Ester-substituted palladium complex as well as preparation method and application thereof

Abstract

The invention discloses an ester group-substituted palladium complex and a preparation method and application thereof, the structural formula of the ester group-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; the ester-substituted palladium complex provided by the invention can be catalytically polymerized at high temperature to prepare the ester thiophene-hexylthiophene copolymer with high molecular weight and high regularity, 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 ester-substituted palladium complexes, and in particular to an ester-substituted palladium complex, a preparation method and application thereof. Background Art

[0002] With the rapid development of optoelectronic material research, thiophene copolymers have received extensive attention due to their good stability and easy modification after doping. Although the synthesis of thiophene polymers has a long history, early thiophene copolymers were used in LED and polymer solar cell devices, and their molecular structures were designed to meet the requirements of LED and polymer solar cell devices. However, the development of perovskite solar cells has only been around for about ten years, and most of the early thiophene copolymers do not meet the requirements of perovskite solar cell devices such as energy level, solubility and heat resistance. Therefore, designing new thiophene copolymers that meet the special requirements of perovskite cell devices is an urgent problem to be solved.

[0003] The HOMO energy level of the homopolymer corresponding to the monomer 3-alkoxythiophene meets the requirements (-5.19eV) and has good solubility. The energy level of P3HT is the best match for perovskite solar cells (-5.20eV), and it is currently a polymer material commonly used in the hole transport layer of perovskite cells. However, its solubility is average (0.1mg / mL), far inferior to the traditional hole transport material small molecule spiro-OMeTAD, which limits the application of P3HT to a certain extent.

[0004] The inventors found in the experiment that the copolymerization of ester thiophene and P3HT can improve the solubility of P3HT to a certain extent. However, there are few existing technologies that record catalysts for preparing copolymerization of ester thiophene and P3HT. Summary of the invention

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

[0006] The object of the present invention is to provide an ester-substituted palladium complex, the structural formula of the ester-substituted palladium complex is shown in formula (I):

[0007]

[0008] Formula (I)

[0009] Among them, R 1 , R 2 , R 3 are independently selected from hydrogen or methyl formate, and R 1 , R2 , R 3 Not hydrogen at the same time.

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

[0011]

[0012] Formula (I)

[0013] Among them, R 1 , R 3 Selected from hydrogen, R 2 Selected from methyl formate.

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

[0015]

[0016] Formula (I)

[0017] Among them, R 1 , R 2 Selected from methyl formate, R 3 Selected from hydrogen.

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

[0019] Ligand With (COD)PdCl 2 reacting to obtain the ester-substituted palladium complex;

[0020] Among them, R 1 , R 2 , R 3 are independently selected from hydrogen or methyl formate, and R 1 , R 2 , R 3 Not hydrogen at the same time.

[0021] In some embodiments of the present invention, the ligand and PdCl 2 The molar ratio is 1:0.51~0.55.

[0022] In some embodiments of the present invention, the reaction temperature is 60-100° C. and the reaction time is 20-50 min.

[0023] Another object of the present invention is to provide the use of the ester-substituted palladium complex or the ester-substituted palladium complex prepared by the preparation method of the ester-substituted palladium complex in the preparation of esterthiophene-hexylthiophene copolymers.

[0024] In some embodiments of the present invention, the structure of the ester thiophene-hexyl thiophene copolymer is shown in formula (II) or formula (III):

[0025]

[0026] Formula (Ⅱ) Formula (Ⅲ)

[0027] The molar percentage of the ester-thiophene chain segment in the ester-thiophene-hexylthiophene copolymer chain segment is 2.6% to 13.9%, and the number average molecular weight of the ester-thiophene-hexylthiophene copolymer is 9.3 to 17.3 KDa.

[0028] In some embodiments of the present invention, in some embodiments of the present invention, the HT value of the esterthiophene-hexylthiophene copolymer is ≥80%.

[0029] In some embodiments of the present invention, the esterthiophene-hexylthiophene copolymer is a random copolymer.

[0030] Another object of the present invention is to provide a method for preparing an ester-thiophene-hexylthiophene copolymer, comprising the following steps:

[0031] Under the catalysis of the ester-substituted palladium complex, 2-bromo-3-ester thiophene and 2-bromo-3-hexyl thiophene react to obtain the ester thiophene-hexyl thiophene copolymer;

[0032] The structural formula of the ester-substituted palladium complex is shown in formula (I):

[0033]

[0034] Formula (I)

[0035] Among them, R 1 , R 2 , R 3 are independently selected from hydrogen or methyl formate, and R 1 , R 2 , R 3 Not at the same time hydrogen;

[0036] 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.

[0037] 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.

[0038] In some embodiments of the present invention, the ratio of the total mole of the 2-bromo-3-ester thiophene and 2-bromo-3-hexyl thiophene to the mole of the ester-substituted palladium complex is 1:0.001-0.01.

[0039] In some embodiments of the present invention, the reaction temperature is 80-120° C. and the reaction time is 12-36 hours.

[0040] In some embodiments of the present invention, the reaction further contains an inorganic base, an organic acid and a solvent.

[0041] In some embodiments of the present invention, the inorganic base includes at least one of potassium carbonate and sodium carbonate.

[0042] In some embodiments of the present invention, the organic acid includes at least one of pivalic acid and caproic acid.

[0043] In some embodiments of the present invention, the solvent includes N,N-dimethylacetamide.

[0044] 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.

[0045] 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.

[0046] In some embodiments of the present invention, after the reaction is completed, a purification step is further included.

[0047] Compared with the prior art, the present invention has the following beneficial effects:

[0048] The ester-substituted 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 and high regularity, 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

[0049] Figure 1 This is the H NMR spectrum of the ester-substituted palladium complex C2 provided in Example 1. DETAILED DESCRIPTION

[0050] 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.

[0051] The ester-substituted palladium complex is prepared by the following reaction route:

[0052]

[0053] 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;

[0054] The structural formula of 2-bromo-3-(2-acetoxymethyl)thiophene is as follows:

[0055] ;

[0056] The structural formula of 2-bromo-3-(2-acetoxyethyl)thiophene is as follows:

[0057] .

[0058] Example 1

[0059] This embodiment provides an ester-substituted palladium complex C1, and its synthesis method is as follows:

[0060] Methyl 2-aminobenzoate (1 mmol), (COD)PdCl 2 (0.51mmol) and dimethylacetamide (3ml) were added into a 10ml single-mouth bottle respectively, and the reaction was carried out at 80℃ for 0.5h. After the reaction was completed, the mixture was cooled to room temperature, and methanol was added to precipitate the solid. The solid was dissolved, passed through a silica gel column, and then dried by spin drying. The yellow solid compound C1 was obtained with a yield of 83%.

[0061] Example 2

[0062] This embodiment provides an ester-substituted palladium complex C2, and its synthesis method is as follows:

[0063] 2-aminoisophthalic acid dimethyl ester (1 mmol), (COD)PdCl 2 (0.51mmol) and dimethylacetamide (3ml) were added into a 10ml single-mouth bottle respectively, and the reaction was carried out at 80℃ for 0.5h. After the reaction was completed, the mixture was cooled to room temperature, and methanol was added to precipitate the solid. The solid was dissolved, passed through a silica gel column, and then dried by spin drying. The yellow solid compound C2 was obtained with a yield of 79%.

[0064] Example 3

[0065] This embodiment provides an ester-substituted palladium complex C3, and its synthesis method is as follows:

[0066] Methyl 4-aminobenzoate (1 mmol), (COD)PdCl 2 (0.51mmol) and dimethylacetamide (3ml) were added into a 10ml single-mouth bottle respectively, and the reaction was carried out at 80℃ for 0.5h. After the reaction was completed, the mixture was cooled to room temperature, and methanol was added to precipitate the solid. The solid was dissolved, passed through a silica gel column, and then dried by spin drying. The yellow solid compound C3 was obtained with a yield of 89%.

[0067] Example 4

[0068] This embodiment provides an ester-thiophene-hexylthiophene copolymer L1, and the synthesis method thereof is as follows:

[0069] Under nitrogen atmosphere, 2-bromo-3-(2-acetoxymethyl)thiophene (0.015mmol), 2-bromo-3-hexylthiophene (0.485mmol), 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 ester-thiophene-hexylthiophene copolymer L1 was obtained by precipitation in methanol. The yield was 74%, the HT value was 90%, the PDI was 3.0, the number average molecular weight Mn was 15.9KDa, and the molar percentage of 3-(2-acetoxymethyl)thiophene segment in the ester-thiophene-hexylthiophene copolymer segment was 3.4%, that is, the copolymerization degree was 3.4mmol; the structures of the ester-substituted palladium complex C1 and the ester-thiophene-hexylthiophene copolymer L1 are shown below:

[0070]

[0071] Among them, x=3.4mmol%, y=96.6mmol%.

[0072] Example 5

[0073] This embodiment provides an ester-thiophene-hexylthiophene copolymer L2, and the synthesis method thereof is as follows:

[0074] Under nitrogen atmosphere, 2-bromo-3-(2-acetoxymethyl)thiophene (0.125mmol), 2-bromo-3-hexylthiophene (0.375mmol), 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 ester-thiophene-hexylthiophene copolymer L2 was obtained by precipitation in methanol. The yield was 61%, the HT value was 84%, the PDI was 2.4, the number average molecular weight Mn was 9.3KDa, and the molar percentage of 3-(2-acetoxymethyl)thiophene segment in the ester-thiophene-hexylthiophene copolymer segment was 13.9%, that is, the copolymerization degree was 13.9mmol; the structures of the ester-substituted palladium complex C1 and the ester-thiophene-hexylthiophene copolymer L2 are shown below:

[0075]

[0076] Among them, x=13.9mmol%, y=86.1mmol%.

[0077] Example 6

[0078] This embodiment provides an ester-thiophene-hexylthiophene copolymer L3, 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), ester-substituted palladium complex C2 (0.25mmol%), pivalic acid (0.15mmol), and dimethylacetamide (4mL) were reacted at 100°C for 24h, and ester-thiophene-hexylthiophene copolymer L3 was obtained by precipitation in methanol. The yield was 72%, the HT value was 93%, the PDI was 3.2, the number average molecular weight Mn was 17.3KDa, and the molar percentage of 3-(2-acetoxymethyl)thiophene segment in the ester-thiophene-hexylthiophene copolymer segment was 4.1%, that is, the copolymerization degree was 4.1mmol; the structures of the ester-substituted palladium complex C2 and the ester-thiophene-hexylthiophene copolymer L3 are shown as follows:

[0080]

[0081] Among them, x=4.1mmol%, y=95.9mmol%.

[0082] Example 7

[0083] This embodiment provides an ester-thiophene-hexylthiophene copolymer L4, 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), ester-substituted palladium complex C3 (0.25mmol%), pivalic acid (0.15mmol), and dimethylacetamide (4mL) were reacted at 100°C for 24h, and ester-thiophene-hexylthiophene copolymer L4 was obtained by precipitation in methanol. The yield was 78%, the HT value was 89%, the PDI was 2.9, the number average molecular weight Mn was 13.8KDa, and the molar percentage of 3-(2-acetoxymethyl)thiophene segment in the ester-thiophene-hexylthiophene copolymer segment was 2.6%, that is, the copolymerization degree was 2.6mmol; the structures of the ester-substituted palladium complex C3 and the ester-thiophene-hexylthiophene copolymer L4 are shown below:

[0085]

[0086] Among them, x=2.6mmol%, y=97.4mmol%.

[0087] Example 8

[0088] This embodiment provides an ester-thiophene-hexylthiophene copolymer L5, and the synthesis method thereof is as follows:

[0089] Under nitrogen atmosphere, 2-bromo-3-(2-acetoxyethyl)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 ester-thiophene-hexylthiophene copolymer L5 was obtained by precipitation in methanol. The yield was 85%, the HT value was 91%, the PDI was 3.3, the number average molecular weight Mn was 14.6KDa, and the molar percentage of 3-(2-acetoxyethyl)thiophene segment in the ester-thiophene-hexylthiophene copolymer segment was 3.9%, that is, the copolymerization degree was 3.9mmol; the structures of the ester-substituted palladium complex C1 and the ester-thiophene-hexylthiophene copolymer L5 are shown as follows:

[0090]

[0091] Among them, x=3.9mmol%, y=96.1mmol%.

[0092] Example 9

[0093] This embodiment provides an ester-thiophene-hexylthiophene copolymer L6, and the synthesis method thereof is as follows:

[0094] Under nitrogen atmosphere, 2-bromo-3-(2-acetoxyethyl)thiophene (0.03mmol), 2-bromo-3-hexylthiophene (0.47mmol), 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 ester-thiophene-hexylthiophene copolymer L6 was obtained by precipitation in methanol. The yield was 76%, the HT value was 88%, the PDI was 3.2, the number average molecular weight Mn was 13.9KDa, and the molar percentage of 3-(2-acetoxyethyl)thiophene segment in the ester-thiophene-hexylthiophene copolymer segment was 4.4%, that is, the copolymerization degree was 4.4mmol; the structures of the ester-substituted palladium complex C2 and the ester-thiophene-hexylthiophene copolymer L6 are shown below:

[0095]

[0096] Among them, x=4.4mmol%, y=95.6mmol%.

[0097] Example 10

[0098] This embodiment provides an ester-thiophene-hexylthiophene copolymer L7, and the synthesis method thereof is as follows:

[0099] Under nitrogen atmosphere, 2-bromo-3-(2-acetoxyethyl)thiophene (0.025mmol), 2-bromo-3-hexylthiophene (0.475mmol), 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 ester-thiophene-hexylthiophene copolymer L7 was obtained by precipitation in methanol. The yield was 73%, the HT value was 87%, the PDI was 3.5, the number average molecular weight Mn was 13.6KDa, and the molar percentage of 3-(2-acetoxyethyl)thiophene segment in the ester-thiophene-hexylthiophene copolymer segment was 4.7%, that is, the copolymerization degree was 4.7mmol; the structures of the ester-substituted palladium complex C3 and the ester-thiophene-hexylthiophene copolymer L7 are shown below:

[0100]

[0101] Among them, x=4.7mmol%, y=95.3mmol%.

[0102] It can be seen from Examples 4 to 10 that the ester-thiophene-hexylthiophene copolymer of the present invention has a random structure and has the characteristics of high regularity and high molecular weight.

[0103] 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. An ester-substituted palladium complex, characterized in that The structural formula of the ester-substituted palladium complex is shown in formula (I): 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.

2. The ester-substituted palladium complex 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 ester-substituted palladium complex 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 method for preparing the ester-substituted palladium complex according to any one of claims 1 to 3, characterized in that: The steps include: Ligand Reaction with (COD)PdCl2 to obtain the ester-substituted palladium complex.

5. The method for preparing an ester-substituted palladium complex according to claim 4, characterized in that: The molar ratio of the ligand to PdCl2 is 1:0.51-0.

55.

6. The method for preparing an ester-substituted palladium complex according to claim 4, characterized in that: The reaction temperature is 60-100° C. and the reaction time is 20-50 min.

7. Use of the ester-substituted palladium complex according to any one of claims 1 to 3 or the ester-substituted palladium complex prepared by the method for preparing the ester-substituted palladium complex according to any one of claims 4 to 6 in the preparation of an esterthiophene-hexylthiophene copolymer.

8. The use according to claim 7, characterized in that: The structure of the ester thiophene-hexyl thiophene copolymer is shown in formula (II) or formula (III): Formula (II) Formula (III) The molar percentage of the ester-thiophene chain segment in the ester-thiophene-hexylthiophene copolymer chain segment is 2.6% to 13.9%, and the number average molecular weight of the ester-thiophene-hexylthiophene copolymer is 9.3 to 17.3 KDa.

9. The use according to claim 7, characterized in that: The HT value of the esterthiophene-hexylthiophene copolymer is ≥80%.

10. The use according to claim 7, characterized in that: The esterthiophene-hexylthiophene copolymer is a random copolymer.

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