JP2014148483A - STABLE π-ELECTRON CONJUGATED COMPOUND AND METHOD OF PRODUCING THE SAME - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a π-electron conjugated compound that is applicable to a wet process as well as a decompression sublimation method, and is also stable with respect to light and oxygen and/or ozone, and a method of producing the compound.SOLUTION: This invention provides a radical derivative of pentacene represented by the formula (I), where the radical group -Y. represents one of the following compounds.

Description

  The present invention relates to a stable π-electron conjugated compound and a method for producing the same. More specifically, the present invention relates to a radical derivative of pentacene which is stable to light, oxygen and / or ozone of an extended π-electron conjugated compound utilizing a stable radical, and a method for producing the same.

  In recent years, in the field of electronic devices such as field effect transistors and thin film transistors, organic semiconductor materials have attracted attention in place of inorganic semiconductor materials typified by silicon that have been conventionally used.

This is because organic semiconductor materials can be manufactured at low cost compared to silicon semiconductor materials; they can be easily used for large-area electronic devices using thin films; high-temperature processes in manufacturing processes using organic semiconductors. It is possible to form a thin film on a plastic substrate because it is not required; it has characteristics such as being able to be used in a flexible large-area device without deteriorating element characteristics against mechanical bending. It is based on.
More specifically, in an electronic element using an organic semiconductor material, characteristics such as impact resistance, light weight, flexibility, low cost, and large area can be exhibited.

  Organic semiconductor materials include organic light-emitting devices such as organic electroluminescent elements, organic field effect transistors, organic solar cells, etc., and quantum light-emitting elements having a hole-injecting and transporting layer, electrophotographic photoreceptors, and mobile information terminals It can be used in a wide variety of organic electronic devices such as electronic devices.

  As a π-electron conjugated compound with a double-bonded and single-bonded site, acene-based materials such as pentacene have a highly expanded π-electron system, so they have excellent hole transport and electron transport properties. For example, the application to organic semiconductor materials (Patent Literature 1, Patent Literature 2, Non-Patent Literature 1 and Non-Patent Literature 2), electroluminescent materials, organic dyes, organic pigments, and the like has been widely studied.

  As π-electron conjugated compounds are widely used as organic semiconductor materials in this way, the obstacle is that many of the π-electron conjugated compounds are highly planar and rigid. Is very strong and has poor solubility in water and organic solvents.

For example, when a π-electron conjugated compound is used as an organic pigment, the pigment tends to aggregate and the dispersion becomes unstable.
In addition, taking organic semiconductor materials and electroluminescent materials as examples, it is difficult to apply a solution process because it is hardly soluble, and there is a problem that vapor deposition such as vacuum deposition is necessary, increasing the manufacturing cost, There is a problem that the manufacturing process becomes complicated.

In recent years, an organic thin film forming method and an organic thin film forming apparatus using a vacuum vapor deposition method of an organic semiconductor material which is a π-electron conjugated compound have also been proposed (Patent Document 3).
However, even in organic semiconductor materials, acene-based materials, especially pentacene, have extremely low solubility in water and organic solvents, require a vacuum deposition process, and have low stability against light and oxygen and / or ozone. Is known (Patent Document 4).

  On the other hand, in recent years, there has been proposed a method of converting a pentacene bicyclo compound having high solvent solubility into pentacene or the like by elimination reaction using a retro Diels-Alder reaction (Patent Document 5). However, this method requires complicated synthesis and a step of removing the leaving group, so that the application range is narrow, and it is necessary to develop a soluble pentacene derivative that can be synthesized more easily.

  A method of applying a soluble precursor of pentacene and forming a film by heating or the like has also been proposed (Non-patent Document 3). However, with this method, it is difficult to remove tetrachlorobenzene molecules that are eliminated from the precursor out of the system, and toxicity of tetrachlorobenzene also becomes a problem.

  Further, there is a method for producing a film of a π-electron conjugated compound by forming a π-electron conjugated compound having a benzene ring such as pentacene and then removing the detachable substituent after film formation. It has been proposed (Patent Document 6). However, although this method seems to allow the formation of pentacene, no consideration is given to the improvement of pentacene light and oxygen and / or ozone stability.

  Therefore, it is stable to light and oxygen and / or ozone, and is soluble in organic solvents, and can be applied to wet processes such as spin coating, blade coating, gravure printing, inkjet coating, dip coating coating, etc. Is required.

Japanese Patent Laid-Open No. 5-05568 WO2006-077788 JP 2008-177283 A JP 2010-67817 A JP 2007-224019 A JP 2012-41327 A

Appl. Phys. Lett., 72, p1854, 1998 J. Am. Chem. Soc., 128, p12604, 2006 J. Appl. Phys., 2136, 79, 1996

  An object of the present invention is to provide a π-electron conjugated compound which is applicable not only to a vacuum sublimation method but also to a wet process and is stable to light and oxygen and / or ozone, and a method for producing the same.

  As a result of diligent efforts and research, the present inventors have found that the above problems can be solved by introducing a group having a stable radical into a π-electron conjugated compound, and the present invention has been completed. .

Thus, according to the present invention, the following general formula (I):
Wherein the group -X- is the following:
And the radical group -Y.
Represents
A radical derivative of pentacene represented by the formula:

According to the invention, the group -X- in the general formula (I) is represented by the following formula:
A radical derivative of pentacene as described above is provided.

According to the invention, the compound of general formula (I) is:
Or the following:
A radical derivative of the above pentacene is provided.

In addition, according to the present invention, in order to obtain the above pentacene radical derivative (1a), the following formula (8):
4- (pentacene-6-yl) benzaldehyde represented by the following formula (9):

Is reacted with 1,3-diamino-1,3-dimethylurea represented by the following formula (1b):
In represented by 2,4-dimethyl-6- (4- (pentacene-6-yl) phenyl) -1,2,4,5 Tetorajinan -3-ON, which through celite carrying Ag ₂ CO ₃ Process the following equation (1a):

There is provided a method for producing a radical derivative of pentacene, characterized in that 2,4-dimethyl-6- (4- (pentacene-6-yl) phenyl) -vadazyl-3-one represented by the formula:

In order to obtain the pentacene radical derivative (2a), the following formula (8):
In the presence of alkali, 2,3-bis (hydroxyamino) -2,3-dimethylbutane sulfate is reacted with 4- (pentacene-6-yl) benzaldehyde represented by the following formula (2b): :

4,4,5,5-tetramethyl-2- (4- (pentacene-6-yl) phenyl) imidazolidine-1,3-diol represented by the formula: (2a):

Of 4,4,5,5-tetramethyl-2- (4-pentacene-6-yl) phenyl) imidazolidine-1,3-dioxyl represented by the formula: A method is provided.

According to the present invention, a radical derivative of pentacene that is stable to light and oxygen and / or ozone and a method for producing the same are provided.
The radical derivative of pentacene according to the present invention is more soluble in organic solvents than pentacene and has high stability to light, oxygen and / or ozone, so that not only vacuum deposition but also spin coating and blade coating are used. Quantum light-emitting devices, electrophotographic photoreceptors, and electronic devices for mobile information terminals having organic field effect transistors and hole injection and transport layers by applying wet processes such as gravure printing, inkjet coating, dip coating coating, etc. Can be used for a wide variety of organic electronic devices.

^{1 is} a ¹ H-NMR spectrum of 2,4-dimethyl-6- (4- (pentacene-6-yl) phenyl) -1,2,4,5-tetrazinan-3-one (1b). 1 is a ¹ H-NMR spectrum of 4,4,5,5-tetramethyl-2- (4- (pentacene-6-yl) phenyl) imidazolidine-1,3-diol (2b). (A) It is a figure which shows the time-dependent change of the ultraviolet-visible spectrum of the saturated THF solution (concentration unknown) of pentacene. (B) It is a figure which shows a time-dependent change of the light absorbency in the measurement wavelength (lambda) = 575nm of the saturated THF solution (concentration unknown) of pentacene. (A) A THF solution of 2,4-dimethyl-6- (4- (pentacene-6-yl) phenyl) -1,2,4,5-tetrazinan-3-one (1b) (concentration 0.945 × 10 ⁻⁴ It is a figure which shows the time-dependent change of the ultraviolet-visible spectrum of M). (B) UV-visible spectrum of a THF solution (concentration 0.993 × 10 ⁻⁴ M) of 2,4-dimethyl-6- (4- (pentacene-6-yl) phenyl) -vadazyl-3-one (1a) It is a figure which shows a time-dependent change. (A) 4,4,5,5-tetramethyl-2- (4- (pentacene-6-yl) phenyl) imidazolidine-1,3-diol (2b) in THF (concentration 0.983 × 10 ⁻⁴ M It is a figure which shows a time-dependent change of the ultraviolet-visible spectrum of). (B) THF solution of 4,4,5,5-tetramethyl-2- (4-pentacene-6-yl) phenyl) imidazolidine-1,3-dioxyl (2a) (concentration 1.02 × 10 ⁻⁴ M) It is a figure which shows the time-dependent change of the ultraviolet-visible spectrum. (A) 2,4-Dimethyl-6- (4- (pentacene-6-yl) phenyl) -1,2,4,5-tetrazinan-3-one (1b), 2,4-dimethyl-6- ( 4- (pentacene-6-yl) phenyl) -vadazyl-3-one (1a), 4,4,5,5-tetramethyl-2- (4- (pentacene-6-yl) phenyl) imidazolidine-1 , 3-diol (2b), and 4,4,5,5-tetramethyl-2- (4-pentacene-6-yl) phenyl) imidazolidine-1,3-dioxyl (2a) It is a figure which shows a time-dependent change. (B) It is a figure which shows the attenuation | damping behavior of the characteristic absorption originating in the pentacene site | part at room temperature of each THF solution of pentacene, 1b, 1a, 2b, and 2a.

  Hereinafter, the present invention will be described with reference to embodiments. However, the present invention is not limited to the following embodiments, and may be arbitrarily modified and implemented without departing from the scope of the present invention. it can.

The radical derivative of pentacene according to the present invention has the general formula (I):
It is represented by

The group -X- in the above general formula (I) is as follows:
Means.

In the general formula (I), the radical group -Y.
Means.

As specific examples of the radical derivative of pentacene represented by the above general formula (I), the following formula (1a):
2,4-dimethyl-6- (4- (pentacene-6-yl) phenyl) -vadazyl-3-one (radical derivative of pentacene (1a)) or the following formula (2a):

4,4,5,5-tetramethyl-2- (4-pentacene-6-yl) phenyl) imidazolidine-1,3-dioxyl (pentacene radical derivative (2a)).

The above pentacene radical derivatives (1a) and (2a) are represented by the following formula (8):
Can be obtained from a common synthetic intermediate represented by the formula (aldehyde compound (8)).

Said aldehyde compound (8) is compoundable according to the following synthetic schemes.

That is, in anhydrous THF, THF of 2- (4-bromophenyl) -1,3-dioxolane (3) and Mg to Grignard reagent, 4- (1,3-dioxolan-2-yl) phenylmagnesium bromide (4) A solution was prepared. This solution was reacted with 6-pentacenone (5) under an argon atmosphere to obtain a mixture of acetal (6) and aldehyde (7), and aluminum foil was wrapped around a laboratory apparatus to mix the mixture of (6) and (7). Treated with concentrated HCl in acetone, added H ₂ O and purified by silica gel chromatography, and isolated 4- (pentacene-6-yl) benzaldehyde (aldehyde compound (8)) as a purple powder by a conventional method. .

  By selecting various reagents with different substitution modes as appropriate in the above synthetic scheme, the synthetic intermediate of the above general formula (I) can be produced in the same manner.

The radical derivatives (1a) and (2a) of pentacene can be synthesized from the aldehyde compound (8) according to the following synthesis scheme.

That is, for example, in 1,2-dichloroethane, the above aldehyde compound (8) and 1,3-diamino-1,3-dimethylurea (9) are heated and reacted in the dark under an argon atmosphere and cooled to room temperature. , Purified by alumina column chromatography by a conventional method, and 2,4-dimethyl-6- (4- (pentacene-6-yl) phenyl) -1,2,4,5-tetrazinan-3-one ( Precursor (1b)), which is treated with celite-supported Ag ₂ CO ₃ in, for example, 1,2-dichloroethane under dark conditions, and purified by alumina column chromatography by a conventional method to give 2,4-dimethyl- 6- (4- (pentacene-6-yl) phenyl) -vadazyl-3-one (radical derivative of pentacene (1a)) was obtained.

Further, the aldehyde compound (8) and 2,3-bis (hydroxyamino) -2,3-dimethylbutane sulfate in a mixed solvent of MeOH-1,2-dichloroethane in the presence of an alkali such as potassium carbonate under dark conditions The reaction was heated under an argon atmosphere, filtered after cooling to room temperature, and 4,4,5,5-tetramethyl-2- (4- (pentacene-6-yl) phenyl) imidazolidine as a purple powder by a conventional method -1,3-diol (precursor (2b)) is obtained, and then this compound is reacted under dark conditions with an aqueous solution of an oxidizing agent such as NaIO ₄ in, for example, dichloromethane. Purification by chromatography gave 4,4,5,5-tetramethyl-2- (4-pentacene-6-yl) phenyl) imidazolidine-1,3-dioxyl (pentacene radical derivative (2a)). .

According to the invention, formulas (1a) and (2a):
The THF derivatives of the pentacene radical derivatives (1a) and (2a) represented by formula (1b) and (2b):

Compared to the THF solutions of the precursors (1b) and (2b) represented by the formula (1) and the THF solution of pentacene (see FIG. 3), the stability is excellent under dissolved saturated air and indoor fluorescent lamps. (See FIGS. 4 to 6).
Furthermore, the radical derivatives (1a) and (2a) of pentacene according to the present invention have higher solubility in organic solvents than pentacene.

Therefore, the radical derivative of pentacene according to the present invention applies not only a vacuum deposition method but also a wet process such as spin coating, blade coating, gravure printing, inkjet coating, dip coating coating, etc. It can be used in a wide variety of organic electronic devices such as quantum light emitting devices having a hole injection transport layer, electrophotographic photoreceptors, and electronic devices for mobile information terminals.
Furthermore, the radical derivative of pentacene according to the present invention is expected to be used not only in oxygen but also in the presence of ozone or NOx (nitrogen oxide).

  EXAMPLES The present invention will be described in detail below by examples, but the present invention is not limited to these examples.

EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to these Examples.
Reagents and solvents used in the following examples were purchased from Aldrich, Tokyo Chemical Industry, Merck or Wako Pure Chemical unless otherwise specified. Note that MeOH and THF were anhydrous grades.
The melting point (mp) was measured using an AZ WAN ATM-1 melting point measuring instrument and showed an uncorrected value.

¹ H-NMR spectra were recorded using either a JEOL Lambda 400 (400 MHz) or BRUKER AVANCE 600 (600 MHz) spectrometer.
¹³ C-NMR spectra were recorded using either a JEOL Lambda 400 (100 MHz) or BRUKER AVANCE 600 (150 MHz) spectrometer.
The chemical shifts of ¹ H-NMR and ¹³ C-NMR are as follows: CHCl ₃ (δ = 7.26 or 77.1) in CDCl ₃ or (CH ₃ ) ₂ SO (δ = 2.49 or 39.5) in (CD ₃ ) ₂ SO. It was recorded in parts per million (δ (ppm)).
Low resolution mass spectrometry (LRMS) and high resolution mass spectrometry (HRMS) were obtained by JEOL JMS-700T for fast atom bombardment ionization (FAB).

All reactions were monitored by thin layer chromatography (TLC) using commercially available thin layer plates (silica gel plate 0.25 mm from Whatman or aluminum oxide 60 _F254 , 0.25 mm from Merck). TLC was visualized using a UV lamp.
For flash chromatography, IR-60 1002W (40/63 mm) manufactured by Daiso Corporation or aluminum oxide 60 manufactured by Merck Corporation was used.
Since pentacene is known to be unstable under ambient light conditions, the synthesis was performed in the dark or by coating the reaction vessel with aluminum foil.

Production Example 1
Synthesis of 6-pentacenenone (5) After stirring at room temperature, a suspension of concentrated sulfuric acid (100 mL) of 6,13-pentacenedione (3.01 g, 9.76 mmol) in H ₂ O (300 mL) was gradually stirred. Suction filtration was performed and the mixture was washed with H ₂ O (150 mL). The obtained yellow solid was suspended in H ₂ O (300 mL) at room temperature, 30% NaOH aqueous solution (100 mL) and Na ₂ S ₂ O ₄ (40 g) were added under argon atmosphere, and 90 ° C. Stir for hours. After cooling to room temperature, it was suction filtered, washed with H ₂ O (150 mL), and then dried under reduced pressure in a desiccator to obtain a pale yellow solid (2.61 g, yield 90%).
¹ H-NMR (400 MHz, CDCl ₃ ) δ (ppm): 8.97 (s, 2H), 8.07 (d, J = 8.0 Hz, 2H), 7.96 (s, 2H), 7.89 (d, J = 8.3 Hz , 2H), 7.61 (t, J = 16.1 Hz, 2H), 7.53 (t, J = 14.2 Hz, 2H), 4.71 (s, 2H)
HRMS (m / z): [ M] + C 22 H 12 O, theoretical; 294.1045, Found: 294.1045.

Production Example 2
Synthesis of 1,3-diamino-1,3-dimethylurea (9) Under argon atmosphere, methyl hydrazine (25 mL, 458 mmol) was added to anhydrous dichloromethane (270 mL). Cooled and stirred. To this was added dropwise a solution of triphosgene (11.1 g, 38 mmol) in anhydrous toluene (110 mL), and the mixture was stirred at −50 ° C. for 4 hours. Thereafter, the mixture was stirred at room temperature for 17 hours. The reaction solution was suction filtered, and the residue was washed with hexane (40 mL). The filtrate was dried under reduced pressure to obtain a pale yellow solid (13.20 g, yield 42%).
mp: 60 ° C .; ¹ H-NMR (400 MHz, CDCl ₃ ) δ (ppm): 4.37 (s, 4H), 3.04 (s, 6H); ¹³ C-NMR (100 MHz, CDCl ₃ ) δ (ppm) : 165.0, 41.1.

Example 1
Synthesis of 4- (pentacene-6-yl) benzaldehyde (8) (aldehyde compound (8)) A suspension of Mg (0.45 g, 18.5 mmol) in THF (3 mL) at room temperature under stirring in an argon atmosphere 2 -(4-Bromophenyl) -1,3-dioxolane (3) (0.1 mL, 0.66 mol) was added and heated to about 50 ° C. with a dryer until the color of the solution changed to dark brown. To this was added dropwise a solution of (3) (1 mL, 6.6 mmol) in THF (4 mL), and the mixture was stirred for 1 hour to give 4- (1,3-dioxolan-2-yl) phenylmagnesium bromide (Grignard reagent (4 )) In THF was prepared. This solution was added dropwise to a solution of 6-pentacenone (5) (0.65 g, 2.21 mmol) in THF (80 mL) under an argon atmosphere and stirred at 59 ° C. for 2 hours. After cooling to room temperature, the organic layer was washed with a saturated aqueous ammonium chloride solution (50 mL × 2), dried over MgSO ₄ , and the filtrate was concentrated under reduced pressure. (CH ₂ Cl) ₂ (10 mL) was added thereto, followed by filtration, and a silica gel column chromatography (developing solvent: (CH ₂ Cl) ₂ followed by EtOAc) gave a mixture of acetal (6) and aldehyde (7). It was.

Since pentacene is sensitive to light and oxygen, the reaction was advanced by wrapping aluminum foil around the experimental equipment in the dark from the following operations. Dissolve the mixture of (6) and (7) in acetone (10 mL), add concentrated HCl (4 mL) at room temperature, stir for 5 minutes, and then add H ₂ O (50 mL) to obtain a purple powder. It was. The powder was collected by filtration, washed with H ₂ O, hexane, and purified by silica gel column chromatography (developing solvent; CH ₂ Cl ₂ : hexane = 2: 1) to isolate a dark purple powder (0.16 g Yield 19%).

mp: 204 ° C .; TLC (CH ₂ Cl ₂ : hexane 2: 1 v / v): Rf = 0.26;
¹ H-NMR (400 MHz, CDCl ₃ ) δ (ppm): 10.28 (s, 1H), 9.04 (s, 1H), 8.69 (s, 2H), 8.22 (d, J = 8.3 Hz, 2H), 8.17 (s, 2H), 7.92 (d, J = 8.6 Hz, 2H), 7.77 (d, J = 8.3 Hz, 2H), 7.72 (d, J = 8.6 Hz, 2H), 7.27-7.34 (m, 4H) ;
¹³ C-NMR (100 MHz, CDCl ₃ ) δ (ppm): 192.2, 146.3, 135.8, 134.8, 132.6, 131.7, 131.2, 130.1, 129.7;
HRMS (m / z): [M] ⁺ C ₂₉ H ₁₈ O, Theoretical: 382.1358; Found: 382.1357;
[M + H] ⁺ C ₂₉ H ₁₉ O, Theoretical value: 382.1436, Found: 382.1426;
Elemental analysis (C ₂₉ H ₁₈ O): C (theoretical value: 91.07, measured value: 90.56), H (theoretical value: 4.74, measured value: 4.92).

Example 2
Synthesis of 2,4-dimethyl-6- (4- (pentacene-6-yl) phenyl) -1,2,4,5-tetrazinan-3-one (1b) (precursor (1b))
4- (pentacene-6-yl) benzaldehyde (8) (0.26 g, 0.68 mmol) and 1,3-diamino-1,3-dimethylurea (9) (0.33 g, 2.79 mmol) of (CH ₂ Cl) ₂ (50 mL) The solution was refluxed in the dark under an argon atmosphere for 3 hours, cooled to room temperature, and purified by alumina column chromatography (developing solvent; EtOH after flowing through (CH ₂ Cl) ₂ ). Obtained (0.23 g, 70% yield).

mp: 206 ° C .; TLC (EtOH): Rf = 0.87;
¹ H-NMR (400 MHz, CDCl ₃ ) δ (ppm): 9.05 (s, 1H), 8.71 (s, 2H), 8.22 (s, 2H), 7.94 (d, J = 8.4 Hz, 2H), 7.84 (d, J = 7.8 Hz, 2H), 7.74 (d, J = 8.4 Hz, 2H), 7.63 (d, J = 7.8 Hz, 2H), 7.32 (t, J = 8.4, Hz, 2H), 7.27 ( t, J = 8.4 Hz, 2H), 5.31 (t, J = 10.2 Hz, H), 4.59 (d, J = 10.2 Hz, 2H), 3.29 (s, 6H);
¹³ C-NMR (100 MHz, CDCl ₃ ) δ (ppm): 155.7, 140.1, 135.7, 134.5, 132.2, 131.6 131.2, 129.8, 128.80, 128.76, 128.1, 127.2, 126.7 126.6, 125.4, 125.2, 125.1, 69.8, 38.2;
HRMS (m / z): [M] ⁺ C ₃₂ H ₂₆ N ₄ O, Theoretical value: 482.2107, Found: 482.2118;
_{^{[M + H] + C 32}} H 27 N 4 O, theoretical value: 483.2185, Found: 483.2166.

Example 3
Synthesis of 2,4-dimethyl-6- (4- (pentacene-6-yl) phenyl) -vadazyl-3-one (1a) (radical derivative of pentacene (1a))
2,4-Dimethyl-6- (4- (pentacene-6-yl) phenyl) -1,2,4,5-tetrazinan-3-one (1b) (0.12 g, 0.25 mmol) and Celite-supported Ag ₂ CO _A solution of ₃ (50 wt%, 0.30 g, 0.54 mol) in (CH ₂ Cl) ₂ (50 mL) was stirred at 52 ° C. for 3 hours in the dark under an argon atmosphere, cooled to room temperature, and then subjected to alumina column chromatography ( Purified with developing solvent; (CH ₂ Cl) ₂ ). Hexane was added to the solution concentrated under reduced pressure to precipitate crystals, and dark purple crystals of 1a were obtained (0.04 g, yield 33%).

mp:> 300 ° C .; TLC ((CH ₂ Cl) ₂ ): Rf = 0.78;
HRMS (m / z): [M] ⁺ C ₃₂ H ₂₃ N ₄ O, Theoretical value: 479.1872, Found: 479.1875;
_{^{[M + H] + C 32}} H 24 N 4 O, theoretical value: 480.1950, Found: 480.1942.

Example 4
Synthesis of 4,4,5,5-tetramethyl-2- (4- (pentacene-6-yl) phenyl) imidazolidine-1,3-diol (2b) (precursor (2b)) 4 under argon atmosphere -(Pentacene-6-yl) benzaldehyde (8) (0.20 g, 0.52 mmol), 2,3-bis (hydroxyamino) -2,3-dimethylbutane sulfate (1.04 g, 4.22 mmol), K ₂ CO ₃ ( 0.51 g, 3.69 mmol) of a mixture of MeOH: (CH ₂ Cl) ₂ = 1: 1 (30 mL) was refluxed in the dark for 72 hours, cooled to room temperature, filtered and H ₂ O And a small amount of (CH ₂ Cl) ₂ to give a purple powder of (2b) (0.20 g, 74% yield).

mp: 225 ° C (decomposition);
¹ H-NMR (600 MHz, (CD ₃ ) ₂ SO) δ (ppm): 9.22 (s, 1H), 8.90 (s, 2H), 8.24 (s, 2H), 8.04 (d, J = 8.4 Hz, 2H), 7.98 (s, 2H), 7.84 (d, J = 7.8 Hz, 2H), 7.76 (d, J = 8.4 Hz, 2H), 7.55 (d, J = 7.8 Hz, 2H), 7.38 (t, J = 8.4 Hz, 2H), 7.33 (t, J = 8.4 Hz, 2H), 1.18 (s, 6H), 1.17 (s, 6H);
¹³ C-NMR (100 MHz, (CD ₃ ) ₂ SO) δ (ppm): 141.6, 137.2, 136.3, 131.0, 130.7, 130.6, 129.3, 128.9, 128.4, 128.2, 128.0, 126.9, 126.7, 125.6, 125.5, 124.5, 90.5, 66.3, 24.6, 17.2;
HRMS (m / z): [M] ⁺ C ₃₅ H ₃₂ N ₂ O ₂ , theoretical value: 512.2464, actual value: 512.2444;
_{^{[M + H] + C 35}} H 33 N 2 O 2, theory: 513.2542, Found: 513.2548.

Example 5
4,4,5,5-Tetramethyl-2- (4-pentacene-6-yl) phenyl) imidazolidine-1,3-dioxyl (2a) (radical derivative of pentacene (2a))
4,4,5,5-tetramethyl-2- (4- (pentacene-6-yl) phenyl) imidazolidine-1,3-diol (2b) (0.10 g, 0.20 mmol) at room temperature in the dark To the CH ₂ Cl ₂ (10 mL) solution was added NaIO ₄ (0.33 g, 1.54 mmol) aqueous solution (20 mL), and the mixture was stirred for 30 min. The organic layer was separated and purified by silica gel column chromatography (developing solvent: CH ₂ Cl ₂ ) to obtain a dark purple powder of (2a) (3.26 mg, yield 3%).
mp> 300 ° C .; TLC (CH ₂ Cl ₂ ): Rf = 0.23;
HRMS (m / z): [M] ⁺ C ₃₅ H ₂₉ N ₂ O ₂ , theoretical: 509.2229; found: 509.2224;
_{^{[M + H] + C 35}} H 30 N 2 O 2, theory: 510.2307; Found: 510.2316.

Test example 1
At room temperature, pentacene was added to THF to prepare a saturated solution of pentacene in THF, and the change with time in the UV-visible absorption spectrum was recorded. The results are shown in FIGS. 3 (a) and (b). FIG. 3B shows the change with time in absorbance at the measurement wavelength λ = 575 nm. Since pentacene is poorly soluble, the concentration of pentacene in the solution was unknown, but it was shown that pentacene in THF was extremely unstable.

Test example 2
2,4-Dimethyl-6- (4- (pentacene-6-yl) phenyl) -1,2,4,5-tetrazinan-3-one (1b) (precursor (1b)) obtained in Example 2 ) In THF (concentration: 0.945 × 10 ⁻⁴ M) was prepared, and the time-dependent change in the UV-visible absorption spectrum was recorded. The result is shown in FIG.
Similarly, THF of 2,4-dimethyl-6- (4- (pentacene-6-yl) phenyl) -vadazyl-3-one (1a) (pentacene radical derivative (1a)) obtained in Example 3 The solution (concentration: 0.993 × 10 ⁻⁴ M) was prepared, and the change with time in the ultraviolet-visible absorption spectrum was recorded. The result is shown in FIG.

  From the above results, the absorbance of the precursor (1b) attenuated significantly in a short time with time, whereas the absorbance of the pentacene radical derivative (1a) showed only a slight attenuation even after 1 hour. The radical derivative (1a) of pentacene was found to be an extremely stable compound.

Test example 3
4,4,5,5-Tetramethyl-2- (4- (pentacene-6-yl) phenyl) imidazolidine-1,3-diol (2b) (precursor (2b)) obtained in Example 4 A THF solution (concentration: 0.983 × 10 ⁻⁴ M) was prepared, and the change with time in the ultraviolet-visible absorption spectrum was recorded. The result is shown in FIG.
Similarly, 4,4,5,5-tetramethyl-2- (4-pentacene-6-yl) phenyl) imidazolidine-1,3-dioxyl (2a) (a radical derivative of pentacene) obtained in Example 5 The THF solution (concentration: 1.02 × 10 ⁻⁴ M) of (2a)) was prepared, and the change with time in the ultraviolet-visible absorption spectrum was recorded. The result is shown in FIG.

  From the above results, the absorbance of the precursor (2b) was significantly attenuated over a short period of time, whereas the absorbance of the pentacene radical derivative (2a) showed only a slight attenuation even after 1 hour. The radical derivative (2a) of pentacene was found to be an extremely stable compound.

Test example 4
In exactly the same manner as in Test Examples 1 to 3, the respective THF solutions of pentacene, precursor (1b), pentacene radical derivative (1a), precursor (2b) and pentacene radical derivative (2a) were prepared, The change with time of the color of each solution was observed. The result is shown in FIG.
Moreover, the result of having measured the change of the light absorbency of the ultraviolet-visible absorption spectrum of each said THF solution at the maximum absorption wavelength of each compound is shown in FIG.6 (b).
6 (a) and (b), 1b represents the precursor (1b), 1a represents the radical derivative (1a) of pentacene, 2b represents the precursor (2b), and 2a represents the radical derivative (2a) of pentacene. Each means. In FIG. 6B, Δ is pentacene (measurement wavelength: λ = 575 nm), ● is 1a (measurement wavelength: λ = 587 nm), ○ is 1b (measurement wavelength: λ = 586 nm), Means 2a (measurement wavelength: λ = 588 nm) and □ means 2b (measurement wavelength: λ = 587 nm).

  From the above test, the precursor solutions (1b) and (2b) in the THF solution were almost faded after 3 minutes, but the pentacene radical derivatives (1a) and (2a) in the THF solution were markedly faded. There wasn't.

In addition, the absorbance over time of the initial absorbance of each THF solution of pentacene, precursors (1b) and (2b) is almost 0 after 10 minutes from the start of measurement, and the π-electron conjugated system in each compound increases with time. It turned out to be affected.
However, in THF solutions of pentacene radical derivatives (1a) and (2a), the decay of absorbance is extremely small, so the π-electron conjugated system of the pentacene skeleton in pentacene radical derivatives (1a) and (2a) has almost no effect over time. It was shown not to receive.

  From the above results, the radical derivatives (1a) and (2a) of pentacene according to the present invention are extremely stable and highly soluble in light and THF solutions, and these compounds are used in the wet process in addition to the conventional vacuum sublimation method. It was shown that it can also be used.

According to the present invention, a radical derivative of pentacene that is stable to light and oxygen and / or ozone and a method for producing the same are provided.
Since the radical derivative of pentacene according to the present invention is highly soluble in organic solvents and has high stability to light, oxygen and / or ozone, not only vacuum deposition but also spin coating, blade coating, and gravure printing. Applying wet processes such as inkjet coating and dip coating, organic field effect transistors, etc., and a wide range of devices such as quantum light emitting devices having hole injection transport layers, electrophotographic photoreceptors and electronic devices for mobile information terminals, etc. It can be used for various organic electronic devices.

Claims (7)

The following general formula (I):
Wherein the group -X- is the following:
And the radical group -Y.
Represents
A radical derivative of pentacene represented by Said group -X- is represented by the following formula:
The radical derivative of pentacene according to claim 1, which is a phenylene group represented by the formula: Said compound of general formula (I) is:
The radical derivative of pentacene according to claim 1, wherein Said compound of general formula (I) is:
The radical derivative of pentacene according to claim 1, wherein   The pentacene radical derivative according to any one of claims 1 to 4, wherein the pentacene derivative is an organic semiconductor material. In order to obtain the radical derivative of pentacene according to any one of claims 1 to 3 or 5, the following formula (8):
4- (pentacene-6-yl) benzaldehyde represented by the following formula (9):
Is reacted with 1,3-diamino-1,3-dimethylurea represented by the following formula (1b):
In represented by 2,4-dimethyl-6- (4- (pentacene-6-yl) phenyl) -1,2,4,5 Tetorajinan -3-ON, which through celite carrying Ag ₂ CO ₃ Process the following equation (1a):
A process for producing a radical derivative of pentacene, characterized in that 2,4-dimethyl-6- (4- (pentacene-6-yl) phenyl) -vadazyl-3-one represented by the formula: In order to obtain the pentacene radical derivative according to claim 1, 2, 4 or 5, the following formula (8):
In the presence of alkali, 2,3-bis (hydroxyamino) -2,3-dimethylbutane sulfate is reacted with 4- (pentacene-6-yl) benzaldehyde represented by the following formula (2b): :
4,4,5,5-tetramethyl-2- (4- (pentacene-6-yl) phenyl) imidazolidine-1,3-diol represented by the formula: (2a):
Of 4,4,5,5-tetramethyl-2- (4-pentacene-6-yl) phenyl) imidazolidine-1,3-dioxyl represented by the formula: Method.