JP2012176929A - NEW PHENANTHRO[9,10-d]IMIDAZOLE DERIVATIVE, LIGHT-EMITTING MATERIAL AND ORGANIC ELECTROLUMINESCENT ELEMENT - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a new phenanthro[9,10-d]imidazole derivative, a light-emitting material comprising the derivative, and an organic EL element using the light-emitting material.SOLUTION: The phenanthro[9,10-d]imidazole derivative is expressed by general formula (1). In the formula, Rto Reach independently represents a group selected from hydrogen and a 1-4C alkyl group, alkoxy group, alkylamino group and alkylaminomethyl group; A represents a group independently selected from the group consisting of a 5-60C aromatic group or a heterocyclic group; B represents a group independently selected from the group consisting of hydrogen and a 5-20C aromatic group or a heterocyclic group; and Z represents a group independently selected from the group consisting of a 3-20C aromatic group or a heterocyclic group.

Description

  The present invention relates to a novel phenanthro [9,10-d] imidazole derivative, a light emitting material comprising the derivative, and an organic electroluminescence device using the derivative.

  With the development of mobile phones, PDAs, and in-vehicle information terminals that support the IT society today, the small and medium display devices used for these have become diversified. In general, a liquid crystal display (LCD) is adopted as a display used for these. In the past, there have been problems with LCDs that are very difficult to reduce in weight and thickness due to the problem of viewing angle dependency and the need for a backlight. However, for these reasons, the light extraction technology has improved due to technological advances such as light distribution films and polarizing plates, and the backlight has changed from a cold cathode tube to a light-weight and small white light-emitting diode (LED). The problem about is almost solved. However, since the LCD is a light receiving / emitting type from the backlight, the configuration of the display for extracting light is complicated.

One display that is often compared to this LCD is an organic electroluminescent display (OLED).
The OLED is a self-luminous display, like a plasma display (PDP), and does not require a backlight like an LCD because of its configuration. Therefore, the structure of the display is simple, it can be made thinner and lighter, and it is suitable as a display means for carrying. In some mobile phones, portable game machines and music players, OLEDs are replacing LCDs.

また緑色蛍光材料では、コダックのＴａｎｇらが最初にＯＬＥＤで使用した下記式で示されるトリス（８−ヒドロキシキノリノラト）アルミニウム（Ａｌｑ_３）がよく用いられている（非特許文献２）。

また赤色蛍光材料については、レーザー色素としても良く用いられている下記式で示す４−（ジシアノメチレン）−２−ｔ−ブチル−６−（１，１，７，７−テトラメチルジュロリジル−９−エテニル）−４Ｈ−ピラン（ＤＣＪＴＢ）などのピラン化合物がよく用いられている（非特許文献３）。

In recent displays, full-color technology has advanced and high definition has been achieved. Even in OLED, in order to take out the three primary colors (blue, green, red) of light, fluorescent materials suitable for this are used. For example, in a blue fluorescent material, 4,4′-bis [2,2-bis (4-methylphenyl) ethenyl] -1,1′-biphenyl represented by the following formula as shown in Non-Patent Document 1 of Enomoto et al. (DTVBi) is well known.

In the green fluorescent material, tris (8-hydroxyquinolinolato) aluminum (Alq ₃ ) represented by the following formula first used by Kodak Tang et al. In the OLED is often used (Non-patent Document 2).

As for the red fluorescent material, 4- (dicyanomethylene) -2-t-butyl-6- (1,1,7,7-tetramethyljulolidyl-) represented by the following formula, which is often used as a laser dye, is used. A pyran compound such as 9-ethenyl) -4H-pyran (DCJTB) is often used (Non-patent Document 3).

Regarding light emission from the OLED, these light emitting materials hold an important key, and materials with good color purity are required. As for luminescent materials, there are high expectations from display manufacturers, and it is important to develop materials with higher efficiency and longer life than today.
Recently, since these three lights are superposed to obtain white light emission, the application technology of organic white illumination has advanced.

H. Tokairin, M .; Matsuura, H .; Higashi, C.I. Hosokawa and T.K. Kusumoto, SPIE processings, 1910, 38 (1993) C. W. Tang and S.M. A. VanSlyke, Appl. Phys. Lett. , 51, 913 (1987) C. H. Chen, C.I. W. Tang, J .; Shi and P.M. Klubek, Macromolecular Symposia (1997), 49-58, 125 (1998)

  The present invention relates to a blue light-emitting material having high color purity and high efficiency, a novel phenanthro [9,10-d] imidazole derivative that can be used for organic electroluminescence display and organic white illumination, a light-emitting material comprising the derivative, and the derivative An object of the present invention is to provide an organic electroluminescence device using the above-mentioned.

（式中、Ｒ^１〜Ｒ^４は水素及び炭素数１〜４のアルキル基、アルコキシ基、アルキルアミノ基、シアノ基からそれぞれ独立して選ばれた基であり、Ａは炭素数５〜６０の芳香族基あるいは複素環基からなる群、Ｂは水素及び炭素数５〜２０の芳香族基あるいは複素環基からなる群、Ｚは炭素数３〜２０の芳香族基あるいは複素環基からなる群からそれぞれ独立して選ばれた基である。）
２） 下記一般式（２）で示されることを特徴とするフェナンスロ［９，１０−ｄ］イミダゾール誘導体。

（式中、Ｒ^１〜Ｒ^４は水素及び炭素数１〜４のアルキル基、アルコキシ基、アルキルアミノ基、フッ素、シアノ基からそれぞれ独立して選ばれた基であり、Ａは炭素数５〜６０の芳香族基あるいは複素環基からなる群、Ｂは水素及び炭素数５〜２０の芳香族基あるいは複素環基からなる群、Ｚは炭素数３〜２０の芳香族基あるいは複素環基からなる群からそれぞれ独立して選ばれた基である。）
３） １）又は２）記載のイミダゾール誘導体からなる発光材料。
４） １）又は２）記載のイミダゾール誘導体を用いた有機エレクトロルミネッセンス素子。 The above problems are solved by the following inventions 1) to 4).
1) A phenanthro [9,10-d] imidazole derivative represented by the following general formula (1).

(In the formula, R ^{1 to} R ⁴ are groups independently selected from hydrogen and an alkyl group having 1 to 4 carbon atoms, an alkoxy group, an alkylamino group, and a cyano group, and A is a group having 5 to 60 carbon atoms. A group consisting of an aromatic group or a heterocyclic group, B is a group consisting of hydrogen and an aromatic group or a heterocyclic group having 5 to 20 carbon atoms, and Z is a group consisting of an aromatic group or a heterocyclic group having 3 to 20 carbon atoms. Group independently selected from each other.)
2) A phenanthro [9,10-d] imidazole derivative represented by the following general formula (2).

(In the formula, R ^{1 to} R ⁴ are groups independently selected from hydrogen and an alkyl group having 1 to 4 carbon atoms, an alkoxy group, an alkylamino group, fluorine, and a cyano group, and A is a group having 5 to 5 carbon atoms. A group consisting of 60 aromatic groups or heterocyclic groups, B is a group consisting of hydrogen and C5-C20 aromatic groups or heterocyclic groups, and Z is a C3-C20 aromatic group or heterocyclic group Group independently selected from the group consisting of
3) A light emitting material comprising the imidazole derivative according to 1) or 2).
4) An organic electroluminescence device using the imidazole derivative described in 1) or 2).

  According to the present invention, it is possible to provide a novel phenanthro [9,10-d] imidazole derivative, a light emitting material comprising the derivative, and an organic electroluminescence element (organic EL element) using the imidazole derivative. Further, since the imidazole derivative of the present invention is a blue light emitting material with high color purity, a high-definition organic EL device can be provided by using this. Further, when the imidazole derivative of the present invention is applied to white light emission technology, white light emission with high color rendering properties can be obtained. Therefore, the imidazole derivative of the present invention is extremely useful industrially.

The measurement result of LC-MS of 2- (naphthyl-2-yl) -1-phenyl-1H-phenanthro [9,10-d] imidazole (Compound No. 1) in Example 1 is shown. The LC-MS measurement result of 2- (binaphthyl-4-yl) -1-phenyl-1H-phenanthro [9,10-d] imidazole (Compound No. 2) in Example 2 is shown. The measurement result of LC-MS of 2-biphenyl-3-yl-1-phenyl-1H-phenanthro [9,10-d] imidazole (Compound No. 3) of Example 3 is shown. LC- of 2- (biphenyl-4-yl) -6,9- (dinaphthalen-2-yl) -1-phenyl-1H-phenanthro [9,10-d] imidazole (Compound No. 4) of Example 4 The measurement result of MS is shown. The measurement result of LC-MS of 2- (biphenyl-4-yl) -1- (4-phenylphenoxy) -1H-phenanthro [9,10-d] imidazole (Compound No. 5) in Example 5 is shown. The LC-MS measurement result of 2- [1,1 ′, 4 ′, 1 ″] terphenyl-4-yl-1H-phenanthro [9,10-d] imidazole (Compound No. 6) in Example 6 is shown. . The LC-MS measurement result of 2- [1,1 ′, 3 ′, 1 ″] terphenyl-5′-yl-1H-phenanthro [9,10-d] imidazole (Compound No. 7) in Example 7 is shown. Show. The measurement result of LC-MS of [4- (1-phenyl-1H-phenanthro [9,10-d] imidazol-2-yl) phenyl] diphenylamine (Compound No. 8) in Example 8 is shown. [5- (1-Phenyl-1H-phenanthro [9,10-d] imidazol-2-yl) -N, N, N ′, N′-tetraphenylbenzene] -1,3-diamine of Example 9 The measurement result of LC-MS of compound number 9) is shown. The measurement result of LC-MS of [4- (1-phenyl-1H-phenanthro [9,10-d] imidazol-2-yl) biphenyl-2-yl] diphenylamine (Compound No. 10) in Example 10 is shown. The measurement result of LC-MS of 2- [4- (carbazol-9-yl)]-1-phenyl-1H-phenanthro [9,10-d] imidazole (Compound No. 11) in Example 11 is shown. The measurement result of LC-MS of 2- [9-ethyl-9H-carbazol-3-yl] -1-phenyl-1H-phenanthro [9,10-d] imidazole (Compound No. 12) of Example 12 is shown. The measurement result of LC-MS of 1-phenyl-2- (4-stilphenyl) -1H-phenanthro [9,10-d] imidazole (Compound No. 13) of Example 13 is shown. LC-MS of 1-phenyl-2- (4-stilphenyl) -6,9- (dinaphthalen-2-yl) -1H-phenanthro [9,10-d] imidazole (Compound No. 14) of Example 14 The measurement results are shown. The LC-MS measurement result of 2- (4-anthracen-4-yl) phenyl-1-phenyl-1H-phenanthro [9,10-d] imidazole (Compound No. 15) in Example 15 is shown. The measurement result of LC-MS of 2- [4- (10-phenylanthracen-9-yl) phenyl] -1-phenyl-1H-phenanthro [9,10-d] imidazole (Compound No. 16) in Example 16 is shown. Show. The measurement result of LC-MS of 2- (4-pyrene-4-yl) phenyl-1-phenyl-1H-phenanthro [9,10-d] imidazole (Compound No. 17) in Example 17 is shown. The LC-MS measurement result of 2- (5-phenylthiophen-2-yl) -1-phenyl-1H-phenanthro [9,10-d] imidazole (Compound No. 18) in Example 18 is shown. The measurement result of LC-MS of 2- (5-diphenyl-4-yl-thiophen-2-yl) -1-phenyl-1H-phenanthro [9,10-d] imidazole (Compound No. 19) in Example 19 is shown. Show. The measurement result of LC-MS of 2- (5-naphthalen-2-yl-thiophen-2-yl) -1-phenyl-1H-phenanthro [9,10-d] imidazole (Compound No. 20) in Example 20 is shown. Show. LC-MS of 2- [5- (carbazol-9-yl-phenyl) -thiophen-2-yl] -1-phenyl-1H-phenanthro [9,10-d] imidazole (Compound No. 21) of Example 21 The measurement results are shown. LC-MS of 2-biphenyl-4-yl-5,10-di (naphthalen-2-yl) -1-phenyl-1H-phenanthro [9,10-d] imidazole (Compound No. 22) of Example 22 The measurement results are shown. The LC-MS measurement result of 2,5,10-tri (naphthalen-2-yl) -1-phenyl-1H-phenanthro [9,10-d] imidazole (Compound No. 23) in Example 23 is shown. The graph which shows the relationship between the current density-voltage of Example 24 and Comparative Example 2. The graph which shows the luminance-voltage relationship of Example 24 and Comparative Example 2. The graph which shows the relationship between the power efficiency of Example 24 and Comparative Example 2-current density. The graph which shows the relationship between the current efficiency of Example 24 and Comparative Example 2-current density. The graph which shows the relationship of the brightness | luminance-current density of Example 24 and Comparative Example 2. FIG. The graph which shows the external quantum efficiency-current density relationship of Example 24 and Comparative Example 2. The graph which shows the current density-voltage relationship of Example 25 and Comparative Example 2. The graph which shows the luminance-voltage relationship of Example 25 and Comparative Example 2. The graph which shows the relationship between the power efficiency of Example 25 and the comparative example 2-current density. The graph which shows the relationship between the current efficiency of Example 25 and the comparative example 2-current density. The graph which shows the relationship of the brightness | luminance-current density of Example 25 and Comparative Example 2. FIG. The graph which shows the external quantum efficiency-current density relationship of Example 25 and Comparative Example 2. The graph which shows the relationship between the current density-voltage of Example 26 and Comparative Example 2. The graph which shows the luminance-voltage relationship of Example 26 and Comparative Example 2. The graph which shows the relationship between the power efficiency of Example 26 and Comparative Example 2-current density. The graph which shows the relationship between the current efficiency of Example 26 and Comparative Example 2-current density. The graph which shows the relationship of the brightness | luminance-current density of Example 26 and Comparative Example 2. FIG. The graph which shows the external quantum efficiency-current density relationship of Example 26 and Comparative Example 2. The graph which shows the current density-voltage relationship of Example 27 and Comparative Example 2. The graph which shows the luminance-voltage relationship of Example 27 and Comparative Example 2. The graph which shows the relationship of the power efficiency-current density of Example 27 and Comparative Example 2. The graph which shows the relationship between the current efficiency of Example 27 and Comparative Example 2-current density. The graph which shows the relationship of the brightness | luminance-current density of Example 27 and Comparative Example 2. FIG. The graph which shows the external quantum efficiency-current density relationship of Example 27 and Comparative Example 2. Sectional drawing which shows an example of the organic EL element of this invention. Sectional drawing which shows an example of the organic EL element of this invention. Sectional drawing which shows an example of the organic EL element of this invention. Sectional drawing which shows an example of the organic EL element of this invention. Sectional drawing which shows an example of the organic EL element of this invention. Sectional drawing which shows an example of the organic EL element of this invention. Sectional drawing which shows an example of the organic EL element of this invention. Sectional drawing which shows an example of the organic EL element of this invention.

Hereinafter, the present invention will be described in detail.
Examples of the alkyl group of R ^{1 to} R ⁴ in the phenanthro [9,10-d] imidazole derivative of the present invention (hereinafter sometimes abbreviated as imidazole derivative α) include a methyl group, an ethyl group, an n-propyl group, an iso group. -Propyl group, n-butyl group, sec-butyl group, iso-butyl group, tert-butyl group and the like.
Similarly, the group consisting of an aromatic group having 5 to 60 carbon atoms or a heterocyclic group of A in the imidazole derivative α includes groups such as the following A-1 to A-106. Examples of R in the group include hydrogen, methyl group, ethyl group, n-propyl group, iso-propyl group, n-butyl group, sec-butyl group, iso-butyl group, and tert-butyl group.

  Similarly, examples of the group consisting of an aromatic group or heterocyclic group having 5 to 20 carbon atoms of B in the imidazole derivative α include groups such as the following B-1 to B-25. Examples of R in the group include hydrogen, methyl group, ethyl group, n-propyl group, iso-propyl group, n-butyl group, sec-butyl group, iso-butyl group, and tert-butyl group.

  Similarly, examples of the group consisting of the aromatic group or heterocyclic group having 3 to 20 carbon atoms of Z in the imidazole derivative α include groups such as the following Z-1 to Z-7. Examples of R in the group include hydrogen, methyl group, ethyl group, n-propyl group, iso-propyl group, n-butyl group, sec-butyl group, iso-butyl group, and tert-butyl group.

（式中、Ｒ^１〜Ｒ^４は水素及び炭素数１〜４のアルキル基、アルコキシ基、アルキルアミノ基、シアノ基からそれぞれ独立して選ばれた基であり、Ａは炭素数５〜６０の芳香族基あるいは複素環基からなる群、Ｂは水素及び炭素数５〜２０の芳香族基あるいは複素環基からなる群、Ｚは炭素数３〜２０の芳香族基あるいは複素環基からなる群からそれぞれ独立して選ばれた基である。）
＜一般式（２）について＞

（式中、Ｒ^１〜Ｒ^４は水素及び炭素数１〜４のアルキル基、アルコキシ基、アルキルアミノ基、シアノ基からそれぞれ独立して選ばれた基であり、Ａは炭素数５〜６０の芳香族基あるいは複素環基からなる群、Ｂは水素及び炭素数５〜２０の芳香族基あるいは複素環基からなる群、Ｚは炭素数３〜２０の芳香族基あるいは複素環基からなる群からそれぞれ独立して選ばれた基である。） The imidazole derivative α of the present invention can be produced, for example, by the following reaction, but is not limited thereto.
<About General Formula (1)>

(In the formula, R ^{1 to} R ⁴ are groups independently selected from hydrogen and an alkyl group having 1 to 4 carbon atoms, an alkoxy group, an alkylamino group, and a cyano group, and A is a group having 5 to 60 carbon atoms. A group consisting of an aromatic group or a heterocyclic group, B is a group consisting of hydrogen and an aromatic group or a heterocyclic group having 5 to 20 carbon atoms, and Z is a group consisting of an aromatic group or a heterocyclic group having 3 to 20 carbon atoms. Group independently selected from each other.)
<About General Formula (2)>

(In the formula, R ^{1 to} R ⁴ are groups independently selected from hydrogen and an alkyl group having 1 to 4 carbon atoms, an alkoxy group, an alkylamino group, and a cyano group, and A is a group having 5 to 60 carbon atoms. A group consisting of an aromatic group or a heterocyclic group, B is a group consisting of hydrogen and an aromatic group or a heterocyclic group having 5 to 20 carbon atoms, and Z is a group consisting of an aromatic group or a heterocyclic group having 3 to 20 carbon atoms. Group independently selected from each other.)

The above reaction is a ring-closing reaction from 9,10-phenanthrenequinone to a phenanthro [9,10-d] imidazole derivative.
The solvent used in the reaction is not particularly limited as long as it is an organic acid, but acetic acid, propionic acid, and butyric acid are preferable, and acetic acid is more preferable. The ammonium salt used in the reaction is not particularly limited, but ammonium acetate, ammonium propionate, ammonium butyrate, ammonium carbonate, and ammonium chloride are preferable, and ammonium acetate is more preferable.

Next, specific examples of the imidazole derivative α of the present invention represented by the general formula (1) are shown. In Tables 1 to 8, for example, “1 (H)” in the A (R) column indicates that the substituent A is A-1 and R is H (hydrogen), and “2 (CH ₃ ) "indicates that the substituent a is a-2, R is is CH _3. The same applies to the B (R) column and the Z (R) column.

Next, specific examples of the imidazole derivative α of the present invention represented by the general formula (2) will be shown. In Tables 9 to 16, the meanings of the symbols in the A (R) column, B (R) column, and Z (R) column are the same as those in Tables 1 to 8.

The imidazole derivative α of the present invention has blue light emission with high color purity. Therefore, it can be used as a light emitting material. In use, it is desirable to form a layer by vapor deposition.
Moreover, an organic EL element can be produced using the imidazole derivative α of the present invention. In that case, it can be used as a light emitting material of the light emitting layer. Further, it may be used in combination with an appropriate host material.

Next, the organic EL element of the present invention will be described.
The organic EL device of the present invention is a device in which a plurality of organic compounds are laminated between an anode and a cathode, and contains the imidazole derivative α of the present invention as a light emitting material of the light emitting layer. The light emitting layer is composed of a light emitting material and a host material. Examples of the configuration of the multilayer organic EL device include, for example, anode / hole transport layer / light emitting layer / electron transport layer / cathode, anode / hole transport layer / light emitting layer / electron transport layer / electron injection layer / cathode, anode / hole. Transport layer / light emitting layer / hole block layer / electron transport layer / cathode, anode / hole transport layer / light emitting layer / hole block layer / electron transport layer / electron injection layer / cathode, anode / hole injection layer (hole injection layer) And a multilayer structure such as / hole transport layer / light emitting layer / hole block layer / electron transport layer / electron injection layer / cathode. Moreover, you may have a sealing layer on a cathode as needed.
Each of the hole transport layer, the electron transport layer, and the light emitting layer preferably has a multilayer structure in which the functions are separated. In addition, the hole transport layer and the electron transport layer can be provided separately with a layer responsible for the injection function (hole injection layer and electron injection layer) and a layer responsible for the transport function (hole transport layer and electron transport layer).

Hereinafter, the constituent elements of the organic EL device of the present invention will be described by taking as an example a configuration comprising an anode / hole transport layer / light emitting layer / electron transport layer / cathode.
The organic EL element of the present invention is preferably supported on a substrate. There is no restriction | limiting in particular about the raw material of a board | substrate, For example, what consists of glass, quartz glass, a transparent plastic etc. which are commonly used for the conventional organic EL element is mentioned.

As an anode of the organic EL device of the present invention, an electrode material may be a single metal having a high work function (4 eV or more), an alloy of metals having a high work function (4 eV or more), a conductive substance, or a mixture thereof. preferable. Specific examples thereof include conductive transparent materials such as metals such as gold, silver, and copper, ITO (indium-tin oxide), tin oxide (SnO ₂ ), and zinc oxide (ZnO), and high conductivity such as polypyrrole and polythiophene. Examples include molecular materials.
The anode can be produced by a method such as vapor deposition, sputtering, or coating using these electrode materials.
The sheet electrical resistance of the anode is preferably several hundred Ω / cm ² or less. The film thickness of the anode is generally about 5 to 1,000 nm, preferably 10 to 500 nm, although it depends on the material.

As the cathode of the organic EL device of the present invention, an electrode material may be a single metal having a low work function (4 eV or less), an alloy of metals having a low work function (4 eV or less), a conductive substance, or a mixture thereof. preferable. Specific examples thereof include lithium, lithium-indium alloy, sodium, sodium-potassium alloy, magnesium, magnesium-silver alloy, magnesium-indium alloy, aluminum, aluminum-lithium alloy, and aluminum-magnesium alloy.
The cathode can be prepared by a method such as vapor deposition or sputtering using these electrode materials.
The sheet electrical resistance of the cathode is preferably several hundred Ω / cm ² or less. The thickness of the cathode is generally about 5 to 1,000 nm, preferably 10 to 500 nm, although it depends on the material.
In order to efficiently extract light emitted from the organic EL device of the present invention, at least one of the anode and the cathode is preferably transparent or translucent.

The hole transport layer of the organic EL device of the present invention is made of a hole transfer compound and has a function of transmitting holes injected from the anode to the light emitting layer. When a hole transfer compound is disposed between two electrodes to which an electric field is applied and holes are injected from the anode, a hole transfer material having a hole mobility of at least 10 ⁻⁶ cm ² / V · sec or more is preferable. As such a hole-transmitting substance, an arbitrary material is selected from materials conventionally used as charge injection materials for holes in photoconductive materials and known materials used for hole transport layers of organic EL devices. Can be used.
Examples of hole transfer materials include phthalocyanine derivatives such as copper phthalocyanine, N, N, N ′, N′-tetraphenyl-1,4-phenylenediamine, N, N′-di (m-tolyl) -N, N Triarylamine derivatives such as' -diphenyl-4,4-diaminophenyl (TPD), N, N'-di (1-naphthyl) -N, N'-diphenyl-4,4-diaminophenyl (α-NPD) , Polyphenylenediamine derivatives, polythiophene derivatives, water-soluble PEDOT-PSS (polyethylenedioxathiophene-polystyrenesulfonic acid), and the like.
The hole transport layer may be a single layer composed of one or two or more of these hole transfer materials, but may be a stack of hole transport layers composed of compounds other than those described above.

Examples of the hole injection material include PEDOT-PSS (polymer mixture) and DNTPD represented by the following formula.

Examples of the hole transport material include TPD, DTASi, α-NPD and the like shown in the following chemical formula.

The electron transport layer of the organic EL device of the present invention is made of an electron transport material and has a function of transmitting electrons injected from the cathode to the light emitting layer. When an electron transport material is arranged between two electrodes to which an electric field is applied and electrons are injected from the cathode, an electron transport material having an electron mobility of at least 10 ⁻⁶ cm ² / V · sec or more is preferable.
As such an electron transport material, an arbitrary material is selected from those conventionally used as an electron charge injection material in a photoconductive material and known materials used in an electron transport layer of an organic EL element. Can be used.
Examples of electron transport materials include quinoline complexes such as tris (8-hydroxyquinolinolato) aluminum complex (Alq ₃ ), 1-N-phenyl-2- (p-biphenylyl) -5- (p-tert -Triazine derivatives such as butylphenyl) -1,3,5-triazine (TAZ), phenanthroline derivatives such as 1,4-di (1,10-phenanthroline-2-yl) benzene (DPB), lithium fluoride And alkali metal halides.
The electron transport layer may be a single layer composed of one or more of these electron transport materials, but may be a stack of electron transport layers composed of compounds other than those described above.

Examples of the electron injecting material include lithium fluoride (LiF), 8-hydroxyquinolinolato lithium complex (Liq) represented by the following formula, phenanthroline derivative lithium complex (LiPB) disclosed in JP 2008-106015, JP Examples thereof include a lithium complex of phenoxypyridine (LiPP) disclosed in 2008-195623.

Examples of the electron transport material include Alq ₃ , TAZ, and DPB represented by the following formula.

The imidazole derivative α of the present invention is used for the light emitting layer of the organic EL device of the present invention. However, conventional color developing materials such as perylene derivatives, naphthacene derivatives, quinacridone derivatives, coumarin derivatives (eg, coumarin 1, coumarin 540, coumarin 545), pyran derivatives (eg, DCM-1, DCM-2, DCJTB, etc.), organometallics Complexes, for example, fluorescent materials such as tris (8-hydroxyquinolinolato) aluminum complex (Alq ₃ ), tris (4-methyl-8-hydroxyquinolinolato) aluminum complex (Almq ₃ ), [2- (4 6-difluorophenyl) pyridyl-N, C2 ′] iridium (III) picolylate (FIrpic), tris {1- [4- (trifluoromethyl) phenyl] -1H-pyrazolate-N, C2 ′} iridium (III) ( Irtfmppz _3), bis [2- (4 ', 6'-difluoro-phenylene ) Pyridinato -N, C2 '] iridium (III) tetrakis (1-pyrazolyl) borate (FIr6), such as phosphorescent material such as tris (2-phenylpyridinato) iridium (III) [Ir _{(ppy) 3]} and It can also be used in combination.

The light emitting layer is formed of a host material and a light emitting material (dopant) [Appl. Phys. Lett. 65 3610 (1989)]. A luminescent material is used in combination with a host material in order to avoid concentration quenching and to efficiently transfer luminescent energy to the luminescent material.
As a host material, a condensed ring compound such as t-butylanthracene (tBA) or perylene (Per) represented by the following formula, 4,4 ′-[di (β, β-diphenylethenyl)]-1,1 It is preferable to use a distyrylarylene compound such as' -biphenyl (DPVBi) or a phenylarylamine compound such as TPD.

  In the organic EL device of the present invention, a hole injection layer composed of an organic conductor may be provided between the anode and the organic compound layer for the purpose of further improving the hole injection property. Examples of the hole injection material include phthalocyanine derivatives such as copper phthalocyanine, polyphenylenediamine derivatives, polythiophene derivatives, and PEDOT-PSS (polyethylenedioxythiophene-polystyrenesulfonic acid) in addition to the imidazole derivative α of the present invention.

The method for forming the hole injection layer and the hole transport layer of the device containing the imidazole derivative α of the present invention is not particularly limited. For example, a dry film formation method (vacuum deposition method, ionization deposition method, etc.), a wet film formation method [solvent coating Method (spin coating method, casting method, ink jet method, etc.) can be used. The film formation of the electron transport layer is limited to dry film formation methods (vacuum vapor deposition method, ionization vapor deposition method, etc.) because the lower layer may be eluted when the wet film formation method is used. For the production of the element, the above film forming method may be used in combination.
When forming each layer such as a hole transport layer, a light emitting layer, and an electron transport layer by a vacuum deposition method, the vacuum deposition conditions are not particularly limited. Usually, under a vacuum of about 10 ⁻⁵ Torr or less, a boat temperature (deposition source temperature) of about 50 to 500 ° C., a substrate temperature of about −50 to 300 ° C., and 0.01 to 50 nm / sec. Vapor deposition is preferred. When forming each layer of a positive hole transport layer, a light emitting layer, and an electron carrying layer using a some compound, it is preferable to co-evaporate the boat which put the compound, respectively controlling temperature.

  When forming the hole injection layer and the hole transport layer by a solvent coating method, the components constituting each layer are dissolved or dispersed in a solvent to obtain a coating solution. Solvents include hydrocarbon solvents (eg, heptane, toluene, xylene, cyclohexane, etc.), ketone solvents (eg, acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.), halogen solvents (eg, dichloromethane, chloroform, chlorobenzene, dichlorobenzene, etc.) Ester solvents (eg, ethyl acetate, butyl acetate, etc.), alcohol solvents (eg, methanol, ethanol, butanol, methyl cellosolve, ethyl cellosolve, etc.), ether solvents (eg, dibutyl ether, tetrahydrofuran, 1,4-dioxane, 1 , 2-dimethoxyethane, etc.), aprotic solvents (eg, N, N′-dimethylacetamide, dimethyl sulfoxide, etc.), water and the like. The solvent may be used alone or a plurality of solvents may be used in combination.

The thickness of each layer such as a hole transport layer, a light emitting layer, and an electron transport layer is not particularly limited, but is usually set to 5 to 5,000 nm.
The organic EL device of the present invention can be protected by providing a protective layer (sealing layer) for the purpose of blocking contact with oxygen, moisture, etc., or by encapsulating the device in an inert substance.
Examples of the inert substance include paraffin, silicon oil, and fluorocarbon. Examples of the material used for the protective layer include fluorine resin, epoxy resin, silicone resin, polyester, polycarbonate, and photocurable resin.

The organic EL device of the present invention can be used as a DC drive device. In the case of applying a DC voltage, light emission is observed when about 1.5 to 20 V is applied with the positive polarity of the anode and the negative polarity of the cathode. The organic EL element of the present invention can also be used as an AC drive element. When an AC voltage is applied, light is emitted when the anode is in a positive state and the cathode is in a negative state.
The organic EL element of the present invention includes, for example, a flat light emitter such as an electrophotographic photosensitive member and a flat panel display, a copying machine, a printer, a backlight of a liquid crystal display, a light source such as an instrument, various light emitting elements, various display devices, various signs, It can be used for various sensors and various accessories.

48 to 51 show cross-sectional views of preferred examples of the organic EL device of the present invention.
FIG. 48 shows an example in which an anode 2, a hole transport layer 5, a light emitting layer 3, an electron transport layer 6 and a cathode 4 are sequentially provided on the substrate 1. This separates the functions of carrier transport and light emission, and the degree of freedom in material selection increases, so that the efficiency of light emission and the degree of freedom in light emission color increase.
FIG. 49 shows an example in which an anode 2, a hole injection layer 7, a hole transport layer 5, a light emitting layer 3, an electron transport layer 6 and a cathode 4 are sequentially provided on the substrate 1. In this case, the provision of the hole injection layer 7 improves the adhesion between the anode 2 and the hole transport layer 5, improves the injection of holes from the anode, and is effective in lowering the voltage of the light emitting element.
FIG. 50 shows an example in which an anode 2, a hole transport layer 5, a light emitting layer 3, an electron transport layer 6, an electron injection layer 8, and a cathode 4 are sequentially provided on the substrate 1. In this case, injection of electrons from the cathode 4 is improved, which is effective for lowering the voltage of the light emitting element.
FIG. 51 shows an example in which an anode 2, a hole injection layer 7, a hole transport layer 5, a light emitting layer 3, an electron transport layer 6, an electron injection layer 8 and a cathode 4 are sequentially provided on the substrate 1. In this case, hole injection is improved from the anode 2 and electron injection is improved from the cathode 4, and the configuration is most effective for low voltage driving.

52 to 55 are sectional views of examples in which the hole block layer 9 is inserted into the element.
The hole blocking layer 9 has an effect of preventing holes injected from the anode or excitons generated by recombination in the light emitting layer 3 from escaping to the cathode 4, and is effective in improving the light emission efficiency of the organic EL element. is there. The hole blocking layer 9 can be inserted between the light emitting layer 3 and the cathode 4, between the light emitting layer 3 and the electron transport layer 6, or between the light emitting layer 3 and the electron injection layer 8. More preferred is between the light emitting layer 3 and the electron transport layer 6.
52 to 55, each of the hole transport layer 5, the hole injection layer 7, the electron transport layer 6, the electron injection layer 8, the light emitting layer 3, and the hole block layer 9 may have a single layer structure or a multilayer structure.
Note that FIGS. 48 to 55 show a basic configuration to the last, and the configuration of the organic EL element of the present invention is not limited to these.

  EXAMPLES Hereinafter, although an Example and a comparative example are shown and this invention is demonstrated further more concretely, this invention is not limited at all by these Examples.

Example 1
Synthesis of 2- (naphthyl-2-yl) -1-phenyl-1H-phenanthro [9,10-d] imidazole (Compound No. 1) 9,10-phenanthrenequinone (10.62 g, 51 mmol), 2- Naphtoaldehyde (8.00 g, 51 mmol), aniline (9.50 g, 102 mmol) and ammonium acetate (9.87 g, 128 mmol) were mixed, and finally 50 mL of acetic acid was added.
The obtained mixture was heated to reflux in an oil bath at 130 ° C. for 2 hours. After the reaction, the mixture was cooled to room temperature, and the precipitated crystals were filtered to obtain 19.30 g of a crude product.
19.17 g of the crude product was dissolved in 200 mL of toluene at 108 ° C. Activated clay was added to the resulting solution, stirred for 30 minutes, filtered hot at 110 ° C., and the temperature was lowered to precipitate crystals. The obtained crystals were dried to obtain 16.76 g of a purified product (yield: 78.2%, Mettler melting point: 230.7 to 231.4 ° C.).
About the said crystal | crystallization, the result of having confirmed the structure with the high performance liquid chromatograph mass spectrometer (henceforth LC-MS) is shown in FIG.

Example 2
Synthesis of 2- (binaphthyl-4-yl) -1-phenyl-1H-phenanthro [9,10-d] imidazole (Compound No. 2) 9,10-phenanthrenequinone (9.37 g, 45 mmol), 4- Phenylbenzaldehyde (8.00 g, 44 mmol), aniline (8.20 g, 88 mmol), and ammonium acetate (8.48 g, 110 mmol) were mixed, and finally 50 mL of acetic acid was added.
The obtained mixture was heated to reflux in an oil bath at 130 ° C. for 2 hours. After the reaction, the mixture was cooled to room temperature, and the precipitated crystals were filtered to obtain 17.73 g of a crude product.
17.59 g of the crude product was dissolved in 200 mL of toluene at 108 ° C. Activated clay was added to the resulting solution, stirred for 30 minutes, filtered hot at 110 ° C., and the temperature was lowered to precipitate crystals. The obtained crystals were dried to obtain 14.81 g of a purified product (yield 75.4%, Mettler melting point 222.2-223.0 ° C.).
The results of confirming the structure of the above crystal by LC-MS are shown in FIG.

Example 3
Synthesis of 2-biphenyl-3-yl-1-phenyl-1H-phenanthro [9,10-d] imidazole (Compound No. 3) 1-phenyl-2- (3-bromophenyl) -1H-phenanthro [9,10 -D] imidazole (MBPM) (9.26 g, 20.0 mmol), phenylboronic acid (2.68 g, 22.0 mmol), potassium carbonate aqueous solution [K ₂ CO ₃ (8.29 g, 60.0 mmol) + water 30 mL ], 200 mL of toluene and 100 mL of ethanol were mixed. After purging with nitrogen for 30 minutes, tetrakis (triphenylphosphine) palladium [Pd (PPh ₃ ) ₄ ] (1.16 g, 1.00 mmol) was added.
The resulting mixture was heated to reflux at 74-75 ° C. for 5 hours under a nitrogen atmosphere. After the reaction, the mixture was cooled to 70 ° C. and separated, and the pH was adjusted by adding 100 mL of water and 35% HCl to the reaction solution (pH 10.31 → 8.21). After liquid separation at 70 ° C., 100 mL of water was added to the solution and stirred at 70 ° C. for 30 minutes. Further, 0.89 g of carbon was added and stirred at 70 ° C. for 30 minutes, followed by hot filtration to recover the solvent to obtain 10.64 g of a concentrated residue.
10.32 g of the concentrated residue was dissolved in a mixed solution of 52 mL of IPA (isopropyl alcohol) and 169 mL of ethyl cellosolve at 110 ° C. Carbon was added to the solution and stirred for 30 minutes, followed by hot filtration, and the temperature was lowered to precipitate crystals. The obtained crystals were suction filtered and dried to obtain 6.49 g of purified product (yield: 72.7%, Mettler melting point: 217.0-218.0 ° C.).
FIG. 3 shows the result of confirming the structure of the above crystal by LC-MS.

Example 4
Synthesis of 2- (biphenyl-4-yl) -6,9- (dinaphthalen-2-yl) -1-phenyl-1H-phenanthro [9,10-d] imidazole (Compound No. 4) (1) 3, Synthesis of 6-dibromo-9,10-phenanthrenequinone A mixture of 9,10-phenanthrenequinone (12.49 g, 60 mmol), iodine (0.61 g, 4 mol%) and nitrobenzene 63 mL was heated to 60 ° C. Then, a bromine nitrobenzene solution [bromine (26.85 g, 168.0 mmol) + nitrobenzene 30 mL] was added dropwise. The mixture was heated and stirred at 58 to 62 ° C. for 1 hour. After the reaction, the mixture was cooled to 25 ° C., and 30 mL of 10% sodium thiosulfate solution was added to the reaction solution. Further, 90 mL of water and 48% sodium hydroxide solution were added to adjust the pH (pH 0.06 → 8.03). The obtained crystal was dried to obtain 19.85 g of a crude product.
19.77 g of the crude product was dissolved in 105 mL of o-dichlorobenzene at 160 ° C. Carbon was added to the solution and stirred for 30 minutes, followed by hot filtration to lower the temperature to precipitate crystals. The obtained crystals were dried to obtain 15.72 g of a purified product (yield: 71.6%, Mettler melting point: 289.8 to 290.8 ° C.).
(2) Synthesis of 2- (biphenyl-4-yl) -6,9-dibromo-1-phenyl-1H-phenanthro [9,10-d] imidazole (BDBPM) The above 3,6-dibromo-9,10- Mixing phenanthrenequinone (10.56 g, 28.0 mmol), 4-phenylbenzaldehyde (5.61 g, 30.8 mmol), aniline (5.22 g, 56.0 mmol), ammonium acetate (5.4 g, 70 mmol) Finally, 280 mL of acetic acid was added.
The obtained mixture was heated to reflux at 116 to 118 ° C. for 3 hours, and the obtained crystals were dried to obtain 16.66 g of a crude product.
16.43 g of the crude product was dissolved in a mixed solution of 82 mL of IPA and 224 mL of DMF at 118 ° C. Carbon was added to the solution and stirred for 30 minutes, followed by hot filtration, and the temperature was lowered to precipitate crystals. The obtained crystals were dried to obtain 12.84 g of a purified product (yield 75.9%, Mettler melting point: not measurable, DSCTm: 304.74 g).
(3) Synthesis of Compound No. 4 BDBPM (7.42 g, 12.0 mmol), naphthalene boronic acid (4.63 g, 26.4 mmol), potassium carbonate aqueous solution [K ₂ CO ₃ (9.95 g, 72.0 mmol) + Water 36 mL], toluene 120 mL, and ethanol 60 mL were mixed. After purging with nitrogen for 30 minutes, Pd (PPh ₃ ) ₄ (1.39 g, 1.20 mmol) was added.
The obtained mixture was heated to reflux at 75 to 76 ° C. for 4 hours under a nitrogen atmosphere, and the obtained crystals were dried to obtain 7.35 g of a crude product.
The crude product (7.13 g) was dissolved in a mixed solution of IPA (21 mL) and DMF (123 mL) at 134 ° C. Carbon was added to the solution and stirred for 30 minutes, followed by hot filtration, and the temperature was lowered to precipitate crystals. The obtained crystals were dried to obtain 4.92 g of a purified product (yield: 58.7%, Mettler melting point: 268.3-269.3 ° C.).
FIG. 4 shows the result of confirming the structure of the above crystal by LC-MS.

Example 5
Synthesis of 2- (biphenyl-4-yl) -1- (4-phenylphenoxy) -1H-phenanthro [9,10-d] imidazole (Compound No. 5) 9,10-phenanthrenequinone (4.20 g, 20 mmol), 4-phenylbenzaldehyde (4.01 g, 22 mmol), 4-aminodiphenyl ether (7.41 g, 40 mmol) and ammonium acetate (3.85 g, 50 mmol) were mixed, and finally 50 mL of acetic acid was added.
The resulting mixture was heated to reflux in an oil bath at 130 ° C. for 3 hours. After the reaction, the mixture was allowed to stand overnight at room temperature, 50 mL of 50% methanol water was added, and the precipitated crude product was suction filtered. Subsequently, the crude product was recrystallized from o-dichlorobenzene to obtain 7.45 g of a purified product (yield 69.2%, Mettler melting point 200.9-201.3 ° C.).
FIG. 5 shows the result of confirming the structure of the crystal by LC-MS.

Example 6
Synthesis of 2- [1,1 ′, 4 ′, 1 ″] terphenyl-4-yl-1H-phenanthro [9,10-d] imidazole (Compound No. 6) 1-phenyl-1H-phenanthro [9,10 -D] imidazole-2- (4-phenylboronic acid) (BPM) (8.99 g, 20.0 mmol), 4-biphenylboronic acid (4.36 g, 22.0 mmol), potassium carbonate aqueous solution [K ₂ CO ₃ (8.29 g, 60.0 mmol) + water 30 mL], toluene 200 mL, and ethanol 100 mL were mixed, and after purging with nitrogen for 30 minutes, Pd (PPh ₃ ) ₄ (1.16 g, 1.00 mmol) was added.
The resulting mixture was heated to reflux at 75-76 ° C. for 5 hours under a nitrogen atmosphere. After the reaction, the reaction solution was cooled to 50 ° C., and the pH was adjusted by adding 100 mL of water and 35% HCl to the reaction solution (pH 11.74 → 8.38). The precipitated crystals were suction filtered and dried to obtain 8.67 g of a crude product.
8.43 g of the crude product was dissolved in a mixed solution of 25 mL IPA and 175 mL chlorobenzene at 100 ° C. Carbon was added to the solution and stirred at 100 ° C. for 30 minutes, followed by hot filtration to lower the temperature to precipitate crystals. The obtained crystals were filtered by suction and dried to obtain 6.49 g of purified product (yield: 67.8%, Mettler melting point: 274.3 to 275.8 ° C.).
FIG. 6 shows the result of confirming the structure of the crystal by LC-MS.

Example 7
Synthesis of 2- [1,1 ′, 3 ′, 1 ″] terphenyl-5′-yl-1H-phenanthro [9,10-d] imidazole (Compound No. 7) 1-phenyl-2- (3,5 -Dibromophenyl) -1H-phenanthro [9,10-d] imidazole (DBPM) (6.98 g, 13.0 mmol), phenylboronic acid (3.49 g, 28.6 mmol), aqueous potassium carbonate solution [K ₂ CO ₃ (10.78 g, 78.0 mmol) + water 39 mL], toluene 130 mL, and ethanol 65 mL were mixed in. After purging with nitrogen for 30 minutes, Pd (PPh ₃ ) ₄ (1.50 g, 1.30 mmol) was added.
The resulting mixture was heated to reflux at 75-76 ° C. for 5 hours under a nitrogen atmosphere. After the reaction, the reaction solution was cooled to 70 ° C. and separated, and 50 mL of water and 35% HCl were added to the reaction solution to adjust the pH (pH 10.09 → 8.11). After liquid separation at 70 ° C., 50 mL of water was added to the solution and stirred at 70 ° C. for 30 minutes. Further, carbon was added and stirred for 30 minutes, followed by hot filtration to recover the solvent to obtain 8.43 g of a concentrated residue.
The concentrated residue (8.27 g) was dissolved in a mixed solution of IPA (41 mL) and chlorobenzene (36 mL) at 87 ° C., and the temperature was lowered to precipitate crystals. The obtained crystals were suction filtered and dried to obtain 4.96 g of a purified product (yield: 73.0%, Mettler melting point: 237.9 to 238.7 ° C.).
FIG. 7 shows the result of confirming the structure of the crystal by LC-MS.

Example 8
Synthesis of [4- (1-phenyl-1H-phenanthro [9,10-d] imidazol-2-yl) phenyl] diphenylamine (Compound No. 8) 9,10-phenanthrenequinone (3.89 g, 18.7 mmol) ), 4- (N, N-diphenylamino) benzaldehyde (5.00 g, 18.3 mmol), aniline (3.41 g, 36.6 mmol), ammonium acetate (3.53 g, 45.8 mmol), and finally 50 mL of acetic acid was added.
The obtained mixture was heated to reflux in an oil bath at 230 ° C. for 5 hours. After the reaction, the mixture was cooled to room temperature, and the precipitated crystals were filtered and dried to obtain 8.48 g of a crude product.
8.37 g of the crude product was dissolved in 98 mL of chlorobenzene at 108 ° C. Activated clay was added to the resulting solution, stirred for 30 minutes, filtered hot at 110 ° C., and the temperature was lowered to precipitate crystals. The obtained crystals were dried to obtain 6.25 g of a purified product (yield 63.5%, Mettler melting point: 281.1 to 281.9 ° C.).
FIG. 8 shows the result of confirming the structure of the crystal by LC-MS.

Example 9
[5- (1-Phenyl-1H-phenanthro [9,10-d] imidazol-2-yl) -N, N, N ′, N′-tetraphenylbenzene] -1,3-diamine (Compound No. 9) Synthesis of 1-phenyl-2- (3,5-dibromophenyl) -1H-phenanthro [9,10-d] imidazole (DBPM) (4.85 g, 9.2 mmol), diphenylamine (3.42 g, 20.2 mmol) ), Sodium-t-butoxide (2.65 g, 27.6 mmol), and 25 mL of toluene. After purging with nitrogen for 30 minutes, palladium acetate (0.08 g, 0.37 mmol) and 5 mL of a tri-t-butylphosphine (0.37 g, 1.8 mmol) / toluene solution were added.
The resulting mixture was heated to reflux at 107-110 ° C. for 3 hours under a nitrogen atmosphere. After the reaction, the reaction mixture was cooled to 50 ° C., and 30 mL of water and 35% HCl, 3.23 g were added to adjust the pH (pH 12.8 → 7.8). The obtained crystals were dried to obtain 5.02 g of a crude product.
A mixed solution of 24 mL of IPA and 56 mL of DMF (dimethyl fumarate) was added to 4.84 g of the crude product, and dissolved at 117 ° C. Carbon was added to the solution and stirred for 30 minutes, followed by hot filtration, and the temperature was lowered to precipitate crystals. The obtained crystals were dried to obtain 4.05 g of a purified product (yield 62.5%, Mettler melting point: 255.4 to 256.2 ° C.).
The result of confirming the structure of the above crystal by LC-MS is shown in FIG.

Example 10
Synthesis of [4- (1-phenyl-1H-phenanthro [9,10-d] imidazol-2-yl) biphenyl-2-yl] diphenylamine (Compound No. 10) (1) 1-phenyl-1H-phenanthro [9 , 10-d] imidazozol-2- (4-phenylboronic acid) (BPMB) 2- (4-Bromophenyl) -1-phenyl-1H-phenanthro [9,10-d] imidazole (22.90 g) , 51.0 mmol) was added with 580 mL of THF (tetrahydrofuran), purged with nitrogen, cooled to -70 ° C, and then added with n-BuLi (1.6 M) (43 mL, 68.9 mmol) under a nitrogen atmosphere. After reacting at −70 ° C. for 1.5 hours, trimethyl borate (7.95 g, 76.5 mmol) was added to the reaction solution, reacted for 1 hour, and further reacted at 18 ° C. to 22 ° C. for 3 hours.
The reaction solution was hydrolyzed by adding 70 mL of water and 35% hydrochloric acid (pH 11.49 → 0.44). Subsequently, it was made to react at 23 to 25 degreeC for 14 hours.
Toluene 150mL was added to the reaction liquid, and it liquid-separated at 40 degreeC. The solution was adjusted to pH by adding 50 mL of water and 48% aqueous sodium hydroxide solution (pH 0.90 → 6.96). After liquid separation at 40 ° C., 50 mL of water was added to the solution and stirred at 40 ° C. for 30 minutes. The solvent was collected to obtain 24.07 g of concentrated residue.
A mixed solution of 80 mL of heptane and 160 mL of chlorobenzene was added to the total amount of the obtained concentrated residue, and the mixture was stirred at 114 ° C. for 1 hour, and stirred at 24 ° C. to 28 ° C. for 1 hour. 13.79 g of BPMB) was obtained (yield: 65.3%).
(2) Synthesis of Compound No. 10 BPMB (7.20 g, 16.5 mmol), 4-bromotriphenylamine (4.86 g, 15.0 mmol), potassium carbonate aqueous solution [K ₂ CO ₃ (6.22 g, 45) 0.0 mmol) +23 mL water], 150 mL toluene, and 75 mL ethanol. After purging with nitrogen for 30 minutes, Pd (PPh ₃ ) ₄ (0.87 g, 0.75 mmol) was added.
The resulting mixture was heated to reflux at 75 ° C. for 6 hours under a nitrogen atmosphere. After the reaction, it was cooled to 70 ° C. and separated. The reaction solution was adjusted to pH by adding 50 mL of water and 35% HCl (pH 9.40 → 8.39). Filtration was performed at 50 ° C., 50 mL of water was added to the filtrate, and the mixture was stirred at 70 ° C. for 30 minutes. Further, carbon was added and stirred for 30 minutes, followed by filtration to recover the solvent to obtain 10.51 g of a concentrated residue.
10.40 g of the obtained concentrated residue was dissolved in a mixed solution of 52 mL of IPA and 65 mL of toluene at 83 ° C., and the temperature was lowered to precipitate crystals. The obtained crystals were dried to obtain 4.60 g of a purified product (yield: 50.0%, Mettler melting point: 264.6 to 265.3 ° C.).
FIG. 10 shows the result of confirming the structure of the above crystal by LC-MS.

Example 11
Synthesis of 2- [4- (carbazol-9-yl)]-1-phenyl-1H-phenanthro [9,10-d] imidazole (Compound No. 11) 9,10-phenanthrenequinone (3.21 g, 15 .4 mmol), 4-carbazol-9-yl-benzaldehyde (4.00 g, 14.7 mmol), aniline (2.74 g, 29.4 mmol), ammonium acetate (2.84 g, 36.8 mmol), and finally 30 ml of acetic acid was added.
The resulting mixture was heated to reflux at 117 ° C. for 2 hours. After the reaction, the mixture was cooled to room temperature, and the precipitated crystals were suction filtered and dried to obtain 7.82 g of a crude product.
7.69 g of the crude product was dissolved in 102 mL of chlorobenzene at 132 ° C. Activated clay was added and stirred for 30 minutes, followed by hot filtration, and the temperature was lowered to precipitate crystals. The crystals precipitated on ice were suction filtered and dried to obtain 6.43 g of a purified product (yield 81.7%, Mettler melting point: not measurable, DSCTm 306.5 ° C.).
FIG. 11 shows the result of confirming the structure of the crystal by LC-MS.

Example 12
Synthesis of 2- [9-ethyl-9H-carbazol-3-yl] -1-phenyl-1H-phenanthro [9,10-d] imidazole (Compound No. 12) 9,10-phenanthrenequinone (4.75 g , 22.8 mmol), N-ethylcarbazole-3-carboxaldehyde (5.00 g, 22.4 mmol), aniline (4.17 g, 44.8 mmol), ammonium acetate (4.32 g, 56.0 mmol). Finally, 50 mL of acetic acid was added.
The obtained mixture was heated to reflux in an oil bath at 130 ° C. for 3 hours. After the reaction, the reaction mixture was cooled to room temperature, and the precipitated crystals were filtered and dried to obtain 8.16 g of a crude product.
7.94 g of the crude product was dissolved in 58 mL of chlorobenzene at 130 ° C. Activated clay was added and stirred for 1 hour, followed by hot filtration, and the temperature was lowered to precipitate crystals. The mixture was stirred in an ice bath for 1 hour, and the precipitated crystals were suction filtered and dried to obtain 6.17 g of a purified product (yield 56.5%, Mettler melting point: 285.6 to 286.4 ° C.).
FIG. 12 shows the result of confirming the structure of the crystal by LC-MS.

Example 13
Synthesis of 1-phenyl-2- (4-stilphenyl) -1H-phenanthro [9,10-d] imidazole (Compound No. 13) 9,10-phenanthrenequinone (4.58 g, 22.0 mmol), 4 -Formyl-trans-stilbene (4.17 g, 20.0 mmol), aniline (3.73 g, 40.0 mmol), ammonium acetate (3.85 g, 50.0 mmol) were mixed, and finally 50 mL of acetic acid was added.
The resulting mixture was heated to reflux at 114-116 ° C. for 2 hours. After the reaction, the mixture was cooled to room temperature, and the precipitated crystals were filtered and dried to obtain 9.59 g of a crude product.
9.41 g of the crude product was dissolved in a mixed solution of IPA 48 mL and chlorobenzene 114 mL at 92 ° C. Carbon was added to the solution and stirred for 30 minutes, followed by hot filtration, and the temperature was lowered to precipitate crystals. The obtained crystals were dried to obtain 6.77 g of a purified product (yield 71.6%, Mettler melting point: 246.9 to 248.4 ° C.).
FIG. 13 shows the result of confirming the structure of the crystal by LC-MS.

Example 14
Synthesis of 1-phenyl-2- (4-stilphenyl) -6,9- (dinaphthalen-2-yl) -1H-phenanthro [9,10-d] imidazole (Compound No. 14) (4-Stylphenyl) -6,9-dibromo-1H-phenanthro [9,10-d] imidazole (10.39 g, 16.0 mmol), 2-naphthaleneboronic acid (6.08 g, 35.2 mmol), carbonic acid A potassium aqueous solution [K ₂ CO ₃ (13.27 g, 96.0 mmol) + water 48 mL], toluene 160 mL, and ethanol 80 mL were mixed. After purging with nitrogen for 30 minutes, Pd (PPh ₃ ) ₄ (1.85 g, 1.60 mmol) was added.
The resulting mixture was heated to reflux at 73-75 ° C. for 4 hours under a nitrogen atmosphere. After the reaction, the reaction solution was cooled to 50 ° C., and the pH was adjusted by adding 80 mL of water and 35% HCl to the reaction solution (pH 11.28 → 8.41). The obtained crystal was dried to obtain 11.71 g of a crude product.
The above crude product (11.48 g) was dissolved in chlorobenzene (38 mL) at 130 ° C., activated clay was added and stirred for 30 minutes, followed by hot filtration to lower the temperature to precipitate crystals. The obtained crystal was dried to obtain 10.97 g of a purified product (yield 94.6%, Mettler melting point: not measurable, DSCTm: 274.5 ° C.).
FIG. 14 shows the result of confirming the structure of the crystal by LC-MS.

Example 15
Synthesis of 2- (4-anthracen-4-yl) phenyl-1-phenyl-1H-phenanthro [9,10-d] imidazole (Compound No. 15) 1-phenyl-1H-phenanthro [9,10-d] imidazole 2- (4-phenylboronic acid) (BPMB) (6.19 g, 14.3 mmol), 9-bromoanthracene (3.34 g, 13.0 mmol), potassium carbonate aqueous solution [K ₂ CO ₃ (5.39 g, 39.0 mmol) +20 mL water], 130 mL toluene, and 65 mL ethanol. After purging with nitrogen for 30 minutes, Pd (PPh ₃ ) ₄ (0.75 g, 0.65 mmol) was added.
The resulting mixture was heated to reflux at 75 ° C. for 5 hours under a nitrogen atmosphere. After the reaction, the solution was cooled to 70 ° C. and separated, and 50 mL of water and 35% HCl were added to the reaction solution to adjust the pH (pH 10.69 → 7.27). After liquid separation at 70 ° C., 50 mL of water was added to the solution and stirred at 70 ° C. for 30 minutes, followed by hot filtration to recover the solvent to obtain 8.26 g of a concentrated residue.
8.26 g of the concentrated residue was dissolved in 290 mL of methyl cellosolve at 123 ° C., and the temperature was lowered to precipitate crystals. The obtained crystals were dried to obtain 5.93 g of a purified product (yield: 83.4%, Mettler melting point: 269.6 to 270.2 ° C.).
FIG. 15 shows the results of confirming the structure of the crystal by LC-MS.

Example 16
Synthesis of 2- [4- (10-phenylanthracen-9-yl) phenyl] -1-phenyl-1H-phenanthro [9,10-d] imidazole (Compound No. 16) 1-phenyl-1H-phenanthro [9, 10-d] imidazole-2- (4-phenylboronic acid) (BPMB) (7.20 g, 16.5 mmol), 9-bromo-10-phenylanthracene (5.05 g, 15.0 mmol), aqueous potassium carbonate solution [ K ₂ CO ₃ (6.22 g, 45.0 mmol) + water 23 mL], toluene 150 mL, and ethanol 75 mL were mixed. After purging with nitrogen for 30 minutes, Pd (PPh ₃ ) ₄ (0.87 g, 0.75 mmol) was added.
The resulting mixture was heated to reflux for 8 hours while stirring at 300 to 77 ° C. (300 rpm) under a nitrogen atmosphere. After the reaction, the solution was cooled to 70 ° C. and separated, and 50 mL of water and 35% HCl were added to the reaction solution to adjust the pH (pH 10.52 → 8.19). After liquid separation at 70 ° C., 50 mL of water was added to the solution, followed by stirring at 65 ° C. for 30 minutes. Further, carbon was added and stirred for 30 minutes, followed by hot filtration to recover the solvent to obtain 10.58 g of a concentrated residue.
10.46 g of the concentrated residue was dissolved in 90 mL of DMF at 150 ° C., and the temperature was lowered to precipitate crystals. The obtained crystal was dried to obtain 5.84 g of a purified product (yield: 62.5%, Mettler melting point: not measurable (300 ° C. or higher), DSCTm: 318.5 ° C.).
FIG. 16 shows the result of confirming the structure of the crystal by LC-MS.

Example 17
Synthesis of 2- (4-pyren-4-yl) phenyl-1-phenyl-1H-phenanthro [9,10-d] imidazole (Compound No. 17) 1-phenyl-1H-phenanthro [9,10-d] imidazole -2- (4-phenylboronic acid) (BPMB) (6.14 g, 14.3 mmol), 1-bromopyrene (3.75 g, 13.0 mmol), potassium carbonate aqueous solution [K ₂ CO ₃ (5.39 g, 39) 0.0 mmol) + water 20 mL], toluene 130 mL, and ethanol 65 mL were mixed. After purging with nitrogen for 30 minutes, Pd (PPh ₃ ) ₄ (0.75 g, 0.65 mmol) was added.
The resulting mixture was heated to reflux at 75 ° C. for 4 hours under a nitrogen atmosphere. After the reaction, the solution was cooled to 70 ° C. and separated, and 50 mL of water and 35% HCl were added to the reaction solution to adjust the pH (pH 10.69 → 8.12). After liquid separation at 70 ° C., 50 mL of water was added to the solution and stirred for 30 minutes. Further, carbon was added and stirred for 30 minutes, followed by hot filtration to recover the solvent to obtain 8.27 g of a concentrated residue.
8.13 g of the concentrated residue was purified by column (developing solvent, toluene: hexane = 2: 1) to obtain 5.36 g of a recovered product.
5.25 g of the recovered product was dissolved in a mixed solution of 26 mL of IPA and 91 mL of DMF at 125 ° C., and the temperature was lowered to precipitate crystals. The obtained crystals were dried to obtain 4.35 g of a purified product (yield: 58.6%, Mettler melting point: 263.3 to 266.6 ° C.).
FIG. 17 shows the result of confirming the structure of the crystal by LC-MS.

Example 18
Synthesis of 2- (5-phenylthiophen-2-yl) -1-phenyl-1H-phenanthro [9,10-d] imidazole (Compound No. 18) 2- (5-Bromothiophen-2-yl) -1- Phenyl-1H-phenanthro [9,10-d] imidazole (18.2 g, 40.0 mmol), phenylboronic acid (5.4 g, 44.0 mmol), potassium carbonate aqueous solution [K ₂ CO ₃ (16.6 g, 120 0.0 mmol) + water 60 mL], toluene 280 mL, and ethanol 140 mL were mixed. After purging with nitrogen for 30 minutes, Pd (PPh ₃ ) ₄ (2.3 g, 2.0 mmol) was added.
The resulting mixture was heated to reflux at 75 ° C. for 4 hours under a nitrogen atmosphere. After the reaction, the reaction solution was cooled to 50 ° C., and 70 mL of water and 35% HCl were added to the reaction solution to adjust the pH (pH 11.48 → 8.55). The obtained crystals were dried to obtain 16.2 g of a crude product.
16.2 g of the above crude product was dissolved in 210 mL of chlorobenzene at 127 ° C. Activated clay was added and stirred for 30 minutes, followed by hot filtration, and the temperature was lowered to precipitate crystals. The obtained crystals were dried to obtain 14.8 g of a purified product (yield: 81.8%, DSCTm: 279.3 ° C.).
FIG. 18 shows the result of confirming the structure of the crystal by LC-MS.

Example 19
Synthesis of 2- (5-diphenyl-4-yl-thiophen-2-yl) -1-phenyl-1H-phenanthro [9,10-d] imidazole (Compound No. 19) (1) 1-phenyl-1H-phenanthro Synthesis of [9,10-d] imidazol-2- (thiophen-2-yl-5-boronic acid) (BSM-2B) 2- (5-Bromo-thiophen-2-yl) -1-phenyl-1H- Phenanthro [9,10-d] imidazole (22.8 g, 50.0 mmol) and 230 mL of THF were mixed. After purging with nitrogen and cooling to −70 ° C., n-BuLi (1.6 M) (39 mL, 62.5 mmol) was added under a nitrogen atmosphere. After reacting at −78 ° C. for 1 hour, trimethyl borate (7.8 g, 75.0 mmol) was added to the reaction solution, reacted at −78 ° C. for 1 hour, and further reacted at 20 ° C. to 25 ° C. for 3 hours. It was.
The reaction solution was hydrolyzed by adding 60 mL of water and 35% HCl, and reacted at 20 ° C. to 25 ° C. for 13 hours.
To the reaction solution, 150 mL of toluene and a 48% NaOH solution were added to adjust the pH (pH 0.23 → 6.80). The obtained crystals were dried to obtain 14.4 g of product (yield: 68.6%).
(2) Synthesis of Compound No. 19 BSM-2B (13.9 g, 33.0 mmol), 4-bromobiphenyl (7.0 g, 30.0 mmol), potassium carbonate aqueous solution [K ₂ CO ₃ (12.4 g, 90 0.0 mmol) +45 mL water], 160 mL toluene, and 80 mL ethanol. After purging with nitrogen for 30 minutes, Pd (PPh ₃ ) ₄ (1.7 g, 1.5 mmol) was added.
The resulting mixture was heated to reflux at 75 ° C. for 2 hours under a nitrogen atmosphere. After the reaction, the reaction solution was cooled to 50 ° C., and 70 mL of water and 35% HCl were added to the reaction solution to adjust the pH (pH 11.42 → 8.39). The obtained crystals were dried to obtain 8.9 g of a crude product.
The crude product (8.9 g) was dissolved in 130 mL of DMF (130 mL). Carbon was added to the solution and stirred for 30 minutes, followed by hot filtration, and the temperature was lowered to precipitate crystals. The obtained crystal was dried to obtain 8.1 g of a purified product (yield: 41.5%, DSCTm: 249.0 ° C.).
FIG. 19 shows the result of confirming the structure of the above crystal by LC-MS.

Example 20
Synthesis of 2- (5-naphthalen-2-yl-thiophen-2-yl) -1-phenyl-1H-phenanthro [9,10-d] imidazole (Compound No. 20) 2- (5-Bromothiophen-2-yl) Yl) -1-phenyl-1H-phenanthro [9,10-d] imidazole (BSM-2) (13.6 g, 30.0 mmol), 2-naphthaleneboronic acid (5.7 g, 33.0 mmol), potassium carbonate Aqueous solution [K ₂ CO ₃ (12.4 g, 90.0 mmol) + water 45 mL], toluene 200 mL, and ethanol 100 mL were mixed. After purging with nitrogen for 30 minutes, Pd (PPh ₃ ) ₄ (1.7 g, 1.5 mmol) was added.
The resulting mixture was heated to reflux at 75 ° C. for 13 hours under a nitrogen atmosphere. After the reaction, the reaction solution was cooled to 50 ° C., and the pH was adjusted by adding 50 mL of water and 35% HCl to the reaction solution (pH 12.57 → 8.60). The obtained crystals were dried to obtain 13.9 g of a crude product.
13.9 g of the crude product was dissolved in 210 mL of chlorobenzene at 125 ° C. Carbon was added to the solution and stirred for 30 minutes, followed by hot filtration, and the temperature was lowered to precipitate crystals.
The obtained crystals were dried to obtain 12.2 g of a purified product (yield: 80.8%, DSCTm: 271.0 ° C.).
FIG. 20 shows the result of confirming the structure of the crystal by LC-MS.

Example 21
Synthesis of 2- [5- (4-carbazol-9-yl-phenyl) -thiophen-2-yl] -1-phenyl-1H-phenanthro [9,10-d] imidazole (Compound No. 21) 2- (5 -Bromothiophen-2-yl) -1-phenyl-1H-phenanthro [9,10-d] imidazole (13.7 g, 30.0 mmol), 4-carbazol-9-yl-phenylboronic acid (4NCPBA) (9 0.5 g, 33.0 mmol), an aqueous potassium carbonate solution [K ₂ CO ₃ (12.4 g, 90.0 mmol) +53 mL of water], toluene 200 mL, and ethanol 100 mL were mixed. After purging with nitrogen for 30 minutes, Pd (PPh ₃ ) ₄ (1.7 g, 1.5 mmol) was added.
The resulting mixture was heated to reflux at 75 ° C. for 3 hours under a nitrogen atmosphere. After the reaction, the reaction solution was cooled to 50 ° C., and the pH was adjusted by adding 50 mL of water and 35% HCl to the reaction solution (pH 11.59 → 8.11). The obtained crystals were dried to obtain 15.6 g of a crude product.
15.6 g of the crude product was dissolved in a mixed solution of 50 mL of ethyl cellosolve and 130 mL of chlorobenzene at 125 ° C. Carbon was added to the solution and stirred for 30 minutes, followed by hot filtration, and the temperature was lowered to precipitate crystals. The obtained crystals were dried to obtain 12.6 g of a purified product (yield: 68.1%, DSCTm: 299.4 ° C.).
FIG. 21 shows the result of confirming the structure of the crystal by LC-MS.

Example 22
Synthesis of 2-biphenyl-4-yl-5,10-di (naphthalen-2-yl) -1-phenyl-1H-phenanthro [9,10-d] imidazole (Compound No. 22) 2-biphenyl-4-yl -5,10-dibromo-1-phenyl-1H-phenanthro [9,10-d] imidazole (BDBPM-1) (7.2 g, 7.0 mmol), 2-naphthaleneboronic acid (2.7 g, 15.4 mmol) ), Potassium carbonate aqueous solution [K ₂ CO ₃ (5.8 g, 42.0 mmol) + water 21 mL], toluene 70 mL, and ethanol 35 mL were mixed. After purging with nitrogen for 30 minutes, Pd (PPh ₃ ) ₄ (0.8 g, 0.7 mmol) was added.
The resulting mixture was heated to reflux at 75 ° C. for 25 hours under a nitrogen atmosphere. After the reaction, the reaction solution was cooled to 50 ° C., and the pH was adjusted by adding 35 mL of water and 35% HCl to the reaction solution (pH 11.39 → 8.2). The obtained crystals were dried to obtain 4.9 g of a crude product.
The crude product (4.9 g) was dissolved in o-dichlorobenzene (258 mL) at 160 ° C. Carbon was added to the solution and stirred for 30 minutes, followed by hot filtration, and the temperature was lowered to precipitate crystals. The obtained crystals were dried to obtain 4.3 g of a purified product (yield: 91.5%, Mettler melting point: 300 ° C. or higher).
FIG. 22 shows the result of confirming the structure of the crystal by LC-MS.

Example 23
Synthesis of 2,5,10-tri (naphthalen-2-yl) -1-phenyl-1H-phenanthro [9,10-d] imidazole (Compound No. 23) 5,10-dibromo-2-naphthalen-2-yl -1-phenyl-1H-phenanthro [9,10-d] imidazole (BDBPM-2) (5.0 g, 8.7 mmol), 2-naphthaleneboronic acid (3.3 g, 19.0 mmol), aqueous potassium carbonate solution [ K ₂ CO ₃ (6.0 g, 43.2 mmol) + water 20 mL], toluene 130 mL, and ethanol 65 mL were mixed. After purging with nitrogen for 30 minutes, Pd (PPh ₃ ) ₄ (1.0 g, 1.1 mmol) was added.
The resulting mixture was heated to reflux at 77 ° C. for 21 hours under a nitrogen atmosphere. After the reaction, the reaction solution was cooled to 50 ° C., and the pH was adjusted by adding 50 mL of water and 35% HCl to the reaction solution (pH 11.79 → 8.3). The obtained crystals were dried to obtain 5.4 g of a crude product.
The above crude product (5.4 g) was dissolved in DMF (510 mL) at 150 ° C. Carbon was added to the solution and stirred for 30 minutes, followed by hot filtration, and the temperature was lowered to precipitate crystals. The obtained crystals were dried to obtain 3.1 g of a purified product (yield: 53.3%, Mettler melting point: 300 ° C. or higher).
FIG. 23 shows the result of confirming the structure of the crystal by LC-MS.

The structures and physical properties of the synthesized imidazole derivatives α are summarized in Table 17 to Table 20 below. In addition, the code | symbol of the column of A, B, Z in a table | surface is the number of substituent A, B, Z illustrated previously except H (hydrogen). The UV column is the value of the ultraviolet absorption peak wavelength, and the PL column is the value of the photoluminescence emission peak wavelength.

HOMO, LUMO, and energy gap (Eg) of imidazole derivatives α (Compound Nos. 1 and 2) of Example 1 and Example 2 were measured. The results are shown in Table 21.
HOMO was measured using AC-1 manufactured by Riken Keiki Co., Ltd., and the value of voltage (eV) at which the sample started ionization was read. The energy gap (Eg) was measured using a UV-visible absorptiometer (UV-1650PC, manufactured by Shimadzu Corporation) for a thin film prepared by a vapor deposition machine. A tangent line was drawn at the short wavelength rising edge of the absorption curve of the thin film, and the obtained wavelength W (nm) of the intersection was substituted into the following equation to obtain Eg.
Eg = 1240 ÷ W
For example, if the value W (nm) obtained by drawing a tangent line is 470 nm, the value of Eg at this time is Eg = 1240 ÷ 470 = 2.63 (eV).
LUMO is a value obtained by subtracting the previously calculated Eg from the HOMO value.
Further, for comparison, HOMO, LUMO, and Eg of blue fluorescent dopant LT-E604 (Comparative Example 1) manufactured by OJEC were measured.

Example 24, Comparative Example 2
An organic EL device using the imidazole derivative α (Compound No. 1) of Example 1 and an organic EL device (Comparative Example 2) using a blue dopant LT-E604 manufactured by Augec Co., Ltd. were prepared and evaluated.

<Configuration of Organic EL Device (Device.1) of Example 24>
・ Anode: ITO (150 nm)
-Hole transport layer: α-NPD (50 nm)
-Light emitting layer: KLDB-01 (compound number 1: 5 wt% dope) (30 nm)
-Electron transport layer: KLET-01 (40 nm)
-Electron injection layer: LiF (0.5 nm)
-Cathode: Al (100 nm)

<Configuration of Organic EL Element (Reference 2) of Comparative Example 2>
・ Anode: ITO (150 nm)
-Hole transport layer: α-NPD (50 nm)
-Light emitting layer: KLDB-01 (LT-E604: 5 wt% dope) (30 nm)
-Electron transport layer: KLET-01 (40 nm)
-Electron injection layer: LiF (0.5 nm)
-Cathode: Al (100 nm)

FIG. 24 shows the current density-voltage relationship of the organic EL elements of Example 24 and Comparative Example 2, FIG. 25 shows the relationship of luminance-voltage, FIG. 26 shows the relationship of power efficiency-current density, and FIG. FIG. 27 shows the relationship of density, FIG. 28 shows the relationship of luminance-current density, and FIG. 29 shows the relationship of external quantum efficiency-current density.
Table 22 shows the results of voltage, current density, power efficiency, current efficiency, external quantum efficiency, and chromaticity coordinates at 100 cd / m ² and 1000 cd / m ² .
As can be seen from the results in Table 22, Device. 1 is reference. Compared to ² , the drive voltage is lower for both 100 cd / m ² and 1000 cd / m ² . Further, in view of the value of chromaticity coordinates, Device. In the case of 1, the color purity at the time of light emission is closer to pure blue.

Example 25
An organic EL device using the imidazole derivative α (Compound No. 2) of Example 2 for the light emitting layer was prepared and evaluated.

<Configuration of Organic EL Device (Device. 2) of Example 25>
・ Anode: ITO (150 nm)
-Hole transport layer: α-NPD (50 nm)
-Light emitting layer: KLDB-01 (compound number 2: 5 wt% dope) (30 nm)
-Electron transport layer: KLET-01 (40 nm)
-Electron injection layer: LiF (0.5 nm)
-Cathode: Al (100 nm)

The current density-voltage relationship of the organic EL elements of Example 25 and Comparative Example 2 is shown in FIG. 30, the brightness-voltage relationship is shown in FIG. 31, the power efficiency-current density relationship is shown in FIG. FIG. 33 shows the relationship of density, FIG. 34 shows the relationship of luminance-current density, and FIG. 35 shows the relationship of external quantum efficiency-current density.
Table 23 shows the results of voltage, current density, power efficiency, current efficiency, external quantum efficiency, and chromaticity coordinates at 100 cd / m ² and 1000 cd / m ² .
As can be seen from the results in Table 23, Device. 2 is reference. Compared to ² , the drive voltage is lower for both 100 cd / m ² and 1000 cd / m ² . Further, in view of the value of chromaticity coordinates, Device. In the case of No. 2, the color purity at the time of light emission is closer to pure blue.

Example 26
An organic EL device using the imidazole derivative α (Compound No. 22) of Example 22 in the light emitting layer was prepared and evaluated.

<Configuration of Organic EL Device (Device. 3) of Example 26>
・ Anode: ITO (150 nm)
-Hole transport layer: α-NPD (50 nm)
-Light emitting layer: KLDB-01 (Compound No. 22: 5 wt% dope) (30 nm)
-Electron transport layer: KLET-01 (40 nm)
-Electron injection layer: LiF (0.5 nm)
-Cathode: Al (100 nm)

36 shows the current density-voltage relationship of the organic EL elements of Example 26 and Comparative Example 2, FIG. 37 shows the luminance-voltage relationship, FIG. 38 shows the power efficiency-current density relationship, and FIG. FIG. 39 shows the relationship of density, FIG. 40 shows the relationship of luminance-current density, and FIG. 41 shows the relationship of external quantum efficiency-current density.
Table 24 shows the results of voltage, current density, power efficiency, current efficiency, external quantum efficiency, and chromaticity coordinates at 100 cd / m ² and 1000 cd / m ² .
As can be seen from the results in Table 24, Device. 3 is reference. Compared to ² , the drive voltage is lower for both 100 cd / m ² and 1000 cd / m ² . Further, in view of the value of chromaticity coordinates, Device. In the case of No. 3, the color purity at the time of light emission is closer to pure blue.

Example 27
An organic EL device using the imidazole derivative α (Compound No. 23) of Example 23 for the light emitting layer was prepared and evaluated.

<Configuration of Organic EL Device (Device. 4) of Example 27>
・ Anode: ITO (150 nm)
-Hole transport layer: α-NPD (50 nm)
-Light emitting layer: KLDB-01 (Compound No. 23: 5 wt% dope) (30 nm)
-Electron transport layer: KLET-01 (40 nm)
-Electron injection layer: LiF (0.5 nm)
-Cathode: Al (100 nm)

FIG. 42 shows the current density-voltage relationship of the organic EL elements of Example 27 and Comparative Example 2, FIG. 43 shows the relationship of luminance-voltage, FIG. 44 shows the relationship of power efficiency-current density, and FIG. FIG. 45 shows the relationship of density, FIG. 46 shows the relationship of luminance-current density, and FIG. 47 shows the relationship of external quantum efficiency-current density.
Table 25 shows the results of voltage, current density, power efficiency, current efficiency, external quantum efficiency, and chromaticity coordinates at 100 cd / m ² and 1000 cd / m ² .
As can be seen from the results in Table 25, Device. 4 is reference. Compared to ² , the drive voltage is lower for both 100 cd / m ² and 1000 cd / m ² . Further, in view of the value of chromaticity coordinates, Device. In the case of No. 4, the color purity at the time of light emission is closer to pure blue.

1 Substrate 2 Anode (ITO)
DESCRIPTION OF SYMBOLS 3 Light emitting layer 4 Cathode 5 Hole (hole) transport layer 6 Electron transport layer 7 Hole (hole) injection layer 8 Electron injection layer 9 Hole block layer

Claims (4)

A phenanthro [9,10-d] imidazole derivative represented by the following general formula (1):

(In the formula, R ^{1 to} R ⁴ are groups independently selected from hydrogen and an alkyl group having 1 to 4 carbon atoms, an alkoxy group, an alkylamino group, and a cyano group, and A is a group having 5 to 60 carbon atoms. A group consisting of an aromatic group or a heterocyclic group, B is a group consisting of hydrogen and an aromatic group or a heterocyclic group having 5 to 20 carbon atoms, and Z is a group consisting of an aromatic group or a heterocyclic group having 3 to 20 carbon atoms. Group independently selected from each other.) A phenanthro [9,10-d] imidazole derivative represented by the following general formula (2):

(In the formula, R ^{1 to} R ⁴ are groups independently selected from hydrogen and an alkyl group having 1 to 4 carbon atoms, an alkoxy group, an alkylamino group, and a cyano group, and A is a group having 5 to 60 carbon atoms. A group consisting of an aromatic group or a heterocyclic group, B is a group consisting of hydrogen and an aromatic group or a heterocyclic group having 5 to 20 carbon atoms, and Z is a group consisting of an aromatic group or a heterocyclic group having 3 to 20 carbon atoms. Group independently selected from each other.)   A light emitting material comprising the imidazole derivative according to claim 1.   The organic electroluminescent element using the imidazole derivative of Claim 1 or 2.

Images