Novel Chalcogenides of Silicon
Organometallics, Vol. 20, No. 25, 2001 5373
Ta ble 6. Cr ysta l Da ta of 2c a n d 3a ,c,e a s Well a s Da ta Collection a n d Refin em en t Deta ils
2c
3a
3c
3e
empirical formula
cryst shape
cryst color
C8H24GeS3Si4
plate
colorless
C8H24Se3Si5
block
colorless
C8H24GeSe3Si4
block
colorless
C8H24Se3Si4Sn
rod
colorless
cryst size
fw
0.70 × 0.50 × 0.12
0.60 × 0.42 × 0.35
0.60 × 0.50 × 0.40
0.80 × 0.30 × 0.20
401.43
497.590
542.11
588.20
cryst syst
monoclinic
P21/c
monoclinic
P21/c
monoclinic
P21/c
monoclinic
P21/c
space group
unit cell dimens
a (Å)
b (Å)
c (Å)
10.2181(15)
11.6391(18)
16.638(3)
93.396(3)
1975.3(5); 4
1.350
2.090
ω scans
none
0.7875/0.3224
15886
5666
4398
0.0298
10.2283(6)
11.6430(7)
16.8521(9)
93.386(2)
2003.4(13); 4
1.650
5.788
ω scans
empirical
0.2365/0.1288
8657
10.238(2)
11.668(2)
16.914(2)
93.775(3)
2016.1(6); 4
1.786
7.154
ω scans
empirical
0.1620/0.0993
16133
10.3290(14)
11.7081(16)
17.066(2)
95.253(2)
2055.2(5); 4
1.901
6.771
ω scans
empirical
0.3445/0.0743
8972
â (deg)
V (Å3); Z
calcd density (g/cm3)
linear abs coeff (mm-1
scan method
abs cor
)
max/min transmissn
no. of measd rflns
no. of indep rflns
no. of obsd rflns
R(int)
4530
3801
0.0201
5779
4516
0.0330
4446
3222
0.0319
θ range for collecn (deg)
2.00-30.82
-14 e h e 14
-14 e k e 16
-23 e l e 18
91.3
0.0274/0.0649
0.0435/0.0707
0.0338/0.3826
1.008
1.99-29.44
-11 e h e 13
-10 e k e 15
-22 e l e 12
81.6
0.0257/0.0638
0.0332/0.0661
0.0410/0
1.99-30.88
-13 e h e 12
-16 e k e 9
-23 e l e 23
90.9
0.0269/0.0577
0.0430/0.0620
0.0281 /0
1.027
1.98-29.41
-13 e h e 9
-10 e k e 15
-19 e l e 21
78.3
0.0296/0.0566
0.0536/0.0629
0.0277/0
index ranges
completeness to θmax (%)
final R1/wR2 a (I > 2σ(I))
final R1/wR2 a (all data)
weighting scheme factors (a/b)a
goodness of fit (S)b on F2
no. of used rflns/params
H locating and refining
max/min e density (e/Å3)
0.997
0.955
5666/153
geom/constr
0.577/-0.363
4530/235
difmap/refall
0.380/-0.542
5779/153
geom/constr
0.423/-0.794
4446/241
difmap/refall
0.512/-0.710
a
2
2
b
R1 ) ∑(||Fo| - |Fc||)/∑|Fo|, wR2 ) [∑(w(Fo - Fc2)2)/∑(wFo2)]1/2), w ) 1/[σ2(Fo2) + (aP)2 + bP], where P ) (Fo + 2Fc2)/3. S )
[∑w(Fo - Fc2)2]/(n - p)1/2, n ) used reflections, p ) used parameters.
2
DIAMOND.31 The ellipsoids of the non-hydrogen atoms are
at the 50% probability level.
2b: Anal. Calcd for C13H26S3Si5 (418.98): C, 37.27; H, 6.25.
Found: C, 37.54; H, 6.18.
2c: GC/MS (m/e, relative intensity) 402 (M+, 5), 387 (M -
Me, 20), 313 (Me7Si4S3, 10), 281 (Me7Si4S2, 45), 223 (Me5Si3S2,
13), 191 (Me5Si3S, 23), 163 (Me5Si2S, 11), 131 (Me5Si2, 30), 116
3. Sta r tin g Ma ter ia ls. S, Se, Te, 1 M Li[BEt3H] in THF
(Super Hydride), RSiCl3, RGeCl3, and RSnCl3 (R ) Me, Ph)
were commercially available. THF was distilled from sodium
potassium alloy prior to use. The other solvents were dried
over KOH or sodium wire. All reactions were carried out under
argon by applying standard Schlenk techniques. MeSi(Si-
ClMe2)3 was prepared as described previously.32
4. P r ep a r a tion of th e Bicyclo[2.2.2]octa n es MeSi(Si-
Me2S)3MR (2a -f: M ) Si, Ge, Sn ; R ) Me, P h ). In a typical
reaction 96 mg (3.0 mmol) of sulfur was dissolved in a mixture
of 6.0 mL of a 1 M solution of Li[BEt3H] and an additional 3
mL of THF to form a Li2S solution. A mixture of 0.33 g (1.0
mmol) of 1 and 1.0 mmol of the appropriate RMCl3 (M ) Si,
Ge, Sn; R ) Me, Ph) dissolved in 1 mL of THF was added
slowly to the stirred Li2S solution in THF at 0 °C. After the
mixture was stirred for 20 min, the solvent was replaced by
10 mL of hexane. The product was filtered from precipitated
lithium chloride, and the solvent was removed in vacuo,
yielding the bicyclo[2.2.2]octanes 2a -f as crystalline residues
in 50-70% yield, with the exception of 2a , which remained a
colorless oil. In the case of the preparation of 2b,d larger
amounts of byproducts were observed by NMR spectroscopy
in the crude products. For further purification the products
were recrystallized from hexane.
(Me4Si2, 14), 73 (Me3Si, 100); mp 182 °C. Anal. Calcd for C8H24
-
GeS3Si4 (401.43): C, 23.94; H, 6.03. Found: C, 23.82; H, 6.51.
2d : GC/MS (m/e, relative intensity) 464 (M+, 11), 449 (M -
Me, 1), 387 (M - Ph, 2), 329 (Me5Si3S3Ge, 9), 313 (Me7Si4S3,
15), 281 (Me7Si4S2, 15), 223 (Me5Si3S2, 41), 209 (22), 178 (Me3-
Si2Ph, 14), 163 (Me2Si2Ph, 32), 135 (Me2SiPh, 100), 73 (Me3-
Si, 78).
2e: GC/MS (m/e, relative intensity) 433 (M - Me, 24), 375
(Me5Si3S3Sn, 2), 343 (Me5Si3S2Sn, 10), 313 (Me7Si4S3, 18), 281
(Me7Si4S2, 11), 223 (Me5Si3S2, 4), 191 (Me5Si3S, 37), 163 (Me5-
Si2S, 6), 131 (Me5Si2, 29), 73 (Me3Si, 100). Anal. Calcd for
C8H24S3Si4Sn (447.53): C, 21.47; H, 5.41. Found: C, 21.10; H,
5.73.
2f: GC/MS (m/e, relative intensity) 510 (M+, 3), 495 (M -
Me, 0.5), 433 (M - Ph, 40), 375 (Me5Si3S3Sn, 35), 343 (Me5-
Si3S2Sn, 11), 313 (Me7Si4S3, 19), 281 (Me7Si4S2, 19), 223 (Me5-
Si3S2, 23), 191 (Me5Si3S, 44), 153 (22), 135 (Me2SiPh, 75), 131
(Me5Si2, 27), 73 (Me3Si, 100).
5. P r ep a r a tion of th e Bicyclo[2.2.2]octa n es MeSi(Si-
Me2Se)3MR (3a -f: M ) Si, Ge, Sn ; R ) Me, P h ). A 0.24 g
quantity (3.0 mmol) of selenium powder was added to a
mixture of 6.0 mL of a 1 M solution of Li[BEt3H] and 3 mL of
THF to form a white Li2Se suspension. As described above, a
mixture of 0.33 g (1.0 mmol) of 1 and 1.0 mmol of the
appropriate RMCl3 (M ) Si, Ge, Sn; R ) Me, Ph) dissolved in
1 mL of THF was added slowly to the stirred Li2Se suspension
at 0 °C. Workup as described in part 4 yielded the bicyclo-
[2.2.2]octanes 3a -f in 50-70% yield as crystalline residues
which could be recrystallized from hexane for further purifica-
2a : GC/MS (m/e, relative intensity) 356 (M+, 31), 341 (M -
Me, 20), 297 (Me5Si4S3CH2, 12), 283 (Me5Si4S3, 11), 251 (Me5-
Si4S2, 3), 223 (Me5Si3S2, 5), 191 (Me5Si3S, 14), 176 (Me4Si3S,
14), 131 (Me5Si2, 17), 116 (Me4Si2, 16), 73 (Me3Si, 100).
(31) Berndt, M.; Brandenburg, K.; Putz H. Diamond 2.1; Crystal
(32) Herzog, U.; Schulze, N.; Trommer, K.; Roewer, G. J . Organomet.
Chem. 1997, 547, 133.