Preparation, characterization, and reactivities of thienyl nickel complexes bearing indenyl ligands

Article abstract of DOI:10.1016/S0022-328X(02)01798-9

The complexes (1-R, 2-R'-indenyl)NiPPh₃(thienyl) (R'=H, R=Me (1); Et (2); i-Pr (3); CH₂Ph (4); R'=Ph, R=Me (5)) have been prepared and characterized by spectroscopic techniques and, in the case of 1, 2 and 5, by X-ray crystallographic studies. When combined with MAO, these compounds catalyze the polymerization of phenylacetylene to cis-transoidal poly(phenylacetylene) with M_w in the range of 5-7.5 × 10⁴ Da. NMR studies have revealed that MAO methylates these complexes without ionizing the Ni-thienyl bond; this implies that the polymerization reactions likely follow a non-cationic mechanism similar to that catalyzed by the corresponding Ni-CC-Ph complexes studied previously. Complexes 1-5 reacted with CF₃SO₃H to produce the corresponding NiOSO₂CF₃ compounds by protonation at the α-C of the thienyl moiety. The compound (1-Bz-indenyl)Ni(PPh₃)(OSO₂CF₃) (9) has been isolated and fully characterized.

Full text of DOI:10.1016/S0022-328X(02)01798-9

Journal of Organometallic Chemistry 660 (2002) 98ꢁ107
/
www.elsevier.com/locate/jorganchem
Preparation, characterization, and reactivities of thienyl nickel
complexes bearing indenyl ligands
Ruiping Wang, Laurent F. Groux, Davit Zargarian *
De´partement de chimie, Universite´ de Montre´al, Montre´al, Quebec, Canada H3C 3J7
Received 26 March 2002; received in revised form 19 July 2002; accepted 31 July 2002
Dedicated to Prof. H. Alper for his 60th birthday
Abstract
The complexes (1-R, 2-R?-indenyl)NiPPh3(thienyl) (R?ꢀ
been prepared and characterized by spectroscopic techniques and, in the case of 1, 2 and 5, by X-ray crystallographic studies. When
/
H, Rꢀ
/
Me (1); Et (2); i-Pr (3); CH2Ph (4); R?ꢀ
/
Ph, RꢀMe (5)) have
/
combined with MAO, these compounds catalyze the polymerization of phenylacetylene to cis-transoidal poly(phenylacetylene) with
Mw in the range of 5ꢁ
thienyl bond; this implies that the polymerization reactions likely follow a non-cationic mechanism similar to that catalyzed by the
corresponding NiꢀCCꢀPh complexes studied previously. Complexes 1ꢁ5 reacted with CF3SO3H to produce the corresponding Niꢀ
OSO2CF3 compounds by protonation at the a-C of the thienyl moiety. The compound (1-Bzꢀindenyl)Ni(PPh3)(OSO2CF3) (9) has
/
7.5ꢂ
/
104 Da. NMR studies have revealed that MAO methylates these complexes without ionizing the Niꢀ
/
/
/
/
/
/
been isolated and fully characterized. # 2002 Elsevier Science B.V. All rights reserved.
Keywords: Indenyl; Thienyl; Triflate; Polyalkynes
1. Introduction
might be inversely proportional to the relative ease with
which the Xꢃ moiety can be abstracted by MAO.
Consistent with this reasoning, NMR monitoring of
The available data on the relative bond energies of
transition metalꢀ
are, in general, stronger (thermodynamically) and more
stable (kinetically) than the analogous Mꢀ
(sp3-C) bonds
[1]. Consistent with this trend, solid-state data have
indicated that the NiꢀC bond in the complexes (1-Meꢀ
Ind)(PR3)NiꢀCCꢀPh [2] is shorter than the correspond-
ing bond in the NiꢀMe analogue [3]. Interestingly,
however, the NiꢀCCꢀPh complex has a higher activity
than the NiꢀMe analogue in the catalytic polymeriza-
tion of ethylene [4] and gives higher Mw and better yields
compared with the NiꢀMe and NiꢀCl analogues in the
polymerization of PhꢀCCꢀH [2]. Since mechanistic
/
C bonds indicate that Mꢀ
/
(sp-C) bonds
mixtures of MAO and Ind(PR3)Niꢀ
NiꢀCCꢀPh moiety was more resistant to ionization
compared with the corresponding NiꢀCl and NiꢀMe
bonds. In addition, reaction conditions which favored
the ionization of the NiꢀX bond (e.g. large excess of
/
X showed that the
/
/
/
/
/
/
/
/
/
/
MAO) led to lower catalytic activities and shorter
polymer chains [2]. Finally, NMR experiments have
indicated that the catalytically inert cations [(In-
d)Ni(PPh3)2]ꢄ, which form during the catalysis, tend
to react more readily with PhCCꢃ versus ꢀCH3 to
?
/
/
/
/
/
/
regenerate the catalytically active, neutral Niꢀ
/
CRn
/
/
complexes [5].
Taken together, these results imply that the nature of
experiments have indicated that these methylaluminox-
ane (MAO) co-catalyzed polymerization reactions pro-
ceed by non-cationic pathways, [2,4] we reasoned that
?
CRn bond in the catalytic precursors has an
the Niꢀ
/
important influence on the catalytic activities of these
compounds. We were, thus, prompted to examine the
the catalytic activity of the pre-catalysts Ind(PR3)Niꢀ
/X
reactivities of analogous complexes bearing Niꢀ
bonds. Initial experiments demonstrated that the Niꢀ
CHꢁCHR (RꢀH, Ph) and Niꢀ(2-pyridyl) complexes
can be generated in solution but decompose during
/
(sp2-C)
/
* Corresponding author. Tel.: ꢄ
7586
E-mail address: zargarian.davit@umontreal.ca (D. Zargarian).
/
1-514-343-2247; fax: ꢄ1-514-343-
/
/
/
/
0022-328X/02/$ - see front matter # 2002 Elsevier Science B.V. All rights reserved.
PII: S 0 0 2 2 - 3 2 8 X ( 0 2 ) 0 1 7 9 8 - 9

R. Wang et al. / Journal of Organometallic Chemistry 660 (2002) 98ꢁ
/107
99
isolation, whereas the Niꢁ
tively easy to isolate and characterize. Therefore, we
have prepared Niꢁthienyl derivatives bearing differently
substituted indenyl ligands and studied their reactivities.
The present paper reports on the preparation of the
/
thienyl analogues were rela-
the other hand, the signals for many of the vinylic
protons in the C6D6 spectra were poorly resolved and/or
/
obscured by the PPh3 resonances.
The 31P{1H}-NMR spectra of complexes 1ꢁ
5 dis-
/
played singlet resonances appearing in a very narrow
range of chemical shifts (ca. 37 ppm), while the 13C{1H}-
NMR spectra confirmed the presence of the Ind and
thienyl moieties. For instance, the 13C{1H}-NMR
spectrum of complex 5 displayed the resonances due to
complexes (1-R, 2-R?-indenyl)NiPPh3(thienyl) (R?ꢀ
RꢀMe (1); Et (2); i-Pr (3); CH2Ph (4); R?ꢀPh, Rꢀ
Me (5)) and their effectiveness in the polymerization of
PhꢀCCꢀH. The easy access to these thienyl complexes
also allowed us to study the possibility of converting
them to the corresponding Niꢁ(thienylcarbene) homo-
logues by protonation at the b-C. These reactions led to
OSO2CF3 com-
/H,
/
/
/
/
/
the four thienyl carbons, two of which are doublets
2
/
(C11: 141.28 ppm, JPꢀC
ꢀ28.4 Hz; C12: 120.50 ppm,
/
3JPꢀC
ꢀ7.6 Hz). As expected, the signals due to the
/
the formation of the corresponding Niꢀ
/
quaternary carbon atoms (i.e. C11 of thienyl and C1,
C3a, and C7a of Ind) are weak and broad, especially
when there is a coupling to the phosphorus nucleus in
the PPh3 ligand.
plexes instead (i.e. protonation at the a-C), as described
below.
2.1. Solid-state structures of 1, 2 and 5
2. Results and discussion
The above structural assignments were confirmed by
crystallographic studies on single crystals obtained for
complexes 1, 2, and 5; to our knowledge, these are the
first crystallographically characterized thienyl com-
Complexes 1ꢁ
reactions of the corresponding NiꢀCl precursors with a
small excess of 2-thienyllithium (Scheme 1). Trituration
of the oily residues obtained from the evaporation of the
reaction mixture with EtOH afforded the Niꢁ
compounds as brown powders in ca. 60ꢁ80% yields.
The spectroscopic characterization of these new com-
1
plexes was quite straight forward, as follows. The H-
NMR spectra displayed most of the anticipated reso-
nances for the three thiophenic protons (i.e. two
doublets and a doublet of doublets), as well as the Ind
and PPh3 peaks characteristic of this class of com-
/
5 were synthesized by the metathetic
/
plexes of nickel. Figs. 1ꢁ
tures of these complexes, while Tables 1ꢁ
/
3 depict the solid-state struc-
3 contain the
/thienyl
/
/
crystal data and selected bond distances and angles. The
overall geometry around the Ni center in these com-
plexes is intermediate between a two-legged piano stool
(assuming h3l
(assuming h1,h2l
arising from the small C1ꢀ
/
h5-Ind) and a distorted square-planar
h3-Ind), with the largest distortion
NiꢀC3 angle (ca. 678). The
/
/
/
1
plane of the phenyl ring in 5 is rotated by 47.68 with
respect to the five-membered ring of the Ind. The thienyl
group in all three complexes is disordered over two sites
pounds. For instance, the H-NMR spectrum of 3 in
acetone-d6 displayed three distinct signals at 6.09 ppm
(d, 3JHꢀH
ꢀ
/
3.2 Hz, H12), 6.63 ppm (dd, 3JHꢀH
ꢀ4.8 and
ꢀ4.8 Hz, H14)
/
3
related by a rotation around the Niꢀ
/
C11 bond; this type
3.2 Hz, H13), and 7.09 ppm (d, JHꢀH
attributed to the thienyl moiety; these resonances are
/
of disorder has been observed in many of the previously
reported structures of thienyl complexes [8]. The site
similar to those reported for the thienyl protons in
Cp(NO)(PPh3)Re(thienyl) [6] and (TpMe )(PMe3)Ir(thie-
2
2
nyl)2
(TpMe
ꢀhydridotris(2,5-dimethylpyrazolyl)bo-
/
rate) [7]. Moreover, the 1H-NMR spectra obtained
from C6D6 solutions of the complexes 3 and 4 displayed
two different signals for the CH(CH3)2 and CH2Ph
protons, respectively, consistent with the C1 symmetry
of the complexes which renders these protons diaster-
eotopic. The CH2 protons in complex 2 are also
diastereotopic, but they gave rise to a broad signal. On
Fig. 1. ORTEP plot (30% probability ellipsoids) for the major rotamer
of complex (1-Meꢀ
/
Ind)Ni(PPh3)(Thienyl) (1). The H atoms have been
Scheme 1.
omitted for clarity.

100
R. Wang et al. / Journal of Organometallic Chemistry 660 (2002) 98ꢁ107
/
Although the disordered thienyl ligands reduce the
accuracy of the NiꢀC11 bond lengths, the values
/
˚
1.92 A for the major rotamers in 1, 3
and 5) are reliable enough to allow a meaningful
obtained (1.91ꢁ
/
comparison with the corresponding Niꢀ
/
C distances in
˚
Ph (ca. 1.86 A) [2]
3
˚
the Niꢀ
/
Me (ca. 1.99 A) and Niꢀ
/
CCꢀ
/
analogues. Therefore, these structural data support the
C bond strengths increase with increas-
ing s-character of the C atom.
notion that Mꢀ
/
2.2. Protonation of thienyl complexes with CF3SO3H
Protonation of Mꢁ
acids HX normally results in the formation of the
corresponding MꢀX and RꢀH products (i.e. protona-
tion at the a-C), whereas Mꢁalkenyl and alkynyl
complexes can give either this type of reaction or
conversion to the corresponding Mꢁcarbene [13] or
Mꢁvinylidene [14] products, respectively (i.e. protona-
/
alkyl complexes with Brønsted
Fig. 2. ORTEP plot (30% probability ellipsoids) for the major rotamer
/
/
of (1-EtꢀInd)Ni(PPh3)(Thienyl) (2). The H atoms have been omitted
/
/
for clarity.
/
/
tion at the b-C). The factors governing the regiochem-
istry of these protonations (or electrophilic attacks) are
not well understood and the precise outcome of each
reaction seems to depend on the electronic nature of the
metallic center, the electronic properties of the ancillary
ligands, and the source of acid (or electrophile) [15]. In
the case of a series of Ruꢁ
/
benzothienyl and Reꢁthienyl
/
complexes, Angelici et al. have shown that protonation
can occur at either the a- or the b-C of the thienyl ligand
to give h1(S)-thiophene (Eq. (1)) or thienylcarbene (Eq.
(2)) complexes, respectively [6,16]. We were interested in
converting the Niꢁ
/
thienyl complexes 1ꢁ5 to their
/
analogous cationic carbene derivatives, but experiments
showed that the protonation reactions take place at the
a-C only, as described below.
Fig. 3. ORTEP plot (30% probability ellipsoids) for the major rotamer
of (1-Me-2-PhꢀInd)Ni(PPh3)(Thienyl) (5). The H atoms and Ph
/
groups of the PPh3 ligand have been omitted for clarity.
ð1Þ
occupancies are ca. 86:14 in 1, 84:16 in 2, and 74:26 in 5;
3 represent the
dominant models.
the orientations shown in Figs. 1ꢁ
/
ð2Þ
The Ni center in each of these complexes is within
reasonable bonding distance from the P, C11, C1, C2,
and C3 atoms, but considerably farther away from C3a
Reacting the compounds 1ꢁ
HBF4×Et2O led to the decomposition of the starting
materials and gave [HPPh3]ꢄ as the only identifiable
product (31P{1H}-NMR: ca. 5 ppm). When HBF4×
H2O
/
5 with one equivalent of
and C7a. The extent of Niꢁ
the so-called ‘slip’ parameter D(Mꢀ
MC7a)ꢃ(MꢀC1ꢄMC3)], [9] which is ca. 0.21 A for the
three complexes studied here. These D(MꢀC) values and
the fold and hinge angles (FA, HA, as defined in Table
3) indicate an intermediate (h5lh3) hapticity for the
Ind ligands in 1, 2, and 5 [10]. Comparison of the NiꢀC1
C3 distances with each other and to the
/Ind interaction is reflected in
/
/
C)ꢀ1/2 [(MꢀC3aꢄ
/
/
/
˚
/
/
/
/
/
was used instead, the starting materials were converted
to their corresponding bis(phosphine) cations, [In-
dNi(PPh3)2][BF4], identified on the basis of their char-
acteristic 31P{1H}-NMR spectra (e.g. for the reaction of
/
/
1 (CDCl3): 35.8 (d, 2JPꢀP
ꢀ
/
25), 32.5 (d, 2JPꢀP
ꢀ25)) [17].
/
and Niꢀ
/
corresponding values in the analogous complexes (In-
d)Ni(PPh3)(X) implies that the trans influences of the
The latter presumably arise from the protonation of the
thienyl moiety at the a-C to generate the unstable
species [IndNi(PPh3)]ꢄ, which is known [17] to give
the bis(phosphine) cations (Scheme 2).
ligands X follow the order PPh3:
/
Me [3] ꢀ
/
thienyl:
/
CCꢀPh [2] ꢀSPh [11] ꢀphthalimide [12] :
/
/
/
/
Clꢃ [3].

R. Wang et al. / Journal of Organometallic Chemistry 660 (2002) 98ꢁ
/107
101
Table 1
Data collection and refinement parameters for complexes 1, 2, 5 and 9
1
2
5
9
Formula
C
32H27NiPS
533.276
Redꢁorange
Block
C33H29NiPS
547.302
Red
C38H31NiPS
609.368
C35H28F3NiO3PS
675.314
Dark red
Molecular weight
Crystal color
Crystal habit
/
Dark brown
Block
Block
Block
Crystal dimensions (mm)
Cell setting
Space group
0.63ꢂ0.46ꢂ0.21
Orthorhombic
Pbca
0.35ꢂ0.30ꢂ0.08
Orthorhombic
Pbca
0.72ꢂ0.36ꢂ0.21
Monoclinic
P21/n
0.43ꢂ0.30ꢂ0.12
Orthorhombic
Pbca
˚
a (A)
17.1552(1)
16.4950(1)
18.3638(1)
17.127(8)
16.716(9)
19.160(5)
10.6902(1)
15.1392(1)
19.6099(1)
104.348(1)
3047.70(4)
4
10.1641(1)
17.3104(1)
36.0549(1)
˚
b (A)
˚
c (A)
b (8)
3
V (A )
˚
5196.50(5)
8
1.3633
5485(4)
8
6343.67(7)
8
1.4142
Z
Dcalc (g cmꢃ3
)
1.3254
1.54056
293(2)
1.3164
1.54178
293(2)
l (Cuꢁ
/
Ka) (cmꢃ1
)
1.54178
293(2)
1.54178
293(2)
Temperature (K)
Diffractometer
2umax (8)
Data collection method
Number of reflections used (I ꢀ2s(I))
R, Rw
Bruker AXS
145.64
Nonius CAD-4
139.64
Bruker AXS
145.78
v scan
Bruker AXS
145.64
v scan
4757
0.0365, 0.0977
v ꢁ/2u scan
v scan
4962
0.0634, 0.1938
2559
0.0407, 0.0831
5648
0.0391, 0.1132
Table 2
Selected bond distances (A) for 1, 2, 5 and 9
Table 3
Selected bond angles (8) for 1, 2, 5 and 9
a
˚
1
2
5
9
1
2
5
9
NiꢀC11(O1)
NiꢀP
NiꢀC1
NiꢀC2
1.912(3)
2.1541(5)
2.1058(17)
2.0742(17)
2.0709(18)
2.3066(17)
2.2924(17)
1.416(3)
1.407(3)
1.449(3)
1.455(3)
1.427(2)
0.21
1.921(4)
2.1551(11)
2.083(3)
2.073(3)
2.088(3)
2.303(3)
2.279(3)
1.412(4)
1.410(4)
1.433(5)
1.436(4)
1.432(4)
0.21
1.909(3)
2.1490(5)
2.0914(17)
2.0853(16)
2.0698(17)
2.2894(17)
2.2853(18)
1.424(3)
1.415(3)
1.450(3)
1.455(3)
1.416(3)
0.21
1.972 (9)
2.2024(8)
2.171(3)
2.076(3)
2.018(3)
2.313(4)
2.360(3)
1.392
C11(O1)ꢀNiꢀP
C3ꢀNiꢀP
C1ꢀNiꢀP
93.50(12)
104.24(5)
169.41(5)
96.1(4)
93.4(3)
105.92(6)
167.89(6)
160.6(3)
66.85(8)
94.2(3)
95.5(7)
98.85(10)
104.05(10)
168.75(10)
159.8(4)
164.0(10)
165.7(7)
65.97(14)
99.7(7)
C11(O1)ꢀNiꢀC3 162.19(13)
NiꢀC3
C3ꢀNiꢁ/C1
66.66(7)
66.50(13)
93.5(4)
NiꢀC3a
NiꢀC7a
C1ꢀC2
C1ꢀNiꢀC11(O1) 95.82(14)
C21ꢀC2ꢀNi
HA*
FA*
124.92(13)
9.21(0.23) 10.06(0.20)
8.44(0.22) 10.84(0.19)
9.53(0.13)
9.46(0.12)
9.48
7.57
C2ꢀC3
1.435(5)
1.452(5)
1.479(5)
1.404(5)
0.24
C3ꢀC3a
C1ꢀC7a
C3aꢀC7a
* HA (hinge angle), angle between the planes defined by C1, C2, C3
and C1, C3, C3a, C7a; FA (fold angle), angle between the planes
defined by C1, C2, C3 and C3a, C4, C5, C6, C7, C7a.
b
DMꢀC
a
Values given are for the major rotamers only.
D(MꢀC)ꢀ1/2[(NiꢀC3aꢄNiꢀC7a)ꢃ(NiꢀC1ꢄNiꢀC3)].
b
Protonating the Niꢁ/thienyl complexes with triflic
acid, CF3SO3H×(HOTf), caused an immediate color
/
change from dark-yellow to red. Analysis by NMR
indicated that the reaction mixtures contained free
thiophene, [18] small amounts of [IndNi(PPh3)2]ꢄ, and
the new derivatives (Rꢀ
31P{1H} resonances at ca. 30 ppm (Scheme 2). On the
other hand, reacting 1ꢁ5 with CF3SO3CH3 led to a slow
conversion of the Niꢁthienyl precursors to a mixture of
/
Ind)(PPh3)Niꢀ
/
OTf displaying
/
/
Scheme 2.
products arising from the addition of Meꢄ at (1) PPh3
to give [PMePh3][OTf], which was identified by its
31P{1H} signal at 22.13 ppm, and at (2) the a-C of the
corresponding Niꢀ
/
OTf (major) and the bis(PPh3) ca-
Niꢁ
/
thienyl moiety to give 2-Meꢀ/thiophene and the
tions (minor).

102
R. Wang et al. / Journal of Organometallic Chemistry 660 (2002) 98ꢁ107
/
We conclude, therefore, that the primary site of
protonation (or electrophilic attack) in the complexes
1ꢁ5 is at the a-C of the Niꢁthienyl moiety. In principle,
/
/
this reaction should lead, initially, to the formation of
sulfur-bound h1(S)-thiophene compounds, [6] but inter-
mediates of the type [Ind(PPh3)Ni(h1(S)-thio-
phene)]ꢄ[OSO2CF3]ꢃ were never detected in our stu-
dies. Indeed, NMR experiments showed that thiophene
does not displace the OTf ligand in the new Niꢀ
products; furthermore, our attempts to generate cationic
Niꢀ
(h1(S)-thiophene) complexes directly from the Niꢀ
Cl precursors have given the bis(PPh3) cations instead.
/
OTf
/
/
These results imply that even if protonation of the Niꢁ
/
thienyl compounds gave Ni-(h1(S)-thiophene) inter-
mediates initially, they would rearrange rapidly to give
Fig. 4. ORTEP plot (30% probability ellipsoids) for the major rotamer
of (1-BzꢀInd)Ni(PPh3)(OTf) (9). The H atoms have been omitted for
clarity.
/
the more stable Niꢀ
Owing to the poor nucleophilicity of the triflate
ligand, Mꢁtriflate complexes can act as precursors to
/OTf analogues.
/
The overall geometry around the Ni center in 9 is very
similar to those of the thienyl complexes discussed
above, but a number of subtle differences can be
observed. For instance, the Ind ligand is more ‘tilted’
and ‘slipped’ in 9 compared with the thienyl derivatives:
highly reactive cationic intermediates. For example,
lanthanide triflates [19] and complexes such as
L2Ti(OTf)2 (Lꢀ
CpꢁInd ligands) [20] act as powerful Lewis acids in
organic synthesis, while Cp*(PMe3)(Me)Ir(OTf) acti-
vates CꢀH bonds of alkanes [21]. Mindful of these
potential reactivities, we sought to isolate and comple-
tely characterize the NiꢀOTf derivatives produced by
the protonation of the Niꢁthienyl complexes. Thus, (1-
Ind)Ni(PPh3)(OSO2CF3) (9) was isolated from the
/various combinations of elaborated
/
˚
˚
0.04 A in
(Niꢀ
/
C1)ꢀ
/
(Niꢀ
/
C3)ꢀ
/
0.15 A in 9 versus 0.01ꢁ
/
/
˚
0.24 in 9 versus 0.21 A in 1, 2, and
1, 2, and 5; DMꢀ
/
Cꢀ
/
5. We have noted previously that such differences in the
coordination mode of Ind are due to the poorer
nucleophilicity and smaller trans influence of the X
ligands such as Cl [3] and phthalimidate [12] compared
/
/
Bzꢀ
/
reaction of 4 with one equivalent of CF3SO3H in
CH2Cl2 and purified by recrystallization from
with better s-donors such as CCꢀ
Another important structural difference between the
NiꢀOTf and NiꢀCRn complexes is the NiꢀP distance,
which is 2.20 A in 9 versus ca. 2.15 A in 1, 2, and 5 and
/Ph [2] and Me [3].
CH2Cl2ꢁ
a mutiplet at 3.00 ppm due to H3, two doublets of
doublets at 3.62 ppm (2JHꢀH 16.6 Hz, 4JPꢀH
4.8 Hz)
/
hexane. The 1H-NMR spectrum of 9 displayed
/
/
/
˚
˚
ꢀ
/
ꢀ
/
˚
2.12 A in the corresponding Niꢀ
/
Me [3] analogue. This
attributed to the diastereotopic benzyl protons, and two
doublets at 5.90 (H4) and 6.09 ppm (H2). In addition,
we observed a 31P{1H} signal at 29.7 ppm (PPh3) and an
might be ascribed to the mismatch between PPh3, a
relatively soft Lewis base, and the Ni center, which is a
harder Lewis acid when it is bonded to ligands such as
OTf versus C-based ligands such as alkynyl, thienyl, Me,
etc. [23].
19F{1H} signal at ꢃ
comparable with the signal at ca. ꢃ
/
79.6 ppm (CF3SO3ꢃ); the latter is
78 ppm for the
/
triflate moiety in trans-[Ni(OTf)(2-C5F4N)(PEt3)2] [22].
2.3. Solid-state structure of 9
2.4. Catalytic effectiveness of the thienyl complexes in the
polymerization of PhCCH
An X-ray diffraction study was carried out on single
crystals obtained from the slow evaporation of toluene
solutions of 9 at room temperature. This study showed
that the OTf moiety exhibits a four-fold orientational
disorder; Fig. 4 depicts an ORTEP diagram for the major
component of 9. The triflate ligand is bonded in an
Recent work in our group has shown that mixtures of
MAO and (1-Meꢀ
in-situ from the Niꢀ
the polymerization of phenylacetylene to cis-transoidal
poly(phenylacetylene) (Mwꢀ2ꢁ6ꢂ
104 Da, Mw/Mnꢀ
1ꢁ3). In order to probe the influence of the ligand X
on this reaction, we studied the catalytic polymerization
of phenylacetylene using the analogous Niꢁthienyl
complexes as pre-catalysts under similar reaction con-
ditions (ten equivalents of MAO, 60 equivalents of Phꢀ
H, THF, room temperature, 24 h). These reactions
/
Ind)Ni(PR3)(X) (Xꢀ
/
Me, generated
/
Cl precursor, and CCPh) catalyze
/
/
/
/
/
h1(O) fashion to the nickel center with an average Niꢀ
/O
˚
distance of 1.955 A, which is longer than the Niꢀ
/
O
/
˚
distance of ca. 1.89 A in Cp*(PEt3)Ni(OR) (Rꢀ
MeC6H4, Me); a similar relationship has been observed
between the NiꢀO bond distances in trans-[Ni(X)(2-
C5F4N)(PEt3)2]: 1.957(2) A for Xꢀ
/
p-
/
/
CCꢀ
/
˚
/OTf versus 1.894(4)
gave the expected cis-transoidal poly(phenylacetylene)
on the basis of their NMR spectra; GPC analyses
˚
A for Xꢀ
/
Oph [22].

R. Wang et al. / Journal of Organometallic Chemistry 660 (2002) 98ꢁ
/107
103
showed that these samples consisted of somewhat longer
chains (Mwꢀ5.0ꢁ7.5ꢂ
104 Da) of much poorer mono-
dispersities (Mw/Mnꢀ3.7ꢁ5.8) compared with the poly-
mers obtained from the NiꢀCCPh reactions (Mwꢁ
5.0ꢂ 1.3).
104 Da and Mw/Mnꢁ
No optimization studies have been carried out for the
polymerization reactions involving the Niꢁthienyl pre-
AMX400 and AV300 spectrometers were employed for
recording 1H- (400 and 300 MHz), 13C{1H}- (100.56 and
75.42 MHz), 19F- (376.31 MHz), and 31P{1H}- (161.92
MHz) NMR spectra at ambient temperature. The NMR
spectra are referenced to solvent resonances (1H- and
13C{1H}-), 85% H3PO4 (0 ppm in 31P{1H}-), and
/
/
/
/
/
/
/
/
/
/
C6H5CF3 (ꢃ
63.9 ppm in 19F-). The elemental analyses
/
catalysts, but NMR experiments have indicated that
these reactions follow a mechanism similar to those
were performed by Laboratoire d’Analyse Ele´mentaire
(Universite´ de Montre´al). The molecular weights of the
poly(phenylacetylene) were determined on a Waters 510
liquid chromatograph equipped with m-styragel columns
and a Waters 410 differential diffractometer. The
catalyzed by the Niꢀ
/
CCPh precursors. Thus, a small
excess of MAO converts 1 to species displaying the
characteristic 31P{1H}- and 1H-NMR signals for the
corresponding Niꢀ
trace of the corresponding cations; addition of Phꢀ
H to this sample initiated the polymerization. In analogy
with our previous reports, we believe that the Niꢁthienyl
Me
counterparts through bimetallic intermediates bearing a
Ni(m-thienyl)(m-Me)Al core. The relatively weakened
/
Me analogue [3], with little or no
precursors (1-Rꢀ
/
Ind)NiPPh3Cl (Rꢀ
/
Me, Et, iPr, and
/
CCꢀ
/
Bz) and (1-Me-2-Phꢀ
/Ind)NiPPh3Cl were prepared as
described elsewhere; [25] 2-thienylithium was prepared
by the deprotonation of thiophene with BuLi. The
compounds MAO, PhCCH, thiophene, and CF3SO3H
were purchased from Aldrich and used as received.
/
complexes are in rapid equilibrium with their Niꢀ
/
Niꢀ
/
R moieties in the latter species facilitate the inser-
4.1. Synthesis of (1-Meꢀ
/
Ind)Ni(PPh3)(thienyl) (1)
tion of the Phꢀ
/
CCꢀ/H. It is not clear yet whether the Ind
ligands undergo slippage during these steps, but the
analogoues Cp complexes are significantly less reactive
in this type of reaction [24].
A stirred benzene solution (25 ml) of 2-thienylithium
(1.10 ml of a 1.0 M solution in THF, 1.10 mmol) was
added dropwise to a stirred benzene solution (15 ml) of
(1-Meꢀ/Ind)Ni(PPh3)Cl (6) (360 mg, 0.74 mmol). The
resulting orange mixture was stirred for 10 min at room
temperature (r.t.), filtered, and the filtrate was evapo-
rated. The orange, oily residue was triturated in 20 ml of
EtOH at r.t. to give the product as a dark yellow powder
3. Summary
The structural studies of complexes 1, 2, and 5 have
shown no major difference in the structures of these
complexes as a function of the different Ind substituents.
(230 mg, 58%). Recrystallization of 1 from a benzeneꢁ
/
EtOH mixture gave single crystals suitable for X-ray
1
analysis. H-NMR (C6D6, 400 MHz): 1.44 (s, IndCH3),
The Niꢀ
found to be intermediate between those of the Niꢀ
and NiꢀCCꢀPh analogues. A brief examination of the
/
C bond lengths in the thienyl complexes were
/
Me
4.05 (br s, H3), 6.27 (d, JHꢀH
ꢀ2.6), 6.39 (s, H2), 6.53 (d,
/
1
4.7). H-
/
/
JHꢀH
ꢀ
/
2.4), 6.97ꢁ
/
7.41 (m, ArH), 7.42 (d, Jꢀ
/
polymerization of phenylacetylene catalyzed by the
thienyl complexes has affirmed the importance of the
NMR (acetone-d6, 300 MHz): 1.26 (d, 3JPꢀH
ꢀ
/
2.6, Indꢀ
/
3
CH3), 4.09 (br s, H3), 6.09 (d, JHꢀH
ꢀ2.0, H12), 6.37
/
3
character of the Niꢀ
reactivities: NiꢁCCPh and Niꢁ
higher activities and longer chains than the Niꢀ
Me precursors.
Protonating the Niꢁ
/
X bond in the precursor for their
thienyl precursors give
ClꢁNiꢀ
(br s, H4), 6.47 (d, JHꢀH
3JHꢀH
3.5, H13), 6.99ꢁ7.42 (m, Aromatic H), 7.02 (t,
3JHꢀH
7.6, H6); the signals for the remaining protons
ꢀ
/2.3, H2), 6.67 (pseudo t,
/
/
ꢀ
/
/
/
/
/
ꢀ
/
were not observed and are presumably obscured by the
aromatic resonances. 13C{1H}-NMR (CDCl3, 100.56
/
thienyl complexes with CF3SO3H
generated the corresponding Niꢀ
/
OTf compounds in-
MHz): 11.51 (Indꢀ
/
CH3), 74.64 (C3), 94.90 (br, C1),
102.70 (C2), 116.90 (C3a), 117.24 (C7a), 121.32 (C13 or
stead of the desired cationic thienyl carbene derivatives.
The solid structure of one of these complexes has
C14), 122.24 (br, C12), 123.48, 124.16, 126.89 (C13 or
3
C14), 127.79 (d, JPꢀC
C of PPh3), 129.54, 129.66, 132.90 (d, JPꢀC
revealed relatively long Niꢀ
/
P and Niꢀ
/O distances.
ꢀ10.4, m-C of PPh3), 128.27 (p-
/
1
Future studies will examine the reactivities of the Niꢀ
/
ꢀ/43.7, i-C
2
OTf derivatives in ligand substitution and polymeriza-
tion reactions.
of PPh3), 133.64 (d, JPꢀC
ꢀ/11.1, o-C of PPh3),
139.93(br, C11). 31P{1H}-NMR (C6D6): 37.26 (s).
Anal. Calc. for C29H24PNiS: C, 72.07; H, 5.10; S, 6.01.
Found: C, 71.95; H, 5.19; S, 5.88%.
4. Experimental
4.2. Synthesis of (1-Etꢀ
/
Ind)Ni(PPh3)(thienyl) (2)
All manipulations and experiments were performed
under an inert atmosphere using standard Schlenk
techniques and/or in a nitrogen-filled glovebox. Dry,
oxygen-free solvents were employed throughout. Bruker
Complex 2 was prepared in the same manner as 1
using 2-thienylithium (0.60 ml of a 1.0 M solution in
THF, 0.60 mmol) and (1-Etꢀ
/
Ind)Ni(PPh3)Cl (7) (198

104
R. Wang et al. / Journal of Organometallic Chemistry 660 (2002) 98ꢁ107
/
3
mg, 0.4 mmol) to give the Niꢁ
brown powder (160 mg, 74%). Red, X-ray quality
crystals were obtained upon cooling (ꢃ20 8C) the
/
thienyl product as a
126.83, 127.83 (d, JPꢀC
ꢀ9.7, m-C of PPh3), 128.32,
/
1
129.01, 129.71 (p-C of PPh3), 133.14 (d, JPꢀC
Hz, i-C of PPh3), 133.70 (d, JPꢀC
ꢀ
/
44.4
2
/
ꢀ
/
11.1 Hz, o-C ꢀ
/
filtrate obtained from the extraction of the brown
1
powder into EtOH. H-NMR (C6D6, 400 MHz): 1.10
PPh3), 134.06, 138.20 (br, C11). 31P{1H}-NMR
(C6D6): 37.42 (s). Anal. Calc. for C34H31PNiS: C,
72.75; H, 5.57; S, 5.71. Found: C, 72.31; H, 5.59; S,
6.28%.
3
(t, JHꢀH
ꢀ
/
7.3, IndCH2CH3), 1.90 (br, IndCH2), 4.07
2.6), 6.46 and 6.54 (d, JHꢀH
4.7), 6.97ꢁ
7.40 (m, ArH). 1H-
NMR (acetone-d6, 300 MHz): 1.07 (t, 3JHꢀH
7.6, Indꢀ
CH2CH3), 1.66 (m, IndꢀCH2), 4.07 (br s, H3), 6.09 (d,
3JHꢀH
2.3, H12), 6.44 (br s, H4), 6.53 (d, JHꢀH
H2), 6.66 (pseudo t, 3JHꢀH 3.5, H13), 7.02 (t, 3JHꢀH
7.6, H6), 7.16ꢁ7.72 (m, Aromatic H); the signals for the
(br s, H3), 6.35 (d, JHꢀH
1.9), 7.40 (d, JHꢀH
ꢀ
/
ꢀ
/
ꢀ
/
/
ꢀ
/
/
4.4. Synthesis of (1-Bzꢀ
/
Ind)Ni(PPh3)(thienyl) (4)
/
3
ꢀ
/
ꢀ/2.8,
Complex 4 was prepared in the same manner as 1
using 2-thienylithium (1.78 ml of a 1.0 M solution in
THF, 1.78 mmol) and (1-Bzꢀ
ꢀ
/
ꢀ
/
/
/
Ind)Ni(PPh3)Cl (9) (500
remaining protons were not observed and are presum-
ably obscured by the aromatic resonances. 13C{1H}-
mg, 0.89 mmol) to give the product as a brown powder
(414 mg, 77%). Extraction into EtOH, followed by
filtration and cooling gave analytically pure material.
1H-NMR (400 MHz, C6D6): 3.24 and 3.27 (br s,
IndCH2), 4.05 (br s, H3), 6.31 (br s), 6.44 (br s), 6.60
NMR (CDCl3, 100.56 MHz): 12.44 (Indꢀ
19.37 (IndꢀCH2), 74.74 (C3), 100.73 (C2), 117.10 (C3a),
117.33 (C7a), 121.40 (br, C12), 121.76 (C13 or C14),
/CH2CH3),
/
3
123.51, 124.09, 126.82, 127.76 (d, JPꢀC
ꢀ
/
9.7, m-C of
PPh3), 129.35 (C13 or C14), 129.64 (p-C of PPh3),
(br s), 6.97ꢁ
/
7.44 (ArH). 1H-NMR (acetone-d6, 300
2
MHz): 2.91 and 3.08 (d, JHꢀH
ꢀ
/
14.5, Indꢀ
1.9, H12), 6.43 (br s, H4),
2.9, H2), 6.73 (dd, 3JHꢀH
4.5 and 3.5,
H13), 7.02 (t, 3JHꢀH
7.0, H6), 7.18ꢁ7.69 (m, Aromatic
/
CH2), 4.11
1
3
132.95 (d, JPꢀC
2JPꢀC 11.1, o-C of PPh3), 138.95 (br, C11). 13C{1H}-
NMR (C6D6, 100.56 MHz): 13.19 (IndꢀCH2CH3),
20.44 (IndꢀCH2), 75.74 (C3), 101.55 (C2), 109.54
(C1), 122.61 and 122.96 (C3a and C7a), 124.50,
ꢀ
/
43.6, i-C of PPh3), 133.61 (d,
(br s, H3), 6.17 (d, JHꢀH
6.56 (d, 3JHꢀH
ꢀ
/
ꢀ
/
ꢀ
/
ꢀ
/
/
ꢀ
/
/
/
H); the signals for the remaining protons were not
observed and are presumably obscured by the aromatic
resonances. 13C{1H}-NMR (CDCl3, 100.56 MHz):
3
125.09, 128.11 (d, JPꢀC
ꢀ
/
2.7, C12), 128.62 (m-C of
2.8, p-C of PPh3), 130.91 (br,
C13 or C14), 134. 12 (d, JPꢀC 42.6, i-C of PPh3),
11.0, o-C of PPh3), 134.86 (br, C11).
31P{1H}-NMR (C6D6): 37.11 (s). Anal. Calc. for
C30H26PNiS: C, 72.42; H, 5.34; S, 5.86. Found: C,
72.14; H, 5.27; S, 5.81%.
2
PPh3), 130.36 (d, JPꢀC
ꢀ
/
32.69 (CH2ꢀ
(C2), 117.17 and 117.49 (C3a and C7a), 121.53, 121.61,
123.68, 124.13, 125.73, 127.04, 127.77 (d, 3JPꢀC
9.7, m-
C of PPh3), 128.65, 129.69 (p-C of PPh3), 133.06 (d,
11.1, o-C
/
Ph), 75.45 (C3), 97.13 (br, C1), 102.37
ꢀ
/
3
134.44 (d, JPꢀC
ꢀ
/
ꢀ
/
1JPꢀC
ꢀ
/
43.7, i-C of PPh3), 133.59 (d, 2JPꢀC
ꢀ
/
of PPh3), 133.99, 138.40 (br, C11), 139.70. 31P{1H}-
NMR (C6D6): 37.11 (s). Anal. Calc. for C38H31PNiS: C,
74.90; H, 5.13; S, 5.26. Found: C, 74.29; H, 5.16; S,
5.08%.
4.3. Synthesis of (1-iPrꢀ
/
Ind)Ni(PPh3)(thienyl) (3)
Complex 3 was prepared in the same manner as 1
using 2-thienylithium (2.20 ml of a 0.66 M solution in
4.5. Synthesis of (1-Me-2-Ph) Ni(PPh3)(thienyl) (5)
THF, 1.46 mmol) and (1-i-Prꢀ
/
Ind)Ni(PPh3)Cl (8) (500
mg, 0.97 mmol) to give the product as a brown powder
(400 mg, 73%). Extraction into EtOH, followed by
Complex 5 was prepared in the same manner as 1
using 2-thienylithium (1.82 ml of a 0.66 M solution in
filtration and cooling gave analytically pure material.
1H-NMR (C6D6, 400 MHz): 1.10 and 1.25 (d, JHꢀH
THF, 1.20 mmol) and (1-Me-2-Phꢀ
/
Ind)Ni(PPh3)Cl (10)
3
ꢀ
/
(450 mg, 0.80 mmol) to give the product as a brown
powder (380 mg, 76%). Crystals of 5 suitable for X-ray
crystallorgraphy were obtained by recrystallization from
6.2 and 6.9, IndCH(CH3)2), 2.36 (br s, IndCH(CH3)2),
4.02 (br s, H3), 6.32 (d, JHꢀH 3.0), 6.52 (d, JHꢀH
2.7), 7.08 (t, JHꢀH 7.3), 7.26ꢁ
(acetone-d6, 400 MHz): 1.10 (d, JHꢀH
ꢀ
/
ꢀ
/
1
ꢀ
/
/7.55 (ArH). H-NMR
a THFꢁ
MHz): 1.58 (d, JPꢀH
3.0, H3), 6.51 (d, JHꢀH
(d, JHꢀH 1.1), 7.79 (d, JHꢀH
d6, 300 MHz): 1.38 (d, JPꢀH
/
toluene mixture at r.t. 1H-NMR (C6D6, 400
3
4
3
ꢀ
/
6.6, Indꢀ
/
ꢀ
/
4.5, IndCH3), 4.32 (d, JPꢀH
7.8), 6.57 (d, JHꢀH 3.3), 7.77
1.4). 1H-NMR (acetone-
4.5, IndꢀCH3), 4.28 (d,
3.1, H3), 6.11 (d, JHꢀH 2.9, H12), 6.45 (d,
4.7 and 3.4, H13),
7.73 (m, Aromatic H); the signals for the remain-
ꢀ
/
3
CH(CH3)2), 4.02 (br s, H3), 6.09 (d, JHꢀH
ꢀ
/
3.2,
ꢀ
/
ꢀ
/
3
H12), 6.50 (d, JHꢀH
ꢀ
/
3.2, H2), 6.57 (br, H4), 6.63
3
4.8 and 3.2, H13), 7.03 (t, JHꢀH
ꢀ
/
ꢀ
ꢀ
/
3
4
(dd, JHꢀH
ꢀ
/
ꢀ
/
8.0,
/
/
H6), 7.09 (d, 3JHꢀH
ꢀ
/
4.8, H14), 7.27ꢁ7.55 (m, Aromatic
/
3JPꢀH
3JHꢀH
7.07ꢁ
ꢀ
ꢀ
/
ꢀ
ꢀ
/
3
3
H); the signals for the remaining protons were not
observed and are presumably obscured by the aromatic
resonances. 13C{1H}-NMR (CDCl3, 100.56 MHz):
20.55 and 22.16 (CH(CH3)2), 25.08 (CH(CH3)2), 74.60
(br, C3), 98.45 (C2), 105.29 (br, C1), 117.28 (C3a),
118.02 (C7a), 120.53 and 121.95 (C13 and C14), 123.84,
/
7.9, H4), 6.69 (dd, JHꢀH
/
/
ing protons were not observed and are presumably
obscured by the aromatic resonances. 13C{1H}-NMR
(CDCl3, 100.56 MHz): 10.23 (CH3ꢀ
/Ind), 74.58 (C3),
91.47 (d, Jꢀ13.19, C1), 116.48, 117.53, 120.50 (d, Jꢀ
/
/

R. Wang et al. / Journal of Organometallic Chemistry 660 (2002) 98ꢁ
/107
105
7.6, C12), 122.87, 123.78, 129.37, 129.70, 124.35, 127.02,
127.19, 127.84 (d, 3JPꢀC
9.7, m-C of PPh3), 128.39 (p-
C of PPh3), 128.32, 129.01,129.19, 132.91 (d, JPꢀC
4.10. Reaction of 5 with CF3SO3H
ꢀ
/
1
ꢀ
/
The general procedure outlined above was used for
the reaction of 5 (16 mg, 0.026 mmol) with CF3SO3H
(2.4 ml, 0.026 mmol) to give (1-Me-2-Ph)Ni(PPh3)(OTf)
/
2
43.7, i-C of PPh3), 133.27, 133.64 (d, JPꢀC
ꢀ
/
11.1, o-C
2
of PPh3), 135.94, 141.28 (d, JPꢀC
ꢀ/28.4, C11).
31P{1H}-NMR (C6D6): 37.36 (s). Anal. Calc. for
C38H31PNiS: C, 74.90; H, 5.13; S, 5.26. Found: C,
73.71; H, 5.16; S, 5.18%.
(10). H-NMR (C6D6): 1.60 (d, JPꢀH
ꢀ
/
6.3 Hz, Indꢀ
/
1
3
3
3
CH3), 3.36 (d, JPꢀH
7.4Hz, H4), 6.79ꢁ
7.96 (m, ArH). 31P{1H}-NMR
(C6D6): 30.63 (s).
ꢀ
/
5.1 Hz, H3), 5.96 (d, JHꢀH
ꢀ
/
4.6. General procedure for the reaction of complexes 1ꢁ
/
5
with one equivalent of CF3SO3H
4.11. Synthesis of (1-Bzꢀ
/
Ind)Ni(PPh3)(OTf) (9)
A 5 mm NMR tube was charged with the Niꢁ
/
thienyl
A CH2Cl2 solution (10 ml) of CF3SO3H (32 ml, 0.36
mmol) was added dropwise to the stirred CH2Cl2
complex and 0.55 ml of C6D6. One equivalent of
CF3SO3H was added to the solution and the tube was
shaken, resulting in an immediate color change (brown
to red). The 1H- and 31P{1H}-NMR spectra of the
sample showed a nearly quantitative conversion to the
solution (20 ml) of (1-Bzꢀ
/
Ind)Ni(PPh3)(thienyl) (220
mg, 0.36 mmol) at r.t. The resulting red mixture was
stirred for 30 min, filtered, and the filtrate was
evaporated to dryness. The residue was crystallized
Niꢀ
/
OTf derivative (6ꢁ
/
10) in all cases.
from CH2Cl2ꢁhexane at r.t. to give the product as a
/
red powder (110 mg, 46%). Crystals suitable for X-ray
diffraction studies were grown by the slow evaporation
of a toluene solution at r.t. 1H-NMR (C6D6, 400 MHz):
4.7. Reaction of 1 with CF3SO3H
2
The general procedure outlined above was used for
the reaction of 1 (15 mg, 0.028 mmol) with CF3SO3H
3.00 (m, H3), 3.62 and 3.34 (dd, JHꢁH
ꢀ
/
16.6 Hz,
7.4 Hz,
1.8 Hz, H2), 6.74 (t, JHꢀH 7.9
Hz, H5), 7.00 (s, ArH), 7.08 (m, ArH), 7.42 (d, 3JHꢀH
6.6 Hz, H7), 7.49 (m, ArH). 13C-NMR (CDCl3, 300
MHz): 33.29 (s, CH2ꢀPh), 61.01 (s, C3), 104.41 (s, C2),
110.24, (d, 2JPꢀC
11.3 Hz, C1), 117.96, 120.06, 126.57,
3
4JPꢀH
H4), 6.09 (d, JHꢀH
ꢀ
/
4.8 Hz, ꢀ
/
CH2ꢀ
/
Ph), 5.90 (d, JHꢀH
ꢀ
/
3
3
(2.5 ml, 0.028 mmol) to give (1-Meꢀ
/
Ind)Ni(PPh3)(OTf)
ꢀ
/
ꢀ
/
(6). 1H-NMR (C6D6, 400 MHz): 1.44 (d, 4JPꢀC
ꢀ
/
5.9 Hz,
ꢀ
/
3
ꢀ
/
CH3ꢀ
/
Ind), 3.04(br s, H3), 5.70(d, JHꢀH
ꢀ/6.4 Hz,
3
H4), 6.16 (s, H2), 6.74 (t, JHꢀH
ꢀ
/
7.4 Hz, H5), 6.90 (t,
3
/
3JHꢀH
ꢀ
/
7.8 Hz, H6), 7.00(m, ArH), 7.33 (d, JHꢀH
ꢀ
/
ꢀ
/
7.4, H7) (m, ArH). 31P{1H}-NMR (C6D6): 30.25 (s).
127.32, 127.76, 128.67 (d, JPꢀC
ꢀ
/
10.8 Hz, m-PPh3),
44.7 Hz, i-PPh3), 130.83 (s, p-
11.9 Hz, o-PPh3), 136.98,
3
129.17, 129.76 (d, 1JPꢀC
ꢀ
ꢀ
/
2
4.8. Reaction of 2 with CF3SO3H
PPh3), 133.86 (d, JPꢀC
/
139.22. 31P{1H}-NMR: 29.66 (s) (in C6D6), 29.13 (s)
The general procedure outlined above was used for
the reaction of 2 (15 mg, 0.027 mmol) with CF3SO3H
(CDCl3). 19F{1H}-NMR: ꢃ
/
79.62 (s) (in C6D6), ꢃ81.30
/
(s) (in CDCl3). IR (KBr): 1626 (m), 1495 (m), 1480 (m),
1436 (s), 1385 (m), 1324 (s), 1263 (s), 1234 (s), 1208 (s),
1180 (s), 1121 (m), 1096 (m), 1032 (s), 1017 (s), 747 (s),
724 (w), 695 (s), 635 (s), 542 (m), 530 (s), 510 (s), 495 (s).
(2.4 ml, 0.027 mmol) to give (1-Etꢀ
/
Ind)Ni(PPh3)(OTf)
7.3 Hz,
CH2), 3.04 (s, H3), 5.80 (d,
(7). 1H-NMR (C6D6, 400 MHz): 1.29 (t, 3JHꢀH
ꢀ
/
ꢀ
/
CH3), 1.74 and 2.27 (m, ꢀ
/
3JHꢀH
ꢀ
/
6.8 Hz, H4), 6.21 (d, JHꢀH
ꢀ
/
2.6 Hz, H2), 6.75
7.0 Hz, H5), 7.08 (t, JHꢀH 7.4 Hz, H6),
8.0 Hz, H4), 7.51 (m,
ArH). 31P{1H}-NMR (C6D6): 30.02 (s). 19F{1H}-
NMR(C6D6): ꢃ79.70 (s).
FABMS (m/z): 525 [Mꢄꢃ
Otf]. Anal. Calc. for
/
3
3
3
(t, JHꢀH
ꢀ
/
ꢀ
/
C35H28PNiO3SF3: C, 62.25; H, 4.18; S, 4.75. Found:
C, 62.81; H, 4.31; S, 4.34%.
3
7.00 (m, ArH), 7.38 (d, JHꢀH
ꢀ
/
/
4.12. Reaction of 1 with CF3SO3CH3
4.9. Reaction of 3 with CF3SO3H
Monitoring the reaction of 1 with a small excess of
CF3SO3CH3 by 31P-NMR (C6D6) spectroscopy showed
The general procedure outlined above was used for
the reaction of 3 (15 mg, 0.027 mmol) with CF3SO3H
the slow conversion of 1 to a mixture of [(1-Meꢀ
/
Ind)Ni(PPh3)2]ꢄ (two d at 35.65 and 33.53 ppm,
(2.4 ml, 0.027 mmol) to give (1-i-Prꢀ
/
Ind)Ni(PPh3)(OTf)
2JPꢀP
ꢀ
/
25 Hz), (1-Meꢀ
/
Ind)Ni(PPh3)(CF3SO3) (s at
1
3
(8). H-NMR (C6D6, 400 MHz): 1.56 (d, JHꢀH
ꢀ
/
6.5
7.0 Hz, CH(CH3)2),
2.6 Hz, 3JPꢀH
30.20 ppm), and [PMePh3]ꢄ (s at 22.13 ppm).
3
Hz, CH(CH3)2), 1.14 (d, JHꢀH
ꢀ
/
2.93 (m, CH(CH3)2), 3.02 (dd, 3JHꢀH
4.8 Hz, H3), 6.06 (d, JHꢀH
ꢀ
/
ꢀ
/
4.13. General procedure for the polymerization of
phenylacetylene
3
ꢀ
/
7.8 Hz, H4), 6.14 (d,
7.9 Hz, H5), 7.18
(s, ArH), 7.01 (m, ArH), 7.51 (m, ArH). 31P{1H}-NMR
(C6D6): 29.30 (s). 19F{1H}-NMR (C6D6): ꢃ
79.79 (s).
3
3JHꢀH
ꢀ
/
2.6 Hz, H2), 6.79 (t, JHꢀH
ꢀ
/
To a THF solution (ca. 1 ml) of the Niꢁ/thienyl pre-
/
catalyst (ca. 40 mg) was added MAO (ten equivalents)

106
R. Wang et al. / Journal of Organometallic Chemistry 660 (2002) 98ꢁ107
/
and phenylacetylene (ca. 50ꢁ
mixture was stirred for 24 h under nitrogen. The
polymerization was quenched by adding a mixture of
/
100 equivalents), and the
selected bond distances and angles are listed in Tables 2
and 3, respectively.
AcOHꢁ
/
MeOH; the resulting yellow solid (ca. 20ꢁ30%
/
1
yield) was washed with hexane and dried in vacuo. H-
5. Supplementary material
NMR (CDCl3, 400 MHz): 6.94 (m, m- and p-H), 6.64
3
(d, JHꢀH
ꢀ6.6 Hz, o-H), 5.85 (s, vinylic H). The
/
Crystallographic data for the structural analyses have
been deposited with the Cambridge Crystallographic
Data Centre (CCDC No.: 182403 for compound 1;
182404 for compound 2; 182405 for compound 5;
182406 for compound 9). Copies of this information
may be obtained free of charge from The Director,
CCDC, 12 Union Road, Cambridge CB2 1EZ, UK
molecular weights of the polymers were determined by
GPC (THF): for 1: Mwꢀ49 829, Mnꢀ13 453, Mw/
Mnꢀ3.7; for 3: Mwꢀ75 642, Mnꢀ12 916, Mw/Mnꢀ
5.8.
/
/
/
/
/
/
4.14. Reaction of Niꢀ
/
thienyl compounds with MAO
(Fax:
ac.uk or www: http://www.ccdc.cam.ac.uk).
ꢄ44-1223-336033; e-mail: deposit@ccdc.cam.
/
Monitoring the reactions of the Niꢁ
/
thienyl complexes
1
with a ten-fold excess of MAO by H- and 31P{1H}-
NMR (C6D6) showed the quantitative conversion to (1-
3
Meꢀ
/
Ind)Ni(PPh3)(Me). 1H-NMR: ꢃ
/
0.72 (d, JPꢀH
ꢀ
/
3
Acknowledgements
5.6 Hz), 1.89 (d, JHꢀH
ꢀ
/
3.9 Hz, Indꢀ
/
CH3), 4.16 (t,
2.9 Hz, H2), 6.47
7.31 (m, ArH). 31P{1H}-
3JHꢀH
ꢀ
/
2.8 Hz, H3), 6.23 (d, JHꢀH
ꢀ
/
3
3
We are grateful to the NSERC (Canada) for research
grants to D.Z., to FCAR (Que´bec) for a scholarship to
R.W., to Dr. Ernesto Rivera for the GPC analyses, and
to Marc-Andre´ Dubois for his help with the syntheses of
the Ind ligands.
(d, JHꢀH
NMR: 48.05 (s)
ꢀ
/
7.8 Hz, H4), 6.22ꢁ
/
4.15. X-ray diffraction studies
The crystal data for complexes 1, 5, and 9 were
collected on a Bruker AXS SMART 2K diffractometer
with graphite-monochromatic CuꢁKa radiation at
/
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¨