JP2007112878A - Benzodithiophene polymer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a π-conjugate polymer having excellent luminescence property and endurance and useful as a polymer material of an organic thin layer EL element and a polymer material for an organic transistor active layer. <P>SOLUTION: The polymer is characterized by having recurring unit represented by general formula (1). [Wherein, Ar is a (substituted) bivalent aromatic hydrocarbon or an aromatic heterocycle; R<SP>1</SP>and R<SP>4</SP>to R<SP>7</SP>are H or a (substituted) alkyl or alkoxy; x is 0 or an integer of 1-4; and when x is ≥2, R<SP>1</SP>may be different each other]. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a novel benzodithiophene polymer from which a π-conjugated polymer extremely useful as a material for organic electronics can be obtained.

  An organic electroluminescence (EL) element and an organic transistor element have been proposed by utilizing the light emission characteristics and charge transport characteristics of organic materials. By using an organic material for these elements, advantages such as light weight, low cost, low manufacturing cost, and flexibility are expected.

  Conventionally, various materials of low molecular weight and high molecular weight have been reported as materials for organic thin film EL elements. In low molecular weight systems, it has been reported that high efficiency is achieved by employing various laminated structures, and that durability is improved by well controlling the doping method. However, in the case of low molecular aggregates, it has been reported that the film state changes over time for a long time, and has an essential problem regarding the stability of the film.

  On the other hand, in the case of polymer materials, energetic studies have been made mainly on π-conjugated polymers such as PPV (poly-p-phenylene vinylene) series and poly-thiophene. However, it is difficult to increase the purity of these material systems and the intrinsically low fluorescence quantum yield is cited as a problem, and at present, high-performance EL devices have not been obtained. .

  As a conventional technique of an organic thin film EL element having a polymer material, a polymer material containing a benzodithiophene moiety in a π-conjugated polymer main chain has been proposed (for example, see Patent Document 1).

  In consideration of the fact that polymer materials are inherently stable in the glass state, if high fluorescence quantum efficiency can be imparted, an excellent EL device can be constructed, and further improvements have been made in this field. .

On the other hand, various materials of low molecular weight and high molecular weight have been reported for organic thin film transistor elements. For example, pentacene, phthalocyanine, fullerene, anthradithiophene, thiophene oligomer, bisdithienothiophene and the like can be given as low molecular weight materials. Examples of the polymer material include several materials such as polythiophene (see, for example, Non-Patent Document 1) and polythienylene vinylene (see, for example, Non-Patent Document 2).
JP 2003-221579 A Soluble and processable regioregular poly (3-hexylthiophene) for thin film field-effect transistor applicatons with high mobility, Zhenan Bao, Ananth Dodabalapur, and Andrew J. Lovinger, Appl. Phys. Lett., Vol.69, No.26, p .4108, 23 December 1996 Polythienylenevinylene thin-film transistor with high carrier mobility, H. Fuchigami, A. Tsumura, and H. Koezuka, Appl. Phy. Lett., Vol.63, No.10, p.1372, 6 September 1993

  However, even in the above materials, there is a problem related to the stability of the film in the low molecular system, while there is a problem in the low performance due to the purity in the high molecular system, and further improvement is desired.

  The present invention has been made in view of the above-mentioned circumstances, and has excellent light emission characteristics and excellent durability as a polymer material for an organic thin film EL element, and as a polymer material for an active layer of an organic transistor. An object is to provide a useful novel π-conjugated polymer.

  In order to achieve the above object, the invention described in claim 1 is a benzodithiophene polymer containing a repeating unit represented by the following general formula (I).

However, in formula (I), Ar represents a substituted or unsubstituted divalent aromatic carbon hydrogen group or aromatic heterocyclic group, R ¹ and R ^{4 to} R ⁷ are each independently a hydrogen atom, A substituted or unsubstituted alkyl group or an alkoxy group is represented, x is 0 or an integer of 1-4, and when x is 2 or more, a plurality of R ¹ may be the same or different.

  The invention described in claim 2 is a benzodithiophene polymer containing a repeating unit represented by the following general formula (II).

However, in formula (II), R ¹ and R ^{4 to} R ⁸ each independently represent a hydrogen atom, a substituted or unsubstituted alkyl group or an alkoxy group, and x and y are each independently 0 or When x and y are each 2 or more, a plurality of R ¹ or R ⁸ may be the same or different from each other.

  The invention described in claim 3 is the benzodithiophene polymer described in claim 1 or claim 2, wherein the carbonyl compound represented by the following general formula (III) and the following general formula (IV) are used. It is obtained by reacting with a phosphorous compound.

In the formula ^{(III), R 1, R} 4 and R ⁷ each independently represent a hydrogen atom, a substituted or unsubstituted alkyl group or alkoxy group, x is 0 or an integer from 1 to 4 , X is 2 or more, the plurality of R ¹ may be the same or different.

In the formula (IV), Z represents —PO (OR ′) ₂ (wherein R ′ represents a lower alkyl group) or —P ⁺ R ″ ₃ Y ⁻ (where R ″ represents a phenyl group or an alkyl group). Y represents a halogen atom), R ⁵ and R ⁶ represent a hydrogen atom, a substituted or unsubstituted alkyl group or an alkoxy group, and Ar represents a substituted or unsubstituted divalent aromatic carbon hydrogen group. Or represents an aromatic heterocyclic group.

  The invention described in claim 4 is represented by the compound represented by the following general formula (V) and the following general formula (VI) in the benzodithiophene polymer according to claim 1 or 2. It is obtained by reacting with a carbonyl compound.

In the formula (V), Z represents —PO (OR ′) ₂ (wherein R ′ represents a lower alkyl group) or —P ⁺ R ″ ₃ Y ⁻ (where R ″ represents a phenyl group or an alkyl group). Y represents a halogen atom), R ¹ , R ⁴ and R ⁷ each independently represents a hydrogen atom, a substituted or unsubstituted alkyl group or an alkoxy group, and x represents 0 or 1 to 1 When x is an integer of 4 and x is 2 or more, the plurality of R ¹ may be the same or different.

In the formula (VI), Ar represents a substituted or unsubstituted divalent aromatic carbon hydrogen group or aromatic heterocyclic group, and R ⁵ and R ⁶ represent a hydrogen atom, a substituted or unsubstituted alkyl group or Represents an alkoxy group.

  The invention described in claim 5 is characterized in that the benzodithiophene polymer described in claim 1 is obtained using a compound represented by the following general formula (VII).

In the formula (VII), Y represents a halogen atom, R ¹ , R ⁴ and R ⁷ each independently represents a hydrogen atom, a substituted or unsubstituted alkyl group or an alkoxy group, and x is 0 or 1 When x is an integer of 2 or more, the plurality of R ¹ may be the same or different from each other.

As described above, according to the present invention, a benzodithiophene polymer containing a repeating unit represented by the general formula (I) (wherein Ar is a substituted or unsubstituted divalent valence) R ¹ and R ^{4 to} R ⁷ each independently represents a hydrogen atom, a substituted or unsubstituted alkyl group or an alkoxy group, and x is 0 or When X is 2 or more, a plurality of R ¹ may be the same or different from each other.), For organic thin-film EL elements having excellent light emission characteristics and excellent durability It is possible to provide a novel arylene vinylene-type benzodithiophene polymer that is very useful as a high molecular weight material and as a charge transporting high molecular weight material for organic transistors. Such a benzodithiophene polymer can be applied as a material for organic electronic devices such as EL elements and optically active elements (memory or display elements) as organic semiconductor elements.

  As a result of intensive studies, the present inventors have found that a novel arylene vinylene polymer containing a benzodithiophene structure as a repeating unit is effective for the above problems, and have completed the present invention.

  Hereinafter, the benzodithiophene polymer of the present embodiment will be described in more detail with reference to the drawings. In addition, this embodiment is not limited to what is described below, A various change is possible in the range which does not deviate from the meaning.

First, the manufacturing method of the benzodithiophene polymer of this embodiment is demonstrated.
The production method of the benzodithiophene polymer of the present embodiment includes, for example, a Wittig-Horner reaction using a carbonyl compound and a phosphonic acid ester compound, a Wittig reaction using a carbonyl compound and a phosphonium salt, a vinyl compound and a halogen compound, Polymerization can be performed using a Heck reaction using GI, GILCH polymerization using a halomethyl compound, or the like. Of these, the Wittig-Horner reaction and Wittig reaction are particularly effective because of the simplicity of the reaction procedure.

As an example, the manufacturing method of the benzodithiophene polymer in this embodiment using Wittig-Horner reaction is demonstrated.
As shown in the following reaction formula (1), the benzodithiophene polymer in the present embodiment includes a solution in which the phosphonic acid ester compound and the aldehyde compound are present stoichiometrically, and a molar amount of at least twice that amount. Mix with base. As a result, the polymerization reaction proceeds and the benzodithiophene polymer of this embodiment can be obtained.

  In the case of producing the benzodithiophene polymer of the present embodiment, for example, the benzodithiophene polymer represented by the general formula (V) having a benzodithiophene group that can be divalent at the site A in the reaction formula (1). It can be synthesized by a reaction between a monomer and a dicarbonyl compound. Alternatively, a similar polymer can be obtained by combining the monomer represented by the general formula (III) having a benzodithiophene moiety at the site B in the reaction formula (1) and the phosphonate compound. it can.

  The dicarbonyl compound represented by the general formula (III) as a monomer can be synthesized by various known reactions. For example, after synthesizing benzodithiophene according to the method described in the following reaction formula (2) described in Journal of Organic Chemistry, 32, 3093, 1967. Alternatively, the reaction of an aryl lithium compound with a carbonylating agent such as DMF, N-formylmorpholine, N-formylpiperidine, or the like as shown in the following reaction formula (4), or the following reaction formula (5) The dicarbonyl compound can be synthesized using a reaction such as Gutterman reaction as shown in FIG.

  Or when superposing | polymerizing using the monomer of the phosphorus compound of the benzodithiophene shown by the said general formula (V), this phosphorus compound can be further induced | guided | derived and synthesized from the said carbonyl compound. For example, as shown below, the carbonyl compound obtained by the above method is converted into an alcohol compound with a reducing agent such as sodium borohydride, and the hydroxyl group is further halogenated with an appropriate halogenating agent such as thionyl chloride. The compound is derived to a halomethyl compound represented by the general formula (VII).

  This halomethyl compound can also be directly synthesized from benzodithiophene by paraformaldehyde and hydrogen halide as shown in the following reaction formula (7).

Using the halomethyl compound represented by the general formula (VII) thus obtained, finally, a trialkylphosphonate ester known as the Michaelis-Arbuzov reaction: P (OR) ₃ (in the formula of trialkylphosphonate ester) , R represents a lower alkyl group) (see reaction formula (8) below) to synthesize a phosphonate ester compound. Polymerization can be performed by the Wittig-Horner reaction using the carbonyl compound or phosphorus compound thus obtained.

Other polymerization methods, when carrying out the polymerization in Wittig reaction, (in PR _3, R represents a phenyl group or an alkyl group) halomethyl compound phosphine compound PR ₃ represented by the general formula (VII) and the reaction The Wittig reagent may be prepared (see the following reaction formula (9)).

  Since this phosphorus compound reacts with a carbonyl compound to form a double bond as in the phosphonate compound described above, a polymer represented by the repeating unit of the general formula (I) or (II) of this embodiment is obtained. be able to.

  Alternatively, when a compound represented by the general formula (VII) is allowed to react with a double mole of the base of this compound in a solvent, the polymerization reaction proceeds easily to obtain a polymer represented by the general formula (I). Is possible. This is called GILCH polymerization, and its details are described, for example, in Macromolecules, 1999, 32, 4295-4932.

  Next, the polymerization reaction by the Wittig-Horner reaction will be described in detail. The base used for the polymerization reaction is not particularly limited as long as a phosphonate carbanion is formed. Examples of such a base include metal alcosides, metal hydrides, and organolithium compounds. Specifically, for example, potassium t-butoxide, sodium t-butoxide, lithium t-butoxide, potassium 2-methyl-2-butoxide, sodium 2-methyl-2-butoxide, sodium methoxide, sodium ethoxide, potassium ethoxy Potassium, methoxide, sodium hydride, potassium hydride, methyl lithium, ethyl lithium, propyl lithium, n-butyl lithium, s-butyl lithium, t-butyl lithium, phenyl lithium, lithium naphthylide, lithium amide, lithium diisopropyl Examples include amides.

  The amount of the base used in the reaction is usually only the same amount as the polymerization active point of the phosphonate compound, but an excessive amount may be used.

  The above base may be added to the reaction system in a solid state or a suspended solution state. However, since the homogeneity of the obtained polymer becomes good, it is particularly preferable to add it as a homogeneous solution.

  As a solvent for dissolving the base, a solvent that forms a stable solution with the base to be used must be selected. As other factors, those having high base solubility are preferable, those that do not impair the solubility of the high molecular weight product produced in the reaction system in the reaction solvent, and further, the high molecular weight product to be produced dissolves well. The solvent to be used is good, and can be arbitrarily selected from generally known alcohol-based, ether-based, amine-based, hydrocarbon-based solvents and the like according to the characteristics of the base used and the high molecular weight to be produced.

  Examples of a combination of a base and a solvent for uniformly dissolving the base include sodium methoxide in methanol, sodium ethoxide in ethanol, potassium t-butoxide in 2-propanol, and potassium t-butoxide in 2-methyl-2. -Propanol solution, potassium t-butoxide in tetrahydrofuran, potassium t-butoxide in dioxane, n-butyllithium in hexane, methyllithium in ether, lithium t-butoxide in tetrahydrofuran, lithium diisopropylamide in cyclohexane, potassium There are various combinations of solutions including a toluene solution of bistrimethylsilylamide, and several solutions are easily available as commercial products. From the viewpoint of mild reaction conditions and ease of handling, metal alkoxide-based solutions are preferably used. Solubility of the resulting polymer, ease of handling, efficiency of the reaction, solubility of the resulting polymer, etc. From the above viewpoint, an ether-based solution of metal t-butoxide is more preferably used, and a tetrahydrofuran solution of potassium t-butoxide is more preferably used.

  In the above polymerization reaction, a base solution may be added to the solution of the phosphonate ester compound and the aldehyde compound, or a solution of the phosphonate ester compound and the aldehyde compound may be added to the base solution. Moreover, you may add to a reaction system simultaneously and there is no restriction | limiting in the order of addition.

The polymerization time in the above polymerization reaction may be appropriately set according to the reactivity of the monomers used or the molecular weight of the desired polymer, but is preferably 0.2 hours to 30 hours.
In addition, the reaction temperature in the above polymerization reaction does not need to be controlled in particular, and the polymerization reaction proceeds well at room temperature. However, heating or cooling can be performed under milder conditions to increase the reaction efficiency. It is.

Moreover, it is also possible to add a molecular weight regulator in order to adjust the molecular weight in the polymerization operation described above, or a sealing agent for sealing the end of the polymer as a terminal modifying group to the reaction system during the reaction, It is also possible to add it at the start of the reaction. Accordingly, a substituent based on the terminator may be bonded to the terminal of the arylamine polymer in the present embodiment.
Examples of the molecular weight regulator and the end-capping agent include compounds having one reactive group such as diethyl benzylphosphonate and benzaldehyde.

  The preferred molecular weight of the benzodithiophene polymer in the present embodiment is about 1,000 to 1,000,000, more preferably 2,000 to 500,000 in terms of polystyrene-reduced number average molecular weight. If the molecular weight is too small, the film formability such as the generation of cracks may be deteriorated and the practicality may be poor. On the other hand, if the molecular weight is too large, the solubility in a general organic solvent is deteriorated, the viscosity of the solution becomes high and the processing by coating becomes difficult, and in some cases, there is a problem in practicality.

  It is also possible to add a small amount of a branching agent during the polymerization in order to improve the mechanical properties. The branching agent used is a compound having three or more polymerization reaction active groups (which may be the same or different). These branching agents may be used alone or in combination.

  The benzodithiophene polymer obtained as described above is used after removing impurities such as the base used in the polymerization, unreacted monomers, terminal terminators, and inorganic salts generated during the polymerization. These purification operations can be purified using conventionally known methods such as reprecipitation, extraction (eg, Soxhlet extraction) ultrafiltration, dialysis, and the like.

  As described above, the benzodithiophene polymer of the present embodiment obtained by the above production method is known as spin coating method, casting method, dipping method, ink jet method, doctor blade method, screen printing method, spray coating, etc. With this film formation method, it is possible to produce a good thin film free from cracks and excellent in strength, toughness, durability and the like, and can be suitably used as a material for various organic electronic devices.

  Next, the polymers represented by the general formulas (I) and (II) of this embodiment will be described in more detail.

  In the present embodiment, the “aromatic carbon hydrogen group or aromatic heterocyclic group” may be either a monocyclic group or a polycyclic group (a condensed polycyclic group or a non-condensed polycyclic group). Naphthalene, biphenyl, terphenyl, pyrene, fluorene, 9,9-dimethylfluorene, azulene, anthracene, triphenylene, chrysene, 9-benzylidenefluorene, 5H-dibenzo [a, d] cycloheptene, triphenylamine, thiophene, benzothiophene, Divalent groups such as dithienylbenzene, furan, benzofuran, carbazole and the like can be mentioned. These may have a substituted or unsubstituted alkyl group and alkoxy group as a substituent.

  The substituted or unsubstituted alkyl group in this embodiment is a linear, branched or cyclic alkyl group having 1 to 25 carbon atoms, and these alkyl groups are further a fluorine atom, a cyano group, a phenyl group or You may contain the phenyl group substituted by the halogen atom or the linear or branched alkyl group. Specifically, methyl group, ethyl group, n-propyl group, i-propyl group, t-butyl group, s-butyl group, n-butyl group, i-butyl group, pentyl group, hexyl group, heptyl group, Octyl, nonyl, decyl, undecyl, dodecyl, 3,7-dimethyloctyl, 2-ethylhexyl, trifluoromethyl, 2-cyanoethyl, benzyl, 4-chlorobenzyl, 4-methyl A benzyl group, a cyclopentyl group, a cyclohexyl group, etc. are mentioned.

Further, in the case of a substituted or unsubstituted alkoxy group, a specific example is one in which an oxygen atom is inserted into the bonding position of the alkyl group to form an alkoxy group (for example, with respect to a methyl group: CH ₃ —). CH ₃ O—, etc., and so on.

  As for these substituents, a plurality of the same ones may be introduced or a plurality of different ones may be introduced. In addition, these alkyl groups and alkoxy groups are further halogen atoms, cyano groups, aryl groups, hydroxyl groups, carboxyl groups, linear, branched or cyclic alkyl groups having 1 to 12 carbon atoms, alkoxy groups or alkylthio groups. An aryl group substituted with a group may be contained.

  The polymer of this embodiment can improve the solubility to a solvent by presence of an alkyl group or an alkoxy group. In these polymers, it is important to improve the solubility in a solvent because the tolerance (flexible-productivity) increases in the production of a wet film-forming process in the production of an organic electronic device. By improving solubility, for example, the choice of coating solvent, the temperature range at the time of solution preparation, and the temperature range and pressure range at the time of solvent drying can be expanded. A high-quality thin film with high purity and high uniformity can be obtained.

  Hereinafter, examples of the present embodiment will be described more specifically. However, the present embodiment is not construed as being limited by the examples described below, and various modifications can be made without departing from the spirit of the present embodiment.

  First, hexyl benzodithiophene (synthesized according to Journal of Organic Chemistry, 32, 3093, 1967.) shown in (a) of the above reaction formula (10) (a) 11.00 g (40.08 mmol) The flask was purged with nitrogen, and then 440 ml of dry diethyl ether was added and cooled to 0 ° C. To this, 77 ml (120.2 mmol) of n-butyllithium 1.56M in hexane was slowly added dropwise, and the mixture was stirred at room temperature for 1.5 hours after the completion of the addition. This was cooled again to 0 ° C., 29.3 ml (400 mmol) of dry DMF (dimethylformamide) was added, and the mixture was stirred for 0.5 hour. The reaction solution was washed with diluted hydrochloric acid and saturated brine in that order, dried over anhydrous sodium sulfate, and then the solvent was distilled off. The residue was purified by column chromatography to obtain 10.1 g (30.28 mmol) of dialdehyde (b) represented by the reaction formula (10) (yield: 76%, melting point: 82-83 ° C.).

  The dialdehyde (b) 7.01 g (21.20 mmol) shown in (b) of the above reaction formula (10) thus obtained was placed in a 500 ml four-necked flask, and the system was purged with nitrogen. did. Next, 150 ml of ethanol and 70 ml of THF were added, and then cooled to 0 ° C., and 2.01 g (53 mmol) of sodium borohydride was added little by little. After the entire amount was added, the mixture was stirred at room temperature for 20 minutes. Thereafter, the mixture was cooled again to 0 ° C., and approximately 60 ml of 1M hydrochloric acid was slowly added. Ethanol was distilled off under reduced pressure, ethyl acetate was added, and the mixture was washed with water and then saturated brine. After drying over anhydrous sodium sulfate, the solvent was distilled off under reduced pressure to obtain 6.96 g (20.81 mmol) of the bishydroxymethyl compound (c) shown in (c) of the above reaction formula (10) ( Yield 99%, melting point 125-127 ° C.).

  Next, 6.95 g (20.78 mmol) of the bishydroxymethyl compound (c) shown in (c) of the above reaction formula (10) obtained by the above operation was placed in a four-necked flask having a capacity of 200 ml, Was replaced with nitrogen. After adding 30 ml of 1,4-dioxane and 4.2 ml (58.18 mmol) of thionyl chloride, the mixture was heated to 50 ° C. and stirred for 4.5 hours. After cooling this to 0 ° C., a small amount of diethyl ether was added to dilute, and a saturated aqueous sodium hydrogen carbonate solution was slowly added until no foaming occurred. Then, after extraction with diethyl ether, the organic layer was washed with saturated brine and dried over anhydrous sodium sulfate. Thereafter, the solvent was distilled off under reduced pressure to obtain 7.64 g (20.57 mmol) of the desired bischloromethyl compound (d) shown in (d) of the above reaction formula (10) (yield 99%, yellow). Viscous liquid).

The ¹ H-NMR spectrum (400 MHz, CDCl ₃ , TMS) of the bischloromethyl compound (d) thus obtained is shown in FIG. 1, and the IR spectrum (using KBr as the window material) is shown in FIG.

  7.00 g (18.85 mmol) of the bischloromethyl compound (d) obtained above and 14.3 ml of triethyl phosphite were placed in a 300 ml four-necked flask and heated to 135 ° C. Here, after stirring at 135 ° C. for 5 hours, triethyl phosphite was distilled off under reduced pressure. The residue was purified by column chromatography to obtain 3.04 g (5.29 mmol) of the target phosphorus compound (e) shown in (e) of the above reaction formula (10) (yield 28%, yellow viscous). liquid).

The ¹ H-NMR spectrum (400 MHz, CDCl ₃ , TMS) of the phosphorus compound (e) thus obtained is shown in FIG. 3, and the IR spectrum (neat, NaCl) is shown in FIG.

<Synthesis of Polymer 1>

  1.522 g (2.648 mmol) of the phosphorus compound (e) obtained in the above synthesis example (reaction formulas 10 (a) to (e)) and the dialdehyde shown in (f) of the above reaction formula (11) (F) 0.848 g (2.648 mmol) was placed in a 200 ml four-necked flask, and the system was purged with nitrogen. Next, 80 ml of dry THF (tetrahydrofuran) and 14.05 mg (0.132 mmol) of benzaldehyde were added. To this solution, 8 ml of 1M THF solution of potassium t-butoxide was added dropwise, and the mixture was stirred for 2 hours after completion of the addition. Furthermore, 60.5 mg (0.265 mmol) of diethyl benzylphosphonate was added and stirred for 1 hour. Thereafter, the reaction solution was poured into water, and the precipitated solid was collected by filtration to obtain 1.107 g of the polymer 1 (crude yield 71%). Furthermore, reprecipitation purification was performed three times from dichloromethane and methanol to obtain 0.624 g of polymer 1 as a red powder (yield 40%). The elemental analysis values at this time are shown in Table 1.

  Further, FIG. 5 shows an IR spectrum (NaCl cast film) of the polymer 1 shown in the obtained reaction formula (11).

<Synthesis of Polymer 2>

  2.724 g (4.824 mmol) of the diphosphonate compound (g) shown in (g) of the above reaction formula (12) and the method described in the above-described synthesis example (reaction formulas 10 (a) to (e)) 2.000 g (4.824 mmol) of dialdehyde (h) in the reaction formula (12) produced by the same method was put into a 200 ml four-necked flask, and the inside of the system was purged with nitrogen. Next, after adding 100 ml of dry THF, 17 ml of a 1M THF solution of potassium t-butoxide was added dropwise to this solution, followed by stirring for 3 hours and then refluxing for 2 hours. Here, after adding 0.10 ml (0.48 mmol) of diethyl benzylphosphonate and refluxing for 1 hour, further adding 0.10 ml (0.96 mmol) of benzaldehyde and refluxing for 1 hour. Then, the reaction solution was poured into water, and the precipitated solid was collected by filtration to obtain 3.046 g of a polymer (crude yield 94%). Further, reprecipitation purification from THF / methanol yielded 2.902 g of polymer 2 as a red powder (yield 90%). The elemental analysis values at this time are shown in Table 2.

  Further, FIG. 6 shows an IR spectrum (NaCl cast film) of the polymer 2 represented by the reaction formula (12).

  The benzodithiophene polymer of the present invention has excellent charge transport characteristics, light emission characteristics, and possibility of thinning by a wet film formation process, and is applicable to various organic (semiconductor) device applications such as organic EL element fields. It has become possible to provide materials that accelerate research. The applicability of the present invention in this field is high.

It is a < ¹ > H-NMR spectrum of the benzodithiophene compound synthesize | combined by this embodiment, a horizontal axis shows ppm and a vertical axis | shaft shows signal intensity | strength (arb.), Respectively. It is an infrared absorption spectrum of the benzodithiophene compound synthesized in the present embodiment, where the horizontal axis represents the wave number (cm ⁻¹ ) and the horizontal axis represents the absorbance (T%). It is a < ¹ > H-NMR spectrum of the other benzodithiophene compound synthesize | combined by this embodiment, a horizontal axis shows ppm and a vertical axis | shaft shows signal intensity | strength (arb.), Respectively. It is an infrared absorption spectrum of the other benzodithiophene compound synthesize | combined by this embodiment, a horizontal axis shows a wave number (cm ^<-1> ) and a horizontal axis shows a light absorbency (T%), respectively. It is an infrared absorption spectrum of the benzodithiophene polymer of this embodiment obtained by the synthesis | combination of the polymer 1, A horizontal axis shows a wave number (cm ^<-1> ) and a horizontal axis shows a light absorbency (T%), respectively. It is an infrared absorption spectrum of the benzodithiophene polymer of this embodiment obtained by the synthesis | combination of the polymer 2, A horizontal axis shows a wave number (cm ^<-1> ) and a horizontal axis shows a light absorbency (T%), respectively.

Claims (5)

A benzodithiophene polymer comprising a repeating unit represented by the following general formula (I):

(In the formula (I), Ar represents a substituted or unsubstituted divalent aromatic carbon hydrogen group or aromatic heterocyclic group, and R ¹ and R ^{4 to} R ⁷ are each independently a hydrogen atom. Represents a substituted or unsubstituted alkyl group or alkoxy group, x is 0 or an integer of 1 to 4, and when x is 2 or more, a plurality of R ¹ may be the same or different. A benzodithiophene polymer comprising a repeating unit represented by the following general formula (II):

(In the formula (II), R ¹ and R ^{4 to} R ⁸ each independently represents a hydrogen atom, a substituted or unsubstituted alkyl group or an alkoxy group, and x and y each independently represents 0 Or an integer of 1 to 4, and when x and y are each 2 or more, a plurality of R ¹ or R ⁸ may be the same or different. The benzodithiophene according to claim 1 or 2, which is obtained by reacting a carbonyl compound represented by the following general formula (III) with a phosphorus compound represented by the following general formula (IV): Polymer.

(In the formula (III), R ¹ , R ⁴ and R ⁷ each independently represents a hydrogen atom, a substituted or unsubstituted alkyl group or an alkoxy group, and x is 0 or an integer of 1 to 4) Yes, when x is 2 or more, the plurality of R ¹ may be the same or different.)

(In the formula (IV), Z represents —PO (OR ′) ₂ (wherein R ′ represents a lower alkyl group) or —P ⁺ R ″ ₃ Y ⁻ (where R ″ represents a phenyl group or An alkyl group, Y represents a halogen atom), R ⁵ and R ⁶ represent a hydrogen atom, a substituted or unsubstituted alkyl group or an alkoxy group, and Ar represents a substituted or unsubstituted divalent aromatic carbon hydrogen. Represents a group or an aromatic heterocyclic group.) 3. The benzodithiophene weight according to claim 1, which is obtained by reacting a compound represented by the following general formula (V) with a carbonyl compound represented by the following general formula (VI): Coalescence.

(In the formula (V), Z represents —PO (OR ′) ₂ (wherein R ′ represents a lower alkyl group) or —P ⁺ R ″ ₃ Y ⁻ (where R ″ represents a phenyl group or An alkyl group, Y represents a halogen atom), R ¹ , R ⁴ and R ⁷ each independently represents a hydrogen atom, a substituted or unsubstituted alkyl group or an alkoxy group, and x is 0 or 1 And when x is 2 or more, the plurality of R ¹ may be the same or different from each other.)

(In the formula (VI), Ar represents a substituted or unsubstituted divalent aromatic carbon hydrogen group or aromatic heterocyclic group, and R ⁵ and R ⁶ represent a hydrogen atom, a substituted or unsubstituted alkyl group, and Or represents an alkoxy group.) The benzodithiophene polymer according to claim 1, which is obtained by using a compound represented by the following general formula (VII).

(In the formula (VII), Y represents a halogen atom, R ¹ , R ⁴ and R ⁷ each independently represents a hydrogen atom, a substituted or unsubstituted alkyl group or an alkoxy group, and x is 0 or When it is an integer of 1 to 4 and x is 2 or more, a plurality of R ¹ may be the same or different.)

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