2698 Organometallics, Vol. 25, No. 10, 2006
Notes
) 125 Hz, indicating sp3-hybridization of the C(1) atom.20 The
phenyl rings of the CHPh2 unit in 2 are twisted, corresponding
to a torsion angle of 40.3°, which is smaller than the torsion
angles in Cp2Zr(CHPh2)2 and Cp2Hf(CHPh2)2 (Zr: 57.8° and
Hf: 56.8°).12
Experimental Section
General Remarks. Commercially available reagents were of
reagent-grade quality and were used as received. 1H and 13C NMR
spectra were recorded on a Bruker ARX 200 or 400 spectrometer.
Lu analyses were performed by complexometric titration with
EDTA as an indicator.
KCHPh2 (1). The compound was prepared according to the
method of Schlosser11 by adding a solution of nBuLi in hexane
(11.6 mL, 1.6 mol/L, 18.56 mmol) to a suspension of tBuOK (2.10
g, 18.71 mmol) and CH2Ph2 (3.14 g, 18.66 mmol) in hexane. The
immediately formed orange precipitate of 1 is separated after 30
min by decantation, washed with toluene and hexane, and dried in
a vacuum. Yield: 3.58 g (93%). 1H NMR (200 MHz, d5-pyridine,
25 °C): δ 7.27-7.08 (m, 8H, Ho/m), 6.28 (tt, J ) 3.4 Hz, J ) 1.2
Hz, 2H, Hp), 5.23 (s, 1H, CH). 13C NMR (100.64 MHz, d5-pyridine,
25 °C): δ 146.3 (s, Ci), 128.8 (d, J ) 152 Hz, Cm), 117.3 (d, J )
152 Hz, Co), 107.2 (d, J ) 159 Hz, Cp), 81.5 (d, J ) 146 Hz,
CHPh2).
Figure 2. Interactions between the K atoms and the phenyl rings
in [1(THF)0.5]∞.
Lu(CH2SiMe3)2(CHPh2)(THF)2 (2). A solution of LiCH2SiMe3
(0.51 g, 5.42 mmol) in pentane (20 mL) was added dropwise to a
stirred suspension of LuCl3(THF)3 (1.37 g, 2.75 mmol) in a solvent
mixture of THF (1 mL), pentane (10 mL), and diethyl ether (20
mL). After stirring the mixture for 2 h, it was cooled to 0 °C. Then
an orange solution of KCHPh2 (1) (0.57 g, 2.76 mmol) in THF (4
mL) was added. After stirring the mixture for a further 30 min, it
was filtered and the solvents were evaporated in a vacuum. The
dark orange, oily residue was extracted with cold pentane. The
filtered extract was slowly concentrated in a vacuum at room
temperature. On cooling the concentrated solution to -78 °C, light
yellow microcrystalline 2 (0.58 g, 32%) precipitated. Mp: 100-
Figure 3. Molecular structure of 2 (30% probability thermal
ellipsoids); hydrogen atoms (except H(1)) have been omitted for
clarity. Selected bond lengths [Å] and angles [deg]: Lu-C(1)
2.449(4), Lu-C(14) 2.346(4), Lu-C(18) 2.344(4), Lu-O(1) 2.306-
(3), Lu-O(2) 2.301(3), C(1)-C(2) 1.460(6), C(1)-C(8) 1.464(5),
C(1)-Lu-C(14) 132.81(15), C(1)-Lu-C(18) 114.09(14), C(14)-
Lu-C(18) 112.96(16), O(1)-Lu-O(2) 176.50(10), O(1)-Lu-C(1)
83.58(12), O(1)-Lu-C(14) 92.99(12), O(1)-Lu-C(18) 90.04(14),
O(2)-Lu-C(1) 93.47(12), O(2)-Lu-C(14) 90.40(12), O(2)-Lu-
C(18) 89.44(14), C(2)-C(1)-C(8) 124.6(3), C(2)-C(1)-Lu 100.4-
(2), C(8)-C(1)-Lu 110.0(3).
1
105 °C (dec). H NMR (400 MHz, C6D6, 25 °C): δ 6.82-7.20
(m, 10H, C6H5), 3.64 (s, 4H, R-CH2, THF), 3.10 (s, 1H, CHPh2),
1.22 (quint, 4H, â-CH2, THF), 0.28, 0.24 (s’s, ratio 1:1.5, 18H,
SiCH3), -0.86, -0.90 (s, ratio 1.5:1, 4H, CH2SiMe3). 13C NMR
(100.64 MHz, C6D6, 25 °C): δ 146.6, 129.4, 123.5, 119.8 (C6H5),
1
75.7 (d, J (13C1H ) 126 Hz, CHPh2), 70.8 (R-CH2, THF), 41.6,
41.1 (CH2SiMe3), 25.0 (â-CH2, THF), 4.7, 4.5 (SiCH3). Anal. Calcd
for C29H49LuO2Si2 (660.84): Lu, 26.48. Found: Lu 26.65.
X-ray Crystal Structure Determination. Crystal data were
collected on a Siemens SMART CCD diffractometer (graphite-
monochromated Mo KR radiation, λ ) 0.71073 Å) by use of ω
scans at 173 K. The structures were solved by direct methods and
refined on F2 using all reflections with the SHELX-97 software
package.21 The non-hydrogen atoms were refined anisotropically.
Hydrogen atoms (except H(1) in 1) were placed in calculated
positions and assigned to an isotropic displacement parameter of
0.08 Å2. The positional and isotropic thermal parameters of the
hydrogen atom H(1) in 1 were refined without constraints. SADABS
was used to perform area-detector scaling and absorption correc-
tions.22 Crystal data for 1: MF ) C30H30K2O; Mw ) 484.74, 0.52
× 0.22 × 0.20 mm3, orthorhombic, Fdd2 (No. 43), a ) 22.1371-
(5) Å, b ) 13.9116(1) Å, c ) 16.2626(4) Å, Z ) 8, V ) 5008.27-
Lu-C(18): 2.34 Å), which in their turn are slightly shorter than
the average value of the corresponding bond lengths in Lu-
(CH2SiMe3)3(THF)2 (2.36 Å).14 However, they agree well with
the Lu-C distances in [Li(THF)3][(C5Me5)Lu(CH2SiMe3)(CH-
(SiMe3)2)Cl] (2.31 and 2.34 Å),16 [Lu(CH2SiMe3)2(crown)-
(THF)x][B(CH2SiMe3)Ph3] (2.34-2.37 Å; [12]-crown-4, x )
1; [15]-crown-5, x ) 0; [18]-crown-6, x ) 0),17 Cp2Lu(CH2-
SiMe3)(THF) (2.38 Å),18 and [LuCl(2,6-(Me2NCH2)2C6H3)(CH2-
SiMe3)]2) (2.39 Å).19 The axis O-Lu-O is almost linear
(176.5°), and the C-Lu-O angles are all close to 90°. In
contrast to 1, the benzhydryl unit is bent, showing the C(1) atom
tetrahedrally coordinated by the lutetium atom, the two phenyl
groups, and the hydrogen atom. This tetrahedral ligand arrange-
ment is also maintained in solutuion, as proved by 1J(13C(1)1H)
(16) van der Heijden, H.; Pasman, P.; de Boer, E. J. M.; Schaverien, C.
J.; Orpen, A. G. Organometallics 1989, 8, 1459-1467.
(17) Arndt, S.; Spaniol, T. P.; Okuda, J. Chem. Commun. 2002, 896-
897.
(18) Schumann, H.; Genthe, W.; Bruncks, N.; Pickardt, J. Organome-
tallics 1982, 1, 1194-1200.
(19) Hogerheide, M. P.; Grove, D. M.; Boersma, J.; Jastrzebski, J. T. B.
H.; Kooijman, H.; Spek, A. L.; van Koten, G. Chem. Eur. J. 1995, 1, 343-
350.
(20) Hesse, M.; Meier, B.; Zeeh, B. Spektroskopische Methoden in der
Organischen Chemie, 3. Auflage; Thieme Verlag: Stuttgart, 1997.
(21) Sheldrick, G. M. SHELXL-97, Program for Crystal Structure
Refinement; Universita¨t Go¨ttingen: Go¨ttingen, Germany, 1997. Sheldrick,
G. M. SHELXS-97, Program for Crystal Structure Solution; Universita¨t
Go¨ttingen: Go¨ttingen, Germany, 1997.
(22) Sheldrick, G. M. SADABS, Program for Empirical Absorption
Correction of Area Detector Data; Universita¨t Go¨ttingen: Go¨ttingen,
Germany, 1996.