Binding modes of a dimethyliminopentanone ligand on nickel pre-catalysts toward olefin polymerization

Article abstract of DOI:10.1016/j.jorganchem.2008.12.038

Nickel complexes prepared using a 4-(2,6-diisopropylphenylimino)-3,3-dimethylpentan-2-one ligand framework are shown. The potassium salt of the ligand is obtained by deprotonation with KH in diethyl ether. Potassium 4-(2,6-diisopropylphenylimino)-3,3-dime

Full text of DOI:10.1016/j.jorganchem.2008.12.038

Journal of Organometallic Chemistry 694 (2009) 1380–1384
Contents lists available at ScienceDirect
Journal of Organometallic Chemistry
journal homepage: www.elsevier.com/locate/jorganchem
Binding modes of a dimethyliminopentanone ligand on nickel pre-catalysts
toward olefin polymerization
a
b
a
Brycelyn M. Boardman a, , Guang Wu , Rene Rojas , Guillermo C. Bazan
*
a Center for Polymer and Organic Solids, Departments of Chemistry & Biochemistry and Materials, University of California, Santa Barbara, California 93106, United States
b Departamento de Química Inorgánica, Facultad de Química, Pontificia Universidad Católica de Chile, Casilla 306, Santiago-22, Chile
a r t i c l e i n f o
a b s t r a c t
Article history:
Received 8 October 2008
Received in revised form 9 December 2008
Accepted 10 December 2008
Available online 25 December 2008
Nickel complexes prepared using
a
4-(2,6-diisopropylphenylimino)-3,3-dimethylpentan-2-one
ligand framework are shown. The potassium salt of the ligand is obtained by deprotonation with
KH in diethyl ether. Potassium 4-(2,6-diisopropylphenylimino)-3,3-dimethyl-pent-2-en-2-olate can
then be reacted with Ni(PMe3)2(g
1-CH2Ph)Cl to yield 4-(2,6-diisopropylphenylimino)-3,3-dimethyl-
pent-2-en-2-olato-j1O](
reacted with Ni(PMe3)(
en-2-olato-
2N,O](
to-j2N,O](
g
g
1-CH2Ph)(PMe3)2Ni (1). The potassium salt of the ligand can also be
3-CH2Ph)Cl to yield bis(4-(2,6-diisopropylphenylimino)-3,3-dimethyl-pent-2-
Keywords:
Nickel
Homogeneous catalysis
Polyethylene
Binding modes
j
g
g
1-CH2Ph)2Ni2 (2) or 4-(2,6-diisopropylphenylimino)-3,3-dimethyl-pent-2-en-2-ola-
1-CH2Ph)(PMe3)Ni (3), depending on the reaction conditions. The addition of five equivalents
of B(C6F5)3 to 1, 2, or 3 yields catalytically active species for the homopolymerization of ethylene. The
polymer products are described by a single molecular weight distribution, consistent with the presence
of a single active site.
Ó 2008 Elsevier B.V. All rights reserved.
1. Introduction
addition of B(C6F5)3 yields 2-tris(pentafluorophenyl)borate-3-
(2,6-diisopropylphenylimino)-but-1-ene(
[7].
Borane coordination to the oxygen stimulates rearrangement of
the ligand and binding of the olefin unit to nickel. This previously
unexplored type of complex led to the formation of high molecular
weight polymer despite the absence of obvious steric bulk around
the coordination sphere of the metal.
Here we report on (4-(2,6-diisopropylphenylimino)-3,3-dim-
ethylpentan-2-one, which is a relatively small ligand framework
and has remote activation capabilities. The synthesis of (4-(2,6-
diisopropylphenylimino)-3,3-dimethylpentan-2-one (Scheme 1)
gives rise to a ligand framework, which is not only capable of re-
mote activation but also of mono, bi, and tridentate binding to
the nickel center. This variety of binding modes allows for several
structures to be isolated and characterized. In the presence of a
Lewis acid such as B(C6F5)3, all three pre-catalyst complexes have
the potential to form the previously observed N/g2–C@C coordina-
tion complex. Preliminary studies show the formation of high
molecular weight polymer, which posses a monomodal molecular
weight distribution, consistent with the formation of a single
active site.
g
3-CH2 Ph)nickel (Fig. 1)
Nickel-based olefin oligomerization and polymerization pre-
catalysts continue to be of interest in industrial and academic lab-
oratories [1].These late metal systems remain relevant due to their
ability to tolerate functional groups, which can facilitate the syn-
thesis of new materials with previously unattained structures
and properties [2]. Neutral species, although less active than the
cationic counterparts, are under investigation because of this high
tolerance toward functionalities [3]. Zwitterionic complexes,
where a partial positive charge formally resides at the metal cen-
ter, constitute a smaller class of pre-catalysts with an intermediate
range of reactivities [4].
Lewis acids are in some cases used to activate the metal center
upon coordination to a basic functionality on the ligand framework
at a site removed from the metal center [5]. This type of activation
places the Lewis acid away from the trajectory of monomer inser-
tion. Previous reports have shown that several ligand frameworks
are suitable for this type of remote Lewis acid activation [6]. How-
ever, until recently most of these systems, lacking substantial aryl
bulk yield low molecular weight products. We recently reported
the synthesis of 3-(2,6-diisopropylphenylimino)-but-1-en-2-ola-
to-j g
2N,O]( 1-CH2 Ph)(trimethylphosphine)nickel, which upon
2. Results and discussion
The synthesis of 4-(2,6-diisopropylphenylimino)-3,3-dimeth-
ylpentan-2-one (L-H) is shown in Scheme 1. 2,6-Diisopropyl ani-
line was added to a mixture of 3,3-dimethyl-2,5-pentanedione,
* Corresponding author.
E-mail addresses: bb2439@columbia.edu (B.M. Boardman), rrojasg@uc.cl (R.
Rojas), bazan@chem.ucsb.edu (G.C. Bazan).
0022-328X/$ - see front matter Ó 2008 Elsevier B.V. All rights reserved.
doi:10.1016/j.jorganchem.2008.12.038

B.M. Boardman et al. / Journal of Organometallic Chemistry 694 (2009) 1380–1384
1381
N
Ni
CH2
O
B(C6F5)3
Fig.
ene(
1. 2-Tris(pentafluorophenyl)borate-3-(2,6-diisopropylphenylimino)-but-1-
g
3-CH2 Ph)nickel; illustration N/
g
2–C@C coordination.
NH2
O
O
(a)
Fig. 2. ORTEP drawing of
omitted for clarity.
1
drawn at 50% probability. Hydrogen atoms were
4
+
structure, shown in Fig. 2, confirms the monodentate O-binding
mode of the 4-(2,6-diisopropyl-phenylimino)-3,3-dimethyl-pent-
1-en-2-olato fragment and that the two coordinating phosphines
are in a cis-orientation relative to each other. The square-planar
geometry around nickel is slightly distorted. For example, the
O–Ni–P(2) and C(20)–Ni–P(1) angles project 13.5° and 17.5°, out
of the plane, respectively in opposite directions. The benzyl ligand
is located cis to the oxygen with an O–Ni–C(20) angle of
90.06(14)°. The Ni–P(1), Ni–P(2), Ni–O(1) and Ni–C(20) bond dis-
tances are 2.2348(12) Å, 2.1374(12) Å, 1.946(3) Å and 1.978(4) Å,
respectively.
OK
O
(b)
N
N
(L-K)
(L-H)
Scheme 1. Ligand synthesis. (a) Catalytic tosic acid, MgSO4, toluene, reflux 72 h. (b)
1.3 eq. KH, Et2O, room temperature, 12 h.
In an attempt to isolate an N,O-bound bidentate complex, we
tosic acid and MgSO4 in toluene. The reaction was allowed to heat
at reflux for three days to afford crude L-H in 82% yield. The crude
material was purified first by distillation, to remove excess pen-
tanedione, followed by crystallization from hexanes. 1H NMR spec-
troscopy confirmed the formation of the desired ligand.
The potassium salt of ligand is obtained by deprotonation of L-H
with excess KH in diethyl ether. The resulting suspension was
filtered and excess solvent was removed to provide potassium
4-(2,6-diisopropyl-phenylimino)-3,3-dimethyl-pent-2-en-2-olate
(L-K) as a white powder in 95% yield.
used the monophsophine species (Ni(
starting material. The reaction of potassium,4-(2,6-diisopropyl-
phenylimino)-3,3-dimethyl-pent-2-en-2-olate with Ni(
3-CH2Ph)
g
3-CH2Ph)Cl(PMe3)) [8] as a
g
Cl(PMe3) was run under two different reaction conditions. At
À35 °C in diethyl ether, a dark red precipitate was isolated in
65% yield (Equation 2). The precipitate was insoluble in deuterated
solvents such as benzene or toluene and decomposed readily in
tetrahydrofuran and dichloromethane, making structural identifi-
cation by NMR spectroscopy inconclusive.
Previous reactions with
a-iminocarboxamide, aminobutanone
and related conjugated ligand frameworks have formed N,N or
N,O bidentate structures when reacted with Ni(
(PMe3)2 [8]. However when L-K was reacted with Ni((
g
g
1-CH2Ph)Cl
1-CH2Ph)Cl
O
Ni
N
(PMe3)2, the ligand coordinated to the metal in a monodentate
fashion, as shown in Equation 1. The 1H NMR spectrum is
consistent with the formation of a single isomer containing a nickel
center ligated by 4-(2,6-diisopropyl-phenylimino)-3,3-dimethyl-
Et2O, 3h
RT
N
Ni
O
2: 65%
Me3P
Cl
OK
+
Ni
j
1-CH2Ph and two PMe3 ligands. Diagnostic
(2)
N
pent-1-en-2-olato,
1H NMR peaks for the ligand backbone and a single peak in the
31P NMR spectrum at d = À21.5 ppm are consistent with the forma-
tion of 4-(2,6-diisopropyl-phenylimino)-3,3-dimethyl-pent-1-en-
Tol: Pentane, 2h
RT
PMe3
Ni
O
N
2-olato-j1O (
g
1-CH2Ph)(PMe3)2 nickel (1) (Equation 1).
3: 88%
Crystals of the isolated product suitable for X-ray analysis were ob-
tained from the slow evaporation of a dilute diethyl ether solution.
The resulting molecular structure, shown in Fig. 3, reveals a dimeric
structure, in which the 4-(2,6-diisopropylphenylimino)-3,3-di-
methyl-pent-1-en-2-olato ligand is coordinated to one metal center
PMe3
N
OK
Me3P
Et2O, RT, 12h
Ni
(1)
N
O
Ni(! 1-CH2Ph)Cl(PMe3)2
1: 86 %
in a N/
g
2–C@C fashion and to the other metal center via the oxygen.
The
g
1-CH2Ph is bound cis to the imine nitrogen. Note that no PMe3
is observed. The square planar geometry around nickel is slightly
distorted with the N–Ni–O(2) and C(1)–Ni–C(8) angles projecting
5.99° and 6.56° out of the plane, respectively in opposite directions.
Single crystals of 1 suitable for X-ray diffraction were obtained by
crystallization from pentane at room temperature. The resulting

1382
B.M. Boardman et al. / Journal of Organometallic Chemistry 694 (2009) 1380–1384
gands. The square-planar geometry around nickel is slightly dis-
torted: the O–Ni–C(20) and N–Ni–P angles project 4.3° and 8.1°,
out of the plane, respectively in opposite directions. The PMe3 is lo-
cated trans to the imine nitrogen and the six membered chelate
adopts a boat conformation. For example, the O–C(1)–C(3), N–
C(4)–C(3), C(4)–N–Ni, and C(1)–O–Ni bond angles are 115.4°,
117.7°, 120.7°, and 123.9° respectively. The benzyl group is located
cis to the imine nitrogen with a N–Ni–C(20) angle of 95.06(17)°.
The Ni–P, Ni–O, Ni–N and Ni–C(20) bond distances are
2.2348(12) Å,
respectively.
2.1374(12) Å,
1.946(3) Å
and
1.978(4) Å,
A 1H NMR study of the reaction of B(C6F5)3 with 1, 2, and 3 was
performed in an attempt to observe the active species of the nickel
complex. In all cases, the formation of an g3 species is observed
with an up field shift of the aromatic protons. However, the forma-
tion of a single species is not observed indicating that the active
species is not very stable. Due to this instability, isolation of the ac-
tive species has not been accomplished. Therefore a preliminary
survey of polymerizations were run with the in situ generation of
the active species by adding 5 equivalents of B(C6F5)3 to 1, 2, or
3. Employing this type of activation, all three pre-catalysts were ac-
tive toward the homopolymerization of ethylene with activities
Fig. 3. ORTEP drawing of
omitted for clarity.
2 drawn at 50% probability. Hydrogen atoms were
The Ni–C(1) and Ni–C(2) bond distances 2.12(3) Å and 2.29(3) Å,
respectively and the double bond character of the C(1)–C(2) bond
distance (1.37(4) Å) indicates the presence of olefin coordination.
We propose therefore, that the product obtained is bis(4-(2,6-diiso-
propylphenylimino)-3,3-dimethyl
CH2Ph)2Ni2 (2), as shown in Equation 2.
If the reaction of L-K with Ni(
3-CH2Ph)Cl(PMe3) is run at room
temperature using a toluene-pentane mixture (1.5:1), no precipi-
tate is observed and the deep orange solution remains clear over
the course of the reaction (Equation 2). The 1H NMR spectrum of
the isolated orange crystals is consistent with the formation of a
single isomer containing a nickel center ligated by 4-(2,6-diisopro-
*
ranging from 230–650 kg/mol h depending on the reaction condi-
pent-2-en-2-olato-j2N,O](g1
-
tions. In all cases, the resulting polymers had an Mn ranging from
240,000 to 294,000, PDI’s ranging from 1.59 to 1.92, and low melt-
ing temperatures ranging from 77 to 87 °C. These low melting tran-
sitions suggest that the isolated polymer is highly branched. While
NMR studies have shown that the active species is unstable and
therefore difficult to isolate, the similarities of the polymer prod-
ucts suggest that 1, 2, and 3 all form the same active species in
the presence of B(C6F5)3.
g
pyl-phenylimino)-3,3-dimethyl-pent-1-en-2-olato,
j
1-CH2Ph and
a PMe3 ligand. The 31P NMR spectrum reveals a single peak at
d = À21.2 ppm. Further elucidation of the structure was accom-
plished by X-ray diffraction studies of a single crystal obtained
from pentane at À35 °C. The resulting structure is shown in
Fig. 4. Therefore, as shown in Equation 2, the product is 4-(2,6-
diisopropylphenylimino)-3,3-dimethyl pent-2-en-2-olato-j2N,O]-
3. Conclusions
Three new organometallic complexes have been isolated and
characterized containing nickel and the 4-(2,6-diisopropylphenyli-
mino)-3,3-dimethylpentan-2-one ligand. The first from the reac-
tion of L-K and Ni(
from the reaction of L-K and Ni(
g
1-CH2Ph)Cl(PMe3)2 to yield 1 and the other
3-CH2Ph)Cl(PMe3) to yield 2 or
(g
1-CH2Ph)(PMe3)Ni (3).
g
The molecular structure of 3 confirms the N,O bidentate binding
mode of the 4-(2,6-diisopropyl-phenylimino)-3,3-dimethyl-pent-
1-en-2-olato fragment, and the presence of
3, depending on the reaction conditions. The addition of excess
B(C6F5)3 to all three structures yields active catalysts for ethylene
homopolymerization. The resulting polymers are described by
monomodal molecular weight distributions, consistent with the
presence of a single active metal site. Due to instability, the active
species was not isolated, however the mono, bi, and tridentante
binding capabilities of this new ligand system allows for new pos-
sibilities in the design of zwitterionic pre-catalysts for ethylene
polymerization.
g
1-CH2Ph and PMe3 li-
4. Experimental
All manipulations were performed under an inert atmosphere
using standard glovebox and Schlenk techniques. All reagents were
used as received from Aldrich unless otherwise specified. Ethylene
was purchased from Matheson Tri-Gas (research grade, 99.99%
pure) and was further purified by passage through an oxygen/
moisture trap (Matheson model 6427-4S). Toluene, THF, hexanes,
and pentane were distilled from sodium benzophenone ketal. All
polymerization reactions were carried out in a Parr autoclave reac-
tor as described below. Toluene for polymerization was distilled
from sodium/potassium alloy. NMR spectra were obtained using
Varian Unity 400 and 500 spectrometers. Polymers were dried
overnight under vacuum and the polymerization activities were
calculated from the mass of product obtained. These values were
within 5% of the calculated mass by measuring the ethylene
Fig. 4. ORTEP drawing of
omitted for clarity.
3 drawn at 50% probability. Hydrogen atoms were

B.M. Boardman et al. / Journal of Organometallic Chemistry 694 (2009) 1380–1384
1383
consumed by use of a mass flow controller. The polymers were
characterized by Gel Permutation Chromatography (GPC) analysis
at 135 °C in o-dichlorobenzene (in a Polymers Laboratories, High
Temperature Chromatograph, Pl-GPC 200) relative to polystyrene
standards. Thermal analysis was performed on a Differential Scan-
ning Calorimeter (DSC) TA-Q20 with a scan rate of 10 °C/min. Ele-
mental analysis was performed on a Leeman Labs Inc. CE440
Elemental Analyzer and a Control Equipment Corporation 440 Ele-
mental Analyzer.
2H, iPr–CH), 1.74 (s, 3H, CH3–C@N), 1.65 (s, 6H, 2CH3), 1.29 (d,
6H, J = 6.8 Hz, iPr–CH3), 1.24 (d, 6H, J = 7.0 Hz, iPr–CH3) 0.85 (s,
18H, 2PMe3). 13C NMR (100 MHz, C6D6, 298 K): d = 176.41(CO),
148.03 (imine), 137.06, 130.34, 129.63, 124.58, 124.05, 123.91
(phenyl/benzyl-C), 53.07 (C-(CH3)2, 28.81(CH2), 27.34 (CH2-ben-
zyl), 25.66 (iPr–CH), 23.95 (CH3C@N), 23.82 (C(CH3)2 23.53 (iPr–
CH3), 23.31 (iPr–CH3), 13.95 (2P(CH3)3). 31P NMR (162 MHz,
C6D6, 25 °C): d = À21.5. Elemental Anal. Calc.: C 65.32, H 9.08, N
2.38; found C 65.49, H 8.91, N 2.45%.
4.1. 4-(2,6-Diisopropylphenylimino)-3,3-dimethylpentan-2-one
4.4. Bis(4-(2,6-diisopropyl-phenylimino)-3,3-dimethyl-pent-1-en-2-
olato)(g
1-CH2Ph)2Ni2 (2)
To
a
solution of 3,3-dimethylpentane-2,4-dione (15.0 g,
0.117 mol) and catalytic tosic acid, in toluene, 2,6-diisopropylani-
line (5.18 g, 0.029 mol) was added. MgSO4 was then added and
the reaction mixture was allowed to stir at reflux for three days.
The reaction was monitored by GC-MS. After three days of reflux
the aniline had been converted to the desired product (97%) and
the diimine structure (3%). Excess pentanedione was removed
using vacuum distillation. The product mixture was then purified
via recrystallization from hexanes at À20 °C. Colorless crystals
were obtained in 60% yield after purification.
Potassium 4-(2,6-diisopropylphenylimino)-3,3-dimethyl-pent-
2-en-2-olate (62.2 mg, 0.191 mmol) was dissolved in diethyl ether
and added dropwise to a diethyl ether solution of Ni(PMe3)(g3
-
CH2Ph)Cl (50.0 mg, 0.191 mmol) at room temperature. Upon addi-
tion of the potassium salt, a large amount of red precipitate was
observed; the reaction was allowed to stir overnight at room tem-
perature. After stirring overnight, the reaction mixture was placed
into the freezer, to allow the fine precipitate to settle. The mixture
was carefully decanted and the solid was washed several times
with cold diethyl ether. The red/violet isolated solid was dried un-
der vacuum. NMR spectroscopic analysis of this compound proved
very difficult as the stability and solubility of this species was very
poor. The isolated product was only slightly soluble in deuterated
solvents such as d-benzene and d-toluene, and rapidly decomposes
in THF and DCM. However crystals suitable for X-ray diffraction
were obtained from the slow evaporation of a very dilute diethyl
ether solution at À35 °C. Details for the X-Ray analysis can be seen
in Table 1.
1H NMR (399.95 MHz,[d6]-benzene, 298 K): d = 7.19–7.13 (m,
3H, phenyl), 2.81 (sept, 2H, J = 4.0 Hz, iPr–CH), 1.99 (s, 3H,
CH3C@O), 1.38 (s, 3H, CH3C@N), 1.32 (s, 6H, 2CH3), 1.19 (d, 6H,
J = 7.2 Hz, 2-iPr–CH3), 1.17 (d, 6H, J = 7.2 Hz, 2-iPr–CH3).13C NMR
(100 MHz, C6D6, 25 °C): d = 208.42 (imine), 172.39 (C@O), 146.86,
136.49, 124.56, 123.95 (ph-C), 58.93 (C–(CH3)2, 28.87 (iPr–CH),
26.38 (CH3CO), 23.93 (CH3C@N), 23.52 (iPr–CH3), 23.30 (iPr–CH3),
17.43 (C(CH3)2. Elemental Anal. Calc.: C 79.39, H, 10.17, N 4.87;
found C 79.48, H 10.18, N 4.95%.
Elemental Anal. Calc.: C 71.52, H 7.77, N 3.27; found C 71.08, H
7.22, N 3.19%.
4.2. Potassium 4-(2,6-diisopropylphenylimino)-3,3-dimethyl-pent-2-
en-2-olate
4.5. 4-(2,6-Diisopropyl-phenylimino)-3,3-dimethyl-pent-1-en-2-
A suspension of KH (90.5 mg, 2.26 mmol) in diethyl ether was
added to a stirring solution of 4-(2,6-diisopropylphenylimino)-
3,3-dimethylpentan-2-one (0.500 g, 1.74 mmol) in diethyl ether
at room temperature. Slow evolution of H2 was observed and the
reaction was allowed to stir overnight at room temperature. After
stirring overnight, the originally cloudy reaction mixture had be-
come clear. The reaction mixture was filtered over celite and ex-
cess diethyl ether was removed. Pentane was added several
times to wash the isolated solid. The potassium salt was isolated
as a pale yellow powder in 98% yield.
olato-j g
2N,O]( 1-CH2Ph)(PMe3) nickel (3)
Potassium 4-(2,6-diisopropyl-phenylimino)-3,3-dimethyl-pent-
2-en-2-olate (54.0 mg, 0.166 mmol) in toluene-pentane (1.5:1 g)
was added drop-wise to a stirring toluene-pentane (1.5:1) solution
Table 1
Crystallographic data for compounds 1, 2, and 3.
Compound
1
2
3
1H NMR (399.95 MHz, [d6]-benzene, 298 K): d = 7.18À7.05 (m,
3H, phenyl), 3.47 (s, 1H, CH2), 3.05 (sept, 2H, J = 6.8 Hz, iPr–CH),
2.73 (s, 1H, CH2), 1.76 (s, 3H, CH3C@N), 1.44 (s, 6H, C(CH3)2),
1.26 (d, 6H, J = 6.8 Hz, iPr–CH3), 1.24 (d, 6H, J = 6.8 Hz, iPr–CH3).
Elemental Anal. Calc.: C 70.10, H 8.67, N 4.30; found C 70.19, H
8.07, N 4.04%.
Empirical formula
Molecular weight
Crystal system
Space group
Unit cell parameters
a (Å)
C32H53NOP2Ni
587.69
Monoclinic
P2(1)/c
C26H35NONi
871.4
Monoclinic
P2(1)/n
C29H44NOPNi
512.33
Monoclinic
C2/c
16.615(4)
11.621(3)
17.460(4)
90
9.828(3)
18.279(5)
13.601(4)
90
30.212(5)
10.6388(16)
18.662(3)
90
109.214(2)
90
5664.2(15)
8
1.202
b (Å)
c (Å)
a
(°)
4.3. 4-(2,6-Diisopropyl-phenylimino)-3,3-dimethyl-pent-1-en-2-
b (°)
90.351(8)
90
3371.1(15)
4
1.159
0.693
109.168(4)
90
2308.0(11)
4
1.256
0.710
olato-g g1-CH2Ph)(PMe3)2 nickel (1)
1O](
c
(°)
V (Å3)
Z
Potassium 4-(2,6-diisopropylphenylimino)-3,3-dimethyl-pent-
2-en-2-olate (48.1 mg, 0.148 mmol) was dissolved in diethyl ether
Dcalc (mg m3)
k (Mo K
a
) (mmÀ1
)
0.762
and added drop-wise to a diethyl ether solution of Ni(PMe3)2(g1
-
Crystal size (mm)
Habit
0.3 Â 0.2 Â 0.2
0.1 Â 0.1 Â 0.1
0.25 Â 0.15 Â 0.1
Blades
Blades
Blades
CH2Ph)Cl (50.0 mg, 0.148 mmol) at room temperature. The reac-
tion was allowed to stir at room temperature overnight. The reac-
tion mixture was filtered over celite and excess diethyl ether was
removed to yield a red/orange solid in 88% yield. Compound 1
was purified via recrystallization from pentane at room
temperature.
Color
h range (°)
Parameters refined
Red/orange
2.11–26.42
546
Red
1.77–26.71
561
Dark orange
2.04–26.37
314
2208
0.0675, 0.1418
1.058 and À0.367
F(000)
1272
936
R1, wR2 [I > 2
Maximum and
r
(I)]
0.0630 0.1421
1.275 and À0.548
0.0641, .1153
0.601 and À1.160
1H NMR (399.95 MHz, [d6]-benzene, 298 K): d = 7.40 (d, 2H,
J = 6.8 Hz, phenyl) 7.19–7.11 (m, 6H, phenyl/benzyl) 3.15 (sept,
minimum
density (e ÅÀ3
)

1384
B.M. Boardman et al. / Journal of Organometallic Chemistry 694 (2009) 1380–1384
of Ni(PMe3)(g
3-CH2Ph)Cl (43.0 mg, 0.164 mmol) and was allowed
References
to stir at room temperature for 12 h. The reaction mixture was fil-
tered over celite and excess solvent was removed under vacuum to
give a red solid. Trituration with pentane and crystallization at
À35 °C overnight gave the desired product as a dark orange solid
in 82% yield.
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(CH3)2, 28.81(CH2), 27.34 (CH2-benzyl), 25.66 (iPr–CH), 23.95
(CH3C@N), 23.82 (C(CH3)2 23.53 (iPr–CH3), 23.31 (iPr–CH3), 13.95
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Supplementary material
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CCDC 680085, 679917, 679916 contain the supplementary crys-
tallographic data for compounds 1, 2, and 3, respectively. These
data can be obtained free of charge from The Cambridge Crystallo-
graphic Data Centre via www.ccdc.cam.ac.uk/data_request/cif.
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Acknowledgments
The authors are grateful to the Department of Energy for finan-
cial support of this work (Grant Number: DE-FG03098ER14910)
and projects FONDECYT 11060384.