Palladium(II) complexes containing a pyridinyliminophosphorane ligand

Article abstract of DOI:10.1002/ejic.200300122

A series of new pyridinyliminophosphorane bidentate ligands with different steric environments [(2-C₆H₄N)PPh₂= NAr (NPN)] and their methylpalladium complexes PdClMe(NPN)] were prepared. From the crystal structure analysis it is evident that the alkyl ligands are always trans to the pyridinyl nitrogen donor, revealing a σ-donating ability of the iminophosphorane. However, the two Pd-Cl bonds in [PdCl₂(NPN)] are essentially the same length. Cationic palladium complexes catalyzed the copolymerization of norbornene/ethylene as well as CO/norbornene. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003.

Full text of DOI:10.1002/ejic.200300122

FULL PAPER
Palladium(II) Complexes Containing a Pyridinyliminophosphorane Ligand
Hung-Ren Wu,[a] Yi-Hung Liu,[a] Shie-Ming Peng,[a] and Shiuh-Tzung Liu*[a]
Keywords: N ligands / Polymerization / Palladium
A series of new pyridinyliminophosphorane bidentate li-
gands with different steric environments [(2-C6H4N)PPh2=
NAr (NPN)] and their methylpalladium complexes
[PdClMe(NPN)] were prepared. From the crystal structure
analysis it is evident that the alkyl ligands are always trans
to the pyridinyl nitrogen donor, revealing a σ-donating abil-
ity of the iminophosphorane. However, the two Pd−Cl bonds
in [PdCl2(NPN)] are essentially the same length. Cationic
palladium complexes catalyzed the copolymerization of nor-
bornene/ethylene as well as CO/norbornene.
( Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim,
Germany, 2003)
Introduction
the corresponding aryl azide under anhydrous conditions
(Scheme 1). Substitution reactions of [PdClMe(COD)] with
pyridine-iminophosphorane (NPN) in dichloromethane at
room temperature readily led to the formation of bidentate
palladium complexes (1a؊c), which were treated with
AgBF4 to yield the corresponding cationic species (2aϪc;
Scheme 1). All the palladium complexes were isolated as
solids and were stable in solution under a nitrogen atmos-
phere.
Since the discovery of highly active diiminopalladium
complexes for the polymerization of olefins under mild con-
ditions by Brookhart’s group,[1] the design of new ligands
to fine-tune the activity of catalysts has received much at-
tention.[2] It is documented that the steric bulkiness around
the active metal center favors chain propagation, leading to
higher molecular-weight and branched polymers.[1,2] An-
other attractive feature in this area is the possibility of em-
ploying late transition metal complexes, containing hetero-
donor systems, since the olefin insertion into the MϪC
bond can be governed by the electronic properties of donor
atoms.[2] Presumably due to the reactivity of iminophos-
phoranes toward moisture[3] and carbonyl groups,[4] the use
of this kind of donor in catalytic polymerization is less-well
explored.[5] Recently, Stephan and Collins’ groups have re-
ported independently that early transition metal complexes
with phosphinimide ligands can catalyze the polymerization
of ethylene.[6,7] While the coordination studies involving im-
inophosphorane toward late transition metal complexes are
well-examined,[4c,8Ϫ12] we would like to contribute our ef-
forts in this area by investigating the behavior of palladium
complexes with a series of bidentate pyridinyliminophos-
phorane ligands as well as their catalytic polymerization ac-
tivity toward olefins.
Results and Discussion
Scheme 1. Preparation of ligands and palladium complexes
Preparation of Complexes
The ligands (La؊Lc) were prepared in high yield by the
Staudinger reaction of 2-diphenylphosphanylpyridine with
In the NMR spectra of the ligands La؊Lc and of the
palladium complexes 1a؊2c, differences between the sub-
1
stituents on the benzene rings were observed. The H, 13C
[a]
and 31P NMR resonances of these related species are quite
similar as shown in Table 1, and are consistent with the ex-
pected structure. It can also be seen that the 31P NMR spec-
Department of Chemistry, National Taiwan University,
Taipei, Taiwan 106, ROC
Fax: (internat.) ϩ886-2/2363 6359
E-mail: stliu@ntu.edu.tw
3152
 2003 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
DOI: 10.1002/ejic.200300122
Eur. J. Inorg. Chem. 2003, 3152Ϫ3159

Palladium(II) Complexes Containing a Pyridinyliminophosphorane Ligand
Table 1. Selected spectroscopic data of ligands and complexes
FULL PAPER
Compound
1H NMR[a]
31P NMR
Pd-CH3
13C NMR
Py-H-6
Pd-NCCH3
Pd-CH3
La
Lb
Lc
1a
1b
1c
2a
2b
2c
8.78 (d, J ϭ 4.6)
8.75 (d, J ϭ 4.8)
8.84 (d, J ϭ 4.0)
9.03 (d, J ϭ 4.5)
9.35 (d, J ϭ 5.1)
9.47 (d, J ϭ 5.1)
9.03 (d, J ϭ 4.7)
9.02 (d, J ϭ 5.1)
9.13 (d. J ϭ 4.7)
Ϫ
Ϫ
Ϫ
Ϫ
Ϫ
Ϫ
2.44
2.42
3.19
Ϫ
Ϫ
Ϫ
0.77
0.60
0.69
0.69
0.55
0.58
14.7
16.5
15.6
26.6
21.7
22.5
34.3
30.3
31.7
Ϫ
Ϫ
Ϫ
Ϫ3.0
Ϫ5.79
Ϫ2.88
1.12
3.20
1.66
[a]
Coupling constant J (in Hz).
tra for 1a؊2c show only one signal for each complex, indi-
cating that one single stereoisomer was formed upon com-
plexation. Fortunately, the detailed structures of 1b, 1c and
2a were further confirmed by a crystal structure analysis,
which showed clearly the stereo relationship of the donors
around the palladium center.
Single crystals suitable for the analysis of the complexes
1b, 1c and 2a·CH2Cl2 were obtained by slow evaporation
of dichloromethane/diethyl ether solutions. The crystal data
of these complexes are collected in Table 2. ORTEP plots
of 1b, 1c and 2a·CH2Cl2 are depicted in Figures 1Ϫ3,
respectively, and selected bond lengths and angles are sum-
marized in Table 3. All the palladium complexes are square
planar with slight distortions, particularly for the angle
N(1)ϪPdϪN(2) (ca. 84°). In all instances, the methyl group
is located trans to the pyridinyl-nitrogen and the PdϪC dis-
˚
tances are in the range 2.000Ϫ2.114 A, which are typical Figure 1. ORTEP plot of the cationic part of complex 1b
palladium-methyl carbon lengths.[13] Examination of
Table 2. Selected crystallographic data of complexes 1b, 1c, 2a and 5
Complex
2a
1b
1c
5
Formula
Mol. wt.
C27H27BCl2F4N3PPd
688.60
C26H26ClN2PPd
539.31
C30H34ClN2PPd
595.41
C25H23Cl2N2PPd
559.72
Crystal system
Space group
triclinic
P1
8.2500(1)
12.3890(1)
15.4960(2)
74.300(1)
87.674(1)
82.592(1)
monoclinic
P21/n
9.5805(1)
14.6296(2)
16.6491(3)
90
98.8701(6)
90
2305.61(6)
4
monoclinic
Cc
10.7780(6)
17.474(1)
15.0640(9)
90
91.986(3)
90
2835.4(3)
4
monoclinic
Cc
9.3350(1)
17.2460(2)
15.2670(2)
90
104.798(1)
90
2376.33(5)
4
¯
˚
a (A)
˚
b (A)
˚
c (A)
α (°)
β (°)
γ (°)
3
˚
V (A )
1511.99(3)
2
1.512
Z
Dcalcd (Mg/m3)
F(000)
1.554
1096
1.395
1224
1.565
1128
692
Crystal size (mm)
θ range
Refln collected
Independent refln.
Refinement method
0.35 ϫ 0.30 ϫ 0.25
2.47Ϫ25.00
9984
5314 (Rint ϭ 0.0206)
Full-matrix least-squares
on F2
0.20 ϫ 0.10 ϫ 0.07
2.31Ϫ27.50
32976
0.25 ϫ 0.20 ϫ 0.10
2.22Ϫ27.50
9688
0.25 ϫ 0.20 ϫ 0.15
2.36Ϫ27.47
27038
5305 (Rint ϭ 0.0695)
5748 (Rint ϭ 0.0713)
5396 (Rint ϭ 0.0449)
R [I Ͼ 2σ(I)]
R1 ϭ 0.0418
wR2 ϭ 0.1194
R1 ϭ 0.0371
wR2 ϭ 0.0900
R1 ϭ 0.0568
wR2 ϭ 0.1329
R1 ϭ 0.0300
wR2 ϭ 0.0714
Eur. J. Inorg. Chem. 2003, 3152Ϫ3159
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H.-R. Wu, Y.-H. Liu, S.-M. Peng, S.-T. Liu
FULL PAPER
groups on the aryl ring readily force this ring to lie almost
perpendicular to the chelating ring in order to relieve the
steric interaction between the ring substituents and the co-
ordinated ligands.
A simple comparison of a few methylpalladium chloride
complexes is summarized in Scheme 2. Several differences
between these structures are: (1) the PdϪCl bond trans to
the phosphane donor is slightly longer than the bonds trans
to the nitrogen donors. (2) The PdϪC bond of 1c is longer
˚
by ca. 0.1 A than the bonds in [PdClMe(P~N)]and
[PdClMe(N~N)]. (3) The bite angle decreases in the order:
1c Ͻ [PdClMe(P~N)] Ͻ [PdClMe(N~N)]. The shorter
length of PdϪN(2) in 1c indicates a stronger coordination
of the nitrogen donor to palladium, thus showing that the
iminophosphorane functionality remains intact. Indeed, the
palladium complexes 1aϪc are fairly stable towards air or
even moisture. In NMR investigations, complexes 2aϪc re-
main unchanged for several days in the presence of water
with trace amounts of coordinating acetonitrile replaced by
water molecules. It is known that the iminophosphorane
moiety undergoes PϪN bond cleavage with water,[3] but
such activity is readily hindered by the chelation upon com-
Figure 2. Molecular structure of 1c
´
plexation, which is quite similar to that reported by Reau
in palladium complexes containing 1,2-bis(triphenylphos-
phinimino)cyclohexane.[8]
Insertion of Carbon Monoxide and Ethylene
The insertion of carbon monoxide into the PdϪC bond
of compounds 2aϪc was studied (Scheme 3). A dichloro-
methane solution of the individual complex was bubbled
with CO and monitored by 31P NMR spectroscopy. All
three complexes, 2aϪc, underwent insertion to yield the
corresponding acyl complexes and the insertion rate fol-
lowed the order of the less steric environments (2a Ͼ 2b Ͼ
2c), as evidenced by NMR spectroscopy. The resulting acyl
complexes 3b and 3c were isolated in stable solid form,
whereas the inserted product 3a readily decomposed in the
absence of a carbon monoxide atmosphere. Selected spec-
troscopic data are summarized in Table 4. The presence of
the 13C chemical shift at δ ϭ 220 ppm and the infrared
stretching frequency around 1700 cmϪ1 clearly demonstrate
the formation of the acetyl group.
Subsequent insertion of ethylene into the Pd-acyl bond
of 3bϪc can be achieved by bubbling ethylene gas through
a dichloromethane solution of the respective palladium
complex. The inserted products 4bϪc were obtained as air-
stable yellow solids and the spectroscopic data (Table 4)
clearly support the structure proposed. The carbonyl
stretching frequency in the range of 1600Ϫ1630 cmϪ1 for
4bϪc suggests that the formation of the five-membered
(C,O) chelate ring provides extra stability for these com-
plexes.[13]
Figure 3. ORTEP drawing of 2a
PdϪN(2)ϪC(4), PdϪN(2)ϪP(1) and P(1)ϪN(2)ϪC(4) re-
veals that the N(2) center is trigonal planar, indicating an
sp2 hybridization of the nitrogen atom. All other bond
lengths and bond angles lie within the usual range even in
the case of 1c, with the bulky substituents on the aryl ring.
However, the dihedral angles of N(1)ϪC(22)ϪP(1)ϪN(2)
and the orientation of the imine [N(2)] aryl ring relative to
the chelating ring appear to be the major differences among
these crystal structures.
The small dihedral angles of N(1)ϪC(22)ϪP(1)ϪN(2) for
1c [6.1(6)°] imply an almost planar geometry for this biden-
tate ligand, whereas a larger deviation of this angle from
planar geometry in both 2a and 1b [2a: 26.9(3)°; 1b:
28.3(3)°] is observed. In fact, the chelating ring in 1c lies in
Complex [PdCl2(Lb)]
˚
a plane with a slight deviation of N(2) by ca. 0.12 A, based
on the calculated plane defined by P(1)ϪC(22)ϪN(1)ϪPd.
In order to find out the difference in the trans influence
The dihedral angle between the chelating ring and the imino between pyridinyl and iminophosphorane nitrogen, the pal-
[N(2)] aryl ring for 1c is 82.6(2)°, showing that the isopropyl ladium dichloride complex [PdCl2(Lb)] (5) was prepared by
3154
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Eur. J. Inorg. Chem. 2003, 3152Ϫ3159

Palladium(II) Complexes Containing a Pyridinyliminophosphorane Ligand
FULL PAPER
˚
Table 3. Selected bond lengths (A) and angles (deg) for 1b, 1c, 2a and 5
Complex
2a, X ϭ N(3)
1b, X ϭ Cl(1)
1c, X ϭ Cl(1)
5, X ϭ Cl(1)
PdϪN(1)
PdϪN(2)
PdϪC(1)
PdϪX
P(1)ϪN(2)
P(1)ϪC(22)
C(22)ϪN(1)
N(2)ϪC(4)
2.173(3)
2.052(3)
2.008(4)
2.005(3)
1.597(3)
1.824(3)
1.337(5)
1.424(4)
2.160(7)
2.090(6)
2.114(7)
2.302(2)
1.595(6)
1.820(8)
1.36(1)
2.170(3)
2.080(3)
2.087(3)
2.3085(8)
1.592(3)
1.819(3)
1.354(4)
1.428(4)
2.070(3)
2.048(3)
PdϪCl(2): 2.291(1)
2.2877(9)
1.590(3)
1.834(3)
1.340(5)
1.426(4)
1.435(9)
N(1)ϪPdϪN(2)
N(1)ϪPdϪC(1)
N(2)ϪPdϪC(1)
N(2)ϪPdϪX
83.9(1)
175.4(1)
92.6(2)
177.9(1)
88.0(2)
126.9(2)
109.0(1)
123.8(2)
104.1(2)
84.9(2)
175.5(3)
92.9(2)
175.8(2)
88.7(2)
124.3(4)
107.7(1)
126.6(2)
107.0(3)
84.4(1)
175.2(1)
91.1(1)
178.98(7)
89.81(8)
121.7(2)
114.3(3)
120.5(5)
106.1(2)
85.0(1)
176.20(9)
C(1)ϪPdϪX
PdϪN(2)ϪC(4)
PdϪN(2)ϪP(1)
P(1)ϪN(2)ϪC(4)
C(22)ϪP(1)ϪN(2)
122.5(2)
108.1(3)
128.0(2)
103.4(2)
ure 4 shows a perspective view of the complex whose selec-
ted bond lengths and bond angles are summarized in
Table 3. As expected, complex 5 shows a square-planar co-
ordination geometry around the metal center, with the
N(1)ϪPdϪN(2) angle deviating slightly from 90° because
of the constraint imposed by the chelating ring. No major
deviation was observed in the bond lengths and angles with
respect to 1b, 1c and 2a. The lengths of both PdϪCl bonds
are essentially identical. However, the PdϪN(1) lengths in
1b, 1c and 2a which is trans to the carbon donors, lie in the
Scheme 2. Summary of bond lengths and bond angles of pal-
ladium complexes
˚
range of 2.16Ϫ2.17 A, whereas the PdϪN(1) distance in 5
˚
is shorter by about 0.1 A. This variation is due to the
stronger trans influence of carbon versus chloride ligands.
From this structural analysis, both nitrogen donors (pyridi-
nyl and iminophosphorane) have a similar trans influence.
However, the pyridinyl-nitrogen donor appears to be some-
what stronger due to the alkyl ligands being trans to the
nitrogen ligand in complexes 1 and 2.
Scheme 3
Table 4. Selected spectroscopic data for 3aϪc and 4bϪc[a]
[b]
Complex
1H NMR
13C NMR
31P NMR
IR (νCO)
-CO-CH3
-CϭO
3a
3b
3c
4b
4c
2.14
1.76
1.79
2.01
1.77
221.5
221.3
220.9
211.6
224.2
22.0
26.3
24.6
28.3
29.8
1728
1713
1713
1623
1660
[a]
[b]
Chemical shifts in ppm, in CDCl3. KBr, cmϪ1
.
simple substitution of [PdCl2(CH3CN)2] with an equimolar
amount of Lb. The complex was readily purified by recrys-
tallization and the crystal structure was determined. Fig- Figure 4. Molecular structure of palladium dichloride complex 5
Eur. J. Inorg. Chem. 2003, 3152Ϫ3159
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H.-R. Wu, Y.-H. Liu, S.-M. Peng, S.-T. Liu
FULL PAPER
Copolymerization
oped by Ruchatz and Fink.[14] Among these catalysts (en-
tries 4Ϫ6), complex 2b appears to be the one with the high-
est activity. On the other hand, the phosphanylimine pal-
ladium complex [PdMe(CH3CN)(P~N)]BF4 does not show
this kind of activity.
The catalytic activity of the cationic palladium complexes
2aϪc was examined. Unlike the corresponding diiminopal-
ladium complexes,[1] this series of complexes were not good
catalysts for the polymerization of ethylene. Nevertheless,
complex 2b was found to catalyze the copolymerization of
carbon monoxide and norbornene (Table 5). Both the
chemical shift in the 13C NMR spectrum and the infrared
stretching frequency of the carbonyl group (δ ϭ 211 ppm
and 1713 cmϪ1 respectively) clearly demonstrate the forma-
tion of the copolymer. As shown in Table 5, the olefin con-
centration does not have any effect on either the molecular
weight or the yield. However, a higher pressure of carbon
monoxide led to the precipitation of palladium black out
of solution and to lower molecular weight copolymers. In
terms of solvent effect, both a coordinating solvent such as
acetonitrile (entry 6) and a non-polar solvent (entry 8) pro-
vide poor conversions. By comparing the catalysts (entries
1, 7 and 9), complex 2b appears to be much more active
than either 2a or 2c. The lower activity of 2c is presumably
due to the steric hindrance of the ligand, whereas in the
case of 2a it is due to the lower stability of the inserted
intermediates as illustrated in the previous section. In terms
of the catalytic copolymerization of CO/norbornene, com-
Table 6. Results of copolymerization of ethylene/norbornene[a]
Entry norbornene Time MN PDI Yield N%[b] Tg
TOF[c]
(h)
(mg)
(°C)
1
2.5
5.0
5.0
5.0
5.0
5.0
24
48
48
24
24
24
31000 1.41 1431 54.2 141.8 110
20000 1.75 1114 61.9 130.2 43
34000 1.61 2378 49.8 144.3 92
35000 1.59 1772 55.5 126.6 137
3600 1.87 538 64.0 154.5 45
2[d]
3
4
5[e]
6[f]
2900 1.44 108 59.7 122.4
8
[a] Ethylene/Norbornene (5 g) with 2b (30 mg) as catalyst in toluene
[b]
(20 mL) at 30 °C unless noted. N%: mol percent of norbornene
[c]
(by Tg method). g·molϪ1·hϪ1 [d] Reaction temperature at 50 °C.
[e]
[f]
2a as the catalyst. 2c as the catalyst.
In summary, a series of pyridinyliminophosphorane li-
gands with different steric influences was prepared and
their methylpalladium complexes appear to be stable to-
ward moisture. As for the reactivity toward insertion of CO
and ethylene, complexes 2bϪc with a sterically hindered en-
vironment can stabilize the inserted intermediates, but not
2a. As for catalysis, complex 2b is a good candidate for the
coplymerization of CO/norbornene and ethylene/norbor-
nene.
plex 2b shows
a
similar activity to that of
[PdMe(P~N)(CH3CN)]BF4.[13a]
Table 5. Results of copolymerization of CO and norbornene[a]
Entry
CO(psi)
MN
PDI
Yield
TOF[b]
1
2
3
4
14.7
200
14.7
200
50
14.7
14.7
150
14.7
5746
3288
5137
2352
2373
2902
2485
Ϫ[f]
1.50
1.93
1.37
1.51
1.43
1.58
1.63
Ϫ
311 mg
204 mg
251 mg
254 mg
216 mg
125 mg
187 mg
76 mg
24
16
19
20
17
10
14
5.9
13
Experimental Section
5
6[c]
7[d]
8[e]
9[g]
General Information: NMR spectra were recorded in CDCl3 or
[D6]acetone on either a Bruker AC-E 200 or AM-300 spectrometer.
Chemical shifts are given in parts per million relative to SiMe4 for
1H and 13C NMR, and 85% H3PO4 for 31P NMR spectroscopy.
Due to the complication of the aromatic region, chemical shifts of
non-aromatic carbons are reported. Infrared spectra were measured
on a Nicolet Magna-IR 550 spectrometer (Series-II) as KBr pellets,
unless otherwise noted. Gel permeation chromatography (GPC)
data were obtained from a Waters Model 590 liquid chromatograph
installed with a Lab Alliance RI 2000 detector using THF as eluent
at room temperature and the polystyrene calibration curve for
analyses. Differential scanning calorimetric (DSC) measurement
was carried out on a TA 2920 system.
1976
1.61
173 mg
[a]
Catalyst: 2b (30 mg), norbornene (5 g), 24 h, in CH2Cl2 (20 mL)
at 30 °C except where noted; norbornene (10 g) was used in entries
[b]
[e]
[d]
3 and 4.
g·molϪ1·hϪ1 [c] In CH2Cl2/CH3CN ϭ 4:1.
2a as the
[f]
catalyst. In toluene. MN[gw] as not determined due to its poor
solubility in organic solvent. 2c as the catalyst.
In addition to the copolymerization of CO/norbornene,
this series of complexes can also copolymerize ethylene and
norbornene. In a typical reaction, 2b (30 mg) was added to
norbornene and ethylene (500 psi) in toluene (20 mL) at 30
°C and after 24 hours, 1.4 g of copolymer was produced.
The results are summarized in Table 6. The appropriate re-
action conditions for this polymerization appear in entry 4
with the ratio of norbornene to ethylene being 55:45. The
mol percentage of the incorporated norbornene units was
All reaction, manipulation and purification steps were performed
under a dry nitrogen atmosphere. Tetrahydrofuran was distilled un-
der nitrogen from sodium benzophenone ketyl. Dichloromethane
and acetonitrile were dried with CaH2 and distilled under nitrogen.
Other chemicals and solvents were of analytical grade and were
used as received unless otherwise stated. 2-Diphenylphosphanylpy-
ridine was prepared by reacting lithium diphenylphosphide with 2-
bromopyridine.[15] Phenyl azide and 2,6-dialkylphenyl azide were
obtained by the diazotization of the corresponding aniline followed
determined by the glass transition point (Tg) method devel- by the substitution of azide anion.[16]
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Palladium(II) Complexes Containing a Pyridinyliminophosphorane Ligand
FULL PAPER
General Procedure for the Preparation of Ligands La؊Lc: 2-Di-
phenylphosphanylpyridine (0.5 g, 1.9 mmol) and dichloromethane py-H), 6.75Ϫ6.66 (m, 3 H, Ar-H), 2.24 (s, 3 H, Ar-CH3), 0.62 (s,
(15 mL) were placed in a degassed round-bottomed flask. A solu-
3 H, Pd-CH3) ppm. 13C NMR: δ ϭ 154.4 (d, JC,P ϭ 134.5 Hz),
tion of aryl azide (1.9 mmol) was transferred into the above flask 151.3 (d, JC,P ϭ 12.9 Hz), 143.1, 137.4 (d, JC,P ϭ 9.52 Hz), 135.9
H, Ar-H), 7.57Ϫ7.55 (m, 2 H, py-H), 7.48Ϫ7.24 (m, 6 H, Ar-H,
under nitrogen. Nitrogen gas was generated immediately and the
resulting mixture was stirred for 2.5 h. After concentration, the de-
sired ligands were obtained as moisture-sensitive, viscous liquids.
(d, JC,P ϭ 5.5 Hz), 133.4 (d, JC,P ϭ 2.8 Hz), 132.7 (d, JC,P
10.1 Hz), 129.1 (d, JC,P ϭ 12.5 Hz), 127.9 (d, JC,P ϭ 2.7 Hz), 126.9
(d, JC,P ϭ 2.7 Hz), 126.3 (d, JC,P ϭ 23.0 Hz), 125.3 (d, JC,P
ϭ
ϭ
95.0 Hz), 123.2 (d, JC,P ϭ 3.2 Hz), 21.9 (s, Ar-CH3), Ϫ5.79 (s,-
PdCH3) ppm. 31P NMR: δ ϭ 21.70 ppm. C26H26ClN2PPd (539.34):
calcd. C 57.90, H 4.86, N 5.19; found C 57.39, H 4.86, N 5.20.
Ligand La: (0.65 g, 96%), 1H NMR (CDCl3): δ ϭ 8.78 (d, J ϭ
4.6 Hz, 1 H, py-H6), 8.34 (dd, J ϭ 7.1, 6.1 Hz, 1 H, py-H4),
7.99Ϫ7.94 (m, 4 H, Ar-H), 7.78Ϫ7.76 (m, 1 H, py-H), 7.51Ϫ7.35
(m, 7 H, Ar-H, py-H), 7.07 (dd, J ϭ 9.0, 8.4 Hz, 2 H, Ar-H), 6.90
(d, J ϭ 8.4 Hz, 2 H, Ar-H), 6.71 (t, J ϭ 9.0 Hz, 1 H, Ar-H) ppm.
Complex 1c: (0.86 g, 76%). M.p. 183Ϫ190 °C (dec). 1H NMR
(CDCl3): δ ϭ 9.47 (d, J ϭ 5.0 Hz, 1 H, py-H6), 7.86Ϫ7.82 (m, 1
H, py-H), 7.80Ϫ7.75 (m, 5 H, Ar-H), 7.54Ϫ7.46 (m, 5 H, Ar-H),
7.35Ϫ7.32 (m, 2 H, py-H), 6.95Ϫ6.84 (m, 3 H, Ar-H), 3.59Ϫ3.56
(m, 2 H, -CH-), 1.34 (d, J ϭ 6.7 Hz, 6 H, -CH3), 0.69 (s, 3 H, Pd-
CH3), 0.55 (d, J ϭ 6.8 Hz, 6 H, -CH3) ppm. 13C NMR: δ ϭ 154.2
13C NMR: δ ϭ 155.2 (d, JC,P ϭ 130.0 Hz), 150.2 (d, JC,P
ϭ
19.1 Hz), 140.0, 136.2 (d, JC,P ϭ 9.0 Hz), 133.0 (d, JC,P ϭ 9.3 Hz),
131.7 (d, JC,P ϭ 2.7 Hz), 130.8, 129.3 (d, JC,P ϭ 19.8 Hz), 128.7,
128.5 (d, JC,P ϭ 11.9 Hz), 125.1 (d, JC,P ϭ 3.0 Hz), 123.4 (d, JC,P ϭ
18.2 Hz), 117.4 ppm. 31P NMR: δ ϭ 14.8 ppm. HRMS (EI): calcd.
for C23H19N2P m/z ϭ 354.1286; found: 354.1277. C23H19N2P
(354.38): calcd. C 77.95, H 5.40; found C 77.59, H 5.38.
(d, JC,P ϭ 136.6 Hz), 151.2 (d, JC,P ϭ 12.6 Hz), 146.1 (d, JC,P
ϭ
5.5 Hz), 139.4 (d, JC,P ϭ 2.1 Hz), 137.4 (d, JC,P ϭ 9.6 Hz), 133.2
(d, JC,P ϭ 2.2 Hz), 132.9 (d, JC,P ϭ 9.7 Hz), 129.0 (d, JC,P
12.2 Hz), 127.2, 126.9, 125.5 (d, JC,P ϭ 94.1 Hz), 124.1 (d, JC,P
ϭ
ϭ
Ligand Lb: (0.68 g, 93%), 1H NMR (CDCl3): δ ϭ 8.75 (d, J ϭ
4.8 Hz, 1 H, py-H6), 8.38 (dd, J ϭ 7.0, 6.2 Hz, 1 H, py-H4),
7.80Ϫ7.75 (m, 5 H, Ar-H), 7.50Ϫ7.48 (m, 2 H, py-H), 7.43Ϫ7.36
(m, 5 H, Ar-H), 6.95Ϫ6.93 (d, J ϭ 7.0 Hz, 2 H, Ar-H), 6.68 (t, J ϭ
7.0 Hz, 1 H, Ar-H), 2.07 (s, 6 H, Ar-CH3) ppm. 13C NMR: δ ϭ
157.2 (d, JC,P ϭ 133.8 Hz), 149.8 (d, JC,P ϭ 20.1 Hz), 146.6, 136.1
2.9 Hz), 123.3 (d, JC,P ϭ 1.8 Hz), 28.3 (ϪCH-),24.7 (s, Ar-
CH3),23.1 (ϪCH3), Ϫ2.88 (s,-PdCH3) ppm. 31P NMR: δ ϭ 22.50
ppm. C30H34ClN2PPd (595.45): calcd. C 60.51, H 5.76, N4.70;
found C 60.23, H 5.68, N 4.73.
General Procedure for the Synthesis of [LXPdMe(CH3CN)]BF4
(2a؊c): An acetonitrile solution of AgBF4 (0.19 g, 0.97 mmol) was
added to a solution of LxPdClMe (0.97 mmol) in dichloromethane
(10 mL) under a nitrogen atmosphere. After stirring for 1 h, re-
moval of AgCl by filtration and concentration gave the crude prod-
uct, which was recrystallized from dichloromethane and diethyl
ether to provide the desired products as yellow solids.
(d, JC,P ϭ 8.9 Hz), 132.8 (d, JC,P ϭ 6.4 Hz), 132.5 (d, JC,P
ϭ
9.2 Hz), 131.3 (d, JC,P ϭ 2.3 Hz), 128.2 (d, JC,P ϭ 12.0 Hz), 127.8,
128.5, 124.8, 123.3, 119.0, 21.4 ppm. 31P NMR: δ ϭ 16.5 ppm.
HRMS calcd. for C25H23N2P m/z ϭ 382.1599; found 382.1596.
C25H23N2P (382.44): calcd. C 78.51, H 6.06; found C 78.22, H 5.79.
Ligand Lc: (0.91 g, 91%), 1H NMR (CDCl3): δ ϭ 8.84 (d, J ϭ
4.0 Hz, 1 H, py-H6), 7.59Ϫ7.41 (m, 7 H, py-H, Ar-H), 7.24Ϫ7.17
(m, 6 H, py-H, Ar-H), 7.09Ϫ6.98 (m, 3 H, Ar-H), 3.40Ϫ3.33 (m,
2 H, -CH-), 1.41 (d, J ϭ 6.9 Hz, 6 H, -CH3), 1.09 (d, J ϭ 6.7 Hz,
6 H, -CH3) ppm. 13C NMR: δ ϭ 156.8 (d, JC,P ϭ 132.3 Hz), 150.1
(d, JC,P ϭ 20.0 Hz), 143.2 (d, JC,P ϭ 4.9 Hz), 140.4, 136.2 (d, JC,P ϭ
8.9 Hz), 134.4, 132.7 (d, JC,P ϭ 9.1 Hz), 128.4 (d, JC,P ϭ 11.9 Hz),
127.1, 125.1, 124.2, 123.2, 118.8, 29.0 (-CH-), 23.8 (-CH3), 22.7 (-
CH3) ppm. 31P NMR: δ ϭ 15.6 ppm. HRMS calcd. for C29H31N2P
m/z ϭ 438.2225; found 438.2233. C29H31N2P (438.54): calcd. C
79.42, H 7.12; found C 79.02, H 6.89.
Complex 2a: (0.40 g, 66%). M.p. 121Ϫ132 °C (dec). 1H NMR
(CDCl3): δ ϭ 9.03 (d, J ϭ 4.7 Hz, 1 H, py-H), 8.02Ϫ7.97 (m, 1 H,
py-H), 7.93Ϫ7.89 (m, 1 H, py-H), 7.73Ϫ7.67 (m, 6 H, py-H, Ar-
H), 7.59Ϫ7.53 (m, 5 H, Ar-H), 6.96 (dd, J ϭ 7.6, 6.2 Hz, 2 H, Ar-
H), 6.87 (d, J ϭ 7.6 Hz, 1 H, Ar-H), 6.80 (t, J ϭ 6.2 Hz, 2 H, Ar-
H), 2.44 (s, 3 H, -NCCH3), 0.69 (s, 3 H, Pd-CH3) ppm. 13C NMR:
δ ϭ 152.3 (d, JC,P ϭ 140.5 Hz), 152.3 (d, JC,P ϭ 12.7 Hz), 144.9,
139.0 (d, JC,P ϭ 10.3 Hz), 134.3 (d, JC,P ϭ 2.9 Hz), 133.3 (d, JC,P ϭ
16.3 Hz), 129.6 (d, JC,P ϭ 12.5 Hz), 128.3, 128.0 (d, JC,P
23.7 Hz), 127.4 (d, JC,P ϭ 8.9 Hz), 122.8, 121.1, 3.25 (NCCH3),
1.12 (s, Pd-CH3) ppm. 31P NMR:
34.34 ppm.
ϭ
δ
ϭ
General Procedure for the Preparation of [LXPdClMe] (1a؊c): A
mixture of [PdClMe(COD)] (0.5 g, 1.89 mmol) with an equimolar
amount of ligand in dichloromethane (5 mL) was stirred at room
temperature under a nitrogen atmosphere. After stirring for 3 h, the
solvents were evaporated and the remaining material was dissolved
in dichloromethane. Pre-dried diethyl ether was slowly added to the
above solution to precipitate the desired complexes as yellow solids.
C26H25BF4N3PPd (603.70): calcd. C 51.73, H4.17, N 6.96; found
C 51.75, H 4.18, N 6.43.
Complex 2b: (0.51 g, 84%). M.p. 182 Ϫ196 °C (dec). 1H NMR
(CDCl3): δ ϭ 9.02 (d, J ϭ 5.1 Hz, 1 H, py-H), 8.01Ϫ7.98 (m, 1
H, py-H4), 7.90Ϫ7.88 (m, 1 H, py-H), 7.78Ϫ7.73 (m, 4 H, Ar-H),
7.62Ϫ7.59 (m, 2 H, Ar-H), 7.56Ϫ7.54 (m, 1 H, py-H), 7.50Ϫ7.46
(m, 4 H, Ar-H), 6.74Ϫ6.68 (m, 3 H, Ar-H), 2.42 (s, 3 H, -NCCH3),
2.14 (s, 6 H, Ar-CH3), 0.55 (s, 3 H, Pd-CH3) ppm. 13C NMR: δ ϭ
152.6 (d, JC,P ϭ 132.8 Hz), 152.4 (d, JC,P ϭ 12.5 Hz), 142.2 (d,
JC,P ϭ 1.5 Hz), 139.2 (d, JC,P ϭ 9.4 Hz), 135.9 (d, JC,P ϭ 5.2 Hz),
134.0 (d, JC,P ϭ 2.7 Hz), 132.6 (d, JC,P ϭ 10.1 Hz), 129.3 (d, JC,P ϭ
12.3 Hz), 128.1 (d, JC,P ϭ 2.3 Hz), 127.4 (d, JC,P ϭ 22.5 Hz), 124.0
(d, JC,P ϭ 95.6 Hz), 124.0 (d, JC,P ϭ 3.0 Hz), 121.1, 21.7 (s, Ar-
CH3), 15.1 (s, -NCCH3), 3.2 (s, Pd-CH3) ppm. 31P NMR: δ ϭ 30.33
ppm. C28H29BF4N3PPd (631.75): calcd. C 53.23, H 4.63, N 6.65;
found C 53.42, H 4.48, N 6.46.
Complex 1a: (0.71 g, 74%). M.p. 180Ϫ196 °C (dec). 1H NMR
(CDCl3): δ ϭ 9.39 (d, J ϭ 4.5 Hz, 1 H, py-H6), 7.84Ϫ7.81 (m, 1
H, py-H), 7.76Ϫ7.64 (m, 6 H, py-H, Ar-H), 7.57Ϫ7.51 (m, 5 H,
Ar-H), 7.36 (m, 1 H, py-H), 6.99Ϫ6.93 (m, 4 H, Ar-H), 6.80Ϫ6.76
(m, 1 H, Ar-H), 0.77 (s, 3 H, Pd-CH3) ppm. 13C NMR: δ ϭ 153.8
(d, JC,P ϭ 143.9 Hz), 151.0 (d, JC,P ϭ 12.8 Hz), 145.9, 137.4 (d,
JC,P ϭ 10.2 Hz), 133.7 133.3, (d, JC,P ϭ 10.3 Hz), 129.3 (d, JC,P
11.2 Hz), 128.0, 127.2 (d, JC,P ϭ 9.8 Hz), 126.9, 125.2, (d, JC,P
ϭ
ϭ
9.2 Hz), 121.8, Ϫ3.0 (s, Pd-CH3) ppm. 31P NMR: δ ϭ 26.56 ppm.
C24H22ClN2PPd (511.29): calcd. C 56.38, H 4.34, N 5.48; found C
56.72, H 4.34, N 5.40.
Complex 2c: (0.27 g, 78%). M.p. 125Ϫ140 °C (dec). 1H NMR
(CDCl3): δ ϭ 9.13 (d, J ϭ 4.6 Hz, 1 H, py-H6), 8.00Ϫ7.99 (m, 1
H, py-H), 7.93Ϫ7.92 (m, 1 H, py-H), 7.65Ϫ7.59 (m, 6 H, py-H,
Complex 1b: (0.8 g, 79%). M.p. 185Ϫ210 °C (dec). 1H NMR
(CDCl3): δ ϭ 9.35 (d, J ϭ 5.1 Hz, 1 H, py-H6), 7.87Ϫ7.82 (m, 5
Eur. J. Inorg. Chem. 2003, 3152Ϫ3159
www.eurjic.org
 2003 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
3157

H.-R. Wu, Y.-H. Liu, S.-M. Peng, S.-T. Liu
FULL PAPER
Ar-H), 7.49Ϫ7.43 (m, 5 H, Ar-H), 6.90 (t, J ϭ 6.8 Hz, 1 H, Ar-
JC,P ϭ 3.1 Hz), 125.1 (d, JC,P ϭ 2.5 Hz), 123.8 (d, JC,P ϭ 2.8 Hz),
H), 6.81 (d, J ϭ 6.8 Hz, 2 H, Ar-H), 3.29 (m, 2 H, -CH-), 2.42 (s, 120.0 (d, JC,P ϭ 102.4 Hz), 37.9, 30.1, 19.9 (Pd-CO-CH3) ppm. 31
P
3 H, -NCCH3), 1.22 (d, J ϭ 6.7 Hz, 6 H, -CH3), 0.58 (s, 3 H, Pd-
CH3), 0.47 (d, J ϭ 6.85 Hz, 6 H, -CH3) ppm. 13C NMR: δ ϭ 152.5 H 4.68, N 4.33; found C 53.53, H 4.38, N 4.21.
(d, JC,P ϭ 134.6 Hz), 152.3 (d, JC,P ϭ 12.5 Hz), 146.2 (d, JC,P
NMR: δ ϭ 28.4 ppm. C29H30BF4N2OPPd (646.76): calcd. C 53.85,
ϭ
Complex 4c: (37 mg, 64%). M.p. 170Ϫ182 °C (dec.). IR (KBr): ν˜ ϭ
1660 cmϪ1(νCO);1H NMR (CDCl3): δ ϭ 8.81 (d, J ϭ 4.3 Hz, 1
H, py-H6), 8.22Ϫ8.20 (m, 1 H, py-H), 8.06Ϫ8.04 (m, 1 H, py-H),
7.65Ϫ7.51 (m, 11 H, py-H, Ar-H), 7.14Ϫ6.94 (m, 3 H, Ar-H),
3.01Ϫ2.96 (m, 2 H, -CH-), 2.27 (m, 2 H), 2.12 (m, 2 H), 1.77 (s, 3
H, Pd-OC-CH3), 1.15 (d, J ϭ 6.7 Hz, 3 H, -CH3), 0.75 (d, J ϭ
6.8 Hz, 3 H, -CH3) ppm. 13C NMR: δ ϭ 224.3, (ϪCO-),151.3 (d,
JC,P ϭ 21.1 Hz), 147.9 (d, JC,P ϭ 3 Hz), 147.0 (d, JC,P ϭ 96.3 Hz),
139.7, 138.1 (d, JC,P ϭ 10.5 Hz), 135.0 (d, JC,P ϭ 2.6 Hz), 134.0 (d,
5.4 Hz), 139.0 (d, JC,P ϭ 9.6 Hz), 138.4 (d, JC,P ϭ 2.7 Hz),133.9 (d,
JC,P ϭ 2.6 Hz), 132.8 (d, JC,P ϭ 9.7 Hz), 129.3 (d, JC,P ϭ 12.2 Hz),
128.3 (d, JC,P ϭ 22.6 Hz), 125.0 (d, JC,P ϭ 2.8 Hz), 124.3 (d, JC,P ϭ
94.9 Hz), 123.6 (d, JC,P ϭ 2.2 Hz), 121.2, 28.4 (-CH-), 24.5 (-CH3),
23.0 (-CH3), 3.19 (NCCH3), 1.66 (Pd-CH3) ppm. 31P NMR: δ ϭ
31.72 ppm. C32H37BF4N3PPd (687.85): calcd. C 55.88, H 5.42, N
6.11; found C 55.62, H 5.95, N 6.53.
General Procedure for the Synthesis of [LXPd(CO-
Me)(CH3CN)]BF4: Carbon monoxide was bubbled through an
acetonitrile solution of [LXPdMe(CH3CN)]BF4 (0.9 mmol) for
20 min. The resulting mixture was passed through celite and the
filtrate was concentrated. The crude product was dissolved in di-
chloromethane and diethyl ether was added to precipitate the de-
sired insertion products as yellow solids. These complexes readily
decomposed due to decarbonylation.
JC,P ϭ 14.5 Hz), 131.2 (d, JC,P ϭ 24.3 Hz), 129.5 (d, JC,P
13.1 Hz), 128.1 (d, JC,P ϭ 3.6 Hz), 124.0, 119.8 (d, JC,P
102.6 Hz), 119.6, 34.8, 29.7, 28.5, 24.7, 23.2, 19.7 (Pd-CO-CH3)
ppm. 31P NMR: δ ϭ 29.8 ppm. C33H38BF4N2OPPd (702.87): calcd.
C 56.39, H 5.45, N 3.99; found C 55.98, H 5.14, N 3.78.
ϭ
ϭ
Complex 5: A mixture of 2,6-dimethylphenyl azide (0.223 g) and 2-
diphenylphosphanylpyridine (0.4 g) was placed in a degassed flask.
Dichloromethane (25 mL) was introduced into the flask with a syr-
inge under nitrogen atmosphere. The resulting mixture was stirred
at room temperature for 2.5 h. [PdCl2(COD)] (0.31 g) in dichloro-
methane was added to the above solution. The reaction mixture
turned yellow immediately. After concentration to a small volume,
diethyl ether was slowly added and the desired product precipi-
tated. The latter was then re-crystallized from diethyl ether/di-
chloromethane to provide 5 as a yellow solid (765 mg, 90%). 1H
NMR (CDCl3): δ ϭ 8.74 (d, J ϭ 4.4 Hz, 1 H, py-H6), 8.38 (m, 1
H, Py-H4), 7.84- 7.78 (m, 5 H, Ar-H), 7.64Ϫ7.62 (m, 2 H, py-H),
7.51Ϫ7.46 (m, 5 H, Ar-H), 6.91Ϫ6.88 (t, J ϭ 7.4 Hz, 1 H), 6.81 (d,
J ϭ 7.4 Hz, 2 H), 2.15 (s, 6 H, -CH3) ppm. 31P NMR: δ ϭ 28.42
ppm. HRFABMS: Calcd for C25H2335Cl2N2PPd: m/z ϭ 558.0011;
found 558.0018. C25H23Cl2N2PPd (559.76): calcd. C 53.64, H 4.14,
N 5.00; found C 53.29, H 3.78, N 4.89.
Complex 3b: (31 mg, 52%). IR (KBr): ν˜ ϭ 1713 cmϪ1 (νCO). 1H
NMR (CDCl3): δ ϭ 8.94 (d, J ϭ 5.4 Hz, 1 H, py-H6), 8.02Ϫ7.97
(m, 1 H, py-H), 7.87Ϫ7.77 (m, 5 H, Ar-H), 7.64Ϫ7.63 (m, 2 H, py-
H), 7.54Ϫ7.53 (m, 5 H, Ar-H), 6.72Ϫ6.68 (m, 3 H, Ar-H), 2.24 (s,
6 H, Ar-CH3), 2.01 (s, 3 H, -NCCH3), 1.77 (s, 3 H, Pd-CO-CH3)
ppm. 13C NMR: δ ϭ 221.3 (ϪCO-), 152.4 (d, JC,P ϭ 129.2 Hz),
152.8 (d, JC,P ϭ 12.3 Hz), 143.2, 139.5 (d, JC,P ϭ 9.2 Hz), 135.5 (d,
JC,P ϭ 5.2 Hz), 134.2, 132.9 (d, JC,P ϭ 10.2 Hz), 129.5 (d, JC,P
ϭ
12.6 Hz), 129.0, 128.5, 127.2 (d, JC,P ϭ 21.6 Hz), 124.3, 123.9 (d,
JC,P ϭ 97.4 Hz), 30.5 (NCCH3), 21.8 (Ar-CH3), 2.3 (Pd-CO-CH3)
ppm. 31P NMR: δ ϭ 26.3 ppm. HRFABMS: calcd. for [M Ϫ BF4
Ϫ CH3CN] m/z ϭ 531.0818; found 531.0822.
Complex 3c: (35 mg, 59%). IR (KBr): ν˜ ϭ 1713 cmϪ1 (νCO);1H
NMR (CDCl3): δ ϭ 8.91 (d, J ϭ 4.8 Hz, 1 H, py-H6), 8.02Ϫ7.97
(m, 1 H, py-H), 7.89Ϫ7.87 (m, 1 H, py-H), 7.72Ϫ7.67 (m, 6 H, Ar-
H, py-H), 7.54Ϫ7.50 (m, 5 H, Ar-H), 6.93 (t, J ϭ 7.7 Hz, 1 H, Ar-
H), 6.86 (d, J ϭ 7.7 Hz, 1 H, Ar-H), 3.38Ϫ3.30 (m, 2 H, -CH-),
2.19 (s, 3 H, -NCCH3), 1.79 (s, 3 H, Pd-CO-CH3), 1.40 (d, J ϭ
5.8 Hz, 6 H, -CH3), 0.59 (d, J ϭ 6.8 Hz, 6 H, -CH3) ppm. 13C
NMR: δ ϭ 221.0 (ϪCO-), 152.6 (d, JC,P ϭ 128.5 Hz), 152.6 (d,
JC,P ϭ 13.1 Hz), 145.8 (d, JC,P ϭ 5.2 Hz), 139.6 (d, JC,P ϭ 3.8 Hz),
Copolymerization of CO/Norbornene: The catalysts and norbor-
nene were placed into a stainless-steel autoclave (100 mL) and dis-
solved in the solvent (20 mL). The reaction mixture was then
pressurized with a mixture of CO and stirred at 30 °C. The reaction
was stopped after the specified time and the resulting white solid
was filtered and washed with 5  HCl followed by water and ace-
tone. The Results are listed in Table 5.
139.4 (d, JC,P ϭ 9.2 Hz), 134.2 (d, JC,P ϭ 2.5 Hz), 133.2 (d, JC,P
ϭ
10.1 Hz), 129.5 (d, JC,P ϭ 12.6 Hz), 129.0, 127.7 (d, JC,P ϭ 22 Hz),
125.1 (d, JC,P ϭ 2.7 Hz), 124.0 (d, JC,P ϭ 90.4 Hz), 124.0, 31.30
(NCCH3), 28.7, 24.2 (-CH3), 23.62 (-CH3), 2.15 (Pd-CO-CH3)
ppm. 31P NMR: δ ϭ 24.7 ppm. HRFABMS: calcd. for [M Ϫ BF4
Ϫ CH3CN] m/z ϭ 587.1439; found 587.1444.
Copolymerization of Ethylene/Norbornene: The procedures for this
coplymerization are similar to the ones of the copolymerization of
CO/norbornene, except that ethylene is replaced by CO. The results
are summarized in Table 6.
General Procedure for the Synthesis of [LXPd(CH2CH2COMe)BF4:
A solution of [LXPd(COMe)(CAN)]BF4 in dichloromethane was
bubbled through ethylene gas for 1.5 h. The purification procedure
was similar to that of [LXPd(COMe)(CAN)]BF4. The desired com-
plexes were obtained as yellow solids.
X-ray Crystallographic Study: Crystals suitable for X-ray determi-
nation were obtained for 1b, 1c, 2a·CH2Cl2, and 5 by slow diffusion
of diethyl ether into a dichloromethane solution at room tempera-
ture. The cell parameters were determined on a Siemens SMART
CCD diffractometer. The crystal data for complexes 1b, 1c,
2a·CH2Cl2 and 5 are listed in Table 2 and their ORTEP plots are
shown in Figures 1Ϫ4 respectively (labels of phenyl groups are
omitted for clear view).
Complex 4b: (38 mg, 65%). M.p. 172Ϫ184 °C (dec.). IR (KBr): ν˜ ϭ
1623 cmϪ1 (νCO). 1H NMR (CDCl3): δ ϭ 9.05 (d, J ϭ 4.7 Hz, 1
H, py-H6), 8.24Ϫ8.22 (m, 1 H, py-H), 8.07Ϫ8.04 (m, 1 H, py-H),
7.73Ϫ7.49 (m, 11 H, py-H, Ar-H), 6.91Ϫ6.78 (m, 3 H, Ar-H), 2.26
(s, 6 H, Ar-CH3), 2.11 (m, 2 H), 2.01 (s, 3 H, -CH3), 1.88 (m, 2 H) CCDC-210737 (1b), -210739 (1c), -210738 (2a·CH2Cl2) and
ppm. 13C NMR: δ ϭ 211.6 (ϪCO-),152.3 (d, JC,P ϭ 129.3 Hz), -210740 (5) contains the supplementary crystallographic data for
151.3 (d, JC,P ϭ 21 Hz), 147.9, 140.0 (d, JC,P ϭ 9.2 Hz), 137.4 (d, this paper. These data can be obtained free of charge at
JC,P ϭ 3.0 Hz), 135.1 (d, JC,P ϭ 2.7 Hz), 133.8 (d, JC,P ϭ 10.4 Hz),
129.5 (d, JC,P ϭ 12.9 Hz), 128.2 (d, JC,P ϭ 21.7 Hz), 128.0 (d,
www.ccdc.cam.ac.uk/conts/retrieving.html [or from the Cambridge
Crystallographic Data Centre, 12, Union Road, Cambridge
3158
 2003 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
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Eur. J. Inorg. Chem. 2003, 3152Ϫ3159

Palladium(II) Complexes Containing a Pyridinyliminophosphorane Ligand
FULL PAPER
[6f]
S. Courtenay, D. W. Stephan, Organometallics 2001, 20,
1442Ϫ1450, and references therein.
CB2 1EZ, UK; Fax: (internat.) ϩ44-1223/336-033; E-mail:
deposit@ccdc.cam.ac.uk].
[7]
[8]
R. Vollmerhaus, P. Shao, N. J. Taylor, S. Collins, Organometall-
ics 1999, 18, 2731Ϫ2733.
´
´
´
M. Sauthier, J. Fornies-Camer, L. Toupet, R. Reau, Organome-
tallics 2000, 19, 553Ϫ562.
Acknowledgments
[9] [9a]
J. Vicente, A. Arcas, D. Bautista, M. C. Ramirez de Arel-
[9b]
We thank the National Science Council for financial support
(NSC90-2113-M-002-038).
lano, Organometallics 1998, 17, 4544Ϫ4550.
S. Fernandez, M. M. Garcia, R. Navarro, E. P. Urriolabeitia,
L. R. Falvello,
´
[9c]
J. Chem. Soc., Dalton Trans. 1998, 3745Ϫ3750.
S. M. Auc-
ott, A. M. Z. Slawin, J. D. Woollins, J. Chem. Soc., Dalton
Trans. 2001, 2279Ϫ2287.
Thornton-Pett, D. L. Ormsby, P. J. Maddox, P. Bres, M. Boch-
mann, J. Chem. Soc., Dalton Trans. 2000, 4247Ϫ4257.
M. Hankin, A. A. Danopoulos, G. Wilkinson, T. K. N. Sweet,
[1]
[9d]
[1a] L. K. Johnson, C. M. Killian, M. Brookhart, J. Am. Chem.
S. Al-Benna, M. J. Sarsfield, M.
[1b]
Soc. 1995, 117, 6414Ϫ6415.
C. M. Killian, D. J. Tempel,
L. K. Johnson, M. Brookhart, J. Am. Chem. Soc. 1996, 118,
[9e]
D.
[1c]
11664Ϫ11665.
D. J. Tempel, L. K. Johnson, R. L. Huff, P.
S. White, M. Brookhart, J. Am. Chem. Soc. 2000, 122,
M. B. Hursthouse, J. Chem. Soc., Dalton Trans. 1996,
[1d]
[9f]
6686Ϫ6700.
O. Daugulis, M. Brookhart, Organometallics
4063Ϫ4069.
P. Imhoff, R. van Asselt, C. J. Elsevier, M. C.
2002, 21, 5926Ϫ5934.
Zoutberg, C. H. Stam, Inorg. Chim. Acta 1991, 184, 73Ϫ87.
[2]
[10] [10a]
Reviews on TM-catalyzed olefin polymerization: [2a] S. D. Ittel,
L. K. Johnson, M. Brookhart, Chem. Rev. 2000, 100,
1169Ϫ1203. [2b] E. Drent, P. H. M. Budzelaar, Chem. Rev. 1996,
K. V. Katti, B. D. Santarsiero, A. A. Pinkerton, R. G.
Cavell, Inorg. Chem. 1993, 32, 5919Ϫ5925. [10b] R. W. Reed, B.
Santarsiero, R. G. Cavell, Inorg. Chem. 1996, 35, 4292Ϫ4300.
R. S. Pandurangi, K. V. Katti, L. Stillwell, C. L. Barnes, J. Am.
Chem. Soc. 1998, 120, 11364Ϫ11373.
[2c]
[2d]
[11]
96, 663Ϫ681.
G. Consiglio, Chimia 2001, 55, 809Ϫ813.
Y. Imanishi, N. Naga, Prog. Polym. Sci. 2001, 26, 1147Ϫ1198.
[2e] C. Bianchini, A. Meli, Coord. Chem. Rev. 2002, 225, 35Ϫ66.
M. W. Avis, C. J. Elsevier, N. Veldman, H. Kooijman, A.
[12] [12a]
[2f]
[12b]
J. Okuda, R. Mulhaupt, in Synthesis of Polymers (Ed.: A.-
L. Spek, Inorg. Chem. 1996, 35, 1518Ϫ1528.
C. J. Elsevier, H. Kooijman, N. Veldman, A. L. Spek, C. J.
Elsevier, Inorg. Chem. 1995, 34, 4092Ϫ4105.
K. Vrieze, J. M. Ernsting, C. J. Elsevier, N. Veldman, A. L.
M. W. Avis,
D. Schlueter), Wiley-VCH Verlag GmbH, Weinheim, Germany.
1999, Vol. 20, 123Ϫ162. [2g]A. Sen, Pure Appl. Chem. 2001, 73,
M. W. Avis,
[12c]
[2h]
251Ϫ254.
G. Helmchen, A. Pfaltz, Acc. Chem. Res. 2000,
[2i]
33, 325Ϫ335.
P. Braunstein, F. Naud, Angew. Chem. 2001,
Spek, K. V. Katti, C. L. Barnes, Organometallics 1996, 15,
[12d]
113, 702Ϫ722; Angew. Chem. Int. Ed. 2001, 40, 680Ϫ699.
H. Staudinger, E. Hauser, Helv. Chim. Acta 1921, 4, 887.
2376Ϫ2392.
M. W. Avis, M. Goosen, C. J. Elsevier, N.
[3]
[4] [4a]
Veldman, H. Kooijman, A. L. Spek, Inorg. Chim. Acta 1997,
264, 43Ϫ60.
A. Schmidpeter, T. von Criegern, Angew. Chem. 1978, 90,
[4b]
[13] [13a]
64Ϫ65; Angew. Chem. Int. Ed. Engl. 1978, 17, 55Ϫ56.
H.
K. R. Reddy, C.-L. Chen, Y.-H. Liu, S.-M. Peng, J.-T.
Alper, R. A. Partis, J. Organomet. Chem. 1972, 35, C40ϪC42.
[4c] C.-Y. Liu, D.-Y. Chen, M.-C. Cheng, S.-M. Peng, S.-L. Liu,
Organometallics 1995, 14, 1983Ϫ1991.
Chen, S.-T. Liu, Organometallics 1999, 18, 2574Ϫ2576. [13b] K.
R. Reddy; K. Surekha, G.-H. Lee, S.-M. Peng, J.-T. Chen, S.-
T. Liu, Organometallics 2001, 20, 1292Ϫ1299.
C.-L. Chen, J.-T. Chen, S.-T. Liu, Organometallics 2001, 20,
[13c]
Y.-C. Chen,
[5] [5a]
W. Keim, R. Appel, A. Storeck, C. Kruger, R. Goddard,
[13d]
Angew. Chem. 1981, 93, 91Ϫ92; Angew. Chem. Int. Ed. Engl.
1285Ϫ1286.
Peng, S.-T. Liu, Organometallics 2001, 20, 5557Ϫ5563.
Y. Shi, Y.-H. Liu, S.-M. Peng, S.-T. Liu, Organometallics 2002,
K. R. Reddy, K. Surekha, G.-H. Lee, S.-M.
[5b]
[13e]
1981, 20, 116Ϫ117.
M. Sauthier, F. Leca, R. Fernando de
P. -
Souza, K. Bernardo-Gusmao, L. F. Trevisan Queiroz, L. Tou-
[13f]
´
pet, R. Reau, New J. Chem. 2002, 26, 630Ϫ635.
21, 3203Ϫ3207.
K. R. Reddy, W. W. Tsai, K. Surekha, G.-
[6] [6a]
N. Yue, E. Hollink, F. Guerin, D. W. Stephan, Organomet-
H. Lee, S.-M. Peng, J.-T. Chen, S.-T. Liu, J. Chem. Soc., Dalton
Trans. 2002, 1776Ϫ1782.
D. Ruchatz, G. Fink, Macromolecules 1998, 31, 4674Ϫ4680.
T. J. Barder, F. A. Cotton, G. L. Powell, S. M. Tetrick, R. A.
Walton, J. Am. Chem. Soc. 1984, 106, 1323Ϫ1332.
I. Ugi, H. Perlinger, L. Behringer, Chem. Ber. 1958, 91, 2330.
Received March 6, 2003
[6b]
allics 2001, 20, 4424Ϫ4433.
Organometallics 2001, 20, 2303Ϫ2308.
Guerin, J. C. Stewart, E. Urbanska, D. W. Stephan, Organome-
N. L. S. Yue, D. W. Stephan,
[6c]
[14]
[15]
J. E. Kickham, F.
[6d]
tallics 2001, 20, 1175Ϫ1182.
L. LePichon, D. W. Stephan,
X. Gao, Q. Wang, Organometallics 2002, 21, 1362Ϫ1366. [6e] L.
LePichon, D. W. Stephan, Inorg. Chem. 2001, 40, 3827Ϫ3829.
[16]
Eur. J. Inorg. Chem. 2003, 3152Ϫ3159
www.eurjic.org
 2003 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
3159