JPH06321935A - Monomer and polymer, and production of polymer - Google Patents

Abstract

PURPOSE:To provide a method for producing a polymer, having a mesogen group (a molecule capable of manifesting a liquid crystal phase by itself) as the side chain and excellent in performance. CONSTITUTION:A 2,5-dihalogenothiophene derivative having a mesogen group at the 3- and/or the 4-positions thereof, e.g. a compound expressed by formula I {X is halogen; R1 is H, cyano, alkyl, substitutive phenyl or benzyl, COR3 (R3 is alkyl, phenyl or benzyl), etc.; R2 is expressed by formula II [Y is single bond, 1-12C alkylene, phenylene, CO, COO, COOalk, COOalkO, etc., (alk is 1-12C alkylene); Z is HC=CH, CH=NNH, N=N(O), C=C, S, etc.; (r) is H, NO2, CN, halogenoalkyl, etc.]reacted with a metal selected between and Zn in the presence of a transition metallic compound to produce a thiophene polymer having the mesogen group in the side chain, e.g. a polymer containing a compound expressed by formula III [alk' is 1-12C alkylene; (k) is 0 or 1; (r') is CN or alkoxy] as a constituent unit and having 1000-20000 number-average molecular weight.

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 therein.

[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 oxidative polymerization method and a chemical oxidative polymerization method are known. (JP-A-2-22742
7, UKPat. 2222508)

However, these polymers contain many impurities (for example, polymerization oxidants, by-products) in the polymer.
However, despite the introduction of the mesogen group and the introduction of a mesogenic group, there were drawbacks such as thermal phase transitions peculiar to liquid crystal molecules, which were difficult to observe.
Moreover, these polymers were insoluble in general solvents, and it was difficult to conduct detailed research and materialization.

[0004]

SUMMARY OF THE INVENTION The present invention provides a method for producing a thiophene polymer having a mesogenic group as a side chain and having excellent performance, and a monomer and a polymer used therefor.

[0005]

According to the present invention, a 2,5-dihalogenothiophene derivative having a mesogenic group at the 3- and / or 4-position is treated 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, characterized by reacting, and a monomer and a polymer used therein.

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

[Chemical 4] {In the formula, X represents a halogen atom, R ₁ represents hydrogen, cyano, alkyl, optionally substituted phenyl or benzyl, and COR ₃ (wherein R ₃ represents alkyl, optionally substituted phenyl or benzyl. .) Or -COOR
₄ (wherein R ₄ is hydrogen, alkyl, optionally substituted phenyl or benzyl), and R ₂ is

[Chemical 5] [Wherein Y is a direct bond, branched or straight chain 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-
(Here, alk and alk 'represent branched or linear alkylene having 1 to 12 carbon atoms), and Z represents -HC.
= CH-, -CH = NNH-, -N = N (O)-, -C
≡C-, -COO-, -N = N-, -S- or a direct bond is shown, and r may have hydrogen, nitro, cyano, halogen such as fluorine, or an asymmetric carbon and may be substituted. alkyl or alkoxy, -COR ₆ (wherein R ₆ represents optionally substituted alkyl may have an asymmetric carbon, phenyl which may be substituted.), - COOR ₇ or OCO
R ₈ (wherein R ₇ and R ₈ represent hydrogen, alkyl which may have an asymmetric carbon and may be substituted, or phenyl which may be substituted). ]] Is a thiophene derivative.

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]

[Chemical 6]

[0009]

[Chemical 7]

[0010]

[Chemical 8]

After completion of the reaction, the desired product can be obtained by carrying out usual post-treatment. The structure is IR, NMR,
Determined from MS etc.

Polymerization reaction is carried out at room temperature to room temperature in an inert solvent such as DMF or HMPA.
Perform at 180 ° C. The halogen of the 2,5-dihalogenothiophene derivative used in the present invention is preferably bromine or iodine, and 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 nickel complex is generally used, such as a system containing PPh ₃ or 2,2′-bipyridine: bpy, 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. As the post-treatment, the target product can be obtained by carrying out a usual post-treatment.

Polymer According to the process of the present invention, the number average molecular weight is usually 100
0 to 20,000 are obtained, which are suitable for being soluble in organic solvents. Further, a copolymer with a copolymerizable monomer (eg, 2,5-dihalogenothiophene derivative) is also possible.

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

[0015]

EXAMPLES The present invention will be described in detail below with reference to examples.

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

[Chemical 9] To a reaction vessel equipped with a thermometer and a stirrer, 2.9 g (11.0 mmol) of 11-bromoundecanoic acid and 4.2 ml of thionyl chloride were added 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, separation and purification by column chromatography gave the desired product. (Ii) Synthesis of 2,5-dibromo-3- [4 '-(4-cyanobiphenyl) oxy] undecanecarbonyloxymethylthiophene

[Chemical 10] In a reaction vessel equipped with a thermometer and a stirrer, 4-hydroxy-
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 the mixture was refluxed. 1.95 g (3.76 mmol) of the product of (i) was added thereto, 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.

Examples of the monomer precursors are shown in Table 1.

[Table 1]

Examples of monomers, including the above examples, are shown in Table 2.

[Table 2]

Example 2 Preparation of Polymer

[Chemical 11] Nickel (II) bromide 0.089 in a well-dried reaction vessel
g (0.41 mmol), triphenylphosphine 0.
799 g (3.04 mmol) and zinc [obtained by stirring in acetic acid, washing with ether and vacuum drying] 0.799 g (1
2.22 mmol) was added. After degassing with a vacuum pump, the atmosphere was replaced with nitrogen, and this operation was repeated 3 times. Dimethylformamide (D
3 ml of MF) was added, and the mixture was stirred at 50 ° C. for 30 minutes under a nitrogen atmosphere. 1.285 g (2.03 mmol) of No. 3 dissolved in 3 ml of DMF was added to the reddish brown contents. The compound of 5 (DiBrESCN-10) was added dropwise, and after completion of the addition, the mixture was stirred at 60 ° C. for 20 hours in a nitrogen atmosphere. After completion of the reaction, the content was concentrated and poured into ether to obtain a precipitate. After washing with a hydrochloric acid / methanol mixture, the mixture was washed with methanol until it became 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%

Examples of polymers obtained in the same manner as in the above Examples are shown in Table 3.

[Table 3]

Test Example 1 Liquid Crystalline Property 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 observation with a polarizing microscope, a fan-shaped structure peculiar to the smectic phase was observed, and No. 1 which exhibited a liquid crystal phase in a wider temperature range. CV measurement of 10 polymers (PDiBrECB-12) was performed. The result is shown in FIG. In FIG. 1, heat is applied to once transform to the isotropic phase, and then the temperature is gradually lowered to grow the structure, and then the measurement is performed. 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 spectroscopy of cast films of 10 polymers (PDiBrECB-12) was performed. The result is shown in FIG. The heat treatment is the one in which the structure is grown by gradually changing the temperature to the isotropic phase and gradually lowering the temperature. From the figure, it can be seen that the absorption due to the π-π ^* conjugated system is shifted from 400 nm to 410 nm. This seems to be due to the increase of the effective conjugation length due to the improvement of the orientation of the polymer main chain. In addition, the absorption of 293 nm due to cyanobiphenyl is greatly reduced by the heat treatment. This is probably because the orientation of the side chains is perpendicular to the light source. From this, it was found that the orientation of the main chain was improved along with the orientation of the side chains, and the effective conjugation length was increased.

[0024]

The manufacturing method of the present invention is soluble in an organic solvent, has few impurities, and the film has a clear thermal phase transition and electric activity, and has the same two basic characteristics of liquid crystallinity and electric activity. It is a suitable method for obtaining a polymer having excellent performance in the molecule. Further, the polymer obtained in the present invention is soluble in general organic solvents, can be easily applied to coating techniques such as the conventional spin coating method, and can control the arrangement of coating films by heat, electrolysis, etc. Can be considered. Especially electrical and electronic devices,
It can be applied to optical elements. For example, an anisotropic conductive material, a dielectric material, an optical switch, a memory material, an alignment film, or the like can be given.

[Brief description of drawings]

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

FIG. 2 No. 10 polymers (PDiBrECB-1
It is a UV-visible spectrum of the cast film of 2).

Claims (3)

[Claims] 1. A 2,5-dihalogenothiophene derivative having a mesogenic group at the 3- and / or 4-position is reacted 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. The formula [I]: {In the formula, X represents a halogen atom, R ₁ represents hydrogen, cyano, alkyl, optionally substituted phenyl or benzyl, and COR ₃ (wherein R ₃ represents alkyl, optionally substituted phenyl or benzyl. .) Or —COOR ₄ (wherein R ₄ represents hydrogen, alkyl, optionally substituted phenyl or benzyl).
And R ₂ is [Wherein Y is a direct bond, branched or straight chain 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-
(Here, alk and alk 'represent branched or linear alkylene having 1 to 12 carbon atoms), and Z represents -HC.
= CH-, -CH = NNH-, -N = N (O)-, -C
≡C-, -COO-, -N = N-, -S- or a direct bond, and r is hydrogen, nitro, cyano, halogen, an alkyl or alkoxy which may have an asymmetric carbon and may be substituted. , —COR ₆ (wherein R ₆ represents alkyl which may have an asymmetric carbon and may be substituted, or phenyl which may be substituted), —COOR ₇ or OCOR ₈ (here, R ₇ , R ₈ represents hydrogen, an optionally substituted alkyl having an asymmetric carbon, or an optionally substituted phenyl)
Indicates. ]} The thiophene derivative represented by these. 3. The formula [II]: {In the formula, alk and alk 'have the same meanings as described above, and k
Represents 0 or 1, and r ′ represents cyano or alkoxy. } The polymer which has the compound represented by these as a structural unit, and has a number average molecular weight of 1,000 to 20,000.