction process is as shown below:

[0075]

[0076] Monomer hexa-n-butyltin, purchased from Aldrich.

[0077] The compound BFDO-Br (0.1 mmol) prepared in Example 1 and hexa-n-butyltin (0.1 mmol) were added to a reaction tube with stirring, after nitrogen was passed for 5 min, super dry N,N-dimethylformamide (DMF) 10 mL was added to the reaction bottle; under ice bath, four times of air exchange; under the protection of nitrogen flow, 10 mg of tetrakis(triphenylphosphine)palladium was added. The reaction tube was closed, heated to 100°C with stirring, and reacted for 24 h; after the reaction was completed, the polymer solution was loaded into a dialysis bag with a molecular weight cutoff radius of 5 kDa, and dialyzed with DMF for 6 d, and the remaining solution in the dialysis bag was collected to obtain a DMF solution of PBFDO-SP, with a yield of 75%.

[0078] Device preparation example 1

[0079] The quartz glass sheet was washed with acetone, micron-sized semiconductor special detergent, deionized water, isopropyl alcohol as cleaning solvent in an ultrasonic cleaning instrument, and after washing, it was placed in a constant temperature oven for standby. Before use, the glass sheet was bombarded with plasma in a plasma etching instrument for 10 min.

[0080] The preparation process of the organic field effect transistor is as follows: high nitrogen-doped silicon is used as the substrate. The substrate is cleaned with deionized water, acetone and isopropanol in an ultrasonic bath, and then dried under a nitrogen stream, and then heated at 120°C for 10 min. 30 nm of Au is prepared on the silicon substrate by vacuum deposition as the source / drain electrode, the channel length (L) is 50 μm, and the channel width (W) is 5.6 mm. Subsequently, the polymers prepared in Example 3 and Example 4 are dissolved to 8 mg mL -1 The film is spin-coated in a nitrogen glove box at 3000 rpm. Then the film is annealed at 180°C for 15 min. Then CYTOP (Asahi Glass, model CTL-809M) is used as the medium, and the film is spin-coated at 2000 rpm and annealed at 100°C for 40 min. Finally, Au (80 nm) is vacuum evaporated as the gate electrode.

[0081] Device preparation example 2

[0082] The preparation process of the organic thermoelectric device is as follows: in a nitrogen-filled glove box, the polymers in Example 1 and Example 2 are dissolved in chloroform at 8 mg / ml, and then blended with different mass fractions of N-DMBI (wherein N-DMBI is used as a dopant in a small amount) to prepare polymer solutions with different doping levels. The solution is drop-coated on a clean glass sheet, and then annealed at 100°C for 1 h to deposit a polymer film on the glass substrate. Then silver electrodes are built on both sides of the glass sheet.

[0083] Test example 1

[0084] The polymers PBFDOTh-T and PBFDOTh-Se prepared in Example 1 and Example 2 are dissolved in chloroform at 8 mg / ml, and spin-coated on a clean quartz glass sheet at 2000 rpm to form a film. The absorption spectrum is tested by a UV-visible absorption spectrometer (Shimadzu, UV3600), and the results are shown in Figure 1

[0085] Test example 2

[0086] The performance of the organic field effect transistor prepared in device preparation example 1 is tested, wherein the applied voltage between the source electrode and the gate electrode is 80V, and the results are shown in Table 1.

[0087] Table 1 Performance parameters of related devices

[0088]

[0089] Test example 3

[0090] ​Electron paramagnetic resonance (ESR) tests were performed on the doped polymers prepared in Device Fabrication Example 2. Samples of polymers PBFDOTh-T or PBFDOTh-Se from Examples 1-2, before and after N-DMBI doping, were placed in dedicated test sample tubes. The paramagnetic signals of the samples were measured using an electron paramagnetic resonance spectrometer, and the results are as follows: Figure 2 As shown, polymers PBFDOTh-T or PBFDOTh-Se were doped with N-DMBI, and the samples exhibited obvious paramagnetic signals, confirming the occurrence of the doping reaction.

[0091] Test Example 4

[0092] The performance of the thermoelectric device prepared in Device Fabrication Example 2 was tested, and the test results are as follows: Figures 3-5 As shown, with the gradual increase of N-DMBI doping concentration (doping concentration refers to the mass ratio of N-DMBI dopant to the quinone resonance structure polymer of benzodifurandione, the same below) (the doping concentration of N-DMBI ranges from 5-30 wt%), the material exhibits a gradually increasing electrical conductivity and a decreasing Seebeck coefficient (absolute value). According to the thermoelectric power factor calculation formula PF = S... 2 σ (where S is the Seebeck coefficient and σ is the conductivity), the material PBFDOTh-Se achieves 22 μW / m² at a doping concentration of 15 wt%. -1 K -2 PBFDOTh-S achieved a maximum power factor of 19 μW m at a doping concentration of 10 wt%. -1 K -2 This figure is at an advanced level in the field.

[0093] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

[0094] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A quinonoid resonance structure-based polymer of benzodifuran dione, characterized by, The structure of the quinoid resonance structure polymer based on benzodifuran dione is shown in the following general formula: ； wherein, The X is selected from O; the π is selected from one or more of the following units: The Y is selected from one or more of Te, Se, S, O; The R1~R6 are independently selected from one or more of hydrogen atom, halogen atom, nitro group, alkyl group, alkyl derivative, phenyl group; One or more carbons on the alkyl derivative are substituted by one or more of oxygen atom, amino group, sulfone group, carbonyl group, aryl group, alkenyl group, alkynyl group, ester group, cyano group, nitro group; And / or One or more hydrogens on the alkyl derivative are substituted by one or more of halogen, hydroxyl group, amino group, carboxyl group, cyano group, nitro group, aryl group, alkenyl group, alkynyl group.

2. The method for preparing a benzo difuran-diketone based quinoid resonance structure polymer according to claim 1, characterized by, The preparation method of the quinoid resonance structure polymer based on benzodifuran dione comprises the following steps: S1, halogen functionalization of benzodifuran dione to obtain an intermediate product; S2, under the protection of inert gas, the substrate including the intermediate product is subjected to Stille polymerization reaction to obtain a product.

3. The method for preparing the quinone resonance structure polymer based on benzodifurandione according to claim 2, characterized in that, The preparation method of the intermediate product is that benzodifuran dione is mixed and reacted with a halogenation reagent in a solvent.

4. The method for preparing the quinone resonance structure polymer based on benzodifurandione according to claim 2, characterized in that, The reaction time is 1-100 h.

5. The method for preparing the quinone resonance structure polymer based on benzodifurandione according to claim 2, characterized in that, The halogenation reagent is selected from one or more of the following: copper bromide, N-bromosuccinimide, liquid bromine, copper chloride, iron chloride, copper iodide, iodine.

6. The application of the quinoid resonance structure polymer based on benzodifuran dione in the field of organic optoelectronic devices according to claim 1.

7. Use of the quinonoid resonance structure-based benzodifuran-dione polymer according to claim 6 in the field of organic optoelectronic devices, characterized in that, The application of the blended material of the quinoid resonance structure polymer including benzodifuran dione and small molecule doping in the field of organic optoelectronic devices.

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