Ethylene polymerization with long-lifetime monopendant thienyl-substituted group 4 metallocenes

Article abstract of DOI:10.1002/aoc.3153

A series of group 4 metallocenes (RCp)[Cp-(bridge)-(2-C₄H ₃S)]MCl₂ [M = Ti (C1, C2, C3, C4); M = Zr (C5, C6, C7, C8)] bearing a pendant thiophene group on a cyclopentadienyl ring have been synthesized, characterized and tested as catalyst precursors for ethylene polymerization. The molecular structures of representative titanocenes C2 and C4 were confirmed by single-crystal X-ray diffraction and revealed that both complexes exist in an expected coordination environment for a monomeric bent metallocene. No intramolecular coordination between the thiophene group and the titanium center could be observed in the solid state. Upon activation by methylaluminoxane (MAO), titanocenes C1, C2, C3, C4 showed moderate catalytic activities and produced high- or ultra-high-molecular-weight polyethylene (M_v 70.5-227.1 × 10⁴gmol^-1). Titanocene C3 is more active and long-lived, with a lifetime of nearly 9h at 30C. At elevated temperatures of 80-110C, zirconocenes C5, C6, C7, C8 displayed high catalytic activities (up to 27.6 × 10⁵g PE (mol Zr) ^-1h^-1), giving high-molecular-weight polyethylene (M _v 11.2-53.7 × 10⁴gmol^-1). Even at 80C, a long lifetime of at least 2h was observed for the C8/MAO catalyst system. Copyright

Full text of DOI:10.1002/aoc.3153

Full Paper
Received: 13 February 2014
Revised: 20 March 2014
Accepted: 20 March 2014
Published online in Wiley Online Library
(wileyonlinelibrary.com) DOI 10.1002/aoc.3153
Ethylene polymerization with long-lifetime
monopendant thienyl-substituted group 4
metallocenes
Aike Li, Wei Xiao, Haiyan Ma and Jiling Huang*
A series of group 4 metallocenes (RCp)[Cp―(bridge)―(2-C4H3S)]MCl2 [M = Ti (C1–C4); M = Zr (C5–C8)] bearing a pendant
thiophene group on a cyclopentadienyl ring have been synthesized, characterized and tested as catalyst precursors for
ethylene polymerization. The molecular structures of representative titanocenes C2 and C4 were confirmed by single-crystal
X-ray diffraction and revealed that both complexes exist in an expected coordination environment for a monomeric bent
metallocene. No intramolecular coordination between the thiophene group and the titanium center could be observed in the
solid state. Upon activation by methylaluminoxane (MAO), titanocenes C1–C4 showed moderate catalytic activities and produced
high- or ultra-high-molecular-weight polyethylene (Mv 70.5–227.1 × 104 g molÀ1). Titanocene C3 is more active and long-lived,
with a lifetime of nearly 9 h at 30°C. At elevated temperatures of 80–110 °C, zirconocenes C5–C8 displayed high catalytic activities
(up to 27.6 × 105 g PE (mol Zr)À1 hÀ1), giving high-molecular-weight polyethylene (Mv 11.2–53.7 × 104 g molÀ1). Even at 80°C, a
long lifetime of at least 2 h was observed for the C8/MAO catalyst system. Copyright © 2014 John Wiley & Sons, Ltd.
Additional supporting information may be found in the online version of this article at the publisher’s web-site.
Keywords: titanocene; zirconocene; thiophene; polymerization; ethylene
To further understand the effects of the extra donor on the Cp
ring as well as the relationship between catalyst structures and
Introduction
Over the past decades, a significant amount of research has been
directed toward the development of group 4 metallocene catalysts
owing to their high catalytic activities for olefin polymerization and
fine control over polymer microstructures.[1–3] We noticed that
modification of the steric and electronic properties at the metal
center by varying the ligand structure has a strong influence on
the catalytic behavior. One of the great achievements in
metallocene catalyst design is the constrained geometry com-
plexes (namely CGC catalysts), which contain a sidearm bearing
an additional chelating donor functionality at the cyclopentadienyl
(Cp) ring and show excellent activity for copolymerization of
ethylene and α-olefins to give novel copolymers.[4–11]
their catalytic behavior, herein we report the syntheses and
characterization of a series of monopendant thienyl-substituted
group 4 metallocenes, and explore the effect of the pendant
thiophene group toward the catalytic behavior for ethylene
polymerization in the presence of MAO.
Results and Discussion
Synthesis of Group 4 Metallocenes (RCp)[Cp―(bridge)―(2-C4H3S)]
MCl2 (C1–C8)
The desired group
4
metallocenes (RCp)[Cp―(bridge)―
Recently, many examples of half-sandwich metallocenes bearing
soft pendant donors such as S-donor, P-donor, alkyl and aryl groups
on the Cp ring have been reported.[12–18] In 2001, Hessen et al. devel-
oped a series of half-sandwich titanocenes with an arene-pendant Cp
ligand,[12] which are excellent catalysts for ethylene trimerization after
activation with methylaluminoxane (MAO). The authors proposed that
this remarkable behavior may be attributed to the arene-pendant
moiety, which is likely to exhibit hemilabile behavior by η6 coordina-
tion.[12,13] In our previous work, we reported that half-sandwich
titanocenes with a thiophene-pendant Cp ligand[14] could selectively
trimerize ethylene to 1-hexene with high activity. It could be envis-
aged that the heterocycle thiophene as an aromatic system may coor-
dinate to the metal center in the η5 mode, and also the heteroatom as
a donor may coordinate to the metal center in the η1 mode. The
thiophene―Cp ligand may serve as a hemilabile ligand in the cata-
lytic trimerization of ethylene. However, to date only a few examples
of group 4 metallocene catalysts bearing sidearm donors on the
Cp rings have been reported for olefin polymerization.[19–21]
(2-C4H3S)]MCl2 [M = Ti (C1–C4); M = Zr (C5–C8)] bearing a
pendant thiophene group on a Cp ring were synthesized in mod-
erate to good yields (35.1–70.6%) by the reaction of (R3Cp)TiCl3 or
(R3Cp)ZrCl3·DME with 1 equiv. of lithium salts [Cp―(bridge)―
(2-C4H3S)]Li that were prepared in situ by treating the corre-
sponding substituted fulvenes with 2-thienyl lithium (Scheme 1).
The resultant group 4 metallocenes C1–C8 were characterized by
1H and 13C NMR and elemental analysis.
In the 1H NMR spectra of C1–C8, the chemical shift of the
proton ortho to the thiophene group appeared at δ = 7.16–7.30 ppm,
*
Correspondence to: Jiling Huang, Laboratory of Organometallic Chemistry,
East China University of Science and Technology, 130 Meilong Road, Shanghai
200237, People’s Republic of China. E-mail: Jlhuang@ecust.edu.cn
Laboratory of Organometallic Chemistry, East China University of Science and
Technology, Shanghai, 200237, People’s Republic of China
Appl. Organometal. Chem. (2014)
Copyright © 2014 John Wiley & Sons, Ltd.

A. Li et al.
R1
Cl
R2
and the thienyl-substituted Cp ring in C2 vary be-
tween 2.322(2) and 2.467(2) Å in accordance with
an η5 coordination of the two Cp ligands to the metal
center. The Ti―C distances to the substituted carbon
are generally longer than that to the unsubstituted
carbon in the Cp ring. The average Ti―Cl bond
lengths of approximately 2.36 Å is comparable to
those previously reported for titanocenes.[22,23] The
Cl1―Ti1―Cl2 bond angle is 93.40(3)°, indicating that
the two chlorides are located in a cis position to each
other. It should be noted that the Ti1―S1 distance is
4.33 Å, indicating no intramolecular coordination be-
tween the thiophene group as a pendant donor and
the titanium center in the solid state.
(R3Cp)TiCl3
Ti
S
Cl
R3
C1: R1 = Me, R2 = Et, R3 = H;
R1
R1 R2
R2
S
C2: R1 = Me, R2 = Et, R3 = Me;
C3: R1 = R2 = cyclo-C5H10, R3 = H;
C4: R1 = R2 = cyclo-C5H10, R3 = Me
_
Li+
Li
S
R1
Cl
R2
S
(R3Cp)ZrCl3¡¤DME
Zr
Cl
R3
Ethylene Polymerization Catalyzed by
Titanocenes C1–C4
C5: R1 = R2 = Me, R3
=
nBu;
nBu;
C6: R1 = Me, R2 = Et, R3
=
C7: R1 = R2 = cyclo-C5H10, R3 = H;
C8: R1 = R2 = cyclo-C5H10, R3 = nBu
The catalytic behavior of titanocenes C1–C4 for ethyl-
ene polymerization were evaluated using MAO as
cocatalyst. The polymerization results are summarized
in Table 2. Under the same conditions, titanocenes C1–
C4 exhibited similar activities but gave much higher molecular-weight
polyethylene (Mv 112.8–155.7 × 104 gmolÀ1) in comparison to that
obtained by Cp2TiCl2 (Mv 52.6 × 104 gmolÀ1) (Fig. 3 and Table 2, en-
tries 1, 4–7).
Scheme 1. Synthesis of titanocenes C1–C4 and zirconocenes C5–C8.
which is similar to that observed for half-sandwich titanium
complex [Cp-C(cyclo-C5H10)-(2-C4H3S)]TiCl3 (at 7.25 ppm).[14]
These results indicate no obvious coordination between the
thiophene group and the metal center in these metallocenes
C1–C8 in solution.
The structures of these titanocenes have an important
influence on the catalytic activity. The activity increases with
the increase in the steric hindrance of the bridging unit at R1
and R2 in the thienyl-substituted Cp moiety. For example, under
the same conditions, C4 with a cyclohexyl bridge (R1 = R2
=
Crystal Structures of Titanocenes C2 and C4
cyclo-C5H10) displayed much higher catalytic activity (1.9 × 105 g
PE (mol Ti)À1 hÀ1) than C2, which features a smaller CMeEt bridge
(R1 = Me, R2 = Et) (1.0 × 105 g PE (mol Ti)À1 hÀ1) (entry 7 vs. entry
5). Although no coordination between the thiophene group and
the titanium center could be observed in the solid state of
titanocenes C2 and C4, the thiophene group could coordinate
to the generated low-valence titanium species when these
titanocenes were activated by MAO.[14] We postulate that the
introduction of more bulky substituents on the bridge unit might
be beneficial to push the pendant thiophene group toward the
Single crystals of titanocenes C2 and C4 suitable for X-ray diffrac-
tion studies were obtained from dichloromethane/nhexane solu-
tion at room temperature. The molecular structures of C2 and C4
are shown in Figs 1 and 2, respectively. The crystallographic data
and structure refinement details are summarized in Table 1, and
the selected bond lengths and angles are listed in Table S1
(supporting information).
Both C2 and C4 were found to be an expected monomeric
bent metallocene compound. As shown in Fig. 1, for example,
the Ti―C bond lengths of both the alkyl-substituted Cp ring
Figure 2. Molecular structure of titanocene C4, with displacement
ellipsoids at the 50% probability level; hydrogen atoms are omitted
for clarity.
Figure 1. Molecular structure of titanocene C2, with displacement ellipsoids
at the 50% probability level; hydrogen atoms are omitted for clarity.
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Appl. Organometal. Chem. (2014)

Thienyl-substituted group 4 metallocenes for ethylene polymerization
Table 1. Crystal data and structure refinement for titanocenes C2
and C4
addition, the Mv value of the resultant polyethylene significantly
decreased upon increase in temperature. This can be attributed
to a facilitated chain transfer reaction via β-H elimination at
elevated temperatures.[25]
C2
C4
Empirical formula
C
19H22Cl2STi
C21H24Cl2STi
427.26
It is worth noting that the most active pre-catalyst, C3, is
remarkably long-lived at ambient temperature. The yield of the
obtained polyethylene was continuously increased during the
polymerization time from 30 min to 9 h (Fig. 4, entries 6, 19–22).
Although the catalytic activity decreases with prolonged
polymerization time, C3 still retains moderate activity of
0.9 × 105 g PE (mol Ti)À1 hÀ1 in 9 h. By contrast, for pre-catalyst
Cp2TiCl2, no obvious increase in polyethylene yield was
observed after 1 h, indicating a short-lived pro-catalyst for
ethylene polymerization. A half-sandwich titanium complex
bearing a pendant thiophene group was previously reported
by Huang et al.[14] The authors proposed that the thiophene
group could coordinate to the generated low-valence titanium
center when the half-sandwich catalyst is activated by MAO. By
analogy, when activated by MAO, the remarkably long catalytic
lifetime (nearly 9 h) of titanocene C3 may be attributable to the
coordination ability of the thiophene group, which can stabilize
the generated active catalytic species, thus leading to the
formation of high- or ultra-high-molecular-weight polyethylene
(up to 227.1 × 104 g molÀ1).
Formula weight
401.23
Space group
P21/c
P21/c
Crystal system
Monoclinic
8.2850(7)
17.7467(15)
12.9976(11)
105.043(2)
1845.6(3)
4
Monoclinic
8.6899(13)
18.048(3)
13.0417(19)
107.878(3)
1946.6(5)
4
a (Å)
b (Å)
c, Å
β (°)
V (Å3)
Z
Dcalcd (Mg mÀ3
)
1.444
1.458
Absorption coefficient
0.863
0.823
(mmÀ1
)
F(000)
832
888
Crystal size (mm)
θ range (°)
0.11 × 0.13 × 0.21 0.11 × 0.15 × 0.21
2.0–26.0
2.3–26.0
Reflections
11058/3620
[Rint = 0.027]
3027 / 7 / 238
11743/3833
[Rint = 0.079]
2264 / 12 / 245
collected/unique
Data with I > 2σ (I) /
restraints / parameters
Goodness–of–fit on F2
1.04
0.95
Final R indices [I > 2σ(I)] R1 = 0.038,
wR2 = 0.096
R1 = 0.049,
wR2 = 0.089
R1 = 0.102,
wR2 = 0.107
0.34 and À0.29
Ethylene Polymerization Catalyzed by Zirconocenes C5–C8
R indices (all data)
R1 = 0.048,
Upon activation with MAO, zirconocenes C5–C8 were investigated
as the catalysts for ethylene polymerization in detail (Table 3). As
observed for titanocenes C1ÀC4, a similar trend was observed for
zirconocenes C5ÀC8, which feature a pendant thiophene group
on a Cp ring that proved beneficial to the production of relatively
higher molecular weight polyethylene in comparison with the
typical Cp2ZrCl2 catalyst (Fig. 5).
Similar to that observed for titanocenes C1–C4, for
zirconocenes C5–C8 the catalytic activity increased remarkably
by increasing the steric hindrance of the bridging unit at R1 and
R2 in the thienyl-substituted Cp moiety. For example, at 80 °C,
C8 with a cyclohexyl as the bridging unit was more beneficial
to the catalytic activity (15.4 × 105 g PE (mol Zr)À1 hÀ1) than
C6, which has a relatively smaller bridge CMeEt ( 9.6 × 105 g
PE (mol Zr)À1 hÀ1) (entry 34 vs. entry 28). C5, with the smallest
bridge group CMe2, showed the lowest catalytic activity (3.2 × 105 g
PE (mol Zr)À1 hÀ1) for ethylene polymerization under the same
conditions (entry 26). This result indicates that the catalytic
activity followed the order C8 (R1 = R2 = cyclo-(C5H10) > C6
(R1 = Me, R2 = Et) > C5 (R1 = R2 = Me).
wR2 = 0.102
0.38 and À0.19
Largest diff. peak and
hole (e ÅÀ3
)
titanium center[15] and strengthen the intramolecular coordina-
tion interaction, thus improving the stability of the catalytically
active species and leading to higher activity. Similar results were
also observed for analogues C1 and C3 (entry 4 vs. entry 6). C3
with a cyclohexyl bridge also displayed relatively higher catalytic
activity (3.2 × 105 g PE (mol Ti)À1 hÀ1) than C1 with a smaller
CMeEt bridge (1.8 × 105 g PE (mol Ti)À1 hÀ1).
The R3 groups on the alkyl-substituted Cp moiety also play an
important role on the catalytic activity. C2 with Me group at the
R3 position displayed relatively lower catalytic activity than C1
(R3 = H) (entry 5 vs. entry 4). A similar trend was also observed
for analogs C3 (R3 = H) and C4 (R3 = Me) (entry 6 vs. entry 7).
These data suggest that the decrease in the steric bulk of the
groups at R3 position is beneficial to the catalytic activity.
The influences of Al/Ti molar ratio, reaction temperature and
ethylene pressure were studied by titanocene C3 as pre-catalyst.
With the increase of the Al/Ti molar ratio from 1000 to 9000, the
catalytic activity was increased from 1.7 × 105 to 3.9 × 105 g PE
(mol Ti)À1 hÀ1 (entries 6, 8–11). Meanwhile, the Mv value of the re-
sultant polyethylene was significantly decreased from 190.3 × 104
to 70.5 × 104 g molÀ1, which is possibly due to the enhanced rate
of chain transfer to aluminum for the termination.[24] Upon
increasing the ethylene pressure, both the catalytic activity and
the molecular weight increased consistently (entries 6, 12–14).
The temperature rise led to enhancement first and then decrease
in the catalytic activity (entries 6, 15–18). Although the highest
activity of 3.2 × 105 g PE (mol Ti)À1 hÀ1 was obtained at 30 °C,
moderate activity of 1.5 × 105 g PE (mol Ti)À1 hÀ1 was still
maintained at elevated temperature up to 80 °C (entry 17). In
When compared with C8, which has a sterically larger nBu
group at the R3 position on the alkyl-substituted Cp moiety, C7
(R3 = H) displayed much lower catalytic activity (3.3 × 105 g PE
(mol Zr)À1 hÀ1) (entry 30). By contrast, titanocenes C4, with a
relatively bulky Me group at R3, showed relatively lower activity
than C3 (R3 = H). Rytter and co-workers reported a series of
zirconocenes (RCp)2ZrCl2 with linear alkyl substituents on ethyl-
ene polymerization and found that the zirconocene with nBu
substituent showed increased activity compared to Cp2ZrCl2.[26]
It was proposed that the higher activity resulted from an agostic
interaction between the metal center and a hydrogen on the
linear alkyl substituent having at least three carbon atoms.[26,27]
So it is possible that the increased activity in C8 compared to
C7 (R = H) may also be attributed to the agostic interaction
n
between the Zr and a γ-H on the Bu substituent in C8.
Appl. Organometal. Chem. (2014)
Copyright © 2014 John Wiley & Sons, Ltd.
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A. Li et al.
Table 2. Ethylene polymerization results catalyzed by titanocenes C1–C4/MAO catalytic systemsa
4
À1
Activityb
MV (10 g mol
)
c
Entry
Catalyst
Al/Ti
Temp (°C)
Time (min)
Pressure (MPa)
Yield (mg)
1
Cp2TiCl2
Cp2TiCl2
Cp2TiCl2
C1
3000
3000
3000
3000
3000
3000
3000
1000
2000
6000
9000
3000
3000
3000
3000
3000
3000
3000
3000
3000
3000
3000
30
30
30
30
30
30
30
30
30
30
30
30
30
30
0
30
1 h
3 h
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
1 h
3 h
6 h
9 h
0.6
0.6
0.6
0.6
0.6
0.6
0.6
0.6
0.6
0.6
0.6
0.1
0.3
1.0
0.6
0.6
0.6
0.6
0.6
0.6
0.6
0.6
137
167
172
92
2.7
1.7
0.6
1.8
1.0
3.2
1.9
1.7
2.5
3.7
3.9
1.2
2.1
4.1
1.9
1.8
1.5
—
52.6
54.3
2
3
55.1
4
128.7
112.8
144.1
155.7
190.3
163.5
116.9
70.5
5
C2
51
6
C3
160
95
7
C4
8
C3
84
9
C3
127
183
194
61
10
11
12
13
14
15
16
17
18
19
20
21
22
C3
C3
C3
77.2
C3
103
204
94
95.3
C3
158.3
185.2d
107.5
74.1d
—
C3
C3
50
80
110
30
30
30
30
91
C3
75
C3
Trace
276
433
715
776
C3
2.8
1.4
1.2
0.9
172.3
202.1
227.1
225.7
C3
C3
C3
aPolymerization conditions: 1 μmol of catalyst, solvent toluene (total volume 25 ml).
bActivity in 105 g PE (mol Ti)À1 hÀ1
cIntrinsic viscosity was determined in decahydronaphthalene at 135 °C and molecular weight was calculated using the relation [η] = 6.77 × 10À4M0v.67
dMw and Mw/Mn were determined by GPC. For entry 15, Mw = 189.5 × 104 gmolÀ1, Mw/Mn = 2.32. For entry 17, Mw = 73.6 × 104 gmolÀ1, Mw/Mn = 2.10.
.
.
Figure 4. Plots of polymerization time versus catalytic activity (●) and
polymer yield (□) of the polyethylene obtained by C3/MAO at 30 °C
(Table 2, entries 6, 19–22).
Figure 3. Viscosity average molecular weight (Mv) of polyethylene
obtained by titanocenes Cp2TiCl2/MAO and C1–C4/MAO at 30 °C in
30 min (Table 2, entries 1, 4–7).
reaction temperature increased due to a faster chain transfer
reaction via β-H elimination at higher temperature.
The performance of pre-catalyst C8 was investigated in detail by
changing the reaction parameters such as Al/Zr molar ratio, poly-
merization temperature and ethylene pressure (entries 32À43).
The catalytic activity significantly increased from 0.5 × 105 g PE
(mol Zr)À1 hÀ1 at 30 °C to 21.9 × 105 g PE (mol Zr)À1 hÀ1 at 110 °C
(entries 32–35). Meanwhile, the Mv value of the resultant polyethyl-
ene significantly decreased from 58.2 × 104 to 13.1 × 104 g molÀ1 as
The variation of the Al/Zr molar ratio had a significant influence
on the catalytic activity and the molecular weight of the resultant
polyethylene (Fig. 6, entries 34, 36À40). As the Al/Zr molar ratio
increased from 100 to 500, the catalytic activity rapidly increased
from 2.8 × 105 to 11.0 ×105 g PE (mol of Zr)À1 hÀ1. Further
increase of the Al/Zr molar ratio from 500 to 6000 resulted in a
slightly increased catalytic activity. Meanwhile, the Mv value of
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Appl. Organometal. Chem. (2014)

Thienyl-substituted group 4 metallocenes for ethylene polymerization
Table 3. Ethylene polymerization results catalyzed by zirconocenes C5–C8/MAO catalytic systemsa
Entry
Catalyst
Al/Zr
Temp. (°C)
Time (min)
Pressure (MPa)
Yield (mg)
Activityb
MVc (104 g molÀ1
)
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
Cp2ZrCl2
Cp2ZrCl2
Cp2ZrCl2
C5
3000
3000
3000
3000
3000
3000
3000
3000
3000
3000
3000
3000
3000
100
80
80
30
60
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
5
0.6
0.6
0.6
0.6
0.6
0.6
0.6
0.6
0.6
0.6
0.6
0.6
0.6
0.6
0.6
0.6
0.6
0.6
0.1
0.3
1.0
0.6
0.6
0.6
0.6
0.6
0.6
0.6
0.6
815
831
1272
159
498
481
670
163
537
25
16.3
8.3
12.7
12.5
3.1
110
80
25.4
3.2
32.8
11.2
33.5
12.7
36.2
12.9
58.2
52.3
40.9d
13.1d
53.7
51.0
48.7
45.5
29.1
32.1
34.5
42.0
23.2
27.6
32.5
41.2
43.7
44.9
47.1
47.0
C5
110
80
10.0
9.6
C6
C6
110
80
13.4
3.3
C7
C7
110
30
10.7
0.5
C8
C8
50
146
772
1094
141
358
551
645
824
359
521
1378
125
267
409
1120
1380
1612
1771
1785
2.9
C8
80
15.4
21.9
2.8
C8
110
80
C8
C8
300
80
7.2
C8
500
80
11.0
12.9
16.5
7.2
C8
1500
6000
3000
3000
3000
3000
3000
3000
3000
3000
3000
3000
3000
80
C8
80
C8
80
C8
80
10.4
27.6
15.0
16.0
16.4
14.9
13.8
10.7
8.9
C8
80
C8
80
C8
80
10
15
45
60
90
120
180
C8
80
C8
80
C8
80
C8
80
C8
80
C8
80
6.0
aPolymerization conditions: 1 μmol catalyst, solvent toluene (total volume 25 ml).
bActivity in 105 g PE (mol Zr)À1 hÀ1
cIntrinsic viscosity was determined in decahydronaphthalene at 135 °C and molecular weight was calculated using the relation [η] = 6.77 × 10À4M0v.67
dMw and Mw/Mn were determined by GPC. For entry 34, Mw = 45.7 × 104 gmolÀ1, Mw/Mn = 2.16. For entry 35, Mw = 11.5 × 104 gmolÀ1, Mw/Mn = 3.12.
.
.
the resultant polyethylene decreased when the Al/Zr molar ratio
increased due to the enhanced rate of chain transfer to alumi-
num for the termination. When the ethylene pressure was
increased, both the catalytic activity and the molecular weight
increased consistently (entries 34, 41À43).
The dependence of catalytic activities of C8 on time is shown
in Fig. 7 (entries 34, 44–51). At 80 °C, on prolonging the reaction
time the catalytic activity increased in the early stage and then
decreased slowly after 15 min. The highest activity of 16.4 ×
105 g PE (mol Zr)À1 hÀ1 was achieved in 15 min (entry 46). How-
ever, the polymer yield continuously increased from 409 to
1771 mg with polymerization time from 15 min to 2 h, while
further enhancement of the polymerization time to 3 h
resulted in a very slight increase of the polymers. This is
presumably due to the limited ethylene uptake in the reaction
mixture, because the polymerization mixture became more
and more viscous after a long period of polymerization. These
results indicate that the catalyst has a minimal lifetime of 2 h.
In contrast, the typical Cp2ZrCl2 catalyst is short-lived. Under
the same condition, no obvious increase in polyethylene yield
was observed after 30 min.
Figure 5. The viscosity average molecular weight (Mv) of polyethylene
obtained by zirconocenes Cp2ZrCl2/MAO and C5–C8/MAO under
different conditions. Polymerization conditions: (A) 80 °C (Table 3, entries
23, 26, 28, 30, 34); (B) 110 °C (Table 3, entries 25, 27, 29, 31, 35).
Appl. Organometal. Chem. (2014)
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A. Li et al.
monomeric bent metallocene. In the presence of MAO, these
monopendant thienyl-substituted titanocenes C1–C4 and zirconocenes
C5–C8 showed a long catalytic lifetime and produced high- or
ultra-high-molecular-weight polyethylene in comparison with
Cp2TiCl2 and Cp2ZrCl2, respectively. This remarkable behavior
may be attributed to the coordination of the thiophene group
as a pendant donor which can stabilize the active catalytic species
when these catalysts are activated by MAO. In addition, bulky
substituents on the bridge unit of the thienyl-substituted Cp ring
was beneficial to the catalytic activity of these titanocenes and
zirconocenes.
Experimental
General Considerations
Figure 6. Plots of Al/Zr molar ratio versus catalytic activity (□) and
viscosity average molecular weight (Mv) (●) of the polyethylene obtained
by C8/MAO at 80 °C (Table 3, entries 34, 36–40).
All manipulations of air- and/or moisture-sensitive compounds
were performed under a dry argon atmosphere using standard
Schlenk techniques unless otherwise noted. All solvents were
refluxed over sodium/benzophenone ketyl or calcium hydride
(CaH2) and then freshly distilled under argon atmosphere before
use. Methylaluminoxane (MAO) (1.5M in toluene) was purchased
from Sigma-Aldrich. Polymerization-grade ethylene was directly
used without further purification. (MeCp)TiCl3,[29] (nBuCp)
ZrCl3·DME,[30] 2-thienyl lithium[14] and substituted fulvenes[31] were
prepared by the literature procedures. All other chemicals were
commercially available and used as received.
Measurements
NMR spectra of complexes were recorded on a Bruker Avance-
400 spectrometer at ambient temperature, with CDCl3 as the sol-
vent (dried over CaH2 for a minimum of 24 h and then distilled
under argon atmosphere before use). Elemental analyses (C, H)
were carried out on an EA-1106 type analyzer. IR spectra were
recorded on a PerkinElmer System 2000 FT-IR spectrometer. 13C
NMR spectra of polyethylene were recorded on a Bruker
Advance-500 spectrometer using 1,2-dichlorobenzene-d4 as
solvent at 100 °C. DSC trace and melting points of polyethylene
were obtained from the second scanning run on a Universal
V2.3C TA instrument at a heating rate of 10 °C minÀ1. The intrinsic
viscosities (η) of polyethylene were measured with an Ubbelohde
viscometer in decahydronaphthalene at 135 °C and viscosity
average molecular weight (Mv) was calculated as follows: [η] =
Figure 7. Plots of polymerization time versus catalytic activity (●) and
polymer yield (□) of the resultant polyethylene obtained by zirconocene
C8/MAO at 80°C (Table 3, entries 34, 44–51).
Polymer Analysis
13C NMR analysis indicated that the resultant polyethylene is
highly linear with no detectable branches (Fig. S1, supporting
information). According to the results of differential scanning
calorimetry (DSC), the obtained polyethylene showed high
melting points (Tm) in the range of 133–145 °C, which also
indicates that the polymer is a linear polyethylene.[25,28] In
addition, the selected gel permeation chromatography (GPC)
analysis of the resultant polyethylene revealed a narrow molecu-
lar weight distribution (Mw/Mn) (sample of entry 15, 2.32; sample
of entry 17, 2.10; sample of entry 34, 2.16; sample of entry 35,
3.12), suggesting that the polyethylene is produced by a single
active species (Figs S2–S5, supporting information).
6.77 × 10À4 Mv0.67 [32]
Molecular weights (Mn and Mw) and
.
polydispersities (Mw/Mn) of polyethylene were determined by
high-temperature GPC using a PL-GPC 220 instrument. The
measurements were recorded at 150 °C using 1,2,4-trichlorobenzene
as a solvent, at a flow rate of 1.0 ml minÀ1. The calibration was made
using polystyrene standard samples.
Synthesis of Group 4 Metallocenes (RCp)[Cp―(bridge)―
(2-C4H3S)]MCl2 (C1–C8)
Synthesis of Cp[Cp―C(MeEt) ― (2-C4H3S)]TiCl2 (C1)
Conclusions
In summary, we have developed a series of new titanocenes and
zirconocenes (RCp)[Cp―(bridge)―(2-C4H3S)]MCl2 bearing
a
pendant thiophene group on a Cp ring. Single-crystal X-ray
diffraction analysis on titanocenes C2 and C4 revealed that both
complexes exist in an expected coordination environment for a
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Appl. Organometal. Chem. (2014)

Thienyl-substituted group 4 metallocenes for ethylene polymerization
To a solution of 2-thienyl lithium (1.621 g, 18.0 mmol) in diethyl
ether (40 ml) was added dropwise a solution of 6-methyl-6-
ethylfulvene (2.163 g, 18.0 mmol) in 10 ml diethyl ether at 0 °C,
and the reaction mixture was warmed to ambient temperature
and stirred overnight. The resulting precipitate was collected by
filtration, washed with dried petroleum ether (20 ml) and dried
under vacuum to afford lithium salt [Cp―C(MeEt)―(2-C4H3S)]Li
(3.012 g, 14.3 mmol). The lithium salt (0.211 g, 1.0 mmol) was
suspended in dried THF (20 ml) and added dropwise to a stirred
solution of CpTiCl3 (0.213 g, 1.0 mmol) in dried THF (20 ml) at
À78 °C, and the reaction mixture was warmed to ambient
temperature and stirred overnight. Then the solvent was
removed under reduced pressure and the residue was washed
with dried hexane (20 ml). The final product was crystallized from
CH2Cl2/hexane by cooling at À30 °C. Titanocene C1 was obtained
as red crystals in 61.0% yield (0.236 g); m.p. 154À156 °C. 1H NMR
(400 MHz, CDCl3) δ 7.24 (dd, 1H, J = 5.1, 1.1 Hz, proton of C13),
7.02 (dd, 1H, J = 5.1, 3.6 Hz, proton of C12),6.92 (dd, 1H, J = 3.6,
1.1 Hz, proton of C11), 6.89 (m, 2H, protons of C3 and C4), 6.63
(m, 1H, proton of C2), 6.21 (s, 5H, protons of C14, C15, C16, C17
and C18), 6.08 (dd, 1H, J = 5.3, 2.9 Hz, proton of C5), 2.08
(m, 2H, protons of C7), 1.83 (s, 3H, protons of C9), 0.78 (t, 3H,
J = 7.3 Hz, protons of C8). 13C NMR (100 MHz, CDCl3) δ 151.55
(C10), 144.85 (C1), 127.41 (C12), 127.02 (C11), 125.31 (C13),
123.85 (C2), 122.37 (C5), 120.81 (C14, C15, C16, C17 and C18),
116.70 (C3), 113.69 (C4), 43.58 (C6), 38.37 (C7), 24.12 (C9), 9.14
(C8). IR (KBr, cmÀ1): v = 3450 (w), 3089 (m), 2974 (m), 2920 (m),
2877 (w), 2858 (w), 1782 (w), 1469 (m), 1440 (m), 1378 (m),
1242 (w), 1049 (m), 1018 (m), 821 (vs), 705 (vs), 423 (m). Anal.
Calcd for C18H20Cl2STi·0.15CH2Cl2: C, 54.51; H, 5.12. Found:
C, 54.38; H, 5.17%. The final product contains about 0.15 equiv.
of dichloromethane, as verified by NMR spectroscopy.
1245 (w), 1224 (w), 1118 (m), 1048 (s), 828 (vs), 818 (vs), 717 (vs),
405 (m). Anal. Calcd for C19H22Cl2STi: C, 56.88; H, 5.53. Found:
C, 56.78; H, 5.64%.
Synthesis of Cp[Cp―C(cyclo-C5H10)―(2-C4H3S)]TiCl2 (C3)
The procedure was similar to the synthesis of C1, using lithium
salt [Cp―C(cyclo-C5H10)―(2-C4H3S)]Li (0.258 g, 1.1 mmol) and
CpTiCl3 (0.234 g, 1.1 mmol). Titanocene C3 was obtained as red
crystals in 70.6% yield (0.321 g); m.p. 152–154 °C. 1H NMR
(400 MHz, CDCl3): δ 7.28 (dd, 1H, J = 5.1, 1.1 Hz, proton of C15),
7.05 (dd, 1H, J = 5.1, 3.6 Hz, proton of C14), 6.94 (dd, 1H, J = 3.6,
1.1 Hz, proton of C13), 6.74 (t, 2H, J = 2.7 Hz, protons of C3 and
C4), 6.46 (t, 2H, J = 2.7 Hz, protons of C2 and C5), 6.18 (s, 5H,
protons of C16, C17, C18, C19 and C20), 2.55 (d, 2H, J = 13.3 Hz,
protons of C7), 2.01 (m, 2H, protons of C11), 1.64 (m, 2H, protons
of C8), 1.56 (m, 1H, proton of C10), 1.46 (m, 2H, protons of C9),
1.24 (m, 1H, proton of C10). 13C NMR (100 MHz, CDCl3) δ 149.18
(C12), 146.30 (C1), 127.34 (C14), 126.20 (C13), 124.27 (C15),
120.76 (C16, C17, C18, C19 and C20), 120.68 (C2 and C5), 118.98
(C3, C4), 44.28 (C6), 38.66 (C7 and C11), 25.54 (C9), 22.62
(C8 and C10). IR (KBr, cmÀ1): v = 3425 (w), 3102 (m), 2933 (s),
2857 (m), 1654 (w), 1469 (m), 1444 (m), 1350 (w), 1262 (w),
1228 (w), 1073 (w), 1018 (m), 821 (vs), 711 (vs), 409 (m). Anal.
Calcd for C20H22Cl2STi·0.25CH2Cl2: C, 55.98; H, 5.22. Found:
C, 55.89; H, 5.45%. The final product contains about 0.25 equiv.
of dichloromethane, as verified by NMR spectroscopy.
Synthesis of (MeCp)[Cp―C(MeEt)―(2-C4H3S)]TiCl2 (C2)
Synthesis of (MeCp)[Cp―C(cyclo-C5H10)―(2-C4H3S)]TiCl2 (C4)
The procedure was similar to the synthesis of C1, using lithium
salt [Cp―C(MeEt)―(2-C4H3S)]Li (0.586 g, 2.8 mmol) and (MeCp)
TiCl3 (0.652 g, 2.8 mmol). Titanocene C2 was obtained as red
crystals (suitable for X-ray diffraction) in 66.3% yield (0.745 g);
m.p. 145–146 °C. 1H NMR (400 MHz, CDCl3): δ 7.23 (dd, 1H, J =
5.1, 1.1 Hz, proton of C13), 7.00 (dd, 1H, J = 5.1, 3.6 Hz, proton of
C12), 6.90 (dd, 1H, J = 3.6, 1.1 Hz, proton of C11), 6.84 (t, 2H, J =
2.4 Hz, protons of C3 and C4), 6.61 (dd, 1H, J = 5.1, 2.2 Hz, proton
of C2), 6.07 (m, 2H, protons of C16 and C17), 5.94 (m, 2H, protons
of C15 and C18), 5.76 (dd, 1H, J = 5.4, 2.9 Hz, proton of C5), 2.31
(s, 3H, protons of C19), 2.08 (m, 2H, protons of C7), 1.81 (s, 3H,
protons of C9), 0.78 (t, 3H, J = 7.3 Hz, protons of C8). 13C NMR
(100 MHz, CDCl3) δ 151.75 (C10), 144.22 (C1), 135.31 (C14),
126.96 (C12), 126.37 (C11), 125.19 (C13), 125.18 (C2), 124.60
(C5), 123.74 (C3), 121.49 (C4), 116.46 (C15), 116.06 (C18), 115.26
(C16), 113.19 (C17), 43.52 (C6), 38.33 (C7), 24.06 (C9), 16.47
(C19), 9.14 (C8). IR (KBr, cm-1): v = 3450 (w), 3111 (m), 3093 (m),
2972 (s), 2919 (m), 2876 (w), 1495 (m), 1446 (m), 1371 (m),
The procedure was similar to the synthesis of C1, using lithium
salt [Cp―C(cyclo-C5H10)―(2-C4H3S)]Li (0.540 g, 2.3 mmol) and
(MeCp)TiCl3 (0.535 g, 2.3 mmol). Titanocene C4 was obtained as
red crystals (suitable for X-ray diffraction) in 58.6% yield
(0.576 g); m.p. 186–187 °C. 1H NMR (400 MHz, CDCl3): δ 7.27
(dd, 1H, J = 5.0, 1.0 Hz, proton of C15), 7.03 (dd, 1H, J = 5.0,
3.6 Hz, proton of C14), 6.92 (dd, 1H, J = 3.6, 1.0 Hz, proton of
C13), 6.70 (t, 2H, J = 2.7 Hz, protons of C3 and C4), 6.42 (t, 2H,
J = 2.7 Hz, protons of C2 and C5), 5.99 (t, 2H, J = 2.6 Hz, protons
of C18 and C19), 5.80 (t, 2H, J = 2.6 Hz, protons of C17 and C20),
2.54 (d, 2H, J = 13.2 Hz, protons of C7), 2.31 (s, 3H, protons of
C21), 2.01 (m, 2H, protons of C11), 1.64 (m, 2H, protons of C8),
1.56 (m, 1H, proton of C10), 1.46 (m, 2H, protons of C9), 1.23
(m, 1H, proton of C10). 13C NMR (100 MHz, CDCl3) δ 149.44
(C12), 145.68 (C1), 135.09 (C16), 127.33 (C14), 126.11 (C13),
125.02 (C2 and C5), 124.16 (C15), 119.87 (C3 and C4), 118.51
Appl. Organometal. Chem. (2014)
Copyright © 2014 John Wiley & Sons, Ltd.
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A. Li et al.
(C17 and C20), 115.55 (C18 and C19), 44.23 (C6), 38.62 (C7 and
C11), 25.59 (C9), 22.66 (C8 and C10), 16.45 (C21). IR (KBr, cmÀ1):
v = 3448 (w), 3098 (m), 2927 (s), 2856 (m), 1497 (w), 1469 (w),
1440 (m), 1265 (w), 1240 (w), 1044 (m), 1018 (w), 846 (vs), 821
(vs), 708 (vs), 412 (w). Anal. Calcd for C21H24Cl2STi·0.05CH2Cl2:
C, 58.59; H, 5.63. Found: C, 58.31; H, 5.58%. The final product
contains about 0.04 equivalents of dichloromethane, as verified
by NMR spectroscopy.
C16 and C17), 5.86 (m, 2H, protons of C15 and C18), 5.72
(dd, 1H, J = 5.3, 2.7 Hz, proton of C5), 2.59 (t, 2H, J = 7.7 Hz,
protons of C19), 2.06 (m, 2H, protons of C7), 1.83 (s, 3H, protons
of C9), 1.48 (m, 2H, protons of C20), 1.30 (m, 2H, protons
of C21), 0.89 (t, 3H, J = 7.3 Hz, protons of C22), 0.77 (t, 3H,
J = 7.3 Hz, protons of C8). 13C NMR (100 MHz, CDCl3) δ 152.46
(C10), 141.02 (C1), 135.89 (C14), 126.99 (C12), 125.10 (C11),
123.73 (C13), 120.12 (C2), 118.42 (C5), 117.70 (C3), 116.18 (C4),
113.68 (C15), 112.94 (C18), 111.80 (C16), 109.56 (C17), 42.89
(C6), 38.65 (C7), 33.15 (C19), 30.04 (C20), 24.29 (C9), 22.58 (C21),
14.09 (C22), 9.25 (C8). IR (KBr, cmÀ1): v = 3449 (w), 3105 (w),
2953 (w), 2924 (m), 2857 (w), 1491 (w), 1459 (w), 1412 (w), 1379
(w), 1241 (w), 1048 (m), 837 (m), 688 (m). Anal. Calcd for
C22H28Cl2SZr: C, 54.30; H, 5.80. Found: C, 54.21; H, 5.85%.
Synthesis of (nBuCp)[Cp―C(Me)2―(2-C4H3S)]ZrCl2 (C5)
Synthesis of Cp[Cp―C(cyclo-C5H10)―(2-C4H3S)]ZrCl2 (C7)
The procedure was similar to the synthesis of titanocene C1
(except that it was recrystallized from hexane), using lithium salt
[Cp―C(Me)2― (2-C4H3S)]Li (0.367 g, 1.90 mmol) and (nBuCp)
ZrCl3·DME (0.785 g, 1.9 mmol). Zirconocene C5 was obtained as
1
a white solid in 40.3% yield (0.362 g); m.p. 117–118 °C. H NMR
(400 MHz, CDCl3): δ 7.16 (dd, 1H, J = 5.1 Hz, J = 1.0 Hz, proton of
C12), 6.93 (dd, 1H, J = 5.1, 3.6 Hz, proton of C11), 6.81 (dd, 1H,
J = 3.6, 1.0 Hz, proton of C10), 6.53 (t, 2H, J = 2.8 Hz, protons of
C3 and C4), 6.32 (t, 2H, J = 2.8 Hz, protons of C2 and C5), 6.05
(t, 2H, J = 2.7 Hz, protons of C15 and C16), 5.99 (t, 2H, J = 2.7 Hz,
protons of C14 and C17), 2.62 (t, 2H, J = 7.7 Hz, protons of C18),
1.83 (s, 6H, protons of C7 and C8), 1.51 (m, 2H, protons of C19),
1.32 (m, 2H, protons of C20), 0.90 (t, 3H, J = 7.3 Hz, protons of
C21). 13C NMR (100 MHz, CDCl3) δ 155.51 (C9), 141.13 (C1),
135.79 (C13), 126.82 (C11), 123.54 (C10), 123.53 (C12), 117.79
(C2 and C5), 115.42 (C3 and C4), 113.89 (C14 and C17), 112.54
(C15 and C16), 39.36 (C6), 33.12 (C18), 31.17 (C19), 30.09
(C7 and C8), 22.59 (C20), 14.08 (C21). IR (KBr, cmÀ1): v = 3449
(w), 3102 (w), 2963 (w), 2927 (w), 2856 (w), 1459 (w), 1381 (w),
1230 (w), 1040 (w), 847 (w), 820 (m), 707 (w). Anal. Calcd for
C21H26Cl2SZr: C, 53.37; H, 5.54. Found: C, 53.56; H, 5.50%.
The procedure was similar to the synthesis of titanocene C1
(except that it was recrystallized from toluene), using lithium salt
[Cp―C(cyclo-C5H10)―(2-C4H3S)]Li (0.728 g, 3.1 mmol) and
CpZrCl3·DME (1.090 g, 3.1 mmol). Zirconocene C7 was obtained
1
as a white solid in 35.1% yield (0.497 g); m.p. 216–217°. H NMR
(400 MHz, CDCl3): δ 7.30 (dd, 1H, J = 5.1, 1.0 Hz, proton of C15),
7.07 (dd, 1H, J = 5.1, 3.6 Hz, proton of C14), 6.99 (dd, 1H,
J = 3.6 Hz, J = 1.0 Hz, proton of C13), 6.53 (t, 2H, J = 2.8 Hz, protons
of C3 and C4), 6.33 (t, 2H, J = 2.8 Hz, protons of C2 and C5), 6.10
(s, 5H, protons of C16, C17, C18, C19 and C20), 2.56 (d, 2H,
J = 13.2 Hz, protons of C7), 1.98 (m, 2H, protons of C11), 1.64
(m, 2H, protons of C8), 1.57 (m, 1H, proton of C10), 1.47 (m, 2H,
protons of C9), 1.24 (m, 1H, proton of C10). 13C NMR (100 MHz,
CDCl3) δ 149.86 (C12), 143.03 (C1), 127.40 (C14), 126.13 (C13),
124.22 (C15), 116.38 (C16, C17, C18, C19 and C20), 115.50 (C2
and C5), 114.54 (C3 and C4), 43.48 (C6), 38.94 (C7 and C11),
25.63 (C9), 22.72 (C8 and C10). IR (KBr, cmÀ1): v = 3425 (w),
3097 (w), 3065 (w), 2930 (m), 2857 (w), 1655 (w), 1443 (w), 1070
(w), 1018 (w), 838 (w), 816 (vs), 711 (s). Anal. Calcd for
C20H22Cl2SZr: C, 52.61; H, 4.86. Found: C, 52.58; H, 5.00%.
Synthesis of (nBuCp)[Cp―C(MeEt)―(2-C4H3S)]ZrCl2 (C6)
Synthesis of (nBuCp)[Cp―C(cyclo-C5H10)―(2-C4H3S)]ZrCl2 (C8)
The procedure was similar to the synthesis of titanocene C1
(except that it was recrystallized from hexane), using lithium salt
[Cp―C(MeEt)―(2-C4H3S)]Li (0.456 g, 2.2 mmol) and (nBuCp)
ZrCl3·DME (0.897 g, 2.2 mmol). Zirconocene C6 was obtained as
a white solid in 44.5% yield (0.472 g); m.p. 94–95 °C. 1H NMR
(400 MHz, CDCl3): δ 7.23 (d, 1H, J = 5.0 Hz, proton of C13),
7.01 (t, 1H, J = 5.0 Hz, J = 4.8 Hz, proton of C12), 6.94 (d, 1H,
J = 3.3 Hz, proton of C11), 6.60 (m, 2H, protons of C3 and C4),
6.49 (d, 1H, J = 2.5 Hz, proton of C2), 6.02 (m, 2H, protons of
The procedure was similar to the synthesis of titanocene C1
(except that it was recrystallized from hexane), using lithium
salt [Cp―C(cyclo-C5H10)―(2-C4H3S)]Li (0.423 g, 1.8 mmol) and
(nBuCp)ZrCl3·DME (0.740 g, 1.8 mmol). Zirconocene C8 was
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Copyright © 2014 John Wiley & Sons, Ltd.
Appl. Organometal. Chem. (2014)

Thienyl-substituted group 4 metallocenes for ethylene polymerization
obtained as a white solid in 39.1% yield (0.361 g); m.p. 116–117 °
C. H NMR (400 MHz, CDCl3): δ 7.27 (d, 1H, J = 7.4 Hz, proton of
Acknowledgments
1
We are grateful for the support from the National Natural Science
Foundation of China (Nos. 21274041 and 20774027) and the key
project of the Chinese Ministry of Education (No. 109064).
C15), 7.05 (t, 1H, J = 4.8 Hz, proton of C14), 6.98 (d, 1H, J =
3.3 Hz, proton of C13), 6.50 (t, 2H, J = 2.6 Hz, protons of C3 and
C4), 6.29 (t, 2H, J = 2.6 Hz, protons of C2 and C5), 5.93 (t, 2H, J =
2.5 Hz, protons of C18 and C19), 5.74 (t, 2H, J = 2.5 Hz, protons
of C17 and C20), 2.59 (t, 2H, J = 7.7 Hz, protons of C21), 2.55 (d,
2H, J = 13.5 Hz, protons of C7), 1.99 (m, 2H, protons of C11),
1.64 (m, 2H, protons of C8), 1.56 (m, 1H, proton of C10), 1.48 (m,
4H, protons of C9 and C22), 1.30 (m, 2H, proton of C23), 1.23
(m, 1H, proton of C10), 0.89 (t, J = 7.4 Hz, 3H, proton of C24).
13C NMR (100 MHz, CDCl3) δ 150.09 (C12), 142.68 (C1), 135.67
(C16), 127.33 (C14), 125.97 (C13), 124.09 (C15), 118.15 (C2 and
C5), 114.84 (C3 and C4), 114.25 (C17 and C20), 112.24 (C18 and
C19), 43.44 (C6), 38.84 (C7 and C11), 33.14 (C21), 29.99 (C22),
25.65 (C9), 22.72 (C8 and C10), 22.57 (C23), 14.08 (C24). IR (KBr,
cmÀ1): v = 3448 (w), 3105 (w), 2927 (s), 2855 (m), 1492 (w),
1448 (w), 1413 (w), 1260 (w), 1044 (w), 935 (w), 840 (w), 812 (w),
688 (m). Anal. Calcd for C24H30Cl2SZr: C, 56.22; H, 5.90. Found: C,
56.31; H, 5.99%.
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Supporting Information
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version of this article at the publisher’s web-site.
Appl. Organometal. Chem. (2014)
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