Application of ester-substituted palladium complex in preparation of long-ether-chain thiophene copolymer

Abstract

The invention discloses an application of an ester-substituted palladium complex in preparation of a long-ether-chain thiophene copolymer, the structural formula of the ester-substituted palladium complex is as shown in formula (I): # imgabs0 # formula (I), R1, R2 and R3 are independently selected from hydrogen or methyl formate group, and R1, R2 and R3 are not hydrogen at the same time; according to the invention, the ester-substituted palladium complex is used for catalytic preparation of the long-ether-chain thiophene copolymer, and the long-ether-chain thiophene copolymer with high molecular weight and high regularity can be obtained.

Description

Technical Field

[0001] The invention relates to the technical field of palladium complexes, and in particular to application of an ester-substituted palladium complex in the preparation of a long ether chain thiophene copolymer. Background Art

[0002] Thiophene copolymer is a good p-type semiconductor (hole conductor). The HOMO and LUMO energy levels of thiophene copolymer are -5.20eV and -3.12eV respectively, which match the energy level of perovskite materials and are equivalent to the traditional hole transport material of PSC, spiro-OMeTAD (2,2′,7,7′-tetrakis-[N,N-di(4-methoxyphenyl)amine]-9,9′-spirobifluorene) (HOMO energy level -5.22eV, LUMO energy level -2.31eV). It is a material with hole transport function that can replace Spiro-OMeTAD.

[0003] In the prior art, thiophene copolymers can be synthesized by Kumada chain growth polymerization, Stille coupling polymerization, FeCl3 oxidation catalysis one-step polymerization and other methods. When preparing thiophene copolymers by Kumada chain growth polymerization method and Stille coupling polymerization method, the synthesis route is very long and requires expensive catalysts and raw materials; while the molecular weight of thiophene copolymers prepared by FeCl3 oxidation catalysis one-step polymerization method is usually low.

[0004] Long ether chain thiophene copolymer is a thiophene copolymer that can effectively improve perovskite solar cells. However, so far, there are few existing technologies that record the preparation of catalysts for the copolymerization of long ether chain thiophene and P3HT. Summary of the invention

[0005] The purpose of the present invention is to overcome the defects and shortcomings of the prior art and provide an application of an ester-substituted palladium complex in the preparation of a long ether-chain thiophene copolymer. The present invention uses the ester-substituted palladium complex for catalytic preparation of a long ether-chain thiophene copolymer to obtain a high molecular weight, high regularity long ether-chain thiophene copolymer.

[0006] The object of the present invention is to provide an application of an ester-substituted palladium complex in the preparation of a long ether chain thiophene copolymer; The structural formula of the ester-substituted palladium complex is shown in formula (I):

[0007] Formula (I) Wherein, R1, R2, and R3 are independently selected from hydrogen or methyl formate, and R1, R2, and R3 are not hydrogen at the same time.

[0008] In some embodiments of the present invention, the structural formula of the ester-substituted palladium complex is shown in formula (I):

[0009] Formula (I) Wherein, R1 and R3 are selected from hydrogen, and R2 is selected from methyl formate.

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

[0011] Formula (I) Wherein, R1 and R2 are selected from methyl formate, and R3 is selected from hydrogen.

[0012] In some embodiments of the present invention, the structural formula of the ester-substituted palladium complex is shown in formula (I):

[0013] Formula (I) Wherein, R1 and R2 are selected from hydrogen, and R3 is selected from methyl formate.

[0014] In some embodiments of the present invention, the long ether chain thiophene copolymer is a copolymer of 3-hexylthiophene and 3-(2-butoxyethyl)thiophene, and the molar percentage of the 3-(2-butoxyethyl)thiophene segment in the long ether chain thiophene copolymer segment is 6.4% to 16.6%.

[0015] In some embodiments of the present invention, the molar percentage of the 3-(2-butoxyethyl)thiophene chain segment in the long ether chain thiophene copolymer chain segment is 6.4% to 9.6%.

[0016] In some embodiments of the present invention, the molar percentage of the 3-(2-butoxyethyl)thiophene segment in the long ether chain thiophene copolymer segment is 10.4% to 16.6%.

[0017] In some embodiments of the present invention, the long ether chain thiophene copolymer is a random copolymer.

[0018] In some embodiments of the present invention, the structure of the long ether chain thiophene copolymer is shown in formula (II):

[0019] Formula (II) Wherein, the number average molecular weight of the long ether chain thiophene copolymer is 8.1~12.1KDa.

[0020] In some embodiments of the present invention, the HT value of the long ether chain thiophene copolymer is ≥85%, and the PDI is ≥2.0.

[0021] Compared with the prior art, the present invention has the following beneficial effects: The ester-substituted palladium complex provided by the present invention can be used to prepare long-ether-chain thiophene copolymers at high temperatures. The prepared long-ether-chain thiophene copolymers have the advantages of high molecular weight and high regularity, and have obvious economic benefits. They have broad application prospects in the fields of solar cells, organic transistors, electrochromic devices, chemical sensors, electromagnetic shielding materials, etc. DETAILED DESCRIPTION

[0022] 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.

[0023] The ester-substituted palladium complex is prepared by the following reaction route:

[0024] 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; The structural formula of 2-bromo-3-(2-butoxyethyl)thiophene is shown below: .

[0025] Example 1

[0026] This embodiment provides an ester-substituted palladium complex C1, and its synthesis method is as follows: Methyl 2-aminobenzoate (1 mmol), (COD)PdCl2 (0.51 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, the mixture was cooled to room temperature and methanol was added to precipitate the solid. The solid was dissolved and passed through a silica gel column, then dried and recrystallized (with anhydrous ethanol). The mixture was filtered and dried to obtain a yellow solid compound C1 with a yield of 83%.

[0027] Example 2

[0028] This embodiment provides an ester-substituted palladium complex C2, and its synthesis method is as follows: Add dimethyl 2-aminoisophthalate (1mmol), (COD)PdCl2 (0.51mmol) and dimethylacetamide (3ml) into a 10ml single-mouth bottle respectively, and react at 80℃ for 0.5h. After the reaction, cool to room temperature, add methanol to precipitate, precipitate solid, dissolve the solid, pass it through a silica gel column, spin dry, recrystallize (anhydrous ethanol), filter and dry to obtain a yellow solid compound C2 with a yield of 79%.

[0029] Example 3

[0030] This embodiment provides an ester-substituted palladium complex C3, and its synthesis method is as follows: Methyl 4-aminobenzoate (1 mmol), (COD)PdCl2 (0.51 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, the mixture was cooled to room temperature and methanol was added to precipitate the solid. The solid was dissolved and passed through a silica gel column, then dried and recrystallized (with anhydrous ethanol). The mixture was filtered and dried to obtain a yellow solid compound C3 with a yield of 89%.

[0031] Example 4

[0032] This embodiment provides a long ether chain thiophene copolymer L1, and the synthesis method thereof is as follows: Under nitrogen atmosphere, 2-bromo-3-(2-butoxyethyl)thiophene (0.025mmol), 2-bromo-3-hexylthiophene (0.475mmol), potassium carbonate (0.75mmol), ester-substituted palladium complex C1 (0.25mmol%), pivalic acid (0.15mmol), and dimethylacetamide (4mL) were reacted at 100°C for 24h, and precipitated in methanol to obtain a long ether chain thiophene copolymer L1 with a yield of 63%, an HT value of 87%, a PDI of 2.4, a number average molecular weight Mn of 11.6KDa, and a molar percentage of 3-(2-butoxyethyl)thiophene segments in the long ether chain thiophene copolymer segments of 6.4%, that is, a copolymerization degree of 6.4mmol; the structures of the ester-substituted palladium complex C1 and the random long ether chain thiophene copolymer L1 are shown below:

[0033] Among them, x=6.4mmol%, y=93.6mmol%.

[0034] Example 5

[0035] This embodiment provides a long ether chain thiophene copolymer L2, and its synthesis method is as follows: Under nitrogen atmosphere, 2-bromo-3-(2-butoxyethyl)thiophene (0.1mmol), 2-bromo-3-hexylthiophene (0.4mmol), potassium carbonate (0.75mmol), ester-substituted palladium complex C1 (0.25mmol%), pivalic acid (0.15mmol), and dimethylacetamide (4mL) were reacted at 100°C for 24h, and precipitated in methanol to obtain a long ether chain thiophene copolymer L2 with a yield of 71%, a HT value of 90%, a PDI of 2.9, a number average molecular weight Mn of 8.1KDa, and a molar percentage of 3-(2-butoxyethyl)thiophene segments in the long ether chain thiophene copolymer segments of 16.6%, that is, a copolymerization degree of 16.6mmol; the structures of the ester-substituted palladium complex C1 and the random long ether chain thiophene copolymer L2 are shown below:

[0036] Among them, x=16.6mmol%, y=83.4mmol%.

[0037] Example 6 This embodiment provides a long ether chain thiophene copolymer L3, and its synthesis method is as follows: Under nitrogen atmosphere, 2-bromo-3-(2-butoxyethyl)thiophene (0.05mmol), 2-bromo-3-hexylthiophene (0.45mmol), potassium carbonate (0.75mmol), ester-substituted palladium complex C2 (0.25mmol%), pivalic acid (0.15mmol), and dimethylacetamide (4mL) were reacted at 100°C for 24h, and precipitated in methanol to obtain a long ether chain thiophene copolymer L3 with a yield of 69%, an HT value of 94%, a PDI of 2.1, a number average molecular weight Mn of 12.1KDa, and a molar percentage of 3-(2-butoxyethyl)thiophene segments in the long ether chain thiophene copolymer segments of 7.3%, that is, a copolymerization degree of 7.3mmol; the structures of the ester-substituted palladium complex C2 and the random long ether chain thiophene copolymer L3 are shown below:

[0038] Among them, x=7.3mmol%, y=92.7mmol%.

[0039] Example 7 This embodiment provides a long ether chain thiophene copolymer L4, and the synthesis method thereof is as follows: Under nitrogen atmosphere, 2-bromo-3-(2-butoxyethyl)thiophene (0.075mmol), 2-bromo-3-hexylthiophene (0.425mmol), potassium carbonate (0.75mmol), ester-substituted palladium complex C2 (0.25mmol%), pivalic acid (0.15mmol), and dimethylacetamide (4mL) were reacted at 100°C for 24h, and precipitated in methanol to obtain a long ether chain thiophene copolymer L4 with a yield of 75%, an HT value of 93%, a PDI of 2.8, a number average molecular weight Mn of 9.3KDa, and a molar percentage of 3-(2-butoxyethyl)thiophene segments in the long ether chain thiophene copolymer segments of 10.4%, that is, a copolymerization degree of 10.4mmol; the structures of the ester-substituted palladium complex C2 and the random long ether chain thiophene copolymer L4 are shown below:

[0040]

[0041] Among them, x=10.4mmol%, y=89.6mmol%.

[0042] Example 8 This embodiment provides a long ether chain thiophene copolymer L5, and its synthesis method is as follows: Under nitrogen atmosphere, 2-bromo-3-(2-butoxyethyl)thiophene (0.04mmol), 2-bromo-3-hexylthiophene (0.46mmol), potassium carbonate (0.75mmol), ester-substituted palladium complex C3 (0.25mmol%), pivalic acid (0.15mmol), and dimethylacetamide (4mL) were reacted at 100°C for 24h, and precipitated in methanol to obtain a long ether chain thiophene copolymer L5 with a yield of 62%, an HT value of 84%, a PDI of 2.5, a number average molecular weight Mn of 11.0KDa, and a molar percentage of 3-(2-butoxyethyl)thiophene segments in the long ether chain thiophene copolymer segments of 6.1%, that is, a copolymerization degree of 6.1mmol; the structures of the ester-substituted palladium complex C3 and the random long ether chain thiophene copolymer L5 are shown below:

[0043] Among them, x=6.1mmol%, y=93.9mmol%.

[0044] Example 9 This embodiment provides a long ether chain thiophene copolymer L6, and its synthesis method is as follows: Under nitrogen atmosphere, 2-bromo-3-(2-butoxyethyl)thiophene (0.05mmol), 2-bromo-3-hexylthiophene (0.45mmol), potassium carbonate (0.75mmol), ester-substituted palladium complex C3 (0.25mmol%), pivalic acid (0.15mmol), and dimethylacetamide (4mL) were reacted at 100°C for 24h, and precipitated in methanol to obtain a long ether chain thiophene copolymer L6 with a yield of 59%, an HT value of 94%, a PDI of 2.7, a number average molecular weight Mn of 8.8KDa, and a molar percentage of 3-(2-butoxyethyl)thiophene segments in the long ether chain thiophene copolymer segments of 9.6%, that is, a copolymerization degree of 9.6mmol; the structures of the ester-substituted palladium complex C3 and the random long ether chain thiophene copolymer L6 are shown below:

[0045] Among them, x=9.6mmol%, y=90.4mmol%.

[0046] It can be seen from Examples 4 to 9 that the long ether chain thiophene copolymer of the present invention has a random structure and has the characteristics of high regularity and high molecular weight.

[0047] 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. Application of ester-substituted palladium complexes in the preparation of long ether chain thiophene copolymers; The structural formula of the ester-substituted palladium complex is shown in formula (I): Formula (I) in, R1, R2, and R3 are independently selected from hydrogen or methyl formate, and R1, R2, and R3 are not hydrogen at the same time.

2. The use according to claim 1, characterized in that: The structural formula of the ester-substituted palladium complex is shown in formula (I): Formula (I) Wherein, R1 and R3 are selected from hydrogen, and R2 is selected from methyl formate.

3. The use according to claim 1, characterized in that: The structural formula of the ester-substituted palladium complex is shown in formula (I): Formula (I) Wherein, R1 and R2 are selected from methyl formate, and R3 is selected from hydrogen.

4. The use according to claim 1, characterized in that: The structural formula of the ester-substituted palladium complex is shown in formula (I): Formula (I) Wherein, R1 and R2 are selected from hydrogen, and R3 is selected from methyl formate.

5. The use according to claim 1, characterized in that: The long ether chain thiophene copolymer is a copolymer of 3-hexylthiophene and 3-(2-butoxyethyl)thiophene, and the molar percentage of the 3-(2-butoxyethyl)thiophene chain segment in the long ether chain thiophene copolymer chain segment is 6.4% to 16.6%.

6. The use according to claim 1, characterized in that: The molar percentage of the 3-(2-butoxyethyl)thiophene chain segment to the long ether chain thiophene copolymer chain segment is 6.4% to 9.6%.

7. The use according to claim 1, characterized in that: The molar percentage of the 3-(2-butoxyethyl)thiophene chain segment to the long ether chain thiophene copolymer chain segment is 10.4% to 16.6%.

8. The use according to claim 1, characterized in that: The long ether chain thiophene copolymer is a random copolymer.

9. The use according to claim 1, characterized in that: The structure of the long ether chain thiophene copolymer is shown in formula (II): Formula (II) Wherein, the number average molecular weight of the long ether chain thiophene copolymer is 8.1~12.1KDa.

10. The use according to claim 1, characterized in that: The long ether chain thiophene copolymer has an HT value of ≥85% and a PDI of ≥2.0.

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