Nickel(II) and palladium(II) complexes with tridentate [C,N,S] and [C,N,P] ligands: Syntheses, characterization, and catalytic norbornene polymerization

Article abstract of DOI:10.1021/om400033n

A series of tridentate monoanionic [C^-,N,X] (X = S, P) nickel(II) complexes [(C₆H₄CH=NPh-2-XPh)NiBr] (X = S (1a), PPh (1b)) and palladium(II) complexes [(C₆H₄CH=NPh-2-XPh) PdCl] (X = S (2a), PPh (2b)) were synthesized from the reactions of La and Lb (La = BrC₆H₄CH=NPh-2-SPh, Lb = BrC₆H ₄CH=NPh-2-PPh₂) with (DME)NiBr₂ and (COD)PdCl₂, respectively, in good yields. All complexes were fully characterized by IR, NMR, and elemental analyses. Single-crystal X-ray diffraction analysis of complex 2a revealed an almost square-planar geometry of the metal center. After activation with methylaluminoxane (MAO), the title complexes 1a,b and 2a,b can be used as catalysts for norbornene polymerization to produce vinyl addition type polynorbornene (PNB) with good catalytic activities. The good catalytic activities of complexes 1b and 2b as procatalysts which contain a P atom as the third coordinated atom can be maintained even at high temperature, demonstrating their excellent thermal stability.

Full text of DOI:10.1021/om400033n

Article
pubs.acs.org/Organometallics
Nickel(II) and Palladium(II) Complexes with Tridentate [C,N,S] and
[C,N,P] Ligands: Syntheses, Characterization, and Catalytic
Norbornene Polymerization
Ya-Lin Qiao and Guo-Xin Jin*
State Key Laboratory of Molecular Engineering of Polymers, Department of Chemistry, Fudan University, Shanghai 200433, People’s
Republic of China
S
* Supporting Information
ABSTRACT: A series of tridentate monoanionic [C−,N,X] (X = S, P) nickel(II) complexes [(C6H4CHNPh-2-XPh)NiBr] (X
= S (1a), PPh (1b)) and palladium(II) complexes [(C6H4CHNPh-2-XPh)PdCl] (X = S (2a), PPh (2b)) were synthesized
from the reactions of La and Lb (La = BrC6H4CHNPh-2-SPh, Lb = BrC6H4CHNPh-2-PPh2) with (DME)NiBr2 and
(COD)PdCl2, respectively, in good yields. All complexes were fully characterized by IR, NMR, and elemental analyses. Single-
crystal X-ray diffraction analysis of complex 2a revealed an almost square-planar geometry of the metal center. After activation
with methylaluminoxane (MAO), the title complexes 1a,b and 2a,b can be used as catalysts for norbornene polymerization to
produce vinyl addition type polynorbornene (PNB) with good catalytic activities. The good catalytic activities of complexes 1b
and 2b as procatalysts which contain a P atom as the third coordinated atom can be maintained even at high temperature,
demonstrating their excellent thermal stability.
ligands were reported. Recently, a series of anilido-imine N−NP
INTRODUCTION
■
and N−NS tridentate nickel and palladium complexes were
Olefin polymerization based on late-transition-metal catalysts
synthesized by our group.13d After activation with methyl-
has been one of the most exciting developments in the area of
aluminoxane (MAO), the nickel(II) complexes can be used as
catalysis, organometallic chemistry, and polymer science in
recent years.1 Norbornene (NB) polymerization has been
catalysts for norbornene polymerization to produce vinyl
addition type polynorbornene (PNB) with high catalytic
activities: up to 5.82 × 107 g of PNB (mol of Ni)−1 h−1.
Chelating anionic aryl carbon atom ligands have become an
important class of ligands in homogeneous catalysis and
materials chemistry.14,15 However, most of them were the so-
called ECE pincer ligands (ECE is [C6H3(CH2E)2-2,6]−, in
which E is NR2, PR2, SR, OMe).14 Few complexes bearing
different donor ligands with [C,X] (X = N, S, P) have been
described, and their olefin polymerization was rarely
developed.16 As an ongoing project, we are interested in the
design of nickel and palladium complexes with dissimilar
donors including an anionic aryl carbon atom as catalysts for
olefin polymerization. Herein, we report a series of nickel(II)
and palladium(II) complexes with aryl carbon tridentate
monoanionic ligands [C−,N,X] (X = S, P) together with their
catalytic activity for NB polymerization.
widely used in industrial production, due to the special optical
and mechanical properties of the polymers.2 Up to now,
catalytic systems based on titanium,3 zirconium,4 cobalt,5
chromium,6 nickel,7 palladium,8 and copper9 have been mainly
investigated for the addition polymerization of NB. Among
these catalysts, nickel complexes bearing chelate [N,O] and
[N,N] ligands exhibited especially high activity.7
The side-arm effect of an extra donor has a strong influence
on catalytic polymerization.10−13 Metal complexes coordinated
by hard atoms (N, O) and soft atoms (P, S) in the side arm
were mainly studied. In 2004, Gibson reported that catalysts
which contain phenoxy-amide ligands bearing soft pendant
donors showed higher ethylene polymerization activity than the
counterparts containing hard donors or systems without a
pendant donor.11a A series of titanium complexes reported by
Tang’s group having extra pendant S and P donors on
salicylaldiminato ligands showed high activities toward ethylene
polymerization and copolymerization with 1-hexene.11b,c Our
group has also done some research in this field.13 However, not
many nickel and palladium complexes bearing these types of
Received: January 15, 2013
Published: March 6, 2013
© 2013 American Chemical Society
1932
dx.doi.org/10.1021/om400033n | Organometallics 2013, 32, 1932−1937

Organometallics
Article
Scheme 1. Synthetic Procedure for La and Lb
RESULTS AND DISCUSSION
■
Synthesis and Characterization of Ligands and
Complexes. The synthesis of ligands La and Lb is outlined
in Scheme 1. Condensation of 2-bromobenzaldehyde with 1
equiv of the corresponding substituent anilines in hexane gave
La and Lb.
All ligands were characterized by elemental analysis and IR
1
1
and H NMR spectroscopy. The H NMR spectrum of La
showed a peak at δ 8.77 ppm and that of Lb at δ 8.57 ppm,
which can be ascribed to the proton CHN. The structures of
La and Lb were further confirmed by single-crystal X-ray
diffraction analysis (Figures 1 and 2). In La, the C7−N1 bond
distance is 1.281(5) Å, while the distance in Lb is 1.265(7) Å,
which is typical of a carbon−nitrogen double bond.
Figure 2. Molecular structure of Lb with thermal ellipsoids drawn at
the 30% level. Selected bond lengths (Å) and angles (deg): Br(1)−
C(1) = 1.893(4), P(1)−C(14) = 1.825(3), P(1)−C(20) = 1.826(3),
P(1)−C(13) = 1.830(3), N(1)−C(7) = 1.281(5), N(1)−C(8) =
1.408(4); C(14)−P(1)−C(20) = 102.86(14), C(14)−P(1)−C(13) =
102.37(14), C(20)−P(1)−C(13) = 101.69(14), C(7)−N(1)−C(8) =
119.6(3), C(2)−C(1)−Br(1) = 118.6(3), C(6)−C(1)−Br(1) =
120.6(3), N(1)−C(7)−C(6) = 121.2(3), C(9)−C(8)−N(1) =
122.5(3), C(13)−C(8)−N(1) = 117.6(3).
catalyze ethylene polymerization. However, they could be used
for norbornene polymerization to afford vinyl addition type
polynorbornene (PNB) with high activities after activation with
MAO. The polymerization results are summarized in Table1,
and the catalytic activities of complexes 1a,b toward
norbornene polymerization at different temperatures are
presented in Figure 4.
Figure 1. Molecular structure of La with thermal ellipsoids drawn at
the 30% level. Selected bond lengths (Å) and angles (deg): Br(1)−
C(9) = 1.900(8), S(1)−C(1) = 1.768(6), S(1)−C(14) = 1.773(6),
N(1)−C(7) = 1.265(7), N(1)−C(2) = 1.415(8); C(1)−S(1)−C(14)
= 103.3(3), C(7)−N(1)−C(2) = 119.8(5), C(6)−C(1)−S(1) =
125.2(5), C(2)−C(1)−S(1) = 115.3(5), N(1)−C(7)−C(8) =
121.6(6), C(10)−C(9)−Br(1) = 116.5(6), C(8)−C(9)−Br(1) =
120.8(6), C(9)−C(8)−C(7) = 123.4(6).
To investigate the reaction parameters affecting vinyl
polymerization of norbornene, the catalyst precursors 1a,b
were typically investigated by changing the ratios of MAO and
the reaction temperature. The activator MAO was essential to
the polymerization of norbornene here. The role of MAO is to
initiate the polymerization and probably create an empty site
for the insertion of the norbornene monomer. The activity data
in Table 1 showed that the optimal Al/Ni ratio was 6000 for
the complex 1a/MAO catalytic system and 8000 for the 1b
system. A lower molecular weight (Mv) of the polymer was
observed as the Al/Ni molar ratio was increased (entries 1−3
and 8−10, Table 1). Additionally, the temperature was also
investigated for the polymerization with the optimum Al/Ni
ratio. We found that the the highest activities were obtained for
the complex 1a/MAO catalytic system at 50 °C and for the 1b/
MAO catalytic system at 100 °C, which indicates that the
[C−,N,P] ligand plays an important role in stabilizing the active
species at high temperature. Nevertheless, as elevated temper-
ature, the molecular weights of PNB decrease. This result is due
to a faster chain transfer and termination at higher temperature.
On comparison of the polymerization behavior of 1a with that
of 1b, the results show that 1a, which has an S atom on the side
arm, has greater catalytic ability than the corresponding
Treatments of the lithium salts of imino ligands with
(DME)NiBr2 and (COD)PdCl2 in THF at room temperature
afforded the desired nickel and palladium complexes 1a,b and
2a,b, respectively (Scheme 2). In the solid state, all products
were stable in dry air but the nickel complexes slowly
decomposed in solution. These complexes were well
1
characterized by H NMR, IR spectra and elemental analyses.
In comparison with the free ligands, the CHN proton signals
1
were shifted approximately 0.1 ppm in the H NMR spectrum,
indicating the formation of M−N (M = Ni, Pd) bonds. To
further confirm the structures of these complexes, a single
crystal suitable for X-ray diffraction analyses was obtained from
a CH2Cl2/hexane solution of 2a (Figure 3). The geometry at
the palladium center can be described as a slightly distorted
quadrilateral structure in which the five atoms Pd(1), N(1),
S(1), C(1), and Cl(1) are nearly coplanar.
Norbornene Polymerization. With methylaluminoxane
(MAO) as cocatalyst, these title complexes were not able to
1933
dx.doi.org/10.1021/om400033n | Organometallics 2013, 32, 1932−1937

Organometallics
Article
Scheme 2. Synthesis of Nickel and Palladium Complexes
Table 1. Results of Norbornene Polymerization Initiated by
a
Complexes 1a,b/MAO and 2a,b/MAO
Al/M
(ratio)
T
(°C)
amt of polymer
(g)
b
c
entry procat.
activity 10−4Mv
1
1a
1a
1a
1a
1a
1a
1a
1b
1b
1b
1b
1b
1b
1b
1b
1b
2a
2b
4000
6000
8000
6000
6000
6000
6000
6000
8000
10000
8000
8000
8000
8000
8000
8000
6000
8000
15
15
15
0
0.586
0.850
0.642
0.653
0.885
1.10
3.52
5.10
3.85
3.92
5.31
6.58
5.13
0.47
0.89
0.77
0.63
0.82
0.91
2.31
3.94
3.67
8.52
8.78
8.38
7.71
5.28
3.95
3.35
2.26
1.37
5.28
3.95
3.35
4.62
2.27
1.79
1.52
1.36
1.36
d
2
3
4
5
30
50
80
15
15
15
0
6
7
0.855
0.079
0.149
0.129
0.105
0.137
0.151
0.385
0.656
0.612
1.421
1.464
8
9
10
11
12
13
14
15
16
17
18
30
50
80
100
120
50
100
Figure 3. Molecular structure of 2a with thermal ellipsoids drawn at
the 30% level. Selected bond lengths (Å) and angles (deg): Pd(1)−
C(1) = 1.994(6), Pd(1)−N(1) = 2.005(5), Pd(1)−Cl(1) =
2.3453(13), Pd(1)−S(1) = 2.3922(15), S(1)−C(13) = 1.785(6),
S(1)−C(14) = 1.788(5), N(1)−C(7) = 1.300(7), N(1)−C(8) =
1.430(7); C(1)−Pd(1)−N(1) = 81.3(2), C(1)−Pd(1)−Cl(1) =
96.87(17), N(1)−Pd(1)−Cl(1) = 177.21(13), C(1)−Pd(1)−S(1) =
165.93(17), N(1)−Pd(1)−S(1) = 84.63(14), Cl(1)−Pd(1)−S(1) =
97.16(5), C(13)−S(1)−C(14) = 102.3(2), C(13)−S(1)−Pd(1) =
96.24(19), C(14)−S(1)−Pd(1) = 104.09(18), C(7)−N(1)−C(8) =
123.5(5), C(7)−N(1)−Pd(1) = 115.9(4), C(8)−N(1)−Pd(1)
=120.6(4), C(2)−C(1)−Pd(1) = 131.1(5), C(6)−C(1)−Pd(1) =
111.9(4).
a
Conditions: group VIII metal complex, 0.5 μmol; solvent,
chlorobenzene (total volume 15 mL); norbornene, 1.68 g; reaction
b
c
time, 20 min. Activity in 106 g of PNB (mol of Ni)
h−1. Mv
−1
measured by the Ubbelohde calibrated viscosimeter technique.
d
Undetermined.
analogous complex 1b, which contains a P atom as the third
coordinated atom. The reason for this might be that the
structure of complex 1a could provide more space in the axial
direction for the coordination and insertion of norbornene in
the polymerization process.13d,17
The nature of the metal has a significant influence on the
activation process. With the same optimum conditions as for
the corresponding nickel complexes, the effects of different
metal centers on the polymerization were explored (entries 17
and 18, Table 1). On comparison of Pd complexes 2a,b with Ni
complexes 1a,b, higher catalytic activities were observed for Pd,
which can probably be attributed to the larger atom
semidiameter. The polymers obtained by palladium(II)
complexes 2a,b are insoluble in chloroform, benzene,
chlorobenzene, 1,2-dichlorobenzene, and N,N-dimethylforma-
mide, which is different from the case for polymers obtained
Figure 4. Catalytic activities of complexes 1a,b toward norbornene
polymerization at different temperatures. Conditions: complexes, 0.5
μmol; solvent, chlorobenzene, total volume 15 mL; norbornene, 1.68
g; Al/Ni (1a, 6000; 1b, 8000); reaction time, 20 min. The activity is
given in units of 104 g of PNB (mol of Ni)−1 h−1.
1934
dx.doi.org/10.1021/om400033n | Organometallics 2013, 32, 1932−1937

Organometallics
Article
H), 7.63 (d, 1H, Ar-H), 7.47 (d, 2H, Ar-H), 7.41 (t, 1H, Ar-H) 7.24−
7.37 (m, 5H, Ar-H), 7.05−7.15 (m, 3H, Ar-H). Anal. Calcd for
C19H14BrNS: C, 61.96; H, 3.83; N, 3.80. Found: C, 61.83; H, 3.95; N,
3.82.
(E)-N-(2-Bromobenzylidene)-2-(diphenylphosphino)-
benzenamine (Lb). A procedure similar to that for the preparation of
La was used, starting from 2-bromobenzaldehyde (0.93 g, 5 mmol), 2-
(diphenylphosphino)benzenamine (1.39 g, 5 mmol), and 0.07 g of
MgSO4 in n-hexane (20 mL). Workup afforded Lb as a light yellow
powder. Pure products were obtained as light yellow crystals by
recrystallization from ethanol in a yield of 55%.
with nickel catalysts. The molecular weights of the polymers
obtained could not be determined because of their insolubility,
which is similar to the results reported.18
1
All polymers showed similar IR and H NMR spectra. The
absence of signals at 1620−1680, 966, and 735 cm−1 in the IR
spectra revealed that there were no traces of double bonds, and
signals only in the 0.9−3.0 ppm range observed in the 1H NMR
spectra supplied the same information.19 These data indicated
that the polymers were vinyl addition type products. Attempts
to determine the glass transition temperature (Tg) of PNB
failed, and the DSC studies did not give an endothermic signal
upon heating to the decomposition temperature (above 450
°C).
IR (KBr): 3481 (m), 3416 (m), 3301 (m), 3044 (w), 2927 (w),
2920 (w), 1614 (s), 1594 (s),1562 (s), 1449 (m), 1434 (s), 1470 (m),
1324 (m), 1172 (m), 1105 (m), 1025 (m), 766 (s), 754 (s), 736 (s),
1
698 (s) cm−1. H NMR (400 MHz, CDCl3): δ 8.57 (s, 1H, CHN-
Ar), 7.92 (d, 1H, Ar−H), 7.71 (t, 3H, Ar-H), 7.49−7.62 (m, 6H, Ar-
H), 7.32 (m, 3H, Ar-H), 7.08 (m, 3H, Ar-H), 6.86 (d, 1H, Ar-H), 6.58
(t, 1H, Ar-H). Anal. Calcd for C25H19BrNP: C, 67.58; H, 4.31; N, 3.15.
Found: C, 67.35; H, 4.35; N, 3.20.
CONCLUSION
■
In summary, a series of tridentate monoanionic [C−,N,X] (X =
S, P) nickel(II) complexes [(C6H4CHNPh-2-XPh)NiBr] (X
= S (1a), PPh (1b)) and palladium(II) complexes
[(C6H4CHNPh-2-XPh)PdCl] (X = S (2a), PPh (2b))
were synthesized and characterized. With methylaluminoxane
(MAO) as cocatalyst, these title complexes were not able to
catalyze ethylene polymerization, but norbornene polymer-
ization was possible to afford vinyl addition type polynorbor-
nene (PNB) with good catalytic activities: up to 8.78 × 106 g of
PNB (mol of Pd)−1 h−1. The molecular weights of the polymers
obtained by palladium(II) complexes 2a,b could not be
determined because of their insolubility.
n
Synthesis of Complexes. Ni[C−NS]Br (1a). BuLi (1.6 M, 0.13
mL, 0.2 mmol) was added by syringe to a solution of La (74 mg, 0.2
mmol) in THF (15 mL) cooled to 0 °C. The resulting orange solution
was stirred at room temperature for 2 h and then was transferred
dropwise into a suspension of (DME)NiBr2 (62 mg, 0.2 mmol) in
dried THF (15 mL) at −78 °C, and the resulting mixture was slowly
warmed to room temperature and stirred overnight at room
temperature. The crude reaction mixture was filtered under nitrogen
and concentrated under reduced pressure to ca. 2 mL, and then dry
hexane (20 mL) was added. The solvent was filtered, and the residual
brown solid was washed with n-hexane. Drying in vacuo produced the
desired nickel complex in a yield of 69%.
IR (KBr): 3436 (s), 2902 (w), 2854 (w), 1632 (s), 1505 (s), 1478
EXPERIMENTAL SECTION
■
(m), 1437 (m), 1261 (m), 1099 (m), 1025 (m), 803 (s), 751 (m), 703
1
(m), 617 (s) cm−1. H NMR (400 MHz, CDCl3): δ 8.67 (s, 1H,
General Data. All manipulations of air- and/or water-sensitive
compounds were carried out under dry argon using standard Schlenk
techniques. Tetrahydrofran (THF), hexane, and toluene were distilled
from sodium−benzophenone. Dichloromethane was distilled from
calcium hydride. Commercial reagents, namely LiAlH4, nBuLi,
methylaluminoxane (MAO, 1.46 M in toluene), and 2-bromobenzal-
dehyde, were purchased from Acros Co. (DME)NiBr2,20 (COD)-
PdCl2,19b 2-(phenylthio)benzenamine,11c and 2-(diphenylphosphino)-
benzenamine11c were synthesized according to the literature
procedures. Norbornene was purified by distillation over sodium and
used as a chlorobenzene solution. Other commercially available
reagents were purchased and used without purification.
CHN-Ar), 7.82 (d, 1H, Ar-H), 7.73 (d, 1H, Ar-H), 7.69 (t, 1H, Ar-
H), 7.48−7.62 (m, 4H, Ar-H), 7.41 (d, 1H, Ar-H), 7.29 (d, 3H, Ar-H),
7.17 (t, 1H, Ar-H), 7.11 (s, 1H, Ar-H). Anal. Calcd for C19H14BrNNiS:
C, 53.45; H, 3.30; N, 3.28. Found: C, 53.43; H, 3.40; N, 3.25.
Ni[C−NP]Br (1b). This complex was prepared as described above for
n
1a, starting from BuLi (1.6 M, 0.13 mL, 0.2 mmol), Lb (89 mg, 0.2
mmol), and (DME)NiBr2 (0.062 g, 0.2 mmol). Workup afforded 1b as
a light brown powder in a yield of 73%.
IR (KBr): 3420 (s), 2957 (w), 1622 (s), 1560 (s), 1436 (m), 1252
(w), 1154 (w), 1120 (m), 1026 (w), 761 (m), 747 (m), 724 (m), 691
(s), 619 (s) cm−1. 1H NMR (400 MHz, CDCl3): δ 8.64 (s, 1H, CH
N-Ar), 8.02 (d, 1H, Ar-H), 7.79 (t, 3H, Ar-H), 7.52−7.70 (m, 6H, Ar-
H), 7.40 (m, 3H, Ar-H), 7.12 (m, 3H, Ar-H), 6.98 (d, 1H, Ar-H), 6.63
(t, 1H, Ar-H). Anal. Calcd for C25H19BrNNiP: C, 59.70; H, 3.81; N,
2.78. Found: C, 59.73; H, 3.85; N, 2.70.
IR spectra were measured on a Nicolet Avatar-360 spectropho-
tometer. NMR measurements were obtained on a Bruker AC 400
spectrometer in CDCl3 solution. The NMR spectra of all the
compounds and complexes were recorded at ambient temperature.
Elemental analyses for C, N, and H were carried out on an Elementar
III Vario EI analyzer.
Pd[C−NS]Cl (2a). This complex was prepared as described above for
n
1a, starting from BuLi (1.6 M, 0.13 mL, 0.2 mmol), La (74 mg, 0.2
1H (500 MHz) and 13C NMR (125 MHz) measurements were
obtained on a Bruker AC500 spectrometer in CDCl3 solution.
Elemental analyses for C, H, and N were carried out on an Elementar
III Vario EI analyzer. The intrinsic viscosity (η) was measured in
chlorobenzene at 25 °C using an Ubbelohde viscometer. Viscosity
mmol), and (COD)PdCl2 (60 mg, 0.2 mmol). Workup afforded 2a as
a brown powder in a yield of 75%.
IR (KBr): 3433 (s), 2936 (w), 1637 (s), 1541 (m), 1475 (m), 1437
(w), 1380 (w), 1188 (w), 1072 (m), 1018 (m), 982 (m), 750 (s), 695
1
(s) cm−1. H NMR (400 MHz, CDCl3): δ 8.75 (s, 1H, CHN-Ar),
average molecular weight (Mv) values of polymer were calculated by
21
the following equation: η = (5.97 × 10−4)Mv0.56
.
7.90 (d, 1H, Ar-H), 7.79 (d, 1H, Ar-H), 7.71 (t, 1H, Ar-H), 7.49−7.61
(m, 4H, Ar-H), 7.43 (d, 1H, Ar-H), 7.33 (d, 3H, Ar-H), 7.15 (t, 1H,
Ar-H), 7.01 (s, 1H, Ar-H). Anal. Calcd for C19H14ClNPdS: C, 53.04;
H, 3.28; N, 3.26. Found: C, 52.98; H, 3.35; N, 3.30.
Synthesis of Ligands. (E)-N-(2-Bromobenzylidene)-2-
(phenylthio)benzenamine (La). A solution of 2-bromobenzaldehyde
(0.93 g, 5 mmol), 2-(phenylthio)benzenamine (1.01 g, 5 mmol), and
0.07 g of MgSO4 in n-hexane (20 mL) was stirred for 12 h at room
temperature. The mixture was then filtered and washed with CH2Cl2.
The combined bright yellow solution was concentrated to dryness to
give a yellow powder. Pure products were obtained as yellow crystals
by recrystallization from ethanol in a yield of 72%.
IR (KBr): 3542 (m), 3465 (s), 3414 (s), 3049 (w), 2952 (w), 2911
(s), 1616 (s), 1565 (m), 1469 (m), 1434 (m), 1355 (m), 1267 (m),
1191 (m), 1057 (m), 1022 (m), 754 (s), 728 (m), 689 (m) cm−1. 1H
NMR (400 MHz, CDCl3): δ 8.77 (s, 1H, CHN-Ar), 8.25 (t, 1H, Ar-
Pd[C−NP]Cl (2b). This complex was prepared as described above for
n
1a, starting from BuLi (1.6M, 0.13 mL, 0.2 mmol), Lb (89 mg, 0.2
mmol), and (COD)PdCl2 (60 mg, 0.2 mmol). Workup afforded 2b as
a brown powder in a yield of 79%.
IR (KBr): 3433 (s), 2957 (w), 2931(w), 1634 (s), 1591 (m), 1457
(m), 1436 (s), 1319 (m), 1257 (m), 1100 (m), 1021 (m), 802 (m),
1
747 (m), 691 (s) cm−1. H NMR (400 MHz, CDCl3): δ 8.72 (s, 1H,
CHN-Ar), 8.17 (d, 1H, Ar-H), 7.84 (t, 3H, Ar-H), 7.63−7.74 (m,
6H, Ar-H), 7.48 (m, 3H, Ar-H), 7.24 (m, 3H, Ar-H), 7.01 (d, 1H, Ar-
1935
dx.doi.org/10.1021/om400033n | Organometallics 2013, 32, 1932−1937

Organometallics
Article
H), 6.77 (t, 1H, Ar-H). Anal. Calcd for C25H19ClNPPd: C, 59.31; H,
3.78; N, 2.77. Found: C, 59.28; H, 3.82; N, 2.74.
AUTHOR INFORMATION
■
Corresponding Author
*G.-X.J.: tel, (+86)-21-65643776; fax, (+86)-21-65641740; e-
mail, gxjin@fudan.edu.cn.
X-ray Crystallography. Single crystals of complexes La, Lb, and
2a suitable for X-ray analysis were obtained from CH2Cl2/n-hexane
solutions. The intensity data of the single crystals were collected on
the CCD-Bruker Smart APEX system. All determinations of the unit
cell and intensity data were performed with graphite-monochromated
Mo Kα radiation (λ = 0.71073 Å). All data were collected at room
temperature or −100 °C using the ω scan technique. These structures
were solved by direct methods using Fourier techniques and refined on
F2 by full-matrix least-squares methods. All the non-hydrogen atoms
were refined anisotropically, and all the hydrogen atoms were included
but not refined.
Notes
The authors declare no competing financial interest.
ACKNOWLEDGMENTS
■
We are grateful to the National Science Foundation of China
(91122017), the Program for Changjiang Scholars and
Innovative Research Team in University (IRT1117), the
National Basic Research Program of China (2011CB808505),
and the Shanghai Science and Technology Committee
(12DZ2275100).
Crystal data for La: C19H14BrNS, Mr = 368.28, T = 293(2) K,
monoclinic, space group C2/c, a = 29.613(19) Å, b = 7.948 (5) Å, c =
17.260(11) Å, β = 123.962(8)°, V = 3369(4) Å3, Z = 8, ρcalcd = 1.452 g
cm−3, 6566 total reflections, 2951 of which were independent (Rint
=
0.1447). The structure was refined to final R1 = 0.0739 (I > 2σ(I)),
wR2 = 0.1211 (all data), GOF = 0.943, and maximum/minimum
residual electron density 0.689/−0.582 e Å−3.
REFERENCES
■
(1) (a) Bianchini, C.; Giambastiani, G.; Rios, I. G.; Mantovani, G.;
Meli, A.; Segarra, A. M. Coord. Chem. Rev. 2006, 250, 1391. (b) Janiak,
C. Coord. Chem. Rev. 2006, 250, 66. (c) Gibson, V. C.; Redshaw, C.;
Solan, G. A. Chem. Rev. 2007, 107, 1745. (d) Nakamura, A.; Ito, S.;
Nozaki, K. Chem. Rev. 2009, 109, 5215. (e) Makio, H.; Terao, H.;
Iwashita, A.; Fujita, T. Chem. Rev. 2011, 111, 2363.
(2) (a) Janiak, C.; Lassahn, P. G. J. Mol. Catal. A: Chem. 2001, 166,
193. (b) Buchmeiser, M. R. Chem. Rev. 2000, 100, 1565. (c) Coates, G.
W. Chem. Rev. 2000, 100, 1223. (d) Blank, F.; Janiak, C. Coord. Chem.
Rev. 2009, 253, 827. (e) McCann, M.; McDonnell, D.; Goodall, B. L. J.
Mol. Catal. A: Chem. 1995, 96, 31.
(3) (a) Tritto, I.; Boggioni, L.; Sacchi, M. C.; Locatelli, P. J. Mol.
Catal. A:Chem. 1998, 133, 139. (b) Hasan, T.; Ikeda, T.; Shiono, T.
Macromolecules 2004, 37, 7432. (c) Li, J.-C.; Gao, W.; Wu, Q.-L.; Li,
H.-C; Mu, Y. J. Organomet. Chem. 2011, 696, 2499.
(4) Nishizawa, O.; Misaka, H.; Kakuchi, T.; Satoh, T. J. Polym. Sci. A:
Polym. Chem. 2008, 46, 1185.
(5) (a) Yasuda, H.; Nakayama, Y.; Sato, Y. J. Organomet. Chem. 2004,
689, 744. (b) Tarte, N. H.; Woo, S. I.; Cui, L.; Gong, Y.-D.; Hwang, Y.
H. J. Organomet. Chem. 2008, 693, 729. (c) Safir, A. L.; Novak, B. M.
Macromolecules 1995, 28, 5396.
(6) (a) Chen, J.-X.; Huang, Y.-B.; Li, Z.-S.; Zhang, Z.-C.; Wei, C.-X.;
Lan, T.-Y.; Zhang, W.-J. J. Mol. Catal. A: Chem. 2006, 259, 133.
(b) Woodman, T. J.; Sarazin, Y.; Garratt, S.; Fink, G.; Bochmann, M. J.
Mol. Catal. A: Chem. 2005, 235, 88.
Crystal data for Lb: C25H19BrNP, Mr = 444.29, T = 173(2) K,
monoclinic, space group P21/c, a = 10.739(2) Å, b = 17.527(4) Å, c =
11.279(2) Å, β = 106.456(3)°, V = 2036.0(7) Å3, Z = 4, ρcalcd =1.449 g
cm−3, 14480 total reflections, 4669 of which were independent (Rint
=
0.0435). The structure was refined to final R1 = 0.0476 (I > 2σ(I)),
wR2 = 0.0541 for all data, GOF = 1.065, and maximum/minimum
residual electron density 1.672/−0.528 e Å−3.
Crystal data for 2a: C19H14ClNPdS, Mr = 430.22, T = 173(2) K,
monoclinic, space group P21/c, a = 12.2201(12) Å, b = 15.1340(16) Å,
c = 9.0568(10) Å, β = 106.708(2)°, V = 1604.2(3) Å3, Z = 4, ρcalcd
=1.781 g cm−3, 11974 total reflections, 3779 of which were
independent (Rint = 0.0625). The structure was refined to final R1 =
0.0447 (I > 2σ(I)), wR2 = 0.1505 for all data, GOF = 0.858, and
maximum/minimum residual electron density 1.359/−0.584 e Å−3.
Polymerization of Ethylene. A 100 mL flask was equipped with
an ethylene inlet and a magnetic stirrer and attached to a vacuum line.
The flask was filled with 30 mL of freshly distilled toluene, MAO (10
wt % in toluene) was added, and the flask was placed in a bath at the
desired polymerization temperature for 10 min. The polymerization
reaction was started by adding a toluene solution of the catalyst
precursor (2 μmol) with a syringe. Then the solvent toluene was
added to make the total volume of the solution 50 mL. The
polymerization was terminated by addition of acidic ethanol (Vethanol
/
Vconcd HCl = 20/1).
Polymerization of Norbornene. In a typical procedure (entry 5,
Table 1), 0.5 μmol of nickel complex 1a in 0.5 mL of chlorobenzene,
1.68 g of norbornene in 3.0 mL of chlorobenzene, and another 9.5 mL
of fresh chlorobenzene were placed in a special polymerization bottle
(50 mL) with a strong stirring under a nitrogen atmosphere. After the
mixture was kept at 30 °C for 10 min, 2.0 mL of MAO was charged
into the polymerization system via syringe and the reaction was
initiated. Twenty minutes later, acidic ethanol (Vethanol/Vconcd HCl = 20/
1) was added to terminate the reaction. The PNB was isolated by
filtration, washed with ethanol, and dried at 80 °C for 48 h under
vacuum. For all polymerization procedures, the total reaction volume
was 15.0 mL, which can be achieved by varying the amount of
chlorobenzene when necessary. IR (KBr, cm−1): 2945 vs, 2867 vs,
1476 m, 1450 s, 1375 m, 1296 m, 1257 m, 1222 m, 1148 m, 1106 m,
(7) (a) Gao, H.-Y.; Guo, W.-J.; Bao, F.; Gui, G.-Q.; Zhang, J.-K.; Zhu,
F.-M.; Wu, Q. Organometallics 2004, 23, 6273. (b) Wang, X.; Liu, S.;
Jin, G.-X. Organometallics 2004, 23, 6002. (c) Chen, F.-T.; Tang, G.-
R.; Jin, G.-X. J. Organomet. Chem. 2007, 692, 3435. (d) Rush, S.;
Reinmuth, A.; Risse, W. Macromolecules 1997, 30, 7375. (e) Sun, W.-
H.; Yang, H.-J.; Li, Z.-L.; Li, Y. Organometallics 2003, 22, 3678.
(f) Deming, T. J.; Novak, B. M. Macromolecules 1993, 26, 7089.
(8) (a) Lassahn, P. G.; Lozan, V.; Janiak, C. Dalton Trans. 2003, 927.
(b) Blank, F.; Scherer, H.; Ruiz, J.; Rodríguez, V.; Janiak, C. Dalton
Trans. 2010, 39, 3609. (c) Blank, F.; Vieth, J.; Ruiz, J.; Rodríguez, V.;
Janiak, C. J. Organomet. Chem. 2011, 696, 473. (d) Blank, F.; Scherer,
H.; Janiak, C. J. Mol. Catal. A: Chem. 2010, 330, 1. (e) Berchtold, B.;
Lozan, V.; Lassahn, P. G.; Janiak, C. J. Polym. Sci. A: Polym. Chem.
2002, 40, 3604.
(9) (a) Carlini, C.; Giaiacopi, S.; Marchetti, F.; Pinzino, C.; Galletti,
A. M. R.; Sbrana, G. Organometallics 2006, 25, 3659. (b) Huang, Y.-B.;
Tang, G.-R.; Jin, G.-Y.; Jin, G.-X. Organometallics 2008, 27, 259.
(c) Tang, G.-R.; Lin, Y.-J.; Jin, G.-X. J. Organomet. Chem. 2007, 692,
4106.
(10) Jone, D. J.; Gibson, V. C; Green, S.; Maddox, P. J. Chem.
Commun. 2002, 1038.
(11) (a) Oakes, D. C. H.; Kimberley, B. S.; Gibson, V. C.; Jones, D.
J.; White, A. J. P.; Williams, D. J. Chem. Commun. 2004, 2174. (b) Hu,
W.-Q.; Sun, X.-L.; Wang, C.; Gao, Y.; Tang, Y.; Shi, L.-P.; Xia, W.;
Sun, J.; Dai, H.-L.; Li, X.-Q.; Yao, X.-L.; Wang, X.-R. Organometallics
1
1040 w, 941 w, 893 m, 805 m. H NMR (o-dichlorobenzene-d4, 500
MHz): δ 0.9−3.05 ppm (m, maxima at 1.50, 1.88, 2.21, 2.59). 13C
NMR (o-dichlorobenzene-d4, 500 MHz): δ 30.2−48.9 ppm (m,
maxima at 32.45, 39.11, 48.42, 48.67).
ASSOCIATED CONTENT
■
S
* Supporting Information
CIF files giving crystallographic data for La, Lb, and 2a. This
material is available free of charge via the Internet at http://
pubs.acs.org.
1936
dx.doi.org/10.1021/om400033n | Organometallics 2013, 32, 1932−1937

Organometallics
Article
2004, 23, 1684. (c) Wang, C.; Ma, Z.; Sun, X.-L.; Gao, Y.; Guo, Y.-H.;
Tang, Y.; Shi, L.-P. Organometallics 2006, 25, 3259.
(12) (a) Tshuva, E. Y.; Groysman, S.; Goldberg, I.; Kol, M.;
Goldschmidt, Z. Organometallics 2002, 21, 662. (b) Siedle, G.;
Lassabn, P. G.; Lozan, V.; Janiak, C.; Kersting, B. Dalton Trans. 2007,
52.
(13) (a) Jia, A.-Q.; Jin, G.-X. Organometallics 2009, 28, 1872.
(b) Zhang, J.; Lin, Y.-J.; Jin, G.-X. Organometallics 2007, 26, 4042.
(c) Jia, A.-Q.; Wang, J.-Q.; Hu, P.; Jin, G.-X. Dalton Trans. 2011, 40,
7730. (d) Shi, X.-C.; Jin, G.-X. Organometallics 2012, 31, 4748.
(14) (a) Singleton, J. T. Tetrahedron 2003, 59, 1837. (b) Albrecht,
M.; van Koten, G. Angew. Chem., Int. Ed. 2001, 40, 3750. (c) van der
Boom, M. E.; Milstein, D. Chem. Rev. 2003, 103, 1759. (d) Albrecht,
M.; Rodríguez, G.; Schoenmaker, J.; van Koten, G. Org. Lett. 2000, 2,
3461. (e) Guillena, G.; Kruithof, C. A.; Casado, M. A.; Egmond, M. R.;
van Koten, G. J. Organomet. Chem. 2003, 668, 3. (f) Chuchuryukin, A.
V.; Huang, R.; van Faassen, E. E.; van Klink, G. P. M.; Lutz, M.;
Chadwick, J. C.; Spek, A. L.; van Koten, G. Dalton Trans. 2011, 40,
8887. (g) Chuchuryukin, A. V.; Huang, R.; Lutz, M.; Chadwick, J. C.;
Spek, A. L.; van Koten, G. Organometallics 2011, 30, 2819.
(15) (a) Bouwkamp, M.; van Leusen, D.; Meetsma, A.; Hessen, B.
Organometallics 1998, 17, 3645. (b) Chan, M. C. W.; Kui, S. C. F.;
Cole, J. M.; McIntyre, G. J.; Matsui, S.; Zhu, N.; Tam, K.-H. Chem.
Eur. J. 2006, 12, 2607. (c) Kui, S. C. F.; Zhu, N.; Chan, M. C. W.
Angew. Chem., Int. Ed. 2003, 42, 1628.
(16) (a) Lee, J.-D.; Kim, S.-J.; Yoo, D.; Ko, J.; Cho, S.; Kang, S. O.
Organometallics 2000, 19, 1695. (b) Lee, T.; Lee, S. W.; Jang, H. G.;
Kang, S. O.; Ko, J. Organometallics 2001, 20, 741. (c) Hu, P.; Yao, Z.-
J.; Wang, J.-Q.; Jin, G.-X. Organometallics 2011, 30, 4935. (d) Zi, G.-F.;
Li, H.-W.; Xie, Z.-W. Organometallics 2002, 21, 3850. (e) Wang, H.-P.;
Wang, Y.-R.; Li, H.-W.; Xie, Z.-W. Organometallics 2001, 20, 5110.
(f) Wang, X.; Jin, G.-X. Organometallics 2004, 23, 6319. (g) Wang, X.;
Weng, L.-H.; Jin, G.-X. Chem. Eur. J. 2005, 11, 5758.
(17) (a) Long, J.-M.; Gao, H.-Y.; Song, K.-M.; Liu, F.-S.; Hu, H.;
Zhang, L.; Zhu, F.-M.; Wu, Q. Eur. J. Inorg. Chem. 2008, 4296.
(18) Liang, H.; Liu, J.-Y.; Li, X.-F.; Li, Y.-S. Polyhedron 2004, 23,
1619.
(19) (a) Ward, L. G. L. Inorg. Synth. 1972, 13, 154. (b) Rulke, R. E.;
̈
Ernsting, J. M.; Spek, A. L.; Elsevier, C. J.; van Leeuwen, P. W. N. M.;
Vrieze, K. Inorg. Chem. 1993, 32, 5769.
(20) Kermagoret, A.; Braunstein, P. Organometallics 2008, 27, 88.
(21) (a) Wang, H.-Y.; Zhang, J.; Meng, X.; Jin, G.-X. J. Organomet.
Chem. 2006, 691, 1275. (b) Wang, H.-Y.; Meng, X.; Jin, G.-X. Dalton
Trans. 2006, 2579. (c) Wang, X.; Jin, G.-X. Chem. Eur. J. 2005, 11,
5758.
1937
dx.doi.org/10.1021/om400033n | Organometallics 2013, 32, 1932−1937