42
Y. Wang et al. / Journal of Organometallic Chemistry 683 (2003) 39Á43
/
meter. 1H-NMR spectra were recorded on a Bruker
DPX 300 spectrometer at 300.13 MHz. 11B-NMR
spectra were recorded on a Varian Inova 400 spectro-
meter at 128.32 MHz. All chemical shifts are reported in
d units with references to the residual protons of the
deuterated solvents for proton chemical shifts, and to
3.4. Preparation of {[h5:s-
Me2C(C5H4)(C2B10H10)]Zr(NMe2)}2{h2:h2-
(C6H5CÄCÄCÄCC6H5)}×THF (5×THF)
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/
To
a
toluene solution (50 ml) of [h5:s-
Me2C(C5H4)(C2B10H10)]Zr(NMe2)2 (4; 0.75 g, 1.76
mmol) was added HCCC6H5 (0.36 g, 3.52 mmol) at
room temperature and the reaction mixture was stirred
for 4 days, leading to a suspension. After removal of
part of solvent (ca. 20 ml), the pale-yellow precipitate
was collected by filtration and washed with hexane (5
external BF3×
/
OEt2 (0.0 ppm) for boron chemical shifts.
Elemental analyses were performed by MEDAC Ltd,
Brunel University, Middlesex, UK.
mlꢃ3) to give 5 as a pale-yellow solid (0.35 g, 38%).
Single-crystals suitable for X-ray analyses were obtained
1
by recrystallization from a THF/toluene solution. H-
/
3.2. Preparation of [h5:s-
Me2Si(C9H6)(C2B10H10)]Zr(m-Me)2AlMe2(NMe2)
(2)
NMR (pyridine-d5): d 7.58 (m, 4H), 7.50 (m, 4H), 7.34
(m, 2H) (CCC6H5), 6.31 (m, 4H), 5.62 (m, 4H) (C5H4),
3.63 (m, 4H, THF), 2.95 (s, 12H) (N(CH3)2), 1.58 (m,
4H, THF), 1.65 (s, 12H) ((CH3)2C). 11B-NMR (pyri-
A 2.0 M solution of AlMe3 in n-hexane (2.50 ml, 5.00
mmol) was slowly added to a toluene (30 ml) solution of
[h5:s-Me2Si(C9H6)(C2B10H10)]Zr(NMe2)2 (1; 0.50 g,
dine-d5): d ꢂ
/
4.28 (2), ꢂ
/
6.35 (2), ꢂ
/
9.91 (4), ꢂ11.82 (2).
/
IR (KBr, cmꢂ1): n 3050 (m), 2973 (m), 2874 (m), 2568
(vs), 1637 (w), 1475 (m), 1259 (m), 1048 (s), 925 (w), 807
(s), 747 (m). Anal. Found: C, 49.31; H, 6.57; N, 2.69.
C40H62B20N2Zr2 (5) Calc.: C, 49.55; H, 6.45; N, 2.89%.
1.01 mmol) with stirring at ꢂ30 8C, resulting in the
/
formation of a yellow suspension. This solution was
then stirred at room temperature overnight. After
removal of ca. 15 ml of solvent, the resultant precipitate
was collected and washed with n-hexane (20 mlꢃ
giving 2 as a yellow solid (0.27 g, 50%). 1H-NMR
(C6D6): d 7.60 (d, Jꢀ7.5 Hz, 1H, indenyl), 7.08Á6.90
(m, 3H, indenyl), 6.10 (d, Jꢀ3.6 Hz, 1H, indenyl), 5.90
(d, Jꢀ3.6 Hz, 1H, indenyl), 2.74 (s, 6H, NMe2), 0.43 (s,
3H, SiMe2), 0.29 (s, 3H, SiMe2), ꢂ0.40 (s, 6H, ZrMe2),
0.64 (s, 6H, AlMe2). 11B-NMR (C6D6): d ꢂ
1.45 (2B),
2.80 (2B), ꢂ8.55 (4B), ꢂ
11.93 (2B). IR (KBr, cmꢂ1):
n 3066 (w), 2958 (m), 2905 (m), 2870 (m), 2563 (vs), 1412
(m), 1257 (m), 1086 (s), 1047 (m), 808 (s). Anal. Found:
C, 42.31; H, 7.72; N, 2.45. C19H40AlB10NSiZr Calc.: C,
42.50; H, 7.50; N, 2.61%.
/
3)
3.5. Ethylene polymerization
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/
/
This experiment was carried out in a 150 ml-glass
reactor equipped with a magnetic stirrer and gas inlets.
The reactor was charged with 2 (3.0 mmol) together with
MMAO (4.5 mmol) and toluene (50 ml). The mixture
was stirred at 60 8C for 0.5 h. Ethylene gas was then
introduced to the reactor and its pressure was main-
tained continuously at 1 atm by means of bubbling. The
polymerization was terminated by addition of acidic
ethanol (100 ml). The white precipitate was filtered off
and washed with ethanol and acetone. The resulting
powder was finally dried in a vacuum oven at 80 8C
overnight (4.49 g).
/
/
ꢂ
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ꢂ
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/
3.3. Preparation of {[h5:s-
Me2Si(C9H6)(C2B10H10)]Zr}2(m-O){m-
3.6. X-ray structure determination
N[AlMe2(THF)]}×
/
0.5(C7H8) (3×/0.5C7H8)
All single-crystals were immersed in Paraton-N oil
and sealed under N2 in thin-walled glass capillaries.
Data were collected at 293 K on a Bruker SMART 1000
Recrystallization of 2 (0.10 g, 0.18 mmol) from THF/
toluene (1:5, 15 ml) at room temperature afforded 3×
0.5C7H8 as pale-yellow crystals over weeks (28 mg,
30%). 1H-NMR (C6D6): d 7.80 (d, Jꢀ
8.5 Hz, 2H,
indenyl), 7.12Á6.80 (m, 8H, indenylꢁphenyl), 6.30 (d,
Jꢀ3.6 Hz, 2H, indenyl), 6.10 (d, Jꢀ3.6 Hz, 2H,
/
CCD diffractometer using MoÁKa radiation. An em-
/
/
pirical absorption correction was applied using the
SADABS program [18]. Both structures were solved by
direct methods and subsequent Fourier difference tech-
niques and refined anisotropically for all non-hydrogen
atoms by full-matrix least squares calculations on F2
using the SHELXTL program package [19]. Most of the
carborane hydrogen atoms were located from difference
Fourier syntheses. All other hydrogen atoms were
geometrically fixed using the riding model. Note that
thermal parameters of the solvated THF molecules in 5
are high, indicating disorder problems, which cause the
/
/
/
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indenyl), 3.65 (m, 4H, THF), 2.04 (s, 1.5H, C6H5CH3),
1.61 (m, 4H, THF), 0.55 (s, 6H, SiMe2), 0.43 (s, 6H,
SiMe2), ꢂ
/
0.75 (s, 6H, AlMe2). 11B-NMR (C6D6): d ꢂ
/
1.48 (2B), ꢂ
/
2.93 (2B), ꢂ
/
8.72 (4B), ꢂ12.03 (2B). IR
/
(KBr, cmꢂ1): n 3071 (w), 2962 (m), 2915 (m), 2865 (m),
2560 (vs), 1417 (m), 1262 (m), 1078 (s), 1056 (m), 821 (s).
Anal. Found: C, 42.21; H, 6.30; N, 1.25. C35.5H62AlB20-
NO2Si2Zr2 Calc.: C, 41.94; H, 6.15; N, 1.38%.
Wang, Yaorong
