Trinuclear tris(ansa-metallocene) complexes of zirconium and hafnium for olefin polymerization

Article abstract of DOI:10.1016/j.jorganchem.2018.09.028

New platforms for trinuclear complexes, 1,3,5-tris(fluoren-2-yl-R)benzene (Ph{2-Flu^RH}₃; R = H (2a), 6-^tBu (2b), 7-^tBu (2c), Tet (2d) (Tet = 2,2,5,5-tetramethyl-tetrahydrobenzofluorene), were synthesized via an acid-catalyzed cyclotrimerization of the corresponding substituted 2-acetylfluorenes. Subsequent nucleophilic addition of the [Ph{2-Flu^R}₃]^3? trianions onto 6,6,-dimethylfulvene afforded the corresponding isopropylidene-bridged pro-ligands Ph{Me₂C(2-Flu^RH)(C₅H₅)}₃ (3a-d). Discrete trinuclear tris(dichloro-ansa-zirconocene and hafnocene), Ph[{Me₂C(2-Flu^R)(C₅H₄)}MX₂]₃ (X = Cl: 4b-d-Zr, 4c,d-Hf) were prepared by salt metathesis reactions. Some zirconium complexes were further alkylated towards the corresponding tris(dialkyls) (X = Me: 5c,d-Zr; X = CH₂SiMe₃: 6c-Zr). The structures of these metal complexes were determined by elemental analyses, and by 1D, inverse 2D heteronuclear correlation, and DOSY NMR spectroscopy, as well as by theoretical computations. Those studies revealed the existence of two isomers, of C₃ and C₁ symmetry respectively, originating from the mutual orientation of the three ansa-metallocene fragments. Preliminary studies on the catalytic performances of the dichloro complexes, upon activation with MAO, in ethylene and propylene homopolymerization and ethylene/1-hexene copolymerization were carried out and compared to those of the monometallic analogues under identical conditions.

Full text of DOI:10.1016/j.jorganchem.2018.09.028

Accepted Manuscript
Trinuclear tris(ansa-metallocene) complexes of zirconium and hafnium for olefin
polymerization
Lars N. Jende, Aurelien Vantomme, Alexandre Welle, Jean-Michel Brusson, Jean-
François Carpentier, Evgueni Kirillov
PII:
S0022-328X(18)30802-7
10.1016/j.jorganchem.2018.09.028
JOM 20585
DOI:
Reference:
To appear in: Journal of Organometallic Chemistry
Received Date: 10 September 2018
Revised Date: 24 September 2018
Accepted Date: 30 September 2018
Please cite this article as: L.N. Jende, A. Vantomme, A. Welle, J.-M. Brusson, Jean.-Franç.
Carpentier, E. Kirillov, Trinuclear tris(ansa-metallocene) complexes of zirconium and hafnium for
olefin polymerization, Journal of Organometallic Chemistry (2018), doi: https://doi.org/10.1016/
j.jorganchem.2018.09.028.
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ACCEPTED MANUSCRIPT
For the Table of Contents entry
Trinuclear group 4 tris(ansa-metallocene) complexes based on an original 1,3,5-phenylene-
tris(isopropylidene-bridged cyclopentadienyl/fluorenyl) platform were synthesized and used as
precatalysts in polymerization of ethylene and propylene and ethylene/1-hexene
copolymerization.
Keywords: ansa-metallocene; trinuclear complexes; olefin polymerization; zirconium
1

ACCEPTED MANUSCRIPT
Trinuclear Tris(ansa-metallocene) complexes of Zirconium and Hafnium for Olefin
Polymerization
1
2
2
3
Lars N. Jende, Aurelien Vantomme, Alexandre Welle, Jean-Michel Brusson, Jean-François
1
,
1,
Carpentier, * and Evgueni Kirillov *
1
Univ Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes), UMR 6226, F-35000
Rennes, France. Corresponding authors: Fax: (+33)(0)223-236-939. E-mail: jean-
francois.carpentier@univ-rennes1.fr; evgueni.kirillov@univ-rennes1.fr
2
3
Total Research and Technology Feluy, Zone Industrielle C, B-7181 Feluy, Belgium
Total S.A., Direction scientifique, 24 Cours Michelet, F-92069 Paris La Défense, France
Abstract
New platforms for trinuclear complexes, 1,3,5-tris(fluoren-2-yl-R)benzene (Ph{2-
R
t
t
3
Flu H} ; R = H (2a), 6- Bu (2b), 7- Bu (2c), Tet (2d) (Tet = 2,2,5,5-tetramethyl-
tetrahydrobenzofluorene), were synthesized via an acid-catalyzed cyclotrimerization of the
corresponding substituted 2-acetylfluorenes. Subsequent nucleophilic addition of the [Ph{2-
R
3−
Flu } ] trianions onto 6,6,-dimethylfulvene afforded the corresponding isopropylidene-bridged
3
R
pro-ligands Ph{Me
2
C(2-Flu H)(C
5
H
5
)}
3
(3a-d). Discrete trinuclear tris(dichloro-ansa-
R
zirconocene and hafnocene), Ph[{Me
2
C(2-Flu )(C
5
H
4
)}MX
2
]
3
(X = Cl: 4b-d-Zr, 4c,d-Hf) were
prepared by salt metathesis reactions. Some zirconium complexes were further alkylated towards
the corresponding tris(dialkyls) (X = Me: 5c,d-Zr; X = CH SiMe : 6c-Zr). The structures of
2
3
2

ACCEPTED MANUSCRIPT
these metal complexes were determined by elemental analyses, and by 1D, inverse 2D
heteronuclear correlation, and DOSY NMR spectroscopy, as well as by theoretical computations.
3 1
Those studies revealed the existence of two isomers, of C and C symmetry respectively,
originating from the mutual orientation of the three ansa-metallocene fragments. Preliminary
studies on the catalytic performances of the dichloro complexes, upon activation with MAO, in
ethylene and propylene homopolymerization and ethylene/1-hexene copolymerization were
carried out and compared to those of the monometallic analogues under identical conditions.
Introduction
The development of unique, more efficient catalytic systems for olefin polymerization
processes has impelled to a rapid progress in the design and synthesis of a variety of dinuclear
1
metallocene compounds, which contain two linked metallocene units. Thereby, a particular
emphasis is given to exploration, fundamental understanding and utilization of cooperative
interactions (electronic and chemical) between the two proximal metal centers.
Many of the reported dinuclear group 4 metal pre-catalysts for olefin polymerization are
based on a homobimetallic platform (Chart 1): (A) non-bridged metallocene units connected by
2
2e,3
hydrocarbon- or silyl/silyloxane- bridges at cyclopentadienyl (Cp) moieties; (B) “constrained-
3
d,4
geometry systems” linked at the Cp/Ind (Ind = indenyl) moieties or at the si1ylene-bridge; and
5
6
(
C) dinuclear bis(ansa-metallocenes) linked at the Cp moieties or at the C1/Si1-bridge,
respectively.
3

ACCEPTED MANUSCRIPT
Chart 1. Schematic drawing of common bimetallic platforms encountered in dinuclear group 4
metal pre-catalysts.
To our knowledge, dinuclear bis(metallocene) systems incorporating fluorenyl (Flu)
ligands are represented by a sole example, namely CpZrCl ((9-Flu)CH CH=CHCH (9-
2
2
2
2
f, 7
Flu))ZrCpCl
2
(Chart 1, A II), which was obtained by a cross-metathesis reaction.
No
significant differences between the catalytic performances of the latter dinuclear system and its
monometallic analogue have been observed in homopolymerization of ethylene and propylene.
The aim of the investigation reported herein was the synthesis and characterization of a
new type of tris(Cp/Flu) pro-ligands based on a 1,3,5-tris(fluoren-2-yl)benzene platform and of
some group 4 trinuclear tris(ansa-metallocene) complexes derived thereof. The catalytic
performances of the synthesized complexes, after activation with MAO, have been investigated
in homogeneous polymerization of ethylene and propylene and ethylene/1-hexene
copolymerization and compared to those of the mononuclear ansa-metallocene reference.
Results and Discussion
4

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Synthesis of 1,3,5-tris(fluoren-2-yl)benzene precursors. Adapting the synthetic
8
procedure described for 1,3,5-tris(fluoren-2-yl)benzene (Ph(2-FluH)
3
, 2a), the substituted
analogues 2b and 2c were synthesized by a 4-dodecylbenzenesulfonic acid (DBSA)-catalyzed
cyclocondensation of the corresponding 2-acetylfluorene derivatives (1b and 1c, respectively)
under solvent-free conditions (Scheme 1, protocol A). However, the products were isolated as
deep red solids, suggesting the presence of products resulting from incomplete condensation.
Switching the reaction conditions to PTSA-catalyzed cyclotrimerization in toluene solution did
not hamper the formation of the red-coloured side-products. Gratifyingly, the use of thionyl
9
chloride as catalyst (Scheme 1, protocol B) resulted in the isolation of analytically pure,
colorless compounds 2a‒c in good yields (52‒55%).
Scheme 1. Synthesis of substituted 2-acetylfluorene and corresponding 1,3,5-tri(fluoren-2-
yl)benzene derivatives.
Tet
A structural analogue, 1,3,5-tris(2-Flu )-benzene (2d, Tet = 2,2,5,5-tetramethyl-
tetrahydrobenzofluorene), was obtained via an improved Friedel-Crafts cycloalkylation of the
1
0
unsubstituted precursor 2a with 2,5-dimethyl-2,5-dichlorohexane (Scheme 2, protocol C).
5

ACCEPTED MANUSCRIPT
Tet
Scheme 2. Synthesis of 1,3,5-Ph(2-Flu H)
3
(2d) via Friedel-Crafts cycloalkylation.
The unsubstituted and highly aromatic compound 2a exhibited poor solubility in most
organic solvents (e.g., diethyl ether, dichloromethane, aliphatic or aromatic hydrocarbons), which
apparently stems from π-interactions. On the other hand, the substituted products 2b‒d were
found readily soluble in the previous solvents. Single crystals of 2c suitable for X-ray diffraction
analysis (Figure 1) were grown by slow evaporation of a dichloromethane/petroleum ether
solution at ambient temperature.
t
Figure 1. Molecular structure of 1,3,5-Ph(2-{7- Bu-FluH})
3
(2c) (atomic displacement
parameters are set at the 50% probability level; hydrogen atoms are omitted for clarity). Selected
bond lengths (Å): C2–C3, 1.485(2), C22–C23, 1.485(2), C42–C43, 1.491(2).
6

ACCEPTED MANUSCRIPT
R
Synthesis of 1,3,5-Ph{Me C(2-Flu H)(C H )} Proligands. The synthesis of
2
5
5
3
monocarbon-bridged fluorenyl-cyclopentadienyl proligands by nucleophilic addition of Cp-type
1
1
anions onto fulvenes is a well-established reaction. Following this pathway, reaction of the in
R
3–
3–
situ generated [Ph{Flu } ] anions [(2a‒d)] with 3.3 equiv of 6,6´-dimethylfulvene in diethyl
3
R
ether and subsequent hydrolysis afforded the desired proligands Ph{Me C(2-Flu H)(C H )}
2
5
5
3
(3a‒d) (Scheme 3) in moderate to good yields (29‒74%).
1) 3.15 eq. nBuLi
Et O, 50 °C, 16 h
2
R1
R1
2) 3.3 eq. 6,6-dimethylfulvene
R2
Et O, 50 °C, 16 h
2
3
3) hydrolysis, workup
R2
3
3a-d
2a-d
R
Scheme 3. Synthesis of Ph{Me C(Flu H)(C H )} proligands 3a-d.
2
5
5
3
At least two isomers, originating from tautomerism within the cyclopentadienyl moieties,
were observed for each of the proligands 3a‒d by NMR spectroscopy. The poor solubility of the
1
3
unsubstituted proligand 3a hindered its characterization by C NMR spectroscopy. For
1
13
proligands 3b-d, all signals in the corresponding H and C NMR spectra were confidently
assigned. In particular, the resonances for the two CH cyclopentadienyl protons appeared at δ
2
3
4
.1–3.3 ppm and the single resonance for the 9-CH proton was observed in the region of δ 4.2‒
1
.4 ppm in the corresponding H NMR spectra (Fig. S15, S17 and S19 for 3b, 3c and 3d,
respectively).
Syntheses of tris(dichloro-ansa-metallocene) complexes. The synthesis of trinuclear
R
metallocene complexes of zirconium and hafnium derived from the Ph{Me C(2-Flu H)(C H )}
3
2
5
5
platforms was performed using a standard salt-metathesis reaction between the ligand hexaanions
7

ACCEPTED MANUSCRIPT
prepared in situ in diethyl ether and the corresponding MCl salt (M = Zr, Hf) (Scheme 4). The
4
typical color change of the suspension reactions from reddish-brown (hexaanions) to pink in the
case of zirconium and orange-yellow in the case of hafnium metal centers indicated the formation
of ansa-metallocene complexes in all cases. Extraction of the colored crude solids with
R
dichloromethane allowed isolating analytically pure complexes Ph({Me C(2-Flu )(C H )}MCl )
2
5
4
2 3
t
t
t
of zirconium (R = 6- Bu (4b-Zr), 7- Bu (4c-Zr), Tet (4d-Zr)) and hafnium (R = 7- Bu (4c-Hf),
Tet (4d-Hf)) in good yields as pink (81-88%) and orange-yellow (56% and 63%)
microcrystalline solids, respectively. On the other hand, due to insolubility issues, this procedure
failed in the case of the unsubstituted complexes 4a-Zr and 4a-Hf as well as for the 6-tert-butyl
substituted complex of hafnium 4b-Hf.
Scheme 4. Synthesis of trinuclear tris(dichloro-ansa-metallocene) complexes 4b‒d-Zr and 4c,d-
Hf.
All attempts to grow single-crystals suitable for X-ray diffraction analysis of the
synthesized tris(dichloro-ansa-metallocene) zirconium and hafnium complexes remained
8

ACCEPTED MANUSCRIPT
unsuccessful so far. The solution structures of these complexes were analyzed by NMR
spectroscopy. Good quality NMR spectra with sharp resonances were obtained for zirconium
complexes 4b-d-Zr, while for the hafnium analogues, conclusive NMR data were obtained only
1
13
for complex 4c-Hf. In each case, the H and C NMR spectroscopic data are consistent with the
existence of two isomers exhibiting C and C symmetries, respectively, and differing by the
3
1
respective orientation of the ansa-metallocene moieties (Chart 2). For example, in the aromatic
1
region of the H NMR spectrum of 4c-Zr (Fig. S24), several series of multiplets were observed
that belong to the Cp moieties (Fig. 2a). These multiplets consist of overlapping quartets whose
3
splitting originates from JHH coupling among non-equivalent hydrogens belonging to the same
1
2
Cp ligands of the two isomers. The presence of the two isomers in a ca. 1:1 ratio was suggested
1
from a simulation of this region of the H NMR spectrum (Fig. 2b): four quartets at δ 6.23, 6.12,
5
.59 and 5.55 ppm from the four nonequivalent Cp hydrogens of the three equivalent ansa-
metallocene units in the C -symmetric isomer, and twelve overlapping quartets at δ 6.23, 6.20,
.12, 5.61, 5.59 and 5.55 ppm from the twelve nonequivalent Cp hydrogens of the three non-
equivalent ansa-metallocene units in the C -symmetric congener.
3
6
1
Chart 2. Schematic representation of the C
metallocenes) 4b-d-Zr/Hf.
3
1
- and C -symmetric isomers of tris(dichloro-ansa-
9

ACCEPTED MANUSCRIPT
1
Figure 2. Detailed H NMR spectra (Cp region) of complex 4c-Zr: (a) experimental (500 MHz,
3
C
6
D
6
, 298 K) and (b) simulated ( JH-H = 2.8 Hz).
Possible geometries of the two C - and C -symmetric isomers of 4c-Zr were modeled by
3
1
DFT computations (Fig. 3; see Experimental Section for details). These calculations returned
1
only 1.4 kcal·mol‒ of energy difference between the two isomers, which corresponds to a
theoretical ratio of ca. 1:10 at room temperature. Note, however, that this minimal energy
1
‒
difference falls within the accuracy of DFT computations usually accepted (2‒3 kcal·mol ) and
is therefore not inconsistent with the ca. 1:1 ratio experimentally observed.
Diffusion NMR experiments (PGSE) allowed an estimation of the translation diffusion
coefficients D for complexes 4b-d-Zr in benzene-d at room temperature; these were found to
t
6
−10
2
−1
fall within a narrow range of 3.6(2)‒3.8(2)·10
m ·s . The corresponding values of the
experimental hydrodynamic radii, rH,PGSE = 8.0‒8.1 Å, are in agreement with the DFT computed
H,DFT values for the isomers of 4c-Zr of 7.9‒8.3 Å.
r
1
0

ACCEPTED MANUSCRIPT
Figure 3. DFT-optimized structures of C -symmetric (top) and C -symmetric (bottom) isomers
3
1
of 4c-Zr.
1
1

ACCEPTED MANUSCRIPT
Syntheses of tris(dialkyl-ansa-metallocene) complexes. Aiming at improving the
solubility and crystallizability of tris(ansa-metallocene) systems, the synthesis of the
1
3
corresponding alkyls was studied. Following a previously reported protocol, reaction of the
parent tris(dichloro-ansa-zirconocene) 4c-Zr and 4d-Zr with 6 equiv of MeMgBr in toluene
yielded after workup the corresponding tris(dimethyl-ansa-zirconocene) complexes Ph({Me C(2-
2
R
Flu )(C H )}ZrMe ) 5c-Zr and 5d-Zr as yellow solids in 77% and 71% yields (Scheme 5,
5
4
2 3
protocol A). Under similar reaction conditions, the treatment of 4c-Zr with Me SiCH MgCl
3
2
R
afforded the corresponding tris(dialkyl) complex Ph({Me C(2-Flu )(C H )}Zr(CH SiMe) ) (6c-
2
5
4
2
2 3
1
4
Zr) as a yellow-orange solid in 80% yield (Scheme 5, protocol B).
Scheme 5. Alkylation of tris(dichloro-ansa-zirconocenes) 4b-d-Zr with Grignard reagents.
Although the tris(dialkyl) complexes 5c,d-Zr and 6d-Zr showed good solubility in
aliphatic (hexane, heptane) and aromatic (benzene, toluene) hydrocarbons, all crystallization
attempts systematically returned microcrystalline precipitates which proved unsuitable for single-
1
5
crystal X-ray diffraction studies. Nevertheless, the recorded NMR spectroscopic data for the
tris(dimethyl) 5c,d-Zr and tris(bis(trimethylsilyl)) 6c-Zr complexes proved informative (see SI).
R
While the chemical shifts for the aromatic hydrogens of the Ph({Me C(2-Flu )(C H )} ligand
2
5
4
3
1
2

ACCEPTED MANUSCRIPT
1
system barely remained unchanged in the corresponding H NMR spectra in all cases (Fig. S32,
S35 and S38, respectively), two groups of broad signals of equal intensity for several isochronous
hydrogens of the six methyl groups (
δ
5c-Zr: ‒0.92 and ‒1.08 ppm, 5d-Zr: ‒0.92 and ‒1.15 ppm,
Me exchange. Also, the
3
C NMR signals for the Zr‒CH groups were found in the range of δ 33.5 to 32.1 ppm for both
respectively), observed at high field, are in agreement with complete Cl
→
1
3
complexes, as assigned by HSQC NMR spectroscopy (Fig. S34 and S36, respectively). On the
other hand, the presence of the two C - and C -symmetric isomeric forms of 5c-Zr and 5d-Zr
3
1
could not be unequivocally established, due to presumably close magnetic equivalence of the
respective nuclei.
1
For the tris(bis(trimethylsilyl)) complex 6c-Zr, the H NMR signals from the SiMe
3
groups
were observed in the region
0.94, 1.49, 1.91 and 2.06 ppm were assigned to the diastereotopic methylenic hydrogens
from six Zr‒(CH Si{CH
signals from several isochronous CH groups appeared at
δ 0.14 to ‒0.01 ppm (Fig. S38). The four overlapping multiplets at δ
‒
‒
‒
‒
1
3
2
3
}
3
)
2
units. In the HSQC spectrum of 6c-Zr (Fig. S40), the C NMR
50.4, 48.6, 45.2, and 44.9 ppm; the
signals from the four different SiCH carbons were found between 2.8 ppm and 3.4 ppm in the
δ
2
δ
3
HMBC NMR spectrum (Fig. S41). These observations clearly evidence the coexistence of two
isomers in 6c-Zr.
Polymerization Studies. The tris(dichloro-ansa-zirconocenes) 4b‒d-Zr, in combination
with MAO, were studied in homogeneous polymerization of ethylene and propylene and in
ethylene/1-hexene copolymerization (toluene solution, 5 bar constant pressure, Tpol = 20 °C and
1
6
6
0 °C). For comparison purposes, the catalytic performance of the monometallic reference
t
metallocene catalysts {Me C(Flu)(C H )}ZrCl (M1) and {Me C(2,7- Bu Flu)(C H )}ZrCl (M2)
2
5
4
2
2
2
5
4
2
1
3

ACCEPTED MANUSCRIPT
were determined under identical conditions. Selected polymerization data are summarized in
Tables 1‒3.
In homopolymerization of ethylene at 20 and 60 °C (Table 1), both mono- and tris-(ansa-
zirconocene) catalysts exhibited quite similar outcome in terms of productivity (compare e.g.
entries 1, 3 vs 5, 7, 9 and 2, 4 vs 6, 8, 10). All the recovered PEs featured melting (T ) and
m
c
crystallization (T ) transitions in a narrow temperature range (132.0‒136.4 °C and 117.2‒118.1
°
C, respectively). The only significant difference observed is a ca. 2-fold increase of the
molecular weight (M ) of polymers obtained with 4b,c,d-Zr with respect to those obtained with
n
their mononuclear analogues (compare entries 6, 8, 10 vs 2, 4, respectively). This may reflect a
moderate propensity of the tris(ansa-zirconocene) systems to influence positively chain growth
due to putative cooperative effects.
a
Table 1. Ethylene Homopolymerization.
d
M
n
c
c
[
Zr]
T
[°C]
pol
m
[g]
pol
Productivity
[kg·mol ·h ]
T
m
T
c
3
d
Run
Precatalyst
(× 10 )
w n
M /M
‒
1
‒1 ‒1
[
µmol·L ]
[°C]
[°C]
‒
1
[
g·mol ]
b
1
M1
M1
30
10
10
10
30
10
30
10
30
10
20
60
20
60
20
60
20
60
20
60
3.22
2.66
0.69
2.79
1.61
2.21
1.41
1.72
1.65
1.54
4,290
7,090
1,820
7,370
4,290
5,890
3,760
4,590
4,400
4,110
135.1
135.1
133.1
132.0
135.9
134.9
135.6
134.3
136.4
135.5
117.9
117.9
n.d.
n.d.
25.7
115.5
39.4
n.d.
n.d.
3.5
4.1
3.9
n.d.
5.5
n.d.
4.6
n.d.
4.5
2
3
4
5
6
7
8
9
M2
M2
n.d.
4b-Zr
4b-Zr
4c-Zr
4c-Zr
4d-Zr
4d-Zr
117.4
117.2
117.9
118.1
117.6
117.4
70.7
n.d.
67.8
n.d.
1
0
64.2
a
Polymerization conditions: 300 mL high-pressure glass reactor; solvent: toluene, 150 mL; P[ethylene] = 5
b
c
d
bar (constant); [MAO]
0 0
/[Zr] = 5,000; t = 15 min. t = 30 min. Determined by DSC from second run.
Determined by GPC.
Homopolymerization of propylene with the investigated catalytic systems afforded
syndiotactic and syndiotactic-enriched polypropylenes (Table 2). In that case, the tris(ansa-
zirconocene) systems appeared to be significantly less productive than the reference catalysts M1
1
4

ACCEPTED MANUSCRIPT
and M2, both at 20 °C and 60 °C (compare entries 1, 3 vs 5, 7, 9 and 2, 4 vs 6, 8, 10). Also, a
lesser stereoselective character of 4b,c,d-Zr is evidenced from a lower content of syndiotactic
4
pentads ([r] = 60‒64 % at 60 °C and 77‒78 % at 20 °C) than those of the mononuclear analogue
4
17
M2 ([r] = 74.7 % at 60 °C and 89.0 % at 20 °C). This was also noticed in the T /T values. As
m
c
for the homopolymerization of ethylene, the nuclearity of catalysts did not affect substantially the
molecular weights (M ) and polydispersities; for both mono- and tris(ansa-metallocene) systems,
n
the M /M
w n
M
values were found in a narrow range (Ð = 2.2‒3.6).
a
Table 2. Propylene Homopolymerization.
d
n
M
c
c
[
M]
T
pol
m
[g]
pol
Prod.
[kg·mol ·h ]
T
m
T
c
[rrrr]
[%]
3
d
Run Prec.
(× 10 )
w n
M /M
-1
-1 -1
17
e
[
µmol·L ] [°C]
[°C]
[°C]
‒
1
[
g·mol ]
b
122.1
34.5
113.1
1
M1
M1
M2
30
10
10
20
60
20
25.7
3.45
6.32
5,710
4,550
8,340
83.6
55.5
97.9
27.0
13.2
35.5
2.7
3.6
2.2
79.3
64.2
89.0
1
2
1
1
1
1
1
1
41.5
50.5
11.7
19.0
26.8
40.2
3
4
5
6
7
8
9
M2
10
30
10
30
10
60
20
60
20
60
19.6
2.01
0.96
1.51
0.76
25,870
890
51.1
90.9
n.d.
90.3
n.d.
16.8
18.8
13.2
25.0
13.4
2.2
3.0
2.7
3.2
2.6
74.7
77.3
61.1
78.5
60.2
4b-Zr
4b-Zr
4c-Zr
4c-Zr
9
3.2
1,280
670
1
1
1
13.9
28.0
40.3
9
6.9
1,010
1
1
1
15.9
26.6
40.2
4d-Zr
4d-Zr
30
10
20
60
1.70
0.97
760
88.6
n.d.
22.2
13.2
3.4
2.7
78.0
64.1
1
0
1,290
109.9
a
Polymerization conditions: 300 mL high-pressure glass reactor; solvent: toluene, 150 mL; p[propylene] = 5 bar
b
c
d
(constant); [MAO] /[Zr] = 5,000; t = 30 min. t = 60 min. Determined by DSC from second run. Determined
0 0
e
13
by GPC. Determined by C NMR spectroscopy.
In ethylene/1-hexene copolymerization (Table 3), a drop in productivity was observed for
the tris(ansa-metallocene) systems 4b-Zr and 4d-Zr (entries 3‒6) as compared to the
mononuclear M2. Also, both catalysts enabled a lower incorporation of 1-hexene than the
1
5

ACCEPTED MANUSCRIPT
reference system M2 (entries 1 and 2) and, therefore, the resulting copolymers exhibited higher
m
T values.
a
Table 3. Ethylene/1-hexene Copolymerization.
c
d
M
n
6
C [%]
b
Ru
n
[M]
T
m
[g]
poly
Prod.
T
m
3
c
Prec.
(× 10 )
g·mol ]
w n
M /M
−
1
−1 −1
[µmol·L ] [°C]
[kg·mol ·h ]
[°C]
mol. wt.
‒
1
[
1
2
M2
M2
30
10
20
60
2.23
8.89
980
97.9
82.3
70.1
29.7
2.7
2.4
4.6 12.6
6.8 17.9
23,470
1
00.8
22.8
00.0
23.4
3
4
4b-Zr
4b-Zr
30
10
20
60
3.61
4.24
1,590
n.d
n.d
3.7
2.6
2.0
7.5
5.8
1
1
1
11,190
37.5
5
6
4d-Zr
4d-Zr
30
10
20
60
1.54
1.53
680
124.9
125.9
n.d
n.d
5.6
0.8
0.7
2.4
2.0
4,040
31.0
a
Polymerization conditions: 300 mL-high pressure glass reactor; solvent: toluene, 150 mL; p[ethylene] = 5
b
0
bar; [MAO]/[Zr] = 5,000; t = 15 min; [1-hexene] = 0.02 mol (2.5 mL); Determined by DSC from second
run. Determined by GPC. Determined by C NMR spectroscopy.
c
d
13
Conclusion
A straightforward synthesis of a series of novel arene-linked tris(Cp/Flu) ligand systems
was developed. These systems were used for the preparation of trinuclear tris(ansa-metallocene)
chlorides and alkyls derived thereof. Solution NMR spectroscopy and theoretical computations
established that these tris(ansa-{Cp/Flu}-metallocene) complexes exist as ca. 1:1 mixtures of
3 1
isomers featuring overall C and C symmetries.
Ethylene and propylene homopolymerization as well as ethylene/1-hexene
copolymerization experiments were conducted using the trinuclear chloride catalyst precursors in
combination with MAO. Comparison with experiments performed with mononuclear analogues
showed no significant intermetallic cooperativity in the trinuclear systems. Though in ethylene
homopolymerization, trinuclear systems behaved equivalently as their mononuclear counterparts
in terms of productivity, providing somewhat higher molecular weight homopolymers, a drop in
the incorporation comonomer content in ethylene/1-hexene copolymerization was observed with
1
6

ACCEPTED MANUSCRIPT
the former precatalysts. Also, the trinuclear systems appeared to be less syndioselective and
productive in propylene homopolymerization as compared to the reference mononuclear catalyst.
The origin of these discrepancies remained unclear so far. Possibly, the excessive steric hindrance
from the bulky MAO anions crowding the trinuclear trication may negatively affect the access of
monomer molecules to the active centers, thus hampering propagation (and hence reducing the
overall productivity) as well as enantiofacial stereodifferentiation. Further investigations in our
laboratories are currently focused on the elaboration of other polynuclear precatalysts with
improved performances and identification of the nature of possible intermetallic cooperative
effects.
Funding and Acknowledgements. This work was financially supported by Total Raffinage-
Chimie (postdoctoral grant to L. J.). C. Orione (CRMPO, UR1) is gratefully acknowledged for
technical assistance in some NMR spectroscopy experiments.
Experimental section
General Considerations. All manipulations (except polymerizations) were performed
under a purified argon atmosphere using standard Schlenk techniques or in a glovebox. Solvents
2
were distilled from Na/benzophenone (THF, Et O) and Na/K alloy (toluene, pentane) under
argon, degassed thoroughly and stored under argon prior to use. Deuterated solvents (benzene-d6,
toluene-d , THF-d ; >99.5% D, Deutero GmbH and Euroisotop) were vacuum-transferred from
8
8
Na/K alloy into storage tubes. CDCl , CD Cl and C D Cl were kept over CaH and vacuum-
3
2
2
2
2
4
2
transferred before use. MAO (30 wt-% solution in toluene, Albemarle; contains ca. 10 wt-% of
free AlMe ) was used as received. Ligand precursors a and b were generously provided by Total
3
1
8
8
19
Petrochemicals. Precursors c, 2a, M1 and M2 were prepared according to literature
1
7

ACCEPTED MANUSCRIPT
protocols. Other starting materials were purchased from Alfa, Strem, Acros or Aldrich, and used
as received.
Instruments and Measurements. NMR spectra of complexes were recorded on Bruker
AM-400 and AM-500 spectrometers in Teflon-valved NMR tubes at 25 °C, unless otherwise
indicated; chemical shifts are reported in ppm vs SiMe using the residual solvent resonances.
4
1
1
1
13
Assignment of resonances was made from 2D H− H COSY, H− C HSQC and HMBC NMR
experiments. Coupling constants are given in Hertz. Elemental analyses (C, H, N) were
performed using a Flash EA1112 CHNS Thermo Electron apparatus. DSC measurements were
performed on a SETARAM Instrumentation DSC 131 differential scanning calorimeter at heating
−1
rate of 10 °C·min ; first and second runs were recorded after cooling to 30 °C; the reported
melting and crystallization temperatures correspond to the second run. GPC analyses of polymer
samples were carried out in 1,2,4-trichlorobenzene at 135 °C at the Total Petrochemicals research
1
3
center in Feluy (Belgium), using polystyrene standards for universal calibration. C NMR
analyses of propylene and copolymer samples were run on a AM-500 Bruker spectrometer (Total
Petrochemicals, Feluy, Belgium) as follows: solutions of ca. 200 mg of PP or PEH polymer in
trichlorobenzene/C D mixture at 135 °C in 10 mm tubes, inverse gated experiment, pulse angle
6
6
9
0°, delay 11 sec, acquisition time 1.25 sec, number of scans 6000.
-(6-(Tert-butyl)-9 -fluoren-2-yl)ethanone (1b). At 0 °C, a solution of AlCl
6.5 mmol) in MeNO (10 mL) was syringed into a mixture of 3-(tert-butyl)-9H-fluorene (2.22 g,
0 mmol) and acetic anhydride (1.33 g, 13 mmol) in MeNO /1,2-dichloroethane (35 + 35 mL).
1
H
3
(2.21 g,
1
1
2
2
The mixture was stirred for 60 min and poured into a beaker with ice (100 g). The mixture was
extracted with hexane (3 × 100 mL). The solvent was evaporated leaving 1b as a pale yellow
1
solid (2.26 g, 8.5 mmol, 52% yield). H NMR (400 MHz, CDCl , 25 °C):
δ 8.16 (s, 1H), 8.04 (dt,
3
J = 8.0, 1.3 Hz, 1H), 7.92-7.87 (m, 2H), 7.55 (d, J = 8.0, 1H), 7.47 (dd, J = 8.0, 1.8, 1H), 3.94 (s,
1
8

ACCEPTED MANUSCRIPT
13
1
2
H, 9-FluH ), 2.69 (s, 3H, COCH ), 1.44 (s, 9H, C(CH ) ). C{ H} NMR (100 MHz, CDCl , 25
2
3
3 3
3
°
C):
δ
198.1 (COCH
3
), 150.4, 146.8, 143.7, 141.8, 140.4, 135.5, 127.7, 125.6, 125.0, 124.8,
), 31.6 (C(CH ), 26.8 (COCH ). Elemental analysis
1
19.5, 117.5, 36.5 (9-Flu), 34.9 (C(CH
3
)
3
3
)
3
3
calcd (%) for C H O (264.36): C 86.32, H 7.63; found: C 86.50, H 7.77
1
9
20
1
-(7-(Tert-butyl)-9H-fluoren-2-yl)ethanone (1c). Using a procedure similar to that
described above for 1b, compound 1c was obtained from AlCl (2.21 g, 16.5 mmol), 2-(tert-
3
butyl)-9H-fluorene (c) (2.22 g, 10 mmol) and acetic anhydride (1.33 g, 13 mmol) in MeNO /1,2-
2
dichloroethane (35 + 35 mL). Product 1c was isolated as a pale yellow solid (2.38 g, 9.0 mmol
1
5
5% yield). H NMR (400 MHz, CDCl
3
, 25 °C):
δ
8.16 (d, J = 0.9, 1H), 8.02 (dt, J = 8.0, 1.3,
1
H), 7.81 (dd, J = 9.6, 8.1, 4H), 7.66 (d, J = 1.0, 1H), 7.49 (dd, J = 8.1, 1.8, 2H), 3.97 (s, 2H, 9-
1
3
1
2 3 3 3 2 2
FluH ), 2.68 (s, 3H, COCH ), 1.42 (s, 9H, C(CH ) ). C{ H} NMR (100 MHz, CD Cl , 25 °C) δ
=
197.7 (COCH ), 151.6, 146.4, 144.7, 143.5, 137.8, 135.3, 127.6, 124.9, 124.8, 124.3, 122.2,
3
1
20.3, 119.3, 36.9 (9-Flu), 34.9 (C(CH ) ), 31.3 (C(CH ) ), 26.6 (COCH ). Elemental analysis
3
3
3 3
3
calcd (%) for C H O (264.36): C 86.32, H 7.63; found: C 86.41, H 7.89.
1
9
20
6
-tBu
1
,3,5-Tris(6-(tert-butyl)-9H-fluoren-2-yl)benzene, Ph(
FluH ) (2b). In a 250 mL
2
3
flask, 1b (3.00 g, 11.35 mmol) was suspended in EtOH (3.3 mL). SOCl (2.25 g, 3.4 mL, 19
2
mmol) was added dropwise over a period of about 20 min. The reaction mixture was stirred and
gently refluxed for 24 h. After completion of the reaction, the mixture was neutralized by
saturated Na CO . The precipitate was collected by filtration, washed with water, ethanol, and a
2
3
small amount of ethyl acetate (20 mL) followed by drying in vacuum to yield the almost pure
product. The crude product was dissolved in CH Cl , precipitated by addition of MeOH and dried
2
2
1
in vacuo. Pure 2b was isolated as a yellow solid (1.77 g, 2.40 mmol, 63%). H NMR (400 MHz,
CDCl , 25 °C): 7 7.96 (m, 3H), 7.96 (s, 3H, PhH), 7.91 (d, J = 1.8, 3H), 7.81 (dd, J = 8.0, 1.6,
H), 7.55 (d, J = 8.0, 3H), 7.43 (dd, J = 8.0, 1.8, 3H), 4.00 (s, 6H, 9-FluH ), 1.48 (s, 27H,
δ
3
3
2
1
9

ACCEPTED MANUSCRIPT
1
3
1
C(CH ) ). C{ H} NMR (100 MHz, CD Cl , 25 °C):
δ
150.1, 144.4, 142.7, 141.5, 141.3, 140.7,
39.7, 126.1, 125.0, 124.6, 124.2, 124.0, 120.0, 116.8, 36.6 (9-Flu), 34.9 (C(CH ), 31.7
54 (739,04): C 92.64, H 7.36; found: C 92.64, H
3
3
2
2
1
3 3
)
(
C(CH
3
)
3
). Elemental analysis calcd (%) for C57H
+
+
t
+
7
.62. ASAP-MS (m/z): 739.4299 ([M + H] ), 738.422([M] ), 683.3676) [(M - Bu + H] ).
7
-tBu
1
,3,5-Tris(7-(tert-butyl)-9H-fluoren-2-yl)benzene, Ph(
FluH2)3 (2c). Using
a
procedure similar to that described above for 2b, compound 2c was obtained from 1c (7.60 g,
2
8.75 mmol) and SOCl (5.70 g, 3.4 mL, 48 mmol). The titled compound 2c was obtained as a
2
1
yellow solid (6.30 g, 8.50 mmol, 88%). H NMR (400 MHz, CDCl , 25 °C):
δ 7.94 (s, 6H, PhH),
3
7
.88 (d, J = 7.9, 3H), 7.79 (d, J = 8.1, 3H), 7.78 (dd, J = 8.0, 1.5, 3H), 7.65 (d, J = 1.7, 3H), 7.49
1
3
(
dd, J = 8.1, 1.8, 3H), 4.02 (s, 6H, 9-FluH
2
), 1.44 (s, 27H, C(CH
3 3
) ). C NMR (100 MHz,
CDCl
3
, 25 °C):
δ
150.2, 144.1, 143.5, 142.6, 141.2, 139.4, 138.8, 126.2, 124.9, 124.1, 124.0,
1
22.0, 119.9, 119.5, 37.1 (9-Flu), 34.9 (C(CH ) ), 31.6 (C(CH ) ). Elemental analysis calcd (%)
3 3 3 3
for C H (739.04): C 92.64, H 7.36; found: C 92.51, H 7.26. ASAP-MS (m/z): 739.429 ([M +
5
7
54
+
+
H] ), 738.422 ([M] ).
,3,5-Tris(6,6,9,9-tetramethyl-7,8,9,11-tetrahydro-6
1
H-benzo[b]fluoren-2-yl)benzene,
Tet
Ph( FluH ) (2d). Using a procedure similar to that described above for 1b, compound 2d was
2
3
obtained from AlCl
3
(3.90 g, 29.0 mmol), 2a (3.15 g, 5.52 mmol), 2,5-dichloro-2,5-
dimethylhexane (3.94 g, 21.0 mmol) in a MeNO
2
/1,2-dichloroethane mixture (80/80 mL).
1
Product 2d was isolated as a pale yellow solid (2.81 g, 3.10 mmol, 56% yield). H NMR (400
MHz, CDCl , 25 °C):
δ
7.98 (s, 3H), 7.96 (s, 3H, PhH), 7.93 (d, J = 7.9, 3H), 7.86 (s, 3H), 7.81
3
(
d, J = 8.1, 3H), 7.61 (s, 3H), 4.01 (s, 6H, 9-FluH ), 1.83 (s, 12H, CH ), 1.48 (s, 18H, C(CH ) ),
2
2
3 2
1
3
1
1
1
1
.43 (s, 18H, C(CH ) ). C{ H} NMR (100 MHz, CDCl , 25 °C):
δ
144.2, 144.0, 143.8, 142.7,
41.4, 140.9, 139.5, 139.1, 128.1, 127.8, 127.1, 126.3, 126.1, 125.3, 125.1, 124.9, 124.0, 123.1,
20.9, 119.9, 117.8, 36.7 (9-Flu), 35.4, 35.3 (C(CH ), 34.7, 34.6 (CH CH ), 32.4, 32.2
3
2
3
3
)
2
2
2
2
0

ACCEPTED MANUSCRIPT
(
C(CH ) ). Elemental analysis calcd (%) for C H (901.31): C 91.95, H 8.05; found: C 91.68, H
3
2
69 72
+
+
+
7
5
2 2 2
.85. ASAP-MS (m/z): 900.563 ([M] ), 790.453 ([M - Me CCp] ), 680.343 ([M - (Me CCp) ] ),
+
70.233 ([M - (Me
2
CCp)
3
] ).
1
,3,5-Tris(9-(2-(cyclopenta-1,3-dien-1-yl)propan-2-yl)-9
H-fluoren-2-yl)benzene,
Ph{Me C(2-FluH)(CpH)} (3a). To a solution of 1,3,5-tri(9H-fluoren-2-yl)benzene (2a) (1.77 g,
2
3
3
.10 mmol) in dry THF (50 mL) was added dropwise at 0 °C n-BuLi (3.7 mL of a 2.5 M solution
in hexane, 9.3 mmol) over 15 min. The mixture was stirred at room temperature overnight. Then,
,6´-dimethylfulvene (0.987 g, 9.30 mmol) was added slowly and the resulting red mixture was
stirred at room temperature for 16 h. The mixture was quenched with saturated NH Cl solution
40 mL), extracted with diethyl ether (3 50 mL), and the combined organic phase was dried
over Na SO /Na CO . After removal of the solvent, the crude product was dissolved in CH Cl ,
6
4
(
×
2
4
2
3
2
2
precipitated by addition of MeOH under vigorous stirring and dried in vacuo. Proligand 3a was
1
recovered as a pale yellow solid (356 mg, 0.59 mmol, 29%). H NMR (400 MHz, CD Cl , 25
2
2
°
C): δ 7.91 (m, 3H), 7.85 (s, 3H, PhH), 7.77 (m, 6H), 7.58 (m, 3H), 7.44(m, 3H) (m, 3H), 7.41
(
m, 3H), 7.35 (m, 3H), 7.28 (m, 3H), 7.06, 6.69, 6.59, 6.54, 6.26, 6.04 (6m, 9H, CpH), 4.35, 4.32
2s, 3H, 9-FluH), 3.31, 3.11 (2s, 6H, CpH ), 1.32, 1.24 (2m, 9H, C(CH ) ), 1.12, 1.07 (2m, 9H,
(
2
3 2
13
1
C(CH ) ). C{ H} NMR (100 MHz, CDCl , 25 °C):
δ
146.2, 145.7, 143.7, 142.5, 141.2, 139.8,
3
2
3
1
5
32.4, 131.3, 127.2, 126.8, 126.6, 126.2, 126.1, 125.1, 124.7, 124.0, 120.1, 120.0, 119.5 (CpH),
8.0 (9-Flu), 40.6 (CpCH ), 37.0 (C(CH ) ), 25.6 (C(CH ) ). Elemental analysis calcd (%) for
2
3 2
3 2
+
C H (889.21): C 93.20, H 6.80; found: C 93.11, H 6.77. ESI-MS (m/z): 911.4596 ([M + Na] ),
6
9
60
+
8
2
05.379 ([(M - Me CCp) + Na] ).
1
,3,5-Tris(6-(tert-butyl)-9-(2-(cyclopenta-1,3-dien-1-yl)propan-2-yl)-9H-fluoren-2-
tBu
2 3
yl)benzene, Ph{Me C(2-(6- FluH))(CpH)} (3b). Using a protocol similar to that described for
3
a, compound 3b was obtained from 2b (1.00 g, 1.35 mmol), n-BuLi (1.7 mL of a 2.5 M solution
2
1

ACCEPTED MANUSCRIPT
in hexane, 4.3 mmol) and 6,6´-dimethylfulvene (0475 g, 4.4 mmol). 3c was isolated as a pale
1
yellow solid (1.00 g, 0.95 mmol, 71%). H NMR (400 MHz, CDCl
3
, 25 °C):
δ
7.88 (m, 3H), 7.84
(s, 3H, PhH), 7.75 (m, 3H), 7.67 (m, 3H), 7.48-7.35 (m, 6H), 7.23 (m, 3H), 7.02, 6.66, 6.59, 6.51,
6
.27, 6.03 (6m, 9H, CpH), 4.26, 4,23 (2s, 3H, 9-FluH), 3.29, 3.09 (2s, 6H, CpH ), 1.45 (s, 27H,
2
1
3
1
C(CH ) ), 1.32 (m, 9H, C(CH ) ), 1.07 (s, 9H, C(CH ) ). C{ H} NMR (100 MHz, CDCl , 25
3
3
3 2
3 2
3
°
C):
δ
158.2 (6-Flu), 150.3, 150.2, 146.4, 142.8, 141.7, 141.5 (Flu), 134.4, 133.3, 132.4, 131.1,
1
26.6, 125.8 (Flu), 125.6, 125.0, 123.6, 123.5, 119.3, 116.3 (CpH), 57.8, 55.5 (9-Flu), 41.0, 40.8
(
C(CH ) ), 40.6, 39.6 (CpCH ), 34.8 (C(CH ) ), 31.7, 31.6 (C(CH ) ), 27.0, 25.3, 24.3 (C(CH ) ).
3 2 2 3 3 3 3 3 2
Elemental analysis calcd (%) for C81H84 (1057.53): C 91.99, H 8.01; found: C 91.71, H 7.79.
+
+
+
ESI-MS (m/z): 1056.6564 ([M] ), 1079.6461 ([M + Na] ), 1095.6188 ([M + K] ).
1
,3,5-Tris(7-(tert-butyl)-9-(2-(cyclopenta-1,3-dien-1-yl)propan-2-yl)-9H-fluoren-2-
tBu
yl)benzene, Ph{Me C(2-(7- FluH))(CpH)} (3c). Using a protocol similar to that described for
2
3
3
a, compound 3c was obtained from 2c (1.42 g, 1.90 mmol), n-BuLi (2.4 mL of a 2.5 M solution
in hexane, 6.00 mmol) and 6,6´-dimethylfulvene (0.665 g, 6.30 mmol). 3c was isolated as a pale
1
yellow solid (1.84 g, 1.74 mmol, 92%). H NMR (400 MHz, CD Cl , 25 °C):
δ 7.90 (dd, J = 7.9,
2
2
1
7
.7, 3H), 7.79 (m, 6H), 7.74 (s, 3H, PhH), 7.67, 7.54 (2t, J = 2.3, 3H), 7.45 (dt, J = 8.2, 2.3, 2H),
.32, 7.23 (2s, 3H, 9-FluH), 7.08, 6.72, 6.60, 6.56, 6.25, 6.04 (6m, 9H, CpH), 4.33, 4.29 (2s, 3H,
FluH), 3.32, 3.13 (2s, 6H, CpH
2
), 1.37, 1.36 (2s, 27H, C(CH
3 3
) ), 1.24, 1.22, 1.15, 1.09 (4s, 18H,
1
3
1
C(CH ) ). C{ H} NMR (100 MHz, CDCl , 25 °C): 158.1, 155.6 (7-Flu), 149.5, 149.4, 146.2,
δ
3
2
3
1
1
4
45.6, 142.7, 142.5, 141.7, 141.6, 138.9, 138.5 (Flu), 134.3, 133.3, 132.3, 131.1, 126.6, 126.3,
25.2, 124.9 (FluH), 124.6, 124.1, 124.0, 123.5, 123.4, 119.3, 118.8 (CpH), 58.1, 55.7 (9-Flu),
1.1, 40.8 (C(CH ) ), 40.6, 39.5 (CpCH ), 34.7 (C(CH ) ), 31.2 (C(CH ) ), 25.4, 23.7 (C(CH ) ).
3
2
2
3 3
3 3
3 2
Elemental analysis calcd (%) for C H (1057.53): C 91.99, H 8.01; found: C 91.66, H 7.93;
8
1
84
2
2

ACCEPTED MANUSCRIPT
+
+
ESI-MS [C H ] (1056.66) [m/z] = 1079.65 ([M + Na] ), 1056.65 ([M] ), 950.85 ([M -
8
1
84
+
+
2 2
Me CCp] ), 107.08 ([Me CCp] ).
1
8
,3,5-Tris(9-(2-(cyclopenta-1,3-dien-1-yl)propan-2-yl)-9H-6,7-(C H16)-fluoren-2-
Tet
yl)benzene, Ph{Me C(2-( FluH))(CpH)} (3d). Using a protocol similar to that described for
2
3
3
a, compound 3c was obtained from 2d (2.60 g, 2.88 mmol), n-BuLi (3.6 mL of a 2.5 M solution
in hexane, 9.1 mmol) and 6,6´-dimethylfulvene (0.965 g, 9.1 mmol). 3d was isolated as a pale
1
yellow solid (2.75 g, 2.12 mmol, 74%). H NMR (400 MHz, CDCl , 25 °C):
δ 7.83 (m, 3H), 7.76
3
(m, 6H), 7.71 (s, 3H, PhH), 7.68 (m, 3H), 7.57, 7.47 (2m, 3H), 7.21, 7.08 (2m, 3H), 7.04, 6.71,
6
.59, 6.52, 6.24, 6.02 (6m, 9H, CpH), 4.25, 4.20 (2s, 3H, FluH), 3.29, 3.11 (2s, 6H, CpH
), 1.43(s, 9H, C(CH ), 1.39 (s, 9H C(CH ), 1.28 (m, 18H, C(CH ), 1.18 (m,
). C{ H} NMR (100 MHz, CDCl , 25 °C): 146.2, 143.7, 143.1, 142.8, 139.1,
34.3, 133.5, 132.5, 131.1, 126.6, 126.3, 124.9, 124.4, 119.2, 117.0, 57.9, 55.5 (9-Flu), 51.3
2
), 1.75
(m, 12H, CH
2
3
)
2
3
)
2
3 2
)
1
3
1
1
1
8H C(CH
3
)
2
3
δ
(
C(CH ) ), 40.7, 39.6 (CpCH ), 35.3 (CH CH ), 34.6, 34.5 (C(CH ) ), 32.2, 31.8 (C(CH ) ), 25.6,
3 2 2 2 2 3 2 3 2
2
9
4,7 (C(CH ) ). Elemental analysis calcd (%) for C H (1219.80): C 91.57, H 8.43; found: C
3 2 93 102
+
1.33, H 8.29; ESI-MS (m/z): 1257.763 ([M + K] ).
tBu
Ph({Me C(2-(6- Flu))(C H )}ZrCl ) (4b-Zr). To a suspension of 3b (840 mg, 0.80
2
5
4
2 3
mmol) in diethyl ether (50 mL) was added n-BuLi (2.00 mL of a 2.5 M solution in hexane, 5.00
mmol) at 50 °C under stirring. After 12 h, the reaction mixture was cooled down to room
temperature and anhydrous ZrCl (583 mg, 2.50 mmol) was added to the sample in the glovebox.
4
The resulting purple/red reaction mixture was stirred at 50 °C for 24 h. Then volatiles were
removed in vacuo and the remaining solid was suspended in CH Cl (50 mL). The suspension
2
2
was filtered over celite under argon. Removal of the solvent in vacuum yielded the desired
complex 4b-Zr as a pink solid. For additional purification, the crude product was dissolved in
benzene (10 mL) followed by precipitation by addition of hexane (15 mL). The clear supernatant
2
3

ACCEPTED MANUSCRIPT
solution was decanted and the slurry was washed with hexane (10 mL). After drying in vacuo,
1
4
b-Zr was obtained as a pink powder (1.02 g, 0.66 mmol, 83%). H NMR (500 MHz, CD
2
Cl
2
, 25
°
C):
δ
8.26 (d, J = 8.6, 3H), 8.14 (d, J = 8.8, 3H), 8.11 (s, 3H), 7.94 (m, 3H), 7.84 (s, 3H, PhH),
7
5
.82 (d, J = 8.5, 6H), 7.76 (dd, J = 8.9, 1.4, 5H), 6.37 (m, 6H, CpH), 5.87 (q, J = 2.8, 3H, CpH),
1
3
1
.80 (q, J = 2.7, 3H, CpH), 2.49, 2.48 (2s, 18H, C(CH ) ), 1.42 (s, 27H, C(CH ) ). C{ H} NMR
3
2
3 3
(
125 MHz, CD Cl , 25 °C): δ 152.3 (6-Flu), 142.9, 141.4, 126.2, 125.3, 125.0, 124.1, 123.3,
2 2
1
22.7, 122.2, 122.0, 121.3, 119.4, 119.0 (FluH), 118.7 (CpH), 114.6 (Cp), 101.9, 101.7 (CpH),
7
9.5 (9-Flu), 40.6 (C(CH ) ), 35.4 (C(CH ) ), 30.7, 28.8 (C(CH ) ). Elemental analysis calcd (%)
3
2
3 3
3 2
for C81
H78Cl
6
Zr
3
(1537.88): C 63.26, H 5.11; found: C 63.55, H 5.32.
tBu
2 5 4 2 3
Ph({Me C(2-(7- Flu))(C H )}ZrCl ) (4c-Zr). Using a protocol similar to that described
for 4b-Zr, complex 4c-Zr was prepared from 3c (0.86 g, 0.81 mmol), n-BuLi (2.05 mL of a 2.5
M solution in hexane, 5.12 mmol) and ZrCl (0.596 g, 2.55 mmol); it was isolated as a pink
4
1
powder (1.10 g, 0.72 mmol, 88%). H NMR (500 MHz, C D , 25 °C):
δ 8.14 (m, 3H), 8.11 (s,
6
6
3
H), 7.95-7.86 (m, 9H), 7.68 (s, 3H, PhH), 7.57 (dd, J = 8.9, 1.4, 3H), 6.22 and 6.20 (2m, 3H,
CpH), 6.13 (m, 3H, CpH), 5.62, 5.59 (2m, 3H, CpH), 5.55 (m, 3H, CpH), 2.09, 2.05 (2s, 9H,
13
1
C(CH ) ), 2.01 and 2.00 (2s, 9H, C(CH ) ), 1.30 (s, 27H C(CH ) ). C{ H} NMR (125 MHz,
3
2
3 2
3 3
C
6
D
6
, 25 °C):
22.3, 122.0, 121.5, 119.2 (FluH), 118.8, 118.4 (CpH), 114.6 (Cp), 101.6, 101.0 (CpH), 79.4 (9-
Flu), 40.2 (C(CH ) ), 35.1 (C(CH ) ), 31.9, 30.7, 28.4, 28.2 (C(CH ) ). Elemental analysis calcd
δ 151.6 (7-Flu), 144.1, 141.9, 126.8, 125.6, 125.3, 124.6, 124.4, 123.2, 122.8,
1
3
2
3 3
3 2
(
%) for C H Cl Zr (1537.88): C 63.26, H 5.11; found: C 62.95, H 5.37.
8
1
78
6
3
Tet
Ph({Me C(2-( Flu))(C H )}ZrCl ) (4d-Zr): Using a protocol similar to that described
2
5
4
2 3
for 4b-Zr, complex 4d-Zr was prepared from 3d (0.96 g, 0.79 mmol), nBuLi (1.98 mL of 2.5M
solution in hexane, 4.96 mmol) and ZrCl (0.578 g, 2.47 mmol); it was isolated as a red powder
4
1
(
1.19 g, 0.64 mmol, 81%). H NMR (400 MHz, C
6
D
6
, 25 °C):
δ
8.15 (m, 3H), 8.11 (m, 3H), 8.08
2
4

ACCEPTED MANUSCRIPT
(s, 3H), 7.93 (m, 3H), 7.86 (m, 3H), 7.66 (s, 3H, PhH), 6.23 (m, 3H, CpH), 6.11 (m, 3H, CpH),
5
1
1
.55 (m, 6H, CpH), 2.09, 2.03, 2.00, 1.97 (4s, 18H, C(CH
3
)
2
), 1.66 ,and 1.62 (2m, 12H, CH
). C{ H} NMR (100 MHz, C , 25 °C): 147.4,
45.9, 128.3, 127.8, 127.6, 127.0, 125.3, 122.2, 121.9, 120.6 (FluH), 118.9, 118.5 (CpH), 114.0
2
),
13
1
.36, 1.36, 1.33, 1.27 (4s, 36H, C(CH
3
)
2
6
D
6
δ
(Cp), 101.5, 100.6 (CpH), 77.9 (9-Flu), 40.0 (C(CH ) ), 35.0 (C(CH ) ), 34.8, 34.7, 33.7
3 2 3 2
(
CH CH ), 32.4, 32.3, 32.1 (C(CH ) ), 28.3, 28.1 (C(CH ) ). Elemental analysis calcd (%) for
2
2
3 2
3 2
C H Cl Zr (1700.15): C 65.70, H 5.69; found: C 66.8, H 6.2.
9
3
96
6
3
tBu
Ph({Me C(2-(6- Flu))(C H )}HfCl ) (4c-Hf). Using a protocol similar to that described
2
5
4
2 3
for 4b-Zr, complex 4c-Hf was prepared from 3c (0.86 mg, 0.81 mmol), nBuLi (2.05 mL of 2.5M
solution in hexane, 5.12 mmol) and HfCl
4
(820 mg, 2.55 mmol); it was isolated as a yellow
, 25 °C): 8.20 (m, 3H), 8.14 (s,
1
powder (0.82 g, 0.45 mmol, 56%). H NMR (400 MHz, C
6
D
6
δ
3
H), 7.89 (m, 6H), 7.73 (m, 3H), 7.55 (m, 3H), 7.42 (m, 3H) 6.20, 6.07 (2m, 6H, CpH), 5.53 and
1
3
1
5
53 (2m, 6H, CpH), 2.10, 2.07, 2.03, 2.02 (4s, 18H, C(CH ) ), 1.31 (s, 27H, C(CH ) ). C{ H}
3 2 3 3
NMR (100 MHz, C D , 25 °C):
δ 151.4 (6-Flu), 144.1, 141.7, 125.2, 124.3, 124.2, 122.1, 122.0,
6
6
1
21.7, 120.6, 120.0 (FluH), 118.0, 117.8 (Cp), 117.1, 117.1, 99.1, 98.5 (CpH), 79.6 (9-Flu), 40.3
(
C(CH ) ), 35.0 (C(CH ) ), 30.8, 28.7, 28.5 (C(CH ) ). Elemental analysis calcd (%) for
3
2
3 3
3 2
C
81
H78Cl
6
Hf
3
(1799.67): C 54.06, H 4.37; found: C 54.81, H 4.95.
Tet
Ph({Me
2
5 4 2 3
C(2-( Flu))(C H )}HfCl ) (4d-Hf). Using a protocol similar to that described
for 4b-Zr, complex 4d-Hf was prepared from 3d (0.86 mg, 0.70 mmol), nBuLi (1.77 mL of
2
.5M solution in hexane, 4.44 mmol) and HfCl (0.711 g, 2.22 mmol); it was isolated as a yellow
4
1
powder (0.86 g, 0.44 mmol, 63%). H NMR data from 2D HSQC NMR (500/125 MHz, CD Cl ,
2
2
2
2
2
5 °C)
δ 8.26, 8.15, 7.90 (FluH), 7.84 (PhH), 7.78, 7.75 (FluH), 6.28, 5.79, 5.72 (CpH), 2.47,
13
1
.44 (C(CH ) ), 1.81, 1.76 (CH ), 1.47, 1.42, 1.34, 1.31 (C(CH ) ); C{ H} (125 MHz, CD Cl ,
3
2
2
3 2
2
2
5 °C):
δ 124.8, 121.7, 124.9 (FluH), 119.9 (PhH), 126.1, 117.4 (Flu), 117.9 (CpH), 116.6 (Cp),
2
5

ACCEPTED MANUSCRIPT
9
9.0, 98.9 (CpH), 77.6 (9-Flu), 40.7 (C(CH ) ), 35.1, 35.1 (CH CH ), 32.0 (C(CH ) ), 29.0
3
2
2
2
3 2
(
C(CH
3
)
2
). No satisfactory elemental analysis could be obtained for this compound.
tBu
2 5 4 2 3
Ph({Me C(2-(7- Flu))(C H )}ZrMe ) (5c-Zr). To a solution of 4c-Zr (154 mg, 0.10
mmol) in toluene (15 mL) was added BrMgMe (0.21 mL of a 3.0M solution in diethyl ether, 0.63
mmol) at room temperature under stirring. The resulting solution was stirred at 70 °C overnight.
Then volatiles were evaporated in vacuo and the residue was extracted with heptane (ca. 15 mL)
1
to give 5b-Zr as a yellow powder (108 mg, 0.77 mmol, 77%). H NMR (400 MHz, C D , 25 °C):
6
6
δ
8.12 (s, 3H), 8.07 (q, J = 1.9, 3H), 8.01 (dd, J = 8.6, 2.1, 3H), 7.98 (d, J = 8.8, 3H), 7.79 (m,
H), 7.68 (s, 3H, PhH), 7.46 (dd, J = 8.8, 1.5, 3H), 6.20 (dq, J = 5.4, 2.7, 3H, CpH), 6.14 – 6.11
3
(
m, 3H, CpH), 5.56 (q, J = 2.8, 3H, CpH), 5.50 (q, J = 2.7, 3H, CpH), 2.04 (s, 9H, C(CH
3
)
2
), 1.99
1
3
1
(
s, 9H, C(CH ) ), 1.30 (s, 27H, C(CH ) ),
−0.92 (s, 9H, Zr-CH3),
−
1.08 (s, 9H, Zr-CH ). C{ H}
3
2
3 2
3
NMR (125 MHz, C D , 25 °C):
δ
149.7 (7-Flu), 140.2, 125.0, 124.6, 124.3, 123.6, 122.0, 121.9,
21.2, 118.6, 118.1, 117.8, 113.0, 112.9 (CpH), 108.9, 101.0, 100.7(CpH), 76.7 (9-Flu), 40.1
C(CH ), 35.0 (C(CH ), 33.2, 32.6 (Zr-CH ), 31.0 , 28.8, 28.6 (C(CH ). Elemental analysis
calcd (%) for C87 (1410.47): C 73.83, H 6.84; found: C 74.01, H 7.11.
6
6
1
(
3
)
2
3
)
3
3
3 2
)
H96Zr
3
Tet
Ph({Me C(2-( Flu))(C H )}ZrMe ) ] (5d-Zr). Using a protocol similar to that described
2
5
4
2 3
for 5c-Zr, complex 5d-Zr was prepared from 4d-Zr (170 mg, 0.10 mmol) and BrMgMe (0.21
mL of a 3.0M solution in diethyl ether, 0.63 mmol); it was isolated as an orange powder (111 mg,
1
7
7
1 µmol, 71%). H NMR (400 MHz, C D , 25 °C):
δ
8.37 (m, 3H), 8.25 (s, 3H), 7.98 (m, 3H),
6
6
.80 (s, 3H, PhH), 7.79 (m, 3H), 7.71 (s, 3H), 6.29 (m, 6H, CpH), 5.65-5.56 (m, 6H, CpH), 2.24
(
s, 9H, C(CH
3
)
2
), 2.22 (s, 9H, C(CH
3
)
2
), 1.80 (m, 12H, CH
2
), 1.51 (s, 9H, C(CH
3
)
2
), 1.50 (s, 9H,
C(CH ) ), 1.45 (s, 9H, C(CH ) ), 1.31 (s, 9H, C(CH ) ),
−1.43 (s, 9H, Zr-CH3),
−1.51 (s, 9H, Zr-
3
2
3 2
3 2
13
1
CH ). C{ H} NMR (100 MHz, CD Cl , 25 °C):
δ 145.9 (7-Flu), 145.8 (6-Flu) 143.5, 142.3,
3
2
2
1
39.7, 139.6 (Flu), 125.9 124.4, 123.2, 121.3(FluH), 121.0 (PhH), 112.8, 112.5 (CpH), 100.8
2
6

ACCEPTED MANUSCRIPT
(
CpH), 75.0 (9-Flu), 40.1 (C(CH ) ), 35.1 (CH CH ), 34.5, 33.5, 32.5, 32.1 (C(CH ) ), 31.9(Zr-
3
2
2
2
3 2
3 3 2
CH ), 29.7, 28.9 (C(CH ) ). No satisfactory elemental analysis could be obtained for this
compound.
Ph({Me C(2-(7- Flu))(C H )}Zr(CH SiMe ) ) (6c-Zr). Using a protocol similar to that
tBu
2
5
4
2
3 2 3
described for 5c-Zr, complex 6c-Zr was prepared from 4c-Zr (77 mg, 50 µmol) and
ClMgCH SiMe (0.31 mL of a 1.0M solution in diethyl ether, 0.31 mmol); it was isolated as a
2
3
1
yellow powder (81 mg, 44 µmol, 80%). H NMR (500 MHz, C D , 25 °C):
δ 8.40-8.32 (m, 3H),
6
6
8
7
1
.31-8.21 (m, 3H), 8.07-8.02 (m, 3H), 7.99-7.92 (m, 3H), 7.90-7.85 (m, 3H), 7.64 (s, 3H, PhH),
.46- 7.40 (m, 3H), 6.65-6.43 (m, 6H), 5.84- 5.52 (m, 6H), 2.22, 2.15, 2.10, 2.00 (m, 18H), 1.35,
.30 (2s, 27H, C(CH ) ), 0.17-0.09 (m, 27H, Si(CH ) ), 0.06 (s, 27H, Si(CH ) ),
−
0.86-
−
1.03 (m,
2.05 and
149.5 (7-Flu),
3
3
3 2
3 2
3
H, Zr-CH H ),
−
1.49 (d, J = 11.7, 3H, Zr-CH H ),
−1.91 (d, J = 11.7, 3H, Zr-CH H ),
−
b
c
a
b
c
d
1
3
1
−
2.08 (2d, J = 11.7, 3H, Zr-CH H ). C{ H} NMR (125 MHz, C D , 25 °C): δ
a b 6 6
1
42.9, 142.8, 139.6, 139.4, 139.3, 126.8, 125.8, 123.2, 122.2, 122.0, 121.5, 118.7 (PhH), 111.7
(
(
Cp) 111.1, 110.3, 101.2, 100.6 (CpH), 77.8 (9-Flu), 50.4, 48.6, 45.2, 44.9 (Zr-CH ), 35.0
2
3 3 3 3 3 2 3 2 3 3
C(CH ) ), 31.5, 31.0 (C(CH ) ), 39.8(C(CH ) ), 28.9, 28.6 (C(CH ) ), 3.4, 2.8 (Si(CH ) ).
Repeated elemental analyses returned low C content for this compound. calcd (%) for
Zr (1848.45): C 68.23, H 7.85; found: C 65.98, H 7.52.
PGSE Measurements. PGSE NMR experiments were performed on a Bruker Avance
C
105
H144Si
6
3
DRX 400 spectrometer equipped with a GREAT 1/10 gradient unit and direct QNP probe with a
Z-gradient coil, using the following parameters: 298 K, no spinning; spectral width = 4807 Hz;
9
0° pulse width of 11.5
width of 0.0016 s; the diffusion encoding pulse strength from 0 to 35 G
increments with 4 dummy scans and 8 scans per increment. The translational coefficients D were
µs; a diffusion delay time of 0.05 s; a total diffusion-encoding pulse
-2
⋅
cm over 12 or 16
t
2
0,13
determined as previously reported.
2
7

ACCEPTED MANUSCRIPT
Polymerization Experiments. Experiments were performed in a 300 mL high pressure
glass reactor equipped with a mechanical stirrer (Pelton turbine) and externally heated with a
double mantle with a thermostated circulating water bath. The reactor was charged with toluene
(150 mL) and MAO (1.5 mL of a 30 wt-% solution in toluene), and propylene (5 bar, Air
Liquide, 99.99%) or ethylene (5 bar, Air Liquide, 99.99%) was introduced. The reactor was
thermally equilibrated at the desired temperature for 30 min. Monomer gas pressure was
decreased to 1 bar, and a solution of the catalyst precursor in toluene (ca. 2 mL) was added by
syringe. The monomer gas pressure was immediately increased to 5 bar (kept constant with a
back regulator) and the solution was stirred for the desired time. The temperature inside the
reactor was monitored using a thermocouple. The polymerization was stopped by venting the
vessel and quenching with a 10 wt.% solution of aqueous HCl in methanol (ca. 6 mL). The
polymer was precipitated in methanol (ca. 500 mL) and 35 wt% aqueous HCl (ca. 10 mL) was
added to dissolve possible catalyst residues. The polymer was collected by filtration, washed with
methanol (ca. 200 mL), and dried under vacuum overnight.
Crystal Structure Determination of 2c. Diffraction data were collected at 100 K using a
Bruker APEX CCD diffractometer with graphite-monochromatized MoK
α radiation (λ =
0
.71073 Å). A combination of and scans was carried out to obtain a unique data set. The
ω
θ
crystal structures were solved by direct methods, remaining atoms were located from difference
Fourier synthesis followed by full-matrix least-squares refinement based on F2 (programs SIR97
2
1
and SHELXL-97). Many hydrogen atoms could be located from the Fourier difference analysis.
Other hydrogen atoms were placed at calculated positions and forced to ride on the attached
atom. The hydrogen atom positions were calculated but not refined. All non-hydrogen atoms
were refined with anisotropic displacement parameters. Crystal data and details of data collection
and structure refinement for the different compounds are given in Table S1. Crystal data, details
2
8

ACCEPTED MANUSCRIPT
of data collection and structure refinement for compound 2c (CCDC 1863112) can be obtained
from the Cambridge Crystallographic Data Centre via www.ccdc.cam.ac.uk/data_request/cif.
Computational Details. All calculations were performed with the TURBOMOLE program
2
2,23,24,25
package using density functional theory (DFT).
BP86 in combination with the resolution identity approximation (RI)
geometry optimizations of stationary point. A triple- zeta valence quality basis set def-TZVP
The gradient corrected density functional
2
6,27
was applied for the
ζ
2
8
was used for all atoms. The stationary points were characterized as energy minima (no negative
Hessian eigenvalues) by vibrational frequency calculations at the same level of theory.
References
1
(
a) M. Ainooson, F. Meyer, in Comprehensive Inorganic Chemistry II (Second Edition),
Elsevier, Amsterdam, 2013, pp. 433 458. (b) M. Delferro, T. J. Marks, Chem. Rev. 2011,
2485. (c) J. P. McInnis, M. Delferro, T. J. Marks, Acc. Chem. Res. 2014, 47,
2557. (d) Invergo, A. M.; Liu, S.; Dicken, R. D.; Mouat, A. R.; Delferro, M.; Lohr, T.
−
1
11, 2450
−
2
545−
L.; Marks, T. J. Organometallics 2018, DOI: 10.1021/acs.organomet.8b00220 and
references cited therein.
2
(
a) S. Jüngling, R. Mühlhaupt, H. Plenio, J. Organomet. Chem. 1993, 460, 191
Yan, A. Chernega, M. L. H. Green, J. Sanders, J. Souter, T. Ushioda, J. Mol. Cat. A: Chem.
998, 128, 119 141. (c) S. K. Noh, J. Kim, J. Jung, C. S. Ra, D.-H. Lee, H. B. Lee, S. W.
Lee, W. S. Huh, J. Organomet. Chem. 1999, 580, 90 97. (d) H.-W. Lee, Y.-H. Park, Cat.
Today 2002, 74, 309 320. (e) S. K. Noh, S. Kim, Y. Yang, W. S. Lyoo, D.-h. Lee, Eur.
Polym. J. 2004, 40, 227 235. (f) J. Kuwabara, D. Takeuchi, K. Osakada, Organometallics
005, 24, 2705 2712. (g) M. H. Lee, S. K. Kim, Y. Do, Organometallics 2005, 24,
−195. (b) X.
1
−
−
−
−
2
−
2
9