Metallocenes having bicyclic cyclopentadiene derivatives as ligands, processes for their preparation and their use as catalysts

The invention relates to a process for the preparation of a compound of the formula XI ##STR1## wherein preferably M.sup.1 is zirconium, the radicals R.sup.1 are alkyl, the radicals R.sup.2 are halogen or alkyl, R.sup.3 is dimethylsilyl or ethylene and n is 2-18, wherein a compound of the formula II ##STR2## is reacted with an alkali metal or alkaline earth metal salt of a malonic ester and then with an alkyl halide, the reaction product is converted by decarboxylation into the corresponding lactone, which is further reacted by known methods to give the compound XI. The compounds of the formula XI, some of which are novel, can advantageously be used as catalysts for olefin polymerization.

The present invention relates primarily to a process for the preparation of 
metallocenes which carry bicyclic derivatives of cyclopentadiene as 
ligands. The majority of these compounds are novel and can advantageously 
be used as catalysts for the preparation of polyolefins which are 
characterized in particular by high stereospecificity, a high melting 
point and good crystallinity. Such polymers are suitable, inter alia, as 
structural materials (large hollow articles, pipes, moldings). 
Derivatives of zirconocene dichloride which are substituted in the ring and 
in which the two substituted cyclopentadienyl groups are bonded to one 
another via an ethylene or a dimethylsilylene bridge have a rigid 
conformation and can therefore be used as catalysts for the stereospecific 
polymerization of propene. The type and arrangement of the substituents 
influence the polymerization rate, the average molecular weight and the 
isotacticity (Chem. Lett. 1989, pages 1853-1856 or EP-A 0 316 155). 
Among the bicyclic derivatives of cyclopentadiene, (substituted) indenyl 
radicals are important as ligands for metallocenes (polymerization 
catalysts). Thus, for example, the preparation of isotactic polypropylene 
with the aid of the catalyst system 
ethylenebis(4,5,6,7-tetrahydro-1-indenyl)zirconiumdichloride/aluminoxane 
has been described (EP-A 185 918). 
Bridged metallocenes which carry bicyclic derivatives of cyclopentadiene as 
ligands, where the cyclopentadienyl moiety may additionally be 
substituted, are likely to have interesting properties and should be 
capable of considerably extending the property spectrum of the polymers 
which can be prepared The use of such catalysts was unsuccessful to date 
because there was no feasible synthesis method for such complexes which 
are substituted in particular in the 2-position on the cyclopentadienyl 
moiety. 
The present invention therefore relates to a process for the preparation of 
a compound of the formula XI 
##STR3## 
wherein M.sup.1 is a metal from the group comprising titanium, zirconium, 
hafnium, vanadium, niobium and tantalum, 
the radicals R.sup.1 are identical or different and are hydrogen, a C.sub.1 
-C.sub.10 -alkyl group, a C.sub.6 -C.sub.10 -aryl group, a C.sub.7 
-C.sub.15 -arylalkyl group or a C.sub.2 -C.sub.10 -alkenyl group, 
the radicals R.sup.2 are identical or different and are a C.sub.1 -C.sub.10 
-alkyl group, a C.sub.1 -C.sub.10 -alkoxy group, a C.sub.6 -C.sub.10 -aryl 
group, a C.sub.6 -C.sub.10 -aryloxy group, a C.sub.2 -C.sub.10 -alkenyl 
group, a C.sub.7 -C.sub.40 -arylalkyl group, a C.sub.7 -C.sub.40 
-alkylaryl group, a C.sub.8 -C.sub.40 -arylalkenyl group or a halogen 
atom, 
R.sup.3 is 
##STR4## 
in which M.sup.2 is silicon, germanium or tin, 
R.sup.4 and R.sup.5 are identical or different and are a hydrogen atom, a 
halogen atom, a C.sub.1 -C.sub.10 -alkyl group, a C.sub.6 -C.sub.10 -aryl 
group, a C.sub.2 -C.sub.10 -alkenyl group, a C.sub.7 -C.sub.40 -arylalkyl 
group, a C.sub.8 -C.sub.40 -arylalkenyl group or a C.sub.7 -C.sub.40 
-alkylaryl group or 
R.sup.4 and R.sup.5, together with the atom which binds them, form a ring 
and p is 1, 2 or 3, and 
n is an integer from 2 to 18, 
wherein a compound of the formula II 
##STR5## 
is reacted with an alkali metal or alkaline earth metal salt of a malonic 
ester, the intermediate formed is reacted, without isolation, with a 
compound R.sup.1 -X, in which R.sup.1 has the stated meaning and X is a 
nucleophilic leaving group, and the reaction product is converted by 
decarboxylation into a lactone of the formula IV 
##STR6## 
which is subjected to a rearrangement reaction to give the corresponding 
enone and then further reacted by known methods to give the compound of 
the formula XI. 
In the formula XI, preferably M.sup.1 is titanium, zirconium or hafnium, 
the radicals R.sup.1 are identical and are a C.sub.1 -C.sub.4 -alkyl 
group, the radicals R.sup.2 are identical and are halogen or a C.sub.1 
-C.sub.4 -alkyl group, M.sup.2 is silicon, R.sup.4 and R.sup.5 are 
identical or different and are hydrogen or a C.sub.1 -C.sub.4 -alkyl 
group, p is 1 or 2 and n is an integer from 4 to 7. 
In particular, M.sup.1 is zirconium, the radicals R.sup.1 are identical and 
are methyl or ethyl, the radicals R.sup.2 are identical and are chlorine 
or methyl, M.sup.2 is silicon, R.sup.4 and R.sup.5 are hydrogen or methyl, 
p is 2 and n is an integer from 4 to 7. 
The present invention furthermore relates to the compounds of the formula 
XI, including the stated preferred ranges, except for the compounds where 
n=4. n is thus preferably a number from 5 to 7. 
The preparation of the compounds XI is illustrated, by way of example, by 
the following reaction schemes 1 and 2: 
##STR7## 
According to Scheme 1, the starting materials used are cyclic ketones I, 
such as, for example, cycloheptanone or cyclooctanone (n=5, 6). In a first 
step applicable to large batches, this ketone is converted, for example 
with trimethyloxosulfurane, into the epoxide II (Equation 1). The 
subsequent central step in the synthesis of the compounds XI, which also 
simultaneously solves the problem of introducing the substituent R.sup.1 
in the .alpha.-position to the bridge R.sup.3 (substitution in the 
2-position on the subsequent cyclopentadienyl moiety), consists in 
cleaving the epoxide with the anion of a malonic ester (Equation 2). This 
is carried out by reacting the epoxide II with an alkali metal or alkaline 
earth metal salt of an alkyl, aryl or alkenyl, preferably (C.sub.1 
-C.sub.10)-alkyl, in particular (C.sub.1 -C.sub.4)-alkyl ester of malonic 
acid. The di-(C.sub.1 -C.sub.4)-alkyl malonates are particularly 
preferred, and among these diethyl malonate. These esters are preferably 
used in the form of their sodium salt. 
A salt-like mass having the presumed constitution III is obtained as a 
first product. It is reacted, without isolation, with a compound R.sup.1 
-X, in which X is a leaving group, such as halogen, preferably bromine or 
iodine, or tosyl. Working up in the alkaline medium and subsequent 
distillation leads to decarboxylation (Equation 3). 
The lactone IV thus obtained can be subjected to a rearrangement 
reaction--by known methods--by stirring in acidic media (for example 
polyphosphoric acid/P.sub.2 O.sub.5 or methanesulfonic acid/P.sub.2 
O.sub.5) to give an enone V, which is the starting material of the diene 
synthesis (Equation 4). This step could be optimized to such an extent 
that it gives the enone in 92% yield. The fact that the reaction 
(preferably alkylation) of the lactonate ion takes place virtually 
quantitatively according to Equation 3 is advantageous, and expensive 
distillative separation operations are therefore dispensed with. In view 
of the thermal sensitivity of the enone, this is an important detail. 
V can be reduced in a classical manner by reducing agents such as sodium 
boranate in the presence of cerium(III) chloride or lithium aluminum 
hydride. However, the corresponding allyl alcohol is not isolated; 
instead, a mixture of the three cyclopentadienyl derivatives IX, which are 
positional isomers, are obtained directly (Equation 8, Scheme 2). 
The reaction, known from the literature, of the diene IX with a compound 
M.sup.3 -R (M.sup.3 =an alkali metal, R=alkyl or hydrogen; in this case, 
for example, butyllithium, Equation 9) and subsequent introduction of the 
bridge R.sup.3 (in the form of a compound X-R.sup.3 -X in which X=Cl, Br 
or tosyl; in this case, for example, R.sup.4.sub.2 SiCl.sub.2, Equation 
10) leads to the compound of the formula VIIa. 
If the other double bond isomer VII is desired, it can be obtained by the 
"Bamford-Stevens method", for example via the tosylhydrazone VI (Equations 
5 and 6). 
The reaction of the isomers VII/VIIa with the alkali metal salt X, 
preferably the lithium salt, gives the ligand system VIII/VIIIa in good 
yields (Equations 7 and 11). The preparation of the metal complexes XI is 
carried out by deprotonation of the cyclopentadiene system VIII/VIIIa with 
a compound of the type M.sup.3 -R (see above; preferably butyllithium) and 
reaction of the resulting dilithio salt with a compound of the formula 
M.sup.1 X.sub.4 (X=halogen, preferably chlorine, in particular zirconium 
tetrachloride) in suitable solvents (for example dimethoxyethane, Equation 
12). The resulting reaction product XI is a mixture of the rac and meso 
complexes. Unbridged metal complexes of the type XII are obtainable by 
reacting the lithium salts X with M.sup.1 X.sub.4 (Equation 13). 
With exception of the steps corresponding to Equations 2 and 3, the stated 
reaction sequence is known, also with regard to the solvent, temperature 
and reaction time parameters; cf. Experientia 11 (1955) 114-115; J. Chem. 
Soc. Chem. Commun. 1978, 601-602; Tetrahedron Lett. 1977, 159-162; C. R. 
Acad. Sci. Paris 267 (1968) 467-470 and the examples. 
The chiral metallocenes are used in the form of the racemate for the 
preparation of highly isotactic poly-1-olefins. However, the pure R or S 
form may also be used. With these pure stereoisomeric forms, it is 
possible to prepare an optically active polymer. However, the meso form of 
the metallocenes should be separated off since the active center (the 
metal atom) for polymerization in these compounds is no longer chiral 
owing to mirror symmetry at the central metal and therefore cannot produce 
a highly isotactic polymer. 
The separation of the stereoisomers is known in principle. 
According to the invention, the cocatalyst used is an aluminoxane of the 
formula 
##STR8## 
for the linear type and/or of the formula 
##STR9## 
for the cyclic type, where, in the formulae, the radicals R may be 
identical or different and are a C.sub.1 -C.sub.6 -alkyl group, a C.sub.6 
-C.sub.18 -aryl group or hydrogen and p is an integer from 2 to 50, 
preferably from 10 to 35. 
Preferably, the radicals R are identical and are methyl, isobutyl, phenyl 
or benzyl, particularly preferably methyl. 
If the radicals R are different, they are preferably methyl and hydrogen or 
alternatively methyl and isobutyl, hydrogen or isobutyl preferably being 
present in an amount of 0.01-40% (number of radicals R). 
The aluminoxane can be prepared in various ways by known processes. One of 
the methods comprises, for example, reacting an aluminum-hydrocarbon 
compound and/or the hydridoaluminum-hydrocarbon compound with water 
(gaseous, solid, liquid or bound--for example as water of crystallization) 
in an inert solvent (such as, for example, toluene). For the preparation 
of an aluminoxane having different alkyl groups R, according to the 
desired composition two different aluminumtrialkyls (AlR.sub.3 
+AlR'.sub.3) are reacted with water (cf. S. Pasynkiewicz, Polyhedron 9 
(1990) 429-430 and EP-A 302 424). 
The exact structure of the aluminoxanes is not known. 
Regardless of the method of preparation, the common feature of all 
aluminoxane solutions is a change in content of unconverted aluminum 
starting compound, which is present in free form or as an adduct. 
It is possible to preactivate the metallocene prior to use in the 
polymerization reaction with an aluminoxane. This considerably increases 
the polymerization activity and improves the particle morphology. 
The preactivation of the transition metal compound is carried out in 
solution. The metallocene is preferably dissolved in a solution of the 
aluminoxane in an inert hydrocarbon. A suitable inert hydrocarbon is an 
aliphatic or aromatic hydrocarbon. Toluene is preferably used. 
The concentration of the aluminoxane in the solution is in the range from 
about 1% by weight to the saturation limit, preferably from 5 to 30% by 
weight, based in each case on the total solution. The metallocene can be 
used in the same concentration but is preferably employed in an amount of 
10.sup.-4 --1 mol per mole of aluminoxane. The preactivation time is 5 
minutes to 60 hours, preferably 5 to 60 minutes. The temperature of 
-78.degree. C. to 100.degree. C., preferably 0.degree. to 70.degree. C., 
is employed. 
The metallocene can also be prepolymerized or can be applied to a carrier. 
The olefin used in the polymerization, or one of the olefins used therein, 
is preferably employed for the prepolymerization. 
Suitable carriers are, for example, silica gels, aluminas, solid 
aluminoxane or other inorganic carriers. Another suitable carrier is a 
polyolefin powder in finely divided form. 
Another possible embodiment of the process according to the invention 
comprises using a salt-like compound of the formula R.sub.x NH.sub.4-x 
BR'.sub.4 or of the formula R.sub.3 PHBR'.sub.4 as a cocatalyst instead of 
or in addition to an aluminoxane. x is 1, 2 or 3, the radicals R are 
identical or different and are alkyl or aryl and R' is aryl which may 
furthermore be fluorinated or partially fluorinated. In this case, the 
catalyst consists of the reaction product of a metallocene with one of the 
stated compounds (cf. EP-A 277 004 and the Preparation Examples E and F). 
To remove catalyst poisons present in the propylene, purification with an 
aluminumalkyl, for example AlMe.sub.3 or AlEt.sub.3, is advantageous. 
Either this purification can be carried out in the polymerization system 
itself or, before addition to the polymerization system, the propylene is 
brought into contact with the Al compound and then separated off again. 
The polymerization or copolymerization is carried out in a known manner in 
solution, in suspension or in the gas phase, continuously or batchwise, in 
one or more stages, at a temperature of 0.degree. to 150.degree. C., 
preferably 30.degree. to 80.degree. C. Olefins of the formula R.sup.1 
--CH.dbd.CH--R.sup.b are polymerized or copolymerized In this formula, 
R.sup.a and R.sup.b are identical or different and are a hydrogen atom or 
an alkyl radical of from 1 to 14 carbon atoms. 
However, R.sup.1 and R.sup.b, together with the carbon atoms binding them, 
may furthermore form a ring. Examples of such olefins are ethylene, 
propylene, 1-butene, 1-hexene, 4-methyl-1-pentene, 1-octene, norbornene 
and norbornadiene. In particular, propylene and ethylene are polymerized. 
If necessary, hydrogen is added as a molecular weight regulator. The total 
pressure in the polymerization system is 0.5 to 100 bar. Polymerization in 
the pressure range of 5 to 64 bar, which is of particular interest in 
industry, is preferred. 
The metallocene is used in a concentration, based on the transition metal, 
of 10.sup.-3 to 10.sup.-8, preferably 10.sup.-4 to 10.sup.-7, mol of 
transition metal per dm.sup.3 of solvent or per dm.sup.3 of reactor 
volume. The aluminoxane is used in a concentration of 10.sup.-5 to 
10.sup.-1 mol, preferably 10.sup.-4 to 10.sup.-2 mol, per dm.sup.3 of 
solvent or per dm.sup.3 of reactor volume. In principle, however, higher 
concentrations are also possible. 
If the polymerization is carried out as a suspension or solution 
polymerization, an inert solvent conventionally used for the Ziegler low 
pressure process is employed. For example, an aliphatic or cycloaliphatic 
hydrocarbon is employed; butane, pentane, hexane, heptane, isooctane, 
cyclohexane and methylcyclohexane may be mentioned as examples of these. 
A gasoline or hydrogenated diesel oil fraction may also be used. Toluene is 
also suitable. Polymerization is preferably carried out in the liquid 
monomer. 
If inert solvents are used, the monomers are metered in as a gas or liquid. 
The polymerization can be carried out for any time since the catalyst 
system to be used according to the invention shows only a slight 
time-dependent decrease in the polymerization activity. 
The process according to the invention is distinguished by the fact that, 
in the temperature range between 30.degree. and 80.degree. C. which is of 
interest in industry, the metallocenes according to the invention produce 
polymers having a high molecular weight, high stereospecificity, a narrow 
molecular weight dispersity and in particular a high melting point, which 
is equivalent to high crystallinity and a high degree of hardness. 
The Examples below are intended to illustrate the invention in detail. 
The reaction sequence starting from cycloheptanone (n=5) and cyclooctanone 
(n=6) where R.sup.1 =CH.sub.3 and R.sup.4 =R.sup.5 =CH.sub.3 is described 
by way of example for all ketones I (CH.sub.2).sub.n+1 CO. 
Unless stated otherwise, the reaction was carried out under a nitrogen 
atmosphere (inert gas). 
1. Preparation of the Lactones IV. 
16.5 g (0.71 mol) of sodium are dissolved in 550 g of absolute ethanol. 
113.6 g (0.71 mol) of diethyl malonate are added dropwise to the solution 
which is warm to the touch. After some time, a spongy precipitate forms 
which consists of the sodium salt of the malonic ester. 0.70 mol of the 
epoxide II is then added dropwise at room temperature. After the addition 
is complete, the mixture is heated under reflux for 6 h. After the first 
two hours, the mass begins to become solid, so that mixing must be carried 
out with a stirrer. Thereafter, stirring is continued for a further 2 
hours at 50.degree. C., after which 85 g (0.75 mol) of methyl iodide are 
added dropwise at room temperature. The mixture is stirred overnight and 
boiled for a further 2 h on the next day. The reflux condenser is replaced 
with a distillation bridge, and the major part of the ethanol is distilled 
off. Owing to the hard consistency of the mass, distillation is supported 
toward the end by applying a slight vacuum, since stronger heating does 
not achieve the aim. The mass of sodium iodide and the ester is boiled 
with 280 ml of 25% strength sodium hydroxide solution until a heavy oil 
begins to separate out. With continuous monitoring by gas chromatography 
the reaction mixture is left at 70.degree.-80.degree. C. for a further 1 h 
during which solid residues also go into solution. The oil is separated 
off in a separating funnel and finally distilled in vacuo. 
Lactone IV (n=5): C.sub.11 H.sub.18 O.sub.2 ; C: calculated 72.5 found 72.9 
H: calculated 9.8 found 9.9 b.p. 112.degree. C. (2 mmHg), 90% of theory 
.sup.1 H-NMR (100 MHz, CDCl.sub.3, 25.degree. C.): 1.08, 1.09, D (J=6.9 Hz) 
3 H; 1.43, 1.39, "D", 12H; 2.58, 2.47, 2.3, 2.25, 2.08, 1.87, "M", 4H 
.sup.13 C-NMR (100 MHz, CDCl.sub.3, 25.degree. C., (DEPT: --CH.sub.3, 
--CH:+, --CH.sub.2 --): 178.8(O) C.dbd.O, 87.02(O) quart. C, 39.51(+)CH, 
15.09(+)CH:, 46.1, 42.45, 39.95, 37.58, 28.66, 21.8, 21.42(-)CH.sub.2 
IR spectrometry: 2292 cm.sup.-1 s, 2863 m, 1768 vs, 1458 m, 1378 m, 1312 w, 
1284 w, 1237 m, 1175 m, 1152 m, 1030 m, 1006 m, 987 m, 936 m-s 
Lactone IV (n=6): 
b.p. 166.degree. C. (10 mm), 82% of theory .sup.1 H-NMR 1 07, 1.09, D 
(J=7.2 Hz) 3H; 1.39 "S" 14H; 2.61, 2.51, 2.45, 2.38, 2.3, 2.19, 2.09, "M" 
4H 
.sup.13 C-NMR: 178.0(O) C=O, 87.8(O) quart. C, 16.3(+)CH.sub.3, 46.5(+)CH 
2. Subjecting the Lactone IV to a Rearrangement Reaction to Give Enones V: 
150 ml of technical-grade methanesulfonic acid (99%) are thoroughly stirred 
with 18 g (0.48 mol) of phosphorus pentoxide for 15 minutes. During this 
procedure, the phosphorus pentoxide is added in small portions. 0.27 mol 
of lactone IV is then added dropwise. The reaction starts with spontaneous 
heating and maintains a temperature of 70.degree. C. for about two hours. 
To complete the reaction, the mixture is allowed to stand for a further 
two hours in an oil bath at 60.degree. C. The melt is now deep red and 
fluoresces slightly in incident sunlight. For working up, it is poured 
into 17% strength sodium carbonate solution (obtained from a total of 600 
g of Na.sub.2 CO.sub.3) with ice. The pale yellow emulsion is extracted 
three times with ether and the combined organic phases are dried with 
sodium sulfate and evaporated down in a rotary evaporator. The remaining 
oil is distilled in vacuo at as low a temperature as possible and over a 
short bridge. 
Enone V (n=5): b.p.: 105.degree. C. (1 mm), 93% of theory 
.sup.1 H-NMR (100 MHz, CDCl.sub.3) 0.77, 0.87, D (J=7.25 Hz) 3H; 1.3, 2.1 
"M" 13H; 
.sup.13 C-NMR (100 MHz, CDCl.sub.3) 210(o) C.dbd.O, 173 (o) C.dbd.C, 161.2 
(o) C.dbd.C, 15.2(+)CH.sub.3, 34.2(+)CH, 39.9, 39.5, 37.8, 28.6, 
28.4(-)CH.sub.2 
Enone V (n=6): b.p.: Only with decomposition, 89% of theory 
.sup.1 H-NMR (400 MHz, CDCl.sub.3) 1.03, 0.96, D (J=7.1 Hz) 3H; 1.31, 1.63, 
"D" 12H; 2.37, 2.31, 2.2, 2.09, "M" 3H; 
.sup.13 C-NMR (100 MHz, CDCl.sub.3): 211(o) C.dbd.O, 173.1(o) C.dbd.C, 
138.8(o) C.dbd.C, 16.5 (+) CH.sub.3, 39.5 (+) CH, 29.8, 28.25, 25.6, 25.4, 
22.02, 22.0, 19.8, (-)CH.sub.2. 
The tosylhydrazones VI of the two compounds were obtained by conventional 
methods, by refluxing for one hour with tosylhydrazine in ethanol, with 
subsequent recrystallization. 
.sup.13 C-NMR: 198, C.dbd.N; 170.4, C.dbd.C, 135.24, C.dbd.C; 155.5, 143.4, 
129.1, 127.9, Ph; 42.1, CH; 17.62, CH--CH.sub.3 ; 21.85, Ph-CH.sub.3 ; 
32.1, 23.38, 27.7, 26.08, 25.79, 21.4, CH.sub.2. 
3. Preparation of the chlorodimethylsilyl-2-methylbicyclodienes VII 
10 mmol of the recrystallized tosylhydrazone VI of one of the two enones 
are dissolved in 40 ml of anhydrous dimethoxyethane (DME) and the solution 
is cooled to -50.degree. C. 15 ml (1.6 m, 24 mmol) of butyllithium also at 
this temperature are added dropwise by means of a capillary (17% excess). 
After about half the amount, there is a virtually spontaneous color change 
to deep red, whereas beforehand each drop of BuLi dissolved only with a 
few reddish streaks, which lost their color again. Stirring is then 
carried out for 45 minutes at this temperature. A pressure relief valve is 
then mounted on the dangling tube and the apparatus is placed in a cooling 
bath at -10.degree. to 5.degree. C. Gas evolution begins shortly 
thereafter, and decolorization to give a yellowish liquid. This can be 
very greatly accelerated by sunlight. After the end of the gas evolution, 
the solvent is stripped off and the greenish precipitate is washed twice 
with hexane in order to remove excess BuLi. This very sensitive salt is 
taken up again with 15 ml of DME, and a large excess of freshly distilled 
dimethyldichlorosilane is added at -20.degree. C. The mixture is allowed 
to warm up slowly to room temperature and the solvent is stripped off. 
Lithium chloride soon separates out, and this mass is extracted with 
methylene chloride and filtered. The filtrate is evaporated to dryness 
(yellow oil which soon becomes blue in the air). For further purification, 
this oil is distilled in a bulb tube. In this procedure, a bulb which is 
filled with Raschig rings and is likewise housed in the oven is connected 
between the receiver and the distillation bulb. Everything in this bulb is 
initially distilled at a low temperature, after which the temperature is 
increased in order to transfer the liquid to the receiver. 
VIIa (n=5): 
.sup.1 H-NMR (100 MHz, CDCl.sub.3, 25.degree. C.): 6.07, S, 1H; 3.27, "S", 
2H; 2.44, 1.66, "M", 10H; 2.1, S, 3H; 0.09, S, 6H 
.sup.13 C-NMR (400 MHz, CDCl.sub.3, 25.degree. C.) 144.1, 139.7, 138.8, 
135.6, 55.73, 32.8, 31.5, 30.15, 27.75, 27.6, 17.6, -0.2. 
4. Preparation of the bicyclodienes IX 
0.1 mol of the enone V is dissolved in 50 ml of methanol. 23.8 g of 
CeCl.sub.3. 7H.sub.2 O (0.1 mol) are dissolved in 70 ml of methanol with 
vigorous stirring and gentle heating. The two solutions are combined in a 
large flask and placed on ice. 3.7 g (0.1 mol) of sodium boranate are now 
added in portions. A full 5 minutes should be allowed between the 
individual additions. The suspension evolves gas vigorously and exhibits 
very pronounced foaming. Half an hour after the last addition, the mixture 
is heated to 50.degree. C. for 2 hours. Gas chromatography is used to 
check for the presence of enone. If this is not the case, concentrated HCl 
is added dropwise to destroy sodium boranate still present. A 
substantially acidic pH should be detected. The emulsion is then 
evaporated to dryness in a rotary evaporator under a slight vacuum. This 
mass is extracted with ether by a method in which vigorous stirring is 
carried out for 20 minutes in a conical flask. After the fourth 
extraction, the organic phase is checked to determine if any diene is 
still present. The combined organic phases are dried with sodium sulfate 
and distilled first at atmospheric pressure and, after removal of the 
ether, in vacuo at 10 mmHg. 
IX (n=5): Diene mixture b.p.: 81.degree. C. (2 mm) 
IR: 3137 cm.sup.-1 w, 1639 w, 1444 s, 1376 m, 1279 w, 1227 w, 1205 w, 1182 
w, 1147 w, 1090 w-m, 982 w, 959 m-w, 
902 m-w, 885 w, 868 w, 811 w 
Preparation of the Lithium Salts X and Reaction to Give the 
Chlorodimethylsilyl Derivatives VII 
0.1 mol of the diene mixture IX is dissolved in 100 ml of dry hexane and 
the solution is cooled to 10.degree. C. 69 ml of a 1.6 molar solution of 
butyllithium is pumped in in the course of half an hour by means of a 
canula. The initially colorless solution becomes cloudy, and a very 
flocculant white solid then separates out. After stirring for 3 hours at 
room temperature, refluxing is continued for 1 hour, the precipitate 
becoming coarser. It is now filtered off under suction over a No. 3 frit. 
By washing several times with hexane with complete suspension, it is freed 
from excess BuLi. It is then dried in a high vacuum to a pulverulent 
consistency. Yield: 79% 
To prepare the chlorodimethylsilyl derivatives VII, the lithium salt is 
suspended in 50 ml of THF and is pumped into a solution of 35 ml of 
freshly distilled dichlorodimethylsilane in the same amount of THF. The 
suspension instantaneously becomes a solution. Occasional cooling with ice 
keeps the liquid at room temperature. Stirring is continued for 1 hour and 
the solvent is stripped off completely. The remaining semicrystalline mass 
is extracted with 4.times.30 ml of methylene chloride. The oil remaining 
after the solvent has been stripped off is distilled in a bulb tube as 
under 3. 
6. Preparation of the Bisdienyldimethylsilyl Derivatives VIII 
Equimolar amounts of lithium salt X and chlorodimethylsilyl derivative VII 
are suspended in toluene and refluxed until chlorodimethylsilyldiene VII 
is no longer detectable by gas chromatography: 3 h with 20 mmol. The end 
of the reaction is detected by the fact that the white solid, very finely 
divided lithium chloride, no longer settles out. The solution is separated 
off from this by immersion filtration with a capillary which has a very 
fine-pore filter screwed on upstream, and is evaporated down. Yield: 89% 
7. Preparation of the Zirconium Complexes XI 
Preparation of the zirconium complex having the bridge ligand VIIIa (n=5) 
3.64 g (10 mmol) of the bridge ligand VIIIa are dissolved in 50 ml of 
ether, and 14 ml of 1.7M BuLi are added at 0.degree. C. This solution is 
stirred for 1 hour at room temperature, after which the solvent is 
stripped off completely. The remaining oil is stirred for a further hour. 
It is then taken up in 40 ml of DME and the solution is cooled to 
-45.degree. C. This solution, which is cloudy in some cases, is pumped 
into a solution of 2.32 g of ZrCl.sub.4 in 40 ml of DME, which solution is 
at the same temperature and may contain needles of ZrCl.sub.4 which have 
separated out again. The mixture is allowed to warm up to room temperature 
in the course of 2 hours, and a clear solution is obtained. This is 
stirred overnight, and a white precipitate separates out. The solution is 
now kept at 80.degree. C. for a further 3 hours. The fine white 
precipitate agglomerates appreciably, and an oil separates out. The 
supernatant solution is poured off and the oil is dissolved in methylene 
chloride and filtered off from insoluble LiCl by means of a capillary 
frit. 
The remaining solution is evaporated to saturation, covered with a layer of 
hexane and stored in a freezer until crystallization occurs. The complex 
is obtained as a rac/meso mixture (1:1) in the form of a yellow powder. 
Yield: 40% of theory 
.sup.1 H-NMR (100 MHz, CDCl.sub.3, 25.degree. C.): 6.08 S 2H, 2.44 S 6H, 
1.78, 1.57, 1.3, 0.93 "M" 10H, 0.69 "T" 6H 
.sup.13 C-NMR (100 MHz, CDCl.sub.3, 25.degree. C.) 121.73, 128.4, 136.1, 
137.32, 139.27, 32.74, 31.79, 28.82, 26.8, 26.65, 17.88, 13.8 
8. Preparation of the Zirconium Complexes XII 
Preparation of the zirconium complex from the cyclopentadienes IX (n=5). 
Under a nitrogen atmosphere, 466 mg (2 mmol) of freshly sublimed ZrCl.sub.4 
are dissolved in 30 ml of dimethoxyethane (DME), which has been cooled to 
-10.degree. C. After stirring for 20 minutes, the zirconium chloride 
dissolved in, the solution is cooled to -40.degree. C. and a suspension, 
at the same temperature, of 612 mg (4 mmol) of lithiumcyclopentadiene X in 
DME is pumped in. The mixture is allowed to warm up to room temperature 
over a period of 1-2 hours and is stirred overnight. All solids dissolve. 
Finally, refluxing is carried out for 3 hours, a fine precipitate of 
lithium chloride forming. The decanted solution is completely evaporated 
and then digested with 30 ml of methylene chloride. Stirring is carried 
out for 10 minutes, after which 10 ml of concentrated HCl are added and 
stirring is continued for a further 20 minutes. The supernatant methylene 
chloride is separated off in a separating funnel, the aqueous phase is 
extracted again with methylene chloride and the combined organic phases 
are dried with sodium sulfate and evaporated to dryness. The remaining 
crystalline mass is dissolved in a mixture of 14 ml of methylene chloride 
and 6 ml of benzene and the solution is heated briefly to the boiling 
point. Fine, slightly lemon yellow needles are precipitated on cooling. 
M.p.: 236.degree. C., yield: 63% of theory .sup.1 H-NMR (100 MHz, 
CDCl.sub.3, 25.degree. C.), 5.94 S 2H, 2.56 "T" 4H, 2.08, 1.92, 1.8, 1.52, 
1.21 "M" 6H 
.sup.13 C-NMR (100 MHz, CDCl.sub.3, 25.degree. C.) 133.14 (O), 121.85 (O), 
117.86 (+), 32.23 (-), 30.72 (-), 28.73 (-), 15.63 (+) 
Metallocenes XI as Polymerization Catalysts 
The meanings are as follows: 
__________________________________________________________________________ 
VN= Viscosity number in cm.sup.3 /g 
M.sub.w = 
Weight average molecular Determined by gel 
weight permeation 
M.sub.w /M.sub.n = 
Molecular weight dispersity 
chromatography 
II= Isotactic index (II = mm + 1/2 mr) determined by 
.sup.13 C-NMR spectroscopy 
n.sub.iso = 
Length of the isotactic blocks (in propylene 
units) (n.sub.iso = 1 + 2 mm/mr) determined by .sup.13 C-NMR 
spectroscopy 
__________________________________________________________________________ 
Melting points and heats of fusion .DELTA.H.sub.m.p. were determined by DSC 
(heating/cooling rate 20.degree. C./min).

EXAMPLE 1 
A dry 24 dm.sup.3 reactor was flushed with nitrogen and filled with 12 
dm.sup.3 of liquid propylene. 
35 cm.sup.3 of a solution of methylaluminoxane in toluene (corresponding to 
52 mmol of Al, mean degree of oligomerization n=17) were then added and 
the batch was stirred for 15 minutes at 30.degree. C. At the same time, 
5.3 mg (0.011 mmol) of 
rac-dimethylsilyl(2-Me-4,5,6,7-tetrahydro-1-indenyl).sub.2 zirconium 
dichloride were dissolved in 13.5 cm.sup.3 of a solution of 
methylaluminoxane in toluene (20 mmol of Al) and preactivated by allowing 
to stand for 15 minutes. The solution was then added to the reactor and 
the polymerization system was brought to 70.degree. C. by heating (in the 
course of 5 minutes) and kept at this temperature for 3 hours by cooling. 
The activity of the metallocene was 50.3 kg of PP per g of metallocene per 
h. 
VN=37 cm.sup.3 /g; M.sub.w =24,300 g/mol; M.sub.w /M.sub.n =2.4; II=96.0%; 
n.sub.iso =62; m.p.=150.degree..degree. C.; .DELTA.H.sub.m.p. =104 J/g. 
EXAMPLE 2 
Example 1 was repeated, except that 19.5 mg (0.04 mmol) of the metallocene 
were used and the polymerization temperature was 50.degree. C. The 
activity of the metallocene was 18.8 kg of PP per g of metallocene per h. 
VN=72 cm.sup.3 /g; M.sub.w =64,750 g/mol; M.sub.w /M.sub.n =2.1; II=96.0%; 
n.sub.iso =64; m.p.=154.degree. C.; .DELTA.H.sub.m.p. =109.5 J/g. 
EXAMPLE 3 
Example 1 was repeated, except that 58.0 mg (0.12 mmol) of the metallocene 
were used and the polymerization temperature was 30.degree. C. The 
activity of the metallocene was 9.7 kg of PP per g of metallocene per h. 
VN=152 cm.sup.3 /g; M.sub.w =171,000 g/mol; M.sub.w /M.sub.n =2.2; 
II=99.9%; n.sub.iso &gt;500; m.p.=160.degree. C.; .DELTA.H.sub.m.p.= 103 J/g. 
EXAMPLE 4 
Example 1 was repeated, except that 6.8 mg (0.015 mmol) of 
ethylene(2-Me-4,5,6,7-tetrahydro-1-indenyl).sub.2 zirconium dichloride 
were used. The metallocene activity was 72.5 kg of PP per g of metallocene 
per h. 
VN=35 cm.sup.3 /g; M.sub.w =20,750 g/mol; M.sub.w /M.sub.n =1.9; II=94.5%; 
n.sub.iso =34; m.p.=141.degree. C.; .DELTA.H.sub.m.p. =92.4 J/g. 
EXAMPLE 5 
Example 4 was repeated, except that 28.1 mg (0.062 mmol) of the metallocene 
were used and the polymerization temperature was 50.degree. C. The 
metallocene activity was 28.5 kg of PP per g of metallocene per h. 
VN=51 cm.sup.3 /g; M.sub.w =28,200 g/mol; M.sub.w /M.sub.n =2.2 II=94 8%; 
n.sub.iso =35; m.p.=143.degree. C.; .DELTA.H.sub.m.p. =97.9 J/g. 
EXAMPLE 6 
Example 4 was repeated, except that 50 mg (0.110 mmol) of the metallocene 
were used and the polymerization temperature was 30.degree. C. The 
metallocene activity was 10.9 kg of PP per g of metallocene per h. 
VN=92 cm.sup.3 /g; M.sub.w =93,800 g/mol; M.sub.w /M.sub.n =2.2; II=95.5%; 
n.sub.iso =48; m.p.=151.degree. C.; .DELTA.H.sub.m.p. =99.0 J/g.