Preparation of palladium complexes of 1,3-di(2-pyridyl)propane derivatives and their use in norbornene polymerization

Article abstract of DOI:10.1016/j.molcata.2003.09.005

A variety of neutral palladium(II) complexes [Pd(L-L)Cl₂] containing 1,3-di(2-pyridyl)propane (1), 1,3-bis(2-pyridyl)-2-pentylpropane (2), 1,3-bis(2-pyridyl)-2-phenylpropane (3a), 1,3-bis(2-pyridyl)-2-tolylpropane (4), and 1,3-bis(2-pyridyl)-2-ferrocenylpropane (5) as chelate ligands (L-L) have been synthesized. The crystal structures of 1,3-diphenyl-2,4-di-pyridin-2-yl- butan-1-ol (3b), 5, [(2)PdCl₂], [(4)PdCl₂], and [(5)PdCl₂] have been determined and show a square planar geometry at palladium(II). The neutral complexes were tested in the polymerization of norbornene and copolymerization of norbornene with norbornene derivatives. The complex bearing the pentyl group exhibited high reactivity to give up to 5.9×10⁵ in molecular weight for the homopolymerization. When [(4)PdCl₂] or [(5)PdCl₂] was used as a catalyst, homopolymers insoluble at 150°C in trichlorobenzene were obtained. However, copolymerization of norbornene with norbornene derivatives 8a-d catalyzed by [(4)PdCl₂] gave soluble copolymers with molecular weights up to 5.1×10⁵.

Full text of DOI:10.1016/j.molcata.2003.09.005

Journal of Molecular Catalysis A: Chemical 210 (2004) 35–46
Preparation of palladium complexes of 1,3-di(2-pyridyl)propane
derivatives and their use in norbornene polymerization
Dong Mok Shina, Seung Uk Sona, Bog Ki Honga, Young Keun Chunga,∗, Sung-Ho Chunb
a
School of Chemistry and Center for Molecular Catalysis, Seoul National University, Seoul 151-747, South Korea
b
LG Chem. Ltd., Science Park, Yu Seong, Science Town, Daejeon 305-380, South Korea
Received 3 September 2003; received in revised form 3 September 2003; accepted 9 September 2003
Abstract
A variety of neutral palladium(II) complexes [Pd(L–L)Cl2] containing 1,3-di(2-pyridyl)propane (1), 1,3-bis(2-pyridyl)-2-pentylpropane
(2), 1,3-bis(2-pyridyl)-2-phenylpropane (3a), 1,3-bis(2-pyridyl)-2-tolylpropane (4), and 1,3-bis(2-pyridyl)-2-ferrocenylpropane (5) as chelate
ligands (L–L) have been synthesized. The crystal structures of 1,3-diphenyl-2,4-di-pyridin-2-yl-butan-1-ol (3b), 5, [(2)PdCl2], [(4)PdCl2], and
[(5)PdCl2] have been determined and show a square planar geometry at palladium(II). The neutral complexes were tested in the polymerization
of norbornene and copolymerization of norbornene with norbornene derivatives. The complex bearing the pentyl group exhibited high reactivity
to give up to 5.9×105 in molecular weight for the homopolymerization. When [(4)PdCl2] or [(5)PdCl2] was used as a catalyst, homopolymers
insoluble at 150 ◦C in trichlorobenzene were obtained. However, copolymerization of norbornene with norbornene derivatives 8a–d catalyzed
by [(4)PdCl2] gave soluble copolymers with molecular weights up to 5.1 × 105.
© 2003 Elsevier B.V. All rights reserved.
Keywords: Neutral palladium(II) complexes; Norbornene; Polymerization; Dipyridyl
1. Introduction
ence the reactivity at the metal center. We now report the
synthesis and structural characterization of Pd(II) dichlo-
ride complexes bearing 1,3-di(2-pyridyl)propane deriva-
tives. Their behavior in norbornene polymerization is also
reported.
Recently, olefin polymerization by late transition metal
complexes has attracted much attention [1]. A prime ob-
jective of such research on olefin polymerization is the
design of catalysts capable of producing high molecular
weight products. A number of neutral and cationic Pd com-
plexes bearing chelating nitrogen ligands have received
significant attention as catalysts for olefin polymerization.
Previous studies were primarily devoted to complexes in-
corporating rigid chelating diimine [2], pyridylimine [3],
bipyridine-type ligands [4], bis(pyrazolyl)methane ligand
[5], tris(pyrazolyl)borata ligands [6], tridentate nitrogen
ligands with varying N-heterocycles [7], or imidazole [8].
Recently, a ligand-deficient, cationic palladium(II)-based
catalytic system was also reported [9]. During the course
of our study on the design of catalysts, we were interested
in investigating the coordination properties of a series of
1,3-di(2-pyridyl)propane-based ligands and in determining
how electronic and steric factors of these ligands influ-
2. Results and discussion
2.1. Preparation of 1,3-di(2-pyridyl)propane derivatives
1,3-Di(2-pyridyl)propane derivatives 1–5, which have the
same organic structural frame except for R, have been pre-
pared according to Eq. (1).
∗
Corresponding author. Tel.: +82-2-8806662; fax: +82-2-8890310.
E-mail address: ykchung@plaza.snu.ac.kr (Y.K. Chung).
(1)
1381-1169/$ – see front matter © 2003 Elsevier B.V. All rights reserved.
doi:10.1016/j.molcata.2003.09.005

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D.M. Shin et al. / Journal of Molecular Catalysis A: Chemical 210 (2004) 35–46
Compounds 1 and 3a were already known [10,11], but
in a polar organic solvent. Single crystals of [(2)PdCl2],
[(4)PdCl2], and [(5)PdCl2] were grown and their structures
were determined by X-ray diffraction studies. The molecu-
lar structures of [(2)PdCl2], [(4)PdCl2], and [(5)PdCl2] are
shown in Figs. 3–5. Selected crystallographic data, bond
lengths, and bond angles are summarized in Tables 1 and 2.
The structures are four coordinate, with ligation to the two
pyridyl nitrogens and two chlorides. The geometry about the
their previous syntheses were somewhat different from ours.
The yields for 2 and 5 were 63 and 89%, respectively. When
benzaldehyde and p-tolualdehyde were used as aldehyde
sources, the yields of 3a and 4 were not so good presumably
due to the formation of byproducts. When benzaldehyde re-
acted with lithiated 2-picoline, we observed the formation
of 3a and 3b in 28 and 21% yields, respectively (Eq. (2)).
(2)
palladium atom is best described as distorted square
planar. The eight-membered chelate ring is not pla-
nar but puckered. The Pd–N bond distances were ob-
served in the range of 2.024(4)–2.044(4) Å and those of
Pd–Cl in the range of 2.282(2)–2.3025(10) Å. Due to the
bichelating of the dipyridyl ligand, the bond angles of
N1–Pd–N2 were in the range of 86.2 (2)–87.73(14)◦ and
the observed bond angles of Cl1–Pd–Cl2 in the range
of 92.36(9)–93.41(4)◦. The bond angles of N1–Pd–N2
are larger than those in other Pd(II) complexes with
pyridinylimine and bipyridine chelating ligands [3,14] and
the bond angles of Cl1–Pd–Cl2 are smaller than those in
other Pd(II) complexes with pyridinylimine and bipyridine
chelating ligands [3,15], respectively. The angles between
the two pyridinyl rings for [(2)PdCl2], [(4)PdCl2], and
[(5)PdCl2] were 86.71(20), 83.99(12), and 79.68(20)◦,
When p-nitrobenzaldehyde was used as an aldehyde source,
the expected product was not obtained. Thus, the reaction
seems to be quite sensitive to the electronic effect of the
aldehyde used. The formation of 3b and 5 was established
by X-ray diffraction studies (Figs. 1 and 2). Selected crys-
tallographic data, bond lengths, and bond angles are sum-
marized in Tables 1 and 2.
2.2. Preparation of palladium(II) complexes
The Pd(II) complexes of [(1)PdCl2], [(2)PdCl2],
[(3a)PdCl2], [(4)PdCl2], and [(5)PdCl2] were prepared
in good yields (73–93%) by addition of 1 equivalent
Na2PdCl4 to the appropriate ligand in a solvent mixture of
nitromethane and methanol (v/v, 1:1; Eq. (3)). A related
palladium(II) complex of [(1)PdCl2] has been reported [12].
(3)
All the palladium complexes have been characterized by
1H NMR spectroscopy and elemental analysis. They are
very air-stable. Complex [(2)PdCl2] is quite soluble in a
polar organic solvent, such as dichloromethane, methanol,
nitromethane, and acetone, but other complexes are only
slightly soluble in nitromethane. It seems that the introduc-
tion of a long alkyl chain, such as a pentyl group, dra-
matically improves the solubility of the palladium complex
respectively. In [(5)PdCl2], the two cyclopentadienyl rings
are eclipsed.
2.3. Homopolymerization of Norbornene and
Copolymerization of Norbornene with 7a–d and 8a–d
The palladium-based catalysts [(1)PdCl2], [(2)PdCl2],
[(3a)PdCl2], [(4)PdCl2], and [(5)PdCl2] can be activated

D.M. Shin et al. / Journal of Molecular Catalysis A: Chemical 210 (2004) 35–46
37
Fig. 1. ORTEP drawing of 3b with 30% thermal ellipsoid.
Fig. 2. ORTEP drawing of 5 with 30% thermal ellipsoid.

38
D.M. Shin et al. / Journal of Molecular Catalysis A: Chemical 210 (2004) 35–46
Table 1
Crystal data and structure refinement for 3b, 5, [(2)PdCl2], [(4)PdCl2], and [(5)PdCl2]
3b
5
[(2)PdCl2]
[(4)PdCl2]
C20 20Cl2N2Pd
[(5)PdCl2]
Empirical formula
Formula weight
Crystal system
Space group
C26H24N2
380.47
O
C23
382.28
H
22FeN2
C
18H24Cl2N2Pd
H
C24H25 Cl2FeN3O2Pd
620.62
445.69
465.68
Monoclinic
P21/n
Monoclinic
P21/n
Triclinic
¯
P1
Monoclinic
P21/c
Orthorhombic
P212121
a (Å)
b (Å)
c (Å)
14.342(3)
5.8334(7)
25.509(8)
10.8813(3)
10.3638(2)
16.6638(5)
9.3084(3)
10.3100(5)
10.9166(4)
9.2050(5)
9.8800(6)
21.3810(9)
8.1797(4)
13.1367(6)
23.0830(6)
α (◦)
β (◦)
γ (◦)
90
105.62(2)
90
90
100.165(3)
107.261(3)
102.132(3)
90
90.630(3)
90
90
90
90
92.7324(15)
90
Volume (Å3)
Z
d (calculated, mg/m3)
θ range (◦)
2055.3(8)
4
1.230
1877.07(8)
4
1.353
945.59(6)
2
1.565
1944.39(18)
4
1.591
2480.37(18)
4
1.662
1.66–24.96
2.19–27.45
2.02–27.46
2.21–27.49
1.76–27.48
No. of total collection
No. of unique data
No. of params refined
2863
2757
358
7373
4096
232
7608
4274
211
5548
4067
226
4740
4740
288
R1
wR2
GOF
0.0533
0.1175
0.993
0.0401
0.1182
1.222
0.0421
0.1285
1.137
0.0371
0.1085
1.194
0.0601
0.1595
1.069
Table 2
Selected bond lengths (Å) and angles (◦) for 3b, 5, [(2)PdCl2], [(4)PdCl2], and [(5)PdCl2]
3b
C(14)–C(20) 1.543(5)
O(1)–C(20) 1.438(4)
C(20)–C(21) 1.512(5)
O(1)–C(20)–C(14) 111.0(3)
C(21)–C(20)–C(14) 111.6(3)
5
Fe(1)–C(6) 2.031(2)
N(1)–C(13) 1.334(4)
Fe(1)–C(1) 2.050(2)
N(2)–C(19) 1.341(3)
C(1)–C(11) 1.507(3)
C(1)–C(2) 1.440(3)
C(5)–C(1)–Fe(1) 69.22(12)
C(1)–C(11)–C(12) 112.15(17)
C(11)–C(1)–Fe(1) 128.15(15)
[(2)PdCl2]
Pd(1)–N(2) 2.034(4)
Pd(1)–N(1) 2.044(4)
N(1)–C(5) 1.342(6)
Cl(1)–Pd(1)–Cl(2) 92.87(6)
N(1)–Pd(1)–Cl(1) 89.66(11)
C(14)–C(12)–C(11) 112.3(11)
C(5)–N(1)–Pd(1) 121.8(3)
Pd(1)–Cl(1) 2.2910(12)
N(2)–C(6) 1.351(6)
Pd(1)–Cl(2) 2.2959(12)
C(12)–C(14) 1.478(10)
N(2)–Pd(1)–N(1) 87.73(14)
N(2)–Pd(1)–Cl(2) 89.65(11)
C(1)–N(1)–Pd(1) 117.6(3)
[(4)PdCl2]
Pd–N(1) 2.024(3)
Pd–N(2) 2.036(3)
N(1)–C(5) 1.344(4)
N(1)–Pd–N(2) 87.13(11)
N(2)–Pd–Cl(1) 89.69(9)
C(5)–N(1)–Pd 121.8(2)
C(14)–C(13)–C(6) 110.0(3)
Pd–Cl(2) 2.2990(10)
N(2)–C(11) 1.346(4)
Pd–Cl(1) 2.3025(10)
C(13)–C(14) 1.525(4)
N(1)–Pd–Cl(2) 89.78(9)
Cl(2)–Pd–Cl(1) 93.41(4)
C(1)–N(1)–Pd 117.7(3)
[(5)PdCl2]
Pd(1)–N(1) 2.025(6)
Pd(1)–Cl(2) 2.283(2)
C(1)–C(11) 1.495(8)
N(1)–Pd(1)–N(2) 86.2(2)
Cl(1)–Pd(1)–Cl(2) 92.36(9)
C(2)–C(1)–C(11) 128.8(7)
C(13)–N(1)–Pd(1) 122.7(4)
Pd(1)–N(2) 2.041(6)
Fe(1)–C(1) 2.060(7)
N(1)–C(13) 1.350(9)
N(1)–Pd(1)–Cl(2) 91.51(18)
N(2)–Pd(1)–Cl(1) 89.88(18)
C(17)–N(1)–Pd(1) 117.5(5)
C(1)–C(11)–C(12) 105.2(5)
Pd(1)–Cl(1) 2.282(2)
Fe(1)–C(6) 2.062(9)
N(2)–C(19) 1.341(9)

D.M. Shin et al. / Journal of Molecular Catalysis A: Chemical 210 (2004) 35–46
39
Table 3
Norbornene homopolymerization resulta
Table 4
Copolymerization of norbornene and monomers with functionalitya
Entry Ratiob
Monomer Mw
Mn
1600 1.06
5200 2.02
7100 2.42
Mw/Mn Yield (%)c
Catalyst
Mw
Mn
Mw/Mn
Yield (%)b
d
1
2
3
4
–
–
7a
7b
7c
1700
10500
17200
20
75
83
70
1
2
3
4c
5c
[(1)PdCl2]
[(2)PdCl2]
[(3a)PdCl2]
[(4)PdCl2]
[(5)PdCl2]
329000
593600
457000
–
112900
216800
154100
–
2.91
2.74
2.97
–
99
99
99
99
99
d
30:1e
15.5:1e 7d
42700 11000 3.88
a
–
–
–
Reaction conditions: [(4)PdCl2]-catalyst 0.1 mol%; MAO/catalyst
= 1000; monomer ratio 1:5; r.t., 6 h in toluene.
a
Reaction conditions: catalyst 0.1 mol%; MAO/catalyst = 1000; r.t.,
b
Ratio calculated by [1H] NMR (norbornene: monomer 7).
5 min in toluene.
c
Isolated yield.
Cannot be calculated by [1H] NMR.
b
Isolated yield.
Insoluble polymer at 150 ◦C in 1,2,4-trichlorobenzene.
d
c
e
Ratio calculated by [1H] NMR in 1,2-dichlorobenzene-d4 at 150 ◦C.
for norbornene polymerization with methylaluminoxane.
Polymerization results and conditions are summarized in
Table 3.
to 7a–d was 5:1, copolymers, showing a poor solubility in
tetrahydrofuran (THF), chloroform, and dichloromethane,
were formed in reasonable yields (70–83%) except for 7a
(20%). In the case of 7a (entry 1), the molecular weight
was only 1700. For 7b–d, the molecular weight ranged from
10,500 to 42,700. The ratios of norbornene to 7c–d in the
copolymers were 30:1 and 15.5:1, respectively. Thus, the
copolymers derived from 7c or 7d consisted of a large frac-
tion of nobornene and a very small fraction of 7c–d. The
GPC profiles of the copolymers did not show a perfect
uni-modal shape, but it looked like two humps, sometimes
merged. The CDCl3-soluble parts of the copolymers derived
from 7c and 7d showed that the ratios of norbornene to 7c
and 7d were 10:1 and 5:1, respectively, meaning that the
copolymers were composed of at least two kinds of poly-
mers. Thus, the use of 7a–d as a monomer in the copolymer-
ization of norbornene was unsuccessful. The low contents
The reaction was completed at room temperature within
5 min. Up to 100% monomer conversion was observed. Poly-
mers obtained were white powdery solids. The molecular
weights of the polynorbornenes were not determined at room
temperature because of their insolubility. Instead, the molec-
ular weights of the polynorbornenes were determined by the
high temperature GPC in 1,2,4-trichlorobenzene at 150 ◦C.
In the cases of [(1)PdCl2], [(2)PdCl2], and [(3a)PdCl2],
molecular weights in the range of 330,000–590,000 were
determined. For the other two cases, we could not achieve
high temperature GPC data due to poor solubility.
Next, we prepared norbornene derivatives 7a–d using
the intermolecular Pauson–Khand reaction products to use
them as monomers in the copolymerization with norbornene
(Eq. (4)).
(4)
Syntheses of 7a–d were previously reported by us [13].
We examined copolymerization of norbornene with 7a–d
using [(4)PdCl2] (0.1 mol%) as a catalyst in toluene for 6 h
(Eq. (5) and Table 4).
(5)
The ratios of 1:1 and 5:1 of norbornene to 7a–d were used.
When the ratio of norbornene to 7a–d was 1:1, formation of
copolymers was not observed. When the ratio of norbornene

40
D.M. Shin et al. / Journal of Molecular Catalysis A: Chemical 210 (2004) 35–46
of 7a–d in the copolymers and the low molecular weight of
the copolymers were presumably due to the polar functional
group in 7a–d as observed in other palladium(II)-catalyzed
copolymerization with norbornene derivatives having polar
functional groups [16]. Thus, we tried to remove a ketone
group from 7a–d.
Compounds 8a–d were prepared in high yields by the
reaction of 7a–d with zinc dust in the presence of TiCl4
(Eq. (6)).
(6)
We examined copolymerization of norbornene with 8a–d
using [(4)PdCl2] (0.1 mol%) as a catalyst in toluene for 1 h
(Table 5). Ratios of 1:1 and 5:1 of norbornene to 8a–d were
used. Copolymers from the 1:1 ratio of norbornene to 8a–d,
which are soluble in THF, chloroform, and dichloromethane,
were formed in reasonable yields (63–66%). The 1H and 13
C
Fig. 3. ORTEP drawing of [(2)PdCl2] with 50% thermal ellipsoid.
NMR spectra of a monomer and copolymer of 8a are shown
in Fig. 6. The 1H NMR spectra showed that the actual ratios
of norbornene to 8a–d were 1.2:1, 2.4:1, 3.3:1, and 1.6:1
for 8a, 8b, 8c, and 8d, respectively. Thus, the compositions
Fig. 4. ORTEP drawing of [(4)PdCl2] with 30% thermal ellipsoid.

D.M. Shin et al. / Journal of Molecular Catalysis A: Chemical 210 (2004) 35–46
41
Fig. 5. ORTEP drawing of [(5)PdCl2] with 30% thermal ellipsoid.
of copolymers for 8a and 8d were close to the ratios of
the used reactants. According to GPC data, the molecular
weight of the copolymers ranged from 96,200 to 332,600.
When 8b was used as a monomer, the highest molecular
weight (332,600) was obtained. It seems that the molecu-
lar weight of the copolymers depended upon the bulkiness
of the monomer used. The order of the molecular weight
of the copolymers was 8b > 8d > 8a > 8c. Copolymers
from the 5:1 ratio of norbornene to 8a–d, which are insol-
uble in organic solvents at room temperature, were formed
in high yields (75–98%). The actual ratios of norbornene
to 8a–d were determined by high temperature 1H NMR
Fig. 6. [1H] and [13C] NMR spectra of: (a) and (c) monomer 8a; and (b) and (d) copolymer of 8a and norbornene with the ratio of 1:1.

42
D.M. Shin et al. / Journal of Molecular Catalysis A: Chemical 210 (2004) 35–46
Table 5
or vacuum-line techniques. Freshly distilled, dry, and
oxygen-free solvents were used throughout. 1H NMR spec-
tra were obtained with a Bruker 300 or 500 spectrome-
ter. Elemental analyses were done at National Center for
Inter-University Research Facilities, Seoul National Univer-
sity, Seoul. Molecular weight and molecular weight distri-
butions were measured by gel permeation chromatography
(GPC) relative to polystyrene standards. Thermal gravi-
metric analysis (TGA) was carried out on TA Instrument
(TGA 2050; heating rate: 10 K/min). Infrared spectra were
recorded on a JASCO FT/IR-660 spectrometer. Anhydrous
toluene, tetrahydrofuran, diethyl ether, and dichloromethane
were used. Methylalumoxane (MAO) was purchased as a
solution in toluene from Akzo (10 wt.% of Al, MMAO
type 4). Compound 1 was previously reported by Leonard
and Boyer [10(a)], Sartoris and Pines [10(b)] and 3a by
Bloc and co-workers [11], and 7a–d were prepared by the
published procedure [13].
Copolymerization of norbornene with new monomersa
Entry Ratiob Ratioc Monomer Mw
Mn
Mw/Mn Yield
(%)d
1
2
3
4
5
6
7
8
1:1
5:1
1:1
5:1
1:1
5:1
1:1
5:1
1.2:1
5.3:1e 8a
2.4:1 8b
7.6:1e 8b
3.3:1 8c
7.2:1e 8c
1.6:1 8d
5.5:1e 8d
8a
125700
56700 2.22
63
98
66
88
66
75
66
98
389500 161800 2.41
332600 121300 2.74
505600 176500 2.86
96200
137400
162100
36000 2.67
53800 2.55
63800 2.54
403000 172800 2.33
a
Reaction conditions: [(4)PdCl2]-catalyst 0.1 mol%; MAO/catalyst
= 1000; r.t., 1 h in toluene.
b
Ratio of reactants (norbornene: monomer 8).
c
Ratio calculated by [1H] NMR.
d
Isolated yield.
e
Ratio calculated by [1H] NMR in 1,2-dichlorobenzene-d4 at 150 ◦C.
spectroscopy in deuterated 1.2-dichlorobenzene. The ratios
of norbornene to 8a–d were 5.3:1, 7.6:1, 7.2:1, and 5.5:1 for
8a, 8b, 8c, and 8d, respectively. The high temperature GPC
data show that the molecular weights of copolymers were
from 137,400 to 505,600. When 8b was used as a monomer,
the highest molecular weight (505,600) was obtained. The
order of the molecular weight of the copolymers was 8b >
8d–a > 8c. Thus, the same trend was observed. Compared
to the homopolymerization of norbornene by the same cata-
lyst [(4)PdCl2], the introduction of 8a–d to the polymer may
relax the steric rigidity or regularity of the homopolymer
and produces soluble copolymers of high molecular weight
at room temperature or at high temperature depending upon
the ratio of norbornene to 8a–d.
4.2. Synthesis of 1,3-di(2-pyridyl)propane derivatives
4.2.1. Synthesis of 2
Diisoproyl amine (3.8 ml, 2.7 mmol) and n-BuLi (11.4 ml,
2.5 M in hexane) were dissolved in 60 ml of THF in a
Schlenk flask at −78 ◦C. After the solution was stirred for
30 min at −78 ◦C, 2-picoline (2.5 ml, 25 mmol) was added
to it. The solution was allowed to warm to room tempera-
ture and stirred for 30 min. To the solution was added hex-
anal (1.0 ml, 8.3 mmol). The resulting solution was stirred
overnight and quenched with water (100 ml). After wash-
ing with saturated NaHCO3 (100 ml), CH2Cl2 (100 ml) was
added to extract the dipyridyl compound. The CH2Cl2 layer
was dried over anhydrous MgSO4, concentrated, and chro-
matographed on a silica gel column eluting with hexane and
diethyl ether (1:1 (v/v)). Removal of the solvent gave the
product in 63% yield (1.40 g, 5.2 mmol). 1H NMR (CDCl3)
δ 8.50 (d, 4.9 Hz, 2H), 7.53 (t, 7.6 Hz, 2H), 7.13 (d, 7.7 Hz,
2H), 7.06 (t, 4.9 Hz, 2H), 2.78 (m, 4H), 2.50 (m, 1H),
1.34–1.17 (m, 8H), 0.82 (t, 6.8 Hz, 3H) ppm; 13C NMR
(CDCl3) δ 162.0, 149.9, 136.8, 124.5, 121.7, 43.6, 40.3, 34.2,
32.8, 27.0, 23.4, 14.9 ppm; HRMS M+ calculated: 268.1939;
observed: 268.1923.
The TGA and DSC study show that copolymers are stable
up to 420 ◦C without noticeable loss of weight. Neither Tm
nor Tg was observed in the range of 20–400 ◦C.
3. Conclusion
A very reactive catalyst system for vinyl-type poly-
merization of norbornene can be obtained by addition of
MAO to Pd(II)–dipyridyl complexes. The polynorbornene
is, however, insoluble in chlorobenzene. Copolymerization
of norbornene and norbornene derivatives 8a–d produces
soluble copolymers in good yields. Due to the ease of struc-
tural variations of their ligand systems the Pd(II)–dipyridyl
complexes might open the way to a new family of late
transition metal cycloolefin polymerization catalysts.
4.2.2. Synthesis of 3a
The same procedure as the synthesis of 2 was applied
except for the use of benzaldehyde instead of hexanal and
elution with diethyl ether and methanol (10:1 (v/v)) instead
of hexane and diethyl ether (1:1 (v/v)). A mixture of 3a
and 3b was obtained as products. Compounds 3a and 3b
have quite similar Rf values in chromatography. To obtain
pure 3a and 3b, a mixture of 3a and 3b was first separated
from other compounds via a chromatography on a silica gel
column eluting with diethyl ether and methanol (10:1 (v/v)).
Compounds 3a and 3b have quite different solubilities in
diethyl ether: 3a is quite soluble but 3b is insoluble. After
removal of the solvent, the solid was put in diethyl ether
4. Experimental
4.1. General
All manipulations of air- and/or moisture-sensitive com-
pounds were carried out with use of standard Schlenk

D.M. Shin et al. / Journal of Molecular Catalysis A: Chemical 210 (2004) 35–46
43
and the solution was stirred for 30 min. Filtration gave 3b
as a solid and 3a could be obtained from the filtrate. The
yields of 3a and 3b were 28 and 21%, respectively. 3a:
1H NMR (CDCl3) δ 8.45 (d, 3.2 Hz, 2H), 7.35 (t, 7.8 Hz,
2H), 7.11 (m, 5H), 6.93 (m, 4H), 3.73 (m, 1H), 3.19 (m,
4H) ppm; 13C NMR (CDCl3) δ 161.0, 150.0, 144.7, 136.9,
129.1, 128.6, 127.1, 124.6, 121.9, 47.3, 45.8 ppm; HRMS
M+ calculated: 274.1470, observed: 274.1472. 3b: 1H NMR
(CDCl3) δ 8.62 (d, 4.8 Hz, 1H), 8.36 (d, 4.8 Hz, 1H), 7.41
(m, 3H), 7.28 (m, 2H), 7.17 (m, 2H), 7.07 (m, 3H), 6.85
(m, 4H), 6.72 (d, 7.8 Hz, 1H), 6.33 (d, 7.8 Hz, 1H), 4.68 (d,
9.0 Hz, 1H), 4.17 (td, 11.6, 4.3 Hz, 1H), 3.30 (d, 11.2 Hz,
1H), 2.93 (t, 13.3 Hz, 1H), 2.71 (dd, 13.7, 4.4 Hz, 1H) ppm.
Analytically calculated for C26H24N2O: C, 82.07; H, 6.36;
N, 7.41. Found: C, 82.23; H, 6.48; N, 7.41.
for C13H14Cl2N2Pd: C, 41.57; H, 3.76: N, 7.46. Found: C,
41.45; H, 3.67; N, 7.17.
4.3.2. Synthesis of [(2)PdCl2]
The same procedure as the synthesis of [(1)PdCl2] was
applied. However, the precipitation did not occur within
2 h. After the solution was stirred 5 h, the solution was
poured into excess diethyl ether to get precipitates. The
precipitate was filtered, washed two times with water, and
1
dried in vacuo. Yield: 90%. H NMR (CDCl3) δ 9.14 (d,
5.3 Hz, 2H), 7.57 (t, 7.7 Hz, 2H), 7.24–7.16 (m, 4H), 4.87
(dd, 13.7, 9.8 Hz, 2H), 3.36 (t, 13.8 Hz, 2H), 1.86–1.31 (m,
8H), 0.98 (t, 6.8 Hz, 3H) ppm; 13C NMR (DMSO-d6) δ
163.79, 152.17, 140.31, 127.41, 124.61, 47.47, 44.22, 32.44,
26.50, 23.00, 22.55, 14.95 ppm. Analytically calculated for
C18H24Cl2N2Pd: C, 48.50; H, 5.43: N, 6.28. Found: C,
48.56; H, 5.39; N, 5.93.
4.2.3. Synthesis of 4
The same procedure as the synthesis of 2 was applied ex-
cept for the use of p-tolualdehyde instead of hexanal and
elution with diethyl ether and methanol (10:1 (v/v)) instead
of hexane and diethyl ether (1:1 (v/v)). Yield: 36%. 1H
NMR (CDCl3) δ 8.47 (d, 4.9 Hz, 2H), 7.43 (t, 7.7 Hz, 2H),
7.03–6.93 (m, 8H), 3.70 (, 7.0 Hz, 1H), 3.16 (m, 4H), 2.24 (s,
3H) ppm; 13C NMR (CDCl3) δ 161.2, 150.0, 141.2, 136.9,
136.4, 129.8, 128.5, 124.6, 121.9, 46.8, 45.9, 22.0 ppm;
HRMS M+ calculated: 288.1626; observed: 288.1622.
4.3.3. [(3a)PdCl2]
Yield: 73%. H NMR (CD3NO2) δ 8.94 (d, 5.9 Hz, 2H),
1
7.70 (m, 4H), 7.50 (m, 4H), 7.29 (m, 3H), 5.18 (t, 13.2,
11.3 Hz, 2H), 3.63 (d, 13.7 Hz, 2H), 3.38 (m, 1H) ppm; 13
C
NMR (DMSO-d6) δ 162.61, 153.39, 141.27, 129.32, 128.83,
127.39, 125.97, 124.94, 123.76, 48.68, 47.87 ppm. Analyti-
cally calculated for C19H18Cl2N2Pd: C, 50.52; H, 4.02: N,
6.25. Found: C, 50.13; H, 4.00; N, 6.20.
4.2.4. Synthesis of 5
4.3.4. [(4)PdCl2]
Yield: 93%. H NMR (CD3NO2) δ 8.93 (d, 6.2 Hz, 2H),
1
The same procedure as the synthesis of 2 was applied ex-
cept for the use of ferrocenecarboxaldehyde instead of hex-
anal and elution with diethyl ether instead of hexane and
7.73 (t, 7.5 Hz, 2H), 7.54 (d, 8.0, 2H), 7.44 (d, 7.4 Hz, 2H),
7.29 (m, 4H), 5.15 (m, 2H), 3.60 (d, 13.2 Hz, 2H), 3.30 (t,
10.8 Hz, 1H) ppm. We could not take the 13C NMR spectrum
because of its poor solubility in any deuterated solvents.
Analytically calculated for C20H20Cl2N2Pd: C, 50.52; H,
4.02: N, 6.25. Found: C, 50.13; H, 4.00; N, 6.20.
1
diethyl ether (1:1 (v/v)). Yield: 89%. H NMR (CDCl3) δ
8.51 (d, 4.9 Hz, 2H), 7.49 (t, 7.7 Hz, 2H), 7.04 (m, 4H), 4.12
(s, 5H), 3.99 (s, 2H), 3.83 (s, 2H), 3.56 (m, 1H), 3.16 (dd,
13.5, 6.2 Hz, 2H), 2.96 (dd, 13.5, 8.0 Hz, 2H) ppm. Analyti-
cally calculated for C23H22FeN2: C, 72.26; H, 5.80: N, 7.33.
Found: C, 72.11; H, 5.82; N, 7.20.
4.3.5. [(5)PdCl2]
1
Yield: 79%. H NMR (CD3NO2) δ 8.91 (d, 4.0 Hz, 2H),
4.3. Synthesis of palladium(II) complexes
7.74 (t, 7.7 Hz, 2H), 7.45 (d, 7.6, 2H), 7.28 (t, 4.4 Hz, 2H),
4.93 (m, 2H), 3.89 (d, 13.3 Hz, 2H), 3.12 (m, 1H) ppm. (We
could not assign the peak positions of Cp protons because of
overlapping with the solvent peaks.) 13C NMR (DMSO-d6)
δ 162.68, 152.30, 140.40, 127.85, 126.29, 124.85, 96.12,
69.52, 68.45, 67.34, 48.74 ppm. Analytically calculated for
C23H22Cl2FeN2Pd: C, 46.45; H, 4.06: N, 6.77. Found: C,
46.41; H, 3.87; N, 6.12.
4.3.1. Synthesis of [(1)PdCl2]
Compound 1 (0.20 g, 1.0 mmol) was dissolved in a mix-
ture solvent of methanol (5.0 ml) and nitromethane (5.0 ml)
at room temperature. Na2PdCl4·3H2O (0.35 g) was added to
the solution. In the beginning, Na2PdCl4·3H2O was com-
pletely dissolved in the solvent. After the solution was stirred
for 1 h, precipitation started. After stirring for an additional
1 h, the precipitate was filtered, successively washed with
methanol and water, and dried in vacuo. 0.85 g of the product
(88%) was obtained. 1H NMR (CD3NO2) δ 8.89 (d, 4.8 Hz,
2H), 7.69 (t, 8.7 Hz, 2H), 7.34 (d, 8.2 Hz, 2H), 7.25 (t, 6.5 Hz,
2H), 4.70 (t, 13.1 Hz, 2H), 3.56 (d, 7.9 Hz, 2H), 2.91 (1H),
1.96 (1H) ppm (the splitting patterns of the peaks at 2.91
and 1.96 ppm were obscure due to the line-broadening). We
could not take the 13C NMR spectrum because of its poor
solubility in any deuterated solvents. Analytically calculated
4.4. Crystal structure determinations of 3b, 5, [(2)PdCl2],
[(4)PdCl2], and [(5)PdCl2]
Single crystals of 3b were grown by slow evaporation of
3b in a solution mixture of methanol and dichloromethane,
single crystals of 5 by slow diffusion of diethyl ether to a so-
lution of 5 in dichloromethane, single crystals of [(2)PdCl2]
by slow evaporation of diffusion of dichloromethane solution
of [(2)PdCl2], single crystals of [(4)PdCl2] by slow diffusion

44
D.M. Shin et al. / Journal of Molecular Catalysis A: Chemical 210 (2004) 35–46
of methanol solution of Na2PdCl4 to a nitromethane solu-
tion of 4, and single crystals of [(5)PdCl2] by slow diffusion
of methanol solution of Na2PdCl4 to a nitromethane solu-
tion of 5, respectively. Diffraction for 3b was measured by
an Enraf–Nonius CAD4 automated diffractometer with an
ω/2θ scan method. Unit cells were determined by centering
25 reflections in the appropriate 2θ range. Other relevant
experimental details are listed in Table 1. Diffraction data
for other compounds were collected on an Enraf–Nonius
CCD single crystal X-ray diffractometer. The structures
were solved by SHELXS-97 and refined by full-matrix
least-squares with SHELXL-97 [14]. All non-hydrogen
atoms were refined anisotropically. All hydrogen atoms in
3b were found in Fourier map and refined. The other hydro-
gen atoms were refined isotropically using the riding model
with 1.2 times the equivalent isotropic temperature factors
of the atoms to which they are attached. Crystallographic
data for the structural analysis has been deposited with
the Cambridge Crystallographic Data Centre, CCDC No.
194993 194989, 194990, 194991and 194992 for compound
3b, 5, [(2)PdCl2], [(4)PdCl2], and [(5)PdCl2], respectively.
50.58, 47.55, 46.27, 44.28, 35.26, 30.73, 23.48, 14.45 ppm;
HRMS (M+) calculated: 278.2035, observed: 278.2036.
8d: Yield: 88%; 1H NMR (CDCl3): δ 7.32–7.13 (m, 5H),
6.17 (s, 2H), 4.86 (t, 2.4 Hz, 1H), 4.29 (t, 2.4 Hz, 1H), 3.26
(d, 10.9 Hz, 1H), 2.87 (s, 1H), 2.67 (s, 1H), 2.59 (d, 8.7 Hz,
1H), 1.71 (t, 8.3 Hz, 1H), 1.63 (m, 1H), 1.57 (d, 9.0 Hz,
1H), 1.42 (d, 8.7 Hz, 1H), 0.97 (d, 6.3 Hz, 3H) ppm; 13C
NMR (CDCl3): δ 158.66, 141.69, 138.64, 137.86, 129.41,
128.62, 126.78, 105.33, 64.13, 51.97, 50.48, 46.12, 46.08,
45.89, 44.43, 19.13 ppm; HRMS (M+) calculated: 236.1565,
observed: 236.1563.
4.6. Homopolymerization of norbornene
4.6.1. Typical procedures
In a glove box, to a solution of [(1)PdCl2] (4.0 mg,
0.011 mmol) in 10 ml of toluene were added norbornene
(1.0 g, 11 mmol) and MAO (7.0 ml). The reaction was com-
pleted within 5 min. The reaction flask was taken from the
glove box and treated with MeOH to quench excess MAO.
The synthesized polymer was added to a solution mixture
of MeOH and HCl (1:1 (v/v)) and stirred for 30 min. Filtra-
tion followed by washing with MeOH gave polymers in a
quantitative yield.
4.5. Synthesis of norbornene derivatives 8a–d
To a solution of Zn dust (4.8 g, 0.073 mol) and CH2Br2
(2.5 ml) in 30 ml of THF at −40 ◦C was slowly added TiCl4
(2.0 ml, 0.019 mol). After the solution was stirred at 5 ◦C
for 3 days, a solution of 7a (2.58 g, 9.9 mmol) in 20 ml
of CH2Cl2 was added. The resulting solution was stirred
overnight and poured into 200 ml of aqueous saturated
NaHCO3 solution. Extraction with diethyl ether followed
by chromatography on a silica gel column eluting with hex-
ane:diethyl ether (20:1 (v/v)) gave 8a in 89% yield (2.28 g).
4.7. Copolymerization of norbornene with 7a–d and 8a–d
4.7.1. Typical procedures for the synthesis of 5:1 copolymer
In a glove box, to a solution of [(4)PdCl2] (5.0 mg,
0.011 mmol) in 10 ml of toluene were added norbornene
(1.0 g, 0.011 mol) and 8c (0.60 g, 2.3 mmol). To the so-
lution was added MAO (7.0 ml). The reaction flask was
taken from the glove box and treated with MeOH to quench
excess MAO. The synthesized polymer was added to a so-
lution mixture of MeOH and HCl (1:1 (v/v)) and stirred for
30 min. Filtration followed by washing with MeOH gave
polymers.
1
8a: H NMR (CDCl3): δ 6.12 (m, 2H), 481 (t, 2.5 Hz,
1H), 4.72 (t, 2.5 Hz, 1H), 2.76 (s, 1H), 2.54 (s, 1H), 2.42 (d,
8.9 Hz, 1H), 2.17 (m, 1H), 1.61 (t, 7.3 Hz, 1H), 1.51–1.29
(m, 15H), 0.91 (m, 6 H) ppm; 13C NMR (CDCl3): δ 158.05,
138.65, 137.54, 102.08, 54.33, 50.78, 50.42, 47.53, 47.18,
46.24, 43.98, 35.48, 30.73, 29.59, 29.21, 23.83, 23.64, 14.52,
14.46 ppm; HRMS (M+) calculated: 258.2348, observed:
258.2351.
1
Entry 1 in Table 4: H NMR (1,2-dichlorobenzene-d4 at
150 ◦C): δ 2.9–2.2 [br m (2.38 maximum)], 2.2–1.7 [br m
(2.05 maximum)], 1.7–1.5 [br m (1.59 maximum)], 1.5–1.2
[br m (1.39 maximum)], 1.20 (br s), 1.07 (br s), 0.96 (br
s) ppm; 13C NMR (1,2-dichlorobenzene-d4 at 150 ◦C): δ
57–50 (br m), 58–40 (br m), 40–38 (br m), 37–35 (br
8b: Yield: 82%; 1H NMR (CDCl3): δ 6.05 (t, 1.9 Hz,
2H), 4.73 (t, 2.5 Hz, 1H), 4.65 (t, 2.6 Hz, 1H), 2.70 (s, 1H),
2.48 (s, 1H), 2.33 (d, 8.9 Hz, 1H), 2.02 (m, 1H), 1.48–1.43
(m, 3H), 1.27–1.22 (m, 6H), 0.99 (d, 2.3 Hz, 3H), 0.83
(t, 6.8 Hz, 3H) ppm; 13C NMR (CDCl3): δ 157.96, 138.60,
137.64, 102.06, 55.62, 52.39, 50.08, 45.96, 45.93, 44.16,
42.54, 29.30, 23.86, 19.74, 14.53 ppm; HRMS (M+) calcu-
lated: 216.1878; observed: 216.1874.
m), 33–27 (br m), 17.5 (br s), 13.5 (br s) ppm; IR νCO
:
1735.6 cm−1
.
1
Entry 2 in Table 4: H NMR (1,2-dichlorobenzene-d4 at
150 ◦C): δ 2.8–1.7 [br m (2.38 maximum)], 1.7–1.4 [br m
(1.58 maximum)], 1.4–1.1 [br m (1.37 maximum)], 0.94
(br s) ppm; 13C NMR (1,2-dichlorobenzene-d4 at 150 ◦C):
δ 56–54 (br m), 54–47 (br m), 47–37 (br m), 36–33 (br
8c: Yield: 81%; 1H NMR (CDCl3): δ 7.31–7.13 (m, 5H),
6.18 (s, 2H), 4.85 (t, 2.7 Hz, 1H), 4.25 (t, 2.7 Hz, 1H), 3.33
(d, 11.7 Hz, 1H), 2.86 (s, 1H), 2.66 (s, 1H), 2.58 (d, 8.8 Hz,
1H), 2.20 (m, 1H), 1.77 (t, 8.4 Hz, 1H), 1.57 (d, 8.5 Hz, 1H),
1.40 (d, 7.3 Hz, 1H), 1.44–1.17 (m, 6H), 0.81 (t, 7.2 Hz,
3H) ppm; 13C NMR (CDCl3): δ 159.03, 142.23, 138.72,
137.78, 129.50, 128.60, 126.74, 105.31, 63.10, 50.65, 50.60,
m), 32–25 (br m), 23 –20 (br m), 15.2 (br s) ppm; IR νCO
:
1744.3 cm−1
.
Entry 3 in Table 4: 1H NMR (1,2-dichlorobenzene-d4
at 150 ◦C): δ 7.3–7.0 (br m), 2.9–2.2 [br m (2.35 max-
imum)], 2.2–1.9 [br m (2.03 maximum)], 1.9–1.6 [br m
(1.70 maximum)], 1.57 (br s), 1.33 (br s), 1.2–0.7 [br m

D.M. Shin et al. / Journal of Molecular Catalysis A: Chemical 210 (2004) 35–46
45
(1.01 maximum)] ppm; 13C NMR (1,2-dichlorobenzene-d4
at 150 ◦C): δ 128–126 (br m), 79.2 (br s), 58–50 (br m),
48–38 (br m), 36.1 (br s), 35–26 (br m), 22.8 (br s), 17.5
1
Entry 6 in Table 5: H NMR (1,2-dichlorobenzene-d4 at
150 ◦C): δ 4.97 (br s), 4.85 (br s), 2.9–2.2 [br m (2.38 maxi-
mum)], 2.2–1.9 [br m (2.06 maximum)], 1.9–1.4 [br m (1.59
maximum)], 1.37 (br s), 1.19 (br s), 0.95 (br s) ppm; 13C
NMR (1,2-dichlorobenzene-d4 at 150 ◦C): δ 66–50 (br m ),
50–47 (br m), 47–41 (br m), 36.3 (br s), 34–28 (br m), 26.3
(br s), 22.9 (br s), 21.2 (br s), 13.7–12.5 (br m) ppm.
(br s), 13.4 (br s) ppm; IR νCO: 1747.2 cm−1
.
1
Entry 4 in Table 4: H NMR (1,2-dichlorobenzene-d4 at
150 ◦C): δ 7.3–7.0 (br m), 3.0–2.2 [br m (2.35 maximum)],
2.2–1.9 [br m (1.96 maximum)], 1.9–1.5 [br m (1.58 max-
imum)], 1.5–1.3 [br m (1.27 maximum)], 1.3–0.6 [br m
(1.02 maximum)] ppm; 13C NMR (1,2-dichlorobenzene-d4
at 150 ◦C): δ 129–126 (br m), 78.3 (br m), 65.3 (br s), 60–48
(br m), 48–39 (br m), 38.1 (br s), 36.2 (br s), 35–26 (br m),
1
Entry 7 in Table 5: H NMR (1,2-dichlorobenzene-d4 at
150 ◦C): δ 7.2–7.0 (br m), 5.03 (br s), 4.38 (br s), 3.0–2.1
[br m (2.37 maximum)], 2.1–1.7 [br m (1.89 maximum)],
1.7–1.4 [br m (1.58 maximum)], 1.4–1.0 [br m (1.34 max-
imum)], 1.0–0.7 [br m (0.81 maximum)] ppm; 13C NMR
(1,2-dichlorobenzene-d4 at 150 ◦C): δ 127–122 (br m),
55–47 (br m), 44–37 (br m), 35–32 (br m), 31–26 (br m),
22–18 (br m), 11.6 (br s) ppm.
17.7 (br s) ppm; IR νCO: 1744.3 cm−1
.
4.7.2. Typical procedures for the synthesis of 1:1 copolymer
To a solution of [(4)PdCl2] (5.0 mg, 0.011 mmol) in
10 ml of toluene were added norbornene (0.50 g, 0.011 mol)
and 8c (1.40 g, 5.5 mmol). To the solution was added
MAO (7.0 ml). The reaction flask was taken from the dry
box and treated with MeOH to quench excess MAO. The
synthesized polymer was added to a solution mixture of
MeOH and HCl (1:1 (v/v)) and stirred for 30 min. While
the solution was stirring, the polymers became oily. Poly-
mers were extracted with dichloromethane. Removal of
the solvent followed by addition of methanol gave solids
polymers.
1
Entry 8 in Table 5: H NMR (1,2-dichlorobenzene-d4 at
150 ◦C): δ 7.2–6.9 (br m), 5.0 (br s), 4.4 (br s), 3.4–2.2
[br m (2.37 maximum)], 2.2–1.8 [br m (2.03 maximum)],
1.8–1.4 [br m (1.58 maximum)], 1.34 (br s), 1.3–0.9 [br m
(1.20 maximum)] ppm; 13C NMR (1,2-dichlorobenzene-d4
at 150 ◦C): δ 130–126 (br m), 55–50 (br m), 48–40 (br m),
36.3 (br s), 35–29 (br m), 21.6 (br s) ppm.
Acknowledgements
Entry 1 in Table 5: 1H NMR (CDCl3): δ 4.81 (br s),
4.72 (br s), 2.8–1.7 (br m), 1.7–1.5 [br m (1.6 maximum)],
1.5–1.4 [br m (1.47 maximum)], 1.4–1.0 br m (1.31 maxi-
mum)], 0.9 (br s) ppm; 13C NMR (CDCl3): δ 60–55 (br m),
55–38 (br m), 38–32 (br m), 32–27 (br m), 23.9 (br s), 14.5
(br s) ppm.
YKC gives thanks to the financial supports from the Min-
istry of Commerce, Industry and Energy of Korea and DMS
gives thanks to the fellowship from the Brain Korea 21.
1
Entry 2 in Table 5: H NMR (CDCl3): δ 4.8–4.6 (br m),
References
2.8–1.8 (br m), 1.8–1.4 [br m (1.46 maximum)], 1.4–1.1 [br
m (1.25 maximum)], 1.05 (br s), 0.90 (br s) ppm; 13C NMR
(CDCl3): δ 60–54 (br m), 54–50 (br m), 50–39 (br m), 37–35
(br m), 33–28 (br m), 23.9 (br s), 20 (br m), 14.5 (br s) ppm.
[1] (a) S. Mecking, Angew. Chem. Int. Ed. 40 (2001) 534;
(b) C. Janiak, P.G. Lassahn, Macromol. Rapid Commun. 22 (2001)
479;
(c) C. Janiak, P.G. Lassahn, J. Mol. Catal. A: Chem. 166 (2001) 193.
[2] (a) L.K. Johnson, C.M. Killian, M. Brookhart, J. Am. Chem. Soc.
117 (1995) 6414;
1
Entry 3 in Table 5: H NMR (CDCl3): δ 7.4–7.0 (br m),
4.86 (br s), 4.20 (br s), 3.2–1.7 (br m), 1.7–1.3 [br m (1.38
maximum)], 1.3–0.9 [br m (1.2 maximum)], 0.9–0.6 [br m
(0.8 maximum)] ppm; 13C NMR (CDCl3): δ 160.8 (br s),
130–122 (br m), 105.3 (br s), 61–50 (br m), 50–40 (br m),
38–35 (br m), 35–26 (br m), 23.5 (br s), 14.5 (br s) ppm.
(b) L.K. Johnson, S. Mecking, M. Brookhart, J. Am. Chem. Soc.
118 (1996) 267;
(c) C.M. Killian, D.J. Tempel, L.K. Johnson, M. Brookhart, J. Am.
Chem. Soc. 118 (1996) 11664;
(d) C.M. Killian, L.K. Johnson, M. Brookhart, Organometallics 16
(1997) 2005;
1
Entry 4 in Table 5: H NMR (CDCl3): δ 7.3–6.9 (br m),
4.85 (br s), 4.26 (br s), 3.1–1.8 (br m), 1.8–1.3 [br m (1.5
maximum)], 1.3–0.6 [br m (0.96 maximum)] ppm; 13C NMR
(CDCl3): δ 160.4 (br s), 130–125 (br m), 107.0 (br s), 62–60
(br m), 60–49 (br m), 49–38 (br m), 38–34 (br m), 34–30
(br m), 23.0 (br s) ppm.
(e) S. Mecking, L.K. Johnson, L. Wang, M. Brookhart, J. Am. Chem.
Soc. 120 (1998) 120, 888;
(f) S.A. Svejda, L.K. Johnson, M. Brookhart, J. Am. Chem. Soc.
121 (1999) 10634;
(g) Z. Guan, P.M. Cotts, E.F. McCord, S. Mclain, Science 283 (1999)
2059;
(h) D.P. Gates, S.A. Svejda, E. Onate, C.M. Killian, L.K. Johnson,
P.S. White, M. Brookhart, Macromolcules 33 (2000) 2320;
(i) M.C. Done, T. Rüther, K.J. Cavell, M. Kilner, E.J. Peacock, N.
Braussaud, B.W. Skelton, A. White, J. Organomet. Chem. 607 (2000)
78;
1
Entry 5 in Table 5: H NMR (1,2-dichlorobenzene-d4 at
150 ◦C): δ 5.09 (br s), 4.89 (br s), 3.9–2.2 [br m (2.38 max-
imum)], 2.2–1.9 [br m (2.04 maximum)], 1.7 (br s), 1.6 (br
s), 1.5–1.2 [br m (1.39 maximum)], 1.17 (br s), 1.05 (br
s), 0.96 (br s) ppm; 13C NMR (1,2-dichlorobenzene-d4 at
150 ◦C): δ 54–48 (br m), 44–38 (br m), 33.7 (br s), 31.9 (br
s), 30–26 (br m), 23.9 (br s), 20.8 (br s), 20.3 (br s), 11.5–10
(br m) ppm.
(j) A.S. Abu-Surrah, M. Kettunen, K. Lappalainen, U. Piironen, M.
Klinga, M. Leskelä, Polyhedron 21 (2002) 27.
[3] T.V. Laine, U. Piironen, K. Lappalainen, M. Klinga, E. Aitola, M.
Leskelä, J. Organomet. Chem. 606 (2000) 112.

46
D.M. Shin et al. / Journal of Molecular Catalysis A: Chemical 210 (2004) 35–46
[4] (a) J.H. Groen, C.J. Elsevier, K. Vrieze, Organometallics 15 (1996)
[10] (a) N.J. Leonard, J.H. Boyer, J. Am. Chem. Soc. 72 (1950) 4818;
(b) N.E. Sartoris, H. Pines, J. Org. Chem. 34 (1969) 2119.
[11] R. Clavreul, B. Bloch, M. Brigodiot, E. Maréchal, Makromol. Chem.
188 (1987) 47.
3445;
(b) J.H. Groen, G.J.P. Delis, P.W.N.M. van Leeuwen, K. Vrieze,
Organometallics 16 (1997) 68;
(c) J.G.P. Delis, P.G. Aubel, K. Vrieze, P.W.N.M. van Leeuwen, N.
Veldman, A.L. Spek, F.J.R. van Neer, Organometallics 16 (1997)
2948;
(d) J.G.P. Delis, P.G. Aubel, K. Vrieze, P.W.N.M. van Leeuwen,
Organometallics 16 (1997) 4150;
[12] K. Hiraki, Y. Fuchita, Y. Matsumoto, Chem. Lett. (1984) 1947.
[13] S.U. Son, D.H. Kim, I.G. Jung, Y.K. Chung, S.G. Lee, S.H. Chun,
J. Polym. Sci. A: Polym. Chem. 41 (2003) 76.
[14] G. M. Sheldrick, SHELX-97, Programs for Crystal Structure Anal-
ysis, University of Göttigen, Germany, 1997.
(e) T. Shareina, G. Hillebrand, H. Fuhrmann, R. Kempe, Eur. J.
Inorg. Chem. (2001) 2421.
[15] (a) T.V. Laine, M. Klinga, M. Leskelä, J. Inorg. Chem. (1999)
959;
[5] S. Tsuji, D.C. Swenson, R.F. Jordan, Organometallics 18 (1999)
4758.
[6] B. Domhoever, W. Klaeui, A. Kremer-Aach, R. Bell, D. Mootz,
Angew. Chem. Int. Ed. 37 (1998) 3050.
[7] R. Ruelke, V.E. Kaasjager, D. Kliphuis, C.J. Elsevier, P.W.N.M. van
Leeuwen, K. Vireze, Organometallics 15 (1996) 668.
[8] M.C. Done, T. Rüther, K.J. Cavell, M. Kilner, E.J. Peacock, N.
Braussaud, B.W. Skelton, A. White, J. Organomet. Chem. 607 (2000)
78.
[9] A.D. Hennis, J.D. Polley, G.S. Long, A. Sen, D. Yandulov, J. Lipin,
G.M. Benedikt, L.F. Rhodes, J. Huffman, Organometallics 20 (2001)
2802.
(b) R.E. Rulke, J.G.P. Delis, A.M. Groot, C.J. Elsevier, P.W.N.M. van
Leeuwen, K. Vrieze, K. Goubitz, H. Schenk, J. Organomet. Chem.
508 (1996) 109;
(c) G.R. Newkome, F.R. Fronczek, V.K. Gupta, W.E. Puckett, D.C.
Pantaleo, G.E. Kiefer, J. Am. Chem. Soc. 104 (1982) 1782;
(d) P.D. Beer, N.C. Fletcher, M.G.B. Drew, T.J. Wear, Polyhedron
16 (1997) 815.
[16] (a) L.S. Boffa, B.M. Novak, Chem. Rev. 100 (2000) 1479;
(b) R.A. Wendt, G. Fink, Macromol. Chem. Phys. 201 (2000)
1365;
(c) A.S. Abu-Surrah, B. Rieger, J. Mol. Catal. A: Chem. 128 (1998)
239.