U.S. patent application number 11/182964 was filed with the patent office on 2005-12-01 for process for producing aryl-aryl coupled compounds.
This patent application is currently assigned to Covion Organic Semiconductors GmbH. Invention is credited to Becker, Heinrich, Falcou, Aurelie, Spreitzer, Hubert, Stossel, Philipp, Treacher, Kevin.
Application Number | 20050263758 11/182964 |
Document ID | / |
Family ID | 7708255 |
Filed Date | 2005-12-01 |
United States Patent
Application |
20050263758 |
Kind Code |
A1 |
Treacher, Kevin ; et
al. |
December 1, 2005 |
Process for producing aryl-aryl coupled compounds
Abstract
The invention relates to the preparation of aryl-aryl coupled
compounds and materials. These materials play an important role in
industry, for example as liquid crystals, pharmaceuticals and
agrochemicals, to mention just a few application areas. These
compounds, in particular, are also of major importance especially
in the high-growth area of organic semi-conductors (for example,
applications in organic or polymeric light-emitting diodes, organic
solar cells, organic ICs).
Inventors: |
Treacher, Kevin; (Northwich,
GB) ; Stossel, Philipp; (Frankfurt, DE) ;
Spreitzer, Hubert; (Viernheim, DE) ; Becker,
Heinrich; (Eppstein-Niederjosbach, DE) ; Falcou,
Aurelie; (Mainz, DE) |
Correspondence
Address: |
CONNOLLY BOVE LODGE & HUTZ, LLP
P O BOX 2207
WILMINGTON
DE
19899
US
|
Assignee: |
Covion Organic Semiconductors
GmbH
Frankfurt am Main
DE
|
Family ID: |
7708255 |
Appl. No.: |
11/182964 |
Filed: |
July 15, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11182964 |
Jul 15, 2005 |
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10495003 |
Aug 23, 2004 |
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6956095 |
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10495003 |
Aug 23, 2004 |
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PCT/EP02/13584 |
Dec 2, 2002 |
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Current U.S.
Class: |
257/40 ;
528/394 |
Current CPC
Class: |
C08G 61/126 20130101;
C08G 61/12 20130101; C08G 61/00 20130101 |
Class at
Publication: |
257/040 ;
528/394 |
International
Class: |
H01L 029/08; C08G
079/08 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 6, 2001 |
DE |
10159946.3 |
Claims
1. (canceled)
2. A poly-arylene or -heteroarylene as claimed in claim 19,
characterised in that the aryl or heteroaryl compounds and the
aromatic or heteroaromatic radicals of the corresponding boron
compounds denote aromatic or heteroaromatic entities containing
from 2 to 40 c atoms which may be substituted by one or more
linear, branched or cyclic alkyl or alkoxy radicals containing from
1 to 20 c atoms wherein one or more non-consecutive CH.sub.2 groups
may also have been replaced by O, S, C.dbd.O or a carboxy group,
substituted or unsubstituted C-2 to C-20 aryl or heteroaryl
radicals, fluorine, cyano, nitro or sulphonic acid derivatives, or
which may be unsubstituted.
3. Poly-arylene or -heteroarylene according to claim 2 wherein said
halogen- or sulphonyloxy-functionalized aryl or heteroaryl are
compounds of formula (I) Ar--(X).sub.n (I) wherein Ar is an aryl or
heteroaryl radical as defined in claim 2, X denotes --Cl, --Br,
--I, --OS(O).sub.2R.sup.1, and R.sup.1 is an alkyl, aryl or
fluorinated alkyl radical, and n denotes at least 1.
4. Poly-arylene or -heteroarylene according to claim 2, wherein the
aromatic or heteroaromatic boron compounds are of the general
formula (II) Ar--(BQ.sub.1Q.sub.2).sub.m (II) wherein Ar is an aryl
or heteroaryl radical as defined in claim 2, Q.sub.1 and Q.sub.2
are the same or different and denote --OH, C.sub.1-C.sub.4alkoxy,
C.sub.1-C.sub.4aryloxy, C.sub.1-C.sub.4alkyl or halogen, or Q.sub.1
and Q.sub.2 together form a C.sub.1-C.sub.4alkylenedioxy group
which may optionally be substituted by one or more
C.sub.1-C.sub.4alkyl groups, or Q.sub.1 and Q.sub.2 and the boron
atom together are part of a boroxine ring of formula (III) 4and m
denotes at least 1.
5. Poly-arylene or -heteroarylene according to claim 19, wherein
the palladium compound consists of a palladium source and
optionally one or more additional components, the palladium source
being either salts of palladium(II), or palladium(0) compounds or
complexes or also metallic palladium, and the additional components
being ligands which can coordinate at the palladium metal
centre.
6. Poly-arylene or -heteroarylene according to claim 5, wherein
said additional component(s)are phosphine ligands from the group of
tri-aryl-phosphines, di-aryl-alkyl-phosphines,
aryl-dialkyl-phosphines, trialkyl-phosphines,
tri-heteroaryl-phosphines, di-heteroaryl-alkyl-phosp- hines,
heteroaryl-dialkyl-phosphines, optionally the substituents on the
phosphorus to be the same or different, chiral or achiral, and
optionally one or more of the substituents to link the phosphorus
groups of a plurality of phosphines and optionally for some of
those links to be one or more metal atoms, except that
triphenylphosphine is not used.
7. Poly-arylene or -heteroarylene according to claim 19, wherein
said water-miscible organic solvents has at least one solvent which
forms a clear, single-phase solution at room temperature both when
at least 5% by weight water is present in the solvent and when at
least 5% by weight solvent is present in water.
8. Poly-arylene or -heteroarylene according to claim 19, wherein
said water-immiscible organic solvent there is used at least one
solvent which no longer forms a clear, single-phase solution at
room temperature, that is to say phase separation is already
discernible, even when less than 5% by weight water is present in
the solvent or even when less than 5% by weight solvent is present
in water.
9. Poly-arylene or -heteroarylene according to claim 19, wherein in
the process, a reaction of one multifunctional compound with a
plurality of mono functional compounds to form one defined compound
of low molecular weight is carried out.
10. Poly-arylene or -heteroarylene according to claim 19, wherein
in the process, at least two different multifunctional compounds
are brought into reaction with one another and a polymeric product
is obtained.
11. Poly-arylene or -heteroarylene according to claim 10,
characterised in that the polymerisation is carried out in at least
two steps, an excess of one monomer being employed in the first
step so that a short-chain polymer having a first composition is
formed, and the remaining monomers being subsequently added in one
or more further step(s) so that finally the ratio of
boron-containing reactive groups and halogen- or
sulphonyloxy-containing reactive groups is 1:1.
12. Poly-arylene or -heteroarylene according to claim 11,
characterised in that the monomer composition of the second or
further steps is different to that of the first step, as a result
of which polymers having a block structure are formed.
13. Poly-arylene or -heteroarylene, having a weight-average degree
of polymerisation DP.sub.2 of at least 1000.
14. (canceled)
15. Electronic components comprising one or more polymer(s)
according to claim 13.
16. Poly-arylene or -heteroarylene according to claim 3, wherein n
is 1 to 20.
17. Poly-arylene or -heteroarylene according to claim 4, wherein m
is 1 to 20.
18. Poly-arylene or -heteroarylene according to claim 13 having a
M.sub.n in the range of 150,000 to 410,000 g/mol.
19. A poly-arylene or -heteroarylene having a weight-average degree
of polymerisation DP.sub.w of at least 1000 obtained by the process
of reacting a halogen- or sulphonyloxy-functional aryl or
heteroaryl compound with an aromatic or heteroaromatic boron
compound in the presence of a catalytic amount of a palladium
compound, a base and a multi-phase solvent mixture wherein an
aryl-aryl or aryl-heteroaryl or heteroaryl-heteroaryl C--C bond is
formed, characterised in that a. the solvent mixture comprises at
least 0.1% by volume of a compound from each of the following
groups i) water-miscible organic solvents ii) water-immiscible
organic solvents iii) water, with the proviso that both alcohols
and carbonyl compounds which contain .alpha.-hydrogen atoms are
excluded; b. and the palladium compound does not contain
triphenylphosphine or the latter is not specifically added to the
reaction mixture.
Description
[0001] The invention relates to the preparation of aryl-aryl
coupled compounds and materials. These materials play an important
role in industry, for example as liquid crystals, pharmaceuticals
and agrochemicals, to mention just a few application areas. These
compounds, in particular, are also of major importance especially
in the high-growth area of organic semi-conductors (for example,
applications in organic or polymeric light-emitting diodes, organic
solar cells, organic ICs).
[0002] For the synthesis of such compounds an extremely wide
variety of alternatives is known but these do not in all cases
offer a solution that is, for example, technically, economically
and ecologically satisfactory. In many processes there occur
undesirable reactions and undesirable products, which have to be
separated off and disposed of by costly means or which cannot be
removed and then may result in problems when the material is
used.
[0003] The efficiency of the process (degree of conversion) is
especially important when the reaction of one or more
multifunctional compound(s) is involved. An example of a reaction
of that kind is the reaction of a multifunctional compound with a
monofunctional compound resulting in a discrete molecule. A further
example is a polymerisation reaction in which one or more
multifunctional compound(s) is/are reacted with one or more further
multifunctional compound(s). In many polymer applications, a high
molecular weight is required in order to obtain the desired
physical properties, for example film formation, flexibility,
mechanical stability and other properties. Especially in the case
of organic semi-conductors, the electrical properties are greatly
influenced by the molecular weight--usually a very high molecular
weight is required in order to prevent defects such as short
circuits in the electrical device. Furthermore, a high degree of
process reproducibility is required for that application. The
degree of polymerisation (DP, average number of repeating units in
the chain) of a polymer built up by step-wise growth is related to
the degree of conversion of the reaction (p) as follows: 1 DP = 1 1
- p
[0004] When a high DP is desired, the reaction needs to be very
efficient, for example p=0.95, DP=20 or p=0.99, DP=100.
[0005] The so-called Suzuki reaction (Synthetic Communications,
11(7), 513, (1981)) has been found to be a suitable reaction for
the preparation of aryl-aryl coupled compounds; it involves the
hetero coupling of a halide- or sulphonoxy-functional aromatic
compound with a compound containing an aryl-boron functionality in
the presence of a base, a palladium compound and a solvent.
[0006] Several variations of the reaction parameters are known.
Generally, it is usual to carry out the reaction using two phases:
an aqueous phase containing the major part of a base and an organic
phase containing the major part of the aryl compounds. As organic
solvent there is often used a non-polar aromatic solvent, for
example benzene, toluene, xylenes (for example, Chem. Commun.,
1598, (1997)). It is also known to carry out the reaction in a
mixture of an aromatic solvent such as, for example, benzene or
toluene and an alcohol such as, for example, methanol or ethanol
(see, for example, J. Med. Chem., 40(4), 437, (1997)). Those
water-miscible solvents serve as reaction accelerators by improving
the contact between the base and the aromatic boron compound.
However, we have found, surprisingly, that the presence of such
.alpha.-H-functional alcohols results in undesirable subsidiary
products and accordingly in a reduction in reaction efficiency.
[0007] EP-A-0694530 teaches that a process based on a combination
of water-soluble complex ligands, a palladium compound soluble in
the organic phase, and sufficient water for the reaction mixture to
form an aqueous phase offers advantages for aryl compounds
especially containing electrophilic groups. However, that process
has several shortcomings:
[0008] Firstly, water-soluble ligands are problematic for highly
non-polar substrates because the concentrations both of the active
catalyst (water-soluble palladium-phosphine complex) and of the
highly non-polar starting materials are not sufficiently high in
the same phase to bring the reaction speed to a sensible level.
That problem with the reaction speed results in an increase in the
occurrence of subsidiary reactions and, as a result, in reduced
reaction efficiency.
[0009] Secondly, the process usually results in yields of only from
90 to 95%, which might be satisfactory for the purposes of
preparing a simple molecule (that is to say a molecule having just
one aryl-aryl coupled unit) but is not adequate for the preparation
of multiply coupled individual molecules or polymers.
[0010] Thirdly, the process is carried out using relatively high
molar ratios of palladium (about 1 mol %), resulting in high costs
and resource-intensive clean-up.
[0011] Fourthly, normally an excess of aromatic boron compound is
also employed in order to compensate for the hydrolysis of the
aryl-boron bond that occurs as a subsidiary reaction. That is
disadvantageous, on the one hand because of the waste of materials
but also, especially in the case of polymerisation, because a molar
ratio of exactly 1:1 is then required in order to obtain high
molecular weights and that molar ratio is adversely affected by the
hydrolysis.
[0012] JP-A-2001/089404 describes a process for the preparation of
polycyclic aromatic compounds wherein an aromatic boron compound is
coupled with an aromatic halogenated compound in the presence of a
carbonyl compound. The fact that the reaction is carried out in the
presence of a base results in problems of undesirable chemical
reactions between the base and the carbonyl compound. Those
subsidiary reactions are not only disadvantageous for the
efficiency of the main reaction but also result in the formation of
relatively large amounts of impurities.
[0013] Processes are also known in which a phase-transfer reagent
is used in order to improve the contact between the base and the
aromatic boron compound:
[0014] 1. U.S. Pat. No. 5,777,070 (WO 99/20675) describes a
polymerisation process for the reaction of a bifunctional aromatic
boron compound with a bifunctional aryl-halide in the presence of
an organic solvent, an aqueous solution of an inorganic base and a
catalytic amount of a palladium complex wherein a phase-transfer
catalyst (for example, a tetraalkylammonium salt) is employed in a
molar ratio of at least 0.01% (and preferably less than 10 mol %),
based on the aromatic boron compound. However, that process has
several problems which are also the subject of criticism in, for
example, WO 00/53656:
[0015] Firstly, the reaction proceeds relatively slowly and the
polymer that is prepared exhibits discoloration.
[0016] Secondly, the reaction is not reproducible in terms of
molecular weight.
[0017] Thirdly, foam formation is observed during the reaction and
deposition of subsidiary products occurs on the reactor wall,
resulting in a process that can be scaled-up only with
difficulty.
[0018] 2. WO 00/53656 reports on a related process, in which as
base there is used an organic compound (for example, a
tetraalkylammonium hydroxide) which is effective in increasing the
concentration of base in the organic phase, resulting in the
reaction's proceeding much more rapidly. However, we have found
that there are disadvantages to the process:
[0019] When the reaction according to the described process is
carried out in a non-polar solvent such as toluene, a white solid
is precipitated from the reaction mixture, which solid can be
re-dissolved only with difficulty (the reaction mixture is still
cloudy even after 20 hours). It is to be presumed that the solid is
a salt of the R.sub.4N.sup.+[ArBR'.su- b.2(OH)].sup.- type. The
reaction accordingly proceeds slowly and still remains
heterogeneous even after a relatively long period, which means that
an end point is not reached. This means, inter alia, that a really
high molecular weight is not obtained in the case of polymers.
[0020] Secondly, under various conditions the reaction results in
various kinds of discoloration; when the reaction is carried out in
the presence of a non-polar solvent such as toluene, the polymer
exhibits a slightly grey-black discoloration, whereas in the
presence of a polar solvent (for example, THF or dioxane) the
polymer has a yellow discoloration. The grey-black colour is due to
decomposition of the palladium catalyst, with colloidal palladium
separating out. The yellow colour indicates decomposition of the
base or of the salt formed therefrom. Those impurities are
undesirable especially in the case of electronic applications (for
example, as organic semi-conductors in light-emitting diodes)
because they result in considerable impairment of quality.
[0021] Furthermore, the use of those bases has further
disadvantages:
[0022] The described bases (and the borate salts formed therefrom)
are, by virtue of their nature, phase-transfer catalysts and
accordingly can be separated off from the product only by
relatively resource-intensive means, resulting in the fact that
work-up takes longer and, therefore, becomes more costly and
residues that may not have been removed can have an adverse effect
in use.
[0023] In addition, such organic bases are generally more expensive
by a factor of from 5 to 10 than the mineral bases otherwise used
(such as, for example, carbonates or phosphates of alkali
metals).
[0024] Furthermore, bases of that kind also result, in many cases,
in foam formation.
[0025] Fourthly, a relatively large amount of catalyst (about 0.15
mol %, based on the amount of aryl-halogen groups) is needed,
resulting in palladium concentrations in the crude polymer in the
range from 100 to 1000 ppm, which in turn results in the problems
of work-up and residual impurities that have already been discussed
a number of times hereinbefore.
[0026] From this critique of the prior art it is clear that there
is still a need for processes of high efficiency which, at a low
catalyst concentration, result in aryl-aryl coupled compounds with
a minimum of undesirable reactions. We have now found surprisingly
that, by using certain solvent mixtures in the presence of very low
concentrations of palladium compounds which do not contain
triphenylphosphine, the Suzuki reaction proceeds with especially
high reaction efficiency.
[0027] The invention accordingly relates to a process for the
reaction of a halogen- or sulphonyloxy-functional aryl or
heteroaryl compound with an aromatic or heteroaromatic boron
compound in the presence of a catalytic amount of a palladium
compound, a base and a solvent mixture wherein an aryl-aryl or
aryl-heteroaryl or heteroaryl-heteroaryl C--C bond is formed,
characterised in that
[0028] a. the solvent mixture comprises at least 0.1% by volume of
a compound from each of the following groups
[0029] i) water-miscible organic solvents
[0030] ii) water-immiscible organic solvents
[0031] iii) water,
[0032] with the proviso that both alcohols and carbonyl compounds
which contain a-hydrogen atoms are excluded;
[0033] b. the palladium compound does not contain
triphenylphosphine or the latter is not actually added to the
reaction mixture.
[0034] The reaction according to the invention can then proceed
(depending on the exact composition and temperature) with either
one or more than one phase or may also change in that regard whilst
the reaction is being carried out. However, the reaction according
to the invention preferably proceeds with more than one phase.
[0035] Aryl or heteroaryl compounds and the aromatic or
heteroaromatic radicals of the corresponding boron compounds are
aromatic or heteroaromatic entities containing from 2 to 40 C atoms
which may be substituted by one or more linear, branched or cyclic
alkyl or alkoxy radicals containing from 1 to 20 C atoms wherein
one or more non-consecutive CH.sub.2 groups may also have been
replaced by O, S, C.dbd.O or a carboxy group, substituted or
unsubstituted C-2 to C-20 aryl or heteroaryl radicals, fluorine,
cyano, nitro or sulphonic acid derivatives, or which may be
unsubstituted. Simple compounds which may preferably be used are
the corresponding substituted or unsubstituted derivatives of
benzene, naphthalene, anthracene, pyrene, biphenyl, fluorene,
spiro-9,9'-bifluorene, phenanthrene, triptycene, pyridine, furan,
thiophene, benzothiadiazole, pyrrole, quinoline, quinoxaline,
pyrimidine and pyrazine. There are, furthermore, expressly included
corresponding (as defined by the text hereinbefore) multifunctional
compounds and also oligomers formed during polymerisation which
have functional aryl or heteroaryl terminal groups.
[0036] The starting compounds for the process according to the
invention are, on the one hand, halogen- or
sulphonyloxy-functionalised aryl or heteroaryl compounds of formula
(I)
Ar--(X).sub.n (I)
[0037] wherein Ar is an aryl or heteroaryl radical as defined
hereinbefore, X denotes --Cl, --Br, --I, --OS(O).sub.2R.sup.1, and
R.sup.1 is an alkyl, aryl or fluorinated alkyl radical and n
denotes at least 1, preferably from 1 to 20, especially 1, 2, 3, 4,
5 or 6.
[0038] The second class of starting compounds for the process
according to the invention comprises aromatic or heteroaromatic
boron compounds of the general formula (II)
Ar--(BQ.sub.1Q.sub.2).sub.m (II)
[0039] wherein Ar is an aryl or heteroaryl radical as defined
hereinbefore, Q.sub.1, and Q.sub.2 are the same or different on
each occurrence and denote --OH, C.sub.1-C.sub.4alkoxy,
C.sub.1-C.sub.4aryloxy, C.sub.1-C.sub.4alkyl or halogen, or Q.sub.1
and Q.sub.2 together form a C.sub.1-C.sub.4alkylenedioxy group
which may optionally be substituted by one or more
C.sub.1-C.sub.4alkyl groups, or Q.sub.1 and Q.sub.2 and the boron
atom together are part of a boroxine ring of formula (III) or of
similar boronic anhydrides or partial anhydrides 1
[0040] and m denotes at least 1, preferably from 1 to 20,
especially 1, 2, 3, 4, 5 or 6.
[0041] For the synthesis of linear polymers, the value 2 is
preferably selected for n and m simultaneously.
[0042] The palladium compound consists of a palladium source and
optionally one or more additional components.
[0043] The palladium source may be either a palladium compound or
metallic palladium. Suitable palladium sources are salts of
palladium(II), or palladium(0) compounds or complexes. Preferred
palladium sources are palladium(II) halides, palladium(II)
carboxylates, palladium(II) .beta.-diketonates,
tris(dibenzylideneacetone)dipalladium(0) (Pd.sub.2 dba.sub.3),
dichloro(bisbenzonitrile)palladium(II),
dichloro(1,5-cyclooctadiene)-palladium(II),
tetrakis(triarylphosphino)pal- ladium(0) or discrete compounds of
palladium with the additional components described as follows.
[0044] Additional components that may be used for the formation of
the active palladium compound are, in the widest sense, ligands
which can coordinate at the palladium metal centre.
[0045] Preferred variants are phosphine ligands from the group of
tri-aryl-phosphines, di-aryl-alkyl-phosphines,
aryl-dialkyl-phosphines, trialkyl-phosphines,
tri-heteroaryl-phosphines, di-heteroaryl-alkyl-phosp- hines,
heteroaryl-dialkyl-phosphines, it being possible for the
substituents on the phosphorus to be the same or different, chiral
or achiral, it being possible for one or more of the substituents
to link the phosphorus groups of a plurality of phosphines and it
also being possible for some of those links to be one or more metal
atoms, with the exception of triphenylphosphine. Furthermore,
halo-phosphines, dihalo-phosphines, alkoxy- or aryloxy-phosphines,
dialkoxy- or diaryloxy-phosphines may also be used.
[0046] Very special preference is given to, inter alia, substituted
triphenylphosphines according to formula (IV), 2
[0047] wherein
[0048] Y.sub.1 to Y.sub.15 are the same or different and are
hydrogen, alkyl, aryl, alkoxy, dialkylamino, chlorine, fluorine,
sulphonic acid, cyano or nitro radicals, with the proviso that at
least 1 but preferably 3 or more of the substituents Y.sub.1 to
Y.sub.15 are not hydrogen. Examples of the variants to which very
special preference is given are tris(o- or m- or p-tolyl)phosphine,
tris(o- or m- or p-anisyl)phosphine, tris(o- or m- or
p-fluorophenyl)-phosphine, tris(o- or m- or
p-chlorophenyl)phosphine, tris(2,6-dimethylphenyl)-phosphine,
tris(2,6-dimethoxyphenyl)phosphine, tris(mesityl)phosphine,
tris(2,4,6-trimethoxyphenyl)phosphine and
tris(pentafluorophenyl)phosphin- e.
[0049] Further preferred ligands are
tert-butyl-di-o-tolylphosphine, di-tert-butyl-o-tolyl-phosphine,
dicyclohexyl-2-biphenylphosphine,
di-tert-butyl-2-biphenylphosphine, triethylphosphine,
tri-iso-propyl-phosphine, tri-cyclohexylphosphine,
tri-tert-butylphosphine, tri-tert-pentylphosphine,
bis(di-tert-butylphosphino)methane and
1,1'-bis(di-tert-butylphosphino)fe- rrocene.
[0050] Triphenylphosphine has been excluded from the invention
because it was found, surprisingly, that it results in an
especially high level of undesirable reactions. The use of the
other ligands according to the invention, as described
hereinbefore, avoids those disadvantages.
[0051] The palladium compound may be either in solid (that is to
say heterogeneous) or dissolved form and, in the latter case, may
be dissolved either in the organic phase or in the aqueous
phase.
[0052] In the process according to the invention, the palladium
compound is usually employed in an amount of from 0.00001 mol % to
5 mol % (palladium), based on the amount of C--C links to be
closed. Preference is given here to the range from 0.001% to 2%,
especially the range from 0.001% to 1%.
[0053] The additional component (ligand) is usually added in the
range from 10:1 to 1:2, preferably in the range from 8:1 to 1:1,
based on the palladium content.
[0054] The bases are used, for example, analogously to U.S. Pat.
No. 5,777,070. There are used, for example, alkali and alkaline
earth metal hydroxides, carboxylates, carbonates, fluorides and
phosphates such as sodium and potassium hydroxide, acetate,
carbonate, fluoride and phosphate or also metal alcoholates,
preferably corresponding phosphates or carbonates. Where
appropriate, mixtures of bases may be used.
[0055] As understood by this Application, a "water-miscible organic
solvent" means a solvent which forms a clear, single-phase solution
at room temperature both when at least 5% by weight water is
present in the solvent and when at least 5% by weight solvent is
present in water.
[0056] Preferred solvents of that kind are organic ethers, esters,
nitrites, tertiary alcohols, sulphoxides, amides and carbonates,
especially ethers and very especially dioxane, tetrahydrofuran,
ethylene glycol ether, DME and various polyethylene glycol ethers.
In the process according to the invention, preference is given to
one or more solvents selected from that class in a range (based on
the total volume of the reaction mixture) from 1 to 90%, especially
in a range from 10 to 75%, very especially in a range from 25 to
75%.
[0057] As understood by this Application, a "water-immiscible
organic solvent" means a solvent which no longer forms a clear,
single-phase solution at room temperature, that is to say phase
separation is already discernible, even when less than 5% by weight
water is present in the solvent or even when less than 5% by weight
solvent is present in water.
[0058] Preferred water-immiscible solvents are aromatic and
aliphatic hydrocarbons, non-polar ethers, chlorine-containing
hydrocarbons, preferably aromatic hydrocarbons, very especially
toluene, xylenes or anisole.
[0059] In the process according to the invention, preference is
given to one or more solvents selected from that class in a range
(based on the total volume of the reaction mixture) from 1 to 70%,
especially in a range from 10 to 50%, very especially in a range
from 15 to 50%.
[0060] The water used is usually of normal quality, that is to say
tap water, where appropriate having been deionised. For special
requirements it is of course possible also to use grades which are
of better purity or from which salts have been removed. In the
process according to the invention, preference is given to using
water in a range (based on the total volume of the reaction
mixture) from 1 to 50%, especially from 5 to 35%.
[0061] The process according to the invention is usually slightly
exothermic, although generally requires slight activation. The
reaction is, therefore, frequently carried out at temperatures
above room temperature. A preferred temperature range is,
therefore, the range between room temperature and the boiling point
of the reaction mixture, especially the temperature range between
40 and 120.degree. C., very especially the range between 40 and
100.degree. C. However, it is also possible that the reaction will
proceed sufficiently rapidly even at room temperature so that no
active heating is required.
[0062] The reaction is performed with stirring, it being possible
to use simple stirrers or high-viscosity stirrers depending on the
viscosity of the reaction mixture. In the case of high viscosities,
vortex breakers may also be used.
[0063] The concentrations of the reaction components will depend
greatly on the reaction in question. Whereas polymerisations
(because of the increase in viscosity they involve) are frequently
carried out at concentrations in the range below 1 mol/l (based on
the C--C bonds to be closed), a higher concentration range may also
be used in the synthesis of defined individual molecules.
[0064] The reaction time may, in principle, be freely selected and
will be based on the speed of the reaction in question. A
technically sensible frame of reference will certainly be in the
range from a few minutes up to 100 hours, preferably in the range
15 from 15 minutes to 24 hours.
[0065] The reaction per se proceeds at normal pressure. However, it
may well also be technically advantageous to proceed at elevated or
reduced pressure. This will depend greatly on the individual
reaction and, especially, on the equipment available.
[0066] The advantages of the described process according to the
invention are, inter a/ia, as follows:
[0067] Outstanding efficiency (degree of conversion), as a result
of which materials are obtained which contain very few flaws. The
process according to the invention is advantageous especially in
the case of multifunctional compounds because the efficiency effect
is then potentiated. Very especially in the case of polymerisations
wherein the starting materials usually contain two groups to be
reacted and the aryl-aryl coupling is carried out a number of times
in succession to form a molecule in the form of a chain, the
process according to the invention results in chains of
extraordinarily great length and in extraordinarily high molecular
weights.
[0068] A particular advantage of the present invention is that, by
virtue of the improved efficiency of the Suzuki reaction, the
amount of expensive palladium catalyst employed can be reduced.
This means that manufacturing costs are reduced and, in addition,
the amounts of residual palladium in the product are dramatically
reduced. This brings technical advantages, for example avoidance of
an impaired product colour, although the reduction in such
impurities is advantageous especially in the case of organic
semi-conductors because the presence of metal residues will result
in impairments in use.
[0069] The further disadvantages, as described hereinbefore for the
Applications WO 00/53656 and U.S. Pat. No. 5,777,070 (WO 99/20675),
either are entirely overcome (for example, relatively expensive
bases or phase-transfer catalysts) or are at least greatly
mitigated (foam formation).
[0070] Because the process according to the invention--as described
hereinbefore--is of very high efficiency, a preferred embodiment is
the reaction of multifunctional molecules either to form defined
individual molecules or to form polymers. As understood by this
Application, "multifunctional" means that a compound contains a
plurality of (for example, two, three, four, five etc.) identical
or similar functional units which, in the reaction in question (in
this case the Suzuki reaction), all react in the same way to
produce one product molecule. "Multifunctional" is intended also to
include molecules that contain a plurality of functional groups
that react with one another (for example, a molecule that contains
both at least one aromatic halogen group and also at least one
aromatic boron group--a so-called AB monomer). The reaction of
multifunctional compounds firstly means herein the reaction of one
multifunctional compound with a plurality of monofunctional
compounds to form one defined compound "of low molecular weight".
When, on the other hand, (at least) two different multifunctional
compounds are brought into reaction with one another, the product
will have a polymeric character. This too expressly constitutes a
Suzuki reaction as understood by this invention.
[0071] As will be seen from the context, "of low molecular weight"
as understood by the present invention denotes molecules having a
defined molar mass, which will always be <10000 g/mol, and also
preferably <2000 g/mol.
[0072] In accordance with the present invention, a polymeric
character is present when the characterising properties (for
example, solubility, melting point, glass transition temperature
etc.) do not change or change only insubstantially when an
individual repeating unit is added or omitted. A simpler definition
(especially to contrast with the statements relating to "of low
molecular weight") is the indication of molecular weight, according
to which a "polymeric character" is to be defined as a molecular
weight of >10000 g/mol.
[0073] As described hereinbefore, a preferred embodiment of the
process according to the invention is the use thereof in the
linking of a multifunctional compound to a plurality of
monofunctional compounds.
[0074] The compounds thereby produced are distinguished by the
absence (or a very low content) of structural defects produced by
the reaction.
[0075] Those compounds, produced by the process according to the
invention, consequently exhibit significant improvements over the
prior art, and the invention accordingly also relates thereto.
[0076] As described hereinbefore, a further preferred embodiment of
the process according to the invention is the use thereof during a
polymerisation reaction. The polyarylenes (this term is here
intended also to include copolymers that do not contain arylene or
heteroarylene units in the main chain) thereby produced are
distinguished by a high (but also readily controllable) molecular
weight and by the absence (or a very low content) of structural
defects produced by the polymerisation. Those polymers, produced by
the process according to the invention, consequently exhibit
significant improvements over the prior art, and the invention
accordingly also relates thereto.
[0077] This process makes possible the preparation of poly-arylenes
or -heteroarylenes having higher molecular weights than previously
known. The highest previously published weight-average degree of
polymerisation (M.sub.w, measured by GPC, divided by the average
molecular weight of the repeating unit(s)) is about 950 and the
process according to the invention yields polymers which in some
cases have significantly higher values (see Example 5). The
invention accordingly relates also to poly-arylenes or
-heteroarylenes having a weight-average degree of polymerisation
DP.sub.w of more than 1000.
[0078] A preferred polymerisation process-according to the
invention may be described as follows:
[0079] As "water-miscible organic solvent" there is used dioxane or
THF in the range from 25 to 75% (based on the total volume of the
solution).
[0080] As "water-immiscible organic solvent" there is used an
aromatic solvent, for example toluene, a xylene, chlorobenzene or
anisole, preferably toluene or a xylene, in the range from 15 to
50%.
[0081] Water is added in the range from about 5 to 50%.
[0082] The monomers are used in a concentration range from 20 to
200 mmol/l. Either the two different functionalities (halide or
sulphonyloxy versus boron groups) are set out in the ratio 1:1 (as
exactly as possible) at the outset or that ratio is brought about
in the course of the reaction by subsequent (either continuous or
batch-wise) addition of one of the two functionalities to an excess
of the other functionality.
[0083] Where appropriate, small amounts of monofunctional compounds
("end-cappers") or tri- or multi-functional groups ("branchers")
are added.
[0084] The palladium compound is added in a ratio of from 1:10000
to 1:50, preferably from 1:5000 to 1:100, based on the number of
bonds to be closed. In this case, preference is given, for example,
to the use of palladium(II) salts such as PdAc.sub.2 or Pd.sub.2
dba.sub.3 and to the addition of ligands such as P(o-Tol).sub.3,
the latter in a ratio of from 1:1 to 1:10, based on Pd.
[0085] As base there is preferably used, for example,
K.sub.3PO.sub.4, which is preferably added in a ratio of from 0.8:1
to 5:1, based on the number of bonds to be closed.
[0086] The reaction is maintained under reflux with vigorous
stirring and carried out over a period of about from 1 hour to 24
hours.
[0087] It has been found to be advantageous at the end of the
reaction to carry out so-called end-capping, that is to say to add
monofunctional compounds which will catch any reactive end groups
in the polymers.
[0088] At the end of the reaction, the polymer may be further
purified by customary purification procedures such as, for example,
precipitation, reprecipitation, extraction and the like. For use in
high-quality applications (for example, polymeric light-emitting
diodes), contamination with organic (for example, oligomeric) and
inorganic substances (for example, Pd residues, base residues)
usually has to be brought to as low a level as possible. That may
be achieved,
[0089] for Pd, in a very great variety of ways, for example by
means of ion-exchangers, liquid-liquid extraction, extraction with
complex-formers and other procedures,
[0090] for the removal of low-molecular-weight substances, for
example by solid-liquid or liquid-liquid extraction or also by
reprecipitation a number of times,
[0091] for the removal of further inorganic impurities, for example
by the procedures already described for Pd and low-molecular-weight
substances and also by extraction with, for example, inorganic
mineral acids.
[0092] In a further possible embodiment of the polymerisation
described above, the polymerisation is carried out in at least two
steps, an excess of one of the monomers being employed in the first
step so that a short-chain polymer having a first composition is
formed. "Short-chain" herein means that there is only formed, at
first, an oligomer having a few (for example, between 3 and 20)
repeating units. The remaining monomers are subsequently added in
one or more further step(s) so that finally the ratio of
boron-containing reactive groups and halogen- or
sulphonyloxy-containing reactive groups is 1:1.
[0093] The monomer composition of the second or further steps is
preferably different to that of the first step, as a result of
which polymers having a block-like structure are formed.
[0094] A "block-like structure" herein means the following: as a
result of the first step there is formed, for example, an oligomer
having the sequence B(AB)N wherein A and B are the two monomer
units used, B being the monomer used in excess and n being the
average length of those oligomers. Subsequently, there is then
added, for example, a monomer C so that the total number of
reactive end groups is balanced out. This results finally in a
polymer mainly comprising sequences as follows:
(C[B(AB).sub.n]).sub.m wherein m is the average chain length of the
polymer thereby defined; that is to say blocks having the structure
B(AB)N alternate with C and the polymer has a block-like structure.
Of course it is also possible, depending on the sequence of monomer
addition, to produce further block-like structures by means of the
process described.
[0095] The process according to the invention makes possible the
preparation of high-molecular-weight polymers having that
block-like form because, in contrast to the processes known
hitherto, it has an especially non-damaging effect on the boron-,
halogen- or sulphonyloxy-containing reactive groups in the absence
of the corresponding counterpart groups.
[0096] Using the process described herein, it is now possible to
prepare, for example, polyarylenes as described in EP-A-842.208, WO
00/22026, WO 00/46321, WO 99/54385, WO 00/55927, WO 97/31048, WO
97/39045, WO 92/18552, WO 95/07955, EP-A-690.086, WO 02/044060 and
in the specification of Application DE 10143353.0, which has not
yet been laid open for public inspection. The polymers prepared by
the process according to the invention frequently exhibit
advantages over the statements made in the cited literature, for
example with respect to freedom from defects, molecular weight,
molecular weight distribution and frequently also, therefore, with
respect to the corresponding properties of use.
[0097] The polymers according to the invention can be used in
electronic components such as organic light-emitting diodes
(OLEDs), organic integrated circuits (O--ICs), organic field-effect
transistors (OFETs), organic thin-film transistors (OTFTs), organic
solar cells (O-SCs), organic laser diodes (O-lasers), organic
colour filters for liquid crystal displays or organic
photoreceptors, to which the present invention also relates.
[0098] The described invention is illustrated by the description
and the examples that are given hereinbelow although it is in no
way limited thereto but may of course be readily applied by the
person skilled in the art to the systems indicated above or
described in the cited literature.
[0099] Part A. Examples of the Process According to the
Invention
[0100] A1: Preparation of Multifunctional Compounds
[0101] Preparation of
2,2',7,7'-tetrakis(biphenyl-4-yl)-9,9'-spirobifluore- ne,
procedure: 2,2',7,7'-Tetrabromo-9,9'-spirobifluorene (158.0 g, 250
mmol), biphenyl-4-boronic acid (239.0 g, 1200 mmol) and potassium
phosphate (447 g, 2100 mmol) were suspended in a mixture of 700 mL
of toluene, 700 mL of dioxane and 1000 mL of water, and argon was
passed through the solution for 30 minutes. There were then added
tris-o-tolylphosphine (0.459 g, 1.5 mmol) and, 5 minutes later, 58
mg (0.25 mmol) of palladium acetate, and the reaction mixture was
heated at 87.degree. C. After 8 hours, the mixture was cooled to
room temperature and the precipitated solid was filtered off and
washed with water and then with toluene, yielding 222 g (96% of
theory) of the desired product, which, according to HPLC without
further purification, had a purity of 99.6%.
[0102] .sup.1H NMR (CDCl.sub.3): 7.98 (d, 4H, H-4), 7.72 (dd, 4H,
H-3), 7.54 (m, 24H, phenyl-H), 7.40 (m, 8H, phenyl-H), 7.31 (m, 4H,
phenyl-H), 7.10 (d, 4H, H-1).
[0103] A2: Preparation of Polymers
[0104] The synthesis of the monomers used in this Application has
been described in the specification of Application WO 02/077060.
The monomers used are reproduced as follows: 3
EXAMPLE P1
[0105] Use of dioxane/toluene mixture with 0.025 mol % Pd.
Copolymerisation of 50 mol % 2', 3, 6, 7'-tetra
(2-methylbutyloxy)spirobi- fluorene-2,7-bisboronic acid ethylene
glycol ester (M1), 50 mol %
2,7-dibromo-9-(2',5'-dimethyl-phenyl)-9-[3",4"-bis(2-methyl-butyloxy)phen-
yl]fluorene (M2) (polymer P1).
[0106] 3.3827 g (5.00 mmol) of M2 (content: 99.85%), 4.0033 g (5.00
mmol) of M1 (content: 99.4%), 4.89 g (21.25 mmol) of
K.sub.3PO.sub.4.H.sub.2O, 15.6 mL of toluene, 46.9 mL of dioxane
and 8.5 mL of water were degassed by passing argon through for 30
minutes. There were then added 4.56 mg (15 .mu.mol) of
tris-o-tolylphosphine and, 5 minutes later, 0.56 mg (2.5 .mu.mol)
of palladium acetate under a protective gas. The suspension was
vigorously stirred under a blanket of argon at an internal
temperature of 87.degree. C. (slight reflux). After 2 hours,
because of the high viscosity, a further 15.6 mL of toluene and
46.9 mL of dioxane were added. After 6 hours, a further 0.30 g of
M1 was added. After heating for a further 1 hour, 0.3 mL of
bromobenzene was added and was heated at reflux for a further 1
hour.
[0107] The reaction solution was diluted with 200 mL of toluene and
the solution was stirred with 100 mL of 1% aqueous NaCN for 3
hours. The organic phase was washed 3 times with H.sub.2O and
precipitation was carried out by adding to 500 mL of methanol. The
polymer was dissolved in 600 mL of THF for 1 hour at
5.sup.0.degree. C., precipitated using 1200 mL of MeOH, washed and
dried in vacuo. Reprecipitation was carried out again in 600 mL of
THF/1200 mL of methanol, followed by filtration under suction and
drying to constant weight. 5.16 g (8.78 mmol, 87.8%) of the polymer
P1 were obtained in the form of a colourless solid.
[0108] .sup.1H NMR (C.sub.2D.sub.2Cl.sub.4): 7.8-7.1 (m, 9H,
fluorene, spiro); 6.6 (br. s, 1H, fluorene), 6.21 (br s, 1H,
spiro); 4.0-3.4 (3.times.m, 6H, OCH.sub.2), 2.16 (s, 1.5H,
CH.sub.3); 1.9-0.7 (m, alkyl H).
[0109] GPC: THF; 1 mL/min, PL-gel 10 .mu.m Mixed-B
2.times.300.times.7.5 mm.sup.2, 35.degree. C., RI detection:
Mw=814000 g/mol, Mn=267000 g/mol.
EXAMPLE P2
[0110] Use of dioxane/toluene mixture with 0.0125 mol % Pd.
Copolymerisation of 50 mol % 2, 3',
6',7'-tetra(2-methylbutyloxy)spirobif- luorene-2,7-bisboronic acid
ethylene glycol ester (M1), 40 mol %
2,7-dibromo-9-(2,5'-dimethyl-phenyl)-9-[3",4"-bis(2-methyl-butyloxy)pheny-
l]fluorene (M2) and 10 mol %
N,N'-bis(4-bromophenyl)-N,N'-bis(4-tert-butyl- phenyl)benzidine
(M3) (polymer P2).
[0111] 13.5308 g (20.00 mmol) of M2 (content: 99.85%), 20.0164 g
(25 mmol) of M1 (content: 99.4%), 3.7932 g (5.00 mmol) of M3
(content: 99.5%), 24.47 g (106.25 mmol) of
K.sub.3PO.sub.4.H.sub.2O, 78 mL of toluene, 234 mL of dioxane and
44 mL of water were degassed by passing argon through for 30
minutes. There were then added 11.4 mg (37 .mu.mol) of
tris-o-tolylphosphine and, 5 minutes later, 1.40 mg (6.25 .mu.mol)
of palladium acetate under a protective gas. The suspension was
vigorously stirred under a blanket of argon at an internal
temperature of 87.degree. C. (slight reflux). After 2 hours,
because of the high viscosity, a further 39 mL of toluene and 117
mL of dioxane were added. After 6 hours, a further 0.36 g of M1 was
added. After heating for a further 30 minutes, 0.5 mL of
bromobenzene was added and was heated at reflux for a further 15
minutes.
[0112] The reaction solution was diluted with 500 mL of toluene and
was stirred with 100 mL of 2% aqueous NaCN for 3 hours. The organic
phase was washed 3 times with H.sub.2O and precipitation was
carried out by adding to 2500 mL of methanol. The polymer was
dissolved in 1500 mL of THF for 1 hour at 50.degree. C.,
precipitated using 3000 mL of MeOH, washed and dried in vacuo.
Reprecipitation was carried out again in 1500 mL of THF/3000 mL of
methanol, followed by filtration under suction and drying to
constant weight. 27.005 g (45.3 mmol, 90.6%) of the polymer P2 were
obtained in the form of a slightly yellowish solid.
[0113] .sup.1H NMR (C.sub.2D.sub.2Cl.sub.4): 7.9-6.8 (m, 10.4 H,
fluorene, spiro, TAD); 6.6 (br. s, 0.8H, fluorene), 6.21 (m, 1H,
spiro); 4.0-3.4 (3.times.m, 5.6H, OCH.sub.2), 2.16 (s, 1.2H,
CH.sub.3);
[0114] 1.9-0.7 (m, alkyl H, including tert-butyl at 1.30).
[0115] GPC: THF; 1 mL/min, PL-gel 10 .mu.m Mixed-B
2.times.300.times.7.5 mm.sup.2, 35.degree. C., RI detection:
Mw=630000 g/mol, Mn=240000 g/mol.
EXAMPLE P3
[0116] Use of toluene/dioxane mixture and 0.1 mol % Pd with
thiophene-containing monomers. Copolymerisation of 50 mol % 2,3',6,
7'-tetra(2-methyl-butyloxy)spirobifluorene-2,7-bisboronic acid
ethylene glycol ester (M1), 35 mol %
4,7-dibromo-benzo[1,2,5]thiadiazole (M4), 10 mol %
N,N'-bis(4-bromophenyl)-N,N'-bis(4-tert-butylphenyl)benzidine (M3)
and 5 mol % bis-4,7-(2'-bromo-5'-thienyl)-2, 1,3-benzothiadiazole
(M5) (polymer P3)
[0117] 8.0065 g (10.00 mmol) of M1 (content: 99.4%), 2.0578 g (7
mmol) of M4 (content: 99.8%), 1.5173 g (2.00 mmol) of M3 (content:
99.5%), 0.4582 g (1.00 mmol) of M5 (content: 99.8%), 10.13 g (44.00
mmol) of K.sub.3PO.sub.4.H.sub.2O, 25 mL of toluene, 75 mL of
dioxane and 50 mL of water were degassed by passing argon through
for 30 minutes. There were then added 36.5 mg (120 .mu.mol) of
tris-o-tolylphosphine and, 5 minutes later, 4.49 mg (20 .mu.mol) of
palladium acetate under a protective gas. The suspension was
vigorously stirred under a blanket of argon at an internal
temperature of 87.degree. C. (slight reflux). After 30 minutes,
because of the high viscosity, a further 40 mL of toluene and,
after 90 minutes, a further 30 mL toluene were added. After 6
hours, a further 0.2 g of M1 was added. After heating for a further
30 minutes, 0.3 mL of bromobenzene was added and was heated at
reflux for a further 15 minutes.
[0118] The reaction solution was diluted with 200 mL of toluene and
was stirred with 100 mL of 2% aqueous NaCN for 3 hours. The organic
phase was washed 3 times with H.sub.2O and precipitation was
carried out by adding to 1000 mL of methanol. The polymer was
dissolved in 600 mL of THF for 1 hour at 50.degree. C.,
precipitated using 1200 mL of MeOH, washed and dried in vacuo.
Reprecipitation was carried out again in 600 mL of THF/1200 mL of
methanol, followed by filtration under suction and drying to
constant weight. 8.65 g (18.8 mmol, 94.2%) of the polymer P3 were
obtained in the form of a deep red solid.
[0119] .sup.1H NMR (CDCl.sub.3): 8.2-6.8 (m, 7.4H, Spiro, TAD,
benzothiadiazole and thiophene); 6.6 (br. s, 0.8H, fluorene), 6.21
(m, 1H, Spiro); 4.0-3.4 (2.times.m, 4H, OCH.sub.2); 1.9-0.7 (m,
alkyl H, including tert-butyl at 1.24).
[0120] GPC: THF; 1 mL/min, PL-gel 10 .mu.m Mixed-B
2.times.300.times.7.5 mm.sup.2, 35.degree. C., RI detection:
Mw=470000 g/mol, Mn=163000 g/mol.
EXAMPLE P4
[0121] Copolymer in 2 steps to form the polymer of block-like
structure. First step, copolymerisation of 12.5 mol %
2',3',6',7'-tetra(2-methylbuty-
loxy)spiro-bifluorene-2,7-bisboronic acid ethylene glycol ester
(M1) and 10 mol %
N,N'-bis(4-bromophenyl)-N,N'-bis(4-tert-butylphenyl)benzidine (M3).
Second step, addition of 37.5 mol % 2, 3, 6,
7'-tetra(2-methylbutyloxy)spirobifluorene-2,7-bisboronic acid
ethylene glycol ester (M1) and 40 mol %
2,7-dibromo-9-(2',5'-dimethyl-phenyl)-9-[3- ",
4"-bis(2-methyl-butyloxy)phenyl]fluorene (M2) (polymer P4)
[0122] 0.8007 g (1.00 mmol) of M1 (content: 99.4%), 0.6069 g (0.80
mmol) of M3 (content: 99.5%), 3.91 g (17.00 mmol) of
K.sub.3PO.sub.4.H.sub.2O, 2.5 mL of toluene, 7.5 mL of dioxane and
8.5 mL of water were degassed by passing argon through for 30
minutes. There were then added 3.65 mg (12 .mu.mol) of
tris-o-tolylphosphine and, 5 minutes later, 0.45 mg (2.0 .mu.mol)
of palladium acetate under a protective gas. The suspension was
vigorously stirred under a blanket of argon at an internal
temperature of 87.degree. C. (slight reflux) for 2 hours. According
to NMR, 20% of the original boronic acid ethylene glycol ester
groups were still present (signal at 4.28 ppm in CDCl.sub.3), which
was also expected from the stoichiometry. Then, there were further
added 2.4020 g (3.00 mmol) of M1 (content: 99.4%), 2.1649 g (3.2
mmol) of M2 (content: 99.85%), 10 mL of toluene and 30 mL of
dioxane. After 2 hours, because of the high viscosity, a further
12.5 mL of toluene and 37.5 mL of dioxane were added. After 6
hours, a further 0.30 g of M1 was added. After heating for a
further 1 hour, 0.3 mL of bromobenzene was added and was heated at
reflux for a further 1 hour. The reaction solution was diluted with
200 mL of toluene and was stirred with 100 mL of 1% aqueous NaCN
for 3 hours. The organic phase was washed 3 times with H.sub.2O and
precipitation was carried out by adding to 400 mL of methanol. The
polymer was dissolved in 300 mL of THF for 1 hour at 50.degree. C.,
precipitated using 600 mL of MeOH, washed and dried in vacuo.
Reprecipitation was carried out again in 300 mL of THF/600 mL of
methanol, followed by filtration under suction and drying to
constant weight. 4.23 g (7.10 mmol, 88.7%) of the polymer P4 were
obtained in the form of a slightly yellowish solid.
[0123] .sup.1H NMR (C.sub.2D.sub.2Cl.sub.4): 7.8-7.7 (m, 1H,
spiro); 7.7-7.1 (m, 9.4H, fluorene, spiro, TAD); 6.6 (br. s, 0.8H,
fluorene), 6.21 (m, 1H, spiro, exhibits an additional large signal
at 6.27 ppm which is to be attributed to TAD-spiro-TAD units,
proving block-like structures); 4.0-3.4 (3.times.m, 5.6H,
OCH.sub.2), 2.16 (s, 1.2H, CH.sub.3); 1.9-0.7 (m, alkyl H,
including tert-butyl at 1.30).
[0124] GPC: THF; 1 mL/min, PL-gel 10 .mu.m Mixed-B
2.times.300.times.7.5 mm.sup.2, 35.degree. C., RI detection:
Mw=480000 g/mol, Mn=150000 g/mol.
EXAMPLE P5
[0125] Use of dioxane/toluene mixture with 0.0125 mol % Pd, monomer
M1 batch of greater purity. Copolymerisation of 50 mol % 2', 3, 6',
7'-tetra(2-methyl-butyloxy)spirobifluorene-2,7-bisboronic acid
ethylene glycol ester (M1), 40 mol %
2,7-dibromo-9-(2',5'-dimethyl-phenyl)-9-[3",
4"-bis(2-methylbutyloxy)phenyl]fluorene (M2) and 10 mol %
N,N'-bis(4-bromophenyl)-N,N'-bis(4-tert-butylphenyl)benzidine (M3)
(polymer P5).
[0126] 2.1649 g (3.20 mmol) of M2 (content: 99.85%), 3.2026 g (4.00
mmol) of M1 (content: 99.8%), 0.6069 g (0.80 mmol) of M3 (content:
99.5%), 3.91 g (17.0 mmol) of K.sub.3PO.sub.4.H.sub.2O, 12.5 mL of
toluene, 37.5 mL of dioxane and 6.8 mL of water were degassed by
passing argon through for 30 minutes. There were then added 3.65 mg
(12 .mu.mol) of tris-o-tolylphosphine and, 5 minutes later, 0.45 mg
(2 .mu.mol) of palladium acetate under a protective gas. The
suspension was stirred vigorously under a blanket of argon at an
internal temperature of 87.degree. C. (slight reflux). After 2
hours, because of the high viscosity, a further 12.5 mL of toluene
and 37.5 mL of dioxane were added. After 6 hours, a further 0.03 g
of M1 was added. After heating for a further 30 minutes, 0.1 mL of
bromobenzene was added and was heated at reflux for a further 15
minutes.
[0127] The reaction solution was diluted with 80 mL of toluene and
was stirred with 100 mL of 2% aqueous NaCN for 3 hours. The organic
phase was washed 3 times with H.sub.2O and precipitation was
carried out by adding to 400 mL of methanol. The polymer was
dissolved in 300 mL of THF for 1 hour at 50.degree. C.,
precipitated using 600 mL of MeOH, washed and dried in vacuo.
Reprecipitation was carried out again in 300 mL of THF/600 mL of
methanol, followed by filtration under suction and drying to
constant weight. 44 g (7.45 mmol, 93.0%) of the polymer P5 were
obtained in the form of a slightly yellow yellowish solid.
[0128] .sup.1H NMR (C.sub.2D.sub.2Cl.sub.4): 7.9-6.8 (m, 10.4H,
fluorene, spiro, TAD); 6.6 (br. s, 0.8H, fluorene), 6.21 (m, 1H,
spiro); 4.0-3.4 (3.times.m, 5.6H, OCH.sub.2), 2.16 (s, 1.2H,
CH.sub.3); 1.9-0.7 (m, alkyl H, including tert-butyl at 1.30).
[0129] GPC: THF; 1 mL/min, PL-gel 10 .mu.m Mixed-B
2.times.300.times.7.5 mm.sup.2, 35.degree. C., RI detection:
Mw=1400000 g/mol, Mn=410000 g/mol, corresponding to a
weight-average degree of polymerisation DP.sub.w of 2350.
[0130] Part B Comparison Examples--not included in the
invention.
COMPARISON EXAMPLE V1
[0131] Use of toluene and triphenylphosphine as ligand, ethanol as
phase-transfer reagent. Copolymerisation of 50 mol %
2',3',6',7'-tetra(2-methyl-butyloxy)spirobifluorene-2,7-bisboronic
acid ethylene glycol ester (M1), 40 mol %
2,7-dibromo-9-(2,5'-dimethyl-phenyl)- -9-[3",
4"-bis(2-methylbutyloxy)phenyl]fluorene (M2) and 10 mol %
N,N'-bis(4-bromophenyl)-N,N'-bis(4-tert-butylphenyl)benzidine (M3)
(polymer V1).
[0132] 2.000 g (2.4979 mmol) of M1 (content: 99.4%), 1.3519 g
(1.9983 mmol) of M2 (content: 99.85%), 0.3789 g (0.4995 mmol) of M3
(content: 99.5%), 2.07 g (8.994 mmol) of K.sub.3PO.sub.4.H.sub.2O,
6 mL of toluene, 3.8 mL of H.sub.2O and 0.2 mL of ethanol were
degassed by passing argon through for 30 minutes. There were then
added 58 mg (0.0499 mmol) of
tetrakis(triphenylphosphino)palladium(0) under a protective gas.
The suspension was stirred vigorously under a blanket of argon at
an internal temperature of 87.degree. C. (slight reflux). After 7
days, the reaction mixture was dark grey and a further 0.2 g of M1
was added. After heating for a further 2 hours, 0.3 mL of
bromobenzene was added and was heated at reflux for a further 1
hour.
[0133] The reaction solution was diluted with 120 mL of toluene and
was stirred with 100 mL of 2% aqueous NaCN for 3 hours. The organic
phase was washed 3 times with H.sub.2O and precipitation was
carried out by adding to 200 mL of methanol. The polymer was
dissolved in 100 mL of THF, precipitated using 200 mL of MeOH,
washed and dried in vacuo. Reprecipitation was carried out again in
100 mL of THF/200 mL of methanol, followed by filtration under
suction and drying to constant weight. 2.07 g (3.48 mmol, 69.6%) of
the polymer V1 were obtained in the form of a yellow solid.
[0134] .sup.1H NMR (C.sub.2D.sub.2Cl.sub.4): 7.9-6.8 (m, 10.4H,
fluorene, spiro, TAD); 6.6 (br. s, 0.8H, fluorene), 6.21 (m, 1H,
spiro); 4.0-3.4 (3.times.m, 5.6H, OCH.sub.2), 2.16 (s, 1.2H,
CH.sub.3); 1.9-0.7 (m, alkyl H, including tert-butyl at 1.30).
[0135] GPC: THF; 1 mL/min, PL-gel 10 .mu.m Mixed-B
2.times.300.times.7.5 mm.sup.2, 35.degree. C., RI detection:
Mw=25000 g/mol, Mn=10400 g/mol.
COMPARISON EXAMPLE V2
[0136] Use of toluene as solvent, triphenylphosphine as ligand and
tetraethylammonium hydroxide as base in accordance with WO
00/53656. Copolymerisation of 50 mol % 2', 3',
6',7'-tetra(2-methylbutyloxy)spirobi- fluorene-2,7-bisboronic acid
ethylene glycol ester (M1) and 50 mol %
2,7-dibromo-9-(2,5'-dimethyl-phenyl)-9-[3",4"-bis(2-methylbutyloxy)phenyl-
]fluorene (M2) (polymer V2). 3.3827 g (5.00 mmol) of M2 (content:
99.85%), 4.0033 g (5.00 mmol) of M1 (content: 99.4%), 17.3 mg (15
.mu.mol) of tetrakis(triphenylphosphino)palladium(0) and 62.5 mL of
toluene were degassed by passing argon through for 10 minutes.
There were then added 8.32 g (22.5 mmol) of 40% aqueous
tetraethylammonium hydroxide solution and 8.32 mL of water under a
protective gas. The suspension was heated under a blanket of argon
at an internal temperature of 87.degree. C., whereupon a white
solid precipitated out, which redissolved after a few minutes
except for a residue at the rim of the flask. After refluxing for 2
hours, 1 mL of bromobenzene was added. After a further hour, 1.5 g
of phenylboronic acid were added and refluxing was carried out for
a further 1 hour.
[0137] The reaction solution was precipitated in 400 mL of
methanol, separated by filtration and subsequently washed with
water and methanol. The polymer was dissolved in 200 mL of toluene
and precipitated in 400 mL of MeOH, washed and dried to constant
weight in vacuo. 5.52 g (9.39 mmol, 93.9%) of the polymer V2 were
obtained in the form of a yellow-grey solid.
[0138] .sup.1H NMR (C.sub.2D.sub.2Cl.sub.4): 7.8-7.1 (m, 9H,
fluorene, spiro); 6.6 (br. s, 1H, fluorene), 6.21 (m, 1H, spiro);
4.0-3.4 (3.times.m, 6H, OCH.sub.2), 2.16 (s, 1.5H, CH.sub.3);
1.9-0.7 (m, alkyl H).
[0139] GPC: THF; 1 mL/min, PL-gel 10 .mu.m Mixed-B
2.times.300.times.7.5 mm.sup.2, 35.degree. C., RI detection:
Mw=149000 g/mol, Mn=44000 g/mol.
[0140] Part C: Production and Characterisation of LEDs:
[0141] LEDs were produced according to the general procedure
outlined hereinbelow. Of course, in individual cases the procedure
had to be adapted to the particular circumstances (for example,
polymer viscosity and optimum polymer layer thickness in the
device). The LEDs described hereinbelow were, in each case,
two-layer systems, that is to say
substrate//ITO//PEDOT//polymer//cathode. PEDOT is a polythiophene
derivative.
[0142] General Procedure for the Production of High-Efficiency,
Long-Life LEDs:
[0143] After the ITO-coated substrates (for example, glass support,
PET film) have been cut to the correct size, they are cleaned in an
ultrasonic bath in a number of cleaning steps (for example, soap
solution, Millipore water, isopropanol).
[0144] For drying, they are blasted using an N.sub.2 gun and stored
in a desiccator. Before coating with the polymer, they are treated
with an ozone plasma apparatus for about 20 minutes. A solution of
the polymer in question (usually in a concentration of 4-25 mg/mL
in, for example, toluene, chlorobenzene, xylene:cyclohexanone
(4:1)) is prepared, dissolution being carried out by stirring at
room temperature. Depending on the polymer, it may also be
advantageous to stir at 50-70.degree. C. for some time. When
dissolution of the polymer is complete, it is filtered through a 5
.mu.m filter and applied using a spin-coater at variable speeds
(400-6000). The layer thicknesses can, as a result, be varied in
the range from about 50 to 300 nm. Beforehand, a conductive
polymer, preferably doped PEDOT or PANI, is usually applied to the
(structured) ITO.
[0145] Electrodes are also applied to the polymer films. This is
usually carried out by thermal vapour deposition (Balzer BA360 or
Pfeiffer PL S 500). The transparent ITO-electrode is connected up
as the anode, and the metal electrode (for example, Ba, Yb, Ca) as
the cathode, and the device parameters are determined. The service
life is defined as the time taken for 50% of the original
brightness to be reached and is measured at 100 cd/m.sup.2.
[0146] The results obtained with the polymers described are
compiled in Table 1.
1 Electroluminescence** Amounts of monomers GPC* Service Visco.***
in polymerisation [%] M.sub.W M.sub.N Max. Voltage at life at 10
mg/mL Polymer Monom. Monom. Monom. Monom. (.multidot.1000
(.multidot.1000 .lambda..sub.max eff. 100 Cd/m.sup.2 100 Cd/m.sup.2
in toluene (type) 1 2 3 4 g/mol) g/mol) [nm] [Cd/A] [V] EL colour
[hours] (cPs) P1 50% M1 50% M2 -- -- 814 267 455 1.0 5.2 Deep blue
1500 29.8 P2 50% M1 40% M2 10% M3 -- 630 240 462 2.5 5.0 Blue 3000
6.8 P3 50% M1 35% M4 10% M3 5% M5 470 163 632 1.8 3.5 Red 8000 5.5
P4, 12.5% M1 -- 10% M3 -- -- -- -- -- -- -- -- -- 1st step P4,
37.5% M1 40% M2 -- -- 480 150 455 1.8 4.5 Deep blue 3500 6.3 2nd
step P5 50% M1 40% M2 10% M3 -- 1400 410 457 2.7 4.2 Blue 4000 76
V1 50% M1 40% M2 10% M3 -- 25 10 475 1.1 7.7 White-blue 20 0.9 V2
50% M1 50% M2 -- -- 149 50 470 0.6 6.2 White-blue 100 1.8 *GPC
measurements THF; 1 mL/min, Pl-gel 10 .mu.m Mixed-B 2 .times. 300
.times. 7.5 mm.sup.2, 35.degree. C., RI detection was calibrated
against polystyrene **For production of polymer LEDs, see Part C
***Viscosity of the polymer solutions at 10 mg/mL in toluene was
measured at 40 s.sup.-1 in a Brookfield LVDV-III Rheometer
(CP-41).
* * * * *