JP5546142B2 - Heterocyclic fused oligothiophene, method for producing the same, and polymer - Google Patents

Description

  The present invention relates to a novel heterocyclic condensed oligothiophene and a method for producing the same. The present invention also relates to a polymer comprising a heterocyclic fused oligothiophene unit.

  Conventionally, various elements (for example, organic light-emitting elements such as organic EL, organic transistors, and organic transistor elements) using the charge transport ability of organic materials have been proposed. By using an organic material for these elements, advantages such as light weight, low cost, low manufacturing cost, and flexibility are expected. Organic compounds having charge transporting ability have been actively studied so far regardless of whether they are high molecular compounds or low molecular compounds. As organic compounds having charge transporting ability, thiophene and polymers containing the thiophene unit have been proposed (Patent Documents 1 to 3).

JP 2006-104471 A JP 2007-261196 A JP 2008-504379 A

  Organic compounds having excellent charge transport ability are limited. Therefore, the development of a new organic compound having an excellent charge transporting ability is the biggest problem in this field. There is also a demand for a method for synthesizing organic compounds having excellent physical properties simply and efficiently.

  An object of the present invention is to provide a novel heterocyclic condensed thiophene compound having a high electron donating property and excellent stability and a polymer containing a monomer unit derived from the compound. Another object of the present invention is to provide a production method capable of efficiently synthesizing the above heterocyclic fused thiophene compound.

Heterocyclic fused ring thiophene compounds of the present invention, a compound represented by the following formula (1) (hereinafter, referred to as "thiophene (1)".) Der is, in the formula (1), R and R 'are monovalent In the present invention, R is a group represented by the following formula (A), and R ′ is a group represented by the following formula (B) . R _{1 to} R ₄ and R _{5 to} R ₁₀ are independently a hydrogen atom, a halogen atom, or a monovalent group . In the present invention, the monovalent group is a methyl group, an ethyl group, or an n-propyl group. I-propyl group, n-butyl group, i-butyl group, sec-butyl group, t-butyl group, pentyl group, isopentyl group, neopentyl group, hexyl group, cyclopentyl group, cyclohexyl group, phenyl group or trialkylsilyl The alkyl group in the trialkylsilyl group is an alkyl group having 1 to 6 carbon atoms .

The polymers of the present invention, the formula (2) a heterocyclic fused ring thiophene units (hereinafter, referred to as "thiophene unit (2)".) Represented Suruga perforated at least in part, thiophene in the present invention a unit (2) Is a heterocyclic fused thiophene unit represented by the formula (2-2) . In formula (2), R and R ′ are monovalent groups. R _{1 to} R ₄ are independently a hydrogen atom, a halogen atom, or a monovalent group. X and X ′ are independently a divalent aryl group, and the thiophene unit (2) in the present invention is represented by the formula (2-2). In the formula (2-2), R _{1 to} R ₁₀ Are independently a hydrogen atom, halogen atom, methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, sec-butyl group, t-butyl group, pentyl group, isopentyl. Group, neopentyl group, hexyl group, cyclopentyl group, cyclohexyl group, phenyl group or trialkylsilyl group, and the alkyl group in the trialkylsilyl group is an alkyl group having 1 to 6 carbon atoms . n is an arbitrary integer.

The method for producing a heterocyclic fused thiophene compound of the present invention comprises a compound represented by formula (3) (hereinafter referred to as “compound (3)”) and a compound represented by formula (4) (hereinafter referred to as “ Compound (4) ") is reacted with thiophene (1). In formulas (1), (3) and (4), R and R ′ are monovalent groups . In the present invention, R is a group represented by the following formula (A), and R ′ is It is group represented by Formula (B) . R _{1 to} R ₄ and R _{5 to} R ₁₀ are independently a hydrogen atom, a halogen atom, or a monovalent group . In the present invention, the monovalent group is a methyl group, an ethyl group, or an n-propyl group. I-propyl group, n-butyl group, i-butyl group, sec-butyl group, t-butyl group, pentyl group, isopentyl group, neopentyl group, hexyl group, cyclopentyl group, cyclohexyl group, phenyl group or trialkylsilyl The alkyl group in the trialkylsilyl group is an alkyl group having 1 to 6 carbon atoms . R ₁₁ and R ₁₂ are independently R _x S- (R _x ; monovalent hydrocarbon group) or an aryl group .

  The heterocyclic fused-ring thiophene compound of the present invention has a higher redox potential and higher electron donating properties than unsubstituted quarter thiophene. In addition, in the heterocyclic condensed thiophene compound of the present invention, redox progresses reversibly and stably, and is stable against redox. Furthermore, the heterocyclic condensed thiophene compound of the present invention can be easily chemically modified. Therefore, a heterocyclic condensed thiophene compound having various physical properties can be prepared by appropriately chemically modifying as necessary. The polymer of this invention contains the unit derived from the said heterocyclic condensed-ring thiophene compound. Therefore, the polymer of the present invention has high electron donating properties and excellent stability. According to the production method of the present invention, the above-mentioned heterocyclic condensed thiophene compound can be synthesized efficiently.

It is a figure which shows the molecular structure of the compound (1B) calculated | required by X-ray single-crystal structure analysis. It is a cyclic voltammogram in a dioxane of a compound (1B).

<1> Thiophene (1)
In formula (1), R _{1 to} R ₄ are each independently a hydrogen atom, a halogen atom, or a monovalent group . In the present invention, the monovalent group is a methyl group, an ethyl group, or an n-propyl group. I-propyl group, n-butyl group, i-butyl group, sec-butyl group, t-butyl group, pentyl group, isopentyl group, neopentyl group, hexyl group, cyclopentyl group, cyclohexyl group, phenyl group or trialkylsilyl It is a group . Examples of the halogen atom include F, Cl, Br, and I.

  Specific examples of the monovalent group include a monovalent hydrocarbon group. Specific examples of the monovalent hydrocarbon group include an alkyl group, an alkenyl group, an alkynyl group, an aryl group, an arylalkyl group, an arylalkenyl group, and an arylalkynyl group.

  There is no particular limitation on the structure of the alkyl group, alkenyl group, and alkynyl group (hereinafter collectively referred to as “alkyl group and the like”). The alkyl group or the like may have a chain structure or a cyclic structure (cycloalkyl group or the like). The alkyl group or the like may be linear or have a side chain. The alkyl group or the like may have one or more other substituents in the structure. The alkyl group or the like may contain one or more atoms other than carbon atoms and hydrogen atoms in the structure. As atoms other than the said carbon atom and a hydrogen atom, 1 type, or 2 or more types of an oxygen atom, a sulfur atom, and a nitrogen atom is mentioned, for example.

  Specific examples of the alkyl group include, for example, methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, sec-butyl group, t-butyl group, pentyl group, Examples include isopentyl group, neopentyl group, hexyl group, heptyl group, octyl group, nonyl group, and 2-ethylhexyl group. Specific examples of the cycloalkyl group include a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a 2-methylcyclohexyl group. As said alkenyl alkyl group, an allyl group and an isopropenyl group are mentioned, for example.

  The structures of the aryl group, arylalkyl group, arylalkenyl group, and arylalkynyl group (hereinafter collectively referred to as “aryl group and the like”) are not particularly limited. Examples of the aryl group include an aryl group derived from a benzene aromatic compound and an aryl group derived from a non-benzene aromatic compound. Specific examples of the aryl group derived from the benzene-based aromatic compound include a phenyl group, an oligoaryl group (such as a naphthyl group), and a heteroaryl group (such as furan, thiophene, pyrrole, and imidazole).

  The aryl group or the like may have one or more other substituents. For example, the aromatic ring contained in the aryl group or the like may have one or more other substituents. For example, the aryl group may be an unsubstituted aryl group or a substituted aryl group. The position of the substituent located on the aromatic ring may be any of o-, m-, and p-. Specific examples of the substituent include one or two of a halogen atom (fluorine atom, chlorine atom, bromine atom, etc.), alkyl group, alkenyl group, aryl group, nitro group, substituted amino group, and alkoxy group. More than species.

  Other examples of the monovalent group include an alkoxy group, a substituted alkoxy group, an alkylthio group, a substituted alkylthio group, a nitro group, an amino group, a substituted amino group, a silyl group, a substituted silyl group, a cyano group, a carbamoyl group, and a substituted group. Carbamoyl, formyl, stannyl, substituted stannyl, imino, substituted imino, boryl, substituted boryl, phosphino, substituted phosphino, silyloxy, substituted silyloxy, alkylsulfonyloxy, and arylsulfonyloxy Groups. For example, the monovalent group can be a trialkylsilyl group. The alkyl group in the trialkylsilyl group usually has 1 to 6 carbon atoms. Specific examples of the trialkylsilyl group include a trimethylsilyl group, a triethylsilyl group, a tri-n-propylsilyl group, and a tri-i-propylsilyl group.

In the formula (1), some or all of R _{1 to} R ₄ may be the same group. In addition, all of R _{1 to} R ₄ may be different groups. For example, R ₁ and R ₄ are “A” (A: a hydrogen atom, a halogen atom, or a monovalent group), and R ₂ and R ₃ are “B” (B: a hydrogen atom, a halogen atom, or a monovalent group). Group).

In formula (1), there is no particular limitation on the specific combination of R _{1 to} R ₄ . For example, R ₂ and R ₃ can be the above monovalent group. More specifically, for example, R ₁ and R ₄ can be hydrogen atoms, and R ₂ and R ₃ can be the monovalent group. It is preferable that R ₂ and R ₃ are the above monovalent group because of excellent stability and efficient production of thiophene (1) while suppressing side reactions. In this case, R ₂ and R ₃ are usually the same group, but may be different groups. R ₂ and R ₃ can be a monovalent hydrocarbon group other than a C _3-8 secondary or tertiary alkyl group.

In formula (1), R and R ′ are monovalent groups . In the present invention, R is a group represented by the above formula (A), and R ′ is represented by the above formula (B). It is a group . The explanation of R _{1 to} R ₄ is appropriate for the content of the monovalent group. The monovalent group is preferably an aryl group. In formula (1), one or both of R and R ′ can be an aryl group.

There are no particular limitations on the type and structure of the aryl group. Examples of the aryl group include an aryl group derived from a benzene aromatic compound and an aryl group derived from a non-benzene aromatic compound. Specific examples of the aryl group derived from the benzene-based aromatic compound include a phenyl group, an oligoaryl group (such as a naphthyl group), and a heteroaryl group (such as furan, thiophene, pyrrole, and imidazole). The aromatic ring contained in the aryl group may have one or more other substituents. For example, the phenyl group includes a substituted phenyl group as well as an unsubstituted phenyl group (C ₆ H ₅ —).

In the present invention, the group represented by the following formula (A) (hereinafter, "aryl group (A)" hereinafter.) Is. In formula (A), R _{5 to} R ₇ are independently a hydrogen atom, a halogen atom, or a monovalent group . In the present invention, the monovalent group is a methyl group, an ethyl group, or an n-propyl group. I-propyl group, n-butyl group, i-butyl group, sec-butyl group, t-butyl group, pentyl group, isopentyl group, neopentyl group, hexyl group, cyclopentyl group, cyclohexyl group, phenyl group or trialkylsilyl It is a group . As for the contents of the halogen atom and the monovalent group, explanations for R _{1 to} R ₄ above are appropriate. R _{5 to} R ₇ may be the same atom or group, or may be different atoms or groups. For example, R ₅ can be a monovalent group, and R ₆ and R ₇ can be hydrogen atoms.

In formula (1), the specific combination of R and R ′ is not particularly limited. R and R ′ may be the same group or different groups. Both R and R ′ are preferably the aryl group. In the present invention, R is an aryl group (A), and R ′ is a group represented by the formula (B) (hereinafter referred to as “aryl group (B)”). In the formula, R _{5 to} R ₁₀ are independently a hydrogen atom, a halogen atom, or a monovalent group . In the present invention, the monovalent group is a methyl group, an ethyl group, an n-propyl group, i- Propyl group, n-butyl group, i-butyl group, sec-butyl group, t-butyl group, pentyl group, isopentyl group, neopentyl group, hexyl group, cyclopentyl group, cyclohexyl group, phenyl group or trialkylsilyl group. . As for the contents of the halogen atom and the monovalent group, explanations for R _{1 to} R ₄ above are appropriate. R _{5 to} R ₇ and R _{8 to} R ₁₀ may be the same group or different groups (that is, the aryl group (A) and the aryl group (B) may be the same group). For example, R ₅ and R ₈ can be monovalent groups, and R ₆ and R ₇ and R ₉ and R ₁₀ can be hydrogen atoms.

  There is no particular limitation on the method for obtaining thiophene (1). Thiophene (1) can usually be obtained by the production method of the present invention described later. Thiophene (1) is easily chemically modified. Therefore, thiophene compounds having various physical properties can be prepared by appropriately chemically modifying thiophene (1) as necessary.

  Thiophene (1) has a bi (thieno [2,3-c] thiophene) skeleton. The bi (thienothiophene) skeleton includes a skeleton (I) in which four four sulfur atoms in thienothiophene are located inside and a skeleton located in the skeleton (II) located outside as follows. is there. Thiophene (1) has a skeleton (I). For skeletons (I) and (II), the stable structures of single molecules in the gas phase were compared using theoretical calculations (B3LYP / 6-311 + G * level). Since the skeleton (I) has a small steric repulsion between the bi (thieno [2,3-c] thiophene) skeletons, the structure in which the two skeletons form a dihedral angle of about 168 ° is a stable conformation. On the other hand, the skeleton (II) has a stable conformation of a structure having a dihedral angle of about 1146 °, and has a more twisted structure than the skeleton (I). That is, the skeleton (I) has a structure advantageous for effective expansion of π conjugation.

<2> Polymer The polymer of the present invention has at least a part of the thiophene unit (2) in the structure, and the thiophene unit (2) in the present invention is a heterocyclic condensed ring represented by the formula (2-2). A thiophene unit . In formula (2), in the formula, R _{1 to} R ₄ are each independently a hydrogen atom, a halogen atom, or a monovalent group, and the thiophene unit (2) in the present invention is represented by formula (2-2). In the formula (2-2), R _{1 to} R ₁₀ are independently a hydrogen atom, a halogen atom, a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, or an i-butyl. Group, sec-butyl group, t-butyl group, pentyl group, isopentyl group, neopentyl group, hexyl group, cyclopentyl group, cyclohexyl group, phenyl group or trialkylsilyl group, and the alkyl group in the trialkylsilyl group is It is a C1-C6 alkyl group . As for the contents of R _{1 to} R ₄ , the explanation in the section of thiophene (1) is appropriate.

  In the formula (2), X and X ′ are divalent aryl groups (groups generated by elimination of two hydrogen atoms bonded to the aromatic ring of the aromatic compound). There is no limitation in particular in the kind and structure of the said bivalent aryl group. Examples of the divalent aryl group include a group derived from a divalent benzene aromatic compound and a group derived from a non-benzene aromatic compound. Specific examples of the group derived from the divalent benzene-based aromatic compound include groups derived from benzene, condensed ring aromatic compounds (such as naphthyl group), and heteroaromatic compounds (such as furan, thiophene, pyrrole, and imidazole). Can be mentioned. In the present invention, one or both of X and X 'can be the above divalent aryl group. The aromatic ring contained in the divalent aryl group may be unsubstituted or may have one or more other substituents.

The divalent aryl group is preferably a group represented by the formula (A ′) (hereinafter referred to as “aryl group (A ′)”). In formula (A ′), R ₆ and R ₇ are each independently a hydrogen atom, a halogen atom, or a monovalent group. As for the contents of the halogen atom and the monovalent group, explanations for R _{1 to} R ₄ above are appropriate. R ₆ and R ₇ may be the same atom or group, or may be different atoms or groups. For example, each of R ₆ and R ₇ may be a hydrogen atom or a monovalent group, or one may be a hydrogen atom and the other may be a monovalent group. At least one of X and X ′ can be an aryl group (A ′).

In formula (2), the specific combination of X and X ′ is not particularly limited. X and X ′ may be the same group or different groups. More specifically, X can be an aryl group (A ′), and X ′ can be a group represented by the formula (B ′) (hereinafter referred to as “aryl group (B ′)”). In the formula, R ₆ , R ₇ , R ₉ , and R ₁₀ are each independently a hydrogen atom, a halogen atom, or a monovalent group. As for the contents of the halogen atom and the monovalent group, explanations for R _{1 to} R ₄ above are appropriate. R ₆ and R ₇ and R ₉ and R ₁₀ may be the same group or different groups (that is, the aryl group (A ′) and the aryl group (B ′) may be the same group). For example, R ₆ and R ₇ and R ₉ and R ₁₀ can all be hydrogen atoms.

  In formula (2), n is an arbitrary integer. n can be in an appropriate range for the purpose of realizing necessary physical properties. Specific examples of the lower limit value of n include 1, 5, 10, 20, or 50. Specifically, the upper limit value of n is, for example, 10, 30, 50, 100, 500, 1,000, 2,000, 5,000, 10,000, 20,000, 50,000, or 100,000. Can be mentioned. More specifically, n can be in the range of 1 to 50,000, 2 to 20,000, 5 to 10,000, 10 to 10,000, 20 to 5,000, for example.

  Specific examples of the thiophene unit (2) include a heterocyclic condensed oligothiophene unit represented by the formula (2-1).

In formula (2-1), Y is a divalent group. There is no particular limitation on the structure of the divalent group. The divalent group may have a chain structure, a cyclic structure, or a structure containing both. The divalent group may have a side chain or other functional group. The divalent group may be composed only of a saturated bond or may contain an unsaturated bond. Examples of the divalent group containing an unsaturated bond include a divalent π-conjugated group (a divalent group having a π bond, and a bi (thieno [2,3- c) a thiophene) skeleton and a group capable of forming a π-conjugated skeleton with X and X ′. Specific examples of the divalent group include, for example, an alkyl group, —CZ ₁ = CZ ₂ — group (Z ₁ and Z ₂ ; a hydrogen atom or a monovalent hydrocarbon group. Contents of the monovalent hydrocarbon group The above explanation is valid.), —C≡C— group, divalent aryl group, —Si (R ₁₃ R ₁₄ ) —, —Si (R ₁₅ R ₁₆ ) —O—Si (R ₁₇ R) _{18) -, N (R 19} ) -, - B (R 20) - and the like. The above explanation is valid for the content of the divalent aryl group. R _{13 to} R ₂₀ are independently a hydrogen atom, a halogen atom, or a monovalent group. As for the contents of the halogen atom and the monovalent group, explanations for R _{1 to} R ₄ above are appropriate. R ₁₃ and R ₁₄ may be the same group or different groups. R _{15 to} R ₁₈ may be the same group or different groups.

The polymers of the present invention, Suruga perforated at least in part thiophene units (2), thiophene unit in the present invention (2) is a heterocyclic fused ring thiophene unit represented by the formula (2-2). The polymer of the present invention may be a polymer composed only of thiophene units (2), or may be a copolymer composed of thiophene units (2) and other monomer units. When the polymer of the present invention is a copolymer, the ratio of thiophene units (2) in all monomer units is not particularly limited. The ratio can be set in an appropriate range as necessary. Examples of the lower limit of the ratio include 1%, 5%, 10%, 20%, 30%, 40%, and 50%. Examples of the upper limit of the ratio include 50%, 60%, 70%, 75%, 80%, 85%, 90%, or 95%. Specifically as said ratio, it is 10 to 90% normally, Preferably it is 20 to 85%, More preferably, it is 30 to 80%, More preferably, it is 40 to 70%.

  There is no limitation in particular in the kind and structure of said other monomer unit. As said other monomer unit, the well-known monomer which can form a conductive polymer can be used.

  There is no particular limitation on the molecular weight of the polymer of the present invention. The molecular weight of the polymer of the present invention can be in an appropriate range for the purpose of realizing necessary physical properties. The molecular weight of the polymer of the present invention is usually 10,000 to 5,000,000 in terms of weight average molecular weight or number average molecular weight.

The polymers of the present invention, Ru polymer der represented by formula (2-2). In the formula, R _{1 to} R ₁₀ are independently a hydrogen atom, a halogen atom, or a monovalent group . In the present invention, the monovalent group is a methyl group, an ethyl group, an n-propyl group, i- Propyl group, n-butyl group, i-butyl group, sec-butyl group, t-butyl group, pentyl group, isopentyl group, neopentyl group, hexyl group, cyclopentyl group, cyclohexyl group, phenyl group or trialkylsilyl group. . n is an arbitrary integer. As for the contents of the halogen atom and the monovalent group, explanations for R _{1 to} R ₄ are appropriate. In addition, the above description is valid for the contents of n.

  The method for obtaining the polymer of the present invention is not particularly limited. The polymer of the present invention can be obtained by using thiophene (1) as a monomer and polymerizing with another monomer as necessary. There are no particular limitations on the content and conditions of the polymerization. The above polymerization can be carried out by a method for obtaining a known thiophene polymer.

  As described above, the polymer of the present invention has a thiophene unit (2). The unit has the same properties as thiophene (1). Therefore, the polymer of the present invention has a high oxidation potential and a high electron donating property. Therefore, the polymer of the present invention can be applied to organic transistors and organic solar cells as an excellent p-type semiconductor material.

<3> Method for Producing Thiophene (1) In the production method of the present invention, compounds (3) and (4) are reacted to obtain thiophene (1). In the formulas (1) and (3), R, R ′ and R _{1 to} R ₄ have the above explanations.

  There is no limitation in particular in the method of obtaining a compound (3). For example, the compound (3) can be obtained by the following method (reference: Org. Lett. 2008, 10, 3591-3594).

Compound (4) includes a compound known as a so-called Lawson reagent or an analog thereof. In formula (4), R ₁₁ and R ₁₂ are each independently R _x S— (R _x ; monovalent hydrocarbon group) or an aryl group. R ₁₁ and R ₁₂ are usually the same group, but may be different groups.

There is no limitation in particular in the kind and structure of the said monovalent hydrocarbon group. Specific examples of the monovalent hydrocarbon group include the alkyl group, alkenyl group, alkynyl group, aryl group, arylalkyl group, arylalkenyl group, and arylalkynyl group. These contents are appropriate to be explained in the above R _{1 to} R ₄ .

  There is no particular limitation on the structure of the aryl group. The aryl group may be a substituted aryl group as well as an unsubstituted aryl group. The aryl group may be a heteroaryl group. The position of the substituent located on the aromatic ring may be any of o-, m-, and p-. Specific examples of the substituent include one or more of alkoxy groups (methoxy group, ethoxy group, phenoxy group and the like).

Specific examples of the compound (4) include compounds in which R ₁₁ and R ₁₂ are a methoxyphenyl group (Lawson reagent) or a phenoxyphenyl group (Beleo reagent), and R ₁₁ and R ₁₂ are thioalkyl groups (Davy reagent; Examples of the alkyl group include compounds having a methyl group, an ethyl group, an n-propyl group, an i-propyl group, or a butyl group) or a thiophenyl group (Japanese reagent).

  The production method of the present invention is usually carried out in a solvent. There is no particular limitation on the type of the solvent. The solvent may be a polar solvent or a nonpolar solvent. The polar solvent may be a protic polar solvent or an aprotic polar solvent. The solvent may be one type of solvent or a mixed solvent of two or more types. Specific examples of the polar solvent include THF, anisole, 1,4-dioxane, cyclopentylmethyl ether, alcohols (for example, methanol, ethanol, and allyl alcohol), and ester compounds (for example, ethyl acetate). . Specific examples of the aprotic polar solvent include DMSO, amide solvents (DMF, DMA, DMI, NMP, etc.), urea solvents, phosphate amide solvents, nitrile solvents, and nitroalkane solvents. A solvent is mentioned. The nonpolar solvent may be an aliphatic organic solvent or an aromatic organic solvent. Examples of the aliphatic organic solvent include pentane, hexane, cyclohexane, and heptane. Furthermore, examples of the aromatic organic solvent include benzene and toluene.

  In the production method of the present invention, the amount and ratio of the compounds (3) and (4) are not particularly limited. The amount and ratio of the compounds (3) and (4) can be appropriately adjusted as necessary.

  There are no particular limitations on the reaction conditions of the production method of the present invention. The reaction time can be 1 to 24 hours, preferably 2 to 12 hours. The reaction temperature can be 20 to 200 ° C, preferably 40 to 150 ° C. The reaction atmosphere is not particularly limited. Specific examples of the reaction atmosphere include an air atmosphere and an argon gas atmosphere. In the production method of the present invention, other substances may be added to the reaction system as long as thiophene (1) can be obtained.

  The production method of the present invention may include other steps as necessary. For example, after completion of the reaction, thiophene (1) can be recovered and purified by a known method such as distillation, adsorption, extraction, recrystallization, or a combination of these methods.

  Hereinafter, the present invention will be described specifically by way of examples. In addition, this invention is not restricted to the form shown in the Example. The embodiment of the present invention can be variously modified within the scope of the present invention depending on the purpose and application.

  In the following examples, the reaction was carried out using a dehydrated solvent under an argon atmosphere unless otherwise specified. Moreover, the commercially available dehydration solvent (made by Kanto Chemical) was used for toluene and THF used for reaction.

(1) Experimental example 1
Compound (1A) (2,2′-bi {4-triisopropylsilyl-4- (2′-thienyl) thieno [2,3-c] thiophene}) was synthesized by the method described below. In addition, compound (1A) was chemically modified by the method described below to synthesize compound (1B). A synthesis scheme is shown below. Note that bis (3-bromo-5-triisopropylsilylthienylacetylene) as a starting material is a known compound (reference document: Angew. Chem. Int. Ed. 2008, 47, 5582).

  Bis (3-bromo-5-triisopropylsilylthienyl) acetylene (3.30 g, 5.00 mmol) in THF solution (50 ml) was added t-butyllithium 1.6 M pentane solution (12.5 ml, 20 ml). 0.0 mmol) was added at −78 ° C. over 7 minutes. After stirring for 1.5 hours, 2-thiophenaldehyde (1.03 ml, 1.23 g, 11.0 mmol) was added over 3 minutes and stirred for 1 hour. Water was added to the reaction solution, THF was distilled off under reduced pressure, the aqueous layer was extracted with chloroform, and the resulting organic layers were combined, washed with water, aqueous ammonium chloride solution and saturated brine, and then dried over magnesium sulfate. did. This was concentrated under reduced pressure, and the residue was purified by silica gel column chromatography (hexane / ethyl acetate = 7/1) to give bis [3- (2′-thienyl) -hydroxymethyl-5-triisopropylsilylthienyl] acetylene. 1.91 g was obtained (2.63 mmol, 53% yield).

  Next, manganese oxide (4.62 g, 53 mmol) was added to a dichloroethane solution (22 ml) of bis [3- (2′-thienyl) -hydroxymethyl-5-triisopropylsilylthienyl] acetylene (1.59 g, 2.20 mmol). And stirred at 40 ° C. for 48 hours. Insoluble matters were filtered off from the reaction mixture, and the filtrate was concentrated under reduced pressure, and then recrystallized from chloroform to obtain compound (3A) (1.50 g, yield 45%).

  Compound (3A) (300 mg, 0.414 mmol) and Lawesson's reagent (2,4-bis (4-methoxyphenyl) -1,3,2,4-dithiadiphosphetan-2,4-disulfide) (185 mg, 0.456 mmol) was added to the toluene solution (10 ml). Subsequently, this was heated under reflux for 3 hours to react the compound (3A) with Lawesson's reagent. The reaction mixture was recrystallized from chloroform to obtain Compound (1A) (248 mg, 0.329 mmol, yield 80%).

  To a THF solution (2 ml) of diisopropylamine (93 μl, 67 mg, 0.66 mmol), n-butyllithium 1.6M hexane solution (0.38 ml, 0.61 mmol) was added at −78 ° C. over 2 minutes, and 30 minutes. After stirring, the temperature was raised to 0 ° C. and stirring was continued for 40 minutes to prepare lithium diisopropylamide in the system.

This solution was added to a THF solution (3 ml) of compound (1A) (200 mg, 0.265 mmol) at −78 ° C. over 3 minutes, stirred for 1 hour, and then chlorotriisopropylsilane (130 μl, 117 mg, 0.609 mmol). ) Was added. An aqueous ammonium chloride solution was added to the reaction mixture, and the aqueous layer was extracted with CH ₂ Cl _{2. The} organic layers were combined, washed with water and an aqueous ammonium chloride solution, and dried over anhydrous magnesium sulfate. This was concentrated under reduced pressure, and then recrystallized using degassed chloroform under an argon atmosphere to obtain dark red crystalline compound (1B) (234 mg, 0.219 mmol, yield 83%).

The spectral data of the compound (1A) and the compound (1B) are shown below. ¹ H-NMR and ¹³ C-NMR spectra were measured by “AL-400” and “GSX-270” manufactured by JEOL Ltd.

Spectral data of the compound (1A);
[1] ¹ H-NMR (400 MHz, CDCl ₃ ); δ 1.12 (d, 36 H, J = 7.6 Hz), 1.43 (sept, 6 H, J = 7.6 Hz), 7.10 (pseudo t , 2H, J = 4.0 Hz), 7.31 (d, 2H, J = 4.0 Hz), 7.33 (d, 2H, J = 3.6 Hz), 7.38 (s, 2H)
[2] ¹³ C-NMR (100 MHz, CDCl ₃ ): δ 11.9, 18.8, 119.7, 122.1, 124.2, 124.8, 125.7, 128.1, 136.8, 139.7, 146.3, 147.1

Spectral data of compound (1B);
[1] ¹ H-NMR (400 MHz, CDCl ₃ ); δ 1.16 (d, 36 H, J = 7.6 Hz), 1.21 (d, 36 H, J = 7.6 Hz), 1.39-1. 46 (m, 12H), 7.24 (d, 2H, J = 3.2 Hz), 7.42 (d, 2H, J = 3.2 Hz), 7.43 (s, 2H)

  The molecular structure of the compound (1B) was examined by X-ray single crystal structure analysis. Single crystals of compound (1B) used for X-ray crystal structure analysis were obtained with chloroform. Intensity data was measured using a Rigaku single crystal CCD X-ray analyzer (Saturn70 with MicroMax-007, MoKα irradiation (λ = 0.71070 mm, graphite monochromator). The structure was solved by the direct method (SHELXS-97). Optimized by -matrix least-squares on F2 (SHELXS-97), atoms other than hydrogen are optimized anisotropically, and hydrogen atoms are arranged using AFIX instruction, and the results are shown in FIG.

In order to investigate the oxidation-reduction characteristics of the compound (1B), the cyclic voltammogram of the compound (1B) in dioxane was examined using an electrochemical analyzer ALS / chi-617A (BAS). A glassy carbon electrode, a platinum counter electrode, and a reference electrode of Ag / AgNO ₃ were used. Measurement was performed in an argon atmosphere using a dioxane solution of a sample containing 0.1 M Bu ₄ N ⁺ PF ₆ ⁻ as a supporting electrolyte. The redox potential was determined based on ferrocene. The result is shown in FIG.

  From FIG. 1, it can be seen that the two bi (thieno [2,3-c] thiophene) skeletons of the compound (1B) have a planar structure and a stable conformation approximate to the result of the above theoretical calculation. From this result, it can be seen that the compound (1B) has a structure advantageous for effective expansion of π conjugation.

From FIG. 2, by applying a positive voltage, an oxidation reaction in two stages was observed. The oxidation potential at the first stage (E _1/2 = + 0.07 V) is similar to that of ferrocene, and it can be seen that the compound (1B) is easily oxidized like ferrocene and has a high electron donating property. Moreover, when it reduced by applying the reverse voltage after oxidation, reduction also progressed reversibly and stably. Since compound (1B) was not decomposed even through this redox process, it can be seen that it is stable against redox. From this result, it can be seen that the compound (1B) is useful as an excellent p-type semiconductor material.

Claims (12)

The heterocyclic condensed-ring thiophene compound represented by following formula (1).

(In the formula, R is a group represented by the following formula (A), and R ′ is a group represented by the following formula (B). R _{1 to} R ₄ are independently a hydrogen atom, a halogen atom, Methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, sec-butyl group, t-butyl group, pentyl group, isopentyl group, neopentyl group, hexyl group, cyclopentyl group Cyclohexyl group, phenyl group or trialkylsilyl group, and the alkyl group in the trialkylsilyl group is an alkyl group having 1 to 6 carbon atoms .)

(Wherein R _{5 to} R ₁₀ are independently a hydrogen atom, a halogen atom, a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, an i-butyl group, a sec-butyl group, t-butyl group, pentyl group, isopentyl group, neopentyl group, hexyl group, cyclopentyl group, cyclohexyl group, phenyl group or trialkylsilyl group, and the alkyl group in the trialkylsilyl group is an alkyl having 1 to 6 carbon atoms. Group .) R ₂ and R ₃ are independently methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, sec-butyl group, t-butyl group, pentyl group, isopentyl group 2. A heterocycle according to claim 1, which is a neopentyl group, a hexyl group, a cyclopentyl group, a cyclohexyl group, a phenyl group or a trialkylsilyl group, and the alkyl group in the trialkylsilyl group is an alkyl group having 1 to 6 carbon atoms. A fused-ring thiophene compound. R ₁ and R ₄ are independently a hydrogen atom, halogen atom, methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, sec-butyl group or t-butyl group. The heterocyclic fused-ring thiophene compound according to claim 2 , wherein R ₆ , R ₇ , R ₉ and R ₁₀ are a hydrogen atom, halogen atom, methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, sec-butyl group or t The heterocyclic fused-ring thiophene compound according to claim 3, which is a -butyl group . The polymer which has a heterocyclic condensed-ring thiophene unit represented by following formula (2-2) at least in part.

(Wherein R _{1 to} R ₁₀ are independently a hydrogen atom, a halogen atom, a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, an i-butyl group, a sec-butyl group, t-butyl group, pentyl group, isopentyl group, neopentyl group, hexyl group, cyclopentyl group, cyclohexyl group, phenyl group or trialkylsilyl group, and the alkyl group in the trialkylsilyl group is an alkyl having 1 to 6 carbon atoms. And n is an arbitrary integer.) R ₂ and R ₃ are independently methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, sec-butyl group, t-butyl group, pentyl group, isopentyl group The polymer according to claim 5 , wherein the polymer is a neopentyl group, a hexyl group, a cyclopentyl group, a cyclohexyl group, a phenyl group or a trialkylsilyl group, and the alkyl group in the trialkylsilyl group is an alkyl group having 1 to 6 carbon atoms . R ₁ and R ₄ are independently a hydrogen atom, halogen atom, methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, sec-butyl group or t-butyl group. The polymer according to claim 6 . R ₆ , R ₇ , R ₉ and R ₁₀ are a hydrogen atom, halogen atom, methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, sec-butyl group or t The polymer according to claim 7, which is a butyl group . A heterocyclic condensed thiophene compound obtained by reacting a compound represented by the following formula (3) with a compound represented by the following formula (4) to obtain a heterocyclic condensed thiophene compound represented by the following formula (1) Manufacturing method.

(In the formula, R is a group represented by the following formula (A), and R ′ is a group represented by the following formula (B). R _{1 to} R ₄ are independently a hydrogen atom, a halogen atom, Methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, sec-butyl group, t-butyl group, pentyl group, isopentyl group, neopentyl group, hexyl group, cyclopentyl group , A cyclohexyl group, a phenyl group or a trialkylsilyl group, and the alkyl group in the trialkylsilyl group is an alkyl group having 1 to 6 carbon atoms, and R ₁₁ and R ₁₂ are independently R _x S— (R _{x is a} monovalent hydrocarbon group) or an aryl group.)

(Wherein R _{5 to} R ₁₀ are independently a hydrogen atom, a halogen atom, a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, an i-butyl group, a sec-butyl group, t-butyl group, pentyl group, isopentyl group, neopentyl group, hexyl group, cyclopentyl group, cyclohexyl group, phenyl group or trialkylsilyl group, and the alkyl group in the trialkylsilyl group has 1 to 6 carbon atoms. The alkyl group of R ₂ and R ₃ are independently methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, sec-butyl group, t-butyl group, pentyl group, isopentyl group The heterocycle according to claim 9, which is a neopentyl group, a hexyl group, a cyclopentyl group, a cyclohexyl group, a phenyl group or a trialkylsilyl group, and the alkyl group in the trialkylsilyl group is an alkyl group having 1 to 6 carbon atoms. A method for producing a fused-ring thiophene compound. R ₁ and R ₄ are independently a hydrogen atom, halogen atom, methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, sec-butyl group or t-butyl group. The method for producing a heterocyclic condensed-ring thiophene compound according to claim 10 . R ₆ , R ₇ , R ₉ and R ₁₀ are a hydrogen atom, halogen atom, methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, sec-butyl group or t The method for producing a heterocyclic condensed thiophene compound according to claim 11, which is a -butyl group .

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