Organometallics
Article
Me3SiC4SiMe3]+; 402 [M−Me3SiC4SiMe3−fluorenone]+; 220
[Cp2Zr]+; 180 [fluorenone]+. Single crystals of 6 for the X-ray
diffraction study were not washed and were not dried in vacuo and
contained one benzene molecule per two molecules of 6.
colorless solution was filtered and evaporated to dryness. The residue
was dissolved in 5 mL of warm acetone, and the solution was filtered
and allowed to stand at room temperature. The next day, the
precipitated colorless crystals of cyclooctatetraene 13 were separated
by decanting of the mother liquor, washed with cold acetone, and
dried in vacuo. The subsequent sublimation in vacuo at 160 °C gave
analytically pure 13. Yield of 13: 0.160 g (30% based on the starting
1).
(12): Mp: > 300 °C. Anal. Calcd for C44H32O4Zr2: C, 65.47; H,
4.00. Found: C, 65.60; H 4.19%. Because of very low solubility of
complex 12 in conventional solvents, its NMR spectra could not be
measured. MS (70 eV, m/z): 402 [1/2M]+; 220 [Cp2Zr]+; 182
[acenaphthenequinone]+.
Synthesis of Complex 10. Complex 1 (0.500 g, 0.819 mmol)
and 0.516 g (2.460 mmol) of benzil were dissolved in 20 mL of
benzene, and the obtained mixture was heated at 80 °C for 30 h to
afford complex 10 in 85% yield according to 1H NMR spectrum. After
carrying the reaction, the resulting solution was evaporated to dryness
in vacuo, and the solid residue underwent a multiple recrystallization
from a benzene/n-hexane (1:3) mixture to give yellow-green crystals
of complex 10, containing also small amounts of cocrystallized benzil
1
as an admixture according to H NMR spectrum (δ 6.95, 7.06, 7.89
(13): Mp: 220−222 °C under Ar. Anal. Calcd for C40H72Si8: C,
61.78; H, 9.33. Found: C, 61.95; H 9.11. 1H NMR (296 K, benzene-
d6, δ, ppm): 0.18 (s, 36H, SiMe3); 0.58 (s, 36H, SiMe3). 13C NMR
(296 K, benzene-d6, δ, ppm): − 0.7 (SiMe3); − 0.4 (SiMe3); 101.4,
105.2 (CC); 135.7, 151.5 (C=C). MS (70 eV, m/z): 673 [M−
SiMe3 − 2Me]+; 615 [M−2SiMe3−Me]+; 603 [M−SiMe3−4Me]+;
585 [M−2SiMe3−3Me]+; 527 [M−3SiMe3−2Me]+; 453 [M−
4SiMe3−2Me+H]+; 73 [SiMe3]+. Single crystals of 13 suitable for
the X-ray diffraction study were grown from n-hexane and were not
washed and were not dried in vacuo.
ppm). Yield of the isolated 10: 0.035 g (5%). Mp: 151−152 °C (dec.)
(under Ar). Anal. Calcd for C44H56O2Si4Zr: C, 64.41; H, 6.88. Found:
C, 63.86; H, 6.72. Although these results are outside the range viewed
as establishing analytical purity, they are provided to illustrate the best
values obtained to date. 1H NMR (296 K, benzene-d6, δ, ppm): 0.04,
0.21, 0.52, 0.74 (s, 9H each, SiMe3); 6.06, 6.11 (s, 5H, Cp); 6.98 (m,
4H m-Ph); 7.12 (m, 2H, p-Ph); 7.45 (m, 4H, o-Ph). 13C NMR (296
K, benzene-d6, δ, ppm): − 0.5, − 0.2, 0.7, 3.7 (SiMe3); 94.7, 97.2,
103.3, 109.2 (CC); 111.9, 112.3 (Cp); 127.2, 127.9, 128.1, 128.2,
128.7, 129.7 (CH arom.); 133.4, 135.8, 136.7, 138.0, 139.3, 139.9,
154.2 (CC, Cipso); 208.2 (CC−Zr). MS (70 eV, m/z): 430 [M−
2Me3SiC4SiMe3]+; 414 [M−2Me3SiC4SiMe3−O]+; 220 [Cp2Zr]+.
Single crystals of 10 for the X-ray diffraction study were obtained by a
multiple recrystallization of the above-mentioned solid residue from a
benzene/n-hexane (1:1) mixture, were not washed and were not dried
and contained one cocrystallized benzil molecule per two molecules
of 10.
Synthesis of Complex 11. Complex 1 (0.482 g, 0.79 mmol) was
dissolved in 15 mL of toluene at room temperature and 0.287 g (1.58
mmol) of acenaphthenequinone was added to the solution. After 3
days, the reaction mixture became dark maroon. After 30 days, the
solution was filtered and evaporated to dryness. The red-brown
residue was washed with n-hexane and dissolved in 5 mL of toluene at
70 °C after which the obtained toluene solution was filtered and
cooled to −40 °C. The next day, the precipitated bright-red crystals of
complex 11 were separated by decanting of the mother liquor, washed
with n-hexane, and dried in vacuo. Yield of 11: 0.540 g (70%). Mp:
249−253 °C (dec.) under Ar. Anal. Calcd for C54H58O4Si4Zr: C,
66.55; H, 6.00. Found: C, 66.43; H, 5.78. 1H NMR (296 K, benzene-
d6, δ, ppm): − 0.44 (s, 9H, SiMe3); 0.30 (s, 9H, SiMe3); 0.46 (s, 9H,
SiMe3); 0.72 (s, 9H, SiMe3); 5.42 (s, 5H, Cp); 6.48 (s, 5H, Cp);
7.26−7,44 (m, 7H, arom.); 7.51−7.56 (m, 2H, arom.); 7.66 (m, 1H,
arom.); 7.97 (m, 1H, arom.); 7.99 (m, 1H, arom.). 13C NMR (296 K,
benzene-d6, δ, ppm): − 1.2, 0.1, 0.9, 1.5 (SiMe3); 101.9, 104.3, 104.7,
106.6 (CC); 112.2, 115.2, (Cp); 118.3, 119.7, 121.5, 121.6, 125.1,
125.2, 126.9, 127.3, 128.5, 129.0, 131.1 (CH, arom.); 95.9, 121.9,
122.5, 131.2, 132.7, 133.4, 135.3, 136.5, 137.2, 142.7, 144.1, 149.0,
149.7, 163.8 (Cq arom. and CC); 201.3 (CO), two signals of
complex 11 are screened by a signal from C6D6. IR (ν, cm−1): 2135,
2122 (CC), 1728 (CO), 1574 (CC). MS (70 eV, m/z): 570
[M−acenaphthenequinone−Cp2Zr]+; 402 [Cp2Zr+acenaphthenequi-
none]+; 220 [Cp2Zr]+. Single crystals of 11 suitable for the X-ray
diffraction study were not washed and were not dried in vacuo.
Synthesis of 12 and 13. Complex 1 (0.816 g, 1.337 mmol) was
dissolved in 30 mL of toluene at 80 °C and to the resulting solution
was slowly added a warm solution of 0.300 g (1.646 mmol) of
acenaphthenequinone in 20 mL of toluene. The mixture was heated at
80 °C for 1 h, and after cooling, the deposited dark red crystals of
complex 12 were filtered, washed twice with n-hexane, then with
THF, and dried in vacuo. Yield of 12: 0.210 g (39% based on the
starting 1). The obtained dark-red filtrate was evaporated to dryness,
the residue was washed with 20 mL of warm n-hexane, then with 50
mL of warm toluene, and dried in vacuo. The resulting toluene extract
containing 11 was concentrated in vacuo to 5 mL and allowed to
stand at −40 °C, which resulted in the deposition of 11. Yield of 11:
0.520 g (65% based on the starting acenaphthenequinone). The
obtained n-hexane solution was passed through alumina, the resulting
Synthesis of Diels−Alder Adduct 16. Complex 1 (0.873 g,
1.430 mmol) , 0.338 g (1.859 mmol) of acenaphthenequinone, and
0.94 mL (11.444 mmol) of cyclopentadiene were added to 20 mL of
benzene, and the obtained mixture was heated under stirring at 60 °C
for 2 h. Then, the resulting dark-red solution was filtered off and
evaporated in vacuo to dryness. The solid residue was extracted with
40 mL of n-hexane, the obtained extract was passed through alumina,
filtered, and evaporated to dryness. The residue was then sublimated
in vacuo at 70 °C to afford colorless crystals of Diels−Alder adduct
16. Yield of 16: 0.098 g (15%). M.p.: 70−71 °C. Anal. Calcd for
1
C25H42Si4: C, 66.00; H, 9.31. Found: C, 66.04; H, 9.26. H NMR
(296 K, benzene-d6, δ, ppm): 0.13 (s, 9H, SiMe3); 0.19 (s, 9H,
SiMe3); 0.31 (s, 9H, SiMe3); 0.44 (s, 9H, SiMe3); 1.83 (m, 1H, CH);
2.06 (m, 1H, CH); 2.76 (br., 1H, CH2); 2.85 (br., 1H, CH2); 5.90
(dd, J5.2, 3.1 Hz, 1H, CH); 6.09 (dd, J5.2, 3.0 Hz, 1H, CH). 13C
NMR (296 K, benzene-d6, δ, ppm): −1.6 (SiMe3), −1.2 (SiMe3),
−0.2 (SiMe3), 0.1 (SiMe3), 46.6, 52.7, 54.4 (CH and CH2); 50.4, 57.4
(Cq); 88.5, 101.8, 102.3,110.6, (CC), 131.8, 134.5 (=CH), 148.3,
160.7 (=C). MS (70 eV, m/z): 454 [M]+; 439 [M−Me]+; 381 [M−
SiMe3]+; 311 [M−2SiMe3]+; 73 [SiMe3]+.
X-ray Diffraction Study. Single-crystal X-ray diffraction experi-
ments were carried out with a Bruker SMART APEX II diffractometer
(graphite monochromated Mo−Kα radiation, λ = 0.71073 Å, ω-scan
technique). The APEX II software41 was used for collecting frames of
data, indexing reflections, determination of lattice constants,
integration of intensities of reflections, scaling, and absorption
correction. All calculations (space group and structure determination,
refinements, graphics, and structure reporting) were made using the
SHELXTL201442 and OLEX243 program packages. The structures
were solved by direct methods and refined by the full-matrix least-
squares technique against F2 with the anisotropic thermal parameters
for all non-hydrogen atoms. Positions of hydrogen atoms were
calculated, and all were included in the refinement by the riding
model with Uiso(H) = 1.5Ueq(X) for hydrogen atoms of methyl
groups and water molecules, and Uiso(H) = 1.2Ueq(X) for other
atoms. Crystals of 5 and 10−12 were two-component twins; in each
case, the intensities were separated into two domains using the
PLATON package,44 and the structures were then refined using
BASF/HKLF 5 SHELXTL instructions. Crystallographic data for 5−7
ASSOCIATED CONTENT
■
S
* Supporting Information
The Supporting Information is available free of charge on the
I
Organometallics XXXX, XXX, XXX−XXX