Conjugated polymers containing heterospiro atoms and their use as electroluminescence materials

A conjugated polymer comprising repeating units of the formula (I), ##STR1## where the symbols and indices have the following meanings: .PSI. is an element of the 4th main group of the Periodic Table with the exception of carbon; PA1 D, E, F, G are identical or different and are --CR.sup.1 R.sup.2 --, --O--, --S--, --NR.sup.3 -- or a chemical bond; PA1 U is --CR.sup.4 .dbd.CR.sup.5 -- or a chemical bond; PA1 V is as defined for U or is --CR.sup.1 R.sup.2 --, --O--, --S--, --NR.sup.3 --, --SiR.sup.1 R.sup.2 --, --SO.sub.2 --, --O--, --CO--; PA1 A are identical or different and are H, a C.sub.1 --C.sub.20 -hydrocarbon radical which can also contain heteroatoms; PA1 T is --O--, --S--, --NR.sup.3 --, --CR.sup.1 R.sup.2 --, --CH.dbd.N--, --CA.dbd.CA--, --CH.dbd.CA--, --CH.dbd.CF-- or --CF.dbd.CF--; PA1 K, Q are identical or different hydrocarbon radicals which can contain heteroatoms and have conjugated electron systems; PA1 M, L are H or a straight-chain or branched alkyl group having from 1 to 22 carbon atoms, Br, Cl, F, CN, NO.sub.2 or CF.sub.3 ; PA1 m, n are identical or different and are 0, 1, 2, 3 or 4; and wherein said polymer is suitable as an electroluminescence material.

RELATED APPLICATION 
This application claims priority to German Application No. 19 615 128.7, 
filed Apr. 17, 1996, incorporated herein by reference. 
BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to the use of conjugated polymers in 
electroluminescence materials, wherein the conjugated polymers comprise at 
least one repeating unit based on a heterospiro framework. Such compounds 
surprisingly have excellent thermal stability, improved solubility in 
organic solvents, improved film-forming properties and particularly good 
electroluminescence with high color purity. 
2. Description of the Related Art 
Several publications are referenced in this application. These references 
describe the state of the art to which this invention pertains, and are 
incorporated herein by reference. 
There is a great industrial need for large-area solid-state light sources 
for a series of applications, predominantly in the field of display 
elements, VDU technology and lighting engineering. What is required of 
these light sources cannot at present be achieved fully satisfactorily 
using any of the existing technologies. 
As an alternative to conventional display and lighting elements such as 
incandescent lamps, gas discharge lamps and non-selfilluminating liquid 
crystal display elements, use has been made for some time of 
electroluminescence (EL) materials and devices such as light-emitting 
diodes (LEDs). 
Apart from inorganic electroluminescence materials, low molecular weight 
organic electroluminescence materials and devices have also been known for 
about 30 years (see, for example, U.S. Pat. No. 3,172,862). However, until 
recently, such devices have been greatly restricted in their practical 
usability. 
WO 90/13148 and EP-A 0 443 861 describe electroluminescence devices 
comprising a film of a conjugated polymer as a light-emitting layer 
(semiconductor layer). Such devices offer numerous advantages such as the 
opportunity of producing large-area, flexible displays simply and 
inexpensively. In contrast to liquid crystal displays, electroluminescence 
displays are selfilluminating and therefore require no additional backward 
lighting source. 
A typical device as described in WO 90/13148 comprises a light-emitting 
layer in the form of a thin, dense polymer film (semiconductor layer), 
which comprises at least one conjugated polymer. A first contact layer is 
in contact with a first surface, a second contact layer is in contact with 
a further surface of the semiconductor layer. The polymer film of the 
semiconductor layer has a sufficiently low concentration of extrinsic 
charge carriers for charge carriers to be introduced into the 
semiconductor layer on application of an electric field between the two 
contact layers, with one contact layer becoming positive relative to the 
other and the semiconductor layer emitting radiation. The polymers used in 
such devices are conjugated. A conjugated polymer is a polymer having a 
delocalized electron system along the main chain. The delocalized electron 
system gives the polymer semiconducting properties and enables it to 
transport positive and/or negative charge carriers with high mobility. 
In WO 90/13148, poly(p-phenylenevinylene) is used as polymeric material for 
the light-emitting layer and it is proposed that the phenyl group in such 
a material be replaced by a heterocyclic or a condensed carbocyclic ring 
system. In addition, poly(p-phenylene), PPP, is also used as 
electroluminescent material. 
Although these materials give good results, the color purity, is 
unsatisfactory. Furthermore, it is virtually impossible to produce a blue 
or white emission using the polymers known hitherto. 
Since, in addition, the development of electroluminescence materials, in 
particular those based on polymers, can in no way be regarded as 
concluded, the manufacturers of lighting and display devices are 
interested in a great variety of electroluminescence materials for such 
devices. This is, inter alia, also because only through study of the 
interaction of the electroluminescence materials with the other components 
of the devices can conclusions be drawn in respect to the quality of the 
electroluminescence material. 
SUMMARY OF THE INVENTION 
The invention relates to novel conjugated polymers comprising at least one 
repeating unit based on a heterospiro framework and to methods of using 
the same as electroluminescent materials. Surprisingly, it has now been 
found that conjugated polymers comprising at least one repeating unit 
based on a heterospiro framework not only have excellent thermal 
stability, improved solubility in organic solvents and improved 
film-forming properties but also, in particular, good electroluminescence 
and photoluminescence having a high color purity. 
Spiro compounds are compounds in which two ring systems are linked by a 
single, tetravalent atom. This atom is referred to as a spiro atom, as 
explained in Handbook of Chemistry and Physics 62.sup.nd ed. (1981-2), CRC 
Press, pages C-23 to C-25. 
Compounds in which two polymers are linked via a single spiro center have 
been proposed, for example, in U.S. Pat. No. 5,026,894 and in J. M. Tour 
et al., J. Am. Chem. Soc. 1990, 112, 5662; J. M. Tour et al., J. Am. Chem. 
Soc. 1991, 113, 7064 and J. M. Tour et al., Polym. Prepr. 1990, 408, as 
materials, however, for molecular electronics. A possible suitability of 
such compounds as electroluminescence materials cannot be deduced 
therefrom. 
The invention accordingly provides conjugated polymers comprising repeating 
units of the formula (I), 
##STR2## 
where the symbols and indices have the following meanings: .PSI. is an 
element selected from the group consisting of Si, Ge, Sn and Pb, 
preferably Sn, Ge, Si, most preferably Ge or Si; 
D, E, F.sup.1, G are identical or different, and are --CR.sup.1 R.sup.2 --, 
--O--, --S--, --NR.sup.3 -- or a chemical bond; where R.sup.1, R.sup.2, 
R.sup.3 are identical or different, and are each a C.sub.1 -C.sub.20 - 
hydrocarbon radical or H or R.sup.1 and R.sup.2 can together form an 
unsubstituted or substituted ring; 
U.sup.1 is --CR.sup.4 .dbd.CR.sup.5 -- or a chemical bond; where R.sup.4, 
R.sup.5 are identical or different, and are as defined for R.sup.1, 
R.sup.2, R.sup.3 or are fluorine or CF.sub.3 ; 
V.sup.1 is as defined for U.sup.1 or is --CR.sup.1 R.sup.2 --, --O--, 
--S--, --NR.sup.3 --, --SiR.sup.1 R.sup.2 --, --SO.sub.2 --, --SO--, 
--CO--where R.sup.1, R.sup.2, R.sup.3 are as defined above; 
A is identical or different and is H, a C.sub.1 -C.sub.20 -, preferably 
C.sub.1 -C.sub.15 -hydrocarbon radical which can also contain heteroatoms, 
preferably --O--, --N or fluorine, most preferably a linear, branched or 
cyclic alkyl, alkoxy or alkyloxycarbonyl group, --CF.sub.3, --CN, 
--NO.sub.2, --NR.sup.6 R.sup.7, --A.sup.2, or --O--A.sup.2 ; 
R.sup.6 and R.sup.7 are identical or different and are H, a C.sub.1 
-C.sub.20 -hydrocarbon radical which can be aliphatic, aromatic, linear, 
branched or alicyclic, wherein R.sup.6 and R.sup.7 can, if desired, 
together form a ring; R.sup.6 and R.sup.7 are preferably methyl, ethyl, 
t-butyl, cyclohexyl, 3-methylphenyl or together 
##STR3## 
A.sup.2 is an aromatic radical having up to 22 carbon atoms, preferably 
phenyl, biphenyl, 1-naphthyl, 2-naphthyl, 2-thienyl, 2-furanyl, wherein 
A.sup.2 can bear one or two radicals as defined for A; 
T is --O--, --S--, --NR.sup.3 --, --CR.sup.1 R.sup.2 --, --CH.dbd.N--, 
--CA.dbd.CA--, --CH.dbd.CA--, --CH.dbd.CF-- or --CF.dbd.CF--, where 
R.sup.1, R.sup.2, R.sup.3 and A are as defined above; T is preferably 
--CH.dbd.CH--; 
K.sup.1, Q are identical or different, hydrocarbon radicals which may 
contain heteroatoms and have conjugated electron systems; where K.sup.1, 
L, M, and Q can also be joined to the groups A in the respective ortho 
positions to form a ring which is saturated, partially unsaturated or 
fully unsaturated, with a fused aromatic ring system preferably being 
present; 
M, L are H or Br, Cl, F, CN, NO.sub.2 or CF.sub.3, or a straight-chain or 
branched alkyl group having from 1 to 22 carbon atoms, where one or more, 
preferably one, --CH.sub.2 -- groups can be replaced by --O--, --CO--O--, 
--O--CO-- and one or more hydrogen atoms of the C.sub.1 -C.sub.22 -alkyl 
group can be replaced by F; 
m, n are identical or different, and are 0, 1, 2, 3 or 4, 
with the following polymers being excepted: 
##STR4## 
wherein: .PSI..dbd.Si 
V.sup.1 .dbd.CO 
and 
##STR5## 
wherein: .PSI..dbd.Si 
V.sup.1 .dbd.CO. 
DETAILED DESCRIPTION OF THE INVENTION 
Preference is given to conjugated polymers comprising repeating units of 
the formula (II), 
##STR6## 
where the symbols and indices have the following meanings: .PSI. is Sn, Ge 
or Si; 
Q, K.sup.1, M are identical or different, and are each one to fifteen 
identical or different arylene and/or heteroarylene and/or vinylene groups 
which may be substituted or unsubstituted; 
A are identical or different and can be as defined in the formula (I); 
M, L are H, Br, Cl, F, CN, NO.sub.2 or CF.sub.3, or a straight-chain or 
branched alkyl group having from 1 to 22 carbon atoms, where one or more, 
preferably one, --CH.sub.2 --groups can be replaced by --O--, --CO--O--, 
--O--CO--and one or more hydrogen atoms of the C.sub.1 --C.sub.22 -alkyl 
group can be replaced by F; 
m, n are identical or different, and are 0 or 1, 
with the following polymers being excepted: 
##STR7## 
wherein: .PSI..dbd.Si 
V.sup.1 .dbd.CO and 
##STR8## 
wherein: .PSI..dbd.Si 
V.sup.1 .dbd.Co. 
The polymers of the invention having the formulae (I) and (II) have, in 
particular, a high color purity of the emission. 
For the purposes of the invention, a polymer is a compound whose 
electroluminescence spectrum remains essentially unchanged on addition of 
further repeating units. 
The polymers of the invention having the formulae (I) and (II) generally 
have from 2 to 1000, preferably from 2 to 500, most preferably from 2 to 
100, repeating units. 
Further preference is given to those polymers of the formula (II) in which 
the symbols and the indices have the following meanings: 
A are identical or different and are R.sup.1, R.sup.2, R.sup.3 and/or 
R.sup.4 ; 
Q, K.sup.1 are identical or different, conjugated C.sub.2 -C.sub.100 
-hydrocarbon radicals, in particular 
##STR9## 
X, Y.sup.1, B.sup.1, D are identical or different, and are CR.sup.5, or N; 
Z, W.sup.1 are identical or different and are --O--, --S--, --NR.sup.5 --, 
--CR.sup.5 R.sup.6 --, --CR.sup.5 50 CR.sup.6 --, --CR.sup.5 50 N--; 
p, q, r are, independently of one another, identical or different and are 
0, or 1 to 5; 
R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.6, R.sup.7, R.sup.8 are 
identical or different and are H, a straight-chain or branched alkyl, 
alkoxy or ester group having from 1 to 22 carbon atoms, aryl and/or 
aryloxy groups, preferably phenyl and/or phenyloxy groups, where the 
aromatic can be substituted by C.sub.1 -C.sub.22 -alkyl, C.sub.1 -C.sub.22 
-alkoxy, Br, Cl, F, CN, and/or NO.sub.2, Br, Cl, F, CN, NO.sub.2, CF.sub.3 
; 
M, L are H, Br, Cl, F, CN, NO.sub.2, CF.sub.3, or a straight-chain or 
branched alkyl group having from 1 to 22 carbon atoms, where one or more, 
preferably one, --CH.sub.2 -- groups can be replaced by --O--, --CO--O--, 
--O--CO-- and one or more hydrogen atoms can be replaced by F; 
with the following polymers being excepted: 
##STR10## 
wherein: .PSI..dbd.Si 
V.sup.1 .dbd.CO 
and 
##STR11## 
wherein: .PSI..dbd.Si 
V.sup.1 .dbd.CO. 
Particular preference is given to compounds of the formula (II) in which: 
Q, K.sup.1 are identical or different and are 
##STR12## 
where: m, n are identical or different and are 0 or 1; 
M, L are H, Br, Cl, F, CN, NO.sub.2 or CF.sub.3, or a straight-chain or 
branched alkyl group having from 1 to 22 carbon atoms, where one or more, 
preferably one, --CH.sub.2 -- groups can be replaced by --O--, --CO--O--, 
--O--CO-- and one or more hydrogen atoms can be replaced by F; or 
with the following polymers being excepted: 
##STR13## 
wherein: .PSI..dbd.Si 
V.sup.1 .dbd.CO 
and 
##STR14## 
wherein: .PSI..dbd.Si 
V.sup.1 .dbd.CO. 
Very particular preference is given to compounds of the formula (II) in 
which: 
Q, K.sup.1 are identical or different and are 
##STR15## 
where: m+n is 0 or 1; 
M, L are H, Br, Cl, F. CN, NO.sub.2 or CF.sub.3, or a straight-chain or 
branched alkyl group having from 1 to 22 carbon atoms, where one or more, 
preferably one, --CH.sub.2 -- groups can be replaced by --O--, --CO--O--, 
--O--CO-- and one or more hydrogen atoms can be replaced by F; 
with the following polymers being excepted: 
##STR16## 
wherein: .PSI..dbd.Si 
V.sup.1 .dbd.CO 
and 
##STR17## 
wherein: .PSI..dbd.Si 
V.sup.1 .dbd.CO. 
For some applications it can be advantageous to replace one or more or all 
hydrogen atoms, preferably those on aromatic rings, by F atoms. 
The compounds of the invention having the formula (I) are homopolymers or 
copolymers, i.e. the compounds of the formula (I) can also have different 
repeating units. 
The polymers of the invention having the formula (I) also have a 
considerably increased solubility in organic solvents and good 
film-forming properties. This makes the production of electroluminescence 
devices easier and increases their life. In addition, the covalently 
bonded arrangement of the substituents via the spiro atoms, perpendicular 
to the conjugated main chain, allows certain properties to be adjusted in 
the build-up of the molecule without interfering with the conjugation in 
the main chain. Thus, the polymer chain can have, for example, charge 
transport or charge injection properties while the substituents have 
light-emitting properties. The emission properties of the compounds used 
according to the invention can be adjusted across the entire range of the 
visible spectrum by selection of suitable substituents. The spatial 
proximity of the two halves fixed by the covalent linkage is here 
favorable for energy transfer (see, for example, B. Liphardt, W. Luttke, 
Liebigs Ann. Chem. 1981, 1118). 
The compounds of the invention having the formula (I) are well suited to 
producing blue electroluminescence. 
The polymers of the invention can be prepared by literature methods known 
per se as are described in standard works on organic synthesis, e.g. 
Houben-Weyl, Methoden der Organischen Chemie, Georg-Thieme-Verlag, 
Stuttgart and in the volumes of the series "The Chemistry of Heterocyclic 
Compounds", A. Weissberger, E. C. Taylor (eds.), in particular volume 
13/5, pp. 30-87. 
The preparation is carried out under reaction conditions that are known and 
suitable for the reactions mentioned. Use can also be made of variants 
known per se that are not mentioned in more detail here. 
Starting compounds used for the preparation of the polymers of the 
invention are preferably monomers having a 9,9'-spirobi-9-stannafluorene, 
9,9'-spirobi-9-germafluorene or particularly preferably 
9,9'-spirobi-9-silafluorene building block, which is in each case 
substituted in the 2,7 or, if desired, 2',7' positions. 
One method of synthesizing these monomers is based, for example, on the 
synthesis of 9,9'-spirobi-9-silafluorene, for example, from 
2,2'-dibromobiphenyl and silicon tetrachloride via 2,2'-dilithiobiphenyl, 
as described by H. Gilman and R. D. Gorsich, J. Am. Chem. Soc. 1958, 80, 
p.1883, which is subsequently further substituted in an appropriate 
manner. 
Possible ways of functionalizing the analogous carbon compound 
9,9'-spirobiflourene are described in J. H. Weisburger, E. K. Weisburger, 
F. E. Ray, J. Am. Chem. Soc. 1959, 72, 4253; F. K. Sutcliffe, H. M. 
Shahidi, D. Paterson, J. Soc. Dyers Colour 1978, 94, 306; and G. Haas, V. 
Prelog, Helv. Chim. Acta 1969, 52, 1202; they are also suitable for 
functionalizing the heterospiro compounds of the invention. 
It can be advantageous to achieve the desired substitution pattern of the 
monomeric 9,9'-spirobi-9-silafluorene by spirolinkage of starting 
materials, which are already appropriately substituted, for example, using 
2,7-difunctionalized 9,9-dichloro-9-silafluorenes, and then, if desired, 
further functionalizing the still free 2',7' positions after formation of 
the spirocenter (e.g. by halogenation or acylation, with subsequent C-C 
linkage after conversion of the acetyl groups into aldehyde groups, or by 
heterocycle formation after conversion of the acetyl groups into 
carboxylic acid groups). 
The further functionalization can be carried out by literature methods 
known per se, as described in standard works on organic synthesis, e.g. 
Houben-Weyl, Methoden der Organischen Chemie, Georg-Thieme Verlag, 
Stuttgart and in the appropriate volumes of the series "The Chemistry of 
Heterocyclic Compounds" by A. Weissberger and E. C. Taylor (Editors). 
For the synthesis of the groups Q, K.sup.1, L, and M reference may be made, 
for example, to DE-A 23 44 732, 24 50 088, 24 29 093, 25 02 904, 26 36 
684, 27 01 591 and 27 52 975 for compounds containing 1,4-phenylene 
groups, DE-A 26 41 724 for compounds containing pyrimidine-2,5-diyl 
groups; DE-A 40 26 223 and EP-A 03 91 203 for compounds containing 
pyridine-2,5-diyl groups; DE-A 32 31 462 for compounds containing 
pyridazine-3,6-diyl groups; N. Miyaura, T. Yanagi and A. Suzuki in 
Synthetic Communications 1981, 11, 513 to 519, DE-C-3 930 663, M. J. 
Sharp, W. Cheng, V. Snieckus in Tetrahedron Letters 1987, 28, 5093; G. W. 
Gray in J.Chem.Soc. Perkin Trans II 1989, 2041 and Mol. Cryst. Liq. Cryst. 
1989, 172, 165, Mol. Cryst. Liq. Cryst. 1991, 204, 43 and 91; EP-A 0 449 
015; WO 89/12039; WO 89/03821; EP-A 0 354 434 for the direct linkage of 
aromatics and heteroaromatics. 
The preparation of disubstituted pyridines, disubstituted pyrazines, 
disubstituted pyrimidines and disubstituted pyridazines may be found, for 
example, in the appropriate volumes of the series "The Chemistry of 
Heterocyclic Compounds" by A. Weissberger and E. C. Taylor (Editors). 
Starting from the abovementioned monomers, the polymerization to give the 
polymers of the invention having the formula (I) is possible by a number 
of methods. 
For example, derivatives of 9,9'-spirobi-9-silafluorene can be polymerized 
oxidatively (e.g. using FeCI.sub.3 ; see, for example, P. Kovacic, N. B. 
Jones, Chem. Ber. 1987, 87, 357 to 379; M. Weda, T. Abe, H. Awano, 
Macromolecules 1992, 25, 5125) or electrochemically (see, for example, N. 
Saito, T. Kanbara, T. Sato, T. Yamamoto, Polym. Bull. 1993, 30, 285). 
Likewise, the polymers of the invention having the formula (I) can be 
prepared from 2,7-difunctionalized 9,9'-spirobi-9-silafluorene 
derivatives. Dihaloaromatics can be polymerized in the presence of 
copper/triphenylphosphine (see, for example, G. W. Ebert, R. D. Rieke, J. 
Org. Chem. 1988, 53, 44829) or nickel/triphenylphosphine catalysts (see, 
for example, H. Matsumoto, S. Inaba, R. D. Rieke, J. Org. Chem. 1983, 48, 
840). 
Aromatic diboronic acids and aromatic dihalides or mixed aromatic 
halide-boronic acids can be polymerized in the presence of palladium 
catalysts by means of coupling reactions (see, for example, M. Miyaura, T. 
Yanagi, A. Suzuki, Synth. Commun. 1981, 11, 513; R. B. Miller, S. Dugar, 
Organometallics 1984, 3, 1261). 
Aromatic distannans can be polymerized in the presence of palladium 
catalysts, for example as described in J. K. Stille, Angew. Chem. Int. Ed. 
Engl. 1986, 25, 508. 
Furthermore, the abovementioned dibromo compounds can be converted into the 
dilithio or digrignard compounds which can then be polymerized with 
further dibromo compound by means of CuCl.sub.2 (see, for example, G. 
Wittig, G. Klar, Liebigs Ann. Chem. 1967, 704, 91; H. A. Staab, F. Bunny, 
Chem. Ber. 1967, 100, 293; T. Kaufmann, Angew. Chem. 1974, 86, 321 to 354) 
or by electron transfer of unsaturated 1,4-dihalo compounds (see, for 
example, S. K. Taylor, S. G. Bennett, K. J. Harz, L. K. Lashley, J. Org. 
Chem. 1981, 46, 2190). 
The synthesis of the polymers of the invention having the formula (I) can, 
however, also be carried out by polymerization of a 2,7-difunctionalized 
9,9'-spirobi-9-silafluorene derivative with a further, appropriately 
difunctionalized compound. 
Thus, for example, 2,7-dibromo-9,9'-spirobi-9-silafluorene can be 
polymerized with biphenyl4,4'-bisboronic acid. This makes it possible to 
build up various heterocyclic units simultaneously with the polymerization 
step, e.g. the formation of oxadiazole units from difunctional carboxylic 
acid halides and difunctional carboxylic acid hydrazides or from the 
corresponding dicarboxylic acid and hydrazine sulfate (B. Schulz, E. 
Leibnitz, Acta Polymer. 1992, 43, page 343; JP-A 05/178, 990, or 
alternatively from dicarboxylic acid halides and bistetrazoles (C. A. 
Abshire, C. S. Marvel, Makromol. Chem. 1961, 44 to 46, page 388). 
To prepare copolymers, for example, different compounds of the formula (I) 
can be copolymerized. 
The work-up is carried out by known methods with which those skilled in the 
art are familiar, as are described, for example, in R. J. Young, P. A. 
Lovell, Introduction to Polymers, Chapman & Hall, London, 1991. For 
example, the reaction mixture can be filtered, diluted with aqueous acid, 
extracted and the crude product obtained after drying and taking off the 
solvent can be further purified by reprecipitation. 
Terminal bromine atoms can be removed reductively, for example using 
LiAlH.sub.4 (see, for example, J. March, Advanced Organic Chemistry, 3rd 
edition, McGraw-Hill, p. 510). 
The polymers of the invention can be used as electroluminescence materials. 
The invention therefore also provides for the use of polymers of the 
formula (I) as electroluminescence material. 
For the purposes of the invention, electroluminescence materials are 
materials that can be used as an active layer in an electroluminescence 
device. Active layer means that the layer is capable of emitting light on 
application of an electric field (light-emitting layer) and/or that it 
improves the injection and/or the transport of the positive and/or 
negative charges (charge injection or charge transport layer). Particular 
mention should be made of the excellent hole conductor properties of the 
materials of the invention, which can be used, for example, as hole 
transport layers in photocopiers and laser printers. 
The invention therefore also provides an electroluminescence material 
comprising one or more polymers of the formula (I). 
The electroluminescence material of the invention usually comprises one or 
more polymers of the formula (I) as main component, i.e. in an amount of 
greater than 50% by weight, or as additive. 
For use as electroluminescence materials, the solutions of the polymers of 
the formula (I) are generally applied in the form of a film to a substrate 
by known methods with which those skilled in the art are familiar, for 
example casting, dipping, spincoating or curtain coating. 
The invention therefore further provides a process for producing an 
electroluminescence material, which comprises applying a polymer of the 
formula (I) in the form of a film to a substrate. 
The invention additionally provides an electroluminescence device, 
comprising one or more active layers, where at least one of these active 
layers comprises one or more polymers of the invention having the formula 
(I). The active layer can be, for example, a light-emitting layer and/or a 
transport layer and/or a charge injection layer. 
The general structure of such electroluminescence devices is described, for 
example, in U.S. Pat. No.4,539,507 and U.S. Pat. No.5,151,629. 
Polymer-containing electroluminescence devices are described, for example, 
in WO 90/13148 or EP-A 0 443861. 
Electroluminescence devices usually comprise an electroluminescing layer 
between a cathode and an anode, where at least one of the electrodes is 
transparent. In addition, an electron injection and/or electron transport 
layer can be introduced between the electroluminescing layer and the 
cathode and/or a hole injection and/or hole transport layer can be 
introduced between the electroluminescing layer and the anode. Suitable 
cathode materials are, for example, Ca, Mg, Al, In, Mg/Ag. Suitable anode 
materials are, for example, Au or ITO (indium oxide/tin oxide) on a 
transparent substrate, for example of glass or a transparent polymer. 
In operation, the cathode is placed at a negative potential relative to the 
anode. This results in injection of electrons from the cathode into the 
electron injection layer/electron transport layer or directly into the 
light-emitting layer. At the same time, holes from the anode are injected 
into the hole injection layer/hole transport layer or directly into the 
light-emitting layer. 
The injected charge carriers move toward one another through the active 
layers under the influence of the applied potential. This leads to 
electron/hole pairs at the interface between charge transport layer and 
light-emitting layer or within the light-emitting layer and these 
recombine with emission of light. The color of the emitted light can be 
varied by means of the compound used as the light-emitting layer, with not 
only copolymers but also mixtures of the polymers of the invention with 
other electrooptically active or passive materials being expressly 
included. 
Electroluminescence devices are employed, for example, as selfilluminating 
display elements such as control lamps, alphanumeric displays, signs and 
in optoelectronic couplers. Owing to their good hole transport properties, 
the materials of the invention are also suitable as photoconductor 
elements, for example in photocopiers and laser printers.

EXAMPLES 
The following examples are illustrative of some of the products and methods 
of making the same falling within the scope of the present invention. They 
are, of course, not to be considered in any way limitative of the 
invention. Numerous changes and modifications can be made with respect to 
the invention. 
Example 1 
2,2'-Dilithiobiphenyl 
26 ml of a solution of 28 mmol of n-BuLi in absolute diethyl ether (ether) 
was added dropwise over a period of 5 minutes to an ice-cooled, vigorously 
stirred solution of 4.0 g (12.9 mmol) of 2,2'-dibromobiphenyl in 40 ml of 
ether and the mixture was subsequently stirred for 5 hours at room 
temperature. 
Example 2 
Bis(biphenyl-2,2'-diyl)silane (9,9'-Spirobi-9-silafluorene) 
A solution of 24 mmol of 2,2'-dilithiobiphenyl in 70 ml of ether prepared 
as described in Example 1 was added dropwise over a period of 1 hour to a 
vigorously stirred solution of 1.87 g (11 mmol) of silicon tetrachloride 
in 30 ml of ether. The mixture was stirred for a further 1.5 hours at room 
temperature and refluxed for 3 hours. Subsequently, 50 ml of benzene were 
added and the mixture was refluxed for a further 2 hours. After shaking 
with 100 ml of water, the organic phase was dried over magnesium sulfate, 
filtered and the major part of the ether was distilled off on a rotary 
evaporator. 1.45 g of crude product having an mp. of from 222.degree. to 
225.degree. C. were isolated from the cooled solution. After evaporation, 
the filtrate gave a further 0.6 g (total yield: 56%). Crystallization from 
ethanol gives a product having a melting point of 227.degree. C. 
______________________________________ 
Elemental analysis: 
% C H Si 
______________________________________ 
Calc. 86.72 4.85 8.44 
Found 86.86 4.98 8.33 
______________________________________ 
The remarkably high stability of this compound is shown by the boiling 
point of 460.degree. C. which is reached without visible decomposition. 
Example 3 
Bis(biphenyl-2,2'-diyl)germane (9,9'-spirobi-9-germafluorene) 
A solution of 50 mmol of 2,2'-dilithiobiphenyl prepared in 140 ml of ether, 
as described in Example 1, was reacted as described in Example 2 with 5.35 
g (25 mmol) of germanium tetrachloride. Work-up and recrystallization from 
ethyl acetate gave 2.77 g (29%) of product. White prisms, melting point 
245.degree. C., boiling point 470.degree. C. without decomposition. 
______________________________________ 
Elemental analysis % Ge 
______________________________________ 
Calc. 19.23 
Found 18.88 
______________________________________ 
Example 4 
Biphenyl-2,2'-diylsilicon dichloride 
78 mmol of 2,2'-dilithiobiphenyl prepared in 230 ml of ether, as described 
in Example 1, were reacted as described in Example 2 with 252 g (1.48 mol, 
i.e. 18-fold excess) of silicon tetrachloride. Distilling off the excess 
SiCl.sub.4 and work-up resulted in 3.5 g of a solid product which was 
recrystallized from ethyl acetate to give 2.89 g (22%) of 
bis(biphenyl-2,2'-diyl)silane, as described in Example 2. The collected 
mother liquors were evaporated and the remaining oil was distilled at 0.01 
mbar, with a small amount of biphenyl going over as first fraction and 
7.41 g (38%) of biphenyl-2,2'-diylsilicon dichloride going over as main 
fraction at from 108.degree. to 110.degree. C. 
______________________________________ 
Elemental analysis: 
% Cl Si 
______________________________________ 
Calc. 28.3 11.33 
Found 26.5 10.75 
______________________________________ 
Example 5 
10,10-Biphenyl-2,2'-diylphenoxasilin 348.481! 
A solution of 120 mmol of 2,2'-dilithio(diphenyl ether) in 180 ml of THF, 
prepared as described in H. Gilman, W. J. Trepka, J. Org. Chem. 1962, 27, 
1418, was added to a solution of 37.7 g (150 mmol) of 
biphenyl-2,2'-diylsilicon dichloride, prepared as described in Example 4, 
in 200 ml of THF. The mixture was stirred for 12 hours at 20.degree. C., 
hydrolyzed with a mixture of ice and sulfuric acid and the aqueous phase 
was extracted with ether. After work-up by distillation at &lt;0.05 mm, the 
main fraction going over at 150.degree. C. was recrystallized from 
ethanol. Yield: 12.5 g (30%). 
Example 6 
Bis(bibenzyl-2,2'-diyl)silane 
A solution of 2.1 ml (20 mmol) of silicon tetrachloride in 50 ml of THF was 
added dropwise to a solution of 2,2'-dilithiobibenzyl, which had 
previously been prepared from 15 g (40 mmol) of 2,2'-dibromobibenzyl and 
97 mmol of 1.7 molar n-butyllithium in a hexane fraction. The mixture was 
refluxed for 1 hour and worked up as in Example 5. 5.0 g of a solidifying 
oil went over between 125.degree. and 210.degree. C. at 0.05 mm and this 
was recrystallized twice to give 1.0 g (13%) of 
bis(bibenzyl-2,2'-diyl)silane having an mp. of 175.degree. C. 
______________________________________ 
Elemental analysis: 
% C H 
______________________________________ 
Calc. 86.60 6.19 
Found 86.21 6.05 
______________________________________ 
Example 7 
Bis(stilbene-2.2'-diyl)silane via 
bis(.alpha..alpha.'(.beta.')-dibromobibenzyl-2,2'-diyl)silane 
A slurry of 1.94 g (5 mmol) of bis(bibenzyl-2,2'-diyl)silane, prepared as 
described in Example 6, and 1.78 g (10 mmol) of N-bromosuccinimide in 100 
ml of tetrachloromethane were heated to boiling while being irradiated 
with a 300 W incandescent tungsten lamp. The succinimide formed was 
filtered off with suction, the filtrate was evaporated to dryness on a 
rotary evaporator, the residue was taken up in 15 ml of toluene and 
admixed with 2 ml of 2-dimethylaminoethanol. The mixture was stirred for 
48 hours and then heated to boiling for 6 hours. The toluene was removed 
under reduced pressure, the residue was admixed with 50 ml of 5% strength 
by weight sodium hydroxide solution and shaken with ether. After drying 
over magnesium sulfate, the ether was evaporated and the residue was 
purified by chromatography on 30 g of silica gel using toluene/cyclohexane 
as eluant. 
Example 8 
3,3',5,5'-Tetraphenyl-9-sila-9-spiro-9H-bifluorene via 
tetrakis(biphenyl4-yl)silane 
10.8 g (46.3 mmol) of 4-bromobiphenyl were dissolved together with 1.95 g 
(11.6 mmol) of silicon tetrachloride in 100 ml of absolute ether and 
subsequently admixed with 2.5 g (110 mmol) of sodium. The mixture was 
heated under reflux until the metal had dissolved and stirred further for 
4 hours at room temperature. After removing the ether, the residue was 
extracted with toluene in a Soxhlet apparatus. Yield: 6.7 g (90%). Mp. 
281.degree. C. from xylene. 
5.4 g (10 mmol) of tetrakis(biphenyl-4-yl)silane were dissolved in 200 ml 
of 1,2-dichlorobenzene and 6.5 g (40 mmol) of iron(III) chloride were 
added a little at a time while passing nitrogen through the solution. The 
mixture was heated to boiling over a period of 3 hours. When HCl could no 
longer be detected as NH.sub.4 Cl in the waste gas, the mixture was 
evaporated on a rotary evaporator, the residue was digested a number of 
times using 5% strength hydrochloric acid and the residue was 
recrystallized from xylene with addition of 1 g of silica gel. Yield: 2.7 
g (51%). 
Example 9 
Biphenyl-2,2'-diyldibenzosilinane 
Bis(2-chlorophenyl)methane was prepared as described in Chang and Gorey, 
Organomet. Chem. 8, 1890 (1989). 0.1 mol of this substance was lithiated 
as described in Example 1 using 0.22 mol of BuLi. The ether solution 
obtained was added dropwise to a solution of 25.1 g (0.1 mol) of 
biphenyl-2,2'-diylsilicon dichloride, prepared as described in Example 4, 
in 150 ml of THF. The mixture was stirred for 12 hours at room 
temperature, hydrolyzed with a mixture of ice and sulfuric acid and the 
aqueous phase was extracted with ether. After work-up by distillation in a 
high vacuum of &lt;0.05 mm of Hg, the main fraction going over at about 
150.degree. C. was recrystallized from ethanol. Yield: 13.9 g (40%). 
Example 10 
Biphenyl-2,2'-diyldibenzosilinan-9-one 
10.4 g (30 mmol) of biphenyl-2,2'-diyldibenzosilinane, prepared as 
described in Example 9, were admixed with a solution of 3.33 g (30 mmol) 
of selenium dioxide dissolved in 22 ml of 1,4-dioxane and 1.4 ml of water. 
The mixture was then heated to boiling, the precipitated selenium was 
filtered off whilst still hot and extracted with hot dioxane. 
Recrystallization from i-propanol gave 9.9 g of product (91%). 
Example 11 
a) 10.10'-(4.4'-Dinitrobiphenyl-2,2'-diyl)dibenzosilinan-9-one 
5.10 g (21 mmol) of Cu(NO.sub.3).sub.2.3H.sub.2 O are taken up at room 
temperature in 40 ml of acetic anhydride and stirred. After a few minutes, 
the internal temperature rises to from about 40.degree. to 45.degree. C. 
with the blue suspension becoming turbid. 3.6 g (10 mmol) of 
biphenyl-2,2'-diyldibenzosilinan-9-one are subsequently added and the 
mixture is stirred further at 40.degree. C. 
After 4 hours at 40.degree. C., the reaction is complete. The color of the 
suspension has changed to turquoise. It is carefully stirred into about 
200 ml of water and shaken a number of times with chloroform. After 
evaporating the organic phase on a rotary evaporator and dissolving the 
residue in chloroform, the solution is precipitated with hexane: 4.7 g of 
colorless product. 
b) 10,10'-(4,4'-Diaminobiphenyl-2,2'-diyl)dibenzosilinan-9-one 
A mixture of 5 g of 
10,10'-(4,4'-dinitrobiphenyl-2,2'-diyl)dibenzosilinan-9-one and 4.5 g of 
iron powder are refluxed in 150 ml of ethanol while 15 ml of concentrated 
HCl are added dropwise over a period of 30 minutes. After refluxing for a 
further 30 minutes, excess iron is filtered off. The green filtrate is 
added to a solution of 400 ml of water, 15 ml of concentrated NH.sub.4 OH 
and 20 g of sodium potassium tartrate. The colorless diamine is filtered 
off from the dark green solution of the iron complex. To purify the 
diamine, it is dissolved in dilute HCl, stirred at room temperature with 
activated carbon (Darco) and filtered. The filtered solution is 
neutralized dropwise with NH.sub.4 OH while stirring mechanically and the 
precipitated product is filtered off with suction. This gives 3.59 of 
virtually colorless 
10,10'-(4,4'-diaminobiphenyl-2,2'-diyl)dibenzosilinan-9-one which is 
further recrystallized from methanol. 
c) 10,10'-(4.4'-Dibromobiphenyl-2,2'-diyl)dibenzosilinan-9-one 
2.0 g of 10,10'-(4,4'-diaminobiphenyl-2,2'-diyl)dibenzosilinan-9-one are 
dissolved in 20 ml of water and 5 ml of concentrated hydrobromic acid, 
cooled to about 0.degree. C. and slowly admixed while maintaining this 
temperature with a solution of 0.8 g of NaNO.sub.2 in about 5 ml of water. 
The mixture is stirred at this; temperature for about 30 minutes and the 
solution of the resulting bisdiazonium salt is poured into an ice-cooled 
solution of 1 g of CuBr in 10 ml of HBr. The resulting solution is stirred 
at 100.degree. C., with gas evolution occurring and the resulting product 
precipitating as a white solid. After gas evolution is complete, the 
product is filtered off with suction, washed with NaHCO.sub.3 solution 
until neutral and washed with water until free of salts. It is 
subsequently reprecipitated from chloroform/hexane: 1.3 g of virtually 
colorless powder. 
The above description of the invention is intended to be illustrataive and 
not limiting. Various changes or modifications in the embodiments 
described may occur to those skilled in the art. These can be made without 
departing from the spirit or scope of the invention.