Preparation and characterization of (1-Me-indenyl)Ni(PR3)(CC-Ph) (R = Cy, Ph) and alkyne polymerization catalysis

Article abstract of DOI:10.1021/om990600a

The complexes (1-Me-Ind)(PR₃)Ni-CC-Ph (R = Ph and Cy) have been prepared and characterized spectroscopically and by means of single-crystal structural analyses. These compounds are inert toward the insertion of alkynes, but when combined with methylaluminoxane (MAO), they form active catalysts for the homogeneous polymerization of phenylacetylene. cis-Poly(Ph-CC-H) is thus obtained with M_w values in the range of 10⁴ and relatively narrow polydispersities. The combination of the corresponding Ni-Cl complexes with MAO gives similar results with Ph-CC-H and also polymerizes 1-hexyne and 3-hexyne, but the degree of polymerization is much lower. Optimization studies have shown that the polymerization reactions give the best results with THF as solvent and a 1:10 ratio of Ni to MAO. Evidence is presented for the involvement in the catalytic cycle of bimetallic species with a Ni(μ-X)(μ-Me)Al core.

Full text of DOI:10.1021/om990600a

5548
Organometallics 1999, 18, 5548-5552
P r ep a r a tion a n d Ch a r a cter iza tion of
(1-Me-in d en yl)Ni(P R3)(CC-P h ) (R ) Cy, P h ) a n d Alk yn e
P olym er iza tion Ca ta lysis
Ruiping Wang, Francine Be´langer-Garie´py, and Davit Zargarian*
De´partement de Chimie, Universite´ de Montre´al, Montre´al, Que´bec, Canada H3C 3J 7
Received J uly 30, 1999
The complexes (1-Me-Ind)(PR3)Ni-CC-Ph (R ) Ph and Cy) have been prepared and
characterized spectroscopically and by means of single-crystal structural analyses. These
compounds are inert toward the insertion of alkynes, but when combined with methylalu-
minoxane (MAO), they form active catalysts for the homogeneous polymerization of
phenylacetylene. cis-Poly(Ph-CC-H) is thus obtained with Mw values in the range of 104
and relatively narrow polydispersities. The combination of the corresponding Ni-Cl
complexes with MAO gives similar results with Ph-CC-H and also polymerizes 1-hexyne
and 3-hexyne, but the degree of polymerization is much lower. Optimization studies have
shown that the polymerization reactions give the best results with THF as solvent and a
1:10 ratio of Ni to MAO. Evidence is presented for the involvement in the catalytic cycle of
bimetallic species with a Ni(µ-X)(µ-Me)Al core.
In tr od u ction
because it promotes a living polymerization process that
can produce narrow dispersitypolymers and copolymers.5a
The search for effective, transition metal catalyzed
systems that can convert alkynes into linear polyalkynes
is driven by the significant promise of the latter materi-
als in applications requiring optical nonlinear and
magnetic susceptibilities, photoconductivity, and gas
permeability.1 The majority of the catalytic systems
reported to date for the preparation of polyalkynes can
be divided into two main groups on the basis of the
polymerization mechanism, namely, metathesis and
insertion polymerizations. Thus, a number of high-
valent, early transition metal compounds containing
halides, aryl oxides, and alkylidenes (e.g., WCl6, MoCl6,
and Ln(ArO)mMdCRR′ where M ) Ta, Nb, Mo, W, etc.)
are known to catalyze the polymerization of aliphatic
alkynes such as t-Bu-CC-H to high Mw polyalkynes
by a metathetic polymerization.2 On the other hand,
aromatic alkynes undergo insertion polymerizations
catalyzed primarily by Rh(I) complexes. For instance,
Ph-CC-H can be polymerized to poly(phenylacetylene)
(PPA) with Mw in the range of 104-106 by {(diene)Rh-
(µ-Cl)}2,3 [(COD)Rh]+[(η6-Ph)BPh3]-/HSiEt3,4 and (nor-
bornadiene)(PPh3)1or2Rh-CC-Ph/4-(dimethylamino)-
pyridine.5 The latter system is especially attractive
We became interested in the catalytic polymerization
of alkynes during the course of our studies on the
dehydropolymerization of PhSiH3 catalyzed by the
complexes IndNi(PR3)X.6 Initial studies on the reactivity
of this family of compounds with alkynes showed that
although the latter do not undergo unassisted insertion
into the Ni-X bond (X ) CC-Ph, Me, etc.), linear
polyalkynes can be produced in the presence of alumi-
num alkyls. The present paper reports the results of our
studies on the preparation of the complexes (1-Me-Ind)-
(PR3)Ni-CC-Ph (R ) Ph and Cy) and their activities
in alkyne polymerization reactions.
Resu lts a n d Discu ssion
The synthesis of (1-Me-Ind)(PPh3)Ni-CC-Ph, 1, can
be accomplished via a metathetic reaction between the
known7 Ni-Cl precursor and Ph-CC-Li+ in benzene;
addition of hexane precipitates the desired product as
a yellow-brown solid in ca. 70% yield (eq 1). Complex 2
was prepared by reacting 1 with PCy3; crystallization
from EtOH gave the desired product in ca. 68% yield
(eq 2). These new complexes were fully characterized
by IR and NMR (1H, 31P{1H}, and 13C{1H}) spectroscopy,
elemental analysis, and X-ray diffraction studies (vide
infra).
(1) (a) Chien, J . C. W. Polyacetylene Chemistry, Physics and Material
Science; Academic Press: New York, 1984. (b) Bredas, J . L.; Street,
G. B. Acc. Chem. Res. 1985, 18, 309. (c) Masuda, T.; Higashimura, T.
Adv. Polym. Sci. 1986, 81, 121. (d) Yoshimura, T. Masuda, T.;
Higashimura, T.; Ishihara, T. J . Polym. Sci., Polym. Chem. Ed. 1986,
24, 3569.
(2) (a) Wallace, K. C.; Liu, A. H.; Davis, W. M.; Schrock, R. R.
Organometallics 1989, 8, 644. (b) Nakayama, Y.; Mashima, K.;
Nakamura, A. Macromolecules 1993, 26, 6267. (c) Nakano, M.; Masuda,
T.; Higashimura, T. Macromolecules 1994, 27, 1344, and references
therein.
(3) Furlani, A.; Napoletano, C.; Russo, M. V.; Feast, W. J . Polym.
Bull. 1986, 16, 311.
(4) Goldberg, Y.; Alper, H. J . Chem. Soc., Chem. Commun. 1994,
1209.
(5) (a) Kishimoto, Y.; Eckerle, P.; Miyatake, T.; Ikariya, T.; Noyori,
R. J . Am. Chem. Soc. 1994, 116, 12131. (b) Kishimoto, Y.; Miyatake,
T.; Ikariya, T.; Noyori, R. Macromolecules 1996, 29, 5054.
(6) Fontaine, F.-G.; Kadkhodazadeh, T.; Zargarian, D. J . Chem. Soc.,
Chem. Commun. 1998, 1253.
(7) Huber, T. A.; Bayrakdarian, M.; Dion, S.; Dubuc, I.; Be´langer-
Garie´py, F.; Zargarian, D. Organometallics 1997, 16, 5811.
10.1021/om990600a CCC: $18.00 © 1999 American Chemical Society
Publication on Web 12/01/1999

(1-Me-indenyl)Ni(PR3)(CC-Ph) (R ) Cy, Ph)
Organometallics, Vol. 18, No. 26, 1999 5549
Ta ble 1. Resu lts of Alk yn e P olym er iza tion Rea ction s Ca ta lyzed by (1-Me-In d )Ni(P R3)X + MAO
run
catalyst
substrate
solvent
cat.:MAO:substrate
Mw (×10-3
)
Mw/Mn
1
2
3
4
5
6
7
8
9
1
2
1
1
1
5
6
5
6
6
5
5
Ph-CC-H
Ph-CC-H
Ph-CC-H
Ph-CC-H
Ph-CC-H
Ph-CC-H
Ph-CC-H
Ph-CC-H
Ph-CC-H
Ph-CC-H
1-hexyne
benzene
benzene
benzene
THF
1:10:100a
1:10:100a
1:20:100a
1:10:100b
1:10:60b
28.1
31.8
10.9
47.4
58.7
15.2
18.1
30.7
20.5
35.2
2.4
1.72
1.55
1.73
1.27
1.32
2.13
1.66
1.16
1.09
2.69
1.37
1.01
THF
benzene
benzene
toluene
toluene
Et2O
1:10:100a
1:10:60a
1:10:100c
1:10:100c
1:10:200b
1:10:100d
1:10:100d
10
11
12
toluene
toluene
3-hexyne
1.3
a
b
d
Workup with AcOH + Et2O. Workup with AcOH + MeOH. c Workup with acetone. Workup with MeOH.
P olym er iza tion Activities. Our previous studies
had indicated that combining the precursor Ni-Cl
compounds with MAO (methylaluminoxane), AgBF4, or
LiAlH4 forms catalytically active species for the polym-
erization of PhSiH3.6 In the case of Ph-CC-H as
substrate, AgBF4 and LiAlH4 proved ineffective as
initiators, but the combination of MAO and complexes
1 or 2 did form an active catalyst for the preparation of
PPA. AlMe3 can replace MAO, but the yield of the PPA
and its Mw decrease. The PPA obtained from the MAO
the alkynyl moiety in 1 with strong acids such as
aqueous HBF4 gives the known8 cation [(1-Me-Ind)Ni-
(PPh3)2]+, presumably by the intermediary of [(1-Me-
Ind)Ni(PPh3)(η2-H-CC-Ph)]+;9 these cations do not
catalyze the polymerization of alkynes.
Monitoring the reaction of 1 and 2 with MAO in C6D6
revealed that these complexes are converted to species
displaying the characteristic 31P{1H} and 1H NMR
signals of the corresponding Ni-Me analogues;7 addi-
tion of Ph-CC-H to this mixture led to the formation
of PPA. On the other hand, similar experiments re-
vealed that the isolated samples of the Ni-Me species
cannot catalyze the formation of PPA in the absence of
MAO. We believe, therefore, that the initial interaction
of MAO with 1 and 2 forms a bimetallic species with a
Ni(µ-CC-Ph)(µ-Me)AlX2 core; the µ-alkynyl ligand in
this compound may eventually be replaced by a second
µ-Me from excess MAO. Similarly, combining the Ni-
Cl precursors 5 and 6 with MAO leads to the species
Ni(µ-Me)2AlX2, which initiate the polymerization (Scheme
1). The Ni-C bonds in these intermediates undergo
alkyne insertion more readily because they are weaker
than the corresponding Ni-C bonds in the monometallic
Ni-CC-Ph and Ni-Me compounds.
1
reactions is a yellow powder whose H NMR spectrum
(CDCl3) contained a sharp singlet at 5.85 ppm for the
vinylic proton in addition to a doublet at 6.64 ppm
(3J H-H ) 6.6 Hz, o-H) and a multiplet at 6.94 ppm
(m- and p-H) for the protons of the Ph rings; this pattern
is characteristic of the head-to-tail cis-transoidal PPA
frequently obtained by a cis insertion mechanism.3,5a
Table 1 summarizes the results of the alkyne polym-
erization reactions we have studied to date. When the
polymerization of Ph-CC-H was carried out in benzene
with 1% of 1 or 2, we obtained PPA samples with similar
Mw and polydispersities (runs 1 and 2). Approximately
10 equiv of MAO with respect to Ni seems to be optimal;
less MAO significantly reduces the yield of PPA, whereas
more MAO leads to smaller Mw polymers (run 3). The
use of THF as solvent for the polymerization reaction
led to significantly longer chains and more narrow
polydispersity (run 4); reducing the Ni-to-Ph-CC-H
ratio also resulted in longer chain lengths (run 5).
The Ni-Cl analogues of 1 and 2 also catalyze the
polymerization of Ph-CC-H in the presence of MAO.
Thus, when combined with MAO, (1-Me-Ind)(PPh3)Ni-
Cl, 5, and (1-Me-Ind)(PCy3)Ni-Cl, 6, give PPA, albeit
with somewhat lower Mw than that produced by their
alkynyl counterparts 1 and 2 (compare runs 6 and 7 to
runs 1 and 2). With toluene as reaction solvent, how-
ever, 5 and 6 give PPA with comparable Mw and
narrower polydispersities (runs 8 and 9), while in Et2O
we obtain relatively high Mw PPA but at the cost of
polydispersity (run 10). Finally, 1-hexyne and 3-hexyne
give low Mw oligomers (runs 11 and 12).
1
Ch a r a cter iza tion of Com p lexes 1 a n d 2. The H
and 31P{1H} NMR spectra of the new complexes display
the characteristic signals observed for the analogous
compounds (1-Me-Ind)Ni(PR3)X (X ) Cl, Me, etc.).7 For
instance, the 31P{1H} signal for 1 is a singlet resonating
at ca. 40 ppm, intermediate between the corresponding
signals for the Ni-Cl (31 ppm) and Ni-Me (48 ppm)
analogues. Similarly, the 1H NMR signal for the H3
proton in 1 (ca. 3.9 ppm) is intermediate between the
analogous signals for the Ni-Cl (ca. 3.3 ppm) and Ni-
Me (ca. 4.2 ppm) species.7 Interestingly, the correspond-
1
ing 31P{1H} and H resonances for 2 are quite similar
to those of the Ni-Me analogue of 2, indicating that the
hapticity of the 1-Me-Ind ligand in these compounds is
similar (vide infra). The IR spectra of both complexes
contained the characteristic absorption for the ν(CC) at
ca. 2090 cm-1
.
The solid-state structures of 1 and 2 are depicted in
Figure 1; the crystallographic data and some selected
bond lengths and angles for these compounds are listed
in Tables 2 and 3, respectively. Some of the structural
features for 1 and 2 are very similar to those found in
The results of our preliminary studies aimed at
identifying the catalytically active species in this system
allow us to make the following comments about the
alkyne polymerization process. The aluminum alkyls
(e.g., MAO) are indispensable for the process, as no
alkyne polymerization takes place in their absence.
Indeed, the alkynyl moiety in compounds 1 and 2 is
fairly inert and does not undergo insertion with alkynes,
alkenes, ketones, aldehydes, or nitriles. Protonation of
(8) Vollmerhaus, R.; G.-Be´langer, F.; Zargarian, D. Organometallics
1997, 16, 4762.
(9) Interestingly, reactions with HBF4 etherate led to the protona-
tion of PPh3 and decomposition of the remainder of the compound.

5550 Organometallics, Vol. 18, No. 26, 1999
Wang et al.
Sch em e 1
single coordination site. The Ni-P bond lengths are
similar in complexes 1 (ca. 2.168 Å) and 2 (ca. 2.161 Å),
falling between the corresponding bonds in the Ni-Me
derivative (2.121 Å) on one hand and the Ni-phthal-
imidato and the Ni-Cl analogues on the other (2.181
and 2.178 Å, respectively). The alkynyl moiety is es-
sentially linear (Ni-C9-C10 ≈ 176° and C9-C10-C11
≈ 178°), and the C9-C10 bond length of ca. 1.200 Å is
in the expected range for a triple bond.11 The sp
character of C9 results in a significantly shorter Ni-
C9 bond in 1 and 2 than the corresponding distance in
the Ni-Me analogue: ca. 1.86 Å versus ca. 1.99 Å, ∆ >
30σ.
The tendency of Ni(II) to form 16-electron complexes
results in some degree of allyl-ene distortion in the Ind
ligand, which is reflected in the different C-C bond
lengths inside the five-membered-ring moiety and the
Ni-C bond distances: C1-C7a and C3-C3a > C1-C2
and C2-C3; Ni-C(3a, 7a) > Ni-C (1-3).12 Interest-
ingly, although the allyl moiety of the Ind ligand is
essentially delocalized in both 1 and 2 (i.e., C1-C2 ≈
C2-C3; ∆ < 4σ), the local symmetry in the coordination
of the allyl moiety is quite different in the two com-
plexes. Thus, Ni-C1 ≈ Ni-C3 (∆ < 4σ) in complex 2,
whereas Ni-C1 > Ni-C3 (∆ > 19σ) in complex 1.
Similar patterns of Ind coordination are also present
in the solid-state structures of the analogous complexes
(Ind)(PPh3)Ni-X, leading us to propose7 that the coor-
dination of the Ind in each case is determined by the
relative trans influences of PPh3 and X. Thus, the
coordination of Ind is unsymmetrical when X is a ligand
such as Cl or phthalimidato with a relatively weak trans
influence compared to PPh3, whereas a symmetrical
coordination is observed with strong trans influence
ligands such as Me. On the basis of the structural
F igu r e 1. ORTEP plots of complexes 1 and 2 with atom-
numbering scheme.
the Ni-Cl,7 Ni-Me,7 and Ni-phthalimidato10 ana-
logues. For example, the atoms P, C1, C2, C3, and C9
are within expected bonding distance from the nickel
center, while the atoms C3a and C7a are considerably
farther. The geometry around Ni may be described as
distorted square planar with the C1dC2 occupying a
(11) International Tables for Crystallography; Kluwer Academic
Publishers: Dordrecht, 1995; Vol. C.
(12) (a) This type of “slip-fold” distortions may be measured in terms
of such parameters as the slip value, defined as ∆M-C ) [1/2(M-C3a
+ M-C7a) - 1/2(M-C1 + M-C3), and the hinge and fold angles (HA
and FA), representing the bending of the Ind ligand at C1/C3 and C3a/
C7a, respectively (refs 12b and 12c); the values of these parameters
for 1 and 2 are listed in Table 3. (b) Baker, R. T.; Tulip, T. H.
Organometallics 1986, 5, 839. (c) Westcott, s. A.; Kakkar, A.; Stringer,
G.; Taylor, N. J .; Marder, T. B. J . Organomet. Chem. 1990, 394, 777.
(10) Dubuc, I.; Dubois, M.-A.; Be´langer-Garie´py, F.; Zargarian, D.
Organometallics 1999, 18, 30.

(1-Me-indenyl)Ni(PR3)(CC-Ph) (R ) Cy, Ph)
Organometallics, Vol. 18, No. 26, 1999 5551
Ta ble 2. X-r a y Cr ysta llogr a p h ic Da ta for 1 a n d 2
1
2
formula and mol wt
crystal color, habit
crystal dimens, mm
cell setting, space group
a, Å
C
36H29NiP, 551.272
C36H47NiP, 569.416
dark red, parallelepiped
0.20 × 0.14 × 0.08
triclinic, P1h
9.916(3)
11.034(4)
15.906(4)
102.63(2)
94.97(2)
110.24(2)
1568.1(8)
2
1.2059
1.54056
dark red, parallelepiped
0.13 × 0.13 × 0.07
triclinic, P1h
10.686(3)
11.493(5)
12.797(3)
92.70(2)
b, Å
c, Å
R, deg
â, deg
95.52(2)
γ, deg
115.73(3)
1402.3(8)
2
1.3056
1.54056
V, Å3
Z
D (calc), g cm-1
λ (Cu KR), cm-1
temp, K
293(2)
293(2)
diffractometer
2θmax, deg
Nonius CAD-4
140.0
ω/2θ scan
5370
0.0361, 0.0534
0.170
Nonius CAD-4
140.0
ω/2θ scan
5940
0.0377, 0.0605
0.383
data coll method
refl used (I > 2σ(I))
R, Rw
max residual, e Å-3
Ta ble 3. Selected Bon d Dista n ces (Å), An gles
(d eg), a n d Oth er Str u ctu r a l P a r a m eter s for 1 a n d
2
polymerization of phenylacetylene. To our knowledge,
the only other group 10 compounds reported to catalyze
the polymerization of alkynes are the following: (a)
Cp2Ni is reported to react with Ph-CC-H at 115 °C to
give cyclic trimers and PPA with Mw of 460-1600;13 (b)
Pd(OAc)2 and (PPh3)2PdCl2 are reported to give PPA
with Mw of 600-2400;14 (c) (PPh3)2Pt(CC-Ph)2 has been
reported to give PPA with Mw in the range of 1000-
2000.15
On the basis of our preliminary results we propose
that the polymerization in the present system proceeds
by the insertion of an alkyne into the Ni-R or Ni-Me
bond in the neutral, bimetallic intermediates of the type
(Ind)(PPh3)Ni(µ-R)(µ-Me)AlX2. Studies aimed at eluci-
dating the operating mechanism of these reactions and
the optimization of the polymerization conditions are
in progress.
1
2
Ni-C1
2.112(3)
2.088(3)
2.053(3)
2.276(4)
2.313(3)
2.1685(12)
1.861(4)
1.415(4)
1.407(4)
1.435(4)
1.413(4)
1.456(4)
1.200(4)
1.428(4)
93.30(10)
167.31(11)
103.14(11)
97.80(14)
163.30(14)
39.36(12)
66.21(14)
39.73(12)
176.7(3)
10.24
2.092(3)
2.067(3)
2.079(3)
2.310(3)
2.293(3)
2.1614(10)
1.855(3)
1.398(3)
1.405(3)
1.442(4)
1.410(3)
1.434(4)
1.200(3)
1.440(3)
94.66(8)
171.85(8)
106.14(8)
92.95(11)
158.95(11)
39.30(9)
66.11(10)
39.62(10)
172.7(2)
9.4
Ni-C2
Ni-C3
Ni-C3a
Ni-C7a
Ni-P
Ni-C9
C1-C2
C2-C3
C3-C3a
C3a-C7a
C7a-C1
C9-C10
C10-C11
P-Ni-C9
P-Ni-C1
P-Ni-C3
C9-Ni-C1
C9-Ni-C3
C1-Ni-C2
C1-Ni-C3
C2-Ni-C3
Ni-C9-C10
HA (deg)a
FA (deg)b
∆M-C (Å)c
Exp er im en ta l Section
Gen er a l Com m en ts. All manipulations and experiments
were performed under an inert atmosphere of nitrogen using
standard Schlenk techniques and/or in an argon-filled glove-
box. Dry, oxygen-free solvents were employed throughout. The
elemental analyses were performed by Laboratoire d’Analyse
EÄ le´mentaire (Universite´ de Montre´al). The 1H (400 MHz), 13C-
{1H} (100.56 MHz), and 31P{1H} (161.92 MHz) NMR spectra
were recorded at ambient temperature; the IR spectra were
recorded as KBr pellets. The GPC measurements were done
using a R410 Waters instrument equipped with a differential
refractometer and ultra styragel columns.
12.01
0.21
8.7
0.21
a
Hinge angle, between the planes defined by C1, C2, C3 and
b
C1, C3, C3a, C7a. Fold angle, between the planes defined by C1,
C2, C3 and C3a, C4, C5, C6, C7, C7a. c “Slippage”: {Ni-C3a +
Ni-C7a}/2 - {Ni-C1 + Ni-C3}/2.
results for complexes 1 and 2 and the Ni-X analogues
reported earlier,7,10 we propose that the trans influences
of the various ligands in this family of compounds vary
in the order PPh3 ≈ Me > PCy3 ≈ CC-Ph > phthal-
imidate ≈ Cl.
(1-Me-In d )Ni(P P h 3)(CC-P h ) (1). A stirring benzene (20
mL) solution of (1-Me-Ind)(PPh3)Ni-Cl (361 mg, 0.74 mmol)
was added dropwise to the stirring benzene (10 mL) suspension
of Ph-CC-Li+ (104 mg, 0.96 mmol). The resultant dark yellow
mixture was stirred for 30 min at room temperature and
filtered, and the filtrate evaporated to dryness. The residue
was crystallized from THF/hexane at room temperature to give
the product as a dark yellow solid (290 mg, 71%). Dark red
crystals of 2 were grown from THF at -20 °C. IR (KBr, cm-1):
3055, 2090 (-CC-), 1588, 1488, 1432, 1094, 749, 702, 528. 1H
Con clu sion . The combination of MAO with the nickel
alkynyl complexes 1 or 2, or with the analogous Ni-Cl
complexes 5 or 6, forms effective catalysts for the
polymerization of Ph-CC-H to all-cis-PPA. In terms
of Mw and polydispersity, the PPA obtained from our
Ni-based system is comparable to those obtained from
most of the reported Rh-based systems3,4 with the
exception of Noyori’s system,5 which gives the highest
Mw PPA. Moreover, the present system represents a
rare example of a group 10 metal-based system for the
(13) Douglas, W. E.; Overend, A. S. J . Organomet. Chem. 1993, 444,
C62, and references therein.
(14) Trumbo, D. L.; Marvel, C. S. J . Polym. Sci.: Part A: Polym.
Chem. 1987, 25, 1027, and references therein.
(15) Furlani, A.; Licoccia, S.; Russo, M. V.; Camus, A.; Marsich, N.
J . Polym. Sci.: Part A: Polym. Chem. 1986, 24, 991.

5552 Organometallics, Vol. 18, No. 26, 1999
Wang et al.
NMR (C6D6): 7.52-6.78 (m, aromatic protons of PPh3, CC-
and then MAO. After stirring for 24 h at room temperature
under nitrogen, the quenching/precipitating agent was added
to give a yellow solid (PPA), which was washed by hexane and
Ph, and Ind), 6.09 (br s, H2 and another Ind proton), 3.87 (br,
2
s, H3), 2.18 (br s, Me). 13C{1H} NMR (CDCl3): 133.9 (d, J P-C
1
) 11.1, o-C), 133.0 (d, J P-C ) 45.8, i-C), 130.9 (s, p-C), 129.8
dried in vacuo. H NMR (CDCl3): 6.94 (m, m- and p-H), 6.64
2
3
(2 s, o- and m-C of CC-Ph), 128.5 (d, J P-C ) 1.4, C1), 128.2,
(d, J H-H ) 6.6, o-H), 5.85 (s, vinylic H).
127.9 (d, 2J P-C ) 10.5, m-C), 127.2, 124.7, 124.3, 124.2, 123.6,
121.0, 117.7, 116.4, 103.0, 76.9 (s, C3), 12.7 (s, Me). 31P{1H}
NMR (C6D6): 40.4(s). Anal. Calcd for C36H29NiP: C 78.43, H
5.32. Found: C 78.06, H 5.27.
X-r a y Diffr a ction Stu d ies. Dark red crystals of 1 and 2
were grown from THF and Et2O, respectively, at -20 °C.
Crystallographic data for these compounds are listed in Table
2. The ω/2θ scan mode was used in both cases to measure
30823 reflections for 1 (5307 independent, 2173 observed with
>2σ(I)) and 28169 reflections for 2 (5940 independent, 3370
observed with >2σ(I)). The structures were solved by direct
methods using SHELXS96 and difmap synthesis using
SHELXL96; refinement on F2 by full-matrix least-squares gave
the R and Rw values indicated in Table 2.
(1-Me-In d )Ni(P Cy3)(CC-P h ) (2). A stirring THF (20 mL)
solution of PCy3 (230 mg, 0.82 mmol) was added dropwise to
the stirring THF (10 mL) solution of 1 (290 mg, 0.54 mmol).
The resultant mixture was stirred for 1 h at room temperature
and then evaporated to dryness. The residue was crystallized
from EtOH at room temperature to give the product as a dark
yellow solid (210 mg, 68%). Dark red crystals of 2 were grown
from Et2O at -20 °C. IR (KBr, cm-1): 2925, 2850, 2091 (-CC-
Ack n ow led gm en t. The authors gratefully acknowl-
edge the financial support of NSERC, FCAR, and
Universite´ de Montre´al. We are indebted to Isabelle
Dubuc for carrying out the initial experiments for the
formation of 1, and to Profs. S. Collins, J . Prud’homme,
and J . Zhu for the use of their GPC instruments.
1
3
), 1594, 1444, 746. H NMR (C6D6): 7.51 (d, J H-H ) 8.0, H12
3
and H16), 7.24 (d, J H-H ) 8.0, H7), 7.06 (m, H13, H14 and
3
3
H15), 6.92 (d, J H-H ) 3.2, H4), 6.90 (br s, H6), 6.88 (t, J H-H
) 1.2, H5), 6.12 (d, 3J H-H ) 2.8, H2), 4.64 (s, H3), 2.16 (d, 4J P-H
) 4.4, Me), 1.62-1.06 (m, PCy3). 13C{1H} NMR (CDCl3): 130.8
(s), 129.0 and 125.5 (s, C3a and C7a), 127.5 (s), 124.2, 124.1,
123.7 and 123.3 (s, C6 and C7), 117.6 and 117.4 (s, C4 and
C7), 114.7 (s, C10), 103.1 (s, C2), 94.1 (br s, C9), 67.0 (s, C3),
Su p p or tin g In for m a tion Ava ila ble: Complete details on
the X-ray analyses of 1 and 2, including tables of bond
distances and angles, anisotropic thermal parameters, and
hydrogen atom coordinates. This material is available free of
charge via the Internet at http://pubs.acs.org.
2
36.0 (d, J P-C ) 21.3, C31), 29.6 (d, J P-C ) 24.4, C32), 27.6 (d,
3J P-C ) 10.7, C33), 26.3 (s, C34), 12.7 (d, J P-C ) 1.5, Me).
3
31P{1H} NMR (C6D6): 49.2 (s). Anal. Calcd for C36H47NiP: C
75.93, H 8.32. Found: C 75.50, H 8.50.
P olym er iza tion of P h en yla cetylen e. To a solution of the
Ni precatalyst in 2 mL of solvent was added phenylacetylene
OM990600A