Quinoline imine palladium complex as well as preparation method and application thereof

Abstract

The invention discloses a quinoline imine palladium complex as well as a preparation method and application thereof, the structural formula of the quinoline imine palladium complex is shown as a formula (I): # imgabs0 # formula (I), wherein R1, R2, R3, R4 and R5 are independently selected from hydrogen and C1-6 alkyl; the quinoline imine palladium complex provided by the invention can be catalytically polymerized at high temperature to prepare the ester thiophene-hexylthiophene copolymer with high molecular weight, high regularity and narrow molecular weight distribution, and has wide application prospects in the fields of solar cells, organic transistors, electrochromic devices, chemical sensors, electromagnetic shielding materials and the like.

Description

Technical Field

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

[0002] Perovskite solar cells include a fluorine-doped tin oxide (FTO) conductive substrate, an electron transport layer, a perovskite photosensitive layer, a hole transport layer, and a counter electrode. The components of perovskite solar cells and their assembly methods determine that the hole transport material needs to have certain energy level requirements and solubility requirements.

[0003] The hole transport material of polymer solar cells can improve the Voc by reducing the highest occupied molecular orbital (HOMO level) of the donor material while ensuring the energy level match with the acceptor material, thereby improving the PCE of the photovoltaic device. For perovskite solar cells, in order to allow the photogenerated holes to be transported from the perovskite layer to the back electrode through the hole transport layer, the HOMO energy level of the hole transport material must be between the perovskite layer and the back electrode. The perovskite layer material generally uses methylammonium lead iodide (CH3NH3PbI3), whose HOMO energy level is -5.43eV, and the energy level of the back electrode gold (Au) is -5.10eV. Therefore, the HOMO energy level of the hole transport layer of the perovskite solar cell should be in the range of -5.43 to -5.10eV. The energy level range of the hole transport layer of the perovskite solar cell is relatively narrow. Therefore, the molecular structure of the hole transport polymer should be designed according to the energy level requirements of the perovskite CH3NH3PbI3 and the back electrode, so as to obtain a thiophene copolymer that meets the hole and electron transport requirements in the perovskite cell device.

[0004] Ester thiophene-hexyl thiophene 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 preparing ester thiophene-hexyl thiophene 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 object of the present invention is to provide a quinoline imine palladium complex, the structural formula of the quinoline imine palladium complex is shown in formula (I):

[0007]

[0008] Formula (I)

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

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

[0011]

[0012] Formula (I)

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

[0014] In some embodiments of the present invention, the structural formula of the quinoline imine palladium complex is as 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 quinoline imine palladium complex, comprising the following steps:

[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 quinoline imine palladium complex or the quinoline imine palladium complex prepared by the preparation method of the quinoline imine palladium complex in the preparation of ester thiophene-hexyl thiophene copolymer.

[0027] In some embodiments of the present invention, the structure of the ester thiophene-hexyl thiophene 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 ester-thiophene-hexylthiophene copolymer, comprising the following steps:

[0034] Under the catalysis of quinoline imine 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 quinoline imine palladium complex is shown in formula (I):

[0036]

[0037] Formula (I)

[0038] Wherein, R1, R2, R3, R4, 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 quinoline imine 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 caproic 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 2-bromo-3-ester thiophene and 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 quinoline imine palladium complex provided by the present invention can be used to prepare an ester-thiophene-hexylthiophene copolymer at high temperature. The prepared ester-thiophene-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 combination with the embodiments, so as to fully understand the purpose, characteristics and effects of the present invention. Obviously, the described embodiments 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 technicians in this field without creative work are all 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] Quinoline imine palladium complex is prepared by the following reaction route:

[0055]

[0056] In the following examples, the ester thiophene segment content in the ester thiophene-hexyl thiophene copolymer was measured by nuclear magnetic resonance, the ester thiophene-hexyl thiophene copolymer was dissolved in deuterated chloroform, TMS was used as an internal standard, and the measurement temperature was 25°C. The molecular weight or degree of polymerization of the ester thiophene-hexyl thiophene copolymer was measured by gel permeation chromatography (GPC) with THF 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 quinoline imine palladium complex C1, and its synthesis method is as follows:

[0063] Under nitrogen atmosphere, 2,6-diisopropylaniline (1.1mmol), 8-quinolinecarboxaldehyde (1mmol), and anhydrous ZnCl2 (0.3g) were added to a branched bottle in sequence, and 5mL of glacial acetic acid was added as a solvent. The temperature was slowly raised to 140°C, and condensed and refluxed for 5h. The reaction was cooled to room temperature, filtered (the solid was rinsed with n-hexane), and the obtained zinc complex was dissolved in a beaker with dichloromethane after drying. A potassium oxalate aqueous solution was added to the beaker and stirred for 12h to dezincify it. The organic layer was separated by standing, anhydrous sodium sulfate was added to remove water, filtered, spin-dried, and recrystallized with 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-mouth bottle respectively, and reacted at 80 °C for 0.5 h. After the reaction was completed, it 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 quinoline imine palladium complex C2, and its synthesis method is as follows:

[0067] Under nitrogen atmosphere, 2,6-dimethylaniline (1.1mmol), 8-quinolinecarboxaldehyde (1mmol), and anhydrous ZnCl2 (0.3g) were added to a branched bottle in sequence, and 5mL of glacial acetic acid was added as a solvent. The temperature was slowly raised to 140°C, and condensed and refluxed for 5h. The reaction was cooled to room temperature, filtered (the solid was rinsed with n-hexane), and the obtained zinc complex was dissolved in a beaker with dichloromethane after drying. A potassium oxalate aqueous solution was added to the beaker and stirred for 12h to dezincify it. The organic layer was separated by standing, anhydrous sodium sulfate was added to remove water, filtered, spin-dried, and recrystallized with 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-mouth bottle respectively, and reacted at 80 °C for 0.5 h. After the reaction was completed, it 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 quinoline imine palladium complex C3, and its synthesis method is as follows:

[0071] Under nitrogen atmosphere, 2,6-diethylaniline (1.1mmol), 8-quinolinecarboxaldehyde (1mmol), and anhydrous ZnCl2 (0.3g) were added to a branched bottle in sequence, and 5mL of glacial acetic acid was added as a solvent. The temperature was slowly raised to 140°C, and condensed and refluxed for 5h. The reaction was cooled to room temperature, filtered (the solid was rinsed with n-hexane), and the obtained zinc complex was dissolved in a beaker with dichloromethane after drying. A potassium oxalate aqueous solution was added to the beaker and stirred for 12h to dezincify it. The organic layer was separated by standing, anhydrous sodium sulfate was added to remove water, filtered, spin-dried, and recrystallized with 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-mouth bottle respectively, and reacted at 80 °C for 0.5 h. After the reaction was completed, it 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 quinoline imine palladium complex C4, and its synthesis method is as follows:

[0075] Under nitrogen atmosphere, 4-tert-butylaniline (1.1mmol), 8-quinolinecarboxaldehyde (1mmol), and anhydrous ZnCl2 (0.3g) were added to a branched bottle in sequence, and 5mL of glacial acetic acid was added as a solvent. The temperature was slowly raised to 140°C, and the mixture was condensed and refluxed for 5h. The reaction was cooled to room temperature, filtered (the solid was rinsed with n-hexane), and the obtained zinc complex was dissolved in a beaker with dichloromethane after drying. A potassium oxalate aqueous solution was added to the beaker and stirred for 12h to dezincify it. The organic layer was separated by standing, anhydrous sodium sulfate was added to remove water, filtered, spin-dried, and recrystallized with 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-mouth bottle respectively, and reacted at 80 °C for 0.5 h. After the reaction was completed, it 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-hexylthiophene copolymer L1, and the synthesis method thereof is as follows:

[0079] Under nitrogen atmosphere, 2-bromo-3-(2-acetoxymethyl)thiophene (0.015mmol), 2-bromo-3-hexylthiophene (0.485mmol), potassium carbonate (0.75mmol), quinoline imine palladium complex C1 (0.25mmol%), pivalic acid (0.15mmol), and dimethylacetamide (4mL) were reacted at 100°C for 24h, and ester thiophene-hexylthiophene copolymer L1 was obtained by precipitation in methanol. The yield was 74%, the HT value was 85%, the PDI was 2.0, the number average molecular weight Mn was 12.4KDa, and the molar percentage of 3-(2-acetoxymethyl)thiophene segment in the ester thiophene-hexylthiophene copolymer segment was 4.7%, that is, the copolymerization degree was 4.7mmol; the structures of the quinoline imine palladium complex C1 and the ester thiophene-hexylthiophene copolymer L1 are as follows:

[0080]

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

[0082] Example 6

[0083] This embodiment provides an ester-thiophene-hexylthiophene copolymer L2, and the synthesis method thereof is as follows:

[0084] Under nitrogen atmosphere, 2-bromo-3-(2-acetoxymethyl)thiophene (0.015mmol), 2-bromo-3-hexylthiophene (0.485mmol), potassium carbonate (0.75mmol), quinoline imine palladium complex C2 (0.25mmol%), pivalic acid (0.15mmol), dimethylacetamide (4mL) were reacted at 100°C for 24h, and ester thiophene-hexylthiophene copolymer L2 was obtained by precipitation in methanol. The yield was 88%, the HT value was 89%, the PDI was 2.3, the number average molecular weight Mn was 10.9KDa, and the molar percentage of 3-(2-acetoxymethyl)thiophene segment in the ester thiophene-hexylthiophene copolymer segment was 6.9%, that is, the copolymerization degree was 6.9mmol; the structures of the quinoline imine palladium complex C2 and the ester thiophene-hexylthiophene copolymer L2 are as follows:

[0085]

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

[0087] Example 7

[0088] This embodiment provides an ester-thiophene-hexylthiophene copolymer L3, and the synthesis method thereof is as follows:

[0089] Under nitrogen atmosphere, 2-bromo-3-(2-acetoxyethyl)thiophene (0.125mmol), 2-bromo-3-hexylthiophene (0.485mmol), potassium carbonate (0.75mmol), quinoline imine palladium complex C3 (0.25mmol%), pivalic acid (0.15mmol), dimethylacetamide (4mL) were reacted at 100°C for 24h, and ester thiophene-hexylthiophene copolymer L3 was obtained by precipitation in methanol. The yield was 81%, the HT value was 93%, the PDI was 2.0, the number average molecular weight Mn was 7.5KDa, and the molar percentage of 3-(2-acetoxyethyl)thiophene segment in the ester thiophene-hexylthiophene copolymer segment was 13.7%, that is, the copolymerization degree was 13.7mmol; the structures of the quinoline imine palladium complex C3 and the ester thiophene-hexylthiophene copolymer L3 are as follows:

[0090]

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

[0092] Example 8

[0093] This embodiment provides an ester-thiophene-hexylthiophene copolymer L4, and the synthesis method thereof is as follows:

[0094] Under nitrogen atmosphere, 2-bromo-3-(2-acetoxyethyl)thiophene (0.125mmol), 2-bromo-3-hexylthiophene (0.485mmol), potassium carbonate (0.75mmol), quinoline imine palladium complex C4 (0.25mmol%), pivalic acid (0.15mmol), dimethylacetamide (4mL) were reacted at 100°C for 24h, and ester thiophene-hexylthiophene copolymer L4 was obtained by precipitation in methanol. The yield was 81%, the HT value was 87%, the PDI was 1.8, the number average molecular weight Mn was 8.4KDa, and the molar percentage of 3-(2-acetoxyethyl)thiophene segment in the ester thiophene-hexylthiophene copolymer segment was 12.0%, that is, the copolymerization degree was 12.0mmol; the structures of the quinoline imine palladium complex C4 and the ester thiophene-hexylthiophene copolymer L4 are shown as follows:

[0095]

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

[0097] It can be seen from Examples 5 to 8 that the ester-thiophene-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 equivalent replacement methods and are included in the protection scope of the present invention.

Claims

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

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

3. The quinoline imine palladium complex according to claim 1, characterized in that The structural formula of the quinoline imine 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, characterized in that: The steps include: Ligand The quinoline imine palladium complex is obtained by reacting with PdCl2.

5. The method for preparing the quinoline imine palladium complex according to claim 4, wherein The molar ratio of the ligand to PdCl2 is 1:1.05-1.

2.

6. The method for preparing the quinoline imine palladium complex according to claim 4, wherein The reaction temperature is 70-90°C and the reaction time is 10-50 minutes.

7. The method for preparing the quinoline imine 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 method for preparing the quinoline imine 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 method for preparing the quinoline imine 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 quinoline imine palladium complex according to any one of claims 1 to 3 or the quinoline imine palladium complex prepared by the method for preparing the quinoline imine palladium complex according to any one of claims 4 to 9 in the preparation of an esterthiophene-hexylthiophene copolymer.

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