JP2001247498A - Organic compound and element using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an organic compound having high chemical and thermal stabilities and functions of carrier-transporting property, and the like. SOLUTION: This organic compound has a skeleton in which three or more aromatic rings are bonded to each other at mutual arbitrary positions and is composed of only >=18 carbon atoms and F. Specifically, the organic compound has a structure represented by the formula C6nF4n+2 or the following formula (1) or (2) or is a compound composed of only C and F, in which a polyacene ring including naphthalene ring is directly bonded. The compound exhibits transporting properties of electron and positive hole and can be used as an electron transporting layer, or the like, of an EL element and can be used as a positive hole-blocking layer when positive hole-blocking function is exhibited and can improve the element life when the compound is used as a protective film.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel organic compound, and more particularly, to an organic compound useful as a luminescent material of an organic electroluminescent device (hereinafter, referred to as an organic EL device) and other functional device materials.

[0002]

2. Description of the Related Art At present, C ₆ H is used as a functional organic film.
₆ (benzene ring) and compounds having a structure mainly composed of C—H bonds are generally used. In addition, various functional organic films are formed using elements such as oxygen (O), nitrogen (N), and sulfur (S) in addition to the C and H elements. These organic materials and organic thin films are electrically insulating films, nonlinear optical materials,
It is used for functional elements such as optical devices and electronic devices such as a hole transport layer and an electron transport layer of an organic EL element.

[0003]

The C—H bond of the conventionally used functional organic material as described above has a slightly small binding energy. Therefore, the C—H bond is exposed to ultraviolet light or a high electric field to be applied. There is a disadvantage that the -H bond is broken and the material deteriorates.

On the other hand, polymer materials such as polytetrafluoroethylene (trade name “Teflon”) as a material mainly composed of C—F bonds are excellent in heat resistance and chemical stability, but have a band gap. The large insulator limits its use. In particular, in a functional element such as an organic EL element that requires functions such as a carrier transport property and a light emitting property, it cannot be used as a required functional organic material.

An object of the present invention is to solve the above-mentioned problems, and an object of the present invention is to provide a novel organic compound having various functions while maintaining thermal and chemical stability. Another object is to provide an organic EL using the above novel organic compound.
It is to provide a functional element such as an element.

[0006]

The novel organic compound according to the present invention has a skeleton in which three or more aromatic rings are bonded to each other at any position, and has 18 or more carbon atoms and carbon atoms of at least 18 carbon atoms.
And only fluorine atoms F.

Another feature of the present invention is that the organic compound is
That is, it is a compound represented by a composition formula C _6n F _{4n + 2} .

Another feature of the present invention is that the organic compound is represented by the following chemical formula (1) or (2):

Embedded image

Embedded image Is a compound represented by the following structure:

In an organic compound according to another feature of the present invention, a polyacene ring of a naphthalene ring or higher is directly bonded at an arbitrary position, and all hydrogen atoms are substituted with fluorine.

Another feature is that the organic compound is represented by the following formula C:
_10n F _{6n + 2} or C _14n F _{8n + 2} or C _{18 n} F _{10n + 2} or C _22n
F _{12n + 2} .

Still another feature of the present invention is that, in a functional device having an organic thin film, the organic thin film contains the above organic compound.

Still another feature is that, in an organic electroluminescent device having at least one organic compound layer formed between electrodes, the organic compound layer contains the organic compound.

The organic compound of the present invention is an aromatic ring having no C—H bond, for example, C ₆ F ₆ (fluorobenzene).
Bind several (at least 3) or C ₁₀ F
₈ (Fluoronaphthalene) More than one acene ring is bonded, and is composed of C and F only. Such CC and C
A compound composed of only -F has increased thermodynamic stability and an increased glass transition temperature and melting point. Therefore, CF
A device using an organic film having a bond can have improved durability and lifetime.

Further, the organic compound of the present invention has a structure in which a plurality of aromatic rings are bonded to each other, and thus has a structure in which a π-conjugated system is spread in a molecule, and exhibits excellent properties such as carrier transportability. I do. In addition, the organic compound of the present invention has an electronegativity of F which is much larger than that of H from the viewpoint of electronic properties, so that an aromatic ring (for example, a benzene ring, a naphthalene ring or a higher acene ring) can be used to convert F Electrons are pulled out to the side, C
Electrons can be easily injected from the cathode as compared with the -H compound.

[0015] Such carrier (electron and hole) transport properties are such that electrons are attracted from the aromatic ring (for example, a benzene ring) to the F side due to the high electronegativity of F as described above, and LUMO (lowest unoccupied molecular or
bital), HOMO (highest occupied molecular orbi)
tal) It is considered that the level is lowered, so that injection of electrons into the organic compound layer becomes easy. Further, it is considered that, because the conjugated system is spread in the molecule, the mobility of the electrons and holes injected into the layer is large, and the electrons and holes can be efficiently transported.

Therefore, the organic compound of the present invention is an organic compound
It can be used as a functional material of a functional element such as an L element, and the use of this organic compound can reduce the element resistance and lower the operating voltage of the element.
For example, when the organic compound of the present invention is used for an organic layer of an organic EL device, for example, an electron transport layer, the electron injection characteristics are improved and the mobility is large as compared with an electron transport layer made of a CH organic compound. As a result, the driving voltage of the organic EL element decreases.

Another feature of the present invention is an organic electroluminescent device in which an organic compound layer is formed between an anode and a cathode.
In the organic compound layer, a hole blocking layer containing the organic compound is provided between the cathode and the organic light emitting layer.

The organic compound of the present invention is a stable compound as described above and has a low HOMO level. Therefore, for example, in an organic EL device, the layer containing the organic compound of the present invention is:
Since the HOMO level is lower than that of a general hole transport layer or light emitting layer, holes can be blocked. Therefore, when used as such a hole blocking layer, holes can be confined in the organic light emitting layer, and the luminous efficiency of the device can be improved.

The C-F of the present invention for the electrodes of the device
If the electrode material is selected so that the barrier height of the compound becomes small, holes can be injected into the CF compound layer of the present invention, and the mobility of the injected holes is sufficiently large as described above. Therefore, it can be used as a hole transport layer of an organic EL device or the like.

Another feature of the present invention is an organic electroluminescent device having an organic compound layer between electrodes, wherein the organic compound is used as a protective film covering the device.

Compared with a device protective film using a C—H compound, the C—F compound of the present invention exhibits a good water-repellent property because the interaction between molecules is low and the surface energy is reduced. For this reason, a high effect as a protective film for preventing intrusion of moisture into a device or the like appears. For example, at present, it is known that water has a very serious effect on the life of an organic EL device.
By using the F compound, the high water repellency of the compound can reduce the amount of water penetrating into the element, and can improve the durability and life of the device.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention (hereinafter, referred to as embodiments) will be described below with reference to the drawings.

[Embodiment 1] The organic compound of the present embodiment has a skeleton in which three or more aromatic rings are bonded to each other at arbitrary positions, has 18 or more carbon atoms C, and has carbon atoms C and fluorine It is composed of only atoms F.

An example of this compound is represented by the following chemical formula

Embedded image

Embedded image And organic compounds A, B, C, D, E, F, and Z represented by the composition formula C _6n F _{4n + 2} . Each of these organic compounds has three or more perfluorinated aromatic rings and has a structure in which a conjugated system has been developed.

Further, as another example of the organic compound of the present embodiment, the following chemical formula

Embedded image

Embedded image Compounds G and H having the structures shown below.

Of the above compounds, for example, compound B, compound C, compound E, compound G, compound H and the like, particularly, a conjugated system has been widely developed because other perfluorinated aromatic rings are bonded to their para positions. It has a molecular structure.

Another example of the organic compound of the present embodiment is an organic compound in which a polyacene ring equal to or more than a naphthalene ring is directly bonded at an arbitrary position, and all hydrogens are substituted with fluorine. As an example of this compound, a composition formula C _10n F _{6n + 2}
Or a compound represented by any of C _14n F _{8n + 2,} C _18n F _{10n +2} or C _22n F _{12n + 2} . More specifically, compounds I, J, K, L, M having the structures shown below
Is mentioned.

[0028]

Embedded image These organic compounds of the present embodiment have water repellency, high thermodynamic stability, and high glass transition temperatures and melting points. In addition, since a plurality of aromatic rings are bonded to each other, the molecule has a structure in which a π-conjugated system is spread in a molecule, and exhibits excellent characteristics such as carrier transportability. In particular,
In these organic compounds, since the electronegativity of F is much higher than that of H, electrons are extracted from the aromatic ring (for example, a benzene ring, a naphthalene ring or a higher acene ring) to the F side, and the LUMO, Low HOMO level, C-
Carriers, especially electron mobility, are superior to H compounds.

[Embodiment 2] In Embodiment 2, a skeleton in which three or more aromatic rings exemplified in Embodiment 1 are bonded at arbitrary positions, the number of carbon atoms of which is 18 or more, and the carbon atom C An organic compound (fluorinated compound) composed only of fluorine atoms F is used as a material for an organic thin film of an optical device or an electronic device.

Hereinafter, as specific examples of these devices, an organic EL element in which at least one organic compound layer is formed between electrodes will be described.

FIG. 1 shows a schematic structure of an organic EL device according to the second embodiment. The organic EL element is formed on a transparent substrate 10 by a first
Electrode 12 and organic compound layer 2 that emits light when an electric field is applied
0 and the second electrode 16 are sequentially laminated.

As the transparent substrate 10, a glass substrate, a transparent ceramics substrate, a diamond substrate or the like can be used. As the first electrode 12, a transparent electrode having high light transmittance and conductivity is used. For example, ITO (In
For example, a thin film material such as dium tin oxide, SnO ₂ , In ₂ O ₃ , or polyaniline can be used.

In the organic EL device, the organic compound layer 20
Is a site that emits light when an electric field is applied, and includes, for example, a single-layer structure of a light-emitting layer, a two-layer structure of a hole transport layer and a light-emitting layer, and a three-layer structure of a hole transport layer, a light-emitting layer, and an electron transport layer. Is done. The organic compound layer 20 may have a thickness of, for example, several tens to several hundreds nm.
In the second embodiment, the organic compound layer 20 has a configuration in which a hole transport layer 22, a light emitting layer 24, and an electron transport layer 26 are formed between an anode and a cathode. As the material of the layer 26, the fluorinated compound (CF compound) described in the first embodiment is used.

As the second electrode 16 formed on the organic compound layer 14, for example, a metal electrode such as Mg, Ag, an Mg-Ag alloy, an Al-Li alloy, or LiF / Al is used.

In the organic compound layer 20 having a three-layer structure, for example, triphenylamine tetramer (TPTE) can be used as the hole transport layer 22. For the light emitting layer 24, for example, a quinolinol aluminum complex (Alq ₃ ) can be used. The hole transport layer 22 and the light emitting layer 24
The present invention is not limited to the above examples, and currently known hole transporting functional molecules and luminescent functional molecules can be used.

As the material of the hole transport layer, for example, the following materials can be used. Aromatic tertiary amines, hydrazones, carbazoles, or derivatives thereof. The aromatic tertiary amine is, for example, N, N'-bis (3-methylphenyl) -N, N'-diphenyl-
(1,1′-biphenyl) -4,4′-diamine (TP
D), triphenylamine such as N, N'-di (1-naphthyl) -N, N'-diphenyl- [1,1'-biphenyl] -4,4'-diamine (α-NPD) and a large amount thereof Body or having a spiro center in the molecule,
It may be a so-called π-electron star burst molecule such as triarylamine.

As the light emitting layer material, for example, the following materials can be used. Materials that give high fluorescence quantum yields in thin film state, such as oxathiazole,
Phenanthrene, triazole, quinacridone, rubrene, coumarin or derivatives thereof, or 8-
A single or combination of a metal complex of a quinone derivative such as hydroxyquinoline with aluminum, zinc, perylium or the like.

As the electron transport layer 26, the CF compound of the first embodiment is used as described above.

In the organic EL device having the above structure, the first electrode 12 is used as an anode, the second electrode 16 is used as a cathode, and holes injected from the anode are transported to the light emitting layer by the hole transport layer. Holes and electrons are injected into the organic compound layer 20 by highly efficiently transporting electrons injected from the cathode by the above-described electron transporting layer made of the fluorinated compound, and holes and electrons are generated in the light emitting layer 24. Recombination excites the light emitting material to obtain fluorescence.

Here, conventionally, as an electron transport function molecule,
Alq also known_ThreeAnd used as the electron transport layer 26
When compared with the CF compound shown in Embodiment 1 above, A
lq _ThreeThe reduction potential representing the LUMO level of -2.38 V
Whereas the CF compound is -2.17 to-
2.49V. Of the organic film constituting the electron transport layer 26
The lower the LUMO level, the lower the
This indicates that electrons are easily injected from the cathode. Therefore, the book
The electron transport layer 26 made of the CF compound of the present invention has Al
Electrons can be easily injected from the electrode, and the CF compound
By using the material as the electron transport layer 26, the
Easy to lower rise voltage (light emission threshold voltage)
Becomes

In particular, among the fluorinated compounds of the first embodiment, compounds having a structure in which the fluorobenzene ring is bonded to each other at the para position to extend the conjugated system, such as compound E, compound H, and compound G, are high. Since they exhibit electron mobility, they are excellent as materials for the electron transport layer of the organic EL device.

Among the compounds of Embodiment 1, for example, the composition formulas C _10n F _{6n + 2} , C _14n F _{8n + 2} , C _18n F _{10n + 2} ,
_22n F _{12n + 2} in polyacene than naphthalene ring represented is superior fluorinated compound bound directly at any position. For example, the compounds I, J, K, L and M described above have a very long π-conjugated system and high electron mobility while maintaining thermal and chemical stability, and exhibit an electron transporting material for an organic EL device. As excellent.

The CF compound according to the present invention comprises
The F bond energy is larger than the C—H bond and has excellent thermal stability. For this reason, the electron transport layer using the CF compound according to the present invention has excellent heat resistance, that is, excellent film stability, against an increase in element temperature during element driving, which is known as an important factor of deterioration of the organic EL element. And greatly contributes to prolonging the half life of luminance of the device.

[Third Embodiment] In the second embodiment, the CF compound of the present invention is used as a material for an electron transport layer of an organic EL device. In the third embodiment, an electrode (cathode) is used.
And used as a hole-blocking layer.
FIG. 2 shows a schematic configuration of the organic EL element according to the third embodiment. First electrode 12, organic compound layer 2 on substrate 10
0, the second electrode 16 is formed, and the organic compound layer 20 includes a hole transport layer 22, a light emitting layer 24, and an electron transport layer 28. Further, between the second electrode 16 serving as a cathode and the light emitting layer 24, more specifically, the electron transport (Alq ₃ ) layer 2
The hole blocking layer 30 using the CF compound described in the first embodiment is formed between the light emitting layer 8 and the light emitting (Alq ₃ ) layer 24.

As described above, the organic EL element emits light by injecting electrons and holes from the cathode and anode into the light emitting layer and recombining them in the light emitting layer. In order to improve the luminous efficiency in such an organic EL device, it is necessary to efficiently recombine electrons and holes in the luminescent layer. At present, an aluminum quinolinol complex (Alq ₃ ), which is frequently used as a light emitting material, is known as a light emitting material that also has an electron transport function. In this Alq ₃ , electrons are mainly transported,
It also transports holes. Therefore, when the Alq ₃ layer is formed as the light-emitting layer also serving as the electron transport layer, even when holes are injected from the anode to the hole transport layer into the light-emitting layer (Alq ₃ layer), all electrons and electrons are present in the light-emitting layer. There are holes that are transported to the cathode without recombination, leading to a decrease in luminous efficiency.

FIG. 3 shows the hole blocking effect when the above-mentioned CF compound (CxFy) is formed as the hole blocking layer 30 between the cathode and the light emitting layer as in the third embodiment. I have. The holes injected from the anode are the HOM of the organic compound layer.
The O level is conducted to reach the Alq ₃ layer, which is the light emitting layer. Since the gap between the HOMO level between the anode and the hole transport layer (TPTE layer) and between the hole transport layer and the light emitting layer is small, holes are injected from the anode toward the light emitting layer.
However, as shown in FIG. 3, since the CF compound of the present invention described in Embodiment 1 has a particularly low HOMO level, holes pass through the barrier between the light emitting layer and the CF compound layer. Can not. Therefore, the CF compound layer functions as a hole blocking layer. On the other hand, since the CF compound has developed a conjugated system and has a low LUMO level, it easily allows electrons to pass therethrough, and functions as a hole blocking layer and exhibits an electron transporting function. Therefore, it is possible to efficiently confine electrons and holes in the light emitting layer and emit light by the presence of the CF compound layer, which is a hole blocking layer also serving as an electron transport function, formed between the cathode and the light emitting layer. Become.

The hole blocking layer is first required to have a sufficient hole blocking property, that is, a sufficiently low HOMO level. Such a condition satisfies all of the above-mentioned compounds A to M and compound Z. In addition, since the device is disposed between the cathode and the light emitting layer, the device needs to have a high electron transport function in order to emit light. As in the above-described Embodiment 2, the electron-transporting property is advantageously a structure in which aromatic rings are long connected to each other at the para-position, and the hole-blocking layer is a compound C rather than the compound B and a compound more than the compound C. E is excellent, and compounds G, H, and the like can easily realize better properties.

[Embodiment 4] In Embodiment 4, a CF compound as described in Embodiment 1 is used as a protective film of an element. In particular, in the case of an organic EL device in which low water resistance of the device is a problem, the use of the CF compound of the present invention as a material for a protective film covering the device can greatly extend the life of the device.

FIG. 4A shows an example of a structure in which the above-mentioned CF compound is used as a protective film of an organic EL device. FIG. 4B shows a configuration for protecting a general organic EL element.

An organic compound layer 20 is formed between the first electrode 12 and the second electrode 16. In the fourth embodiment, the second electrode is formed on the organic compound layer 20 so that at least the organic compound layer 20 is not exposed to the outside air. After the formation of 16, a protective film 40 made of a CF compound is formed so as to cover almost the entire surface of the element formed on the substrate 10. CF according to the present invention
Since the organic compound can be formed on the device by vapor deposition, device manufacture becomes very simple. On the other hand, in general, organic EL
As shown in FIG. 4 (b), after the device is formed, the substrate 10 is placed in a dry nitrogen (N ₂ ) atmosphere to shield the device from the outside air.
A housing that covers the element is bonded to (actually, the first electrode 12) and sealed.

The CF organic compound of the present invention can form a dense film exhibiting excellent water repellency.
Only by forming a protective film using this CF compound so as to cover the L element, an effect equivalent to that obtained by sealing the organic EL element as shown in FIG. 4B can be obtained. Further, since the CF compound which is an organic compound can be formed into a film by an evaporation method, the element can be protected without attaching a special sealing housing or the like. Therefore, organic EL
It is also very effective in reducing the thickness and size of the device, and the device can be manufactured by a simple process.

The material of the organic compound layer 20 of the organic EL device is the same as that of the second and third embodiments.
It is possible to use a -F compound and a CF compound as the protective film, and it is also possible to produce the organic compound layer and the protective film with a common manufacturing apparatus. As the material of the protective film, any of the CF compounds described in Embodiment 1 can be used. However, Compound A or Compound D having a twisted or branched structure is more preferable than Compounds E, H, and G.
Etc. are better.

In the embodiment 2-4, not only the CF compound shown in the embodiment 1 but also one or two
A CF compound having only one carbon and fluorine having two aromatic rings may be used.

[0054]

Embodiments of the present invention will be described below.

Example 1 In Example 1, a compound A (C ₆₀ F ₄₂ ) having a structure in which a total of 10 fluorobenzenes were bonded as an example of the synthesis of a CF compound according to the present invention was used as an example. formula

Embedded image This will be described below with reference to FIG.

(I) Compound 1 (1,3,5-trifluoro-2,4,6-
Synthesis of tris (2,4,6-trifluorophenyl) benzene) Magnesium (2.91 g, 120 m) under an argon stream
mol) and 1-bromo-2,4,6-trifluorobenzene [1-bromo-2,4,6-trifluorobenzene] (25.3)
g, 120 mmol) and Grignard reagent prepared in THF (120 ml) was added to anhydrous copper bromide (34.4 g, 240 mmol).
mmol), and the mixture was stirred at room temperature for 1 hour, and then dioxane (30 ml) was added and the mixture was further stirred for 1 hour. To this suspension, 1,35-tribromo-2,4,6-trifluorobenzene [1,3,5-tribromo-2,4,6-trifluorobenzene]
(9.22 g, 25.0 mmol) in toluene (200
ml) solution and stirred at 80 ° C. for 4 days. After the reaction mixture was filtered and the solvent was distilled off under reduced pressure, the residue was dissolved in toluene. The toluene solution was washed with 3M hydrochloric acid, further washed with saturated saline, dried over anhydrous magnesium sulfate, and toluene was distilled off under reduced pressure. The obtained reaction mixture was recrystallized from ethanol / water to obtain the desired compound 1: 1,
3,5-trifluoro-2,4,6-tris (2,4
6-trifluorophenyl) benzene [1,3,5-trifluor
o-2,4,6-tris (2,4,6-trifluorophenyl) benzene] (7.
61 g, 58%). The filtrate is further concentrated under reduced pressure,
The residue was separated and purified by silica gel column chromatography (hexane) to give compound 1 (1.40).
g, 11%).

When the melting point of Compound 1 was measured,
p. = 157 ° C-158 ° C in chloroform-d
¹⁹ F-nuclear porcelain resonance spectrum ( ¹⁹ F-NMR (470.
4 MHz, CDCl ₃ )), the chemical shift δ
Is 56.50-56.58 (m, 3F), 56.28
-56.37 (m, 3F), 54.96-55.06
It was observed at the position (m, 6F). Further, ¹ H-nuclear porcelain resonance spectrum ( ¹ H-NMR (50 H
0 MHz, CDCl ₃ )), δ is 6.80-6.
86 (m, 6H). Mass spectrometry (EI
MS (m / z, relative intensity)
y)), 522 (M ⁺ , 100%), 261 (M ⁺
-2C ₆ H ₂ F _3, the peak of 33.5%) was observed.
From these analyses, it was confirmed that Compound 1 was C ₂₄ H ₆ F ₁₂ .

(Ii) Compound 2 (1,3,5-trifluoro-2,4,
6-tris (3,5-dibromo-2,4,6-trifluorophenyl) benzene)
Bromine was added dropwise to a mixture of the above compound 1 (5.60 g, 12.4 mmol) and reduced iron at room temperature, and the mixture was stirred at 60 ° C. for 3 days. An aqueous solution of sodium thiosulfate was added to the reaction mixture, and the mixture was extracted with dichloromethane. The organic layer was washed with saturated saline, dried over anhydrous magnesium sulfate, and then concentrated under reduced pressure. The resulting reaction mixture was recrystallized from hexane,
Target compound 2: 1,3,5-trifluoro-2,
4,6-tris (3,5-dibromo-2,4,6-trifluorophenyl) benzene [1,3,5-trifluoro-2,4,6-
tris (3,5-dibromo-2,4,6-trifluorophenyl) benzene]
(9.71 g, 79%).

When the melting point of Compound 2 was measured, M
p: 269 ° C.-270 ° C., ¹⁹
F-nuclear porcelain resonance spectrum ( ¹⁹ F-NMR (470.4
MHz, CDCl ₃ )), the chemical shift δ
Are 70.35 (s, 3F), 60.61 (s, 6
F), 59.04 (s, 3F). Mass spectrometry (EIMS (m / z, relative int
efficiency)), 989 (M ⁺ , 3.4)
^{%), 991 (M + +2,30.1} %), 993 (M + +
4,56.9%), 995 (M ⁺⁺ 6,100%), 9
97 (M ^{+ +} 5,54.8%), 999 (M ⁺ +10,3
8.2%) was observed. From these analyses,
Compound 2 was confirmed to be C ₂₄ Br ₆ F ₁₂ .

(Iii) Compound A (1,3,5-trifluoro-2,
4,6-tris (3,5-bis (pentafluorophenyl) -2,4,6-trifluor
Synthesis of magnesium (0.292 g, 12.
0 mmol) and bromopentafluorobenzene [bromop
entafluorobenzene] (2.97 g, 12.0 mmo
l) Grign adjusted in THF (30 ml)
An anhydrous copper bromide (3.44 g, 24.0 mm) was added to the ard reagent.
ol), and the mixture was stirred at room temperature for 1 hour, and then dioxane (15 ml) was added and the mixture was further stirred for 1 hour. To this suspension was added a solution of compound 2 (0.996 g, 1.00 mmol) in toluene (30 ml), and the mixture was stirred at 80 ° C. for 24 hours. The reaction mixture was filtered, the solvent was distilled off under reduced pressure, and the residue was dissolved in toluene. The toluene solution was washed with 3M hydrochloric acid, further washed with saturated saline, dried over anhydrous magnesium sulfate, and toluene was distilled off under reduced pressure. The target compound A: 1,3,5-trifluoro-2,4,4 was obtained by separating and purifying the obtained reaction mixture by silica gel column chromatography (hexane / toluene = 20/1).
6-tris (3,5-bis (pentafluorophenyl)
-2,4,6-trifluorophenyl) benzene (1.
29 g, 85%).

When the melting point of Compound A was measured, M
p: Very high at 273 ° C-274 ° C. In addition, ¹⁹ F-nuclear porcelain resonance spectrum ( ¹⁹ F-N
When MR (470.4 MHz, CDCl ₃ )) was measured, the chemical shift δ was 61.04 (s, 3F), 6
0.67 (s, 6F), 60.43 (s, 3F), 2
4.26-24.49 (m, 12F), 13.31
(T, J = 21.6 Hz, 6F), 2.42-2.60
It was observed at the position (m, 12F). Mass spectrometry (EIM
S (m / z, relative intensity)
In the result of y)), a peak of 1518 (M ⁺ , 100%) was observed. From these analyzes, Compound A, C _{6 0
F42} was confirmed.

Example 2 Examples 2-1 and 2-2 of an example in which an organic EL device was produced by using the CF organic compound of the present invention as an electron transport layer material as shown in Embodiment 2 It will be described as.

(Preparation of Device) The device configuration is as shown in FIG. 1 described above. As the substrate 10, a glass substrate on which ITO serving as the first electrode 12 was patterned was used. The substrate 10 is ultrasonically cleaned in the order of an organic alkali cleaning agent Semico Clean 56 (Furuuchi Chemical), pure water, acetone and ethanol, and then subjected to UV ozone treatment to remove organic contaminants on the ITO surface, and quickly deposited. It was set on the device. Next, a mask for an organic compound layer is attached in a vacuum, and then the hole transporting layer 22 [triphenylamine tetramer] is first formed into an organic compound layer 20 by heating to 60 nm by a carbon crucible heating, and the light emitting layer 24 [quinolinol] Aluminum complex (Alq ₃ )] of 40 nm and an electron transport layer 26 [C
-F compound] was deposited in the order of 20 nm. The deposition rate was 2 to 6 nm / min.

Next, the mask was changed to a cathode electrode (second electrode) in a vacuum, and LiF was changed from a Ta boat to 3 nm / mi.
n and Al were deposited from a PBN crucible at a deposition rate of 10 nm / min at 0.5 nm and 160 nm, respectively, to obtain a second electrode 16 having a laminated structure. Each film constituting the device was formed under a condition of 5 × 10 ⁻⁷ Torr or less with respect to the degree of vacuum.

As the electron transporting layer 26, seven types of organic EL devices were prepared using the compounds A, B, C, D, E, F and Z described in Example 2-1. In Example 2-2, two types of organic EL devices were prepared using the above compounds I and J as the electron transport layer 26, respectively.

As Comparative Example 1, an element having a structure in which Alq ₃ was deposited to a thickness of 20 nm in place of the electron transport layer 26 in FIG. 1 was manufactured.

(Characteristic evaluation) Organic E prepared by the method described above
For the L element, the relationship between the applied voltage and the emission luminance and the relationship between the injection current density and the emission luminance were measured in a chamber sufficiently purged with nitrogen, and the luminous efficiency was also calculated. Further, a current was injected so that the initial luminance became 2400 cd / m ^2, and the dependence of the luminance on the driving voltage was measured.

The results of the evaluation of Example 2-1 are shown in FIGS.
As shown in FIG. All of these organic EL devices have a light emitting layer A
green emission from lq ₃ was obtained. In Comparative Example 1, Al
q ₃ also serves as a light-emitting layer and an electron transporting layer, the rise voltage is 4V. In the present Example 2-1, many of the devices provided with the electron transport layer 26 made of the CF compound have a rising voltage that is not as low as Comparative Example 1, but the electrons are still sufficiently emitted from the Al electrode. Injected into the transport layer. In addition, as shown in FIG. 6, all of the devices of Example 2-1 had a light emission luminance of 1000 cd / m ² or more, and electrons were transported to the light emitting layer 24 (Alq ₃ ). I understand. In particular, a device using compound E in which fluorobenzene is bonded to the para position and the service system is extended for the longest time has the best characteristics, and the EL device shown in FIGS.
The characteristics are almost the same as those of the comparative example of Alq ₃ .

The half-life of the luminance when the initial luminance was 2400 cd / m ² was 15 hours in Comparative Example 1, and each element on which the CF electron transport layer 26 of Example 2 was formed was: It showed a half life of about 20 hours.

The evaluation result of Example 2-2 is shown in FIG.
And FIG. First, compound I or compound J is transferred by electron transport.
Each of the organic EL elements used for the transfer layer was composed of a light-emitting layer Alq_Three
Green light was obtained. And as shown in FIG.
Alq_ThreeIs Comparative Example 1 in which the light emitting layer and the electron transporting layer are combined.
Compounds I and J were charged while the rising voltage was 4V.
The organic EL device according to Example 2-2 used in the
V or less, a low start-up voltage,
Sufficient electrons from the electrode are electrons of the perfluorinated compound (CF)
It can be seen that it has been injected into the transport layer. Example 2
Very low rise voltage compared to each device
It can be seen that it has been realized. FIG. 9 shows the emission luminance.
As shown, in the organic EL device of Example 2-2, 1000
0 cd / m ^TwoThe above has been achieved, and is completely different from Comparative Example 1.
Equivalent or better characteristics are obtained, and electrons are emitted from the light emitting layer Alq
_ThreeYou can see that it has been transported up to.

Example 3 An example in which an organic EL device was produced using the CF organic compound of the present invention as a hole-blocking layer material as described in Embodiment 3 will be described below as Example 3.

(Fabrication of Device) The structure of the organic EL device of Example 3 is as shown in FIG. As the substrate 10,
The same glass substrate 10 with cleaned ITO (12) as in Example 2 was used. After mounting the mask for the organic film in a vacuum, heating the carbon crucible, as an organic film,
60 n of the hole transport layer 22 [triphenylamine tetramer]
m, light emitting layer 24 [aluminum quinolinol complex (Al
q ₃ )] is 20 nm, then the C—F organic compounds (compounds B and C) as described in the first embodiment are 5 nm as the hole blocking layer 30, and the Alq ₃ is 35 as the electron transport layer 28.
nm. These film formation rates are 2 to 6 nm / mi.
n.

Next, the mask was changed to a cathode electrode in a vacuum, and the LiF electron injection layer was removed from the Ta boat by 2 nm / min.
At 0.5 nm and Al from the PBN crucible at 10 nm / mi
A film having a thickness of 160 nm was formed at a deposition rate of n to obtain a second electrode 16 having a laminated structure. Each film constituting the element was formed under a condition of 5 × 10 ⁻⁷ Torr or less with respect to the degree of vacuum.

Further, as Comparative Example 2, an organic EL device having no hole blocking layer (organic compound layer: TPTE / Alq ₃ ) was manufactured.

(Characteristic evaluation) Organic E prepared by the above method
For the L element, the relationship between the injection current density and the light emission luminance and the relationship between the applied voltage and the light emission luminance were measured in a chamber sufficiently purged with nitrogen, and the light emission efficiency was also calculated. Further, a current was injected so that the initial luminance became 2400 cd / m ^2, and the dependence of the luminance on the driving voltage was measured.

The evaluation results are shown in FIGS. The driving voltage of the device using the compounds B and C as the hole blocking layer 30 as in Example ₃ is reduced to the same level as that of Comparative Example 2 of Alq ₃ . This indicates that the CF compound used as the hole blocking layer sufficiently functions as the electron transporting layer. Further, as compared with the device in which the C—F compound layer as the electron transport layer was formed at the interface between the Al cathode and the Alq ₃ layer as the light emitting layer as in Example 2 above, the compound of the present Example 3 Regardless of whether attention is paid to B or C, the emission luminance is improved in each step. Therefore, the luminous efficiency was improved by preparing an organic EL device using the CF compound of the present invention for the hole shielding layer, and Comparative Example 2
It can be seen that the luminous efficiency (cd / A) equal to or higher than that of the element having no hole blocking layer can be easily achieved.

The half-life of the luminance when the initial luminance is set to 2400 cd / m ² is increased to 20 hours or more in each element according to Example 2 as compared with 15 hours in Comparative Example 2, and the life is prolonged. It has become possible.

Example 4 An example in which the CF organic compound of the present invention is used as a protective film of an organic EL device as described in Embodiment 4 will be described below as Example 4.

(Preparation of Device) The device was prepared in the same manner as in Comparative Examples 1 and 2 of Examples 2 and 3 up to the step of preparing an Al cathode. The organic compound having a two-layer structure of TPTE and Alq ₃ was used. An element including the layer 20 was manufactured (see FIG. 4A). Thereafter, in Example 4, as shown in FIG. 4A, the CF compound (compounds A, B, and D) of the present invention described in Embodiment 1 was deposited as the protective film 40 at a deposition rate of 5 nm.
/ Min at 300 nm. In addition, as Comparative Examples 3 and 4, an element having no protective film formed thereon and an element sealed with dry nitrogen by a sealing housing as shown in FIG. 4B were produced.

(Evaluation of Characteristics) As shown in FIG. 12, the organic EL device having the protective film 40 formed in the present Example 4 was different from the device having no protective film formed (Comparative Example 3).
In any of the devices using Compounds A, B, and D, the luminance half life of the device is prolonged in each step, and a dark spot, which is a light emission defect generated due to deterioration of an organic compound layer or the like, hardly grows. The device in which the CF compound according to Example 4 was formed as the protective film 40 showed almost the same life as the device driven in dry nitrogen (Comparative Example 4). Therefore, it can be seen that by adding a simple step of forming a protective film by vapor deposition, it is possible to realize an element having a long life equal to or longer than that of an element in which the element is sealed with dry nitrogen and a sealing housing.

The prolongation of the life of the element is as follows.
The CF compound according to the present invention is excellent in water repellency and has a high effect of preventing intrusion of moisture in the air, and thus is found to be excellent as a protective film.

[0082]

The CF compound according to the present invention is thermally,
It has very high chemical stability, and can exhibit functions such as carrier transportability of electrons and holes or hole blocking properties.

When such an organic compound having a CF bond is used as a functional material of a device such as an organic EL device, a device having good durability and high performance can be obtained. When the organic compound of the present invention is used for an organic compound layer of an organic EL device, for example, an electron transport layer, electron injection characteristics are higher than an electron transport layer composed of a CH organic compound, and electron mobility in the layer is higher. Since it is large, the luminous efficiency can be improved, the drive voltage can be reduced, and the life of the element can be improved. In addition, when used as a hole blocking layer of an organic EL element, the luminous efficiency of the element can be further improved.

The organic compound of the present invention is useful also as a protective film, and when used for device protection, contributes to prolonging the life of the device and is very effective in terms of reducing the thickness of the display panel. Further, since this protective film can be formed by vapor deposition or the like, it can be easily manufactured.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of an organic EL device according to a second embodiment of the present invention.

FIG. 2 is a diagram illustrating a configuration of an organic EL device according to a third embodiment of the present invention.

FIG. 3 is a diagram illustrating a hole blocking function of an organic EL element according to a third embodiment of the present invention.

FIG. 4 shows organic E according to Embodiment 4 of the present invention and a comparative example.
FIG. 3 is a diagram illustrating a configuration of an L element.

FIG. 5 is a diagram showing the relationship between the applied voltage and the current density of the devices of Example 2-1 and Comparative Example 1.

FIG. 6 is a diagram showing a relationship between applied voltage and light emission luminance of the devices of Example 2-1 and Comparative Example 1.

FIG. 7 is a diagram showing a relationship between injection current density and light emission luminance of the devices of Example 2-1 and Comparative example 1.

FIG. 8 is a diagram showing the relationship between applied voltage and current density of the devices of Example 2-2 and Comparative Example 1.

FIG. 9 is a diagram showing the relationship between the applied voltage and the light emission luminance of the devices of Example 2-2 and Comparative Example 1.

FIG. 10 is a diagram showing the relationship between applied voltage and current density of the devices of Example 3 and Comparative Example 2.

FIG. 11 is a diagram showing the relationship between the current density and the luminous efficiency of the devices of Example 3 and Comparative Example 2.

FIG. 12 is a diagram showing a relationship between driving time and light emission luminance of the elements of Example 4 and Comparative Example 3.

[Explanation of symbols]

10 substrate (transparent substrate), 12 first electrode (anode), 1
6 Second electrode (cathode), 20 organic compound layer, 22 hole transport layer, 24 light emitting layer, 26 CxFy layer (electron transport layer), 28 electron transport layer, 30 hole shield layer (CxFy)
layer).

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Atsushi Miura 41-Cho, Yokomichi, Nagakute-cho, Aichi-gun, Aichi Prefecture Inside Toyota Central Research Laboratory Co., Ltd. (1) Inside Toyota Toyota Central Research Institute Co., Ltd. (72) Inventor Yasunori Taga 41, Nagakute-cho, Aichi-gun, Aichi Prefecture (72) Inventor Toshiyasu Suzuki 11-11 Misono-cho, Kariya-shi, Aichi Prefecture 2F, 6F, F-term (reference) 3K007 AB12 CA01 CB01 DB03 FA01 4H006 AA01 AA03 AB92

Claims (12)

[Claims] 1. An organic compound having a skeleton in which three or more aromatic rings are bonded to each other at arbitrary positions, comprising 18 or more carbon atoms C, and comprising only carbon atoms C and fluorine atoms F. 2. The organic compound according to claim 1, wherein the composition is represented by C _6n F _{4n + 2} . 3. The organic compound according to claim 1, wherein the compound is represented by the following chemical formula (1) or (2). Embedded image An organic compound represented by the structure shown in 4. An organic compound in which a polyacene ring not less than a naphthalene ring is directly bonded at an arbitrary position, and all hydrogens are substituted by fluorine. 5. The organic compound according to claim 4, wherein the composition is represented by C _10n F _{6n + 2} . 6. The organic compound according to claim 4, wherein the composition formula is represented by C _14n F _{8n + 2} . 7. The organic compound according to claim 4, wherein the composition is represented by C _18n F _{10n + 2} . 8. The organic compound according to claim 4, wherein the composition formula is represented by C _22n F _{12n + 2} . 9. A functional element having an organic thin film, wherein the organic thin film contains the organic compound according to any one of claims 1 to 8. 10. An organic electroluminescent device having at least one organic compound layer formed between electrodes, wherein the organic compound layer is an organic compound according to any one of claims 1 to 8. An organic electroluminescent device comprising: 11. An organic electroluminescent device in which an organic compound layer is formed between an anode and a cathode, wherein the organic compound layer is provided between the cathode and the organic light-emitting layer. An organic electroluminescent device comprising a hole blocking layer containing the organic compound according to claim 8. 12. An organic electroluminescent device comprising an organic compound layer between electrodes, wherein the organic compound according to claim 1 is used as a protective film covering the device. An organic electroluminescent device comprising: