U.S. patent application number 13/537908 was filed with the patent office on 2012-10-18 for triarylamine containing polymers and electronic devices.
This patent application is currently assigned to SUMITOMO CHEMICAL COMPANY, LIMITED. Invention is credited to Yang Cheng, Michael Inbasekaran, Chun WANG, Wanglin Yu.
Application Number | 20120264977 13/537908 |
Document ID | / |
Family ID | 36565659 |
Filed Date | 2012-10-18 |
United States Patent
Application |
20120264977 |
Kind Code |
A1 |
WANG; Chun ; et al. |
October 18, 2012 |
TRIARYLAMINE CONTAINING POLYMERS AND ELECTRONIC DEVICES
Abstract
A conjugated or partially conjugated polymer including a
structural unit of Formula I in the backbone: ##STR00001## where
Ar.sub.1 and Ar.sub.2 are each independently a substituted or
unsubstituted arylene or hetero arylene group with two or more
aromatic rings fused together and Ar.sub.3 is an aryl or heteroaryl
group of C.sub.4 to C.sub.40 or substituted aryl or heteroaryl
group of C.sub.4 to C.sub.40 and devices containing such polymer.
In addition, a composition of Formula V ##STR00002## wherein
Ar.sub.1 and Ar.sub.2 are arylene or heteroarylene groups and
Ar.sub.3 is an aryl or heteroaryl group and wherein X is a leaving
group such as halogen, boronic acid or boronate ester.
Inventors: |
WANG; Chun; (Midland,
MI) ; Inbasekaran; Michael; (Midland, MI) ;
Yu; Wanglin; (Midland, MI) ; Cheng; Yang;
(Midland, MI) |
Assignee: |
SUMITOMO CHEMICAL COMPANY,
LIMITED
Tokyo
JP
|
Family ID: |
36565659 |
Appl. No.: |
13/537908 |
Filed: |
June 29, 2012 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
11667106 |
Sep 12, 2007 |
8247800 |
|
|
PCT/US2005/043222 |
Dec 1, 2005 |
|
|
|
13537908 |
|
|
|
|
60633357 |
Dec 3, 2004 |
|
|
|
Current U.S.
Class: |
564/427 ;
564/429 |
Current CPC
Class: |
C08F 226/02
20130101 |
Class at
Publication: |
564/427 ;
564/429 |
International
Class: |
C07C 211/59 20060101
C07C211/59; C07C 211/61 20060101 C07C211/61; C07C 217/92 20060101
C07C217/92 |
Claims
1. A composition of Formula V ##STR00022## wherein Ar.sub.1 and
Ar.sub.2 are arylene or hetero-arylene groups and Ar.sub.3 is an
aryl or heteroaryl group and wherein X is a leaving group.
2. The composition of claim 1, wherein X is a halogen, boronic acid
or boronate ester.
3. The composition of claim 2, wherein X is bromine.
4. The composition of claim 1, Ar.sub.1 and Ar.sub.2 are each
independently a substituted or unsubstituted arylene or
heteroarylene group with two or more aromatic rings fused
together.
5. The composition of claim 4, wherein Ar.sub.1 and Ar.sub.2 are a
substituted or unsubstituted naphthalenediyl, anthracenediyl or
fluorenediyl.
6. The composition of claim 5, wherein Ar.sub.1 and Ar.sub.2
comprise a fluorene having the Formula II ##STR00023## where Q is
R.sup.1 or Ar, wherein Ar is a aryl or heteroaryl group of C.sub.4
to C.sub.40 or substituted aryl or heteroaryl group of C.sub.4 to
C.sub.40; R.sup.1 is independently, in each occurrence H,
C.sub.1-40 hydrocarbyl or C.sub.3-40 hydrocarbyl containing one or
more S, N, O, P or Si atoms, or both of R.sup.1 together with the
9-carbon on the fluorene may form a C.sub.5-20 ring structure that
may contain one or more S, N, Si, P or O atoms; R.sup.2 is
independently in each occurrence a C.sub.1-C.sub.40 hydrocarbon,
C.sub.3-C.sub.40 hydrocarbyl containing one or more heteroatoms of
S, N, O, P or Si, or a substituted or unsubstituted aryl group or
heteroaryl group; n is independently in each occurrence, 0-3.
7. The composition of claim 6, wherein Ar.sub.3 is an aryl or
heteroaryl group of C.sub.4 to C.sub.40 or a substituted aryl or
heteroaryl group of C.sub.4 to C.sub.40.
8. The composition of claim 7, wherein Ar.sub.3 is a aryl or
heteroaryl group having Formula III ##STR00024## where R.sup.3 is a
C.sub.1-40 hydrocarbon, C.sub.3-40 hydrocarbyl containing one or
more heteroatoms of S, N, O, P or Si, or a substituted or
unsubstituted aryl group or heteroaryl group.
Description
[0001] This application is a divisional application of U.S.
application Ser. No. 11/667,106 filed Sep. 12, 2007, which is a
National Stage of PCT/US2005/043222 filed Dec. 1, 2005, which
claims the benefit of the provisional application, U.S. Application
No. 60/633,357, filed Dec. 3, 2004. The entire disclosure of the
prior applications are hereby incorporated by reference.
[0002] This invention relates to polymeric compositions comprising
triarylamines and electronic devices comprising such
compositions.
BACKGROUND
[0003] Conjugated polymers are known to have optoelectronic
properties. Several reports have demonstrated blue light emission
from fluorene homopolymers, e.g., A. W. Orrice; D. D. C. Bradley,
M. T. Bernius; M. Inbasekaran, W. Wu, E. P. Woo; Appl. Prep. Lett.
1998, 73, Y. Young and Q. Pei; J. Appl. Prep. 81, 3294 (1997). WO
01/81294 A1 teaches a fluorene polymer that is end-capped with a
charge transporting tricyclic arylamine. U.S. Pat. No. 5,874,179
(Kreuder et al) teaches optoelectronic polymers based on
polyphenylenevinylene with nitrogen containing comonomers.
Additionally, Kreuder further teaches that fluorene could be part
of a fused nitrogen containing ring structure in a
polyphenylenevinylene based polymer.
[0004] WO 2004/024670 describes a process for producing a high
purity triarylamine and diarylamine at low cost by reacting an
aromatic halogen compound with an aromatic amine in the presence of
organic salt, a copper catalyst and a base. The aryl groups can be
naphthalene group. JP 20022175883 describes an organic
electroluminescent device comprising the triaryl amine compound
emitting blue violet light. A synthesis of tri-(4-bromonaphthyl)
amine was described in detail and this compound is reported to emit
violet-blue light in an organic electroluminescent device. Momura
et al. (Macromolecules, 37(4) 2004 1204-1210) describe the
synthesis of di(1-naphthyl)-4-tolylamine homopolymer and its
application as a hole transporting layer in organic light-emitting
devices. JP 1999184109 describes the composition of an
electrophotographic photoreceptor that possesses a triarylamine
derivative based charge transport layer and the electrophotographic
apparatus using this photoreceptor. The triarylamine used as a
charge transport layer has one substituted aryl group, Ar, and two
fluorenyl groups attached to the nitrogen atom.
[0005] A need remains for optoelectronic materials and devices that
exhibit good conductivity with improved efficiency, which emit a
deep blue light with high brightness and at relatively low
operating voltages.
SUMMARY OF THE INVENTION
[0006] The present inventors have discovered that the inclusion of
a triarylamine moiety of a particular type in the main chain of a
conjugated or partially conjugated polymer provides remarkably
improved conductivity at low voltages as well as higher device
efficiency compared to prior art technology and which is capable of
deep blue light emission.
[0007] More specifically, the instant invention is a conjugated or
partially conjugated polymer comprising a structural unit of
Formula I on the backbone:
##STR00003##
wherein Ar.sub.1 and Ar.sub.2 are each independently a substituted
or unsubstituted arylene or hetero-arylene group with two or more
aromatic rings fused together and Ar.sub.3 is an aryl or heteroaryl
group of C.sub.4 to C.sub.40 or substituted aryl or heteroaryl
group of C.sub.4 to C.sub.40.
[0008] In another aspect, the invention is a film comprising
Formula I. In another aspect, the invention is a blend of the
polymer comprising Formula I with at least one additional
conjugated polymer. In yet another aspect, the invention is an
electroluminescent device comprising a film comprising a polymer
comprising Formula I. In another aspect, the invention is a
photocell comprising a first electrode, a film comprising the
polymer comprising Formula I and a second electrode.
[0009] In a yet further aspect, the invention is a field effect
transistor comprising: (a) an insulator layer, the insulator layer
being an electrical insulator, the insulator layer having a first
side and a second side; (b) a gate, the gate being an electrical
conductor, the gate being positioned adjacent the first side of the
insulator layer; (c) a semiconductor layer, the semiconductor layer
comprising the polymer comprising Formula I and a second electrode;
(d) a source, the source being an electrical conductor, the source
being in electrical contact with the first end of the semiconductor
layer; and (e) a drain, the drain being an electrical conductor,
the drain being in electrical contact with the second end of the
semiconductor layer.
[0010] In another aspect, the invention is a composition of Formula
V
##STR00004##
[0011] wherein Ar.sub.1 and Ar.sub.2 are arylene or heteroarylene
groups and Ar.sub.3 is an aryl or heteroaryl group and wherein X is
a leaving group such as halogen, boronic acid or boronate
ester.
DETAILED DESCRIPTION OF THE INVENTION
[0012] In one embodiment, the invention is a polymer comprising a
conjugated or partially conjugated polymer with a structural unit
of Formula I:
##STR00005##
wherein Ar.sub.1 and Ar.sub.2 are each independently a substituted
or unsubstituted arylene or hetero-arylene group with two or more
aromatic rings fused together and Ar.sub.3 is an aryl or heteroaryl
group of C.sub.4 to C.sub.40 or substituted aryl or heteroaryl
group of C.sub.4 to C.sub.40. Ar.sub.1 and Ar.sub.2 are preferably
substituted or unsubstituted naphthalenediyl, anthracenediyl or
fluorenediyl. If Ar.sub.1 and Ar.sub.2 comprise a fluorenediyl,
such fluorenediyl can have the Formula II
##STR00006##
where Q is R.sup.1 or Ar, wherein Ar is a arylene or heteroarylene
group of C.sub.4 to C.sub.40 or substituted arylene or
heteroarylene group of C.sub.4 to C.sub.40; R.sup.1 is
independently, in each occurrence H, C.sub.1-40 hydrocarbyl or
C.sub.3-40 hydrocarbyl containing one or more S, N, O, P or Si
atoms, or both of R.sup.1 together with the 9-carbon on the
fluorene may form a C.sub.5-20 ring structure that may contain one
or more S, N, O, P or Si atoms; R.sup.2 is independently in each
occurrence a C.sub.1-C.sub.40 hydrocarbon, C.sub.3-C.sub.40
hydrocarbyl containing one or more heteroatoms of S, N, O, P or Si,
which are incorporated into the carbon-carbon bond, or a
substituted or unsubstituted aryl group or heteroaryl group; n is
independently in each occurrence, 0-3.
[0013] Ar.sub.3 is a substituted or unsubstituted aryl or
heteroaryl group. Ar.sub.3 is preferably an aryl or heteroaryl
group having Formula III
##STR00007##
where R.sup.3 is a C.sub.1-40 hydrocarbon, C.sub.3-40 hydrocarbyl
containing one or more heteroatoms of S, N, O, P or Si, or a
substituted or unsubstituted aryl group or heteroaryl group.
[0014] In another embodiment, the invention is a polymer comprising
a conjugated or partially conjugated polymer with a structural unit
of Formula IV:
##STR00008##
[0015] wherein Ar.sub.1 and Ar.sub.2 are each independently a
substituted or unsubstituted arylene or hetero arylene group with
two or more aromatic rings fused together; Ar.sub.3 is an aryl or
heteroaryl group of C.sub.4 to C.sub.40 or substituted aryl or
heteroaryl group of C.sub.4 to C.sub.40; and Y is a residual unit
of a monomer of a conjugated polymer which polymer may optionally
additionally include monomers of a non-conjugated polymer. Ar.sub.1
and Ar.sub.2 are preferably substituted or unsubstituted
naphthalenediyl, anthracenediyl or fluorenediyl.
[0016] The Y moiety of Formula IV is preferably independently in
each occurrence selected from the group of conjugated units of the
formulas or a combination of the formulas:
##STR00009## ##STR00010## ##STR00011##
wherein the conjugated units may bear one or more substitutents,
such substituents being independently in each occurrence C.sub.1-20
hydrocarbyl, C.sub.1-20 hydrocarboxyloxy, C.sub.1-20 thioether,
C.sub.1-20 hydrocarbyloxycarbonyl, C.sub.1-20 hydrocarboxy
carbonyloxy, cyano, or fluoro group;
X.sub.1 is O or S;
Q is R.sup.1 or Ar;
[0017] R.sup.6 is independently, in each occurrence H, C.sub.1-40
hydrocarbyl or C.sub.3-40 hydrocarbyl containing one or more S, N,
O, P or Si atoms; n is independently in each occurrence, 0-3; Ar is
an aryl or heteroaryl group of C.sub.4 to C.sub.40 or substituted
aryl or heteroaryl group of C.sub.4 to C.sub.40; R.sup.1 is
independently, in each occurrence H, C.sub.1-40 hydrocarbyl or
C.sub.3-40 hydrocarbyl containing one or more S, N, O, P or Si
atoms, or both of R.sup.1 together with the 9-carbon on the
fluorene may form a C.sub.5-20 ring structure that may contain one
or more S, N, Si, P or O atoms; R.sup.5 is independently, in each
occurrence H, C.sub.1-40 hydrocarbyl or C.sub.3-40 hydrocarbyl
containing one or more S, N, O, P or Si atoms, or both of R.sup.5
together with the 9-carbon on the fluorene may form a C.sub.5-20
ring structure that may contain one or more S, N, Si, P or O atoms;
and R.sup.4 is independently in each occurrence C.sub.1-20
hydrocarbyl, C.sub.1-20 hydrocarbyloxy, C.sub.1-20 thioether,
C.sub.1-20 hydrocarbyloxycarbonyl, C.sub.1-20
hydrocarbylcarbonyloxy, or cyano or fluoro group.
[0018] The optionally additional monomers of a non-conjugated
polymer preferably comprise a polycarbonate monomer, a polystyrene
monomer, a polyester monomer, a polyacrylate monomer or a mixture
thereof. The instant invention includes the polymer comprising
Formula I dissolved or dispersed in a solvent. The instant
invention includes a film the polymer comprising Formula I. The
instant invention includes a blend of the polymer comprising
Formula I with at least one additional conjugated polymer.
[0019] In another embodiment, the invention is an
electroluminescent device comprising at least one organic film
comprising the polymer comprising Formula I, arranged between an
anode material and a cathode material such that under an applied
voltage, the organic film emits blue light which is transmitted
through a transparent exterior portion of the device.
[0020] In another embodiment, the invention is a field effect
transistor comprising: (a) an insulator layer, the insulator layer
being an electrical insulator, the insulator layer having a first
side and a second side; (b) a gate, the gate being an electrical
conductor, the gate being positioned adjacent the first side of the
insulator layer; (c) a semiconductor layer, the semiconductor layer
comprising the polymer comprising Formula I and a second electrode;
(d) a source, the source being an electrical conductor, the source
being in electrical contact with the first end of the semiconductor
layer; and (e) a drain, the drain being an electrical conductor,
the drain being in electrical contact with the second end of the
semiconductor layer. The instant invention also includes a
photocell comprising a first electrode, a film comprising the
polymer comprising Formula I and a second electrode.
[0021] The instant invention is also a composition of Formula V
##STR00012##
wherein Ar.sub.1 and Ar.sub.2 are each independently substituted or
unsubstituted arylene or hetero arylene group with two or more
aromatic rings fused together and Ar.sub.3 is an aryl or heteroaryl
group of C.sub.4 to C.sub.40 or substituted aryl or heteroaryl
group of C.sub.4 to C.sub.40.
[0022] Ar.sub.1 and Ar.sub.2 are preferably substituted or
unsubstituted naphthalenediyl, anthracenediyl or fluorenediyl. If
Ar.sub.1 and Ar.sub.2 comprise a fluorenediyl, such fluorenediyl
can have the Formula II
##STR00013##
where Q is R.sup.1 or Ar, wherein Ar is a aryl or heteroaryl group
of C.sub.4 to C.sub.40 or substituted aryl or heteroaryl group of
C.sub.4 to C.sub.40; R.sup.1 is independently, in each occurrence
H, C.sub.1-40 hydrocarbyl or C.sub.3-40 hydrocarbyl containing one
or more S, N, O, P or Si atoms, or both of R.sup.1 together with
the 9-carbon on the fluorene may form a C.sub.5-20 ring structure
that may contain one or more S, N, O, P or Si atoms; R.sup.2 is
independently in each occurrence a C.sub.1-C.sub.40 hydrocarbon,
C.sub.3-C.sub.40 hydrocarbyl containing one or more heteroatoms of
S, N, O, P or Si, or a substituted or unsubstituted aryl group or
heteroaryl group; n is independently in each occurrence, 0-3.
[0023] Ar.sub.3 is a substituted or unsubstituted aryl or
heteroaryl group. Ar.sub.3 is preferably an aryl or heteroaryl
group having Formula III
##STR00014##
where R.sup.3 is a C.sub.1-40 hydrocarbon, C.sub.3-40 hydrocarbyl
containing one or more heteroatoms of S, N, O, P or Si, or a
substituted or unsubstituted aryl group or heteroaryl group.
[0024] In another embodiment, additional conjugated Y units include
hole transporting moieties, electron transporting moieties, and/or
light emitting moieties. The additional units are used to optimize
one or more of the following: charge injection, charge transport,
electroluminescent device efficiency and lifetime. In this
embodiment, the conjugated unit Y is selected from the group of
conjugated units of the formulas or a combination of the
formulas:
##STR00015## ##STR00016## ##STR00017##
wherein the conjugated units may bear one or more substitutents,
such substituents being independently in each occurrence C.sub.1-20
hydrocarbyl, C.sub.1-20 hydrocarboxyloxy, C.sub.1-20 thioether,
C.sub.1-20 hydrocarbyloxycarbonyl, C.sub.1-20
hydrocarboxycarbonyloxy, cyano, or fluoro group;
X.sub.1 is O or S;
Q is R.sup.1 or Ar;
[0025] R.sup.6 is independently, in each occurrence H, C.sub.1-40
hydrocarbyl or C.sub.3-40 hydrocarbyl containing one or more S, N,
O, P or Si atoms; n is independently in each occurrence 0-3; Ar is
an aryl or heteroaryl group of C.sub.4 to C.sub.40 or substituted
aryl or heteroaryl group of C.sub.4 to C.sub.40; R.sup.1 is
independently, in each occurrence H, C.sub.1-40 hydrocarbyl or
C.sub.3-40 hydrocarbyl containing one or more S, N, O, P or Si
atoms, or both of R.sup.1 together with the 9-carbon on the
fluorene may form a C.sub.5-20 ring structure that may contain one
or more S, N, Si, P or O atoms; R.sup.5 is independently, in each
occurrence H, C.sub.1-40 hydrocarbyl or C.sub.3-40 hydrocarbyl
containing one or more S, N, O, P or Si atoms, or both of R.sup.5
together with the 9-carbon on the fluorene may form a C.sub.5-20
ring structure that may contain one or more S, N, Si, P or O atoms;
and R.sup.4 is independently in each occurrence C.sub.1-20
hydrocarbyl, C.sub.1-20 hydrocarbyloxy, C.sub.1-20 thioether,
C.sub.1-20 hydrocarbyloxycarbonyl, C.sub.1-20
hydrocarbylcarbonyloxy, cyano or fluoro group.
[0026] The polymers of the invention have a weight average
molecular weight of about 10,000 Daltons or greater, 20,000 Daltons
or greater, and preferably 50,000 Daltons or greater; 1,000,000
Daltons or less, 500,000 Daltons or less, and preferably 400,000
Daltons or less. Molecular weights are determined using gel
permeation chromotography using polystyrene as an internal
standard.
[0027] The polymers demonstrate a polydispersity (Mw/Mn) of 10 or
less, 5 or less, 4 or less and preferably 3 or less.
[0028] The polymers of this invention may be assembled by any known
coupling reaction for making aromatic compounds. Preferably, the
Suzuki coupling reaction is used. The Suzuki reaction couples
aromatic compounds using a diboronated aromatic moiety and a
dihalogenated aromatic moiety. The reaction allows for the creation
of long chain, high molecular weight polymers. Additionally, by
controlling the sequence of addition, either random or block
copolymers may be produced.
[0029] Preferably, the Suzuki reaction starts with a diboronated
monomer. The Suzuki process is taught in U.S. Pat. No. 5,777,070,
which is expressly incorporated herein by reference.
[0030] Toluene or xylenes are the preferred solvents for the Suzuki
reaction to prepare the polymers of the instant invention. Sodium
carbonate in water is the preferred base, a palladium complex
catalyst, such as tetrakis(triphenylphosphine)palladium or
dichlorobis(triphenylphosphine)palladium(II) is the preferred
catalyst, and a phase transfer catalyst, preferably, a quaternary
ammonium salt is used to speed up the reaction for achieving high
molecular weight in a short period of time. Monoaryl amines,
unsubstituted on the nitrogen atom, are commercially available from
many commercial vendors including Aldrich Chemical Company. Triaryl
substituted amines are produced through the reaction of a
N-unsubstituted precursor with a brominated or iodinated aryl or
substituted aryl compound. The ratio of monoarylamine to bromoaryl
or iodoaryl or substituted bromo or iodo aryl is 1 to 2.2-4. The
materials are reacted in the presence of a catalyst. Preferably,
the catalyst is tris(dibenzylideneacetone)dipalladium and
tri-t-butylphosphine. Preferably, sodium tert-butoxide may be used
as the base. The materials are heated and refluxed for about 15
hours at 80-110.degree. C. in toluene. The solution is cooled.
Triaryl amine is isolated and further brominated with bromination
techniques known to those skilled in the art. The most preferred
brominating agent is N-bromosuccinimide in a solvent such as DMF or
methylene chloride.
[0031] Another aspect of this invention is related to polymer
blends. The blends comprise a polymer containing structural units
of Formula I or Formula I blended with at least one other
conjugated polymer. As used herein, the term "conjugated polymer"
means a polymer with a backbone of overlapping .pi. orbitals.
Conjugated polymers that may be used in the blends include
polyflourenes, poly(arylenevinylene), polyphenylenes,
polyindenofluorenes and polythiophenes, including homopolymers,
co-polymers or substituted homopolymers and/or copolymers of any of
these conjugated polymers.
[0032] Preferably, the polymer blend is composed of at least 1
weight percent of a polymer containing units of Formula I. The most
preferred polymer blends have high photoluminescent and
electroluminescent efficiency. Other additives such as viscosity
modifiers, antioxidants and coating improvers may optionally be
added. Additionally, blends of two or more low polydispersity
polymers of similar compositions but different molecular weight can
also be formulated.
[0033] Another aspect of this invention is the films formed from
the polymers of the invention. Such films can be used in polymeric
light emitting diodes, photovoltaic cells and field effect
transistors. Preferably, such films are used as emitting layers or
charge carrier transport layers. The films may also be used as
protective coatings for electronic devices and as fluorescent
coatings. The thickness of the film or coating is dependent upon
the use.
[0034] Generally, such thickness can be from 0.005 to 200 microns.
When the coating is used as a fluorescent coating, the coating or
film thickness is from 50 to 200 microns. When the coatings are
used as electronic protective layers, the thickness of the coating
can be from 5 to 20 microns. When the coatings are used in a
polymeric light-emitting diode, the thickness of the layer formed
is 0.005 to 0.2 microns. The polymers of the invention form good
pinhole-free and defect-free films.
[0035] The films are readily formed by coating the polymer
composition from another embodiment of this invention in which the
composition comprises the polymer and at least one organic solvent.
Preferred solvents are aliphatic hydrocarbons, chlorinated
hydrocarbons, aromatic hydrocarbons, ketones, ethers and mixtures
thereof. Additional solvents which can be used include
1,2,4-trimethylbenzene, 1,2,3,4-tetramethyl benzene, pentylbenzene,
mesitylene, cumene, cymene, cyclohexylbenzene, diethylbenzene,
tetralin, decalin, 2,6-lutidine, 2-fluoro-m-xylene,
3-fluoro-o-xylene, 2-chlorobenzotrifluoride, dimethylformamide,
2-chloro-6-fluorotoluene, 2-fluoroanisole, anisole,
2,3-dimethylpyrazine, 4-fluoroanisole, 3-fluoroanisole,
3-trifluoro-methylanisole, 2-methylanisole, phenetole,
4-methylansiole, 3-methylanisole, 4-fluoro-3-methylanisole,
2-fluorobenzonitrile, 4-fluoroveratrol, 2,6-dimethylanisole,
3-fluorobenzonitrile, 2,5-dimethylanisole, 2,4-dimethylanisole,
benzonitrile, 3,5-dimethylanisole, N,N-dimethylaniline, ethyl
benzoate, 1-fluoro-3,5-dimethoxybenzene, 1-methylnaphthalene,
N-methylpyrrolidinone, 3-fluorobenzotrifluoride, benzotrifluoride,
benzotrifluoride, dioxane, trifluoromethoxybenzene,
4-fluorobenzotrifluoride, 3-fluoropyridine, toluene,
2-fluorotoluene, 2-fluorobenzotrifluoride, 3-fluorotoluene,
4-isopropylbiphenyl, phenyl ether, pyridine, 4-fluorotoluene,
2,5-difluorotoluene, 1-chloro-2,4-difluorobenzene,
2-fluoropyridine, 3-chlorofluorobenzene, 3-chlorofluorobenzene,
1-chloro-2,5-difluorobenzene, 4-chlorofluorobenzene, chlorobenzene,
o-dichlorobenzene, 2-chlorofluorobenzene, p-xylene, m-xylene,
o-xylene or mixture of o-, m-, and p-isomers. It is preferable that
such solvents have relatively low polarity. High boilers and
solvent mixtures are better for ink jetting, but xylenes and
toluene are best for spin coating. Preferably, the solution
contains from about 0.1 to 5 percent of a polymer comprising a
structural unit of Formula I. Films can be prepared by means well
known in the art including spin-coating, spray-coating,
dip-coating, roll-coating, offset printing, ink jet printing,
screen printing, stamp-coating or doctor blading.
[0036] In another embodiment, the invention is a composition
comprising a polymer or polymer blend of the invention in a
solvent. Solvents which can be used include toluene, xylene, a
mixture of o, m and p-isomers of xylene, mesitylene,
diethylbenzene, ethylbenzene or benzene derivatives of higher
substituted level. Preferably, the solution contains from 0.1 to 10
weight percent of the composition. For thin coatings, it is
preferred that the composition contains from 0.5 to 5.0 percent by
weight of the composition. The composition is applied to the
appropriate substrate by the desired method and the solvent is
allowed to evaporate. Residual solvent may be removed by vacuum,
heat and/or by sweeping with an inert gas such as nitrogen.
[0037] The polymers of this invention demonstrate strong
electroluminesence in addition to photoluminesence. Thus, another
aspect of the invention relates to organic electroluminescent (EL)
devices having a film comprising the polymers of this invention.
Preferably, the EL devices of this invention emit light when
subjected to an applied voltage of 20 volts or less, 10 volts or
less and preferably 6 volts or less.
[0038] An organic EL device typically consists of an organic film
sandwiched between an anode and a cathode. When a positive bias is
applied to the device, holes are injected into the organic film
from the anode, and electrons are injected into the organic film
from the cathode. The combination of a hole and an electron may
give rise to an exciton that may undergo radiative decay to the
ground state by liberating a photon.
[0039] In practice, the anode is commonly a mixed oxide of tin and
indium for its conductivity and transparency. The mixed oxide (ITO)
is deposited on a transparent substrate such as glass or plastic so
that the light emitted by the organic film may be observed. The
organic film may be the composite of several individual layers each
designed for a distinct function. Because holes are injected from
the anode, the layer next to the anode should have the
functionality of transporting holes. Similarly, the layer next to
the cathode should have the functionality of transporting
electrons. In many instances, the electron or hole transporting
layer may also act as the emitting layer. In some instances, a
single layer may perform the combined functions of hole and
electron transport and light emission.
[0040] The metallic cathode may be deposited either by thermal
evaporation or by sputtering. The thickness of the cathode may be
from 1 nm to 1000 nm. The preferred metals are calcium, magnesium,
indium, aluminum and barium. A thin layer (1-10 nm) of an alkali or
alkaline metal halide, e.g., LiF, NaF, CsF or RbF, may be used as a
buffering layer between the light emitting polymer and the cathode,
calcium, barium, or magnesium. Alloys of these metals may also be
used. Alloys of aluminum containing 1 to 5 percent of lithium and
alloys of magnesium containing at least 80 percent of magnesium are
preferred.
[0041] In another embodiment, the electroluminescent device
comprises at least one hole injecting polymer film (PEDOT film, for
example) and a light-emitting polymer film comprised of the
composition of the invention, arranged between an anode material
and a cathode material such that under an applied voltage, holes
are injected from the anode material into the light emitting
polymer via the hole-injecting polymer film and electrons are
injected from the cathode material into the light-emitting polymer
film when the device is forward biased, resulting in light emission
from the light-emitting layer. In another embodiment, layers of
hole-transporting polymers are arranged so that the layer closest
to the anode has the lowest oxidation potential, with the adjacent
layers having progressively higher oxidation potentials. By these
methods, electroluminescent devices having relatively high light
output per unit voltage may be prepared.
[0042] Another embodiment of the invention relates to photocells
comprising one or more of the polymers of the invention wherein the
polymers are present as single-layer films or as multiple-layer
films, whose combined thickness is in the range of 10 nm to 1000
nm, in the range of 25 nm to 500 nm, or preferably in the range of
50 nm to 300 nm. When two or more polymers are used, they may be
deposited separately as distinct layers or deposited as one layer
from a solution containing a blend of the desired polymers.
[0043] "Photocells" mean a class of optoelectronic devices that can
convert incident light energy into electrical energy. Examples of
photocells are photovoltaic devices, solar cells, photodiodes, and
photodetectors. A photocell generally comprises a transparent or
semi-transparent first electrode deposited on a transparent
substrate. A polymer film is then formed onto the first electrode
that is, in turn, coated by a second electrode. Incident light
transmitted through the substrate and the first electrode is
converted by the polymer film into excitons that can dissociate
into electrons and holes under the appropriate circumstances, thus,
generating an electric current.
[0044] Another embodiment of the invention relates to
metal-insulator-semiconductor field effect transistors comprising
one or more of the polymers of the invention which serve as a
semiconducting polymer. A field effect transistor comprises five
elements. The first element is an insulator layer. The insulator
layer is an electrical insulator, having a first side and a second
side. The second element is a gate. The gate is an electrical
conductor. The gate is positioned adjacent the first side of the
insulator layer.
[0045] The third element is a semiconductor layer. The
semiconductor layer comprises a polymer comprising a structural
unit of Formula I above. The semiconductor layer has a first side,
a second side, a first end and a second end, the second side of the
semiconductor layer being adjacent to the second side of the
insulator layer. The polymer is deposited onto an insulator wherein
the polymers are present as single-layer films or as multiple-layer
films whose combined thickness is in the range of 10 nm to 1000 nm,
in the range of 25 nm to 500 nm, or preferably in the range of 50
nm to 300 nm.
[0046] The fourth element of a field effect transistor is a source.
The source is an electrical conductor. The source is in electrical
contact with the first end of the semiconductor layer. The fifth
element is a drain. The drain is an electrical conductor. The drain
is in electrical contact with the second end of the semiconductor
layer. A negative voltage bias applied to the gate causes the
formation of a hole conduction channel in the semiconductor layer
connecting the source to the drain. A positive bias applied to the
gate causes the formation of an electron-conducting channel in the
semiconductor layer.
[0047] As with electroluminiscent devices, the polymer films
comprising the semiconductor layer may be formed by solvent-based
processing techniques such as spin-coating, roller-coating,
dip-coating, spray-coating and doctor-blading and ink jet printing.
When two or more polymers are used, they may be deposited
separately as distinct layers or deposited as one layer from a
solution containing a blend of the desired polymers.
[0048] Two electrodes (source and drain) are attached to the
semiconducting polymer and a third electrode (gate) onto the
opposite surface of the insulator. If the semiconducting polymer is
hole transporting (i.e, the majority carriers are positive holes),
then applying a negative DC voltage to the gate electrode induces
an accumulation of holes near the polymer-insulator interface,
creating a conduction channel through which electric current can
flow between the source and the drain. The transistor is in the
"on" state. Reversing the gate voltage causes a depletion of holes
in the accumulation zone and cessation of current. The transistor
is in the "off" state.
EXAMPLES
[0049] The following examples are included for illustrative purpose
and do not limit the scope of the claims.
Synthesis of 1,1'-dinaphthyl (4-butyl)phenyl amine (DNA) monomer
precursor
##STR00018##
[0050] 1-bromonaphthalene: 22.78 g (110 mmol) 4-n-butylaniline:
7.46 g, 50 mmol Pd.sub.2 (dba).sub.3: 1.007 g, 1.1 mmol
P(t-Bu).sub.3: 0.89 g (8.9 g in 10% hexane solution), 4.4 mmol
tBuONa: 14.8 g, 154 mmol To a three-necked flask equipped with a
reflux condenser, 1-bromonaphthalene, 4-butylaniline, Pd.sub.2
(dba).sub.3, P(t-Bu).sub.3, t-BuONa and toluene (150 ml) are added
and stirred at 80 deg C. until the 4-butylaniline disappears as
shown by HPLC analysis. After the reaction is completed, the
reaction mixture is passed through a column packed with 6 inches of
neutral alumina, and 2 L of toluene eluent is collected. The
solvent is removed on rotary evaporator. The residue is extracted
with 250 ml of diethyl ether, and the organic layer is washed with
3.times.200 ml of brine. The organic layer is dried over MgSO.sub.4
and concentrated on a rotary evaporator. The crude product is
recrystallized from toluene/ethanol (1:1 in volume) mixture. The
final product is an off-white powder with a purity of 99% by HPLC;
the yield is 56%.
Synthesis of
4-bromo-N-(4-bromo-1-naphthalenyl)-N-(4-butylphenyl)-1-napthalenamine
monomer
##STR00019##
[0051] To 1 g (2.49 mmol) of DNA dissolved in 40 ml of methylene
chloride is added 0.89 g (5.0 mmol) of N-bromosuccinimide (NBS)
dissolved in .about.15 ml of DMF (plus 5 ml for wash) at 0.degree.
C. (cooled in ice bath). With the addition of the NBS solution, the
reaction mixture changes from colorless to brown. After the
addition of NBS, the reaction mixture is stirred at this
temperature for 2 h. The reaction mixture is transferred to a 500
ml separatory funnel and washed with 3.times.300 ml of distilled
water. All of the water layers are combined and washed with 250 ml
of CH.sub.2Cl.sub.2. The combined organic layer is dried over
MgSO.sub.4. The solvent is removed on a rotary evaporator and a
dark brown oil is obtained. This crude product is recrystallized
from 200 ml of isopropyl alcohol and 1 g of an off-white powdery
product is obtained. The yield is 71.4%. The purity as determined
by HPLC is 99.0%.
Synthesis of 1,1'-dinaphthyl (4-butoxy)phenyl amine (DNOA) monomer
precursor
##STR00020##
[0052] 1-bromonaphthalene: 22.78 g (110 mmol) 4-butoxyaniline: 8.26
g, 50 mmol Pd.sub.2 (dba).sub.3: 1.007 g, 1.1 mmol P(t-Bu).sub.3:
0.89 g (8.9 g in 10% hexane solution), 4.4 mmol tBuONa: 14.8 g, 154
mmol To a three-necked flask equipped with a reflux condenser,
1-bromonaphthalene, 4-butoxyaniline, Pd.sub.2 (dba).sub.3,
P(t-Bu).sub.3, t-BuONa and toluene (150 ml) are added and stirred
at 80.degree. C. until the 4-butoxyaniline disappears as shown by
HPLC analysis. After the reaction is completed, the reaction
mixture is passed through a column packed with 6 inches of neutral
alumina, and 2 L of toluene eluent is collected. The solvent is
removed on rotary evaporator. The residue is extracted with 250 ml
of diethyl ether, and the organic layer is washed with 3.times.200
ml of brine. The organic layer is dried over MgSO.sub.4 and
concentrated on a rotary evaporator. The crude product is
recrystallized from isopropanol. The final product is an off-white
powder with a purity of 98.5% as determined by HPLC; the yield is
54%.
Synthesis of
4-bromo-N-(4-bromo-1-naphthalenyl)-N-(4-butoxyphenyl)-1-napthalenamine
monomer
##STR00021##
[0054] To 3.6 g (8.62 mmol) of DNOA dissolved in 100 ml of
methylene chloride is added 3.05 g (17.15 mmol) of
N-bromosuccinimide (NBS) dissolved in .about.20 ml of DMF (plus 5
ml for washing) at 0.degree. C. (cooled in ice bath). With the
addition of the NBS solution, the reaction mixture changes from
colorless to brown. After the addition of NBS, the reaction mixture
is stirred at this temperature for 2.5 h. The reaction mixture is
transferred to a 500 ml separatory funnel and washed with
3.times.300 ml of distilled water. All of the water layers are
combined and washed with 250 ml of CH.sub.2Cl.sub.2. The combined
organic layer is dried over MgSO4. The solvent is removed on a
rotary evaporator and a dark brown oil is obtained. This crude
product is recrystallized from 200 ml of isopropyl alcohol and 2.2
g of an off-white powdery product is obtained. The yield is 44%.
The purity as determined by HPLC is 98.3%.
Polymer 1:
Copolymerization of
4-bromo-N-(4-bromo-1-naphthalenyl)-N-(4-butylphenyl)-1-napthalenamine
with 2,7-bis(1,3,2-dioxaborolan-2-yl)-9,9-dioctylfluorene and
2,7-dibromo-9,9-bis(4-ethyloxyethyloxyphenyl)fluorene
[0055] To a 250 mL three-necked round bottom flask equipped with a
stirrer shaft, glass stopper and reflux condenser are added
2,7-bis(1,3,2-dioxaborolan-2-yl)-9,9-dioctylfluorene (2.5024 g,
4.7088 mmol), 2,7-dibromo-9,9-bis(4-ethoxyethoxyphenyl)fluorene
(2.2843 g, 3.4967 mmol), 4,4'-dibromo-1,1'-dinaphthyl
(4-butyl)phenyl amine (0.6447 g, 1.1655 mmol), phase transfer
agent, Aliquot 336 (0.69 g), and 35 mL of toluene. The solids are
allowed to dissolve in the toluene at 65.degree. C. Then 10 ml of
2M Na.sub.2 CO.sub.3 solution are added to the reaction solution.
The reaction mixture is allowed to stirred under nitrogen for 5
minutes, then 3.1 mg of
trans-dichloro-bis(triphenylphosphine)palladium (II) (3.2 mg,
0.0045 mmol) are added together with 5 ml toluene. Total volume of
the mixture is 50 ml. The reaction flask is heated up to
105.degree. C. The whole system is connected to a nitrogen line
through the reflux condenser so that a dynamic blanket of nitrogen
is maintained over the solution throughout the duration of the
reaction. In one and one half hour, all solids are back into
solution and the stirring rate is increased. In three hours, the
polymer solution appears to be very viscous and is capped with 0.5
g of phenyl boronic acid and 15 ml of THF together with 90 ml of
toluene. The reaction is continued for 16.5 hr. Then 5 g of DDC
dissolved in 40 ml of water are added to the above reaction flask
and the temperature is lowered to 84.degree. C. The reaction is
allowed to proceed for 4 hrs.
[0056] The reaction mixture is removed from the oil bath and the
polymer solution is transferred to a 1 L separatory funnel. The
water layer is separated from the polymer solution (16 mL). The
polymer solution is then washed 4 times with 250 mL of 4% acetic
acid solution. The polymer solution is further washed with 100 ml
of 10% acetic acid solution twice and 3 times with 200 mL of water.
A column of silica (3 inches) and alumina (3 inches) is prepared. 1
L of toluene is run through the column before running the polymer
solution through the column. 1500 ml of toluene eluent is
collected. The polymer solution is concentrated on a rotary
evaporator to .about.400 ml and precipitated into 2.5 L methanol.
The polymer fibers are then dissolved in .about.350 mL of CMOS
toluene and precipitated a second time into 2.5 L of CMOS methanol.
Polymer fibers are collected via filtration and allowed to dry
overnight in a vacuum oven at 60.degree. C. 2.1 g of polymer are
collected. GPC analysis indicates an M.sub.p of 202,457 grams per
mole, an M.sub.n of 158,324 grams per mole, an M.sub.w=403,410
grams per mole and a polydispersity index (PDI) of 2.55.
Polymer 2:
[0057] Monomers and reagents used for the polymerization are listed
as follows: 2,7-bis(1,3,2-dioxaborolan-2-yl)-9,9-dioctylfluorene
(2.4866 g, 4.6870 mmol),
2,7-dibromo-9,9-bis(4-ethoxyethoxyphenyl)fluorene (2.2766 g, 3.4804
mmol),
4-bromo-N-(4-bromo-1-naphthalenyl)-N-(4-butoxyphenyl)-1-napthalenamine
(0.6736 g, 1.1601 mmol), phase transfer agent, aliquot 336 (0.7 g),
trans-dichloro-bis(triphenylphosphine)palladium (II) (3.3 mg,
0.0045 mmol), 10 ml of 2M Na.sub.2CO.sub.3 solution and 50 mL of
toluene. The procedure is the same as used for Polymer 1. 2.5 g of
Polymer 2 is obtained. GPC analysis: Mp=150,050, Mn=68,894;
Mw=584,663, PDI=8.5.
Polymer 3:
[0058] Monomers and reagents used for the polymerization are listed
as follows: 2,7-bis(1,3,2-dioxaborolan-2-yl)-9,9-dioctylfluorene
(2.5003 g, 4.7072 mmol),
2,7-dibromo-9,9-bis(4-ethoxyethoxyphenyl)fluorene (2.2549 g, 3.4488
mmol),
4-bromo-N-(4-bromo-1-naphthalenyl)-N-(4-butylphenyl)-1-napthalenamine
(0.6590 g, 1.1651 mmol),
N,N'-bis(4-butylbenzene)-N,N'-bis(4-bromophenyl)-1,4-phenylenediamine
(0.0323 g, 0.0466 mmol), phase transfer agent, aliquot 336 (0.7 g),
trans-dichloro-bis(triphenylphosphine)palladium (II) (3.2 mg,
0.0045 mmol), 10 ml of 2M Na.sub.2CO.sub.3 solution and 50 ml of
toluene. The procedure is the same as used for Polymer 1. 2.0 g of
Polymer 3 is obtained. GPC analysis: Mp=276,259, Mn=176,537;
Mw=379,016, PDI=2.1
Polymeric Light Emitting Diode (PLED) Using Polymer 1:
[0059] Polymer 1 (60 mg) is dissolved in 6 mL of xylenes. The
solution is heated to 70.degree. C. and shaken for a minimum of 60
minutes before being filtered warm through a 0.22 microliter
syringe filter. On a cleaned ITO (indium tin oxide) coated glass
substrate, an 80 nm film of 1:16
polyethylenedioxythiopene:polystyrene sulfonic acid (PEDOT:PSS) is
deposited and baked at 200.degree. C. for 15 minutes in air on a
hotplate. On the top of the PEDOT:PSS film, F8-TFB (copolymer of
9,9-dioctylfluorene and N-(4-butylphenyl)diphenylamine) interlayer
solution is spin coated at 4500 RPM from 0.5 wt/vol %, baked at 180
degree in an oven for 20 minutes under N2, to give a thickness of
5-10 nm. On the top of F8TFB interlayer, an 80 nm film of polymer 1
is spin coated from a 1.0 wt/vol % xylenes solution and baked at
130.degree. C. under nitrogen in an oven for one hour. The cathode
metals (Ba (5 nm)/A1 (150 nm)) are then vacuum deposited over the
polymer film. The device emits blue light (CIE Coordinates: x=0.16
y=0.22) under a dc voltage drive, and has a maximum brightness of
4235 cd/m.sup.2 at 10 volts with an average light efficiency of
2.13 cd/A at 1000 cd/m.sup.2.
PLED Using Polymer 2:
[0060] The device fabrication is similar to that of the PLED made
using Polymer 1. The device emits blue light (CIE Coordinates:
x=0.15 y=0.21) under a dc voltage drive, and has a maximum
brightness of 8357 cd/m.sup.2 at 10 volts with an average light
efficiency of 3.52 cd/A at 1000 cd/m.sup.2.
PLED Using Polymer 3:
[0061] The device fabrication is similar to that of the PLED made
using Polymer 1. The device emits blue light (CIE Coordinates:
x=0.16 y=0.27) under a dc voltage drive, and has a maximum
brightness of 15083 cd/m.sup.2 at 10 volts with an average light
efficiency of 6.67 cd/A at 1000 cd/m.sup.2.
CONCLUSION
[0062] While this invention has been described as having preferred
aspects, the instant invention can be further modified within the
spirit and scope of this disclosure. This application is,
therefore, intended to cover any variations, uses, or adaptations
of the present invention using the general principles disclosed
herein. Further, this application is intended to cover such
departures from the present disclosure as come within the known or
customary practice in the art to which this invention pertains and
which fall within the limits of the appended claims.
* * * * *