KR102392669B1 - Organic compound and organic thin film and electronic device - Google Patents

Abstract

[화학식 4]

상기 화학식 2 내지 4에서, Ar¹ 내지 Ar⁶, X¹ 및 X², R¹ 내지 R⁴는 명세서에서 기재한 바와 같다. It relates to an organic compound represented by the following Chemical Formula 1, an organic thin film including the compound, an organic thin film transistor, and an electronic device.
[Formula 1]
A - B
In Formula 1, the A moiety and the B moiety are each independently a condensed polycyclic group in which four or more rings are fused, a group represented by any one of the following Chemical Formulas 2 to 4,
[Formula 2] [Formula 3]

[Formula 4]

In Formulas 2 to 4, Ar ¹ to Ar ⁶ , X ¹ and X ² , R ¹ to R ⁴ are the same as described in the specification.

Description

Organic compounds, organic thin films and electronic devices

It relates to organic compounds, organic thin films and electronic devices.

A flat panel display device, such as a liquid crystal display (LCD), an organic light emitting diode display (OLED display), and an electrophoretic display, includes a plurality of pairs of electric field generating electrodes and a space between them. containing an electro-optically active layer. A liquid crystal display includes a liquid crystal layer as an electro-optical active layer, and an organic light-emitting display includes an organic light emitting layer as an electro-optically active layer.

One of the pair of electric field generating electrodes is usually connected to a switching element to receive an electric signal, and the electro-optical active layer converts the electric signal into an optical signal to display an image.

A flat panel display device uses a thin film transistor (TFT), which is a three-terminal device, as a switching device, and a gate line that transmits a scan signal for controlling the thin film transistor and a signal to be applied to the pixel electrode A data line for transmitting is provided in the flat panel display.

Among these thin film transistors, research on organic thin film transistors (OTFTs) including organic semiconductors such as small molecules or polymers instead of inorganic semiconductors such as silicon (Si) is being actively conducted.

The organic thin film transistor is attracting attention as a core element of a flexible display device because it can be made in a form such as a fiber or a film due to the characteristics of an organic material. In addition, since the organic thin film transistor can be manufactured by a solution process such as inkjet printing, it can be easily applied to a large-area flat panel display, which is limited only by the deposition process.

One embodiment provides an organic compound applicable to an electronic device such as an organic thin film transistor.

Another embodiment provides an organic thin film including the organic compound.

Another embodiment provides an electronic device including the organic thin film.

According to one embodiment, an organic compound represented by the following Chemical Formula 1 is provided.

[Formula 1]

A - B

In Formula 1,

A moiety and B moiety are each independently a condensed polycyclic group in which four or more rings are fused, a group represented by any one of the following Chemical Formulas 2 to 4,

[Formula 2] [Formula 3]

[Formula 4]

In Formulas 2 to 4,

Ar ¹ To Ar ⁶ are each independently a substituted or unsubstituted pentagonal ring or a substituted or unsubstituted hexagonal ring,

Ar ³ to Ar ⁶ At least one of them is a substituted or unsubstituted pentacyclic ring containing a heteroatom,

Ar ¹ and Ar ² each form a fused ring with an adjacent ring,

Ar ³ To Ar ⁶ Form a fused ring with an adjacent ring, respectively,

X ¹ and X ² are each independently O, S, Se, Te or NR ^a ,

R ¹ to R ⁴ and R ^a are each independently hydrogen, a substituted or unsubstituted C1 to C30 alkyl group, a substituted or unsubstituted C3 to C30 cycloalkyl group, a substituted or unsubstituted C6 to C30 aryl group, a substituted or unsubstituted a C7 to C30 arylalkyl group, a substituted or unsubstituted C1 to C30 heteroalkyl group, a substituted or unsubstituted C2 to C30 heterocycloalkyl group, a substituted or unsubstituted C2 to C30 heteroaryl group, a substituted or unsubstituted C2 to C30 an alkenyl group, a substituted or unsubstituted C2 to C30 alkynyl group, a hydroxyl group, a halogen atom, or a combination thereof;

a to g are each independently an integer of 0 to 3,

provided that a+b≥2, c+d≥2 and e+f+g≥2,

* is the connection point.

Wherein Ar ¹ To Ar ⁶ Each independently may be a substituted or unsubstituted benzene ring, or a substituted or unsubstituted heterocycle.

At least one of Ar ¹ and Ar ² includes O, S, Se, Te or NR ^a may be a heterocyclic group, wherein at least one of Ar ³ to Ar ⁶ is O, S, Se, Te or NR ^a may be a heterocyclic group, wherein R ^a is hydrogen, a substituted or unsubstituted C1 to C30 alkyl group, a substituted or unsubstituted C3 to C30 cycloalkyl group, a substituted or unsubstituted C6 to C30 aryl group, a substituted or unsubstituted C7 to C30 arylalkyl group, substituted or unsubstituted C1 to C30 heteroalkyl group, substituted or unsubstituted C2 to C30 heterocycloalkyl group, substituted or unsubstituted C2 to C30 heteroaryl group, substituted or unsubstituted C2 to C30 alkenyl group , a substituted or unsubstituted C2 to C30 alkynyl group, a hydroxyl group, a halogen atom, or a combination thereof.

The A moiety and the B moiety may each independently be one of the groups listed in Group 1 below.

[Group 1]

In group 1,

X ¹ to X ⁴ are each independently O, S, Se, Te or NR ^a ,

R ¹ to R ⁹ and R ^a are each independently hydrogen, a substituted or unsubstituted C1 to C30 alkyl group, a substituted or unsubstituted C3 to C30 cycloalkyl group, a substituted or unsubstituted C6 to C30 aryl group, a substituted or unsubstituted a C7 to C30 arylalkyl group, a substituted or unsubstituted C1 to C30 heteroalkyl group, a substituted or unsubstituted C2 to C30 heterocycloalkyl group, a substituted or unsubstituted C2 to C30 heteroaryl group, a substituted or unsubstituted C2 to C30 an alkenyl group, a substituted or unsubstituted C2 to C30 alkynyl group, a hydroxyl group, a halogen atom, or a combination thereof;

R ¹ to R ⁹ are each independently present or two adjacent ones thereof are fused to form a fused ring,

* is the connection point.

The A moiety and the B moiety of Formula 1 may not be positioned on the same plane and may have torsion.

The organic compound may be a compound listed in Group 2 below.

[Group 2]

According to another embodiment, an organic thin film including the organic compound is provided.

According to another embodiment, it includes a gate electrode, an organic semiconductor overlapping the gate electrode, and a source electrode and a drain electrode electrically connected to the organic semiconductor, wherein the organic semiconductor is an organic compound represented by the following Chemical Formula 1 may include

[Formula 1]

A - B

In Formula 1,

A moiety and B moiety are each independently a condensed polycyclic group in which four or more rings are fused, a group represented by any one of the following Chemical Formulas 2 to 4,

[Formula 2] [Formula 3]

[Formula 4]

In Formulas 2 to 4,

Ar ¹ To Ar ⁶ are each independently a substituted or unsubstituted pentagonal ring or a substituted or unsubstituted hexagonal ring,

Ar ³ to Ar ⁶ At least one of them is a substituted or unsubstituted pentacyclic ring containing a heteroatom,

Ar ¹ and Ar ² each form a fused ring with an adjacent ring,

Ar ³ To Ar ⁶ Form a fused ring with an adjacent ring, respectively,

X ¹ and X ² are each independently O, S, Se, Te or NR ^a ,

R ¹ to R ⁴ and R ^a are each independently hydrogen, a substituted or unsubstituted C1 to C30 alkyl group, a substituted or unsubstituted C3 to C30 cycloalkyl group, a substituted or unsubstituted C6 to C30 aryl group, a substituted or unsubstituted a C7 to C30 arylalkyl group, a substituted or unsubstituted C1 to C30 heteroalkyl group, a substituted or unsubstituted C2 to C30 heterocycloalkyl group, a substituted or unsubstituted C2 to C30 heteroaryl group, a substituted or unsubstituted C2 to C30 an alkenyl group, a substituted or unsubstituted C2 to C30 alkynyl group, a hydroxyl group, a halogen atom, or a combination thereof;

a to g are each independently an integer of 0 to 3,

provided that a+b≥2, c+d≥2 and e+f+g≥2,

* is the connection point.

Wherein Ar ¹ To Ar ⁶ Each independently may be a substituted or unsubstituted benzene ring, a substituted or unsubstituted heterocyclic group.

At least one of Ar ¹ and Ar ² includes O, S, Se, Te or NR ^a may be a heterocyclic group, and at least one of Ar ³ to Ar ⁶ is O, S, Se, Te or NR ^a may be a heterocyclic group, wherein R ^a is hydrogen, a substituted or unsubstituted C1 to C30 alkyl group, a substituted or unsubstituted C3 to C30 cycloalkyl group, a substituted or unsubstituted C6 to C30 aryl group, a substituted or unsubstituted C7 to C30 arylalkyl group, substituted or unsubstituted C1 to C30 heteroalkyl group, substituted or unsubstituted C2 to C30 heterocycloalkyl group, substituted or unsubstituted C2 to C30 heteroaryl group, substituted or unsubstituted C2 to C30 alkenyl group , a substituted or unsubstituted C2 to C30 alkynyl group, a hydroxyl group, a halogen atom, or a combination thereof.

The A moiety and the B moiety of Formula 1 may each independently be one of the groups listed in Group 1 below.

[Group 1]

In group 1,

X ¹ to X ⁴ are each independently O, S, Se, Te or NR ^a ,

R ¹ to R ⁹ and R ^a are each independently hydrogen, a substituted or unsubstituted C1 to C30 alkyl group, a substituted or unsubstituted C3 to C30 cycloalkyl group, a substituted or unsubstituted C6 to C30 aryl group, a substituted or unsubstituted a C7 to C30 arylalkyl group, a substituted or unsubstituted C1 to C30 heteroalkyl group, a substituted or unsubstituted C2 to C30 heterocycloalkyl group, a substituted or unsubstituted C2 to C30 heteroaryl group, a substituted or unsubstituted C2 to C30 an alkenyl group, a substituted or unsubstituted C2 to C30 alkynyl group, a hydroxyl group, a halogen atom, or a combination thereof;

R ¹ to R ⁹ are each independently present or two adjacent ones thereof are fused to form a fused ring,

* is the connection point.

The A moiety and the B moiety of Formula 1 may not be positioned on the same plane and may have torsion.

The organic semiconductor may include an organic compound listed in Group 2 below.

[Group 2]

According to another embodiment, an electronic device including the organic thin film transistor is provided.

The electronic device may include a liquid crystal display device, an organic light emitting device, an electrophoretic device, an organic photoelectric device, and an organic sensor.

According to another embodiment, an electronic device including the organic thin film is provided.

An organic compound having improved charge mobility and improved solubility is provided.

1 is a cross-sectional view illustrating an organic thin film transistor according to an exemplary embodiment.

Hereinafter, embodiments of the present invention will be described in detail so that those of ordinary skill in the art to which the present invention pertains can easily implement them. However, the present invention may be embodied in many different forms and is not limited to the embodiments described herein.

Unless otherwise defined herein, 'substituted' means that a hydrogen atom in a compound is a halogen atom (F, Br, Cl, or I), a hydroxy group, an alkoxy group, a nitro group, a cyano group, an amino group, an azido group, an amino group Dino group, hydrazino group, hydrazono group, carbonyl group, carbamyl group, thiol group, ester group, carboxyl group or its salt, sulfonic acid group or its salt, phosphoric acid or its salt, C1 to C20 alkyl group, C2 to C20 alkenyl group, C2 to C20 alkynyl group, C6 to C30 aryl group, C7 to C30 arylalkyl group, C1 to C30 alkoxy group, C1 to C20 heteroalkyl group, C3 to C20 heteroarylalkyl group, C3 to C30 cycloalkyl group, C3 to C15 cycloalkenyl group, It means substituted with a substituent selected from a C6 to C15 cycloalkynyl group, a C3 to C30 heterocycloalkyl group, and combinations thereof.

In addition, unless otherwise defined herein, 'hetero' means containing 1 to 3 heteroatoms selected from N, O, S, Se and P.

Hereinafter, an organic compound according to an embodiment will be described.

The organic compound according to the exemplary embodiment may be represented by the following Chemical Formula 1.

[Formula 1]

A - B

In Formula 1,

A moiety and B moiety are each independently a condensed polycyclic group in which four or more rings are fused, a group represented by any one of the following Chemical Formulas 2 to 4,

[Formula 2] [Formula 3]

[Formula 4]

In Formulas 2 to 4,

Ar ¹ To Ar ⁶ are each independently a substituted or unsubstituted pentagonal ring or a substituted or unsubstituted hexagonal ring,

Ar ³ to Ar ⁶ At least one of them is a substituted or unsubstituted pentacyclic ring containing a heteroatom,

Ar ¹ and Ar ² each form a fused ring with an adjacent ring,

Ar ³ To Ar ⁶ Form a fused ring with an adjacent ring, respectively,

X ¹ and X ² are each independently O, S, Se, Te or NR ^a ,

R ¹ to R ⁴ and R ^a are each independently hydrogen, a substituted or unsubstituted C1 to C30 alkyl group, a substituted or unsubstituted C3 to C30 cycloalkyl group, a substituted or unsubstituted C6 to C30 aryl group, a substituted or unsubstituted a C7 to C30 arylalkyl group, a substituted or unsubstituted C1 to C30 heteroalkyl group, a substituted or unsubstituted C2 to C30 heterocycloalkyl group, a substituted or unsubstituted C2 to C30 heteroaryl group, a substituted or unsubstituted C2 to C30 an alkenyl group, a substituted or unsubstituted C2 to C30 alkynyl group, a hydroxyl group, a halogen atom, or a combination thereof;

a to g are each independently an integer of 0 to 3,

provided that a+b≥2, c+d≥2 and e+f+g≥2,

* is the connection point.

The organic compound is a low molecular weight compound in which the A moiety, which is a condensed polycyclic group in which four or more rings are fused, and the B moiety, which is a condensed polycyclic group in which four or more rings are fused, are connected by a single bond. The organic compound not only increases packing and stacking between molecules by appropriately controlling the number of fused rings to increase the planarity of the compound, but also connects the fused polycyclic groups with a single bond between molecules. Charge mobility can be increased by increasing the overlap of orbitals. In this case, the A moiety and the B moiety may have a structure twisted at a predetermined angle without being positioned on the same plane.

Compared with a structure in which the A moiety and the B moiety are fused to each other, the organic compound having a structure in which the A moiety and the B moiety are connected by a single bond while maintaining the overlap between molecules, the synthesis process is easy and solubility is can be raised Accordingly, the organic compound can increase the yield while having a condensed polycyclic structure and can be easily applied to a solution process when forming an organic thin film later.

The A moiety and the B moiety may each be a fused form of a substituted or unsubstituted benzene ring and a substituted or unsubstituted heterocyclic group.

At least one of Ar ¹ and Ar ² includes O, S, Se, Te or NR ^a may be a heterocyclic group, wherein at least one of Ar ³ to Ar ⁶ is O, S, Se, Te or NR ^a It may be a heterocyclic group. where R ^a is hydrogen, a substituted or unsubstituted C1 to C30 alkyl group, a substituted or unsubstituted C3 to C30 cycloalkyl group, a substituted or unsubstituted C6 to C30 aryl group, a substituted or unsubstituted C7 to C30 arylalkyl group, substituted or an unsubstituted C1 to C30 heteroalkyl group, a substituted or unsubstituted C2 to C30 heterocycloalkyl group, a substituted or unsubstituted C2 to C30 heteroaryl group, a substituted or unsubstituted C2 to C30 alkenyl group, a substituted or unsubstituted It may be a C2 to C30 alkynyl group, a hydroxyl group, a halogen atom, or a combination thereof.

For example, Ar ¹ and Ar ² in Formula 2 or 3 may be different from each other, for example, one of Ar ¹ and Ar ² may be a substituted or unsubstituted benzene ring, and the other may be a substituted or unsubstituted heterocyclic group. there is.

For example, any one of Ar ³ to Ar ⁶ of Formula 4 may be different. For example, Ar ³ and Ar ⁴ may be the same and Ar ⁵ may be different. In this case, Ar ³ and Ar ⁴ may be a substituted or unsubstituted heterocyclic group, and Ar ⁵ may be a substituted or unsubstituted benzene ring. For example, Ar ⁴ and Ar ⁵ may be the same and Ar ³ may be different. In this case, Ar ⁴ and Ar ⁵ may be a substituted or unsubstituted benzene ring, and A ³ may be a substituted or unsubstituted heterocyclic group. For example, Ar ³ and Ar ⁵ may be the same and Ar ⁴ may be different, wherein Ar ³ and Ar ⁵ may be a substituted or unsubstituted benzene ring, Ar ⁴ may be a substituted or unsubstituted heterocyclic group, or Ar ³ and Ar ⁵ may be a substituted or unsubstituted heterocyclic group and Ar ⁴ may be a substituted or unsubstituted benzene ring.

The A moiety and the B moiety may be the same or different.

The A moiety and the B moiety may be, for example, each independently one of the groups listed in Group 1, but is not limited thereto.

[Group 1]

In group 1,

X ¹ to X ⁴ are each independently O, S, Se, Te or NR ^a ,

R ¹ to R ⁹ and R ^a are each independently hydrogen, a substituted or unsubstituted C1 to C30 alkyl group, a substituted or unsubstituted C3 to C30 cycloalkyl group, a substituted or unsubstituted C6 to C30 aryl group, a substituted or unsubstituted a C7 to C30 arylalkyl group, a substituted or unsubstituted C1 to C30 heteroalkyl group, a substituted or unsubstituted C2 to C30 heterocycloalkyl group, a substituted or unsubstituted C2 to C30 heteroaryl group, a substituted or unsubstituted C2 to C30 an alkenyl group, a substituted or unsubstituted C2 to C30 alkynyl group, a hydroxyl group, a halogen atom, or a combination thereof;

R ¹ to R ⁹ are each independently present or two adjacent ones thereof are fused to form a fused ring,

* is the connection point.

The organic compound may be, for example, one of the compounds listed in Group 2 below, but is not limited thereto.

[Group 2]

The organic compound may be implemented as an organic thin film through a deposition or solution process. The organic thin film may be applied to various devices including organic semiconductors. For example, the organic compound may be applied to an organic thin film transistor, and may be applied as a charge transport layer and/or an active layer in an electronic device such as a solar cell, an organic light emitting display device, and an organic sensor.

Hereinafter, an example of an organic thin film transistor including the organic compound will be described with reference to the drawings.

In order to clearly express various layers and regions in the drawings, the thicknesses are enlarged. Throughout the specification, like reference numerals are assigned to similar parts. When a part, such as a layer, film, region, plate, etc., is "on" another part, it includes not only the case where it is "directly on" another part, but also the case where there is another part in between. Conversely, when we say that a part is "just above" another part, we mean that there is no other part in the middle.

1 is a cross-sectional view illustrating an organic thin film transistor according to an exemplary embodiment.

A gate electrode 124 is formed on a substrate 110 made of transparent glass, silicon, or plastic. The gate electrode 124 is connected to a gate line (not shown) that transmits a gate signal. The gate electrode 124 may include gold (Au), copper (Cu), nickel (Ni), aluminum (Al), molybdenum (Mo), chromium (Cr), tantalum (Ta), titanium (Ti), alloys thereof, or A combination of these can be made.

A gate insulating layer 140 is formed on the gate electrode 124 . The gate insulating layer 140 may be made of an organic material or an inorganic material, and examples of the organic material include a polyvinyl alcohol-based compound, a polyimide-based compound, a polyacryl-based compound, and polystyrene ( polystyrene)-based compounds, and soluble high molecular compounds such as benzocyclobutane (BCB), and examples of the inorganic material include silicon nitride (SiN _x ) and silicon oxide (SiO ₂ ).

A source electrode 173 and a drain electrode 175 are formed on the gate insulating layer 140 . The source electrode 173 and the drain electrode 175 face the gate electrode 124 . The source electrode 173 is connected to a data line (not shown) that transmits a data signal. The source electrode 173 and the drain electrode 175 are gold (Au), copper (Cu), nickel (Ni), aluminum (Al), molybdenum (Mo), chromium (Cr), tantalum (Ta), and titanium (Ti). ), their alloys, or a combination thereof.

An organic semiconductor 154 is formed on the source electrode 173 and the drain electrode 175 . The organic semiconductor 154 may be made of the above-described organic compound. The organic semiconductor 154 may be formed by preparing the above-described organic compound in the form of a solution, for example, by a solution process such as spin coating, slit coating, or inkjet printing. However, the present invention is not limited thereto, and the above-described organic compound may be formed by a dry process such as vapor deposition.

Herein, an organic thin film transistor having a bottom gate structure has been described as an example of the organic thin film transistor, but the present invention is not limited thereto and may be equally applied to an organic thin film transistor having any structure such as an organic thin film transistor having a top gate structure.

The organic thin film transistor may be applied to various electronic devices as a switching device or a driving device, and the electronic device may include, for example, a liquid crystal display device, an organic light emitting display device, an electrophoretic display device, an organic photoelectric device, and an organic sensor.

The embodiments of the present invention described above will be described in more detail through the following examples. However, the following examples are for illustrative purposes only and do not limit the scope of the present invention.

Synthesis of organic compounds

Synthesis example One

[Scheme 1]

(1) Synthesis of 2,2'-bis[[1-hydroxy-(3- bromo- 2- thienyl ) methyl ]-5,5' -bibenzothiophene ] (Intermediate 1)

5.8 g (21 mmol) of bis-thieno [3,2:b] thiophene was dissolved in 500 mL dry ether, which was cooled to 0° C. in butyl After dropwise addition to 100 mL of dry ether solution containing lithium (13 mL of 2.5M in hexane solution), the temperature is gradually increased and the mixture is stirred at room temperature for 2 hours. To the turbid solution, 5.2 g (27 mmol) of 3-bromothiophene-2-aldehyde (5.2 g (27 mmol) , filtered off the precipitated material and washed several times with water and ether to obtain Intermediate 1. The yield is 60%.

¹ H-NMR (500 MHz, CDCl ₃ ): δ ppm 7.33 (d, 2H), 7.29 (s, 2H), 7.28 (s, 2H), 6.98 (d, 2H), 6.40 (d, 2H), 2.80 (s, 2H).

(2) Synthesis of 2,2'-bis[[(3- bromo- 2- thienyl ) methyl ]-5,5' -bibenzothiophene ] (Intermediate 2)

After dissolving 2.9 g (4.5 mmole) of Intermediate 1 in 200 mL of dichloromethane (CH ₂ Cl ₂ ), 2.3 g (7.3 mmole) of ZnI ₂ and NaCNBH ₃ 2.0 g (32 mmole) are added slowly. The mixture was stirred at room temperature for 24 hours, and then passed through a Celite pad. The filtrate was washed with a saturated solution of ammonium chloride and water, respectively, dried over MgSO ₄ and concentrated under reduced pressure to obtain a yellow oil. The yellow oil is purified by silica chromatography to obtain Intermediate 2. The yield is 70%.

¹ H-NMR (500 MHz, CDCl ₃ ): δ ppm 7.32 (d, 2H), 7.25 (s, 2H), 7.21 (s, 2H), 6.97 (d, 2H), 4.40 (s, 4H).

(3) Synthesis of 2,2'-bis[[(3- formyl -2- thienyl ) methyl ]-5,5' - bibenzothiophene ] (Intermediate 3)

To a solution of ether (200 mL) cooled to -78°C in which t-butyllithium (15 mmole) is dissolved, a THF solution (100 mL) of 3.2 g (10.5 mmole) of Intermediate 2 is slowly added dropwise. Then, after stirring at -78°C for about 30 minutes, 1.2 g of DMF is added and the mixture is stirred for about 2 hours again. Then, water was poured to terminate the reaction, 200 mL of ethyl acetate was added, washed with water and brine, the organic layer was dried over MgSO4 and concentrated under reduced pressure to obtain a colorless oil. The colorless oil is purified by silica chromatography to obtain Intermediate 3. The yield is 60%.

¹ H-NMR (500 MHz, CDCl ₃ ): δ ppm 10.1 (s, 2H), 7.39 (s, 2H), 7.29 (d, 2H), 7.17 (s, 2H), 7.14 (s, 2H), 7.06 (d, 2H), 4.74 (s, 4H).

(4) Synthesis of 2,2'-bis[ benzothieno[6,5- f ]thieno [3,2 - b ]thiophene]] (Compound 4)

0.9 g of Intermediate 3 is dissolved in 50 mL of 1,2-dichlorobenzene, and 0.9 g of Amberlyst 15 is added. Then, the mixture is heated through a microwave reactor at 130° C. for 12 hours. Subsequently, the temperature is lowered to room temperature to precipitate Amberlyst 15, and the suspended matter is skipped off and filtered to obtain compound 4 as an ivory-colored solid. The yield is 50%.

1H NMR (300 MHz, CDCl3): δ ppm 8.32 (d, 2H), 7.50 (d, 2H), 7.47 (d, 2H), 7.43 (d, 2H), 7.32 (d, 2H).

Synthesis example 2

[Scheme 2]

(1) Synthesis of 4,4' -bis(3-methylthio)naphthalen -2-yl) biphenyl

Put 5.97 g (0.043 mol) of K2CO3 into a 3-neck flask under a nitrogen atmosphere, add 60 ml of distilled water, and then add 100 ml of THF. 5 g (0.0148 mol) of 3-(methylthio)-2,3-dihydronaphthalen-2-yl trifluoromethanesulfonate and 0.0061 ml of biphenyl-4,4'-diboronic acid were added to the solution, and tetrakis ( Triphenylphosphine) palladium (0) 1.07 g (0.00093 mol) is added, and then refluxed. After 5 hours, 1N HCl solution was added to terminate the reaction, followed by extraction with ethyl acetate. Then, after drying over MgSO4 and removing the solvent, the obtained solid was washed several times with ether to obtain 2 g of 4,4'-bis(3-methylthio)naphthalen-2-yl)biphenyl as a yellow solid. The yield is 65%.

¹ H-NMR (500 MHz, CDCl ₃ ): δ ppm 7.89 (s, 1H), 7.79 (m, 2H), 7.62 (s, 1H), 7.49 (m, 1H), 7.44 (m, 1H), 7.29 (d, 1H), 7.26 (d, 1H), 2.55 (s, 3H).

(2 ) Synthesis of 4,4' -bis(3-methylsulfinyl)naphthalen -2-yl) biphenyl

1 g (0.00197 mol) of 4,4'-bis (3-methylthio) naphthalen-2-yl) biphenyl obtained in (1) was suspended in 100 ml of acetic acid, and then 0.46 g (0.0041 mol) of a 30% H2O2 solution was slowly added. do. Then, after stirring for 24 hours while heating to 40 ℃ acetic acid is removed to obtain a yellow solid 4,4'-bis (3-methylsulfinyl) naphthalen-2-yl) biphenyl 0.5 g.

¹ H-NMR (500 MHz, CDCl ₃ ): δ ppm 8.62 (s, 1H), 8.03 (m, 1H), 7.97 (s, 1H), 7.93 (m, 1H), 7.63 (m, 2H), 7.27 (d, 1H), 7.24 (m, 1H), 2.60 (s, 3H).

(3) 6,6'- Binaphtho[2,3-b]benzo Synthesis of [2,3-d]thiophene

4,4'-bis(3-methylsulfinyl)naphthalen-2-yl)biphenyl obtained in (2) was added to 8ml of trifluoromethanesulfonic acid, and then stirred for 24 hours. Then, 80 ml of H 2 O/pyridine (8:1 v/v) solution was added to the solution and refluxed for 30 minutes. The resulting solid is filtered to give an orange solid 4,4'-bis(3-methylsulfinyl)naphthalen-2-yl)biphenyl.

Maldi-Mass (m/z): [M]+ calcd for C32H18S2 466.08; found 465.91

Synthesis example 3

[Scheme 3]

(One) 6-(4,4,5,5- tetramethyl -1,3,2- dioxaborolane -2 days) of benzothiophene synthesis

6-bromo-benzo[b]thiophene (Compound 1) 70g (0.33mol), bis(pinacolato)diboron 92.2g (1.1eq), PdCl2(dppf) 14.5g (6mol%), potassium acetate 97g ( 3eq) was stirred under reflux in 1,4-dioxane. After overnight, the temperature is lowered to room temperature and concentrated. Pass the crude mixture through a silica pad to obtain compound 2.

(2) Synthesis of 6,6' - bibenzothiophene

6-bromo-benzo[b]thiophene 70g (0.33mol), Compound 2 0.33mol (1eq), Pd(PPh3)4 19g (5mol%), and sodium bicarbonate 83g (3eq) in a DME/H2O mixed solvent under reflux stirring . After 22 hours, the temperature was lowered to room temperature and extracted with ethyl acetate and water. The organic layer was treated with MgSO4 and concentrated by filtration to obtain a solid compound. Recrystallization to obtain 70 g of Compound 3.

¹ H-NMR (300 MHz, CDCl ₃ ): δ ppm 8.15 (s, 2H), 7.89 (d, 2H), 7.66 (d, 2H), 7.45 (d, 2H), 7.36 (d, 2H)

(3) Synthesis of 2,2'-bis[(3- bromo- 2- thienyl ) -hydroxymethyl ]-6,6' - bibenzothiophene

Stir LDA (2.2eq) under a THF solvent in a nitrogen atmosphere. Compound 3 dissolved in THF at -10°C is added dropwise. After stirring for one hour while maintaining -5℃~0℃, lower the temperature to -78℃. 94 g (2.5eq) of 3-bromothiophene-2-carbaldehyde dissolved in a small amount of THF was added dropwise, and the temperature was gradually raised to room temperature. After completion sat. After quenching with NH4Cl, it is extracted with ethyl acetate and water. The organic layer was treated with MgSO4 and concentrated by filtration. Then, column purification is performed to obtain compound 4.

¹ H-NMR (300 MHz, CDCl ₃ ): δ ppm 8.04 (s, 2H), 7.78 (d, 2H), 7.62 (d, 2H), 7.32 (d, 2H), 7.29 (s, 2H), 6.98 (d, 2H), 6.49 (d, 2H), 2.84 (d, 2H)

(4) Synthesis of 2,2'-bis[(3- bromo- 2- thienyl ) methyl ]-6,6' - bibenzothiophene

After suspending compound 4 in DCM, ZnI2 (3.2 eq) and NaBH3CN (14 eq) are added. The mixture is stirred overnight. After completion of the reaction, the reaction solution is filtered through a Celite pad. After concentration, the obtained solid is recrystallized to obtain compound 5 (89 g).

¹ H-NMR (300 MHz, CDCl ₃ ): δ ppm 8.01 (s, 2H), 7.77 (d, 2H), 7.61 (d, 2H), 7.24 (d, 2H), 7.14 (s, 2H), 6.99 (d, 2H), 4.42 (s, 4H)

(5) Synthesis of 2,2'-bis[(3- formyl -2- thienyl ) methyl ]-6,6' - bibenzothiophene

20 g (32.44 mmol) of Compound 5 and 14.4 mL (4eq) of 1-formylpiperidine were dissolved in THF under an argon environment, and then cooled to -78°C. 85.8 mL (4.5eq) of 1.7 M t-BuLi was slowly added dropwise, and after stirring for 10 minutes, the temperature was raised to -30°C. Sat. Pour into NH4Cl solution for quenching, and extract with ethyl acetate. The organic layer was dried over MgSO4 and concentrated under reduced pressure to obtain 6.76 g of Compound 6 by column/recrystallization.

¹ H-NMR (300 MHz, CDCl ₃ ): δ ppm 10.1 (s, 2H), 8.14 (s, 2H), 7.84 (d, 2H), 7.66 (d, 2H), 7.38 (d, 2H), 7.16 (s, 2H), 7.01 (d, 2H), 4.44 (s, 4H)

(6) 6,6'- Bythienobenzo[5,6-b]benzo Synthesis of [2,3-d]thiophene

In a nitrogen atmosphere, benzene was added to 19.5 g (37.89 mmol) of Compound 6, 29.3 g of amberlyst 15 was added, and then water was removed from the mixture using a Dean-Stark trap. After completion, the suspension was carefully decanted and filtered to obtain 11.4 g of a pale gray compound 7 .

Maldi-Mass (m/z): [M] + calcd for C28H14S4 478.00; found 477.81

Fabrication of organic thin film transistors

Example One

First, the cleaned SiO2 silicon wafer substrate covered with 3000Å is exposed to O ₂ plasma, and then dipped in octadecyltrichlorosilane solution diluted to a concentration of 10 mM in hexane to change the surface to hydrophobicity. Then, the organic compound obtained in Synthesis Example 2 was deposited to a thickness of 700 Å through a vacuum vapor deposition method while the temperature of the substrate was changed from room temperature to 200°C. Then, an organic thin film transistor is manufactured by depositing the source and drain electrodes with gold (Au) to a thickness of 1000 Å using a shadow mask.

Example 2

An organic thin film transistor was manufactured in the same manner as in Example 1, except that the organic compound obtained in Synthesis Example 3 was used instead of the organic compound obtained in Synthesis Example 2.

evaluation

The charge mobility and the current flashing ratio (I _on /I _off ) of the organic thin film transistors according to Examples 1 and 2 were calculated.

The charge mobility of the organic thin film transistor was obtained from the saturation region current equation, a graph using (I _SD ) ^1/2 and V _G as variables, and obtained from the slope:

where I _SD is the source-drain current, m or m _FET is the charge mobility, C ₀ is the capacitance of the gate insulating film, W is the channel width, L is the channel length, V _G is the gate voltage, and , V _T is the threshold voltage.

The cutoff leakage current (I _off ) is a current that flows in the off state, and was calculated as the minimum current in the off state in the current ratio. The current on/off ratio (I _on /I _off ) was calculated as the ratio of the maximum current value in the on state and the minimum current value in the off state.

The results are shown in Table 1.

Charge mobility (cm ² /Vs) Current Flashing Ratio (I _on /I _off ) Example 1 2.1 2.0 x 10 ⁷ Example 2 1.5 1.8 x 10 ⁷

Referring to Table 1, it can be seen that the organic thin film transistors according to Examples 1 and 2 have excellent characteristics by securing a charge mobility of 1 cm ² /Vs or more and a current flashing ratio of 10 ⁷ or more.

Although preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements by those skilled in the art using the basic concept of the present invention as defined in the following claims are also presented. It belongs to the scope of the invention.

110: substrate 124: gate electrode
140: gate insulating film 154: organic semiconductor
173: source electrode 175: drain electrode

Claims (16)

An organic compound represented by the following formula (1):
[Formula 1]
A - B
In Formula 1,
A moiety and B moiety are each independently one of the groups listed in Group 1 below,
[Group 1]

In group 1,
X ¹ to X ⁴ are each independently S, Se or Te,
R ¹ To R ⁹ are each independently hydrogen, a substituted or unsubstituted C1 to C30 alkyl group, a substituted or unsubstituted C3 to C30 cycloalkyl group, a substituted or unsubstituted C6 to C30 aryl group, a substituted or unsubstituted C7 to C30 arylalkyl group, substituted or unsubstituted C1 to C30 heteroalkyl group, substituted or unsubstituted C2 to C30 heterocycloalkyl group, substituted or unsubstituted C2 to C30 heteroaryl group, substituted or unsubstituted C2 to C30 alkenyl group, a substituted or unsubstituted C2 to C30 alkynyl group, a hydroxyl group, a halogen atom, or a combination thereof;
R ¹ to R ⁹ are each independently present or two adjacent ones thereof are fused to form a fused ring,
* is the connection point.
delete delete delete In claim 1,
An organic compound in which the A moiety and the B moiety of Formula 1 are not located on the same plane and have torsion.
In claim 1,
The organic compound is one of those listed in group 2:
[Group 2]

An organic thin film comprising the organic compound according to any one of claims 1, 5 and 6.
gate electrode,
an organic semiconductor overlapping the gate electrode, and
A source electrode and a drain electrode electrically connected to the organic semiconductor
including,
The organic semiconductor is an organic thin film transistor including an organic compound represented by the following Chemical Formula 1:
[Formula 1]
A - B
In Formula 1,
A moiety and B moiety are each independently one of the groups listed in Group 1 below,
[Group 1]

In group 1,
X ¹ to X ⁴ are each independently S, Se or Te,
R ¹ To R ⁹ are each independently hydrogen, a substituted or unsubstituted C1 to C30 alkyl group, a substituted or unsubstituted C3 to C30 cycloalkyl group, a substituted or unsubstituted C6 to C30 aryl group, a substituted or unsubstituted C7 to C30 arylalkyl group, substituted or unsubstituted C1 to C30 heteroalkyl group, substituted or unsubstituted C2 to C30 heterocycloalkyl group, substituted or unsubstituted C2 to C30 heteroaryl group, substituted or unsubstituted C2 to C30 alkenyl group, a substituted or unsubstituted C2 to C30 alkynyl group, a hydroxyl group, a halogen atom, or a combination thereof;
R ¹ to R ⁹ are each independently present, or two adjacent ones thereof are fused to form a fused ring,
* is the connection point.
delete delete delete In claim 8,
The organic thin film transistor having a torsion in the A moiety and the B moiety of Formula 1 are not located on the same plane.
In claim 8,
wherein the organic compound is one of those listed in group 2:
[Group 2]

An electronic device comprising the organic thin film transistor according to any one of claims 8, 12 and 13.
15. In claim 14,
The electronic device may be a liquid crystal display device, an organic light emitting device, an electrophoretic device, an organic photoelectric device, or an organic sensor.
An electronic device comprising the organic thin film according to claim 7 .

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