Bis(oligosilanyl)chalcogenides [Me3Si)xMe3-xSi]2E, alkalimetal oligosilanylchalcogenolates (Me3Si)xMe3-xSi-EMI and oligosilanylchalcogenols (Me3Si)xMe3-xSi-EH (E = S, Se, Te) syntheses and NMR study

Article abstract of DOI:10.1016/S0022-328X(02)01672-8

Bis(oligosilanyl)chalcogenides [(Me₃Si)_x Me_3-x Si]₂E, alkalimetal oligosilanylchalcogenolates (Me₃Si)_x Me_3-x Si-EM^I and oligosilanylchalcogenols (Me₃Si)_x Me_3-x Si-EH (x=1-3; E=S, Se, Te) were synthesized and characterized by ¹H-, ¹³C-, ²⁹Si-, ⁷⁷Se- and ¹²⁵Te-NMR spectroscopy. Trends of NMR parameters (chemical shifts, coupling constants) are discussed.

Full text of DOI:10.1016/S0022-328X(02)01672-8

Journal of Organometallic Chemistry 660 (2002) 36ꢂ
/42
www.elsevier.com/locate/jorganchem
Bis(oligosilanyl)chalcogenides [(Me Si) Me
3
Si] E, alkalimetal
2
x
3ꢀx
I
EM and
oligosilanylchalcogenolates (Me Si) Me
3
SiÃ
/
x
3ꢀx
oligosilanylchalcogenols (Me Si) Me
3
SiÃ
/
EH (EꢁS, Se, Te)
/
x
3ꢀx
Syntheses and NMR study
Heike Lange, Uwe Herzog *
Institut f u¨ r Anorganische Chemie, TU Bergakademie Freiberg, Leipziger Strasse 29, D-09596 Freiberg, Germany
Received 13 February 2002; accepted 14 June 2002
Abstract
I
Bis(oligosilanyl)chalcogenides [(Me
silanylchalcogenols (Me Si)
Me3ꢀxSiÃ
Te-NMR spectroscopy. Trends of NMR parameters (chemical shifts, coupling constants) are discussed. # 2002 Published by
3
Si)
x
Me3ꢀxSi]
2
E, alkalimetal oligosilanylchalcogenolates (Me
3
Si)
x
Me3ꢀxSiÃ
/
EM and oligo-
1
13
29
77
3
x
/
EH (xꢁ
/
1ꢂ3; Eꢁ
/
/
S, Se, Te) were synthesized and characterized by H-, C-, Si-, Se- and
1
25
Elsevier Science B.V.
Keywords: Bis(oligosilanyl)chalcogenides; Alkalimetal oligosilanylchalcogenolates; NMR study
1
. Introduction
The siliconꢂchalcogen chemistry is dominated by the
formation of cyclic and polycyclic compounds. Apart
complex thio- and selenoaluminates, prepared from
LiAlH and H E [9].
A more facile and high-yield approach to disilylchal-
cogenides starts from the elemental chalcogens and
lithiumtriethylboranate [10], see Eq. (1).
4
2
/
from these species only a few acyclic compounds
containing a SiÃ
/
EÃ
3
/
Si unit are known. Disilylchalcogen-
ð1Þ
ides such as (Me Si) E (Eꢁ
/
S [1], Se [2ꢂ4], Te [5]) have
/
2
been prepared and utilized as chalcogen transfer
reagents, e.g. by Fenske et al. in the preparation of
nanosized copper chalcogenide clusters. Depending on
the reaction conditions clusters containing up to 146
copper atoms have been isolated [6].
The thus formed lithium chalcogenides are partially
soluble in THF and are therefore far more reactive. A
convenient alternative route to (Me Si) S starts from
3
2
(Me Si) NH and H S in the presence of 1% imidazole
3 2 2
[
11,12].
Arnold and coworkers [13] as well as Klinkhammer
and coworkers [14] have shown that elemental tellurium
Li bond of tris(trimethylsilyl)silyl
Several synthetic routes towards disilylchalcogenides
have been described.
For instance, starting from the corresponding chlor-
osilane the reaction with Na Se or Li Te, prepared from
inserts into the SiÃ
/
2
2
lithium prepared from Si(SiMe ) and MeLi in THF
3 4
the elements in liquid NH , furnished (Me Si) Se in 83%
3
with formation of the lithium tellurolate (Me Si) SiTeLi
3
3
2
3
yield [7] and (Me Si) Te in 40% yield [8]. Disilylsulfides
3
which has also been characterized by a crystal structure
analysis [15]. Treatment of the tellurolate with HOTf or
HCl under controlled reaction conditions yielded the
corresponding tellurol (Me Si) SiTeH [14,16].
2
and selenides (Me H
n
Si) E have also been obtained
2
3ꢀn
by reaction of the corresponding silyliodides with
3
3
Marschner [17] showed tris(trimethylsilyl)silyl potas-
sium to be prepared conveniently by the reaction of
*
94058
Correspondong author. Tel.: ꢃ
/
49-3731-394343; fax: ꢃ49-3731-
/
t
Si(SiMe ) with KO Bu in THF; this is a convenient
alternative route towards oligosilanyl anions (Eq (2)).
3
0
3 4
E-mail address: uwe.herzog@chemie.tu-freiberg.de (U. Herzog).
022-328X/02/$ - see front matter # 2002 Published by Elsevier Science B.V.
PII: S 0 0 2 2 - 3 2 8 X ( 0 2 ) 0 1 6 7 2 - 8

H. Lange, U. Herzog / Journal of Organometallic Chemistry 660 (2002) 36ꢂ
/
42
37
ð2Þ
The aim of this work was to synthesize and char-
acterize a series of acyclic bis(oligosilanyl)chalcogenides,
alkalimetal oligosilanylchalcogenolates and oligosilanyl-
chalcogenols because these compounds might serve as
interesting synthons in the preparation of other chalco-
genides. Furthermore, we are interested in the NMR
data (chemical shifts, coupling constants) of these
acyclic compounds. They may be compared with data
of cyclic and polycyclic organosilicon chalcogenides
[
18ꢂ
/
23] and conclusions with respect to the effects of
ring formation on the NMR parameters can be drawn.
2
. Results and discussion
Scheme 1.
2
[
.1. Bis(oligosilanyl)chalcogenides,
(Me Si) Me
Si] E (xꢁ
/
0ꢂ
/
3, EꢁS, Se, Te)
/
3
x
3ꢀx
2
1
marized in Table 1. Remarkably the values of the J
coupling constants increase with number x of SiMe
SiE
Bis(oligosilanyl)chalcogenides have been obtained by
treatment of the corresponding chlorosilanes (Me Si) -
Me3ꢀxSiCl with a suspension of Li E in THF prepared
3
2
units in each oligosilanyl unit whereas the J coupling
SiE
3
x
constants decrease significantly. As to be expected, dSi
2
of the central silicon atoms as well as d are shifted to
E
in situ from Li[BEt H] and elemental E.
3
higher field with increasing x.
ð3Þ
2.2. Potassium oligosilanylchalcogenolates
In the case of Eꢁ
Me3ꢀxSiCl (xꢁ0, 1, 2) can alternatively be reacted
with H S in the presence of NEt . While for xꢁ
/
S the chlorosilanes (Me Si) -
(Me
(Me
3
3
Si)
Si)
x
x
Me3ꢀxSiÃ
/
EK and oligosilanylchalcogenols
EH (EꢁS, Se, Te)
3
x
/
Me3ꢀxSiÃ
/
/
/
0
2
3
hexamethyldisilthiane was the only reaction product, for
xꢁ1, a mixture of the disilthiane and pentamethyldisi-
lanethiol emerged. For xꢁ2 heptamethyltrisilane-2-
The reactions of hypersilyl potassium prepared from
t
(Me Si) Si and KO Bu with elemental chalcogens in
3 4
/
/
THF afforded the related potassium hypersilylchalco-
genolates, see Eq. (4).
thiol [24] was formed exclusively (Scheme 1).
The different reaction products reflect an increase in
steric shielding caused by the raising number of
trimethylsilyl units attached. It prevents more or less
the reaction of the initially formed thiol with a second
molecule of the chlorosilane to give the bis(oligosila-
nyl)sulfide.
Apart from the mass spectrum the most significant
proof of the presence of a thiol is the occurrence of an
1
SH resonance in the H-NMR spectra. The NMR data
of all bis(oligosilanyl)chalcogenides prepared are sum-
ð4Þ
This type of reaction could also be applied to the
branched tetrasilane MeSi(SiMe3)3 yielding the new
heptamethyltrisilan-2-yl potassium and finally potas-
sium heptamethyltrisilanylchalcogenolates:
The related silyl lithium derivative, (Me Si) SiMeLi
3
2
has been reported previously, in THF solution it
ð5Þ

38
H. Lange, U. Herzog / Journal of Organometallic Chemistry 660 (2002) 36ꢂ42
/
Table 1
3 x 2
NMR data of disilylchalcogenides [(Me Si) Me3ꢀx Si] E (EꢁS, Se, Te; xꢁ0, 1, 2, 3), chemical shifts in ppm, coupling constants in Hz
n
1
J
1
Compound
d
E
d
Si
J
SiE
SiSi
d
C
J
SiC
d
H
(
Me
Me
3
Si)
2
S
ꢂ
ꢂ/
/
14.65
A: ꢀ17.89
B: 0.22
ꢂ
ꢂ/
/
ꢂ
/
4.12
ꢀ2.80
1.35
53.9
46.6
44.4
46.5
39.1
0.353
0.139
0.382
0.154
0.463
0.240
A
Si Si Me
B
(
3
2
)
2
S
88.4
73.9
60.4
A
Si )
B
Si Me]
[
(Me
(Me
3
2
2
S
ꢂ/
A: ꢀ14.86
B: ꢀ20.98
A: ꢀ10.65
B: ꢀ49.91
11.76
ꢂ/
ꢀ1.55
ꢀ2.62
0.96
A
Si )
B
Si ]
[
3
3
2
S
ꢂ/
ꢂ/
ꢂ/
107.4
21.9
ꢂ/
ꢂ/
ꢂ/
(
Me
Me
3
Si)
A
Si Si Me
2
Se
ꢀ337
ꢀ405
ꢂ/
4.56
ꢀ2.46
1.99
52.5
45.2
42.0
46.0
0.452
0.133
0.512
0.172
0.549
0.256
B
(
3
2
)
2
Se
A: ꢀ17.24
B: ꢀ3.26
A: ꢀ15.01
B: ꢀ27.47
A: ꢀ10.96
B: ꢀ60.47
ꢀ4.7
A: ꢀ16.48
B: ꢀ23.46
A: ꢀ14.73
B: ꢀ54.53
A: ꢀ10.95
B: ꢀ97.11
87.8
71.9
57.6
129.3
12.6
A
Si )
B
Si Me]
[
(Me
(Me
3
2
2
Se
ꢀ555
ꢀ629
ꢀ1.27
ꢀ3.57
1.24
135.6
9.5
A
Si )
B
Si ]
[
3
3
2
Se
45.4
151.2
274.6
45.2
ꢂ/
ꢂ/
51.0
ꢂ/
(
Me Si)
3
2
Te
ꢀ852
ꢀ948
ꢂ/
5.58
ꢀ2.42
1.51
0.604
0.143
0.664
0.196
0.648
0.284
A
Si Si Me
B
[(Me
[(Me
[(Me
3
3
3
2
)
2
]Te
84.1
68.0
54.9
318.0
24.3
40.8
45.5
33.0
A
Si )
B
Si Me]
2
2
Te
ꢀ1158
ꢀ1240
ꢀ0.97
ꢀ5.27
1.79
324.1
18.0
A
Si )
B
Si ]
3
2
Te
347.2
ꢂ/
ꢂ/
ꢂ/
2
revealed very similar Si NMR chemical shifts [25]
9
these series of compounds (Eꢁ
between the dSi values of the central silicon atom in
[(Me Si) Me Si] E and the corresponding
EH increase with the number of
/
S, Se, Te) the differences
ꢃ
suggesting that here too solvent separated ions M(thf)
ꢀ
n
and Me Si3 are present.
7
3
x
3ꢀx
2
Treatment of potassium oligosilanylchalcogenolates
with anhydrous acetic acid afforded the corresponding
thiols, selenols and tellurols, Eq. (6).
(Me Si) Me3ꢀxSi Ã
/
3
x
Me Si groups x; this might be a result of the higher
steric hindrance of two bulky silyl units in the bis(oli-
gosilanyl)chalcogenides (Fig. 1). The increasing steric
3
7
effect is also evident from a comparison of the Se- and
7
1
25
Te-NMR shift values of the analogous selenium and
tellurium compounds. NMR investigations on several
classes of cyclic and polycyclic silselenanes and siltellur-
ð6Þ
anes [19ꢂ
/
21] as well as chalcogenobutyl substituted
Since the cleavage of octamethyltrisilane with potas-
sium tert-butanolate in THF failed, the corresponding
pentamethyldisilanylchalcogenolates could not be pre-
pared via this route, Eq. (7).
1
25
silanes [26] have shown that the
Te-NMR chemical
shifts parallel the corresponding Se-NMR values with
a factor of 2.5ꢂ2.7. While the initial slope at d :0 ppm
for all pairs of compounds studied here varies between
.7 and 3.1 (Fig. 2) it becomes flatter for larger x (more
7
7
/
/
E
2
negative values of dSe and dTe).
The similarity of the NMR data observed for the
potassium hypersilylchalcogenolates with those reported
previously for lithium hypersilylthiolate, selenolate and
tellurolate [14] suggests that these compounds should be
regarded to exist as solvent separated ions in solution.
This interpretation is in agreement with the increased
ð7Þ
However, THF solutions of these compounds were
obtained when chloropentamethyldisilane was reacted
with excess Li E, see Eq. (8).
2
1
1
JSiSe and J
number of the chalcogen atoms decreases to one in the
coupling constants*the coordination
/
SiTe
ð8Þ
chalcogenolate ions. On the other hand, in the related
1
1
selenols and tellurols much smaller JSiSe and JSiTe
values are observed than in compounds with a SiÃEÃSi
unit.
The NMR data of all alkalimetal oligosilanylchalco-
genolates and the related thiols, selenols and tellurols
synthesized so far are summarized in Tables 2 and 3. In
/
/

H. Lange, U. Herzog / Journal of Organometallic Chemistry 660 (2002) 36ꢂ
/
42
39
Table 2
I
NMR data of lithium and potassium oligosilanylchalcogenolates (Me
shifts in ppm, coupling constants in Hz
3 x
Si) Me3ꢀx SiÃEM (EꢁS, Se, Te; xꢁ1, 2, 3) in THF solution, chemical
1
1
1
Compound
d
E
d
Si
J
SiE
J
SiSi
d
C
J
SiC
d
H
A
Si Me
B
Si SLi
Me
3
2
ꢂ
/
A: ꢀ21.29
B: ꢀ9.95
ꢂ
/
95.2
80.3
66.6
91.9
77.5
64.1
87.5
73.4
60.7
ꢀ1.81
5.37
41.3
42.3
39.8
ꢀ0.013
0.154
0.016
0.207
0.074
A
Si )
B
MeSi SK
(
(
Me
Me
3
2
ꢂ/
A: ꢀ19.37
B: ꢀ31.85
A: ꢀ16.30
B: ꢀ62.15
A: ꢀ21.87
B: ꢀ17.79
A: ꢀ20.16
B: ꢀ41.95
A: ꢀ18.20
B: ꢀ77.55
A: ꢀ21.67
B: ꢀ46.43
A: ꢀ20.11
B: ꢀ75.28
A: ꢀ18.68
B: ꢀ119.57
ꢂ/
ꢀ1.40
ꢀ1.02
0.10
A
Si )
B
Si SK
3
3
ꢂ/
ꢂ/
41.3
ꢂ/
ꢂ/
ꢂ/
A
Si Me
B
Si SeLi
Me
3
2
ꢀ572
164.7
172.6
170.6
429
ꢀ2.26
4.79
ꢀ0.011
0.289
0.030
0.349
0.096
A
Si )
B
MeSi SeK
(
(
Me
3
2
ꢀ641
ꢀ1.39
ꢀ1.4
0.30
A
Si )
B
Si SeK
Me
3
3
ꢀ816
42.3
ꢂ/
ꢂ/
ꢂ/
A
Si Me
B
Si TeLi
Me
3
2
ꢀ1338
ꢀ1443
ꢀ1652
ꢀ2.52
4.05
0.014
0.486
0.064
0.568
0.140
A
Si )
B
MeSi TeK
(
(
Me
3
2
424
ꢀ1.25
ꢀ3.52
0.53
42.0
43.1
A
Si )
B
Si TeK
Me
3
3
407
ꢂ/
ꢂ/
ꢂ/
3
. Experimental
Me Si in a 10 mm sample tube was used for lock and
4
calibration.
2
9
Si INEPT spectra were also recorded in order to
obtain a sufficient signal-to-noise ratio which allows the
3
.1. NMR and GCꢂ
/
MS measurements
1
resolution of the JSiC, JSiSe
1,2
1,2
1
JSiTe or J
,
satellites.
SiSi
7
7
125
Se and
Te and spectra were determined using an
NMR spectra were recorded on a Bruker DPX 400 in
CDCl solution and with Me Si as internal standard for
7
7
125
IGATED pulse program. Coupled Se- and Te-NMR
spectra of the selenols and tellurols prepared gave
doublets with coupling constants identical to the values
3
13
4
1
29
H, C and Si. External CDCl solutions of Ph Se
2
3
2
(dSe 460 ppm [27]) and Ph Te (d : 422 ppm [28]) were
2 2
used as standards for Se and Te.
Te
125
1
7
7
determined from the satellites in the H-NMR spectra.
Mass spectra were measured on a Hewlett-Packard
ꢀ
3
ꢃ
ꢀ
4
ꢃ
ꢃ
THF solutions of Me Si K ; Me Si K ;
ꢀ
7
9
ꢀ
ꢃ
ꢀ
ꢃ
5971 (ionization energy 70 eV, column 30 mꢄ
/0.25
Me Si S Li , Me Si E K and Me Si E K were
4
5
2
7
3
9
mmꢄ0.25 mm, phenylmethylpolysiloxane, column tem-
/
sealed in 7 mm glass tubes and external CDCl with
3
Table 3
NMR data of oligosilanylchalcogenoles (Me
in Hz
3 x
Si) Me3ꢀx SiÃEH (EꢁS, xꢁ1, 2, 3; EꢁSe, Te, xꢁ2, 3), chemical shifts in ppm, coupling constants
n
1
1
J
1
Compound
d
E
d
Si
J
SiE
J
SiSi
d
C
SiC
d
H
(CH
3
)
d
H
(EH)
J
EH
A
Si Si Me
B
Me
3
2
ÃSH
ꢂ
/
A: ꢀ17.66
B: 0.73
ꢂ
/
90.9
72.6
60.3
70.8
57.8
67.5
55.4
ꢀ2.50
2.29
44.5
42.8
45.2
35.9
45.2
0.122
0.408
0.166
0.388
0.213
ꢀ0.28
ꢀ0.46
ꢀ0.84
ꢀ2.73
ꢀ3.22
ꢀ8.24
ꢀ8.96
ꢂ
/
A
Si )
B
MeSi SH
(
(
(
(
(
(
Me
3
2
3
2
3
2
3
ꢂ/
A: ꢀ14.49
B: ꢀ25.99
A: ꢀ11.25
B: ꢀ60.88
A: ꢀ14.12
B: ꢀ31.71
A: ꢀ11.4
B: ꢀ69.9
A: ꢀ13.19
B: ꢀ55.04
A: ꢀ11.20
B: ꢀ100.15
ꢂ/
ꢀ1.96
ꢀ2.56
ꢀ0.27
ꢂ/
A
B
Me
Me
Me
Me
Me
3
3
3
3
3
Si )
Si SH
ꢂ/
ꢂ/
ꢂ/
A
Si )
B
MeSi SeH
ꢀ379
ꢀ476
ꢀ814
ꢀ950
7.9
ꢀ1.78
ꢀ3.37
ꢀ0.02
45.4
34.5
46.2
0.178
0.501
0.225
41.0
36.8
62.1
74.3
94.5
B7
87.1
15.5
232.8
11.2
209.0
A
Si )
B
Si SeH
A
Si )
B
MeSi TeH
ꢀ1.43
ꢀ4.95
0.56
46.2
32.6
46.1
0.197
0.675
0.251
A
Si )
B
Si TeH

40
H. Lange, U. Herzog / Journal of Organometallic Chemistry 660 (2002) 36ꢂ42
/
2
9
, (ꢀ)E[SiMe3ꢀx (SiMe
Fig. 1. Si-NMR chemical shift of the central silicon atoms in E[SiMe3ꢀx (SiMe
function of x (EꢁS, Se, Te).
3
)
x
]
2
3
)
x
] and HE[SiMe3ꢀx (SiMe
3
)
x
] as a
/
ꢀ
1
perature 80 8C (3 min)/20 K min , He flow 0.5 ml
min ).
3.3. Reaction of chlorosilanes (Me Si) Me3ꢀxSiCl
3 x
ꢀ
1
(xꢁ
/
0, 1, 2) with H Sꢂ
/NEt3
2
Chlorosilane (Me Si) Me3ꢀxSiCl (xꢁ
/
0, 1, 2, 2.0
mmol) were dissolved in 10 ml hexane and a stream of
3
x
3
.2. Starting materials
dried H S was bubbled through the stirred solution
2
Hydrogen sulphide (H S), sulfur, selenium, tellurium,
2
while 0.28 ml (2.0 mmol) of NEt were slowly added by
3
Et N, 1 M LiBEt H in THF (Super Hydride), Me SiCl
3
3
3
a syringe. After stirring for 30 min the reaction mixture
was filtered from precipitated ammonium salts and the
solvent was removed in vacuo. The products are
and HOAc are commercially available. ClSi Me [29],
2
5
(
[
Me Si) SiClMe [30], (Me Si) SiCl [31], (Me Si) SiMe
3 2 3 3 3 3
32] and (Me Si) Si [33] were prepared as described.
3 4
(
(
Me Si) S, a mixture of Me Si SH and (Me Si ) S
3 2 5 2 5 2 2
Except for THF, which was distilled from sodium
potassium alloy prior to use, all solvents were dried
over KOH or sodium wire. The reactions were carried
out under an atmosphere of argon applying standard
Schlenk techniques.
35:65) and oily (Me Si) SiMeSH.
3
2
Me Si SH: GCꢂ
/
MS (m/e, relative intensity): 164
5
2
ꢃ
(
(
M , 2), 149 (MÃMe, 55), 133 (Me Si S, 2), 131
/
3
2
Me Si , 2), 91 (Me SiSH, 8), 73 (Me Si, 100).
5
2
2
3
1
25
77
Fig. 2. Comparison of Te- and Se-NMR chemical shifts in E[SiMe3ꢀx (SiMe
, (ꢀ)E[SiMe3ꢀx (SiMe
3
)
x
]
Te). For all three classes of compounds, the initial slope varies between 2.7 and 3.1.
2
3
)
x
] and HE[SiMe3ꢀx (SiMe
3
)
x
] (EꢁSe,
/

H. Lange, U. Herzog / Journal of Organometallic Chemistry 660 (2002) 36ꢂ
/
42
41
ꢃ
(
21 (Me Si S, 20), 191 (Me Si S, 4), 163 (Me Si S, 4),
Me Si ) S: GCꢂ
/
MS: 294 (M , 1), 279 (MÃ
/
Me, 3),
3.6. Preparation of oligosilanylselenols and -tellurols
5
2 2
2
1
7
3
5
3
5
2
31 (Me Si , 15), 116 (Me Si , 30), 73 (Me Si, 100).
5
Oligosilanylchalcogenolate (1.0 mmol) in THF solu-
tion (see above) was cooled in an ice bath and reacted
with 0.060 g (1.0 mmol) of anhydrous AcOH. The
solvent was removed in vacuo and replaced by 10 ml
hexane. After filtration the hexane was evaporated in
vacuo to furnish the oligosilanylselenols and oligosila-
nyltellurols as yellow oily residues.
2
4
2
3
ꢃ
Me Si SH: GCꢂ
/
MS: 222 (M , 11), 207 (MÃ/Me, 5),
7
3
191 (Me Si S, 3), 148 (Me Si S, 23), 133 (Me Si S, 51),
2
1
5
3
4
2
3
19 (Me Si SH, 5), 73 (Me Si, 100).
3
2
2
3
.4. Reaction of chlorosilanes (Me Si) Me3ꢀxSiCl
3 x
(
xꢁ
/
0, 1, 2, 3) with Li E (Eꢁ
/
S, Se, Te)
2
3.7. Lithium pentamethyldisilanylchalcogenolates
Chlorosilane (Me Si) Me3ꢀxSiCl (xꢁ
/0, 1, 2, 3, 2.0
3
x
mmol) were added to a suspension of 1.0 mmol of Li E
2
Si Me Cl (0.17 g, 1.0 mmol) of was added to a THF
2
5
in THF at 0 8C prepared from 2.0 ml of a 1 M solution
solution of 1.2 mmol of Li E prepared from 2.4 ml of a 1
2
of LiBEt H in THF and 1.0 mmol of E. After stirring
for 30 min the solvent THF was removed in vacuo and
M LiBEt H solution and 1.2 mmol of E (EꢁS, Se, Te).
/
3
3
The resulting reaction mixture was concentrated in
vacuo to remove the by-product BEt and the residue
10 ml of hexane was added. The suspension was filtered
and the solvent removed from the filtrate in vacuo to
3
was dissolved in 1 ml of THF and analyzed by NMR
revealing the formation of Me Si E Li(thf) .
furnish pure bis(oligosilanyl)chalcogenides [(Me Si) -
3
x
5
2
n
Me3ꢀxSi] E as oily residues.
2
ꢃ
(
37 (Me Si S, 39), 249 (Me Si S, 34), 232 (Me Si , 54),
Me Si ) S: GCꢂ
/
MS: 410 (M , 4), 395 (MÃ
/
Me, 5),
7
3 2
3
2
1
Acknowledgements
1
1
5
7
4
8
4
21 (Me Si S, 9), 191 (Me Si S, 13), 189 (Me Si , 10),
7
3
5
3
7
3
31 (Me Si , 40), 73 (Me Si, 100).
5
The authors thank the ‘Deutsche Forschungsge-
meinschaft’ and the ‘Fonds der Chemischen Industrie’
for financial support.
2
3
ꢃ
(
69 (Me Si Se, 11), 239 (Me Si Se, 2), 181 (Me Si Se,
Me Si ) Se: GCꢂ
/
MS: 342 (M , 2), 327 (MÃ
/
Me, 1),
5
2 2
2
7 3 5 3 3 2
3
), 131 (Me Si , 14), 116 (Me Si , 16), 73 (Me Si, 100).
5
2
4
2
3
References
3.5. Preparation of oligosilanyl potassium and reaction
with chalcogens
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1
2] D. Fenske, H. Krautscheid, Angew. Chem. 102 (1990) 1513.
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[
[
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3
3
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t
ml of THF and 0.50 g (4.4 mmol) of KO Bu was added.
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(
[
[
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(
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A
1
(
(
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/
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SiSi
1
3
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B
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/
0.069 (Si Me ), ꢀ
/
3
[
[
[
[
10] M.R. Detty, M.D. Seidler, J. Org. Chem. 47 (1982) 1354.
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[
[
14] G. Becker, K.W. Klinkhammer, S. Lartiges, P. B o¨ ttcher, W. Poll,
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Analogously, 1.0 g (3.1 mmol) of Si(SiMe3)4 was
dissolved in 4 ml of THF and 0.40 g (3.6 mmol) of
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t
KO Bu were added to give a THF solution of hypersi-
A
lylpotassium [(Me Si ) Si K(THF) [NMR (ppm, Hz):
B
3
3
n
[16] B.O. Dabbousi, P.J. Bonasia, J. Arnold, J. Am. Chem. Soc. 113
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2
9
1
13
1
Si: ꢀ
/
4.95 (A), ꢀ194.24 (B, JSiSi: 8.9); C: 6.81, H:
/
t
.144] and Me SiO Bu.
[
[
17] C. Marschner, Eur. J. Inorg. Chem. (1998) 221.
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0
3
Subsequent addition of 3.1 mmol of powdered sulfur,
selenium or tellurium, respectively, yielded a THF
[19] U. Herzog, G. Rheinwald, J. Organomet. Chem. 627 (2001) 23.
solution of a potassium hypersilylcogenolate ((Me3-
[20] U. Herzog, U. B o¨ hme, G. Rheinwald, J. Organomet. Chem. 627
(2001) 144.
Si) SiE K(thf) ).
3
n

42
H. Lange, U. Herzog / Journal of Organometallic Chemistry 660 (2002) 36ꢂ42
/
[
[
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1
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[
[
[
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[
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