JP2011184362A - Pyrene compound and organic el element using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic EL element with high properties, such as luminous efficiency and color purity. <P>SOLUTION: The invention relates to an organic EL element 11 which includes: an anode 2; a cathode 6; and an organic compound layer which is sandwiched between the anode 2 and the cathode 6 and contains at least a luminescent layer 4; and in the luminescent layer 4, a pyrene compound represented by formula (1) is contained, wherein A<SB>1</SB>and A<SB>2</SB>each represents a substituent group which has a partial skeleton in which two to four fluorene skeletons are mutually connected in series at positions 2 and 7 of the pyrene ring, and A<SB>1</SB>and A<SB>2</SB>may be identical or different. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a pyrene compound and an organic EL device using the same.

  The pyrene skeleton possessed by the pyrene compound has a feature that conjugation is greatly expanded. For this reason, in order to take advantage of this feature, application of pyrene compounds in various fields has been studied. Specifically, the material for optical recording media represented by patent document 1, the constituent material of the organic EL element represented by patent document 2, etc. are mentioned.

  Although it is not restricted to a pyrene compound, luminous efficiency, color purity, etc. are mentioned as a characteristic requested | required as a constituent material of an organic EL element. However, the conventional pyrene compound does not have these characteristics sufficiently, and a compound having higher characteristics is demanded.

JP 2004-42485 A JP 2006-140235 A

Chem. Commun. , 2005, 2172-2174 Organic Letters, 7 (10), 1907-1910, 2005.

  An object of the present invention is to provide an organic EL device having high characteristics such as luminous efficiency and color purity.

  The pyrene compound of the present invention is represented by the following general formula (1).

（式（１）において、Ａ₁及びＡ₂は、それぞれ下記一般式（２）で示される置換基を表す。尚、Ａ₁及びＡ₂は、同じであっても異なっていてもよい。

(In formula (1), A ₁ and A ₂ each represent a substituent represented by the following general formula (2). A ₁ and A ₂ may be the same or different.

（式（２）において、Ｒ₁₁、Ｒ₁₂、Ｒ₁₃及びＲ₁₄は、それぞれアルキル基を表す。Ｒ₁₁、Ｒ₁₂、Ｒ₁₃及びＲ₁₄は、それぞれ同じであっても異なっていてもよい。
Ｒ₁、Ｒ₂、Ｒ₃及びＲ₄は、それぞれアルキル基、アリール基、アラルキル基を表す。ａ、ｂ、ｃ及びｄは、それぞれ０乃至３の整数を表す。ａが２以上の場合、複数のＲ₁は、それぞれ同じであっても異なっていてもよい。ｂが２以上の場合、複数のＲ₂は、それぞれ同じであっても異なっていてもよい。ｃが２以上の場合、複数のＲ₃は、それぞれ同じであっても異なっていてもよい。ｄが２以上の場合、複数のＲ₄は、それぞれ同じであっても異なっていてもよい。
ｌは、１乃至３の整数を表す。
Ｘは、単結合、アリーレン基又は２価の複素環基を表す。
Ｙは、水素原子、アリール基、置換アミノ基、複素環基又は下記一般式（３）で示される置換基を表す。

(In the formula (2), R ₁₁ , R ₁₂ , R ₁₃ and R ₁₄ each represents an alkyl group. R ₁₁ , R ₁₂ , R ₁₃ and R ₁₄ may be the same or different. .
R ₁ , R ₂ , R ₃ and R ₄ each represents an alkyl group, an aryl group or an aralkyl group. a, b, c and d each represents an integer of 0 to 3; When a is 2 or more, the plurality of R ₁ may be the same or different from each other. When b is 2 or more, the plurality of R ₂ may be the same or different. When c is 2 or more, the plurality of R ₃ may be the same or different from each other. When d is 2 or more, the plurality of R ₄ may be the same or different.
l represents an integer of 1 to 3.
X represents a single bond, an arylene group or a divalent heterocyclic group.
Y represents a hydrogen atom, an aryl group, a substituted amino group, a heterocyclic group, or a substituent represented by the following general formula (3).

（式（３）において、ｍ及びｎは、０乃至３の整数を表す。
Ｚ₁は、アリーレン基又は２価の複素環基を表す。
Ｚ₂は、水素原子、アリール基、置換アミノ基又は複素環基を表す。）））

(In Formula (3), m and n represent the integer of 0 thru | or 3.
Z ₁ represents an arylene group or a divalent heterocyclic group.
Z ₂ represents a hydrogen atom, an aryl group, a substituted amino group or a heterocyclic group. )))

  ADVANTAGE OF THE INVENTION According to this invention, an organic EL element with high characteristics, such as luminous efficiency and color purity, can be provided.

It is a cross-sectional schematic diagram which shows the example of embodiment in the organic EL element of this invention.

  First, the pyrene compound of the present invention will be described. The pyrene compound of the present invention is represented by the following general formula (1).

（式（１）において、Ａ₁及びＡ₂は、それぞれ下記一般式（２）で示される置換基を表す。尚、Ａ₁及びＡ₂は、同じであっても異なっていてもよい。

(In formula (1), A ₁ and A ₂ each represent a substituent represented by the following general formula (2). A ₁ and A ₂ may be the same or different.

（式（２）において、Ｒ₁₁、Ｒ₁₂、Ｒ₁₃及びＲ₁₄は、それぞれアルキル基を表す。Ｒ₁₁、Ｒ₁₂、Ｒ₁₃及びＲ₁₄は、それぞれ同じであっても異なっていてもよい。
Ｒ₁、Ｒ₂、Ｒ₃及びＲ₄は、それぞれアルキル基、アリール基、アラルキル基を表す。ａ、ｂ、ｃ及びｄは、それぞれ０乃至３の整数を表す。ａが２以上の場合、複数のＲ₁は、それぞれ同じであっても異なっていてもよい。ｂが２以上の場合、複数のＲ₂は、それぞれ同じであっても異なっていてもよい。ｃが２以上の場合、複数のＲ₃は、それぞれ同じであっても異なっていてもよい。ｄが２以上の場合、複数のＲ₄は、それぞれ同じであっても異なっていてもよい。
ｌは、１乃至３の整数を表す。
Ｘは、単結合、アリーレン基又は２価の複素環基を表す。
Ｙは、水素原子、アリール基、置換アミノ基、複素環基又は下記一般式（３）で示される置換基を表す。

(In the formula (2), R ₁₁ , R ₁₂ , R ₁₃ and R ₁₄ each represents an alkyl group. R ₁₁ , R ₁₂ , R ₁₃ and R ₁₄ may be the same or different. .
R ₁ , R ₂ , R ₃ and R ₄ each represents an alkyl group, an aryl group or an aralkyl group. a, b, c and d each represents an integer of 0 to 3; When a is 2 or more, the plurality of R ₁ may be the same or different from each other. When b is 2 or more, the plurality of R ₂ may be the same or different. When c is 2 or more, the plurality of R ₃ may be the same or different from each other. When d is 2 or more, the plurality of R ₄ may be the same or different.
l represents an integer of 1 to 3.
X represents a single bond, an arylene group or a divalent heterocyclic group.
Y represents a hydrogen atom, an aryl group, a substituted amino group, a heterocyclic group, or a substituent represented by the following general formula (3).

（式（３）において、ｍ及びｎは、０乃至３の整数を表す。
Ｚ₁は、アリーレン基又は２価の複素環基を表す。
Ｚ₂は、水素原子、アリール基、置換アミノ基又は複素環基を表す。）））

(In Formula (3), m and n represent the integer of 0 thru | or 3.
Z ₁ represents an arylene group or a divalent heterocyclic group.
Z ₂ represents a hydrogen atom, an aryl group, a substituted amino group or a heterocyclic group. )))

  Hereinafter, the substituent represented by the following general formula (2) will be described.

As the alkyl group represented by R ₁₁ , R ₁₂ , R ₁₃ and R ₁₄ in the formula (2), methyl group, ethyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, hexyl Group, octyl group, decyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, octadecyl group, cyclopentyl group, cyclohexyl group and the like.

As the alkyl group represented by R ₁ , R ₂ , R ₃ and R ₄ in the formula (2), methyl group, ethyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, hexyl Group, octyl group, decyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, octadecyl group, cyclopentyl group, cyclohexyl group and the like.

Examples of the aryl group represented by R ₁ , R ₂ , R ₃ and R ₄ in the formula (2) include a phenyl group, a tolyl group, a biphenyl group, a naphthyl group, an anthryl group, and a fluorenyl group.

Examples of the aralkyl group represented by R ₁ , R ₂ , R ₃ and R ₄ in the formula (2) include a benzyl group, a phenethyl group, a phenylpropyl group, a naphthylmethyl group, and a naphthylethyl group.

  Examples of the arylene group represented by X in the formula (2) include divalent substituents derived from a benzene skeleton, a biphenyl skeleton, a naphthalene skeleton, a fluorene skeleton, an anthracene skeleton, a skeleton shown below, and the like.

  Examples of the divalent heterocyclic group represented by X in the formula (2) include divalent substituents derived from a thiophene skeleton, a furan skeleton, a pyridine skeleton, a thiazole skeleton, a quinoline skeleton, a carbazole skeleton, and the like.

  Examples of the aryl group represented by Y in the formula (2) include a phenyl group, a tolyl group, a biphenyl group, a naphthyl group, an anthryl group, and a fluorenyl group.

  Examples of the substituted amino group represented by Y in the formula (2) include dimethylamino group, diethylamino group, diphenylamino group, di- (tert-butyl) -phenylamino group, naphthylphenylamino group, fluorenylphenylamino group and the like. Is mentioned.

  Examples of the heterocyclic group represented by Y in the formula (2) include a thienyl group, a furyl group, a pyridyl group, a thiazolyl group, a quinolyl group, and a carbazolyl group.

  Next, the substituent represented by the formula (3) represented by Y in the formula (2) will be described.

Examples of the arylene group represented by Z ₁ in Formula (3) include divalent substituents derived from a benzene skeleton, a biphenyl skeleton, a naphthalene skeleton, a fluorene skeleton, an anthracene skeleton, and the like.

Examples of the divalent heterocyclic group represented by Z ₁ in Formula (3) include divalent substituents derived from a thiophene skeleton, a furan skeleton, a pyridine skeleton, a thiazole skeleton, a quinoline skeleton, a carbazole skeleton, and the like.

Examples of the aryl group represented by Z ₂ in the formula (3) include a phenyl group, a tolyl group, a biphenyl group, a naphthyl group, an anthryl group, and a fluorenyl group.

Examples of the substituted amino group represented by Z ₂ in formula (3) include a dimethylamino group, a diethylamino group, a diphenylamino group, a naphthylphenylamino group, and a fluorenylphenylamino group.

Examples of the heterocyclic group represented by Z ₂ in the formula (3) include a thienyl group, a furyl group, a pyridyl group, a thiazolyl group, a quinolyl group, and a carbazolyl group.

  The pyrene compound of the present invention can be synthesized by utilizing a well-known cross coupling method. Specifically, it can synthesize | combine using a Suzuki coupling, Stille coupling, Negishi coupling, Tamao coupling, etc. From the viewpoint of the toxicity of the reagent to be used, preferably, Suzuki coupling is used. In the case of Suzuki coupling, a compound having a boronic acid group or a boronic acid ester group is reacted with a compound having a halogen atom or a pseudohalogen compound in the presence of a palladium catalyst to obtain a pyrene compound as a target compound. be able to.

  The pyrene compound of the present invention has a substituent having a partial skeleton in which two to four fluorene skeletons are connected in series to each other at the 2nd and 7th positions of the pyrene ring, specifically, in the formula (2) It is a compound containing the indicated substituent.

  Here, the 2-position and 7-position of the pyrene ring are electronically unique sites in the pyrene ring, and even if the substituent represented by the formula (2) is introduced at this position, the emission wavelength of the compound itself is large. Since it does not increase the wavelength, it is suitable as a light emitting material having a short emission wavelength such as blue or green. Further, by introducing the substituent represented by the formula (2), the luminous efficiency and color purity of the device are improved.

  Specific examples of the pyrene compound of the present invention are listed below. However, the pyrene compound shown below is only a specific example, and the present invention is not limited thereto.

  Next, the organic EL element of the present invention will be described in detail.

  The organic EL device of the present invention includes an anode, a cathode, and an organic compound layer that is sandwiched between the anode and the cathode and includes at least a light emitting layer.

  Hereinafter, the organic EL device of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic cross-sectional view showing an example of an embodiment of the organic EL element of the present invention.

  In the organic EL element 11 shown in FIG. 1A, an anode 2, a hole transport layer 3, a light emitting layer 4, an electron transport layer 5 and a cathode 6 are laminated on a substrate 1 in this order. Note that the organic EL element 11 shown in FIG. 1A is sealed and protected by a protective member 7.

  The organic EL element 12 shown in FIG. 1B is different from the organic EL element 11 in FIG. 1A in that a hole injection layer 8 is provided between the anode 2 and the hole transport layer 3, an electron transport layer 5 and a cathode 6. The electron injection layer 9 is inserted between the two.

  However, the mode shown in FIG. 1 is only a part of the embodiment of the present invention, and the present invention is not limited to this. For example, a part of the charge transport layer (hole transport layer 3, electron transport layer 5) / charge injection layer (hole injection layer 8, electron injection layer 9) illustrated in FIG. 1 may be omitted. Further, the charge transport layer and the charge injection layer may be omitted, and the organic compound layer may be only the light emitting layer 4. That is, as the configuration of the organic compound layer, it is sufficient that the light emitting layer 4 is included, and whether or not the other layers are included is arbitrary.

  In the organic EL device of the present invention, the light emitting layer 4 contains the pyrene compound of the present invention. In the organic EL device of the present invention, the light emitting layer 4 may be composed of only the pyrene compound of the present invention, but may be composed of a host and a guest. In the case where the light emitting layer 4 is composed of a host and a guest, the pyrene compound of the present invention may be a host or a guest, but is preferably a host.

  As the substrate 1 used in the organic EL element of the present invention, a generally used material such as a glass substrate, a quartz substrate, a plastic substrate, a stainless steel substrate, or the like is used.

  As a constituent material of the anode 2, a material having a large work function is preferably used. Specifically, commonly used conductive materials such as metal oxides such as indium tin oxide (ITO), zinc indium oxide, zinc oxide and tin oxide, and conductive polymers such as polythiophene, polypyrrole and polyaniline are used. .

  The hole injection layer 8 and the hole transport layer 3 are layers having functions of assisting hole injection into the light emitting layer 4 and transporting holes to a light emitting region such as the light emitting layer 4. For this reason, the hole injection transport material which is a constituent material of the hole injection layer 8 and the hole transport layer 3 is preferably a compound having a large hole mobility and a large ionization energy. Preferable examples of the hole injecting and transporting material include PEDOT / PSS and triarylamine.

  The light emitting layer 4 naturally includes the pyrene compound of the present invention, but it is possible to use a known light emitting material together with the pyrene compound of the present invention.

  The electron transport layer 5 and the electron injection layer 9 are layers having functions of assisting electron injection into the light emitting layer 4 and transporting electrons to a light emitting region such as the light emitting layer 4. For this reason, the electron injecting and transporting material which is a constituent material of the electron injecting layer 9 and the electron transporting layer 5 is preferably a compound having a large electron mobility and a higher electron affinity than the light emitting layer material. Specific examples include tris (8-quinolinol) aluminum, bathophenanthroline and the like.

  As a constituent material of the cathode 6, a metal material having a small work function is preferably used. Specific examples include simple metals such as aluminum and magnesium, metal alloys such as magnesium and silver, and aluminum-lithium fluoride laminates.

  The protective member 7 is provided for the purpose of preventing the produced organic EL element from coming into contact with oxygen or moisture in the atmosphere. Specific examples include metal oxides such as silicon nitride, organic materials such as fluororesin and polyparaxylylene, silicone resins, and the like.

  Each layer which comprises the organic EL element demonstrated so far is formed and laminated | stacked by the method used generally. Specific examples of the method include a vacuum deposition method, a sputtering method, a spin coating method, and a casting method.

  For example, a plurality of organic EL elements of the present invention can be provided (arranged) in a matrix to form a display device such as a display. In the case of constituting a display device, an electronic member such as a TFT is appropriately provided as necessary in addition to the organic EL element of the present invention.

  EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited by these Examples.

[Example 1] Exemplified Compound No. 1 Synthesis of 12 (1) Synthesis of Intermediate Compound X1 Intermediate Compound X1 was synthesized according to the method described in Non-Patent Document 1. Specifically, intermediate compound X1 was synthesized from pyrene according to the following synthesis scheme.

(2) Synthesis of Intermediate Compound X2 Intermediate compound X2 was synthesized according to the method described in Non-Patent Document 2. Specifically, intermediate compound X2 was synthesized according to the following synthesis scheme.

  (3) Exemplified Compound No. Synthesis of 12

After flowing nitrogen into the reaction vessel and replacing the inside of the reaction system with nitrogen, the following reagents and solvents were charged into the reaction vessel.
Toluene: 60 mL
Ethanol: 30mL
10% by weight aqueous sodium carbonate solution: 30 mL
Tetrakis (triphenylphosphine) palladium: 34.9 mg
Intermediate compound X1: 450.2 mg
Intermediate compound X2: 1.38 g

  Next, in order to remove oxygen remaining in the reaction system, bubbling with argon gas was performed for several minutes. Next, the reaction container was heated with a temperature-controlled heating medium, and stirred for 15 hours while refluxing the reaction solution. Next, after cooling the reaction solution to room temperature, solvent extraction was performed to recover the organic layer. Next, the collected organic layer was dried with anhydrous magnesium sulfate. Next, this organic layer was filtered to remove the desiccant, and then the solvent was distilled off under reduced pressure to obtain a crude product. Next, this crude product was purified by column chromatography, whereby Exemplified Compound No. 0.68 g of 12 was obtained.

Example 2 Production of Organic EL Element The organic EL element shown in FIG. 1A was produced by the following method.

  First, a glass substrate (substrate 1) on which ITO (anode 2) was formed was subjected to UV-ozone cleaning. Next, PEDOT / PSS (manufactured by HC Stark) was spin-coated so as to have a film thickness of 32 nm, and then baked on a hot plate to form the hole transport layer 3. Next, Exemplified Compound No. 12 and toluene were mixed to prepare a 1 wt% toluene solution. Next, after spin-coating this toluene solution on the hole transport layer 3, the light emitting layer 4 was formed by baking with a hotplate. At this time, the film thickness of the light emitting layer 4 was 36 nm. Next, the substrate formed up to the light emitting layer 4 was transferred to a vacuum chamber. Next, a compound A shown below was formed on the light emitting layer 4 by vacuum deposition to form an electron transport layer 5. At this time, the thickness of the electron transport layer 5 was set to 20 nm. Next, lithium fluoride was deposited on the electron transport layer 5 by a vacuum deposition method to form a LiF film. At this time, the thickness of the LiF film was set to 0.5 nm. Next, an aluminum film was formed on the LiF film by vacuum deposition to form an Al film. At this time, the thickness of the Al film was set to 85 nm. The LiF film and the Al film described above function as the cathode 6. Finally, an organic EL element was obtained by sealing with the protective member 7. EL emission was observed for the obtained organic EL element. At this time, the color purity was (0.16, 0.08) in terms of CIE coordinates.

[Example 3]
In Example 2, when the toluene solution was prepared, the solute was converted to Exemplified Compound No. An organic EL device was produced in the same manner as in Example 2 except that the mixture was 12 and the compound B represented by the following formula (weight ratio; Exemplified Compound No. 12: Compound B = 80: 20). did. The characteristics of the obtained organic EL device were evaluated. As a result, blue light emission with an emission luminance of 920 cd / m ² and an emission efficiency of 2.1 cd / A was obtained at 43 mA / cm ² .

  As described above in detail, the pyrene compound of the present invention is useful as a constituent material of an organic EL device. An organic EL device using the pyrene compound of the present invention as a constituent material is excellent in characteristics such as luminous efficiency and color purity. For this reason, the organic EL element of the present invention is useful as a constituent member of a display.

  1: substrate, 2: anode, 3: hole transport layer, 4: light emitting layer, 5: electron transport layer, 6: cathode, 7: protective member, 8: hole injection layer, 9: electron injection layer, 11 (12) : Organic EL device

Claims (3)

A pyrene compound represented by the following general formula (1):

(In formula (1), A ₁ and A ₂ each represent a substituent represented by the following general formula (2). A ₁ and A ₂ may be the same or different.

(In the formula (2), R ₁₁ , R ₁₂ , R ₁₃ and R ₁₄ each represents an alkyl group. R ₁₁ , R ₁₂ , R ₁₃ and R ₁₄ may be the same or different. .
R ₁ , R ₂ , R ₃ and R ₄ each represents an alkyl group, an aryl group or an aralkyl group. a, b, c and d each represents an integer of 0 to 3; When a is 2 or more, the plurality of R ₁ may be the same or different from each other. When b is 2 or more, the plurality of R ₂ may be the same or different. When c is 2 or more, the plurality of R ₃ may be the same or different from each other. When d is 2 or more, the plurality of R ₄ may be the same or different.
l represents an integer of 1 to 3.
X represents a single bond, an arylene group or a divalent heterocyclic group.
Y represents a hydrogen atom, an aryl group, a substituted amino group, a heterocyclic group, or a substituent represented by the following general formula (3).

(In Formula (3), m and n represent the integer of 0 thru | or 3.
Z ₁ represents an arylene group or a divalent heterocyclic group.
Z ₂ represents a hydrogen atom, an aryl group, a substituted amino group or a heterocyclic group. ))) An anode and a cathode;
An organic compound layer sandwiched between the anode and the cathode and including at least a light emitting layer,
An organic EL device comprising the light emitting layer containing the pyrene compound according to claim 1.   A display device comprising a plurality of the organic EL elements according to claim 2.

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