11140 Inorganic Chemistry, Vol. 49, No. 23, 2010
Stewart et al.
Table 1. Crystallographic Data and Parameters for Compounds 3, 4, and 5
3
4
5
empirical formula
Fw
T, K
C16H45NO6SSi5Sn
994.80
223(2)
C30H64N6O11Si8Sn4
1384.35
273(2)
C37H96N6S2Si12Sn3
1382.47
228(2)
cryst size (mm)
cryst syst
space group
0.27 ꢀ 0.27 ꢀ 0.07
monoclinic
P2(1)/c
15.7984(10)
12.5326(8)
19.7492(13)
0.575 ꢀ 0.345 ꢀ 0.23
monoclinic
P2(1)/n
21.7653(13)
12.5964(9)
22.5189(13)
0.41 ꢀ 0.39 ꢀ 0.23
triclinic
P1
˚
a, A
11.6460(11)
17.4939(16)
18.1905(17)
112.364(4)
98.788(4)
97.166(4)
3318.5(5)
2
1.384
1.429
0.0243
0.0725
˚
b, A
˚
c, A
R, deg
β, deg
γ, deg
130.152(4)
115.917(2)
3
˚
volume, A
3807.7(4)
4
1.735
2.831
0.0345
0.0821
5553.0(6)
4
1.656
2.001
0.0322
0.0820
Z
calc. density, g/cm3
μ (MoKR), mm-1
R1[I > 2σ(I)]a
wR2[I > 2σ(I)]b
P
P
P
P
a R1 = ||Fo| - |Fc||/ |Fo|. b wR2 = { w(Fo2 - Fc2)2/ w(Fo2)2}1/2
.
temperature over a 2 h period with stirring. The resulting
solution was added dropwise through a cannula to a solution
of tin dichloride (3.58 g, 19.0 mmol) in 50 mL of a mixture of
THF/Et2O held at 0 °C. The reaction mixture was allowed to
warm to room temperature while stirring overnight. The lithium
chloride precipitate was filtered using a glass frit and Celite as a
filtering aid. The solvent was removed from the filtrate at
reduced pressure, and the crude product was distilled at reduced
pressure(45μHg). The product was collected between 87-100 °Cas
a red oil. Yield: 5.18 g (63%). 1H NMR (250 MHz, C6D6) δ 0.76 (s,
4H, CH2), 0.18 (s, 6H, CH3) ppm. 13C{1H} NMR (63 MHz, C6D6)
δ 11.57 (s, CH2), 4.04 (s, CH3) ppm. 119Sn{1H} (93 MHz, C6D6) δ
808 (Lit. δ = 79823 or 82122) ppm.
Reaction of Bis(2,2,5,5-tetramethyl-2,5-disila-1-azacyclopent-
1-yl)tin (2) with CO2 to Give Sn4( μ4-O){μ2-O2CN[SiMe2-
(CH2)]2]4}( μ2-NdCdO)2 (4). In an argon-purged Fisher Porter
reactor tube, bis(2,2,5,5-tetramethyl-2,5-disila-1-azacyclopent-
1-yl)tin (0.20 g, 0.45 mmol) was dissolved in 20 mL of anhydrous
pentane at room temperature. The bottle was charged with CO2
(60 psig) and allowed to react for approximately an hour. The
solvent was removed at reduced pressure, and the crude product
was extracted with toluene, filtered, and cooled to -20 °C. After
several days at low temperature yellow crystals were obtained.
The crystals were isolated and identified as Sn4( μ4-O){μ2-
O2CN[SiMe2(CH2)2]4}( μ2-NdCdO)2 4 (0.08 g, yield 50%
1
based on tin, mp 102-104 °C). H NMR (250 MHz, C6D6) δ
0.71 (s, 16H, CH2), 0.40 (s, 24H, Si(CH3)2) ppm. 13C{1H} NMR
(63 MHz, C6D6) δ 180.5 (NdCdO), 167.9 (CO2), 8.4 (CH2), -0.4
(CH3) ppm. 119Sn{1H} (93 MHz, C6D6) δ -316 ppm. IR
(Nujol): ν = 2277 (w), 2171 (s). Anal. Calcd for C30H64N6O11-
Si8Sn4 (Mw = 1384.39): C, 26.03; H, 4.66 N; 6.07. Found: C,
25.82; H, 4.62; N, 3.98. The predominant byproduct from the mother
liquors was 2,2,5,5-tetramethyl-2,5-disila-1-oxacyclopentane and
was identified by GC-MS. (Calcd for C6H16OSi2, 160.4). GC-
MS m/z (relative intensity, ion): 160 (16%, Mþ), 145 (100%,
Mþ - CH3),117(100%,Me3SiO(CH2)2þ),73(90%,CH3SiOCH2þ).
Reaction of Bis(2,2,5,5-tetramethyl-2,5-disila-1-aza-cyclopent-1-
yl)tin (2) with OCS. Under an argon atmosphere, a solution of
bis(2,2,5,5-tetramethyl-2,5-disila-1-aza-cyclopent-1-yl)tin (0.54 g,
1.20 mmol) and petroleum ether (3 g) was cooled to -78 °C and
then evacuated to remove the argon. At -78 °C carbonyl sulfide
(2.4 mmol) was condensed into the reaction vessel. As the
reaction warmed to room temperature a red-brown precipitate
formed. The precipitate was filtered from solution and washed
several times with petroleum ether. Upon drying 0.15 g of a rust-
colored solid was collected. IR (Nujol): ν = 2277 (m), 2066 (s),
1972 (m), 1255 (m) 1054 (m), 794 (m) cm-1. Elemental analysis of
C, H, N, S, and Sn gave: C, 11.92; H, 1.74; N, 6.48; S, 17.7; Sn,
52.4. The GC-MS of the filtrate indicated petroleum ether and 2,2,5,5-
tetramethyl-2,5-disila-1-oxacyclopentane (Calcd for C6H16OSi2,
160.4). (GC-MS m/z (relative intensity, ion) 160 (10%, Mþ), 145
(100%, Mþ - CH3).
Reaction of Bis[bis(trimethylsilylamido)]tin(II) (1) with OCS
to Give Sn4( μ4-O)( μ2-OSiMe3)5(η1-NdCdS) (3). Under argon,
a Fisher Porter tube (fitted with a 120 psig pressure relief valve
for safety) was loaded with [(Me3Si)2N]2Sn (1.44 g; 3.28 mmol)
and dissolved in hexanes (2 g). To this system was attached a
74 cc stainless steel bomb. The solution was cooled to -100 °C
and evacuated to remove the argon. The bomb was charged with
60 psig of OCS which was then condensed into the cooled
[(Me3Si)2N]2Sn/hexanes solution. This was repeated once more
with 60 psig and then 20 psig to give a total of 140 psig of OCS
(30.3 mmol). The reaction mixture was allowed to stir and
slowly warm to 25 °C where it changed color from orange to
yellow. The reaction was allowed to stir overnight at room
temperature to eventually give a dark brown, cloudy solution.
This solution was cooled to -78 °C, and the excess OCS was
removed under vacuum (alternatively the OCS can be removed
under a stream of argon). The crude product obtained consisted
of a black oil and solids (in some reactions a tin mirror was
deposited on the sides of the glass vessel). The crude product was
filtered and washed with pentane to give a black powder (0.15 g,
Sn metal). From the pentane washings, colorless crystals of
Sn4( μ4-O)( μ2-OSiMe3)5(η1-NdCdS) were obtained (0.31 g;
39% based on Sn; mp 192-193 °C dec.; slight color change to
tan at 160 °C). The volatiles were removed from the filtrate
under an argon purge and analyzed by GC-MS. The byproducts
were found to be the following: Me3SiOSiMe3; (Me3Si)2NH;
Me3SiNdCdS; Me3SiN(H)C(S)OSiMe3; Me3SiNdCdN-
SiMe3. The byproducts were not quantified. 1H NMR (250
MHz, CDCl3) δ 0.23 (s, CH3) ppm. 13C{1H} NMR (63 MHz,
CDCl3) δ 176.52 (N-C-S), 3.63 (CH3) ppm. 119Sn{1H} (93 MHz,
CDCl3, ref to Me4Sn) δ 108-107 (broad mult), -143 (s) ppm.
IR (Nujol): ν = 2044 (s), 1263 (s), 1249 (s), 871 (s), 838 (s), 751
(s) cm-1. Anal. Calcd for C16H45NO6SSi5Sn4 (MW = 994.86):
C, 19.32; H, 4.56; N, 1.41. Found: C, 19.03; H, 4.04; N, 1.35.
Reaction of Bis(2,2,5,5-tetramethyl-2,5-disila-1-aza-cyclo-
pent-1-yl)tin (2) with CS2 to Give (5). To a solution of bis-
(2,2,5,5-tetramethyl-2,5-disila-1-azacyclopent-1-yl)tin (1.50 g,
3.44 mmol) in hexane (7 g) held at room temperature, CS2
(1.0 mL, 13.1 mmol) was added dropwise. The reaction was
immediate with the color changing from red-orange to dark
green. The reaction was allowed to stir for 1 h. Volatiles were
removed until crystallization began to occur. The dark green