JPH0625658A - Organic electroluminescent element - Google Patents

Abstract

PURPOSE:To obtain an org. EL element having an excellent acid resistance and a low ionization potential and comprising a high-melting compd. having at least one ferrocenevinyl unit of a specific molecular structure sandwiched between a pair of electrodes. CONSTITUTION:This org. electroluminescent element comprises a compd. contg. at least one ferrocenevinyl unit of the formula and sandwiched between a pair of electrodes. In the formula, A and B are each independently hydrogen, a 1-6C alkyl group, a ferrocenyl group, or a substd. or unsubstd. aryl group wherein a substituent(s), if any, is a 1-6C alkyl group, a 1-6C alkoxyl group, a 6-18C aryloxy group, a phenyl group, a cyano group, a nitro group, a hydroxyl group, or a halogen atom.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic electroluminescence device (organic EL device), and more specifically, it has excellent oxidation resistance, can lower the ionization potential, and has a high melting point of the compound to prevent crystallization. The present invention relates to an organic EL element that can be manufactured.

[0002]

2. Description of the Related Art An EL device utilizing electroluminescence is a thin flat panel display which utilizes the features of high visibility due to self-emission and excellent impact resistance because it is a complete solid state device. It is used in devices, backlights of liquid crystal displays, and flat light sources. The EL element currently put into practical use is a dispersion type EL element. In this dispersion type EL element, several tens of V, 10 kHz
Since an alternating voltage of z or more is required, the driving circuit is complicated. On the other hand, the organic thin film EL element has a drive voltage of 10
Since it can be reduced to about V and emits light with high brightness, research has been actively conducted in recent years, and many organic thin film EL devices have been developed (CW Tang and S.A.
Van Slyke, Appl. Phys. Let
t. , Vol. 51, pp. 913-915 (198
7); JP-A-63-264629). These organic thin film EL devices are of a laminated type of transparent electrode / hole injection layer / light emitting layer / back electrode, and holes can be efficiently injected into the light emitting layer by the hole injection layer. As this hole injection material, an ionization potential showing hole mobility is used.
Tertiary amine derivatives represented by triphenylamine derivatives as small as 5.4 to 5.5 eV are good. However, these triphenylamine derivatives are easily oxidized and have a drawback that the thin film is easily crystallized because the compound has a low melting point. Further, like distyrylbenzene, the ionization potential cannot be reduced to 5.9 to 6.0 eV by simply including a vinyl unit, and cannot be used as a hole injecting material.

[0003]

Therefore, the present inventors have conducted diligent research to solve the above-mentioned drawbacks of the prior art, develop an organic EL device having excellent acid resistance, a small ionization potential, and a high melting point of a compound. Overlaid. As a result, they have found that the above object can be sufficiently achieved by sandwiching the ferrocene vinyl unit between the electrodes of the organic EL element. The present invention has been completed based on such findings.

That is, the present invention has the general formula (I)

[0005]

[Chemical 4]

(In the formula, A and B each independently represent hydrogen, an alkyl group having 1 to 6 carbon atoms, a ferrocenyl group, a substituted or unsubstituted aryl group having 6 to 20 carbon atoms,
A and B may be the same or different. Here, the substituent represents an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an aryloxy group having 6 to 18 carbon atoms, a phenyl group, a cyano group, a nitro group, a hydroxyl group or halogen. The present invention provides an organic electroluminescence device comprising a compound having one or more ferrocene vinyl units represented by the formula (1) sandwiched between a pair of electrodes.

The present invention is an organic EL device in which a compound represented by the above general formula (I) containing one or more ferrocene vinyl units is sandwiched between electrodes of the organic EL device. Here, the compound may be a monomer or an oligomer. Here, as the alkyl group having 1 to 6 carbon atoms, methyl group, ethyl group, n-propyl group, i-propyl group, n
-Butyl group, i-butyl group, sec-butyl group, t-butyl group, isopentyl group, t-pentyl group, neopentyl group, isohexyl group and the like. 6 to 20 carbon atoms
Examples of the aryl group include a phenyl group, a biphenyl group, a naphthyl group, an anthracenyl group, a terphenyl group, and a pyrenyl group. Examples of the alkyl group having 1 to 6 carbon atoms as the substituent include methyl group, ethyl group, n-propyl group, i
-Propyl group, n-butyl group, i-butyl group, sec-
Butyl group, t-butyl group, isopentyl group, t-pentyl group, neopentyl group, isohexyl group and the like,
Examples of the alkoxy group having 1 to 6 carbon atoms include methoxy group, ethoxy group, n-propoxy group, i-propoxy group, n-
Butyloxy group, i-butyloxy group, sec-butyl group, t-butyloxy group, isopentyloxy group, t-
Examples thereof include a pentyloxy group and neopentyloxy group, and examples of the aryloxy group having 6 to 18 carbon atoms include a phenoxy group and a naphthyloxy group.

As an example of the compound represented by the general formula (I), the general formula (II)

[0009]

[Chemical 5]

(In the formula, R ^{1 to} R ⁴ each independently represent hydrogen, an alkyl group having 1 to 6 carbon atoms, a ferrocenyl group, a substituted or unsubstituted aryl group having 6 to 20 carbon atoms,
R ^{1 to} R ⁴ may be the same or different. Here, the substituent represents an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an aryloxy group having 6 to 18 carbon atoms, a phenyl group, a cyano group, a nitro group, a hydroxyl group or halogen. R ¹ and R ² or R ³ and R ⁴ may combine with a substituent to form a substituted or unsubstituted saturated five-membered ring or a substituted or unsubstituted saturated six-membered ring. ) And (III)

[0011]

[Chemical 6]

(Where R^FiveAnd R⁶Are independent
Hydrogen, an alkyl group having 1 to 6 carbon atoms, a ferrocenyl group,
Shows a substituted or unsubstituted aryl group having 6 to 20 carbon atoms.
And R ^FiveAnd R⁶May be the same or different. This
Here, the substituent bonded to the aryl group has 1 to 6 carbon atoms.
Alkyl group, C1-C6 alkoxy group, C6-C
18 aryloxy groups phenyl group, cyano group, nitro
Indicates a group, hydroxyl group or halogen. Also, Ar is a substitution
Or an unsubstituted arylene group having 6 to 20 carbon atoms,
Single or multiple substitutions, bond
The part may be ortho, para, or meta, and arylene
A substituted or unsubstituted saturated five-membered ring bonded to groups or
A substituted or unsubstituted saturated 6-membered ring may be formed. here
Thus, the substituent bonded to the arylene group has 1 carbon atom.
~ 6 alkyl group, C1-6 alkoxy group, carbon
Number 6-18 aryloxy group, phenyl group, cyano
Indicates a group, nitro group, hydroxyl group or halogen. )
Compounds that can be mentioned. Here, the substituents are the same as above.
Is. Compounds represented by the above general formulas (II) and (III)
The product has two vinyl moieties (-CH = C =) in one molecule.
It has a cis position, but cis
The body or the trans body can be combined. Compound of the present invention
The items may be either of them, or may be a mixture, but it is preferable.
All of them are in trans form.

Specific examples of the compound represented by the general formula (I) are:

[0014]

[Chemical 7]

[0015]

[Chemical 8]

Specific examples of the compound represented by the general formula (II) include

[0017]

[Chemical 9]

[0018]

[Chemical 10]

[0019]

[Chemical 11]

[0020]

[Chemical 12]

[0021]

[Chemical 13]

[0022]

[Chemical 14]

[0023]

[Chemical 15]

[0024]

[Chemical 16]

[0025]

[Chemical 17]

Specific examples of the compound represented by the general formula (III) include

[0027]

[Chemical 18]

[0028]

[Chemical 19]

[0029]

[Chemical 20]

[0030]

[Chemical 21]

[0031]

[Chemical formula 22]

[0032]

[Chemical formula 23]

[0033]

[Chemical formula 24]

[0034]

[Chemical 25]

[0035]

[Chemical formula 26]

[0036]

[Chemical 27]

And the like. The above general formula (I)-
The synthesis method of the compound represented by (III) is “J.Phys.Chem.”
94, 2847-2851 (1990),
"Bull. Chem. Soc. Jpn.", Volume 50, 1021-102
P. 2 (1977), "Inorg. Chem." Vol. 12, 1
Pp. 998-2004 (1973), "J. Chem. Soc., Ch.
em.Commun. "p. 151 (1983).

The structure of the organic EL device of the present invention is as follows.
Examples include anode / light emitting layer / cathode, anode / hole injection layer / light emitting layer / cathode, anode / light emitting layer / electron injection layer / cathode, anode / hole injection layer / light emitting layer / electron injection layer / cathode. Any configuration may be used. In addition, it is preferable that all the organic EL elements having these configurations are supported by the substrate. There is no particular limitation on this substrate, and glass, transparent plastic, quartz, or the like conventionally used for organic EL elements can be used. The layer containing a compound containing a ferrocene vinyl unit (hereinafter referred to as a ferrocene derivative) is preferably a hole injection layer or a light emitting layer, and particularly preferably a hole injection layer.

The hole injection layer containing a ferrocene derivative may have a single-layer structure composed of only a ferrocene derivative, or a composite layer composed of a layer of a ferrocene derivative and a compound conventionally used as a hole injection material for an organic EL device. It may have a layered structure. Further, it may have a single-layer structure or a multi-layer structure including a layer composed of a mixture of a ferrocene derivative and a substance conventionally used as a hole injection material of an organic EL device. The hole injection layer containing a ferrocene derivative uses a ferrocene derivative and, if necessary, another hole injection material,
It can be formed by a vacuum deposition method, a casting method, a coating method, a spin coating method, or the like. Further, it may be formed by a casting method using a solution in which a silanamin derivative is dispersed in a transparent polymer such as polycarbonate, polyurethane, polystyrene, polyarylate or polyester, a coating method, a spin coating method, or a simultaneous vapor deposition method with a transparent polymer. You can

Further, the light emitting layer containing the ferrocene derivative is
It may have a single-layer structure composed only of a ferrocene derivative, or may have a multi-layer structure of a ferrocene derivative and a substance conventionally used as a light emitting material for an organic EL device. Further, it may have a single-layer structure or a multi-layer structure including a layer composed of a mixture of a ferrocene derivative and a substance conventionally used as a hole injection material of an organic EL device. The light emitting layer containing a ferrocene derivative can be formed by using a ferrocene derivative and, if necessary, another light emitting material by a vacuum deposition layer, a casting method, a coating method, a spin coating method, or the like.

In the organic EL device of the present invention, the layers other than the layer containing the ferrocene derivative can be formed by using the same material as the conventional organic EL device. For example, as the material of the anode, a metal having a large work function (4 eV or more),
Alloys, electrically conductive compounds or mixtures thereof are preferably used. Specifically, metals such as Au, CuI, I
Dielectric transparent materials such as TO, SnO ₂ and ZnO can be used. The anode can be formed into a thin film by a vapor deposition method, a sputtering method, or the like. When the light emitted from the light emitting layer is taken out from the anode, the transmittance of the anode is preferably higher than 10%.
The sheet resistance of the anode is preferably several hundred Ω / □ or less.
Although the thin film of the anode depends on the material, it is usually 10 nm to 1 μm,
It is preferably 10 to 200 nm.

As a material of the cathode, a metal, an alloy, an electrically conductive compound having a small work function (4 eV or less) or a mixture thereof is preferably used. As a specific example,
Sodium, sodium-potassium alloy, magnesium, lithium, magnesium / copper mixture, Al / Al ₂
Examples include O ₃ and indium. The cathode is a thin film that can be formed by vapor deposition or sputtering. When the light emitted from the light emitting layer is taken out from the cathode, the transmittance of the cathode is 10
It is desirable to be larger than%. The sheet resistance of the cathode is preferably several hundred Ω / □ or less. The thin film of the cathode depends on the material, but is usually 10 nm to 1 μm, preferably 50 to 200.
nm. In order to efficiently extract the light emitted from the light emitting layer, at least one of the cathodes is preferably formed of a transparent or semitransparent material as described above.

When the luminescent layer of the present invention is formed of a ferrocene derivative and another substance, or when it is formed only of a substance other than the ferrocene derivative, examples of the luminescent material other than the ferrocene derivative include polycyclic compounds. A compound having a good thin film forming property such as a condensed direction compound, a fluorescent whitening agent such as a benzoxazole-based compound, a benzothiazole-based compound, a benzimidazole-based compound, a metal chelate oxanoide compound, or a distyrylbenzene-based compound can be used. Here, as specific examples of the polycyclic fused directional group compound, a condensed ring light-emitting substance containing anthracene, naphthalene, phenanthrene, pyrene, chrysene, perylene skeleton, or the like, and 8 to 20, preferably 8 condensed rings And the like. Further, examples of the fluorescent whitening agent of benzoxazole type, benzothiazole type, benzimidazole type and the like include those disclosed in JP-A-59-194393. Typical examples are 2,
5-bis (5,7-di-t-pentyl-2-benzoxazolyl) -1,3,4-thiadiazole; 4,4'-
Bis (5,7-t-pentyl-2-benzoxazolyl) stilbene; 4,4′-bis (5,7-di- (2-
Methyl-2-butyl) -2-benzoxazolyl) stilbene; 2,5-bis (5,7-di-t-pentyl-2
-Benzoxazolyl) thiophene; 2,5-bis (5
-(Α, α-Dimethylbenzyl) -2-benzoxazolyl) thiophene; 2,5-bis (5,7-di- (2-
Methyl-2-butyl) -2-benzoxazolyl)-
3,4-Diphenylthiophene; 2,5-bis (5-methyl-benzoxazolyl) thiophene; 4,4-bis (2-benzoxazolyl) biphenyl; 5-methyl-
2- (2- (4- (5-methyl-2-benzoxazolyl) phenyl) vinyl) benzoxazole; 2- (2
-(4-Chlorophenyl) vinyl) naphtho (1,2-
d) Benzoxazoles such as oxazole, 2,2 '
Benzothiazoles such as-(p-phenylenedivinylene) -bisbenzothiazole, 2- (2- (4- (2-benzimidazolyl) phenyl) vinyl) benzimidazole, 2- (2- (4-carboxyphenyl) vinyl )
Fluorescent brighteners such as benzimidazole series such as benzimidazole can be mentioned.

As the metal chelated oxanoide compound, for example, those disclosed in JP-A-63-295695 can be used. As typical examples thereof, tris (8-quinolinol) aluminum, bis (8-quinolinol) magnesium, bis (benzo (f) -8-quinolinol) zinc, bis (2-methyl-8-quinolinolato) aluminum oxide, tris ( 8-quinolinol) indium, tris (5-methyl-8-quinolinol) aluminum, 8-quinolinol lithium, tris (5-chloro-8-quinolinol)
Gallium, bis (5-chloro-8-quinolinol) calcium, poly (zinc (II) -bis (8-hydroxy-5)
Examples include 8-hydroxyquinoline-based metal complexes such as -quinolinonyl) methane) and dilithium epindridione.

As the distyrylbenzene compound, for example, those disclosed in European Patent No. 0,373,582 can be used. As a typical example thereof, 1,4-bis (2-methylstyryl) benzene;
1,4-bis (3-methylstyryl) benzene; 1,4
-Bis (4-methylstyryl) benzene; distyrylbenzene; 1,4-bis (2-ethylstyryl) benzene; 1,4-bis (3-ethylstyryl) benzene;
1,4-bis (2-methylstyryl) -2-methylbenzene; 1,4-bis (2-methylstyryl) -2-ethylbenzene and the like.

Further, the distyrylpyrazine derivative disclosed in JP-A-2-252793 can also be used as a light emitting material. Typical examples are 2,5-
Bis (4-methylstyryl) pyrazine; 2,5-bis (4-ethylstyryl) pyrazine; 2,5-bis (2-
(1-naphthyl) vinyl) pyrazine; 2,5-bis (4
-Methoxystyryl) pyrazine; 2,5-bis (2-
(4-biphenyl) vinyl) pyrazine; 2,5-bis (2- (1-pyrenyl) vinyl) pyrazine and the like.

In addition, the dimethylidene derivative disclosed in European Patent No. 0,388,768 or JP-A-3-231970 can be used as a light emitting material. Typical examples thereof are 1,4-phenylenedimethyridin; 2,5-xylylenedimethyridinide; 2,6-naphthyylenedimethyridin; 4,4'-biphenylenedimethyridin; 4,4 ''. -P-Telephenylenedimethylidene; 9,10-anthracene diyldimethylidene; 4,
4 '-(2,2-di-t-butylphenylvinyl) biphenyl; 4,4'-(2,2-diphenylvinyl) biphenyl and the like, and derivatives thereof.

Further, as a light emitting material, Japanese Patent Laid-Open No. 2-1 is used.
Coumarin derivatives disclosed in JP-A-91694, perylene derivatives disclosed in JP-A-2-196885, naphthalene derivatives disclosed in JP-A-2-255789, JP-A-2-289676, and the like. Examples thereof include a phthaloperinone derivative disclosed in JP-A-2-88689, and a styrylamine derivative disclosed in JP-A-2-250292. These luminescent materials can be appropriately selected according to the intended luminescent color, performance and the like.

Further, the above-mentioned light emitting material includes US Pat.
It may be formed by adding the fluorescent substance disclosed in the specification of No. 9,292. The base substance at this time may be a ferrocene derivative or a light emitting material other than the ferrocene derivative. Further, it may be a mixture of a ferrocene derivative and a light emitting material. When the light emitting layer is formed by adding the fluorescent substance, the addition amount of the fluorescent substance is preferably several mol% or less. Since the fluorescent substance emits light in response to the recombination of electrons and holes, it plays a part of the light emitting function. Furthermore, as the light emitting material, a compound having no thin film property can be used. Specific examples thereof include 1,4-diphenyl-1,
3-butadiene; 1,1,4,4-tetraphenyl-
1,3-butadiene; tetraphenylcyclopentadiene and the like. However, the organic EL device using these compounds having no thin film property has a drawback that the device life is short.

The hole injecting layer provided as necessary in the organic EL device of the present invention may be a layer containing a ferrocene derivative as long as the light emitting layer contains the ferrocene derivative,
The layer may not be included. For the hole injection layer other than the ferrocene derivative, various substances that have been conventionally used as hole injection materials for organic EL devices can be used.

When a layer containing a ferrocene derivative is provided as the hole injecting layer, this hole injecting layer is as described above, and preferably has a single layer structure consisting of only the ferrocene derivative or a ferrocene derivative and a porphyrin compound or an organic compound. It has a multilayer structure with a p-type thiophene-containing oligomer which is a semiconductor oligomer.

Typical examples of the above porphyrin compounds include porphine; 5,10,15,20-tetraphenyl-21H, 23H-porphine copper (II); 5,10,
15,20-Tetraphenyl 21H, 23H-porphine cuprous (II); 5,10,15,20-Tetrakis (pentafluorophenyl) -21H, 23H-porphine; Silicon phthalocyanine oxide; Aluminum phthalocyanine chloride; Phthalocyanine (metal free) ); Dilithium phthalocyanine; copper tetramethyl phthalocyanine; copper phthalocyanine; chromium phthalocyanine; zinc phthalocyanine; lead phthalocyanine; titanium phthalocyanine oxide; magnesium phthalocyanine; copper octamethyl phthalocyanine.

As the p-type thiophene-containing oligomer,
In particular

[0054]

[Chemical 28]

(Where, k is 1, 2 or 3, and m is 1, 2 or
Or 3, n is 1, 2 or 3, and k +
m + n ≧ 5, and R ⁷ , R ⁸ and R ⁹ each independently represent an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms or a cyclohexyl group. The organic semiconducting oligomer represented by) is suitable.

In the organic EL device of the present invention, the electron injection layer provided as necessary may have a function of transmitting the electrons injected from the cathode to the light emitting layer, and its material is conventionally known. It can be appropriately selected from electron injection materials. Examples of preferable electron injection materials include:

[0057]

[Chemical 29]

[0058]

[Chemical 30]

[0059]

[Chemical 31]

[0060]

[Chemical 32]

[0061]

[Chemical 33]

Examples thereof include compounds represented by: Note that the electron injection layer is a layer having any of an electron injection property, a transport property, and a hindrance property, and a crystalline or non-crystalline material such as Si-based, SiC-based, CdS-based can also be used.

In the organic EL device of the present invention, a layer for improving the adhesion between the layers can be used. Specific examples of the material for this layer include quinolinol metal complex compounds such as tris (8-quinolinol) aluminum and tris (8-quinolinol) indium.

The organic EL device of the present invention can be manufactured, for example, as follows according to its constitution. In the case of an organic EL device composed of an anode / a light emitting layer (including a ferrocene derivative) / a cathode I A thin film of a desired electrode substance, for example, an anode substance, on a suitable substrate is 1 μm or less, preferably in the range of 10 to 200 nm. Then, the anode is formed by a method such as vapor deposition or sputtering so as to have the above film thickness. Next, a light emitting layer is provided by forming a thin film of the ferrocene derivative represented by the general formulas (I) to (III) on this anode plate. The ferrocene derivative can be formed into a thin film by a method such as a vacuum vapor deposition method, a spin coating method, or a casting method, but the vacuum vapor deposition method is preferable because it is homogeneous and it is difficult to form pinholes.
When the vacuum vapor deposition method is applied, the vapor deposition conditions differ depending on the type of the ferrocene derivative used, the crystal structure or association structure of the target light emitting layer, etc.
~ 400 ° C, vacuum degree 10 ^-5 ~ 10 ^-3 Pa, vapor deposition rate 0.0
1 to 50 nm / sec, substrate temperature −50 to 300 ° C., film thickness 5
It is preferable to appropriately select in the range of nm to 5 μm. After forming the light emitting layer, a thin film made of a cathode material is formed on the light emitting layer by a method such as vapor deposition or sputtering so as to have a film thickness of 1 μm or less, preferably 10 to 200 nm, to prepare a cathode. As a result, the target organic EL device can be obtained. In addition, in the manufacturing of this organic EL element, it is also possible to manufacture the organic EL element by reversing the manufacturing order.

In the case of an organic EL device having a structure of anode / light emitting layer (including a ferrocene derivative) / cathode II An anode is prepared in the same manner as above. Then, a thin film is formed by applying a solution containing a hole injecting material, a light emitting material, an electron injecting material and a binder (polyvinylcarbazole etc.) to this anode plate, or a thin film is formed from this solution by a dip coating method. To form a light emitting layer. Then, a thin film made of a cathode material is formed on the light emitting layer in the same manner as described above to form a cathode, whereby the target organic EL device can be obtained. The light emitting layer may have a multi-layer structure by forming a thin film of a desired light emitting material on the layer formed as described above by a vacuum deposition method or the like. Alternatively, the light emitting layer can be formed by simultaneously vapor depositing the light emitting material together with the hole injecting material and the electron injecting material. In addition, in the manufacturing of this organic EL element, it is also possible to manufacture the organic EL element by reversing the manufacturing order.

In the case of an organic EL device having a structure of anode / hole injection layer (including ferrocene derivative) / light emitting layer / cathode: An anode is prepared on a suitable substrate in the same manner as described above. Next, a hole injection layer is provided by forming a thin film of the ferrocene derivative represented by the general formulas (I) to (III) on this anode plate. The hole injection layer can be formed in the same manner as the light emitting layer in. Then, a light emitting layer is formed on the hole injection layer using a desired light emitting material. This light emitting layer can be formed by thinning the light emitting material by a vacuum vapor deposition method, a spin coating method, a casting method or the like, but it is easy to obtain a uniform film and it is difficult to form pinholes. Therefore, it is preferable to form it by a vacuum deposition method. Then, a thin film made of a cathode material is formed on the light emitting layer in the same manner as described above to form a cathode, whereby the target organic EL device can be obtained. In addition, in the manufacturing of this organic EL element, it is also possible to manufacture the organic EL element by reversing the manufacturing order.

In the case of an organic EL device having a structure of anode / hole injection layer (including ferrocene derivative) / light emitting layer / electron injection layer / cathode, an anode to a light emitting layer are prepared in the same manner as above. . Next, a film thickness 1 of the electron injection material is formed on the light emitting layer.
An electron injection layer having a thickness of less than or equal to μm, preferably 5 to 100 nm is formed by vapor deposition, sputtering, or the like. Then, a thin film made of a cathode material is formed on the electron injection layer in the same manner as described above to form a cathode, whereby the target organic EL element can be obtained. In addition, in the manufacturing of this organic EL element, it is also possible to manufacture the organic EL element by reversing the manufacturing order.

The organic EL device of the present invention, which can be manufactured as described above, emits light by applying a DC voltage of 5 to 40 V with the anode having a positive polarity and the cathode having a negative polarity. Even if a voltage is applied with the opposite polarity, no current flows and no light emission occurs. When an alternating voltage is applied, light emission occurs only when the anode has a positive polarity and the cathode has a negative polarity. When an AC voltage is applied, the AC waveform may be arbitrary. The ionization potential of the ferrocene derivatives represented by the general formulas (I) to (III) is 5.3 to 5.5e.
Since it is as low as V, the organic EL element of the present invention can be driven at a low voltage. In addition, a thin film of a ferrocene derivative can be recrystallized over time by a conventional amine-based material (for example,
N, N'-diphenyl-N, N'-bis- (3-methylphenyl)-(1,1'-biphenyl) -4,4'-diamine: TPD) deteriorates the device life as compared with the case of using It is possible to obtain a difficult organic EL element.

[0069]

EXAMPLES The present invention will be described in more detail with reference to Synthesis Examples, Examples and Comparative Examples. Synthesis example 1

[0070]

[Chemical 34]

Synthesis of the following phosphorus compound containing biphenylene (phosphonate ester)

[0072]

[Chemical 35]

1.0 g and ferrocene carboxaldehyde
(Aldrich) 0.9 g dry dimethyl sulfoxide
And 0.5 g of potassium t-butoxide was added to the solution.
In addition, the mixture was stirred under an argon stream at room temperature for 6 hours. Reaction liquid
Exhibited a reddish brown suspension. 50 g of the obtained reaction liquid
To 100 ml of methylene chloride.
Extracted. After drying the extracted organic layer with potassium carbonate,
The solvent was distilled off and the residue was purified with a silica gel column. Moreover,
By recrystallizing the obtained purified product with methylene chloride.
Thus, 0.15 g (yield 12%) of reddish orange scale crystals were obtained.
The melting point of the obtained compound was 300 ° C, and mass spectrometry was performed.
As a result, only the peak at m / Z = 574 was obtained and the target product was obtained.
Was confirmed. The result of elemental analysis is C ₃₆H₃₀F
e₂= 574.33, C: 75.49% (theoretical value: 7
5.29%), H: 4.98% (theoretical value: 5.26%)
It was Also, ionization potential (manufactured by Riken Keiki, in the atmosphere
Photoelectron spectroscopy) is 5.38 eV, absorption spectrum
(In dimethylformamide) has λ max = 350 nm (ε
= 4.6 x 10^Fourmol^-1・ Liter ・ cm^-1)
It was

Example 1 A glass substrate having a numerical aperture (NA) of 40 and having a size of 25 mm × 75 mm × 1.1 mm and having a thickness of 100 nm (made by HOYA) of ITO was transparently supported on a glass substrate. It was used as a substrate.
The substrate was ultrasonically cleaned in isopropyl alcohol for 5 minutes, then blown with nitrogen to be dried, and then UV ozone cleaning (UV300, manufactured by Samco International) was performed.
It was done for 0 minutes. On this transparent support substrate, a resistance heating boat made of molybdenum, in which 200 mg of the ferrocene derivative obtained in Synthesis Example 1 (hereinafter abbreviated as FeVBi) was placed, and a dimethylidene-based luminescent material 4,4′-bis-
A resistance heating boat made of molybdenum containing (2,2-diphenylvinyl) -1,1′-biphenyl (hereinafter, abbreviated as DPVBi) and tris (8-quinolinol) aluminum (hereinafter, Alq) which is an electron transporting substance. 2)
A molybdenum resistance heating boat containing 00 mg was attached to each energizing terminal block. Then, this transparent supporting substrate was fixed to a substrate holder of a commercially available vacuum vapor deposition apparatus (manufactured by Nippon Vacuum Technology Co., Ltd.), and the vacuum chamber was depressurized to 1 × 10 ⁻⁴ Pa. Then, the boat containing FeVBi was heated to 320 ° C.
Then, the film was heated up to a vapor deposition rate of 0.4 to 0.6 nm / sec and vapor-deposited on the transparent support substrate to form a FeVBi layer (corresponding to a hole injection layer) having a film thickness of 60 nm. Next, the boat containing DPVBi was heated, and FeVB was deposited at a deposition rate of 0.4 to 0.6 nm / sec.
A DPVBi layer (corresponding to a light emitting layer) having a film thickness of 40 nm was formed by vapor deposition on the i layer. Next, the boat containing Alq was heated and vapor-deposited on the DPVBi layer at a vapor deposition rate of 0.1 to 0.3 nm / sec to form an Alq layer (corresponding to an electron injection layer) having a film thickness of 20 nm. Next, the vacuum layer was opened, and a molybdenum boat containing magnesium and a tungsten filament boat containing silver were newly attached to the energizing terminal block.
In addition, the previously obtained glass substrate / ITO film / FeVBi
A vapor deposition mask was attached over the layer / DPVBi layer / Alq layer. After decompressing the vacuum chamber to 1 × 10 ^-4 Pa again, first, the filament boat containing silver was energized to deposit silver at a deposition rate of 0.09 to 0.1 nm / sec and, at the same time, the boat containing magnesium. Energize to vapor deposition rate 1.
Magnesium was vapor deposited at 4-1.7 nm / sec. This 2
A 150 nm thick magnesium / silver layer (corresponding to a cathode) was formed on the Alq layer by the original simultaneous vapor deposition, and the target organic EL device could be obtained. The magnesium / silver layer of the organic EL device thus obtained is used as a cathode for ITO.
When a voltage of 15 V was applied using the film as an anode, 50
A blue emission of cd / m ² was observed. This means that the FeVBi layer having the hole injecting ability efficiently injects holes into the DPV.
It shows that the blue light emission of DPVBi was performed to carry it to the Bi layer.

Further, in order to evaluate the thin film maintaining ability (oxidation resistance), T was used as a typical example of a ferrocene derivative and a tertiary amine.
Comparisons were made using PD. An FeVBi layer having a film thickness of 60 nm was prepared in the same manner as in the example, and allowed to stand in the air at room temperature for one month, and then observed with an optical microscope. As a result, no destruction of the FeVBi layer due to recrystallization was observed. Similarly, a TPD film was prepared using TPD and tested. As a result, destruction of the TPD layer due to recrystallization was observed.

[0076]

As described above, the organic EL device of the present invention is
By containing the ferrocene vinyl unit, the oxidation resistance is excellent, the ionization potential can be lowered, and the melting point can be increased. Therefore, the organic EL element of the present invention is expected to be effectively used in various fields as having high practical value.

Claims (4)

[Claims] 1. A compound represented by the general formula (I): (In the formula, A and B are independently hydrogen and a carbon number of 1
~ 6 alkyl group, ferrocenyl group, substituted or unsubstituted aryl group having 6 to 20 carbon atoms, and A and B may be the same or different. Here, the substituent is an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms,
It represents an aryloxy group having 6 to 18 carbon atoms, a phenyl group, a cyano group, a nitro group, a hydroxyl group or halogen. ) An organic electroluminescence device comprising a compound having one or more ferrocene vinyl units represented by the formula (1) sandwiched between a pair of electrodes. 2. A compound having a ferrocene vinyl unit is represented by the general formula (II): (In the formula, R ^{1 to} R ⁴ are independently hydrogen and carbon atoms 1
~ 6 alkyl group, ferrocenyl group, substituted or unsubstituted aryl group having 6 to 20 carbon atoms, and R ^{1 to} R ⁴ may be the same or different. Here, the substituent is an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms,
It represents an aryloxy group having 6 to 18 carbon atoms, a phenyl group, a cyano group, a nitro group, a hydroxyl group or halogen. Also,
R ¹ and R ² or R ³ and R ⁴ may combine with a substituent to form a substituted or unsubstituted saturated five-membered ring or a substituted or unsubstituted saturated six-membered ring. The organic electroluminescent element of Claim 1 which is a compound represented by these. 3. A compound having a ferrocene vinyl unit.
The compound has the general formula (III):(In the formula, R^FiveAnd R⁶Are independently hydrogen and carbon
Alkyl groups, ferrocenyl groups, substituted or
An unsubstituted aryl group having 6 to 20 carbon atoms, R ^FiveAnd
And R⁶May be the same or different. Where ally
The substituent bonded to the alkyl group is an alkyl group having 1 to 6 carbon atoms,
C1-C6 alkoxy group, C6-C18 aryl
Luoxy group Phenyl group, cyano group, nitro group, hydroxyl group
Or halogen. Ar is substituted or unsubstituted
Represents an arylene group having 6 to 20 carbon atoms of
Or more than one may be substituted, and the binding site is
It may be any of g, para, and meta, and is bonded to the arylene groups.
Substituted or unsubstituted saturated five-membered ring or substituted or
An unsubstituted saturated 6-membered ring may be formed. Where ally
The substituent bonded to the len group may be an alkyl group having 1 to 6 carbon atoms.
Kill group, alkoxy group having 1 to 6 carbon atoms, 6 to 18 carbon atoms
Aryloxy group, phenyl group, cyano group, nitro
Indicates a group, hydroxyl group or halogen. ) 4. An organic electroluminescent device, characterized in that the hole injection material comprises the compound according to any one of claims 1 to 3.