Tailor-made synthesis of functional substituted oligo- and polysilanes from silyl triflates and (aminosilyl)lithium compounds

Article abstract of DOI:10.1016/S0022-328X(03)00158-X

Diethylamino substituted silyllithium compounds have been prepared in situ from the corresponding phenylchlorosilanes and lithium. These reagents undergo coupling reactions with triflate derivatives of silanes and oligosilanes. Exchange processes analogous to metal-halogen exchange and Si-Si bond cleavage, which are side reactions with chlorosilanes, were not observed. Based on the coupling reaction and the amino-to-triflate transformation, functionalized tri-, tetra-, penta- and hexasilanes have been synthesized. α,ω-Triflate substituted oligosilanes containing π-systems have also been obtained. These compounds are useful building blocks for new organosilicon polymers. The formation of the silicon polymers at low temperatures, in short reaction times, and with high yields is reported. The ²⁹Si-NMR spectra indicate a regular, alternating arrangement of the building blocks in the polymer backbone.

Full text of DOI:10.1016/S0022-328X(03)00158-X

Journal of Organometallic Chemistry 685 (2003) 70Á78
/
www.elsevier.com/locate/jorganchem
Tailor-made synthesis of functional substituted oligo- and polysilanes
from silyl triflates and (aminosilyl)lithium compounds
Wolfram Uhlig *
Laboratory of Inorganic Chemistry, Swiss Federal Institute of Technology Zurich, ETH-Honggerberg, CH-8093 Zurich, Switzerland
¨
Received 9 December 2002; received in revised form 20 February 2003; accepted 27 February 2003
Abstract
Diethylamino substituted silyllithium compounds have been prepared in situ from the corresponding phenylchlorosilanes and
lithium. These reagents undergo coupling reactions with triflate derivatives of silanes and oligosilanes. Exchange processes
analogous to metalÁ
/
halogen exchange and SiÃ/Si bond cleavage, which are side reactions with chlorosilanes, were not observed.
Based on the coupling reaction and the amino-to-triflate transformation, functionalized tri-, tetra-, penta- and hexasilanes have been
synthesized. a,v-Triflate substituted oligosilanes containing p-systems have also been obtained. These compounds are useful
building blocks for new organosilicon polymers. The formation of the silicon polymers at low temperatures, in short reaction times,
and with high yields is reported. The 29Si-NMR spectra indicate a regular, alternating arrangement of the building blocks in the
polymer backbone.
# 2003 Elsevier Science B.V. All rights reserved.
Keywords: Aminosilanes; Oligosilanes; Silyl triflates
1. Introduction
HPh2Siꢀ [18] have been reported. The first two
derivatives are postulated active species generated in
situ in the presence of quenching agents, and the last is
obtained in about 10% yield and tends to polymerize
readily.
Stable, functional substituted silyl anions are firstly
described by the groups of Tamao [19,20] and Roewer
and coworkers [21]. (Dialkylamino)phenyl substituted
chlorosilanes are able to form silyllithium compounds.
Because the generated lithium species have an unusually
high stability, compared with the other known silyl-
lithium compounds, they are useful synthons for the
synthesis of oligosilane structures. (Aminosilyl)lithium
compounds readily react with chlorosilanes to yield a
varity of aminosubstituted oligosilanes. By treatment
with acyl chloride [19,22] or hydrogen chloride [23,24],
these amino-oligosilanes can be converted into chloro-
Polysilanes have received much attention due to their
interesting chemical and physical properties [1,2]. To
investigate these properties, synthetic methodologies for
structurally well-defined oligosilanes have been devel-
oped. The standard method for the SiÃ
/
Si chain elonga-
tion is based on a combination of two steps: (1) coupling
of (organosilyl)lithium compounds with silanes bearing
good leaving groups (halogen, triflate) and (2) conver-
sion of the organic groups (phenyl, para-tolyl, para-
anisyl, allyl) on the silicon atoms in good leaving groups
[3Á
successful in the syntheses of dendric polysilanes with
regular three-dimensional structures [6Á10].
/
5]. Based on this methodology, several groups were
/
Synthetically useful silyl anions have long been
limited to only several simple triorganosilyl anions
such as Ph3Siꢀ, Ph2MeSiꢀ, PhMe2Siꢀ [11], Me3Siꢀ
oligosilanes, which work as precursors for further SiÃ
/Si
chain elongation. In the reaction of (aminosilyl)lithium
compounds with chloro-oligosilanes, however, cleavage
[12Á
/
14] and (Me3Si)3Siꢀ [15]. Although three functional
silyl anions, Cl3Siꢀ [16], (RO)nMe3ꢀnSiꢀ [17], and
of the SiÃ
coupling products. Moreover, metalÁ
processes cannot be suppressed. Therefore, Tamao
proposed the use of the mixed reagent (R2N)R2SiLiÁ
/Si bond often occurs to lower the yields of the
/halogen exchange
* Tel.: ꢁ
/
41-163-34505; fax: ꢁ
/41-163-21149.
E-mail address: uhlig@inorg.chem.ethz.ch (W. Uhlig).
/
0022-328X/03/$ - see front matter # 2003 Elsevier Science B.V. All rights reserved.
doi:10.1016/S0022-328X(03)00158-X

W. Uhlig / Journal of Organometallic Chemistry 685 (2003) 70Á
/78
71
R1MgBr [25]. The authors assume the in situ formation
of (aminosilyl)alkylmagnesium species. The selectivity of
the silylation increases as the alkyl group R1 became
bulkier. Side reactions were completely suppressed in the
lyl)lithium compound dissolved in THF. The reaction
proceed very quickly and ROP of THF is not observed
under these conditions. The trisilanes 1aÁ
the disilanes 4aÁ4c can be converted by reaction with
triflic acid into the trisilanyl bis(triflates) 2aÁ2c and
disilanyl triflates 5aÁ5c, respectively. These compounds
/
1c as well as
/
case of R1ꢂ
i-propyl. This method is highly effective, if
/
/
the chloro-oligosilane does not contain any other
functional groups. However, i-PrMgBr is regenerated
during the silylation process and can attack functional
/
are precursors for further chain elongation. The reaction
with [(diethylamino)diphenylsilyl]lithium leads to the
groups, for instance SiÃ
/
H bonds. Our investigations in
28] have shown that
pentasilanes 3aÁ
/
3c and the trisilanes 6aÁ6c.
/
the field of silyl triflates [26Á
/
The reaction of [bis(diethylamino)phenylsilyl]lithium
[21] with silyl triflates proceeds analogously. The
formation of the disilane 7 is shown in Scheme 3 as an
example. Conversion with triflic acid and chain elonga-
tion with LiSiPh2(NEt2) lead to the branched tetrasilane
9.
organolithium and organomagnesium compounds react
rapidly and completely with silyl triflates at low
temperatures. Interestingly, it was found that no ex-
change processes analogous to metalÁhalogen exchange
/
occur. Therefore we investigated systematic, stepwise
syntheses of oligosilanes and organosilicon polymers
from silyl triflates and (aminosilyl)lithium anions.
The described reaction pathways are useful for the
synthesis of new structurally well-defined organosilicon
polymers. Recently, we reported on the synthesis of
hydrogen-rich organosilicon polymers from a,v-bis(tri-
2. Results and discussion
fluoromethylsulfonyloxy)-substituted
organosilicon
compounds and organometallic dinucleophiles [31,32].
The polymers were obtained in excellent yields. Ex-
The highly reactive silyl triflates and silyl bis(triflates)
are obtained by reaction of the corresponding aminosi-
lanes with triflic acid in diethyl ether as shown in
Schemes 1 and 2 [29]. The substitution patterns at the
silicon atoms are variable. Functional substituted si-
lanes, e.g. vinyl, allyl or hydrogen derivatives, can also
be obtained. [(Diethylamino)diphenylsilyl]lithium is
formed from (diethylamino)diphenylchlorosilane with
change processes analogous to metalÁhalogen exchange
/
or other side reaction were not observed. Consequently,
a regular alternating arrangement of organosilicon and
organic groups was found in the polymeric backbone,
indicated by narrow signals in the 29Si-NMR spectra.
The terminal triflate substituted disilanes, disilylalkynes
and 1,4-disilylbenzenes can be modified by reaction with
[(diethylamino)diphenylsilyl]lithium. We obtained the
tetrasilane 10, the 1,2-bis(disilanyl)ethyne 11 and 1,4-
bis(disilanyl)benzene 12 (Scheme 4). This compounds
contain terminal amino groups, which can be exchanged
by triflic acid. It should be emphasized that compounds
lithium in THF. Yields of both reactions are high (90Á
/
95%). Therefore, the products are used for following
reaction without further purification. Silyl triflates and
(aminosilyl)lithium compounds react to give aminosub-
stituted trisilanes 1aÁ
/
1c (Scheme 1) and disilanes 4aÁ4c
/
(Scheme 2). It must be considered, that silyl triflates are
not stable in THF for an extended time, because they
can initiate the cationic ring-opening polymerization
(ROP) of cyclic ethers [30]. Therefore, the silyl triflate
(in diethyl ether) is added in drops to the (aminosi-
10Á/12 contain several different bonds, which can be
easily cleaved by triflic acid, e.g. SiÃ
/
Ph, and SiÃH. But
/
the amino substituent is the best leaving group [26]. We
obtained selectively the triflate substituted derivatives
Scheme 1.

72
W. Uhlig / Journal of Organometallic Chemistry 685 (2003) 70Á78
/
Scheme 2.
13Á
/
15 (Scheme 5). These compounds are new useful
unsaturated organic groups. The syntheses are carried
out using a small excess of the organolithium com-
pound. Under these conditions we obtained polymers
containing terminal ethyne or thienylene groups after
hydrolysis of the reaction mixture. Contrary, a small
excess of the bis(triflate) derivative leads to copolymers
with terminal triflate groups. After hydrolysis these
polymers always involve small proportions of undesired
siloxy units in the backbone.
precursors for organosilicon polymers.
Further synthetic modifications of 13 and 14 are
summarized in Schemes 6 and 7. Conversions of 15 are
described in [33]. The reaction with LiSiPh2(NEt2) leads
to the elongation of the silicon chain (16,20). The
reduction with the graphite intercallation compound
C8K gave the copolysilane 18 and the copolymer 22,
which contains an alternating arrangement of tetrasilane
units and ethyne groups in the backbone. The best
results were obtained using the ‘inverse reducing
method’ (addition of C8K in portions to the silyl triflate
solution). Otherwise, an excess of the strong reducing
We could confirm the formation of 16Á23 at low
/
temperatures, in short reaction times, and with high
yields. The structural characterization was mainly based
on NMR spectroscopy. 29Si-NMR chemical shifts are
particularly useful. The 1H-, 13C-, and 29Si-NMR
spectra of all compounds are consistent with the
proposed structures of the polymer chain. As expected,
one observes relatively broad signals, which are typical
for organosilicon polymers. However, the half-band
agent C8K leads to SiÃ
of triflate ions. The organometallic dinucleophiles 1,2-
dilithioethyne LiCÅCLi and 2,5-dilithiothienylene
LiC4H2SLi react with 13 and 14 to give the copolymers
17, 19, 21, 23. These compounds are characterized by a
regular alternating arrangement of oligosilane units and
/
Si bond cleavage and reduction
/
widths of the 29Si-NMR signals, 80Á
150 Hz, are
/
Scheme 3.

W. Uhlig / Journal of Organometallic Chemistry 685 (2003) 70Á
/78
73
Scheme 4.
narrower than those in the case of organosilicon
polymers prepared from chlorosilanes (100Á250 Hz).
The narrower signals of 17Á19 and 21Á23 indicate the
regular alternating arrangement of the building blocks
in the polymer backbone resulting from the fact that the
condensation reactions are not accompanied by ex-
to determine the content of the organometallic com-
pounds quantitatively before use. However, molecular
weights can also fall below 5000 when diluted solutions
are used. Other changes such as the use of different
solvents and reaction temperatures are being currently
investigated. Thus, molecular weights reported in the
experimental section are those found under the condi-
tions specified there.
The described polymers are solids. They are soluble in
the usual organic solvents such as toluene, chloroform,
and THF. Defined melting points are not observed. The
solids become highly viscous fluids, with concentration
of volume, at temperatures between 170 and 220 8C.
These conversions occur within temperature intervals of
about 208. Moreover, decomposition (hydrogen elim-
ination) is observed during the melting process. Further
work will be directed to investigations of the thermal
behaviour of the compounds.
/
/
/
change processes analogous to metalÁhalogen exchange.
/
The 13C-NMR data also support this view. Thus, only
isolated ethynyl groups (d13C: 112 ppm) are detectable
in the spectra of 17, and 21. Diethynyl units Ã
CÅCÃ
(d13C: 82 ppm*; 90 ppm8), which are produced in
variable yields (5Á15%) by the reaction of Li2C2 with
dihalogenosilanes, are not observed. Weight-average
molecular weights in the range of Mwꢂ8000Á16 000,
relative to polystyrene standards, were found by GPC.
They correspond to polymerization degrees of nꢂ15Á
30. The polydispersities (Mw/Mn) were found in the
range 2.5Á3.1. It must be emphasized, that the mole-
/
C*Å
/
C8Ã
/
/
/
/
/
/
/
/
/
cular weights are strongly determined by the reaction
conditions. Higher values of Mw were obtained using
more concentrated solutions of the reactants. The exact
compliance with the stoichiometric ratio of 1:1 is
another important requirement. It is therefore necessary
In general, polymers composed of alternating silylene
units and p-electron systems are insulators. However,
when the polymers are treated with an oxidizing agent,
they became conducting. Preliminary doping studies
showed, when cast films of selected polymers were
Scheme 5.

74
W. Uhlig / Journal of Organometallic Chemistry 685 (2003) 70Á78
/
Scheme 6.
exposed to iodine vapor under reduced pressure, that
the conductivity of the films increased and reached
almost constant values after 10 h. The conductivity at
3. Experimental
3.1. General
this point was found to be 3.6ꢃ
/
10ꢀ5 (19) and 8.9ꢃ
/
10ꢀ5 S cmꢀ1 (23).
All reactions were carried out under nitrogen or argon
using Schlenk tubes. Solvents were dried and distilled
before use. The strongly hygroscopic triflic acid must be
distilled before use and should be kept under nitrogen.
Traces of moisture in CF3SO3H always led to undesired
formation of siloxanes during the protodeamination reac-
tion. Detailed information about the purification is
included in [34], chapter 7. The 1H-, 13C-, and 29Si-
NMR spectra are obtained on a Bruker AC-250
Obviously, the synthetic methods described here may
currently appear to be too expensive for technical
application. However, the essential advantage of the
silyl triflate chemistry consists of the possibility of
preparing, with relatively little efforts, small amounts
of numerous differently structured organosilicon poly-
mers for investigations in the field of materials and
surface science.
Scheme 7.

W. Uhlig / Journal of Organometallic Chemistry 685 (2003) 70Á
/78
75
spectrometer; the chemical shifts are relative to tetra-
methylsilane. The 29Si-NMR spectra were measured for
solutions containing 0.1 mol.% of the relaxation reagent
Cr(acac)3. The average molecular weights of the poly-
mers were determined by GPC. Solutions of silyl
triflates in THF are not stable for an extended time,
because they can initiate the cationic ROP of cationic
ethers. However, reactions of silyl triflates with organo-
lithium or organomagnesium compounds dissolved in
THF can be carried out, because these reactions proceed
very quickly. The following derivatives were prepared by
oils in high yields (90Á
products were obtained in higher than 95% chemoselec-
tivity as indicated from NMR measurements. The
/
95%). The desired coupling
disilanes 4aÁ
Attempts to distillate the higher oligosilanes were not
successful. The compounds were decomposed. 1aÁc,
3aÁc, 6aÁc, 9, 10, 16, 20 can be recrystallized from
dichloromethane to give the oligosilanes as white
crystalls (25Á30%). Because of the substantial loss of
/
4c and 7 can be purified by distillation.
/
/
/
/
yield during distillation and recrystallization it is re-
commended to use the raw products for further reac-
published methods: Li2C2 [35], C8K [36], (TfO)H2SiÃ
SiH2(OTf) [31], (Et2N)Ph2SiCl [20], (Et2N)2PhSiCl [21],
MeRSi(OTf)2 [26,29], LiÃC4H2SÃLi [37,38].
/
XÃ
/
tions without purification.
1
1a: M.p.: 143Á
/
146 8C. H-NMR (C6D6): dꢂ
/
0.21 (d,
/
/
MeSi), 0.96 (t, CH3), 2.97 (q, NCH2), 3.77 (q, SiH),
7.22Á 3.7
7.53 (Ph). 13C{1H}-NMR (C6D6): dꢂ
(MeSi), 14.4 (CH3), 40.6 (CH2N), 126.8, 128.3, 134.7,
140.6 (Ph). 29Si{1H}-NMR (C6D6): dꢂ
14.7 (SiN);
63.0 (SiH). Anal. Calc. for C33H44N2Si3 (553.0): C,
/
/
ꢀ
/
3.2. Synthesis of [(diethylamino)diphenylsilyl]lithium
[19]
/
ꢀ
/
ꢀ
/
To a suspension of 0.7 g (0.1 mol) lithium in THF (50
ml) was added at 0 8C a solution of 2.9 g (0.01 mol)
(Et2N)Ph2SiCl dissolved in THF (50 ml). After 5 min the
start of the reaction was indicated by a greenish
coloured solution. After stirring for 4 h the lithiation
was completed and the solution was separated from the
lithium for using in further reactions. From NMR
spectroscopic measurements we conclude, that the
reaction proceeds quantitatively.
71.68; H, 8.02; N, 5.07. Found: C, 71.44; H, 7.77; N,
4.80.
1
1b: M.p.: 157Á
/
161 8C. H-NMR (C6D6): dꢂ
/
0.53 (s,
7.56 (Ph).
3.1 (MeSi), 15.1 (CH3),
39.8 (CH2N), 126.5, 127.9, 135.2, 141.3 (Ph). 29Si{1H}-
NMR (C6D6): dꢂ 15.7 (SiN); ꢀ37.4 (SiMe). Anal.
Me2Si), 0.92 (t, CH3), 2.94 (q, NCH2), 7.19Á
/
13C{1H}-NMR (C6D6): dꢂ
/
ꢀ
/
/
ꢀ
/
/
Calc. for C34H46N2Si3 (567.0): C, 72.02; H, 8.18; N,
4.94. Found: C, 71.56; H, 8.11; N, 5.13.
1
1c: M.p.: 149Á
/
153 8C. H-NMR (C6D6): dꢂ
/
0.64 (s,
6.43 (m, Vi),
7.61 (Ph). 13C{1H}-NMR (C6D6): dꢂ
3.9
3.3. Synthesis of [bis(diethylamino)phenylsilyl]lithium
[21]
MeSi), 0.95 (t, CH3), 3.00 (q, NCH2), 5.67Á
/
7.15Á
/
/
ꢀ
/
(MeSi), 15.7(CH3), 40.9 (CH2N), 127.1, 128.0, 135.0,
140.9 (Ph), 133.6, 136.1 (Vi). 29Si{1H}-NMR (C6D6):
To a suspension of 0.7 g (0.1 mol) lithium in THF (50
ml) was added at 0 8C a solution of 2.85 g (0.01 mol)
(Et2N)2PhSiCl dissolved in THF (50 ml). After 5 min the
start of the reaction was indicated by a greenish
coloured solution. After stirring for 4 h the lithiation
was completed and the dark red solution was separated
from the lithium for using in further reactions. The 29Si-
NMR spectrum of the solution shows only one signal
dꢂ
/
ꢀ
/
15.0 (SiN);
ꢀ40.6 (SiVi). Anal. Calc. for
/
C35H46N2Si3 (579.0): C, 72.60; H, 8.01; N, 4.84. Found:
C, 72.27; H, 7.68; N, 5.11.
1
3a: M.p.: ꢀ
/
200 8C (dec.). H-NMR (C6D6): dꢂ
/0.23
(d, MeSi), 0.99 (t, CH3), 3.04 (q, NCH2), 3.67 (q, SiH),
7.16Á 3.3
7.66 (Ph). 13C{1H}-NMR (C6D6): dꢂ
(MeSi), 14.6 (CH3), 39.5 (CH2N), 127.0Á141.5 (Ph).
29Si{1H}-NMR (C6D6): dꢂ
15.9 (SiN), ꢀ36.8 (SiPh),
62.5 (SiH). Anal. Calc. for C57H64N2Si5 (917.6): C,
/
/
ꢀ
/
/
(dꢂ
/
ꢁ
/
27.5 ppm).
/
ꢀ
/
/
ꢀ
/
3.4. Formation of SiÃ
/
Si bonds by reaction of silyl
74.61; H, 7.03; N, 3.05. Found: C, 75.02; H, 6.86; N,
2.80.
triflates with (aminosilyl)lithium compounds (general
procedure)
1
3b: M.p.: ꢀ
/
200 8C (dec.). H-NMR (C6D6): dꢂ
/0.57
(s, Me2Si), 0.98 (t, CH3), 3.00 (q, NCH2), 7.13Á
(Ph). 13C{1H}-NMR (C6D6): dꢂ
(CH3), 40.4 (CH2N), 126.0Á
(C6D6): dꢂ 14.0 (SiN); ꢀ
Anal. Calc. for C58H66N2Si5 (931.6): C, 74.78; H, 7.14;
N, 3.01. Found: C, 75.19; H, 7.30; N, 2.85.
/
7.72
The corresponding silyl triflate (0.005 mol of silyl
bis(triflate) or 0.01 mol of silyl triflate) dissolved in 50
ml of diethyl ether was added to a solution of the
(aminosilyl)lithium compound (0.01 mol), in 100 ml of a
THF, at 0 8C within 10 min. The reaction mixture was
stirred at room temperature for 2 h. After that time the
solution became colourless. The solvent was removed
under reduced pressure and replaced by 100 ml of
toluene. Lithium triflate precipitated as a white solid
and was filtered off. Toluene was removed under
vacuum leaving the oligosilanes as yellow, highly viscous
/
ꢀ
/
2.9 (MeSi), 14.7
141.5 (Ph). 29Si{1H}-NMR
34.3 (SiMe); ꢀ37.6 (SiPh).
/
/
ꢀ
/
/
/
1
3c: M.p.: ꢀ
/
200 8C (dec.). H-NMR (C6D6): dꢂ
/
0.68
6.54 (m,
7.80 (Ph). 13C{1H}-NMR (C6D6): dꢂ
4.1
(MeSi), 16.0 (CH3), 41.4 (CH2N), 126.5Á140.5 (Ph),
132.9, 137.0 (Vi). 29Si{1H}-NMR (C6D6): dꢂ
14.8
(SiN), ꢀ37.1 (SiPh), ꢀ40.0 (SiVi). Anal. Calc. for
(s, MeSi), 0.99 (t, CH3), 2.89 (q, NCH2), 5.71Á
/
Vi), 7.02Á
/
/
ꢀ
/
/
/
ꢀ
/
/
/

76
W. Uhlig / Journal of Organometallic Chemistry 685 (2003) 70Á78
/
C59H66N2Si5 (943.6): C, 75.10; H, 7.05; N, 2.97. Found:
C, 74.66; H, 6.77; N, 3.09.
139.9 (Ph). 29Si{1H}-NMR (C6D6): dꢂ
39.1 (SiH). IR (film): nꢂ
2149 (SiH) cmꢀ1. Anal.
Calc. for C16H32N2Si2 (308.6): C, 62.27; H, 10.45; N,
/
ꢀ
/
11.8 (SiN),
ꢀ
/
/
4a: B.p. 115Á
0.27 (d, MeSi), 0.94 (t, CH3), 2.93 (q, NCH2), 3.81 (sept,
SiH), 7.21Á 3.0
7.57 (Ph). 13C{1H}-NMR (C6D6): dꢂ
(MeSi), 14.8 (CH3), 40.9 (CH2N), 127.0, 128.9, 135.0,
140.4 (Ph). 29Si{1H}-NMR (C6D6): dꢂ
16.0 (SiN);
39.5 (SiH). IR (film): nꢂ
2142 (SiH) cmꢀ1. Anal.
/
118 8C/0.5 mbar. 1H-NMR (C6D6): dꢂ
/
9.08. Found: C, 61.98; H, 10.37; N, 8.88.
1
/
/
ꢀ
/
9: M.p.: ꢀ
/
200 8C (dec.). H-NMR (C6D6): dꢂ
/0.25
(d, MeSi), 1.06 (t, CH3), 2.91 (q, NCH2), 3.84 (sept,
SiH), 7.03Á 3.5
7.91 (Ph). 13C{1H}-NMR (C6D6): dꢂ
(MeSi), 15.6 (CH3), 42.1 (CH2N), 128.0Á140.0 (Ph).
29Si{1H}-NMR (C6D6): dꢂ
14.7 (SiN), ꢀ40.4 (SiH),
75.6 (PhSiSi3). IR (film): nꢂ
2151 (SiH) cmꢀ1. Anal.
/
ꢀ
/
/
/
ꢀ
/
ꢀ
/
/
/
Calc. for C18H27NSi2 (313.6): C, 68.94; H, 8.68; N, 4.47.
Found: C, 69.25; H, 8.35; N, 4.42.
/
ꢀ
/
/
ꢀ
/
/
4b: B.p. 128Á
0.61 (s, MeSi), 0.99 (t, CH3), 2.89 (q, NCH2), 5.72Á
(m, Vi), 7.12Á
7.66 (Ph). 13C{1H}-NMR (C6D6): dꢂ
4.1 (MeSi), 14.0(CH3), 39.5 (CH2N), 126.8, 128.2,
134.2, 140.1 (Ph), 132.6, 135.1 (Vi). 29Si{1H}-NMR
(C6D6): dꢂ 17.0 (SiN), ꢀ21.7 (SiVi). Anal. Calc. for
/
132 8C/0.8 mbar. 1H-NMR (C6D6): dꢂ
/
Calc. for C40H52N2Si4 (672.3): C, 71.37; H, 7.79; N,
4.16. Found: C, 71.09; H, 7.88; N, 4.00.
/
6.51
1
/
/
10: M.p.: ꢀ
/
200 8C (dec.). H-NMR (C6D6): dꢂ
/
0.98
7.56 (Ph).
16.0 (CH3), 42.3 (CH2N),
127.2, 128.4, 135.8, 140.4 (Ph). 29Si{1H}-NMR (C6D6):
ꢀ
/
(t, CH3), 2.97 (q, NCH2), 3.91 (s, SiH), 7.22Á
/
13C{1H}-NMR (C6D6): dꢂ
/
/
ꢀ
/
/
C20H29NSi2 (339.6): C, 70.73; H, 8.61; N, 4.12. Found:
C, 71.14; H, 8.30; N, 3.87.
dꢂ
/
ꢀ
/
17.8 (SiN), ꢀ
/
81.5 (SiH). IR (film): nꢂ2147 (SiH)
/
cmꢀ1. Anal. Calc. for C32H44N2Si4 (569.1): C, 67.54; H,
7.79; N, 4.92. Found: C, 67.13; H, 7.48; N, 5.19.
1
4c: B.p. 130Á
/
134 8C/0.5 mbar. H-NMR (C6D6): dꢂ
/
0.38 (s, MeSi), 0.91 (t, CH3), 2.96 (q, NCH2), 1.54 (d,
SiCH2), 4.92 (m, CH2), 5.98 (m, CH), 7.12Á7.66 (Ph).
13C{1H}-NMR (C6D6): dꢂ
3.0 (MeSi), 15.2 (CH3),
40.0 (CH2N), 126.5, 127.9, 134.8, 141.0 (Ph), 12.4, 115.7,
136.7 (Allyl). 29Si{1H}-NMR (C6D6): dꢂ
16.5 (SiN),
18.1 (SiAllyl). Anal. Calc. for C21H31NSi2 (353.7): C,
11: 1H-NMR (C6D6): dꢂ
NCH2), 3.98 (s, SiH), 7.21Á
(C6D6): dꢂ15.5 (CH3), 39.8 (NCH2), 111.2 (CÅ
126.5, 127.9, 135.1, 141.2 (Ph). 29Si{1H}-NMR (C6D6):
dꢂ 16.2 (SiN), ꢀ74.9 (SiCÅC). IR (film): nꢂ2144
(SiH), 2034 (CÅ
C) cmꢀ1. Anal. Calc. for C34H44N2Si4
/
0.93 (t, CH3), 2.87 (q,
7.58 (Ph). 13C{1H}-NMR
C),
/
/
/
ꢀ
/
/
/
/
ꢀ
/
/
ꢀ
/
/
/
/
ꢀ
/
/
71.32; H, 8.84; N, 3.96. Found: C, 70.95; H, 8.56; N,
4.13.
(593.1): C, 68.86; H, 7.48; N, 4.72. Found: C, 68.56; H,
7.36; N, 4.55.
1
6a: M.p.: 161Á
/
165 8C. H-NMR (C6D6): dꢂ
/0.31 (d,
12: 1H-NMR (C6D6): dꢂ
/
0.97 (t, CH3), 2.95 (q,
7.67 (Ph). 13C{1H}-NMR
14.6 (CH3), 40.3 (NCH2), 127.0Á142.5 (Ph).
29Si{1H}-NMR (C6D6): dꢂ
18.8 (SiN), ꢀ60.9 (SiH).
IR (film): nꢂ
2152 (SiH) cmꢀ1. Anal. Calc. For
MeSi), 0.97 (t, CH3), 2.96 (q, NCH2), 3.88 (sept, SiH),
7.06Á 4.1
7.88 (Ph). 13C{1H}-NMR (C6D6): dꢂ
(MeSi), 16.0 (CH3), 42.7 (CH2N), 127.0Á141.5 (Ph).
29Si{1H}-NMR (C6D6): dꢂ
14.9 (SiN), ꢀ36.5 (SiPh),
39.5 (SiH). IR (film): nꢂ
2139 (SiH) cmꢀ1. Anal.
NCH2), 4.17 (s, SiH), 7.04Á
/
/
/
ꢀ
/
(C6D6): dꢂ
/
/
/
/
ꢀ
/
/
/
ꢀ
/
/
/
ꢀ
/
/
C38H48N2Si4 (645.1): C, 70.75; H, 7.50; N, 4.34. Found:
C, 71.02; H, 7.28; N, 4.29.
16: M.p.: ꢀ
Calc. for C30H37NSi3 (495.9): C, 72.66; H, 7.52; N, 2.82.
Found: C, 72.97; H, 7.53; N, 2.70.
1
/
200 8C (dec.). H-NMR (C6D6): dꢂ
/
0.91
7.67 (Ph).
14.7 (CH3), 41.9 (CH2N),
140.5 (Ph). 29Si{1H}-NMR (C6D6): dꢂ
16.5
2149
1
6b: M.p.: 170Á
/
174 8C. H-NMR (C6D6): dꢂ
/
0.65 (s,
6.55 (m, Vi),
7.81 (Ph). 13C{1H}-NMR (C6D6): dꢂ
3.6
(MeSi), 14.8 (CH3), 41.4 (CH2N), 126.5Á140.5 (Ph),
132.6, 135.1 (Vi). 29Si{1H}-NMR (C6D6): dꢂ
17.0
(SiN), ꢀ21.7 (SiVi), ꢀ37.9 (SiPh). Anal. Calc. for
(t, CH3), 2.88 (q, NCH2), 3.93 (s, SiH), 7.15Á
13C{1H}-NMR (C6D6): dꢂ
127.0Á
(SiN), ꢀ
/
MeSi), 1.01 (t, CH3), 2.87 (q, NCH2), 5.66Á
/
/
7.08Á
/
/
ꢀ
/
/
/
ꢀ
/
/
/
37.1 (SiPh), ꢀ
/
82.7 (SiH). IR (film): nꢂ
/
/
ꢀ
/
(SiH) cmꢀ1. Anal. Calc. for C56H64N2Si6 (932.6): C,
72.04; H, 6.91; N, 3.00. Found: C, 71.84; H, 7.10; N,
2.92.
/
/
C32H39NSi3 (521.9): C, 73.64; H, 7.53; N, 2.68. Found:
C, 73.35; H, 7.47; N, 2.65.
1
20: M.p.: ꢀ
/
200 8C (dec.). H-NMR (C6D6): dꢂ
/
0.94
7.83 (Ph).
14.5 (CH3), 40.1 (CH2N),
142.0 (Ph). 29Si{1H}-NMR (C6D6):
36.8 (SiPh), ꢀ79.7 (SiH). IR (film):
2139 (SiH), 2032 (CÅ
C) cmꢀ1. Anal. Calc. for
1
6c: M.p.: 162Á
/
167 8C. H-NMR (C6D6): dꢂ
/
0.33 (s,
(t, CH3), 2.95 (q, NCH2), 4.01 (s, SiH), 7.11Á
13C{1H}-NMR (C6D6): dꢂ
112.3 (CÅC), 128.0Á
dꢂ 14.9 (SiN), ꢀ
nꢂ
/
MeSi), 0.95 (t, CH3), 2.99 (q, NCH2), 1.61 (d, SiCH2),
4.99 (m, CH2), 6.02 (m, CH), 7.04Á
7.75 (Ph). 13C{1H}-
NMR (C6D6): dꢂ 3.6 (MeSi), 14.8 (CH3), 40.9
(CH2N), 126.5Á141.0 (Ph), 12.9, 116.5, 137.7 (Allyl).
29Si{1H}-NMR (C6D6): dꢂ
16.5 (SiN), ꢀ18.1 (SiAl-
lyl), ꢀ36.2 (SiPh). Anal. Calc. for C33H41NSi3 (535.9):
/
/
/
/
/
ꢀ
/
/
ꢀ
/
/
/
/
/
/
/
ꢀ
/
/
C58H64N2Si6 (956.7): C, 72.74; H, 6.74; N, 2.93. Found:
/
C, 72.81; H, 6.65; N, 2.79.
C, 73.95; H, 7.71; N, 2.61. Found: C, 74.19; H, 7.90; N,
2.49.
3.5. Reaction of aminosilanes with triflic acid (conversion
of silyl amino in silyl triflate groups, general procedure)
1
7: B.p. 111Á
/
114 8C/0.3 mbar. H-NMR (C6D6): dꢂ
/
0.28 (d, MeSi), 1.02 (t, CH3), 2.87 (q, NCH2), 3.76 (sept,
SiH), 7.22Á 2.4
7.53 (Ph). 13C{1H}-NMR (C6D6): dꢂ
(MeSi), 15.1 (CH3), 40.9 (CH2N), 126.3, 128.0, 135.6,
/
/
ꢀ
/
A solution of triflic acid (0.02 mol per each silyl
amino group) in 50 ml of diethyl ether was added to a

W. Uhlig / Journal of Organometallic Chemistry 685 (2003) 70Á
/78
77
solution of the aminosilane (0.01 mol) in 100 ml of
diethyl ether at 0 8C over 30 min with stirring. The
ammonium salt of triflic acid precipitated quantitatively
as white solid and was filtered off. The solvent was
removed under reduced (50 8C/1 mbar) and the silyl
triflates were obtained as pale yellow oils.
13: 1H-NMR (C6D6): dꢂ
(Ph). 13C{1H}-NMR (C6D6): dꢂ
/
4.16 (s, SiH), 7.09Á
/
7.73
/
117.6 (CF3), 126.6,
128.1, 136.0, 140.8 (Ph). 29Si{1H}-NMR (C6D6): dꢂ
/
ꢁ
/
15.3 (SiOTf), ꢀ
/
77.0 (SiH). IR (film): nꢂ2147 (SiH)
/
cmꢀ1. Anal. Calc. for C26H24F6O6S2Si4 (722.9): C,
43.20; H, 3.35. Found: C, 42.98; H, 3.45.
Attention! Silyl triflates containing SiÃ
/H bonds
14: 1H-NMR (C6D6): dꢂ
(Ph). 13C{1H}-NMR (C6D6): dꢂ
(CF3), 126.5Á
140.5 (Ph). 29Si{1H}-NMR (C6D6): dꢂ
18.6 (SiOTf), ꢀ72.9 (SiH). IR (film): nꢂ2153 (SiH),
2031 (CÅ
C) cmꢀ1. Anal. Calc. For C28H24F6O6S2Si4
(746.9): C, 45.02; H, 3.24. Found: C, 45.46; H, 3.01.
15: 1H-NMR (C6D6): dꢂ
4.28 (s, SiH), 6.97Á7.71
(Ph). 13C{1H}-NMR (C6D6): dꢂ
127.0Á142.5 (Ph).
29Si{1H}-NMR (C6D6): dꢂ
17.3 (SiOTf), ꢀ61.6
(SiH). IR (film): nꢂ
2156 (SiH) cmꢀ1. Anal. Calc. For
/
4.13 (s, SiH), 7.11Á
/
7.64
should not be distilled. Attempts to distill these com-
pounds often lead to explosion.
/
111.2 (CÅC), 117.3
/
/
/
2a: 1H-NMR (C6D6): dꢂ
/
0.37 (d, MeSi), 3.88 (q,
7.86 (Ph). 13C{1H}-NMR (C6D6): dꢂ
1.5
(MeSi), 118.4 (CF3), 125.5, 126.3, 132.0, 138.3 (Ph).
29Si{1H}-NMR (C6D6): dꢂ
16.5 (SiOTf), ꢀ61.3
(SiH). IR (film): nꢂ
2153 (SiH) cmꢀ1. Anal. Calc. for
ꢁ
/
/
/
SiH), 7.09Á
/
/
ꢀ
/
/
/
ꢁ
/
/
/
/
/
/
/
C27H24F6O6S2Si3 (706.8): C, 45.88; H, 3.42. Found: C,
46.17; H, 3.67.
/
ꢁ
/
/
/
1
2b: H-NMR (C6D6): dꢂ
/
0.67 (s, Me2Si), 7.04Á
0.9 (MeSi),
117.8(CF3), 125.0, 125.9, 132.4, 138.3 (Ph). 29Si{1H}-
NMR (C6D6): dꢂ 17.8 (SiOTf), ꢀ38.3 (SiMe). Anal.
/
7.79
C32H28F6O6S2Si4 (799.0): C, 48.10; H 3.53. Found: C,
47.77; H, 3.39.
(Ph). 13C{1H}-NMR (C6D6): dꢂ
/
ꢀ
/
/
ꢁ
/
/
3.6. Synthesis of the polymers 17, 19, 21, 23 (general
procedure)
Calc. for C28H26F6O6S2Si3 (720.9): C, 46.65; H, 3.64.
Found: C, 46.25; H, 3.55.
1
2c: H-NMR (C6D6): dꢂ
/
0.73 (s, MeSi), 5.59ꢀ
7.77 (Ph). 13C{1H}-NMR (C6D6): dꢂ
1.7 (MeSi), 118.2 (CF3), 125.3, 127.0, 133.1, 140.2
(Ph), 132.0, 136.1 (Vi). 29Si{1H}-NMR (C6D6): dꢂ
16.0 (SiOTf), 42.1 (SiVi). Anal. Calc. for
/
6.38
The silyl bis(triflates) 13 or 14, respectively (0.02 mol)
dissolved in 100 ml of diethyl ether were added to a
slurry or solution of the corresponding organolithium
compound (Li2C2 or LiC4H2SLi, 0.021 mol), in 200 ml
of THF, at 0 8C within 10 min. The reaction mixture
was stirred at room temperature for 2 h. Afterwards 2
ml of isopropanol were added to destroy remaining
traces of the organometallic reagents. The solvent was
removed under reduced pressure and replaced by 300 ml
of toluene. Lithium triflate precipitated as a white solid
and was filtered off. Toluene was removed under
(m, Vi), 7.04ꢀ
/
/
ꢀ
/
/
ꢁ
/
ꢀ
/
C29H24F6O6S2Si3 (732.9): C, 47.53; H, 3.58. Found: C,
47.16; H, 3.34.
1
5a: H-NMR (C6D6): dꢂ
/
0.55 (d, MeSi), 3.73 (sept,
7.81 (Ph). 13C{1H}-NMR (C6D6): dꢂ
1.0
(MeSi), 117.6 (CF3), 124.8, 127.3, 135.1, 139.7 (Ph).
29Si{1H}-NMR (C6D6): dꢂ
17.5 (SiOTf), ꢀ36.8
(SiH). IR (film): nꢂ
2144 (SiH) cmꢀ1. Anal. Calc. for
SiH), 7.03Á
/
/
ꢀ
/
/
ꢁ
/
/
/
vacuum leaving the polymers as yellowÁ
in high yields.
17: M.p.: ꢀ
(s, SiH), 7.25Á
111.6 (CÅC), 126.5Á
(C6D6): dꢂ 38.2 (SiPh), ꢀ
2146 (SiH), 2036 (CÅ
C) cmꢀ1. Mwꢂ
/brown powders
C15H17F3O3SSi2 (390.5): C, 46.13; H, 4.39. Found: C,
45.75; H, 4.20.
1
/
200 8C (dec.). H-NMR (C6D6): dꢂ
7.66 (Ph). 13C{1H}-NMR (C6D6): dꢂ
140.0 (Ph). 29Si{1H}-NMR
82.0 (SiH). IR (film): nꢂ
8300; Mw:Mnꢂ
/
3.92
1
5b: H-NMR (C6D6): dꢂ
/
0.68 (s, MeSi), 5.70Á
7.62 (Ph). 13C{1H}-NMR (C6D6): dꢂ
1.3 (MeSi), 119.5 (CF3), 125.0, 127.4, 135.4, 140.6
(Ph), 132.8, 134.6 (Vi). 29Si{1H}-NMR (C6D6): dꢂ
16.9 (SiOTf), 20.0 (SiVi). Anal. Calc. for
/
6.55
/
/
(m, Vi), 6.99ꢀ
/
/
/
/
ꢀ
/
/
ꢀ
/
/
/
/
ꢁ
/
/
/
/
ꢀ
/
2.5. Anal. Calc. for C26H24Si4 (448.8): C, 69.58; H, 5.39.
C17H19F3O3SSi2 (416.6): C, 49.02; H, 4.60. Found: C,
48.71; H, 4.40.
Found: C, 69.77; H, 5.49.
1
19: M.p.: ꢀ
(s, SiH), 7.18Á
dꢂ127.0Á
141.5 (Ph, Th). 29Si{1H}-NMR (C6D6): dꢂ
21.3 (SiPh), ꢀ82.4 (SiH). IR (film): nꢂ2153 (SiH)
cmꢀ1. Mwꢂ
12 400; Mw:Mnꢂ2.8. Anal. Calc. for
/
200 8C (dec.). H-NMR (C6D6): dꢂ
/
4.04
5c: 1H-NMR (C6D6): dꢂ
/
0.49 (s, MeSi), 1.62 (d,
SiCH2), 4.97 (m, CH2), 5.88 (m, CH), 7.05Á7.61 (Ph).
13C{1H}-NMR (C6D6): dꢂ
2.6 (MeSi), 118.0 (CF3),
126.0, 127.5, 135.6, 139.7 (Ph), 14.1, 116.9, 137.0 (Allyl).
29Si{1H}-NMR (C6D6): dꢂ
17.7 (SiOTf), ꢀ16.9
/
7.64 (Ph, Th). 13C{1H}-NMR (C6D6):
/
/
/
/
/
ꢀ
/
ꢀ
/
/
/
/
/
/
ꢁ
/
/
C28H26SSi4 (506.9): C, 66.34; H, 5.17. Found: C,
66.18; H, 5.31.
(SiAllyl). Anal. Calc. for C18H21F3O3SSi2 (430.6): C,
50.21; H, 4.92. Found: C, 49.83; H, 5.20.
1
21: M.p.: ꢀ
(s, SiH), 7.14Á
111.6, 112.2 (CÅ
(C6D6): dꢂ 36.5 (SiPh), ꢀ
2145 (SiH), 2038 (CÅ
C) cmꢀ1. Mwꢂ
/
200 8C (dec.). H-NMR (C6D6): dꢂ
/3.87
1
8: H-NMR (C6D6): dꢂ
/
0.65 (d, MeSi), 3.87 (sept,
7.89 (Ph). 13C{1H}-NMR (C6D6): dꢂ
1.4
(MeSi), 119.5 (CF3), 127.0, 127.9, 136.2, 141.3 (Ph).
29Si{1H}-NMR (C6D6): dꢂ
1.8 (SiOTf), ꢀ35.7 (SiH).
/
7.71 (Ph). 13C{1H}-NMR (C6D6): dꢂ
C), 128.0Á
141.5 (Ph). 29Si{1H}-NMR
79.7 (SiH). IR (film): nꢂ
15 600; Mw:Mnꢂ
/
SiH), 7.08Á
/
/
/
/
/
ꢀ
/
/
/
/
ꢁ
/
/
/
/
/
Anal. Calc. for C10H12F6O6S2Si2 (462.5): C, 25.97; H,
2.62. Found: C, 26.44; H, 2.44.
2.7. Anal. Calc. for C28H24Si4 (472.8): C, 71.12; H, 5.12.
Found: C, 71.31; H, 5.21.

78
W. Uhlig / Journal of Organometallic Chemistry 685 (2003) 70Á78
/
1
[3] K. Tamao, A. Kawachi, Ad. Organomet. Chem. 38 (1995) 1.
[4] P.D. Lickiss, C.M. Smith, Coord. Chem. Rev. 145 (1995) 75.
[5] J. Belzner, U. Dehnert, in: Z. Rappoport, Y. Apeloig (Eds.), The
Chemistry of Organic Silicon Compounds, vol. 2 (chapter 14),
Wiley, Chichester, 1998 (chapter 14).
23: M.p.: ꢀ
(s, SiH), 7.12Á
dꢂ111.8 (CÅC), 125.5Á
(C6D6): dꢂ 20.8 (SiPh), ꢀ
2138 (SiH), 2041 (CÅ
C) cmꢀ1. Mwꢂ
/
200 8C (dec.). H-NMR (C6D6): dꢂ
7.66 (Ph, Th). 13C{1H}-NMR (C6D6):
139.5 (Ph, Th). 29Si{1H}-NMR
78.9 (SiH). IR (film): nꢂ
13 900; Mw:Mnꢂ
/
3.99
/
/
/
/
/
ꢀ
/
/
/
/
/
/
[6] (a) L.B. Lambert, J.L. Pflug, C.L. Stern, Angew. Chem. 107
(1995) 106;
2.6. Anal. Calc. for C30H26SSi4 (530.9): C, 67.87; H,
(b) L.B. Lambert, J.L. Pflug, C.L. Stern, Angew. Chem. Int. Ed.
Engl. 34 (1995) 98.
4.94. Found: C, 68.01; H, 5.12.
[7] H. Suzuki, Y. Kimata, S. Satoh, A. Kuriyama, Chem. Lett. 24
(1995) 293.
3.7. Synthesis of the polymers 18 and 22 by reduction of
silyl triflates with potassium graphite
[8] A. Sekiguchi, M. Nanjo, C. Kabuto, H. Sakurai, J. Am. Chem.
Soc. 117 (1995) 4195.
[9] J. Lambert, J.L. Pflug, J.M. Denari, Organometallics 15 (1996)
615.
A solution of the silyl bis(triflates) 13 or 14, respec-
tively (0.01 mol) in 150 ml of diethyl ether was stirred at
0 8C. Potassium graphite C8K was added in small
portions over a period of 2 h. Afterwards the mixture
is stirred for 3 h at room temperature. During this time
the colour was changing from gold bronze to black. The
resulting graphite was filtered off. The solvent was
removed under reduced pressure and replaced by 200
ml of toluene. Potassium triflate precipitated as a white
solid and was filtered off. Toluene was removed under
[10] M. Nanjo, A. Sekiguchi, Organometallics 17 (1998) 492.
[11] H. Gilman, G.D. Lichtenwalter, J. Am. Chem. Soc. 80 (1958)
608.
[12] H. Sakurai, A. Okada, M. Kira, K. Yonezawa, Tetrahedron Lett.
12 (1971) 1511.
[13] W.C. Still, J. Org. Chem. 41 (1976) 3063.
[14] R. Corriu, C. Guerin, B. Kolani, Bull. Soc. Chim. Fr. 122 (1985)
974.
[15] J. Dickhaut, B. Giese, Org. Synth. 70 (1991) 164.
[16] R.A. Benkeser, Acc. Chem. Res. 4 (1971) 94.
[17] H. Watanabe, K. Higuchi, T. Goto, T. Muraoka, J. Inose, M.
Kagejama, Y. Iizuka, M. Nozaki, Y. Nagai, J. Organomet. Chem.
218 (1981) 27.
reduced pressure leaving the polymers as yellowÁ
powders in 85Á90% yield.
18: M.p.: ꢀ200 8C (dec.). H-NMR (C6D6): dꢂ
(s, SiH), 7.20Á
127.0Á
139.5 (Ph). 29Si{1H}-NMR (C6D6): dꢂ
(SiPh), ꢀ84.7 (SiH). IR (film): nꢂ
Mwꢂ11100; Mw:Mnꢂ3.1. Anal. Calc. for C24H24Si4
(424.8): C, 67.86; H, 5.69. Found: C, 67.77; H, 5.55.
/
brown
/
1
/
/
3.92
/
7.75 (Ph). 13C{1H}-NMR (C6D6): dꢂ
/
[18] K. Tamao, N. Ishida, T. Tanaka, M. Kumada, Organometallics 2
(1983) 1694.
/
/
ꢀ
/
36.0
[19] (a) K. Tamao, A. Kawachi, Y. Ito, J. Am. Chem. Soc. 114 (1992)
3989;
/
/
2151 (SiH) cmꢀ1
.
/
/
(b) A. Kawachi, K. Tamao, J. Am. Chem. Soc. 122 (2000) 1919.
[20] K. Tamao, A. Kawachi, Y. Nakagawa, Y. Ito, J. Organomet.
Chem. 473 (1994) 29.
1
22: M.p.: ꢀ
(s, SiH), 7.12Á
110.9 (CÅC), 127.0Á
(C6D6): dꢂ 37.1 (SiPh), ꢀ
2138 (SiH), 2040 (CÅ
C) cmꢀ1. Mwꢂ
/
200 8C (dec.). H-NMR (C6D6): dꢂ
7.70 (Ph). 13C{1H}-NMR (C6D6): dꢂ
139.5 (Ph). 29Si{1H}-NMR
81.5 (SiH). IR (film): nꢂ
10 400; Mw:Mnꢂ
/
3.83
[21] K. Trommer, U. Herzog, U. Georgi, G. Roewer, J. Prakt. Chem.
340 (1998) 557.
/
/
/
/
[22] A. Kawachi, K. Tamao, Bull. Chem. Soc. Jpn 70 (1997) 945.
[23] K. Tamao, G.-R. Sun, A. Kawachi, S. Yamaguchi, Organome-
tallics 16 (1997) 780.
/
ꢀ
/
/
/
/
/
/
[24] K. Trommer, U. Herzog, G. Roewer, J. Organomet. Chem. 540
(1997) 119.
2.9. Anal. Calc. for C26H24Si4 (448.8): C, 69.58; H, 5.39.
Found: C, 69.81; H, 5.44.
[25] A. Kawachi, K. Tamao, J. Organomet. Chem. 601 (2000) 259.
[26] W. Uhlig, Chem. Ber. 129 (1996) 733.
[27] W. Uhlig, in: M. Gielen, R. Willem, B. Wrackmeier (Eds.), Solid
State Organometallic Chemistry, Wiley, Chichester, 1999, p. 397.
[28] W. Uhlig, J. Prakt. Chem. 342 (2000) 132.
[29] W. Uhlig, C. Tretner, J. Organomet. Chem. 467 (1994) 31.
[30] J.S. Hrkach, K. Matyjaszewski, J. Polym. Sci. Part A. Polym.
Chem. 33 (1995) 285.
Acknowledgements
This work was supported by the ETH Zurich, by
¨
Schweizer Nationalfonds zur Forderung der Wis-
¨
senschaften, by Wacker-Chemie GmbH, Burghausen,
and by Siemens (Schweiz) AG. Furthermore the autor
thanks Prof. R. Nesper for support of this investigation.
[31] W. Uhlig, Silicon Chem. 1 (2002) 129.
[32] W. Uhlig, in: N. Auner, J. Weis (Eds.), Organosilicon Chemistry
V, Wiley-VCH, Weinheim, in press.
[33] W. Uhlig, Z. Naturforsch., 586 (2003) 183.
[34] H. Emde, D. Domsch, H. Feger, U. Frick, A. Gotz, H.H.
¨
Hergott, K. Hofmann, W. Kober, K. Krageloh, T. Oesterle, W.
¨
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