JP3241866B2 - Method for producing polymer and polymer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a process for producing a thiophene polymer having a mesogen group (a molecule which exhibits a liquid crystal phase by itself) as a side chain and having excellent performance, and a monomer and a polymer used for the process.

[0002]

2. Description of the Related Art As a method for producing a thiophene polymer having a mesogen group as a side chain, an electrolytic oxidation polymerization method and a chemical oxidation polymerization method are known. (UKPat.22250
08)

[0003] However, these polymers have many impurities (for example, polymerization oxidizing agents and by-products) in the polymers.
However, despite the introduction of mesogen groups, there is a disadvantage that a thermal phase transition peculiar to liquid crystal molecules is hardly observed.
In addition, these polymers are insoluble in general solvents and difficult to carry out detailed research and materialization.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for producing a thiophene polymer having a mesogen group as a side chain and having excellent performance, and a monomer and a polymer used therefor.

[0005]

The present invention provides a 2,5-dihalogenothiophene derivative having a mesogen group at the 3- and / or 4-position with a metal selected from the group consisting of magnesium and zinc in the presence of a transition metal compound. A method for producing a thiophene polymer having a mesogen group as a side chain, and a monomer and a polymer used for the method.

The 2,5-dihalogenothiophene derivative having a mesogen group at the 3- and / or 4-position used in the present invention has a mesogen group only at one of the 3- or 4-position.
The other may be substituted with a substituent. These are, for example, of the formula [I]

Embedded image In the formula, X represents a halogen atom, R ₁ represents hydrogen, cyano, alkyl, phenyl or benzyl which may be substituted, COR ₃ (where R ₃ represents alkyl, phenyl or benzyl which may be substituted) .) Or -COOR
₄ wherein R ₄ represents hydrogen, alkyl, phenyl or benzyl which may be substituted, and R ₂ represents

Embedded image [Where Y is a direct bond, a branched or linear alkylene having 1 to 12 carbon atoms, phenylene, -CO-, -C
OO-, -COOalk-, -COOalkO-, -C
OOalkN (R ₅₎ - (wherein R ₅ is alkyl.), - alkCOOalk'O -, - alkO-,
-AlkOalk'O-, -alkOCOalk'O-
(Where alk and alk 'represent a branched or straight-chain alkylene having 1 to 12 carbon atoms), and Z is -HC.
= CH-, -CH = NNH-, -N = N (O)-, -C
≡C-, -COO-, -N = N-, -S- or a direct bond, and r may have hydrogen, nitro, cyano, halogen such as fluorine, asymmetric carbon, or may be substituted Alkyl or alkoxy, -COR ₆ (where R ₆ represents alkyl which may have an asymmetric carbon or may be substituted, phenyl which may be substituted), -COOR ₇ or OCO
And R ₈ (where R ₇ and R ₈ represent hydrogen, alkyl optionally having asymmetric carbon and optionally substituted, and phenyl optionally substituted). ] The thiophene derivative represented by｝.

The 2,5-dihalogenothiophene derivative having a mesogen group at the 3- and / or 4-position used in the present invention is produced by appropriately selecting the following reaction formula or a known similar reaction.

[0008]

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[0009]

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[0010]

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After completion of the reaction, the desired product can be obtained by performing ordinary post-treatments. The structures are IR, NMR,
Determined from MS and the like.

The polymerization reaction is carried out in an inert solvent such as DMF or HMPA at room temperature to
Perform at 180 ° C. The halogen of the 2,5-dihalogenothiophene derivative used in the present invention is preferably bromine or iodine, and is preferably a compound having high reactivity with a transition metal compound. Further, as a transition metal compound as a catalyst, tetrakis (triphenylphosphine) nickel:
Ni (PPh ₃ ) ₄ , bis (1,5-cyclooctadiene) nickel: Ni (cod) ₂ or Ni (co
d) Triphenylphosphine as a neutral ligand in ₂ :
A zero-valent complex of nickel is generally used, such as a system to which PPh ₃ or 2,2′-bipyridine: bpy is added, or a system obtained by reducing a divalent nickel compound. The amount of the catalyst is 0.01 to 2 equivalents, preferably 0.05 to 0.8 equivalents, and more preferably 0.05 to 0.5 equivalents, based on the raw material organic compound. In the post-treatment, the target product is obtained by performing ordinary post-treatment.

According to the preparation of the polymers present invention, the number average molecular weight typically 1,00
0 to 20,000 are obtained, which are suitable organic solvent soluble. Further, a copolymer with a copolymerizable monomer (for example, a 2,5-dihalogenothiophene derivative or the like) is also possible.

Polymer film The obtained polymer is dissolved in an organic solvent, and a film can be formed by, for example, a casting method, an immersion method, a spray method, an ultrasonic atomization method, a spin coating method or the like. Incidentally, if necessary, mixing of the polymers obtained in the present invention, mixing with other polymers, stabilizers, various inorganics including plasticizers, etc.
Numerous treatment methods well known in the art, such as the addition of additives such as organics and metals, can also be used.

[0015]

Next, the present invention will be described in detail with reference to examples.

Example 1 Production of Monomer (i) Synthesis of 2,5-dibromo-3- (11-bromoundecanecarbonyloxy) methylthiophene

Embedded image 2.9 g (11.0 mmol) of 11-bromoundecanoic acid and 4.2 ml of thionyl chloride were added to a reaction vessel equipped with a thermometer and a stirrer, and reacted at 50 ° C. for 3 hours. After completion of the reaction, excess thionyl chloride was distilled off to obtain 11-bromoundecanoyl chloride. Next, 3.0 g (11 mmol) of 2,5-dibromo-3-hydroxymethylthiophene, 2.8 g (27.7 mmol) of triethylamine and 20 ml of THF were added to another reaction vessel, and TH was added through a dropping funnel.
11-Bromoundecanoyl chloride dissolved in 15 ml of F was added dropwise and stirred overnight. After completion of the reaction, THF and triethylamine were distilled off, and the obtained product was dissolved in chloroform and washed with water. After dehydration with a desiccant, the product was separated and purified by column chromatography to obtain the desired product. (Ii) Synthesis of 2,5-dibromo-3- [4 '-(4-cyanobiphenyl) oxy] undecanecarbonyloxymethylthiophene

Embedded image 4-hydroxy- was added to a reaction vessel equipped with a thermometer and a stirrer.
0.74 g (3.76 mmol) of 4'-cyanobiphenyl and 1.3 g (9.3 mmol) of anhydrous potassium carbonate,
40 ml of acetone and a catalytic amount of potassium iodide were added and refluxed. Thereto was added 1.95 g (3.76 mmol) of the product (i), and the mixture was refluxed for 24 hours. After completion of the reaction, the solvent was distilled off and the residue was dissolved in chloroform and washed with water. After dehydration, it was separated and purified by column chromatography.

Table 1 shows examples of monomer precursors.

[Table 1]

Table 2 shows examples of monomers including the above examples.

[Table 2]

Example 2 Preparation of polymer

Embedded image 0.089 Nickel (II) bromide in a well-dried reaction vessel.
g (0.41 mmol), triphenylphosphine 0.1 g.
799 g (3.04 mmol) and zinc [agitated in acetic acid, washed with ether and dried in vacuum] 0.799 g (1
2.22 mmol) was added. After deaeration with a vacuum pump, the atmosphere was replaced with nitrogen, and this operation was repeated three times. There, dimethylformamide (D
MF), and the mixture was stirred at 50 ° C for 30 minutes under a nitrogen atmosphere. 1.285 g (2.03 mmol) of No. 1 dissolved in 3 ml of DMF was dissolved in the reddish brown contents. Compound 5 (DiBrESCN-10) was added dropwise, and after the completion of the addition, the mixture was stirred at 60 ° C. for 20 hours under a nitrogen atmosphere. After completion of the reaction, the content was concentrated and poured into ether to obtain a precipitate. After washing with a mixed solution of hydrochloric acid and methanol, the mixture was washed with methanol until neutral. After dissolving in chloroform, the mixture was poured into ether cooled in an ice bath to obtain a polymer. Yield 0.384g Yield 40.0%

Table 3 shows examples of polymers obtained in the same manner as in the above Examples.

[Table 3]

Test Example 1 Liquid Crystallinity of Polymer The results of measuring the phase transition temperature of the obtained polymer are shown in Table 3 above.

Test Example 2 Cyclic Voltammogram (CV) In a polarizing microscope observation, a fan-shaped structure peculiar to the smectic phase was observed, and a liquid crystal phase was developed in a wider temperature range. CV measurement of 10 polymers (PDiBrECB-12) was performed. The result is shown in FIG. FIG. 1 shows the results of measurement after the structure was grown by gradually lowering the temperature after the transition to the isotropic phase once by applying heat. Oxidation current and reduction current flowed, and the color of the polymer changed to blue in the oxidation state and orange in the reduction state.

Test Example 3 (UV-Visible) Spectrum No. UV-visible spectrum measurement was performed on cast films of 10 polymers (PDiBrECB-12). The result is shown in FIG. The heat treatment is a process in which the structure is once transformed into an isotropic phase and the temperature is gradually lowered to grow the structure. From the figure, it can be seen that the absorption due to the π-π ^* conjugate system shifts from 400 nm to 410 nm. This is thought to be due to an increase in the effective conjugate length due to the improvement in the orientation of the polymer main chain. Further, the absorbance at 293 nm caused by cyanobiphenyl is greatly reduced by the heat treatment. This seems to be due to the orientation direction of the side chain being perpendicular to the light source. From this, it was found that the orientation of the main chain was improved together with the orientation of the side chain, and the effective conjugate length was increased.

[0024]

According to the production method of the present invention, the film is soluble in an organic solvent, has few impurities, and the film has a clear thermal phase transition and electrical activity, and has the same two basic characteristics of liquid crystallinity and electrical activity. This is a preferable method for obtaining a polymer having excellent performance in a molecule. In addition, the polymer obtained in the present invention is soluble in general organic solvents, can be easily applied by a conventional coating technique such as spin coating, and can control the arrangement of coating films by heat, electrolysis, and the like. Can be considered. Especially electrical and electronic devices,
Applicable to optical elements. For example, there are an anisotropic conductive material, a dielectric material, an optical switch, a memory material, an alignment film, and the like.

[Brief description of the drawings]

FIG. 10 polymers (PDiBrECB-1)
It is a cyclic voltammogram of 2).

FIG. 10 polymers (PDiBrECB-1)
It is a UV-visible spectrum of the cast film of 2).

Claims (2)

(57) [Claims] 1. A method comprising reacting a 2,5-dihalogenothiophene derivative having a mesogen group at the 3- and / or 4-position with a metal selected from the group consisting of magnesium and zinc in the presence of a transition metal compound. A method for producing a thiophene polymer having a mesogen group as a side chain. 2. A compound of the formula [II] 中 wherein alk and alk 'are branched or linear carbon
Represents an alkylene of the formulas 1 to 12 , k represents 0 or 1,
r 'represents cyano or alkoxy. A polymer having a compound represented by｝ as a constituent unit and having a number average molecular weight of 1,000 to 20,000.