Boron-substituted aromatic compounds

Abstract

To provide organic semiconductor materials that reduce the increase of manufacturing costs and the complexity of the manufacturing process in organic electronics devices.SOLUTION: The present invention provides a novel boron-substituted aromatic compound represented by general formula (1), an organic thin film containing the compound, and an organic electronic device having the organic thin film.

Description

Technical Field

[0001] The present invention relates to a novel boron-substituted aromatic compound, an organic thin film containing the compound, and an organic electronic device having the organic thin film. Background Art

[0002] Organic electronic devices have potential for application development in multiple fields. Compared with inorganic devices, these devices are superior in terms of low weight, low power consumption, flexibility and the like (Non-Patent Document 1); however, the low charge mobility of organic semiconductors is one of the major weaknesses (Non-Patent Document 2), and a method of doping a small amount of charge carriers is widely used to improve mobility (Non-Patent Document 3).

[0003] However, a doping method that adds a dopant prepared separately from the organic semiconductor material requires cost for preparing the dopant and an additional addition process, leading to increased manufacturing costs and complication of the manufacturing process for organic electronic devices.

[0004] That is, an organic semiconductor material that can use an inexpensive dopant, can be doped through a simple process, and exhibits high mobility is strongly demanded for achieving a breakthrough in organic electronic devices. Prior Art Documents Non-Patent Documents

[0005] Non-Patent Document 1 (a) HEKatz, AJLovinger, J.Johnson, C.Kloc, T.Siegrist, W.Li, Y.-Y.Lin, A.Dodabalapur, Nature, 2000, 404, 478; (b) IDWSamuel, GATurnbull, Chem.Rev., 2007, 107, 1272; (c) JEAnthony, Angew. Chem. Int.Ed.,2008, 47, 452.

Wood 2

Table 3

[0006] The present invention has been made in view of the above conventional problems, and an object of the present invention is to provide an organic semiconductor compound that can be doped through a simple process using an inexpensive dopant, an organic thin film containing the organic semiconductor compound, and an organic electronic device including the organic thin film having high charge mobility. Means for Solving the Problem

[0007] As a result of intensive studies, the present inventors have found that the above problems can be solved by using a boron-substituted aromatic compound having a specific structure, and have accomplished the present invention.

[0008] That is, the present invention provides: [1] The following formula (1)

[0009] [ka]

[0010] (In formula (1), R1 and R2 each independently represent a hydrogen atom, an alkyl group, or an aromatic group, and the hydrogen atom of the alkyl group or aromatic group may be substituted with a substituent, and R1 and R2 may form a linked structure.) Ar is given by the following equations (2) to (4)

[0011] [ka]

[0012] X represents any aromatic group selected from the following, where the hydrogen atoms of the aromatic group may be substituted with substituents, and X represents an oxygen atom, a sulfur atom, or a selenium atom. Compounds represented by, [2] The compound described in [1] that forms a structure in which R1 and R2 are linked, [3] The compound described in [1] above, wherein the Fermi level in the solid state is -4.8 eV or higher. [4] The carrier density in the solid state measured in the atmosphere was 2.0 × 10⁻⁶ 16 / cm 3 The compounds described in [1] above, [5] Organic thin film containing the compound described in any one of the above items [1] to [4], [6] Organic electronic device comprising the organic thin film described in [5] above, Regarding. [Effects of the Invention]

[0013] By using the compounds of the present invention, it is possible to provide organic semiconductor compounds that can be doped using inexpensive dopants in a simple process, organic thin films containing the organic semiconductor compound, and organic electronic devices with high charge mobility equipped with the organic thin film. [Modes for carrying out the invention]

[0014] The boron-substituted aromatic compound of the present invention (hereinafter also simply referred to as "the compound of the present invention") is represented by the above formula (1). In formula (1), R1 and R2 each independently represent a hydrogen atom, an alkyl group, or an aromatic group.

[0015] The alkyl groups represented by R1 and R2 in formula (1) may be linear, branched, or cyclic, and their number of carbon atoms is not particularly limited. Specific examples of alkyl groups represented by R1 and R2 in formula (1) include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, iso-butyl group, allyl group, t-butyl group, n-pentyl group, n-hexyl group, n-octyl group, n-decyl group, n-dodecyl group, n-tridecyl group, n-tetradecyl group, n-cetyl group, n-heptadecyl group, 2-ethylhexyl group, 3-ethylheptyl group, 4-ethyloctyl group, 2-butyloctyl group, 3-butylnonyl group, and 4-butyl Examples of alkyl groups include decyl group, 2-hexyldecyl group, 3-octylundecyl group, 4-octyldodecyl group, 2-octyldodecyl group, 2-decyltetradecyl group, cyclopropyl group, cyclobutyl group, cyclopentyl group, and cyclohexyl group. C1 to C24 alkyl groups are preferred, C1 to C20 alkyl groups are more preferred, C1 to C12 alkyl groups are even more preferred, C1 to C6 alkyl groups are particularly preferred, and C1 to C4 alkyl groups are most preferred. Furthermore, R1 and R2 are preferably the same substituent. Furthermore, the hydrogen atoms in the alkyl groups represented by R1 and R2 in formula (1) may be substituted with substituents. The substituents that substitute for the hydrogen atoms in the alkyl group are not particularly limited, but examples include alkyl groups and / or aromatic groups.

[0016] The alkyl groups to be substituted for the alkyl groups represented by R1 and R2 in formula (1) are not particularly limited, but specific examples include those identical to the alkyl groups represented by R1 and R2.

[0017] The aromatic groups substituted for the alkyl groups represented by R1 and R2 in formula (1) are residues obtained by removing one hydrogen atom from the aromatic ring of an aromatic compound, and the compounds that become aromatic groups are not particularly limited as long as they are aromatic compounds. Specific examples include aromatic hydrocarbon groups such as phenyl, biphenyl, naphthyl, and anthuryl groups; heterocyclic groups such as pyridyl, quinolyl, isoquinolyl, carbazolyl, thienyl, furyl, and pyranyl groups; and condensed heterocyclic groups such as benzothienyl and benzofuryl groups, with phenyl groups being preferred.

[0018] The aromatic groups represented by R1 and R2 in formula (1) are not particularly limited, but specific examples include those identical to the aromatic groups substituted for the alkyl groups represented by R1 and R2 in formula (1), with phenyl groups being preferred.

[0019] R1 and R2 in formula (1) may be structures formed by linking residues from which one hydrogen atom has been removed (i.e., R1 and R2 are linked to each other). Specific examples of such structures include divalent residues obtained by removing two hydrogen atoms from a linear, branched, or cyclic alkylene group which may have substituents, divalent residues obtained by removing two hydrogen atoms from an aromatic ring which may have substituents, or divalent residues obtained by removing two hydrogen atoms from a heterocycle which may have substituents.

[0020] Examples of linear, branched, or cyclic alkylene groups that may have the substituents include alkylene groups having 1 to 8 carbon atoms, such as methylene, ethylene, propylene, butylene, pentylene, hexylene, heptylene, and octylene groups. The positions of the carbon atoms from which hydrogen atoms are removed in the alkylene group may be different or the same. Among these, alkylene groups having 1 to 6 carbon atoms are preferred, and alkylene groups having 2 to 6 carbon atoms are particularly preferred.

[0021] Examples of divalent residues obtained by removing two hydrogen atoms from an aromatic ring which may have the substituent include divalent residues obtained by removing two hydrogen atoms from an aromatic ring such as a phenylene group or a naphthylene group, and divalent residues obtained by removing two hydrogen atoms from a five-membered or six-membered heterocycle such as a furan ring, a pyrrole ring, an imidazole ring, a thiophene ring, a pyrazole ring, an oxazole ring, a thiazole ring, a pyridine ring, and a pyrazine ring. Among these, the phenylene group and the naphthylene group are preferred, and the phenylene group is particularly preferred.

[0022] The substituents that may be present in the structure formed by the bonding of R1 and R2 are not particularly limited, but specific examples include those that are the same as those that substitute for the alkyl groups represented by R1 and R2.

[0023] In formula (1), Ar is an aromatic group selected from formulas (2) to (4), with formula (2) or (3) being preferred, and formula (2) being more preferred.

[0024] Next, a method for synthesizing the compound represented by formula (1) will be described. The synthesis method is not particularly limited, but as shown in formula (5), a boron substituent can be introduced to a halogen-substituted aromatic compound obtained by known synthesis methods or combinations thereof using a palladium catalyst. Alternatively, as shown in formulas (6) and (7), a boron substituent can be introduced by reacting a boron source with a base such as alkyllithium. In formulas (5) and (6), Y represents a halogen atom such as a chlorine atom, a bromine atom, or an iodine atom, and R1 and R2 in formulas (5) to (7) are the same as R1 and R2 in formula (1).

[0025] [ka]

[0026] The compound represented by formula (1) obtained by the above method is preferably purified to remove impurities and increase its purity before being used for the production of organic thin films (described later). The purification method is not particularly limited, and known methods such as recrystallization, column chromatography, adsorption purification using adsorbents such as activated carbon, and vacuum sublimation purification can be employed. These methods can also be combined as needed.

[0027] The following are specific examples of compounds represented by formula (1) of the present invention, but the compounds represented by formula (1) of the present invention are not limited to these specific examples.

[0028] [ka]

[0029] From the viewpoint of doping with an oxidizing atmosphere, the Fermi level of the compound of the present invention is preferably -4.8 eV or higher, more preferably -4.7 eV or higher, even more preferably -4.6 eV or higher, even more preferably -4.5 eV or higher, even more preferably -4.4 eV or higher, particularly preferably -4.3 eV or higher, and most preferably -4.2 eV or higher.

[0030] In this specification, ionization potential refers to values ​​measured by known methods such as cyclic voltammetry and photoelectron spectroscopy. Measurement by photoelectron spectroscopy is preferred for solid-state materials. The solid state is not particularly limited as long as the material being measured is in a solid state, but it is often in the form of a powder or thin film. Methods for preparing thin films include dry processes such as vapor deposition and various solution processes. Examples of solution processes include spin coating, drop casting, dip coating, spraying, relief printing methods such as flexographic printing and resin relief printing, planar printing methods such as offset printing, dry offset printing, and pad printing, intaglio printing methods such as gravure printing, stencil printing methods such as screen printing, mimeograph printing, and ringgraph printing, inkjet printing, microcontact printing, and methods combining multiple of these techniques. When forming a film using a solution process, it is preferable to apply and print an organic solvent solution containing the compound of the present invention onto a substrate using the above method, and then evaporate the organic solvent to form a thin film.

[0031] In an organic thin film containing the compound of the present invention, the content of the compound is not particularly limited, but is preferably 0.01 to 100% by mass, more preferably 1 to 100% by mass, even more preferably 50 to 100% by mass, particularly preferably 90 to 100% by mass, and most preferably 99 to 100% by mass.

[0032] Furthermore, the film thickness is not particularly limited as long as it is suitable for the application, but is preferably 0.01 to 1000 nm, more preferably 1 to 500 nm, even more preferably 10 to 500 nm, particularly preferably 20 to 500 nm, and most preferably 50 to 400 nm.

[0033] The method for measuring carrier density is not particularly limited, and examples thereof include a method of producing a field-effect transistor and determining the value based on its field-effect mobility, electrical conductivity in the direction between the source electrode and the drain electrode, and elementary charge, and a method of measuring an electron spin resonance (ESR) spectrum and determining the value based on the obtained number of spins. When measurement is performed on a solid-state compound, the compound is often in a powder form or a thin film form, and the aforementioned methods can be mentioned as methods for producing the thin film.

[0034] From the viewpoint of conductivity, a higher carrier density is preferable. The carrier density of the compound of the present invention, as measured in a solid state, is 2.0 × 10 16 / cm 3 or more, preferably 2.0 × 10 16 to 1.0 × 10 21 / cm 3 , more preferably 5.0 × 10 16 to 1.0 × 10 21 / cm 3 / cm 3 , still more preferably 5.0 × 10 16 to 5.0 × 10 20 / cm 3 , even more preferably 5.0 × 10 16 to 1.0 × 10 20 / cm 3 .

[0035] An organic thin film containing the compound of the present invention is suitably used in the organic electronic device of the present invention. Representative examples of the organic electronic device of the present invention include organic electroluminescent devices, organic field-effect transistors (OFET), thermoelectric conversion elements, organic solar cells (OSC) such as perovskite solar cells, organic photosensors, organic light-emitting diodes, organic integrated circuits (OIC), organic thin film transistors (OTFT), and organic photoreceptors, but the organic electronic device of the present invention is not limited thereto.

[0036] Specific examples of organic electroluminescent devices include organic light-emitting transistors (OLETs), organic field-quenched devices (OFQDs), organic light-emitting electrochemical cells (OLECs, LECs, LEECs), organic laser diodes (O-lasers), and organic light-emitting diodes (OLEDs).

[0037] An organic field-effect transistor controls the current flowing between two electrodes (source electrode and drain electrode) placed in contact with a semiconductor film made of an organic semiconductor material containing the compound of the present invention by applying a voltage to another electrode called a gate electrode. The organic thin film containing the compound of the present invention can be used in any conventionally known organic field-effect transistor. In an organic field-effect transistor, the thermal oxide film on the n-doped silicon wafer with a thermal oxide film functions as an insulating layer, and the n-doped silicon wafer serves as both the substrate and the gate electrode.

[0038] The performance of an organic field-effect transistor depends on the amount of current that flows when a potential is applied between the source and drain electrodes while a potential is applied to the gate. By using the measurement result of this current value in the following equation (a), which expresses the electrical characteristics of the carrier species generated in the organic semiconductor layer, the mobility can be calculated. Id=ZμCi(Vg-Vt) 2 / 2L···(a) In equation (a), Id is the saturated source-drain current, Z is the channel width, Ci is the capacitance of the insulator, Vg is the gate potential, Vt is the threshold potential, L is the channel length, and μ is the determining mobility (cm). 2 The equation is (Vs). Ci is the dielectric constant of the SiO2 insulating film used, Z and L are determined by the device structure of the organic transistor device, Id and Vg are determined when measuring the current value of the field-effect transistor device, and Vt can be determined from Id and Vg. By substituting each value into equation (a), the mobility at each gate potential can be calculated.

[0039] A thermoelectric conversion element has a first electrode, a thermoelectric conversion layer, and a second electrode on a substrate, and the organic thin film containing the compound of the present invention can be used in any conventionally known thermoelectric conversion element.

[0040] The thermoelectric conversion layer, which consists of an organic thin film containing the compound of the present invention, may be formed by either a dry process or a solution process. Furthermore, the thermoelectric conversion layer in the thermoelectric conversion element may consist of one or more layers. If there are multiple thermoelectric conversion layers, the element may consist of multiple layers made only of organic thin films containing the compound of the present invention, or it may consist of thermoelectric conversion layers made of organic thin films containing the compound of the present invention and thermoelectric conversion layers that do not contain the compound of the present invention.

[0041] A perovskite solar cell has a structure in which a hole transport layer and an electron transport layer are stacked above and below a perovskite layer, and this stack is sandwiched between two electrodes. The compound of the present invention can be used in any of the organic thin films that make up the device.

[0042] The organic photosensor has a structure in which an organic thin film containing an organic active layer with photoelectric conversion function is sandwiched between two electrodes, and the compound of the present invention can be used in either of the organic thin films that make up the element.

[0043] Organic light-emitting diodes (OLEDs) have a structure in which an organic thin film containing an organic active layer that emits light when a voltage is applied is sandwiched between two electrodes, and the compound of the present invention can be used in either of the organic thin films that make up the device.

[0044] When fabricating organic electronic devices using organic thin films containing these compounds of the present invention, doping may be performed at any stage to increase the carrier density. The doping method and dopant are not particularly limited, but exposure to an oxidizing atmosphere is preferred due to the cost of the dopant and the simplicity of the doping process. The oxidizing atmosphere is not particularly limited, but one containing oxygen, such as air, is particularly preferred.

[0045] Organic electronic devices using an organic thin film containing the doped compound of the present invention may be dedoped by exposing them to a reducing atmosphere, and the resulting change in electrical properties can be detected for atmosphere detection. The reducing atmosphere is not particularly limited, but examples include those containing hydrogen or amine vapor. [Examples]

[0046] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. In the examples, unless otherwise specified, "parts" refers to "parts by mass," and "%" refers to "mass percent." "M" represents molar concentration. Unless otherwise specified, the reaction temperature refers to the internal temperature within the reaction system. Nuclear magnetic resonance spectra in the examples were measured using a Bruker Avance III 500 and a JEOL JNM-ECS400, with the solvents described in the examples. Elemental analysis was performed using a JM10 from J-Science Lab and an MT-6 CHN CORDER from Yanaco Technical Science. MS spectra were measured using a JEOL JMS-T100GCV. Electron spin resonance (ESR) spectra were measured using a Bruker Magnettech ESR 5000. Fermi levels were measured using a RIKEN FAC-2. Field-effect transistor mobility was measured using a Keithley 4200-SCS semiconductor parameter analyzer.

[0047] Example 1 (Synthesis of the compound represented by No. 1 above) Under a nitrogen atmosphere, 0.42 parts (1.0 mmol) of the compound represented by formula (a), obtained by a known method, 2.6 parts (10 mmol) of 4,4,4',4',5,5,5',5'-octamethyl-2,2'-bi(1,3,2-dioxaborolane) (B2pin2), 0.0047 parts (0.021 mmol) of palladium(II) acetate, 0.019 parts (0.05 mmol) of 2-dicyclohexylphosphino-2',6'-dimethoxybiphenyl (sphos), and 0.644 parts (3.0 mmol) of tripotassium phosphate hydrate were dissolved in 50 mL of 1,4-dioxane. The mixed solution obtained above was stirred at 120°C for 3 hours. The reaction solution was then purified by silica gel chromatography and gel permeation column chromatography using chloroform as the mobile phase, and then by sublimation purification to obtain 0.326 parts (0.699 mmol, yield 69.8%) of the compound represented by No. 1 as a yellow solid. The melting point, nuclear magnetic resonance spectrum, HR-MS spectrum, and elemental analysis results of the obtained compounds are as follows. mp 363.5 ℃. 1 H-NMR (CDCl3, 500 MHz): δ (ppm) 8.48 (s, 1H), 8.45 (s, 1H), 8.42 (s, 1H), 8.38 (s, 1H), 8.35 (s, 1H), 8.05-8.03 (m, 1H), 8.01 (d, J = 9.0 Hz, 1H), 7.96-7.94 (m, 1H), 7.87 (dd, J = 8.3, 0.7 Hz, 1H) 7.55-7.52 (m, 2H), 1.42 (s, 12H). 13 C NMR (CDCl3, 125 MHz): δ (ppm) 140.87, 140.68, 135.89, 134.40, 133.82, 133.21, 132.66, 132.34, 131.54, 131.27, 130.85, 130.05, 128.33, 127.36, 127.30, 125.97, 125.68, 123.32, 122.46, 120.28, 119.95, 84.06, 24.98. HRMS (FD) m / z: Calcd for C 28 H 23 BO2S2[M]+: 466.1233. Found: 466.1230. Elemental analysis: Calcd for C 28 H 23 BO2S2: C, 72.10; H, 4.97. Found: C, 72.02; H, 4.98. The carrier density of the obtained compound in air was determined from ESR spectral measurements to be 1.5 × 10⁻⁶. 17 / cm 3 That was the case. Furthermore, a thin film of the compound with a thickness of 50 nm was fabricated on a glass substrate on which ITO had been deposited by vacuum deposition, and the Fermi level was measured to be -4.2 eV.

[0048] [ka]

[0049] Example 2 (Fabrication and evaluation of organic field-effect transistor A using the compound represented by No. 1 obtained in Example 1) A 40 nm thick thin film of the compound represented by No. 1 obtained in Example 1 was formed on an n-doped silicon wafer with a Si thermal oxide film surface-treated with octyltrichlorosilane by resistance heating vacuum deposition at a substrate temperature of 100°C and an deposition rate of 0.1 to 0.2 Å / second. Next, a 60 nm thick thin film of Au was formed on the thin film obtained above using a shadow mask at a substrate temperature of room temperature and an deposition rate of 0.2 Å / second, thereby fabricating a source electrode and a drain electrode with a channel length of 100 μm and a channel width of 1200 μm, respectively, and a top-contact type organic field-effect transistor A was fabricated.

[0050] Example 3 (Synthesis of the compound represented in No. 11 above) 0.1 parts (0.43 mmol) of the compound represented by formula (b), obtained by a known method, was mixed with tetrahydrofuran (20 mL). Under a nitrogen atmosphere, 2.8 M n-butyllithium (0.2 mL, 0.56 mmol) was added at -50°C and the mixture was stirred for 2 hours. Then, isopropoxyboronic acid pinacol (0.2 mL, 0.99 mmol) was added at -50°C and the mixture was stirred for 30 minutes. The temperature was raised to 20°C and the mixture was stirred overnight. The resulting reaction mixture was quenched with water (10 mL) and extracted using dichloromethane. The resulting organic layer was dried with sodium sulfate and the solvent was removed by distillation under reduced pressure. The resulting solid was purified by silica gel chromatography and gel permeation column chromatography with dichloromethane as the mobile phase to obtain the compound represented by No. 7 (0.046 parts, 0.13 mmol, yield 30%). The results of the nuclear magnetic resonance spectroscopy, MS, and elemental analysis of the obtained compounds are as follows. 1 H-NMR (CDCl3, 500 MHz): δ (ppm) 8.62 (s, 1H), 8.56 (s, 2H), 8.51 (s, 1H), 8.00 (d, J = 10.0 Hz, 2H), 7.97 (s, 1H), 7.43-7.41 (m, 2H), 1.41 (s, 12H). FD+(eiFi) m / z: Calcd for C 22 H 21 BO2S[M+]:360.14. Found: 360.14 Elemental analysis: Calcd for C 22 H 21 BO2S: C, 81.37; H, 6.54. Found: C, 81.41; H, 6.46. The carrier density of the obtained compound in air was determined from ESR spectral measurements to be 3.9 × 10⁻⁶. 17 / cm 3 That was the case. Furthermore, a thin film of the compound with a thickness of 50 nm was fabricated on a glass substrate on which ITO had been deposited using vacuum deposition, and the Fermi level was measured to be -4.5 eV.

[0051] [ka]

[0052] Example 4 (Synthesis of the compound represented by No. 8 above) 0.1 parts (0.32 mmol) of the compound represented by formula (c), obtained by a known method, was mixed with tetrahydrofuran (20 mL). Under a nitrogen atmosphere, 2.8 M n-butyllithium (0.2 mL, 0.56 mmol) was added at -50°C and the mixture was stirred for 2 hours. Then, isopropoxyboronic acid pinacol (0.2 mL, 0.99 mmol) was added at -50°C and the mixture was stirred for 30 minutes. The temperature was raised to 20°C and the mixture was stirred overnight. The resulting reaction mixture was quenched with water (10 mL) and extracted using dichloromethane. The resulting organic layer was dried with sodium sulfate and the solvent was removed by distillation under reduced pressure. The resulting solid was purified by silica gel chromatography and gel permeation column chromatography with dichloromethane as the mobile phase to obtain the compound represented by No. 7 (0.0046 parts, 0.13 mmol, yield 30%). The results of the nuclear magnetic resonance spectroscopy, MS, and elemental analysis of the obtained compounds are as follows. 1 H-NMR (CDCl3, 500 MHz): δ (ppm) 9.04 (s, 1H), 8.71 (s, 1H), 8.55 (s, 1H), 8.51 8.15 (s, 1H), 8.04-8.01 (m, 2H), 7.45-7.41 (m, 2H), 1.45 (s, 12H). FD+(eiFi) m / z: Calcd for C 22 H 21 BO2S[M+]:360.14. Found: 360.14 Elemental analysis: Calcd for C 22 H 21 BO2S: C, 73.34; H, 5.88. Found: C, 72.79; H, 6.54. The carrier density of the obtained compound in air was determined from ESR spectral measurements to be 2.7 × 10⁻⁶. 17 / cm 3 That was the case. Furthermore, a thin film of the compound, obtained to a thickness of 50 nm, was fabricated on a glass substrate on which ITO had been deposited using vacuum deposition, and the Fermi level was measured to be -4.45 eV.

[0053] [ka]

[0054] Example 5 (Synthesis of the compound represented by No. 9 above) 0.1 parts (0.43 mmol) of the compound represented by formula (d), obtained by a known method, was mixed with tetrahydrofuran (20 mL). Under a nitrogen atmosphere, 2.8 M n-butyllithium (0.2 mL, 0.56 mmol) was added at -50°C and the mixture was stirred for 2 hours. Then, triisopropoxyborane (0.2 mL, 0.87 mmol) was added at -50°C and the mixture was stirred for 30 minutes. After raising the temperature to 20°C, the mixture was stirred for 2 hours. The resulting reaction solution was quenched with water (10 mL) and liquid-liquid extracted using 1 M hydrochloric acid aqueous solution (20 mL) dichloromethane. The resulting organic layer was dried with sodium sulfate, and the solvent was removed under reduced pressure to obtain the compound represented by No. 9 (0.12 parts, 0.43 mmol, yield 100%).

[0055] [ka]

[0056] Example 6 (Synthesis of the compound represented in No. 10 above) The compound represented by No. 9 obtained in Example 5 (0.12 parts, 0.43 mmol) was mixed with toluene (20 mL), and 1,2-dihydroxybenzene (0.5 parts, 4.5 mmol) was added under a nitrogen atmosphere. The mixture was heated to reflux temperature and stirred for 12 hours. The resulting reaction solution was cooled, the precipitated solid was filtered off, and the compound represented by No. 10 (0.032 parts, 0.091 mmol, yield 21%) was obtained as an orange solid by sublimation purification. The nuclear magnetic resonance spectra and MS results for the obtained compounds are as follows. 1H-NMR (DMSO-d6, 500 MHz): δ (ppm) 8.78 (s, 1H), 8.72 (s, 1H), 8.71 (s, 1H), 8.67 (s, 1H), 8.10-8.08 (m, 2H), 8.10 (s, 1H), 7.48-7.47 (m, 2H), 6.72-6.70 (m, 2H), 6.60-6.58 (m, 2H), FD+(eiFi) m / z: Calcd for C22H13BO2S[M+]:352.07. Found: 352.07

[0057] [ka]

[0058] Example 7 (Synthesis of the compound represented in No. 11 above) The compound represented by No. 9 obtained in Example 5 (0.12 parts, 0.43 mmol) was mixed with toluene (20 mL), and 1,2-dihydroxyethane (0.55 parts, 8.9 mmol) was added under a nitrogen atmosphere. The mixture was heated to reflux temperature and stirred for 12 hours. The resulting reaction solution was cooled, hexane (20 mL) was added, and the precipitated solid was filtered off. Sublimation purification was performed to obtain the compound represented by No. 11 (29 mg, 0.095 mmol, yield 22%) as a yellow solid. The nuclear magnetic resonance spectra and MS results for the obtained compounds are as follows. 1H-NMR (CDCl 3, 500 MHz): δ (ppm) 8.63 (s, 1H), 8.61 (s, 1H), 8.51 (s, 1H), 8.53 (s, 1H), 8.03-8.01 (m, 2H), 8.00 (s, 1H), 7.44-7.43 (m, 2H), 4.48 (s, 4H). FD+(eiFi) m / z: Calcd for C 18 H 13 BO2S[M+]:304.07. Found:304.07 Elemental analysis: Calcd for C 18 H 13 BO2S: C, 68.27; H, 4.63. Found: C, 71.08; H, 4.31.

[0059] [ka]

[0060] Example 8 (Synthesis of the compound represented in No. 12 above) 0.12 parts, 0.43 mmol of the compound represented by No. 9 obtained in Example 5 was mixed with toluene (20 mL), and 0.5 parts, 4.8 mmol of 2,2-dimethyl-1,3-propanediol was added under a nitrogen atmosphere. The mixture was heated to reflux temperature and stirred for 12 hours. The resulting reaction solution was cooled and extracted using dichloromethane. The resulting organic layer was dried using sodium sulfate, and the solvent was removed by distillation under reduced pressure. The resulting solid was purified by silica gel column chromatography and sublimation using dichloromethane as the mobile phase to obtain the compound represented by No. 12 (46 mg, 0.13 mmol, yield 30%). The nuclear magnetic resonance spectra and MS results for the obtained compounds are as follows. 1H-NMR (CDCl3, 500 MHz): δ (ppm) 8.61 (s, 1H), 8.55 (s, 2H), 8.01-7.99 (m, 2H), 7.90 (s, 1H), 7.43-7.41 (m, 2H), 3.84 (s, 4H), 1.08 (s, 6H). FD+(eiFi) m / z: Calcd for C 21 H 19 BO2S[M+]:346.12. Found: 346.12 Elemental analysis: Calcd for C 21 H 19 BO2S: C, 72.71; H, 5.56. Found: C, 72.85; H, 5.53. A thin film of the compound was fabricated on a glass substrate on which ITO had been deposited, using vacuum deposition to a thickness of 50 nm. The Fermi level was measured and found to be -4.37 eV.

[0061] [ka]

[0062] Example 9 (Synthesis of the compound represented in No. 13 above) 100 mg, 0.46 mmol of the compound represented by formula (e), obtained by a known method, was mixed with tetrahydrofuran (20 mL). Under a nitrogen atmosphere, 2.8 M n-butyllithium (0.2 mL, 0.56 mmol) was added at -50°C and the mixture was stirred for 2 hours. Then, isopropoxyboronic acid pinacol (0.2 mL, 0.99 mmol) was added at -50°C and the mixture was stirred for 30 minutes. The temperature was raised to 20°C and the mixture was stirred overnight. The resulting reaction mixture was quenched with water (10 mL) and extracted using dichloromethane. The resulting organic layer was dried with sodium sulfate and the solvent was removed by distillation under reduced pressure. The resulting solid was purified by silica gel chromatography and gel permeation column chromatography with dichloromethane as the mobile phase to obtain the compound represented by No. 13 (46 mg, 0.13 mmol, yield 29%). The results of the nuclear magnetic resonance spectroscopy, MS, and elemental analysis of the obtained compounds are as follows. 1 H-NMR (CDCl3, 500 MHz): δ (ppm) 8.58 (s, 1H), 8.55 (s, 1H), 8.32 (s, 1H), 8.10 (s, 1H), 8.00-7.97 (m, 2H), 7.52 (s, 1H), 7.44-7.39 (m, 2H), 1.43 (s, 12H). FD+(eiFi) m / z: Calcd for C 22 H 21 BO3[M+]:344.16. Found: 344.16 Elemental analysis: Calcd for C 22 H 21 BO3: C, 76.77; H, 6.15. Found: C, 76.61; H, 6.18.

[0063] [ka]

[0064] Example 10 (Synthesis of the compound represented in No. 14 above) 0.1 parts (0.36 mmol) of the compound represented by formula (f), obtained by a known method, was mixed with tetrahydrofuran (20 mL). Under a nitrogen atmosphere, 2.8 M n-butyllithium (0.2 mL, 0.56 mmol) was added at -50°C and the mixture was stirred for 2 hours. Then, isopropoxyboronic acid pinacol (0.2 mL, 0.99 mmol) was added at -50°C and the mixture was stirred for 30 minutes. The temperature was raised to 20°C and the mixture was stirred overnight. The resulting reaction mixture was quenched with water (10 mL) and extracted using dichloromethane. The resulting organic layer was dried with sodium sulfate and the solvent was removed by distillation under reduced pressure. The resulting solid was purified by silica gel chromatography and gel permeation column chromatography with dichloromethane as the mobile phase to obtain the compound represented by No. 14 (46 mg, 0.13 mmol, yield 29%). The results of the nuclear magnetic resonance spectroscopy, MS, and elemental analysis of the obtained compounds are as follows. 1 H-NMR (CDCl3, 500 MHz): δ (ppm) 8.61 (s, 1H), 8.58 (s, 1H), 8.57 (s, 1H), 8.47 (s, 1H), 8.22 (s, 1H), 8.02-8.00 (m, 2H), 7.46-7.42 (m, 2H), 1.40 (s, 12H). FD+(eiFi) m / z: Calcd for C 22 H 21 BO2Se[M+]:408.08. Found: 408.08 Elemental analysis: Calcd for C 22 H 21 BO2Se: C, 64.89; H, 5.20. Found: C, 64.92; H, 5.26.

[0065] [ka]

[0066] Example 11 (Synthesis of the compound represented in No. 15 above) 0.1 parts (0.36 mmol) of the compound represented by formula (g), obtained by a known method, was mixed with tetrahydrofuran (20 mL). Under a nitrogen atmosphere, 2.8 M n-butyllithium (0.2 mL, 0.56 mmol) was added at -50°C and the mixture was stirred for 2 hours. Then, triisopropoxyborane (0.2 mL, 0.87 mmol) was added at -50°C and the mixture was stirred for 30 minutes. The temperature was raised to 20°C and the mixture was stirred for 2 hours. The resulting reaction mixture was quenched with water (10 mL) and extracted using 1 M hydrochloric acid (20 mL) dichloromethane. The resulting organic layer was dried with sodium sulfate, and the solvent was removed under reduced pressure to obtain the compound represented by No. 15 (0.12 parts, 0.36 mmol, 100% yield).

[0067] [ka]

[0068] Example 12 (Synthesis of the compound represented in No. 16 above) The compound represented by No. 15 obtained in Example 11 (0.12 parts, 0.36 mmol) was mixed with toluene (20 mL), and 1,2-dihydroxybenzene (0.5 parts, 4.5 mmol) was added under a nitrogen atmosphere. The mixture was heated to reflux temperature and stirred for 12 hours. The resulting reaction solution was cooled, the precipitated solid was filtered off, and the compound represented by No. 16 (0.019 parts, 0.091 mmol, yield 21%) was obtained as an orange solid. The nuclear magnetic resonance spectra and MS results for the obtained compounds are as follows. 1 H-NMR (CDCl3, 500 MHz): δ (ppm) 8.73 (s, 1H), 8.69 (s, 1H), 8.67 (s, 1H), 8.58 (s, 1H), 8.54 (s, 1H), 8.08-8.06 (m, 2H), 7.51-7.48 (m, 2H), 7.40-7.38 (m, 2H), 7.21-7.19 (m, 2H). FD+(eiFi) m / z: Calcd for C 22 H 13 BO2Se[M+]:400.02. Found: 400.02 Elemental analysis: Calcd for C 22 H 13 BO2Se: C, 66.21; H, 3.28. Found: C, 65.79; H, 3.47.

[0069] [ka]

[0070] Comparative Example 1 (Measurement of carrier density and Fermi level of the compound represented by (X)) Instead of the compound represented by No. 1 obtained in Example 1, the carrier density and Fermi level of a compound represented by the following formula (X), synthesized by a known method, were measured. As a result, the carrier density was 1.5 × 10⁻⁶. 16 / cm 3 The Fermi level was -4.9 eV.

[0071] [ka]

[0072] Comparative Example 2 (Fabrication of comparative organic field-effect transistor B) A comparative organic field-effect transistor B was fabricated using the same procedure as in Example 1, except that the compound represented by formula (X) above was used instead of the compound represented by No. 1 obtained in Example 1.

[0073] (Evaluation of mobility) For organic field-effect transistors A and B fabricated in Example 1 and Comparative Example 1, mobility measurements were performed immediately after fabrication under a nitrogen atmosphere with a drain voltage of -60V. Subsequently, mobility measurements were performed again after standing in air for 4 days, and the relative mobility compared to immediately after fabrication was determined and evaluated according to the following criteria. The results are shown in Table 1 as evaluation results for organic field-effect transistors. • Evaluation criteria The relative mobility is as follows: If the value is 0.80 or higher: "A" If the value is less than 0.80 but greater than or equal to 0.65: "B" Less than 0.65 and above: "C" If the value is less than 0.50 but greater than or equal to 0.35: "D" If less than 0.35: "E" In practical terms, it is preferable for organic field-effect transistors to be doped by exposure to the atmosphere, thereby improving their mobility, or to experience only a small decrease in mobility. Therefore, "A" represents the best performance, and "E" represents the worst performance.

[0074] [Table 1] [Industrial applicability]

[0075] By using the compounds of the present invention, it is possible to provide organic semiconductor compounds that can be doped using inexpensive dopants in a simple process, organic thin films containing the organic semiconductor compound, and organic electronic devices with high charge mobility equipped with the organic thin film.

Claims

1. The following formula (1) 【Chemistry 1】 (In formula (1), R １ and R ２ Each of these independently represents a hydrogen atom, an alkyl group, or an aromatic group, and the hydrogen atom of the alkyl group or aromatic group may be substituted with a substituent, R １ and R ２ They may form a structure in which they are connected. Ar is given by the following formula (2) 【Chemistry 2】 (This represents an aromatic group, and the hydrogen atoms of the aromatic group may be substituted with substituents.) A compound represented by the formula.

2. R １ and R ２ The compound according to claim 1, which forms a structure in which the elements are linked together.

3. The compound according to claim 1, wherein the Fermi level in the solid state is -4.8 eV or higher.

4. The carrier density in the solid state measured in the atmosphere was 2.0 × 10⁻⁶. １６ / cm ３ The compound according to claim 1, wherein the above conditions apply.

5. An organic thin film comprising the compound according to any one of claims 1 to 4.

6. An organic electronic device comprising an organic thin film according to claim 5.

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