ω-phenylalkyl-substituted zirconocene dichloride complexes as catalyst precursors for homogeneous ethylene polymerization

Article abstract of DOI:10.1016/S0022-328X(00)00009-7

The reaction of ω-phenyl-1-bromoalkanes with cyclopentadienyl sodium, indenyl lithium or fluorenyl lithium forms ω-phenylalkyl-substituted ligand precursors in high yields. The corresponding anions react with zirconium tetrachloride to give ω-phenylalkyl-

Full text of DOI:10.1016/S0022-328X(00)00009-7

www.elsevier.nl/locate/jorganchem
Journal of Organometallic Chemistry 599 (2000) 275–287
v-Phenylalkyl-substituted zirconocene dichloride complexes as
catalyst precursors for homogeneous ethylene polymerization
Erik H. Licht, Helmut G. Alt *, M. Manzurul Karim 1
Laboratorium fu¨r Anorganische Chemie, Uni6ersita¨t Bayreuth, D-95440 Bayreuth, Germany
Received 19 October 1999; accepted 19 November 1999
Abstract
The reaction of v-phenyl-1-bromoalkanes with cyclopentadienyl sodium, indenyl lithium or fluorenyl lithium forms v-pheny-
lalkyl-substituted ligand precursors in high yields. The corresponding anions react with zirconium tetrachloride to give
v-phenylalkyl-substituted zirconocene dichloride complexes. After activation with methylaluminoxane, these complexes are highly
active catalysts for homogeneous ethylene polymerization. The nature of the v-phenyl substituents determines the polymerization
activities of the catalysts to a large extent. The polymerization results of 28 new complexes are compared. © 2000 Elsevier Science
S.A. All rights reserved.
Keywords: Zirconium; Catalysis; Ethylene polymerization; Metallocene complexes
1. Introduction
2. Results and discussion
Metallocene dichloride complexes with Group IV
metals have received much attention in the past few
years because they are excellent catalysts for the poly-
merization of a-olefins [1–24]. The number of ways in
which the aromatic ligands and the bridging groups (for
ansa-complexes) can be modified is virtually unlimited.
This ability to vary the composition of the metallocene
complexes allows ‘tailoring’ of the catalyst precursors.
The activation of these complexes with methylalumi-
noxane (MAO) as a cocatalyst produces homogeneous
catalysts that are well suited for the investigation of the
structure–property relationships of catalysts and poly-
mers. In this paper, we describe 28 unbridged zir-
conocene dichloride complexes (27–54) that contain
one alkyl or silyl substituent with a terminal phenyl or
naphthyl group on the p-ligand.
2.1. Synthesis and characterization of substituted
cyclopentadiene, indene and fluorene deri6ati6es
2.1.1. Synthesis of the substituted cyclopentadiene
deri6ati6es 1a,b–15a,b
Liquid ammonia is an excellent solvent for the
reaction of cyclopentadienyl sodium [25] with
v-phenyl-1-bromo alkanes. Due to the low reaction
temperature of −40°C, the monosubstituted product is
obtained exclusively. The dimerization of the
cyclopentadiene derivative is avoided. Compared with
other synthesis methods [26], the yields are almost
quantitative [27] because subsequent distillation steps
can be avoided. The products consist of two isomers
differing in the position of the double bonds in the
cyclopentadienyl rings (Fig. 1).
We studied to what extent type and length of these
substituents determine the catalytic properties of the
corresponding complexes during ethylene poly-
merization.
Using this procedure, the following cyclopentadiene
derivatives were synthesized (Fig. 2):
2.1.2. Synthesis of the substituted indene deri6ati6es
16–21
Indene derivatives substituted in position 1 are
synthesized by the reaction of indenyllithium [28] with
1-haloalkanes or trialkyl chloro silanes in diethyl ether.
The double bond of the resulting indene derivative is
* Corresponding author. Tel.: +49-921-552555; fax: +49-921-
552157.
E-mail address: helmut.alt@uni-bayreuth.de (H.G. Alt)
1 Humboldt awardee from Jahangirnagar University, Dhaka,
Bangladesh.
0022-328X/00/$ - see front matter © 2000 Elsevier Science S.A. All rights reserved.
PII: S0022-328X(00)00009-7

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E. H. Licht et al. / Journal of Organometallic Chemistry 599 (2000) 275–287
Fig. 1. Synthesis of 4-methylbenzyl-1,2-cyclopentadiene and isomer (9a,b).
Fig. 2. Overview of the synthesized cyclopentadiene derivatives 1a,b–15a,b (only one isomer is illustrated).
always in position 2. The indene derivatives shown in
Fig. 3 were synthesized using this method.
numbers in recent years [31–36]. They are accessible by
the reaction of cyclopentadienyl, indenyl or fluorenyl
alkali metal salts with the metal tetrachlorides of tita-
nium, zirconium or hafnium in diethyl ether (Fig. 6).
The unbridged metallocene dichloride complexes
shown in Fig. 7 were synthesized using this method.
As long as there is only one substituent on the
cyclopentadienyl ligand, only rac and meso isomers
must be considered due to the hindered rotation of the
Indene can also be substituted in position 2 using a
multi-step synthesis [29]. The starting compound 2-in-
danone [30] is reacted with v-phenylalkyl magnesium
bromide in diethyl ether. The product is hydrolyzed
and subsequently water is removed by addition of
p-toluenesulfonic acid to produce the 2-(v-phenylalkyl)
indenes 22 and 23 (Fig. 4).
2.1.3. Synthesis of the fluorene deri6ati6es 24–26
(substituted in position 9)
The fluorene derivatives 24–26, substituted in posi-
tion 9, were synthesized analogously to the synthesis
method mentioned in Section 2.1.2. Fluorenyl lithium
was reacted with 1-bromoalkane in diethyl ether (Fig.
5).
2.1.4. Spectroscopic characterization of compounds
1a,b–26
1
Compounds 1a,b–26 were characterized by H-, 13C-
and 29Si-NMR spectroscopy. The spectroscopic data
are listed in the Section 3.
2.2. Synthesis of metallocene dichloride complexes
Unbridged, symmetrically substituted metallocene
dichloride complexes with cyclopentadienyl, indenyl
and fluorenyl ligands have been synthesized in large
Fig. 3. Overview of the synthesized indene derivatives 16–21.

E. H. Licht et al. / Journal of Organometallic Chemistry 599 (2000) 275–287
277
Fig. 4. Synthesis of 2-(v-phenylalkyl)indene compounds 22 and 23.
Fig. 5. Synthesis of the substituted fluorene derivatives 24–26.
Fig. 6. Synthesis of the unbridged, symmetrically substituted bis[4-methylbenzyl-(h5-cyclo-pentadienyl)] zirconium dichloride complex 35.
p-ligands around their metal bond axis. An additional
substituent in position 3 of the cyclopentadienyl ligand
induces chirality upon complexation because the two
prochiral ligands can coordinate in three different ways
(a,a/b,b/a,b) (Fig. 8). An analogous situation can be
expected for indenyl derivatives with a substituent in
position 1 (46).
The 1-phenyl-1-methylethyl-substituted metallocene
dichloride complexes 52–54 were synthesized using a
‘one-pot’ reaction. Phenyl lithium was reacted with
6,6-dimethylfulvene in diethyl ether and the resulting
salt was reacted with half an equivalent of metal tetra-
chloride (Fig. 9).
indenyl ligand (46) can exist as various isomers (see Fig.
8). In these cases a differentiation of the signals is not
always possible. The data are listed in Section 3.
2.4. Polymerization of ethylene
The synthesized metallocene complexes are suitable
precursors for catalytic olefin polymerization and were
used for the homogeneous polymerization of ethylene.
The complexes were activated by adding a 3000-fold
molar excess of MAO. In this way, an active catalyst
system was formed as indicated by a color change.
In the following discussion, the polymerization results
of only some complex types are discussed in order to
capture the large volume of data and to interpret clearly
the important information. The polymerization
activities of the activated metallocene complexes, the
2.3. Spectroscopic characterization of metallocene
dichloride complexes
(
The metallocene complexes 27–54 were characterized
viscosity average molecular weights Mp, the fusion
1
by H-, 13C- and 29Si-NMR spectroscopy. Complexes
enthalpies DHm, the melting temperatures Tm and the
degrees of crystallinity h of the resulting polymers are
listed in Table 1.
32–34 with two different substituents on the cyclopen-
tadienyl ligand or one substituent in position 1 of an

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E.H. Licht et al. / Journal of Organometallic Chemistry 599 (2000) 275–287
Fig. 7. Overview of the synthesized metallocene dichloride complexes 27–51.

E.H. Licht et al. / Journal of Organometallic Chemistry 599 (2000) 275–287
279
Fig. 8. Possible isomers of disubstituted bis(cyclopentadienyl) complexes (only the rac forms are illustrated).
Fig. 9. Synthesis of the bis[(1-phenyl)1-methylethyl(h5-cyclopentadienyl) metal dichloride complexes 52–54.
Table 1
Overview of the ethylene polymerization experiments a and polymer analytic results
Activity (kg PE g−1 Zr h−1
)
Mp (kg mol−1
)
DSC
(
Catalyst precursor
Tm (°C)
126.7
129.8
136.8
140.0
125.6
139.9
136.0
133.1
134.1
130.0
140.7
139.0
135.1
130.4
124.8
133.9
136.7
128.3
133.2
144.6
137.6
DHm (J g−1
180.4
161.9
155.1
152.0
177.8
143.1
149.0
150.6
152.3
168.8
144.6
154.8
120.2
133.0
203.7
153.5
152.4
157.8
132.1
125.9
159.5
)
h (%) b
62.2
55.8
53.5
52.4
61.3
49.4
51.4
52.0
52.5
58.2
49.9
53.4
41.5
45.9
70.3
52.8
27
28
30
31
32a–c
33a–c
34a–c
35
36
37
38
39
40
41
140.2
336.7
1506.0
4970.0
881.0
359.3
582.3
1880.9
1784.0
1120.4
129.0
529.0
23.3
1020.1
868.0
780.0
987.1
183.0
56.3
340
350
390
270
320
620
570
310
340
590
420
260
1050
490
370
370
380
480
360
90
43a–c
44a–c
45a–c
46a–c
49
52.6
54.4
45.6
43.4
50
51
17.0
24.0
75
55.0
52 (M=Ti)
53 (M=Zr)
7.6
5.8
130
300
Not determined
Not determined
a Homogeneous polymerization; MAO as cocatalyst (Zr:Al=1: 3000); in n-pentane at 60°C.
b Degree of crystallinity relative to the fusion enthalpy of 100% crystalline polyethylene.

280
E. H. Licht et al. / Journal of Organometallic Chemistry 599 (2000) 275–287
Fig. 10. Comparison of the polymerization activities of the metallocene dichloride complexes 27–30, 38, 53/MAO and the molecular weights of
the obtained polyethylenes. Homogeneous polymerization of ethylene after the activation with MAO (Zr:Al=1:3000), in n-pentane, at 60°C.
2.4.1. Influence of the spacer chain length on the poly-
merization beha6ior of the symmetrically substituted
metallocene dichloride complexes 27–30
The chain length of the alkyl or silyl substituent has a
strong impact on the polymerization behavior of the
metallocene complexes synthesized. Fig. 10 shows a
comparison of the polymerization activities for homoge-
neous polymerizations of the v-phenylalkyl substituted
bis(cyclopentadienyl) zirconium dichloride complexes
27–30.
The polymerization activity of the metallocene dichlo-
ride complexes increases with increasing chain length of
the alkylidene spacer located between the cyclopentadi-
enyl ligand and the bulky phenyl group. The decreasing
steric shielding of the catalytic center by the phenyl
group and the improved separation of the MAO counter
ion from the active, cationic catalyst center may both be
reasons for the observed improvement in activities due
to increasing spacer chain length [37].
Substitution of the carbon spacer atom 53 with a
silicon atom significantly increases the polymerization
activity of the corresponding metallocene complex 38.
The reason for this might be the increased bond length
of CꢀSi compared to CꢀC [38], but it could also be
caused by the Lewis-acidic character of the heteroatom
(Fig. 10).
A significant increase in polymerization activity can
also be observed if both methyl groups of the
isopropylidene spacer are substituted with hydrogen
atoms (e.g. metallocene complex 27). The poly-
merization activities of the metallocene complexes 27
and 38 indicate that the methylene spacer 27 has a
similar steric effect on the active cationic catalyst center
to the dimethylsilylene spacer. In contrast, the
molecular weights of the synthesized polymers do not
exhibit any general trends for these three metallocene
complexes.
2.4.2. Influence of the spacer type on the
polymerization beha6ior
The type and the substitution of the spacer atom in
the a-position to the p-ligand have the most influence on
the polymerization activities of the metallocene catalysts
studied. The reason for this behavior could be steric
hindrance of the active center (Fig. 11). The metallocene
complexes with isopropylidene spacer groups 53 exhibit
the lowest polymerization activity. Both methyl groups
and the phenyl group are rigidly linked to the carbon in
the a-position. This structural element seems to partially
block the free coordination site (Fig. 11).
Fig. 11. Steric influence of the bulky phenyl isopropylidene group on
the active catalyst center (MAO counterion not illustrated).

E.H. Licht et al. / Journal of Organometallic Chemistry 599 (2000) 275–287
281
The unsubstituted parent compounds Cp2ZrCl2 and
Ind2ZrCl2, when activated with MAO under the same
reaction conditions, show activities of 1490 and 3200 kg
PE g−1 Zr h−1. This is considerably lower than the
activity of 30/MAO (4970 kg PE g−1 Zr h−1).
over sodium sulfate–silica gel and the solvent evapo-
rated in vacuo. The products were obtained as colorless
to light yellow oils in 80–90% yields and were charac-
terized in Table 2.
3.5. General synthesis procedure for the indene
deri6ati6es 16–21
3. Experimental
Indene, 4.5 ml (33.0 mmol), was dissolved in 100 ml
diethyl ether and mixed with 20.6 ml (33.0 mmol)
n-butyllithium (1.6 M in n-hexane) at −78°C. The
reaction mixture was stirred for 4 h at r.t. At −78°C,
33.0 mmol of the corresponding a-phenylalkyl bromide
or dimethylphenylchloro silane were added and the
reaction mixture was stirred for 3 h at r.t. Subse-
quently, the mixture was hydrolyzed with 50 ml of
water and the organic phase dried over sodium sulfate.
The solvent was evaporated in vacuo, the residue dis-
solved in n-pentane and the solution filtered over silica
gel. After the solvent was evaporated, the products
were obtained as colorless oils in 80–90% yields.
3.1. NMR spectroscopy
Bruker ARX 250, AC 300 and DRX 500 spectrome-
ters were available for recording NMR spectra. The
organometallic samples were transferred into the NMR
tubes under argon and measured at 25°C. The chemical
shifts in the 1H-NMR spectra are referenced to the
residual proton signal of the solvent (l=7.24 ppm for
chloroform, l=7.15 ppm for benzene) and in 13C-
NMR spectra to the solvent signal (l=77.0 ppm for
chloroform-d1, l=128.0 ppm for benzene-d6).
3.2. Mass spectroscopy
3.6. General synthesis procedure for the indene
deri6ati6es 22 and 23
Routine measurements were performed on a Varian
MAT CH7 instrument (direct inlet, electron impact
ionization 70 eV) in the Central Analytical Department
at the University of Bayreuth. GC–MS spectra were
recorded using a Varian 3700 gas chromatograph in
Over 2 h, a solution of 20.0 g (157.6 mmol) 2-in-
danone in 200 ml diethyl ether was added dropwise to
a solution of 3.83 g (157.6 mmol) magnesium and 157.6
mmol of the corresponding a-phenylalkyl bromide in
200 ml diethyl ether. The reaction mixture was stirred
overnight at r.t. and subsequently hydrolyzed with di-
luted hydrochloric acid at 0°C. The organic phase was
then washed with 100 ml saturated sodium bicarbonate
solution and dried over sodium sulfate. Next the sol-
vent was evaporated in vacuo, and the corresponding
2-indanol derivative was obtained in 85–90% yield.
This product was dissolved in 150 ml toluene, mixed
with 3.0 g (16.1 mmol) p-toluenesulfonic acid and
heated under reflux with a water separator until no
further water was separated. The dark-brown suspen-
sion was successively washed with 100 ml of saturated
sodium bisulfate solution and 100 ml of water. The
organic phase was dried over sodium sulfate. The color-
less solution was evaporated in vacuo, the residue dis-
solved in n-pentane and the products crystallized at
−20°C. The indene derivatives precipitated as color-
less, crystalline solids in 60–70% yields and are charac-
terized in Table 2.
combination with
spectrometer.
a
Varian MAT 312 mass
3.3. Gas chromatography
Organic compounds were analyzed using a Carlo–
Erba HRGC gas chromatograph with flame ionization
detector. The J&W fused silica column was 30 m long
and 0.32 mm in diameter with a film thickness of 0.25
mm. Helium served as a carrier gas. The following
temperature program was used:
starting phase: 3 min at 50°C;
heating phase: 5°C min−1 (15 min);
plateau phase: 310°C (15 min).
3.4. General synthesis procedure for the cyclopentadiene
deri6ati6es 1a,b–15
Cyclopentadiene or methylcyclopentadiene, 160.0
mmol, was placed in a reaction flask, and 100 ml
ammonia were condensed into it at −78°C. Within 1
h, 100.0 mmol of the corresponding a-phenylethylbro-
mide or chlorosilane dissolved in 100 ml n-pentane
were added dropwise to the dark brown solution at
−78°C. The reaction mixture was stirred for 2 h at
−78°C and then slowly warmed up to room tempera-
ture (r.t.) where the ammonia evaporated. The residue
was mixed with 200 ml n-pentane, the solution filtered
3.7. General synthesis procedure for the
phenylalkylidene fluorene deri6ati6es 24–26
Fluorene, 6.0 g (36.1 mmol), was dissolved in 150 ml
diethyl ether and slowly mixed with 22.6 ml (36.1
mmol) n-butyllithium (1.6 M in n-hexane) at r.t. The
reaction mixture was stirred for 4 h at r.t. An equiva-

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E.H. Licht et al. / Journal of Organometallic Chemistry 599 (2000) 275–287
Table 2
Characterization of compounds 1a,b–26
a
Compound 1H-NMR (J(H,H) in Hz)
13C-NMR b
GC (s)
942
M+ [m/e]
1a,b
2a,b
3a,b
4a,b
7.50–7.15 (m, 10H), 6.60–6.72, 6.42–6.35, 6.29–
6.24, 6.21–6.03 (4m, 6H), 3.83, 3.81 (2s, 4H),
3.07, 2.95 (2m, 4H)
(Cq): 148.1, 144.8, 139.8
(CH): 134.5, 133.9, 132.3, 131.3, 129.0, 128.4,
128,3, 126.9, 125.8
(CH2): 43.0, 41.5, 37.7, 36.3
(Cq): 148.9, 146.4, 142.1
(CH): 134.5, 133.6, 132.3, 130.5, 128.3, 128.2,
126.7, 126.1, 125.7, 125.6
156
7.52–7.23 (m 10H), 6.66–6.54, 6.47–6.39, 6.39–
6.32, 6.25–6.17 (4m, 6H), 3.44–2.94 (m, 8H),
2.94–2.75 (m, 4H)
1254
1324
1439
170
184
198
(CH2): 43.3, 41.2, 36.0 35.2, 32.5, 32.0
(Cq): 148.6, 146.2, 142.4
7.42–7.18 (m, 10H), 6.58–6.48, 6.47–6.24, 6.17–
6.10 (4m, 6H), 3.05–3.00 (m, 2H), 3.00–2.95 (m, (CH): 134.6, 133.7, 132.4, 130.4, 128.4, 128.2,
2H), 2.81–2.63 (m, 4H), 2.60–2.43 (m, 4H), 2.08– 126.5, 126.0, 125.6, 125.2
1.89 (m, 4H)
7.41–7.16 (m, 10H), 6.57–6.48, 6.43–6.22, 6.15–
(CH2): 43.2, 41.2, 35.6, 35.5, 31.4, 30.4, 30.2, 29.3
(Cq): 148.5, 146.2, 142.2
6.09 (4m, 6H), 3.07–3.02 (m, 2H), 3.00–2.93 (m, (CH): 134.4, 133.5, 132.6, 130.2, 128.5, 128.2,
2H), 2.80–2.65 (m, 4H), 2.58–2.41 (m, 6H), 2.00– 126.3, 125.8, 125.4, 125.0
1.83 (m, 6H)
(CH2): 43.0, 41.1, 35.2, 35.3, 31.3, 30.2, 30.1,
29.0, 28.8, 28.5
5a,b
7.45–7.19 (m, 10H), 6.56–6.49, 6.46–6.24, 6.17–
(Cq): 148.5, 146.3, 142.1
6.10 (4m, 6H), 3.04–3.01 (m, 2H), 3.00–2.94 (m, (CH): 134.5, 133.7, 132.5, 130.3, 128.4–128.3,
2H), 2.80–2.61 (m, 4H), 2.57–2.35 (m, 8H), 2.07– 126.4, 126.2, 125.4, 125.2
1513
212
1.80 (m, 8H)
(CH2): 43.2, 41.0, 35.0, 35.4, 31.3, 30.2, 30.0,
29.1, 28.9, 28.8, 28.3, 28.1
6a,b
7.73–7.42 (m, 10H), 6.67 (m, 1H), 6.57 (m, 1H), (Cq): 139.9, 139.0, 137.9
6.42 (m, 1H), 6.21 (m, 1H), 4.01 (m, 4H), 3.21
(m, 2H), 2.23 (m. 2H), 1.50 (m, 6H)
(CH): 128.6, 128.3, 128.0, 126.9, 126.2
(CH2): 41.7, 37.4, 34.8
(CH3): 13.8, 13.7
1004
1147
1278
1139
170
184
198
200
7a,b
7.50–7.37 (m, 10H), 6.28 (m, 3H), 6.03 (m, 1H), (Cq): 142.9, 142.3, 138.9
3.07–2.97 (m, 8H), 2.18 (m, 4H), 1.43 (s, 6H)
(CH): 128.5, 128.4, 128.0, 126.2
(CH2): 38.2, 33.8, 33.3, 31.1, 29.3
(CH3): 13.8, 13.5
8a,b
7.51–7.37 (m, 10H), 6.27 (m, 3H), 6.02 (m, 1H), (Cq): 142.8, 142.1, 138.6
3.07–2.78 (m, 10H), 2.18 (m, 6H), 1.42 (s, 6H)
(CH): 128.6, 128.4, 128.1, 126.3
(CH2): 38.2, 37.2, 35.6, 35.5, 31.4, 30.4, 30.2, 29.3
(CH3): 13.8, 13.6
12a,b c
7.82–7.58 (m, 10H), 6.92–6.64 (m, 6H), 1.63–1.57 (Cq): 147.0, 138.7
(m, 4H)), 0.62–0.41 (m, 12H)
(CH): 133.7, 133.4, 132.9, 130.8, 130.5, 128.8,
127.7, 126.7, 124.7, 123.0, 121.1, 51.4
(CH2): 34.7, 29.7
(CH3): 0.8, −2.1, −4.5
(Cq): 147.0, 139.6
(CH): 142.7, 138.2, 132.9, 130.6, 128.4, 128.3,
128.2, 124.4, 124.2, 124.1
(CH2): 26.8, 25.9
13a,b d
14a,b e
7.42–7.19 (m, 10H), 6.84–6.66 (m, 6), 2.42–2.25
(m, 4H), 0.42–0.05 (m, 12)
1814
2110
214
228
(CH3): −2.7, −4.3
7.40–7.20 (m, 16H), 2.81–2.78 (m, 2H), 1.10–1.03 (Cq): 147.0, 145.0
(m, 2H) 0.27–0.17 (m, 12H)
(CH): 128.3, 128.2, 127.91, 127.7, 127.3, 127.1,
125.5, 125.4, 124.5, 124.3, 31.23, 30.9
(CH2): 29.4, 29.2, 20.3, 19.6
(CH3): 14.4, 14.1, 0.1, −0.3, −2.4
(Cq): 147.2, 144.8, 141.0
(CH): 139.1, 131.2, 129.2, 128.5, 126.9, 126.5,
124.9, 123.4, 121.4, 52.0
(CH2): 38.2
(Cq): 147.2, 144.8, 141.0
(CH): 139.6, 132.2, 129.31, 127.5, 126.8, 125.8,
123.8, 122.1, 121.3, 50.9
(CH2): 34.6, 34.1
16
17
18
7.54–7.36 (m, 9H), 6.96 (m, 1H), 6.62 (m, 1H),
3.85 (m, 1H), 3.23 (m, 1H), 2.87 (m, 1H)
1723
1807
2050
206
220
234
8.01–7.48 (m, 9H), 7.16–7.14 (m, 1H), 6.82–6.78
(m,1H), 3.51–3.28 (m, 1H), 2.84–2.79 (m, 2H),
2.53–2.42 (m, 2H)
7.55–7.49 (m, 9H), 7,17–7.15 (m, 1H), 6.84–6.78
(m, 1H), 3.53–3.28 (m, 1H), 2.84–2.75 (m, 2H),
2.53 (m, 2H)
(Cq): 147.2, 144.8, 141.0
(CH): 139.8, 132.2, 129.3, 128.5, 126.5, 124.9,
125.8, 123.8, 122.0, 121.3, 51.9
(CH2): 36.2, 34.5, 34.1

E. H. Licht et al. / Journal of Organometallic Chemistry 599 (2000) 275–287
283
a
Compound 1H-NMR (J(H,H) in Hz)
13C-NMR b
GC (s)
M+ [m/e]
19
20
21 f
22
23
24
25
26
7.90–7.66 (m, 9H), 7.66–7.33 (m, 1H), 7.03–7.00 (Cq): 147.6, 144.1, 142.2
(m, 1H), 3.94–3.92 (m, 1H), 3.13–3.05 (t, 2H) [7.5], (CH): 138.9, 130.7, 128.1, 128.0, 125.7, 124.5, 2091
248
2.41–1.96 (m, 6H).
122.6, 120.8, 118.8, 50.1
(CH2): 35.6, 31.9, 31.2, 27.2
7.55–7.29 (m, 9H), 6.93–6.92 (m, 2H), 6.68–6.66 (Cq): 147.8, 144.2, 142.6
(m, 2H), 3.63–3.56 (m, 1H), 2.76–2.70 (m, 2H), (CH): 139.3, 130.7, 128.3, 128.2, 126.1, 125.5, 2193
262
250
206
220
206
220
234
2.04–1.49 (m, 8H).
124.6, 122.7, 120.9, 50.4.5
(CH2): 35.9, 31.3, 31.2, 29.5, 27
7.41–7.01 (m, 9H), 6.82 (d, 1H) [5.0], 6.51–6.48 (m, (Cq): 144.6, 144.1, 137.3
1H), 3.63–3.61 (m, 1H), 0.82 (s, 3H), 0.03 (s, 3H). (CH): 135.2, 133.6, 129.2, 129.2, 127.6, 124.9, 1814
123,6, 122.8, 120.9, 45.5
(CH3): −0.5, −0.6
7.39 (m, 9H), 6.54 (s, 1H), 3.84 (s, 2H), 3.30 (s, (Cq): 149.2, 141.6, 139.9
2H)
(CH): 128.8, 128.4, 128.3, 128.1, 127.7, 126.5, 1765
126.2, 123.8, 123.4, 120.0
(CH2): 40.8, 37.9
7.36– 7.10 (m, 9H), 6.54 (s, 1H), 3.32 (s, 2H), 2.85 (Cq): 147.1, 142.5, 140.3
(m, 4H) (CH): 128.9, 128.5, 128.3, 128.0, 127.8, 126.8, 1875
126.4, 126.2, 124.0, 123.6, 121.3, 121.0, 120.2
(CH2): 47.3, 46.5, 39.1
7.80 (d, 2H), 7.45–7.20 (m, 11H), 4.29 (t, 1H) [7.6], (Cq): 146.8, 140.8, 139.8
3.17 (d, 2H) [7.6]
(CH): 129.5, 128.2, 127.1,
126.6, 124.8, 48.6
(CH2): 40.0
1647
7.92 (d, 2H), [7.5], 7.69 (d, 2H) [7.5], 7.54–7.27 (m, (Cq):145.9, 142.3, 141.2
9H), 4.19 (t, 1H), [5.0], 2.64–2.48 (m, 4H)
(CH): 128.2, 128.2, 126.9, 126.9, 125.7, 124.2, 1838
119.8, 47.1
(CH2): 34.7, 31.5
7.69 (d, 2H), [7.5], 7.42 (d, 2H) [7.5], 7.34–7.02 (m, (Cq): 146.9, 142.3, 141.2
9H), 3.93 (t, 1H [7.5], 2.51 (t,2H) [7.5], 2.05–1.96 (CH): 128.2, 128.2, 126.9, 126.9, 125.7, 124.2, 1970
(m, 2H),1.52–1.42 (m, 2H)
119.8, 47.1
(CH2): 35.9, 31.7, 25.0
a 25°C, in chloroform-d1 l [ppm] rel. chloroform (7.24).
b 25°C, in chloroform-d1 l [ppm] rel. chloroform-d1 (77.0).
c l (29Si)=−2.9 ppm.
d l (29Si)=3.0 ppm.
e l (29Si)=17.6/15.3 ppm.
f l (29Si)=−1.7 ppm.
lent amount of the respective v-phenylalkylbromide
derivative was added at −78°C. Subsequently, the
reaction mixture was stirred overnight at r.t. and hy-
drolyzed with 50 ml water. The organic phase was dried
over sodium sulfate and the solvent evaporated in
vacuo. The residue was dissolved in n-pentane, the
solution filtered over silica gel and the solvent evapo-
rated in vacuo. The respective v-phenylalkyl-substi-
tuted fluorene derivatives were obtained as colorless,
crystalline solids. The yields were 85–95%.
(a) Ether-insoluble metallocene dichloride complexes:
the solvent was evaporated in vacuo and the residue
washed twice with 50 ml n-pentane. The residue was
extracted with dichloromethane, the solution was
filtered over sodium sulfate and the solvent was evapo-
rated in vacuo. The yields were 70–80%.
(b) Ether-soluble metallocene dichloride complexes:
the suspension was filtered over sodium sulfate and the
solution evaporated. The residue was washed twice with
n-pentane and freed from solvent residues in vacuo.
The yields were 70–90%. The complexes are character-
ized in Table 3.
3.8. General synthesis procedure for the metallocene
dichloride complexes 27–41
3.9. General synthesis procedure for the
bis[(1-phenyl-1-methylethyl)-p5-cyclopentadienyl] metal
dichloride complexes 52–54
The ligand precursor (10.0 mmol) was dissolved in
100 ml diethyl ether and at −78°C mixed with 6.3 ml
(10.0 mmol) n-butyllithium (1.6 M in n-hexane). Then
1.2 g (5.0 mmol) zirconium tetrachloride was added at
−78°C and the reaction mixture was stirred overnight
at r.t.
6,6-Dimethylfulvene (2.4 ml, 20.0 mmol) was dis-
solved in 150 ml diethyl ether and mixed with 10.0 ml
(20.0 mmol) phenyl lithium (2 M solution in 70:30

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E. H. Licht et al. / Journal of Organometallic Chemistry 599 (2000) 275–287
Table 3
1H-, 13C- and 29Si-NMR data for the metallocene dichloride complexes 27–54
a
Complex
1H-NMR (J(H,H) in Hz)
13C-NMR b
[M+] (m/e)
473
27
7.46–7.12 (m, 10H), 6.39–6.32 (m, 4H), 6.28–6.16 (m, (Cq): 141.1, 134.2
4H), 3.98 (s, 4H) (CH): 128.6, 128.2, 128.3, 116.8, 112.4
(CH2): 35.7
7.47–7.14 (m, 10H), 6.39–6.29 (m, 4H), 6.26–6.16 (m, (Cq): 141.0, 133.9
4H), 3.14–2.90 (m, 8H) (CH): 128.5, 128.3, 128.2, 116.6, 112.1
(CH2): 36.6, 32.0
7.36–6.52 (m, 10H), 6.05–5.60 (m, 8H), 2.86–2.27 (m, (Cq): 143.0, 136.0
8H), 2.95–2.57 (m, 4H) (CH): 128.7, 126.1, 116.6, 112.0
(CH2): 35.8, 32.8, 30.0
7.39–7.17 (m, 10H), 6.29 (m, 4H), 6.21 (m, 4H), 2.68 (Cq): 142.3, 134.6
(m, 8H), 1.67 (m, 8H) (CH): 128.3, 128.2, 125.6, 116.6, 112.1
(CH2): 35.5, 30.9, 30.1, 29.9
7.39–7.24 (m, 10H), 6.34 (m, 4H), 6.25 (m, 4H), 2.71 (Cq): 142.5, 134.8
(m, 4H), 1.78–1.42 (m, 32H) (CH): 128.3, 128.1, 128.0, 116.6, 112.1
(CH2): 35.7, 31.1, 30.4, 29.9, 28.8
7.31–7.15 (m, 20H), 6.11–5.95 (m, 12H), 3.96 (m, 8H), (Cq): 148.5, 148.3, 132.9, 132.4, 132.3
28
501
29
529
30
557
31
585
32a–c
2.23 (s, 6H), 2.05 (s, 6H)
(CH): 128.6, 128.5, 126.2, 125.6, 125.4, 118.7, 118.2,
501
116.3, 116.1, 115.5, 114.6, 113.6, 112.0, 107.0, 106.7,
106.2
(CH2): 35.8, 35.3
(CH3): 16.0, 13.1
33a–c
7.32–7.14 (m, 20H), 6.10–5.95 (m, 12H), 2.88 (m,
16H), 2.22 (s, 6H), 2.05 (s, 6H)
(Cq): 148.6, 148.3, 132.8, 132.5, 132.2
(CH): 128.7, 128.5, 126.3, 125.7, 125.5, 118.8, 118.2,
116.4, 116.1, 115.7, 114.5, 113.4, 112.1, 107.2, 106.8,
106.0
529
(CH2): 37.0, 35.8, 32.6, 30.2
(CH3): 16.1, 13.3
34a–c
7.34–7.17 (m, 20H), 6.12–6.06 (m, 12H), 2.74–2.56 (m, (Cq): 148.6, 148.3, 132.8, 132.2
16H), 2.20 (s, 6H), 2.13 (s, 6H), 1.86 (m, 8H) (CH): 128.3, 128.0, 125.7, 118.4, 116.2, 116.1, 114.1,
557
501
113.7, 106.7, 106.3
(CH2): 35.6, 35.4, 32.4, 31.2, 30.1, 27.8
(CH3): 16.0, 13.5
35
7.12 (m, 8H), 6.22 (m, 8H), 3.99 (s, 4H), 2,35 (s, 6H) (Cq): 136.4, 135.9, 133.8
(CH): 129.1, 128.6, 116.8, 112.4
(CH2): 35.7
(CH3): 21.0
36
37
7.18–7.12 (m, 4H), 7.11–6.93 (m, 4H), 6.23 (m, 4H),
6.16 (m, 4H), 3.98 (s, 4H)
(Cq): 163.5, 135.3, 133.6
(CH): 130.4, 117.1, 115.5, 115.2, 112.4
(CH2): 35.3
(Cq): 139.7, 138.0, 133.6
(CH): 128.0, 126.6, 116.9, 112.8
(CH2): 36.0
513
529
7.01 (m, 6H), 6.42 (m, 8H), 4.11 (m, 4H), 2.47 (m,
12H)
(CH3): 21.2
38 c
39 d
40 e
7.56–7.39 (m, 10H), 6.63–6.61 (m, 4H), 6.32–6.30 (m, (Cq): 137.9, 123.7
4H), 0.64 (s, 12H) (CH): 134.1, 134.0, 133.9, 129.3, 129.2, 127.8, 127.7,
560
588
616
127.6, 126.0, 117.0
(CH3): −1.8
7.23–6.84 (m, 10H), 6.52–6.50 (m, 4H), 6.45–6,42 (m, (Cq): 139.2, 125.0
4H), 2.25 (s, 4H), 0.27 (s, 12H). (CH): 128.2, 128.2, 128.1, 125.7, 124.1, 115.7
(CH2): 27.2. 27.0
(CH3): −2.6
7.40–7.29 (m, 18H), 2.85–2.78 (m, 4H), 1.01–1.03 (m, (Cq): 144.9, 144.1
4H), 0.25 (s, 12H)
(CH): 128.3, 128.1, 127.84, 127.7, 127.5, 127.4, 127.2,
126.9, 126.4, 125.7, 125.5, 125.4, 124.9, 124.3
(CH2): 29.3, 28.5, 19.5, 13.5
(CH3): −0.5, −1.5
41
7.80–7.74 (m, 6H), 7.6 (m, 2H), 7.48–7.41 (m, 4H),
7.34 (m, 1H), 7.31 (m, 1H), 6.22 (m, 8H), 4.17 (s,
4H)
(Cq): 137.3, 133.6, 133.5, 132.2
(CH): 128.2, 127.6, 127.5, 127.4, 127.1, 126.1, 125.6,
117.0, 112.7
411
(CH2): 36.3

E. H. Licht et al. / Journal of Organometallic Chemistry 599 (2000) 275–287
285
Table 3 (Continued)
a
Complex
1H-NMR (J(H,H) in Hz)
13C-NMR b
[M+] (m/e)
42a–c
7.63–7.54 (m, 8H), 7.37–7.11 (m, 28H), 6.28 (d, 2H)
[3.1], 6.04 (d, 2H) [3.1], 5.82 (d, 2H) [3.1], 5.29 (d,
2H) [3.1], 4.41–4.01 (m, 8H)
(Cq): 139.7, 139.5, 127.5, 121.8, 121.7
(CH): 128.9, 128.8, 128.7, 128.5, 128.4, 126.5, 126.4,
126.3, 126.2, 125.8, 125.6, 123.8, 122.1, 120.8, 99.2, 99.1
(CH2): 34.1, 33.9
573
43a–c
7.65–7.13 (m, 36 H), 6.21 (d, 2H) [3.1], 5.92 (d, 2H)
[3.1], 5.84 (d, 2H) [3.1], 5.60 (d, 2H) [3.1], 3.41–2.77
(m, 16H)
(Cq): 141.2, 127.3, 122.3
(CH): 128.5, 128.3, 128.2, 127.3, 127.0, 126.3, 126.0,
125.9, 125.8, 125.7, 125.5, 125.4, 125.3, 125.0, 123.7,
123.6, 120.3, 99.1, 98.9
601
629
657
717
573
(CH2): 36.0, 35.9, 30.2, 29.9
44a–c
45a–c
7.42–7.15 (m, 36H), 6.3(d, 2H) [3.2], 6.04 (d, 2H)
[3.2], 5.83 (d, 2H), 3.2], 5.65 (d, 2H) [3.2], 3.01–2.58
(m, 16H), 1.94–1.60 (m, 8H)
(Cq): 141.8, 127.2, 126.0, 126.0, 122.9, 122.8
(CH): 128.3, 126.1, 125.8, 125.7, 125.7, 125.6, 125.4,
125.3, 123.7, 123.7, 121.8, 120.3, 99.2, 99.2
(CH2): 35.6, 35.5, 31.5, 27.7, 27.4
(Cq): 150.8, 148.2, 145.7, 144.6, 144.3, 143.9, 142.6,
141.8, 125.7, 124.0, 123.6
(CH): 142.0, 139.2, 130.4, 128.2, 128.1,126.0, 125.6,
125.5, 125.5, 124.1, 124.0, 124.0, 123.6, 123.6, 121.7,
120.1, 118.3, 117.5, 99.9
7.43–7.23 (m, 36H), 6.42 (d, 2H) [2.8], 6.16 (d, 2H)
[2.8], 5.97 (d, 2H) [2.8], 5.76 (d, 2H), [2.8], 2.99–2.59
(m, 12H), 1.66–1.53 (m, 20H)
(CH2):35.0, 33.7, 33.0, 23.3, 23.2
46a–c f
7.61–7.18 (m, 36H), 4.49–4.47 (m, 2H), 6.41–6.40 (m, (Cq): 144.3, 144.1, 137.2, 134.1, 129.4
3H), 6.06–6.04 (m, 2H), 5.70–5.68 (m, 2H), 0.73–0.64 (CH): 134.1, 129.3, 127.9, 127.1, 127.0, 127.0, 126.9,
(24H)
126.4, 126.2, 126.1, 125.5, 121.0, 114.1, 113.5, 106.1,
105.2
(CH3): −0.6, −0.7, −1.2, −1.3
47
48
49
7.67–7.64 (m, 4H), 7.25–7.18 (m, 10H), 7.01 (m, 4H), (Cq): 132.8, 128.9, 126.7
5.85 (s, 4H), 3.70 (s, 4H) (CH): 129.1, 129.0, 126.5, 126.0, 125.9, 106.3
(CH2): 38.0
7.66–7.62 (m, 4H), 7.25–7.19 (m, 10H), 7.04 (m, 4H), (Cq): 133.2, 131.4, 126.8
5.74 (s, 4H), 2.70–2.60 (m, 8H)
(CH): 128.9, 128.8, 126.6, 125.9, 125.7, 105.7
(CH2): 36.9, 33.7
(Cq): 140.8, 130.9, 118.1, 105.0
(CH): 128.3, 128.2, 127.8, 126.9, 126.7, 126.3, 125.9,
124.6, 124.4, 122.5, 119.9
601
673
7.93–7.79 (m, 8H), 7.46–6.48 (m,1 8H), 4.17 (s, 4H)
(CH2): 30.8
50
51
7.84–7.79 (m, 8H), 7.43–6.94 (m, 18H), 3.13 (t, 4H)
[7.5], 2.69 (t, 4H) [7.5]
Cq): 141.6, 128.5, 119.9, 105.8
(CH): 128.4, 128.3, 128.3, 127.0, 126.5, 125.8, 124.1,
124.0, 123.9, 123.4, 119.9
701
729
(CH2): 36.2, 27.6
7.77–7.73 (m, 8H), 7.37–7.10 (m, 18H), 2.85–2.79 (m, (Cq): 142.0, 130.3, 118.5, 104.6
4H), 2.61–2.55 (m, 4H), 1.76–1.70 (m, 4H) (CH): 128.4, 128.3, 126.9 126.8, 126.6, 125.8, 124.3,
124.2, 123.9, 123.4, 119.8
(CH2): 34.0, 29.8, 23.2
52
53
54
7.31–7.17 (m, 10H), 6.49 (m, 4H), 6.11 (m, 4H), 1.79 (Cq): 149.3, 146.6, 41.2
(s, 12H) (CH): 128.2, 126.3, 126.2, 121.2, 118.1
(CH3): 29.0
7.35–7.17 (m, 10H), 6.40 (m, 4H), 6.05 (m, 4H), 1.83 (Cq): 149.8, 143.1, 40.4
(s, 12H) (CH): 128.1, 126.1, 126.0, 117.2, 113.0
(CH3): 29.3
7.36–7.16 (m, 10H), 6.38 (m, 4H), 6.05 (m, 4H), 1.82 (Cq): 149.7 143.7 40.3
(s, 12H) (CH): 128.1, 126.2 126.1 116.5, 112.0
(CH3): 29.3
485
529
616
a 25°C, in chloroform-d1 l [ppm] rel. chloroform (7.24).
b 25°C, in chloroform-d1 l [ppm] rel. chloroform-d1 (77.0).
c l (29Si)=−10.8 ppm.
d l (29Si)=−5.2 ppm.
e l (29Si)=−1.3 ppm.
f l (29Si)=−10.3/−10.4 ppm.
(wt%) cyclohexane–diethyl ether at −78°C. The white
suspension was stirred for 4 h at r.t. Then 10.0 mmol of
the corresponding metal tetrachloride were added at
−78°C and the reaction mixture was stirred overnight
at r.t. The solvent was evaporated and the residue was
washed twice with 50 ml n-pentane. The residue was

286
E.H. Licht et al. / Journal of Organometallic Chemistry 599 (2000) 275–287
(
extracted with dichloromethane, the solution was
filtered over sodium sulfate and the solvent evaporated.
The yields were 80–90%. MS. 52: m/e=485 [M+]. 53:
m/e=529 [M+]. 54: m/e=616 [M+].
over glass wool. Mp was determined using a calibration
curve that was available for the selected concentration.
Acknowledgements
3.10. Acti6ation of the metallocene complexes
with methylaluminoxane (MAO)
We thank the Deutsche Forschungsgemeinschaft, the
Alexander von Humboldt Foundation and Phillips
Petroleum Company (Bartlesville, OK, USA) for finan-
cial support and the Witco Company for the supply of
MAO.
The corresponding metallocene complex (10–15 mg)
was activated with MAO (30% in toluene) (metal:Al=
1:3000). The catalyst solution, containing 0.5–1.5 mg
metallocene complex, was used within
homopolymerization.
1 h for
References
3.11. Homopolymerization of ethylene
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A volume of n-pentane (500 ml) was placed in a 1 l
Bu¨chi laboratory autoclave, mixed with the catalyst
solution and the autoclave thermostated at 60°C. An
ethylene pressure (99.98% ethylene) of 10 bar was ap-
plied after an inside temperature of 50°C was reached
(sometimes the polymerization reactions were highly
exothermic). The mixture was stirred for 1 h at 60°C
(92°C) and the reaction terminated by releasing the
pressure in the reactor. The polymer obtained was dried
in vacuo.
3.12. Characterization of the polyethylene samples
3.12.1. Differential scanning calorimetry (DSC)
Phase transitions on the polymer samples were mea-
sured using DSC techniques (Pyris DSC 7 instrument).
For the measurements, 5–12 mg dried polymer were
fused into standard aluminum pans (¥ 7 mm) and
measured under nitrogen cooling, using the following
temperature program:
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First heating phase: from 25–200°C (heating rate
40°C min−1).
Isothermal phase: 3 min.
Cooling phase: from 200 to −40°C (cooling rate
20°C min−1).
Second heating phase: from −40 to 200°C (heating
rate 20°C min−1).
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Melting points and fusion enthalpies were taken from
the second heating course. The temperature was lin-
early corrected relative to indium (m.p. 429.78 K). The
fusion enthalpy of indium (Hm=28.45 J g−1) was used
for calibration.
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3.12.2. Viscosimetry
The viscosity average molecular-weight determina-
tions of the polyethylene samples were performed on an
Ubbelohde precision capillary viscometer in cis/trans-
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