Dialkyl titanium complexes that contain a sulfur-linked bis(phenolato) ligand: The structure of an olefin polymerization catalyst precursor

Article abstract of DOI:10.1016/S0022-328X(02)01802-8

The sulfur-linked bis(phenol)2,2∥-thiobis(2-tert-butyl-4- methylphenol), tbmpH₂, reacted cleanly with titanium tetrachloride to give the orange titanium dichloro complex [Ti(tbmp)Cl₂]₂ in virtually quantitative yield. Reac

Full text of DOI:10.1016/S0022-328X(02)01802-8

Journal of Organometallic Chemistry 663 (2002) 158ꢁ163
/
www.elsevier.com/locate/jorganchem
Dialkyl titanium complexes that contain a sulfur-linked
bis(phenolato) ligand:
The structure of an olefin polymerization catalyst precursor
Stefan Fokken, Frank Reichwald, Thomas P. Spaniol, Jun Okuda ꢀ
Institut fur Anorganische Chemie und Analytische Chemie, Johannes Gutenberg-Universitat, Duesbergweg 10-14,
¨
D-55099 Mainz, Germany
¨
Received 31 May 2002; accepted 31 July 2002
Dedicated to Professor Pascual Royo on the occasion of his 65th birthday
Abstract
The sulfur-linked bis(phenol) 2,2?-thiobis(2-tert-butyl-4-methylphenol), tbmpH2, reacted cleanly with titanium tetrachloride to
give the orange titanium dichloro complex [Ti(tbmp)Cl2]2 in virtually quantitative yield. Reaction of the dichloro complex
[Ti(tbmp)Cl2]2 with methyllithium at low temperature gave the unexpectedly thermally robust, yellow dimethyl complex
[Ti(tbmp)Me2]. The reaction of the dichloro complex with benzyl Grignard reagent in pentane afforded the highly crystalline
dibenzyl complex [Ti(tbmp)(CH2Ph)2] as a 1,4-dioxane adduct. The single crystal X-ray crystallography revealed a centrosymmetric
1,4-dioxane-bridged molecule that contains two fragments containing six-coordinate titanium centers with the tridentate tbmp
ligand in a facial fashion and two h1-benzyl ligands. When [Ti(tbmp)Me2] was activated with B(C6F5)3 in toluene, ethylene was
polymerized.
# 2002 Elsevier Science B.V. All rights reserved.
Keywords: Titanium; Phenolato ligands; Alkyl complexes; Polymerization catalysts
1. Introduction
experimental data for the actual catalysts remains
relatively scarce. This is partly due to the difficulty to
prepare, to isolate, and to structurally characterize the
dialkyl derivatives of the type [Ti(tbmp)R2], not to
mention the alkyl cations. We report here the synthesis
and structure of two dialkyl complexes [Ti(tbmp)R2]
Among the ancillary ligand systems introduced to
develop non-metallocene a-olefin polymerization cata-
lysts [1], the sulfur-linked dianionic ligand based on 2,2?-
thiobis(2-tert-butyl-4-methylphenol), tbmpH2, was one
of the earliest examples [2]. Titanium complexes that
contain a tbmp ligand were shown to be remarkably
versatile olefin polymerization catalysts precursors when
activated by methylaluminoxane [3,4]. Theoretical cal-
(RꢃMe, CH2Ph) that contain a tbmp ligand, along
/
with experiments aimed at generating the alkyl cations
[Ti(tbmp)R]ꢂ.
culations have suggested that the titaniumꢁsulfur inter-
/
action in the putative intermediate [Ti(tbmp)Me(H2CÄ
/
2. Results and discussion
CH2)]ꢂ results in the relative decrease of the olefin
insertion barrier, thus higher polymerization activity [5].
Although the thioether coordination of the tbmp ligand
As was previously reported [3,6], the reaction of
titanium tetrachloride in toluene with 2,2?-thiobis(2-
tert-butyl-4-methylphenol), tbmpH2, results in the clean
formation of dark brown dichloro complex
[Ti(tbmp)Cl2] (1) which is dimeric according to an X-
ray structure analysis [6e]. In contrast to the sparingly
soluble dinuclear di(isopropoxy) derivative [Ti(tbm-
was recognized in various titanium complexes [6ꢁ8],
/
ꢀ Corresponding author. Tel.: ꢂ
3925605
E-mail address: okuda@mail.uni-mainz.de (J. Okuda).
/
49-6131-3925333; fax: ꢂ49-6131-
/
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 8 0 2 - 8

S. Fokken et al. / Journal of Organometallic Chemistry 663 (2002) 158ꢁ
/163
159
p)(OiPr)2]2 [6a,6b,7], the dichloro complex 1 readily
dissolves in basic solvents such as THF and DMSO.
Previously 1 was isolated as a diethyl ether solvate [3].
By carefully removing the solvent from THF solutions
of 1, analytically pure mono(THF) adduct
[Ti(tbmp)Cl2(THF)] (1a or 1b) could be isolated in
quantitative yield (Scheme 1). Although structural
characterization was not performed, we give preference
to the cis isomer 1a, since in the trans isomer 1b the
strong p-donor ligands O and Cl would be trans to each
other.
The dimethyl complex 2 could be crystallized from
aliphatic hydrocarbons, but the single crystal that was
obtained showed only very poor diffraction of X-rays.
Data collection was performed at ꢄ80 8C. The crystal
/
solution showed a structure between a trigonal biypra-
mid and square pyramid with a titanium center bearing
a tridentate tbmp ligand and two inequivalent methyl
groups [9]. The titaniumÃ
/
sulfur bond distance of over
˚
2.8 A is among the longest in titanium complexes
containing the tbmp ligand [6,7]. Compared with the
dimethyl titanium complex that contain the methylene-
The reaction of the dichloro complex [Ti(tbmp)Cl2]
bridged bis(phenolato) ligand [{2,2?-CH2(OC6H2Ã
MeÃ6-tBu)2}TiMe2] [10], however, the presence of a
titaniumꢁsulfur interaction is evident from the confor-
mation of the eight-membered chelate ring. Due to the
very low quality of the experimental data, details from
the structure analysis are not discussed further.
The reaction of 1 with benzyl Grignard reagent
Mg(CH2Ph)Br in pentane resulted in the clean forma-
tion of the dibenzyl complex [Ti(tbmp)(CH2Ph)2] which
/
4-
(1) with methyllithium below ꢄ
/
40 8C in pentaneꢁ
/
/
diethyl ether gave an orange solution that decomposed
rapidly above 0 8C to a black intractable reaction
mixture of unknown composition. Continued experi-
mentation, however, eventually resulted in the isolation
of yellow crystalline dimethyl complex [Ti(tbmp)Me2]
(2). It was crucial to perform the work-up as quick as
possible. The dimethyl complex 2 appears to be some-
what stabilized in ethereal solutions and unexpectedly
robust in pure state. In solution, it started to decompose
only above 70 8C. The NMR spectra of 2 indicate a
structure with Cs-symmetry in solution (Scheme 2). The
two methyl groups are inequivalent, giving rise to two
/
could only be isolated as
a
1,4-dioxanate
[Ti(tbmp)(CH2Ph)2]2(m-C4H8O2) (3) (Scheme 2). Well-
formed crystals could be readily isolated from pentane
solutions and a crystal structure analysis was performed.
Fig. 1 shows an ORTEP diagram and Table 1 lists selected
bond parameters. In the lattice, two [Ti(tbmp)(CH2Ph)2]
fragments are connected by a 1,4-dioxane molecule in a
1
singlets at 1.22 and 1.51 ppm in the H-NMR spectra
and to two quartets at 64.1 (1JCH
ꢃ
/
122 Hz) and 66.4
124 Hz) in the 13C-NMR spectra. No
ppm (1JCH
ꢃ
/
coalescence of these signals was observed up to 70 8C,
suggesting that an exchange of the two methyl position
is associated with a high energy barrier.
Scheme 1.
Scheme 2.

160
S. Fokken et al. / Journal of Organometallic Chemistry 663 (2002) 158ꢁ163
/
[6f]. The titaniumÃ
/
oxygen bond distances are 1.822(1)
˚
and 1.893(1) A and comparable with the bond length of
˚
average 1.892(2) A found in [Ti(tbmp)(OiPr)2]2 [6a,6b,7]
˚
or 1.865(2) A in [{2,2?-N(CH2CH2OMe)(OC6H2Ã
/4,6-
tBu2)2}Ti(CH2Ph)2] [11]. The relatively large difference
in the two bond lengths is due to the trans-influence of
the benzyl group. A similar situation was previously
found in [Ti(tbmp){C6H4(CH2NMe2)-2}Cl] (1.831(3),
˚
1.879(3) A) [6a,6b]. The two monohapto bonded benzyl
groups are arranged in a cis-position with titaniumÃ
/
˚
carbon bond lengths of 2.170(3) and 2.115(2) A. They
are somewhat longer than titaniumÃcarbon distances
found in other dibenzyl titanium complexes such as
[Ti{2,2?-(OC6H2Ã6-tBuÃ4-OMe)2}(CH2Ph)2}] (2.08(1)
A) [3] and [Ti{2,2?-CH2OCH2(OC6H2Ã6-tBuÃ4-
/
/
/
˚
/
/
˚
Me)2}(CH2Ph)2] (2.086(5) and 2.109(4) A) [12]. The
angles at the a-carbon atoms are remarkably large with
116.1(2) and 121.8(2)8 and may reflect the considerable
steric crowding of the ligand sphere around the octahe-
dral titanium center.
According to the solution NMR spectra in CDCl3 at
room temperature, the 1,4-dioxane molecule is engaged
in a fast dissociative equilibrium on the NMR time
scale, as can be seen from the sharp singlet at 3.66 ppm
for all six protons. Furthermore, the two benzyl groups
at the five-coordinate ligand sphere give rise to two
separate sets of signals. Thus, two sharp singlets are
recorded at 25 8C in C6D6 at 3.24 and 3.29 ppm. They
remain inequivalent up to 65 8C, when the two singlets
of the benzylic coalesce. The observation that the
benzylic methylene protons are singlets further corro-
Fig. 1. ORTEP drawing of the molecular structure of 3. Hydrogen
atoms are omitted for clarity. Key atoms are labeled.
borates
the
presence
of
a
Cs-symmetric
[Ti(tbmp)(CH2Ph)2] species. All attempts at isolating a
pure Lewis-base free [Ti(tbmp)(CH2Ph)2] failed,
although a dark red oil of this composition was
previously reported [3].
Table 1
˚
Selected bond lengths (A) and angles (8) for [Ti(tbmp)(CH2Ph)2]2(m-
C4H8O2) (3)
The reaction of the dimethyl complex 2 with the
Lewis-acidic activators B(C6F5)3, [NPhMe2H][B(C6F5)4]
or [Ph3C][B(C6F5)4] in bromobenzene or dichloro-
methane remained inconclusive due to considerable
Bond lengths
TiÃO1
TiÃO3
TiÃC30
1.893(1)
2.233(1)
2.115(2)
TiÃO2
TiÃC23
TiÃS
1.822(1)
2.170(3)
2.8699(6)
decomposition above ꢄ
solution formed in such reactions reproducibly poly-
merized ethylene, albeit in low yield. Even at ꢄ80 8C
was it not possible to record reasonable NMR spectra,
since only broad, featureless signals were observed. At
this time we conclude that the tetra-coordinated alkyl
cation [Ti(tbmp)Me]ꢂ as the putative catalyst must be
extremely electrophilic and unstable. The five-coordi-
/
20 8C. However, the dark red
Bond angles
O1ÃTiÃO2
O1ÃTiÃC23
O1ÃTiÃS
O2ÃTiÃC23
O2ÃTiÃS
O3ÃTiÃC30
C23ÃTiÃS
C23ÃTiÃC30
C31ÃC30ÃTi
94.47(6)
149.17(9)
72.30(4)
95.68(7)
74.66(4)
98.91(8)
82.48(8)
103.4(1)
121.8(2)
O1ÃTiÃO3
O1ÃTiÃC30
O2ÃTiÃO3
O2ÃTiÃC30
O3ÃTiÃC23
O3ÃTiÃS
81.41(5)
104.6(1)
165.86(6)
95.22(8)
81.69(7)
91.21(4)
168.90(8)
116.1(2)
/
C30ÃTiÃS
C24ÃC23ÃTi
nate, 10-electron dialkyl complexes [Ti(tbmp)R2] (Rꢃ
/
Me, CH2Ph) themselves exhibit high Lewis-acidity and
easily add a Lewis-base such as an ether molecule to
form octahedral, 12-electron complexes. Finally, we
note that the related five-coordinate bis(anilido) di-
methyl complex [{(tBu-d6-N-o-C6H4)2O}TiMe2] exhi-
bits a trigonal biyramidal structure in the solid state, but
is fluxional in solution [13].
centrosymmetric fashion. In each of the fragment the
tbmp ligand is bonded to the octahedral titanium(IV)
center in a facial fashion with a titaniumÃ
/
sulfur distance
˚
of 2.8699(6) A. This bond distance is only surpassed by
5
˚
the value of 2.907(1) A found in [Ti(tbmp)(h -C5H5)Cl]

S. Fokken et al. / Journal of Organometallic Chemistry 663 (2002) 158ꢁ
/163
161
1
C(CH3)3), 35.1 (s, C(CH3)3), 75.0 (t, JCH
3. Experimental
ꢃ/156 Hz,
1
THF), 129.9 (s, C-2), 129.9 (d, JCH
ꢃ/154 Hz, C-5),
3.1. General considerations
131.4 (d, 1JCH
6), 164.8 (s, C-1). Anal. Calc. for C26H36Cl2O3STi: C,
57.05; H, 6.63. Found: C, 57.09; H, 6.45%.
ꢃ/162 Hz, C-3), 132.1 (s, C-4), 136.8 (s, C-
All manipulations were carried out under Ar atmo-
sphere in a glovebox or by using the standard Schlenk
techniques in oven-dried glassware. The solvents Et2O,
C6H5CH3, THF, n-C6H14 and n-C5H12 were dried by
3.4. [Ti(tbmp)Me2] (2)
refluxing over sodiumꢁ
/
bezophenone and CH2Cl2 over
A supension of [Ti(tbmp)Cl2] (1) (2.0 g, 4.2 mmol) in
50 ml of C5H12 was treated with methyllithium in Et2O
CaH2 under an inert gas and distilled freshly before use.
Titanium tetrachloride was purchased from Acros and
used without further purification. tbmpH2 was prepared
according to literature [14]. H- and 13C-NMR spectra
were recorded on a Bruker DRX 400 spectrometer (1H:
400 MHz; 13C: 100 MHz) at 25 8C. C6D6, THF-d8,
C6D5Br and CDCl3 were purchased from Deutero and
purified by conventional methods before use. The
chemical shifts were referenced internally according to
the residual solvent resonances and reported relative to
Me4Si. Mass spectra were obtained on a Finnigan 8230
spectrometer. Elemental analysis was performed by the
Microanalytical Laboratory of this department.
(5.3 ml, 8.4 mmol) ꢄ44 8C. The reaction mixture was
/
warmed to room temperature (r.t.) and was stirred for 1
h during which time the color turned yellow. After rapid
extraction of the residue with 20 ml of C5H12 and
filtration, the combined filtrates were concentrated to 15
1
ml. Cooling to ꢄ30 8C afforded 0.5 g of yellow
/
1
microcrystals (29%). H-NMR (C6D6): d 1.56 (s, 18H,
C(CH3)3), 1.59 (s, 3H, TiCH3), 1.73 (s, 3H, TiCH3), 1.97
4
(s, 6H, 4-CH3), 7.04 (d, 2H, JHH
ꢃ0.5 Hz, 5-C6H2),
/
ꢃ
7.32 (d, 2H, 4JHH 0.5 Hz, 3-C6H2). 1H-NMR (CDCl3):
d 1.22 (s, 3H, TiCH3), 1.51 (s, 3H, TiCH3), 1.52 (s, 18H,
/
C(CH3)3), 2.26 (s, 6H, 4-CH3), 7.11 (s, 2H, 5-C6H2), 7.35
(s, 2H, 3-C6H2). 13C-NMR (CDCl3): dꢃ
/
20.8 (pt q,
3
126.5 Hz, JCH
3.2. [Ti(tbmp)Cl2]2 (1)
1JCH
1JCH
2JCH
ꢃ
/
ꢃ
/
4.4 Hz, 4-CH3), 29.6 (m q,
3
126.0 Hz, JCH
1
3.7 Hz, C(CH3)3), 64.1 (q, JCH
ꢃ
/
ꢃ4.7 Hz, C(CH3)3), 35.3 (m,
/
Titanium tetrachloride (5.0 ml, 45.6 mmol) was slowly
added to a stirred solution of tbmpH2 (16.4 g, 45.6
mmol) in 60 ml of C6H5CH3. Hydrogen chloride formed
was vented through a valve. After 15 h the precipitation
of the product was complete. The solvent was removed
and the product was dried in vacuo to give 20.2 g (42.6
mmol, 93%) of dark brown microcrystals. 1H-NMR
ꢃ
/
ꢃ
/122.4 Hz,
1
TiCH3), 66.4 (q, JCH
1
C6H2), 129.9 (m d, JCH
ꢃ/123.6 Hz, TiCH3), 125.8 (s, 2-
3
ꢃ
/
154.3 Hz, JCH
6.1 Hz, 6-C6H2), 132,7 (m d,
4.4 Hz, 3-C6H2), 136.8 (s, 4-
4.4 Hz, 1-C6H2). EI MS: m/z
ꢃ
/
4.5 Hz, 5-
2
C6H2), 131.2 (q, JCH
ꢃ
ꢃ
ꢃ
/
1JCH
C6H2), 164.0 (pt, JCH
ꢃ
/
/
3
160.7 Hz, JCH
3
/
419 (100%, [Mꢂꢄ
/
Me]), 404 (89%, [Mꢂꢄ
2Me]), 358
/
(Me2SO-d6, 25 8C): d 1.32 (s, 18H, C(CH3)3), 2.12 (s,
(54%, tbmpHꢂ); 149 (45%, C4H9C6H4Oꢂ), 57 (91%,
2
4
6H, 4-CH3), 6.84 (d, JHH
ꢃ/1.7 Hz, 2H, C6H2-5), 6.94
C4Hꢂ9 ): Anal. Calc. for C24H34O2STi (434.5): C, 66.35;
H, 7.89; S, 7.38. Found: C, 65.33; H, 7.80; S, 7.72%.
4
(d, JHH
ꢃ
/
1.7 Hz, 2H, C6H2-3). 13C{1H}-NMR
1
(Me2SO-d6, 25 8C): d 20.4 (q, JCH
ꢃ126.2 Hz, 4-
/
1
CH3), 29.4 (q, JCH
C(CH3)3), 121.9 (s, C-2), 127.5 (d, JCH
5), 128.7 (s, C-4), 130.7 (d, 1JCH
172.9 Hz, C-3), 137.4
(s, C-6), 151.9 (s, C-1). EI MS: m/z 474 (62%, [M]ꢂ),
459 (6%, [Mꢄ
CH3]ꢂ), 439 (5%, [MꢄCl]ꢂ), 424 (100%,
[MꢄCH3,
2CH3]2ꢂ), 204
ꢃ
/
125.8 Hz, C(CH3)3), 34.5 (s,
3.5. [Ti(tbmp)(CH2Ph)2]2(1,4-C4H8O2) (3)
1
ꢃ147.0 Hz, C-
/
ꢃ
/
To a solution of [Ti(tbmp)Cl2] (1) (2.0 g, 4.2 mmol) in
50 ml of C5H12 was added a solution of benzyl
magnesium bromide (5.8 ml, 1.44 M, 8.4 mmol) in
/
/
/
Ã
/
Cl]ꢂ), 222 (15%, [Mꢄ
/
THF at ꢄ34 8C. The cooling bath was removed and
/
(22%), 57 (31%, [C4H9]ꢂ). Anal. Calc. for
C22H28Cl2O2STi: C, 55.59; H, 5.94. Found: C, 55.48;
H, 6.04%.
after stirring for 40 min 1,4-dioxane (0.9 ml, 84 mmol)
was added. The dark red solution was stirred for 30 min
at r.t. Filtration, concentration to 4 ml, and cooling to
ꢄ30 8C afforded dark red crystals; yield 1.25 g (51%).
/
3.3. [Ti(tbmp)Cl2(THF)] (1a)
1H-NMR (C6D6): d 1.51 (s, 18H, C(CH3)3), 2.10 (s, 6H,
4-CH3), 3.24 (s, 2H, CH2Ph), 3.29 (s, 2H, CH2Ph), 3.34
3
The adduct was isolated in quantitative yield as dark
red crystals by dissolving [Ti(tbmp)Cl2] (1) in THF and
(s, 4H, C4H8O2), 6.74 (t, JHH
ꢃ
/
7.4 Hz, 1H, para-
7.1 Hz, 2H, ortho-
7.6 Hz, 3H, meta- and
para-CH2C6H5), 7.03 (d, JHH 1.6 Hz, 2H, 5-C6H2),
1.6 Hz, 2H, 3-C6H2), 7.32 (t, 2H,
3
CH2C6H5), 6.91 (d, JHH
ꢃ
/
1
3
removing the solvent at ꢄ
/
78 8C in vacuo. H-NMR
CH2C6H5), 6.97 (pt, JHH
ꢃ
/
4
(CDCl3): d 1.37 (s, 18H, C(CH3)3), 2.02 (m, 4H, THF),
2.25 (s, 6H, 4-CH3), 4.41 (m, 4H, THF) 7.04 (d, 4JHH
ꢃ
/
4
ꢃ
/
7.24 (d, JHH
3JHH
ꢃ
/
1.7 Hz, 2H, 5-H) 7.16 (d, 4JHH
ꢃ
ꢃ
/
1.7 Hz, 2H, 3-H). 13C-
127 Hz, 4-CH3), 25.5
ꢃ
/
7.4 Hz, meta-CH2C6H5), 7.44 (d, 2H, JHH
ꢃ
/
3
1
NMR (CDCl3): d 20.9 (q, JCH
/
7.9 Hz, ortho-CH2C6H5). 1H-NMR (CDCl3): d 1.43
(s, 18H, C(CH3)3), 2.21 (s, 6H, 4-CH3), 2.94 (s, 2H,
1
(t, JCH
1
134 Hz, THF), 29.4 (q, JCH
ꢃ
/
ꢃ
/
126 Hz,

162
S. Fokken et al. / Journal of Organometallic Chemistry 663 (2002) 158ꢁ163
/
CH2Ph), 3.03 (s, 2H, CH2Ph), 3.66 (s, 4H, C4H8O2),
3
Copies of this information may be obtained free of
charge from The Director, CCDC, 12 Union Road,
6.71 (d, JHH
3JHH
ꢃ7.1 Hz, 2H, ortho-CH2C6H5), 6.76 (t,
/
3
7.4 Hz, 1H, para-CH2C6H5), 6.97 (pt, JHH
ꢃ
/
ꢃ
/
Cambridge CB2 1EZ, UK (Fax: ꢂ44-1223-336033; or e-
/
7.6 Hz, 3H, meta- and para-CH2C6H5), 7.03 (d, 4JHH
ꢃ
/
mail: deposit@ccdc.cam.ac.uk or www: http://
www.ccdc.cam.ac.uk).
4
1.6 Hz, 2H, 5-C6H2), 7.21 (d, JHH
ꢃ1.6 Hz, 2H, 3-
/
C6H2), 7.25 (m, 4H, ortho- and meta-CH2C6H5).
13C{1H}-NMR (CDCl3):
d
20.8 (4-CH3), 29.8
(C(CH3)3), 35.2 (C(CH3)3), 67.0 (C4H8O2), 90.0
(CH2C6H5), 97.4 (CH2C6H5), 123.0 (para-CH2C6H5),
123.5 (para-CH2C6H5), 126.2 (2-C6H2), 127.1 (meta-
CH2C6H5), 127.7 (meta-CH2C6H5), 128.5 (ortho-
CH2C6H5), 128.6 (ortho-CH2C6H5) 129.8 (5-C6H2),
131.3 (4-C6H2), 132.5 (3-C6H2), 136.8 (6-C6H2), 143.4
(ipso-CH2C6H5), 146.7 (ipso-CH2C6H5), 164.6 (1-
Acknowledgements
This work was supported by the German Federal
Ministry of Education and Research, BASF AG, and
the Fonds der Chemischen Industrie. Professor Pascual
Royo is thanked for his long lasting friendship and his
great hospitality.
C6H2). EI MS: m/z 495 (13%, [Mꢂꢄ
C7H7]), 91
/
(100%, C7Hꢂ7 ): Anal. Calc. for C76H92O6S2Ti2
(1261.4): C, 72.36; H, 7.35; S, 5.08. Found: C, 72.92;
H, 7.05; S, 5.22%.
References
[1] G.J.P. Britovsek, V.C. Gibson, D.F. Wass, Angew. Chem. Int.
Ed. Engl. 38 (1999) 428.
3.6. X-ray crystal structure analysis of 3
[2] (a) T. Miyatake, K. Mizunuma, Y. Seki, M. Kakugo, Macromol.
Chem. Rapid Commun. 10 (1989) 349;
Single crystals suitable for X-ray crystal structure
analysis were obtained by cooling of concd. C6H14
(b) T. Miyatake, K. Mizunuma, M. Kakugo, Macromol. Chem.
Macromol. Symp. 66 (1993) 203.
solutions to ꢄ
Mrꢃ1261.44, triclinic, 0.18ꢅ
(No. 2), aꢃ9.525(1), bꢃ11.858(1), cꢃ
aꢃ101.124(2), bꢃ 100.815(2), gꢃ112.274(2)8, Vꢃ
1748.6(3) A , Zꢃ2/2, rcalc Ka
1.198 Mg mꢄ3, Moꢁ
0.71073 A), Bruker AXS diffractometer, semi-
empirical absorption correction, Tꢃ193 K, v scans,
38Bu B288, F(000)ꢃ672, m(MoꢁKa)ꢃ
0.338 mmꢄ1
/
30 8C. Crystal data: C76H92O6S2Ti2,
[3] A. van der Linden, C.J. Schaverien, N. Meijboom, C. Ganter,
A.G. Orpen, J. Am. Chem. Soc. 117 (1995) 3008.
¯
/
/
0.461ꢅ0.795 mm, P1
/
˚
/
/
/
17.800(2) A,
[4] (a) F.G. Sernetz, R. Mulhaupt, S. Fokken, J. Okuda, Macro-
¨
molecules 30 (1997) 1562;
/
/
/
/
3
(b) J. Okuda, E. Masoud, Macromol. Chem. Phys. 199 (1998) 543.
[5] (a) R.D.J. Froese, D.G. Musaev, T. Matsubara, K. Morokuma, J.
Am. Chem. Soc. 119 (1997) 7190;
˚
/
ꢃ
/
/
˚
(lꢃ
/
/
(b) R.D.J. Froese, D.G. Musaev, K. Morokuma, Organometallics
18 (1999) 373.
/
/
/
/
/
,
[6] (a) S. Fokken, T.P. Spaniol, H.-C. Kang, W. Massa, J. Okuda,
Organometallics 15 (1996) 5069;
number of reflections measured 15 690, 8327 indepen-
dent reflections. The structure was solved by direct
methods (SHELXS-86) [15] and refined (SHELXL-97) [16]
(b) S. Fokken, Doctoral Thesis, University of Marburg, 1995.;
(c) J. Okuda, S. Fokken, H.-C. Kang, W. Massa, Polyhedron 17
(1998) 943;
against all F2 data, resulting in R1ꢃ
0.099 for all observed reflections with I ꢀ
ness-of-fitꢃ0.933.
/
0.0426 and wR2ꢃ
/
/2s(I), good-
(d) S. Fokken, T.P. Spaniol, J. Okuda, F.G. Sernetz, R.
Mulhaupt, Organometallics 16 (1997) 4240;
¨
/
(e) Y. Nakayama, K. Watanabe, N. Ueyama, A. Nakamura, A.
Harada, J. Okuda, Organometallics 19 (2000) 2498;
(f) F. Amor, S. Fokken, T. Kleinhenn, T.P. Spaniol, J. Okuda, J.
Organomet. Chem. 621 (2001) 3.
3.7. Ethylene polymerization by [(tbmp)TiMe2] (2)
A Schlenk tube (50 ml) with B(C6F5)3 (20 mg, 39
mmol) was evacuated and filled with ethene (1 bar).
After addition of 9 ml of C6H5CH3 the solution was
stirred for 5 min and a solution of complex 2 (10 mg, 23
mmol) in 1.5 ml of C6H5CH3 was added. The polymer-
ization was stopped after 5 min by adding 1 ml of
methanolic HCl and the polymer was precipitated from
MeOH. Filtration and drying overnight in vacuo at r.t.
gave 24 mg of polyethylene.
[7] L. Porri, A. Ripa, P. Colombo, E. Miano, S. Capelli, S.V. Meille,
J. Organomet. Chem. 514 (1996) 213.
[8] For a leading reference on transition metal complexes containing
the tbmp ligand, see: P.L. Arnold, L.S. Natrajan, J.J. Hall, S.J.
Bird, C. Wilson, J. Organomet. Chem. 647 (2002) 205.
[9] The following lattice parameters were found: aꢃ
/
24.701(4), bꢃ
/
˚
8.1540(3), cꢃ
/
11.903(8) A, bꢃ/104.112(6)8, tentative space group
P21/c (No. 14); T.P. Spaniol, F. Reichwald, J. Okuda, unpub-
lished results.
[10] (a) C. Floriani, F. Corazza, W. Lesueur, A. Chiesi-Villa, C.
Guastini, Angew. Chem. Int. Ed. Engl. 28 (1989) 66;
(b) J. Okuda, S. Fokken, H.-C. Kang, W. Massa, Chem. Ber. 128
(1995) 221.
[11] E.Y. Tshuva, I. Goldberg, M. Kol, Z. Goldschmidt, Chem.
Commun. (2001) 2120.
[12] V. Reimer, T.P. Spaniol, J. Okuda, H. Ebeling, A. Tuchbreiter, R.
4. Supplementary material
Crystallographic data for the structural analysis have
been deposited with the Cambridge Crystallographic
Data Centre, CCDC no. 193062 for compound 3.
Mulhaupt, Inorg. Chim. Acta, in press.
¨
[13] (a) R. Baumann, R. Stumpf, W.M. Davis, L.-C. Liang, R.R.
Schrock, J. Am. Chem. Soc. 121 (1999) 7822;

S. Fokken et al. / Journal of Organometallic Chemistry 663 (2002) 158ꢁ
/163
163
(b) R. Baumann, W.M. Davis, R.R. Schrock, J. Am. Chem. Soc.
119 (1997) 3830.
[15] G.M. Sheldrick, SHELXS-86, A Program for Crystal Structure
Solution, University of Gottingen, Germany, 1986.
¨
[16] G.M. Sheldrick, SHELXL-97, A Program for Crystal Structure
Refinement, University of Gottingen, Germany, 1997.
¨
[14] T.K. Prakasha, R.O. Day, R.R. Holmes, J. Am. Chem. Soc. 115
(1993) 2690.