JP6753191B2 - Thiophene compound - Google Patents

Description

The present invention relates to thiophene compounds.

In recent years, self-doping conductive polymers have been used in applications such as antistatic agents, solid electrolytes for capacitors, conductive coating materials, transparent electrodes, transparent conductive films, chemical sensors, actuators, and organic EL, and the self-doping type is used. A thiophene compound is used as a monomer for a conductive polymer. Examples of such a monomer include a compound having an alkyloxymethyl sulfonate group at the 2-position of 2,3-dihydro-thieno [3,4-b] -1,4-dioxin, and a hydroxymethyl group at the 2-position. (Self-doped conductive polymer comonomer) and the like are known (see Patent Documents 1 and 2).

Japanese Patent No. 4974095 Japanese Unexamined Patent Publication No. 2014-065898

The conventionally known self-doping conductive polymer is usually polymerized in an aqueous solvent, but for the polymerization reaction, a polymer having a higher degree of polymerization tends to be obtained as the monomer concentration is higher. It is expected that the conductivity will be improved by increasing the molecular weight of the polymer in this way. That is, while there is a technical demand for increasing the monomer concentration during the polymerization reaction, there is a problem that it is difficult to increase the monomer concentration during the polymerization reaction because the solubility of the conventional thiophene monomer is not so high.

The present inventor has completed the present invention as a result of repeated diligent studies to solve the above problems. That is, the present invention relates to a novel thiophene compound used as a conductive material as shown below.
[1] The following formula (1)

[In the above formula (1), R ³ and R ⁴ are the same or different, and represent a hydrogen atom or a group represented by the following general formula (2).

{In formula (2), M ¹ represents a hydrogen ion, an alkali metal ion, a conjugate acid of an amine compound, or a quaternary ammonium cation. R ¹ represents a hydrogen atom, a linear or branched alkyl group having 1 to 6 carbon atoms, or a halogen atom. m represents an integer of 1 to 6. }]]
A thiophene compound represented by.
[2] The thiophene compound according to [1], wherein m is 2 or 3.
[3] The thiophene compound according to [1] or [2], wherein R ¹ is a methyl group.

The applicant of the present application has found that the thiophene compound described in the present invention has a higher water solubility than a conventionally known thiophene monomer, and has an effect of easily increasing the monomer concentration during the polymerization reaction. Further, it has been found that since it is excellent in compatibility with a conventionally known thiophene monomer, it is easy to increase the monomer concentration even in a copolymerization reaction with a conventionally known thiophene monomer.

Further, the conductive polymer using the thiophene compound of the present invention as a monomer has a higher self-doping rate than the conventionally known conductive polymer, and has an effect of remarkably exhibiting high conductivity performance.

Hereinafter, the present invention will be described in detail. The thiophene compound of the present invention is a thiophene compound represented by the above formula (1).

In the above formula (1), R ³ and R ⁴ are the same or different, and represent a hydrogen atom or a group represented by the above general formula (2).

In the above formula (2), M ¹ represents a hydrogen ion, an alkali metal ion, a conjugate acid of an amine compound, or a quaternary ammonium cation.

In the above formula (2), R ¹ represents a hydrogen atom, a linear or branched alkyl group having 1 to 6 carbon atoms, or a halogen atom. The R ¹ is the same or different from each other in that the thiophene compound of the present invention has excellent solubility, and is preferably a hydrogen atom, a linear or branched alkyl group having 2 to 5 carbon atoms, or a halogen atom. The same or different, it is more preferably a hydrogen atom or a linear or branched alkyl group having 2 to 4 carbon atoms.

In the above equation (2), m represents an integer of 1 to 6. The m is the same or different, preferably an integer of 2 to 5, and more preferably the same or different, 2 or 3, in that the thiophene compound of the present invention is excellent in solubility.

Incidentally, as described above, R ³ and for R ⁴ is optionally the same or different and when there are two R ^1, two M ^1, and two m in the molecule, two R ¹ two M ^1, and for the two m, both may each be the same or different.

The alkali metal ion is not particularly limited, and examples thereof include Li ion, Na ion, and K ion.

The conjugated acid of the amine compound may be an amine compound in which hydron (H ⁺ ) is added to the amine compound to form a cationic species, and the amine compound reacts with a sulfonic acid group to form a conjugated acid. Although not particularly limited, it is represented by an amine compound represented by N (R ⁵ ) ₃ having a sp3 mixed orbital [as a conjugated acid [NH (R ⁵ ) ₃ ] ⁺ . ], Or a pyridine compound having an sp2 hybrid orbital, an imidazole compound, and the like.

The substituent R ⁵ is not particularly limited, for example, each independently, a hydrogen atom, exemplified such as an alkyl group having 1 to 6 carbon atoms and having an alkyl group, or a substituent having 1 to 6 carbon atoms be able to.

The alkyl group having 1 to 6 carbon atoms is not particularly limited, but for example, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, and the like. Examples thereof include a tert-butyl group, an n-pentyl group, an isopentyl group, a neopentyl group, a tert-pentyl group, a cyclopentyl group, an n-hexyl group, a 2-ethylbutyl group, a cyclohexyl group and the like.

The alkyl group having 1 to 6 carbon atoms having the above substituent is not particularly limited, but is selected from the group consisting of, for example, a halogen atom, an alkyl group having 1 to 6 carbon atoms, an amino group, and a hydroxy group. Examples thereof include an alkyl group having 1 to 6 carbon atoms having the above-mentioned group, and specific examples thereof include, but are not limited to, a trifluoromethyl group and a 2-hydroxyethyl group.

Of these, from the viewpoint of excellent thiophene compound solubility present invention, examples of the substituent R ^5, each independently, a hydrogen atom, a methyl group, an ethyl group, or a 2-hydroxyethyl group.

The amine compound represented by N (R ⁵ ) ₃ forming the conjugate acid of the amine compound is not particularly limited, but for example, ammonia, methylamine, dimethylamine, ethylamine, triethylamine, normal-propylamine, etc. Isopropylamine, normal butylamine, tertiary butylamine, hexylamine, ethanolamine compounds (eg aminoethanol, dimethylaminoethanol, methylaminoethanol, diethanolamine, N-methyldiethanolamine, triethanolamine), 3-amino-1,2- Examples thereof include propanediol, 3-methylamino-1,2-propanediol, 3-dimethylamino-1,2-propanediol, 1,4-butanediamine and the like.

The amine compound having an sp2 mixed orbital forming a conjugate acid of the amine compound is not particularly limited, but is not particularly limited, but is an imidazole compound (for example, imidazole, N-methylimidazole, 1,2-dimethylimidazole, etc.), pyridine, picoline, etc. , Lucidin and the like are exemplified.

Among these, amine compounds used for the conjugate acid of amine compounds include ethanolamine compounds (monoethanolamine, diethanolamine, and triethanolamine), imidazole compounds (imidazole, N-methylimidazole, and 1,2-dimethylimidazole). ) Is preferable.

The quaternary ammonium cation is not particularly limited, and examples thereof include a tetramethylammonium cation, a tetraethylammonium cation, a tetranormal propylammonium cation, a tetranormal butyl ammonium cation, and a tetranormal hexyl ammonium cation. Be done. From the viewpoint of availability, a tetramethylammonium cation or a tetraethylammonium cation is preferable.

The linear and branched alkyl groups having 1 to 6 carbon atoms in R ¹ are not particularly limited, but are methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, and the like. sec-butyl group, tert-butyl group, n-pentyl group, isopentyl group, neopentyl group, tert-pentyl group, cyclopentyl group, n-hexyl group, 2-ethylbutyl group, cyclohexyl group, n-octyl group, etc. Can be mentioned.

Examples of the halogen atom in R ¹ include a fluorine atom, a chlorine atom, a bromine atom and the like.

R ¹ is preferably the same or different from each other in terms of industrial availability, and is preferably a hydrogen atom, a methyl group, an ethyl group, or a fluorine atom.

m is the same or different and represents an integer of 1-6. The m is the same or different, preferably an integer of 1 to 4, and more preferably the same or different, 2 or 3, in that the thiophene compound of the present invention is excellent in solubility.

The thiophene compound of the present invention is not particularly limited, and examples thereof include the following compounds.

The thiophene compound exemplified above can be produced according to a known method (for example, Journal of Electrical Chemistry, 443, 217-226 (1998)). Among the thiophene compounds of the present invention, the thiophene compound represented by the following formula (4) is derived from 2,3-bis (hydroxymethyl) -thieno [3,4-b] -1,4-dioxin and sultone compounds. Can be synthesized. Further, if necessary, for the thiophene compound represented by the following formula (4) can be guided to the acid M ³ is a hydrogen atom by acid treatment. Further, an amine salt can be obtained by treating this sulfonic acid with an amine.

[In the above formula (4), M ³ represents an alkali metal ion. R ² represents a hydrogen atom, a linear or branched alkyl group having 1 to 6 carbon atoms, or a halogen atom. ]
In addition, the thiophene compound of the present invention can be produced by changing the type and amount of the reagent used in the above reaction.

The thiophene compound of the present application is only the thiophene compound represented by the above general formula (1) in an aqueous or polar solvent in the presence or absence of a polyanion, or is not particularly limited, but is described in the following formula ( A polymer can be obtained by chemically oxidatively polymerizing a mixture with another thiophene compound represented by 5), (6), (7), (8) and the like.

[In the formula, R is synonymous with R ¹ described above, and M is synonymous with M ¹ described above. ]
The weight average molecular weight of the conductive polymer made from the thiophene compound of the present invention is not particularly limited, but is usually in the range of 10 to 1 million in terms of polystyrene sulfonic acid, and the polymer to unreacted monomers and the like. From the viewpoint of removing low molecular weight impurities and inorganic salts, it is more preferably in the range of 1,000 to 200,000.

The conductive polymer made from the thiophene compound of the present invention is only the thiophene compound represented by the above general formula (1) in an aqueous solvent or a polar solvent in the presence of an oxidizing agent, or with other thiophene compounds. It can be produced by chemically oxidizing and polymerizing in a mixed state.

The thiophene compound different from the above general formula (1) is not particularly limited, but for example, 3-[(2,3-dihydrothieno [3,4-b]-[1,4] dioxin-2- Il) methoxy] -1-methyl-1-sodium propanesulfonate, 3-[(2,3-dihydrothieno [3,4-b]-[1,4] dioxin-2-yl) methoxy] -1-ethyl Sodium -1-propanesulfonate, 3-[(2,3-dihydrothieno [3,4-b]-[1,4] dioxin-2-yl) methoxy] -1-propyl-1-sodium propanesulfonate, 3-[(2,3-dihydrothieno [3,4-b]-[1,4] dioxin-2-yl) methoxy] -1-butyl-1-sodium propanesulfonate, 3-[(2,3-) Dihydrothieno [3,4-b]-[1,4] dioxin-2-yl) methoxy] -1-pentyl-1-sodium propanesulfonate, 3-[(2,3-dihydrothieno [3,4-b]] -[1,4] Dioxin-2-yl) methoxy] -1-hexyl-1-sodium propanesulfonate, 3-[(2,3-dihydrothieno [3,4-b]-[1,4] dioxin- 2-Il) methoxy] -1-isopropyl-1-sodium propanesulfonate, 3-[(2,3-dihydrothieno [3,4-b]-[1,4] dioxin-2-yl) methoxy] -1 -Sodium isobutyl-1-propanesulfonate, 3-[(2,3-dihydrothieno [3,4-b]-[1,4] dioxin-2-yl) methoxy] -1-isopentyl-1-propanesulfonic acid Sodium, 3-[(2,3-dihydrothieno [3,4-b]-[1,4] dioxin-2-yl) methoxy] -1-fluoro-1-sodium propanesulfonate, 3-[(2,2) 3-Dihydrothieno [3,4-b]-[1,4] dioxin-2-yl) methoxy] -1-methyl-1-potassium propanesulfonate, 3-[(2,3-dihydrothieno [3,4-] b]-[1,4] dioxin-2-yl) methoxy] -1-methyl-1-propanesulfonic acid, 3-[(2,3-dihydrothieno [3,4-b]-[1,4] dioxin -2-yl) methoxy] -1-methyl-1-propanesulfonate ammonium, or 3-[(2,3-dihydrothieno [3,4-b]-[1,4] dioxin-2-yl) methoxy] -1-Methyl-1-propanesulfonic acid Examples thereof include lithium ammonium.

The solvent used in the polymerization reaction is preferably water or a solvent containing water. Examples of water include pure water, and distilled water and ion-exchanged water may be used. Further, the solvent may contain a solvent other than water, and for example, an alcohol solvent may be contained. Examples of the alcohol solvent include methanol, ethanol, propanol, butanol and the like. Further, the solvent may be degassed or replaced with an inert gas such as nitrogen.

The amount of the solvent used in the polymerization reaction is preferably, for example, an amount that dissolves the thiophene compound used in the polymerization reaction such as the thiophene compound represented by the general formula (1), and is not particularly limited, but is polymerized. The range is preferably 0.1 to 100 times by weight, more preferably 1 to 20 times by weight, based on the total amount of the thiophene compound charged in the reaction.

The oxidizing agent used in the polymerization reaction is one that promotes oxidative polymerization by an oxidative dehydrogenation reaction, and is not particularly limited, but for example, persulfates, iron salts (III), hydrogen peroxide, and the like. Examples thereof include permanganate, dichromate, cerium (IV) sulfate, oxygen and the like, and these may be used alone or in combination of two or more.

Here, examples of persulfates include persulfate, ammonium persulfate, sodium persulfate, potassium persulfate and the like.

Specific examples of the iron salt (III) include FeCl ₃ , Fe ₂ (SO ₄ ) ₃ , iron perchlorate, and iron para-toluenesulfonate (III). These may use anhydrides or hydrates.

Specific examples of the permanganate include sodium permanganate, potassium permanganate, magnesium permanganate, and the like.

Specific examples of the dichromate include ammonium dichromate and potassium dichromate.

Among these oxidizing agents, FeCl ₃ , Fe ₂ (SO ₄ ) ₃ , or a combination system of persulfate and iron salt (III) is particularly preferable in that a polymer having a higher molecular weight can be obtained.

The amount of the oxidizing agent used in the polymerization reaction is not particularly limited, but is based on the number of moles of the thiophene compound (monomer) charged in the polymerization reaction such as the thiophene compound represented by the general formula (1). , 0.5 to 50 times the molar amount, more preferably 1 to 20 times the molar amount. More preferably, it is 1 to 10 times mol.

The pressure of the polymerization reaction may be normal pressure, reduced pressure, or pressurized.

The reaction atmosphere of the polymerization reaction may be in the atmosphere or in an inert gas such as nitrogen or argon. More preferably, it is in an inert gas.

The reaction temperature of the polymerization reaction is not particularly limited, but is preferably in the range of −10 to 150 ° C., and more preferably in the range of 5 to 100 ° C.

The reaction time of the polymerization reaction is not particularly limited, but is preferably in the range of 0.5 to 200 hours, more preferably in the range of 0.5 to 80 hours.

The reaction method of the polymerization reaction is not particularly limited, but for example, a thiophene compound such as the thiophene compound represented by the general formula (1) is dissolved in water in advance, and an oxidizing agent is added thereto at once or slowly. On the contrary, an aqueous solution of a thiophene compound such as the thiophene compound represented by the above general formula (1) may be added dropwise to the solid or aqueous solution of the oxidizing agent at once or slowly. When two or more kinds of oxidizing agents are used, each oxidizing agent may be added in sequence.

The method for purifying the water-soluble conductive polymer of the present invention obtained by the polymerization reaction is not particularly limited, but for example, solvent washing, reprecipitation, centrifugation, ultrafiltration, dialysis, and ion exchange resin. Processing and the like can be mentioned. Each may be performed alone or in combination.

A typical isolation and purification method for the water-soluble conductive polymer of the above invention is as follows, for example.

First, the aqueous solution after the polymerization reaction is added to a poor solvent such as acetone to precipitate a water-soluble conductive polymer, and then the copolymer obtained by vacuum filtration is washed with the poor solvent until the filtrate becomes colorless and transparent. To do. As another method, the aqueous solution after the polymerization reaction may be desalted by ultrafiltration or dialysis.

When the Na salt-type water-soluble conductive polymer thus obtained is subsequently converted into an H-type water-soluble conductive polymer in which M is a hydrogen ion, it is treated with a cation exchange resin. Examples of the treatment method include a method of passing an aqueous solution of the obtained Na salt-type water-soluble conductive polymer through a column filled with a cation exchange resin, and a body feed method of adding a cation exchange resin to the aqueous solution. And so on. In this case, it is preferable to remove the cation exchange resin with a filter paper after the treatment. The aqueous solution thus obtained is roughly concentrated, added to a poor solvent such as acetone to precipitate, and the solid obtained by vacuum filtration is thoroughly washed with the poor solvent, dried under reduced pressure, and H-type water-soluble conductive. A polymer is obtained.

Further, when forming a salt with various ammonium salts, for example, an aqueous solution of an H-salt type water-soluble conductive polymer diluted with a stock solution of various amine compounds or ammonium salts, an aqueous solution thereof, or another suitable solvent. readily M by adding it can be converted to ammonium salt type water-soluble electroconductive polymer is a NH ₄ ^+. For example, in the case of treatment with aqueous ammonia, the reaction solution is roughly concentrated, the aqueous solution is added to a poor solvent such as acetone to precipitate the copolymer, and then the solid obtained by vacuum filtration is prepared with the poor solvent. An ammonium salt-type water-soluble conductive polymer can be obtained by washing and drying under reduced pressure.

Centrifugal sedimentation and homogenization may be performed in each step of the post-polymerization treatment, if necessary. As a result, the filtration efficiency can be improved. Furthermore, when persulfate is used as the polymerization oxidant, ultrafiltration, dialysis, and cation / anion exchange resin mixing treatment are performed to remove the inorganic salt.

As described above, an aqueous solution of a conductive polymer using the thiophene compound represented by the general formula (1) as a monomer can be produced, and the aqueous solution of the conductive polymer can be used for various purposes. It can be used and expanded.

The method for preparing the aqueous conductive polymer solution is not particularly limited, but it is achieved by mixing and dissolving it with water at room temperature or under heating (preferably 100 ° C. or lower). At that time, a general mixing / dissolving operation using a stirrer tip or a stirring blade can be used, and as other methods, ultrasonic irradiation and homogenization treatment (for example, use of a mechanical homogenizer, an ultrasonic homogenizer, a high-pressure homogenizer, etc.) May be done. When the homogenization treatment is performed, it is preferable to carry out the homogenization treatment while cooling the polymer in order to prevent thermal deterioration.

The concentration of the water-soluble conductive polymer of the present invention in the aqueous solution of the conductive polymer is not particularly limited, but is usually 50% by weight or less, preferably 20% by weight or less, more preferably 10 from the viewpoint of viscosity. It is less than% by weight.

A conductive coating can be produced using the water-soluble conductive polymer of the present invention. For example, a conductive film can be easily obtained by applying and drying the above-mentioned water-soluble conductive polymer aqueous solution to a base material. Examples of the base material include glass, plastic, polyester, polyacrylate, polycarbonate, resist substrate and the like. Examples of the coating method include a casting method, a dipping method, a barcode method, a roll coating method, a gravure coating method, a flexographic printing method, a spray coating method, an inkjet printing method and the like. Not particularly limited as ^thickness, but 10 - 2-10 ² range of μm are preferred. The surface resistance value of the obtained coating film is not particularly limited, but is preferably in the range of 1 to ⁹ Ω / □.

Sufficient water solubility for molding to various uses means that the particle size (D50) measured by a particle size distribution measuring device is 5 nm or less in an aqueous polymer solution of 10% by weight or less prepared at room temperature or under heating. In addition, it is water-soluble enough to pass a 0.02 μm filter.

Further, good conductivity means conductivity in which the conductivity (electrical conductivity) in the film state is 10 ^-3 S / cm or more.

Examples of the present invention will be described in more detail below, but the present invention is not construed as being limited to these examples. The analytical instruments used in this embodiment are listed below.
[NMR measurement]
Equipment: VXR-300S manufactured by VARIAN
[GC-MS]
Equipment: JMS-K9 manufactured by JEOL Ltd.
[Q-TOF LC / MS]
Equipment: Compact made by Bruker Daltonics
Example 1 Synthesis of 2,3-bis (hydroxymethyl) -2,3-dihydro-thieno [3,4-b] -1,4-dioxin Raw material 2,3-bis (hydroxymethyl) -2,3 -Dihydro-thieno [3,4-b] -1,4-dioxin was synthesized by the production method represented by the following formula (5).

a) Synthesis of 2,3-bis (chloromethyl) -2,3-dihydro-thieno [3,4-b] -1,4-dioxin Under a nitrogen atmosphere, 3,4-dimethoxythiophene 22 in a 500 ml eggplant-shaped flask. .7 g (157.2 mmol), 1,4-dichloro-2,3-butanediol 75.0 g (471.7 mmol), p-toluenesulfonic acid monohydrate 4.5 g (23.6 mmol), and toluene 300 g After charging, the mixture was stirred at 95 ° C. for 24 hours. After allowing to cool, 57 g of a 7 wt% sodium hydrogen carbonate aqueous solution was added and stirred, then extracted with toluene, washed with water, and then dehydrated with anhydrous magnesium sulfate. Subsequently, silica gel column chromatography purification gave 2,3-bis (chloromethyl) -2,3-dihydro-thieno [3,4-b] -1,4-dioxin as 21.3 g of a yellow oil. It was confirmed by NMR that it was the target product.
^{1 1} H-NMR (CDCl ₃ ) δ (ppm); 6.38 (s, 2H), 4.45 (t, 2H, J = 3.8Hz), 3.79 (d, 4H, J = 3.8Hz) )
¹³ C-NMR (CDCl ₃ ) δ (ppm); 42.27, 72.98, 101.13, 139.88
b) Synthesis of 2,3-bis (acetoxymethyl) -2,3-dihydro-thieno [3,4-b] -1,4-dioxin Under a nitrogen atmosphere, 2,3-bis (chloro) was placed in a 200 ml eggplant-shaped flask. After charging 7.8 g (32.7 mmol) of methyl) -2,3-dihydro-thieno [3,4-b] -1,4-dioxin, 9.6 g (98.1 mmol) of potassium acetate, and 119 g of dimethyl sulfoxide. , 98 ° C. for 5.5 hours. After allowing to cool, the mixture was extracted with toluene, washed with water, and dehydrated with anhydrous sodium sulfate. Subsequently, silica gel column chromatography purification gave 2,3-bis (acetoxymethyl) -2,3-dihydro-thieno [3,4-b] -1,4-dioxin as 6.2 g of a yellow solid. It was confirmed by NMR and GC-MS that it was the target product.
^{1 1} H-NMR (CDCl ₃ ) δ (ppm); 6.40 (s, 2H), 4.29-4.38 (m, 6H), 2.10 (s, 6H)
¹³ C-NMR (CDCl ₃ ) δ (ppm); 20.94, 62.70, 72.23, 100.67, 140.49, 170.72
GC-MS (EI, PCI): Mw = 286 was detected in 2,3-bis (acetoxymethyl) -2,3-dihydro-thieno [3,4-b] -1,4-dioxin (C12H14O6S). It was attributable.

c) Synthesis of 2,3-bis (hydroxymethyl) -2,3-dihydro-thieno [3,4-b] -1,4-dioxin Under a nitrogen atmosphere, 2,3-bis (acetoxy) was placed in a 200 ml eggplant-shaped flask. Methyl) -2,3-dihydro-thieno [3,4-b] -1,4-dioxin 8.0 g (28.0 mmol), sodium hydroxide 5.7 g (139.9 mmol), toluene 5 g, methanol 78 g After charging, the mixture was stirred at 65 ° C. for 4 hours. According to the law, after distilling off the solvent and concentrating, dichloromethane was added and then neutralized with 10 wt% hydrochloric acid. Subsequently, it was extracted with dichloromethane, washed with water, and dehydrated with sodium sulfate. Further, silica gel column chromatography purification gave 2,3-bis (hydroxymethyl) -2,3-dihydro-thieno [3,4-b] -1,4-dioxin as 2.3 g of a yellow solid. It was confirmed by NMR and GC-MS that it was the target product.
^{1 1} H-NMR (CD ₃ OD) δ (ppm); 6.40 (s, 2H), 4.10-4.12 (m, 2H), 3.86-3.93 (m, 4H), 3 .34 (s, 2H)
¹³ C-NMR (CD ₃ OD) δ (ppm); 60.74,75.27,99.08,141.70
GC-MS (EI): Mw = 202 detected and can be attributed to 2,3-bis (hydroxymethyl) -2,3-dihydro-thieno [3,4-b] -1,4-dioxin (C8H10O4S) Met.

Example 2 3,3'-[(2,3-dihydrothieno [3,4-b] -1,4-dioxin-2,3-diyl) dimethoxy] -bis (sodium 1-methyl-1-propanesulfonate) ) Synthesis In a nitrogen atmosphere, after charging 1.1 g (27.2 mmol) of 60% sodium hydroxide and 10 ml of tetrahydrofuran in a 200 ml eggplant-shaped flask, 2,3-bis (hydroxymethyl) -2,3-dihydro-thieno A mixture consisting of 2.2 g (10.9 mmol) of [3,4-b] -1,4-dioxin and 20 ml of tetrahydrofuran was added. Then, the reaction solution was raised to the reflux temperature, and the mixture was stirred at the same temperature for 1 hour. Then, a mixed solution consisting of 3.4 g (25.0 mmol) of 2,4-butanesulton and 20 ml of tetrahydrofuran was added dropwise, and the mixture was stirred at the same temperature for 3.5 hours. After cooling, the obtained reaction solution was added dropwise to acetone to reprecipitate. By filtering and vacuum-drying the obtained powder, 3,3'-[(2,3-dihydrothieno [3,4-b] -1,4-dioxin-2,3-diyl) dimethoxy] -bis ( 1-Methyl-1-sodium propanesulfonate) was obtained as a pale yellow solid of 3.9 g. It was confirmed by NMR and LC-MS that it was the target product.
^{1 1} H-NMR (D ₂ O) δ (ppm); 6.46 (s, 2H), 4.25-4.29 (m, 2H), 3.62-3.73 (m, 8H), 2 .87-2.91 (m, 2H) 2.13-2.15 (m, 2H), 1.58-1.60 (m, 2H), 1.20 (d, 6H, J = 5.7Hz) )
_{^{13 C-NMR (D 2 O}} ) δ (ppm); 14.55,30.87,52.84,68.92,69.15,73.58,100.85,140.04
Q-TOF LC / MS (ESI, negative mode): m / z = 473.061 was detected and 3,3'-[(2,3-dihydrothieno [3,4-b] -1,4-dioxin- 2,3-diyl) dimethoxy] -bis (1-methyl-1-sodium propanesulfonate) (C16H24Na2O10S3) can be assigned to a monovalent anion (C16H25O10S3) with two sodiums removed and one hydrogen attached. there were.

The thiophene compound of the present invention can be used as a monomer of a conductive polymer used in applications such as antistatic agents, solid electrolytes for capacitors, conductive coating materials, transparent electrodes, transparent conductive films, chemical sensors, actuators, and organic EL. In particular, since the thiophene compound of the present invention has two sulfonic acid groups that also have a role of dissolving in water and as a dopant, the obtained conductive polymer is highly water-soluble and has a high self-doping rate. It is expected to become a conductive polymer.

Claims (2)

The following formula (1)
[In the above formula (1), ^{R 3} represents a group represented by the following general formula (2), ^{R 4} represents a group represented by the water atom or the following general formula (2).
{In formula (2), M ¹ represents a hydrogen ion, an alkali metal ion, a conjugate acid of an amine compound, or a quaternary ammonium cation. R ¹ represents a hydrogen atom, a linear or branched alkyl group having 1 to 6 carbon atoms, or a halogen atom. m is the same or different and represents 2 or 3 . }]]
A thiophene compound represented by. The thiophene compound according to claim 1, wherein R ¹ is a methyl group.