TW201811857A - Boron-containing polymer and use thereof - Google Patents

Abstract

Provided is a boron-containing polymer for organic semiconductors which has deep LUMO/HOMO potentials and which contains a unit structure having a large [pi]-conjugated plane and, despite this, can be made to have a high molecular weight due to the high solubility. According to some embodiments of the present invention, provided is a boron-containing polymer containing a structural unit represented by formula (1), which includes a structure W that has at least two boron-nitrogen coordination bonds and a structure [pi] that is a divalent substituent having a conjugated structure. In formula (1), m is 0 or 1, and structure W is represented by formula (2) or (3). In formulae (2) and (3), rings X1, X2, and Z each represent a monocycle or fused ring having a conjugated structure, rings Y1 and Y2 each represent a five-membered ring having the boron-nitrogen coordination bond, either [alpha]1 or [alpha]3 is a nitrogen atom, either [alpha]2 or [alpha]4 is a nitrogen atom, and R1 to R4 may be the same or different and each represent a monovalent substituent which comprises at least one optionally substituted, linear or branched C10-40 alkyl group and which may have be bonded to the boron atom through another skeleton.

Description

   Boron-containing polymer compound and use thereof   

The invention relates to a boron-containing polymer compound and uses thereof.

With the practical use of organic semiconductor devices, there is a need for organic semiconductors that are high-performance and can be applied to inexpensive coating processes. Among them, polymer organic semiconductors have the advantages of easily obtaining excellent film quality and stable element characteristics during coating. In addition, in order to make the polymer organic semiconductor have a higher mobility, it is expected to introduce a unit structure having a larger π conjugate area and a further high molecular weight body.

On the other hand, Non-Patent Document 1 discloses the content of deepening the LUMO / HOMO level by introducing a boron-nitrogen coordination bond structure, and Patent Document 1 discloses the content that can improve the performance of an organic semiconductor.

    [Background Literature]         [Patent Literature]    

[Non-Patent Document 1] Angew. Chem. Int. Ed. 2015, 54, 3648-3652.

[Patent Document 1] International Publication No. 2006/070817

However, a polymer organic semiconductor having a unit with a large π conjugate area decreases in solubility if the polymer is quantified, and the stability in the solution also deteriorates accordingly. Therefore, there are problems in the processing of the coating process. In general, in order to further improve solubility, a chain substituent may be bonded to a π-conjugated unit, and the chain substituent may be extended or branched. However, since the arrangement of molecules in an organic semiconductor has a great influence on the characteristics, if no chain-like substituents are arranged at appropriate positions on the structure, the arrangement of the molecules in the dried organic semiconductor film has a large characteristic. If the chain-like substituents are not arranged at appropriate positions on the structure, the arrangement and arrangement of molecules in the dried organic semiconductor film will become inappropriate. In organic semiconductors, the mobility of molecules is also greatly affected by the arrangement of molecules. Even if the solubility is improved, the mobility may not be further improved. Therefore, it is very difficult to balance solubility and mobility.

Furthermore, although the possibility of deepening the LUMO / HOMO level and improving the performance of an organic semiconductor has been disclosed, what is obtained in Patent Document 1 is limited to a dimer structure. In Non-Patent Document 1, although the polymerization was successful, the side chain was inappropriate, the π conjugate area of the unit structure was small, and sufficient semiconductor characteristics were not obtained.

The present invention has been made in view of such circumstances, and provides a boron-containing polymer compound for an organic semiconductor. The boron-containing polymer compound for an organic semiconductor has a deep LUMO / HOMO level and a wide π-conjugated plane in a unit structure. At the same time, it can quantify high molecular weight based on high solubility, and is suitable for organic semiconductor containing organic thin film solar cells, organic EL, organic transistors, organic memory, electronic paper, thermoelectric conversion elements, light sensors and other applications. Boron polymer compound.

According to several aspects of the present invention, there is provided a boron-containing polymer compound including at least a structural unit represented by the following formula (1), the structural unit including a structure W having two boron-nitrogen coordination bonds as Structure π of a divalent substituent of a yoke structure, m represents 0 or 1, and the following formula (2) or (3) represents the structure W, [Chemical 3] Rings X ¹ , X ² , and Z represent a monocyclic or fused ring having a conjugated structure, and rings Y ¹ and Y ² are 5-membered rings having the boron-nitrogen coordination bond, and either of α ¹ and α ³ is Nitrogen atom, either one of α ² and α ⁴ is a nitrogen atom, R ¹ to R ⁴ may be the same or different, and may be bonded to boron through another skeleton, indicating that there is at least one carbon atom that can be substituted is 10 to A monovalent substituent of a linear or branched alkyl group of 40.

The present inventors have studied a boron-containing polymer compound having excellent mobility, and found that by introducing at least two boron-nitrogen coordination bonds into a broad unit structure of a conjugate plane, an alkyl group-containing The substituent can provide a polymer compound having a deep LUMO / HOMO level and a high molecular weight that contributes to improvement in mobility, and has a wide conjugate plane in the unit structure. The polymer compound can be used as an organic semiconductor.

The following illustrates various embodiments of the present invention. The embodiments shown below can be combined with each other.

The weight average molecular weight is preferably 2 × 10 ⁴ to 1 × 10 ⁶ .

Preferably, W is bonded to adjacent W or π through a 5-membered ring in W.

According to another aspect of the present invention, an organic semiconductor containing the above-mentioned boron-containing polymer compound is provided.

An embodiment of the present invention will be described below. Various characteristic items shown in the embodiments described below can be combined with each other. In addition, each characteristic item independently establishes the invention.

The boron-containing polymer compound according to one embodiment of the present invention can be used as an organic semiconductor, and is a polymer compound represented by the following formula (1).

That is, a polymer compound having a structure including a structure W having at least two boron-nitrogen coordination bonds as a unit structure. The unit structure preferably contains a structure π as a divalent substituent having a conjugate structure in addition to W. That is, m is 0 or 1, preferably 1. This is because the structure containing π is assumed to have two structures functioning as a donor and an acceptor in the unit structure, and the interaction between the molecular chains tends to be strong and the mobility is improved.

The unit structure represented by W in the above formula (1) is a structure having at least two boron-nitrogen coordination bonds represented by the following formula (2) or (3).

From the viewpoint of mobility, it is preferable to have at least two boron-nitrogen coordination bonds in the unit structure. It is thought that the electronic deviation between boron and nitrogen strengthens the interaction between the molecular chains, and it is considered that by including more than two boron-nitrogen coordination bonds in the unit structure, the electronic deviation becomes larger, The interaction between the molecular chains becomes stronger, thereby increasing mobility. From the viewpoint of ease of synthesis, it is preferable to have two boron-nitrogen coordination bonds in the unit structure.

As another effect of having a boron-nitrogen coordination bond, it is expected to deepen the LUMO / HOMO level and improve atmospheric stability. In one embodiment of the present invention, the effect is further improved by including two or more boron-nitrogen coordination bonds in the unit structure.

W is composed of rings X ¹ and X ² and Y ¹ and Y ² and Z. The rings X ¹ , X ² and Z represent a monocyclic or fused ring having a conjugated structure.

α ¹ and α ² may be the same or different from each other, and are preferably the same. In addition, α ³ and α may be the same or different from each other, and are preferably the same. In the same case, compared with different cases, it has the advantage of easier synthesis, and because of the high symmetry, the arrangement and arrangement of molecular chains is easy to become appropriate, and the mobility is easy to become high.

One of α ¹ and α ³ is a boron atom in the ring Y ¹ and a nitrogen atom forming a boron-nitrogen coordination bond, and the other is not particularly limited, and is, for example, a carbon atom. In addition, one of α ² and α ⁴ is a boron atom in the ring Y ² and a nitrogen atom forming a boron-nitrogen coordination bond, and the other is not particularly limited, and is, for example, a carbon atom.

Rings X ¹ and X ² are monocyclic or fused rings having a conjugated structure, and sometimes contain nitrogen atoms forming a boron-nitrogen coordination bond.

The rings X ¹ and X ² may not contain heteroatoms, and a heterocyclic ring containing a heteroatom is preferred. Heterocycles are, for example, pyrrole, furan, thiophene, selenophene, imidazole, oxazole, oxazole, thiazole, pyridine, pyrimidine, pyridazine, pyrazine, etc., or these condensed structures, and more preferably contain a sulfur atom, such as thiophene , Thienothiophene, benzothiophene, benzodithiophene, thiazole, thiazolothiazole, and the like, and more preferably thiophene or thiazole.

When the rings X ¹ and X ² include a boron atom in the rings Y ¹ and Y ² and a nitrogen atom forming a boron-nitrogen coordination bond, for example, they are imidazole, ombiazole, thiazole, pyridine, and the like. Thiazole pyridine is preferred, and rings X ¹ and X ² contain a sulfur atom, for example, thiazole.

The monocyclic or fused rings of the rings X ¹ and X ² may be substituted within a range that does not impair the characteristics of the semiconductor, and there is no limitation on the substituent. Specifically, the ring may be a linear, branched, or cyclic alkyl or alkoxy group. Group, alkylthio group, sulfo group, hydroxy group, carboxyl group, amino group, amido group, ester group, phenyl group, etc., and may also be a straight or branched chain substituted with sulfonate group, hydroxy group, carboxyl group, amino group, halo group The chain-like alkyl group, alkoxyalkyl group, epoxyalkyl group, phenyl group, and the like may have a plurality of substituents.

W is bonded to adjacent W or π through a 5- or 6-membered ring in W, and is preferably bonded through a 5-membered ring. This is because in a 5-membered ring, it is considered that there is less steric repulsion from the adjacent W or π, and it is easy to form a continuous planar structure and improve mobility.

Ring Z is a monocyclic or fused ring having a conjugated structure, and sometimes contains a nitrogen atom that forms a boron-nitrogen coordination bond. The ring Z may or may not include a heteroatom, and examples thereof include benzene, naphthalene, anthracene, pyrazine, thienothiophene, benzodithiophene, thiazolothiazole, and benzobisthiazole.

When the ring Z includes a boron atom in the rings Y ¹ and Y ² and a nitrogen atom forming a boron-nitrogen coordination bond, the ring Z is, for example, pyrazine, thiazolothiazole, naphthyridine, benzobisthiazole, pyrazinebisthiazole Wait. Preferred is thiazolothiazole or benzobisthiazole.

The rings Y ¹ and Y ² are 5-membered rings having a boron-nitrogen coordination bond. The boron atom forming the boron-nitrogen coordination bond in the rings Y ¹ and Y ² has an alkyl group-containing substituent R ¹ to R ⁴ which may be the same or different.

When W has two boron-nitrogen coordination bonds, the two boron atoms may be located on different sides as in the above formula (2) or on the same side as in (3) above. The substituents introduced into each ring differ in their proper positions, and are not limited to any one or in any case. Since they have two boron-nitrogen coordination bonds, they can be considered to have the same effect. However, from the viewpoint of ease of synthesis, as in the above formula (2), it is often more advantageous when it is located on different sides.

R ¹ to R ⁴ may be the same or different, and are monovalent substituents having at least one linear or branched alkyl group having 10 to 40 carbon atoms which may be substituted. An alkyl group of R ¹ to R ⁴ is directly bonded to a boron atom, and R ¹ to R ⁴ may be bonded through another skeleton. The number of carbon atoms of the alkyl group is preferably 12 or more, and more preferably 14 or more. The number of carbon atoms of the alkyl group is preferably 30 or less, and more preferably 25 or less. It should be noted that the above carbon number is 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30 , 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, and may be within a range between any two of the values exemplified here. When such an alkyl group-containing substituent is introduced, an organic semiconductor can be produced by a coating process having high solubility in a solvent. Here, the solubility in a solvent means the solubility mainly in a halogen-based solvent, an aromatic solvent, etc., specifically, with respect to chloroform, chlorobenzene, dichlorobenzene, toluene, mesitylene, and benzene. Solubility of methyl ether, tetrahydronaphthalene and cyclohexylbenzene.

Examples of the substituent that can replace the alkyl group in R ¹ to R ⁴ include a sulfonic acid group, a hydroxyl group, an alkoxy group, an alkylthio group, a carboxyl group, an ester group, an amino group, an amido group, a halo group, and a phenyl group.

When R ¹ to R ^{4 are} bonded by other skeletons, the other skeletons described above include, for example, heteroatoms such as oxygen, nitrogen, and sulfur, benzene rings, naphthalene rings, Austrian rings, anthracene rings, phenanthrene rings, pyrene rings, and fluorene. Ring, tetracene ring, triphenylene ring, fluorene ring, halobenzene ring, fluorene ring, fluoranthene ring, pentacene ring, this ring, pentaphen ring, sane ring, dermatan ring and other aromatic rings, pyridine, imidazole You may combine multiple heterocyclic rings, such as thiophene and thiophene. In addition, an alkyl chain having 1 to 6 carbon atoms may be further interposed between another skeleton and boron.

R ¹ to R ^{4 are} preferably a straight-chain or branched alkyl group directly bonded to boron, or bonded to boron via oxygen or sulfur and / or phenyl, benzyl, phenylhexyl, and more preferably a straight-chain or branched A chain alkyl group is directly bonded to boron, and a linear alkyl group is more preferably directly bonded to boron.

As a specific structure of W, specifically, the structure shown by following formula (4) is illustrated, but it is not limited to this.

[Chemical 4]

    <1. Synthesis of boron-containing compounds>    

W represented by the above formula (2) or (3) can be synthesized by various methods, and W represented by the above formula (2) can be synthesized by, for example, the following reaction formula (5) or the following reaction formula (6).

(R ¹ to R ⁴ in formula (5) are the same as those in chemical formula (2), and R ⁵ represents halogen.)

(R ¹ to R ⁴ in formula (6) are the same as those in chemical formula (2), and R ⁵ represents halogen.)

    <1-1. Introduction of boron substituents>    

The compound WA-1 or WB-1 and the reaction solvent are weighed in a reaction container substituted with an inert gas, and after cooling, a base is added, and after stirring for several hours, a substituted borane is added and stirred. After the reaction is completed, a purification step is performed to obtain WA-2 or WB-2 into which a boron substituent is introduced.

The reaction container is not particularly limited, and glass, Teflon (registered trademark), or the like can be used.

The reaction solvent is not particularly limited as long as it is a solvent capable of reacting, and examples thereof include tetrahydrofuran, t-butyl methyl ether, acetonitrile, phenol, benzene, toluene, and the like.

Examples of the inert gas include nitrogen, argon, and helium.

The stirring method is not particularly limited, and a stirrer or a shaker may be used.

The purification step may be any method as long as the objects can be separated, and known methods may be used. Specifically, methods such as liquid separation extraction, separation by column chromatography, and recrystallization may be used. These methods may be combined. Separation and purification.

The base is not particularly limited as long as it is a base capable of undergoing a BN cross-linking reaction. Examples thereof include bases such as alkyllithium, and specifically, methyllithium, n-butyllithium, sec-butyllithium, and tertiary Butyl lithium and the like.

The cooling temperature when the alkali is added is -100 ° C to -50 ° C, and preferably 90 ° C to -70 ° C. Specifically, the temperature is, for example, -100, -90, -80, -70, -60, or 50 ° C, and may be within a range between any two values exemplified herein.

The stirring for several hours after the base is added is not particularly limited, and it is, for example, 1 to 6 hours, and preferably 1 to 4 hours. Specifically, the time is, for example, 1, 2, 3, 4, 5, or 6 hours, and may be within a range between any two values exemplified herein.

The substituted borane is not particularly limited as long as it has a substituent R ¹ to R ⁴ that can be used in the present invention and can perform a BN crosslinking reaction.

The stirring time after the borane is added is not particularly limited, and is, for example, 1 to 24 hours, and preferably 8 to 24 hours. Specifically, the time is, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 15, 18, 21, or 24 hours, and may be any two of the examples illustrated here. The range between values.

The stirring temperature after adding the borane is -78 ° C to 25 ° C, and preferably 0 ° C to 25 ° C. Specifically, the temperature is, for example, 0, 5, 10, 15, 20, or 25 ° C, and may be within a range between any two values exemplified herein.

In addition, in the BN cross-linking reaction, boron tribromide is used for borane, and BBr _{2 is} used as a cross-linked product, and then a Grignard reaction can be performed using a Grignard reagent such as an alkyl magnesium bromide. To introduce substituents R ¹ to R ⁴ .

Π in the formula (1) represents a divalent substituent having a conjugated structure, and is preferably represented by the following formula (7).

Here, V ¹ and V ² may be the same or different, and are divalent aromatic rings or heterocyclic rings having -CR ⁶ = CR ^6- , -C≡C-, and 2 to 40 carbon atoms. Substituted or substituted by one or more groups R ⁶ , A and B may be the same or different, and represent an integer of 0 to 2.

R ⁶ represents H, halogen, cyano, or a linear or branched alkyl, alkoxy, or alkylthio group having 1 to 40 carbon atoms.

More preferably, the site bonded to W is -CH = CH-, -C≡C-, or a 5-membered ring. This is because, in these cases, there is less steric repulsion with the bonded W, and it is easy to form a continuous planar structure, which improves mobility. Specifically, although the structure shown by following formula (8) is illustrated, it is not limited to this.

[Chemical 8]

The boron-containing polymer compound of the present invention only needs to contain a copolymer in the polymer compound, and the copolymer contains the structure shown in the chemical formula (1), but in order to make the interaction between the molecular chains stronger It is preferable to include an alternating copolymer in which m in the chemical formula (1) is 1, and W and π are alternately arranged.

The weight average molecular weight (weight average molecular weight, Mw) of the boron-containing polymer compound of the present invention is a polystyrene-equivalent value measured by gel permeation chromatography (hereinafter referred to as "GPC"), and is usually 2 × 10 ⁴ ~ 2 × 10 ⁸ . From the viewpoint of the balance of mobility, solubility, and film-forming property, the weight average molecular weight of the polymer compound is preferably 2 × 10 ⁴ to 1 × 10 ⁶ , and more preferably 3 × 10 ⁴ to 5 × 10 ⁵ .

The polymerization method of the boron-containing polymer compound containing the above formula (1) is not particularly limited, and Suzuki Coupling, Stille Coupling, Ullmann reaction, Gera Glaser Reaction, Heck reaction, Negishi coupling, round head coupling, Kumagata coupling, etc. From the viewpoint of ease of synthesis or less restrictions on the monomers that can be used, Suzuki coupling or Stiller coupling is preferred .

As a method for polymerizing by Suzuki coupling, generally, W and / or π to which boric acid or a boronic acid ester is bonded, and W and / or π to be halogenated are used as raw materials, and the reaction is performed in an environment of a palladium catalyst and a base. The polymerization method is preferably performed in an inert atmosphere such as argon or nitrogen in a reaction system in which the catalyst does not lose activity. For example, it is preferably performed in a system sufficiently substituted with argon or nitrogen.

As a method for polymerizing by Stiller coupling, there are generally mentioned those using W and / or π to which organotin is bonded, and W and / or π to be halogenated as raw materials, and reacted and polymerized in an environment of a palladium catalyst. The method is preferably performed in an inert atmosphere such as argon or nitrogen in a reaction system in which the catalyst does not lose activity. For example, it is preferably performed in a system sufficiently substituted with argon or nitrogen.

The application of the boron-containing polymer compound of the present invention is not limited, and it can be used as a P-type organic semiconductor, an n-type organic semiconductor, or a bipolar semiconductor, and can also be applied to an organic thin-film solar cell, an organic EL, an organic transistor, and an organic memory. , Electronic paper, thermoelectric conversion elements, sensors, etc.

    [Example]         <Measurement of molecular weight>    

In the following examples, the weight average molecular weight of the polymer compound (polymer) was determined using a high-speed GPC device (manufactured by ToSoh Corporation, model HLC-8320GPC ECcOSEC) and an ultraviolet absorption detector (manufactured by ToSoh Corporation, model UV-8320). It is measured and calculated by polystyrene conversion. Trichloromethane was used as the measurement solvent, and TSKguardcolumn HHR-H × 1 + TSKgeL GMHHR-H × 1 (both manufactured by ToSoh Corporation) was used for the GPC column.

    <Evaluation of solubility>    

The boron-containing polymer compound was 0.5% by weight, mixed with chloroform, and stirred at 20 ° C for 15 minutes. The completely dissolved was ○, and the dissolved residue was ×.

    <Measurement of Ionization Potential (HOMO)>    

A solution of boron-containing polymer compound (P1) dissolved in chloroform at a concentration of 5 mg / g was dropped on a conductive film of glass with a fluorine-doped tin oxide film, and a sample dried at room temperature and air was used as a measurement sample. The measurement was performed using an ionization potential measuring device (PYS-201, manufactured by Sumitomo Heavy Industries, Ltd.).

    <Measurement of Energy Gap (Eg) and LUMO>    

A solution in which a polymer compound containing boron was dissolved in chloroform was used to measure an ultraviolet-visible absorption spectrum using an ultraviolet-visible near-infrared spectrophotometer (JASCO, V-670). Value as Eg. Then, the values of the ionization potential (HOMO) and Eg were subtracted to convert the LUMO.

    <Measurement of mobility>    

The measurement of the mobility is performed based on the evaluation of a field effect transistor (TFT).

On a glass substrate on which a Cr gate electrode having a thickness of 500 Å was formed, coating was performed using a ZEOCOAT ES2110-10 (manufactured by ZEON, Japan) spin coating method (500rPm / 3Sec. And 2000rPm / 15Sec.) At 90 ° C for 2 min. After heating, it was heated at 150 ° C for 1hr. Heating is performed to form a gate insulating film. Next, a boron-containing polymer compound (P1) solution (0.5 wt%, chlorobenzene solvent) was applied on a substrate by a spin coating method (1000 rPm, 60 Sec.), And on a hot plate under a nitrogen atmosphere. At 80 ° C for 30min. Return processing is performed to form an organic semiconductor film. Next, gold was vacuum-evaporated to a film thickness of 50 nm using a metal mask to form a source electrode and a drain electrode having a channel length of 50 μm, and a bottom gate top contact organic thin film transistor was fabricated. .

The thus-produced organic transistor was measured for current-voltage (I-V) characteristics under an atmospheric environment, and the degree of charge mobility was determined from a saturated region.

    <Synthesis of W>     Synthesis Example 1: Synthesis of boron-containing compounds A1 and A1-2     ‧Synthesis of 2,5-bis (3-bromo-2-thiophene) benzobisthiazole (A1-1)    

Into a 500 mL Schlenk tube substituted with nitrogen, 4.40 g (17.9 mmmol) of 2,5-diamino-1,4-benzenedithiol dihydrochloride and 50 g of polyphosphoric acid were put, and stirred at 100 ° C for 3 hours. To this solution was added a solution of 7.80 g (37.7 mmol) of 3-bromothiophene 2-carboxylic acid (47 g) of cyclobutane, and the mixture was stirred with superheating at 100 ° C for 5 hours. The reaction solution was cooled to room temperature, and after adding water, the solid was collected by filtration. The obtained solid was washed with dimethylformamide to obtain 2,5-bis (3-bromo-2-thiophene) benzobisthiazole (A1-1) as a yellow solid. 8.03 g (15.6 mmol) And the yield is 87%.

    ‧Synthesis of boron-containing compound A1    

In a 500 mL Schlenk tube substituted with nitrogen, 1.00 g (1.94 mmol) of 2,5-bis (3-bromo-2-thiophene) benzobisthiazole (compound A1-1) and 75 mL of dehydrated tetrahydrofuran were charged. 5.1 mL (8.15 mmol) of tert-butyllithium 1.6M solution was added dropwise at -78 ° C, and the mixture was directly stirred for 1 hour. To this solution, 42.7 mL (3.89 mmol) of a tris (hexadecyl) borane 0.91M solution described later was added dropwise at -78 ° C.

Here, the tris (hexadecyl) borane solution was adjusted by the following steps: put 1-hexadecene 3.3 mL (11.6 mmol), 35 mL of dehydrated tetrahydrofuran in a nitrogen-substituted Schlenk tube, 4.3 mL (3.88 mmol) of a 0.9M solution of borane-tetrahydrofuran complex was added dropwise at ℃, and the mixture was directly stirred for 1 hour.

The reaction solution was slowly returned to room temperature and stirred at room temperature for 3 hours. After the reaction solution was concentrated, by column chromatography using hexane as a developing solvent, 1.09 g (0.85 mmol) of the boron-containing compound (A1) was obtained as a yellow solid, and the yield was 44%.

    ‧Synthesis of boron-containing compound A1-2    

In a 100 mL Schlenk tube substituted with nitrogen, 0.4 g (0.31 mmol) of a boron-containing compound (compound A1), 20 mL of dehydrated tetrahydrofuran, tetramethylpyridinylmagnesium chloride, lithium chloride 1.0M were added dropwise at 0 ° C. The solution was 1.9 mL (1.90 mmol) and directly stirred for 1 hour. To this solution, 0.38 g (1.90 mmol) of trimethyltin chloride was added to the solution, and the mixture was stirred at the same temperature for 1 hour. Next, the reaction solution was returned to room temperature and stirred at room temperature for 1 hour. After the reaction solution was concentrated, column chromatography using chloroform as a developing solvent yielded 0.39 g (0.24 mmol) of a boron-containing compound (A1-2) as a pale orange solid with a yield of 79. %.

Synthesis Example 2: Synthesis of boron-containing compounds A2 and A2-2     ‧Synthesis of boron-containing compound A2    

In the method for synthesizing the boron-containing compound A1, dimesytrilylfluoroborane was used as a raw material instead of tris (hexadecyl) borane, and 0.463 g (0.543 mmol) of A2 was obtained as a yellow solid, and The yield was 28%.

    ‧Synthesis of boron-containing compound (A2-2)    

The boron compound A2-2 cannot be synthesized because A2 is intolerant.

    <Synthesis and Evaluation of Boron-containing Polymer Compounds>     Example 1: Synthesis and Evaluation of Boron-containing Polymer Compound (P1)

In a nitrogen-substituted 20 mL Schlenk tube, 0.1 g (0.024 mmol) of the boron-containing compound (A1-2) and 20.2 mg (0.024 mmol) of 5,5'-dibromo 2,2'- Bithiophene (Tokyo Chemical Industry), 2.9 mg (5 mol%) of tris (dibenzylideneacetone) dipalladium, 1.9 mg (10 mol%) of tris (o-tolyl) phosphine, 5 mL of chlorobenzene, 8 The mixture was stirred under heating and refluxing for 1 hour. Next, 100 mg (0.309 mmol) of 2-tributylstannylthiophene was added, and the reaction was performed for 30 minutes. After returning to room temperature, methanol was added, and solids were recovered by filtration, and low-molecular substances were removed by Soxhlet extraction using methanol and hexane. Finally, by Soxhlet extraction using chloroform, the extracted chloroform was concentrated, and methanol was added to precipitate a solid, followed by filtration and recovery, to obtain 61 mg of a boron-containing polymer compound (P1) as a thick purple solid. The weight average molecular weight of the obtained polymer compound was measured by GPC method, and it was 63,000. The measured HOMO value was -5.7 eV, the Eg value was 2.0 eV, and the LUMO converted from these was -3.7 eV. In addition, a solubility test was performed, and as a result, chloroform was sufficiently dissolved. Evaluation based on the transistor was performed, and the result was 1.8 × 10 ^-3 cm ² / VS, and the On / Off value was 10 ⁶ . The evaluation results are shown in Table 1.

Example 2: Synthesis and Evaluation of Boron-containing Polymer Compound (P2)

In the synthesis method of the boron-containing polymer compound (P1), 5,5 ''-dibromo-2,2 ': 5', 2 ''-trithiophene (Tokyo Chemical Industry) is used instead of 5,5'-di Bromine-2,2'-bisthiophene (Tokyo Chemical Industry), and 63 mg of a boron-containing polymer compound (P2) as a thick purple solid was obtained. The evaluation results are shown in Table 1.

Example 3: Synthesis and Evaluation of Boron-containing Polymer Compound (P3)

In the synthesis method of the boron-containing polymer compound (P1), 4,7-bis (5-bromo-2-thiophene) -2,1,3-benzothiadiazole is used instead of 5,5'-dibromo- 2,2'-bisthiophene (Tokyo Chemical Industry), 52 mg of a boron-containing polymer compound (P3) was obtained as a blue solid. The evaluation results are shown in Table 1.

Example 4: Synthesis and evaluation of boron-containing polymer compound (P4)

In the method for synthesizing the boron-containing polymer compound (P1), 2,6-dibromodithieno [3,2-B: 2 ', 3'-d] thiophene is used instead of 5,5'-dibromo-2 , 2'-bisthiophene (Tokyo Chemical Industry), 58 mg of a boron-containing compound (P4) was obtained as a thick purple solid. The evaluation results are shown in Table 1.

Example 5: Synthesis and evaluation of boron-containing polymer compound (P5)

In the method for synthesizing a boron-containing polymer compound (P1), the following compound B was used instead of 5,5'-dibromo-2,2'-dithiophene (Tokyo Chemical Industry), and a boron-containing compound as a green solid was obtained. 81mg of molecular compound (P5). The evaluation results are shown in Table 1.

Should be explained, refer to J. Mater. Chem. C, 2014, 2, 3457 and J. Mater. Chem. C, 2014, 2, 6376 Synthesis of compound B1.

Comparative Example 1

As described above, since A2 has no solubility with respect to chlorobenzene, a polymer having A2 cannot be synthesized as A2-2 as a polymerization precursor, and therefore cannot be evaluated. The results are shown in Table 1.

Comparative Example 2

P3HT (Verazol HT, weight average molecular weight 47,000, manufactured by Kenken Chemical Co., Ltd.) was used in place of the boron-containing polymer compound (P1) in Example 1, and the return condition during transistor production was changed to 150 ° C for 30 minutes. Other than that, evaluation was performed by the same method. The results are shown in Table 1.

【Table 1】     

With respect to the comparative examples, Examples 1 to 5 exhibited high solubility in all chloroform. In addition, the semiconductor characteristics exhibit P-type semiconductor characteristics, a mobility of 10 ^-4 cm ² / VS or more, and an On / Off value of 10 ⁴ or more. On the other hand, in Comparative Example 1, polymerization was not possible, and Comparative Example 2 had a dissolved residue with respect to chloroform, and obtained high solubility. In addition, regarding semiconductor characteristics, since the ionization potential is low, the atmospheric stability is also the highest, and the On / Off value becomes a low value.

Claims (4)

A boron-containing polymer compound including a structural unit represented by the following formula (1), the structural unit including a structure W having at least two boron-nitrogen coordination bonds and a structure as a divalent substituent having a conjugated structure π, m represents 0 or 1, and the following formula (2) or (3) represents the structure W, The rings X ¹ , X ² , and Z represent a monocyclic or fused ring having a conjugated structure, and the rings Y ¹ and Y ² are 5-membered rings having the boron-nitrogen coordination bond, and either of α ¹ and α ³ is A nitrogen atom, either of α ² and α ⁴ is a nitrogen atom, R ¹ to R ⁴ may be the same or different, and may be bonded to boron through another skeleton, which means that at least one carbon atom that can be substituted is 10 to A monovalent substituent of a linear or branched alkyl group of 40. The weight-average molecular weight of the boron-containing polymer compound according to claim 1 is 2 × 10 ⁴ to 1 × 10 ⁶ .     The boron-containing polymer compound according to claim 1 or 2, wherein W is bonded to adjacent W or π through a 5-membered ring in W.         An organic semiconductor containing the boron-containing polymer compound according to any one of claims 1 to 3.