Preparation of half-titanocenes of thiophene-fused trimethylcyclopentadienyl ligands and their ethylene copolymerization reactivity

Article abstract of DOI:10.1016/j.jorganchem.2011.03.014

Methylthiophene-fused or dimethylthiophene-fused trimethylcyclopentadienyltitanium trichloride complexes, (η⁵- Me₄RC₇S)TiCl₃ (R = Me or H), are prepared, from which a chloride ligand is replaced with 2,6-diisopropylphenoxy, di(tert-butyl)ketimide, or tri(tert-butyl)phosphinimide ligand to yield (η⁵-Me₄RC₇S)TiXCl₂ (11, R = Me, X = iPr₂C₆H₃O-; 12, R = H, X = iPr ₂C₆H₃O-; 13, R = Me, X = tBu₂C = N-; 14, R = H, X = tBu₂C = N-; 15, R = Me, X = tBu₃P = N-; 16, R = H, X = tBu₃P = N-). The molecular structures of 11, 14, and 16 are confirmed by X-ray crystallography. The Cp(centroid)-Ti-N angles of 11, 14, and 16 (119.83°, 111.98°, and 125.34°, respectively) are significantly larger than the corresponding angle observed for the related thiophene-fused and tetrahydroquinaldine-linked cyclopentadienyl complex (1), [(η⁵-(Me₄C₇S)-(2-MeC₉H ₉N-κN)]TiMe₂ (106.6°). The phenoxy complexes 11 and 12 show negligible activity, while the ketimido and phosphinimido complexes 13-16 exhibit good activities (5-20 × 10⁶ g/molTi h) for ethylene/1-octene copolymerization. The ketimido-complexes 13 and 14 are able to incorporate a high amount of 1-octene (15-16 mol%), while the phosphinimido-complexes 15 and 16 are not as capable (8 mol% 1-octene) under the identical polymerization conditions. The catalytic performance of 13-16 is inferior to 1 in terms of activity and comonomer incorporation.

Full text of DOI:10.1016/j.jorganchem.2011.03.014

Journal of Organometallic Chemistry 696 (2011) 2451e2456
Contents lists available at ScienceDirect
Journal of Organometallic Chemistry
journal homepage: www.elsevier.com/locate/jorganchem
Preparation of half-titanocenes of thiophene-fused trimethylcyclopentadienyl
ligands and their ethylene copolymerization reactivity
*
Eun Seok Park, Ji Hae Park, Hoseop Yun, Bun Yeoul Lee
Department of Molecular Science and Technology and Energy System Division, Ajou University, Suwon 443-749, South Korea
a r t i c l e i n f o
a b s t r a c t
Article history:
Methylthiophene-fused or dimethylthiophene-fused trimethylcyclopentadienyltitanium trichloride
complexes, (
h
5-Me4RC7S)TiCl3 (R ¼ Me or H), are prepared, from which a chloride ligand is replaced
Received 20 January 2011
Received in revised form
5 March 2011
with 2,6-diisopropylphenoxy, di(tert-butyl)ketimide, or tri(tert-butyl)phosphinimide ligand to yield
(
h
5-Me4RC7S)TiXCl2 (11, R ¼ Me, X ¼ iPr2C6H3Oe; 12, R ¼ H, X ¼ iPr2C6H3Oe; 13, R ¼ Me, X ¼ tBu2C ¼ Ne; 14,
Accepted 8 March 2011
R ¼ H, X ¼ tBu2C ¼ Ne; 15, R ¼ Me, X ¼ tBu3P ¼ Ne; 16, R ¼ H, X ¼ tBu3P ¼ Ne). The molecular structures of
11, 14, and 16 are confirmed by X-ray crystallography. The Cp(centroid)eTieN angles of 11, 14, and 16
(119.83ꢀ, 111.98ꢀ, and 125.34ꢀ, respectively) are significantly larger than the corresponding angle obser-
ved for the related thiophene-fused and tetrahydroquinaldine-linked cyclopentadienyl complex (1),
Keywords:
Half-titanocenes
Thiophene-fused
Cyclopentadienyl
Polymerization
[(h k
5-(Me4C7S)-(2-MeC9H9N- N)]TiMe2 (106.6ꢀ). The phenoxycomplexes 11 and 12 show negligible activity,
while the ketimido and phosphinimido complexes 13e16 exhibit good activities (5e20 ꢁ 106 g/molTi h) for
ethylene/1-octene copolymerization. The ketimido-complexes 13 and 14 are able to incorporate a high
amount of 1-octene (15e16 mol%), while the phosphinimido-complexes 15 and 16 are not as capable (8 mol
% 1-octene) under the identical polymerization conditions. The catalytic performance of 13e16 is inferior to
1 in terms of activity and comonomer incorporation.
Ó 2011 Elsevier B.V. All rights reserved.
1. Introduction
performances of the metallocene and bridged half-metallocene
complexes that are constructed using thiophene-fused cyclo-
Metallocene and bridged half-metallocene complexes con-
structed using thiophene-fused cyclopentadienyl ligands have been
reported to exhibit enhanced polymerization activities, especially
with a high molecular-weight polymer [1e5]. Recently, we also
observed some advantageous catalytic performances for half-tita-
nocenes of thiophene-fused and tetrahydroquinaldine-linked
cyclopentadienyl ligands (1, 2) [6]. Complex 1 exhibits higher
activity with production of higher molecular-weight polymer than
the tetramethylcyclopentadienyl analogue.
pentadienyl ligands prompted us to prepare nonbridged half-tita-
nocene analogues.
Nonbridged half-titanocene complexes have drawn much
attention as a homogeneous Ziegler catalyst in olefin polymeriza-
tion [7]. They are simply prepared from TiCl4 through the succes-
sive replacement of two chlorides with
-donor ligand and anionic ancillary donor ligand such as aryloxo
h
5-cyclopentadienyl-type
p
[8,9], ketimide [10,11], or phosphinimide ligand [12,13]. They are
advantageous in terms of simplicity of preparation over the anal-
ogous bridged half-titanocene complexes. For the bridged
complexes, the ligand is elaborately prepared and the metalation
conditions are costly in some cases. The advantageous
2. Results and discussion
2.1. Synthesis and characterization
A
thiophene-fused cyclopentenones (3 and 4) are atom-
* Corresponding author. Tel.: þ82 31 219 1844; fax: þ82 31 219 2394.
E-mail address: bunyeoul@ajou.ac.kr (B.Y. Lee).
economically synthesizable in large scale (50-g scale) using the
0022-328X/$ e see front matter Ó 2011 Elsevier B.V. All rights reserved.
doi:10.1016/j.jorganchem.2011.03.014

2452
E.S. Park et al. / Journal of Organometallic Chemistry 696 (2011) 2451e2456
R
Me
R
Me
R
Me
Me
R
S
Me
R
Me
Me
Cl
Cl
HO
O
Me
SiMe3
Me
S
S
i)
ii)
S
iii)
iv)
Me
Me
Me
Me
+
Me
S
Ti
Me
Me
O
Cl
Me
Me
5 (R = Me)
6 (R = H)
7 (R = Me)
8 (R = H)
9 (R = Me)
10 (R = H)
3 (R = Me)
4 (R = H)
Scheme 1. i) polyphosphoric acid; ii) MeLi then HCl (2 N); iii) nBuLi then Me3SiCl; iv) TiCl4.
inexpensive starting materials, tiglic acid and the corresponding
thiophene (Scheme 1). Dissolving two components in poly-
phosphoric acid successively triggers the FriedeleCraft acylation
and the Nazarov-cyclization to generate 3 and 4 in one pot. The
Nazarov-cyclization is one of the best tools to construct a cyclo-
pentadiene or cyclopentenone system [14e16]. In case of 3, an
amount of uncyclized compound (w30%) is concomitantly
obtained that is removed through chromatography. In case of 4, the
desired product is obtained almost quantitatively and can be iso-
lated through vacuum distillation. Addition of MeLi to 3 or 4 in
diethyl ether and subsequent acidic work-up affords the desired
thiophene-fused cyclopentadienes 5 and 6 in 74%e76% yield. The
1,5-sigmatropic rearrangement is facile in the substituted cyclo-
pentadiene system, causing isomerism and, consequently,
producing complicated and broad NMR signals. However, in the
case of 5 and 6, the 1,5-sigmatropic rearrangement is not allowed
due to the aromacity of thiophene ring. Hence, a single set of sharp
signals are observed in the 1H and 13C NMR spectra. After substi-
tution of a proton on 5 or 6 with a trimethylsilyl group, addition of
TiCl4 in methylene chloride yields the corresponding cyclo-
pentadienyl-TiCl3 complexes 9 or 10 in 63%e64% yield. In the 1H
NMR spectrum of 9, just five singlet methyl signals are observed at
1.9e2.2 ppm. In the 1H NMR spectrum of 10, four singlet methyl
signals are observed at the same region along with a vinyl signal at
6.22 ppm.
Addition of 2,6-diisopropylphenoxy lithium to 9 or 10 in toluene
gives a nonbridged aryloxo half-titanocene complex 11 or 12 in
46%e68% yield (equation (1)). A single septet signal is observed at
3.2 ppm, indicating the two isopropyl groups are equivalent.
Addition of (tBu)2C]NLi to 9 or 10 in toluene gives the corres-
ponding nonbridged ketimido half-titanocene complex 13 or 14 in
71%e97% yield (equation (2)). The two tert-butyl units are equiva-
lent in these complexes and a single signal is observed at 1.14 ppm
for the tert-butyl-CH3 protons in the 1H NMR spectrum and at
31.2 ppm for the tert-butyl-CH3 carbon in the 13C NMR spectrum.
Addition of (tBu)3P]NLi to 9 or 10 in toluene also gives the cor-
responding nonbridged phosphinimido half-titanocene complex 15
or 16 in 96%e97% yield (equation (3)). The tert-butyl proton signal
is observed at 1.22 ppm as a doublet (J ¼ 13 Hz) coupled with
a phosphorus atom. A phosphorous signal is observed at 47 ppm in
the 31P NMR spectrum.
2.2. X-ray crystallographic studies
The molecular structures of 11, 14, and 16 were determined by
X-ray crystallography (Figs. 1e3). The metrical parameters are
summarized in Table 1 compared with those observed in the
bridged complex 1. The Cp(centroid)eTieN angles, which have
been used as a qualitative measure for the openness of the reaction
site, are 119.83ꢀ, 111.98ꢀ, and 125.34ꢀ for 11, 14, and 16 respectively.
The angles are significantly larger than those observed for the
related bridged complexes such as 1 (106.62ꢀ) and the CGC, [Me2Si
(
h5-Me4C5)(NtBu)]TiCl2 (107.6ꢀ), indicating that the reaction sites in
the nonbridged complexes 11, 14, and 16 are not so widely opened
as in the bridged complexes 1 and the CGC. Among the nonbridged
three complexes, the angle of the ketimido-complex 14 is the
smallest (111.98ꢀ), suggesting the highest capability for comonomer
incorporation. The TieOeC angle in 11 is 163.32(18)ꢀ, indicating
a geometry between the trigonal and the linear arrangement,
which is attributed to the significant amount of
p-donation from
oxygen to titanium. Deviation of the TieNeC and TieNeP angles in
14 and 16 (165.5(2)ꢀ and 169.19(16)ꢀ, respectively) from the ideal
trigonal angle (120ꢀ) also indicate
p
-donation from nitrogen to
titanium. The larger TieNeC angle in the phosphinimido-complex
16 than in ketimido-complex 14 implies the increased -donation
in the phosphinimido-complex 16. Due to this increased -dona-
p
p
tion, the TieN distance in phosphinimido-complex 16 (1.773(2) Å)
is shorter than in ketimido-complex 14 (1.844(2) Å). The TieN
distances in both ketimido-complexes 14 and phosphinimido-
complex 16 are shorter than that of the amido-complex 1 (1.934
(3) Å). While the TieN distance is shorter in 16 than in 14, the TieCp
(cent) and TieCl distances are longer in 16 than in 14. The TieCp

E.S. Park et al. / Journal of Organometallic Chemistry 696 (2011) 2451e2456
2453
Fig. 1. Thermal ellipsoid plot (30% probability level) of 11.
(cent) distances in both 14 and 16 are longer (2.052 and 2.099 Å,
respectively) than that in 1 (2.041 Å). In 14, the thiophene ring is
positioned at the opposite side of the (tBu)2C]N ligand, passing
through the Ti center. In contrast, the thiophene ring in 16 is situ-
ated close to the (tBu)3P]N ligand.
Fig. 3. Thermal ellipsoid plot (30% probability level) of 16.
versus entries 7 and 8). Activities of the ketimido-complexes 13 and
14 are almost the same with that of Cp*Ti[NC(tBu)2]Cl2 (entries
3 and 5 versus 9), while activities of the phosphinimido-complexes
13 and 14 are almost half of that of Cp*Ti[NP(tBu)3]Cl2 (entry
7 and 8 versus 11). All the complexes screened in this study
displays significantly lower activity than the bridged complex 1
(67 ꢁ 106 g/molTi h, entry 12). Higher activities are attained when
the ketimido-complexes 13 and 14 are activated with MMAO
instead of [Ph3C][B(C6F5)4] (19e20 g/molTi h, entries 4 and 6).
The ketimido-complexes 13 and 14, when activated with [Ph3C]
[B(C6F5)4], are able to incorporate fairly high amount of 1-octene
(15e16 mol%) while the phosphinimido-complexes 13 and 14 are
not so capable (8 mol% 1-octene). This trend agrees with the Cp
(centroid)eTieN angles observed in X-ray crystallography. The
angle of the ketimido-complex 14 is smaller (111.98ꢀ) than that of
the phosphinimido-complex 16 (125.34ꢀ), indicating that the
reaction site of 14 is more widely opened and, hence, that 14 is
capable of incorporating a higher amount of 1-octene. Almost the
same trend is observed for the Cp*-complexes (entries 9 and 11;
18 mol% for Cp*Ti[NC(tBu)2]Cl2, 5 mol% for Cp*Ti[NP(tBu)3]Cl2).
Attachment of one more methyl group on the thiophene ring does
not influence the activity and the 1-octene incorporation capability
when the complexes are activated with [Ph3C][B(C6F5)4]. When
activated with MAO, compound 13, bearing two methyl substituent
2.3. Polymerization studies
The newly prepared complexes 11e16 were screened for
ethylene/1-octene copolymerization after activation with (Ph3C)[B
(C6F5)4] and iBu3Al. Triisobutylaluminum is added both as a scav-
enger and as an alkylating agent. The polymerization results are
summarized in Table 2 compared with those of the related
complexes of Cp*Ti[NC(tBu)2]Cl2 (Cp*, pentamethylcyclopenta-
dienyl), Cp*Ti[NP(tBu)3]Cl2, and 1. The phenoxy complexes, 11 and
12 show negligible activity in the polymerization conditions, while
the ketimido- and phosphinimido-complexes 13e16 exhibit good
activities (5e20 ꢁ 106 g/molTi h). The phosphinimido-complexes
15 and 16 are more active than the ketimido-complexes 13 and 14
under the identical polymerization conditions (entries 3 and 5
Table 1
Selected bond distances (Å) and angles (ꢀ) in 11, 14, 16, and 1.
11
14
16
1
TieCp(cent)
2.042
2.052
2.099
2.041
TieN or TieO
TieCl(1)
TieCl(2)
SeC(Cp)
SeC
OeC, NeC, or NeP
Cp(cent)eTieN (or O)
Cl(1)eTieCl(2)
Cl(1)eTieN (or O)
Cl(2)eTieN (or O)
1.7858(19) 1.844(2)
1.773(2)
1.934(3)
2.2617(9)
2.2608(9)
1.739(3)
1.786(4)
1.368(3)
119.83
2.2772(8) 2.3032(8)
2.2931(8) 2.3108(8)
1.719(3)
1.755(3)
1.268(3)
111.98
1.728(3)
1.727(3)
1.611(2)
125.34
1.730(3)
1.769(3)
106.62
102.38(3)
102.65(7)
102.07(7)
100.36(3) 100.60(3)
104.73(7) 102.96(8)
103.80(7) 102.25(8)
TieOeC, TieNeC, or TieNeP 163.32(18) 165.5(2)
169.19(16)
Fig. 2. Thermal ellipsoid plot (30% probability level) of 14.

2454
E.S. Park et al. / Journal of Organometallic Chemistry 696 (2011) 2451e2456
Table 2
3.2. Compound 5
Ethylene/1-octene copolymerization results.a
Entry Catalyst
Yield (g) Activityb [Oct]c (mol%) Mw (ꢁ10ꢂ3) Mw/Mn
MeLi (29.7 mL, 47.6 mmol, 1.6 M in diethyl ether) was added
dropwise to a stirred solution of 3 (7.71 g, 39.7 mmol) in diethyl
ether (77 mL) at ꢂ78 ꢀC. The solution was stirred overnight at room
temperature. Water (40 mL), ethyl acetate (40 mL), and aqueous
HCl (2 N, 80 mL) were successively added. After the two phase
solution was stirred for 10 min, the organic phase was collected and
then washed with saturated aqueous Na2CO3 solution (80 mL). The
product was extracted with additional ethyl acetate (3 ꢁ 100 mL).
The combined organic phase was dried over anhydrous MgSO4.
Removal of the solvent with a rotary evaporator gave a residue that
was purified by column chromatography on silica gel eluting with
hexane and ethyl acetate (v/v, 20:1). The product was obtained as
1
2
11
12
13
13
14
14
15
16
w0
w0
3
0.25
0.64
0.23
0.66
0.45
0.40
5.0
19
4.6
20
9.0
8.0
6.1
17
23
67
15
19
16
13
8
464
27
288
39
543
752
522
90
204
295
2.81
2.25
2.78
2.49
2.44
2.17
2.82
2.69
3.32
1.73
4d
5
6d
7
8
8
9
Cp*Ti[NC(tBu)2]Cl2 0.31
18
13
5
10d Cp*Ti[NC(tBu)2]Cl2 0.55
11
Cp*Ti[NP(tBu)3]Cl2 1.1
0.84
12e
1
21
a
Polymerization conditions: 30 mL toluene solution of 1-octene (0.30 M, 1.0 g),
a yellowish oil (5.62 g, 74%). 1H NMR (C6D6):
d
3.03 (q, J ¼ 7.2 Hz, 1H,
1.0 mmol Ti, 4.0 mmol [Ph3C][B(C6F5)4], 0.20 mmol Al(iBu)3, 60 psig ethylene, 3 min,
80 ꢀC initial temperature.
CH), 2.41 (s, 3H, CH3), 2.19 (s, 3H, CH3), 2.00 (s, 3H, CH3), 1.96 (s, 3H,
b
Activity in unit of 106 g/molTi h.
CH3), 1.27 (d, J ¼ 7.6 Hz, 3H, CH3) ppm. 13C{1H} NMR (C6D6):
d 11.99,
c
1-Octene content in the copolymer determined by the 1H NMR.
12.36, 14.01, 14.31, 45.22, 128.06, 128.38, 131.03, 141.50, 142.07,
149.97 ppm. HRMS (EI): m/z calcd ([M]þ C12H16S) 192.0973. Found:
192.0974.
d
MMAO (Al/Ti ¼ 3000) and 2 min of reaction time are employed.
e
0.25
m
mol of 1 and 1.0
m
mol of [Ph3C]þ[B(C6F5)4]ꢂ is employed (data from
reference [10]).
3.3. Compound 6
on the thiophene ring, shows a high 1-octene incorporation (entry
4, 19 mol%), but compound 14, bearing one methyl substituent on
the thiophene ring, shows a significantly lower 1-octene incorpo-
ration (entry 6; 13 mol%). All the complexes are inferior in terms of
1-octene incorporation capability to the bridged complex 1 (entry
12; 21 mol%), which can also be inferred from small Cp(centroid)e
TieN angle of 1 (106.6ꢀ).
In the case of ketimido-complexes, 13, bearing two methyl
substituent on the thiophene ring, provides higher molecular-
weight polymer than 14 [Mw, 4 64 000 (entry 3) versus Mw,
2 88 000 (entry 5)]. These molecular weights are lower than that of
polymer obtained with Cp*Ti[NC(tBu)2]Cl2 [Mw, 5 22 000 (entry 9)].
This trend is reversed in cases of phosphinimido complexes. The
complex 15 bearing two methyl substituents on the thiophene ring
provides a lower molecular-weight polymer than 16, bearing one
methyl substituent on the thiophene ring [Mw, 5 43 000 (entry 7)
versus Mw, 7 52 000 (entry 8)]. These molecular weights are higher
than that of the polymer obtained with Cp*Ti[NP(tBu)3]Cl2 [Mw,
2 04 000 (entry 11)]. When the complexes are activated with
MMAO, significantly lower molecular-weight polymers are
obtained (Mw, 27 000e90 000), probably due to a chain transfer
reaction to MMAO (entries 4, 6, and 10). The molecular weight
distributions are narrow in all cases (Mw/Mn, 2.2e3.3), indicating
a single active site.
The compound was synthesized from 4 using the same condi-
tions and procedure as those for 5. It was purified by column
chromatography on silica gel eluting with hexane and ethyl acetate
(v/v, 20:1). The product was obtained as a yellowish oil (76%).
1H NMR (C6D6):
d
6.69 (s, 1H, C]CH), 3.01 (q, J ¼ 7.6 Hz, 1H, CH),
2.53 (s, 3H, CH3), 1.99 (s, 3H, CH3), 1.93 (s, 3H, CH3), 1.21 (d, J ¼ 8 Hz,
3H, CH3) ppm. 13C{1H} NMR (C6D6):
12.09, 12.36, 15.63, 16.32,
d
45.23, 119.88, 128.13, 137.91, 141.66, 144.73, 149.79 ppm. HRMS (EI):
m/z calcd ([M]þ C11H14S) 178.0816. Found: 178.0815.
3.4. Complex 7
To a solution of 5 (5.62 g, 29.2 mmol) in hexane (56 mL) was
added nBuLi (42.8 mmol) at ꢂ30 ꢀC. After the solution was stirred
for 4 days at room temperature, the precipitates were collected by
filtration and washed with hexane. Drying at a reduced pressure
gave a yellowish solid (4.78 g, 83%). The collected solids (5.77 g,
29.1 mmol) were dissolved in THF (75 mL) and the solution was
cooled to ꢂ78 ꢀC. Trimethylsilyl chloride (4.07 mL, 32.0 mmol) was
added with a syringe. After the solution was stirred overnight at
room temperature, the solvent was removed using a vacuum line.
Pentane was added to the residue and the solution was filtered over
Celite. The filtrate was dried using a vacuum line to give a yellowish
oil (5.96 g, 77%). 1H NMR spectrum indicated a mixture of two
isomers in a 2:1 ratio. 1H NMR (C6D6):
d 2.22 (s,1H, CH3), 2.20 (s, 2H,
3. Experimental section
CH3), 2.17 (s, 2H, CH3), 2.08 (s, 2H, CH3), 2.08 (s, 1H, CH3), 1.95 (s, 1H,
CH3), 1.84 (s, 2H, CH3), 1.81 (s, 1H, CH3), 1.40 (s, 1H, CH3), 1.35 (s, 2H,
CH3), ꢂ0.04 (s, 6H, Si(CH3)3), ꢂ0.11 (s, 3H, Si(CH3)3) ppm. 13C{1H}
3.1. General remarks
NMR (C6D6):
d
ꢂ3.09, ꢂ1.32, 12.37, 12.90, 13.05, 14.08, 14.28, 14.34,
All manipulations were performed under an inert atmosphere
using standard glove box and Schlenk techniques. Toluene, hexane,
THF, diethyl ether, and CH2Cl2 were distilled from benzophenone
ketyl. Me3SiCl was dried over CaH2 and transferred under the
vacuum to reservoirs. The NMR spectra were recorded on a Varian
Mercury plus 400. Elemental analyses were carried out at the
Analytical Center, Kyunghee University. Mass spectra were
obtained on a Micromass VG Autospec. Gel permeation chro-
matograms (GPC) were obtained at 140 ꢀC in trichlorobenzene
using a Waters Model 150-Cþ GPC and the data were analyzed
14.74, 18.08, 48.84, 50.26, 125.44, 128.06, 129.81, 131.52, 133.41,
142.05, 142.49, 143.36, 143.79, 148.84, 151.00 ppm. HRMS (EI): m/z
calcd ([M]þ C15H24SSi) 264.1368. Found: 264.1369.
3.5. Compound 8
The compound was synthesized from 6 using the same condi-
tions and procedure as those for 7. The product was obtained as
a yellowish oil (98%). 1H NMR spectrum indicated a mixture of two
isomers in a 2:1 ratio. 1H NMR (C6D6):
d 6.58 (s, 0.66H, C]CH), 6.54
using a polystyrene analyzing curve. Compounds 3, 4, and (tBu)3
PSiMe3 were prepared according to the procedure and conditions
reported in the literature [6,17].
(s, 0.33H, C]CH), 2.34 (s, 2H, CH3), 2.32 (s, 1H, CH3), 1.99 (s, 1H,
CH3), 1.96 (s, 2H, CH3), 1.83 (s, 1H, CH3), 1.81 (s, 2H, CH3), 1.34 (s, 1H,
CH3), 1.32 (s, 2H, CH3), ꢂ0.07 (s, 3H, Si(CH3)3), ꢂ0.12 (s, 6H, Si
-

E.S. Park et al. / Journal of Organometallic Chemistry 696 (2011) 2451e2456
2455
(CH3)3) ppm. 13C{1H} NMR (C6D6):
15.94,16.69,16.84,17.84, 48.85, 49.60,116.83,120.40,128.51,128.96,
137.61, 140.30, 142.62, 143.35, 144.00, 145.31, 149.76, 151.31 ppm.
HRMS (EI): m/z calcd ([M]þ C14H22SSi) 250.1211. Found: 250.1211.
d
ꢂ3.12, ꢂ2.61, 12.50, 13.11, 13.23,
(t-Bu)2 (0.123 g, 0.868 mmol) in toluene (1.2 mL) at ꢂ30 ꢀC. The
prepared solution was added to a solution of 9 (0.300 g, 0.868 mmol)
in toluene (4.2 mL). After the mixed solution was stirred at room
temperature for 12 h, it was filtered over Celite. The solvent was
removed under vacuum. The compound was purified by recrystalli-
3.6. Complex 9
zation in hexane at ꢂ30 ꢀC (0.273 g, 71%). 1H NMR (C6D6):
d 2.38 (s,
3H, CH3), 2.10 (s, 3H, CH3), 2.04 (s, 3H, CH3), 2.00 (s, 3H, CH3), 1.99 (s,
To a solution of 7 (5.96 g, 22.5 mmol) in dichloromethane
(110 mL) was added TiCl4 (30.75 g, 22.53 mmol, 1 M in dichloro-
methane) at ꢂ78 ꢀC. After stirring for 5 h at room temperature, the
solvent was removed using a vacuum line. The residue was dis-
solved in toluene (80 mL) and the solution was filtered over Celite.
Removal of the solvent gave a dark black solid (4.92 g, 64%). 1H NMR
3H, CH3), 1.14 (s, 18H, C(CH3)3) ppm. 13C{1H} NMR (C6D6):
d 13.18,
14.36, 14.75, 14.96, 15.15, 31.16, 47.71, 117.62, 120.77, 126.82, 130.74,
132.69, 139.62, 140.49, 203.49 ppm. Anal. Calc. (C21H33Cl2NSTi): C,
56.01; H, 7.39; N, 3.11. Found: C, 56.30; H, 7.61; N, 3.48%.
3.11. Complex 14
(C6D6):
d
2.19 (s, 3H, CH3), 2.13 (s, 3H, CH3), 1.96 (s, 3H, CH3), 1.94 (s,
13.04, 14.62,
3H, CH3), 1.90 (s, 3H, CH3) ppm. 13C{1H} NMR (C6D6):
d
It was synthesized from 10 using the same conditions and
procedure as those for 13. It was purified by recrystallization in
15.20, 15.36, 15.90, 127.72, 127.98, 138.56, 139.77, 144.32,
145.41 ppm. Anal. Calc. (C12H15Cl3STi): C, 41.71; H, 4.38. Found: C,
41.53; H, 4.12%.
hexane at ꢂ30 ꢀC (97%). 1H NMR (C6D6):
d 6.39 (s, 1H, C]CH), 2.27
(s, 3H, CH3), 2.15 (s, 3H, CH3), 2.09 (s, 3H, CH3), 1.99 (s, 3H, CH3), 1.14
(s, 18H, C(CH3)3) ppm. 13C{1H} NMR (C6D6):
d 14.47, 15.34, 15.41,
3.7. Complex 10
17.31, 31.17, 47.75, 117.67, 118.85, 119.13, 132.49, 132.59, 139.23,
148.63, 203.40 ppm. Anal. Calc. (C20H31Cl2NSTi): C, 55.06; H, 7.16; N,
3.21. Found: C, 55.23; H, 7.35; N, 3.51%.
It was synthesized from 8 using the same conditions and
procedure as those for 10. The product was obtained as a dark black
solid (63%). 1H NMR (C6D6):
d
6.23 (s, 1H, C]CH), 2.18 (s, 3H, CH3),
2.12 (s, 3H, CH3), 2.02 (s, 3H, CH3), 1.93 (s, 3H, CH3) ppm. 13C{1H}
NMR (C6D6): 15.40, 15.94, 16.03, 17.19, 118.74, 127.84, 139.47,
3.12. Complex 15
d
A solution of (tBu)3PSiMe3 (0.251 g, 0.868 mmol) in toluene
(1.2 mL) was added to a solution of 9 (0.300 g, 0.868 mmol) in
toluene (3 mL) at ꢂ30 ꢀC. After the mixed solution was stirred for
5 h at 80 ꢀC, volatiles were removed under vacuum. The compound
was purified by recrystallization in hexane at ꢂ30 ꢀC (0.440 g, 96%).
139.83, 144.84, 153.72 ppm. Anal. Calc. (C11H13Cl3STi): C, 39.85; H,
3.95. Found: C, 39.67; H, 3.71%.
3.8. Complex 11
1H NMR (C6D6):
d 2.46 (s, 3H, CH3), 2.33 (s, 3H, CH3), 2.25 (s, 3H,
A solution of (2,6-iPr2C6H3)OLi in toluene was prepared by
mixing tert-BuLi (0.333 g, 0.868 mmol, 1.7 M in solution in pentane)
and (2,6-iPr2C6H3)OH in toluene (1.2 mL). The prepared solution
was added to a solution of 9 (0.300 g, 0.868 mmol) in toluene
(4.2 mL) at ꢂ30 ꢀC. After the mixed solution was stirred at room
temperature for 12 h, it was filtered over Celite. Solvent was
removed using a vacuum line. The compound was purified by
recrystallizion in hexane at ꢂ30 ꢀC (0.197 g, 46%). 1H NMR (C6D6):
CH3), 2.21 (s, 3H, CH3), 2.10 (s, 3H, CH3), 1.21 (d, JPH ¼ 13.2 Hz, 27H,
PC(CH3)3) ppm. 13C{1H} NMR (C6D6):
13.68, 13.92, 14.12, 14.87,
15.24, 30.32, 42.46, 42.90, 114.65, 117.87, 126.66, 126.91, 131.04,
136.86, 138.04 ppm. 31P{1H} NMR (C6D6):
46.64 ppm. Anal. Calc.
(C24H42Cl2NPSTi): C, 54.76; H, 8.04; N, 2.66. Found: C, 54.98; H,
8.22; N, 2.87%.
d
d
3.13. Complex 16
d
7.01 (d, J ¼ 7.6 Hz, 2H, meta), 6.93 (t, J ¼ 7.4 Hz, 1H, para), 3.20
(septet, J ¼ 6.8 Hz, PheCH), 2.33 (s, 3H, CH3), 2.13 (s, 3H, CH3), 1.99
(s, 3H, CH3), 1.90 (s, 3H, CH3), 1.74 (s, 3H, CH3), 1.29 (d, J ¼ 6.8 Hz, 6H,
CH(CH3)2), 1.24 (d, J ¼ 6.8 Hz, 6H, CH(CH3)2) ppm. 13C{1H} NMR
It was synthesized from 10 using the same conditions and
procedure as those for 15. It was purified by recrystallization in
hexane at ꢂ30 ꢀC. Yield was 97%. 1H NMR (C6D6):
d 6.49 (s, 1H, C]
(C6D6):
d
12.95, 13.71, 14.53, 14.76, 15.02, 24.63, 24.82, 27.99, 122.58,
CH), 2.37 (s, 3H, CH3), 2.35 (s, 3H, CH3), 2.21 (s, 3H, CH3), 2.17 (s, 3H,
123.59, 123.91, 124.23, 126.19, 132.78, 135.78, 139.86, 140.95, 143.02,
160.27 ppm. Anal. Calc. (C24H32Cl2OSTi): C, 59.15; H, 6.62. Found: C,
59.42; H, 6.53%.
CH3), 1.19 (d, JPH ¼ 13.2 Hz, 27H, PC(CH3)3) ppm. 13C{1H} NMR
(C6D6): d 14.15,14.64, 14.90,17.52, 30.25, 42.49, 42.92,115.72,117.23,
117.99, 129.51, 131.50, 135.66, 144.26 ppm. 31P{1H} NMR (C6D6):
46.98 ppm. Anal. Calc. (C23H40Cl2NPSTi): C, 53.91; H, 7.87; N, 2.73.
d
3.9. Complex 12
Found: C, 53.72; H, 7.80; N, 2.49%.
It was synthesized from 10 using the same conditions and
procedure as those for 11. It was purified by recrystallization in
3.14. Ethylene/1-octene copolymerization
hexane at ꢂ30 ꢀC (68%). 1H NMR (C6D6):
d
6.99 (d, J ¼ 7.2 Hz, 2H,
In a glove box, 30 mL of toluene solution of 1-octene (1.0 g,
0.30 M) was added to a dried 60 mL glass reactor. The reactor was
assembled, brought out from the glove box, and heated to 80 ꢀC
using a mantle. An activated catalyst was prepared by mixing the
meta), 6.90 (t, J ¼ 7.4 Hz, 1H, para), 6.04 (s, 1H, C]CH3), 3.18 (septet,
J ¼ 6.8 Hz, CH), 2.25 (s, 3H, CH3), 2.20 (s, 3H, CH3), 2.02 (s, 3H, CH3),
1.70 (s, 3H, CH3),1.27 (d, J ¼ 6.8 Hz, 6H, CH(CH3)2),1.25 (d, J ¼ 6.8 Hz,
6H, CH(CH3)2) ppm. 13C{1H} NMR (C6D6):
d
13.80, 15.42, 15.57, 16.79,
complex (1.0
m
mol), (iBu)3Al (0.20 mmol), and [C(C6H5)3]þ[B
24.55, 24.70, 28.07, 115.99, 123.07, 123.76, 123.85, 124.23, 134.31,
135.54, 139.52, 139.74, 151.20, 159.89 ppm. Anal. Calc.
(C23H30Cl2OSTi): C, 58.36; H, 6.39. Found: C, 58.67; H, 6.43%.
(C6F5)4]ꢂ (4.0
mmol) or MMAO-4 (Akzo, 7.0 wt% Al in toluene, Al/
Ti ¼ 3000) for 5 min. After the activated catalyst was added with
a syringe, the ethylene gas (60 psig) was fed immediately. After
polymerization was conducted for 2 or 3 min, the ethylene gas was
vented. Methanol (10 mL) was added immediately. Concentrated
aqueous HCl (10 mL) was added and the two-phase solution was
stirred for 1 h. With the ketimido-complexes, the toluene phase was
collected and solvent was removed using a rotary evaporator to
3.10. Complex 13
A solution of LiN]C(t-Bu)2 in toluene was prepared by mixing
tert-BuLi (0.333 g, 0.868 mmol,1.7 M solution in pentane) and HN]C

2456
E.S. Park et al. / Journal of Organometallic Chemistry 696 (2011) 2451e2456
Table 3
Acknowledgments
Crystallographic parameters of 11, 14, and 16a.
This work was supported by Mid-carrier Researcher Program
11
14
16
(No. 2010-0000360) and by Priority Research Centers Program
(2010-0028294) through NRF grant funded by the MEST of Korean
government.
Formula
Fw
a, Å
b, Å
c, Å
C24H32Cl2OSTi C20H31Cl2NSTi C23H40Cl2NPSTi
487.36
9.8772(6)
14.1347(9)
18.2093(13)
90
107.1329(19)
90
2429.4(3)
monoclinic
P21/c
436.31
512.39
17.2415(10)
8.7086(4)
19.1042(10)
90
13.5458(15)
90
2629.6(2)
monoclinic
P21/n
8.5606(4)
11.6136(4)
12.0684(5)
78.6898(11)
69.0316(13)
82.9022(14)
1096.75(8)
triclinic
P-1
a
, deg
, deg
Appendix. Supplementary material
b
g
, deg
CCDC Nos. 796171 (11); 800660 (14); 802055 (16) contain the
supplementary crystallographic data for this paper. Crystallo-
graphic data for structural analysis have been deposited with the
Cambridge Crystallographic Data Center . Copies of this information
may be obtained free of charge form The Director, CCDC, 12, Union
Road, Cambridge CB2 1EZ, UK (fax: þ44 1223 336033: e-mail:
deposit@ccdc.cam.ac.uk or www: http://www.ccdc.cam.ac.uk).
V, Å3
Crystal system
Space group
D(calc), g cmꢂ1
Z
1.332
1.321
1.294
4
2
4
m
, mmꢂ1
0.671
0.732
0.679
No. of data collected
No. of unique data [R(int)] 4280[0.0279]
No. of variables
R(%)
Rw(%)
18091
15660
24147
4996[0.0310]
350
6008[0.0620]
418
262
0.0469
0.1225
1.041
0.0460
0.1496
1.117
0.0593
0.1681
1.053
References
Goodness of fit
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aData collected at 150(2)
K
with Mo
K
a
radiation
(l(K
a
)
¼
0.7107 Å), R
(I), Rw ¼ [S[w(Fo ꢂFc2)2]/S[w(Fo)2]2]1/2 with
2
(F) ¼ SjjFojꢂjFcjj/SjFoj with Fo > 2.0
s
F
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were calculated by the analysis of the 1H NMR spectra of the
copolymers. In the 1H NMR spectra, the methyl (CH3) signal
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be calculated from the integration values of the two regions.1H NMR
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3.15. X-ray crystallography
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mounted onto a thin glass fiber with epoxy glue and placed in
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diffractometer. The structures were solved by direct methods
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