U.S. patent application number 13/084321 was filed with the patent office on 2011-08-04 for polymeric light emitting substance and polymer light emitting device using the same.
This patent application is currently assigned to SUMITOMO CHEMICAL COMPANY, LIMITED. Invention is credited to Shuji DOI, Hideyuki IKEHIRA, Yasuyuki KURITA, Takahiro UEOKA.
Application Number | 20110187969 13/084321 |
Document ID | / |
Family ID | 26612161 |
Filed Date | 2011-08-04 |
United States Patent
Application |
20110187969 |
Kind Code |
A1 |
IKEHIRA; Hideyuki ; et
al. |
August 4, 2011 |
POLYMERIC LIGHT EMITTING SUBSTANCE AND POLYMER LIGHT EMITTING
DEVICE USING THE SAME
Abstract
A polymeric light emitting substance having a polystyrene
reduced number-average molecular weight of from 10.sup.3 to
10.sup.8 wherein this light emitting substance has in the main
chain or side chain a metal complex structure showing light
emission from the triplet excited state, and the substance can form
a light emitting layer by industrially simple application methods
such as a spin coat method, inkjet method, printing method and the
like.
Inventors: |
IKEHIRA; Hideyuki;
(Mukou-shi, JP) ; UEOKA; Takahiro; (Tsukuba-shi,
JP) ; DOI; Shuji; (Tsukuba-shi, JP) ; KURITA;
Yasuyuki; (Tsukuba-shi, JP) |
Assignee: |
SUMITOMO CHEMICAL COMPANY,
LIMITED
Osaka
JP
|
Family ID: |
26612161 |
Appl. No.: |
13/084321 |
Filed: |
April 11, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10103848 |
Mar 25, 2002 |
7947340 |
|
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13084321 |
|
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|
Current U.S.
Class: |
349/69 ;
252/301.35; 313/504; 427/162; 428/220 |
Current CPC
Class: |
C09K 2211/1037 20130101;
H01L 51/0038 20130101; C09K 2211/1029 20130101; Y10T 428/10
20150115; C09K 2211/185 20130101; C09K 2211/1425 20130101; H01L
51/0039 20130101; H01L 51/0088 20130101; C08G 61/122 20130101; C09K
2211/182 20130101; C08G 2261/312 20130101; C08G 2261/5242 20130101;
C08G 61/02 20130101; H01L 51/5012 20130101; H01L 51/0035 20130101;
C09K 2211/1014 20130101; C09K 2323/00 20200801; H01L 51/0085
20130101; C09K 2211/1408 20130101; C09K 11/06 20130101; Y10T
428/1352 20150115; C08G 2261/1526 20130101; H01L 51/0036 20130101;
H01L 51/0089 20130101; C09K 2211/1092 20130101; H01L 51/0059
20130101; H01L 51/0094 20130101; H01L 51/0084 20130101; H01L
51/0087 20130101; C08G 2261/3422 20130101; C09K 2211/1007
20130101 |
Class at
Publication: |
349/69 ;
252/301.35; 313/504; 427/162; 428/220 |
International
Class: |
G02F 1/13357 20060101
G02F001/13357; C09K 11/06 20060101 C09K011/06; H01J 1/63 20060101
H01J001/63; B05D 5/06 20060101 B05D005/06; B05D 3/00 20060101
B05D003/00; B32B 27/32 20060101 B32B027/32 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 27, 2001 |
JP |
2001-089623 |
Sep 28, 2001 |
JP |
2001-302909 |
Claims
1. A solution comprising an organic solvent and polymer light
emitting substance, wherein the polymeric light emitting substance
has a polystyrene reduced number-average molecular weight of from
10.sup.3 to 10.sup.8 and the polymeric light emitting substance has
in the main chain or side chain a metal complex structure showing
light emission from the triplet excited state, wherein the metal
complex structure showing light emission from the triplet excited
state is represented by the below formula (6): ##STR00043## wherein
M represents a metal atom having an atomic number of 50 or more and
showing a possibility of the intersystem crossing between the
singlet state and the triplet state in this complex by a
spin-orbital mutual action; Ar represents a ligand bonded to M via
one or more of a nitrogen atom, an oxygen atom, a carbon atom, a
sulfur atom and a phosphorus atom, with bonding to a polymer at an
arbitrary position; L represents a hydrogen atom, a hydrocarbon
group having 1 to 10 carbon atoms, a carboxylate group having 1 to
10 carbon atoms, a diketonate group having 1 to 10 carbon atoms, a
halogen atom, an amide group, an imide group, an alkoxide group, an
alkylmercapto group, a carbonyl ligand, an arylene ligand, an
alkene ligand, an alkyne ligand, an amine ligand, an imine ligand,
a nitrile ligand, an isonitrile ligand, a phosphine ligand, a
phosphine oxide ligand, a phosphate ligand, an ether ligand, a
sulfone ligand, a sulfoxide ligand or a sulfide ligand; m
represents an integer of 1 to 5; and o represents an integer of 0
to 5.
2. A solution according to claim 1, wherein the light emitting
substance has a metal complex structure showing light emission from
the triplet excited state in the main chain.
3. A solution according to claim 2, wherein the light emitting
substance has a metal complex structure showing light emission from
the triplet excited state at least one of the ends of the main
chain.
4. A solution according to claim 1, wherein the light emitting
substance has a metal complex structure showing light emission from
the triplet excited state in the side chain.
5. A solution according to claim 4, wherein an aromatic ring
contained in at least one of the ligand of the metal complex
structure and an aromatic ring contained in the main chain are
connected via a single bond.
6. A solution according to claim 1, wherein the light emitting
substance has two or more kinds of the metal complex structure
showing light emission from the triplet excited state.
7. A solution according to claim 1, wherein the main chain
comprises a conjugated polymer.
8. A solution according to claim 1, wherein at least one ligand
contained in the metal complex structure comprises the same
structure with a repeating unit contained in the main chain.
9. A solution according to claim 1, wherein the light emitting
substance comprising one or more repeating units of the general
formula (1) and one or more repeating units having a metal complex
structure showing light emission from the triplet excited state:
##STR00044## wherein Ar.sub.1 represents an arylene group or a
divalent heterocyclic compound group; R.sub.1 and R.sub.2 each
independently represent a hydrogen atom, an alkyl group, an aryl
group, a monovalent heterocyclic compound group or a cyano group;
and n represents 0 or 1.
10. A solution according to claim 1, wherein the light emitting
substance comprising one or more repeating units of the formula
(2), ##STR00045## wherein Ar.sub.2 and Ar.sub.3 each independently
represent an arylene group, or a divalent heterocyclic compound
group, and Ar.sub.2 does not cross-link to Ar.sub.3; R.sub.11
represents an alkyl group, an aryl group, a mono-valent
heterocyclic compound group, a group represented by the below
formula (3) or (4); the symbol t is an integer from 1 to 4,
##STR00046## wherein Ar.sub.4 is an arylene group or a divalent
heterocyclic compound group: R.sub.12 represents a hydrogen atom,
an alkyl group, an aryl group, a mono-valent heterocyclic group, or
a group represented by the below formula (4); Z.sub.1 represents
--CR.sub.13.dbd.CR.sub.14-- or --C.ident.C--, R.sub.13 and R.sub.14
each independently represents a hydrogen atom, an alkyl group, an
aryl group, a mono-valent heterocyclic group, or a cyano group; the
symbol u is an integer from 0 to 2; ##STR00047## wherein Ar.sub.5
and Ar.sub.6 each independently represents an arylene group or a
divalent heterocyclic compound group; R.sub.15 represents an alkyl
group, an aryl group, or a mono-valent heterocyclic group; and the
symbol v is an integer from 1 to 4.
11. A solution according to claim 9, wherein the light emitting
substance comprising one or more repeating units of the formula
(5), ##STR00048## wherein R.sub.11 means the same as above;
R.sub.18 and R.sub.19 represent substituents on aromatic ring of a
halogen atom, an alkyl group, an alkenyl group, an aralkyl group,
an arylthio group, an arylalkenyl group, a cyclic alkenyl group, an
alkoxy group, an aryloxy group, an alkyloxy carbonyl group, an
aralkyloxy carbonyl group, an aryloxy carbonyl group, an aryl
group, or a mono-valent heterocyclic group; the symbols a and b
each independently represent an integer from 0 to 3; and when a or
b is 2 or more, R.sub.18 and R.sub.19 are the same or different
mutually, which may be connected to form a ring.
12. A solution according to any one of claims 9 to 11, wherein the
amount of the repeating units having a metal complex structure
showing light emission from the triplet excited state is 0.01 mol %
or more and 10 mol % or less based on the total amount of the
repeating units of the general formulas (1), (2) and (5), and the
repeating units having a metal complex structure showing light
emission from the triplet excited state.
13. A solution according to claim 1, wherein M is rhenium atom,
osmium atom, iridium atom, platinum atom, or gold atom.
14. A solution according to claim 1, wherein M is samarium atom,
europium atom, gadolinium atom, terbium atom or dysprosium
atom.
15. A solution according to claim 1, wherein M bonds to at least
one carbon atom.
16. A solution according to claim 1, wherein Ar represents a
bidentate ligand forming a 5-membered ring by bonding to M via a
nitrogen atom, an oxygen atom, a carbon atom, a sulfur atom or a
phosphor atom.
17. A solution according to claim 1, wherein Ar represents a
bidentate ligand represented by the formula (7), ##STR00049##
wherein R.sub.3 to R.sub.10 independently represent a halogen atom,
an alkyl group, an alkenyl group, an aralkyl group, an arylthio
group, an arylalkenyl group, a cyclic alkenyl group, an alkoxy
group, an aryloxy group, an alkyloxy carbonyl group, an aralkyloxy
carbonyl group, an aryloxy carbonyl group, or an aryl group; and at
least one of R.sub.3 to R.sub.10 is a bonding group to a polymer
chain.
18. A solution according to claim 1, wherein the organic solvent is
selected from chloroform, methylene chloride, dichloroethane,
tetrahydrofuran, toluene, xylene, acetone, methyl ethyl ketone,
butyl acetate or ethylcellosolve acetate.
19. A solution according to claim 1, wherein the polymeric light
emitting substance is dissolved in the solvent in an amount of 0.1%
by weight or more.
20. A method of forming a film, which method comprises removal of
the solvent by drying after coating with a solution according to
claim 1.
21. A method according to claim 20, wherein the method is selected
from coating method, casting method, micro gravure coating method,
gravure coating method, bar coating method, roll coating method,
wire bar coating method, dip coating method, spray coating method,
screen printing method, flexo printing method, offset printing
method or inkjet printing method.
22. A film formed by removal of the solvent by drying after coating
with a solution according to claim 1.
23. A film according to claim 22, wherein the thickness is from 1
nm to 1 .mu.m.
24. A polymer light emitting device comprising at least a light
emitting layer between a pair of electrodes composed of an anode
and a cathode at least one of which is transparent or
semi-transparent wherein the light emitting layer comprises a film
according to claim 22 or 23.
25. A flat light source comprising a polymer light emitting device
according to claim 24.
26. A segment display comprising a polymer light emitting device
according to claim 24.
27. A dot matrix display comprising a polymer light emitting device
according to claim 24.
28. A liquid crystal display comprising a polymer light emitting
device according to claim 24 as a back-light.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This is a continuation application of U.S. application Ser.
No. 10/103,848, filed Mar. 25, 2002, which claims priority of
Japanese Application No. 2001-089623 filed Mar. 27, 2001, and
Japanese Application No. 2001-302909 filed Sep. 28, 2001, the
entire disclosures of the prior applications are incorporated
herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a polymeric light emitting
substance, a method of producing the same, a complex which can be a
monomer used in producing the same, and a polymer light emitting
device using this polymeric light emitting substance (hereinafter,
referred to as polymer LED in some cases).
[0004] 2. Description of the Related Art
[0005] Regarding light emitting materials used in a light emitting
layer in a light emitting device, it is known that a device using
in a light emitting layer a metal complex showing light emission
from the triplet excited state (hereinafter, referred to as complex
emitting triplet luminescence) has high light emitting
efficiency.
[0006] As the complex emitting triplet luminescence, known are, for
example, Ir(ppy)3 containing iridium as a center metal (Appl. Phys.
Lett., 75, 4 (1999)), PtOEP containing platinum as a center metal
(Nature, 395, 151 (1998), Eu(TTA)3-phen containing europium as a
center metal (Jpn. J. Appl. Phys., 34, 1883 (1995)) and the
like.
##STR00001##
[0007] However, for forming a light emitting layer using the
above-mentioned known complex emitting triplet luminescence, there
are usually only used methods such as a vacuum deposition method
and the like, and it is difficult to form a light emitting layer by
an application method.
[0008] An object of the present invention is to provide a novel
light emitting substance having a complex emitting triplet
luminescence structure in the molecule and capable of forming a
light emitting layer by an application method, a method of
producing the same, a novel complex which can be a monomer used in
producing the same, and a polymer light emitting device using this
polymeric light emitting substance.
SUMMARY OF THE INVENTION
[0009] The present inventors have intensively studied for solving
the above-mentioned problems, and resultantly found that a
polymeric light emitting substance having a polystyrene reduced
number-average molecular weight of from 10.sup.3 to 10.sup.8
wherein this light emitting substance has in the main chain or side
chain a metal complex structure showing light emission from the
triplet excited state has a complex emitting triplet luminescence
structure in the molecule, and a light emitting layer can be formed
by an application method using this light emitting substance,
leading to completion of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0010] The polymeric light emitting substance is a polymeric light
emitting substance having a polystyrene reduced number-average
molecular weight of from 10.sup.3 to 10.sup.8 wherein this light
emitting substance has in the main chain or side chain a metal
complex structure showing light emission from the triplet excited
state, and particularly, it is preferable that the polymeric light
emitting substance is a conjugated type polymeric light emitting
substance.
[0011] Here, the conjugated type polymeric light emitting substance
means a polymeric light emitting substance in which a de-localized
.pi. electron pair is present along the main chain skeleton of a
polymer. Regarding this de-localized electron, an unpaired electron
or lone electron pair may participate in resonance instead of a
double bond, in some cases.
[0012] A complex emitting triplet luminescence which is a mother
body of a metal complex structure showing light emission from the
triplet excited state, in the present invention, will be
described.
[0013] The complex emitting triplet luminescence is usually a heavy
metal complex, and refers, for example, to a complex which can
cause phosphorescence light emission from the above-mentioned
complex. However, complexes providing observation of fluorescence
light emission in addition to this phosphorescence light emission
are also included.
[0014] The center metal of a complex emitting triplet luminescence
is usually an atom having an atomic number of 50 or more, and is a
metal manifesting a spin-orbital mutual action on this complex and
showing a possibility of the intersystem crossing between the
singlet state and the triplet state.
[0015] As the center metal of a complex emitting triplet
luminescence, for example, rhenium, iridium, osmium, scandium,
yttrium, platinum, gold, and europium such as lanthanoids, terbium,
thulium, dysprosium, samarium, praseodymium, and the like, are
listed, and iridium, platinum, gold and europium are preferable,
iridium, platinum and gold are particularly preferable.
[0016] The ligand of a complex emitting triplet luminescence is
usually an organic ligand, and the number of carbon atoms is
usually from about 4 to 60.
[0017] As the ligand of a complex emitting triplet luminescence,
for example, 8-quinolinol and derivatives thereof, benzoquinolinol
and derivatives thereof, 2-phenyl-pyridine and derivatives thereof,
2-phenyl-benzothiazole and derivatives thereof,
2-phenyl-benzoxazole and derivatives thereof, porphyrin and
derivatives thereof, and the like are listed.
[0018] Examples of the complex emitting triplet luminescence
include followings.
##STR00002## ##STR00003## ##STR00004## ##STR00005##
##STR00006##
[0019] Here, R represents each independently a group selected from
a hydrogen atom, alkyl group, alkoxy group, alkylthio group,
alkylsilyl group, alkylamino group, aryl group, aryloxy group,
arylalkyl group, arylalkoxy group, arylalkenyl group, aryl alkynyl
group, arylamino group, monovalent heterocyclic compound group, and
cyanno group. In order to improve the solubility in a solvent, it
is preferable that the repeating unit including substituent has a
form of little symmetry.
[0020] The alkyl group may be linear, branching or cyclic, and has
usually about one to 20 carbon atoms. Examples thereof include
specifically methyl group, ethyl group, propyl group, i-propyl
group, butyl group, i-butyl group, t-butyl group, pentyl group,
hexyl group, heptyl group, octyl group, 2-ethylhexyl group, nonyl
group, decyl group, 3,7-dimethyloctyl group, lauryl group, etc.
Among them, pentyl group, hexyl group, octyl group, 2-ethylhexyl
group, decyl group, and 3,7-dimethyl octyl group are
preferable.
[0021] The alkoxy group may be linear, branching or cyclic, and has
usually about one to 20 carbon atoms.
[0022] Examples thereof include specifically methoxy group, ethoxy
group, propyloxy group, i-propyloxy group, butoxy group, i-butoxy
group, t-butoxy group, pentyloxy group, hexyloxy group,
cyclohexyloxy group, heptyloxy group, octyloxy group,
2-ethylhexyloxy group, nonyloxy group, decyloxy group,
3,7-dimethyloctyloxy group, lauryloxy group etc. Among them,
pentyloxy group, hexyloxy group, octyloxy group, 2-ethylhexyloxy
group, decyloxy group, and 3,7-dimethyl octyloxy group are
preferable.
[0023] The alkylthio group may be linear, branching or cyclic, and
has usually about one to 20 carbon atoms. Examples thereof include
specifically methylthio group, ethylthio group, propylthio group,
and i-propylthio group, butylthio group, i-butylthio group,
t-butylthio group, pentylthio group, hexylthio group,
cyclohexylthio group, heptylthio group, octylthio group,
2-ethylhexylthio group, nonylthio group, decylthio group,
3,7-dimethyloctylthio group, laurylthio group etc. Among them,
pentylthio group, hexylthio group, octylthio group,
2-ethylhexylthio group, decylthio group, and 3,7-dimethyloctylthio
group are preferable.
[0024] The alkylsilyl group may be linear, branching or cyclic, and
has usually about one to 60 carbon atoms. Examples thereof include
specifically methylsilyl group, ethylsilyl group, propylsilyl
group, and i-propylsilyl group, butylsilyl group, i-butylsilyl
group, t-butylsilyl group, pentylsilyl group, hexylsilyl group,
cyclohexylsilyl group, heptylsilyl group, octylsilyl group,
2-ethylhexylsilyl group, nonylsilyl group, decylsilyl group,
3,7-dimethyloctylsilyl group, laurylsilyl group, trimethylsilyl
group, ethyldimethylsilyl group, propyldimethylsilyl group,
i-propyldimethylsilyl group, butyldimethylsilyl group,
t-butyldimethylsilyl group, pentyldimethylsilyl group,
hexyldimethylsilyl group, heptyldimethylsilyl group,
octyldimethylsilyl group, 2-ethylhexyldimethylsilyl group,
nonyldimethylsilyl group, decyldimethylsilyl group,
3,7-dimethyloctyl-dimethylsilyl group, lauryldimethylsilyl group,
etc. Among them, pentylsilyl group, hexylsilyl group, octylsilyl
group, 2-ethylhexylsilyl group, decylsilyl group,
3,7-dimethyloctylsilyl group, pentyldimethylsilyl group,
hexyldimethylsilyl group, octyldimethylsilyl group,
2-ethylhexyl-dimethylsilyl group, decyldimethylsilyl group,
3,7-dimethyloctyl-dimethylsilyl group are preferable.
[0025] The alkylamino group may be linear, branching or cyclic, and
has usually about one to 40 carbon atoms. Either monoalkylamino
group or dialkylamino group may be available. Examples thereof
include specifically methylamino group, dimethylamino group,
ethylamino group, diethylamino group, propylamino group,
i-propylamino group, butylamino group, i-butylamino group,
t-butylamino group, pentylamino group, hexylamino group,
cyclohexylamino group, heptylamino group, octylamino group,
2-ethylhexylamino group, nonylamino group, decylamino group,
3,7-dimethyloctylamino group, laurylamino group, etc. Among them,
pentylamino group, hexylamino group, octylamino group,
2-ethylhexylamino group, decylamino group, and
3,7-dimethyloctylamino group are preferable.
[0026] The aryl group has usually about 6 to 60 carbon atoms.
Examples thereof include phenyl group, C.sub.1-12 alkoxyphenyl
group (C.sub.1-12 means that the number of carbon atoms is from 1
to 12), C.sub.1-12 alkylphenyl group, 1-naphtyl group, 2-naphtyl
group, etc. Among them, C.sub.1-12 alkoxyphenyl group, and
C.sub.1-12 alkylphenyl group are preferable.
[0027] The aryloxy group has usually about 6 to 60 carbon atoms.
Examples thereof include specifically, phenoxy group, C.sub.1-12
alkoxyphenoxy group, C.sub.1-12 alkylphenoxy group, 1-naphtyloxy
group, 2-naphtyloxy group, etc. Among them, C.sub.1-12
alkoxyphenoxy group, and C.sub.1-12 alkylphenoxy group are
preferable.
[0028] The arylalkyl group has usually about 7 to 60 carbon atoms.
Examples thereof include specifically, phenyl-C.sub.1-12alkyl
group, C.sub.1-12alkoxyphenyl-C.sub.1-12alkyl group, C.sub.1-12
alkylphenyl-C.sub.1-12alkyl group, 1-naphtyl-C.sub.1-12alkyl group,
2-naphtyl-C.sub.1-12 alkyl group, etc. Among them,
C.sub.1-12alkoxyphenyl-C.sub.1-12alkyl group, and
C.sub.1-12alkylphenyl-C.sub.1-12alkyl group are preferable.
[0029] The arylalkoxy group has usually about 7 to 60 carbon atoms.
Examples thereof include specifically, phenyl-C.sub.1-12alkoxy
group, C.sub.1-12alkoxyphenyl-C.sub.1-12alkoxy group,
C.sub.1-12alkylphenyl-C.sub.1-12alkoxy group,
1-naphtyl-C.sub.1-12alkoxy group, 2-naphtyl-C.sub.1-12alkoxy group,
etc. Among them, C.sub.1-12alkoxyphenyl-C.sub.1-12alkoxy group, and
C.sub.1-12alkylphenyl-C.sub.1-12alkoxy group are preferable.
[0030] The aryl alkenyl group has usually about 8 to 60 carbon
atoms. Examples thereof include specifically, cis-phenyl alkenyl
group, trans-phenyl alkenyl group, cis-tolyl alkenyl group,
trans-tolyl alkenyl group, cis-1-naphtyl alkenyl group,
trans-1-naphtyl alkenyl group, cis-2-naphtyl alkenyl group,
trans-2-naphtyl alkenyl group, etc.
[0031] The aryl alkynyl group has usually about 8 to 60 carbon
atoms. Examples thereof include specifically, phenyl alkynyl group,
tolyl alkynyl group, 1-naphtyl alkynyl group, 2-naphtyl alkynyl
group, etc.
[0032] The arylamino group has usually about 6 to 60 carbon atoms.
Examples thereof include specifically, diphenylamino group,
C.sub.1-12 alkoxyphenylamino group, di(C.sub.1-12 alkoxyphenyl)
amino group, di(C.sub.1-12 alkylphenyl)amino group, 1-naphtylamino
group, 2-naphtylamino group, etc. Among them
C.sub.1-12alkylphenylamino group, and di(C.sub.1-12
alkylphenyl)amino group are preferable.
[0033] The monovalent heterocyclic compound group means an atomic
group of a heterocyclic compound in which one hydrogen atom is
removed, and has usually about 4 to 60 carbon atoms. Examples
thereof include thienyl group, C.sub.1-12alkylthienyl group,
pyroryl group, furyl group, pyridyl group, C.sub.1-12alkylpyridyl
group, etc. Among them, thienyl group, C.sub.1-12 alkylthienyl
group, pyridyl group, and C.sub.1-12alkylpyridyl group are
preferable.
[0034] In order to improve the solubility of a polymeric light
emitting substance in a solvent, it is suitable that at least one
of the substituents contains an alkyl chain having cyclic or long
chain structure. Examples thereof include cyclopentyl group,
cyclohexyl group, pentyl group, hexyl group, octyl group,
2-ethylhexyl group, decyl group, and 3,7-dimethyloctyl group. Two
of the alkyl chain terminals may be connected to form a ring.
Moreover, a part of carbon atoms in the alkyl chain may be
substituted by a group containing hetero atom, and examples of the
hetero atom include an oxygen atom, a sulfur atom, a nitrogen atom,
etc.
[0035] The aryl group and heterocyclic compound group in R may
contain further one or more of substituents.
[0036] Complexes emitting triplet luminescence conventionally used
are low molecular weight EL materials, which are disclosed in, for
example: Nature, (1998), 395, 151; Appl. Phys. Lett. (1999), 75(1),
4; Proc. SPIE-Int. Soc. Opt. Eng. (2001), 4105 (Organic
Light-Emitting Materials and Devices N), 119; J. Am. Chem. Soc.,
(2001), 123, 4304; Appl. Phys. Lett., (1997), 71(18), 2596; Syn.
Met., (1998), 94(1), 103; Syn. Met., (1999), 99(2), 1361; and Adv.
Mater., (1999), 11(10), 852.
[0037] The metal complex structure showing light emission from the
triplet excited state indicates a structure derived from the
above-mentioned complex emitting triplet luminescence.
[0038] The polymeric light emitting substance having in the main
chain a metal complex structure showing light emission from the
triplet excited state means a case in which the main chain of the
light emitting substance has an aromatic ring or condensed ring
thereof coordinated to a complex structure showing light emission
from the triplet excited state, or has a metal.
[0039] The polymeric light emitting substance having in the side
chain a metal complex structure showing light emission from the
triplet excited state means a case in which an aromatic ring or
condensed ring thereof coordinated to a complex structure showing
light emission from the triplet excited state is connected to the
main chain via an atom such as oxygen atom, sulfur atom, selenium
atom, etc.; a direct bond such as a single bond, and double bond;
or a divalent group such as methylene group, alkylene group,
arylene group, etc.
[0040] One example of the mode of the present invention is a
polymeric light emitting substance which contains two kinds or more
of metal complex structures showing light emission from the triplet
excited state. Each of the metal complex structures may have the
same or different metals. Each of the metal complex structures may
have the same or different emitting colors. For example, a polymer
may contain both of metal complex structures one of which emits
green and the other emits red. By designing the amount of the metal
complex structures appropriately, the emitting color can be
controlled, desirably.
[0041] In the polymeric light emitting substance of the present
invention, the main chain preferably comprises a conjugated
polymer.
[0042] Of polymeric light emitting substances of the present
invention, preferable is a polymeric light emitting substance
comprising one or more repeating units of the general formula (1)
and one or more repeating units having a metal complex structure
showing light emission from the triplet excited state:
##STR00007##
(wherein, Ar.sub.1 represents an arylene group or a divalent
heterocyclic compound group. R.sub.1 and R.sub.2 each independently
represent a hydrogen atom, alkyl group, aryl group, monovalent
heterocyclic compound group or cyano group. n represents 0 or
1).
[0043] Of them, a polymeric light emitting substance wherein the
amount of repeating units having a metal complex structure showing
light emission from the triplet excited state is 0.01 mol % or more
and 10 mol % or less based on the total amount of repeating units
of the general formula (1) and repeating units having a metal
complex structure showing light emission from the triplet excited
state, is more preferable. When the amount of repeating units
having a metal complex structure showing light emission from the
triplet excited state is too large or too small, an effect of high
light emission efficiency tends to lower.
[0044] As the repeating unit having a metal complex structure
showing light emission from the triplet excited state, groups
having bonding sites, remaining after removal of hydrogen atoms
from the above-mentioned ligand of the complex emitting triplet
luminescence, are exemplified.
[0045] As the repeating unit having a metal complex structure
showing light emission from the triplet excited state, also listed
are those in which the substituent of Ar.sub.1 or, R.sub.1 or
R.sub.2 in the above-mentioned repeating unit of the formula (1) is
a monovalent group having a metal complex structure showing light
emission from the triplet excited state. Preferable examples
thereof are as follows.
##STR00008## ##STR00009## ##STR00010##
[0046] R is the same as above.
[0047] The monovalent group having a metal complex structure
showing light emission from the triplet excited state is a group
having one bonding site, remaining after removal of one hydrogen
atom from the above-mentioned ligand of the complex emitting
triplet luminescence.
[0048] The polymeric light emitting substance of the present
invention may have a monovalent group in which the end of the main
chain has a metal complex structure showing light emission from the
triplet excited state.
[0049] In the general formula (1), Ar.sub.1 means an arylene group
or a divalent heterocyclic compound group. Ar.sub.1 may have a
substituent such as an alkyl group, alkoxy group, alkylthio group,
alkylsilyl group, alkylamino group, aryl group, aryloxy group,
arylalkyl group, arylalkoxy group, alylalkenyl group, arylalkynyl
group, arylamono group, monovalent heterocyclic compound group or
cyano group. Examples of the substituents are the same with the
above R.
[0050] Ar.sub.1 may be an arylene group or a divalent heterocyclic
compound group contained in all materials conventionally used as an
EL light emitting material. Monomers which do not inhibit the
triplet luminescence are preferable. Examples of these materials
are described in WO99/12989, WO00/55927, WO01/49769A1,
WO01/49768A2, WO98/06773, U.S. Pat. No. 5,777,070, WO99/54385,
WO00/46321 and U.S. Pat. No. 6,169,163B1.
[0051] In the present invention, the arylene group means a divalent
group derived from an aromatic hydrocarbon having a benzene ring, a
condensed ring, and those in which independent benzene rings and/or
condensed rings are bonded directly or through groups such as
vinylene.
[0052] The arylene group has usually 6 to 60 carbon atoms,
preferably 6 to 20. Examples thereof include: phenylene groups (for
example, the below structures of Nos. 1 to 3), naphthalenediyl
groups (the below structures of Nos. 4 to 13), anthracenylene
groups (the below structures of Nos. 14 to 19), biphenylene groups
(the below structures of Nos. 20 to 25), triphenylene groups (the
below structures of Nos. 26 to 28), stilbene-diyl (the below
structures of A to D), distilbene-diyl (the below structures of E
and F), condensed-ring compound groups (the below structures of
Nos. 29 to 38), etc. Here, the number of carbon atoms of the
substituent is not counted as the number of carbon atoms of the
arylene group.
##STR00011## ##STR00012## ##STR00013## ##STR00014## ##STR00015##
##STR00016##
[0053] The divalent heterocyclic compound group means an atomic
group of a heterocyclic compound in which two hydrogen atoms are
removed, and has usually about 4 to 60, preferably 4 to 20 carbon
atoms. Here, the number of carbon atoms of the substituent is not
counted as the number of carbon atoms of the divalent heterocyclic
compound group.
[0054] Here, the heterocyclic compound means that an organic
compound having a cyclic structure in which at least one heteroatom
such as oxygen, sulfur, nitrogen, phosphor, boron, etc. is
contained in the cyclic structure as the element other than carbon
atoms.
[0055] Examples of the divalent heterocyclic compound group include
the followings.
[0056] Divalent heterocyclic compound groups containing nitrogen as
the heteroatom, such as: pyridine-diyl groups (the below structures
of Nos. 39 to 44), diazaphenylene groups (the below structures of
Nos. 45 to 48), quinolinediyl groups (the below structures of Nos.
49 to 63), quinoxalinediyl groups (the below structures of Nos. 64
to 68), acridinediyl groups (the below structures of Nos. 69 to
72), bipyridyldiyl groups (the below structures of Nos. 73 to 75),
phenanthrolinediyl groups (the below structures of Nos. 76 to 78),
etc.; groups having fluorene structure containing silicon,
nitrogen, sulfur, selenium, etc. as the hetero atom (the below
structures of Nos. 79 to 93). In view of light emitting efficiency,
preferable are carbazoles represented by formulae 82 to 84
containing a nitrogen atom or those having an aromatic amine
monomer such as triphenyldiyl.
[0057] Exemplified are 5-membered-ring heterocyclic compound groups
containing silicon, nitrogen, sulfur, selenium, etc. as the
heteroatom (below structures of Nos. 94 to 98).
[0058] Exemplified are 5-membered-ring condensed heterocyclic
compound groups containing silicon, nitrogen, sulfur, selenium,
etc. as the heteroatom (below structures of Nos. 99 to 109),
benzodiazole, benzooxadiazole-4,7-diyl, etc.
[0059] Exemplified are groups of 5-membered-ring heterocyclic
compound groups containing silicon, nitrogen, sulfur, selenium,
etc. as the heteroatom which form dimer or oligomer by bonding at
a-position of the hetero atom (below structures of Nos. 110 to
118).
[0060] Exemplified are groups of 5-membered-ring heterocyclic
compound groups containing silicon, nitrogen, sulfur, selenium,
etc. as the heteroatom which bond to a phenyl group at a-position
of the hetero atom (below structures of Nos. 112-118).
##STR00017## ##STR00018## ##STR00019## ##STR00020## ##STR00021##
##STR00022## ##STR00023## ##STR00024## ##STR00025## ##STR00026##
##STR00027##
[0061] Here, R means a group as the same with those described
above.
[0062] In the above formula (1), n is 0 or 1.
[0063] R.sub.1 and R.sub.2 in formula (1) represent each
independently a group selected from a hydrogen atom, an alkyl
group, an aryl group, a monovalent heterocyclic compound group, and
a cyano group.
[0064] In the case where R.sub.1 and R.sub.2 are substituents other
than a hydrogen atom or a cyano group, the alkyl group may be
linear, branching or cyclic, and has usually about one to 20 carbon
atoms. Examples thereof include specifically methyl group, ethyl
group, propyl group, butyl group, pentyl group, hexyl group, heptyl
group, octyl group, nonyl group, decyl group, lauryl group, etc.
Among them, methyl group, ethyl group, pentyl group, hexyl group,
heptyl group, and an octyl group are preferable.
[0065] The aryl group has usually about 6 to 60 carbon atoms.
Examples thereof include specifically phenyl group, C.sub.1-12
alkoxyphenyl group, C.sub.1-12alkylphenyl group, 1-naphtyl group,
2-naphtyl group, etc. Among them, phenyl group and C.sub.1-12
alkylphenyl group are preferable.
[0066] The monovalent heterocyclic compound group has usually about
4 to 60 carbon atoms. Examples thereof include specifically thienyl
group, C.sub.1-12 alkylthienyl group, pyroryl group, furyl group,
pyridyl group, C.sub.1-12 alkylpyridyl group, etc. Among them,
thienyl group, C.sub.1-12 alkylthienyl group, pyridyl group, and
C.sub.1-12 alkylpyridyl group are preferable.
[0067] In view of light emitting efficiency, it is suitable that
one or more of the repeating units represented by the formula (2)
below are contained as a repeating unit other than that represented
by the above formula (1).
##STR00028##
[0068] In the formula, Ar.sub.2 and Ar.sub.3 each independently
represent an arylene group, or a divalent heterocyclic compound
group. Ar.sub.2 does not cross-link to Ar.sub.3. R.sub.11
represents an alkyl group, an aryl group, a mono-valent
heterocyclic compound group, a group represented by the below
formula (3) or (4). The symbol t is an integer from 1 to 4.
##STR00029##
[0069] In the formula, Ar.sub.4 is an arylene group or a divalent
heterocyclic compound group. R.sub.1 represents a hydrogen atom, an
alkyl group, an aryl group, mono-valent heterocyclic group, or a
group represented by the below formula (4). Z.sub.12 represents
--CR.sub.13.dbd.CR.sub.14-- or --C.ident.C--. R.sub.13 and R.sub.14
each independently represents a hydrogen atom, an alkyl group, an
aryl group, mono-valent heterocyclic group, or cyano group. The
symbol u is an integer from 0 to 2.
##STR00030##
In the formula, Ar.sub.5 and Ar.sub.6 each independently represents
an arylene group or a divalent heterocyclic compound group.
R.sub.15 represents an alkyl group, an aryl group, or mono-valent
heterocyclic group. R.sub.16 represents a hydrogen atom, an alkyl
group, an aryl group, or mono-valent heterocyclic group. The symbol
v is an integer from 1 to 4.
[0070] Examples of the arylene group and divalent heterocyclic
compound group in Ar.sub.2 to Ar.sub.6 include the same with those
exemplified in the above Ar.sub.1.
[0071] Examples of the alkyl group, aryl group and mono-valent
heterocyclic compound group in R.sub.11 to R.sub.16 include the
same with those exemplified in the above R.sub.1 or R.sub.2.
[0072] Concrete examples of the repeating units represented by the
above formula (2) are as follows.
##STR00031## ##STR00032## ##STR00033##
[0073] R is the same as above.
[0074] It is also suitable that one or more of the repeating units
represented by the below formula (5) are contained as a repeating
unit other than that represented by the above formula (1).
##STR00034##
In the formula, R.sub.11 means the same as above. R.sub.18 and
R.sub.19 represent substituents on aromatic ring. Examples thereof
include a halogen atom, alkyl group, alkenyl group, aralkyl group,
arylthio group, arylalkenyl group, cyclic alkenyl group, alkoxy
group, aryloxy group, alkyloxy carbonyl group, aralkyloxy carbonyl
group, aryloxy carbonyl group, aryl group, or mono-valent
heterocyclic compound group. The symbols a and b each independently
represent an integer from 0 to 3. When a or b is 2 or more,
R.sub.18 and R.sub.19 are the same or different mutually, which may
be connected to form a ring.
[0075] Examples of the mono-valent heterocyclic compound group,
alkoxy group include the same with those exemplified in the above
R.sub.1 and R.sub.2.
[0076] Exemplified are: fluorine atom, chlorine atom, bromine atom
and iodine atom as the halogen atom; methyl group, ethyl group,
n-propyl group, iso-propyl group, n-butyl group, iso-butyl group,
t-butyl group, n-amyl group, noepentyl group, n-hexyl group,
n-oxtyl group, n-nonyl group, 2,3,4-trimethyl-3-pentyl group,
2,4-dimethyl-3-pentyl group, etc. as the alkyl group;
2-methyl-1-propenyl group and 2-butenyl group, etc. as the alkenyl
group; benzyl group, 2-phenylethyl group, 2-naphthylethyl group,
diphenylmethyl group, etc. as the aralkyl group; thiophenyl group,
etc. as the arylthio group; trans-.beta.-styryl group,
3-phenyl-1-propenyl group, etc. as the arylalkenyl group;
1-cyclohexenyl group, etc. as the cyclic alkenyl group; methoxy
group, ethoxy group, n-propoxy group, t-butoxy group, etc. as the
alkoxy group; phenoxy group, naphthyloxy group, diphenyloxy group,
etc. as the aryloxy group; methoxy carbonyl group, ethoxy carbonyl
group, t-butyloxy carbonyl group, etc. as the alkyoxy carbonyl
group; benzyloxy carbonyl group, etc. as the aralkyloxy carbonyl
group; phenyloxy carbonyl group, etc. as the aryloxy carbonyl
group; pheny group, naphtyl group, biphenyl group, furyl group,
etc. as the aryl group.
[0077] A protecting group may be used to stabilize the terminal
group of a polymeric light emitting substance in accordance with
the present invention since if an active polymerizable group
remains intact, there is a possibility of reduction of the light
emitting property and life of the polymeric light emitting
substance when the material is used in a device. Groups having a
conjugated bond continued to the conjugated structure of the main
chain are preferable, and examples thereof include structures
containing a bond to an aryl group or a heterocyclic compound group
via a vinylene group. Specifically, substituents described in JP-A
No. 9-45478, chemical formula 10, and the like are exemplified.
[0078] The polymeric light emitting substance of the present
invention may also contain repeating units other than the repeating
unit of the general formula (1) and the repeating unit having a
metal complex structure showing light emission from the triplet
excited state, in an amount not deteriorating light emission
property and charge transfer property. Further, the repeating unit
of the general formula (1), the repeating unit having a complex
structure showing light emission from the triplet excited state,
and other repeating units may be connected in the form of
non-conjugated units, or these non-conjugated parts may be
contained in the repeating units. As the bonding structure, there
are exemplified the following structures, combinations of the
following structures with a vinylene group, combinations of two or
more of the following structures, and the like. Here, R is a group
selected from the same substituents as described above, and Ar
represents a hydrocarbon group having 6 to 60 carbon atoms.
##STR00035##
[0079] In the polymeric light emitting substance of the present
invention, the amount of the repeating units having a metal complex
structure showing light emission from the triplet excited state is
0.01 mol % or more and 10 mol % or less based on the total amount
of the repeating units of the general formulas (1), (2) and (5),
and the repeating units having a metal complex structure showing
light emission from the triplet excited state.
[0080] The polymeric light emitting substance of the present
invention is characterized by emitting the light from the complex
of the below formula (6):
##STR00036##
In the formula, M represents a metal atom having an atomic number
of 50 or more and showing a possibility of the intersystem crossing
between the singlet state and the triplet state in this complex by
a spin-orbital mutual action. Ar represents a ligand bonded to M,
via one or more of a nitrogen atom, oxygen atom, carbon atom,
sulfur atom and phosphorus atom, with bonding to a polymer at an
arbitrary position. L represents a hydrogen atom, hydrocarbon group
having 1 to 10 carbon atoms, carboxylate group having 1 to 10
carbon atoms, diketonate group having 1 to 10 carbon atoms, halogen
atom, amide group, imide group, alkoxide group, alkylmercapto
group, carbonyl ligand, arylene ligand, alkene ligand, alkyne
ligand, amine ligand, imine ligand, nitrile ligand, isonitrile
ligand, phosphine ligand, phosphine oxide ligand, phosphite ligand,
ether ligand, sulfone ligand, sulfoxide ligand or sulfide ligand. m
represents an integer of 1 to 5. o represents an integer of 0 to
5.
[0081] As the halogen atom represented by X, iodine, bromine,
chlorine and the like are exemplified. As the arylsulfonyloxy
group, a pentafluorophenylsulfonyloxy group, p-toluenesulfonyloxy
group and the like are exemplified, and as the alkylsulfonyloxy
group, a methanesulfonyloxy group, trifluoromethanesulfonyloxy
group and the like are exemplified.
[0082] Of them, M is preferably rhenium atom, osmium atom, iridium
atom, platinum atom, samarium atom, europium atom, gold atom,
gadolinium atom, terbium atom or dysprosium atom, more preferably
iridium atom, platinum atom, or gold atom, and further preferably
iridium atom.
[0083] Ars are the same or different mutually and represent a
ligand bonded to M, via one or more of a nitrogen atom, oxygen
atom, carbon atom, sulfur atom and phosphorus atom, with bonding to
a polymer at an arbitrary position.
[0084] Of them, it is preferable that Ar is a tetra-dentate ligand
bonded to M, via any four atoms of a nitrogen atom, oxygen atom,
carbon atom, sulfur atom and phosphorus atom. For example, as a
ligand in which four pyrrole rings are connected in the form of
ring, 7,8,12,13,17,18-hexakisethyl-21H,23H-porphyrin is
specifically listed.
[0085] Further, it is also that Ar is a bidentate ligand forming a
5-membered ring by bonding to M, via any two atoms of a nitrogen
atom, oxygen atom, carbon atom, sulfur atom and phosphorus
atom.
[0086] It is more preferable that M bonds to at least one carbon
atom and Ar is bidentate ligand represented by the below formula
(7).
##STR00037##
In the formula, R.sup.3 to R.sup.10 represent halogen atom, alkyl
group, alkenyl group, aralkyl group, arylthio group, arylalkenyl
group, cyclic alkenyl group, alkoxy group, aryloxy group, alkyloxy
carbonyl group, aralkyloxy carbonyl group, aryloxy carbonyl group,
or aryl group. At least one of R.sup.3 to R.sup.10 is a bonding
group to a polymer chain.
[0087] As Ar, exemplified are ligands constituted by connecting
heterocyclic rings such as a pyridine ring, thiophene ring,
benzooxazole ring and the like, and a benzene ring, and specific
examples thereof include phenylpyridine, [0088]
2-(p-phenylphenyl)pyridine, 7-bromobenzo[h]quinoline, [0089]
2-(4-thiophen-2-yl)pyridine, [0090]
2-(4-phenylthiophen-2-yl)pyridine, 2-phenylbenzooxazole, [0091]
2-(p-phenylphenyl)benzooxazole, 2-phenylbenzothiazole, [0092]
2-(p-phenyphenyl)benzothiazole, [0093]
2-(benzohiophen-2-yl)pyridine and the like, which may have one or
more substituents.
[0094] As the substituents of Ar, exemplified are a halogen atom,
alkyl group, alkenyl group, aralkyl group, arylthio group,
arylalkenyl group, cyclic alkenyl group, alkoxy group, aryloxy
group, alkyloxy carbonyl group, aralkyloxy carbonyl group, aryloxy
carbonyl group, aryl group, or mono-valent heterocyclic compound
group. Concrete examples are the same as those represented in
R.sub.18 and R.sub.19.
[0095] Examples of L in the general formula (6) include: methyl
group, ethyl group, propyl group, butyl group, cyclohexyl group as
the alkyl group; phenyl group, tolyl group, 1-naphtyl group,
2-naphtyl group, etc. as the aryl group; and phenylpyridine,
2-(p-phenylphenyl)pyridine, 7-bromobenzo[h]quinoline, [0096]
2-(4-thiophen-2-yl)pyridine, [0097]
2-(4-phenylthiophen-2-yl)pyridine, 2-phenylbenzooxazole, [0098]
2-(p-phenylphenyl)benzooxazole, 2-phenylbenzothiazole, [0099]
2-(p-phenyphenyl)benzothiazole, [0100]
2-(benzohiophen-2-yl)pyridine, etc. as the heterocyclic compound
group.
[0101] The carboxylate group having 1 to 10 carbon atoms is not
particularly restricted, and examples thereof include an acetate
group, naphthenate group, 2-ethylhexanoate group and the like. As
the diketonate group having 1 to 10 carbon atoms is not
particularly restricted, and examples thereof include an
acetylacetonate group and the like. The halogen atom is not
particularly restricted, and examples thereof include a fluorine
atom, chlorine atom, bromine atom, iodine atom and the like. The
amide group is not particularly restricted, and examples thereof
include a dimethylamide group, diethylamide group, diisopropylamide
group, dioctylamide group, didecylamide group, didodecylamide
group, bis(trimethylsilyl)amide group, diphenylamide group,
N-methylanilide, anilide group and the like. The imide group is not
particularly restricted, and examples thereof include a
benzophenoneimide and the like. The alkoxy group is not
particularly restricted, and examples thereof include a methoxide
group, ethoxide group, propoxide group, butoxide group, phenoxide
group and the like. The alkylmercapto group is not particularly
restricted, and examples thereof include a methylmercapto group,
ethylmercapto group, propylmercapto group, butylmercapto group,
phenylmercapto group and the like. The arene ligand is not
particularly restricted, and examples thereof include benzene,
toluene, xylene, trimethylbenzene, hexamethylbenzene, naphthalene
and the like. The alkene ligand is not particularly restricted, and
examples thereof include ethylene, propylene, butene, hexene,
decene and the like. The alkyne ligand is not particularly
restricted, and examples thereof include acetylene,
phenylacetylene, diophenylacetylene and the like. The amine ligand
is not particularly restricted, and examples thereof include
triethylamine, tributylamine and the like. The imine ligand is not
particularly restricted, and examples thereof include a
benzophenoneimine, methylethylimine and the like. The nitrile
ligand is not particularly restricted, and examples thereof include
acetonitrile, benzonitrile and the like. The isonitrile is not
particularly restricted, and examples thereof include
t-butylisonitrile, phenylisonitrile and the like. The phosphine
ligand is not particularly restricted, and examples thereof include
triphenylphosphine, tritolylphosphine, tricyclohexylphosphine,
tributylphosphine and the like. The phosphine oxide ligand is not
particularly restricted, and examples thereof include
tributylphosphine oxide, triphenylphosphine oxide and the like. The
phosphite ligand is not particularly restricted, and examples
thereof include triphenylphosphite, tritolylphosphite,
tributylphosphite, triethylphosphite and the like. The ether ligand
is not particularly restricted, and examples thereof include
dimethyl ether, diethyl ether, tetrahydrofuran and the like. The
sulfone ligand is not particularly restricted, and examples thereof
include dimethylsulfone, dibutylsulfone and the like. The sulfoxide
ligand is not particularly restricted, and examples thereof include
dimethylsulfoxide, dibutylsulfoxide and the like. The sulfide
ligand is not particularly restricted, and examples thereof include
ethyl sulfide, butyl sulfide and the like.
[0102] The above-mentioned polymeric light emitting substance may
be a random, block or graft copolymer, or a polymer having an
intermediate structure of them, for example, a random copolymer
having a property of block. From the standpoint of obtaining a
polymeric light emitting substance having high quantum yield of
light emission, a random copolymer having a property of block, and
a block or graft copolymer is preferable, rather than a complete
random copolymer.
[0103] As this polymeric light emitting substance, those showing
light emission in solid state are suitably used, due to utilization
of light emission from a thin film.
[0104] As the good solvent for the above-mentioned polymeric light
emitting substance, chloroform, methylene chloride, dichloroethane,
tetrahydrofuran, toluene, xylene, mesitylene, tetralin, decalin,
n-butylbenzene and the like are exemplified. Depending on the
structure and molecular weight of a polymeric light emitting
substance, the polymeric light emitting substance can be usually
dissolved in these solvents in an amount of 0.1% by weight or
more.
[0105] The polymeric light emitting substance of the present
invention has a polystyrene reduced number-average molecular weight
of from 10.sup.3 to 10.sup.8. The total number of the repeating
structures varies also depending on the repeating structure and
ratio thereof. From the standpoint of film formation property, it
is generally that the total number of repeating units is preferably
from 20 to 10000, further preferably from 30 to 10000, particularly
preferably from 50 to 5000.
[0106] When the polymeric light emitting substance of the present
invention is used as a light emitting material of a polymer LED, it
is preferable to conduct polymerization after purification of a
monomer before polymerization, by methods such as distillation,
sublimation purification, re-crystallization and the like, since
the purity thereof exert an influence on light emitting property,
and it is preferable to effect purification treatment such as
re-precipitation purification, chromatography fractionation and the
like, after synthesis.
[0107] The polymeric light emitting substance of the present
invention can be produced by polymerization using as a raw material
a monomer having a polymerization active group derived from the
complex emitting triplet luminescence. When there is a possibility
of decomposition of a monomer having a polymerization active group
derived from the complex emitting triplet luminescence, under
polymerization conditions, it may also be permissible that
polymerization is conducted using as a raw material a monomer
having a polymerization active group derived from the complex
emitting triplet luminescence, to obtain a polymer, and this
polymer is reacted with a center metal of the complex emitting
triplet luminescence.
[0108] As the polymerization active group use here, there are
listed, for example, a formyl group, phosphonium group, halogen
groups such as bromine, iodine, chlorine and the like, vinyl group,
halomethyl group, acetonitrile group, alkylsulfonyloxy groups such
as a trifluoromethanesulfonyloxy group and the like,
arylsulfonyloxy groups such as a toluenesulfonyloxy group and the
like, though varying depending on the polymerization method.
[0109] The polymeric light emitting substance of the present
invention can be produced by polymerization using a monomer having
a polymerization active group derived from the complex emitting
triplet luminescence and, if necessary, other monomers as raw
materials, according to JP-A No. 5-202355, for example.
[0110] Namely, exemplified are:
[1] a polymerization of a compound having aldehyde group with a
compound having phosphonium salt group according to Wittig
reaction; [2] a polymerization of a compound having aldehyde group
and phosphonium salt group according to Wittig reaction; [3] a
polymerization of a compound having vinyl group with a compound
having halogen group according to Heck reaction; [4] a
polymerization of a compound having vinyl group and halogen group
according to Heck reaction; [5] a polymerization of a compound
having aldehyde group with a compound having alkyl phosphonate
group according to Horner-Wadsworth-Emmons method; [6] a
polymerization of a compound having aldehyde group and alkyl
phosphonate group according to Horner-Wadsworth-Emmons method; [7]
a polycondensation of a compound having two methyl halide groups
according to de-hydrohalogenation method; [8] a polycondensation of
a compound having two sulfonium salt groups according to the
sulfonium salt decomposing method; [9] a polymerization of a
compound having aldehyde group with a compound having acetonitrile
group according to Knoevenagel reaction; [10] a polymerization of a
compound having aldehyde group and acetonitrile group according to
Knoevenagel reaction; and [11] a polymerization of a compound
having two or more aldehyde groups according to the McMurry
reaction. The polymerizations [1] to [11] are shown as follows.
##STR00038## ##STR00039##
[0111] When a vinylene group is not contained in the main chain,
there are exemplified methods in which polymerization is effected
with using a monomer having a polymerizable group derived from a
complex emitting triplet luminescence, and if necessary, using
another monomer:
[12] a method of polymerization according to a Suzuki coupling
reaction, [13] a method of polymerization according to a Grignard
reaction, [14] a method of polymerization using a Ni(0) catalyst,
[15] a method of polymerization using an oxidizing agent such as
FeCl.sub.3 and the like, a method of oxidation polymerization
electrochemically, [16] a method according to decomposition of an
intermediate polymer having a suitable releasing group, and the
like. The polymerization methods [12] to [16] are shown as
follows.
##STR00040##
[0112] Among the above, methods of effecting polymerization
according to Wittig reaction, Heck reaction,
Horner-Wadsworth-Emmons method, Knoevenagel reaction, Suzuki
coupling reaction, Grignard reaction, and a polymerization using a
Ni(0) catalyst are suitable since reaction control is easy. In view
of the availability of the raw materials and simple operationality
of the polymerization reaction, polymerizations according to Suzuki
coupling reaction or Grignard reaction, and a polymerization using
a Ni(0) catalyst are preferable.
[0113] Monomers can be reacted with dissolving in a solvent if
necessary, with using an appropriate catalyst such as, for example,
an alkali, and at a temperature of above the melting point and
below the boiling point of the organic solvent. Known methods can
be used as described in: Organic Reactions, volume 14, pages
270-490, (John Wiley & Sons, Inc., 1965); Organic Reactions,
volume 27, pages 345-390 (John Wiley & Sons, Inc., 1982);
Organic Synthesis, Collective Volume VI, pages 407-411 (John Wiley
& Sons, Inc., 1988); Chemical Review, volume 95, page 2457
(1995); J. Organomet. Chem., volume 576, page 147 (1999); J. Prakt.
Chem., volume 336, page 247 (1994); and Makromol. Chem. Macromol.
Symp., volume 12, page 229 (1987).
[0114] Though the organic solvent varies also depending on
compounds and reactions used, it is generally preferable that
de-oxygen treatment is sufficiently performed on the solvent used
and the reaction thereof is allowed to progress under an inert
atmosphere, to suppress a side reaction. Further, it is preferable
to conduct dehydration treatment likewise (however, this is not
applicable in the case of a reaction in a two-phase system with
water, such as a Suzuki coupling reaction.).
[0115] An alkali and a suitable catalyst are added appropriately
for progressing a reaction. These may advantageously be selected
depending on the reaction used. It is preferable that this alkali
or catalyst is sufficiently dissolved in a solvent used for the
reaction. As the method of mixing an alkali or catalyst, there is
exemplified a method in which a solution of an alkali or catalyst
is added slowly while stirring the reaction solution under an inert
atmosphere such as argon, nitrogen and the like, or the reaction
solution is added slowly to the solution of an alkali or catalyst,
conversely.
[0116] In the method of producing a polymeric light emitting
substance of the present invention, monomers may be mixed and
reacted at one time, or mixed divisionally, if necessary.
[0117] Regarding more specific reaction conditions in the case of a
Wittig reaction, Horner reaction, Knoevengel reaction and the like,
an alkali is used in an equivalent amount or more, preferably from
1 to 3 equivalent based on the functional group of a monomer, and
reacted. The alkali is not particularly restricted, and there can
be used, for example, potassium-t-butoxide, sodium-t-butoxide,
metal alcolates such as sodium ethylate, lithium methylate and the
like, hydride reagents such as sodium hydride and the like, amide
such as sodiumamide and the like. As the solvent,
N,N-dimethylformadide, tetrahydrofuran, dioxane, toluene and the
like are used. The temperature for the reaction is usually from
room temperature to about 150.degree. C. The reaction time is, for
example, from 5 minutes to 40 hours, and time for sufficient
progress of polymerization may be permissible, and there is no
necessity of leaving for a long period of rime after completion of
the reaction, therefore, the reaction time is from 10 minutes to 24
hours. The concentration in the reaction may be appropriately
selected in the range from about 0.01 wt % to the maximum solution
concentration, since reaction efficiency is poor when too thin and
reaction control is difficult when too thick, and usually is in the
range from 0.1 wt % to 20 wt %. In the case of a Heck reaction,
monomers are reacted in the presence of a base such as
triethylamine and the like, using a palladium catalyst. A solvent
having a relatively high boiling point such as
N,N-dimethylformamide, N-methylpyrrolidone and the like is used,
the reaction temperature is from about 80 to 160.degree. C., and
the reaction time is from about 1 hour to 100 hours.
[0118] In the case of a Suzuki coupling reaction,
palladium[tetrakis(triphenylphosphine)], palladium acetates and the
like, for example, are used, and an inorganic base such as
potassium carbonate, sodium carbonate, barium hydroxide and the
like, an organic base such as triethylamine and the like, and an
inorganic salt such as cesium fluoride and the like are added in an
amount of equivalent or more, preferably from 1 to 10 equivalent
based on monomers, and reacted. An inorganic salt may be reacted in
the form of an aqueous solution, in a two-phase system. As the
solvent, N,N-dimethylformamide, toluene, dimethoxyethane,
tetrahydrofuran and the like are exemplified. Though depending on
the solvent, a temperature of from about 50 to 160.degree. C. is
preferably used. It may also be permissible to heat the reaction
solution to a temperature near the boiling point of the solvent, to
cause reflux. The reaction time is from about 1 hour to 200
hours.
[0119] In the case of a Grignard reaction, a method is exemplified
in which a halogenated compound and metal Mg are reacted in an
ether-based solvent such as tetrahydrofuran, diethyl ether,
dimethoxyethane and the like to prepare a Grignard reagent solution
which is mixed with a monomer solution prepared separately, and a
nickel or palladium catalyst is added while paying attention to
excess reaction to the resulted mixture which is then heated to
cause a reaction under reflux. A Grignard reagent is used in
equivalent or more, preferably from 1 to 1.5 equivalent, more
preferably from 1 to 1.2 equivalent based on monomers. Also in the
case of polymerization by methods other than this, the reaction can
be conducted according to known methods.
[0120] The method of producing a polymeric light emitting substance
of the present invention is a production method, comprising
reacting a monomer of X.sub.1-A-X.sub.2 (wherein, X.sub.1 and
X.sub.2 each independently represent a halogen atom,
alkylsulfonyloxy group or arylsulfonyloxy group. -A- represents a
repeating unit having a metal complex structure showing light
emission from the triplet excited state.) with
X.sub.3--Ar.sub.1-X.sub.4 (wherein, X.sub.3 and X.sub.4 each
independently represent a halogen atom, alkylsulfonyloxy group or
arylsulfonyloxy group.) in the presence of a Ni catalyst.
[0121] Another method of producing a polymeric light emitting
substance of the present invention is a production method,
comprising reacting a monomer of Y.sub.1-A-Y.sub.2 (wherein,
Y.sub.1 and Y.sub.2 each independently represent a boric acid group
or borate group.) with a monomer of Z.sub.1--Ar--Z.sub.2 (wherein,
Z.sub.1 and Z.sub.2 represent a halogen atom, alkylsulfonyloxy
group or arylsulfonyloxy group.) in the presence of a Pd
catalyst.
[0122] Still another method of producing a polymeric light emitting
substance of the present invention is a production method,
comprising reacting a monomer of Y.sub.3--Ar.sub.1--Y.sub.4
(wherein, Y.sub.3 and Y.sub.4 each independently represent a boric
acid group or borate group.) with a monomer of Z.sub.3-A-Z.sub.4
(wherein, Z.sub.3 and Z.sub.4 each independently represent a
halogen atom, alkylsulfonyloxy group or arylsulfonyloxy group.) in
the presence of a Pd catalyst.
[0123] Particularly, the amount of a monomer of X.sub.1-A-X.sub.2,
a monomer of Y.sub.1-A-Y.sub.2, or a monomer of Z.sub.3-A-Z.sub.4,
is from 0.01 mol % or more and 10 mol % or less based on the total
amount of monomers.
[0124] By method of producing a polymeric light emitting substance
of the present invention, a polymeric light emitting substance
having in the main chain or side chain of the polymer a metal
complex structure showing light emission from the triplet excited
state can be easily synthesized, leading to a significant
industrial advantage.
[0125] In the above-mentioned polymers, -A- represents a repeating
unit having a metal complex structure showing light emission from
the triplet excited state, and specifically, there are listed
divalent groups in which any two of Rs in above-exemplified complex
emitting triplet luminescence are bonding sites with the adjacent
repeating unit.
[0126] As the halogen atom represented by X.sub.1, X.sub.2,
X.sub.3, X.sub.4, Z.sub.1, Z.sub.2, Z.sub.3 and Z.sub.4, iodine,
bromine, chlorine and the like are exemplified. As the
arylsulfonyloxy group, a pentafluorophenylsulfonyloxy group,
p-toluenesulfonyloxy group and the like are exemplified, and as the
alkylsulfonyloxy group, a methanesulfonyloxy group,
trifluoromethanesulfonyloxy group and the like are exemplified.
[0127] As the boric acid group and borate group represented by
Y.sub.1, Y.sub.2, Y.sub.3 and Y.sub.4, a boric acid group, dimethyl
borate, ethylene borate, trimethylene borate and the like are
exemplified.
[0128] As the example of reaction in the presence of a Ni catalyst,
a method of polymerization using the above-mentioned Ni(0) catalyst
is exemplified.
[0129] As the nickel catalyst, an
ethylenebis(triphenylphosphine)nickel complex,
tetrakis(triphenylphosphine) nickel complex, bis(cyclooctadienyl)
nickel complex, and the like, are exemplified.
[0130] As the example of reaction in the presence of a Pd catalyst,
the above-mentioned Suzuki coupling reaction is exemplified.
[0131] As the palladium catalyst, palladium acetate, palladium
[tetrakis(triphenylphosphine)] complex,
bis(tricyclohexylphosphine)palladium complex, and the like, are
exemplified.
[0132] The complex of the present invention will be described
below.
[0133] The complex of the present invention has a ligand carrying a
bromine atom, chlorine atom, iodine atom, arylsulfonyloxy group,
alkylsulfonyloxy group and the like as a reactive functional group,
and is a novel complex having iridium, platinum, europium or gold
as a center metal, and a complex which can be a monomer, a raw
material of the polymeric light emitting substance of the present
invention. This complex solves a problem that the above-mentioned
known complex has no reactive functional group, and it is difficult
to convert the complex into a derivative or to use the complex as a
monomer for polymer synthesis.
[0134] The complex of the present invention is a complex of the
general formula (8):
##STR00041##
In the formula, L, M, Ar, m and o are the same as those described
above. X represents a halogen atom, arylsulfonyloxy group or
alkylsulfonyloxy group.
[0135] As the halogen atom represented by X, iodine, bromine,
chlorine and the like are exemplified. As the arylsulfonyloxy
group, a pentafluorophenylsulfonyloxy group, p-toluenesulfonyloxy
group and the like are exemplified, and as the alkylsulfonyloxy
group, a methanesulfonyloxy group, trifluoromethanesulfonyloxy
group and the like are exemplified.
[0136] Of them, preferable is the complex wherein when energies of
the singlet state and the triplet state of the complex of the
formula (8) in which all Xs represent a hydrogen atom are
calculated by a B3LYP method, the different between the energies of
the singlet state and the triplet state is 6 eV or less. This
difference is preferably 4 eV or less, further preferably 2 eV or
less.
[0137] Particularly, complexes of the general formula (9) is
preferable.
M'(Ar').sub.q(L')r (9)
In the formula, M' represents an iridium atom, platinum atom or
gold atom. Ar's are the same or different and represent a bidentate
ligand forming a 5-membered ring by bonding to M', via a nitrogen
atom and carbon atom, the bidentate ligand containing at least one
bromine atom. L' s each independently represent a hydrogen atom,
alkyl group, aryl group, heterocyclic compound group, hydrocarbon
group having 1 to 10 carbon atoms, carboxylate group having 1 to 10
carbon atoms, diketonate group having 1 to 10 carbon atoms, halogen
atom, amide group, imide group, alkoxide group, alkylmercapto
group, carbonyl ligand, arylene ligand, alkene ligand, alkyne
ligand, amine ligand, imine ligand, nitrile ligand, isonitrile
ligand, phosphine ligand, phosphine oxide ligand, phosphite ligand,
ether ligand, sulfone ligand, sulfoxide ligand or sulfide ligand. q
represents an integer of 1 to 3. r represents an integer of 0 to
2.
[0138] Specific examples of the ligand Ar' of the complex of the
general formula (9) include, when represented in the form (Ar'H) in
which a hydrogen atom is added to a carbon atom bonded to [0139] M,
2-m-bromophenylpyridine, [0140] 2-(m-bromo-p-phenylphenyl)pyridine,
[0141] 7-bromobenzo[h]quinoline, [0142]
2-(5-bromo-4-thiophen-2-yl)pyridine, [0143]
2-(5-bromo-4-phenylthiophen-2-yl)pyridine, [0144]
2-m-bromophenylbenzooxazole, [0145]
2-(m-bromo-p-phenylphenyl)benzooxazole, [0146]
2-m-bromophenylbenzothiazole, [0147]
2-(m-bromo-p-phenylphenyl)benzothiazole, [0148]
2-(6-bromobenzothiophen-2-yl)pyridine, [0149]
2-bromo-7,8,12,13,17,18-hexakisethyl-21H,23H-porphyrin, [0150]
6-bromo-1,10-phenanethroline, [0151]
benzoyl-p-bromobenzoyl-methane, [0152]
(4-bromothenoyl)trifluoroacetone and the like, and preferable are
2-m-bromophenylpyridine, 7-bromobenzo[h]quinoline,
2-m-bromophenylbenzooxazole, 2-m-bromophenylbenzothiazole and the
like.
[0153] The ligand Ar' of the complex of the general formula (9) may
have a substituent such as a halogen atom, alkyl group, alkenyl
group, aralkyl group, arylthio group, arylalkenyl group, cyclic
alkenyl group, alkoxy group, aryloxy group, alkyloxycarbonyl group,
aralkyloxycarbonyl group, aryl group and the like.
[0154] Specific examples of the substituent represented by Ar' are
as follows.
[0155] As the halogen atom, a fluorine atom, chlorine atom, bromine
atom, iodine atom and the like are listed, as the alkyl group, a
methyl, ethyl group, n-propyl group, isopropyl group, n-butyl
group, isobutyl group, t-butyl group, n-amyl group, neopentyl
group, n-hexyl group, cyclohexyl group, n-octyl group, n-nonyl
group, 2,3,4-trimethyl-3-pentyl group, 2,4-dimethyl-3-pentyl group
and the like are listed, as the alkenyl group, a
2-methyl-1-propenyl group, 2-butenyl group and the like are listed,
as the aralkyl group, a benzyl group, 2-phenylethyl group,
2-naphtylethyl group, diphenylmethyl group and the like are listed,
as the arylthio group, a thiophenyl group and the like are listed,
as the arylalkenyl group, a trans (3 styryl group,
3-phenyl-1-propenyl group and the like are listed, as the cyclic
alkenyl group, a 1-cyclohecenyl group and the like are listed, as
the alkoxy group, a methoxy group, ethoxy group, n-propoxy group,
t-butoxy group and the like are listed, as the aryloxy group, a
phenoxy group, naphthyloxy group, diphenyloxy group and the like
are listed, as the alkyloxycarbonyl group, a methoxycarbonyl group,
ethoxycarbonyl group, t-butyloxycarbonyl group, as the
aralkyloxycarbonyl group, a benzyloxycarbonyl group and the like
are listed, as the aryloxycarbonyl group, a phenyloxycarbonyl and
the like are listed, and as the aryl group, a phenyl group,
naphthyl group, biphenyl group, furyl group and the like are
listed, respectively.
[0156] The above-mentioned substituents other than halogen atoms
may be substituted with, for example, halogen atoms such as a
fluorine atom, chlorine atom, bromine atom, iodine atom and the
like; alkoxy groups such as a methoxy group, ethoxy group,
n-propoxy group, t-butoxy group and the like; aryloxy groups such
as a phenoxy group and the like; lower alkyl groups such as a
methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl
group, isobutyl group, t-butyl group, n-amyl group, neopentyl
group, n-hexyl group and the like; lower alkylthio groups such as a
n-propylthio group, t-butylthio group and the like; arylthio groups
such as a phenylthio group, and a nitro group, hydroxyl group and
the like.
[0157] The hydrocarbon group having 1 to 10 carbon atoms
represented by L in the general formula (8) and L' in the general
formula (9) is not particularly restricted, and examples thereof
include a methyl group, ethyl group, propyl group, butyl group,
cyclohexyl group, benzyl group, phenyl group and the like. The
carboxylate group having 1 to 10 carbon atoms is not particularly
restricted, and examples thereof include an acetate group,
naphthenate group, 2-ethylhexanoate group and the like. As the
diketonate group having 1 to 10 carbon atoms is not particularly
restricted, and examples thereof include an acetylacetonate group
and the like. The halogen atom is not particularly restricted, and
examples thereof include a fluorine atom, chlorine atom, bromine
atom, iodine atom and the like. The amide group is not particularly
restricted, and examples thereof include a dimethylamide group,
diethylamide group, diisopropylamide group, dioctylamide group,
didecylamide group, didodecylamide group, bis(trimethylsilyl)amide
group, diphenylamide group, N-methylanilide, anilide group and the
like. The imide group is not particularly restricted, and examples
thereof include a benzophenoneimide and the like. The alkoxy group
is not particularly restricted, and examples thereof include a
methoxide group, ethoxide group, propoxide group, butoxide group,
phenoxide group and the like. The alkylmercapto group is not
particularly restricted, and examples thereof include a
methylmercapto group, ethylmercapto group, propylmercapto group,
butylmercapto group, phenylmercapto group and the like. The arylene
group is not particularly restricted, and examples thereof include
benzene, toluene, xylene, trimethylbenzene, hexamethylbenzene,
naphthalene and the like. The alkene ligand is not particularly
restricted, and examples thereof include ethylene, propylene,
butene, hexene, decene and the like. The alkyne ligand is not
particularly restricted, and examples thereof include acetylene,
phenylacetylene, diophenylacetylene and the like. The amine ligand
is not particularly restricted, and examples thereof include
triethylamine, tributylamine and the like. The imine ligand is not
particularly restricted, and examples thereof include a
benzophenoneimine, methylethylimine and the like. The nitrile
ligand is not particularly restricted, and examples thereof include
acetonitrile, benzonitrile and the like. The isonitrile is not
particularly restricted, and examples thereof include
t-butylisonitrile, phenylisonitrile and the like. The phosphine
ligand is not particularly restricted, and examples thereof include
triphenylphosphine, tritolyiphosphine, tricyclohexylphosphine,
tributylphosphine and the like. The phosphine oxide ligand is not
particularly restricted, and examples thereof include
tributylphosphine oxide, triphenylphosphine oxide and the like. The
phosphite ligand is not particularly restricted, and examples
thereof include triphenylphosphite, tritolylphosphite,
tributylphosphite, triethylphosphite and the like. The ether ligand
is not particularly restricted, and examples thereof include
dimethyl ether, diethylether, tetrahydrofuran and the like. The
sulfone ligand is not particularly restricted, and examples thereof
include dimethylsulfone, dibutylsulfone and the like. The sulfoxide
ligand is not particularly restricted, and examples thereof include
dimethylsulfoxide, dibutylsulfoxide and the like. The sulfide
ligand is not particularly restricted, and examples thereof include
ethyl sulfide, butyl sulfide and the like.
[0158] Specific examples of the complex (9) of the present
invention include, regarding those containing an iridium atom as a
center metal M' for example, tris(2-m-bromophenylpyridine)iridium
(III), bis(2-m-bromophenylpyridine)(phenylpyridine)iridium (III),
(2-m-bromophenylpyridine)di(phenylpyridine)iridium (III),
bis(7-bromobenzo[h]quinoline)acetylacetonate iridium (III),
bis{2-(5-bromothiophen-2-yl)pyridine}acetylacetonate iridium (III),
[0159] bis(2-(3-bromophenyl)benzooxazole)acetylacetonate iridium
(III), bis(2-(3-bromophenyl)benzothiazole)acetylacetonate iridium
(III), [0160]
bis{2-(5-bromobenzothiophen-2-yl)pyridine}acetylacetonate iridium
(III) and the like.
[0161] Examples of the complex (3) of the present invention
include, regarding those containing a platinum atom as a center
metal M', bis(2-m-bromophenylpyridine)platinum(II), [0162]
(2-m-bromophenylpyridine)(phenylpyridine)platinum (II), [0163]
(7-bromobenzo[h]quinoline)acetylacetonate platinum(II), [0164]
{2-(5-bromothiophen-2-yl)pyridine}acetylacetonate platinum (II),
(2-(3-bromophenyl)benzooxazole)acetylacetonate platinum (II),
[0165] (2-(3-bromophenyl)benzothiazole)acetylacetonate platinum
(II), [0166] (2-(5-bromobenzothiophen-2-yl)pyridine)acetylacetonate
platinum (II) and the like.
[0167] Examples of the complex (3) of the present invention
include, regarding those containing a gold atom as a center metal
M', [0168] tris(2-m-bromophenylpyridine)(phenylpyridine)gold (III),
[0169] bis(2-m-bromophenylpyridine)(phenylpyridine) gold (III),
[0170] (2-m-bromophenylpyridine)di(phenylpyridine) gold (III),
[0171] bis(7-bromobenzo[h]quinoline)acetylacetonate gold (III),
[0172] bis{2-(5-bromothiophen-2-yl)pyridine}acetylacetonate gold
(III), bis(2-(3-bromophenyl)benzooxazole)acetylacetoante gold
(III), [0173] bis(2-(3-bromophenyl)benzothiazole)acetylacetonate
gold (III), [0174]
bis(2-(5-bromobenzothiophen-2-yl)pyridine)acetylacetonate gold
(III) and the like.
[0175] Examples of the complex (3) of the present invention
include, regarding those containing an europium atom as a center
metal M', [0176]
(6-bromo-1,10-phenanethroline)tris(dibenzoylmethane)europium (III),
[0177] (6-bromo-1,10-phenanathroline)tris[(4-bromothenoyl)trifluo
roacetone]europium (III), and the like.
[0178] Of them, those in which Ar' is a bidentate ligand of the
general formula (10) and r is 0 are preferable, those in which one
or more of R.sup.21 to R.sup.28 represent a bromine atom are more
preferable, those in which R.sup.23 represents a bromine atom and
other groups represent a hydrogen atom are particularly
preferable.
##STR00042##
In the formula, R.sup.21 to R.sup.28 each independently represent a
hydrogen atom, halogen atom, alkyl group, alkenyl group, aralkyl
group, arylthio group, arylalkenyl group, cyclic alkenyl group,
alkoxy group, aryloxy group, alkyloxycarbonyl group,
aralkyloxycarbonyl group, aryloxycarbonyl group, or aryl group. At
least one of R.sup.21 to R.sup.28 represents a bromine atom.
[0179] Specific examples of, R.sup.21 to R.sup.28 are the same as
the concrete examples of the substituent on the ligand Ar' of a
complex of the formula (9) describe above.
[0180] The method of producing a complex of the present invention
will be described using a method of producing a complex of the
general formula (9).
[0181] The complex of the general formula (9) can be produced by
reacting a complex of the general formula (11):
M'-(L')s (11)
(L' has the same meaning as for L' in the formula (9). s represents
an integer of 0 to 3) with a compound of the general formula
(12):
Ar'H (12)
(Ar' has the same meaning as for Ar' in the formula (9). Ar'H means
that a hydrogen atom is added to a carbon atom bonded to M' in
Ar'.).
[0182] As L', ligands providing a smooth interchange reaction are
preferable, such as carboxylate, diketonate group, amide group,
imide group, carbonyl ligand, arylene ligand, alkene ligand, alkyne
ligand, imine ligand, nitrile ligand, ether ligand, sulfone ligand,
sulfoxide ligand, sulfide ligand and the like, since they are
bonded to a center metal relatively weakly.
[0183] As the above-mentioned Ar'H, commercially available reagents
may be used, alternatively, Ar'H may be produced by a known
method.
[0184] In the production method of the present invention, the ratio
of the amount of the complex (11) to the amount of the ligand (12)
is about from 1/0.5 to 1/10 (=complex/ligand) by mol, though it
varies depending on the intended complex prepared.
[0185] The reaction is usually conducted in a solvent. As the
solvent, for example, ether-based solvents such as diethyl ether,
tetrahydrofuran, tertiary butyl methyl ether, dioxane, and the
like; hydrocarbon-based solvents such as hexane, cyclohexane,
toluene, xylene and the like; ester-based solvents such as ethyl
acetate, methyl propionate and the like, halogen-based solvents
such as dichloromethane, chloroform, 1,2-dichloroethane and the
like, ketone-based, solvents such as acetone, methyl isobutyl
ketone, diethyl ketone and the like, and alcohol-based solvents
such as ethanol, butanol, ethylene glycol, glycerin and the like,
are used. The used amount of the solvent is not particularly
restricted, and usually, from 10 to 500-fold by weight based on the
total amount of complexes and ligands which are raw materials.
[0186] The reaction temperature is not particularly restricted, and
usually from about 50 to 350.degree. C. The reaction time is not
particularly restricted, and usually from about 30 minutes to 30
hours.
[0187] In the synthesis operation, a solvent is poured into a
flask, and the atmosphere in the flask was deaerated with an inert
gas, for example, a nitrogen gas or argon gas, according to
bubbling and the like, while stirring the solvent, then, a complex
(11) and a ligand (12) are added. The reaction solution is heated,
to a temperature at which ligand exchange occurs, while stirring
under an inner gas atmosphere, and the mixture is heat-insulated
and stirring. The completion of the reaction can be determined by
stop of decrease in the raw materials by TLC monitor and high
performance liquid chromatography, or disappearance of one of the
raw materials.
[0188] Removal of the intended substance from the reaction mixture
and purification thereof differ depending on the complex, and
usually complex purification means are used.
[0189] For example, a 1 N aqueous hydrochloric acid solution which
is a poor solvent for a complex is added to cause precipitation of
the complex, and this is removed by filtration and this solid is
dissolved in an organic solvent such as dichloromethane, chloroform
and the like. This solution is filtrated to remove insoluble
substances, and concentrated again, and subjected to purification
by silica gel column chromatography (dichloromethane elution), and
intended fraction solutions are collected, and to this is added,
for example, a suitable amount of methanol (poor solvent), and the
mixture is concentrated to precipitate the intended complex which
if filtrated and dried to obtain a complex. The method of producing
a complex (9) or (10) is not restricted to the above-mentioned
method.
[0190] A polymeric light emitting substance can be produced by
using the complex of the present invention as a monomer.
[0191] Next, the polymer LED of the present invention will be
illustrated. The polymer LED of the present invention is a polymer
LED comprising at least a light emitting layer between a pair of
electrodes composed of an anode and a cathode at least one of which
is transparent or semi-transparent wherein the light emitting layer
contains a polymeric light emitting substance of the present
invention.
[0192] As the polymer LED of the present invention, there are
listed polymer LEDs having an electron transporting layer disposed
between a cathode and a light emitting layer, polymer LEDs having a
hole transporting layer disposed between an anode and a light
emitting layer, polymer LEDs having an electron transporting layer
disposed between a cathode and a light emitting layer and having a
hole transporting layer disposed between an anode and a light
emitting layer.
[0193] There are listed polymer LEDs having an electron conductive
polymer layer disposed between at least either one of the
electrodes and a light emitting layer in adjacent with the
electrode; and LEDs having a buffer layer having an average
thickness of 2 nm or less, disposed between at least either one of
the electrodes and a light emitting layer in adjacent with the
electrode.
[0194] For example, the following structures a) to d) are
specifically exemplified.
[0195] a) anode/light emitting layer/cathode
[0196] b) anode/hole transporting layer/light emitting
layer/cathode
[0197] c) anode/light emitting layer/electron transporting
layer/cathode
[0198] d) anode/hole transporting layer/light emitting
layer/electron transporting layer/cathode
(wherein, "/" indicates adjacent lamination of layers. Hereinafter,
the same.)
[0199] Herein, the light emitting layer is a layer having function
to emit a light, the hole transporting layer is a layer having
function to transport a hole, and the electron transporting layer
is a layer having function to transport an electron.
[0200] Herein, the electron transporting layer and the hole
transporting layer are generically called a charge transporting
layer.
[0201] The light emitting layer, hole transporting layer and
electron transporting layer may also each independently used in two
or more layers.
[0202] Of charge transporting layers disposed adjacent to an
electrode, that having function to improve charge injecting
efficiency from the electrode and having effect to decrease driving
voltage of an device are particularly called sometimes a charge
injecting layer (hole injecting layer, electron injecting layer) in
general.
[0203] For enhancing adherence with an electrode and improving
charge injection from an electrode, the above-described charge
injecting layer or insulation layer having a thickness of 2 nm or
less may also be provided adjacent to an electrode, and further,
for enhancing adherence of the interface, preventing mixing and the
like, a thin buffer layer may also be inserted into the interface
of a charge transporting layer and light emitting layer.
[0204] The order and number of layers laminated and the thickness
of each layer can be appropriately applied while considering light
emitting efficiency and life of the device.
[0205] In the present invention, as the polymer LED having a charge
injecting layer (electron injecting layer, hole injecting layer)
provided, there are listed a polymer LED having a charge injecting
layer provided adjacent to a cathode and a polymer LED having a
charge injecting layer provided adjacent to an anode.
[0206] For example, the following structures e) to p) are
specifically exemplified.
[0207] e) anode/charge injecting layer/light emitting
layer/cathode
[0208] f) anode/light emitting layer/charge injecting
layer/cathode
[0209] g) anode/charge injecting layer/light emitting layer/charge
injecting layer/cathode
[0210] h) anode/charge injecting layer/hole transporting
layer/light emitting layer/cathode
[0211] i) anode/hole transporting layer/light emitting layer/charge
injecting layer/cathode
[0212] j) anode/charge injecting layer/hole transporting
layer/light emitting layer/charge injecting layer/cathode
[0213] k) anode/charge injecting layer/light emitting
layer/electron transporting layer/cathode
[0214] l) anode/light emitting layer/electron transporting
layer/charge injecting layer/cathode
[0215] m) anode/charge injecting layer/light emitting
layer/electron transporting layer/charge injecting
layer/cathode
[0216] n) anode/charge injecting layer/hole transporting
layer/light emitting layer/electron transporting layer/cathode
[0217] o) anode/hole transporting layer/light emitting
layer/electron transporting layer/charge injecting
layer/cathode
[0218] p) anode/charge injecting layer/hole transporting
layer/light emitting layer/electron transporting layer/charge
injecting layer/cathode
[0219] As the specific examples of the charge injecting layer,
there are exemplified layers containing an conducting polymer,
layers which are disposed between an anode and a hole transporting
layer and contain a material having an ionization potential between
the ionization potential of an anode material and the ionization
potential of a hole transporting material contained in the hole
transporting layer, layers which are disposed between a cathode and
an electron transporting layer and contain a material having an
electron affinity between the electron affinity of a cathode
material and the electron affinity of an electron transporting
material contained in the electron transporting layer, and the
like.
[0220] When the above-described charge injecting layer is a layer
containing an conducting polymer, the electric conductivity of the
conducting polymer is preferably 10.sup.-5 S/cm or more and
10.sup.3 S/cm or less, and for decreasing the leak current between
light emitting pixels, more preferably 10.sup.-5 S/cm or more and
10.sup.2 S/cm or less, further preferably 10.sup.-5 S/cm or more
and 10.sup.1 S/cm or less.
[0221] Usually, to provide an electric conductivity of the
conducting polymer of 10.sup.-5 S/cm or more and 10.sup.3 S/cm or
less, a suitable amount of ions are doped into the conducting
polymer.
[0222] Regarding the kind of an ion doped, an anion is used in a
hole injecting layer and a cation is used in an electron injecting
layer. As examples of the anion, a polystyrene sulfonate ion,
alkylbenzene sulfonate ion, camphor sulfonate ion and the like are
exemplified, and as examples of the cation, a lithium ion, sodium
ion, potassium ion, tetrabutyl ammonium ion and the like are
exemplified.
[0223] The thickness of the charge injecting layer is for example,
from 1 nm to 100 nm, preferably from 2 nm to 50 nm.
[0224] Materials used in the charge injecting layer may properly be
selected in view of relation with the materials of electrode and
adjacent layers, and there are exemplified conducting polymers such
as polyaniline and derivatives thereof, polythiophene and
derivatives thereof, polypyrrole and derivatives thereof,
poly(phenylene vinylene) and derivatives thereof, poly(thienylene
vinylene) and derivatives thereof, polyquinoline and derivatives
thereof, polyquinoxaline and derivatives thereof, polymers
containing aromatic amine structures in the main chain or the side
chain, and the like, and metal phthalocyanine (copper
phthalocyanine and the like), carbon and the like.
[0225] The insulation layer having a thickness of 2 nm or, less has
function to make charge injection easy. As the material of the
above-described insulation layer, metal fluoride, metal oxide,
organic insulation materials and the like are listed. As the
polymer LED having an insulation layer having a thickness of 2 nm
or less, there are listed polymer LEDs having an insulation layer
having a thickness of 2 nm or less provided adjacent to a cathode,
and polymer LEDs having an insulation layer having a thickness of 2
nm or less provided adjacent to an anode.
[0226] Specifically, there are listed the following structures q)
to ab) for example.
[0227] q) anode/insulation layer having a thickness of 2 nm or
less/light emitting layer/cathode
[0228] r) anode/light emitting layer/insulation layer having a
thickness of 2 nm or less/cathode
[0229] s) anode/insulation layer having a thickness of 2 nm or
less/light emitting layer/insulation layer having a thickness of 2
nm or less/cathode
[0230] t) anode/insulation layer having a thickness of 2 nm or
less/hole transporting layer/light emitting layer/cathode
[0231] u) anode/hole transporting layer/light emitting
layer/insulation layer having a thickness of 2 nm or
less/cathode
[0232] v) anode/insulation layer having a thickness of 2 nm or
less/hole transporting layer/light emitting layer/insulation layer
having a thickness of 2 nm or less/cathode
[0233] w) anode/insulation layer having a thickness of 2 nm or
less/light emitting layer/electron transporting layer/cathode
[0234] x) anode/light emitting layer/electron transporting
layer/insulation layer having a thickness of 2 nm or
less/cathode
[0235] y) anode/insulation layer having a thickness of 2 nm or
less/light emitting layer/electron transporting layer/insulation
layer having a thickness of 2 nm or less/cathode
[0236] z) anode/insulation layer having a thickness of 2 nm or
less/hole transporting layer/light emitting layer/electron
transporting layer/cathode
[0237] aa) anode/hole transporting layer/light emitting
layer/electron transporting layer/insulation layer having a
thickness of 2 nm or less/cathode
[0238] ab) anode/insulation layer having a thickness of 2 nm or
less/hole transporting layer/light emitting layer/electron
transporting layer/insulation layer having a thickness of 2 nm or
less/cathode
[0239] In producing a polymer LED, when a film is formed from a
solution by using such polymeric light emitting substance soluble
in an organic solvent, only required is removal of the solvent by
drying after coating of this solution, and even in the case of
mixing of a charge transporting material and a light emitting
material, the same method can be applied, causing an extreme
advantage in production. As the film forming method from a
solution, there can be used coating methods such as a spin coating
method, casting method, micro gravure coating method, gravure
coating method, bar coating method, roll coating method, wire bar
coating method, dip coating method, spay coating method, screen
printing method, flexo printing method, offset printing method,
inkjet printing method and the like.
[0240] Regarding the thickness of the light emitting layer, the
optimum value differs depending on material used, and may properly
be selected so that the driving voltage and the light emitting
efficiency become optimum values, and for example, it is from 1 nm
to 1 .mu.m, preferably from 2 nm to 500 nm, further preferably from
5 nm to 200 nm.
[0241] In the polymer LED of the present invention, alight emitting
material other than the above-mentioned polymeric light emitting
substances may be mixed in a light emitting layer. Further, in the
polymer LED according to the instant application, a light emitting
layer containing a light emitting material other than the
above-mentioned polymeric light emitting substance may be laminated
with a light emitting layer containing the above-mentioned
polymeric light emitting substance.
[0242] As the light emitting material, known materials can be used.
In a compound having lower molecular weight, there can be used, for
example, naphthalene derivatives, anthracene or derivatives
thereof, perylene or derivatives thereof; dyes such as polymethine
dyes, xanthene dyes, coumarine dyes, cyanine dyes; metal complexes
of 8-hydroxyquinoline or derivatives thereof, aromatic amine,
tetraphenylcyclopentane or derivatives thereof, or
tetraphenylbutadiene or derivatives thereof, and the like.
[0243] Specifically, there can be used known compounds such as
those described in JP-A Nos. 57-51781, 59-195393 and the like, for
example.
[0244] When the polymer LED of the present invention has a hole
transporting layer, as the hole transporting materials used, there
are exemplified polyvinylcarbazole or derivatives thereof,
polysilane or derivatives thereof, polysiloxane derivatives having
an aromatic amine in the side chain or the main chain, pyrazoline
derivatives, arylamine derivatives, stilbene derivatives,
triphenyldiamine derivatives, polyaniline or derivatives thereof,
polythiophene or derivatives thereof, polypyrrole or derivatives
thereof, poly(p-phenylenevinylene) or derivatives thereof,
poly(2,5-thienylenevinylene) or derivatives thereof, or the
like.
[0245] Specific examples of the hole transporting material include
those described in JP-A Nos. 63-70257, 63-175860, 2-135359,
2-135361, 2-209988, 3-37992 and 3-152184.
[0246] Among them, as the hole transporting materials used in the
hole transporting layer, preferable are polymer hole transporting
materials such as polyvinylcarbazole or derivatives thereof,
polysilane or derivatives thereof, polysiloxane derivatives having
an aromatic amine compound group in the side chain or the main
chain, polyaniline or derivatives thereof, polythiophene or
derivatives thereof, poly(p-phenylenevinylene) or derivatives
thereof, poly(2,5-thienylenevinylene) or derivatives thereof, or
the like, and further preferable are polyvinylcarbazole or
derivatives thereof, polysilane or derivatives thereof and
polysiloxane derivatives having an aromatic amine compound group in
the side chain or the main chain. In the case of a hole
transporting material having lower molecular weight, it is
preferably dispersed in a polymer binder for use.
[0247] Polyvinylcarbazole or derivatives thereof are obtained, for
example, by cation polymerization or radical polymerization from a
vinyl monomer.
[0248] As the polysilane or derivatives thereof, there are
exemplified compounds described in Chem. Rev., 89, 1359 (1989) and
GB 2300196 published specification, and the like. For synthesis,
methods described in them can be used, and a Kipping method can be
suitably used particularly.
[0249] As the polysiloxane or derivatives thereof, those having the
structure of the above-described hole transporting material having
lower molecular weight in the side chain or main chain, since the
siloxane skeleton structure has poor hole transporting property.
Particularly, there are exemplified those having an aromatic amine
having hole transporting property in the side chain or main
chain.
[0250] The method for forming a hole transporting layer is not
restricted, and in the case of a hole transporting layer having
lower molecular weight, a method in which the layer is formed from
a mixed solution with a polymer binder is exemplified. In the case
of a polymer hole transporting material, a method in which the
layer is formed from a solution is exemplified.
[0251] The solvent used for the film forming from a solution is not
particularly restricted providing it can dissolve a hole
transporting material. As the solvent, there are exemplified
chlorine solvents such as chloroform, methylene chloride,
dichloroethane and the like, ether solvents such as tetrahydrofuran
and the like, aromatic hydrocarbon solvents such as toluene, xylene
and the like, ketone solvents such as acetone, methyl ethyl ketone
and the like, and ester solvents such as ethyl acetate, butyl
acetate, ethylcellosolve acetate and the like.
[0252] As the film forming method from a solution, there can be
used coating methods such as a spin coating method, casting method,
micro gravure coating method, gravure coating method, bar coating
method, roll coating method, wire bar coating method, dip coating
method, spray coating method, screen printing method, flexo
printing method, offset printing method, inkjet printing method and
the like, from a solution.
[0253] The polymer binder mixed is preferably that does not disturb
charge transport extremely, and that does not have strong
absorption of a visible light is suitably used. As such polymer
binder, polycarbonate, polyacrylate, poly(methyl acrylate),
poly(methyl methacrylate), polystyrene, poly(vinyl chloride),
polysiloxane and the like are exemplified.
[0254] Regarding the thickness of the hole transporting layer, the
optimum value differs depending on material used, and may properly
be selected so that the driving voltage and the light emitting
efficiency become optimum values, and at least a thickness at which
no pin hole is produced is necessary, and too large thickness is
not preferable since the driving voltage of the device increases.
Therefore, the thickness of the hole transporting layer is, for
example, from 1 nm to 1 .mu.m, preferably from 2 nm to 500 nm,
further preferably from 5 nm to 200 nm.
[0255] When the polymer LED of the present invention has an
electron transporting layer, known compounds are used as the
electron transporting materials, and there are exemplified
oxadiazole derivatives, anthraquinonedimethane or derivatives
thereof, benzoquinone or derivatives thereof, naphthoquinone or
derivatives thereof, anthraquinone or derivatives thereof,
tetracyanoanthraquinodimethane or derivatives thereof, fluorenone
derivatives, diphenyldicyanoethylene or derivatives thereof,
diphenoquinone derivatives, or metal complexes of
8-hydroxyquinoline or derivatives thereof, polyquinoline and
derivatives thereof, polyquinoxaline and derivatives thereof,
polyfluorene or derivatives thereof, and the like.
[0256] Specifically, there are exemplified those described in JP-A
Nos. 63-70257, 63-175860, 2-135359, 2-135361, 2-209988, 3-37992 and
3-152184.
[0257] Among them, oxadiazole derivatives, benzoquinone or
derivatives thereof, anthraquinone or derivatives thereof, or metal
complexes of 8-hydroxyquinoline or derivatives thereof,
polyquinoline and derivatives thereof, polyquinoxaline and
derivatives thereof, polyfluorene or derivatives thereof are
preferable, and
2-(4-biphenyl)-5-(4-t-butylphenyl)-1,3,4-oxadiazole, benzoquinone,
anthraquinone, tris(8-quinolinol) aluminum and polyquinoline are
further preferable.
[0258] The method for forming the electron transporting layer is
not particularly restricted, and in the case of an electron
transporting material having lower molecular weight, a vapor
deposition method from a powder, or a method of film-forming from a
solution or melted state is exemplified, and in the case of a
polymer electron transporting material, a method of film-forming
from a solution or melted state is exemplified, respectively. When
film-forming is conducted from a solution or melted state, a
polymer binder may be used together.
[0259] The solvent used in the film-forming from a solution is not
particularly restricted provided it can dissolve electron
transporting materials and/or polymer binders. As the solvent,
there are exemplified chlorine solvents such as chloroform,
methylene chloride, dichloroethane and the like, ether solvents
such as tetrahydrofuran and the like, aromatic hydrocarbon solvents
such as toluene, xylene and the like, ketone solvents such as
acetone, methyl ethyl ketone and the like, and ester solvents such
as ethyl acetate, butyl acetate, ethylcellosolve acetate and the
like.
[0260] As the film-forming method from a solution or melted state,
there can be used coating methods such as a spin coating method,
casting method, micro gravure coating method, gravure coating
method, bar coating method, roll coating method, wire bar coating
method, dip coating method, spray coating method, screen printing
method, flexo printing method, offset printing method, inkjet
printing method and the like.
[0261] The polymer binder to be mixed is preferably that which does
not extremely disturb a charge transport property, and that does
not have strong absorption of a visible light is suitably used. As
such polymer binder, poly(N-vinylcarbazole), polyaniline or
derivatives thereof, polythiophene or derivatives thereof,
poly(p-phenylene vinylene) or derivatives thereof,
poly(2,5-thienylene vinylene) or derivatives thereof,
polycarbonate, polyacrylate, poly(methyl acrylate), poly(methyl
methacrylate), polystyrene, poly(vinyl chloride), polysiloxane and
the like are exemplified.
[0262] Regarding the thickness of the electron transporting layer,
the optimum value differs depending on material used, and may
properly be selected so that the driving voltage and the light
emitting efficiency become optimum values, and at least a thickness
at which no pin hole is produced is necessary, and too large
thickness is not preferable since the driving voltage of the device
increases. Therefore, the thickness of the electron transporting
layer is, for example, from 1 nm to 1 .mu.m, preferably from 2 nm
to 500 nm, further preferably from 5 nm to 200 nm.
[0263] The substrate forming the polymer LED of the present
invention may preferably be that does not change in forming an
electrode and layers of organic materials, and there are
exemplified glass, plastics, polymer film, silicon substrates and
the like. In the case of a opaque substrate, it is preferable that
the opposite electrode is transparent or semitransparent.
[0264] In the present invention, it is preferable that an anode is
transparent or semitransparent, and as the material of this anode,
electron conductive metal oxide films, semitransparent metal thin
films and the like are used. Specifically, there are used indium
oxide, zinc oxide, tin oxide, and films (NESA and the like)
fabricated by using an electron conductive glass composed of
indium.tin.oxide (ITO), indium.zinc.oxide and the like, which are
metal oxide complexes, and gold, platinum, silver, copper and the
like are used, and among them, ITO, indium.zinc.oxide, tin oxide
are preferable. As the fabricating method, a vacuum vapor
deposition method, sputtering method, ion plating method, plating
method and the like are used. As the anode, there may also be used
organic transparent conducting films such as polyaniline or
derivatives thereof, polythiophene or derivatives thereof and the
like.
[0265] The thickness of the anode can be appropriately selected
while considering transmission of a light and electric
conductivity, and for example, from 10 nm to 10 .mu.m, preferably
from 20 nm to 1 .mu.m, further preferably from 50 nm to 500 nm.
[0266] Further, for easy charge injection, there may be provided on
the anode a layer comprising a phthalocyanine derivative conducting
polymers, carbon and the like, or a layer having an average film
thickness of 2 nm or less comprising a metal oxide, metal fluoride,
organic insulating material and the like.
[0267] As the material of a cathode used in the polymer LED of the
present invention, that having lower work function is preferable.
For example, there are used metals such as lithium, sodium,
potassium, rubidium, cesium, beryllium, magnesium, calcium,
strontium, barium, aluminum, scandium, vanadium, zinc, yttrium,
indium, cerium, samarium, europium, terbium, ytterbium and the
like, or alloys comprising two of more of them, or alloys
comprising one or more of them with one or more of gold, silver,
platinum, copper, manganese, titanium, cobalt, nickel, tungsten and
tin, graphite or graphite intercalation compounds and the like.
Examples of alloys include a magnesium-silver alloy,
magnesium-indium alloy, magnesium-aluminum alloy, indium-silver
alloy, lithium-aluminum alloy, lithium-magnesium alloy,
lithium-indium alloy, calcium-aluminum alloy and the like. The
cathode may be formed into a laminated structure of two or more
layers.
[0268] The film thickness of a cathode can be appropriately
selected in view of electric conductivity and durability, and for
example, it is from 10 nm to 10 .mu.m, preferably from 20 nm to 1
.mu.m, further preferably from 50 nm to 500 nm.
[0269] As the method for fabricating a cathode, there are used a
vacuum vapor deposition method, sputtering method, lamination
method in which a metal thin film is adhered under heat and
pressure, and the like. Further, there may also be provided,
between a cathode and an organic layer, a layer comprising an
conducting polymer, or a layer having an average film thickness of
2 nm or less comprising a metal oxide, metal fluoride, organic
insulation material and the like, and after fabrication of the
cathode, a protective layer may also be provided which protects the
polymer LED. For stable use of the polymer LED for a long period of
time, it is preferable to provide a protective layer and/or
protective cover for protection of the device in order to prevent
it from outside damage.
[0270] As the protective layer, there can be used a polymer
compound, metal oxide, metal fluoride, metal borate and the like.
As the protective cover, there can be used a glass plate, a plastic
plate the surface of which has been subjected to
lower-water-permeation treatment, and the like, and there is
suitably used a method in which the cover is pasted with an device
substrate by a thermosetting resin or light-curing resin for
sealing. If space is maintained using a spacer, it is easy to
prevent an device from being injured. If an inner gas such as
nitrogen and argon is sealed in this space, it is possible to
prevent oxidation of a cathode, and further, by placing a desiccant
such as barium oxide and the like in the above-described space, it
is easy to suppress the damage of an device by moisture adhered in
the production process. Among them, any one means or more are
preferably adopted.
[0271] For obtaining light emission in plane form using the polymer
LED of the present invention, an anode and a cathode in the plane
form may properly be placed so that they are laminated each other.
Further, for obtaining light emission in pattern form, there are a
method in which a mask with a window in pattern form is placed on
the above-described plane light emitting device, a method in which
an organic layer in non-light emission part is formed to obtain
extremely large thickness providing substantial non-light emission,
and a method in which any one of an anode or a cathode, or both of
them are formed in the pattern. By forming a pattern by any of
these methods and by placing some electrodes so that independent
on/off is possible, there is obtained a display device of segment
type which can display digits, letters, simple marks and the like.
Further, for forming a dot matrix device, it may be advantageous
that anodes and cathodes are made in the form of stripes and placed
so that they cross at right angles. By a method in which a
plurality of kinds of polymeric light emitting substances emitting
different colors of lights are placed separately or a method in
which a color filter or luminescence converting filter is used,
area color displays and multi color displays are obtained. A dot
matrix display can be driven by passive driving, or by active
driving combined with TFT and the like. These display devices can
be used as a display of a computer, television, portable terminal,
portable telephone, car navigation, view finder of a video camera,
and the like.
[0272] Further, the above-described light emitting device in plane
form is a thin self-light-emitting one, and can be suitably used as
a flat light source for back-light of a liquid crystal display, or
as a flat light source for illumination. Further, if a flexible
plate is used, it can also be used as a curved light source or a
display.
EXAMPLES
[0273] Examples will be shown below to explain the present
invention further in detail, but these examples do not limit the
scope of the invention.
[0274] Here, the number-average molecular weight was measured in
polystyrene-reduced number-average molecular weight by a gel
permeation chromatography (GPC) using chloroform as a solvent.
Example 1
Production of 2-(bromophenyl)pyridine
[0275] 3 g (19.3 mmol) of 2-phenylpyridine and 40 mg (0.716 mmol)
of an iron powder were mixed and stirred. 4.0 g (25 mmol) of
bromine was dropped paying attention to heat generation while
stirring and cooling the mixture to 0.degree. C., and the mixture
was heated up to 90.degree. C. and stirred for 10 hours. After
completion of the reaction, this reaction mixture was dissolved in
chloroform, and washed with a 5% aqueous sodium thiosulfate
solution. The chloroform solution was dried over sodium sulfate,
then, concentrated, and the residue was purified by silica gel
column chromatography, to obtain the intended
2-(bromophenyl)pyridine.
[0276] The yield amount was 1.6 g (6.83 mmol) and the yield was
35.4%. M+ was measured to be 234.0 by LC-MS.
<Production of tris(2-bromophenyl)pyridine)iridum (III)>
[0277] 50 mg (0.1021 mmol) of a trisacetylacetonateiridum (III)
complex and 95.6 mg (0.4084 mmol) of 2-bromophenylpyridine and 20
ml of glycol were poured into a 50 ml flask in the form of eggplant
and refluxed for 10 hours. To this reaction solution was added 100
ml of a 1 N hydrochloric acid aqueous solution, and the mixture was
stirred for 30 minutes, The precipitated solid was removed by
filtration, and dissolved again in a small amount of methylene
chloride, to give a solution. This solution was filtrated by silica
gel column chromatography, to remove excess metal decomposed
substances derived from the iridium complex. Thereafter, the
resulted solution was concentrated to the intermediate extent, and
methanol was added to this and the precipitated yellow solid was
recovered by filtration.
[0278] 10.12 mg (0.0113 mmol) of the intended substance,
tris(2-(bromophenyl) pyridine) iridium (III) was obtained. The
yield was 11.1%. M+ was measured to be 893 by FD-MS.
Example 2
Production of
bis(2-(phenyl)pyridine)mono(2-(bromophenyl)pyridine)iridium
(III)
[0279] 0.642 g (1.31 mmol) of a trisacetylacetonateiridium (III)
complex, 0.41 g (1.75 mmol) of 2-(bromophenyl)pyridine, 0.54 g (3.5
mmol) of 2-(phenyl)pyridine and 50 ml of glycol were poured into a
100 ml flask in the form of eggplant and refluxed for 10 hours. To
this reaction solution was added 100 ml of a 1 N hydrochloric acid
aqueous solution, and the mixture was stirred for 30 minutes, The
precipitated solid was removed by filtration, and dissolved again
in a small amount of methylene chloride, to give a solution. This
solution was filtrated by silica gel column chromatography, to
remove excess metal decomposed substances derived from the iridium
complex. Thereafter, the resulted solution was concentrated to the
intermediate extent, and methanol was added to this and the
precipitated yellow solid was recovered by filtration.
[0280] 0.13 g (0.177 mmol) of a mixture consisting of
bis(2-(phenyl)pyridine)mono(2-(bromophenyl)pyridine)iridum (III) as
the main component was obtained. The yield was about 13.5%. M+ was
measured to be 733 by FD-MS. This mixture is a mixture of
tris(2-(bromophenyl)pyridine)iridium (III) complex (complex 4),
[0281] mono(2-(phenyl)pyridine)bis(2-(bromophenyl)pyridine)iridium
(III) complex (complex 3), [0282]
bis(2-(phenyl)pyridine)mono(2-(bromophenyl)pyridine)iridium (III)
complex (complex 2), and [0283] tris(2-(phenyl)pyridine)iridium
(III) complex (complex 1). The ratios of them measured by FD-MS are
as shown in Table 1.
TABLE-US-00001 [0283] TABLE 1 FD-MS of complex Peak Composition
ratio (%) Remarks Complex 1 31 12.2 Discharged out of the system
without reaction Complex 2 86 33.7 Reacted to the end of a molecule
Complex 3 100 39.2 Complex 4 38 14.9
Example 3
Synthesis of Polymeric Light Emitting Substance 1
[0284] 0.403 g (0.735 mmol) of 9,9-dioctyl-2,7-dibromofluorene,
0.321 g (0.735 mmol) of N-octyl-3,6-dibromocarbazole, 0.022 g of
[0285] bis(2-(phenyl)pyridine)mono(2-(bromophenyl)pyridine)iridium
(III) (0.03 mmol: this mixtures is a mixture of a [0286]
tris(2-(bromophenyl)pyridine)iridium (III) complex, [0287]
mono(2-(phenyl)pyridine)bis(2-(bromophenyl)pyridine)iridium (III)
complex, [0288]
bis(2-(phenyl)pyridine)mono(2-(bromophenyl)pyridine)iridium (III)
complex, and tris(2-(phenyl)pyridine)iridium (III) complex, and in
charging, [0289]
bis(2-(phenyl)pyridine)mono(2-(bromophenyl)pyridine)iridium (III)
having a molecular weight of 733 was used) and 0.55 g (3.5 mmol) of
2,2'-bipyridyl were charged in a reaction vessel, then, the
atmosphere in the reaction vessel was purged with a nitrogen gas.
To this was added 40 ml of tetrahydrofuran (dehydrated solvent)
previously degassed by bubbling of an argon gas. Then, to this
mixed solution was added 0.96 g (3.5 mmol) of
bis(1,5-cyclooctadiene) nickel (0), the resulted mixture was
stirred for 10 minutes at room temperature, then, they were reacted
for 8 hours at 60.degree. C. The reaction was conducted under a
nitrogen atmosphere. After the reaction, this solution was cooled,
then, poured into a mixed solution of 10 ml of 25% ammonia
water/150 ml of methanol/50 ml of ion exchanged water, and they
were stirred for about 30 minutes. Then, the produced precipitate
was filtrated and recovered. This precipitation was dried, then,
dissolved in chloroform. This solution was filtrated to remove
insoluble substances, then, this solution was poured into methanol,
to cause re-precipitation, and the produced precipitation was
recovered. This precipitation was dried under reduced pressure, to
obtain 0.11 g of a polymer. This polymer is called polymeric light
emitting substance 1.
[0290] The polymeric light emitting substance 1 had a polystyrene
reduced weight-average molecular weight of 4.4.times.10.sup.5 and a
polystyrene reduced number-average molecular weight of
1.9.times.10.sup.5.
[0291] The polymeric light emitting substance 1 is a copolymer
containing 9,9-dioctyl-2,7-fluorene, N-octyl-3,6-carbazole and
tris(2-(phenyl)pyridine)iridium (III) complex as repeating
units.
Example 4
Synthesis of Polymeric Light Emitting Substance 2
[0292] 0.403 g (0.735 mmol) of 9,9-dioctyl-2,7-dibromofluorene,
0.496 g (0.735 mmol) of [0293]
N,N'-diphenyl-N,N'-bis(3-methyl-4-bromophenyl)benzidine, 0.022 g of
[0294] bis(2-(phenyl)pyridine)mono(2-(bromophenyl)pyridine)iridium
(III) (0.03 mmol: this mixtures is a mixture of a [0295]
tris(2-(bromophenyl)pyridine)iridium (III) complex, [0296]
mono(2-(phenyl)pyridine)bis(2-(bromophenyl)pyridine)iridium (III)
complex, [0297]
bis(2-(phenyl)pyridine)mono(2-(bromophenyl)pyridine)iridium (III)
complex, and tris(2-(phenyl)pyridine)iridium (III) complex, and in
charging, [0298]
bis(2-(phenyl)pyridine)mono(2-(bromophenyl)pyridine)iridium (III)
having a molecular weight of 733 was used) and 0.55 g (3.5 mmol) of
2,2'-bipyridyl were charged in a reaction vessel, then, the
atmosphere in the reaction vessel was purged with a nitrogen gas.
To this was added 40 ml of tetrahydrofuran (dehydrated solvent)
previously degassed by bubbling of an argon gas. Then, to this
mixed solution was added 0.96 g (3.5 mmol) of
bis(1,5-cyclooctadiene)nickel (0), the resulted mixture was stirred
for 10 minutes at room temperature, then, they were reacted for 8
hours at 60.degree. C. The reaction was conducted under a nitrogen
atmosphere. After the reaction, this solution was cooled, then,
poured into a mixed solution of 10 ml of 25% ammonia water/150 ml
of methanol/50 ml of ion exchanged water, and they were stirred for
about 30 minutes. Then, the produced precipitate was filtrated and
recovered. This precipitation was dried, then, dissolved in
chloroform. This solution was filtrated to remove insoluble
substances, then, this solution was poured into methanol, to cause
re-precipitation, and the produced precipitation was recovered.
This precipitation was dried under reduced pressure, to obtain 0.35
g of a polymer. This polymer is called polymeric light emitting
substance 2.
[0299] The polymeric light emitting substance 2 had a polystyrene
reduced weight-average molecular weight of 3.6.times.10.sup.5 and a
polystyrene reduced number-average molecular weight of
1.8.times.10.sup.4.
[0300] The polymeric light emitting substance 2 is a copolymer
containing 9,9-dioctyl-2,7-fluorene, [0301]
N,N'-diphenyl-N,N'-bis(3-methylphenyl)benzidine and [0302]
tris(2-(phenyl)pyridine)iridium (III) complex as repeating
units.
Example 5
Synthesis of Polymeric Light Emitting Substance 3
[0303] 0.806 g (1.47 mmol) of 9,9-dioctyl-2,7-dibromofluorene,
0.022 g of [0304]
bis(2-(phenyl)pyridine)mono(2-(bromophenyl)pyridine)iridium (III)
(0.03 mmol: this mixtures is a mixture of a [0305]
tris(2-(bromophenyl)pyridine) iridium (III) complex, [0306]
mono(2-(phenyl)pyridine)bis(2-(bromophenyl)pyridine)iridium (III)
complex, [0307]
bis(2-(phenyl)pyridine)mono(2-(bromophenyl)pyridine)iridium (III)
complex, and tris(2-(phenyl)pyridine)iridium (III) complex, and in
charging, [0308] bis(2-(phenyl)pyridine)mono(2-(bromophenyl)
pyridine) iridium (III) having a molecular weight of 733 was used)
and 0.55 g (3.5 mmol) of 2,2'-bipyridyl were charged in a reaction
vessel, then, the atmosphere in the reaction vessel was purged with
a nitrogen gas. To this was added 40 ml of tetrahydrofuran
(dehydrated solvent) previously degassed by bubbling of an argon
gas. Then, to this mixed solution was added 0.96 g (3.5 mmol) of
bis(1,5-cyclooctadiene) nickel (0), the resulted mixture was
stirred for 10 minutes at room temperature, then, they were reacted
for 8 hours at 60.degree. C. The reaction was conducted under a
nitrogen atmosphere. After the reaction, this solution was cooled,
then, poured into a mixed solution of 10 ml of 25% ammonia
water/150 ml of methanol/50 ml of ion exchanged water, and they
were stirred for about 30 minutes. Then, the produced precipitate
was filtrated and recovered. This precipitation was dried, then,
dissolved in chloroform. This solution was filtrated to remove
insoluble substances, then, this solution was poured into methanol,
to cause re-precipitation, and the produced precipitation was
recovered. This precipitation was dried under reduced pressure, to
obtain 0.11 g of a polymer. This polymer is called polymeric light
emitting substance 3.
[0309] The polymeric light emitting substance 3 had a polystyrene
reduced weight-average molecular weight of 7.6.times.10.sup.4 and
polystyrene reduced number-average molecular weight of
1.2.times.10.sup.4.
[0310] The polymeric light emitting substance 3 is a copolymer
containing 9,9-dioctyl-2,7-fluorene, and [0311]
tris(2-(phenyl)pyridine)iridium (III) complex as repeating
units.
Example 6
Polymer LED
[0312] On a glass substrate carrying there on an ITO film adhered
at a thickness of 150 nm by a sputtering method, a film was formed
at a thickness of 50 nm by spin coat using a solution of
poly(ethylenedioxythiophene)/polstyrenesulfonic acid (Baytron,
manufactured by Bayer), and dried at 120.degree. C. for 5 minutes
on a hot plate. Then, a film was formed at a thickness of about 70
mm by spin coat using a 0.5 wt % solution of the polymeric light
emitting substance 1 in chloroform. Further, this was dried at
80.degree. C. under reduced pressure for 1 hour, then, lithium
fluoride was deposited at a thickness of 0.4 nm as a cathode buffer
layer, calcium was deposited at a thickness of 25 nm, then,
aluminum was deposited at a thickness of 40 nm, as a cathode, to
produce a polymer LED. The degree of vacuum in deposition was
always 1 to 8.times.10.sup.-6 Torr. By applying voltage on the
resulted device, EL light emission from the polymeric light
emitting substance 1 was obtained. The intensity of EL emission was
approximately in proportion to current density.
Example 6
Calculation Examples of Intersystem Crossing
[0313] The structure of the minimum triplet excited state of a
tris(2-phenylpyridine) iridium complex was analyzed by a B3LYP
method using the LANL2MB base function. Regarding the structure,
the difference between energy between the minimum singlet excited
state and the minimum triplet excited state was measured by a TDDFT
method at B3LYP/LANL2MB level, to find it was 0.87 eV. For the
calculation, Caussian 98 program was used.
[0314] The polymeric light emitting substance of the present
invention has a complex emitting triplet luminescence structure in
the molecule, and can form a light emitting layer by industrially
simple application methods such as a spin coat method, inkjet
method, printing method and the like. Further, the polymeric light
emitting substance of the present invention contains a complex
emitting triplet luminescence, and can manifest high light emitting
efficiency. Therefore, the polymeric light emitting substance of
the present invention can be used suitably as a light emitting
material of a polymer LED, and the like. According to the
production method of the present invention, this polymeric light
emitting substance can be produced easily. The polymer LED of the
present invention can be preferably used in apparatuses such as a
back light of a liquid crystal display, light sources in the form
of curve or flat plate for illumination, display elements of
segment type, flat panel displays of dot matrix, and the like.
* * * * *