1314
M.-X. Li et al. / Polyhedron 30 (2011) 1313–1317
1H NMR (400 MHz, CDCl3): 7.41–7.38 (m, 2H, Ph-H), 7.31–7.27
Ph
(m, 3H, Ph-H), 2.27 (s, 6H, C5-Me), 2.04 (s, 6H, C5-Me) ppm. 13C
NMR (100 MHz, CDCl3): 131.3, 129.0, 128.3, 128.1, 126.5, 123.3,
105.5, 95.4, 82.6, 12.8, 12.5 ppm. MS (EI): m/z 601.9 (17, M+),
221.1 (10, CpI+), 380.9 (40, M+ꢁCpI).
Ph
Ph
Ph
Ph
Ph
ZrCl2
Ph
ZrCl2
Ph
6
7
2.5. Preparation of CpICp⁄ZrCl2 (3)
Chart 1.
To a solution of CpIH (2.526 g, 11.36 mmol) in hexane (70 mL)
was gradually added nBuLi (11.42 mmol, 2.33 M in hexane) at
0 °C. Then it was slowly warmed to room temperature and stirred
overnight. The resulting suspension was filtered and evaporated to
dryness. Cp⁄ZrCl3 (3.781 g, 11.36 mmol) was added to the lithium
salt, the flask was cooled to ꢁ78 °C, and methylene chloride
(120 mL) was slowly added. After stirring overnight, the solution
was filtered through Celite. The solvent was removed in vacuo,
and the crude product was recrystallized from a mixture of diethyl
ether and hexane to give a pale yellow solid. Yield: 1.768 g (30%).
M.p. 141–142 °C. Anal. Calc. for C27H32Cl2Zr: C, 62.52; H, 6.22.
Found: C, 62.32; H, 6.31%. 1H NMR (400 MHz, CDCl3): 7.55–7.51
(m, 2H, Ph-H), 7.40–7.31 (m, 3H, Ph-H), 2.09 (s, 6H, C5-Me), 2.08
(s, 15H, Cp⁄), 2.03 (s, 6H, C5-Me) ppm. 13C NMR (100 MHz, CDCl3):
131.0, 130.1, 128.6, 128.3, 124.7, 123.3, 105.1, 95.8, 83.3, 12.7, 12.3,
11.8 ppm. MS (EI): m/z 516.0 (30, M+), 381.0 (95, M+ꢁCp⁄), 295.0
(40, M+ꢁCpI), 221.2 (17, CpI+), 135.1 (5, Cp⁄+).
THF (80 mL) was gradually added nBuLi (84.15 mmol, 1.67 M in
hexane) at 0 °C. After it was slowly warmed to room temperature
and stirred for 5 h, a solution of 2,3,4,5-tetramethylcyclopent-2-
enone (11.630 g, 84.15 mmol) in THF (30 mL) was added dropwise.
The reaction mixture was stirred overnight and then quenched
with saturated NH4Cl aqueous solution (30 mL). The aqueous layer
was extracted with diethyl ether, and the combined organics were
dried over Na2SO4. After removal of solvents the residue was dis-
solved in diethyl ether (100 mL), H2SO4 (3 M, 70 mL) was added,
and then this mixture was stirred overnight. The reaction mixture
was again quenched with a saturated NH4Cl aqueous solution, sep-
arated, extracted with diethyl ether, and dried. After removal of
solvents the residue was chromatographed over a silica gel column
with hexane as eluent to give 8.044 g (43%) of CpIH as yellow oil.
Anal. Calc. for C17H18: C, 91.84; H, 8.16. Found: C, 91.64; H,
8.36%. 1H NMR (400 MHz, CDCl3): d 7.35 (br d, J = 5.1 Hz, 2H, Ph-
H), 7.18 (t, J = 7.5, 6.6 Hz, 3H, Ph-H), 2.77 (br d, J = 3.7 Hz, 1H,
C5H), 1.96 (s, 3H, C5-Me), 1.77 (s, 3H, C5-Me), 1.69 (s, 3H, C5-Me),
1.10 (d, J = 5.5 Hz, 3H, C5-Me) ppm. 13C NMR (100 MHz, CDCl3): d
159.3, 149.2, 143.4, 134.5, 131.0, 128.2, 127.2, 102.0, 95.4, 86.7,
51.5, 14.4, 13.4, 12.1, 10.8 ppm. MS (EI): m/z 222.2 (100, M+).
2.6. Preparation of CpIICp⁄ZrCl2 (4)
By using a similar procedure to that described above, reaction of
CpIIH with nBuLi and Cp⁄ZrCl3 afforded complex 4 in 38% yield as
yellow solid. M.p. 195–196 °C. Anal. Calc. for C25H28Cl2Zr: C,
61.20; H, 5.75. Found: C, 61.23; H, 5.89%. 1H NMR (400 MHz,
CDCl3): 7.49–7.46 (m, 2H, Ph-H), 7.37–7.33 (m, 3H, Ph-H), 6.25
(s, 2H, C5H2), 2.08 (s, 15H, Cp⁄), 2.05 (s, 6H, C5-Me) ppm. 13C
NMR (100 MHz, CDCl3): 131.2, 128.4, 127.6, 124.9, 123.0, 120.7,
100.6, 91.1, 83.3, 13.3, 12.3 ppm. MS (EI): m/z 353.0 (72, M+ꢁCp⁄),
295.0 (86, M+ꢁCpII), 135.1 (7, Cp⁄+).
2.3. Preparation of CpI2TiCl2 (1)
To a solution of CpIH (4.479 g, 20.15 mmol) in hexane (120 mL)
was gradually added nBuLi (20.04 mmol, 2.33 M in hexane) at 0 °C.
Then it was slowly warmed to room temperature and stirred over-
night. The resulting suspension was filtered and evaporated to dry-
ness. THF (100 mL) and TiCl4ꢀ2THF (3.346 g, 10.02 mmol) were
added to the reaction mixture through a cannula at ꢁ78 °C and
the reaction mixture was stirred at room temperature overnight.
After removal of solvent under reduced pressure the residue was
extracted with CH2Cl2 and the solution was filtered through Celite.
The solvent was removed in vacuo, and the crude product was
recrystallized from a mixture of diethyl ether and hexane. About
2.756 g (49%) of 1 was obtained as red crystals. M.p.: 179–180 °C.
Anal. Calc. for C34H34Cl2Ti: C, 72.74; H, 6.10. Found: C, 72.51; H,
5.99%. 1H NMR (400 MHz, CDCl3): d 7.55 (m, 2H, Ph-H), 7.34 (m,
3H, Ph-H), 2.47 (s, 6H, C5-Me), 2.28 (s, 6H, C5-Me) ppm. 13C NMR
(100 MHz, CDCl3): 135.0, 134.2, 131.9, 128.7, 128.3, 122.7, 118.3,
98.9, 82.2, 14.4, 13.4 ppm. MS (EI): m/z 221.1 (100, CpI+), 339.0
(20, M+ꢁCpI).
2.7. Preparation of CpIIICp⁄ZrCl2 (5)
By using a similar procedure to that described above, reaction of
CpIIIH with nBuLi and Cp⁄ZrCl3 afforded complex 5 in 32% yield as
yellow solid. M.p. 277–278 °C. Anal. Calc. for C35H32Cl2Zr: C,
68.38; H, 5.25. Found: C, 68.32; H, 5.31%. 1H NMR (400 MHz,
CDCl3): 7.52 (m, 2H, Ph-H), 7.38 (m, 7H, Ph-H and C5-Ph), 7.28
(m, 6H, Ph-H and C5-Ph), 6.72 (s, 2H, C5H2), 1.89 (s, 15H, Cp⁄)
ppm. 13C NMR (100 MHz, CDCl3): 132.7, 131.4, 130.0, 128.6,
128.5, 128.0, 127.7, 125.9, 122.8, 103.2, 92.4, 82.9, 12.1 ppm. MS
(EI): m/z 612.1 (11, M+), 476.9 (7, M+ꢁCp⁄), 295.0 (20, M+ꢁCpIII).
2.8. Crystallographic studies
2.4. Preparation of CpI2ZrCl2 (2)
Single crystals of complex 2 suitable for X-ray diffraction were
obtained from hexane/Et2O solution at ꢁ20 °C. Data collections
were performed with a Rigaku Saturn 70 diffractometer equipped
with a rotating anode system at 113(2) K by using graphite-mono-
To a solution of CpIH (4.572 g, 20.56 mmol) in hexane (120 mL)
was gradually added nBuLi (20.50 mmol, 2.33 M in hexane) at 0 °C.
Then it was slowly warmed to room temperature and stirred over-
night. The resulting suspension was filtered and evaporated to dry-
ness. ZrCl4 (2.389 g, 10.25 mmol) was added to the lithium salt, the
flask was cooled to ꢁ78 °C, and CH2Cl2 (150 mL) was slowly added.
After stirring overnight, the solution was filtered through Celite.
The solvent was removed in vacuo, and the crude product was
recrystallized from a mixture of diethyl ether and hexane to give
yellow-green crystals. Yield: 2.480 g (40%). M.p.: 144–145 °C. Anal.
Calc. for C34H34Cl2Zr: C, 67.52; H, 5.67. Found: C, 67.32; H, 5.31%.
chromated Mo K
a
radiation (
x
ꢁ 2h scans, k = 0.71073 Å). Semi-
empirical absorption corrections were applied. The structure was
solved by direct methods and refined by full-matrix least squares.
All calculations were performed by using the SHELXL-97 program
system. All non-hydrogen atoms were refined anisotropically.
Hydrogen atoms were assigned idealized positions and were in-
cluded in structure factor calculations. The crystal data and sum-
mary of X-ray data collection are presented in Table 1.