A quinolinimine palladium complex and its preparation method and application

Abstract

The present invention discloses a quinolinimine palladium complex and its preparation method and application. The structural formula of the quinolinimine palladium complex is shown in formula (I): wherein R1, R2, R3, R4 and R5 are independently selected from hydrogen, C 1~6 Alkyl; The quinoline imine palladium complex provided by the present invention can be catalyzed and polymerized at high temperature to produce an ester-thiophene-hexylthiophene copolymer with high molecular weight, high regularity and narrow molecular weight distribution, which has broad application prospects in the fields of solar cells, organic transistors, electrochromic devices, chemical sensors, electromagnetic shielding materials, etc.

Description

Technical Field

[0001] The present invention relates to the technical field of quinolinimine palladium complexes, in particular to a quinolinimine palladium complex and a preparation method and application thereof. Background Art

[0002] Perovskite solar cells consist of a fluorine-doped tin oxide (FTO) conductive substrate, an electron transport layer, a perovskite photoactive layer, a hole transport layer, and a counter electrode. The components of a perovskite solar cell and their assembly methods dictate the energy level and solubility requirements for the hole transport material.

[0003] Hole transport materials for polymer solar cells can improve the Voc of the donor material by lowering the highest occupied molecular orbital (HOMO) while ensuring energy level matching with the acceptor material, thereby improving the PCE of the photovoltaic device. For perovskite solar cells, to ensure that photogenerated holes can be transported from the perovskite layer through the hole transport layer to the back electrode, the HOMO energy level of the hole transport material must be between the perovskite layer and the back electrode. The perovskite layer material typically uses methylammonium lead iodide (CH3NH3PbI3), which has a HOMO energy level of -5.43 eV, while the back electrode gold (Au) has an energy level of -5.10 eV. Therefore, the HOMO energy level of the hole transport layer in perovskite solar cells should be within the range of -5.43 to -5.10 eV. The energy level range required for the hole transport layer in perovskite solar cells is relatively narrow. Therefore, the molecular structure of the hole transport polymer must be designed based on the energy level requirements of the perovskite CH3NH3PbI3 and the back electrode, thereby obtaining a thiophene copolymer that meets the hole and electron transport requirements in perovskite solar cell devices.

[0004] Ester thiophene-hexylthiophene copolymer is a potential thiophene copolymer that can meet the hole and electron transport requirements in perovskite cell devices, but to date, there are few existing technical records of catalysts for the preparation of ester thiophene-hexylthiophene copolymers. Summary of the Invention

[0005] The object of the present invention is to overcome the defects and shortcomings of the prior art and provide a quinoline imine palladium complex, which can be catalytically polymerized at high temperature to produce an ester-based thiophene-hexylthiophene copolymer with high molecular weight, high regularity and narrow molecular weight distribution.

[0006] The present invention aims to provide a quinolinimine palladium complex, the structural formula of which is shown in formula (I):

[0007]

[0008] Formula (I)

[0009] wherein R1, R2, R3, R4, and R5 are independently selected from hydrogen, C1~6 alkyl.

[0010] In some embodiments of the present invention, the structural formula of the quinolinimine palladium complex is shown in Formula (I):

[0011]

[0012] Formula (I)

[0013] wherein R1, R2, R3, R4, and R5 are independently selected from hydrogen, C 2~4 alkyl.

[0014] In some embodiments of the present invention, the structural formula of the quinolinimine palladium complex is shown in Formula (I):

[0015]

[0016] Formula (I)

[0017] Wherein, R1, R2, R3, R4 and R5 are independently selected from hydrogen, methyl, ethyl, isopropyl and tert-butyl.

[0018] Another object of the present invention is to provide a method for preparing the quinolinimine palladium complex, comprising the steps of:

[0019] ligand The quinoline imine palladium complex is obtained by reacting with PdCl2.

[0020] In some embodiments of the present invention, the molar ratio of the ligand to PdCl2 is 1:1.05~1.2.

[0021] In some embodiments of the present invention, the reaction temperature is 70-90° C., and the reaction time is 10-50 min.

[0022] In some embodiments of the present invention, the preparation of the ligand comprises the following steps:

[0023] 8-Quinolinecarboxaldehyde and substituted aniline Reaction to obtain the ligand.

[0024] In some embodiments of the present invention, the molar ratio of 8-quinolinecarboxaldehyde to substituted aniline is 1:1.05-1.2.

[0025] In some embodiments of the present invention, the reaction temperature is 130-150° C., and the reaction time is 4-8 hours.

[0026] Another object of the present invention is to provide the use of the quinolinimine palladium complex or the quinolinimine palladium complex prepared by the preparation method of the quinolinimine palladium complex in the preparation of esterthiophene-hexylthiophene copolymers.

[0027] In some embodiments of the present invention, the structure of the esterthiophene-hexylthiophene copolymer is shown in Formula (II) or Formula (III):

[0028]

[0029] Formula (II) Formula (III)

[0030] The molar percentage of the ester-thiophene chain segment in the ester-thiophene-hexylthiophene copolymer chain segment is 4.7% to 13.7%, and the number average molecular weight of the ester-thiophene-hexylthiophene copolymer is 7.5 to 12.4 KDa.

[0031] In some embodiments of the present invention, the HT value of the esterthiophene-hexylthiophene copolymer is ≥80%, and the PDI is ≤2.5.

[0032] In some embodiments of the present invention, the esterthiophene-hexylthiophene copolymer is a random copolymer.

[0033] Another object of the present invention is to provide a method for preparing an esterthiophene-hexylthiophene copolymer, comprising the following steps:

[0034] Under the catalysis of quinolinimine palladium complex, 2-bromo-3-ester thiophene and 2-bromo-3-hexyl thiophene react to obtain the ester thiophene-hexyl thiophene copolymer;

[0035] The structural formula of the quinolinimine palladium complex is shown in formula (I):

[0036]

[0037] Formula (I)

[0038] wherein R1, R2, R3, R4, and R5 are independently selected from hydrogen, C 1~6 alkyl;

[0039] The 2-bromo-3-ester thiophene is selected from at least one of 2-bromo-3-(2-acetoxyethyl)thiophene and 2-bromo-3-(2-acetoxymethyl)thiophene.

[0040] In some embodiments of the present invention, the molar ratio of the 2-bromo-3-ester thiophene to the 2-bromo-3-hexyl thiophene is 3-25:75-97.

[0041] In some embodiments of the present invention, the ratio of the total mole of the 2-bromo-3-ester thiophene and the 2-bromo-3-hexyl thiophene to the mole of the quinolinimine palladium complex is 1:0.001-0.01.

[0042] In some embodiments of the present invention, the reaction temperature is 80-120° C., and the reaction time is 12-36 hours.

[0043] In some embodiments of the present invention, the reaction further contains an inorganic base, an organic acid and a solvent.

[0044] In some embodiments of the present invention, the inorganic base includes at least one of potassium carbonate and sodium carbonate.

[0045] In some embodiments of the present invention, the organic acid includes at least one of pivalic acid and hexanoic acid.

[0046] In some embodiments of the present invention, the solvent includes N,N-dimethylacetamide.

[0047] In some embodiments of the present invention, the ratio of the total mole of the 2-bromo-3-ester thiophene and the 2-bromo-3-hexyl thiophene to the mole of the inorganic base is 1-1.5:1-1.5.

[0048] In some embodiments of the present invention, the ratio of the total mole of the 2-bromo-3-ester thiophene and the 2-bromo-3-hexyl thiophene to the mole of the organic acid is 2.5-4.5:1.

[0049] In some embodiments of the present invention, after the reaction is completed, a purification step is further included.

[0050] Compared with the prior art, the present invention has the following beneficial effects:

[0051] The quinolinimine palladium complex provided by the present invention can be used to prepare an esterthiophene-hexylthiophene copolymer at high temperature. The prepared esterthiophene-hexylthiophene copolymer has the advantages of high molecular weight, high regularity and narrow molecular weight distribution, has obvious economic benefits, and has broad application prospects in the fields of solar cells, organic transistors, electrochromic devices, chemical sensors, electromagnetic shielding materials, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 This is the H NMR spectrum of the quinoline imine palladium complex C1 provided in Example 1. DETAILED DESCRIPTION

[0053] The following will clearly and completely describe the concept of the present invention and the technical effects produced in conjunction with the embodiments, so as to fully understand the purpose, characteristics and effects of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention. The test methods used in the embodiments are all conventional methods unless otherwise specified; the materials, reagents, etc. used, unless otherwise specified, can all be reagents and materials obtained from commercial channels.

[0054] Quinolinimine palladium complexes are prepared by the following reaction scheme:

[0055]

[0056] In the following examples, the esterthiophene segment content in the esterthiophene-hexylthiophene copolymer was determined by nuclear magnetic resonance spectroscopy. The esterthiophene-hexylthiophene copolymer was dissolved in deuterated chloroform, TMS was used as the internal standard, and the measurement temperature was 25°C. The molecular weight or degree of polymerization of the esterthiophene-hexylthiophene copolymer was determined by gel permeation chromatography (GPC) using THF as the mobile phase. Wherein, HT and HT values ​​represent isotacticity, and PDI represents molecular weight distribution index;

[0057] The structural formula of 2-bromo-3-(2-acetoxymethyl)thiophene is as follows:

[0058] ;

[0059] The structural formula of 2-bromo-3-(2-acetoxyethyl)thiophene is as follows:

[0060] .

[0061] Example 1

[0062] This embodiment provides a quinolinimine palladium complex C1, the synthesis method of which is as follows:

[0063] Under a nitrogen atmosphere, 2,6-diisopropylaniline (1.1 mmol), 8-quinolinecarboxaldehyde (1 mmol), and anhydrous ZnCl2 (0.3 g) were added to a flask in sequence. 5 mL of glacial acetic acid was added as a solvent. The temperature was slowly raised to 140°C and refluxed for 5 h. The reaction was cooled to room temperature and filtered (the solid was rinsed with n-hexane). After drying, the resulting zinc complex was dissolved in dichloromethane in a beaker. A potassium oxalate aqueous solution was added to the beaker and stirred for 12 h to dezincify it. The organic layer was separated and anhydrous sodium sulfate was added to remove water. The mixture was filtered, spin-dried, and recrystallized from anhydrous ethanol to obtain a yellow solid ligand L1 with a yield of 59%.

[0064] Ligand L1 (1 mmol), PdCl2 (1.1 mmol), and dimethylacetamide (3 ml) were added into a 10 ml single-necked bottle, respectively, and reacted at 80°C for 0.5 h. After the reaction, the mixture was cooled to room temperature and methanol was added for precipitation to obtain a yellow solid compound C1 with a yield of 86%.

[0065] Example 2

[0066] This embodiment provides a quinolinimine palladium complex C2, the synthesis method of which is as follows:

[0067] Under nitrogen atmosphere, 2,6-dimethylaniline (1.1 mmol), 8-quinolinecarboxaldehyde (1 mmol), and anhydrous ZnCl2 (0.3 g) were added to a flask in sequence. 5 mL of glacial acetic acid was added as a solvent. The temperature was slowly raised to 140°C and refluxed for 5 h. The reaction was cooled to room temperature and filtered (the solid was rinsed with n-hexane). After drying, the resulting zinc complex was dissolved in dichloromethane in a beaker. A potassium oxalate aqueous solution was added to the beaker and stirred for 12 h to dezincify it. The organic layer was separated by standing, and anhydrous sodium sulfate was added to remove water. The mixture was filtered, spin-dried, and recrystallized from anhydrous ethanol to obtain a yellow solid ligand L2 with a yield of 68%.

[0068] Ligand L2 (1 mmol), PdCl2 (1.1 mmol), and dimethylacetamide (3 ml) were added into a 10 ml single-necked bottle, respectively, and reacted at 80°C for 0.5 h. After the reaction, the mixture was cooled to room temperature and methanol was added for precipitation to obtain a yellow solid compound C2 with a yield of 88%.

[0069] Example 3

[0070] This embodiment provides a quinolinimine palladium complex C3, the synthesis method of which is as follows:

[0071] Under nitrogen atmosphere, 2,6-diethylaniline (1.1 mmol), 8-quinolinecarboxaldehyde (1 mmol), and anhydrous ZnCl2 (0.3 g) were added to a flask in sequence. 5 mL of glacial acetic acid was added as a solvent. The temperature was slowly raised to 140°C and refluxed for 5 h. The reaction was cooled to room temperature and filtered (the solid was rinsed with n-hexane). After drying, the resulting zinc complex was dissolved in dichloromethane in a beaker. A potassium oxalate aqueous solution was added to the beaker and stirred for 12 h to dezincify it. The organic layer was separated by standing, and anhydrous sodium sulfate was added to remove water. The mixture was filtered, spin-dried, and recrystallized from anhydrous ethanol to obtain a yellow solid ligand L3 with a yield of 62%.

[0072] Ligand L3 (1 mmol), PdCl2 (1.1 mmol), and dimethylacetamide (3 ml) were added into a 10 ml single-necked bottle, respectively, and reacted at 80°C for 0.5 h. After the reaction, the mixture was cooled to room temperature and methanol was added for precipitation to obtain a yellow solid compound C3 with a yield of 84%.

[0073] Example 4

[0074] This embodiment provides a quinolinimine palladium complex C4, the synthesis method of which is as follows:

[0075] Under a nitrogen atmosphere, 4-tert-butylaniline (1.1 mmol), 8-quinolinecarboxaldehyde (1 mmol), and anhydrous ZnCl2 (0.3 g) were added to a flask in sequence. 5 mL of glacial acetic acid was added as a solvent, and the temperature was slowly raised to 140°C. The mixture was refluxed under condensation for 5 h. The reaction was cooled to room temperature and filtered (the solid was rinsed with n-hexane). After drying, the resulting zinc complex was dissolved in dichloromethane in a beaker. A potassium oxalate aqueous solution was added to the beaker and stirred for 12 h to dezincify it. The mixture was allowed to stand and the organic layer was separated. Anhydrous sodium sulfate was added to remove water, filtered, spin-dried, and recrystallized from anhydrous ethanol to obtain a yellow solid ligand L4 with a yield of 67%.

[0076] Ligand L4 (1 mmol), PdCl2 (1.1 mmol), and dimethylacetamide (3 ml) were added into a 10 ml single-necked bottle respectively, and the mixture was reacted at 80°C for 0.5 h. After the reaction, the mixture was cooled to room temperature and methanol was added for precipitation to obtain a yellow solid compound C4 with a yield of 89%.

[0077] Example 5

[0078] This embodiment provides an ester thiophene-hexyl thiophene copolymer L1, the synthesis method of which is as follows:

[0079] Under a nitrogen atmosphere, 2-bromo-3-(2-acetoxymethyl)thiophene (0.015 mmol), 2-bromo-3-hexylthiophene (0.485 mmol), potassium carbonate (0.75 mmol), quinolinimine palladium complex C1 (0.25 mmol%), pivalic acid (0.15 mmol), and dimethylacetamide (4 mL) were reacted at 100° C. for 24 h, and precipitated in methanol to obtain an esterthiophene-hexylthiophene copolymer L1 with a yield of 74%, an HT value of 85%, a PDI of 2.0, a number average molecular weight Mn of 12.4 KDa, and a molar percentage of 3-(2-acetoxymethyl)thiophene segments in the esterthiophene-hexylthiophene copolymer segments of 4.7%, i.e., a degree of copolymerization of 4.7 mmol). The structures of the quinolinimine palladium complex C1 and the esterthiophene-hexylthiophene copolymer L1 are shown below:

[0080]

[0081] Among them, x=4.7mmol%, y=95.3mmol%.

[0082] Example 6

[0083] This embodiment provides an ester thiophene-hexyl thiophene copolymer L2, the synthesis method of which is as follows:

[0084] Under a nitrogen atmosphere, 2-bromo-3-(2-acetoxymethyl)thiophene (0.015 mmol), 2-bromo-3-hexylthiophene (0.485 mmol), potassium carbonate (0.75 mmol), quinolinimine palladium complex C2 (0.25 mmol%), pivalic acid (0.15 mmol), and dimethylacetamide (4 mL) were reacted at 100° C. for 24 h, and precipitated in methanol to obtain an esterthiophene-hexylthiophene copolymer L2 with a yield of 88%, an HT value of 89%, a PDI of 2.3, a number average molecular weight Mn of 10.9 KDa, and a molar percentage of 3-(2-acetoxymethyl)thiophene segments in the esterthiophene-hexylthiophene copolymer segments of 6.9%, i.e., a degree of copolymerization of 6.9 mmol). The structures of the quinolinimine palladium complex C2 and the esterthiophene-hexylthiophene copolymer L2 are shown below:

[0085]

[0086] Among them, x=6.9mmol%, y=93.1mmol%.

[0087] Example 7

[0088] This embodiment provides an esterthiophene-hexylthiophene copolymer L3, the synthesis method of which is as follows:

[0089] Under a nitrogen atmosphere, 2-bromo-3-(2-acetoxyethyl)thiophene (0.125 mmol), 2-bromo-3-hexylthiophene (0.485 mmol), potassium carbonate (0.75 mmol), quinolinimine palladium complex C3 (0.25 mmol%), pivalic acid (0.15 mmol), and dimethylacetamide (4 mL) were reacted at 100° C. for 24 h, and precipitated in methanol to obtain an esterthiophene-hexylthiophene copolymer L3 with a yield of 81%, an HT value of 93%, a PDI of 2.0, a number average molecular weight Mn of 7.5 KDa, and a molar percentage of 3-(2-acetoxyethyl)thiophene segments in the esterthiophene-hexylthiophene copolymer segments of 13.7%, i.e., a degree of copolymerization of 13.7 mmol). The structures of the quinolinimine palladium complex C3 and the esterthiophene-hexylthiophene copolymer L3 are shown below:

[0090]

[0091] Among them, x=13.7mmol%, y=86.3mmol%.

[0092] Example 8

[0093] This embodiment provides an ester thiophene-hexyl thiophene copolymer L4, the synthesis method of which is as follows:

[0094] Under a nitrogen atmosphere, 2-bromo-3-(2-acetoxyethyl)thiophene (0.125 mmol), 2-bromo-3-hexylthiophene (0.485 mmol), potassium carbonate (0.75 mmol), quinolinimine palladium complex C4 (0.25 mmol%), pivalic acid (0.15 mmol), and dimethylacetamide (4 mL) were reacted at 100° C. for 24 h, and precipitated in methanol to obtain an esterthiophene-hexylthiophene copolymer L4 with a yield of 81%, an HT value of 87%, a PDI of 1.8, a number average molecular weight Mn of 8.4 KDa, and a mole percentage of 3-(2-acetoxyethyl)thiophene segments in the esterthiophene-hexylthiophene copolymer segments of 12.0%, i.e., a degree of copolymerization of 12.0 mmol). The structures of the quinolinimine palladium complex C4 and the esterthiophene-hexylthiophene copolymer L4 are shown below:

[0095]

[0096] Among them, x=12.0mmol%, y=88.0mmol%.

[0097] It can be seen from Examples 5 to 8 that the esterthiophene-hexylthiophene copolymer of the present invention has a random structure and has the characteristics of high regularity, high molecular weight and narrow molecular weight distribution.

[0098] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be considered as equivalent replacement methods and are included in the scope of protection of the present invention.

Claims

1. A quinolinimine palladium complex, characterized in that The structural formula of the quinolinimine palladium complex is shown in formula (I): Formula (I) wherein R1, R2, R3, R4, and R5 are independently selected from hydrogen, C 1~6 alkyl.

2. The quinolinimine palladium complex according to claim 1, wherein The structural formula of the quinolinimine palladium complex is shown in formula (I): Formula (I) wherein R1, R2, R3, R4, and R5 are independently selected from hydrogen, C 2~4 alkyl.

3. The quinolinimine palladium complex according to claim 1, wherein The structural formula of the quinolinimine palladium complex is shown in formula (I): Formula (I) Wherein, R1, R2, R3, R4 and R5 are independently selected from hydrogen, methyl, ethyl, isopropyl and tert-butyl.

4. The method for preparing the quinoline imine palladium complex according to any one of claims 1 to 3, wherein The steps include: ligand The quinoline imine palladium complex is obtained by reacting with PdCl2.

5. The preparation method of quinolinimine palladium complex according to claim 4, wherein The molar ratio of the ligand to PdCl2 is 1:1.05~1.

2.

6. The preparation method of the quinolinimine palladium complex according to claim 4, wherein The reaction temperature is 70-90° C. and the reaction time is 10-50 min.

7. The preparation method of the quinolinimine palladium complex according to claim 4, wherein The preparation of the ligand comprises the following steps: 8-Quinolinecarboxaldehyde and substituted aniline Reaction to obtain the ligand.

8. The preparation method of the quinolinimine palladium complex according to claim 7, wherein The molar ratio of the 8-quinolinecarboxaldehyde to the substituted aniline is 1:1.05-1.

2.

9. The preparation method of the quinolinimine palladium complex according to claim 7, wherein The reaction temperature is 130-150° C. and the reaction time is 4-8 hours.

10. Use of the quinolinimine palladium complex according to any one of claims 1 to 3 or the quinolinimine palladium complex prepared by the method for preparing the quinolinimine palladium complex according to any one of claims 4 to 9 in the preparation of an esterthiophene-hexylthiophene copolymer.

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