JPH05279457A - Polythiophene derivative and its production - Google Patents

Abstract

PURPOSE:To obtain the subject self-preservable derivative with high electrical conductivity, excellent in liquid crystal and orientation properties useful for electro-optical devices, etc., by e.g. electrolytic oxidative polymerization of a specific thiophene derivative. CONSTITUTION:The objective derivative of formula III can be obtained by electrolytic oxidative polymerization or chemical oxidative polymerization of a thiophene derivative of formula I [k is 1-30; R<1> is H or 1-30C alkyl; R<2> is of formula II (R<3> is CN, NO2, etc.), etc.].

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a polythiophene derivative exhibiting liquid crystallinity and a method for producing the same.

[0002]

2. Description of the Related Art Polythiophene, polypyrrole and polyaniline have been attracting attention as polymer materials having interesting functions such as conductivity and electrochromism. Recently, development of a secondary battery utilizing the reversible redox function of a conductive polymer and application to an electrolyte of an electrolytic capacitor have been carried out.

However, since these polymers are insoluble and infusible, there is a problem that they are difficult to mold, and in the application thereof, the method of electrodeposition on the electrode by electrolytic oxidative polymerization was mainly used.

As a method of compensating for this drawback, it has been found that a long chain alkyl group is introduced as a side chain of the main chain skeleton to impart solubility (Sato et al., Journal of Chemical Society, Chemical Communication, 873).
P., 1986, Elsenbaumara, Synthetic Metals, vol. 15, p. 169, 1986, Sugimoto et al., Chemistry Press, vol. 1, p. 635, 1986, Yoshino et al., Japanese Journal of Applied Physics, 23.
Volume, 899 pages, 1986 and Yoshino et al., Japanese Journal of Applied Physics, 26, 1038.
Page, 1987).

Further, JP-A-174436 and JP-A-1-79023 are known as polythiophenes having an alkoxy group introduced therein.

[0006]

However, the above polythiophenes have a problem that the orientation and liquid crystallinity are not sufficient. INDUSTRIAL APPLICABILITY The present invention is to carry out electrolytic oxidative polymerization or chemical oxidative polymerization of a polythiophene derivative as a film capable of self-holding, having high conductivity and exhibiting liquid crystallinity and orientation, and a thiophene derivative having a liquid crystal group in a side chain. To provide a simple method for producing the polythiophene derivative.

[0007]

As a result of detailed investigations on the properties of substituted polythiophenes, the present inventors found that polythiophene consisting of a thiophene derivative having a specific liquid crystal group at the 3- and 4-positions is soluble in a general-purpose organic solvent. Moreover, they have found that they can be easily formed into a film, exhibit liquid crystallinity, and exhibit better orientation than conventional materials, and have completed the present invention.

That is, the present invention has the general formula (I):

[0009]

[Chemical 7]

(Wherein k is an integer of 1 to 30, R ¹ is a hydrogen atom or an alkyl group having 1 to 30 carbon atoms, and R ² is

[0011]

[Chemical 8]

[0012]

[Chemical 9]

(In the formula, R ³ is --CN, --NO ₂ ,-(C
H ₂ ) _m CH ₃ (m = 0 to 29) or -O- (CH ₂ )
a polythiophene derivative having a repeating unit represented by _n CH ₃ (n = 0 to 29)) is represented by the general formula (II):

[0014]

[Chemical 10]

A polythiophene derivative having a repeating unit represented by the formula (wherein k and R ² are the same as above),
General formula (III):

[0016]

[Chemical 11]

The thiophene derivative represented by the formula (wherein k, R ¹ and R ² are the same as those described above) is subjected to electrolytic oxidative polymerization or chemical oxidative polymerization.
And a general formula (IV) for producing the polythiophene derivative of

[0018]

[Chemical 12]

The present invention relates to a method for producing a polythiophene derivative represented by the general formula (II), which comprises subjecting a thiophene derivative represented by the formula (wherein k and R ² are the same as above) to electrolytic oxidative polymerization or chemical oxidative polymerization.

[0020]

EXAMPLES The thiophene derivative of the present invention has the general formula (I):

[0021]

[Chemical 13]

And general formula (II):

[0023]

[Chemical 14]

It has a repeating unit represented by:

K in the above general formulas (I) and (II)
Is an integer of 1 to 30, preferably 4 to 20. When k exceeds 30, the polymer does not exhibit the liquid crystallinity which is the object of the present invention.

R ¹ in the general formula (I) represents a hydrogen atom or a linear or branched alkyl group having 1 to 30 carbon atoms, preferably 1 to 20 carbon atoms. When R ¹ exceeds 30, the polymer does not exhibit the liquid crystallinity which is the object of the present invention. As a specific alkyl group, for example, -C
_{H 3, -CH 2 CH 3,} - (CH 2) 2 CH 3, - (C
_{H 2) 3 CH 3, -} (CH 2) 5 CH 3, - (CH 2)
_{7 CH 3, - (CH 2} ) 9 CH 3, - (CH 2) 11 CH
_{3, - (CH 2) 13} CH 3, - (CH 2) 17 CH 3, -
(CH ₂ ) ₂₄ CH ₃ and other (CH ₂ ) _j CH ₃ (j is 0
~ CH (C
_{H 3) 2, -CH 2 CH} (CH 3) 2, - (CH 2) 2
_{CH (CH 3) 2, -CH} 2 C (CH 3) 2 CH 2 -,
_{- (CH 2) 3 CH (} CH 3) 2, - (CH 2) 4 CH
_{(CH 3) 2, - (} CH 2) 5 CH (CH 3) but ₂ and the _{like, -CH 3, -CH 2 CH 3} , - (C
_{H 2) 2 CH 3, -} (CH 2) 3 CH 3, - (CH 2)
_{5 CH 3, - (CH 2} ) 7 CH 3, - (CH 2) 9 CH
_{3, - (CH 2) 11} CH 3, - (CH 2) 17 CH 3, -
_{CH (CH 3) 2, -CH} 2 CH (CH 3) 2, - (C
H ₂ ) ₂ CH (CH ₃ ) _{2 and the} like are preferable.

R in the above general formulas (I) and (II)
² is

[0028]

[Chemical 15]

[0029]

[Chemical 16]

Is a group represented by:

In the formula, R ³ is --CN, --NO ₂ ,-(CH
_{2) m} CH ₃ or _{-O (CH 2) n CH 3} . Here, m and n represent the integer of 0-29.

Specific examples of R ² include, for example,

[0033]

[Chemical 17]

[0034]

[Chemical 18]

[0035]

[Chemical 19]

[0036]

[Chemical 20]

[0037]

[Chemical 21]

[0038]

[Chemical formula 22]

[0039]

[Chemical formula 23]

[0040]

[Chemical formula 24]

[0041]

[Chemical 25]

And the like.

In these, m and n are both
It is preferably 0 to 19.

Preferred specific examples of the repeating unit represented by the general formula (I) include, for example,

[0045]

[Chemical formula 26]

[0046]

[Chemical 27]

[0047]

[Chemical 28]

[0048]

[Chemical 29]

[0049]

[Chemical 30]

[0050]

[Chemical 31]

[0051]

[Chemical 32]

[0052]

[Chemical 33]

[0053]

[Chemical 34]

[0054]

[Chemical 35]

[0055]

[Chemical 36]

[0056]

[Chemical 37]

[0057]

[Chemical 38]

[0058]

[Chemical Formula 39]

[0059]

[Chemical 40]

[0060]

[Chemical 41]

[0061]

[Chemical 42]

[0062]

[Chemical 43]

[0063]

[Chemical 44]

[0064]

[Chemical formula 45]

[0065]

[Chemical formula 46]

[0066]

[Chemical 47]

[0067]

[Chemical 48]

[0068]

[Chemical 49]

[0069]

[Chemical 50]

[0070]

[Chemical 51]

[0071]

[Chemical 52]

[0072]

[Chemical 53]

And the like.

In these, m and n are both
It is preferably 0 to 19, j is preferably 0, 1, 2,
3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 15, 1
7, 19, k are preferably 4, 5, 6, 7, 8, 9, 10, 1
2, 14, 16, 18, and 20.

Preferred specific examples of the repeating unit represented by the general formula (II) include, for example,

[0076]

[Chemical 54]

[0077]

[Chemical 55]

[0078]

[Chemical 56]

[0079]

[Chemical 57]

[0080]

[Chemical 58]

[0081]

[Chemical 59]

[0082]

[Chemical 60]

[0083]

[Chemical formula 61]

[0084]

[Chemical formula 62]

[0085]

[Chemical formula 63]

[0086]

[Chemical 64]

[0087]

[Chemical 65]

[0088]

[Chemical formula 66]

[0089]

[Chemical formula 67]

[0090]

[Chemical 68]

[0091]

[Chemical 69]

[0092]

[Chemical 70]

[0093]

[Chemical 71]

[0094]

[Chemical 72]

[0095]

[Chemical formula 73]

And the like.

Preferred specific examples of m, n and k in these are the same as those in the repeating unit represented by the general formula (I).

The number average molecular weight of the polythiophene derivative of the present invention is usually 1,500 to 1,000,000, preferably 3,000 to 400,000. If the number average molecular weight is less than 1,500, the moldability of the polymer film may be impaired. On the other hand, if it exceeds 1,000,000, unfavorable effects such as an increase in liquid crystallinity may occur. In addition, those having a number average molecular weight in the range of 3,000 to 400,000 have particularly good film-forming properties even when a mechanical film-forming method is used, and the stretching ratio can be increased. The degree of alignment of the liquid crystal groups in the chains and side chains can be increased.

From the measurement of the phase transition temperature of the polymer of the present invention,

[0100]

[Chemical 74]

It has been confirmed that the smectic or nematic liquid crystal state is realized at a temperature around room temperature.

The polymer liquid crystal of the present invention can be used by forming it into a film by an ordinary film forming method such as casting method and stretching method. The film-like polymer having a thickness of several tens to several hundreds of μm is used for not only two ordinary glass substrates but also a large glass substrate, a curved glass substrate, a polyester film, or the like for sandwiching the liquid crystal display,
It can be used in various optoelectronic fields such as electro-optical shutters. It is also possible to apply a polymer solution dissolved in a suitable solvent to the surface of a substrate such as a glass substrate and evaporate the solvent to form a film in a state of being in direct contact with the surface of the substrate.

The polymer of the present invention has a liquid crystallinity exhibiting a nematic phase or a smectic phase and a typical polymer property of being easy to mold, and therefore has many applications in the fields of optoelectronics and information storage. there is a possibility. For example, it can be used as various electro-optical devices such as liquid crystal displays such as digital display of various shapes, electro-optical shutters and light control materials.

The polymer of the present invention may optionally contain various additives such as inorganic compounds, organic compounds and metals including a mixture of the above polymers, a mixture with other polymers, a stabilizer and a plasticizer. Can be improved by various treatment methods well known in the art such as addition of

Next, the method for producing the polymer liquid crystal of the present invention having the repeating units represented by the general formulas (I) and (II) will be specifically described.

General formula (III):

[0107]

[Chemical 75]

And general formula (IV):

[0109]

[Chemical 76]

The method for producing the thiophene derivative represented by is described in the specification of the patent application (title of the invention: thiophene derivative and its production method) submitted at the same time as the present application.

In the method for producing the polymers represented by the general formulas (I) and (II) by the electrolytic oxidation method of the present invention, the supporting electrolyte (a) is H ⁺ , Li ⁺ , Na ⁺ , K ⁺ , R ⁴ _Four
At least one cation selected from the group consisting of N ⁺ and R ⁴ ₂ P ⁺ (wherein R ⁴ independently of each other represents a hydrogen atom, an alkyl group, a cycloalkyl group or an aryl group); and (b) _{^{BF 4 -, AsF 4 -,}} AsF 6 -,
SbF ₆ ⁻ , AbCl ₆ ⁻ , PF ₆ ⁻ , ClO ₄ ⁻ , H
It is a salt with at least one anion selected from the group consisting of SO ₄ ⁻ and SO ₄ ²⁻ .

In the electrolytic oxidation method, a solution in which the supporting electrolyte is dissolved in an amount of 0.001 to 1 mol / l is used as an electrolytic solution, and 0.001 to 1 mol / l of the thiophene derivative (III) is added to the electrolytic solution.
Alternatively, by adding a compound represented by the thiophene derivative (IV) and applying a direct current, the polymer is deposited and grown on the anode surface to obtain a film.

The solvent of the electrolytic solution may be any one capable of dissolving the compound represented by the general formula (III) or (IV), and examples thereof include organic solvents such as acetonitrile, benzonitrile, dimethylformamide, tetrahydrofuran and nitrobenzene. Water or mixtures thereof can be used.

The kinds of the supporting electrolyte and the solvent, the applied current value, the voltage value, etc. differ depending on the kind of the raw material compound.

On the other hand, in the method for producing a polymer of the compounds represented by the general formulas (I) and (II) by the chemical oxidation method, the oxidizing agent is the thiophene derivative represented by the general formulas (III) and (IV). Any substance having an oxidation potential higher than the potential can be used without particular limitation. For example Fe
³⁺ compound, H ₂ O ₂ , S ₂ O ₄ ^2- compound, Cl ₂ , Br
Strong oxidizing agents or RuO ₄ ^2-compounds such as _2, OsO ₄ ^-
Compounds, highly oxidized oxyacid ion donors such as MnO ₄ ²⁻ compounds, or noble metal acid ion donors such as IrCl ₆ ⁻ compounds, PtCl ₆ ²⁻ compounds, PdCl ₄ ²⁻ compounds, AuCl ₄ ²⁻ compounds. . In particular, ruthenium (III) tris (vasophenanthroline sulfonic acid) and ruthenium (III) tris (bipyridine sulfonic acid) are preferable examples.

In the chemical oxidation method, the reaction can be carried out in either a solvent system or a non-solvent system, and the polymer is obtained as a powder or a film-like solid.

As the reaction solvent, any solvent which does not react with the oxidizing agent can be used without particular limitation. Preferably, water, lower alcohols, acetonitrile, chloroform or a mixed solvent thereof is used.

In the solvent-type reaction, the concentrations of the raw material compound and the oxidizing agent are not particularly limited, and each is 0.001 mol / l.
The reaction can be carried out in the range of to saturated solution.

Preferred specific examples of the thiophene derivative represented by the general formula (III) are, for example,

[0120]

[Chemical 77]

[0121]

[Chemical 78]

[0122]

[Chemical 79]

[0123]

[Chemical 80]

[0124]

[Chemical 81]

[0125]

[Chemical formula 82]

[0126]

[Chemical 83]

[0127]

[Chemical 84]

[0128]

[Chemical 85]

[0129]

[Chemical 86]

[0130]

[Chemical 87]

[0131]

[Chemical 88]

[0132]

[Chemical 89]

[0133]

[Chemical 90]

[0134]

[Chemical Formula 91]

[0135]

[Chemical Formula 92]

[0136]

[Chemical formula 93]

[0137]

[Chemical 94]

[0138]

[Chemical 95]

[0139]

[Chemical 96]

[0140]

[Chemical 97]

[0141]

[Chemical 98]

[0142]

[Chemical 99]

[0143]

[Chemical 100]

[0144]

[Chemical 101]

[0145]

[Chemical 102]

[0146]

[Chemical 103]

[0147]

[Chemical 104]

And the like.

Preferred specific examples of the thiophene derivative represented by the general formula (IV) are, for example,

[0150]

[Chemical 105]

[0151]

[Chemical formula 106]

[0152]

[Chemical formula 107]

[0153]

[Chemical 108]

[0154]

[Chemical 109]

[0155]

[Chemical 110]

[0156]

[Chemical 111]

[0157]

[Chemical 112]

[0158]

[Chemical 113]

[0159]

[Chemical 114]

[0160]

[Chemical 115]

[0161]

[Chemical formula 116]

[0162]

[Chemical 117]

[0163]

[Chemical 118]

[0164]

[Chemical formula 119]

[0165]

[Chemical 120]

[0166]

[Chemical 121]

[0167]

[Chemical formula 122]

[0168]

[Chemical 123]

[0169]

[Chemical formula 124]

And the like.

Next, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples. The structure of the obtained compound is NM
It was confirmed by R and IR, and the molecular weight was measured by GPC and shown in terms of polystyrene conversion.

The transition temperature was measured and the liquid crystal phase was confirmed by DSC and a polarization microscope, respectively. The heat resistance was evaluated by TG-DTA.

In the equation showing the phase transition behavior, the phase state is shown by the following abbreviations.

Glass: glass state, N: nematic phase liquid crystal state, S: smectic phase liquid crystal state, I: isotropic phase state, and the numbers represent the phase transition temperature in ° C.

The electric field response speed and the contrast ratio were measured by the following methods.

Measurement of electric field response speed: A polymer was sandwiched between glass substrates with ITO of 20 × 10 mm, and a thickness was set with a spacer.
It was adjusted to 10 μm, an electric field of 5 × 10 ⁶ V / m was applied, and the response time of the change in the amount of transmitted light (0 → 90%) was measured.

Measurement of contrast ratio: When the extinction position was searched by rotating the sample while applying a positive electric field to the sample under a crossed Nicols with a polarization microscope, the amount of transmitted light at this time was set to 1, and when a negative electric field was applied next. The contrast ratio = n: 1, where n is the amount of transmitted light.

Example 1 Formula:

[0179]

[Chemical 125]

Synthesis of polythiophene derivative consisting of repeating unit represented by

[0181]

[Chemical formula 126]

0.461 g of the thiophene derivative represented by
(10.0 mmol) was added to a solvent containing 10 ml of tetrahydrofuran containing 0.486 g (3.0 mmol) of FeCl _{3 to} obtain a homogeneous mixture. The mixed solution was applied onto a glass plate and the solvent was gradually evaporated to form a polymerized film on the glass plate.
The polymer film was thoroughly washed with ethanol until the washing liquid was not colored, and dried. The polymerization yield of the film was 82%.

This dried polymer film was prepared by using tetrahydrofuran, dimethylformamide, diethyl ether, ethyl acetate,
It was dissolved in a general-purpose organic solvent such as acetone.

The obtained polymer was analyzed by ¹ H-NMR analysis, I
It was identified by R spectrum analysis and confirmed to be the target.

¹ H-NMR spectrum analysis result (δ, p
_{pm, CDCl 3): 0.80~2.00 (} 16H), 4.00 (2H), 4.
15 (2H), 6.99 (2H), 7.00 (1H), 7.59 (4H), 8.09 (2H) IR spectrum analysis result (cm ^-1 , KBr): Absorption derived from ester: 1725, 1260 Absorption derived from cyano : 2240 Absorption derived from ether: 1100 GPC (tetrahydrofuran) molecular weight of this polymer
As a result, the number average molecular weight in terms of polystyrene was Mn = 4300.

The phase transition behavior was as follows.

[0187]

[Chemical 127]

Further, a tetrahydrofuran polymer solution (2
(Wt%) was cast on a glass plate, and after removing the solvent, a film was obtained.

This polymer was uniaxially stretched and oriented at a rate of 1 cm / sec at 200% at 130 ° C. in an AC electric field of 2 × 10.
^{When 6} V / m was applied and the change in the amount of transmitted light was measured,
The contrast ratio was 20: 1 and the response time at 50 ° C. was 0.9 s.

Example 2 Formula:

[0191]

[Chemical 128]

Synthesis formula of polythiophene derivative consisting of repeating unit represented by:

[0193]

[Chemical formula 129]

0.838 g of thiophene derivative represented by
(10.0 mmol) was added to a solvent containing 10 ml of tetrahydrofuran containing 0.486 g (3.0 mmol) of FeCl _{3 to} obtain a homogeneous mixture. The mixed solution was applied onto a glass plate and the solvent was gradually evaporated to form a polymerized film on the glass plate.
The polymer film was thoroughly washed with ethanol until the washing liquid was not colored, and dried. The polymerization yield of the film was 78%.

The dried polymer film was prepared by using tetrahydrofuran, dimethylformamide, diethyl ether, ethyl acetate,
It was dissolved in a general-purpose organic solvent such as acetone.

The obtained polymer was analyzed by ¹ H-NMR analysis, I
It was identified by R spectrum analysis and confirmed to be the target.

¹ H-NMR spectrum analysis results (δ, p
_{pm, CDCl 3): 0.80~2.00 (} 32H), 4.00 (4H), 4.
15 (4H), 6.99 (4H), 7.59 (8H), 8.09 (4H) IR spectrum analysis result (cm ^-1 , KBr): Absorption derived from ester: 1725, 1260 Absorption derived from cyano: 2240 Derived from ether Absorption: 1100 The molecular weight of this polymer is GPC (tetrahydrofuran)
As a result, the number average molecular weight in terms of polystyrene was Mn = 8400.

The phase transition behavior was as follows.

[0199]

[Chemical 130]

In addition, a tetrahydrofuran polymer solution (2
(Wt%) was cast on a glass plate, and after removing the solvent, a film was obtained.

A film obtained by uniaxially stretching and orienting this polymer at 200% at 130 ° C. at a speed of 1 cm / sec was subjected to an AC electric field of 2 × 10.
^{When 6} V / m was applied and the change in the amount of transmitted light was measured,
The contrast ratio was 20: 1 and the response time at 50 ° C was 0.5 s.

[0202]

INDUSTRIAL APPLICABILITY The polythiophene derivative of the present invention has a specific liquid crystal group in its side chain, and therefore is soluble in a general-purpose organic solvent and exhibits liquid crystallinity in a wide temperature range. Further, a roll film forming method or the like can easily form a thin film having a thickness of several tens of μm or less and good flatness and stability, and can be easily stretched at a high ratio. As a result, a liquid crystal group It is a polythiophene that is practically advantageous in that it can be improved in orientation and can be remarkably improved in liquid crystallinity such as contrast ratio. Therefore, the polymer of the present invention can be advantageously used as a display device having a large screen or a bent screen, an optical shutter and a light control material, and is useful as various electro-optical devices.

Claims (4)

[Claims] 1. A compound represented by the general formula (I): (In the formula, k is an integer of 1 to 30, R ¹ is a hydrogen atom or an alkyl group having 1 to 30 carbon atoms, and R ² is [Chemical 3] (Wherein, R ³ is _{-CN, -NO 2, - (CH} 2) m CH
₃ (m = _0~29) or _{-O- (CH 2) n CH 3} (n
A polythiophene derivative having a repeating unit represented by the following)). 2. General formula (II): A polythiophene derivative having a repeating unit represented by the formula (k and R ² are the same as above). 3. General formula (III): The method for producing a polythiophene derivative according to claim 1, wherein the thiophene derivative represented by the formula (k, R ¹ and R ² are the same as above) is electrolytically or oxidatively polymerized. 4. General formula (IV): The method for producing a polythiophene derivative according to claim ² , wherein the thiophene derivative represented by the formula (wherein k and R ² are the same as above) is electrolytically or oxidatively polymerized.