Synthesis, structure, and ethylene polymerization behavior of nickel complexes based on benzoylmethylenetri(2-alkoxylphenyl)phosphorane

Article abstract of DOI:10.1039/c2dt12052f

Several new nickel complexes are prepared by the treatment of the stabilized ylide benzoylmethylenetri(2-alkoxylphenyl)phosphorane with Ni(cod)₂ in the presence of PPh₃. X-Ray diffraction studies reveal that a distorted square planar geometry around Ni(ii) is adopted. Upon treatment with Ni(cod)₂, the nickel complexes are sufficiently robust for ethylene polymerization. The existence of 2-alkoxyl-aryl substituents on phosphorus improves the catalytic activities. The highest activity (2.1 × 10⁶ g mol^-1 h^-1) is achieved when tri(2-isopropoxy-phenyl)phosphorane is employed (5e), which is one order higher than the corresponding SHOP catalyst. NMR analysis shows that the polyethylene mainly contains terminal double bonds and is highly linear.

Full text of DOI:10.1039/c2dt12052f

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PAPER
Synthesis, structure, and ethylene polymerization behavior of nickel
complexes based on benzoylmethylenetri(2-alkoxylphenyl)phosphorane†
Da-Wei Wan,a Yan-Shan Gao,b Jun-Fang Li,b Qi Shen,a Xiu-Li Sun*b and Yong Tangb
Received 28th October 2011, Accepted 12th January 2012
DOI: 10.1039/c2dt12052f
Several new nickel complexes are prepared by the treatment of the stabilized ylide benzoylmethylenetri(2-
alkoxylphenyl)phosphorane with Ni(cod)2 in the presence of PPh3. X-Ray diffraction studies reveal that a
distorted square planar geometry around Ni(II) is adopted. Upon treatment with Ni(cod)2, the nickel
complexes are sufficiently robust for ethylene polymerization. The existence of 2-alkoxyl-aryl substituents
on phosphorus improves the catalytic activities. The highest activity (2.1 × 106 g mol−1 h−1) is achieved
when tri(2-isopropoxy-phenyl)phosphorane is employed (5e), which is one order higher than the
corresponding SHOP catalyst. NMR analysis shows that the polyethylene mainly contains terminal
double bonds and is highly linear.
Introduction
In recent years, late-transition metal based complexes as catalysts
for the polymerization of olefins and functionalized olefins
under moderate conditions have been of considerable interest
Scheme 1 Structure of SHOP-type complexes.
because of their high functional group tolerance.1 Of the cata-
lysts developed, the family of nickel and palladium complexes
based on either α-diimine2 or salicylaldimine3 have been investi-
gated extensively. SHOP (Shell Higher Olefin Process)4–6 type
catalysts have been known for their unusual selectivity-control-
ling effect in the oligomerization of ethylene. They were also
useful in catalyzing the ethylene into a polymer in the presence
of bis(cyclooctadiene)nickel (Ni(cod)2). To date, efforts have
been made to improve their activity and broaden the scope of
their application. Most of the modifications are focused on R2
and R3 groups of the chelating carbon backbone and/or the
ligand L (Scheme 1).7 For example, Ostoja-Starzewski and Witte
disclosed a kind of nickel complex which is highly active
leading to highly linear polyethylene.7a Gibson and his co-
Scheme 2 Synthesis of the ylides and nickel complexes.
workers successfully enhanced the ethylene polymerization
activity on introduction of bulky substituents at the site adjacent
introduction of ortho-methylphenyl groups on the phosphorus
to the oxygen donor group (Scheme 2).7e,f However, very few
resulted in the reduction of the activity compared with the parent
examples involved the influence of the properties of R1 on the
[P,O]Ni catalyst.7e During our ongoing research into ylide chem-
catalytic olefin polymerization behaviors. The only example was
istry8 and metal complex catalyzed olefin polymerization,9 we
reported by Gibson et al., in which they had found that the
found recently that the 2-alkoxyl group of the phenyl of phos-
phorane in SHOP-type nickel complexes could enhance the
activity of ethylene polymerization significantly. In this paper,
we will report the results.
aState Key Laboratory of Organic Synthesis of Jiangsu Province,
College of Chemistry, Chemical Engineering and Material Science,
Soochow University, Suzhou, 215123, People’s Republic of China,
China. E-mail: qshen@suda.edu.cn; Fax: +86 512 65880305;
Results and discussion
Tel: +86 512 65882806
bState Key Laboratory of Organometallic Chemistry, Shanghai Institute
Design, synthesis, and characterization of complexes
of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling
Road, Shanghai, 200032, China. E-mail: xlsun@sioc.ac.cn
†CCDC reference numbers 847790–847793. For crystallographic data
in CIF or other electronic format see DOI: 10.1039/c2dt12052f
It was found that introducing a pendant donor in the ligand can
either stabilize a Lewis acidic metal center or modify the
4552 | Dalton Trans., 2012, 41, 4552–4557
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Fig. 3 Molecular structure of complex 5d.
Fig. 1 Molecular structure of complex 5b.
Fig. 4 Molecular structure of complex 5e.
Fig. 2 Molecular structure of complex 5c.
the selected bond lengths (Å) and angles (°) of 5b, 5c, 5d, and
5e are summarized in Table 1.
geometry around the metal and thus tune the catalytic behaviors
of the complexes.10 By employing this strategy, we recently
designed several catalysts for olefin polymerization, which
showed unique properties such as increasing activity and improv-
ing tolerance of impurity.9 On the basis of these studies, we
designed and synthesized nickel complexes based on benzoyl-
methylenetri(2-alkoxylphenyl)phosphorane 5.
As shown in Fig. 1, nickel complex 5b adopts a distorted
square planar geometry around nickel. The P1, C9, P2 and O1
atoms are nearly coplanar, with P1 and P2 occupying the trans
position (bond angles of P2–Ni–P1 and O1–Ni–C9: 170.37(3)°
and 173.18(10)°). The 2-MeOC6H4 rings on phosphorus are
inclined by 82.51° and 64.27° to this plane. Comparing with the
reported SHOP nickel complexes,4,7e the bond length of Ni–P1
is lengthened (2.1833(7) Å vs. 2.168 and 2.165(1) Å) because of
the introduction of steric hindrance around phosphorus. Whereas
both the length of Ni–P2 and Ni–O1 are shorter than those of 5a
(2.2184(7) Å vs. 2.230 Å and 1.9048(16) Å vs. 1.914 Å).
Noticeably, the distance between Ni and O2 is shorter than the
sum of the Ni and O van der Waals radii (2.985 Å vs 3.15 Å),11
indicating a weak interaction between O2 and Ni atoms.
Complex 5 was readily prepared in 61–76% yields by the oxi-
dative addition of the β-keto phosphorus(V) ylide 4 to Ni(cod)2
in the presence of PPh3 according to the literature method.4 The
ylides 4 were easily available from the corresponding phos-
phonium salts, which were synthesized by treating tri(2-alkox-
yaryl)phosphines with α-bromoacetophenone in CH2Cl2 at room
temperature or in refluxed toluene. All complexes were well
1
characterized by H NMR, 31P NMR, 13C NMR, and elemental
analysis. The 31P NMR analysis of the complexes shows a
typical AB signal at around 20 ppm. The molecular structures of
5 were further determined by X-ray diffraction (Fig. 1–4) and
The molecular structures of 5c, 5d, and 5e are similar to that
of 5b. In all cases, a distorted square planar geometry around
This journal is © The Royal Society of Chemistry 2012
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Table 1 Selected bond lengths (Å) and angles (°) for 5b, 5c, 5d,
and 5e
Table 2 Ethylene polymerization results with complexes 5
Activity
(105 g
5b
5c
5d
5e
Temp
Time
(hour)
Yield
(g)
Mvb (g
Entrya Catalyst (°C)
mol−1
)
mol−1 h−1
)
Ni(1)–C(9)
Ni(1)–P(2)
Ni(1)–O(1)
Ni(1)–P(1)
O(1)–C(1)
C(1)–C(2)
C(2)–P(1)
1.889(3)
2.2184(7)
1.9048(17) 1.901(3)
2.1833(7)
1.313(3)
1.355(3)
1.775(2)
1.898(6)
1.881(5)
1.890(2)
2.2168(14) 2.2243(13) 2.2078(7)
1.905(3) 1.8959(17)
2.1928(14) 2.1768(13) 2.1785(7)
1.306(6)
1.339(7)
1.768(5)
1
2
3
4
5
6
7
8
9
10
5a
5b
5c
5d
5e
5e
5e
5f
60
60
60
60
60
75
90
60
60
60
1
1
1
1
1
1
1
1
4
4
0.52
1.98
3.64
2.06
3500
1700
1100
1400
1.04
3.96
7.28
4.12
21.06
17.50
10.28
6.26
0.47
4.38
1.317(4)
1.337(5)
1.768(4)
1.313(3)
1.360(3)
1.772(2)
10.53 1300
8.75
5.14
3.13
0.95
8.76
1800
1600
4300
5500
2800
C(9)–Ni(1)–O(1) 173.18(10) 172.1(2)
177.76(18) 176.77(9)
C(9)–Ni(1)–P(1) 96.21(8)
O(1)–Ni(1)–P(1) 86.21(6)
C(9)–Ni(1)–P(2) 92.96(8)
O(1)–Ni(1)–P(2) 85.00(6)
95.11(16)
85.82(11)
93.91(16)
85.28(11)
95.20(13)
86.07(9)
90.17(13)
88.99(9)
96.72(7)
86.15(5)
91.97(7)
85.43(5)
5a
5d
a Conditions: 5 μmol catalyst, 50 μmol Ni(cod)2, solvent: toluene, Vtotal
50 mL, ethylene pressure: 10 atm. b Mv measured as ASTM D 1601.
nickel atom is adopted. P1, C9, P2 and O, and Ni are nearly
coplanar. All 2-ROC6H4 rings are oriented nearly orthogonally
to this plane (to phenyl ring A: 75.62° (5c) to 73.72° (5d); to
phenyl ring B: 63.22° (5c) to 69.70° (5d)). No matter the steric
hindrance of the OR group, the angles around phosphorus are
similar: C2–P1–Ni varied from 98.14(19)° to 98.98(2)°. All of
the distances between Ni and O2 are shorter than the sum of the
Ni and O van der Waals radii,11 and the distances of Ni–O2
decrease in the order of OEt (2.963 Å, 5c) > O(CH2)4CH3
(2.904 Å, 5d) > OiPr (2.871 Å, 5e), suggesting a gradually stron-
ger O2⋯Ni interaction in the complexes with the increasing of
steric hindrance. We attempted to develop crystals of complex 5f
suitable for X-ray analysis but failed.
in the ethylene polymerization at 60 °C and 10 atm, the activity
was nearly sustained when the reaction time was lengthened
from 1 h to 4 h (entries 4 vs. 10), which is clearly different from
that of 5a. These results showed that the modification by intro-
duction of an alkoxyl group at the 2-position of a phenyl group
on the phosphorus of a SHOP-type catalyst could improve the
catalytic behavior of ethylene polymerization. The probable
reason is that there is a weak interaction between nickel and the
oxygen (either O3 or O4) of the alkoxyl group, which tuned the
electronic properties and stabilized the catalytic species. Many
attempts to grow a single-crystal without a PPh3 group failed.
The true role will be further investigated.
1H NMR analysis shows that the polyethylene generated con-
sists of about 90% terminal double bonds and high linearity.
When OR is an alkoxyl group, a low molecular weight is
obtained no matter the steric bulk of R. While a higher molecular
weight for PE was observed in the case of R being a benzyl
group.
Ethylene polymerization
In the presence of a phosphine scavenger Ni(cod)2, complexes
5a–f were investigated as catalysts for ethylene polymerization.
As shown in Table 2, in contrast to the parent SHOP catalyst, the
introduction of the alkoxyl group at the ortho position of the
phenyl group on the phosphorus improved the activity evidently.
For instance, compared with 5a, the installation of OMe group
nearly quadrupled the activity when ethylene was polymerized
under a 10 atmosphere pressure at 60 °C for 1 hour (entries 1
and 2). Under the same conditions, replacing OMe with the OEt
group further increased the activity to 7.28 × 105 g mol−1 h−1
(entries 2 and 3). When OBn was introduced, the activity
reached 6.26 × 105 g mol−1 h−1 (entry 8). These results suggest
that the steric hindrance of the alkoxyl groups on phosphorus
influences the catalytic behavior apparently. The influence of the
steric hindrance on the activity was further supported by compar-
ing the results of ethylene polymerization promoted by com-
plexes 5d and 5e. By employing complex 5e bearing OiPr
groups, the highest activity of 21.06 × 105 g mol−1 h−1 was
obtained, which is one order higher than that of 5a (entries 5 vs.
1). In the presence of 5e and Ni(cod)2, increasing the polymeriz-
ation temperature from 60 °C to 75 °C, a slightly reduced
activity was observed (entries 5 vs. 6). Further increasing the
polymerization temperature to 90 °C halved the activity, demon-
strating that this catalyst is quite stable considering the solubility
of ethylene in toluene at 90 °C is lower than that at 60 °C (entry
7). We proposed that the introduced alkoxyl group can stabilize
the active species. For example, in the case of 5d being applied
Conclusions
In summary, a series of tri(2-alkoxylphenyl)phosphorane derived
SHOP-type nickel complexes have been designed and syn-
thesized by the reaction of benzoylmethylenetri(2-alkoxylphe-
nyl)phosphorane with Ni(cod)2. In the presence of ethylene. The
highest activity of 2.1 × 106 g mol−1 h−1 was achieved when an
OiPr group was installed. X-Ray crystallographic studies
confirmed the molecular structures and a gradually stronger
O2⋯Ni interaction is observed with the increasing in the bulki-
ness of the R group. This provides an efficient way to modify
SHOP catalysts for olefin polymerization. Further investigations
are in progress in our laboratory.
Experimental section
General information
All air or moisture sensitive manipulations were carried out
under a nitrogen atmosphere using Schlenk techniques. 1H
NMR, 13C NMR, 31P NMR spectra were recorded on Varian
Mercury 300 spectrometer and Varian 400 MR spectrometer.
4554 | Dalton Trans., 2012, 41, 4552–4557
This journal is © The Royal Society of Chemistry 2012

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Table 3 Summary of crystallographic data for 5b–5e
5b
5c
5d
5e
Formula
Fw
C47H42Ni4O4P2
791.46
C50H48NiO4P2
833.53
C59H66NiO4P2
959.79
C53H54NiO4P2
875.61
Cryst syst
Space group
Monoclinic
P2(1)/c
Monoclinic
C2/c
Monoclinic
P2(1)/n
Monoclinic
P2(1)/c
a, Å
b, Å
c, Å
V, Å3
18.1954 (3)
10.2494(5)
21.1754(10)
3935.2(3)
4
1.336
1.93 to 26.00
1656
41.597(3)
10.8709(8)
21.9171(16)
8712.7(11)
8
1.271
2.09 to 25.50
3504
14.5218(3)
23.7365(5)
18.5141(4)
5893.8(2)
4
1.179
3.19 to 67.48
2240
17.5838(15)
13.0885(11)
20.7174(18)
4726.7(7)
4
1.230
1.85 to 25.50
1848
Z
D(calcd), Mg m−3
2θ range, °
F(000)
Reflections collected/
unique
Data/restraints/parameters 7714/0/490
Goodness of fit
R1 (I > 2σ(I))
wR2 (I > 2σ(I))
48 022/7714[R(int) =
0.0507]
22 539/8099[R(int) =
0.0686]
8099/25/518
0.913
0.066
0.160
39 123/10 463[R(int) =
0,0240]
10 463/7/624
1.026
0.052
0.152
24 458/878[R(int) =
0.0916]
8783/0/547
0.864
0.056
0.127
1.063
0.037
0.095
Mass spectra were carried out with a HP5989A spectrometer.
Elemental analysis was performed by the Analytical Laboratory
of Shanghai Institute of Organic Chemistry, Chinese Academy
of Sciences. MV was measured by an Ubbelohde Viscometer for
testing the dilute solution viscosity as ASTMD 1601 at 135 °C
in decahydronaphthalene, the molecular weight correlating with
intrinsic viscosity equation is Mv = 5.37 × 104 [η]1.37. Toluene,
hexane, CH2Cl2 and other solutions were purified by MB
SPS-800 system. Ni(cod)2 was purchased from Alfa Aesar.
7.03–6.80 (m, 16H), 6.62 (t, J = 7.2 Hz, 1H), 6.53 (dd, J = 3.9
Hz, 5.1Hz, 1H), 6.42–6.32 (m, 2H), 5.73 (d, J = 7.8 Hz, 1H),
5.54 (s, 1H, –CvCH), 3.22 (s, 3H, –OCH3), 3.12 (s, 3H,
–OCH3), 2.90 (s, 3H, –OCH3). 13C NMR (100 MHz, CDCl3): δ
179.9, 179.8, 179.6, 179.5, 162.1, 162.1, 160.8(8), 160.8(4),
160.6, 138.6, 138.4, 137.2, 137.18, 136.2, 136.0, 134.4, 134.3,
133.0, 132.9, 132.8, 132.5(5), 132.5(1), 132.4, 132.2, 132.0,
131.9, 130.9, 130.3, 129.0, 128.7, 128.5, 128.4, 128.2, 127.7,
127.5, 127.4, 127.1, 127.0, 122.6, 122.1, 121.7, 121.6 120.3,
120.2, 120.0, 119.9, 118.6, 110.7(4), 110.7, 110.0(3), 110.0(0),
106.6, 78.7, 78.2, 77.3, 55.3, 55.1, 53.5. 31P NMR (121.4 MHz,
CDCl3): δ 23.87 (d, J = 291.4 Hz), 17.51 (d, J = 291.4 Hz).
Anal. calcd for C47H42NiO4P2: C, 71.32; H, 5.35; found: C,
70.79; H, 5.82.
X-Ray structure determination
Crystal data12 and details of data collection and structure refine-
ments are given in Table 3. Data for 5b, 5c, and 5e were col-
lected at 293 K on a Bruker SMART 1000 CCD diffractometer
using Mo K (λ = 0.71073 Å) radiation. Data for 5d were col-
lected at 133 K on a Bruker APEXII diffractometer using Cu K
(λ = 1.54178 Å) radiation. An empirical absorption was applied
using the SADABS program. All structures were solved by
direct methods and subsequent Fourier difference techniques and
refined anisotropically for all nonhydrogen atoms by full-matrix
least-squares calculations on F2 using the SHELXTL program
package. All hydrogen atoms were geometrically fixed using the
riding model.
{[Ni(2-OEtC6H4)2PvCHC(Ph)O][(2-OEtC6H4)PPh3]}
(5c).
1
Yield: 0.26 g, 62%. H NMR (300 MHz, C6D6): δ 8.78–8.71
(m, 1H), 8.01–7.95 (m, 1H), 7.51–7.46 (m, 6H), 7.46–6.95 (m,
17H), 6.88 (t, J = 7.2 Hz, 1H), 6.57–6.50 (m, 2H), 6.50–6.40
(m, 2H), 6.15–6.02 (m, 1H), 5.66 (d, J = 7.5 Hz, 1H), 5.20 (s,
1H, –CvCH), 3.78 (t, J = 7.2 Hz, 1H, –OCH2CH3), 3.56 (t, J =
6.6 Hz, 1H, –OCH2CH3), 3.40 (t, J = 6.6 Hz, 2H, –OCH2CH3),
3.11 (t, J = 5.4 Hz, 1H, –OCH2CH3), 2.99 (t, J = 7.5 Hz, 1H,
–OCH2CH3), 1.40 (t, J = 6.3 Hz, 3H, –OCH2CH3), 0.73 (t, J =
6.3 Hz, 3H, –OCH2CH3), 0.25 (s, 3H, –OCH2CH3). 13C NMR
(75 MHz, CDCl3): δ 180.1, 180.0, 179.8, 179.7, 161.8, 160.4,
160.0, 138.5, 138.3, 137.4, 136.1, 135.8, 134.5, 134.3, 132.3,
132.2, 131.8(9), 131.8(5), 131.8, 131.5, 130.3, 130.0, 129.2,
129.0, 127.7, 127.5, 127.4, 127.1, 127.0, 124.0, 123.3, 122.8,
122.2(3), 122.2(0), 121.8, 119.8, 119.6, 119.5, 118.2, 109.9,
107.3, 78.9, 78.2, 77.4, 63.0, 62.2, 61.5, 15.4, 13.8, 13.3. 31P
NMR (121.4 MHz, CDCl3): δ 23.83 (d, J = 292.1 Hz), 19.84 (d,
J = 293.5 Hz). Anal. calcd for C50H48NiO4P2: C, 72.05; H,
5.80; found: C, 72.12; H, 5.85.
Typical procedure for the synthesis of nickel complexes
Using 5b as an example, to a solution of Ni(cod)2 (2.0 g,
7.27 mmol) in toluene (50 mL) was added a mixture of ylide 4b
(1.91 g, 7.27 mmol) and PPh3 (1.91 g, 7.27 mmol) in toluene
(150 mL) at 0 °C. The resulting mixture was stirred for 24 hours
at room temperature and 2 hours at 50 °C. After filtration, the
solvent was removed under reduced pressure to afford yellow
powder, which was recrystallized in toluene–hexane (v/v: 10/1)
to give the pure product 5b.
{[Ni(2-OC5H11C6H4)2PvCHC(Ph)O][(2-OC5H11C6H4)PPh3]}
(5d). Yield: 0.68 g, 71%. 1H NMR (300 MHz, C6D6): δ
9.19–9.14 (m, 1H), 8.37–8.36 (m, 1H), 7.75–7.60 (m, 6H),
7.60–7.50 (m, 2H), 7.28–7.20 (m, 2H), 7.14–6.80 (m, 14H),
6.70–6.61 (m, 2H), 6.47 (t, J = 8.4 Hz, 2H), 6.31 (t, J = 7.2 Hz,
{[Ni(2-OMeC6H4)2PvCHC(Ph)O][(2-OMeC6H4)PPh3]} (5b).
1
Yield 3.93 g, 68%. H NMR (300 MHz, C6D6): δ 8.74 (dd, 1H,
J = 7.8 Hz, 13.8 Hz), 7.81–7.70 (m, 8H), 7.55–7.52 (m, 2H),
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1H), 5.86 (d, 1H, J = 7.8 Hz), 5.66 (s, 1H, –CvCH), 3.70–3.55
(m, 1H), 3.50–3.38 (m, 1H), 3.32–3.20 (m, 2H), 3.07–2.91(m,
2H), 1.97–0.30 (m, 27H). 13C NMR (100 MHz, C6D6): δ 181.1,
180.9(2), 180.9(0), 180.8, 162.7, 161.4, 160.3, 139.2, 139.1,
137.9, 136.7, 135.0, 134.9, 133.0, 132.8, 132.7, 132.4, 130.8,
130.4, 129.5, 129.3, 127.8, 127.7, 127.6, 124.7, 123.4, 122.9,
122.4, 120.3, 119.1, 110.7, 110.3, 108.3, 79.6, 79.1, 67.7, 67.1,
31.9, 30.2, 29.2, 28.9, 28.5, 28.3, 28.1, 23.2, 23.0, 22.9, 22.8,
14.4, 14.3, 14.2. 31P NMR (161.9 MHz, CDCl3): δ 22.86 (d, J =
in toluene, followed by a solution of Ni(cod)2 (10 equiv.) in
toluene at the desired temperature under nitrogen atmosphere.
Then the autoclave was pressurized by ethylene for 1 or 4 h. The
reaction was quenched by venting the autoclave. The mixture
was poured into a solution of acidified ethanol (200 mL of 10%
HCl) and stirred for 12 hours. The polymer was isolated by fil-
tration, washed with ethanol and dried under vacuum at 70 °C to
constant weight.
291.2 Hz), 19.79 (d,
C59H66NiO4P2: C, 73.83; H, 6.93; found: C, 74.44, H, 7.15.
J = 296.6 Hz) Anal. calcd for
Acknowledgements
We thank the financial support from the Natural Sciences Foun-
dation of China (No. 20821002, 21174159), the Major State
Basic Research Development Program (Grant No.
2009CB825300), the Science and Technology Commission of
Shanghai Municipality, and Chinese Academy of Sciences.
{[Ni(2-OiPrC6H4)2PvC(Ph)O][(2-OiPr-C6H4)PPh3]}
(5e).
1
Yield: 0.57 g, 65%. H NMR (300 MHz, CDCl3): δ 8.75 (brs,
1H), 8.10–7.96 (m 1H),7.52–7.07 (m, 23H), 6.90 (t. J = 6.9 Hz,
1H), 6.70–6.58(m, 2H), 6.54 (t, J = 7.2 Hz, 1H), 6.32–6.24(m,
1H), 6.13 (t, J = 6.9 Hz, 1H), 6.06 (t, J = 6.9 Hz, 1H), 5.87 (d, J
= 8.1 Hz, 1H), 5.36 (s, 1H, –CvCH), 4.40–4.36 (m, 1H, –OCH
(CH3)2), 4.02–3.82 (m, 2H, –OCH(CH3)2), 1.52 (d, 3H, J = 4.8
Hz, –OCH(CH3)2), 1.22 (d, 3H, J = 5.1 Hz, –OCH(CH3)2), 1.15
(d, 3H, J = 5.1 Hz, –OCH(CH3)2), 0.78 (d, 3H, J = 5.7 Hz,
–OCH(CH3)2), 0.69 (brs, 3H, –OCH(CH3)2), 0.27 (brs, 3H,
–OCH(CH3)2). 13C NMR (75 MHz, CDCl3): 179.5, 179.3,
179.2, 179.1, 161.1, 159.4, 158.9, 157.9, 138.4, 1382, 137.8,
137.7, 137.0, 136.8, 134.5, 134.4, 132.8, 132.2, 132.1, 131.9,
131.8, 131.5, 131.1, 130.7, 130.3, 129.6, 129.0, 127.5, 127.4,
127.0, 127.0, 124.3, 124.1, 123.8, 123.6, 123.1, 123.0, 123.6,
122.4, 121.9, 119.6, 119.4, 119.0, 118.0, 111.4, 110.5, 109.6,
108.3, 80.1, 79.9, 79.5, 79.3, 69.0, 68.3, 67.8, 67.3, 22.8, 22.2,
21.8, 21.0, 20.3. 31P NMR (121.4 MHz, CDCl3): δ 21.24 (d, J =
Notes and references
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296.3 Hz), 17.81 (d,
J = 294.5 Hz) Anal. calcd for
C53H54NiO4P2: C, 72.70; H, 6.22; found: C, 72.24; H, 6.54.
{[Ni(2-OBnC6H4)PvCHC(Ph)O][(2-OBnC6H4)PPh3]}
(5f).
1
Yield: 0.62 g, 61%. H NMR (300 MHz, C6D6): δ 9.25–9.22
(m, 1H), 8.37–8.35 (m, 1H),7.83–7.78 (m, 2H), 7.71–7.65 (m,
8H), 7.48–7.45 (m, 2H), 7.33–7.20 (m, 7H), 7.08–6.92 (m,
26H), 6.86–6.74 (m, 3H), 6.70–6.61 (m, 5H), 6.48 (d, J = 8.7
Hz, 1H), 6.39 (t, J = 7.2 Hz, 1H), 5.86 (d, J = 7.8 Hz, 1H), 5.67
(s, 1H, –CvCH), 4.57–4.43 (m, 4H, –OCH2Ph), 4.30 (d, J =
11.7, 1H, –OCH2Ph), 4.09–4.05 (d, J = 11.4, 1H, –OCH2Ph).
13C NMR (75 MHz, C6D6): δ 180.9, 180.8, 162.6(9), 162.6(6),
160.6(3), 160.8, 159.6, 139.1, 139.0, 138.96, 138.9, 138.0,
137.4, 136.8, 134.9(8), 134.9(2), 134.8, 133.9, 133.6, 133.4(4),
133.4(0), 133.3, 132.6, 132.5, 132.4, 132.2, 131.6, 131.1, 130.8,
129.5, 128.9(6), 128.9(0). 128.8, 128.7(1), 128.7(0), 128.5(4),
128.5(1), 128.4, 128.3, 127.9(3), 127.9(0), 127.8, 127.7(4),
127.7(0), 127.5(3), 127.5(0), 127.4(4), 127.4(0), 127.3(2),
127.3(0), 127.2, 127.1, 127.0, 122.6, 121.2, 121.1, 121.0,
120.9(4), 120.9(0), 120.8, 119.7, 111.8, 111.3, 109.0, 79.5,
79.0, 70.2, 69.7, 69.0. 31P NMR (121.4 MHz, CDCl3):
δ 22.56 (d, J = 303.5 Hz), 18.78 (d, J = 291.4 Hz). Anal.
calcd for C65H54NiO4P2: C, 76.56; H, 5.34; found: C, 76.33;
H, 5.23.
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Dalton Trans., 2012, 41, 4552–4557 | 4557