KR0131435B1 - Poly 3-alkylthiopene derivatives substituted by ester group having processability and process for preparing the same - Google Patents

Abstract

Polyalkylthiopene derivative generated by substituting ester group of structural formulas(III) or (IV) is prepared by (1) adding a monomer of a structural formula(I) or a compound in which monomer of structural formula(I) and 3-alkylthiopene of structural formula(II) are mixed at a proper rate to acetonitrile solution in which anhydrous ferric chloride is dissolved with nitrogen, (2) precipitating, filter, wash in methanol and dry it in vacuum state. X is the figure ranged from 0.1 to 0.9.

Description

Processable ester group substituted poly 3-alkylthiophene derivatives and preparation method thereof

1 is a photograph of the surface of the cast film after blending of polyoctylthiophene and polymethylmethacrylate,

2 is a photograph of the surface of the cast film after blending of poly (3- (2-propionyloxy) thiophene) and polymethylmethacrylate prepared in the present invention.

The present invention relates to a 3-alkylthiophene derivative substituted with an est group, a novel poly 3-alkylthiophene derivative polymerized from this derivative, and a method for producing the same. More specifically, the present invention relates to a novel polythiophene derivative having excellent processability and physical properties by introducing an ester group into a thiophene side chain and a method for producing the same.

In recent years, conductive polymer compounds that have been studied for over two decades have been exploded due to their application to solid electrolytic capacitors, secondary batteries, light emitting diodes, and sensors. However, such a conductive polymer compound is very interesting because its electrical conductivity is superior to other polymer materials, but its practicality is halved because its performance is very inferior to other polymer materials in general.

Various methods have been proposed to overcome these problems, and one of them is a method of increasing the processability of the compound by replacing an alkyl group with a long chain length in the side chain of the conductive polymer compound. Representative examples thereof include poly (3-alkylthiophene). The poly (3-alkylthiophene) having 4 or more carbon atoms in the alkyl chain is not only soluble in general organic solvents such as chloroform, toluene, hexane and tetrahydrofuran, but also can be melted by heat and its mechanical properties. It is a conductive polymer compound that is excellent and is expected to be very practical in the future.

Polym. Master, Sci. Eng., 53, 79 (1983); Chem. Express 1,635 (1985). Applications of poly (3-alkylthiophenes) dissolved in such solvents include secondary batteries (J. Electroch. Soc., 137, 3793 (1990)), field effect transistors [Synth. Met., 58, 187 (1993). ) And light emitting diodes (J. Appl. Phys. 72, 564 (1992)).

However, the introduction of such a hydrocarbon-only alkyl chain apolarized the properties of the poly (3-alkylthiophene), and also has a disadvantage that the conversion to other substituents is very difficult because the alkyl chain consisting of hydrocarbons is almost no reactivity.

The present inventors have intensively studied to solve the disadvantages of the prior art, and as a result, by introducing a chain having an ester group introduced into the side chain of polythiophene instead of an alkyl chain, the excellent processability of poly (3-alkylthiophene) At the same time, since the physical properties have a slight polarity, the physical properties can be improved, and it is found that the conversion to other substituents is facilitated by the continuous reaction, thereby completing the present invention.

That is, an object of the present invention is to synthesize a new thiophene monomer having an ester group introduced therein as a monomer of a conductive polymer compound, and polymerize the monomer by a chemical or electrochemical method to provide a conductive polymer having excellent processability and physical properties. Doing.

Monomers (I-A to I-J) used in the present invention can be represented by the following structural formula (I).

The alkylthiophene derivatives (IIA'-IIC ') used in the present invention can be represented by the following structural formula (II).

In more detail, the monomers (I-A- to IJ) are prepared to synthesize homopolymers (III-A to III-J) of the following structural formula (III), and the structural formula (I) Poly (3-alkylthiophene) derivatives (IV-AA 'to IV-J) of the following structural formula (IV) which are copolymers of monomers of (II) and 3-alkylthiophene derivatives (IIA' to II'C) -C ').

Wherein R is as defined in formula (I).

Wherein R is as defined in formula (I), R 'is as defined in formula (), and X has a value between 0.1 and 0.9.

The thiophene derivative represented by Structural Formula (I) was prepared using the following two methods.

Method A

3-thienylethanol and each corresponding organic acid were dissolved in benzene solution and then refluxed in the presence of some acid, and the water produced during this reaction was removed using a Dean-Stark apparatus. The resulting reaction was distilled under reduced pressure to obtain pure thiophene ester.

Method B

After 3-teenylethanol and triethylamine were dissolved in methylene chloride, each of the corresponding organic acid chlorides was dissolved in methylene chloride and added dropwise thereto at 0 ° C. The resulting reaction was distilled under reduced pressure to obtain pure thiophene ester.

Thus prepared monomers of formula (I) were synthesized using oxidative chemical polymerization and electrochemical polymerization to synthesize high molecular compounds of formula (III), and the monomers of formula (I) and 3-alkyl thi of formula (II) Offen was mixed in an appropriate ratio to synthesize a polythiophene copolymer of the formula (IV) by oxidation polymerization and electropolymerization.

The chemical polymerization method is carried out as follows. The monomer of the purified thiophene derivative is dripped at the acetonitrile solution in which anhydrous ferric chloride is melt | dissolved. The mixture is stirred for 3 to 24 hours, then poured into methanol to produce a precipitate which is then filtered to give an undissolved black solid. This solid is washed using a Soxhlet apparatus until no more yellow solution of ferric chloride is eluted with methanol. The remaining solid was vacuum dried at 40 ° C. for 24 hours to obtain 40-50% of a polythiophene derivative as a maroon solid.

The electrochemical polymerization is carried out as follows. After dissolving a thiophene derivative having a concentration of 0.05 to 2.0 M in an acetonitrile solution in which an electrolyte of 0.02 to 0.2 M concentration is dissolved, a platinum or stainless steel plate is used as a working electrode and a negative electrode to produce a constant current or constant voltage method. . When manufacturing using a constant current, the current density is set to 0.1 to 1 A / cm 2. The polythiophene derivative film produced on the electrode surface is peeled off from the electrode and purified.

The electrolyte is an alkylammonium salt such as perchlorate, hexafluorophosphate, toluenesulfonate or tetrafluoroborate.

The copolymer of Structural Formula (IV) was prepared by the above-mentioned oxidation polymerization or cell polymerization by mixing the monomer of Structural Formula (I) and 3-alkylthiophene of Structural Formula (II) in an appropriate ratio. Here, 3-hexylthiophene or 3-octylthiophene of the 3-alkylthiophenes used produced the best copolymers. In addition, the ratio of the alkylthiophene and the thiophene of structural formula (I) in this copolymer can be adjusted by changing the ratio of the monomer at the time of superposition | polymerization.

In order to confirm that the electrical conductivity of the polyalkylthiophene thus produced was increased by doping, the film obtained by casting several synthesized polythiophenes was doped with ferric chloride to measure the electrical conductivity. The results are shown in Table 1 below.

* POT: Polyoctylthiophene

After some synthesized polythiophene was spin coated onto the glass plate, the contact angle was measured to compare the affinity for water. From this result, it turns out how much the affinity of the polythiophene which substituted the ester group with respect to water changes. The contact angle measurement results for water are shown in Table 2 below.

As can be seen from the table, copolymers IV-AB and IV-IB have hydrophobicity similar to that of polyoctylthiophene, and homopolymers III-A, III-I and III-J are significantly It can be seen that the surface has a better hydrophilicity. Therefore, it can be seen that the hydrophilicity to water is improved due to the substitution of the ester group.

And, when the polythiophenes of the structural formulas (III) and (IV) substituted with ester groups are cast on glass, polyethylene terephthalate (PET) film and polyethylene (PE) film, the coating is more effective than polyoctylthiophene having only an alkyl chain. You can observe this much better. This is because the polar ester group is mixed with the copolymer rather than the cohesive alkyl group, and when cast on glass or polyethylene film, the solvent evaporates and the aggregation of the alkyl period does not occur, and the coating is spread evenly.

After dissolving polyoctylthiophene, III-A, IV-A-B and IV-I-B in tetrahydrofuran, the absorbance spectra in the visible region were measured and the results are shown in Table 3 below.

As can be seen from the table, the maximum absorption wavelengths of III-A, IV-I-B ', and IV-IB' having ester groups as substituents are shorter than those of polyoctylthiophene having only alkyl groups as substituents. Observed movement. This means that the double bond is shortened by substitution of the ester group. As a result, it can be seen that the band gap of the polythiophene substituted with the ester group was reduced.

It can be seen that the polythiophene substituted with the ester group having such a polar group is superior to the polyoctylthiophene in blending with a high molecular compound having a polar group such as polymethylmethacrylate. That is, less phase separation occurs in blending between polymer compounds having polar groups.

In FIG. 1, polyoctylthiophene and polymethyl methacrylate were dissolved in chloroform, and the surface of the cast film was enlarged 100 times. In FIG. 2, III-A and polymethyl methacrylate were dissolved in chloroform. The photograph which enlarged the surface of the cast film 100 times was shown. The introduction of the ester group results in much smaller and more uniform phase separation than polyoctylthiophene containing only alkyl groups, which has much better physical properties in blendin.

In the present invention, a polythiophene derivative substituted with an ester group was synthesized, and its redox and electro-optic properties were similar to those of conventional polyalkylthiophene, but because of its polarity, they were well mixed with a high molecular compound such as polymethylmethacrylate. In addition, it was possible to synthesize materials with improved physical properties, which are well coated on surfaces such as glass.

The invention is explained in more detail in the following non-limiting examples.

Example 1 (A) Riban Synthesis of Thiophene of Formula (I)

15 g of 2- (3-thienyl) ethanol were dissolved in 70 ml of purified dichloromethane, and 32.5 ml of triethylamine was added to the solution, followed by stirring well at 0 ° C. This solution was slowly added to the solution in which each corresponding carboxylic acid acyl chloride was diluted with 37 ml of dichloromethane. The reaction was stirred at 0 ° C. for 2 hours, then reacted at room temperature for about 12 hours, and then poured into 100 ml of distilled water. The dichloromethane layer was separated using a separating funnel, and the organic layer was washed with 5% hydrochloric acid solution and distilled water in that order. The separated organic solution was dried over anhydrous magnesium sulfate, filtered and the filtrate was concentrated under reduced pressure. The remaining yellow oil was distilled under vacuum to give thiophene esters (Ⅰ-A to I-J).

(Yield: about 80-95%).

Example 2 (B) General Synthesis of Thiophene Ester of Structural Formula (2)

Water produced while dissolving 2- (3-thienyl) ethane (0.1M), organic carboxylic acid (0.11M) and toluenesulfonic acid (0.001M) in benzene 150, was then refluxed through a Dean-Stark apparatus. Removed. After reacting for about 10 hours, when no more water is produced in the reaction, the temperature of the reaction is cooled to room temperature, washed with distilled water and saturated aqueous sodium bicarbonate (NaHCO 3) solution, and then dried over anhydrous sodium sulfate. . After filtration of the reaction, the filtrate was removed using a rotary evaporator to remove the material with low boiling point, followed by distillation of the oil in vacuo to give thiophene ester ().

Example 3 General Preparation of Polythiophene Derivatives of Structural Formula (III)

Anhydrous ferric chloride (24 mM) was placed in a three-necked flask, and 40 ml of acetonitrile was added and dissolved in a nitrogen atmosphere, and the monomer (6 mM) of the thiophene derivative purified at 0 ° C was slowly added dropwise. The mixture was stirred for 24 hours, then poured into 500 ml of methanol to precipitate and then filtered to give a black solid. This black solid was washed with Soxhlet apparatus using methanol until no more yellow solution of ferric chloride was eluted. The remaining solid was dried in a vacuum oven at 40 ° C. for 24 hours to obtain polythiophene (yield: 40-50%).

Examples 3.1 to 3.10

Example 3.1

Poly (3- (2-propionyloxyethyl) thiophene) was synthesized using the method of Example 3 above.

-Weight average molecular weight 78,000

-Elemental Analysis for (C ₉ H ₁₀ O ₂ S) n:

Yield = 47%

Example 3.2

Poly (3- (2-butyryloxyethyl) thiophene) was synthesized using the method of Example 3 above.

-Weight average molecular weight 74,000

-Elemental Analysis for (C ₁₀ H ₁₂ O ₂ S) n:

Yield = 46%

Example 3.3

Poly (3- (2-pentanoyloxyethyl) thiophene) was synthesized using the method of Example 3 above.

-Weight average molecular weight 72,000

-Elemental Analysis for (C ₁₁ H ₁₄ O ₂ S) n:

Yield = 45%

Example 3.4

Poly (3-2 (-hexanoyloxyethyl) thiophene) was synthesized using the method of Example 3 above.

-Weight average molecular weight 70,000

-Elemental Analysis for (C ₁₂ H ₁₆ O ₂ S) n:

Yield = 42%

Example 3.5

Poly (3-2 (-heptanoyloxyethyl) thiophene) was synthesized using the method of Example 3 above.

-Weight average molecular weight 77,000

-Elemental Analysis for (C ₁₃ H ₁₈ O ₂ S) n:

Yield = 47%

Example 3.6

Poly (3-2 (-octanoyloxyethyl) thiophene) was synthesized using the method of Example 3 above.

-Weight average molecular weight 68,000

-Elemental Analysis for (C ₁₄ H ₂₀ O ₂ S) n:

Yield = 47%

Example 3.7

Poly (3-2 (-nonanyloxyethyl) thiophene) was synthesized using the method of Example 3 above.

-Weight average molecular weight : 67,000

-Elemental Analysis for (C ₁₅ H ₂₂ O ₂ S) n:

Yield = 47%

Example 3.8

Poly (3-2 (-decanoyloxyethyl) thiophene) was synthesized using the method of Example 3 above.

-Weight average molecular weight 75,000

-Elemental Analysis for (C ₁₆ H ₂₆ O ₂ S) n:

Yield = 48%

Example 3.9

Poly (3-2 (-acryloyloxyethyl) thiophene) was synthesized using the method of Example 3 above.

-Weight average molecular weight 40,000

-Elemental Analysis for (C ₉ H ₈ O ₂ S) n:

Yield = 45%

Example 3.10

Poly (3-2 (-isovaleryloxyethyl) thiophene) was synthesized using the method of Example 3 above.

-Weight average molecular weight 71,000

-Elemental Analysis for (C ₁₁ H ₁₄ O ₂ S) n:

Yield = 47%

Example 4 General Preparation of Polythiophene Copolymers of Structural Formula (IV)

The polythiophene copolymer of the structural formula (IV) was synthesize | combined by the method similar to Example 3, but adding the monomer of structural formula (I) and the structural formula (II) in an appropriate ratio. The water specificity of this copolymer was 50 to 70%, and the proportion of monomers in the polymer can be adjusted according to the reactivity of each monomer and the concentration at the time of polymerization. That is, X in Structural Formula (IV) can be adjusted as desired from 0.1 to 0.9. The following examples describe the synthesis of copolymers where X is 0.5.

Examples 4.1 to 4.10

Example 4.1

-The poly [3- (2-propionyloxyethyl) thiophenoco- (3-octylthiophene)] was synthesized using the method of Example 4 above.

-Weight average molecular weight 54,000

-Elemental Analysis for (C ₂₁ H ₂₈ O ₂ S ₂ ) n:

Yield = 54%

Example 4.2

Poly [3- (2-acryloyloxyethyl) thiophene-co- (3-octylthiophene)] was synthesized using the method of Example 4 above.

-Weight average molecular weight 55,000

-Elemental Analysis for (C ₂₁ H ₂₆ O ₂ S ₂ ) n:

Yield = 52%

Example 4.3

Poly [3- (2-isovaleryloxyethyl) thiopheno- (3-octylthiophene)] was synthesized using the method of Example 4 above.

-Weight average molecular weight 40,000

-Elemental Analysis for (C ₂₃ H ₃₂ O ₂ S ₂ ) n:

Yield = 50%

Example 4.4

Poly [3- (2-butyryloxyethyl) thiophene-co- (3-octylthiophene)] was synthesized using the method of Example 4 above.

-Weight average molecular weight : 50,000

-Elemental Analysis for (C ₂₂ H ₃₀ O ₂ S ₂ ) n:

Yield = 50%

Example 4.5

Poly [3- (2-pentanoylethylethyl) thiophenoco- (3-octylthiophene)] was synthesized using the method of Example 4 above.

-Weight average molecular weight 51,000

-Elemental Analysis for (C ₂₃ H ₃₂ O ₂ S ₂ ) n:

Yield = 53%

Example 4.6

Poly [3- (2-hexanoyloxyethyl) thiophenoco- (3-octylthiophene)] was synthesized using the method of Example 4 above.

-Weight average molecular weight : 50,000

-Elemental Analysis of (C ₂₄ H ₃₄ O ₂ S ₂ ) n:

Yield = 50%

Example 4.7

-The poly [3- (2-hemtanoyloxyethyl) thiophenone- (3-octylthiophene)] was synthesized using the method of Example 4 above.

-Weight average molecular weight 52,000

-Elemental Analysis for (C ₂₅ H ₃₆ O ₂ S ₂ ) n:

Yield = 50%

Example 4.8

Poly [3- (2-octanoyloxyethyl) thiophenoco- (3-octylthiophene)] was synthesized using the method of Example 4 above.

-Weight average molecular weight 54,000

-Elemental Analysis for (C ₂₆ H ₃₈ O ₂ S ₂ ) n:

Yield = 52%

Example 4.9

-The poly [3- (2-nonanyloxyethyl) thiophenone- (3-octylthiophene)] was synthesized using the method of Example 4 above.

-Weight average molecular weight 57,000

-Elemental Analysis for (C ₂₇ H ₄₀ O ₂ S ₂ ) n:

Yield = 55%

Example 4.10

Poly [3- (2-decanoyloxyethyl) thiophenoco- (3-octylthiophene)] was synthesized using the method of Example 4 above.

-Weight average molecular weight : 50,000

-Elemental Analysis for (C ₂₈ H ₄₂ O ₂ S ₂ ) n:

Example 5 Electrochemical Synthesis of Polythiophene Copolymers of Structural Formula (IV)

After dissolving the thiophene monomer in the acetonitrile solution in which the supporting electrolyte (0.1M) is dissolved, polythiophene is produced by the constant current method (0.1 mA to 1 A / cm 2) or the constant voltage method (1.6 V relative to the caramel reference electrode). I was. After the film was produced, it was completely reduced in the same electrolyte solution, washed with methanol, peeled off from the electrode, and washed with methanol again. After washing, the film was dried in vacuo to afford purified polythiophene. The polythiophene thus prepared showed almost the same properties as the polythiophene prepared in Example 3.

The polythiophene derivative substituted with the ester group thus prepared showed the following characteristics.

First, the maximum absorption wavelength of the plealkylthiophene was shortened by the substitution of the burner ester group in the absorption spectrum of the visible region, which means that the connection of the double bond was shortened. As a result, it can be seen that the band cap of polythiophene was reduced.

Second, since the polyalkylthiophene was modified to have polarity by the introduction of a polar ester group, such polymers exhibited better adhesion and coating properties than conventional polyalkylthiophenes consisting solely of hydrocarbons.

Third, the introduction of a polar ester group facilitates blending with a high molecular compound having the same polarity as polymethylmethacrylate.

This feature can be very useful for the newly synthesized ester substituted polythiophene as a material of a photodiode, a sensor, a field effect transistor or a light emitting diode.

Claims (3)

To the acetonitrile solution in which anhydrous ferric chloride was dissolved in a nitrogen atmosphere, a monomer of the following structural formula (I) was added, or a monomer of the structural formula (I) and 3-alkylthiophene of the following structural formula (II) were added in an appropriate ratio. To form a precipitate, which is filtered, washed with methanol, and dried in vacuo, thereby producing a polyalkylthiophene derivative substituted with an ester group of the following structural formula (III) or (IV). Wherein R is as defined in formula (I). Wherein R is as defined in formula (I), R 'is as defined in formula (II), and X has a value between 0.1 and 0.9. The polyalkylthiophene derivatives of formula (III) include poly (3-2 (-propionyloxyethyl) thiophene), poly (3-2 (-butylyloxyethyl) thiophene), poly (3-2 (- Pentanoyloxyethyl) thiophene), poly (3-2 (-hexanoyloxyethyl) thiophene), poly (3-2 (-heptanoyloxyethyl) thiophene), poly (3-2 (-octanyl oil) Oxyethyl) thiophene), poly (3-2 (-nonanyloxyethyl) thiophene), poly (3-2 (-decaneyloxyethyl) thiophene), poly (3-2 (-acryloyloxy Ethyl) thiophene) or poly (3-2 (-isovaleryloxyethyl) thiophene). The polyalkylthiophene derivatives of formula (IV) are poly [3- (2-propionyloxyethyl) thiophene- (3-octylthiophene), poly [3- (2-acryloyloxyethyl) thiophene Co- (3-octylthiophene), poly [3- (2-isovaleryloxyethyl) thiophene ball- (3-octylthiophene), poly [3- (2-butyryloxyethyl) thiophene ball -(3-octylthiophene), poly [3- (2-pentanoyloxyethyl) thiophene ball- (3-octylthiophene), poly [3- (2-hexaneyloxyethyl) thiophene ball- ( 3-octylthiophene), poly [3- (2-heptanoyloxyethyl) thiophene- (3-octylthiophene), poly [3- (2-octanyloxyethyl) thiophene-g- (3- Octylthiophene), poly [3- (2-nonanyloxyethyl) thiophene- (3-octylthiophene) or poly [3- (2-decaneylyloxyethyl) thiophene- (3-octylthione) Offen).