380
F. Cervantes-Lee et al. / Journal of Organometallic Chemistry 686 (2003) 379Á382
/
butyllithium solution (1.7-M in pentane) over a period
of 20 min. The solution became a bright yellow and was
permitted to stir for 1 h. At this time a solution of 19.3 g
(0.05 mol) of Ph3SnCl was added slowly (20 min) at the
same temperature. The solution was stirred and per-
mitted to warm slowly to room temperature and then
was treated with 50 ml of hexanes to facilitate precipita-
tion of LiCl. Four washings with a saturated solution of
NH4Cl were followed by separation of the organic layer.
After drying with MgSO4 overnight, filtration and
removal of the solvent produced a white solid material.
This was recrystallized from a mixture of methylene
chloride and hexane to yield 13.9 g (0.025 mol, 50%) of
208 minꢁ1. Background counts were taken with a
stationary crystal and total background time to scan
time ratio of 0.5. Three standard reflections were
monitored every 97 reflections and showed an intensity
decay of less than 2% which was considered acceptable.
The collection was conducted over slightly more than
one quadrant of reciprocal space, in the range ꢁ
/
195
/
h 50, 05k 59, ꢁ185l 519 for a total of 3641
/
/
/
/
/
/
reflections which after merging equivalents produced a
set of 3510 unique reflections with an reliability para-
meter Rint
and polarization effects and a semi-empirical absorption
ꢀ1.46%. The data were corrected for Lorentz
/
correction was also applied.
Me3Si(Me3Ge)(Ph3Sn)CH (2), m.p. 96Á
/
98 8C. NMR
data, (CDCl3, ppm): H: 0.11 (s, 1H, CH), 0.13 (s, 6H,
SiMe3); 0.24 (s, 6H, GeMe3), 7.57Á7.72 (m, 5H, C6H5);
29Si: 3.49 (2JSiÃSn 26 Hz); 119Sn: ꢁ
86.7.
In a similar manner the permethylated silylgermyl-
stannylmethane, Me3Si(Me3Ge)(Me3Sn)CH (1) was
produced in 62% yield, purified by distillation at
72 8C/0.1 mmHg; Anal.(Galbraith Laboratories), Calc.
1
2.3. Structure refinement
/
ꢀ
/
/
Analysis of the data set based on cell parameters,
systematically absent reflections and counting statistics
lead to selection of space group P21/c (no. 14). The
structure was solved by direct methods and refined by
full-matrix least-squares, based on F2, in a PC using the
SHELEX-97 public domain software package. All hydro-
(Found): C, 32.66 (33.01); H, 7.67 (8.00): NMR (CDCl3,
1
ppm): H: ꢁ
0.18 (SnMe3,
/
0.60 (CH), 0.03 (SiMe3); 0.12 (GeMe3),
117
gen atoms were placed at calculated positions with CÃ
/
H
119
J
ꢀ
/
74 Hz,
J
ꢀ
/
77 Hz,): 13C:
1.35 (CH), 3.15
SnÃH
SnÃH
˚
bond distances of 0.96 A and average isotropic thermal
parameters of 0.08. For the last cycle of refinement of
268 parameters and 3510 reflections, the maximum and
minimum residual electron densities were 0.306 and
ꢁ
/
5.58 (SnMe3, JCÃSn
ꢀ
/
320 Hz), ꢁ
/
(SiMe3), 3.28 (GeMe3): 29Si: 2.69 (2JSiÃSn
ꢀ26.5 Hz);
/
119Sn: 12.1.
Using the known PhMe2Si(GeMe3)CH2 [4] as starting
material in the same manner as above, Me2PhSi(Me3-
Ge)(Me3Sn)CH (3) was obtained in 72% yield as a
3
˚
0.443 electrons per A and the final R-values, as
ꢁ
/
defined in SHELEX-97, were Rꢀ
/
0.0395 and Rwꢀ0.0650
/
for all data. The structure of 2 is presented in Fig. 1.
The germanium and silicon atoms are statistically
distributed in two atomic positions in ca. 50/50% ratio.
Pertinent crystallographic data are given in Table 1, and
selected bond angles and lengths in Table 2.
colorless oil purified by distillation at 108Á
/
110 8C at
0.05 mmHg. Anal: Calc. (Found) C, 41.9 (42.2), H, 7.04
(6.93); NMR (CDCl3, ppm): 1H:
ꢁ
/
0.22 (CH,
74.0), 0.05 (SnMe3,
49.8 Hz,); 0.16
5.89 (SnMe3,
ꢀ313.0 Hz), 2.82
SnÃC
119
117
J
J
ꢀ
/
77.2 Hz,
J
117
ꢀ
/
SnÃH
SnÃH
SnÃH
J
119
ꢀ
/
51.0 Hz,
ꢀ
/
SnÃH
(GeMe3), 0.33, 0.34 (SiMe2): 13C; ꢁ
/
119
117
J
ꢀ
/
328.0 Hz,
J
/
ꢁ
/
SnÃC
(CH), 1.20, 1.53 (SiMe2), 2.74 (GeMe3), 127.6, 128.5,
133.40, 142.0 (ipso) (Ph); 29Si: 1.72 (2JSiÃSn
ꢀ25.8 Hz);
/
119Sn: 14.1.
2.2. X-ray data collection
A colorless fragment of approximate dimensions
0.38ꢃ0.36ꢃ0.20 mm. was mounted in a random
/
/
orientation at the tip of glass fiber for X-ray examina-
tion and data collection. All data were collected at 296
K on a Siemens R3m/v single-crystal diffractometer with
graphite-monochromated MoÁ
Ka)ꢀ0.71073. Unit cell parameters and standard devia-
tions were obtained by least-squares fit of 50 randomly
selected reflections in the 2u range of 15Á308. They
/
Ka radiation; l(MoÁ
/
/
/
indicated monoclinic symmetry which was confirmed by
oscillation photographs around each crystallographic
axis. Intensity data were collected in the v-scan mode
with a scan range of 1.48 in v and a variable speed of 3Á
/
Fig. 1. Structure of 2.
Cervantes-Lee, Francisco
