U.S. patent application number 11/159390 was filed with the patent office on 2006-02-02 for organic electroluminescence device.
This patent application is currently assigned to Idemitsu Kosan Co., Ltd.. Invention is credited to Takashi Arakane, Chishio Hosokawa, Hidetsugu Ikeda, Sanae Tagami.
Application Number | 20060024523 11/159390 |
Document ID | / |
Family ID | 17611415 |
Filed Date | 2006-02-02 |
United States Patent
Application |
20060024523 |
Kind Code |
A1 |
Tagami; Sanae ; et
al. |
February 2, 2006 |
Organic electroluminescence device
Abstract
An organic electroluminescence device which exhibits an
excellent purity of color and a high efficiency of light emission,
has a long life and emits reddish light and a novel compound having
these characteristics are provided. The organic electroluminescence
device comprises an organic layer disposed between at least one
pair of electrodes, wherein the organic layer comprises a compound
having a fluoranthene skeleton structure substituted at least with
an amine group or an alkenyl group.
Inventors: |
Tagami; Sanae;
(Sodegaura-shi, JP) ; Ikeda; Hidetsugu;
(Sodegaura-shi, JP) ; Hosokawa; Chishio;
(Sodegaura-shi, JP) ; Arakane; Takashi;
(Sodegaura-shi, JP) |
Correspondence
Address: |
OBLON, SPIVAK, MCCLELLAND, MAIER & NEUSTADT, P.C.
1940 DUKE STREET
ALEXANDRIA
VA
22314
US
|
Assignee: |
Idemitsu Kosan Co., Ltd.
Chiyoda-ku
JP
|
Family ID: |
17611415 |
Appl. No.: |
11/159390 |
Filed: |
June 23, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10847307 |
May 18, 2004 |
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11159390 |
Jun 23, 2005 |
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09675201 |
Sep 29, 2000 |
6815090 |
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10847307 |
May 18, 2004 |
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Current U.S.
Class: |
428/690 ;
313/504; 313/506; 428/917 |
Current CPC
Class: |
C07D 223/26 20130101;
C07D 279/26 20130101; C09K 2211/1014 20130101; H01L 51/5048
20130101; C07D 223/14 20130101; C07C 217/94 20130101; C07D 471/06
20130101; H01L 51/006 20130101; C07C 2601/14 20170501; Y10S 428/917
20130101; C09K 2211/1011 20130101; C09K 2211/1007 20130101; C07D
223/28 20130101; H01L 51/0054 20130101; H01L 51/0059 20130101; C07D
219/14 20130101; C07C 229/68 20130101; C07D 295/135 20130101; C09K
2211/1029 20130101; C07C 13/62 20130101; C09K 2211/1037 20130101;
C07C 217/92 20130101; C07D 295/155 20130101; H01L 51/0081 20130101;
C07C 2603/54 20170501; C07C 255/42 20130101; C07C 211/61 20130101;
H01L 51/5012 20130101; H05B 33/14 20130101; C07C 255/58 20130101;
C09K 11/06 20130101; C07D 295/02 20130101; H01L 51/0056 20130101;
C07C 13/70 20130101 |
Class at
Publication: |
428/690 ;
428/917; 313/504; 313/506 |
International
Class: |
H05B 33/12 20060101
H05B033/12 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 30, 1999 |
JP |
279462/1999 |
Claims
1-10. (canceled)
11. An organic electroluminescence device which comprises an
organic layer disposed between at least one pair of electrodes,
wherein the organic layer comprises a host material and a compound
selected from compounds represented by the following general
formula [1], [2], and [4] to [16]: ##STR41## ##STR42## ##STR43##
wherein X.sup.1 to X.sup.20 each independently represents hydrogen
atom, a linear, branched or cyclic alkyl group having 1 to 20
carbon atoms, a linear, branched or cyclic alkoxy group having 1 to
20 carbon atoms, a substituted or unsubstituted aryl group having 6
to 30 carbon atoms, a substituted or unsubstituted aryloxy group
having 6 to 30 carbon groups, a substituted or unsubstituted
arylamino group having 6 to 30 carbon atoms, a substituted or
unsubstituted alkylamino group having 1 to 30 carbon atoms, a
substituted or unsubstituted arylalkylamino group having 7 to 30
carbon atoms or a substituted or unsubstituted alkenyl group having
8 to 30 carbon atoms; a pair of adjacent groups represented by
X.sup.1 to X.sup.20 and a pair of adjacent substituents to groups
represented by X.sup.1 to X.sup.20 may form a cyclic structure in
combination; when a pair of adjacent substituents are aryl groups,
the pair of substituents may be a single group; and at least one of
substituents represented by X.sup.1 to X.sup.i, i representing a
number of 12 to 20, comprises an amine group or an alkenyl
group.
12. The organic electroluminescence device according to claim 11,
wherein the organic layer is at least one of a hole transporting
layer and a light emitting layer.
13. The organic electroluminescence device according to claim 11,
wherein the organic layer comprises 1 to 70% by weight of said
compound.
14. The organic electroluminescence device according to claim 11,
wherein a layer of an inorganic compound is disposed between the
organic layer and any of the electrodes.
15. The organic electroluminescence device according to claim 12,
wherein a layer of an inorganic compound is disposed between the
organic layer and any of the electrodes.
16. The organic electroluminescence device according to claim 13,
wherein a layer of an inorganic compound is disposed between the
organic layer and any of the electrodes.
17. The organic electroluminescence device according to claim 11,
which emits reddish light.
18. The organic electroluminescence device according to claim 12,
which emits reddish light.
19. The organic electroluminescence device according to claim 13,
which emits reddish light.
20. The organic electroluminescence device according to claim 14,
which emits reddish light.
21. The organic electroluminescence device according to claim 15,
which emits reddish light.
22. The organic electroluminescence device according to claim 16,
which emits reddish light.
23. The organic electroluminescence device according to claim 11,
wherein the organic layer comprises said compound and isomers
thereof.
24. The organic electroluminescence device according to claim 12,
wherein the organic layer comprises said compound and isomers
thereof.
25. The organic electroluminescence device according to claim 13,
wherein the organic layer comprises said compound and isomers
thereof.
26. The organic electroluminescence device according to claim 14,
wherein the organic layer comprises said compound and isomers
thereof.
27. The organic electroluminescence device according to claim 17,
wherein the organic layer comprises said compound and isomers
thereof.
28. The organic electroluminescence device according to claim 23,
wherein, among said compound and the isomers thereof, a ratio of an
amount by mole of an isomer which can emit light having a longer
wavelength to an amount by mole of an isomer which can emit light
having a shorter wave is in a range of 90:10 to 60:40.
29. The organic electroluminescence device according to claim 24,
wherein, among said compound and the isomers thereof, a ratio of an
amount by mole of an isomer which can emit light having a longer
wavelength to an amount by mole of an isomer which can emit light
having a shorter wave is in a range of 90:10 to 60:40.
30. The organic electroluminescence device according to claim 25,
wherein, among said compound and the isomers thereof, a ratio of an
amount by mole of an isomer which can emit light having a longer
wavelength to an amount by mole of an isomer which can emit light
having a shorter wave is in a range of 90:10 to 60:40.
31. The organic electroluminescence device according to claim 11,
wherein said host material is selected from the group consisting of
anthracene, naphthalene, phenanthrene, pyrene, tetracene, coronene,
chrysene, perylene, phthaloperylene, naphthaloperylene, perynone,
phthaloperynone, naphthaloperynone, and rubrene.
Description
TECHNICAL FIELD
[0001] The present invention relates to an organic
electroluminescence device which is used as a light source such as
a planar light emitting member of televisions and a back light of
displays, exhibits an excellent purity of color and a high
efficiency of light emission, has a long life and emits reddish
light and to a novel compound having these characteristics.
BACKGROUND ART
[0002] Electroluminescence (referred to as EL, hereinafter) devices
using organic compounds are expected to be used for inexpensive
full color display devices of the solid light emission type which
can display a large area and development thereof has been actively
conducted. In general, an EL device is constituted with a light
emitting layer and a pair of electrodes faced to each other at both
sides of the light emitting layer. When a voltage is applied
between the electrodes, electrons are injected at the side of the
cathode and holes are injected at the side of the anode. The
electrons are combined with the holes in the light emitting layer
and an excited state is formed. When the excited state returns to
the normal state, the energy is emitted as light.
[0003] Although the practical application of organic EL devices has
started recently, devices for full color displays are still under
development. In particular, a material for organic EL devices which
exhibits an excellent purity of color and a high efficiency of
light emission, has a long life and emits reddish light has been
desired.
[0004] In an attempt to satisfy the above desire, a device emitting
red light in which a derivative of naphthacene or pentacene is
added to a light emitting layer is disclosed in Japanese Patent
Application Laid-Open No. Heisei 8(1996)-311442. Although this
device exhibits an excellent purity of red light, the device
exhibits an efficiency of light emission as low as 0.7 lm/W and has
an insufficient average life which is shorter than 150 hours. An
average life of at least several thousand hours is necessary for
practical applications. A device in which a compound derived from
dicyanomethylene (DCM) is added to a light emitting layer is
disclosed in Japanese Patent Application Laid-Open No. Heisei
3(1991)-162481. However, this device exhibits an insufficient
purity of red light. In Japanese Patent Application Laid-Open Nos.
Heisei 10(1998)-340782 and Heisei 11(1999)-40360, organic EL
devices using fluoranthene compounds are disclosed. However, the
devices using the compounds disclosed in the above patent
applications do not emit yellow to red light. The efficiency of
light emission is as small as 4 cd/A or smaller and
insufficient.
DISCLOSURE OF THE INVENTION
[0005] The present invention has been made to overcome the above
problems and has an object of providing an organic EL device which
exhibits an excellent purity of color and a high efficiency of
light emission, has a long life and emits reddish light and a novel
compound having these characteristics.
[0006] As the result of extensive studies by the present inventors
to develop an organic electroluminescence device (referred to as an
organic EL device, hereinafter) having the above advantageous
properties, it was found that the object can be achieved by using a
compound having a fluoranthene skeleton structure substituted at
least with an amine group or an alkenyl group as the light emitting
material.
[0007] The organic electroluminescence device of the present
invention comprises an organic layer disposed between at least one
pair of electrodes, wherein the organic layer comprises a compound
having a fluoranthene skeleton structure substituted at least with
an amine group or an alkenyl group.
[0008] It is preferable that the above compound is a compound
selected from compounds represented by the following general
formulae [1] to [18]: ##STR1## ##STR2## ##STR3## wherein X.sup.1 to
X.sup.20 each independently represents hydrogen atom, a linear,
branched or cyclic alkyl group having 1 to 20 carbon atoms, a
linear, branched or cyclic alkoxy group having 1 to 20 carbon
atoms, a substituted or unsubstituted aryl group having 6 to 30
carbon atoms, a substituted or unsubstituted aryloxy group having 6
to 30 carbon groups, a substituted or unsubstituted arylamino group
having 6 to 30 carbon atoms, a substituted or unsubstituted
alkylamino group having 1 to 30 carbon atoms, a substituted or
unsubstituted arylalkylamino group having 7 to 30 carbon atoms or a
substituted or unsubstituted alkenyl groups having 8 to 30 carbon
atoms; a pair of adjacent groups represented by X.sup.1 to X.sup.20
and a pair of adjacent substituents to groups represented by
X.sup.1 to X.sup.20 may form a cyclic structure in combination;
when a pair of adjacent substituents are aryl groups, the pair of
substituents may be a single group; and at least one of
substituents represented by X.sup.1 to X.sup.i, i representing a
number of 12 to 20, comprises an amine group or an alkenyl group;
##STR4## wherein R.sup.1 to R.sup.4 each independently represent an
alkyl group having 1 to 20 carbon atoms or a substituted or
unsubstituted aryl group having 6 to 30 carbon atoms; in one or
both of a pair of groups represented by R.sup.1 and R.sup.2 and a
pair of groups represented by R.sup.3 and R.sup.4, the groups
forming the pair may be bonded through --O-- or --S--; R.sup.5 to
R.sup.16 represents hydrogen atom, a linear, branched or cyclic
alkyl group having 1 to 20 carbon atoms, a linear, branched or
cyclic alkoxy group having 1 to 20 carbon atoms, a substituted or
unsubstituted aryl group having 6 to 30 carbon atoms, a substituted
or unsubstituted aryloxy group having 6 to 30 carbon groups, a
substituted or unsubstituted arylamino group having 6 to 30 carbon
atoms, a substituted or unsubstituted alkylamino group having 1 to
30 carbon atoms, a substituted or unsubstituted arylalkylamino
group having 7 to 30 carbon atoms or a substituted or unsubstituted
alkenyl groups having 8 to 30 carbon atoms; a pair of adjacent
groups represented by R.sup.5 to R.sup.16 and a pair of adjacent
substituents to groups represented by R.sup.5 to R.sup.16 may form
a cyclic structure in combination; and at least one of substituents
represented by R.sup.5 to R.sup.16 comprises an amine group or an
alkenyl group.
[0009] The novel compound of the present invention is a compound
represented by any of the above general formulae [1] to [18].
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 shows the .sup.1H-NMR spectrum of an example of the
novel compound of the present invention.
[0011] FIG. 2 shows the .sup.1H-NMR spectrum of another example of
the novel compound of the present invention.
[0012] FIG. 3 shows the .sup.1H-NMR spectrum of still another
example of the novel compound of the present invention.
THE MOST PREFERRED EMBODIMENT TO CARRY OUT THE INVENTION
[0013] The organic electroluminescence device of the present
invention comprises an organic layer disposed between at least one
pair of electrodes, wherein the organic layer comprises compounds
having a fluoranthene skeleton structure substituted at least with
an amine group or an alkenyl group.
[0014] This compound is a novel compound and is represented by any
of the above general formulae [1] to [18].
[0015] In general formulae [1] to [16], X.sup.1 to X.sup.20 each
independently represents hydrogen atom, a linear, branched or
cyclic alkyl group having 1 to 20 carbon atoms, a linear, branched
or cyclic alkoxy group having 1 to 20 carbon atoms, a substituted
or unsubstituted aryl group having 6 to 30 carbon atoms, a
substituted or unsubstituted aryloxy group having 6 to 30 carbon
groups, a substituted or unsubstituted arylamino group having 6 to
30 carbon atoms, a substituted or unsubstituted alkylamino group
having 1 to 30 carbon atoms, a substituted or unsubstituted
arylalkylamino group having 7 to 30 carbon atoms or a substituted
or unsubstituted alkenyl groups having 8 to 30 carbon atoms; a pair
of adjacent groups represented by X.sup.1 to X.sup.20 and a pair of
adjacent substituents to groups represented by X.sup.1 to X.sup.20
may form a cyclic structure in combination; when a pair of adjacent
substituents are aryl groups, the pair of substituents may be a
single group; and at least one of substituents represented by
X.sup.1 to X.sup.i, i representing a number of 12 to 20, comprises
an amine group or an alkenyl group. That a pair of adjacent
substituents may be a single group when the pair of adjacent
substituents are aryl groups means that the adjacent bonds for the
pair of substituents are bonded to the same single divalent
aromatic ring group.
[0016] In general formulae [17] and [18], R.sup.1 to R.sup.4 each
independently represent an alkyl group having 1 to 20 carbon atoms
or a substituted or unsubstituted aryl group having 6 to 30 carbon
atoms; in one or both of a pair of groups represented by R.sup.1
and R.sup.2 and a pair of groups represented by R.sup.3 and
R.sup.4, the groups forming the pair may be bonded through --O-- or
--S--; R.sup.5 to R.sup.16 represents hydrogen atom, a linear,
branched or cyclic alkyl group having 1 to 20 carbon atoms, a
linear, branched or cyclic alkoxy group having 1 to 20 carbon
atoms, a substituted or unsubstituted aryl group having 6 to 30
carbon atoms, a substituted or unsubstituted aryloxy group having 6
to 30 carbon groups, a substituted or unsubstituted arylamino group
having 6 to 30 carbon atoms, a substituted or unsubstituted
alkylamino group having 1 to 30 carbon atoms, a substituted or
unsubstituted arylalkylamino group having 7 to 30 carbon atoms or a
substituted or unsubstituted alkenyl groups having 8 to 30 carbon
atoms; a pair of adjacent groups represented by R.sup.5 to R.sup.16
and a pair of adjacent substituents to groups represented by
R.sup.5 to R.sup.16 may form a cyclic structure in combination; and
at least one of substituents represented by R.sup.5 to R.sup.16
comprises an amine group or an alkenyl group.
[0017] Preferable compounds among the compounds represented by
general formulae [1] to [18] are shown in the following.
[0018] It is preferable that the fluoranthene skeleton structure
comprises at least 5 condensed rings and more preferably at least 6
condensed rings. By using the compounds having this structure,
light having a longer wave length such as yellowish to reddish
light can be emitted.
[0019] It is preferable that the fluoranthene skeleton structure is
substituted with an amino group. By using the compound having this
structure, a light emitting material having a longer life can be
obtained.
[0020] It is preferable that the amino group is a substituted or
unsubstituted arylamino group and more preferably a substituted or
unsubstituted diarylamino group. By using the compound having this
structure, a device showing a smaller decrease in the light
emission at increased concentrations of the compound and exhibiting
a high efficiency can be obtained even when the above compound is
added to the light emitting layer in a concentration as high as 2%
or higher.
[0021] It is preferable that the above compound has a symmetric
structure having an axial symmetry or a symmetry with respect to
plane. By using the compound having this structure, durability of
the device is improved and the quantum efficiency of fluorescence
is enhanced.
[0022] It is preferable that the above compound has at least ten
six-membered rings or five-membered rings. The compound has a glass
transition temperature of 100.degree. C. or higher due to this
structure and heat stability of a layer composed of or comprising
this compound is improved. It is preferable that the above compound
has an aryl group, a cyclic alkyl group, an aryloxy group, an
arylthio group or an arylalkyl group each having 4 or more carbon
atoms. Since these groups exhibit steric hindrance and the decrease
in the light emission at increased concentrations of the compound
can be prevented.
[0023] It is preferable that, in general formulae [17] and [18],
R.sup.15 and R.sup.9 each represent a group having a substituent.
When the compound represented by general formula [17] or [18] has
this structure, the compound has an improved stability against
oxidation and reduction and the life of the device can be
extended.
[0024] When the fluoranthene skeleton structure is substituted with
two amino groups, two alkenyl groups or a combination of an amino
group and an alkenyl group, the compound having this fluoranthene
skeleton structure has isomers.
[0025] Examples of the isomers are described in the case where the
fluoranthene skeleton structure is
7,14-diphenylacenaphtho[1,2-k]-fluoranthene.
[0026] Dibromo-substituted acenaphtho[1,2-k]fluoranthene has two
isomers, i.e.,
3,10-dibromo-7,14-diphenylacenaphtho[1,2-k]fluoranthene (isomer A)
and 3,11-dibromo-7,14-diphenylacenaphtho[1,2-k]fluoranthene (isomer
B).
[0027] The final product obtained from isomer A and isomer B as the
intermediates contains an amino-substituted compound derived from
isomer A and an amino-substituted compound derived from isomer B.
When the final product is prepared, the relative amounts of isomer
A and isomer B contained in the final product is different
depending on the process of the preparation. (1) The
dibromo-substituted compounds may be obtained from a solution
portion of a reaction mixture in which the dibromo-substituted
compounds are dissolved. (2) The dibromo-substituted compounds may
also be obtained from precipitates formed by recrystallization from
a solution which is obtained by dissolving the product obtained
above from the solution portion of the reaction mixture. (3) The
dibromo-substituted compounds may also be obtained from the
solution left after the above recrystallization. By suitably
selecting the process and the type of the solvent used for the
treatment, the object compound containing various amounts of isomer
A and isomer B and, specifically, having a ratio of the amount by
mole of isomer A to the amount in mole of isomer B in the range of
10:90 to 90:10, can be obtained.
[0028] It is preferable that the error in the ratio of the amounts
by mole of the isomers is: (i) isomer A: isomer B=x.+-.10: y.+-.10
(x+y=100) and more preferably (ii) isomer A: isomer B=x.+-.5:
y.+-.5 (x+y=100). When the relation (i) is satisfied, the ratio of
the amounts of the isomers will be described as approximately
constant and, when the relation (ii) is satisfied, the ratio of the
amounts of the isomers will be described as constant,
hereinafter.
[0029] When the above compound of the present invention has
isomers, a plurality of isomers can be comprised in the organic
layer. It is preferable that the device is prepared under the
condition that the ratio of the amounts of the isomers is kept
approximately constant or constant. By preparing the device in this
manner, the spectrum of the light emitted from the device can be
kept the same. In other words, the color of the emitted light can
be kept the same. Moreover, the color of the emitted light can be
changed by changing the ratio of the amounts of the isomers.
Naturally, the organic layer may comprise a single compound with
exclusion of any other isomers.
[0030] When a compound contains isomers as described above, one of
the isomers can emit light having a longer wavelength than that of
light emitted from other isomers. Therefore, light having a longer
wavelength such red light can be emitted when the ratio of the
amount by mole of the isomer which can emit light having a longer
wavelength to the amount by mole of the isomer which can emit light
having a shorter wavelength is preferably in the range of 90:10 to
60:40 and more preferably in the range of 99:1 to 70:30.
[0031] Taking advantage of the difference in the chemical shift in
.sup.1H-NMR between the isomers, the ratio of the amounts of the
isomers can be calculated from the ratio of the areas of peak
signals assigned to each isomer.
[0032] It is preferable that the organic layer is at least one of a
hole transportation layer and a light emitting layer.
[0033] A layer of an inorganic compound may be disposed between the
organic layer and the electrode.
[0034] The organic EL device of the present invention emits reddish
light.
[0035] Examples of the compounds represented by general formulae
[1] to [18] of the present invention include (A-1) to (A-18) and
(B-1) to (B-17) which are shown in the following. However, the
present invention is not limited to these compounds shown as the
examples. In the formulae shown in the following, Me means methyl
group and Et means ethyl group. ##STR5## ##STR6## ##STR7## ##STR8##
##STR9## ##STR10## ##STR11## ##STR12## ##STR13## ##STR14##
##STR15## ##STR16## ##STR17## ##STR18## ##STR19## ##STR20##
##STR21## ##STR22##
[0036] Since the compound used for the organic EL device of the
present invention has the fluoranthene skeleton structure
substituted with an amine group or an alkenyl group, the compound
exhibits a high yield of fluorescence and emits reddish or
yellowish light. Therefore, the organic EL device using this
compound emits reddish to yellowish light, exhibits a high
efficiency of light emission and has a long life.
[0037] The organic EL device of the present invention is a device
in which one or a plurality of organic thin films are disposed
between an anode and a cathode. When the device has a single
organic layer, a light emitting layer is disposed between an anode
and a cathode. The light emitting layer contains a light emitting
material and may also contain a hole injecting material to
transport holes injected at the anode to the light emitting
material or an electron injecting material to transport electrons
injected at the cathode to the light emitting material. It is
preferable that the light emitting layer is formed with a light
emitting material having a very high quantum efficiency of
fluorescence emission and excellent ability to transfer holes and
electrons and a uniform thin film is formed. The organic EL device
having a multi-layer structure has a laminate structure such as:
(an anode/a hole injecting layer/a light emitting layer/a cathode),
(an anode/a light emitting layer/an electron injecting layer/a
cathode) and (an anode a hole injecting layer/a light emitting
layer/an electron injecting layer/a cathode).
[0038] In the light emitting layer, where necessary, conventional
light emitting materials, doping materials, hole injecting
materials and electron injecting materials may be used in addition
to the compound represented by any of general formulae [1] to [18]
of the present invention. It is preferable that these compounds are
added to any of the light emitting layer, the electron injecting
layer, the hole transporting layer or the hole injecting layer in a
concentration of 1 to 70% by weight and more preferably in a
concentration of 1 to 20% by weight. In particular, it is
preferable that the compound of the present invention is used as
the doping material.
[0039] Deterioration in the luminance and the life caused by
quenching can be prevented by the multi-layer structure of the
organic EL. Where necessary, light emitting materials, other doping
materials, hole injecting materials and electron injecting
materials may be used in combination. By using other doping
materials, the luminance and the efficiency of light emission can
be improved and red light and white light can be emitted. The hole
injecting layer, the light emitting layer and the electron
injecting layer may each have a multi-layer structure having two or
more layers. When the hole injecting layer has a multi-layer
structure, the layer into which holes are injected from the
electrode is referred to as the hole injecting layer and the layer
which receives holes from the hole injecting layer and transports
holes from the hole injecting layer to the light emitting layer is
referred to as the hole transporting layer. When the electron
injecting layer has a multi-layer structure, the layer into which
electrons are injected from the electrode is referred to as the
electron injecting layer and the layer which receives electrons
from the electron injecting layer and transports electrons from the
electron injecting layer to the light emitting layer is referred to
as the electron transporting layer. These layers are each selected
and used in accordance with factors such as the energy level, heat
resistance and adhesion with the organic layers or the metal
electrodes of the material.
[0040] Examples of the material which can be used in the organic
layer as the light emitting material or the host material in
combination with the compound represented by any of general
formulae [1] to [18] include anthracene, naphthalene, phenanthrene,
pyrene, tetracene, coronene, chrysene, fluoresceine, perylene,
phthaloperylene, naphthaloperylene, perynone, phthaloperynone,
naphthaloperynone, diphenylbutadiene., tetraphenylbutadiene,
coumarine, oxadiazole, aldazine, bisbenzoxazoline, bisstyryl,
pyrazine, cyclopentadiene, metal complexes of quinoline, metal
complexes of aminoquinoline, metal complexes of benzoquinoline,
imines, diphenylethylene, vinylanthracene, diaminocarbazole,
pyrane, thiopyrane, polymethine, merocyanine, chelates of oxinoid
compounds with imidazoles, quinacridone, rubrene, stilbene
derivatives and fluorescent pigments. However, the above material
is not limited to the compounds described above as the
examples.
[0041] As the hole injecting material, a compound which has the
ability to transfer holes, exhibits an excellent effect of hole
injection from the anode and an excellent effect of hole injection
to the light emitting layer or the light emitting material,
prevents transfer of excited components formed in the light
emitting layer into the electron injecting layer or the electron
injecting material and has excellent ability to form a thin film is
preferable. Examples of the above compound include phthalocyanine
derivatives, naphthalocyanine derivatives, porphyrin derivatives,
oxazole, oxadiazole, triazole, imidazole, imidazolone,
imdazolethione, pyrazoline, pyrazolone, tetrahydroimidazole,
oxazole, oxadiazole, hydrazone, acylhydrazone, polyarylalkanes,
stilbene, butadiene, triphenylamines of the benzidine-type,
triphenylamines of the styrylamine type, triphenylamines of the
diamine type, derivatives of these compounds and macromolecular
compounds such as polyvinylcarbazole, polysilane and conductive
macromolecules. However, the above compound is not limited to the
compounds described above as the examples.
[0042] Among the hole injection materials which can be used in the
organic EL device of the present invention, aromatic tertiary amine
derivatives and phthalocyanine derivatives are more effective.
[0043] Examples of the aromatic tertiary amine derivative include
triphenylamine, tritolylamine, tolyldiphenylamine,
N,N'-diphenyl-N,N'-(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine,
N,N,N',N'-(4-methylphenyl)-1,1'-phenyl-4,4'-diamine,
N,N,N',N'-(4-methylphenyl)-1,1'-biphenyl-4,4'-diamine,
N,N'-diphenyl-N,N'-dinaphthyl-1,1'-biphenyl-4,4'-diamine,
N,N'-(methylphenyl)-N,N'-(4-n-butylphenyl)phenanthrene-9,10-diamine,
N,N-bis(4-di-4-tolylaminophenyl)-4-phenylcyclohexane and oligomers
and polymers having a skeleton structure of these aromatic tertiary
amines. However, the aromatic tertiary amine derivative is not
limited to the compounds described above as the examples.
[0044] Examples of the phthalocyanine (Pc) derivative include
H.sub.2Pc, CuPc, CoPc, NiPc, ZnPc, PdPc, FePc, MnPc, ClAlPc,
ClGaPc, ClInPc, ClSnPc, Cl.sub.2SiPc, (HO)AlPc, (HO)GaPc, VOPc,
TiOPc, MoOPc, GaPc-O--GaPc and corresponding derivatives of
naphthalocyanine. However, the derivatives of phthalocyanine and
naphthalocyanine are not limited to the compounds described above
as the examples.
[0045] As the electron injecting material, a compound which has the
ability to transport electrons, exhibits an excellent effect of
electron injection from the cathode and an excellent effect of
electron injection to the light emitting layer or the light
emitting material, prevents transfer of excited components formed
in the light emitting layer into the hole injecting layer and has
excellent ability to form a thin film is preferable. Examples of
the above compound include fluorenone, anthraquinodimethane,
diphenoquinone, thiopyrane dioxide, oxazole, oxadiazole, triazole,
imidazole, peryleneteteracarboxylic acid, fluorenylidenemethane,
anthraquinodimethane, anthrone and derivatives of these compounds.
However, the above compound is not limited to the compounds
described above as the examples. The charge injecting property can
be improved by adding an electron accepting material to the hole
injecting material or by adding an electron donating material to
the electron injecting material.
[0046] In the organic EL device of the present invention, more
effective electron injecting materials are metal complex compounds
and five-membered derivatives containing nitrogen.
[0047] Examples of the metal complex compound include
8-hydroxy-quinolinatolithium, bis(8-hydroxyquinolinato)zinc,
bis(8-hydroxy-quinolinato)copper,
bis(8-hydroxyquinolinato)manganese,
tris(8-hydroxy-quinolinato)aluminum,
tris(2-methyl-8-hydroxyquinolinato)aluminum,
tris(8-hydroxyquinilinato)gallium,
bis(10-hydroxybenzo[h]quinolinato)-beryllium,
bis(10-hydroxybenzo[h]quinolinato)zinc,
bis(2-methyl-8-quinolinato)chlorogallium,
bis(2-methyl-8-quinolinato)(o-cresolato) gallium,
bis(2-methyl-8-quinolinato)(1-naphtholato)aluminum and
bis(2-methyl-8-quinolinato)(2-naphtholato)gallium. However, the
metal complex compound is not limited to the compounds described
above as the examples.
[0048] Preferable examples of the five-membered derivative
containing nitrogen include derivatives of oxazoles, thiazoles,
thiadiazoles and triazoles. Specific examples include
2,5-bis(1-phenyl)-1,3,4-oxazole, dimethylPOPOP,
2,5-bis(1-phenyl)-1,3,4-thiazole,
2,5-bis(1-phenyl)-1,3,4-oxadiazole,
2-(4'-tert-butylphenyl)-5-(4''-biphenyl)-1,3,4-oxadiazole,
2,5-bis(1-naphthyl)-1,3,4-oxadiazole,
1,4-bis[2-(5-phenyloxadiazolyl)]benzene,
1,4-bis[2-(5-phenyloxadiazolyl)-4-tert-butylbenzene],
2-(4'-tert-butyl-phenyl)-5-(4''-biphenyl)-1,3,4-thiadiazole,
2,5-bis(1-naphthyl)-1,3,4-thiadiazole,
1,4-bis[2-(5-phenylthiadiazolyl)]benzene,
2-(4'tert-butylphenyl)-5-(4''-biphenyl)-1,3,4-triazole,
2,5-bis(1-naphthyl)-1,3,4-triazole and
1,4-bis[2-(5-phenyltriazolyl)]benzene. However, the five-membered
derivative containing nitrogen is not limited to the compounds
described above as the examples.
[0049] In the organic EL device of the present invention, the
organic layer may contain at least one of light emitting materials,
doping materials, hole injecting materials and electron injecting
materials in the same layer in addition to the compound represented
by any of general formulae [1] to [18]. In order to improve
stability of the organic EL device of the present invention with
respect to the temperature, the humidity and the atmosphere, a
protecting layer may be formed on the surface of the device or the
entire device may be protected with silicon oil or a resin.
[0050] As the conductive material used for the anode of the organic
EL device, a material having a work function of 4 eV or greater is
suitable. Examples of such a material include carbon, aluminum,
vanadium, iron, cobalt, nickel, tungsten, silver, gold, platinum,
palladium, alloys of these metals, metal oxides used for ITO
substrates and NESA substrates such as tin oxide and indium oxide
and organic conductive resins such as polythiophene and polypyrrol.
As the conductive material used for the cathode, a material having
a work function smaller than 4 eV is suitable. Examples of such a
material include magnesium, calcium, tin, lead, titanium, yttrium,
lithium, ruthenium, manganese, aluminum and alloys of these metals.
However, the materials used for the anode and the cathode are not
limited to the materials described above as the examples. Typical
examples of the alloy include alloys of magnesium and silver,
alloys of magnesium and indium and alloys of lithium and aluminum.
However, the alloy is not limited to these alloys described as the
examples. The composition of the alloy is controlled by the
temperature of the source of vapor deposition, the atmosphere and
the degree of vacuum and can be adjusted suitably. The anode and
the cathode may have a multi-layer structure having two or more
layers, where necessary.
[0051] In the organic EL device of the present invention, it is
preferable that a layer of a chalcogenide, a metal halide or a
metal oxide (this layer may occasionally be referred to as a
surface layer) is disposed on the surface of at least one of the
pair of electrodes prepared as described above. Specifically, it is
preferable that a layer of a chalcogenide (including an oxide) of a
metal such as silicon and aluminum is disposed on the surface of
the anode at the side of the layer of the light emitting medium and
a layer of a metal halide or a metal oxide is disposed on the
surface of the cathode at the side of the layer of the light
emitting medium. Due to the above layers, stability in driving can
be improved.
[0052] Preferable examples of the chalcogenide include SiO.sub.x
(1.ltoreq.x.ltoreq.2), AlO.sub.x (1.ltoreq.x.ltoreq.1.5), SiON and
SiAlON. Preferable examples of the metal halide include LiF,
MgF.sub.2, CaF.sub.2 and fluorides of rare earth metals. Preferable
examples of the metal oxide include Cs.sub.2O, Li.sub.2O, MgO, SrO,
BaO and CaO.
[0053] In the organic EL device of the present invention, it is
preferable that a mixed region of an electron transmitting compound
and a reducing dopant or a mixed region of a hole transmitting
compound and an oxidizing dopant is disposed on the surface of at
least one of the pair of electrodes prepared as described above.
Due to the mixed region disposed on the surface of the pair of
electrodes, the electron transmitting compound is reduced to form
an anion and injection and transportation of electrons from the
mixed region into the light emitting medium can be facilitated. The
hole transmitting compound is oxidized to form a cation and
injection and transportation of holes from the mixed region into
the light emitting medium is facilitated. Preferable examples of
the oxidizing dopant include various types of Lewis acid and
acceptor compounds. Preferable examples of the reducing dopant
include alkali metals, compounds of alkali metals, alkaline earth
metals, rare earth metals and compounds of these metals.
[0054] In the organic EL device, to achieve efficient light
emission, it is preferable that at least one face of the device is
sufficiently transparent in the wave length region of the emitted
light. It is preferable that the substrate is also transparent. The
transparent electrode is disposed in accordance with vapor
deposition or sputtering using the above conductive material in a
manner such that the prescribed transparency is surly obtained. It
is preferable that the electrode disposed on the light emitting
face has a transmittance of light of 10% or greater. The substrate
is not particularly limited as long as the substrate has sufficient
mechanical strength and strength at high temperatures and is
transparent. Glass substrates or transparent films of resins may be
used. Example of the transparent films of resins include films of
polyethylene, ethylene-vinyl acetate copolymers, ethylene-vinyl
alcohol copolymers, polypropylene, polystyrene, polymethyl
methacrylate, polyvinyl chloride, polyvinyl alcohol, polyvinyl
butyral, nylon, polyether ether ketones, polsulfones, polyether
sulfones, tetrafluoroethylene-perfluoroalkyl vinyl ether
copolymers, polyvinyl fluoride, tetrafluoroethylene-ethylene
copolymers, tetrafluoro-ethylene-hexafluoropropylene copolymers,
polychlorotrifluoro-ethylene, polyvinylidene fluoride, polyesters,
polycarbonates, polyurethanes, polyimides, polyether imides,
polyimides and polypropylene.
[0055] Each layer of the organic EL device of the present invention
can be formed suitably in accordance with a dry process of film
formation such as vacuum vapor deposition, sputtering, plasma
plating and ion plating or a wet process of film formation such as
spin coating, dipping and flow coating. The thickness of the film
is not particularly limited. However, it is necessary that the
thickness be set at a suitable value. When the thickness is greater
than the suitable value, a high voltage must be applied to obtain a
prescribed output of light and the efficiency decreases. When the
thickness is smaller than the suitable value, pin holes are formed
and a sufficient luminance cannot be obtained even when the
electric field is applied. In general, the suitable range of the
thickness is 5 nm to 10 .mu.m. A thickness in the range of 10 nm to
0.2 .mu.m is preferable.
[0056] When the device is produced in accordance with a wet
process, materials forming each layer are dissolved or dispersed in
a suitable solvent such as ethanol, chloroform, tetrahydrofuran and
dioxane and a film is formed from the solution or the suspension.
The solvent is not particularly limited. In any organic thin layer,
suitable resins and additives may be used to improve the property
to form a film and to prevent formation of pin holes. Examples of
the resin which can be used include insulating resins such as
polystyrene, polycarbonates, polyarylates, polyesters, polyamides,
polyurethanes, polysulfones, polymethyl methacrylate, polymethyl
acrylate and cellulose, copolymers derived from these resins,
photoconductive resins such as poly-N-vinylcarbazole and polysilane
and conductive resins such as polythiophene and polypyrrol.
Examples of the additive include antioxidants, ultraviolet light
absorbents and plasticizers.
[0057] As described above, when the compound of the present
invention is used for the organic layer of the organic EL device,
the organic EL device exhibiting an excellent purity of color and a
high efficiency of light emission, having a long life and emitting
red light can be obtained.
[0058] The organic EL device of the present invention can be used
for a planar light emitting member such as a flat panel display of
wall televisions, a back light for copiers, printers and liquid
crystal displays, a light source of instruments, display panels and
a marker light.
[0059] The present invention will be described more specifically
with reference to Synthesis Examples and Examples in the
following.
SYNTHESIS EXAMPLE 1
Compound A-1
[0060] 3,10- and
3,11-Bisdiphenylamino-7,14-diphenylacenaphtho[1,2-k]-fluoranthene
was synthesized via the reaction route shown in the following:
##STR23## ##STR24##
(A) Synthesis of 3,10- and
3,11-dibromo-7,14-diphenyl-acenaphtho[1,2-k]fluoranthenes
[0061] In accordance with the J. B. Allen's process, 3,10- and
3,11-dibromo-7,14-diphenylacenaphtho[1,2-k]fluoranthenes (7) were
synthesized using acenaphthenequinone (1) as the starting material
via 7,14-diphenylacenaphtho[1,2-k]fluoranthene (6). The structures
of 3,10- and
3,11-dibromo-7,14-diphenylacenaphtho[1,2-k]fluoranthenes were
identified from FD-MS (the field desorption mass spectra) and the
.sup.1H-NMR spectra. The chemical shifts in .sup.1H-NMR agreed with
the measured values reported by Allen (J. D. Debad, A. I. Bard, J.
Chem. Soc., Vol. 120, 2476 (1998)).
(B) Synthesis of 3,10- and
3,11-diphenylamino-7,14-diphenyl-acenaphthofluoranthenes (Compound
A-1)
[0062] Into 150 ml of toluene, 3.56 g (5.6 mmole) of 3,10- and
3,11-dibromo-7,14-diphenylacenaphtho[1,2-k]fluoranthenes (7), 1.89
g (11.2 mmole) of diphenylamine, 0.06 g (0.3 mmole) of palladium
acetate, 0.22 g (1.1 mmole) of tri-tert-butylphosphine and 1.51 g
(14.0 mmole) of sodium tert-butoxide were dissolved at the room
temperature and the reaction was allowed to proceed for 6 hours
while the mixture was refluxed under heating. The resultant
reaction mixture was filtered. The filtrate was concentrated and
4.8 g of a red orange powdery solid was obtained. After the solid
was dissolved in toluene, the solution was fractionated in
accordance with the column chromatography using a column packed
with silica gel and 4.1 g of the main component was obtained. The
main component was confirmed to be 3,10- and
3,11-diphenylamino-7,14-diphenylacenaphthofluoranthenes (Compound
A-1) from FD-MS (812) and the structure of Compound (7).
Precipitates in the reaction mixture separated by the filtration
was washed with acetone and water and dried and 0.6 g of a powdery
solid was obtained. The obtained solid was confirmed to have the
same structure as that of the product obtained from the filtrate
from FD-MS (812) and the .sup.1H-NMR spectrum.
[0063] Similarly, Compound A-16 (Synthesis Example 2), Compound
B-15 (Synthesis Example 3), Compound A-8 (Synthesis Example 4),
Compound B-18 (Synthesis Example 5) and Compound B-17 (Synthesis
Example 6) which are compounds of 3,10- and
3,11-diamino-7,14-diphenylacenaphtho-[1,2-k]fluoranthenes were
synthesized via the reaction routes shown in the following:
##STR25## ##STR26##
SYNTHESIS EXAMPLE 2
Compound A-16
[0064] The reaction was conducted in accordance with the same
procedures as those conducted in Synthesis Example 1 (B) except
that 2.31 g (11.7 mmole) of p,p'-ditolylamine was used in place of
diphenylamine. After the reaction was completed, the reaction
mixture was filtered. The filtrate was washed with water and
concentrated and a red powdery solid was obtained. The obtained
solid was fractionated in accordance with the column chromatography
using a column packed with silica gel and 2.9 g of the main
component having a high purity was obtained. The main component was
confirmed to be Compound A-16 from FD-MS (868).
SYNTHESIS EXAMPLE 3
Compound B-15
[0065] The reaction was conducted in accordance with the same
procedures as those conducted in Synthesis Example 1(B) except that
2.27 g (11.7 mmole) of iminostilbene was used in place of
diphenylamine. After the reaction was completed, the product
precipitated in the reaction mixture was separated, repeatedly
washed with acetone and water and dried and 3.4 g of a red orange
powdery solid was obtained. The obtained solid was dissolved in
tetrahydrofuran and fractionated in accordance with the thin layer
chromatography using a thin layer of silica gel and 2.3 g of the
main component having a high purity was obtained. The main
component was confirmed to be Compound B-15 from FD-MS (862).
SYNTHESIS EXAMPLE 4
Compound A-8
[0066] The reaction was conducted in accordance with the same
procedures as those conducted in Synthesis Example 1(B) except that
1.0 g (11.7 mmole) of piperidine was used in place of
diphenylamine. After the reaction was completed, the reaction
mixture was filtered. The filtrate was washed with water and
concentrated and a red powdery solid was obtained. The obtained
solid was dissolved in toluene and fractionated in accordance with
the column chromatography using a column packed with silica gel and
2.1 g of the main component having a high purity was obtained. The
main component was confirmed to be Compound A-8 from FD-MS
(644).
SYNTHESIS EXAMPLE 5
Compound B-18
[0067] The reaction was conducted in accordance with the same
procedures as those conducted in Synthesis Example 1(B) except that
1.96 g (11.7 mmole) of carbazole was used in place of
diphenylamine. After the reaction was completed, the product
precipitated in the reaction mixture was separated, repeatedly
washed with acetone and water and dried and 3.8 g of a red orange
powdery solid was obtained. The obtained solid was dissolved in
tetrahydrofuran and fractionated in accordance with the thin layer
chromatography using a thin layer of silica gel and 2.0 g of the
main component having a high purity was obtained. The main
component was confirmed to be Compound B-18 from FD-MS (808).
SYNTHESIS EXAMPLE 6
Compound B-17
[0068] The reaction was conducted in accordance with the same
procedures as those conducted in Synthesis Example 1(B) except that
2.33 g (11.7 mmole) of phenothiazine was used in place of
diphenylamine. After the reaction was completed, the reaction
mixture was filtered. The filtrate was washed with water,
concentrated and dried and 4.2 g of a orange powdery solid was
obtained. The obtained solid was dissolved in toluene and
fractionated in accordance with the thin layer chromatography using
a layer of silica gel and 2.6 g of the main component having a high
purity was obtained. The main component was confirmed to be
Compound B-17 from FD-MS (872).
SYNTHESIS EXAMPLE 7
Compound A-4
[0069] Compound A-4 was synthesized via the reaction route shown in
the following: ##STR27## ##STR28##
[0070] In the synthesis of Compound (8), the reaction mixture was
examined in accordance with the thin layer chromatography and the
reaction was allowed to continue until the spot of Compound (6)
disappeared. After the reaction was completed, the reaction mixture
was washed with a 0.1N aqueous solution of sodium hydroxide,
concentrated and fractionated in accordance with the column
chromatography using a column packed with silica gel and Compound
(8) was obtained.
[0071] The reaction was conducted in accordance with the same
procedures as those conducted in Synthesis Example 1(B) except that
3.12 g (5.6 mmole) of Compound (8) was used in place of Compound
(7) and 0.51 g (11.5 mmole) of piperidine was used in place of
diphenylamine. The solid obtained by the reaction was dissolved in
toluene and fractionated in accordance with the column
chromatography using a column packed with silica gel and 2.2 g of
Compound (9) having a high purity was obtained.
[0072] Compound (9) in an amount of 5.61 g (10.0 mmole) was
dissolved into 30 ml of dimethylformamide. To the obtained
solution, 1.68 g (11.0 mmole) of phosphorus oxychloride was added
and the mixture was refluxed under heating. After the reaction was
completed, the reaction mixture was filtered and the filtrate was
fractionated in accordance with the column chromatography using a
column packed with silica gel and 4.0 g of the main component
having a high purity was obtained. The main component was confirmed
to be Compound (10) from FD-MS (589).
[0073] Compound (10) in an amount of 4.7 g (8.0 mmole) was reacted
with 0.7 g (10.6 mmole) of malonitrile. The reaction product
precipitated in the reaction mixture was separated and dissolved in
tetrahydrofuran. The obtained solution was fractionated in
accordance with the thin layer chromatography using a thin layer of
silica gel and 3.6 g of red orange crystals having a high purity
were obtained. The crystals were confirmed to be Compound A-4 from
FD-MS (637).
SYNTHESIS EXAMPLE 8
Compound A-14
[0074] Compound A-14 was synthesized via the reaction route shown
in the following (S. H. Tucker, J. Chem. Soc., 1462 (1958)):
##STR29##
SYNTHESIS EXAMPLE 9
Compound A-6
[0075] Compound A-6 was synthesized via the reaction route shown in
the following: ##STR30##
SYNTHESIS EXAMPLE 10
Compound B-5
[0076] Compound B-5 was synthesized via the reaction route shown in
the following (Beil. 5(3) 2278): ##STR31##
SYNTHESIS EXAMPLE 11
Compound A-12)
[0077] Compound A-12 was synthesized via the reaction route shown
in the following: ##STR32## ##STR33##
SYNTHESIS EXAMPLE 12
[0078] A composition containing
3,10-bisdiphenylamino-7,14-diphenyl-acenaphtho[1,2-k]fluoranthene
and
3,11-bisdiphenylamino-7,14-diphenyl-acenaphtho[1,2-k]fluoranthene
in a ratio of the amounts by mole in the range of 20:80 to 30:70
was synthesized via the reaction route shown in the following:
##STR34##
(A) Synthesis of a Composition (18) Containing 3,10- and
3,11-dibromo-7,14-diphenylacenaphtho[1,2-k]fluoranthenes in a Ratio
of the Amounts by Mole of 22:78
[0079] The solution portion of the reaction mixture obtained in
Synthesis Example 1(A) was concentrated, dissolved in
tetrahydrofuran and recrystallized and the formed precipitates were
removed. The solution portion was concentrated and a dibromo
compound was obtained. This dibromo compound was confirmed to be a
composition containing 3,10- and
3,11-dibromo-7,14-diphenylacenaphtho[1,2-k]fluoranthenes in a ratio
of the amounts by mole of 22:78 from the .sup.1H-NMR spectrum.
(B) Synthesis of a Composition Containing 3,10- and
3,11-bisdiphenylamino-7,14-diphenylacenaphtho[1,2-k]fluoranthenes
in a Ratio by the Amounts by Mole in the Range of 20:80 to
30:70
[0080] Into 100 ml of toluene, 5.00 g (7.9 mmole) of the
composition containing 3,10- and
3,11-dibromo-7,14-diphenylacenaphtho[1,2-k]-fluoranthenes in a
ratio of the amounts by mole of 22:78 (18), 2.78 g (16.5 mmole) of
diphenylamine, 0.09 g (0.09 mmole) of palladium acetate, 0.44 g
(2.2 mmole) of tri-tert-butylphosphine and 2.12 g (19.6 mmole) of
sodium tert-butoxide were dissolved and the reaction was allowed to
proceed for 6 hours while the mixture was refluxed under heating.
After the reaction was completed, the reaction mixture was
filtered. The filtrate was concentrated and fractionated in
accordance with the column chromatography using a column packed
with silica gel and 6.20 g of a red orange powdery solid was
obtained. This solid was confirmed to be a composition containing
3,10-bisdiphenylamino-7,14-diphenylacenaphtho-[1,2-k]fluoranthene
and
3,11-bisdiphenylamino-7,14-diphenylacenaphtho-[1,2-k]fluoranthene
in a ratio of the amounts by mole in the range of 20:80 to 30:70
from FD-MS (812) and the .sup.1H-NMR spectrum (H: 400 MHz; the
solvent of the measurement: DMSO (120.degree. C.); shown in FIG.
1).
SYNTHESIS EXAMPLE 13
[0081] 5,12- and/or
5,13-Bisdiphenylamino-9,16-diphenylfluorantheno[8,9-a]aceanthrylenes
were synthesized via the reaction route shown in the following:
##STR35##
(A) Synthesis of 9,16-diphenylfluorantheno[8,9-a]aceanthrylene
(19)
[0082] With reference to the Bandyopadhyai's process,
9,16-diphenylfluorantheno[8,9-a]aceanthrylene was synthesized by
the reaction of 1,3-diphenylcyclopenta[a]aceanthrylen-2-one and
acenaphthylene using aceanthrylenequinone as the starting material
[Indian J. Chem., Vol. 21B, 91 (1982)].
(B) Synthesis of 5,12- and/or
5,13-dibromo-9,16-diphenyl-fluorantheno[8,9-a]aceanthrylene
(20)
[0083] Into 240 ml of methylene chloride, 4.00 g (7.6 mmole) of
9,16-diphenylfluorantheno[8,9-a]aceanthrylene (19) was dissolved.
While the obtained mixture was refluxed under heating, 18.0 ml of a
1M methylene chloride solution of bromine was added dropwise and
the reaction was allowed to proceed for 2 hours. The resultant
reaction mixture was washed with an aqueous solution of sodium
hydroxide and pure water and concentrated and 5.06 g of a yellow
brown powdery solid was obtained. The solid was confirmed to be
5,12-dibromo-9,16-diphenyl-fluorantheno[8,9-a]aceanthrylene and/or
5,13-dibromo-9,16-diphenyl-fluorantheno[8,9-a]aceanthrylene from
FD-MS (686) and the .sup.1H-NMR spectrum.
(C) Synthesis of 5,12- and/or
5,13-bisdiphenylamino-9,16-diphenyl-fluorantheno[8,9-a]aceanthrylene
[0084] Into 200 ml of toluene, 5.00 g (7.4 mmole) of 5,12- and/or
5,13-dibromo-9,16-diphenylfluorantheno[8,9-a]aceanthrylene (20),
2.75 g (16.2 mmole) of diphenylamine, 0.09 g (0.4 mmole) of
palladium acetate, 0.43 g (2.2 mmole) of tri-tert-butylphosphine
and 2.05 g (20.6 mmole) of sodium tert-butoxide were dissolved and
the reaction was allowed to proceed for 5 hours while the mixture
was refluxed under heating. After the reaction was completed, the
reaction mixture was filtered. The filtrate was concentrated and
fractionated in accordance with the column chromatography using a
column packed with silica gel and 4.27 g of a black purple powdery
solid of the main component was obtained. The main component was
confirmed to be 5,12- and/or
5,13-bisdiphenylamino-9,16-diphenylfluorantheno[8,9-a]aceanthrylene
from FD-MS (862) and the .sup.1H-NMR spectrum (H: 400 MHz; the
solvent of the measurement: DMSO (120.degree. C.); shown in FIG.
2).
SYNTHESIS EXAMPLE 14
[0085] 3,11- and/or
3,12-Bisdiphenylamino-7,16-diphenylfluorantheno[8,9-k]fluoranthene
was synthesized via the reaction route shown in the following:
##STR36## ##STR37##
(A) Synthesis of 2,5-diphenylfluorantheno[11',12'-3,4]furan
(21)
[0086] In accordance with the N. Campbell's process [J. Chem. Soc.,
1555 (1949)], 2,5-diphenylfluorantheno[11',12'-3,4]furan (21) was
synthesized by the reaction of 7,8-dimethylacenaphthene-7,8-diol
which was synthesized in accordance with the S. H. Tucker's process
[J. Chem. Soc., 1462 (1958)] and trans-1,2-dibenzoylethylene.
(B) Synthesis of 7,16-diphenylfluorantheno[8,9-k]fluoranthene
(22)
[0087] Into a mixed solvent containing 500 ml of xylene and 660 ml
of methylene chloride, 5.00 g (12.7 mmole) of
2,5-diphenylfluorantheno-[11',12'-3,4]furan (21) and 3.86 g (19.0
mmole) of acenaphthylene were added and the mixture was refluxed
under heating for 3 hours. The solution was cooled and 16.0 ml of a
1M methylene chloride solution of BBr.sub.3 was added dropwise to
the cooled solution. The obtained solution was heated at 60.degree.
C. for 4 hours. The resultant reaction mixture was washed with an
aqueous solution of sodium hydrogencarbonate and pure water,
concentrated and purified in accordance with the column
chromatography using a column packed with silica gel and 3.20 g of
yellow crystals were obtained. The crystals were confirmed to be
7,16-diphenylfluorantheno[8,9-k]fluoranthene (22) from FD-MS (528)
and the .sup.1H-NMR spectrum.
(C) Synthesis of 3,11- and/or
3,12-dibromo-7,16-diphenyl-fluorantheno[8,9-k]fluoranthene (23)
[0088] Into 230 ml of methylene chloride, 2.30 g (4.3 mmole) of
7,16-diphenylfluorantheno[8,9-k]fluoranthene (22) was dissolved.
While the obtained solution was refluxed under heating, 9.0 ml of a
1M methylene chloride solution of bromine was added dropwise to the
solution and then the reaction was allowed to proceed for 2 hours.
The resultant reaction mixture was washed with an aqueous solution
of sodium hydroxide and pure water and concentrated and 3.06 g of a
light yellow brown crystals were obtained. The crystals were
confirmed to be 3,11- and/or
3,12-dibromo-7,16-diphenylfluorantheno[8,9-k]fluoranthene (23) from
FD-MS (686) and the .sup.1H-NMR spectrum.
(D) Synthesis of 3,11- and/or
3,12-bisdiphenylamino-7,16-diphenylfluorantheno[8,9-k]fluoranthene
[0089] Into 120 ml of toluene, 3.92 g (5.7 mmole) of 3,11- and/or
3,12-dibromo-7,16-diphenylfluorantheno[8,9-k]fluoranthene (23),
2.03 g (12.0 mmole) of diphenylamine, 0.07 g (0.07 mmole) of
palladium acetate, 0.33 g (1.7 mmole) of tri-tert-butylphosphine
and 1.56 g (14.4 mmole) of sodium tert-butoxide were dissolved and
the reaction was allowed to proceed for 6 hours while the mixture
was refluxed under heating. After the reaction was completed, the
reaction mixture was filtered. The filtrate was purified in
accordance with the column chromatography using a column packed
with silica gel and 4.27 g of a orange powdery crystals were
obtained. The crystals were confirmed to be 3,11- and/or
3,12-bisdiphenylamino-7,16-diphenylfluorantheno[8,9-k]fluoranthene
from FD-MS (862) and the .sup.1H-NMR spectrum (H: 400 MHz; the
solvent of the measurement: DMSO (120.degree. C.); shown in FIG.
3).
SYNTHESIS EXAMPLE 15
[0090] A composition containing
3,10-bisditolylamino-7,14-diphenyl-acenaphtho[1,2-k]fluoranthene
and
3,11-bisditolylamino-7,14-diphenyl-acenaphtho[1,2-k]fluoranthene in
a ratio of the amounts by mole in the range of 80:20 to 90:10 was
synthesized.
(A) Synthesis of a Composition (18) Containing 3,10- and
3,11-dibromo-7,14-diphenylacenaphtho[1,2-k]fluoranthenes
[0091] The solution portion of the reaction mixture obtained in
Synthesis Example 1(A) was concentrated, dissolved entirely in
tetrahydrofuran and recrystallized and the formed precipitates were
removed. The solution portion was concentrated and a dibromo
compound was obtained. This dibromo compound was confirmed to be a
composition containing 3,10- and
3,11-dibromo-7,14-diphenylacenaphtho-[1,2-k]fluoranthenes
containing in a ratio of the amounts by mole in the range of 80:20
to 90:10 from the .sup.1H-NMR spectrum.
(B) Synthesis of a Composition Containing 3,10- and
3,11-bisditolylamino-7,14-diphenylacenaphtho[1,2-k]fluoranthenes in
a Ratio of the Amounts by Mole in the Range of 80:20 to 90:10
[0092] In accordance with the same procedures as those conducted in
Synthesis Example 12(B) except that di-p,p-tolylamine was used in
place of diphenylamine, a composition (A-16) containing 3,10- and
3,11-bisditolylamino-7,14-diphenylacenaphtho[1,2-k]fluoranthenes in
a ratio of the amounts by mole in the range of 80:20 to 90:10 was
synthesized.
SYNTHESIS EXAMPLE 16
[0093] A composition containing
3,10-bisdiphenylamino-7,14-diphenyl-acenaphtho[1,2-k]fluoranthene
and
3,11-bisdiphenylamino-7,14-diphenyl-acenaphtho[1,2-k]fluoranthene
in a ratio of the amounts by mole in the range of 80:20 to 90:10
was synthesized.
(A) Synthesis of a Composition (18) Containing 3,10- and
3,11-dibromo-7,14-diphenylacenaphtho[1,2-k]fluoranthenes
[0094] The composition containing the dibromo compounds was
obtained in accordance with the same procedures as those conducted
in Synthesis Example 15(A).
(B) Synthesis of a Composition (A-1) Containing 3,10- and
3,11-bisdiphenylamino-7,14-diphenyloacenaphtho[1,2-k]fluoranthenes
in a Ratio of the Amounts by Mole in the Range of 80:20 to
90:10
[0095] In accordance with the same procedures as those conducted in
Synthesis Example 12(B) using the composition obtained above in
(A), a composition containing
3,10-bisdiphenylamino-7,14-diphenylacenaphtho-[1,2-k]fluoranthene
and 3,11
-bisdiphenylamino-7,14-diphenylacenaphtho-[1,2-k]fluoranthene in a
ratio of the amounts in mole in the range of 80:20 to 90:10 was
synthesized.
EXAMPLE 1
[0096] On a cleaned glass plate having an ITO electrode, the
following compound (H232) as the hole injecting material was vapor
deposited so that a film having a thickness of 60 nm was formed.
##STR38## Then, the following compound (NPD) as the hole
transporting material was vapor deposited so that a film having a
thickness of 20 nm was formed. ##STR39##
[0097] Subsequently, an aluminum complex of 8-hydroxyquinoline
(Alq) and 3,10- and
3,11-diphenylamino-7,14-diphenylacenaphthofluoranthenes (Compound
A-1) as the materials for the light emitting layer were vapor
deposited so that a film containing 2.1% by mole of Compound A-1
and having a thickness of 50 nm was formed. The structure of Alq is
shown in the following: ##STR40## An electron injecting layer was
formed by vapor deposition of Alq alone so that the formed film had
a thickness of 10 nm. A layer of an inorganic compound was formed
on the electron injecting layer by vapor deposition of LiF so that
the formed film had a thickness of 0.2 nm. On the thus formed
layer, aluminum was vapor deposited so that an electrode having a
thickness of 170 nm was formed and an organic EL device was
obtained. The vapor depositions for forming the above layers were
conducted under 10.sup.-6 Torr while the substrate was kept at the
room temperature.
[0098] The light emitting property of this device was as follows:
the luminance under application of a direct current of 5.5 V: 103
cd/m.sup.2; the efficiency of light emission: as high as 6.2 cd/A.
The emitted light was orange light having chromaticity coordinates
of (0.56, 0.44). When the device was driven under a constant
current at an initial luminance of 500 cd/m.sup.2, the half-life
was as long as 2600 hours.
[0099] This example shows that an organic EL device exhibiting a
high performance can be obtained by using Compound A-1 as the
doping material. The spectrum of the light emitted by the device
was obtained and found to be the same as the fluorescence spectrum
of the doping material. Thus, it is shown that the doping material
worked as the center of light emission.
COMPARATIVE EXAMPLE 1
[0100] An organic EL device was obtained in accordance with the
same procedures as those conducted in Example 1 except that rubrene
was vapor deposited in place of Compound A-1 so that a film
containing 4.0% by mole of rubrene was formed.
[0101] The light emitting property of this device was as follows:
the luminance under application of a direct current of 5.5 V: 105
cd/m.sup.2; the efficiency of light emission: 7.6 cd/A. However,
the emitted light was yellow light having chromaticity coordinates
of (0.50, 0.50). The half-life was 1000 hours when the device was
driven under a constant current at an initial luminance of 500
cd/m.sup.2 and shorter than that of the device of Example 1.
COMPARATIVE EXAMPLE 2
[0102] An organic EL device was obtained in accordance with the
same procedures as those conducted in Example 1 except that
fluorantheno[8,9-k]fluoranthene described in Japanese Patent
Application Laid-Open No. Heisei 11(1999)-40360 was vapor deposited
in place of Compound A-1 so that a film containing 2% by mole of
this fluoranthene was formed.
[0103] The light emitting property of this device was as follows:
the luminance under application of a direct current of 5.5 V: 35
cd/m.sup.2; the efficiency of light emission: 3.0 cd/A. The emitted
light was yellow green light. The half-life was as short as 300
hours when the device was driven under a constant current at an
initial luminance of 500 cd/m.sup.2.
COMPARATIVE EXAMPLE 3
[0104] An organic EL device was obtained in accordance with the
same procedures as those conducted in Example 1 except that
7,14-diphenylacenaphtho[1,2-k]fluoranthene described in Japanese
Patent Application Laid-Open No. Heisei 11(1999)-168445 was vapor
deposited in place of Compound A-1 so that a film containing 2% by
mole of this fluoranthene was formed.
[0105] The light emitting property of this device was as follows:
the luminance under application of a direct current of 6 V: 69
cd/m.sup.2; the efficiency of light emission: 1.3 cd/A. The emitted
light was yellow green light. The efficiency was smaller than that
of a device in which Alq alone was used as the light emitting
material. The half-life was as short as 400 hours when the device
was driven under a constant current at an initial luminance of 500
cd/m.sup.2. When the spectrum of the light emitted by the device
was obtained, the spectrum did not agree with the fluorescence
spectrum of the doping material. Thus, it was found that the above
compound did not emit light and the yellow green light was emitted
from Alq. The doping material did not work as the light emitting
material.
EXAMPLES 2 to 11
[0106] Organic EL devices were obtained in accordance with the same
procedures as those conducted in Example 1 except that compounds
shown in Table 1 were vapor deposited in place of Compound A-1.
[0107] The light emitting properties of these devices were obtained
in accordance with the same methods as those used in Example 1. The
voltage applied in the measurements, the luminance, the efficiency
of light emission, the color of the emitted light and the half-life
when the device was driven under a constant current at an initial
luminance of 500 cd/m.sup.2 are shown in Table 1.
EXAMPLE 12
[0108] An organic EL device was obtained in accordance with the
same procedures as those conducted in Example 1 except that the
composition containing the prescribed relative amounts of the
isomers which was obtained in Synthesis Example 12 (Compound A-1)
was used for the light emitting layer in a concentration of 100%
and Alq was not used.
[0109] The light emitting property of this device was as follows:
the luminance under application of a direct current of 4.5 V: 80
cd/m.sup.2; the efficiency of light emission: 3.5 cd/A. The
half-life was as long as 2100 hours when the device was driven
under a constant current at an initial luminance of 500 cd/m.sup.2.
The device had a longer life than that of the device of Example 1
and can be used also as the main light emitting material.
EXAMPLE 13
[0110] An organic EL device was obtained in accordance with the
same procedures as those conducted in Example 1 except that the
composition containing the prescribed relative amounts of the
isomers which was obtained in Synthesis Example 15 (Compound A-16)
was used for the light emitting layer in place of Compound A-1.
[0111] The light emitting property of this device was as follows:
the luminance under application of a direct current of 5.5 V: 94
cd/m.sup.2; the efficiency of light emission: 5.94 cd/A. The
emitted light was reddish orange light having chromaticity
coordinates of (0.60, 0.39). The half-life was as long as 3200
hours when the device was driven under a constant current at an
initial luminance of 500 cd/m.sup.2.
EXAMPLE 14
[0112] An organic EL device was obtained in accordance with the
same procedures as those conducted in Example 1 except that the
composition containing the prescribed relative amounts of the
isomers which was obtained in Synthesis Example 16 (Compound A-1)
was used for the light emitting layer in place of Compound A-1.
[0113] The light emitting property of this device was as follows:
the luminance under application of a direct current of 6 V: 100
cd/m.sup.2; the efficiency of light emission: 4.75 cd/A. The
emitted light had chromaticity coordinates of (0.58, 0.42). The
half-life was as long as 1800 hours when the device was driven
under a constant current at an initial luminance of 500 cd/m.sup.2.
The light having more reddish color than that of the light emitted
in Example 1 could be emitted by using the above compound. This
result was obtained because the composition contained a greater
amount of the isomer
3,11-bisdiphenylamino-7,14-diphenylacenaphtho[12-k]fluoranthene
which could emit light having a longer wavelength. TABLE-US-00001
TABLE 1 Efficiency Volt- Lumi- of light Color of Half- Com- age
nance emission emitted life pound (V) (cd/m.sup.2) (cd/A) light
(hour) Example 2 A-2 5.5 140 5.7 reddish 2800 orange Example 3 A-8
5.8 120 3.6 orange 2100 Example 4 A-14 5.2 120 6.1 red 2700 Example
5 A-16 6.0 170 4.7 reddish 3100 orange Example 6 B-3 6.0 160 3.2
reddish 1900 orange Example 7 B-15 5.5 130 2.8 orange 1800 Example
8 B-17 5.8 110 2.0 reddish 1700 orange Example 9 B-18 6.1 120 2.8
reddish 2000 orange Example 10 A-4 7.2 110 3.7 red 1000 Example 11
B-5 6.0 120 6.7 yellowish 1800 green
INDUSTRIAL APPLICABILITY
[0114] As described above in detail, the organic
electroluminescence device of the present invention which utilizes
the compound selected from the compounds represented by general
formulae [1] to [18] emits yellowish to reddish light, exhibits an
excellent purity of color and a high efficiency of light emission
and has a long life.
[0115] Therefore, the organic electroluminescence device of the
present invention is advantageously used as a light source such as
a planar light emitting member of televisions and a back light of
displays.
* * * * *