U.S. patent application number 13/920234 was filed with the patent office on 2013-12-26 for compound having substituted anthracene ring structure and pyridoindole ring structure and organic electroluminescence device.
The applicant listed for this patent is HODOGAYA CHEMICAL CO., LTD.. Invention is credited to Shuichi Hayashi, Sawa Izumi, Naoaki Kabasawa, Shigeru Kusano, Norimasa YOKOYAMA.
Application Number | 20130341604 13/920234 |
Document ID | / |
Family ID | 42059722 |
Filed Date | 2013-12-26 |
United States Patent
Application |
20130341604 |
Kind Code |
A1 |
YOKOYAMA; Norimasa ; et
al. |
December 26, 2013 |
COMPOUND HAVING SUBSTITUTED ANTHRACENE RING STRUCTURE AND
PYRIDOINDOLE RING STRUCTURE AND ORGANIC ELECTROLUMINESCENCE
DEVICE
Abstract
The present invention provides an organic compound having
excellent properties, which is excellent in
electron-injection/transport performance, has hole-blocking ability
and is high stability in a thin-film state, as a material for an
organic electroluminescence device having a high efficiency and a
high durability, and provides is an organic electroluminescence
device having a high efficiency and a high durability using the
compound. The present invention relates to a compound having a
substituted anthracene ring structure and a pyridoindole ring
structure represented by general formula (1); and an organic
electroluminescence device having a pair of electrodes and at least
one organic layer interposed between the electrodes in which the at
least one organic layer contains the compound. ##STR00001##
Inventors: |
YOKOYAMA; Norimasa;
(Ibaraki, JP) ; Hayashi; Shuichi; (Ibaraki,
JP) ; Izumi; Sawa; (Tokyo, JP) ; Kabasawa;
Naoaki; (Ibaraki, JP) ; Kusano; Shigeru;
(Ibaraki, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
HODOGAYA CHEMICAL CO., LTD. |
Tokyo |
|
JP |
|
|
Family ID: |
42059722 |
Appl. No.: |
13/920234 |
Filed: |
June 18, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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13120665 |
Mar 24, 2011 |
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PCT/JP2009/066450 |
Sep 18, 2009 |
|
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13920234 |
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Current U.S.
Class: |
257/40 ; 546/85;
546/87 |
Current CPC
Class: |
C09K 2211/1014 20130101;
C09K 2211/1029 20130101; H01L 51/0072 20130101; H01L 51/0059
20130101; C09K 2211/1011 20130101; H01L 51/5092 20130101; C09K
11/06 20130101; H05B 33/14 20130101; H01L 51/0067 20130101; C07D
471/04 20130101; H01L 51/5048 20130101; H01L 51/0058 20130101 |
Class at
Publication: |
257/40 ; 546/85;
546/87 |
International
Class: |
H01L 51/00 20060101
H01L051/00 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 24, 2008 |
JP |
2008-243937 |
Claims
1. A compound comprising a substituted anthracene ring structure
and a pyridoindole ring structure, represented by formula (1):
##STR00033## wherein: Ar.sub.1 and Ar.sub.2 are each independently
a substituted or unsubstituted aromatic hydrocarbon group; R.sub.1,
R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.6, R.sub.7, and R.sub.8
are each independently a hydrogen atom, a fluorine atom, a chlorine
atom, a cyano group, a trifluoromethyl group, a linear or branched
alkyl group comprising 1 to 6 carbon atoms, a substituted or
unsubstituted aromatic hydrocarbon group, a substituted or
unsubstituted aromatic heterocyclic group, or a substituted or
unsubstituted condensed polycyclic aromatic group; W, X, Y, and Z
are each a carbon atom or a nitrogen atom, provided that only one
of W, X, Y, and Z is a nitrogen atoms and the nitrogen atom does
not have a substituent R.sub.1 to R.sub.4; and A is a divalent
group of formula (A1-a): ##STR00034## wherein; n1 is 1 or 2;
R.sub.9, R.sub.10, and R.sub.11 are each independently a hydrogen
atom, a fluorine atom, a chlorine atom, a cyano group, a
trifluoromethyl group, a linear or branched alkyl group comprising
1 to 6 carbon atoms, a substituted or unsubstituted aromatic
hydrocarbon group, or a substituted or unsubstituted aromatic
heterocyclic group; D and E are each a carbon atom or a nitrogen
atom, provided that when one or two of D and E are a nitrogen atom,
the nitrogen atom does not have a substituent R.sub.9 to R.sub.11
or bonding group and when n1 is 2, a plurality of R.sub.9's,
R.sub.10's, R.sub.11's, D's, and E's, may be different from each
other.
2. The compound of claim 1, wherein in formula (A1-a), n1 is 1 and
at least one of D and E is a nitrogen atom.
3. The compound of claim 1, wherein in formula (A1-a), n1 is 1 and
each of D and E are nitrogen atoms.
4. The compound of claim 1, wherein A is a divalent group of
formula (A1-b): ##STR00035## wherein R.sub.13, R.sub.14, R.sub.15,
R.sub.16, and R.sub.17 are each independently a hydrogen atom, a
fluorine atom, a chlorine atom, a cyano group, a trifluoromethyl
group, a linear or branched alkyl group having 1 to 6 carbon atoms,
a substituted or unsubstituted aromatic hydrocarbon group, or a
substituted or unsubstituted aromatic heterocyclic group
5. The compound of claim 1, wherein A is a divalent group of
formula (A1-c): ##STR00036## wherein R.sub.13, R.sub.14, R.sub.15,
and R.sub.16 are each independently a hydrogen atom, a fluorine
atom, a chlorine atom, a cyano group, a trifluoromethyl group, a
linear or branched alkyl group having 1 to 6 carbon atoms, a
substituted or unsubstituted aromatic hydrocarbon group, or a
substituted or unsubstituted aromatic heterocyclic group.
6. The compound of claim 1, wherein A is a divalent group of
formula (A1-d): ##STR00037## wherein R.sub.13, R.sub.14, R.sub.15,
and R.sub.16 are each independently a hydrogen atom, a fluorine
atom, a chlorine atom, a cyano group, a trifluoromethyl group, a
linear or branched alkyl group having 1 to 6 carbon atoms, a
substituted or unsubstituted aromatic hydrocarbon group, or a
substituted or unsubstituted aromatic heterocyclic group.
7. The compound of claim 1, wherein A is a divalent group of
formula (A1-e): ##STR00038## wherein R.sub.13 and R.sub.14 are each
independently a hydrogen atom, a fluorine atom, a chlorine atom, a
cyano group, a trifluoromethyl group, a linear or branched alkyl
group having 1 to 6 carbon atoms, a substituted or unsubstituted
aromatic hydrocarbon group, or a substituted or unsubstituted
aromatic heterocyclic group.
8. An organic electroluminescence device, comprising a pair of
electrodes and at least one organic layer interposed between the
electrodes, wherein the organic layer comprises the compound of
claim 1.
9. The organic electroluminescence device of claim 8, wherein the
organic layer comprises an electron-transport layer and the
compound of formula (1) is present in the electron-transport
layer.
10. The organic electroluminescence device of claim 8, wherein the
organic layer comprises a hole-blocking layer and the compound of
formula (1) is present in the hole-blocking layer.
11. The organic electroluminescence device of claim 8, wherein the
organic layer comprises a light-emitting layer and the compound of
formula (1) is present in the light-emitting layer.
12. The organic electroluminescence device of claim 8, wherein the
organic layer comprises an electron-injection layer and the
compound of formula (1) is present in the electron-injection layer.
Description
REFERENCE TO PRIOR APPLICATIONS
[0001] This application is a continuation of U.S. application Ser.
No. 13/120,665, filed Mar. 24, 2011, now allowed; which is a 371 of
International application PCT/JP2009/066450, filed Sep. 18, 2009;
and to Japanese patent application 2008-243937, filed Sep. 24,
2008, all incorporated herein by reference.
TECHNICAL FIELD
[0002] The present invention relates to a compound suitable for an
organic electroluminescence device which is a self-luminescent
device suitable for various displaying devices and a device. More
specifically, it relates to a compound having a substituted
anthracene ring structure and a pyridoindole ring structure and to
an organic electroluminescence device using the compound.
BACKGROUND ART
[0003] Since organic electroluminescence devices are
self-luminescent devices, they are bright and excellent in
visibility as compared with liquid-crystalline devices and capable
of giving clear display, so that the organic electroluminescence
devices have been actively studied.
[0004] In 1987, C. W. Tang et al. of Eastman Kodak Company put an
organic electroluminescence device using organic materials into
practical use by developing a device having a multilayered
structure wherein various roles are assigned to respective
materials. They formed a lamination of a fluorescent material
capable of transporting electrons and an organic material capable
of transporting holes, so that both charges are injected into the
layer of the fluorescent material to emit light, thereby achieving
a high luminance of 1000 cd/m2 or more at a voltage of 10 V or
lower (see e.g., Patent Documents 1 and 2). [0005] Patent Document
1: JP-A-8-48656 [0006] Patent Document 2: Japanese Patent No.
3194657
[0007] To date, many improvements have been performed for practical
utilization of the organic electroluminescence devices, and high
efficiency and durability have been achieved by an
electroluminescence device wherein an anode, a hole-injection
layer, a hole-transport layer, a light-emitting layer, an
electron-transport layer, an electron-injection layer, and a
cathode are sequentially provided on a substrate, to further
segmentalize various roles (see e.g., Non-Patent Document 1).
[0008] Non-Patent Document 1: Japan Society of Applied Physics
Ninth Workshop Preprint, pp. 55-61 (2001)
[0009] Moreover, for the purpose of further improvement of luminous
efficiency, utilization of triplet exciton has been attempted and
utilization of a phosphorescent material has been investigated (see
e.g., Non-Patent Document 2). [0010] Non-Patent Document 2: Japan
Society of Applied Physics Ninth Workshop Preprint, pp. 23-31
(2001)
[0011] The light-emitting layer can be also prepared by doping a
charge-transport compound, generally called a host material, with a
fluorescent material or a phosphorescent material. As described in
the above-mentioned Workshop Preprints, the choice of the organic
materials in organic electroluminescence devices remarkably affects
various properties such as efficiency and durability of the
devices.
[0012] In the organic electroluminescence devices, the charges
injected from the both electrode are recombined in the
light-emitting layer to attain light emission. However, since the
mobility of holes is higher than the mobility of electrons, a
problem of reduction in efficiency caused by a part of the holes
passing through the light-emitting layer arises. Therefore, it is
required to develop an electron-transport material in which the
mobility of electrons is high.
[0013] A representative light-emitting material,
tris(8-hydroxyquinoline)aluminum (hereinafter referred to as Alq3)
is commonly used also as an electron-transport material. However,
since it has a work function of 5.8 eV, it cannot be considered
that the material has hole-blocking capability.
[0014] As a technique to prevent the passing of a part of holes
through the light-emitting layer and to improve probability of
charge recombination in the light-emitting layer, there is a method
of inserting a hole-blocking layer. As hole-blocking materials,
there have been hitherto proposed triazole derivatives (see e.g.,
Patent Document 3), bathocuproine (hereinafter referred to as BCP),
a mixed ligand complex of aluminum (BAlq) (see e.g., Non-Patent
Document 2), and the like.
[0015] On the other hand, as an electron-transport material
excellent in hole-blocking ability, there is proposed
3-(4-biphenylyl)-4-phenyl-5-(4-t-butylphenyl)-1,2,4-triazole
(hereinafter referred to as TAZ) (see e.g., Patent Document 3).
[0016] Patent Document 3: Japanese Patent No. 2734341
[0017] Since TAZ has a work function as large as 6.6 eV and thus
exhibits a high hole-blocking ability, it is used as an
electron-transport hole-blocking layer to be laminated onto the
cathode side of a fluorescence-emitting layer or
phosphorescence-emitting layer prepared by vacuum deposition,
coating or the like, and contributes to increase the efficiency of
organic electroluminescence devices (see e.g., Non-Patent Document
3). [0018] Non-Patent Document 3: Fiftieth Meeting of Japan Society
of Applied Physics and Related Societies, 28p-A-6 Lecture Preprint,
p. 1413 (2003)
[0019] However, TAZ has a great problem of having low electron
transport property, and it is necessary to prepare an organic
electroluminescence device in combination with an
electron-transport material having a higher electron transport
property (see e.g., Non-Patent Document 4). [0020] Non-Patent
Document 4: Japan Society of Applied Physics, Journal of Organic
Molecules/Bioelectronics Section, Vol. 11, No. 1, pp. 13-19
(2000)
[0021] Further, BCP has a work function as large as 6.7 eV and a
high hole-blocking ability, but has a low glass transition point
(Tg) which is 83.degree. C., so that it is poor in thin-film
stability and thus it cannot be considered that it sufficiently
functions as a hole-blocking layer.
[0022] All the materials are insufficient in thin-film stability or
are insufficient in the function of blocking holes. In order to
improve characteristic properties of the organic
electroluminescence devices, it is desired to develop an organic
compound which is excellent in electron-injection/transport
performances and hole-blocking ability and is highly stable in a
thin-film state.
SUMMARY OF THE INVENTION
Problems to be Solved by the Invention
[0023] Objects of the present invention are to provide an organic
compound having excellent properties, which is excellent in
electron-injection/transport performances, has hole-blocking
ability and has high stability in a thin-film state, as a material
for an organic electroluminescence device having a high efficiency
and a high durability, and to provide an organic
electroluminescence device having a high efficiency and a high
durability using the compound.
[0024] As physical properties of the organic compound to be
provided by the invention, there may be mentioned (1) a good
electron injection characteristic, (2) a high electron mobility,
(3) an excellent hole-blocking ability, (4) good stability in a
thin-film state, and (5) excellent thermal resistance. In addition,
as physical properties of the organic electroluminescence device to
be provided by the invention, there may be mentioned (1) high
luminous efficiency, (2) low emission initiation voltage, (3) low
practical driving voltage.
Means for Solving the Problems
[0025] Thus, in order to achieve the above objects, the present
inventors have designed and chemically synthesized compounds having
a substituted anthracene ring structure and a pyridoindole ring
structure, with focusing on the fact that the pyridoindole ring
structure has an excellent electron-transport performance and is
excellent in thermal resistance. The present inventors have
experimentally produced various organic electroluminescence devices
using the compounds, and have extensively performed property
evaluation of the devices. As a result, they have accomplished the
invention.
[0026] That is, the invention provides: a compound having a
substituted anthracene ring structure and a pyridoindole ring
structure, represented by the following general formula (1); and an
organic electroluminescence device comprising a pair of electrodes
and at least one organic layer interposed between the electrodes,
wherein the at least one organic layer contains the compound:
##STR00002##
(wherein Ar.sub.1 and Ar.sub.2 may be the same or different from
each other and each represents a substituted or unsubstituted
aromatic hydrocarbon group, R.sub.1 to R.sub.8 may be the same or
different and each represents a hydrogen atom, a fluorine atom, a
chlorine atom, a cyano group, a trifluoromethyl group, a linear or
branched alkyl group having 1 to 6 carbon atoms, a substituted or
unsubstituted aromatic hydrocarbon group, a substituted or
unsubstituted aromatic heterocyclic group, or a substituted or
unsubstituted condensed polycyclic aromatic group, W, X, Y and Z
each represents a carbon atom or a nitrogen atom, and A represents
a single bond or a divalent group represented by the following
general formula (A1), provided that only one of W, X, Y and Z is a
nitrogen atom and the nitrogen atom does not have a substituent
R.sub.1 to R.sub.4):
##STR00003##
(wherein n1 represents an integer of 1 or 2, R.sub.9 to R.sub.12
may be the same or different and each represents a hydrogen atom, a
fluorine atom, a chlorine atom, a cyano group, a trifluoromethyl
group, a linear or branched alkyl group having 1 to 6 carbon atoms,
a substituted or unsubstituted aromatic hydrocarbon group, or a
substituted or unsubstituted aromatic heterocyclic group, D, E and
G each represents a carbon atom or a nitrogen atom, provided that
when all of or one or two of D, E and G are a nitrogen atom, the
nitrogen atom does not have a substituent R.sub.9 to R.sub.12 or
bonding group and when n1 is an integer of 2, a plurality of
R.sub.9's, R.sub.10's, R.sub.11's, R.sub.12's, D's, E's or G's may
be different from each other).
[0027] The "aromatic hydrocarbon group" in the substituted or
unsubstituted aromatic hydrocarbon group represented by Ar.sub.1 or
Ar.sub.2 in general formula (I) specifically includes a phenyl
group, a biphenylyl group, a terphenylyl group, a naphthyl group,
an anthryl group and a phenanthryl group.
[0028] The "substituent" in the substituted aromatic hydrocarbon
group represented by Ar.sub.1 or Ar.sub.2 in general formula (1)
specifically includes a fluorine atom, a chlorine atom, a cyano
group, a hydroxyl group, a nitro group, a linear or branched alkyl
group having 1 to 6 carbon atoms, a cyclopentyl group, a cyclohexyl
group, a linear or branched alkoxy group having 1 to 6 carbon
atoms, a dialkylamino group substituted with a linear or branched
alkyl group having 1 to 6 carbon atoms, phenyl group, naphthyl
group, anthryl group, styryl group, pyridyl group, pyridoindolyl
group, quinolyl group and benzothiazolyl group. These substituents
may be further substituted.
[0029] The "aromatic hydrocarbon group", the "aromatic heterocyclic
group" and the "condensed polycyclic aromatic group" in the
substituted or unsubstituted aromatic hydrocarbon group, the
substituted or unsubstituted aromatic heterocyclic group, or the
substituted or unsubstituted condensed polycyclic aromatic group,
represented by R.sub.1 to R.sub.8 in general formula (1),
specifically include a phenyl group, a biphenylyl group, a
terphenylyl group, a tetrakisphenyl group, a styryl group, a
naphthyl group, an anthryl group, an acenaphthenyl group, a
fluorenyl group, a phenanthryl group, an indenyl group, a pyrenyl
group, a pyridyl group, a triazyl group, a pyrimidyl group, a
furanyl group, a pyrazyl group, a thienyl group, a quinolyl group,
an isoquinolyl group, a benzofuranyl group, a benzothiophenyl
group, an indolyl group, a carbazolyl group, a benzoxazolyl group,
a benzothiazolyl group, a quinoxalyl group, a benzimidazolyl group,
a pyrazolyl group, a dibenzofuranyl group, a dibenzothiophenyl
group, a naphthyridinyl group, a phenanthrolinyl group and an
acridinyl group.
[0030] The "substituent" in the substituted aromatic hydrocarbon
group, the substituted aromatic heterocyclic group, or the
substituted condensed polycyclic aromatic group, represented by
R.sub.1 to R.sub.8 in general formula (1), specifically includes a
fluorine atom, a chlorine atom, a trifluoromethyl group, a linear
or branched alkyl group having 1 to 6 carbon atoms, a phenyl group,
a biphenylyl group, a terphenylyl group, a tetrakisphenyl group, a
styryl group, a naphthyl group, a fluorenyl group, a phenanthryl
group, an indenyl group and a pyrenyl group, and these substituents
may be further substituted.
[0031] The linear or branched alkyl group having 1 to 6 carbon
atoms, represented by R.sub.1 to R.sub.8 in general formula (1),
specifically includes a methyl group, an ethyl group, an n-propyl
group, an i-propyl group, an n-butyl group, an i-butyl group, a
t-butyl group, an n-pentyl group, an i-pentyl group, a t-pentyl
group, an n-hexyl group, an i-hexyl group and a t-hexyl group.
[0032] The divalent group represented by A in general formula (I)
includes a phenylene group, a biphenylene group, a pyridylene
group, a bipyridylene group, a pyrimidylene group, a
bis-pyrimidylene group, a triazylene group, a bis-triazylene group,
and a divalent group represented by the following general formula
(A2):
##STR00004##
(wherein R.sub.13 to R.sub.19 may be the same or different and each
represents a hydrogen atom, a fluorine atom, a chlorine atom, a
cyano group, a trifluoromethyl group, a linear or branched alkyl
group having 1 to 6 carbon atoms, a substituted or unsubstituted
aromatic hydrocarbon group, or a substituted or unsubstituted
aromatic heterocyclic group).
[0033] The "aromatic hydrocarbon group" and the "aromatic
heterocyclic group" in the substituted or unsubstituted aromatic
hydrocarbon group or the substituted or unsubstituted aromatic
heterocyclic group, represented by R.sub.9 to R.sub.19 in general
formula (A1) and general formula (A2), and the "substituent"
thereof include the same groups as described in R.sub.1 to R.sub.8
of general formula (1).
[0034] Also, the linear or branched alkyl group having 1 to 6
carbon atoms, represented by R.sub.9 to R.sub.19 in general formula
(A1) and general formula (A2), includes the same groups as
described in R.sub.1 to R.sub.8 of general formula (1).
[0035] The compound having a substituted anthracene ring structure
and a pyridoindole ring structure, which is represented by general
formula (1) of the invention, is a novel compound, provides high
electron mobility as compared with conventional electron-transport
materials, has an excellent hole-blocking ability, and is stable in
a thin-film state.
[0036] The compound having a substituted anthracene ring structure
and a pyridoindole ring structure, which is represented by general
formula (1) of the invention, can be used as a constituent material
for an electron-transport layer of an organic electroluminescence
device (hereinafter, abbreviated as organic EL device). The use of
the material exhibiting a higher electron injection/mobility as
compared with conventional materials provides effects of improving
electron transport efficiency from the electron-transport layer to
a light-emitting layer to enhance luminous efficiency and also
lowering a driving voltage to enhance durability of the organic EL
device.
[0037] The compound having a substituted anthracene ring structure
and a pyridoindole ring structure, which is represented by general
formula (1) of the invention, can be also used as a constituent
material for a hole-blocking layer of an organic EL device. The use
of the material excellent in hole-blocking ability and also
excellent in electron transport property as compared with
conventional materials and having high stability in a thin-film
state provides effects of lowering a driving voltage, improving
current resistance, and enhancing maximum emission luminance of the
organic EL device, while exhibiting a high luminous efficiency.
[0038] The compound having a substituted anthracene ring structure
and a pyridoindole ring structure, which is represented by general
formula (1) of the invention, can be also used as a constituent
material for a light-emitting layer of an organic EL device. The
use of a light-emitting layer prepared by using the material of the
invention excellent in electron transport property as compared with
conventional materials and having a wide band-gap as a host
material for the light-emitting layer and making a fluorescent
material or a phosphorescent material, called a dopant, carried
thereon provides an effect of realizing an organic EL device
exhibiting a lowered driving voltage and having an improved
luminous efficiency.
[0039] The organic EL device of the invention uses the compound
having a substituted anthracene ring structure and a pyridoindole
ring structure, which compound exhibits high electron mobility as
compared with conventional electron-transport materials, has an
excellent hole-blocking ability and is stable in a thin-film state.
Therefore, it becomes possible to realize high efficiency and high
durability.
Advantageous Effects of the Invention
[0040] The compound having a substituted anthracene ring structure
and a pyridoindole ring structure of the invention is useful as a
constituent material for an electron-transport layer, a
hole-blocking layer, or a light-emitting layer of an organic EL
device, and the compound exhibits an excellent hole-blocking
ability, is stable in a thin-film state, and has excellent thermal
resistance. The organic EL device of the invention exhibits a high
luminous efficiency, whereby the practical driving voltage of the
device can be lowered. By lowering the light emission initiation
voltage, the durability can be improved.
BRIEF DESCRIPTION OF THE DRAWINGS
[0041] FIG. 1 is a 1H-NMR chart of the compound (Compound 3) of
Invention Example 1.
[0042] FIG. 2 is a 1H-NMR chart of the compound (Compound 9) of
Invention Example 2.
[0043] FIG. 3 is a 1H-NMR chart of the compound (Compound 15) of
Invention Example 3.
[0044] FIG. 4 is a 1H-NMR chart of the compound (Compound 27) of
Invention Example 4.
[0045] FIG. 5 is a 1H-NMR chart of the compound (Compound 6) of
Invention Example 5.
[0046] FIG. 6 is a 1H-NMR chart of the compound (Compound 12) of
Invention Example 6.
[0047] FIG. 7 is a 1H-NMR chart of the compound (Compound 42) of
Invention Example 7.
[0048] FIG. 8 is a 1H-NMR chart of the compound (Compound 43) of
Invention Example 8.
[0049] FIG. 9 is a 1H-NMR chart of the compound (Compound 73) of
Invention Example 9.
[0050] FIG. 10 is a 1H-NMR chart of the compound (Compound 30) of
Invention Example 10.
[0051] FIG. 11 is a 1H-NMR chart of the compound (Compound 75) of
Invention Example 11.
[0052] FIG. 12 is a drawing showing the constitution of the EL
devices of Examples 14 to 22.
[0053] FIG. 13 is a drawing showing the constitution of the EL
device of Comparative Example 1.
MODE FOR CARRYING OUT THE INVENTION
[0054] The compound having a substituted anthracene ring structure
and a pyridoindole ring structure is a novel compound, and this
compound can be synthesized, for example, as follows. A
corresponding halogenoanilinopyridine is subjected to a cyclization
reaction with a palladium catalyst to synthesize a pyridoindole
ring (see, for example, Non-Patent Document 5) and then condensed
with a halide of various aromatic hydrocarbon compounds, condensed
polycyclic aromatic compounds or aromatic heterocyclic compounds,
whereby a compound having a corresponding pyridoindole ring
structure can be synthesized. Furthermore, the compound having a
corresponding pyridoindole ring structure is subjected to a
cross-coupling reaction such as Suzuki coupling (see, for example,
Non-Patent Document 6) with a boronic acid or boronic acid ester
having an anthracene ring structure (see, for example, Patent
Document 4) synthesized by a known method, whereby a compound
having a substituted anthracene ring structure and a pyridoindole
ring structure can be synthesized. [0055] Non-Patent Document 5: J.
Chem. Soc., Perkin Trans. 1, p. 1505 (1999) [0056] Non-Patent
Document 6: Synthesis, 1 (1976) [0057] Patent Document 4:
International Publication WO 2005/097756
[0058] Among the compounds having a substituted anthracene ring
structure and a pyridoindole ring structure, which is represented
by general formula (1), specific examples of preferred compounds
are shown below, but the invention is not limited to these
compounds.
##STR00005## ##STR00006## ##STR00007## ##STR00008## ##STR00009##
##STR00010## ##STR00011## ##STR00012## ##STR00013## ##STR00014##
##STR00015## ##STR00016## ##STR00017## ##STR00018## ##STR00019##
##STR00020## ##STR00021## ##STR00022## ##STR00023## ##STR00024##
##STR00025## ##STR00026## ##STR00027## ##STR00028## ##STR00029##
##STR00030##
[0059] Purification of these compounds was performed by
purification by column chromatography, adsorption purification with
silica gel, active carbon, activated clay, or the like, a
recrystallization or crystallization method with a solvent, or the
like. Identification of the compounds was performed by NMR
analysis. As physical properties, glass-transition temperature (Tg)
and melting point measurement were carried out. The melting point
serves as an indicator of vapor deposition properties, and the
glass transition point (Tg) serves as an indicator of stability in
a thin-film state.
[0060] The melting point and the glass transition point were
measured using a powder material by means of a highly sensitive
differential scanning calorimeter DSC 3100S manufactured by Bruker
AXS.
[0061] Further, the work function was measured by preparing a thin
film of 100 nm on an ITO substrate and using a photo-electron
spectroscopy in air (Model AC-3, manufactured by Riken Keiki Co.,
Ltd.). The work function is regarded as an indicator of
hole-blocking ability.
[0062] Examples of the structure of the organic EL device of the
invention include a structure having an anode, a hole-injection
layer, a hole-transport layer, a light-emitting layer, a
hole-blocking layer, an electron-transport layer and a cathode in
this order on a substrate, and a structure further having an
electron-injection layer between the electron-transport layer and
the cathode. In these multilayer structures, it is possible to omit
several layers of the organic layers and, for example, the
structure may have a constitution sequentially having an anode, a
hole-transport layer, a light-emitting layer, an electron-transport
layer and a cathode on a substrate.
[0063] As the anode of the organic EL device, an electrode material
having a large work function, such as ITO or gold, is used. As the
hole-injection layer, other than copper phthalocyanine
(hereinafter, simply referred to as CuPc), materials such as
starburst-type triphenylamine derivative and various triphenylamine
tetramers, and coat-type polymer materials may be used.
[0064] For the hole-transport layer, a benzidine derivative such as
N,N'-diphenyl-N,N'-di(m-tolyl)-benzidine (hereinafter, simply
referred to as TPD),
N,N'-diphenyl-N,N'-di(.alpha.-naphthyl)-benzidine (hereinafter,
simply referred to as NPD) and N,N,N',N'-tetrabiphenylylbenzidine,
various triphenylamine tetramers, and the like may be used. Also,
for the hole-injection/transport layer, coat-type polymer materials
such as poly(3,4-ethylenedioxythiophene) (hereinafter, simply
referred to as PEDOT)/poly(styrene sulfonate) (hereinafter, simply
referred to as PSS) may be used.
[0065] As for the light-emitting layer, hole-blocking layer, and
electron-transport layer of the organic EL device of the present
invention, other than the compound having a substituted anthracene
ring structure and a pyridoindole ring structure, a compound having
hole-blocking action, such as aluminum complexes, thiazole
derivatives, oxazole derivatives, carbazole derivatives,
polydialkylfluorene derivatives, phenanthroline derivatives such as
BCP and triazole derivatives such as TAZ, may be used.
[0066] A conventional light-emitting material such as aluminum
complex and styryl derivative is used for the light-emitting layer
and the compound having a substituted anthracene ring structure and
a pyridoindole ring structure of the present invention is used for
the hole-blocking layer or electron-transport layer, whereby a
high-performance organic EL device can be produced. Also, a
fluorescent material such as quinacridone, coumarin and rubrene can
be used as the host material of the light-emitting layer. As
regards the phosphorescent material, for example, a green
phosphorescent material such as phenylpyridine iridium complex
Ir(ppy).sub.3, a blue phosphorescent material such as FIrpic and
Fir6, and a red phosphorescent material such as Btp2Ir(acac), are
used. As regards the host material at this time, for example, a
carbazole derivative such as 4,4'-di(N-carbazolyl)biphenyl
(hereinafter, simply referred to as CBP),
4,4',4''-tri(N-carbazolyl)triphenylamine (hereinafter, simply
referred to as TCTA) and 1,3-bis(carbazol-9-yl)benzene
(hereinafter, simply referred to as mCP) may be used as a
hole-injecting/transporting host material, and such as
2,2',2''-(1,3,5-phenylene)tris(1-phenyl-1H-benzimidazole)
(hereinafter, simply referred to as TPBI) may be used as an
electron-transporting host material, whereby a high-performance
organic EL device can be produced.
[0067] Furthermore, the compound having a substituted anthracene
ring structure and a pyridoindole ring structure can be used as the
electron-transport layer through multilayering or co-deposition
with conventional electron-transport material(s).
[0068] The organic EL device of the invention may have an
electron-injection layer. As the electron-injection layer, other
than the compound of the present invention, lithium fluoride or the
like may be used. For the cathode, an electrode material having a
low work function such as aluminum, or an alloy having a low work
function such as aluminum magnesium is used as an electrode
material.
[0069] Embodiments of the invention will be illustrated in greater
detail with reference to the following Examples, but the invention
should not be construed as being limited thereto so long as not
exceeding the gist of the invention.
Example 1
Synthesis of 9,10-Diphenyl-2-(5H-pyrido[4,3-b]indol-5-yl)anthracene
(Compound 3)
[0070] In a nitrogen atmosphere, 4.7 g of
2-bromo-9,10-diphenylanthracene, 2.6 g of 5H-pyrido[4,3-b]indole,
0.4 g of copper powder, 4.3 g of potassium carbonate, 0.3 ml of
dimethyl sulfoxide and 30 ml of n-dodecane were added to a reaction
vessel, then heated and stirred at 210.degree. C. for 18 hours.
After cooling to room temperature, 300 ml of chloroform and 30 ml
of methanol were added thereto and insoluble materials were removed
by filtration. The filtrate was concentrated under reduced pressure
to obtain a crude product, and the crude product was purified by
column chromatography (carrier: NH silica gel, eluent:
toluene/chloroform) to obtain 1.7 g (yield: 30%) of
9,10-diphenyl-2-(5H-pyrido[4,3-b]indol-5-yl)anthracene (Compound 3)
as a yellow powder.
[0071] The structure of the obtained yellow powder was identified
using NMR. FIG. 1 shows the results of .sup.1H-NMR measurement.
[0072] The following 24 hydrogen signals were detected on
.sup.1H-NMR (CDCl.sub.3). .delta. (ppm)=9.35 (1H), 8.48 (1H), 8.18
(1H), 7.95 (1H), 7.85 (1H), 7.77 (2H), 7.66 (2H), 7.61-7.29 (13H),
7.36 (1H), 7.29 (1H).
Example 2
Synthesis of
9,10-Diphenyl-2-[4-(5H-pyrido[4,3-b]indol-5-yl)phenyl]anthracene
(Compound 9)
[0073] In a nitrogen atmosphere, 4.7 g of
9,10-diphenylanthracene-2-boronic acid, 2.8 g of
5-(4-bromophenyl)-5H-pyrido[4,3-b]indole, 0.50 g of
tetrakistriphenylphosphine palladium, 15 ml of an aqueous 2 M
potassium carbonate solution, 20 ml of toluene and 1.5 ml of
ethanol were added to a reaction vessel, then heated under reflux
with stirring for 18 hours. After cooling to room temperature, a
crude product was collected by filtration, and the crude product
was purified by column chromatography (carrier: silica gel, eluent:
toluene/ethyl acetate) to obtain 1.6 g (yield: 32%) of
9,10-diphenyl-2-[4-(5H-pyrido[4,3-b]indol-5-yl)phenyl]anthracene
(Compound 9) as a yellow powder.
[0074] The structure of the obtained yellow powder was identified
using NMR. FIG. 2 shows the results of .sup.1H-NMR measurement.
[0075] The following 28 hydrogen signals were detected on
.sup.1H-NMR (CDCl.sub.3). .delta. (ppm)=9.39 (1H), 8.52 (1H), 8.22
(1H), 8.01 (1H), 7.86 (1H), 7.79 (2H), 7.73 (2H), 7.70-7.64 (5H),
7.61-7.53 (8H), 7.49 (2H), 7.49-7.34 (4H).
Example 3
Synthesis of
9,10-Diphenyl-2-[6-(5H-pyrido[4,3-b]indol-5-yl)pyridin-3-yl]anthracene
(Compound 15)
[0076] In a nitrogen atmosphere, 4.5 g of
9,10-diphenylanthracene-2-boronic acid, 3.0 g of
5-(5-bromopyridin-2-yl)-5H-pyrido[4,3-b]indole, 0.55 g of
tetrakistriphenylphosphine palladium, 19 ml of an aqueous 2 M
potassium carbonate solution, 72 ml of toluene and 18 ml of ethanol
were added to a reaction vessel, then heated under reflux with
stirring for 18 hours. After cooling to room temperature, 100 ml of
toluene and 100 ml of water were added thereto, followed by
stirring, and the organic layer was separated by liquid separation.
The organic layer was dried over magnesium sulfate, and then
concentrated under reduced pressure to obtain a crude product. The
crude product was purified by column chromatography (carrier: NH
silica gel, eluent: toluene) to obtain 3.0 g (yield: 57%) of
9,10-diphenyl-2-[6-(5H-pyrido[4,3-b]indol-5-yl)pyridin-3-yl]anthracene
(Compound 15) as a yellow powder.
[0077] The structure of the obtained yellow powder was identified
using NMR. FIG. 3 shows the results of .sup.1H-NMR measurement.
[0078] The following 27 hydrogen signals were detected on
.sup.1H-NMR (CDCl.sub.3). .delta. (ppm)=9.37 (1H), 8.90 (1H), 8.56
(1H), 8.18 (1H), 8.06-8.10 (1H), 8.01 (1H), 7.83-7.90 (2H), 7.74
(3H), 7.47-7.68 (13H), 7.33-7.41 (3H).
Example 4
Synthesis of
9,10-Diphenyl-2-[6-(5H-pyrido[4,3-b]indol-5-yl)pyridin-2-yl]anthracene
(Compound 27)
[0079] In a nitrogen atmosphere, 4.7 g of
9,10-diphenylanthracene-2-boronic acid, 2.8 g of
5-(6-bromopyridin-2-yl)-5H-pyrido[4,3-b]indole, 0.51 g of
tetrakistriphenylphosphine palladium, 22 ml of an aqueous 2 M
potassium carbonate solution, 72 ml of toluene and 18 ml of ethanol
were added to a reaction vessel, then heated under reflux with
stirring for 17 hours. After cooling to room temperature, 100 ml of
toluene and 100 ml of water were added thereto, followed by
stirring, and the organic layer was separated by liquid separation.
The organic layer was dried over magnesium sulfate, and then
concentrated under reduced pressure to obtain a crude product. The
crude product was purified by column chromatography (carrier: NH
silica gel, eluent: toluene) to obtain 2.7 g (yield: 54%) of
9,10-diphenyl-2-[6-(5H-pyrido[4,3-b]indol-5-yl)pyridin-2-yl]anthracene
(Compound 27) as a yellow powder.
[0080] The structure of the obtained yellow powder was identified
using NMR. FIG. 4 shows the results of .sup.1H-NMR measurement.
[0081] The following 27 hydrogen signals were detected on
.sup.1H-NMR (CDCl.sub.3). .delta. (ppm)=9.37 (1H), 8.48-8.53 (2H),
8.15 (1H), 8.07 (1H), 7.78-7.89 (3H), 7.64-7.74 (4H), 7.48-7.63
(10H), 7.41-7.46 (2H), 7.30-7.38 (3H).
Example 5
Synthesis of
9,10-Di(naphthalen-2-yl)-2-(5H-pyrido[4,3-b]indol-5-yl)anthracene
(Compound 6)
[0082] In a nitrogen atmosphere, 3.0 g of
2-bromo-9,10-di(naphthalen-2-yl)anthracene, 1.2 g of
5H-pyrido[4,3-b]indole, 0.2 g of copper powder, 1.7 g of potassium
carbonate, 0.1 ml of dimethyl sulfoxide and 6 ml of n-dodecane were
added to a reaction vessel, then heated and stirred at 210.degree.
C. for 8 hours. After cooling to room temperature, 80 ml of toluene
was added thereto, followed by stirring under heating, and the
insoluble materials were removed by filtration at 80.degree. C. The
filtrate was concentrated under reduced pressure to obtain a crude
product, and the crude product was purified by column
chromatography (carrier: NH silica gel, eluent: toluene/ethyl
acetate) to obtain 1.9 g (yield: 54%) of
9,10-di(naphthalen-2-yl)-2-(5H-pyrido[4,3-b]indol-5-yl)anthracene
(Compound 6) as a yellow powder.
[0083] The structure of the obtained yellow powder was identified
using NMR. FIG. 5 shows the results of .sup.1H-NMR measurement.
[0084] The following 28 hydrogen signals were detected on
.sup.1H-NMR (CDCl.sub.3). .delta. (ppm)=9.30 (1H), 8.45 (1H), 8.13
(2H), 8.06 (4H), 7.89-8.00 (5H), 7.81 (2H), 7.61-7.71 (4H), 7.54
(2H), 7.46 (2H), 7.38-7.41 (3H), 7.30 (2H).
Example 6
Synthesis of
9,10-Di(naphthalen-2-yl)-2-[4-(5H-pyrido[4,3-b]indol-5-yl)phenyl]anthrace-
ne (Compound 12)
[0085] In a nitrogen atmosphere, 3.5 g of
9,10-di(naphthalen-2-yl)anthracene-2-boronic acid, 2.2 g of
5-(4-bromophenyl)-5H-pyrido[4,3-b]indole, 0.35 g of
tetrakistriphenylphosphine palladium, 10 ml of an aqueous 2 M
potassium carbonate solution, 40 ml of toluene and 10 ml of ethanol
were added to a reaction vessel, then heated under reflux with
stirring for 8 hours. After cooling to room temperature, 80 ml of
toluene and 20 ml of water were added thereto, followed by
stirring, and the organic layer was separated by liquid separation.
The organic layer was dried over magnesium sulfate, and then
concentrated under reduced pressure to obtain a crude product. The
crude product was purified by column chromatography (carrier: NH
silica gel, eluent: toluene) to obtain 2.4 g (yield: 52%) of
9,10-di(naphthalen-2-yl)-2-[4-(5H-pyrido[4,3-b]indol-5-yl)phenyl]anthrace-
ne (Compound 12) as a yellow powder.
[0086] The structure of the obtained yellow powder was identified
using NMR. FIG. 6 shows the results of .sup.1H-NMR measurement.
[0087] The following 32 hydrogen signals were detected on
.sup.1H-NMR (CDCl.sub.3). .delta. (ppm)=9.36 (1H), 8.48 (1H), 8.19
(1H), 8.14 (2H), 8.05-8.08 (5H), 7.97 (2H), 7.90 (1H), 7.61-7.79
(11H), 7.51 (2H), 7.44 (2H), 7.32-7.37 (3H), 7.30 (1H).
Example 7
Synthesis of
9,10-Diphenyl-2-[4'-(5H-pyrido[4,3-b]indol-5-yl)biphenyl-4-yl]anthracene
(Compound 42)
[0088] In a nitrogen atmosphere, 2.8 g of
9,10-diphenylanthracene-2-boronic acid, 3.0 g of
5-(4'-bromobiphenyl-4-yl)-5H-pyrido[4,3-b]indole, 0.40 g of
tetrakistriphenylphosphine palladium, 10 ml of an aqueous 2 M
potassium carbonate solution, 15 ml of toluene and 2 ml of ethanol
were added to a reaction vessel, then heated under reflux with
stirring for 2 hours. After cooling to room temperature, 60 ml of
toluene and 50 ml of water were added thereto, followed by
stirring, and the organic layer was separated by liquid separation.
The organic layer was dried over magnesium sulfate, and then
concentrated under reduced pressure to obtain a crude product. The
crude product was purified by column chromatography (carrier: NH
silica gel, eluent: toluene/ethyl acetate) to obtain 3.0 g (yield:
62%) of
9,10-diphenyl-2-[4'-(5H-pyrido[4,3-b]indol-5-yl)biphenyl-4-yl]anthracene
(Compound 42) as a yellow powder.
[0089] The structure of the obtained yellow powder was identified
using NMR. FIG. 7 shows the results of .sup.1H-NMR measurement.
[0090] The following 32 hydrogen signals were detected on
.sup.1H-NMR (CDCl.sub.3). .delta. (ppm)=9.40 (1H), 8.54 (1H), 8.23
(1H), 7.99 (1H), 7.83 (3H), 7.48-7.73 (21H), 7.39 (1H), 7.35
(3H).
Example 8
Synthesis of
9,10-Di(naphthalen-2-yl)-2-[4'-(5H-pyrido[4,3-b]indol-5-yl)biphenyl-4-yl]-
anthracene (Compound 43)
[0091] In a nitrogen atmosphere, 2.0 g of
9,10-di(naphthalen-2-yl)anthracene-2-boronic acid, 1.5 g of
5-(4'-bromobiphenyl-4-yl)-5H-pyrido[4,3-b]indole, 0.20 g of
tetrakistriphenylphosphine palladium, 6 ml of an aqueous 2 M
potassium carbonate solution, 23 ml of toluene and 6 ml of ethanol
were added to a reaction vessel, then heated under reflux with
stirring for 5 hours. After cooling to room temperature, 50 ml of
toluene and 20 ml of water were added thereto, followed by
stirring, and the organic layer was separated by liquid separation.
The organic layer was dried over magnesium sulfate, and then
concentrated under reduced pressure to obtain a crude product. The
crude product was purified by column chromatography (carrier: NH
silica gel, eluent: toluene/ethyl acetate) to obtain 1.8 g (yield:
63%) of
9,10-di(naphthalen-2-yl)-2-[4'-(5H-pyrido[4,3-b]indol-5-yl)biphenyl-4-yl]-
anthracene (Compound 43) as a yellow powder.
[0092] The structure of the obtained yellow powder was identified
using NMR. FIG. 8 shows the results of .sup.1H-NMR measurement.
[0093] The following 36 hydrogen signals were detected on
.sup.1H-NMR (CDCl.sub.3). .delta. (ppm)=9.39 (1H), 8.52 (1H), 8.22
(1H), 8.13 (2H), 8.04-8.07 (5H), 7.97 (2H), 7.87 (1H), 7.57-7.80
(17H), 7.48 (2H), 7.38 (1H), 7.33 (3H).
Example 9
Synthesis of
9,10-Diphenyl-2-[5-(5H-pyrido[4,3-b]indol-5-yl)pyridin-3-yl]anthracene
(Compound 73)
[0094] In a nitrogen atmosphere, 3.2 g of
9,10-diphenylanthracene-2-boronic acid, 2.4 g of
5-(5-bromopyridin-3-yl)-5H-pyrido[4,3-b]indole, 0.44 g of
tetrakistriphenylphosphine palladium, 11 ml of an aqueous 2 M
potassium carbonate solution, 15 ml of toluene and 2 ml of ethanol
were added to a reaction vessel, then heated under reflux with
stirring for 2 hours. After cooling to room temperature, 30 ml of
toluene and 20 ml of water were added thereto, followed by
stirring, and the organic layer was separated by liquid separation.
The organic layer was dried over magnesium sulfate, and then
concentrated under reduced pressure to obtain a crude product. The
crude product was purified by column chromatography (carrier: NH
silica gel, eluent: toluene/ethyl acetate) to obtain 2.2 g (yield:
52%) of
9,10-diphenyl-2-[5-(5H-pyrido[4,3-b]indol-5-yl)pyridin-3-yl]anthracene
(Compound 73) as a yellow powder.
[0095] The structure of the obtained yellow powder was identified
using NMR. FIG. 9 shows the results of .sup.1H-NMR measurement.
[0096] The following 27 hydrogen signals were detected on
.sup.1H-NMR (CDCl.sub.3). .delta. (ppm)=9.41 (1H), 8.94 (1H), 8.82
(1H), 8.55 (1H), 8.23 (1H), 8.03 (1H), 8.00 (1H), 7.87 (1H), 7.74
(2H), 7.57-7.65 (7H), 7.49-7.54 (5H), 7.37-7.45 (4H), 7.29
(1H).
Example 10
Synthesis of
9,10-Di(naphthalen-2-yl)-2-[6-(5H-pyrido[4,3-b]indol-5-yl)pyridin-2-yl]an-
thracene (Compound 30)
[0097] In a nitrogen atmosphere, 3.5 g of
9,10-di(naphthalen-2-yl)anthracene-2-boronic acid, 2.2 g of
5-(6-bromopyridin-2-yl)-5H-pyrido[4,3-b]indole, 0.35 g of
tetrakistriphenylphosphine palladium, 10 ml of an aqueous 2 M
potassium carbonate solution, 40 ml of toluene and 10 ml of ethanol
were added to a reaction vessel, then heated under reflux with
stirring for 5 hours. After cooling to room temperature, 100 ml of
toluene and 100 ml of water were added thereto, followed by
stirring, and the organic layer was separated by liquid separation.
The organic layer was dried over magnesium sulfate, and then
concentrated under reduced pressure to obtain a crude product. The
crude product was purified by column chromatography (carrier: NH
silica gel, eluent: toluene) to obtain 2.2 g (yield: 48%) of
9,10-di(naphthalen-2-yl)-2-[6-(5H-pyrido[4,3-b]indol-5-yl)pyridin-2-yl]an-
thracene (Compound 30) as a yellow powder.
[0098] The structure of the obtained yellow powder was identified
using NMR. FIG. 10 shows the results of .sup.1H-NMR
measurement.
[0099] The following 31 hydrogen signals were detected on
.sup.1H-NMR (CDCl.sub.3). .delta. (ppm)=9.32 (1H), 8.55 (1H), 8.22
(1H), 8.03-8.13 (8H), 7.85-7.95 (4H), 7.58-7.78 (11H), 7.44 (1H),
7.28-7.35 (3H), 7.21 (1H).
Example 11
Synthesis of
9,10-Diphenyl-2-[4-(8-phenyl-5H-pyrido[4,3-b]indol-5-yl)phenyl]anthracene
(Compound 75)
[0100] In a nitrogen atmosphere, 2.8 g of
9,10-diphenylanthracene-2-boronic acid, 2.4 g of
5-(4-bromophenyl)-8-phenyl-5H-pyrido[4,3-b]indole, 0.21 g of
tetrakistriphenylphosphine palladium, 16 ml of an aqueous 2 M
potassium carbonate solution, 40 ml of toluene and 10 ml of ethanol
were added to a reaction vessel, then heated under reflux with
stirring for 4 hours. After cooling to room temperature, 100 ml of
toluene and 100 ml of water were added thereto, followed by
stirring, and the organic layer was separated by liquid separation.
The organic layer was dried over magnesium sulfate, and then
concentrated under reduced pressure to obtain a crude product. The
crude product was purified by column chromatography (carrier: NH
silica gel, eluent: toluene/ethyl acetate) to obtain 2.7 g (yield:
69%) of
9,10-diphenyl-2-[4-(8-phenyl-5H-pyrido[4,3-b]indol-5-yl)phenyl]anthracene
(Compound 75) as a yellow powder.
[0101] The structure of the obtained yellow powder was identified
using NMR. FIG. 11 shows the results of .sup.1H-NMR
measurement.
[0102] The following 32 hydrogen signals were detected on
.sup.1H-NMR (CDCl.sub.3). .delta. (ppm)=9.43 (1H), 8.53 (1H), 8.41
(1H), 8.02 (1H), 7.86 (1H), 7.79 (2H), 7.63-7.74 (10H), 7.53-7.61
(9H), 7.49 (2H), 7.34-7.38 (4H).
Example 12
[0103] With respect to the compounds of the present invention, the
melting point and glass transition point were measured by a
high-sensitivity differential scanning calorimeter (DSC 3100S,
manufactured by Bruker AXS K.K.).
TABLE-US-00001 Glass Transition Melting Point Point Compound of
Invention Example 1 269.degree. C. 130.degree. C. Compound of
Invention Example 2 323.degree. C. 153.degree. C. Compound of
Invention Example 3 311.degree. C. 148.degree. C. Compound of
Invention Example 4 176.degree. C. 138.degree. C. Compound of
Invention Example 5 320.degree. C. 170.degree. C. Compound of
Invention Example 6 342.degree. C. 186.degree. C. Compound of
Invention Example 7 283.degree. C. 161.degree. C. Compound of
Invention Example 8 363.degree. C. 190.degree. C. Compound of
Invention Example 9 240.degree. C. 140.degree. C. Compound of
Invention Example 10 295.degree. C. 168.degree. C.
[0104] The compounds of the present invention have a glass
transition point of 100.degree. C. or more, and this reveals that
the compounds of the present invention are stable in the thin-film
state.
Example 13
[0105] Using each of the compounds of the present invention, a
deposited film having a film thickness of 100 nm was formed on an
ITO substrate and measured for the work function by means of an
atmospheric photoelectron spectrometer (Model AC-3, manufactured by
Riken Keiki Co., Ltd.).
TABLE-US-00002 Work Function Compound of Invention Example 1 6.24
eV Compound of Invention Example 2 5.88 eV Compound of Invention
Example 3 5.80 eV Compound of Invention Example 4 5.90 eV Compound
of Invention Example 5 5.83 eV Compound of Invention Example 6 5.79
eV Compound of Invention Example 7 5.80 eV Compound of Invention
Example 8 5.73 eV Compound of Invention Example 9 5.85 eV Compound
of Invention Example 10 5.83 eV
[0106] As seen above, the compounds of the present invention have a
value larger than is a work function of 5.4 eV possessed by a
general hole-transport material such as NPD and TPD, and have a
high hole-blocking ability.
Example 14
[0107] An organic EL device was produced, as shown in FIG. 12, by
sequentially depositing a hole-injection layer 3, a hole-transport
layer 4, a light-emitting layer 5, a hole-blocking layer 6, an
electron-transport layer 7, an electron-injection layer 8, and a
cathode (aluminum electrode) 9 on a glass substrate 1 having
previously formed thereon an ITO electrode as a transparent
electrode 2.
[0108] Specifically, the glass substrate 1 having ITO formed
thereon to a film thickness of 150 nm was washed with an organic
solvent, and the surface was then washed by an oxygen plasma
treatment. Thereafter, the glass substrate with an ITO electrode
was fixed in a vacuum deposition device, and the pressure therein
was reduced to 0.001 Pa or less. Subsequently, Compound 79 having a
structural formula shown below was formed thereon as the
hole-injection layer 3 to cover the transparent electrode 2 at a
deposition rate of 1.0 .ANG./sec to a film thickness of 20 nm. On
the hole-injection layer 3, Compound 80 having a structural formula
shown below was formed as the hole-transport layer 4 at a
deposition rate of 1.0 .ANG./sec to a film thickness of 40 nm. On
the hole-transport layer 4, Compound 81 having a structural formula
shown below and Compound 82 having a structural formula shown below
were formed as the light-emitting layer 5 to a film thickness of 30
nm by performing binary deposition at deposition rates giving a
deposition rate ratio of Compound 81:Compound 82=5:95 (Compound 81:
1.52 .ANG./sec, Compound 82: 0.08 .ANG./sec). On the light-emitting
layer 5, the compound of invention Example 1 (Compound 3) was
formed as the hole-blocking layer-cum-electron-transport layer 6
and 7 at a deposition rate of 1.0 .ANG./sec to a film thickness of
30 nm. On the hole-blocking layer-cum-electron-transport layer 6
and 7, lithium fluoride was formed as the electron-injection layer
8 at a deposition rate of 0.1 .ANG./sec to a film thickness of 0.5
nm. Finally, aluminum was deposited to a film thickness of 150 nm
to form the cathode 9. The produced organic EL device was subjected
to measurement of characteristic properties at ordinary temperature
in the atmosphere.
[0109] The measurement results of light emitting characteristics
when applying a direct voltage to the organic EL device produced
using the compound of invention Example 1 (Compound 3) are shown
together in Table 1.
##STR00031## ##STR00032##
Example 15
[0110] An organic EL device was produced by the same method as in
Example 14 except for depositing the compound of invention Example
2 (Compound 9) to a film thickness of 30 nm as the hole-blocking
layer-cum-electron-transport layer 6 and 7 in place of the compound
of invention Example 1 (Compound 3). The produced organic EL device
was subjected to measurement of characteristic properties at
ordinary temperature in the atmosphere.
[0111] The measurement results of light emitting characteristics
when applying a direct voltage to the organic EL device produced
are shown together in Table 1.
Example 16
[0112] An organic EL device was produced by the same method as in
Example 14 except for depositing the compound of invention Example
3 (Compound 15) to a film thickness of 30 nm as the hole-blocking
layer-cum-electron-transport layer 6 and 7 in place of the compound
of invention Example 1 (Compound 3). The produced organic EL device
was subjected to measurement of characteristic properties at
ordinary temperature in the atmosphere.
[0113] The measurement results of light emitting characteristics
when applying a direct voltage to the organic EL device produced
are shown together in Table 1.
Example 17
[0114] An organic EL device was produced by the same method as in
Example 14 except for depositing the compound of invention Example
4 (Compound 27) to a film thickness of 30 nm as the hole-blocking
layer-cum-electron-transport layer 6 and 7 in place of the compound
of invention Example 1 (Compound 3). The produced organic EL device
was subjected to measurement of characteristic properties at
ordinary temperature in the atmosphere.
[0115] The measurement results of light emitting characteristics
when applying a direct voltage to the organic EL device produced
are shown together in Table 1.
Example 18
[0116] An organic EL device was produced by the same method as in
Example 14 except for depositing the compound of invention Example
5 (Compound 6) to a film thickness of 30 nm as the hole-blocking
layer-cum-electron-transport layer 6 and 7 in place of the compound
of invention Example 1 (Compound 3). The produced organic EL device
was subjected to measurement of characteristic properties at
ordinary temperature in the atmosphere.
[0117] The measurement results of light emitting characteristics
when applying a direct voltage to the organic EL device produced
are shown together in Table 1.
Example 19
[0118] An organic EL device was produced by the same method as in
Example 14 except for depositing the compound of invention Example
6 (Compound 12) to a film thickness of 30 nm as the hole-blocking
layer-cum-electron-transport layer 6 and 7 in place of the compound
of invention Example 1 (Compound 3). The produced organic EL device
was subjected to measurement of characteristic properties at
ordinary temperature in the atmosphere.
[0119] The measurement results of light emitting characteristics
when applying a direct voltage to the organic EL device produced
are shown together in Table 1.
Example 20
[0120] An organic EL device was produced by the same method as in
Example 14 except for depositing the compound of invention Example
7 (Compound 42) to a film thickness of 30 nm as the hole-blocking
layer-cum-electron-transport layer 6 and 7 in place of the compound
of invention Example 1 (Compound 3). The produced organic EL device
was subjected to measurement of characteristic properties at
ordinary temperature in the atmosphere.
[0121] The measurement results of light emitting characteristics
when applying a direct voltage to the organic EL device produced
are shown together in Table 1.
Example 21
[0122] An organic EL device was produced by the same method as in
Example 14 except for depositing the compound of invention Example
8 (Compound 43) to a film thickness of 30 nm as the hole-blocking
layer-cum-electron-transport layer 6 and 7 in place of the compound
of invention Example 1 (Compound 3). The produced organic EL device
was subjected to measurement of characteristic properties at
ordinary temperature in the atmosphere.
[0123] The measurement results of light emitting characteristics
when applying a direct voltage to the organic EL device produced
are shown together in Table 1.
Example 22
[0124] An organic EL device was produced by the same method as in
Example 14 except for depositing the compound of invention Example
9 (Compound 73) to a film thickness of 30 nm as the hole-blocking
layer-cum-electron-transport layer 6 and 7 in place of the compound
of invention Example 1 (Compound 3). The produced organic EL device
was subjected to measurement of characteristic properties at
ordinary temperature in the atmosphere.
[0125] The measurement results of light emitting characteristics
when applying a direct voltage to the organic EL device produced
are shown together in Table 1.
Comparative Example 1
[0126] For comparison, the material of the hole-blocking
layer-cum-electron-transport layer 6 and 7 in Example 14 was
replaced with Alq.sub.3, and an organic EL device was produced
under the same conditions as in Example 14. The produced organic EL
device was subjected to measurement of characteristic properties at
ordinary temperature in the atmosphere.
[0127] The measurement results of light emitting characteristics
when applying a direct voltage to the organic EL device produced
are shown together in Table 1.
TABLE-US-00003 TABLE 1 Lumi- Luminous Power Voltage nance
Efficiency Efficiency [V] [cd/m.sup.2] [cd/A] [lm/W] (@10 mA/ (@10
mA/ (@10 mA/ (@10 mA/ Compound cm.sup.2) cm.sup.2) cm.sup.2)
cm.sup.2) Exam- Compound 3 5.10 850 8.55 5.20 ple 14 Exam- Compound
9 4.15 982 9.82 7.48 ple 15 Exam- Compound 15 4.80 844 8.42 5.50
ple 16 Exam- Compound 27 4.00 932 9.30 7.32 ple 17 Exam- Compound 6
5.33 920 9.20 5.43 ple 18 Exam- Compound 12 4.69 968 9.68 6.49 ple
19 Exam- Compound 42 3.95 900 9.00 7.16 ple 20 Exam- Compound 43
4.15 1047 10.47 7.92 ple 21 Exam- Compound 73 5.48 919 9.19 5.26
ple 22 Com- Alq.sub.3 5.80 820 8.25 4.40 para- tive Exam- ple 1
[0128] As shown in Table 1, the driving voltage at a current
density of 10 mA/cm.sup.2 was 5.80 V of Alq.sub.3, whereas in all
of Examples 14 to 22, the driving voltages were as low as from 3.95
to 5.48 V, and moreover, all of luminance, luminous efficiency and
power efficiency at a current density of 10 mA/cm.sup.2 were
enhanced.
[0129] The emission initiation voltages were measured using the
same organic EL devices as above, and the results are shown
below.
TABLE-US-00004 Voltage [V] Example 14 Compound 3 3.0 Example 15
Compound 9 2.9 Example 16 Compound 15 2.9 Example 17 Compound 27
2.8 Example 18 Compound 6 3.0 Example 19 Compound 12 2.9 Example 20
Compound 42 2.8 Example 21 Compound 43 2.8 Example 22 Compound 73
3.1 Comparative Example 1 Alq.sub.3 3.2
[0130] As a result, in comparison with Comparative Example 1 using
Alq.sub.3, the emission initiation voltage was lowered in Examples
14-22.
[0131] As shown above, it could be found that the organic EL device
of the invention has an excellent luminous efficiency and a power
efficiency, and also achieves a remarkable reduction in the
practical driving voltage as compared with a devices using Alq3
used as a general electron-transporting material.
[0132] While the invention has been described in detail and with
reference to specific embodiments thereof, it will be apparent to
one skilled in the art that various changes and modifications can
be made therein without departing from the spirit and scope
thereof.
[0133] This application is based on Japanese Patent Application No.
2008-243937 which was filed on Sep. 24, 2008, and the contents
thereof are incorporated herein by reference.
INDUSTRIAL APPLICABILITY
[0134] Since the compound having a substituted anthracene ring
structure and a pyridoindole ring structure according to the
invention exhibits a good electron-injection property and an
excellent hole-blocking ability, and is stable in a thin-film
state, it is excellent as a compound for use in organic EL devices.
By producing an organic EL device using the compound, high
efficiencies can be obtained and a reduction in practical driving
voltage and an improvement in durability can be attained. It
becomes possible to spread the compound onto applications of, for
example, electric home appliances and illuminations.
DESCRIPTION OF REFERENCE NUMERALS AND SIGNS
[0135] 1: Glass substrate [0136] 2: Transparent electrode [0137] 3:
Hole-injection layer [0138] 4: Hole-transport layer [0139] 5:
Light-Emitting layer [0140] 6: Hole-blocking layer [0141] 7:
Electron-transport layer [0142] 8: Electron-injection layer [0143]
9: Cathode
* * * * *