Synthesis of elastomeric polypropylene in bulk using C1- symmetric ansa-metallocenes. New aspects of the synthesis of 1-(fluoren-9-yl)-2-(2-methyl-5,6-dihydrocyclopenta[f]-1H-inden-1-yl)ethane and complexes of zirconium and hafnium with this li

Article abstract of DOI:10.1007/s11172-005-0264-x

Isomeric 1-(fluoren-9-yl)-2-(2-methyl-5, 6-dihydrocyclopenta [f]-1 H-indenyl) ethanes 1a,b and C ₁-symmetric metallocenes, viz., rac-1-(η⁵-fluoren-9-yl)-2-(2-methyl-5, 6-dihydrocyclopenta [f]-η⁵-inden-1-yl) ethanezirconium

Full text of DOI:10.1007/s11172-005-0264-x

400
Russian Chemical Bulletin, International Edition, Vol. 54, No. 2, pp. 400—413, February, 2005
Synthesis of elastomeric polypropylene in bulk
using C1ꢀsymmetric ansaꢀmetallocenes. New aspects of
the synthesis of 1ꢀ(fluorenꢀ9ꢀyl)ꢀ2ꢀ(2ꢀmethylꢀ5,6ꢀdihydrocyclopenta[ f ]ꢀ1Hꢀ
indenꢀ1ꢀyl)ethane and complexes of zirconium and hafnium with this ligand
a
a
a
a
a
P. M. Nedorezova,a E. N. Veksler, E. S. Novikova, V. A. Optov, A. O. Baranov, A. M. Aladyshev,
ꢀ
V. I. Tsvetkova,a B. F. Shklyaruk,b D. P. Krut´ko,c A. V. Churakov,d L. G. Kuz´mina,d and J. A. K. Howarde
aN. N. Semenov Institute of Chemical Physics, Russian Academy of Sciences,
4 ul. Kosygina, 119991 Moscow, Russian Federation.
Fax: +7 (095) 137 8284. Eꢀmail: pned@chph.ras.ru
bA. V. Topchiev Institute of Petrochemical Synthesis, Russian Academy of Sciences,
29 Leninsky prosp., 119991 Moscow, Russian Federation.
Fax: +7 (095) 955 2224
cDepartment of Chemistry, M. V. Lomonosov Moscow State University,
1 Leninskie Gory, 119992 Moscow, Russian Federation.
Fax: +7 (095) 932 8846. Eꢀmail: kdp@org.chem.msu.su
dN. S. Kurnakov Institute of General and Inorganic Chemistry, Russian Academy of Sciences,
31 Leninsky prosp., 119991 Moscow, Russian Federation.
Fax: +7 (095) 954 1279. Eꢀmail: churakov@igic.ras.ru
eDepartment of Chemistry, University of Durham,
South Road, Durham DH1 3LE, UK.
Fax: +44 (0191) 384 4737. Eꢀmail: j.a.k.howard@durham.ac.uk
Isomeric 1ꢀ(fluorenꢀ9ꢀyl)ꢀ2ꢀ(2ꢀmethylꢀ5,6ꢀdihydrocyclopenta[ f ]ꢀ1Hꢀindenyl)ethanes 1a,b
5
and C1ꢀsymmetric metallocenes, viz., racꢀ{1ꢀ(η ꢀfluorenꢀ9ꢀyl)ꢀ2ꢀ(2ꢀmethylꢀ5,6ꢀdihydroꢀ
5
5
cyclopenta[ f ]ꢀη ꢀindenꢀ1ꢀyl)ethane}zirconium dichloride (9) and racꢀ{1ꢀ(η ꢀfluorenꢀ9ꢀyl)ꢀ
5
2ꢀ(2ꢀmethylꢀ5,6ꢀdihydrocyclopenta[ f ]ꢀη ꢀindenꢀ1ꢀyl)ethane}hafnium dichloride (10), with
these ligands were synthesized by modified procedures. The structures of compounds 1b (two
crystalline modifications) and 10 were established by Xꢀray diffraction analysis. The synthesis
of polypropylene (PP) in bulk was studied in the presence of polymethylalumoxaneꢀactivated
metallocenes 9 and 10 in the temperature range of 30—70 °C. It was demonstrated that
triisobutylaluminum can be used as a cocatalyst. In this case, the molecular weight of PP
increases by a factor of ∼2. An increase in the reaction temperature leads to an increase in
stereoregularity and crystallinity of PP. The polymer synthesized at high temperatures crystalꢀ
lizes in the γ form. The resulting PP is characterized by a wide range of properties from rigid
crystalline thermoplastic to amorphous elastomeric. Samples, which have a high molecular
weight and moderate isotacticity, exhibit high elastomeric and durability properties.
Key words: zirconium, hafnium, C1ꢀsymmetric ansaꢀmetallocenes, Xꢀray diffraction analyꢀ
sis, propene polymerization, elastomeric polypropylene, microstructure, phase state.
The design of highly efficient homogeneous systems
desired and polyolefins with different microstructures can
be prepared by varying the composition, structure, and
symmetry type of metallocenes. Catalytic systems based
on these complexes offer wide possibilities to prepare new
polymeric materials with unique properties, in particular,
elastomeric polypropylene (PP).
Elastomeric PP, whose molecules consist of alternatꢀ
ing stereoregular and random blocks, has been prepared
for the first time5 as a lowꢀmolecularꢀweight byꢀproduct
based on Group IV metal sandwich complexes opened up
new possibilities for extending the grade range and fields
of application of materials based on homoꢀ and copolyꢀ
mers of αꢀolefins.1—4 Due to the presence of active cenꢀ
ters of the same type, these catalysts give a possibility to
prepare polymers with a narrow molecularꢀweight distriꢀ
bution and compositionally homogeneous copolymers.
The stereospecificity of the reactions can be varied as
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 392—404, February, 2005.
1066ꢀ5285/05/5402ꢀ0400 © 2005 Springer Science+Business Media, Inc.

Synthesis of elastomeric polypropylene in bulk
Russ.Chem.Bull., Int.Ed., Vol. 54, No. 2, February, 2005
401
in the synthesis of isotactic PP using heterogeneous cataꢀ
lytic systems. The discovery of metallocene catalysts,
which ensure the formation of elastomeric PP as the maꢀ
jor product in high yield, has inspired new interest in the
synthesis of this polymer.
step, and established the crystal structures of compound
1b and the hafnium sandwich derived from 1b.
Results and Discussion
Several types of homogeneous metallocene catalysts
proved to be efficient in the synthesis of elastomeric PP:
(1) bisꢀindenyl 2ꢀarylꢀsubstituted complexes;6,7
(2) "hybrid" systems involving simultaneously several
types of metallocenes;8,9 (3) C1ꢀsymmetric ansaꢀmetalloꢀ
cenes.10—13
Of particular interest is the examination of the possiꢀ
bility of synthesizing elastomeric PP with the use of
C1ꢀsymmetric ansaꢀmetallocenes. Earlier,12,13 several such
complexes have been synthesized and the most active
complexes have been revealed. The scheme of polymer
chain growth, which has been described for the first time
in the publication,14 was used as the basis for the mechaꢀ
nism of action of C1ꢀsymmetric metallocenes.15 This
mechanism assumes the presence of two centers with difꢀ
ferent stereospecificity and the competition between the
chain growth and chain migration without monomer inꢀ
sertion. In this case, the polymer chain growth should
lead to alternation of short isotactic sequences separated
by single stereo defects.
The aim of the present study was to examine the efꢀ
fects of the nature of metal in the C1ꢀsymmetric comꢀ
plexes, the modes of their activation, and the conditions
of propene polymerization in bulk on the catalytic activꢀ
ity, microstructure, heatꢀtransfer, and mechanical propꢀ
erties of the polymers. We also carried out a thorough
study of 1ꢀ(fluorenꢀ9ꢀyl)ꢀ2ꢀ(2ꢀmethylꢀ5,6ꢀdihydrocycloꢀ
penta[ f ]ꢀ1Hꢀindenyl)ethanes 1a,b serving as ligands, inꢀ
vestigated the structures of intermediates formed in each
Synthesis of 1ꢀ(fluorenꢀ9ꢀyl)ꢀ2ꢀ(2ꢀmethylꢀ5,6ꢀdihydroꢀ
cyclopenta[ f ]ꢀ1Hꢀindenꢀ1ꢀyl)ethane (1b). Bisꢀcycloꢀ
pentadienyl ligand 1b was prepared according to a known
procedure15 presented in Scheme 1.
The drawback of this method is that the synthesis of
the starting triflate 3 requires the use of expensive triꢀ
fluoromethanesulfonic anhydride. We attempted to perꢀ
form this reaction with the use of tosylate 6 instead of
compound 3. However, the reaction mixture contained
(1H NMR spectroscopic data) target products 1a,b along
with spiro compound 7, the starting indene 4, and other
unidentifiable compounds in comparable amounts
(Scheme 2, method 1).
We succeeded in separating the reaction mixture by
silica gel column chromatography and isolating all main
products (4, 1a, and 7) in pure form. The total yield of
compounds 1a and 7 was 49%. In our opinion, the formaꢀ
tion of spiro compound 7 is attributable to deprotonation
of tosylate 6 with lithium salt 5 as the side reaction folꢀ
lowed by intramolecular nucleophilic substitution. It
should be noted that the reaction with compound 3 (see
Ref. 15) did not afford byꢀproduct 7, which may be assoꢀ
ciated with a considerable increase in the rate of nucleoꢀ
philic substitution in going from tosylate 6 to triflate 3.
Interestingly, the ligand prepared by the method 1 was
isolated as isomer 1a (the amount of isomer 1b was <5%;
1H NMR spectroscopic data). This can be explained as
follows. Initially, the reaction affords isomer 1b, which
can, apparently, be deprotonated at the indenyl ring with
Scheme 1
Reagent and conditions: i. (CF3SO2)2O, CH2Cl2, Py, 0 °C. ii. BuLi, dioxane, 0 °C. iii. THF, 20 °C.

402
Russ.Chem.Bull., Int.Ed., Vol. 54, No. 2, February, 2005
Nedorezova et al.
Scheme 2
an excess of lithium salt 5 present in the solution to form
the anion. The latter gives the target ligand as the thermoꢀ
dynamically most stable isomer 1a upon quenching of the
reaction mixture. It should be noted that isomer 1b
has been isolated earlier15 under analogous conditions
(the addition of triflate 3 to a solution of salt 5; see
Scheme 1).
yield of the target products 1a,b due to the side reaction
giving rise to spiro compound 7. Under particular condiꢀ
tions, the latter process becomes the major reaction (see
Scheme 2, method 2). Nevertheless, in spite of relatively
low yields, we isolated isomers 1a and 1b in pure form
(white crystalline compounds). Their structures were unꢀ
1
ambiguously established by H and 13C NMR spectrosꢀ
With the aim of preventing side processes, which ocꢀ
cur in the reaction mixture in the presence of an excess of
anion 5, we attempted to perform this reaction by mixing
reagents in the reverse order (see Scheme 2, method 2).
As expected, the percentage of unidentifiable products in
the mixture decreased substantially. The total yield of
compounds 1b and 7 was 80%. However, the ratio of
these compounds changed in an undesirable way (see
Scheme 2). In our opinion, an increase in the percentage
of spiro compound 7 in the reaction mixture can be exꢀ
plained as follows. In this case, several competitive proꢀ
cesses can occur at different rates. The initial step of the
reaction involves slow nucleophilic substitution giving rise
to the target product 1b along with fast deprotonation of
tosylate 6 with lithium salt 5. The further intramolecular
nucleophilic substitution affords product 7. In these sysꢀ
tems, deprotonation occurs much more rapidly than nuꢀ
cleophilic substitution. Therefore, in the initial step of the
synthesis according to the method 2, the concentration of
tosylate 6 is substantially higher than that of lithium salt 5,
and the latter is virtually completely consumed for
deprotonation of compound 6, resulting in an undesirable
change in the ratio of products 1 and 7 compared to the
method 1.
copy. Earlier,15 compound 1b has been described as a
yellow oil.
Xꢀray diffraction study of compound 1b. The molecular
structures of two crystalline modifications of isomer 1b
were established by Xꢀray diffraction. One modification
(monoclinic, space group P21/c) was prepared by slow
crystallization from CH2Cl2, and another modification
(orthorhombic, space group Pbca) was obtained by crysꢀ
tallization from the mother liquor during isolation of
ligand 1 (a benzene—hexane—CH2Cl2 solvent mixture).
The molecular structure of the monoclinic modification
of 1b is shown in Fig. 1. The bond lengths and bond
angles for both modifications are given in Table 1. The
structure of the monoclinic modification of 1b consists of
crystallographically equivalent molecules. The fluorenyl
fragment is planar within 0.029(2) Å. The coordinaꢀ
tion environment of the fluorenyl C(1) atom is nearly
tetrahedral (see Table 1). The C(14)—C(15) bond has
an antiperiplanar conformation (the C(1)—C(14)—
C(15)—C(16) torsion angle is 170.5(1)°). The exocyclic
angles at the C(16)=C(17) double bond are smaller (∼10°)
than the endocyclic angles due to the geometric requireꢀ
ments of the C(16)—C(17)—C(18)—C(19)—C(27) fiveꢀ
membered ring. All C—C bond lengths in molecule 1b
have standard values tabulated for the corresponding bond
types in organic compounds.16
Therefore, the use of cheaper but less reactive tosylate
6 instead of triflate 3 led to a substantial decrease in the

Synthesis of elastomeric polypropylene in bulk
Russ.Chem.Bull., Int.Ed., Vol. 54, No. 2, February, 2005
403
C(28)
C(28)
C(10)
C(11)
C(12)
C(10)
C(9)
C(8)
C(7)
C(6)
C(11)
C(18)
C(19)
C(17)
C(16)
C(18)
C(19)
C(17)
C(16)
C(12)
C(13)
C(15)
C(14)
C(15)
C(13)
C(9)
C(8)
C(20)
C(27)
C(1)
C(2)
C(3)
C(4)
C(27)
C(26)
C(1)
C(20)
C(7)
C(21)
C(22)
C(14)
C(26)
C(25)
C(21)
C(6)
C(5)
C(2)
C(3)
C(25)
C(24)
C(22)
C(23)
C(5)
C(24)
C(23)
C(4)
Fig. 2. Orthogonal superposition of molecule 1b (the monoꢀ
clinic modification, space group P21/c) and two crystallographiꢀ
cally independent molecules 1b (the orthorhombic modificaꢀ
tion, space group Pbca).
Fig. 1. Molecular structure of compound 1b (the monoclinic
modification, space group P21/c).
There are two crystallographically independent molꢀ
ecules in the structure of the orthorhombic modification
of 1b. On the whole, the geometric parameters (bond
lengths, bond angles, and torsion angles) of both molꢀ
ecules 1b in the orthorhombic modification and molecule
1b in the monoclinic modification have very similar valꢀ
ues (see Table 2). This is clearly seen from the results
of the orthogonal superposition of these three molꢀ
ecules based on the coordinates of all nonhydrogen atꢀ
oms (Fig. 2).
Synthesis of zirconium and hafnium complexes was carꢀ
ried out according to a known procedure,15 which was
slightly improved. Deprotonation of ligand 1 with BunLi
in diethyl ether afforded dilithium salt 8 in virtually quanꢀ
titative yield, and this reaction product was characterized
by 1H and 13C NMR spectroscopy (Scheme 3). The reacꢀ
tion of salt 8 with ZrCl4 or HfCl4 in toluene produced the
corresponding ansaꢀcomplexes 9 and 10 in high yields.
The resulting metallocenes were characterized by 1H and
13C NMR spectroscopy. The structure of the hafnium
complex was established by Xꢀray diffraction.
Single crystals of complex 10 were prepared by slow
crystallization from CH2Cl2. The molecular structure of
compound 10 is shown in Fig. 3. The bond lengths and
bond angles are given in Table 2. On the whole, the geoꢀ
metric parameters of molecule 10 are similar to those
found earlier15 for isostructural zirconium analog 9. In
the hafnium complex, the metal—ligand bonds are slightly
shorter than those in the zirconium complex, whereas the
bond angles remain virtually unchanged (see Table 2).
Propene polymerization in the presence of catalysts
based on complexes 9 and 10. Data on the catalytic activꢀ
ity of systems based on complexes 9 and 10 activated with
polymethylalumoxane (MAO) and selected properties of
the resulting PP are given in Table 3. The MAO concenꢀ
tration was 0.46—1.1 g L–1. As the polymerization temꢀ
Table 1. Selected bond lengths (d) and bond angles (ω) in molecules 1b (space groups P21/c and Pbca)
Bond
d/Å
Angle
ω/deg
P21/c
Pbca*
P21/c
Pbca*
I
II
I
II
С(1)—С(2)
1.515(2)
1.518(2)
1.539(2)
1.540(2)
1.502(2)
1.356(2)
1.469(2)
1.514(2)
1.496(2)
1.506(2)
1.505(8)
1.508(8)
1.533(6)
1.514(6)
1.499(6)
1.336(7)
1.441(7)
1.512(6)
1.490(7)
1.495(6)
1.502(8)
1.503(7)
1.531(6)
1.531(6)
1.492(6)
1.342(7)
1.492(7)
1.511(7)
1.474(7)
1.499(6)
С(13)—С(1)—С(14)
C(2)—C(1)—С(14)
C(1)—C(14)—С(15)
C(14)—C(15)—С(16)
C(15)—C(16)—С(17)
C(15)—C(16)—С(27)
C(16)—C(17)—С(28)
C(16)—C(17)—С(18)
C(18)—C(17)—С(28)
C(17)—C(18)—С(19)
115.2(1)
114.5(1)
113.0(1)
112.2(1)
128.2(1)
122.6(1)
127.6(1)
110.5(1)
121.9(1)
103.4(1)
113.6(5) 115.6(5)
116.5(5) 114.6(5)
115.0(4) 113.0(4)
112.9(4) 113.7(4)
127.0(6) 129.1(6)
123.2(6) 121.7(6)
129.2(6) 128.0(6)
109.3(5) 110.0(6)
121.5(5) 121.9(5)
103.7(5) 103.8(5)
C(1)—C(13)
C(1)—C(14)
C(14)—C(15)
C(15)—C(16)
C(16)—C(17)
C(16)—C(27)
C(17)—C(18)
C(17)—C(28)
C(18)—C(19)
* Two independent molecules I and II.

404
Russ.Chem.Bull., Int.Ed., Vol. 54, No. 2, February, 2005
Nedorezova et al.
Scheme 3
Table 2. Selected bond lengths (d) and bond
angles (ω) in molecule 10
Bond
d/Å
Hf(1)—Cl(2)
Hf(1)—Cl(1)
C(1)—C(14)
C(14)—C(15)
C(15)—C(16)
Hf(1)—Flu*
Hf(1)—Ind**
2.384(2)
2.401(1)
1.514(5)
1.522(6)
1.495(5)
2.252
2.203
Angle
ω/deg
Cl(2)—Hf(1)—Cl(1)
C(1)—C(14)—C(15)
C(16)—C(15)—C(14)
Flu*—Hf(1)—Ind**
97.03(5)
111.9(3)
111.8(3)
129.0
С(1)—С(14)—С(15)—С(16)
36.2(5)
5
* Flu is the center of the η ring of fluorene.
5
** Ind is the center of the η ring of indene.
perature increases from 30 to 70 °C, the yield of PP inꢀ
creases and reaches 104 (kg PP) (mmol Zr)–1 h–1 for the
9—MAO system and 14 (kg PP) (mmol Hf)–1 h–1 for the
10—MAO system (see Table 3). The activity of the cataꢀ
lytic system based on complex 10 is lower than that of the
system based on complex 9 throughout the temperature
range. A decrease in the polymerization rate in the reacꢀ
tions with the use of hafnocenes is generally accompanied
by a substantial increase in the molecular weight of the
polymers. The smaller size of the Hf atom and an increase
in the charge on this atom lead to metal—carbon bond
strengthening,17 generally resulting in a decrease in the
reaction rates of the monomer insertion and limitation of
the polymer chain growth due to βꢀhydride elimination.18
The kinetic curves of propene polymerization in the
presence of the 9—MAO and 10—MAO catalytic systems
are shown in Fig. 4. For both catalytic systems, the maxiꢀ
mum activity is observed at the initial instant of time
followed by a decrease in the polymerization rate. The
activation energies of polymerization in the presence of
the 9—MAO and 10—MAO catalytic systems were estiꢀ
mated from the maximum observed polymerization rates.
These energies are 11.4 and 16.9 kcal mol–1, respectively.
An increase in the polymerization temperature leads
to an increase in regularity of the polymers (see Table 3).
For the 9—MAO system at high concentrations of the
monomer (10—12 mol L–1), the regularity gradually inꢀ
creases with increasing temperature. At low concentraꢀ
tions of the monomer (1.1 mol L–1), the regularity of PP
reaches the maximum observed value already at 50 °C.15
It should be noted that, unlike metallocenes with the
symmetry C2 19,20 and Cs,21,22 C1ꢀsymmetric metallocenes
are characterized by an increase in the degree of isotacticity
C(23)
C(22)
C(21)
C(20)
C(19)
C(24)
C(25)
C(26)
C(15)
C(27)
C(18)
C(16)
C(17)
C(28)
Cl(2)
C(14)
C(13)
Hf(1)
C(3)
C(1)
C(2)
Cl(1)
C(12)
C(11)
C(10)
C(4)
C(8)
C(7)
C(6)
C(9)
C(5)
Fig. 3. Molecular structure of compound 10.

Synthesis of elastomeric polypropylene in bulk
Russ.Chem.Bull., Int.Ed., Vol. 54, No. 2, February, 2005
405
Table 3. Propene bulk polymerization in the presence of the 9—MAO and 10—MAO catalytic systems
Run
Comꢀ Т/°C
plex
[M]•10–6 Аl : Ma
/mol
[МАО]
/g L–1
tb
/min
Yield
/g
Activityc
D998/D973
M.p.
/°C
1
2
3
4
5
6
9
9
9
10
10
10
30
50
70
30
50
70
1.66
1.00
0.63
2.94
1.73
1.28
3800
4480
5064
2602
4090
4250
0.9
0.65
0.5
1.1
1.0
0.8
45
120
30
180
120
60
26.3
50.0
33.0
13.0
21.0
35.0
21.1
25.0
104.0
1.5
6.0
14.0
0.25
0.33
0.58
0.26
0.42
0.45
—
123
120
—
53—76
55—87
a M = Zr, Hf; molar ratio.
b Polymerization time.
c In (kg PP) (mmol M)–1 h–1
.
of PP with increasing polymerization temperature. These
changes become clear from the scheme of the polypropyꢀ
lene synthesis in the presence of C1ꢀsymmetric metalloꢀ
cenes.15 An increase in the reaction temperature and a
decrease in the concentration of the monomer promote
an increase in the rate of chain migration without monoꢀ
mer insertion and, correspondingly, an increase in the
amount of isotactic pentads. To the contrary, an increase
in the concentration of the monomer increases the probꢀ
ability of the insertion of the monomer at a nonselective
coordination vacancy, resulting in a decrease in isoꢀ
tacticity.15 It should be noted that an increase in the
monomer concentration in the PP synthesis with the use
of C2ꢀ and Csꢀsymmetric metallocenes facilitates an inꢀ
crease in regularity of PP due to a relative decrease in the
rates of the processes producing stereoꢀ and regioerrors in
the polymer chain.19—21
The formation of single stereo defects giving rise to
mrrm sequences in the polymer chain, is generally conꢀ
firmed by the fact that the mmmr : mmrr : mrrm pentad
ratio is 2 : 2 : 1. The data on the stereo composition of PP
prepared at 70 °C in the presence of MAOꢀactivated comꢀ
plexes 9 and 10 are given in Table 4. It can be seen that
these pentad contents are satisfactorily described by this
ratio.
keff/L (mol Zr)–1 min–1
8000
7000
6000
5000
4000
3000
2000
1000
a
3
2
1
0
20
40
60
80
t/min
We examined the possibility to partially replace MAO
with triisobutylaluminum (TIBA). A need to search for
alternative cocatalysts is associated primarily with a high
cost of MAO and the necessity of using large excesses
of MAO. Earlier,22,23 it has been demonstrated that
keff/L (mol Zr)–1 min–1
2200
2000
1800
1600
1400
b
Table 4. Pentad composition of polypropylene prepared in the
presence of the 9—MAO and 10—MAO catalytic systems at 70 °C
3
1200
400
300
200
100
Composition
Run 3
Run 6
2
mmmm
mmmr
rmmr
mmrr
rmrr + mmrm
mrmr
rrrr
mrrr
mrrm
47.16
13.41
3.26
13.66
4.76
3.52
2.35
4.04
7.15
43.30
15.54
2.40
14.44
4.66
4.70
2.18
4.25
7.41
1
0
40
80
120
160
t/min
Fig. 4. Kinetic curves of propene bulk polymerization in the
presence of the 9—MAO (a) and 10—MAO (b) catalytic systems
at polymerization temperatures of 30 (1), 50 (2), and 70 °C (3).
For the polymerization conditions, see Table 3.

406
Russ.Chem.Bull., Int.Ed., Vol. 54, No. 2, February, 2005
Nedorezova et al.
Table 5. Propene bulk polymerization with the use of the catalytic systems based on TIBAꢀactivated complexes 9 and 10 (polymerizaꢀ
tion temperature was 50 °C)
Run Comꢀ [M]•10–6 Al(MAO)/Ma Al(TIBA)/Ma
Al(TIBA)/
/Al(MAO)
[TIBA]
/g L–1
tb
/min
Yield
/g
Activityc
D998/D973
plex
/mol
2
5
7
8
9
10
11
9
10
9
9
9
1.0
4480
4090
300
300
300
300
320
—
—
—
—
—
—
120
120
65
60
60
50
21.0
12
40
36
25
6.0
14
27
28
0.33
0.42
0.25
0.25
0.22
0.36
0.33
1.73
0.79
1.53
1.27
2.50
2.56
1865
1047
753
223
550
6.1
3.4
2.5
0.7
1.7
0.7
0.7
0.45
0.26
0.6
9
10
40
120
50
0.22
30
0.043
a M = Zr, Hf; molar ratio.
b Polymerization time.
c In (kg PP) (mmol M)–1 h–1
.
dimethyl derivatives of 2,2´ꢀdisubstituted bisꢀindenyl
zirconocenes can be successfully activated with TIBA,
the change in the TIBA : metallocene ratio influencing
substantially both the stereoregularity and molecular
weight of the resulting polymers. We suggested that TIBA
can be used as a cocatalyst for complexes 9 and 10
predissolved in small amounts of MAO, which is required
for the formation of dimethyl derivatives. The results of
propene polymerization in the presence of the combined
cocatalysts are given in Table 5 and presented in Fig. 5.
The Al(TIBA) : Zr molar ratio was measured in a wide
range from 1860 to 220. At high Al(TIBA) : Zr ratios, the
system exhibits the highest activity at the initial instant of
time, after which sharp deactivation occurs (see Fig. 5).
A decrease in the Al(TIBA) : Zr ratio leads to a decrease
in the initial activity; however, the catalytic system is
more stable. The yield of PP became comparable with
that obtained in the reaction with the use of polyꢀ
methylalumoxaneꢀactivated complex 9 in the absence of
a TIBA additive. In the presence of the latter as a cocataꢀ
lyst, the concentration of the organoaluminum compound
can be decreased to 0.26 g L–1 without a loss of activity
(see Table 5, run 10).
The stereoregularity of the polypropylene synthesized
depends on the Al(TIBA) : Zr ratio (see Table 5). For the
Al(TIBA) : Zr ratios varying from 750 to 1860, the reguꢀ
larity of the chain is smaller than that of PP prepared in
the presence of the 9—MAO system, whereas a further
decrease in this ratio to 220 leads to the formation of a
polymer characterized by higher stereoregularity. The reꢀ
sults of our study provided evidence that TIBA influences
the active centers of the catalytic complex. Most likely, at
higher Al(TIBA) : Zr ratios, TIBA hinders the polymer
chain migration without monomer insertion, resulting in
a decrease in the regularity of PP. The use of complex 10
as the catalyst in the presence of TIBA leads to a sharp
decrease in the catalytic activity (see Table 5). Presumꢀ
ably, steric hindrances resulting from interactions of comꢀ
plex 10 with the bulky isobutyl fragments of TIBA hinder
the insertion of the propylene molecule into the polymer
chain.
The molecular weights of the polymers, which were
synthesized at 50 °C in the presence of the 9—MAO,
10—MAO, and 9—MAO—TIBA catalytic systems, are
given in Table 6 (samples were synthesized in runs 2, 5,
and 8, see Tables 3 and 5). As expected, the molecular
keff/L (mol Zr)–1 min–1
4000
3500
3
3000
2500
2
Table 6. Molecularꢀweight characteristics of the polymers synꢀ
thesized with the use of catalytic systems based on complexes 9
and 10
2000
1500
1
1000
500
Run
Comꢀ Mw•10–3 Мn•10–3 Mw/Mn MZ•10–3
plex
0
2
5
8
9
10
9
146
177
294
76
96
131
1.9
1.8
2.2
240
277
540
20
40
60
80
100
t/min
Fig. 5. Kinetic curves of propene bulk polymerization with the
use of the 9—TIBA—MAO catalytic system: Al(TIBA) : Zr =
1700 (1), 700 (2), and 220 (3). The polymerization temperature
was 50 °C. For the polymerization conditions, see Table 5.
Note. Mw, Mn, and MZ are the weightꢀaverage, numberꢀaverage,
and Zꢀaverage molecular weights, respectively.

Synthesis of elastomeric polypropylene in bulk
Russ.Chem.Bull., Int.Ed., Vol. 54, No. 2, February, 2005
407
weights of the polymers synthesized with the use of the
10—MAO catalytic system under identical polymerizaꢀ
tion conditions are higher than those preprared in the
presence of the 9—MAO system. It is particularly interꢀ
esting that the molecular weight of PP prepared using
activation with TIBA increases by a factor of ∼2. These
data indicate that TIBA inhibits reactions limiting the
polymer chain growth and confirm that TIBA is involved
in the active centers. Therefore, the use of TIBA as the
cocatalyst allows one to vary the molecularꢀweight charꢀ
acteristics and microstructure of PP.
a
3
An analogous increase in the molecular weight of PP
was observed also for propene bulk polymerization in the
presence of the (2ꢀPhInd)2ZrMe2—TIBA catalytic sysꢀ
tem compared to the (2ꢀPhInd)2ZrCl2—MAO system (Ind
is indenyl).22,23 It should be noted that the combined
cocatalyst has virtually no effect on the molecular weight
of PP prepared in the presence of systems based on
Me2SiInd2ZrCl2 and Ph2C(Cp)(Flu)ZrCl2 (Flu is
fluorenyl).24,25
2
We studied polymers, which were prepared under variꢀ
ous polymerization conditions with the use of complexes
9 and 10, by Xꢀray diffraction and examined the heatꢀ
transfer properties and the deformation behavior of the
polymers.
1
8
12
16
20
24
28 2θ/deg
Xꢀray diffraction patterns of PP obtained at different
polymerization temperatures are given in Fig. 6, a and b.
An increase in the reaction temperature results in the
formation of PP, whose properties vary from those of a
completely amorphous polymer (30 °C) to those of a
polymer characterized by pronounced crystallinity peaks
(70 °C). The degree of crystallinity of PP prepared with
the use of both types of catalytic systems is as high as
30—37%. It can be seen that PP synthesized in the presꢀ
ence of complex 10 is characterized by more diffuse crysꢀ
tallinity peaks, which is evidence for a smaller size of
crystallites. Interestingly, PP prepared at high temperaꢀ
tures crystallizes in the γ form. This fact is generally assoꢀ
ciated with the presence of a large number of stereoꢀ and
regioerrors in the polymer chain.26
b
3
2
We analyzed the crystal structures of the polymers
synthesized with the use of the 9—MAO and 10—MAO
catalytic systems in runs 3 and 6. The results of our study
were compared with analogous results obtained in the
investigation of the γ form of isotactic PP with high crysꢀ
tallinity.27,28 For the PP samples prepared in runs 3 and 6,
the c parameter characterizing the size of the unit cell of
the crystallites along the Z axis is 42.45 and 42.20 Å,
respectively. These values differ only slightly from those
found earlier for the γ form of isotactic PP.27,28 Presumꢀ
ably, the c parameter is independent of the degree of
crystallinity of PP. The main difference is that crystallites
of PP grow differently in different planes. The parameters
of the structure are virtually equal along the 00l direction
(L008 ∼200 Å) and differ slightly from the corresponding
1
8
12
16
20
24
28 2θ/deg
Fig. 6. Xꢀray diffraction patterns of PP prepared in the presence
of the 9—MAO (a) and 10—MAO (b) catalytic systems at polyꢀ
merization temperatures of 30 (1), 50 (2), and 70 °C (3).
values for the γ form of isotactic PP, which was prepared
by crystallization of the polymer at high pressures,28
whereas the sizes of the crystallites in other directions of
the planes (L111, L117, L202, L026) are noticeably different.
For example, L202 is 230 Å along the h0l direction,28

408
Russ.Chem.Bull., Int.Ed., Vol. 54, No. 2, February, 2005
Nedorezova et al.
Stress/MPa
higher than those of the samples synthesized with the use
of complex 10 (60—80 °C) (see Table 3). The lower meltꢀ
ing point of PP prepared in the presence of complex 10
and the character of Xꢀray diffraction patterns suggest
that macromolecules of this polymer contain shorter isoꢀ
tactic sequences compared to PP synthesized in the presꢀ
ence of complex 9.
The stressꢀstrain curves of elastomeric PP and the
hysteresis curves are shown in Fig. 7, a and b. The data on
the stressꢀstrain characteristics of the polymers are given
in Table 7. It can be seen that more stereoregular PP
samples with high crystallinity are characterized by higher
strength, larger Young's moduli, and residual strain.
Samples of PP prepared at 30 °C possess better elastoꢀ
meric properties. For example, elastomeric PP syntheꢀ
sized in the presence of complex 9 is characterized by the
largest strain (>1750%) and the residual strain ε300 of 20%.
Elastomeric PP prepared in the presence of complex 10
has ε300 = 12%, and the residual strain after rupture is as
low as 14%. Interestingly, this polymer can be reinforced
during strain. In this case, the rupture stress is 16 MPa.
The possibility of reinforcing is associated with the presꢀ
ence of small crystallizable propylene sequences in the
polymer.
18
16
14
12
10
8
3
a
2
6
4
1
2
0
400
800
1200
Strain (%)
Stress/MPa
b
12
6
1
2
3
The samples of elastomeric PP synthesized in the
presence of the combined MAO + TIBA cocatalyst
(runs 8—10) have a lower degree of crystallinity and higher
elastomeric properties compared to the samples prepared
under the same polymerization conditions with the use of
only MAO as the cocatalyst (run 2). The residual strain
ε300 for the samples prepared in runs 8—10 varies in a
range of 12.3—16.8%, whereas ε300 for the sample preꢀ
pared in run 2 is 43% (see Table 7).
0
200
400
600
800
Strain (%)
Fig. 7. Stressꢀstrain curves of PP prepared in the presence of the
9—MAO (a) and 10—MAO catalytic systems (b) at polymerizaꢀ
tion temperatures of 30 (1), 50 (2), and 70 °C (3).
To summarize, we investigated the effects of the leavꢀ
ing group and the order in which the reagents are mixed
on the yield of the target ligand in the synthesis of
metallocenes 9 and 10 and determined the structures of
byꢀproducts. The crystal structures of ligand 1b and
whereas this parameter in our samples changes to 113 Å
(run 3) and 85 Å (run 6).
The melting points of the PP samples prepared in the
presence of complex 9 (120—123 °C) are substantially
Table 7. Stressꢀstrain characteristics of polymers (the strain rate was 500 mm min–1
)
Run
Comꢀ
plex
D998/D973
Crystalliꢀ
nity (%)
Е
σ
ε
ε
ε
res
r
r
300
MPa
%
1
2
3
4
5
6
8
9
9
9
9
10
10
10
9
0.25
0.33
0.58
0.25
0.42
0.45
0.25
0.22
0.36
0
18
36
16
29
36
13
7
3.4
21.6
324.0
31.7
84.7
187.0
12.5
7.2
>1.5
9.12
19.1
16.0
17.2
8.9
11.6
8.08
10.0
>1750
884
735
865
916
19.8
43.2
62.7
12.0
38.1
67.8
12.3
10.8
16.8
—
51
487
14
115
473
27
577
1008
1000
863
9
9
26
54
10
17
18.4
Note. E is Young's modulus, σ is the rupture stress, ε is the rupture strain, ε300 is the residual strain, and ε
res
r
r
is the residual stress measured for samples immediately after tests (related to the initial length of the sample).

Synthesis of elastomeric polypropylene in bulk
Russ.Chem.Bull., Int.Ed., Vol. 54, No. 2, February, 2005
409
3
3
CH2O, JH,H = 6.6 Hz); 4.04 (t, 1 H, H(9), JH,H = 6.6 Hz);
7.25 and 7.31 (both t, 2 H each, H(2), H(3), H(6), H(7), 3JH,H
hafnium sandwich 10 were established. Highly active PP
with a controlled structure of the polymer chain can be
synthesized by varying the structure of the metallocene
catalyst, polymerization conditions, and the nature of the
cocatalyst. The properties of the resulting PP vary from
rigid thermoplastic to amorphous elastomeric. The use of
TIBA instead of MAO holds more promise for the prepaꢀ
ration of elastomeric PP.
=
8.0 Hz); 7.35 and 7.70 (both m, 4 H each, H(1), H(4), H(5),
H(8) and H arom. of tosyl). 13C{1H} NMR (CDCl3, 25 °C), δ:
21.60 (Me); 32.29 (CH2CH2OH); 43.62 (CH(9)); 67.71 (CH2O);
119.98, 124.25, 127.05, 127.33, 127.85, 129.79 (CH arom.);
132.93, 144.71 (C arom. of tosyl); 140.83, 145.64 (C arom. of
fluorene).
2ꢀMethylꢀ5,6ꢀdihydrocyclopenta[ f ]ꢀ1Hꢀindene
(4).15
1H NMR (CDCl3, 25 °C), δ: 2.11 (quint, 2 H, CH2CH2CH2,
3JH,H = 7.2 Hz); 2.16 (s, 3 H, Me); 2.93 (t, 4 H, CH2CH2CH2,
3JH,H = 7.2 Hz); 3.26 (s, 2 H, CH2 of indene); 6.46 (s, 1 H,
=CH of indene); 7.13 and 7.25 (both s, 1 H each, H arom.).
13C{1H} NMR (CDCl3, 25 °C), δ: 16.78 (Me); 25.86
(CH2CH2CH2); 32.63, 32.71 (CH2CH2CH2); 42.17 (CH2 of
indene); 115.63 (=CH of indene); 119.52, 127.05 (CH arom.);
139.55, 141.71, 142.05, 144.36, 145.01 (C arom., =CMe).
1ꢀ(Fluorenꢀ9ꢀyl)ꢀ2ꢀ(2ꢀmethylꢀ5,6ꢀdihydrocyclopenta[ f ]ꢀ
1Hꢀindenꢀ3ꢀyl)ethane (1a) and 1ꢀ(fluorenꢀ9ꢀyl)ꢀ2ꢀ(2ꢀmethylꢀ5,6ꢀ
dihydrocyclopenta[f]ꢀ1Hꢀindenꢀ1ꢀyl)ethane (1b). Method 1.
A 2.5 M BunLi solution in hexane (10.0 mL, 25.0 mmol) was
added with stirring to a solution of indene 4 (3.63 g, 21.3 mmol)
in THF (50 mL) at –20 °C for 15 min. The reaction mixture was
warmed to ∼20 °C and heated on a water bath at 55 °C for
20 min. Then a solution of tosylate 6 (7.30 g, 20.0 mmol) in
THF (50 mL) was slowly (∼4 h) added to the resulting lithium
salt at ∼20 °C. The reaction mixture was allowed to stand for
∼18 h and heated at 60 °C for 30 min. The solvent was removed
in vacuum created by a waterꢀaspirator pump. The residue was
dried under high vacuum and washed on a filter with benzene
(3×50 mL). The extract (TLC data, benzene—light petroleum,
1 : 9) contained three compounds, including the starting inꢀ
dene 4. The mixture was separated by column chromatography
on silica gel (light petroleum as the eluent). The latter fraction
was eluted from the column with benzene. The fraction 3 was
concentrated, and the precipitate was washed on a filter with
hexane and dried under high vacuum. The fraction 2 was conꢀ
centrated, and the resulting compound was crystallized from
hexane, twice washed on a filter with a minimum amount of
cold hexane, and dried under high vacuum. The fraction 1 was
worked up analogously.
Experimental
Metallocenes were synthesized under an atmosphere of highꢀ
purity argon or in evacuated allꢀsealed Schlenkꢀtype vessels.
The solvents were dried before use according to standard proceꢀ
dures.29 Ethylene oxide was purified by drying over CaH2 at
–18 °C and twice freezing from CaH2 under high vacuum. Comꢀ
mercial ZrCl4, HfCl4, AlCl3, and indane (Aldrich) were used.
Chlorides ZrCl4 and HfCl4 were additionally purified by subliꢀ
mation in a stream of hydrogen at 330—350 °C. Methacrylic
acid chloride was prepared by the reaction of methacrylic acid
with an excess of PCl3 and purified by fractional distillation.
The 1H and 13C NMR spectra were recorded on a Varian
VXRꢀ400 spectrometer (400 and 100 MHz, respectively) with
the use of the signals of the residual protons and signals of the
carbon atoms of the corresponding deuterated solvents, respecꢀ
tively, as the internal standards (δ 7.24 and δ 77.0 (CDCl3),
H
C
δ
5.32 and δ 53.8 (CD2Cl2), δ 1.73 and δ 25.3 (THFꢀd8)).
H
C H C
Elemental analysis was carried out on an automated CarloꢀErba
analyzer.
2ꢀ(Fluorenꢀ9ꢀyl)ethanol (2) was prepared from fluorene
(36.5 g, 214.0 mmol) according to a known procedure.30 Comꢀ
pound 2 contained (1H NMR spectroscopic data) ∼15% of
9,9´ꢀbis(2ꢀhydroxyethyl)fluorene as an impurity. Repeated crysꢀ
tallization from a 2 : 3 toluene—light petroleum mixture did not
lead to a change in the product ratio. The target compound was
purified by column chromatography on silica gel (CH2Cl2 as the
eluent). After removal of the solvent and highꢀvacuum drying,
compound 2 was obtained as white crystals in a yield of 26.4 g
1
(59%). H NMR (CDCl3, 25 °C), δ: 1.20 (br.s, 1 H, OH); 2.29
(q, 2 H, CH2CH2OH, JH,H = 6.8 Hz); 3.58 (t, 2 H, CH2OH,
3
3JH,H = 6.8 Hz); 4.12 (t, 1 H, H(9), 3JH,H = 6.8 Hz); 7.27—7.38
(m, 4 H, H(2), H(3), H(6), H(7)); 7.53 and 7.75 (both d,
2 H each, H (1), H(4), H(5), H(8), 3JH,H = 8.0 Hz).
Fraction 3 (compound 1a). A white powdered compound,
the yield was 1.87 g (26%). Found (%): C, 92.73; H, 7.20.
C
28H26. Calculated (%): C, 92.77; H, 7.23. 1H NMR (CDCl3,
9,9´ꢀBis(2ꢀhydroxyethyl)fluorene. 1H NMR (CDCl3, 25 °C),
25 °C), δ: 1.83 (s, 3 H, Me); 2.08 (m, 2 H, CH2CH2CH2 of
indane); 2.11 and 2.30 (both m, 2 H each, bridging CH2CH2);
2.89 (m, 4 H, CH2CH2CH2 of indane); 3.11 (s, 2 H, CH2 of
3
δ: 1.20 (br.s, 2 H, OH); 2.37 (t, 4 H, CH2CH2OH, JH,H
=
6.8 Hz); 2.99 (t, 4 H, CH2OH, 3JH,H = 6.8 Hz); 7.25—7.72 (m,
8 H, H arom.).
3
indene); 4.10 (t, 1 H, H(9) of fluorene, JH,H = 5.0 Hz); 6.91
2ꢀ(Fluorenꢀ9ꢀyl)ethyl tosylate (6).31 Tosyl chloride (17.2 g,
90.0 mmol) was added with stirring to a solution of alcohol 2
(19.0 g, 90.0 mmol) in pyridine (150 mL) at 0 °C. The reaction
mixture was allowed to warm to ∼20 °C, kept for ∼18 h, and
poured into ice water. The product was extracted with Et2O
(3×150 mL). The combined ethereal extracts were washed with
dilute HCl until pH became weakly acidic and then with water
and dried with MgSO4. The solution was concentrated in vacuum
created by a waterꢀaspirator pump, and the precipitate was filꢀ
tered off, washed on a filter with hexane, and dried under high
vacuum. A white crystalline compound was obtained in a yield
of 22.0 g (67%). 1H NMR (CDCl3, 25 °C), δ: 2.29 (q, 2 H,
and 7.17 (both s, 1 H each, H arom. of indene); 7.36 (m, 4 H,
H(2), H(3), H(6), H(7) arom. of fluorene); 7.58 and 7.78 (both d,
3
2 H each, H(1), H(4), H(5), H(8) arom. of fluorene, JH,H
=
7.1 Hz). 13C{1H} NMR (CDCl3, 25 °C), δ: 13.78 (Me); 20.45,
31.19 (bridging CH2CH2); 25.92 (CH2CH2CH2 of indane);
32.64, 32.84 (CH2CH2CH2 of indane); 41.98 (CH2 of indene);
47.58 (CH(9) of fluorene); 113.96, 119.42 (CH arom. of inꢀ
dene); 119.87, 124.17, 126.93, 126.99 (CH arom. of fluorene);
136.72, 137.43, 139.54, 141.00, 141.77, 144.99 (=C, C arom. of
indene); 141.41 (C(4a), C(4b) of fluorene); 147.01 (C(8a), C(9a)
of fluorene).
Fraction 2 (spiro[fluoreneꢀ9,1´ꢀcyclopropane] (7)). A crysꢀ
talline snowꢀwhite compound, the yield was 0.93 g (24%).
3
CH2CH2O, JH,H = 6.6 Hz); 2.44 (s, 3 H, Me); 3.99 (t, 2 H,

410
Russ.Chem.Bull., Int.Ed., Vol. 54, No. 2, February, 2005
Nedorezova et al.
1H NMR (CDCl3, 25 °C), δ: 1.72 (s, 4 H, CH2); 7.05 and 7.83
(both d, 2 H each, H(1), H(4), H(5), H(8), JH,H = 7.4 Hz);
1JC,H = 128 Hz); 29.56 and 31.57 (both t, bridging CH2CH2,
1JC,H = 120 Hz); 33.82 and 33.98 (both t, CH2CH2CH2 of
indane, JC,H = 128 Hz); 88.72 (d, CH arom. of C(5)ꢀindene,
1JC,H = 160 Hz); 95.94 (s, C(9) of fluorene); 106.72 (s, CCH2
of C(5)ꢀindene); 107.09, 114.33, 118.78, and 118.81 (all d,
C(1)—C(8) of fluorene, 1JC,H = 149—153 Hz); 112.65 and 113.36
(both d, CH arom. of C(6)ꢀindene, 1JC,H = 149 Hz); 122.23 and
135.65 (both s, C(4a), C(4b), C(8a), C(9a) of fluorene); 124.04
(s, CMe of C(5)ꢀindene); 126.82 (2 C), 129.22, and 129.86
(all s, C arom. of C(6)ꢀindene).
3
7.29 and 7.35 (both t, 2 H each, H(2), H(3), H(6), H(7), 3JH,H
=
=
1
1
7.4 Hz). 13C NMR (CDCl3, 25 °C), δ: 18.30 (t, CH2, JC,H
164 Hz); 29.41 (s, C(9)); 118.57 (d, CH arom., 1JC,H = 156 Hz);
1
119.94 (d, CH arom., JC,H = 158 Hz); 125.93 and 126.75
(both d, CH arom., 1JC,H = 159 Hz); 139.81 and 148.07 (both s,
C arom.).
Fraction 1 (starting indene 4). The yield was 0.83 g (25%).
Method 2. A solution of lithium salt 5, which was prepared
analogously to the method 1 from a solution of indene 4 (6.00 g,
35.2 mmol) in THF (80 mL), was slowly added to a solution of
tosylate 6 (12.84 g, 35.2 mmol) in THF (80 mL) at ∼20 °C
for ∼6 h. The reaction mixture was kept for ∼18 h, quenched
with a saturated aqueous solution of NH4Cl (5 mL), and worked
up analogously to the method 1.
The reaction with compound 1a was carried out analogously.
5
racꢀ{1ꢀ(η ꢀFluorenꢀ9ꢀyl)ꢀ2ꢀ(2ꢀmethylꢀ5,6ꢀdihydrocycloꢀ
5
penta[ f ]ꢀη ꢀindenꢀ1ꢀyl)ethane}zirconium dichloride (9). The synꢀ
thesis was carried out in allꢀsealed evacuated vessels. Zirconium
chloride ZrCl4 (1.18 g, 5.1 mmol) was added to a suspension of
salt 8 (2.00 g, 5.1 mmol) in toluene (100 mL) at –30 °C. The
reaction mixture was allowed to warm to ∼20 °C (the precipitate
was virtually completely dissolved), stirred at ∼20 °C for 15 h,
heated at 95 °C for 4 h, cooled to ∼20 °C, and allowed to stand
for ∼18 h. The solution was decanted and the residue was exꢀ
tracted with toluene (2×100 mL). The extract was concentrated
to ∼15 mL with heating and then cooled to 0 °C. The crystals
that precipitated were separated from the mother liquor, twice
washed with a minimum amount of cold toluene and then with
Et2O (2×30 mL), and dried under high vacuum. An orangeꢀ
red crystalline compound was obtained in a yield of 1.38 g
(2.6 mmol). The mother liquor was again worked up to obtain
an additional amount of the product (0.24 g, 0.5 mmol). The
total yield was 1.62 g (61%). Found (%): C, 64.28; H, 4.59.
C28H24Cl2Zr. Calculated (%): C, 64.35; H, 4.63. 1H NMR
(CD2Cl2, 25 °C), δ: 1.96—2.06 (m, 2 H, CH2CH2CH2 of
indane); 2.15 (s, 3 H, Me); 2.82—3.00 (m, 4 H, CH2CH2CH2 of
indane); 3.81 and 4.14 (both m, 1 H each, bridging CH2); 4.02
and 4.66 (both m, 1 H each, bridging CH2); 6.04 (s, 1 H, H arom.
of C(5)ꢀindene); 7.08 and 7.78 (both s, 1 H each, H arom. of
C(6)ꢀindene); 7.09, 7.26, 7.38, and 7.57 (all t, 1 H each, H(2),
H(3), H(6), H(7) of fluorene, 3JH,H ≈ 8.0 Hz); 7.53, 7.73, 7.87,
and 7.88 (all d, 1 H each, H(1), H(4), H(5), H(8) of fluorene,
3JH,H ≈ 8.0 Hz). 13C{1H} NMR (CD2Cl2, 25 °C), δ: 15.44 (Me);
26.50, 28.68, 30.23, 32.60, 32.88 (CH2 of the bridge and indane);
107.43 (CH arom. of C(5)ꢀindene); 116.72, 119.52, 122.84,
124.11, 124.37, 124.66, 125.16, 125.89, 127.74, 128.46
(CH arom. of C(6)ꢀindene and fluorene); 103.93, 121.67, 123.54,
123.58, 126.71, 128.51, 130.48, 131.84, 143.54, 145.05 (2 C)
(C arom.).
Fraction 3 (compound 1b). A white powdered compound.
The yield was 2.12 g (17%). Found (%): C, 92.70; H, 7.22.
C
28H26. Calculated (%): C, 92.77; H, 7.23. 1H NMR (CDCl3,
25 °C), δ: 1.39—1.79 (m, 4 H, bridging CH2CH2); 1.90 (s, 3 H,
Me); 2.11 (m, 2 H, CH2CH2CH2 of indane); 2.91 (m, 4 H,
CH2CH2CH2 of indane); 3.07 (t, 1 H, CHCH2 of indene,
3JH,H = 4.5 Hz); 3.88 (t, 1 H, H(9) of fluorene, 3JH,H = 4.9 Hz);
6.41 (s, 1 H, =CH of indene); 6.99 and 7.08 (both s, 1 H,
H arom. of indene); 7.28—7.40 (m, 5 H, H arom. of fluorene);
7.45 (d, 1 H, H arom. of fluorene, 3JH,H = 7.3 Hz); 7.76 (d, 2 H,
H arom. of fluorene, 3JH,H = 7.4 Hz). 13C NMR (CDCl3, 25 °C),
1
δ: 15.07 (q, Me, JC,H = 127 Hz); 23.74 and 25.85 (both t,
1
bridging CH2CH2, JC,H = 122 Hz); 25.79 (t, CH2CH2CH2 of
indane, 1JC,H = 127 Hz); 32.71 and 32.74 (both t, CH2CH2CH2
of indane, 1JC,H = 130 Hz); 47.04 (d, CH(9) of fluorene, 1JC,H
=
1
128 Hz); 50.96 (d, CHCH2 of indene, JC,H = 126 Hz); 115.57
1
(d, =CH of indene, JC,H = 157 Hz); 118.85, 119.70, 119.75,
124.05, 124.30, 126.74, 126.82, 126.86 (2 CH), and 127.03 (all d,
CH arom., 1JC,H = 155—160 Hz); 139.63, 142.20, 143.65, 145.06,
and 147.69 (all s, =CMe and C arom. of indene); 141.31 (C(4a),
C(4b) of fluorene); 146.89, 147.11 (C(8a), C(9a) of fluorene).
Fraction 2 (compound 7). The yield was 4.34 g (64%).
Fraction 1 (starting indene 4). The yield was 3.75 g (63%).
Dilithium derivative of 1ꢀ(fluorenꢀ9ꢀyl)ꢀ2ꢀ(2ꢀmethylꢀ5,6ꢀ
dihydrocyclopenta[ f ]ꢀ1Hꢀindenꢀ1ꢀyl)ethane (8). The synthesis
was carried out in allꢀsealed evacuated vessels. A 2.7 M BunLi
solution in hexane (7.0 mL, 18.9 mmol) was added portionwise
with vigorous stirring to a suspension of compound 1b (3.00 g,
8.3 mmol) in Et2O (80 mL) at –20 °C for 5 min. The reaction
mixture was allowed to warm to ∼20 °C and kept for ∼18 h. The
solvent was distilled off to a liquid nitrogen cooled tube. The
residue was twice washed on a porous glass membrane with a
4 : 1 Et2O—hexane mixture (100 mL) and then with pure hexane
(50 mL) and dried under high vacuum. An orangeꢀbrown powꢀ
dered compound was obtained in a yield of 3.00 g (91%). There
are four molecules of dilithium salt 8 per Et2O molecule
(1H NMR spectroscopic data). 1H NMR (THFꢀd8, 25 °C), δ:
2.09 (m, 2 H, CH2CH2CH2 of indane); 2.51 (s, 3 H, Me); 2.93
and 3.00 (both m, 2 H each, CH2CH2CH2 of indane); 3.09 and
3.24 (both m, 2 H each, bridging CH2CH2); 5.61 (s, 1 H, H arom.
of C(5)ꢀindene); 6.37 and 6.86 (both br.t, 2 H each, H(2), H(3),
H(6), H(7) of fluorene); 7.09 and 7.47 (both s, 1 H each, H arom.
of C(6)ꢀindene); 7.52 and 7.88 (both br.d, 2 H each, H(1),
H(4), H(5), H(8) of fluorene). 13C NMR (THFꢀd8, 25 °C), δ:
14.94 (q, Me, 1JC,H = 124 Hz); 28.23 (t, CH2CH2CH2 of indane,
5
racꢀ{1ꢀ(η ꢀFluorenꢀ9ꢀyl)ꢀ2ꢀ(2ꢀmethylꢀ5,6ꢀdihydrocycloꢀ
5
penta[ f ]ꢀη ꢀindenꢀ1ꢀyl)ethane}hafnium dichloride (10). The synꢀ
thesis was carried out analogously to the synthesis of zirconium
complex 9 starting from salt 8 (0.95 g, 2.46 mmol) and HfCl4
(0.79 g, 2.46 mmol). A yellow crystalline compound was obꢀ
tained in a yield of 1.18 g (78%). Found (%): C, 55.05; H, 3.89.
C28H24Cl2Hf. Calculated (%): C, 55.14; H, 3.97. 1H NMR
(CD2Cl2, 25 °C), δ: 1.94—2.06 (m, 2 H, CH2CH2CH2 of
indane); 2.23 (s, 3 H, Me); 2.84—3.03 (m, 4 H, CH2CH2CH2 of
indane); 3.94 and 4.10 (both m, 1 H each, bridging CH2); 4.21
and 4.61 (both m, 1 H each, bridging CH2); 5.92 (s, 1 H, H arom.
of C(5)ꢀindene); 7.09 and 7.75 (both s, 1 H each, H arom. of
C(6)ꢀindene); 7.03, 7.23, 7.33, and 7.48 (all t, 1 H each, H(2),
H(3), H(6), H(7) of fluorene, 3JH,H ≈ 8.0 Hz); 7.48, 7.74, 7.86,
and 7.88 (all d, 1 H each, H(1), H(4), H(5), H(8) of fluorene,
3JH,H ≈ 8.0 Hz). 13C{1H} NMR (CD2Cl2, 25 °C), δ: 15.20 (Me);

Synthesis of elastomeric polypropylene in bulk
Russ.Chem.Bull., Int.Ed., Vol. 54, No. 2, February, 2005
411
26.59, 27.94, 29.44, 32.52, 32.79 (CH2 of bridge and indane);
104.66 (CH arom. of C(5)ꢀindene); 116.66, 119.26, 122.63,
123.96, 124.22, 124.34, 125.06, 125.60, 127.44, 128.26
(CH arom. of C(6)ꢀindene and fluorene); 99.54, 119.03, 121.90,
123.89, 126.24, 127.79, 129.91, 130.10, 143.08, 144.92 (2 C)
(C arom.).
Xꢀray diffraction study of compounds 1b (two modifications)
and 10. The structures were solved by direct methods using the
SHELXꢀ86 program package.32 All nonhydrogen atoms were
refined anisotropically by the fullꢀmatrix leastꢀsquares method
against F 2 (SHELXLꢀ97).33 For the monoclinic modification of
1b and for compound 10, all H atoms were located from differꢀ
ence electron density series and refined isotropically. In the
structure of the orthorhombic modification of 1b, all H atoms
were placed in calculated positions and refined using a riding
model. The crystallographic data, details of Xꢀray diffraction
data collection, and characteristics of structure refinement
for 1b (P21/c), 1b (Pbca), and 10 are given in Table 8. Complete
tables of atomic coordinates, bond angles, and bond angles were
deposited with the Cambridge Structural Database.
Polymerization. Polymethylalumoxane (Witco; a 10% soluꢀ
tion in toluene) and triisobutylaluminum (Aldrich) were used
without additional purification. The kinetics of propene polyꢀ
merization was studied on an apparatus equipped with a
0.4ꢀL autoclaveꢀtype reactor. The apparatus was evacuated at
60—70 °C for 1 h. Then MAO or TIBA was supplied to the
reactor filled with the liquid monomer, after which a solution of
metallocene in MAO was added (at the polymerization temꢀ
perature). Polymerization was carried out at a constant pressure
of the monomer in the mode of complete filling of the reacꢀ
tor with the liquefied monomer in the temperature range of
30—70 °C. The polymerization rate was calculated from the
amount of the propene consumed, which was determined using
a calibration syringe. The activity of the systems under study was
characterized by the effective polymerization rate constant
–1
–1
keff = Wp•Cm •CM
,
where Wp/mol L–1 min–1 is the propene polymerization rate at a
particular instant of time in the unit volume of the reaction
Table 8. Crystallographic data, details of Xꢀray diffraction study, and characteristics of structure refinement of 1b (P21/c), 1b (Pbca),
and 10
Parameter
1b
1b
10
Molecular formula
Molecular weight
Crystal system
Space group
C
28H26
C28H26
362.49
Orthorhombic
Pbca
C28H26Cl2Hf
609.86
362.49
Monoclinic
P21/c
Triclinic
P–1
a/Å
b/Å
c/Å
α/deg
9.5443(4)
8.2592(3)
25.949(1)
—
95.694(2)
—
2035.4(1)
4
1.183
19.978(4)
16.311(4)
25.705(9)
—
—
—
8376(4)
16
1.150
7.854(4)
10.861(5)
14.410(1)
70.91(5)
75.24(5)
79.57(4)
1116.8(8)
2
β/deg
γ/deg
V/Å3
Z
dcalc/g cm–3
1.814
F(000)
776
0.066
«Bruker SMART»
100
3104
0.065
596
4.923
µ(MoꢀKα)/mm–1
Diffractometer
«EnrafꢀNonius CAD4»
T/K
Scan mode
293
ω
293
ω
ω
θ Scan range/deg
Ranges of indices of measured reflections
1.58—28.00
–12 < h < 12,
–10 < k < 10,
–31 < l < 34
13115
2.04—24.98
0 < h < 23,
0 < k < 19,
–30 < l < 0
7347
2.13—24.97
–9 < h < 9,
–11 < k < 12,
–3 < l < 17
5070
Number of measured reflections
Number of independent reflections
Absorption correction
4910 (Rint = 0.0767)
—
7347 (Rint = 0.0000)
—
3898 (Rint = 0.0220)
ψ Scan
Transmission (min/max)
Number of parameters in refinement
R factor using reflections with I > 2σ(I )
—
358
—
508
0.27464/0.42504
377
R1 = 0.0172,
wR2 = 0.0407
1.055
R1 = 0.0576,
wR2 = 0.1511
1.013
0.0010(9)
–0.346/0.463
R1 = 0.0606,
wR2 = 0.1122
0.816
0.00031(5)
–0.203/0.184
Goodnessꢀofꢀfit on F 2
Extinction coefficient
Residual electron
0.0022(2)
–0.533/0.694
density (min/max)/e Å–3

412
Russ.Chem.Bull., Int.Ed., Vol. 54, No. 2, February, 2005
Nedorezova et al.
mixture, Cm/mol L–1 is the concentration of the monomer in
the liquid phase, and CM/mol L–1 is the concentration of
metallocene in the unit volume of the reaction mixture.
Study of the properties of polymers. The microstructures of
PP samples were determined by IR and 13C NMR spectroscopy.
The stereoregularity parameters were determined from the inꢀ
tensity ratio of the absorption bands D998/D973 (macrotacticity)
according to a known procedure.34 The 13C NMR spectra of
polymer solutions in 1,2ꢀC2D2Cl4 (5—10 wt.%) were recorded
on a Bruker ACꢀ200 instrument at 110 °C.
2. MetalloceneꢀBased Polyolefins: Preparation, Properties and
Technology, Eds J. Scheirs and W. Kaminsky, Wiley, New
York, 2000, 1, 2.
3. W. Kaminsky, J. Chem. Soc., Dalton Trans., 1998, 9, 1413.
4. V. I. Tsvetkova, Vysokomol. Soedin., Ser. C, 2000, 42, 1954
[Polym. Sci., Ser. C, 2000, 42 (Engl. Transl.)].
5. G. Natta, G. Mazzanti, G. Crespi, and G. Moraglio, Chim.
Ind. Milan, 1957, 39, 275.
6. G. W. Coates and R. M. Waymouth, Science, 1995,
267, 217.W
The molecularꢀweight characteristics of PP were determined
on a Waters 150ꢀC gel chromatograph at 145 °C in oꢀdichloꢀ
robenzene with the use of an HTꢀµꢀstyragel linear column caliꢀ
brated with polystyrene.
7. N. M. Bravaya, P. M. Nedorezova, and V. I. Tsvetkova, Usp.
Khim., 002, 71, 57 [Russ. Chem. Rev., 2002, 71, 49 (Engl.
Transl.)].
8. S. Lieber and H.ꢀH. Brintzinger, Macromolecules, 2000,
33, 9192.
The melting point of PP was determined by the DSC method
on a DuPont Instrument at a heating and cooling rate of
9. J. C. W. Chien, Y. Iwamoto, and M. D. Rausch, J. Polym.
Sci., Part A, 1999, 37, 2439.
10 °C min–1
.
Xꢀray diffraction measurements were carried out on a
DRONꢀ3M diffractometer in the transmission mode (asymmetꢀ
ric, focusing on the detector, a quartz primary beam monochroꢀ
mator) using CuꢀKα radiation. The Xꢀray diffraction patterns
were scanned in the diffraction angle range 2θ = 6—36° with a
step ∆2θ = 0.04° and the accumulation time τ = 10 s. The Xꢀray
diffraction patterns were processed using the Peak Fit ver. 4.0
program package. To separate scattering from the amorphous
and crystalline components in the Xꢀray patterns of PP, a comꢀ
pletely amorphous PP sample was used (see Table 3, run 1).
Samples for physicochemical tests were prepared by pressing
at 190 °C. Irganox (∼0.8 wt.%) was introduced into the polymer
as the stabilizer. The tensile tests were carried out on an Instron
1122 instrument on bladeꢀshaped samples (the crossꢀsection was
1.5×5 mm, and the base length was 35 mm) in the following
10. J. C. W. Chien, G. H. Llinas, and M. D. Rausch, J. Polym.
Sci., Part A, 1992, 30, 2601.
11. W. J. Gautier, J. F. Corrigan, N. J. Taylor, and S. Collins,
Macromolecules, 1995, 28, 3771.
12. J. Kukral and B. Rieger, Macromol. Symp., 2002, 177, 71.
13. B. Rieger, C. Troll, and J. Preuschen, Macromolecules, 2002,
35, 5742.
14. G. Guerra, L. Cavallo, G. Moscardi, M. Vacatello, and
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15. U. Dietrich, M. Hackmann, B. Rieger, M. Klinga, and
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16. F. H. Allen, O. Kennard, D. G. Watson, L. Brammer,
A. G. Orpen, and R. Taylor, J. Chem. Soc., Perkin Trans. 2,
1987, 1.
17. D. J. Cardin, M. F. Lappert, C. L. Raston, and P. I. Riley, in
Comprehensive Organometallic Chemistry, Eds G. Wilkinson,
F. Gordon, A. Stone, and E. W. Abel, Pergamon Press,
Oxford—New York—Toronto—Sydney—Paris—Frankfurt,
1982, 3, 551.
mode: (1) stretching by 300% at a rate of 500 mm min–1
;
(2) traverse at a rate of 500 mm min–1 to the zero tension;
(3) repeated stretching of the sample at a rate of 500 mm min–1
until rupture occurred. The elasticity of the polymers was estiꢀ
mated using the residual strain (ε300) or the residual stress (ε
expressed in % and determined from the equation:
)
18. A. Razavi, L. Peters, L. Nafpliotis, D. Vereecke, K. D. Dauw,
J. L. Atwood, and U. Thewald, Macromol. Symp., 1995,
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20. F. Auriemma and C. De Rosa, Macromolecules, 2002,
35, 9057.
21. V. Busico, L. Caporaso, R. Cipullo, and L. Landriani, J. Am.
Chem. Soc., 1996, 118, 2105.
22. A. N. Panin, Z. M. Dzhabieva, P. M. Nedorezova, V. I.
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Bravaya, J. Polym. Sci., Part A, 2001, 39, 1915.
23. O. N. Babkina, N. M. Bravaya, P. M. Nedorezova,
S. L. Saratovskikh, and V. I. Tsvetkova, Kinet.
Katal., 2002, 43, 371 [Kinet. Catal., 2002, 43, 341 (Engl.
Transl.)].
24. P. M. Nedorezova, V. I. Tsvetkova, A. M. Aladyshev, D. V.
Savinov, A. N. Klyamkina, V. A. Optov, and D. A.
Vysokomol. Soedin., Ser. A, 2001, 43, 595 [Polym. Sci., Ser. A,
2001, 43, 356 (Engl. Transl.)].
res
–1
ε = (L1 – L0)•L0 •100,
where L1 is the final length of the sample after removal of loadꢀ
ing as the stretching became as large as 300% or after rupture,
and L0 is the initial length of the sample.
We thank L. G. Echevskaya and M. A. Matsko for meaꢀ
suring the molecularꢀweight characteristics of polypropyꢀ
lene samples. We also acknowledge A. N. Shchegolikhin
for performing DSC and IR analyses of these samples.
This study was financially supported by the Russian
Foundation for Basic Research (Project No. 03ꢀ03ꢀ32566)
and the Foundation of the President of the Russian Fedꢀ
eration (Program for Support of Young Doctors, Grant
MKꢀ3697.2004.3).
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Synthesis of elastomeric polypropylene in bulk
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Received May 21, 2004;
in revised form October 18, 2004