JP2713361B2 - Poly (2,2'-bithiazole-5,5'-diyl) polymer having long-chain alkyl group, method for producing and using the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a dihalogenated aromatic compound having a long-chain alkyl group as a substituent, for example, 5,5'-dihalogenated-2,2'-bithiazole,
A divalent residue obtained by removing two halogen atoms from 2,2'-dihalogenated-5,5'-bithiazole as a repeating structural unit, having a π-conjugated system along the main chain, and (2,2'-bithiazole) having a novel alkyl substituent which is rendered conductive by dynamic doping, exhibits high stability in air, is soluble in organic solvents, and is a ligand for a metal element -5,5'-diyl) polymer and its production and use.

[0002]

2. Description of the Related Art In recent years, π-conjugated high molecular compounds have been attracting attention as electrically and optically functional materials. These π
Conjugated polymer compounds have a one-dimensional π-electron spread along the main chain, so that the electrical and optical anisotropy between the direction along the main chain and the direction perpendicular to the direction is large. Can be seen. To exert this anisotropy effectively, it is important to orient the main chain of the polymer, but the one-dimensional spread of π electrons makes these polymers rigid, insoluble and infusible. Therefore, it is difficult to control and orient to an arbitrary shape. As these conductive polymers, various substances having a π-conjugated system along the main chain, for example, those shown in the following Chemical Formula 17 are known.

[0003]

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[0004]

However, most of the π-conjugated conductive polymers proposed hitherto have a rigid structure and are often insoluble and insoluble in organic solvents and the like. There is no special processing means. Therefore, the moldability and shapeability are poor, and the use thereof is also limited, which is a problem in bringing out their characteristic functions. For this reason, attempts have been made to improve the solubility of polythiophene, poly-p-phenylene, polypyrrole and the like in organic solvents by introducing a substituent.

[0005] However, these substances only become p-type conductors mainly by oxidation. Therefore, it is desired to develop a substance having physical properties not found in the conventional conductive polymer by devising the molecular structure. For example, unlike a conventional conductive polymer, if a π-conjugated conductive polymer that can easily become an n-type conductor in combination with a p-type conductor can be obtained, it can be used as a material for a semiconductor device.

Further, when a polymer having a main chain having π-conjugated conductivity and exhibiting a rigid structure acts on a metal element as a ligand, for example, the ligand has a semiconductor band structure. Thus, a polymer metal complex having a non-conventional electronic state and a non-conventional coordination state such as easily exhibiting a coordination unsaturated state due to the rigidity of the ligand can be obtained.

For example, the following chemical formula 18

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The poly (2,2'-bipyridine-5,5'-diyl) represented by the formula (1) is a substance which is liable to become an n-type conductor by reduction, and has a repeating structural unit such as 2,2'-bipyridine. It has a coordinating ability for metal elements due to its high chelating ligand structure, but it is soluble only in specific solvents such as formic acid or concentrated sulfuric acid, and its use is extremely narrow. Has a high molecular weight, so that a durable film or the like cannot be obtained, and there is a problem that its use range is narrowed.

The polyalkylpyridine represented by the above formula has a sufficiently high molecular weight, exhibits high solubility in general organic solvents such as chloroform, and is a substance which easily becomes an n-type conductor by reduction. However, since it has an alkylpyridine structure as a repeating constitutional unit and is mainly constituted by a head-to-tail bond, there is a problem that the ability to coordinate to a metal ion or the like is considerably poor as a whole.

Under the above circumstances, the present invention has been completed as a result of a search for a conductive polymer having a new molecular structure and an intensive study to solve the above problems.

An object of the present invention is to have a sufficiently high molecular weight, excellent heat resistance, solubility in an organic solvent, control of the degree of depolarization and electrochemical redox potential, and an effect on metal atoms. A poly (2,2'-bithiazole-5,5'-diyl) polymer having a novel alkyl substituent serving as a ligand and a method for producing the same.

Another object of the present invention is to provide such novel poly (2,2'-bithiazole-
The 5,5′-diyl) polymer is converted into a molded product such as a fiber or a film, a conductive material such as an n-type conductor, a material for a battery, an electrochromic device material, a material for an electronic device such as a transistor or a diode, and further, It is used as an effective ligand for a metal element.

[0013]

SUMMARY OF THE INVENTION The present invention relates to a dihalogenated aromatic compound having 5,5'-dihalogenated-2,2 'having a long-chain alkyl group as a substituent at the 4-position of two thiazole groups. -2,2'-dihalogenated-5 having a bithiazole or a long-chain alkyl group at the 4-position as a substituent
5'-bithiazole which is derived by removing two halogen atoms from

[0014]

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[0015]

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(Wherein R and R 'represent H or an alkyl group having 1 or more carbon atoms, and at least one of R and R' represents a long-chain alkyl group having 4 or more carbon atoms). And the degree of polymerization (n) is 10
This is achieved by the above-mentioned alkyl-substituted poly (2,2'-bithiazole-5,5'-diyl) polymer. Here, if the degree of polymerization (n) is less than 10, it may not be possible to exert a sufficient function as a polymer. In addition, the present inventors have experimentally confirmed the excellent properties and usefulness of the polymer of the present invention by the production method described below, but the polymer of the present invention is not limited to Examples. .

Further, at least one of the alkyl groups (R, R ') is a long-chain alkyl group having at least 4 carbon atoms, for example, a hexyl group, a pentyl group, an octyl group, a decyl group, a dodecyl group and the like. R and R 'may both be a long-chain alkyl group having 4 or more carbon atoms, or only one of them may be a long-chain alkyl group having 4 or more carbon atoms. R, R '
When only one of them is a long-chain alkyl group having 4 or more carbon atoms, the other may be H or a short-chain alkyl group having 1 or 2 carbon atoms. If the carbon number of both R and R 'is less than 4, it is not preferable because it becomes difficult to dissolve in an organic solvent. Further, the compound of the present invention has such a long-chain alkyl group in its structure, and therefore has a sufficiently high molecular weight. The dihalogenated aromatic compound can be obtained, for example, by the following method. Next Formula 21

[0018]

Embedded image Is reacted with sodium hydride, n-butyllithium, and alkyl halide (the alkyl group has 3 or more carbon atoms) in a tetrahydrofuran solution to alkylate the methyl acetoacetate (manufactured by Tokyo Chemical Industry Co., Ltd.). To produce a compound represented by the formula:

[0019]

Embedded image (R in the formula represents an alkyl group having 4 or more carbon atoms.) A compound represented by the above formula (22) is chlorinated with sulfuryl chloride to obtain a compound represented by the formula (23).

[0020]

Embedded image Then, the mixture is refluxed in an aqueous sulfuric acid solution to produce 1-chloroketone represented by the following formula.

[0021]

Embedded image Dithiooxamide is added to this ethanolic solution of 1-chloroketone and reacted under reflux to obtain 4,4'-dialkyl-2,2'-bithiazole shown in Chemical formula 25.

[0022]

Embedded image Then, the 4,4'-dialkyl-2,2'-bithiazole and the halogen are refluxed in chloroform to obtain a dihalogenated aromatic compound represented by the following formula (26). An inventive polymer is produced.

[0023]

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The novel alkyl-substituted poly (2,2) of the present invention
The 2'-bithiazole-5,5'-diyl) polymer can be formed into a good fiber or film after dissolving in an organic solvent by utilizing its excellent properties, and the polymer can be used as a reducing agent or a chemical.・ Reduced by electrochemical doping, battery material, electrochromic device material,
It can be used as a material for an electronic element such as a transistor or a diode, a conductive material such as an n-type conductor, or a ligand for a metal element.

The alkyl-substituted poly (2,3- (2)) according to the present invention
The 2'-bithiazole-5,5'-diyl) polymer can be prepared by adding a dihalogenated aromatic compound represented by the formula (28), for example, an alkyl-substituted 5,5'-dihalogenated-2,2'-bithiazole in an organic solvent. It is obtained by adding and reacting at least a mole of a zero-valent nickel compound and dehalogenating. A suitable reaction temperature is between room temperature and the boiling point of the solvent, and the reaction is completed in about 1 to 48 hours. Examples of the organic solvent include N, N-dimethylformamide,
Acetonitrile, toluene, tetrahydrofuran and the like are applicable.

A zero-valent nickel compound takes a halogen from a halogenated aromatic compound and causes a coupling reaction between aromatic groups [for example, “Synthesis”,
736 (1984)]. This reaction is represented by the following chemical formula 29.

[0027]

Embedded image (Where Ar and Ar ′ represent aromatic groups, X represents a halogen atom, L represents a neutral ligand, and therefore NiLm represents a zero-valent nickel compound.)

Therefore, when an aromatic compound having two halogens in a molecule, for example, an alkyl-substituted 5,5'-dihalogenated-2,2'-bithiazole is reacted with an equimolar or more zero-valent nickel compound, The polymer is obtained by the dehalogenation reaction shown in Chemical formulas 28 and 29.

[0029]

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[0030]

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Here,

[Outside 1] Is an alkyl-substituted 5,5'-dihalogenated-2,2'-bithiazole (R and R 'are H or an alkyl group having 1 or more carbon atoms, and at least one of R and R' has 4 or more carbon atoms)
The above is a long-chain alkyl group, and X represents halogen.

In the above reaction, the zero-valent nickel compound is added to the reaction system immediately before the polymerization reaction (so-called in situ).
The synthesized product can be used as it is, or a product synthesized and isolated in advance can be used. Such a zero-valent nickel compound is, for example, a nickel complex generated by a reduction reaction or a ligand exchange reaction in the presence of a neutral ligand, and the neutral ligand includes 1,5-cyclooctadiene, 2,2'-bipyridine, triphenylphosphine and the like can be exemplified.

The present invention will be described more specifically and in detail by the following examples and comparative examples.

Example 1 0.40 g of bis (1,5-
Cyclooctadiene) nickel complex (Ni (cod) ₂ ) (1.
4 mmol) and 0.22 g of 2,2'-bipyridine (bpy)
(1.4 mmol) was added to 60 ml of N, N-dimethylformamide (DMF), and an additional 0.50 g of 5,5'-dibromo-4,4'-diheptyl-2,2'-bithiazole (0.96 mmol) was added. added. This solution was reacted at a reaction temperature of 60 ° C. for 48 hours to perform polymerization. As the polymerization proceeds, the alkyl-substituted poly (2,2′-bithiazole-
A brown precipitate of (5,5'-diyl) polymer was formed. After the completion of the reaction, the precipitate is collected by filtration, and the following (a) to
Using the substance (e), the polymer was washed several times in the following order to purify the polymer.

(A) Ammonia water (28%), (B) Methyl alcohol, (C) Warm aqueous solution of disodium ethylenediaminetetraacetate, (D) Distilled water, (E) Wash with methyl alcohol, vacuum dry, brown 0.30 g of an alkyl-substituted poly (2,2'-bithiazole-5,5'-
Diyl) polymer was obtained. The yield of the polymer was 90%.

FIG. 1 shows the infrared absorption spectrum of this polymer. At 2840 to 2960 cm ^-1 , CH stretching vibration due to a heptyl group in the side chain is observed, and at 1370 to 1480 cm ^-1 , absorption due to skeleton vibration of the thiazole ring and bending vibration of the methylene group in the side chain are observed.

In addition, the polymer in chloroform-d
FIG. 2 shows the ¹ H-NMR. δ = 0.8-3.0 ppm
(Internal standard: tetramethylsilane), a peak derived from a side chain heptyl group, and a peak derived from terminal thiazole ring hydrogen were observed at δ = 7.0 ppm. The elemental analysis value of the obtained polymer was 64.1% for carbon, 8.6% for hydrogen, and 7.7% for nitrogen.
Met.

Infrared absorption spectrum,¹H-NMR, element
The result of the analysis indicates that the polymer has a structure shown in the following formula.
I support that. In addition, based on Chemical Formula 30, (C
₂₀H ₃₀N_TwoS_Two)_nOf the elemental analysis calculated for carbon was 66.2.
%, 8.4% of hydrogen and 7.7% of nitrogen.

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Since the above polymer has a long-chain alkyl group as a side chain, it was soluble not only in acid solvents such as trifluoroacetic acid and dichloroacetic acid but also in chloroform (dissolution amount: about 1 mg / ml). It was also partially soluble in toluene, tetrahydrofuran, ether, etc. (to the extent that the solution was colored yellow). The polymer was found to have a polymerization average molecular weight of 1100 (based on polystyrene) by gel permeation chromatography.

Poly (4,4'-diheptyl-2,2'-
The UV-visible absorption spectrum of (bithiazole-5,5'-diyl) showed an absorption peak derived from a π-π ^* transition at about 420 nm in trifluoroacetic acid and about 410 nm in chloroform.

Example 2 0.94 g of bis (1,5-
Cyclooctadiene) nickel complex (Ni (cod) ₂ ) (3.
4 mmol) and 0.53 g of 2,2'-bipyridine (bpy)
(3.4 mmol) was added to 60 ml of N, N-dimethylformamide (DMF), and 1.0 g of 5,5'-dibromo-4,4'-dibutyl-2,2'-bithiazole (2.3 mmol) was added. Was added. This solution was reacted at a reaction temperature of 60 ° C. for 48 hours to perform polymerization. As the polymerization proceeds, the alkyl-substituted poly (2,2′-bithiazole-5,
A brown precipitate of 5'-diyl) polymer formed. After the completion of the reaction, the precipitate is collected by filtration, and the following (a) to (e)
Was washed several times in the following order using this substance, and the polymer was purified.

(A) Aqueous ammonia (28%), (b) methyl alcohol, (c) a hot aqueous solution of disodium ethylenediaminetetraacetate, (d) distilled water, (e) washing with methyl alcohol, vacuum drying, brown drying 0.50 g of an alkyl-substituted poly (2,2'-bithiazole-5,5'-
Diyl) polymer was obtained. The yield of the polymer was 80%.

FIG. 3 shows the infrared absorption spectrum of this polymer. At 2840 to 2980 cm ⁻¹ , CH stretching vibration due to the side chain butyl group is observed, and at 1370 to 1560 cm ⁻¹ , absorption due to skeleton vibration of the thiazole ring and bending vibration of the side chain methylene group are observed.

FIG. 4 shows ¹ H-NMR of the polymer in deuterated trifluoroacetic acid. δ = 0.6-3.3 pp
In m, a butyl group in the side chain was observed, and in δ = 7.8 ppm, a peak derived from hydrogen at the terminal thiazole ring was observed. The elemental analysis value of the obtained polymer was 59.5% for carbon and 6 for hydrogen.
7% and nitrogen 9.8%.

The results of the infrared absorption spectrum, ¹ H-NMR, and elemental analysis support that the polymer has a structure represented by the following formula. In addition, 0.3 molecules of water are contained as water of hydration in the repeating unit of the formula (C ₁₄ H _{18).
N 2 S 2 · 0.3H 2 O} ) Calculated elemental analysis of _n carbon 59.4%, hydrogen 6.6%, a 9.9% nitrogen.

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Since the above polymer has a long-chain alkyl group as a side chain, it is not only soluble in acid solvents such as trifluoroacetic acid and dichloroacetic acid but also partially dissolved in chloroform, toluene, tetrahydrofuran, ether and the like. It was soluble (to the extent that the solution turned yellow).

When the molecular weight of poly (4,4'-dibutyl-2,2'-bithiazole-5,5'-diyl) was measured by a light scattering method in trifluoroacetic acid, the weight average molecular weight was 21,000 (degree of polymerization). 75).

The ultraviolet-visible absorption spectrum of poly (4,4'-dibutyl-2,2'-bithiazol-5,5'-diyl) was π-π at about 420 nm in trifluoroacetic acid.
^* Shows an absorption peak derived from the transition.

Example 3 The poly (4,4'-dialkyl-2,2'-bithiazole) obtained in Examples 1 and 2
A chloroform solution or a trifluoroacetic acid solution of a 5,5'-diyl) polymer was applied to a platinum electrode, and the solvent was removed to prepare a polymer film. It was confirmed by infrared spectroscopy that substantially no solvent remained in these films. The cyclic voltammogram of the polymer film was measured in an acetonitrile solution containing 0.1 mol / 1 of (C ₂ H ₅ ) ₄ NBF ₄ . As a result, all of the present polymers were Ag / Ag ⁺
Cation is doped at about -2.1 V (n-type doping), and about -1.9 V in reverse sweep.
The cation was found to be undoped (relative to Ag / Ag ⁺ ). At the time of doping, the color of the polymerized film changed from reddish brown to black, and the reverse coloration was observed during undoping. Thus, both of the present polymers were capable of electrochemical reduction, that is, electrochemical n-type doping, and exhibited electrochromic properties together with the doping. This indicates that the polymer has n-type conductivity and can be used as a battery electrode material and an electrochromic device material.

The poly (4,4'-diheptyl-2,2'-bithiazole-5,5'-diyl) polymer obtained in Example 1 was dissolved in a trifluoroacetic acid solution and a chloroform solution at a ratio of 1.0.times. It was prepared at a concentration of 10 ^-5 mol / 1. The excitation wavelength of this solution was 440 nm, 4
The fluorescence spectrum was measured at 20 nm. As a result, light emission was observed at 570 nm in a trifluoroacetic acid solution and at 560 nm in a chloroform solution. Example 2
In the trifluoroacetic acid solution (1.0 × 10 ⁻⁵ mol / 1 per unit structure) of the poly (4,4′-dibutyl-2,2′-bithiazole-5,5′-diyl) polymer obtained in The fluorescence spectrum was measured at an excitation wavelength of 430 nm. As a result, light emission was observed at 570 nm.

As described above, the present polymer is a substance having a fluorescence emission ability. This indicates that the present polymer can basically be used also as a material for electroluminescence.

Comparative Example 1 The same procedure as in Examples 1 and 2 was carried out except that 5,5'-dibutyl-4,4'-dimethyl-2,2'-bithiazole was used as a monomer. A poly (4,4'-dimethyl-2,2'-bithiazole-5,5'-diyl) polymer (weight average molecular weight by light scattering method was 3200) was obtained. This polymer was soluble in acid solvents such as trifluoroacetic acid and dichloroacetic acid, but was almost insoluble in general organic solvents because the side chain was a methyl group. On the other hand, when a long-chain alkyl group such as a butyl group is introduced into the side chain, not only is it soluble in acid solvents such as trifluoroacetic acid and dichloroacetic acid, but also the solubility in general organic solvents is remarkably improved. Was done.

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[0052]

According to the present invention, the novel alkyl-substituted poly (2,2)
The 2'-bithiazole-5,5'-diyl) polymer has a sufficiently high molecular weight, excellent heat resistance, and high stability in air because a long-chain alkyl group is introduced into its structure. Shows that it is soluble in many organic solvents,
The fields of application and applications are expanding, and dry molding into fibers, membranes, and the like is possible by using a solution obtained by dissolving in an appropriate solvent. Furthermore, by chemical and electrochemical reduction,
Shows a clear change in color, becomes an n-type conductor, has excellent properties not found in conventional conductive polymers used as electrochromic, photoluminescent, and electroluminescent materials, and coordinates with metal elements. Can be a child. The film or the fibrous substance obtained according to the present invention can be easily applied to a conductive film and a conductive fiber, and the application to an electrochromic device or an electroluminescent element can be realized by forming the film or the fibrous substance. Also,
According to the method of the present invention, a π-conjugated conductive polymer that easily becomes an n-type conductor together with a p-type conductor can be easily and inexpensively synthesized.

[Brief description of the drawings]

FIG. 1 is a diagram showing an infrared absorption spectrum of an example of the polymer of the present invention.

FIG. 2 is a diagram showing a proton NMR spectrum of an example of the polymer of the present invention.

FIG. 3 is a diagram showing an infrared absorption spectrum of another example of the polymer of the present invention.

FIG. 4 is a diagram showing a proton NMR spectrum of another example of the polymer of the present invention.

Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location D01F 6/74 D01F 6/74 Z H01B 1/12 H01B 1/12 Z H01L 51/00 H01L 29/28 (56 References. O. WOLF, M .; S. WRIG HTON, CHEM. MATER. , 6 (1994) 1526 I.P. H. JENKINS, P .; G. FIG. PICKUP, MACROMOLECULES ES, 26 (1993) 4450 BOLOGNESI, M .; CAT ELLANI, S.M. DESTR, W. PORZIO, SYNTH. MET. , 18 (1987) 129

Claims (7)

(57) [Claims] 1. The following chemical formula (1) or (2) derived from a dihalogenated aromatic compound having a long-chain alkyl group as a substituent at the 4-position of two thiazolediyl groups by removing two halogen atoms. ] Embedded image (In the formula, R and R ′ represent H or an alkyl group having 1 or more carbon atoms, and at least one of R and R ′ has 4 or more carbon atoms.
The above shows a long-chain alkyl group. A) a polyvalent (2,2'-bithiazole-) having an alkyl substituent having a degree of polymerization n of 10 or more as a repeating structural unit
5,5'-diyl) polymer. 2. The following chemical formula 3 or chemical formula 4 Embedded image (In the formula, R and R 'represent H or an alkyl group having 1 or more carbon atoms, and at least one of R and R' is a long-chain alkyl group having 4 or more carbon atoms, and X represents a halogen. A) reacting a dihalogenated aromatic compound represented by the formula (1) with a metal or a metal compound having a dehalogenating ability in the presence of a nickel compound, and dehalogenating two halogen atoms to polymerize the compound. Or 6 Embedded image (In the formula, R and R ′ represent H or an alkyl group having 1 or more carbon atoms, and at least one of R and R ′ is a long-chain alkyl group having 4 or more carbon atoms and n represents 10 or more. The method for producing a poly (2,2'-bithiazole-5,5'-diyl) polymer having an alkyl substituent represented by the formula: 3. The following chemical formula 7 or 8 derived from a dihalogenated aromatic compound having a long-chain alkyl group as a substituent at the 4-position of two thiazole groups by removing two halogen atoms. Embedded image (In the formula, R and R ′ represent H or an alkyl group having 1 or more carbon atoms, and at least one of R and R ′ has 4 or more carbon atoms.
The above shows a long-chain alkyl group. A) a polyvalent (2,2'-bithiazole-) having an alkyl substituent having a degree of polymerization n of 10 or more as a repeating structural unit
(5,5'-diyl) A film or a fibrous substance comprising the polymer obtained by dissolving the polymer in a general organic solvent such as chloroform, toluene, tetrahydrofuran or the like. 4. A dihalogenated aromatic compound having a long-chain alkyl group as a substituent at the 4-position of two thiazole groups, which is derived by removing two halogen atoms from a dihalogenated aromatic compound. Embedded image (In the formula, R and R ′ represent H or an alkyl group having 1 or more carbon atoms, and at least one of R and R ′ has 4 or more carbon atoms.
The above shows a long-chain alkyl group. A) a polyvalent (2,2'-bithiazole-) having an alkyl substituent having a degree of polymerization n of 10 or more as a repeating structural unit
An electrochromic device comprising a (5,5'-diyl) polymer. 5. The following compound derived from a dihalogenated aromatic compound having a long-chain alkyl group as a substituent at the 3-, 4- or 6-position of two thiazole groups by removing two halogen atoms: Chemical formula 12 Chemical formula 11 Embedded image (In the formula, R and R ′ represent H or an alkyl group having 1 or more carbon atoms, and at least one of R and R ′ has 4 or more carbon atoms.
The above shows a long-chain alkyl group. ) Is a recurring constitutional unit, and has a degree of polymerization n of 10 or more, and has an alkyl substituent and a poly (2,2'-bithiazole-
Photoluminescence consisting of (5,5'-diyl) polymer. 6. The following compound derived from a dihalogenated aromatic compound having a long-chain alkyl group as a substituent at the 4-position of two thiazole groups by removing two halogen atoms:
Or 14 Embedded image (In the formula, R and R ′ represent H or an alkyl group having 1 or more carbon atoms, and at least one of R and R ′ has 4 or more carbon atoms.
The above shows a long-chain alkyl group. ) Is a recurring constitutional unit, and has a degree of polymerization n of 10 or more, and has an alkyl substituent and a poly (2,2'-bithiazole-
5,5'-diyl) A material for an n-type semiconductor device comprising a polymer. 7. The following compound derived from a dihalogenated aromatic compound having a long-chain alkyl group as a substituent at the 4-position of two thiazole groups by removing two halogen atoms:
Or 16 Embedded image (In the formula, R and R ′ represent H or an alkyl group having 1 or more carbon atoms, and at least one of R and R ′ has 4 or more carbon atoms.
The above shows a long-chain alkyl group. ) Is a recurring constitutional unit, and has a degree of polymerization n of 10 or more, and has an alkyl substituent and a poly (2,2'-bithiazole-
5,5'-diyl) a ligand for a metal element composed of a polymer.