JP2011046615A - Thiophene derivative - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polythiophene which is especially high in stereo regularity and is excellent in solubility in organic solvents. <P>SOLUTION: There are provided a compound represented by formula (1) (wherein, R is a 1 to 20C hydrocarbon group; X<SP>1</SP>and X<SP>2</SP>are each identically or differently Br or I), and a polymer obtained by polymerizing the compound. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a novel thiophene derivative and polythiophenes using the same.

  Conductive polymers are applied as through-hole plating, antistatic agents, and solid electrolytes for capacitors, as well as alternatives to ITO (indium tin oxide), organic transistor materials, and EC hole injection layer materials. Highly expected. So far, polyaniline, polypyrrole, and polythiophenes are known as highly conductive polymers.

  Among these, as polythiophenes, poly (3,4-ethylenedioxythiophene) (PEDOT) has high conductivity and is known to be useful for solid electrolytes (Patent Documents 1 and 2, Non-Patent Documents 1 and 2).

JP 2006-128403 A JP 2008-60295 A

Journal of The Electrochemical Society 2009, 156, G65-G70 Synthetic Metal 1999, 102, 973-974

However, development of a conductive polymer having higher conductivity, higher stereoregularity, and improved solubility in a solvent is desired.
Accordingly, an object of the present invention is to provide polythiophenes having particularly high stereoregularity and excellent solubility in organic solvents.

  Therefore, the present inventor has made various studies to improve the electrochemical properties, optical properties, solubility and the like of polythiophenes, and has an iminomethyl group at the 3-position represented by the following formula (1). And polythiophenes obtained by polymerizing thiophenes having a bromine atom and an iodine atom at the 2-position and 5-position have high stereoregularity, excellent organic solvent solubility and electrochemical properties, and the present invention Was completed.

  That is, the present invention provides the following formula (1):

(In the formula (1), R represents a hydrocarbon group having 1 to 20 carbon atoms, X ¹ and X ² are the same or different and indicate a bromine atom or an iodine atom.)
The compound represented by these is provided.

  The present invention also provides a polymer obtained by polymerizing the compound represented by the above formula (1).

  The present invention also provides a polymer having a repeating unit represented by the following formula (2) and having a head-tail structure of 70% or more.

(In the formula (2), R represents a hydrocarbon group having 1 to 20 carbon atoms.)

  Moreover, this invention includes the process with which the compound represented by following formula (3) and the compound represented by following formula (4) are made to react, It represents with said Formula (1) characterized by the above-mentioned. A method for producing a compound is provided.

(In formula (3), X ¹ and X ² have the same meanings as those in formula (1) above.)

(In formula (4), R has the same meaning as in formula (1) above.)

  Furthermore, this invention includes the process of acid-treating the polymer obtained by superposing | polymerizing the compound represented by said Formula (1), following formula (6) characterized by the above-mentioned.

The manufacturing method of the polymer which has a repeating unit represented by these is provided.

  Since the polymer of the present invention has high stereoregularity, good solubility in organic solvents, and excellent film formation, it can be easily formed into a film, so that conductive materials, antistatic agents, etc. Useful as.

The ¹ H-NMR spectrum of LR-P3HIT (a) and HR-P3HIT (b) is shown. The inside of the square frame is an enlarged view of part b. The ultraviolet-visible absorption spectrum of THF (a) and chloroform solution (d) of HR-P3HIT and THF (b) and chloroform solution (c) of LR-P3HIT are shown. The ultraviolet-visible absorption spectrum of the film produced from the THF (a) and chloroform solution (d) of HR-P3HIT, and the film produced from the THF (b) and chloroform solution (c) of LR-P3HIT is shown. The TGA curve of HR-P3HIT and LR-P3HIT is shown. The UV-visible absorption spectrum of the P3HIT film (solid line, upper part of the photograph) and the P3TCHO film (dotted line, lower part of the photograph) obtained after treatment with hydrochloric acid gas are shown. The top of the photo is yellow and the bottom is red. The FT-IR spectrum of the film | membrane (a) of P3HIT and the film | membrane (b) of P3TCHO is shown. The FT-IR spectrum of P3HIT (a) and P3TCHO (b) is shown.

  This invention compound is represented by the said Formula (1), and R shows a C1-C20 hydrocarbon group in Formula (1). Examples of the hydrocarbon group include an aliphatic hydrocarbon group having 1 to 20 carbon atoms, an aromatic hydrocarbon group having 6 to 20 carbon atoms, and a hydrocarbon group having an aliphatic group and an aromatic group having 1 to 20 carbon atoms in total. Is mentioned. As a C1-C20 aliphatic hydrocarbon group, a C1-C20 saturated or unsaturated linear, branched or cyclic hydrocarbon group is mentioned.

  Examples of the aliphatic hydrocarbon group include a linear or branched alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an alkynyl group having 2 to 20 carbon atoms, and a cycloalkane group having 3 to 20 carbon atoms. And a C 5-20 cycloalkene group. Specific examples include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, hexyl, octyl, decyl, dodecyl. Group, tetradecyl group, hexadecyl group and the like alkyl group having 1 to 18 carbon atoms; vinyl group, 1-propenyl group, allyl group, butenyl group, pentenyl group and other alkenyl groups having 2 to 18 carbon atoms; propynyl group, butenyl group C2-C18 alkynyl group such as cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, etc .; C3-C7 cycloalkyl group such as cyclopentenyl group, cyclohexenyl group, etc. A cycloalkenyl group etc. are mentioned.

  Examples of the aromatic hydrocarbon group having 6 to 20 carbon atoms include a phenyl group, a naphthyl group, an anthracenyl group, a phenanthrenyl group, and a pyreryl group.

  Examples of the hydrocarbon group having an aliphatic group and an aromatic group include aralkyl groups having 7 to 20 carbon atoms in total. Specific examples include benzyl group, phenethyl group, naphthylmethyl group, naphthylethyl group and the like.

  Among these hydrocarbon groups, an alkyl group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, an aromatic hydrocarbon group having 6 to 14 carbon atoms, and an aralkyl group having 7 to 14 carbon atoms are preferable.

X ¹ and X ² are the same or different and each represents a bromine atom or an iodine atom. Both X ¹ and X ² may be a bromine atom or an iodine atom, one may be a bromine atom, and the other may be an iodine atom. It is particularly preferable that X ¹ and X ² are different from each other because the resulting polymer has high stereoregularity.

  The compound represented by the formula (1) can be produced, for example, according to the following reaction formula.

(Wherein X ¹ , X ² and R are as defined above.)

  That is, by reacting 3-formylthiophene (5) with a brominating agent or iodinating agent to obtain a compound of formula (3), and then reacting it with an amine of formula (4), The compound of the present invention represented can be obtained.

  Examples of the halogenating agent used for bromination or iodination of 3-formylthiophene include N-bromosuccinimide, N-iodosuccinimide, N-bromophthalimide, and N-iodophthalimide. The halogenation reaction may be performed in a polar solvent such as N, N-dimethylformamide, N, N-dimethylacetamide, chloroform, or a mixed solvent thereof at a temperature of 0 ° C. to 150 ° C. for 30 minutes to 80 hours.

In order to introduce different halogen atoms into X ¹ and X ² , for example, 3-formylthiophene is brominated at the 5-position of thiophene with an equimolar or small excess of brominating agent, and then 2 of thiophene with an iodinating agent. The position may be iodinated. The reaction conditions are the same.

  The reaction between the compound of formula (3) and the amines (4) is a so-called Schiff base reaction, in which an amine is added to the compound of formula (3) in an alcohol, hydrocarbon, ether, or mixed solvent thereof. What is necessary is just to make it react at the temperature of room temperature-200 degreeC.

  The polymer of the present invention is a polymer obtained by polymerizing the compound represented by the formula (1). The weight average molecular weight is preferably 1,000 to 500,000, particularly 5,000 to 50,000. Further, Mw / Mn is preferably 1.05 to 4.0, particularly preferably 1.05 to 2.5.

  The polymer of the present invention has a repeating unit represented by the following formula (2).

(Wherein R is as defined above)

The polymer of the present invention has a repeating unit represented by the formula (2), but since it has a substituent at the 3-position, the repeating unit has a head-head structure; a head-tail structure, a tail-head structure, There may be four kinds of stereoregularity of tail-tail structure. These stereoregularities can be analyzed by NMR spectroscopy, and the degree of stereoregularity can be determined by integration. In the present invention, a polymer having particularly high stereoregularity can be obtained by using the compound of the formula (1) in which X ¹ and X ² are different. In the present invention, a polymer having a head-head structure and a head-tail structure is obtained, and a polymer having a head-tail structure of 70% or more, particularly 95% or more is particularly preferable because of excellent optical properties.

The polymer of the present invention can also be polymerized by subjecting the compound of the formula (1) to an electrochemical synthesis method. However, from the viewpoint of obtaining a polymer with high stereoregularity, a metal exchange reaction and a nickel catalyst are used. Polymerization is preferably performed by a cross coupling method. Metal exchange reagents include isopropyl magnesium chloride, methyl magnesium bromide, ethyl magnesium chloride, propyl magnesium chloride, butyl magnesium bromide, hexyl magnesium chloride, dodecyl magnesium chloride, dicyclohexyl magnesium chloride, isopropyl magnesium chloride, t-butyl magnesium chloride, vinyl Grignard reagents such as magnesium bromide are preferred. NiCl ₂ (dppp), NiCl ₂ (dppe), or the like is used as the nickel catalyst. In the reaction, it is preferable to first perform a metal exchange reaction on the compound of the formula (1) in an ether solvent such as THF and then cross-couple with a nickel catalyst. The metal exchange reaction may be performed at 0 to room temperature for 15 minutes to 5 hours. The cross coupling reaction may be performed at room temperature to reflux temperature for 1 hour to 50 hours.

  Moreover, the polymer which has the repeating unit of the said Formula (2) obtained can be converted into polythiophene which has a repeating unit represented by following formula (6) by acid-processing.

  The obtained poly (formylthiophene) also retains the high stereoregularity and has excellent optical properties.

  Examples of acids used for the acid treatment include hydrochloric acid, sulfuric acid, nitric acid, hydrobromic acid, hydroiodic acid, acetic acid, trifluoroacetic acid, p-toluenesulfonic acid, p- (tripleomethyl) benzenesulfonic acid, Examples thereof include fluorosulfonic acid. The acid treatment can be performed after the polymer having the repeating unit of the formula (2) is formed into a film. In this case, the acid treatment is preferably performed with hydrochloric acid gas or the like.

  The polymer obtained by the present invention is useful as a conductive material, an antistatic film and the like because it has not only excellent conductivity but also optical properties based on high stereoregularity.

  EXAMPLES Next, although an Example is given and this invention is demonstrated in detail, this invention is not limited to this at all.

Example 1-1.
Synthesis of 2,5-dibromo-3-formylthiophene Mixing of 3-thiophenecarbaldehyde (5.00 g, 44.6 mmol), N, N-dimethylformamide (50 mL), N-bromosuccinimide (20.6 g, 116 mmol) The solution was stirred at room temperature for 65 hours and then poured into ice water. After extraction with ethyl acetate, the organic phase was washed with 5% sodium hydroxide and water. After drying with magnesium sulfate and distilling off the solvent, the residue was purified by silica gel column chromatography (chloroform: hexane = 1: 1) to obtain the desired product (10.5 g) as a white solid in a yield of 87%. It was.
¹ H-NMR (CDCl ₃ ): δ (ppm) 7.34 (s, Th-H, 1H), 9.78 (s, CHO, 1H).

Example 1-2.
Synthesis of 2,5-dibromo-3-hexyliminomethylthiophene 2,5-dibromo-3-formylthiophene (2.00 g, 7.42 mmol), methanol (50 mL), n-hexylamine (0.75 g, 7. 42 mmol) was refluxed for 20 minutes, and the solvent was distilled off under reduced pressure to obtain the oily target product (2.5 g) in a yield of 96%.
¹ H-NMR (CDCl ₃ ): δ (ppm) 0.89 (t, J = 6.8 Hz, CH ₃ , 3H), 1.29-1.36 (m, CH ₂ , 6H), 1.62-1.68 (m, CH ₂ , 2H ), 3.57 (dt, J = 7.0 and 1.2 Hz, = NCH ₂ , 2H), 7.41 (s, Th-H, 1H), 8.15 (t, J = 1.2 Hz, CH = N, 1H).

Example 2-1.
Synthesis of 5-bromo-3-formylthiophene Mixing of 3-thiophenecarbaldehyde (5.00 g, 44.6 mmol), N, N-dimethylformamide (50 mL), N-bromosuccinimide (9.52 g, 53.5 mmol) The solution was stirred at room temperature for 24 hours and then poured into ice water. After extraction with ethyl acetate, the organic phase was washed with 5% sodium hydroxide and water. After drying over magnesium sulfate and distilling off the solvent, the residue was purified by silica gel column chromatography (chloroform: hexane = 1: 1) to obtain a colorless oily target product (4.3 g) in a yield of 51%. It was.
¹ H-NMR (CDCl ₃ ): δ (ppm) 7.51 (d, J = 1.6 Hz, Th-H, 1H), 8.01 (d, J = 1.6 Hz, Th-H, 1H), 9.78 (s, CHO , 1H).

Example 2-2.
Synthesis of 5-bromo- 2-iodo-3-formylthiophene Iodine (0.59 g, 2.3 mmol) at 0 ° C. in a solution of 5-bromo-3-formylthiophene (0.88 g, 4.61 mmol) in dichloromethane (10 mL) ) And iodosobenzene acetate (20.8 g, 2.51 mmol) were added. After raising the temperature to room temperature and stirring for 3 hours, 10% aqueous sodium thiosulfate solution (20 mL) was added. After stirring for 5 minutes, extraction with ethyl acetate was performed, and the organic phase was dried over magnesium sulfate. After the solvent was distilled off, the residue was purified by silica gel column chromatography (hexane: chloroform = 1: 1) to obtain the desired product (1.1 g) as a yellow solid in a yield of 76%.
¹ H-NMR (CDCl ₃ ): δ (ppm) 7.29 (s, Th-H, 1H), 9.56 (s, CHO, 1H).

Example 2-3.
Synthesis of 5-bromo-2-iodo-3-hexylimiminothiophene 5-bromo-2-iodo-3-formylthiophene (0.15 g, 0.47 mmol), methanol (5 mL), n-hexylamine (0.051 g , 0.50 mmol) was stirred at 50 ° C. for 20 minutes, and then the solvent was distilled off under reduced pressure to obtain the desired product as a colorless solid in a yield of 96%.
¹ H-NMR (CDCl ₃ ): δ (ppm) 0.90 (t, J = 7.0 Hz, CH ₃ , 3H), 1.30-1.37 (m, CH ₂ , 6H), 1.65-1.68 (m, CH ₂ , 2H ), 3.59 (dt, J = 7.0 and 1.2 Hz, = NCH ₂ , 2H), 7.34 (s, Th-H, 1H), 7.98 (dt, J = 1.2 and 0.4 Hz, CH = N, 1H).

Example 3
Synthesis of LR-P3HIT To a solution of 2,5-dibromo-3 -hexyliminomethylthiophene (0.71 g, 2.0 mmol) in THF (20 mL) at 0 ° C., 2.0 M THF solution of isopropylmagnesium chloride (1.0 mL) , 2.0 mmol) and stirred at 0 ° C. for 30 minutes. Thereafter, NiCl ₂ (dppp) (5.4 mg, 0.010 mmol) was added and the mixture was refluxed for 20 hours, then returned to room temperature and reprecipitated with 200 mL of methanol. The precipitate was collected by filtration, and purified by column chromatography (eluent: THF) using silica gel treated with triethylamine to obtain the desired product LR-P3HIT (0.23 g) as a purple solid in a yield of 60%. It was.
M _w = 1.92 × 10 ⁴ , M _w / M _n = 2.3
¹ H-NMR (CDCl ₃ ): δ (ppm) 0.91 (t, J = 7.0 Hz, CH ₃ , 3H), 1.35-1.48 (br s, CH ₂ , 6H), 1.71-1.75 (br s, CH ₂ , 2H), 3.67 (br s, = NCH ₂ , 2H), 7.73 (br s, Th-H, 1H), 8.61 (br s, CH = N, 1H).

Example 4
Synthesis of HR-P3HIT To a solution of 5-bromo-2-iodo-3 -hexyliminomethylthiophene (0.80 g, 2.0 mmol) in THF (20 mL) at 0 ° C., a 2.0 M THF solution of isopropylmagnesium chloride (1 0.0 mL, 2.0 mmol) was added, and the mixture was stirred at 0 ° C. for 30 minutes. Thereafter, NiCl ₂ (dppp) (5.4 mg, 0.010 mmol) was added and the mixture was refluxed for 20 hours, then returned to room temperature and reprecipitated with 200 mL of methanol. The precipitate was collected by filtration and purified by column chromatography (eluent: THF) using silica gel treated with triethylamine to obtain the target product HR-P3HIT (0.25 g) as a purple solid in a yield of 65%. It was.
M _w = 2.51 × 10 ⁴ , M _w / M _n = 2.3
¹ H-NMR (CDCl ₃ ): δ (ppm) 0.90 (t, J = 6.8 Hz, CH ₃ , 3H), 1.33-1.41 (br s, CH ₂ , 6H), 1.70-1.75 (br s, CH ₂ , 2H), 3.67 (br s, = NCH ₂ , 2H), 7.73 (br s, Th-H, 1H), 8.61 (br s, CH = N, 1H).

The stereoregularity of the polymer obtained this time was determined from the ¹ H-NMR spectrum. LR-P3HIT (a) obtained from 2,5-dibromo-3-3 hexyliminomethylthiophene has 70% head-to-tail (HT) structure and 30% head-to-head (HH) structure based on the integration ratio. Confirmed to do. HR-P3HIT (b) obtained from 5-bromo-2-iodo-3-hexylimiminothiophene showed high stereoregularity with an HT structure of 95% (FIG. 1).

The UV-visible absorption spectra of THF (a) and chloroform solution (d) of HR-P3HIT and THF (b) and chloroform solution (c) of LR-P3HIT were measured (FIG. 2).
From FIG. 2, the maximum absorption wavelength is as follows.
HR-P3HIT: Chloroform: 425 nm THF: 393 nm
LR-P3HIT: Chloroform: 423 nm THF: 410 nm

  The maximum absorption wavelengths of HR-P3HIT and LR-P3HIT are both found on the longer wavelength side in the chloroform solvent having higher polarity than THF.

UV-visible absorption spectra of a film prepared from THF (a) and chloroform solution (d) of HR-P3HIT and a film prepared from THF (b) and chloroform solution (c) of LR-P3HIT were measured (FIG. 3). ).
From FIG. 3, the maximum absorption wavelength is as follows.
HR-P3HIT: Chloroform: 487 nm THF: 408 nm Chlorobenzene: 408 nm Dichlorobenzene: 405 nm
LR-P3HIT: Chloroform: 467 nm THF: 416 nm

In the HR-P3HIT film and the LR-P3HIT film, as in the case of the solution, the maximum absorption wavelength is observed on the longer wavelength side in the chloroform solvent having a higher polarity than THF.
The ultraviolet-visible absorption spectrum of the film formed with chloroform showed a peak top on the long wavelength side as the stereoregularity of the polymer was higher.

TGA curves of HR-P3HIT and LR-P3HIT were measured (FIG. 4).
From FIG. 4, the TGA measurement result of the polymer in a nitrogen stream shows that 10% weight loss temperature (Td ₁₀ ) is 299 ° C. for HR-P3HIT, 261 ° C. for HR-P3HIT, and HR-P3HIT with higher positional regularity. It shows higher thermal stability than LR-P3HIT.

Example 5 FIG.
Fabrication of P3TCHO membrane from poly (3-hexyliminomethylthiophene) (P3HIT) membrane

  P3HIT having a regioregularity of 95% was dissolved in chloroform to prepare a 10 mg / mL concentration solution. P3HIT was formed on a glass substrate using a spin coater. The obtained film was heated at 150 ° C. for 5 minutes, and then the red film was allowed to stand for 30 seconds on a concentrated hydrochloric acid beaker, whereby the color of the film quickly changed from red to black purple. The black purple film was washed with methanol and then dried to obtain a P3TCHO film. It was confirmed that the black purple-colored P3TCHO film thus obtained was treated with triethylamine vapor as it was for 30 seconds to return to the original orange color of P3HIT.

FIG. 5 shows an ultraviolet-visible absorption spectrum of a P3HIT film (solid line, upper part of the photograph) and a P3TCHO film (dotted line, lower part of the photograph) obtained after treatment with hydrochloric acid gas and a photograph of the film.
From FIG. 5, the maximum absorption wavelength of the P3HIT film was 495 nm, the maximum absorption wavelength of the P3TCHO film was 550 nm, and a long wavelength shift of 55 nm was observed due to the introduction of an aldehyde group that is a strong electron-withdrawing group.

FT-IR spectra of the P3HIT film (a) and the P3TCHO film (b) were measured (FIG. 6).
From FIG. 6, when FT-IR of the P3HCHO film obtained by the hydrochloric acid gas treatment of the P3HIT film and the P3HIT film was measured by the ATR method, the C = N stretching peak was observed at 1627 cm ⁻¹ in the case of the P3HIT film. On the other hand, when the membrane is repaired with hydrochloric acid gas, the C═N stretching peak almost disappears and a new C═O stretching peak appears at 1667 cm ⁻¹ .

Example 6
Production of P3TCHO from P3HIT

P3HIT 5.0 mg (2.5 × 10 ⁻² mmol) having a regioregularity of 95% was dissolved in 1 mL of THF, added dropwise to 5 mL of 1M aqueous hydrochloric acid solution, and stirred for 5 minutes. The precipitate was filtered and washed with methanol. After drying, 2.3 mg (84%) of the target product P3TCHO as a black solid was obtained.
The obtained P3TCHO was insoluble in most organic solvents (THF, DMF, DMSO, CHCl _3, etc.).

The FT-IR spectra of P3HIT (a) and P3TCHO (b) are shown in FIG.
From FIG. 7, when the FT-IR of P3TCHO obtained from the solution reaction of P3HIT and hydrochloric acid was measured by the ATR method, the C = N stretching peak (1627 cm ^-1 ) of P3HIT almost disappeared and the C = O stretching of P3TCHO. A peak appeared at 1673 cm ⁻¹ .

Claims (7)

A compound represented by the following formula (1).

(In the formula (1), R represents a hydrocarbon group having 1 to 20 carbon atoms, X ¹ and X ² are the same or different and indicate a bromine atom or an iodine atom.) The compound according to claim 1, wherein one of X ¹ and X ² is a bromine atom and the other is an iodine atom.   A polymer obtained by polymerizing the compound according to claim 1. A polymer having a repeating unit represented by the following formula (2) and having a head-tail structure of 70% or more.

(In the formula (2), R represents a hydrocarbon group having 1 to 20 carbon atoms.) The method for producing a compound according to claim 1, further comprising a step of reacting a compound represented by the following formula (3) with a compound represented by the following formula (4).

(In formula (3), X ¹ and X ² have the same meanings as those in formula (1) above.)

(In formula (4), R has the same meaning as in formula (1) above.) The method for producing a compound according to claim 5, comprising a step of reacting a compound represented by the following formula (5) with a brominating agent or an iodinating agent to obtain a compound represented by the above formula (3). .

The following formula (6), comprising a step of acid-treating the polymer according to claim 3.

The manufacturing method of the polymer which has a repeating unit represented by these.

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